Mechanisms of Motor Symptom Improvement by Long-Term Tai Chi Training in Parkinson's Disease Patients

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Therefore, we investigated the mechanism of long-term Tai Chi training on improving motor symptoms in PD. Methods 95 early-stage PD patients were enrolled and randomly divided into Tai Chi (N = 32), brisk walking (N = 31) and no-exercise group (N = 32). All subjects were assessed at baseline, 6 months and 12 months after one-year intervention. Motor symptoms were evaluated by Berg balance scale (BBS), Unified PD rating scale (UPDRS), Timed Up and Go test (TUG) and 3D gait analysis. Functional MRI, plasma cytokine and metabolomics, blood Huntingtin interaction protein 2 ( HIP2 ) mRNA levels were analyzed to investigate the mechanisms of Tai Chi training at macro and molecular level. The longitudinal effects of self-changes were calculated using repeated measures ANOVA. Generalized estimating equations (GEE) was used to assess the association of longitudinal data of rating scales. Switch rates were used into the fMRI analysis. False discovery rate (FDR) correction was used to perform multiple correction. Results Tai Chi group had better performance in BBS, UPDRS, TUG and step width. Besides, Tai Chi had more advantages in improving BBS, step width than brisk walking. Improved BBS was correlated with enhanced visual network function and downregulation of IL-1β. Improvements in UPDRS were associated with enhanced default mode network function, decreased L-malic acid and 3-phosphoglyceric acid, increased adenosine and HIP2 mRNA levels. In addition, arginine biosynthesis, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids were also improved by Tai Chi. Conclusions Long-term Tai Chi training improved motor function, especially gait and balance, in PD. Enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration might be the mechanisms of Tai Chi effects. Trial registration: This study is registered at Chinese Clinical Trial Registry (Registration number: ChiCTR-OPC-16008074; Registration date: March 8, 2016). Translational Medicine Neurology Parkinson’s disease Tai Chi Motor symptoms Mechanism Brain network. Figures Figure 1 Figure 2 Background Parkinson disease (PD) is the second most common neurodegenerative disease globally, characterized by bradykinesia, resting tremor and rigidity [ 1 ]. With the progression of disease, patients lose postural stability and have difficulty in gait and balance, causing frequent falls and disability in daily living [ 2 ]. Although some motor symptoms, such as tremor and rigidity, may be alleviated by drug therapy, some clinical features such as postural instability are less responsive to medication and need alternative treatments [ 3 ]. Physical exercises were shown to improve mobility, gait, balance and quality of life in PD [ 4 , 5 ]. Tai Chi, brisk walking and tango dancing demonstrated the highest level of evidence of efficacy, especially in improving postural stability [ 6 – 8 ]. Tai Chi, a mind-body exercise that utilizes continuous, curved, and spiral body movements with breathing control [ 9 ], was shown to have improved aerobic capacity, muscle strength, balance, and motor control, as well as reduced stress and anxiety in older adults [ 10 ]. High quality of evidence from randomized controlled trials done by Fuzhong Li et al. found improvement of maximal excursion, direction control, gait velocity and quality of life after 6-month Tai Chi training in PD patients [ 6 , 11 ]. However, previous studies focusing on Tai Chi training only showed the short-term (up to 6 months) benefits for PD patients. Owing to the progressive nature of PD, the long-term effects of such interventions should be concerned. What’s more important, the beneficial mechanisms of Tai Chi remain largely unclear. Evidence based on animal studies of neurodegenerative disease found that physical exercise might improve the production of neurotrophic factors, neurotransmitters, and hormones, promoting many processes such as synaptic plasticity, neurogenesis, angiogenesis, and autophagy [ 12 ]. Several studies focusing on the mechanisms of Tai Chi in older adults have shown improved brain metabolism and muscle energetics using brain 1 H MRS and a muscle 31 P MRS [ 13 ], enhanced default mode network (DMN) connectivity using resting-state functional MRI (rs-fMRI) [ 14 ]. However, the mechanisms of Tai Chi training on PD patients were not investigated. It is necessary to understand the inner physiological changes of the brain and body by Tai Chi training on PD patients. Functional MRI and blood biomarkers tests probably will give us a deep insight into the mechanisms of Tai Chi in PD. Rs-fMRI was widely used to explore the brain function and neuroplasticity at macro level. In addition, molecular biomarkers in the blood of PD, which can reflect pathogenesis and disease progression, also provide us ways to study mechanisms of Tai Chi [ 15 , 16 ]. Previous animal studies showed that exercise might bring benefits to PD through inhibiting oxidative stress, repairing mitochondrial damage, and promoting the production of growth factors [ 4 ]. To investigate the mechanisms of Tai Chi training in PD patients, cytokines and metabolomics analysis in blood were chosen. Huntingtin interaction protein 2 (HIP2) is an E2 ubiquitin-conjugating enzyme associated with neurodegenerative diseases, decreased HIP2 expression has been reported in the blood [ 17 – 19 ] and the substantia nigra of PD patients [ 20 ]. Reduction of HIP2 expression could cause motor function impairment and increased vulnerability to dopaminergic degeneration in Parkinson’s disease models [ 21 ]. Thus, HIP2 could also be a genuine disease-relevant biomarker for PD. Thus, combined analysis of cytokines, metabolomics, and HIP2 mRNA were used in order to discover the underlying mechanisms of long-term Tai Chi training in PD at molecular level. Finally, our study is to discover the long-term effect of Tai Chi training on motor symptoms of PD. More importantly, fMRI and blood biomarkers (including cytokines, metabolomics and HIP2 mRNA) were used to explore the underlying mechanisms of Tai Chi training. Methods We conducted a one-year RCT to evaluate the impact of long-term Tai Chi training on motor symptoms in PD patients and more importantly investigate the related mechanisms. Subjects 95 early stage (Hoehn-Yahr 1-2.5) PD patients (50-80 years old) were recruited. The medication was stable at least 3 months before recruitment and not changed during follow-up unless necessary due to the disease progression. Our study was approved by Ruijin Hospital Ethic Committee of Shanghai Jiao Tong University School of Medicine at December 04, 2014. This study is registered at Chinese Clinical Trial Registry (Registration number: ChiCTR-OPC-16008074; Registration date: March 8, 2016). PD was diagnosed by two movement disorder specialists (SDC, YYT). All of the PD patients met both the PD diagnostic criteria of United Kingdom Brain Bank [22] and Movement Disorders Society [23]. All participants provided written informed consents. Randomization After recruitment, participants were randomly assigned to Tai Chi (N=32), brisk walking (N=31) and control group (N=32) without stratification. The randomization method is to draw lots. Then, 12-month exercise intervention (Tai Chi, brisk walking or non-exercise) with strict quality control was introduced. Details could be seen in Additional File 1 . Assessments Berg Balance Scale (BBS), Unified PD rating scale (UPDRS), Time up and Go test (TUG) and Spatial 3D gait analysis were used to assess the motor symptoms, gait and balance of PD patients. Assessments were performed at baseline, 6 months and 12 months. Investigation of mechanisms Mechanisms were investigated by fMRI, plasma cytokines and metabolomics, and the blood HIP2 mRNA levels. Assessments were done at baseline, 6 months and 12 months. Details could be seen in Additional File 1 . Statistical analysis R (version 3.5.1), RStudio (version 1.1463) and related packages were introduced into statistical analysis. MATLAB R2018a (version 9.4.0.813654, MathWorks, Inc.) was used into the analysis of fMRI. All analyses about clinical measurements were conducted on an intention-to-treat basis. Analysis of variance (ANOVA) was used to compare numerical demographic information. Pearson Chi-Square test or Fisher test was used into analysis at categorical demographic information. Shapiro-Wilk normality test was used to assess the normality of variables. Independent-sample t-tests (with 95% confidence intervals) were used to compare group means. Data were presented in the way of between-group differences. The longitudinal effects of self-changes were calculated using repeated measures ANOVA. Switch rates were used into the fMRI analysis [24] . The least absolute shrinkage and selection operator (LASSO), linear regression and Bayesian belief network (BBN) were introduced to analyze fMRI. Generalized estimating equations (GEE) was used to assess the association of longitudinal data of rating scales. Mixed effect regression using restricted maximum likelihood method was introduced to analyze cytokine levels, HIP2 levels and metabolites. Bonferroni correction was used in performing multiple corrections. Pathway analysis was performed using MetaboAnalyst 4.0 platform. Enrichment analysis was performed using MetaboAnalyst 4.0 platform referenced with the small molecule pathway database (SMPDB). False discovery rate (FDR) correction was used to perform multiple correction. Detailed could be seen in Additional File 1 . Results Baseline characteristics of participants 95 patients were recruited in this study at baseline (Tai Chi group 32, brisk walking group 31, control group 32). All of them were Han ethnicity. No patients presented either on-off phenomenon or dyskinesias. Three groups were matched in age, gender, disease duration and education. 66 patients finished 6-month and 12-month follow-up. Details were shown in Table 1 and Figure 1 . There were no differences of levodopa equivalent daily dosage (LEDD) at baseline and 12-month visit between the groups. Table 1 Demographic information of all the subjects Tai Chi Group (N = 32) Brisk Walking Group (N = 31) Control Group (N = 32) p value Gender, Female (N (%)) 15 (46·88) 9 (29·41) 13 (41·18) 0·500 Age at baseline (mean ± SD) 62·7 (5·51) 61·9 (5.64) 61·9 (6·76) 0·400 Education, years (mean ± SD) 13·60 (2·71) 13·10 (2·57) 12·40 (2·83) 0·472 History of Hypertension (N (%)) 7 (21·88) 3 (11·76) 5 (17·65) 0·800 History of Diabetes mellitus (N (%)) 1 (3·13) 0 (0·00) 1 (3·13) 1·000 History of smoking (N (%)) 2 (6·25) 2 (6·25) 2 (6·25) 0·600 Family History (N(%)) 8 (25·00) 5 (17·65) 3 (11·76) 0·600 Tremor dominant (N (%)) 22 (68·75) 22 (64·71) 17 (58·82) 0·800 Disease duration (mean ± SD) 5·91 (4·01) 3·82 (1·87) 4·32 (2·46) 0·082 Hoehn – Yahr staging (N (%)) 1·0 1·5 2·0 2·5 9 (28·13) 5 (15·63) 13 (40·63) 5 (15·63) 8 (25·81) 7 (22·58) 13 (41·94) 3 (9·68) 1 (3·13) 11 (34·38) 13 (40·63) 7 (21·88) 0·097 LEDD at baseline (mean ± SD) 326 (197) 260 (174) 347 (109) 0·800 LEDD (mean ± SD) 56·33 (91·68) 39.71 (83·30) 57·21 (107·24) 0·939 LEDD, levodopa equivalent daily dosage; N, number; SD, standard deviation LEDD: LEDD at 12 months minus LEDD at baseline Clinical improvements Patients showed better performance after Tai Chi training in BBS ( p ≤0.035). In addition, Tai Chi improved the performance in BBS (6 months: p= 0.006, 12 months: p= 0.044) since 6 months and lasted to 12 months. Compared to brisk walking, Tai Chi had more advantages in improving BBS scores (6 months: p= 0.005, 12 months: p= 0.022). (Additional File 2-Table S1, Figure 2.A) Patients showed better changes after Tai Chi training in UPDRS and TUG ( p ≤0.045). Tai Chi group showed improvement in UPDRS at 12 months compared with controls (UPDRS: p= 0.015, UPDRS-III: p <0.001). In addition, Tai Chi improved the performance in TUG (6 months: p= 0.017, 12 months: p= 0.011). Tai Chi improved patients’ performance in step width (severer side: 6 months: p= 0.002, 12 months: p <0.001; milder side: 6 months: p <0.001, 12 months: p <0.001) compared with controls since 6 months and lasted to 12 months. When compared to brisk walking, Tai Chi also showed advantages in improving step width (severer side: 6 months: p= 0.03, 12 months: p= 0.03; milder side: 6 months: p= 0.004, 12 months: p= 0.111). (Additional File 2-Table S1, Figure 2. B-D) Mechanisms of Tai Chi effects f MRI switch rates Better performances of BBS (p=0.044) in Tai Chi group were associated with the changes of visual network (VN). Improvements in UPDRS ( p= 0.023) and UPDRS-III ( p= 0.006) of PD patients were associated with enhancements of default mode network (DMN) after Tai Chi training. (Additional File 2-Table S2, Figure 2. E-H) Cytokines The levels of IL-1β (6 months: p= 0.013, 12 months: p= 0.028), IL-5 (6 months: p= 0.028, 12 months: p= 0.248), IL-7 (6 months: p= 0.032, 12 months: p= 0.016) and IL-9 (6 months: p= 0.037, 12 months: p= 0.019) were significantly downregulated in Tai Chi group compared with control group. ( Additional File 2-Table S3) Levels of IL-13 (6 months: p= 0.002, 12 months: p= 0.005), PDGF-BB (6 months: p= 0.022, 12 months: p= 0.011), MIP-1β (6 months: p= 0.003, 12 months: p= 0.008) and MCP-1 (6 months: p= 0.032, 12 months: p= 0.06) were stable in Tai Chi group but significantly increased in controls. The relatively stable levels of IL-13 (6 months: p= 0.019, 12 months: p= 0.021) and MCP-1 (6 months: p= 0.0007, 12 months: p= 0.022) were seen in Tai Chi group compared with brisk walking group. ( Additional File 2-Table S3) In addition, upregulation and downregulation of MIP-1α were respectively seen in control group ( p= 0.006) and brisk walking group ( p= 0.029), while Tai Chi group had no changes at 6 months. But MIP-1α returned to the baseline level in three groups at 12 months. ( Additional File 2-Table S3) Higher level of GM-CSF was found in Tai Chi group while no change was seen either in control group (6 months: p= 0.005, 12 months: p= 0.011) or in brisk walking group (6 months: p= 0.006, 12 months: p= 0.014). Those changes above could be observed since 6 months and lasted to 12 months. ( Additional File 2-Table S3) Furthermore, by analyzing the association between changes of cytokines and changes of clinical presentations, we found that downregulation of IL-1β were positively related to improved BBS scores ( p ≤0.031). ( Additional File 2-Table S4) Metabolomics We tested 123 metabolites, of which 27 metabolites showed statistically changes. After Bonferroni correction, 11 metabolites were left significant. Fumaric acid, L-aspartic acid and pyroglutamic acid were decreased after Tai Chi training only at 6 months ( p ≤0.033). Downregulation of homocysteine and methionine sulfoxide, and upregulation of azelaic acid were seen in Tai Chi group both at 6 months ( p ≤0.005) and 12 months ( p ≤0.032). L-malic acid, 3-phosphoglyceric acid were downregulated, while L-fucose, adenosine and pipecolic acid were upregulated after Tai Chi training at 12 months ( p ≤0.028). ( Additional File 2-S5) We also found several associations between metabolites and clinical presentations. The L-malic acid, 3-phosphoglyceric acid, and adenosine were associated with changes of UPDRS ( p ≤0.043). The L-malic acid, L-fucose, and pipecolic acid were associated with the changes of UPDRS-III ( p ≤0.041). ( Additional File 2-Table S6) Pathway analysis showed group differences in arginine biosynthesis both at 6 months (Tai Chi v.s. Control: p =0.007; Tai Chi v.s. Brisk Walking: p =0.006) and 12 months (Tai Chi v.s. Brisk Walking: p < 0.001). ( Additional File 2-Table S7, Additional File 3-Figure S1-3) In enrichment analysis, significant group difference was found in urea cycle both at 6months (Tai Chi v.s. Control: p =0.009; Tai Chi v.s. Brisk Walking: p =0.05) and 12 months (Tai Chi v.s. Brisk Walking: p < 0.001). ( Additional File 2-Table S8, Additional File 3-Figure S4-6) In association analysis, TCA cycle was correlated with BBS ( p= 0.037), UPDRS ( p= 0.002), UPDRS-III ( p= 0.014). Beta oxidation of very long chain fatty acids was relevant to UPDRS ( p= 0.033), UPDRS-III ( p= 0.033). ( Additional File 2-Table S9) HIP2 mRNA levels The control group showed tendency of downregulation of HIP2 mRNA ( p = 0.697). Compared with controls, the HIP2 mRNA level was elevated after Tai Chi training since 6 months ( p <0.001) and lasted to 12 months ( p <0.001). Tai Chi training seemed to be better in upregulating HIP2 mRNA level than brisk walking ( p =0.277). ( Additional File 3-Figure S7) We found that the difference of UPDRS and UPDRS-III was associated with the change of HIP2 mRNA level after Bonferroni correction (p<0.005). Association between the difference of BBS and the change of HIP2 mRNA level was also detected, but it did not survive after Bonferroni correction. (Additional File 2-Table S10) Discussion Long-term beneficial effects of Tai Chi on improving balance, and other motor symptoms in PD were found in our study. Tai Chi improved BBS, UPDRS, TUG, step width, indicating its beneficial effects on motor symptoms (including gait and balance). Tai Chi had more advantages in improving BBS, step width than brisk walking. More importantly, we want to explore the mechanisms of Tai Chi in improving the motor symptoms of PD. By using fMRI testing, we found the association between changes of BBS and the switch of VN. Relationship between improvement of UPDRS and the function of DMN was also positive. Plasma cytokines IL-1β, IL-5, IL-7, IL-9, IL-13, MCP-1, MIP-1a, MIP-1β were relatively downregulated and GM-CSF were upregulated after Tai Chi training. Among them, downregulation of IL-1β were positively related to improved BBS scores. Decreased L-malic acid and 3-phosphoglyceric acid, and increased adenosine were associated with changes of UPDRS in PD after Tai Chi training, while downregulation of L-malic acid, upregulation of L-fucose and pipecolic acid were related to changes of UPDRS-III. Arginine biosynthesis, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids were also affected by Tai Chi. The HIP2 mRNA levels were significantly elevated after Tai Chi training, and its change was correlated with the changes of UPDRS and UPDRS-III in PD by Tai Chi. Our study found significant improvement of motor function (especially gait and balance) in PD patients after Tai Chi training, which was consistent with the results of previous studies [ 6 , 11 ]. The mechanism of Tai Chi’s beneficial effects might be associated with the improved brain networks function in PD patients. Our results indicated association between enhanced VN function and improved BBS scores. The VN was composed by bilateral striate and extrastriate visual areas [ 25 ]. Visual-proprioceptive sensory conflict could influence gait and balance [ 26 ]. The visual cue lessens the vestibular noise and improves personal balance in environment [ 26 ]. PD patients with freezing of gait displayed reduced network connections in VN [ 27 , 28 ]. Thus, improved VN function might explain for the better performance of BBS in PD after Tai Chi training. We also observed change of DMN was related to improvement in UPDRS and UPDRS-III. The DMN included the hippocampus, parahippocampal, fusiform and angular gyrus, the precuneus and the middle temporal gyrus [ 25 ]. Precuneus is one of the functional hub regions of DMN, and its interactions with sensorimotor network were positively associated with motor performances [ 29 ]. Thus, improvement of DMN could explain the improved motor function in PD after Tai Chi training since connection of precuneus to motor areas might be associated to processes of motor mental imagery and planning [ 29 ]. Proinflammatory cytokines were downregulated after Tai Chi training. Among them, decreased IL-1β was correlated with improved BBS score. Inflammation plays an important role in the pathogenesis and disease progression of PD [ 15 ]. Meta-analysis of inflammatory cytokines in PD demonstrated significantly higher blood levels of IL-1β compared with healthy controls [ 30 ]. IL-1β plays an important role in different neurobiological processes, such as neuroinflammation, neurotoxicity, and host defense. Therefore, this cytokine has been linked to both acute and chronic neurodegenerative conditions [ 31 ]. PD symptoms were observed in IL-1β wild-type animals, IL-1β may contribute to the initiation or progression of PD [ 31 ]. Decreased IL-1β, indicating reduced inflammation, might explain for the improved BBS in PD patients after Tai Chi training. As for the results of metabolomics analysis, dysregulation of metabolites and metabolic pathways in PD were revealed, which were mainly associated with amino acid metabolism (pipecolic acid, L-fucose, arginine biosynthesis), energy metabolism (L-malic, 3-phosphoglyceric acid, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids) and neurotransmitters metabolism (adenosine) [ 32 ]. L-arginine, which participated in the synthesis of nitric oxide, could affect oxidative stress and energy metabolism playing a key role in the pathogenesis of PD [ 33 ]. Deficiency of TCA cycle enzymes and dysfunction of mitochondria, which regulated neuroinflammation and neurodegeneration, were also observed in PD [ 34 ]. The coupling of adenosine with its specific receptors acts as an upstream neuromodulator for neurotransmitters such as acetylcholine, glutamate, g-amino-butyric acid (GABA), and dopamine that is implicated in the modulation of multiple body functions [ 35 ]. Our results indicated improved amino acid metabolism, energy metabolism and neurotransmitters metabolism in PD patients after Tai Chi training. HIP2 is an E2 ubiquitin-conjugating enzyme via UPS pathway related to protein cleavage [ 36 ]. Impaired UPS system is related with protein aggregation, causing inflammation and abnormal oxidation [ 37 ]. Reduction of the HIP2 expression led to spontaneous motor function impairment and increased vulnerability to dopaminergic degeneration in PD models [ 21 ]. In our previous study, the HIP2 mRNA level was found downregulated in 20 PD patients and then elevated after one-year Tai Chi training accompanying improved motor function [ 21 ]. Our present study further confirmed that Tai Chi could reverse the downregulation of HIP2 mRNA in a larger PD cohort, and linked its change with the improvement of motor function in PD patients after Tai Chi training, indicating Tai Chi’s role in decreasing the vulnerability to dopaminergic degeneration in PD. Based on the above evidence from fMRI and blood biomarkers, we found enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration in PD after Tai Chi training. Limitations There were some limitations in our study. First, the number of subjects in our study is not enough. Because of the small sample, validity might be lost, therefore, larger sized cohort studies are warranted. The dropout is inevitable in the long-time visit, causing the relatively small sample amount. Second, the dropout rate of brisk walking and control could not be ignored. Since Tai Chi was monitored in fixed Tai Chi class, it was much easier to keep training than brisk walking. Besides, patients in the Tai Chi class were willing to stick to Tai Chi training since they had benefited from it. Conclusions Our study revealed that long-term Tai Chi training improves PD patients with motor function, especially in gait and balance. Enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration might be the mechanisms of Tai Chi effects. List Of Abbreviations ANOVA, analysis of variance; BBN, Bayesian belief network; BBS, Berg Balance scale; DMN, default mode network; FDR, false discovery rate; fMRI, functional magnetic resonance imaging; GEE, generalized estimating equations; GM-CSF, granulocyte-macrophage colony stimulating factor; HIP2 , Huntingtin interaction protein 2; IL, interleukin; LASSO, least absolute shrinkage and selection operator; LEDD, levodopa equivalent daily dosage; MCP1, monocyte chemotactic protein 1; MIP, macrophage inflammatory protein; PD, Parkinson's disease; PDGF, platelet derived growth factor; TCA, tricarboxylic acid cycle; TUG, Timed Up and Go test; UPDRS, Unified Parkinson's Disease Rating Scale; UPS, ubiquitin proteasome; VN, visual network. Declarations Ethics approval and consent to participate This study was approved by Ruijin Hospital Ethic Committee of Shanghai Jiao Tong University School, and all participants have given written informed consents. Consent for publication Not applicable. Availability of data and materials The datasets used and analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding This work was supported by grants from the National Natural Science Foundation of China (grant numbers 81430022, 91332107, 81371407, 81801267), Shanghai Municipal Science and Technology Major Project (2018SHZDZX05) and Shanghai Municipal Education Commission (2017NKX001). Authors’ contributions GL and PH performed clinical assessment, run the statistical analysis and drafted the manuscript. SSC, YCH and XS performed clinical assessment. QYJ performed fMRI scan. PH performed gait assessment. GYH and BYL made fMRI analysis. YXL made fMRI data management. JX and ZW joined the study design. SDC and YYT performed patient recruitment and diagnosis. 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Visual contribution to human standing balance during support surface tilts. Hum Mov Sci. 2015;41:147–64. Ruan X, Li Y, Li E, Xie F, Zhang G, Luo Z, et al. Impaired Topographical Organization of Functional Brain Networks in Parkinson's Disease Patients With Freezing of Gait. Front Aging Neurosci. 2020;12:580564. Rogge AK, Röder B, Zech A, Hötting K. Exercise-induced neuroplasticity: Balance training increases cortical thickness in visual and vestibular cortical regions. Neuroimage. 2018;179:471–79. Thibes RB, Novaes NP, Lucato LT, Campanholo KR, Melo LM, Leite CC, et al. Altered Functional Connectivity Between Precuneus and Motor Systems in Parkinson's Disease Patients. Brain Connect. 2017;7:643–47. Qin XY, Zhang SP, Cao C, Loh YP, Cheng Y. Aberrations in Peripheral Inflammatory Cytokine Levels in Parkinson Disease: A Systematic Review and Meta-analysis. JAMA Neurol. 2016;73:1316–24. Saghazadeh A, Ferrari CC, Rezaei N. 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Impairment of the ubiquitin-proteasome system by protein aggregation. Science. 2001;292:1552–5. Supplementary Files AdditionalFile1Protocols.docx AdditionalFile2TableS1S10.docx AdditionalFile3FigureS1S7.docx CONSORT2010Checklist.doc Cite Share Download PDF Status: Published Journal Publication published 07 Feb, 2022 Read the published version in Translational Neurodegeneration → Version 1 posted Editorial decision: Major revision 14 Nov, 2021 Review # 4 received at journal 11 Nov, 2021 Review # 3 received at journal 06 Nov, 2021 Review # 2 received at journal 04 Nov, 2021 Reviews received at journal 01 Nov, 2021 Reviewer # 4 agreed at journal 31 Oct, 2021 Reviewer # 3 agreed at journal 31 Oct, 2021 Reviewer # 2 agreed at journal 01 Oct, 2021 Reviewers invited by journal 27 Sep, 2021 Reviewer # 1 agreed at journal 26 Sep, 2021 Review # 1 received at journal 26 Sep, 2021 Editor assigned by journal 14 Sep, 2021 Submission checks completed at journal 13 Sep, 2021 Editor invited by journal 13 Sep, 2021 First submitted to journal 07 Sep, 2021 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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21:11:58","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-884753/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-884753/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s40035-022-00280-7","type":"published","date":"2022-02-07T14:19:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":14116010,"identity":"4bcffbe9-21bf-4e1e-b6be-97f4383beac4","added_by":"auto","created_at":"2021-09-29 15:51:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1199501,"visible":true,"origin":"","legend":"The flow chart of the patient recruitment and follow up","description":"","filename":"OnlineFigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/16a850e13ff12dc99745ec9f.png"},{"id":14116014,"identity":"7e016428-0b6c-4ed3-914f-228e3d40ffa8","added_by":"auto","created_at":"2021-09-29 15:51:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":3523196,"visible":true,"origin":"","legend":"Changes of motor symptoms between groups and related fMRI changes. (A-D) The changes of rating scales between 3 groups. Data are shown as mean ± SEM. (A) Berg Balance Scale, (B) UPDRS – Total Score, (C) UPDRS – Part III, (D) Timed Up and Go Test. (E-H) Neural networks associated with the changes of rating scales: (E) Visual network associated with Berg Balance scale; (F) Default mode network associated with UPDRS – Total score; (G) Ventral salient network associated with UPDRS – Total score, but not significant; (H) Default mode network associated with UPDRS – Part III.","description":"","filename":"OnlineFigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/b6096d08ad7820522b246c32.png"},{"id":17992932,"identity":"0f0c6587-8348-4927-8c78-c7ed11ea02b0","added_by":"auto","created_at":"2022-02-07 14:19:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1135992,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/038d36e1-7bef-4f11-a1ae-bc1d042f15c2.pdf"},{"id":14116011,"identity":"d57bd0ed-c1fc-4727-9347-314d8a2aaa10","added_by":"auto","created_at":"2021-09-29 15:51:04","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":253443,"visible":true,"origin":"","legend":"","description":"","filename":"AdditionalFile1Protocols.docx","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/fba2746357347c9462c32ce3.docx"},{"id":14116013,"identity":"3a5e54a0-a123-4e4e-b71f-0a38e640976b","added_by":"auto","created_at":"2021-09-29 15:51:04","extension":"docx","order_by":7,"title":"","display":"","copyAsset":false,"role":"supplement","size":464516,"visible":true,"origin":"","legend":"","description":"","filename":"AdditionalFile2TableS1S10.docx","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/307785604def4b4363293bc6.docx"},{"id":14116015,"identity":"9cb39ed1-c7e6-4628-bcda-7c7dbeafe54b","added_by":"auto","created_at":"2021-09-29 15:51:05","extension":"docx","order_by":8,"title":"","display":"","copyAsset":false,"role":"supplement","size":17172980,"visible":true,"origin":"","legend":"","description":"","filename":"AdditionalFile3FigureS1S7.docx","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/5c88a366af4ae7d9da6ac8bc.docx"},{"id":14116012,"identity":"ddad0c62-35ba-4636-b863-a50ac8e8cc21","added_by":"auto","created_at":"2021-09-29 15:51:04","extension":"doc","order_by":9,"title":"","display":"","copyAsset":false,"role":"supplement","size":227328,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORT2010Checklist.doc","url":"https://assets-eu.researchsquare.com/files/rs-884753/v1/c6e0a4a443ce46d15fc44b54.doc"}],"financialInterests":"","formattedTitle":"\u003cp\u003eMechanisms of Motor Symptom Improvement by Long-Term Tai Chi Training in Parkinson's Disease Patients\u003c/p\u003e","fulltext":[{"header":"Background","content":"\u003cp\u003eParkinson disease (PD) is the second most common neurodegenerative disease globally, characterized by bradykinesia, resting tremor and rigidity [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. With the progression of disease, patients lose postural stability and have difficulty in gait and balance, causing frequent falls and disability in daily living [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Although some motor symptoms, such as tremor and rigidity, may be alleviated by drug therapy, some clinical features such as postural instability are less responsive to medication and need alternative treatments [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePhysical exercises were shown to improve mobility, gait, balance and quality of life in PD [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Tai Chi, brisk walking and tango dancing demonstrated the highest level of evidence of efficacy, especially in improving postural stability [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Tai Chi, a mind-body exercise that utilizes continuous, curved, and spiral body movements with breathing control [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], was shown to have improved aerobic capacity, muscle strength, balance, and motor control, as well as reduced stress and anxiety in older adults [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. High quality of evidence from randomized controlled trials done by Fuzhong Li et al. found improvement of maximal excursion, direction control, gait velocity and quality of life after 6-month Tai Chi training in PD patients [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, previous studies focusing on Tai Chi training only showed the short-term (up to 6 months) benefits for PD patients. Owing to the progressive nature of PD, the long-term effects of such interventions should be concerned.\u003c/p\u003e \u003cp\u003eWhat\u0026rsquo;s more important, the beneficial mechanisms of Tai Chi remain largely unclear. Evidence based on animal studies of neurodegenerative disease found that physical exercise might improve the production of neurotrophic factors, neurotransmitters, and hormones, promoting many processes such as synaptic plasticity, neurogenesis, angiogenesis, and autophagy [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Several studies focusing on the mechanisms of Tai Chi in older adults have shown improved brain metabolism and muscle energetics using brain \u003csup\u003e1\u003c/sup\u003eH MRS and a muscle \u003csup\u003e31\u003c/sup\u003eP MRS [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], enhanced default mode network (DMN) connectivity using resting-state functional MRI (rs-fMRI) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, the mechanisms of Tai Chi training on PD patients were not investigated. It is necessary to understand the inner physiological changes of the brain and body by Tai Chi training on PD patients.\u003c/p\u003e \u003cp\u003eFunctional MRI and blood biomarkers tests probably will give us a deep insight into the mechanisms of Tai Chi in PD. Rs-fMRI was widely used to explore the brain function and neuroplasticity at macro level. In addition, molecular biomarkers in the blood of PD, which can reflect pathogenesis and disease progression, also provide us ways to study mechanisms of Tai Chi [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Previous animal studies showed that exercise might bring benefits to PD through inhibiting oxidative stress, repairing mitochondrial damage, and promoting the production of growth factors [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. To investigate the mechanisms of Tai Chi training in PD patients, cytokines and metabolomics analysis in blood were chosen. Huntingtin interaction protein 2 (HIP2) is an E2 ubiquitin-conjugating enzyme associated with neurodegenerative diseases, decreased \u003cem\u003eHIP2\u003c/em\u003e expression has been reported in the blood [\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] and the substantia nigra of PD patients [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Reduction of \u003cem\u003eHIP2\u003c/em\u003e expression could cause motor function impairment and increased vulnerability to dopaminergic degeneration in Parkinson\u0026rsquo;s disease models [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Thus, \u003cem\u003eHIP2\u003c/em\u003e could also be a genuine disease-relevant biomarker for PD. Thus, combined analysis of cytokines, metabolomics, and \u003cem\u003eHIP2\u003c/em\u003e mRNA were used in order to discover the underlying mechanisms of long-term Tai Chi training in PD at molecular level.\u003c/p\u003e \u003cp\u003eFinally, our study is to discover the long-term effect of Tai Chi training on motor symptoms of PD. More importantly, fMRI and blood biomarkers (including cytokines, metabolomics and \u003cem\u003eHIP2\u003c/em\u003e mRNA) were used to explore the underlying mechanisms of Tai Chi training.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe conducted a one-year RCT to evaluate the impact of long-term Tai Chi training on motor symptoms in PD patients and more importantly investigate the related mechanisms.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSubjects\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e95 early stage (Hoehn-Yahr 1-2.5) PD patients (50-80 years old) were recruited. The medication was stable at least 3 months before recruitment and not changed during follow-up unless necessary due to the disease progression. Our study was approved by Ruijin Hospital Ethic Committee of Shanghai Jiao Tong University School of Medicine at December 04, 2014. This study is registered at Chinese Clinical Trial Registry (Registration number: ChiCTR-OPC-16008074; Registration date: March 8, 2016). PD was diagnosed by two movement disorder specialists (SDC, YYT). \u0026nbsp;All of the PD patients met both \u0026nbsp;the PD diagnostic criteria of United Kingdom Brain Bank [22] and Movement Disorders Society [23]. All participants provided written informed consents.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRandomization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAfter recruitment, participants were randomly assigned to Tai Chi (N=32), brisk walking (N=31) and control group (N=32) without stratification. The randomization method is to draw lots. Then, 12-month exercise intervention (Tai Chi, brisk walking or non-exercise) with strict quality control was introduced. Details could be seen in \u003cstrong\u003eAdditional File 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAssessments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBerg Balance Scale (BBS), Unified PD rating scale (UPDRS), Time up and Go test (TUG) and Spatial 3D gait analysis were used to assess the motor symptoms, gait and balance of PD patients. Assessments were performed at baseline, 6 months and 12 months.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInvestigation of mechanisms\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMechanisms were investigated by fMRI, plasma cytokines and metabolomics, and the blood \u003cem\u003eHIP2\u003c/em\u003e mRNA levels. Assessments were done at baseline, 6 months and 12 months. Details could be seen in \u003cstrong\u003eAdditional File 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eR (version 3.5.1), RStudio (version 1.1463) and related packages were introduced into statistical analysis. MATLAB R2018a (version 9.4.0.813654, MathWorks, Inc.) was used into the analysis of fMRI.\u003c/p\u003e\n\u003cp\u003eAll analyses about clinical measurements were conducted on an intention-to-treat basis. Analysis of variance (ANOVA) was used to compare numerical demographic information. Pearson Chi-Square test or Fisher test was used into analysis at categorical demographic information. Shapiro-Wilk normality test was used to assess the normality of variables. Independent-sample t-tests (with 95% confidence intervals) were used to compare group means. Data were presented in the way of between-group differences. The longitudinal effects of self-changes were calculated using repeated measures ANOVA.\u003c/p\u003e\n\u003cp\u003eSwitch rates were used into the fMRI analysis [24] . The least absolute shrinkage and selection operator (LASSO), linear regression and Bayesian belief network (BBN) were introduced to analyze fMRI.\u003c/p\u003e\n\u003cp\u003eGeneralized estimating equations (GEE) was used to assess the association of longitudinal data of rating scales. Mixed effect regression using restricted maximum likelihood method was introduced to analyze cytokine levels,\u003cem\u003e\u0026nbsp;HIP2\u003c/em\u003e levels and metabolites. Bonferroni correction was used in performing multiple corrections. Pathway analysis was performed using MetaboAnalyst 4.0 platform. Enrichment analysis was performed using MetaboAnalyst 4.0 platform referenced with the small molecule pathway database (SMPDB). False discovery rate (FDR) correction was used to perform multiple correction. Detailed could be seen in \u003cstrong\u003eAdditional File 1\u003c/strong\u003e.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eBaseline characteristics of participants\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e95 patients were recruited in this study at baseline (Tai Chi group 32, brisk walking group 31, control group 32). All of them were Han ethnicity. No patients presented either on-off phenomenon or dyskinesias. Three groups were matched in age, gender, disease duration and education. 66 patients finished 6-month and 12-month follow-up. Details were shown in \u003cstrong\u003eTable 1 and Figure 1\u003c/strong\u003e. There were no differences of levodopa equivalent daily dosage (LEDD) at baseline and 12-month visit between the groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1 Demographic information of all the subjects\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003eTai Chi Group\u003c/p\u003e\n \u003cp\u003e(N = 32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003eBrisk Walking Group\u003c/p\u003e\n \u003cp\u003e(N = 31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003eControl Group\u003c/p\u003e\n \u003cp\u003e(N = 32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.691629955947137%\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eGender, Female (N (%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e15 (46\u0026middot;88)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e9 (29\u0026middot;41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e13 (41\u0026middot;18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;500\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eAge at baseline (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e62\u0026middot;7 (5\u0026middot;51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e61\u0026middot;9 (5.64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e61\u0026middot;9 (6\u0026middot;76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;400\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eEducation, years (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e13\u0026middot;60 (2\u0026middot;71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e13\u0026middot;10 (2\u0026middot;57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e12\u0026middot;40 (2\u0026middot;83)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;472\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eHistory of Hypertension (N (%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e7 (21\u0026middot;88)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e3 (11\u0026middot;76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e5 (17\u0026middot;65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;800\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eHistory of Diabetes mellitus (N (%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e1 (3\u0026middot;13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e0 (0\u0026middot;00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e1 (3\u0026middot;13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e1\u0026middot;000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eHistory of smoking (N (%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e2 (6\u0026middot;25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e2 (6\u0026middot;25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e2 (6\u0026middot;25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;600\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eFamily History (N(%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e8 (25\u0026middot;00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e5 (17\u0026middot;65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e3 (11\u0026middot;76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;600\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eTremor dominant (N (%))\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e22 (68\u0026middot;75)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e22 (64\u0026middot;71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e17 (58\u0026middot;82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;800\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eDisease duration (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e5\u0026middot;91 (4\u0026middot;01)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e3\u0026middot;82 (1\u0026middot;87)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e4\u0026middot;32 (2\u0026middot;46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;082\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eHoehn \u0026ndash; Yahr staging (N (%))\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;1\u0026middot;0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;1\u0026middot;5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;2\u0026middot;0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;2\u0026middot;5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e9 (28\u0026middot;13)\u003c/p\u003e\n \u003cp\u003e5 (15\u0026middot;63)\u003c/p\u003e\n \u003cp\u003e13 (40\u0026middot;63)\u003c/p\u003e\n \u003cp\u003e5 (15\u0026middot;63)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e8 (25\u0026middot;81)\u003c/p\u003e\n \u003cp\u003e7 (22\u0026middot;58)\u003c/p\u003e\n \u003cp\u003e13 (41\u0026middot;94)\u003c/p\u003e\n \u003cp\u003e3 (9\u0026middot;68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e1 (3\u0026middot;13)\u003c/p\u003e\n \u003cp\u003e11 (34\u0026middot;38)\u003c/p\u003e\n \u003cp\u003e13 (40\u0026middot;63)\u003c/p\u003e\n \u003cp\u003e7 (21\u0026middot;88)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;097\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eLEDD at baseline (mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e326 (197)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e260 (174)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e347 (109)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;800\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"38.91336270190896%\"\u003e\n \u003cp\u003eLEDD\u0026nbsp;(mean \u0026plusmn; SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e56\u0026middot;33 (91\u0026middot;68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"20.851688693098385%\"\u003e\n \u003cp\u003e39.71 (83\u0026middot;30)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.27165932452276%\"\u003e\n \u003cp\u003e57\u0026middot;21 (107\u0026middot;24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"9.691629955947137%\"\u003e\n \u003cp\u003e0\u0026middot;939\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"top\" width=\"100%\"\u003e\n \u003cp\u003eLEDD, levodopa equivalent daily dosage; N, number; SD, standard deviation\u003c/p\u003e\n \u003cp\u003eLEDD: LEDD at 12 months minus LEDD at baseline\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical improvements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients showed better performance after Tai Chi training in BBS (\u003cem\u003ep\u003c/em\u003e\u0026le;0.035). In addition, Tai Chi improved the performance in BBS (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.006, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.044) since 6 months and lasted to 12 months. Compared to brisk walking, Tai Chi had more advantages in improving BBS scores (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.005, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.022). \u003cstrong\u003e(Additional File 2-Table S1, Figure 2.A)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients showed better changes after Tai Chi training in UPDRS and TUG (\u003cem\u003ep\u003c/em\u003e\u0026le;0.045). Tai Chi group showed improvement in UPDRS at 12 months compared with controls (UPDRS:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.015, UPDRS-III: \u003cem\u003ep\u003c/em\u003e \u0026lt;0.001). In addition, Tai Chi improved the performance in TUG (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.017, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.011). Tai Chi improved patients\u0026rsquo; performance in step width (severer side: 6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.002, 12 months:\u003cem\u003e\u0026nbsp;p\u003c/em\u003e \u0026lt;0.001; milder side: 6 months:\u003cem\u003e\u0026nbsp;p\u003c/em\u003e \u0026lt;0.001, 12 months:\u003cem\u003e\u0026nbsp;p\u003c/em\u003e \u0026lt;0.001) compared with controls since 6 months and lasted to 12 months. When compared to brisk walking, Tai Chi also showed advantages in improving step width (severer side: 6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.03, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.03; milder side: 6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.004, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.111). \u003cstrong\u003e(Additional File 2-Table S1, Figure 2. B-D)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMechanisms of Tai Chi effects\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ef\u003c/strong\u003e\u003cstrong\u003eMRI switch rates\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBetter performances of BBS (p=0.044) in Tai Chi group were associated with the changes of visual network (VN). Improvements in UPDRS (\u003cem\u003ep=\u003c/em\u003e0.023) and UPDRS-III (\u003cem\u003ep=\u003c/em\u003e0.006) of PD patients were associated with enhancements of default mode network (DMN) after Tai Chi training.\u003cstrong\u003e\u0026nbsp;(Additional File 2-Table S2, Figure 2. E-H)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCytokines\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe levels of IL-1\u0026beta; (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.013, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.028), IL-5 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.028, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.248), IL-7 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.032, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.016) and IL-9 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.037, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.019) were significantly downregulated in Tai Chi group compared with control group.\u003cstrong\u003e\u0026nbsp;(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S3)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLevels of IL-13 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.002, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.005), PDGF-BB (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.022, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.011), MIP-1\u0026beta; (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.003, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.008) and MCP-1 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.032, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.06) were stable in Tai Chi group but significantly increased in controls. The relatively stable levels of IL-13 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.019, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.021) and MCP-1 (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.0007, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.022) were seen in Tai Chi group compared with brisk walking group. \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File\u0026nbsp;2-Table S3)\u003c/strong\u003e In addition, upregulation and downregulation of MIP-1\u0026alpha; were respectively seen in control group (\u003cem\u003ep=\u003c/em\u003e 0.006) and brisk walking group (\u003cem\u003ep=\u003c/em\u003e 0.029), while Tai Chi group had no changes at 6 months. But MIP-1\u0026alpha; returned to the baseline level in three groups at 12 months. \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S3)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHigher level of GM-CSF was found in Tai Chi group while no change was seen either in control group (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.005, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.011) or in brisk walking group (6 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e 0.006, 12 months:\u003cem\u003e\u0026nbsp;p=\u003c/em\u003e0.014). Those changes above could be observed since 6 months and lasted to 12 months. \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S3)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFurthermore, by analyzing the association between changes of cytokines and changes of clinical presentations, we found that downregulation of IL-1\u0026beta; were positively related to improved BBS scores (\u003cem\u003ep\u003c/em\u003e \u0026le;0.031). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S4)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMetabolomics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe tested 123 metabolites, of which 27 metabolites showed statistically changes. After Bonferroni correction, 11 metabolites were left significant. Fumaric acid, L-aspartic acid and pyroglutamic acid were decreased after Tai Chi training only at 6 months (\u003cem\u003ep\u003c/em\u003e\u0026le;0.033). Downregulation of homocysteine and methionine sulfoxide, and upregulation of azelaic acid were seen in Tai Chi group both at 6 months (\u003cem\u003ep\u003c/em\u003e\u0026le;0.005) and 12 months (\u003cem\u003ep\u003c/em\u003e\u0026le;0.032). L-malic acid, 3-phosphoglyceric acid were downregulated, while L-fucose, adenosine and pipecolic acid were upregulated after Tai Chi training at 12 months (\u003cem\u003ep\u003c/em\u003e\u0026le;0.028).\u003cstrong\u003e\u0026nbsp;(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-S5)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe also found several associations between metabolites and clinical presentations. The L-malic acid, 3-phosphoglyceric acid, and adenosine were associated with changes of UPDRS (\u003cem\u003ep\u003c/em\u003e\u0026le;0.043). The L-malic acid, L-fucose, and pipecolic acid were associated with the changes of UPDRS-III (\u003cem\u003ep\u003c/em\u003e\u0026le;0.041). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S6)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePathway analysis showed group differences in arginine biosynthesis both at 6 months (Tai Chi v.s. Control: \u003cem\u003ep\u003c/em\u003e=0.007; Tai Chi v.s. Brisk Walking: \u003cem\u003ep\u003c/em\u003e=0.006) and 12 months (Tai Chi v.s. Brisk Walking:\u003cem\u003e\u0026nbsp;p\u003c/em\u003e \u0026lt; 0.001). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File\u0026nbsp;2-Table S7,\u0026nbsp;Additional File\u0026nbsp;3-Figure S1-3)\u003c/strong\u003e In enrichment analysis, significant group difference was found in urea cycle both at 6months (Tai Chi v.s. Control: \u003cem\u003ep\u003c/em\u003e=0.009; Tai Chi v.s. Brisk Walking: \u003cem\u003ep\u003c/em\u003e=0.05) and 12 months (Tai Chi v.s. Brisk Walking:\u003cem\u003e\u0026nbsp;p\u003c/em\u003e \u0026lt; 0.001). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S8, Additional File 3-Figure S4-6)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn association analysis, TCA cycle was correlated with BBS (\u003cem\u003ep=\u003c/em\u003e0.037), UPDRS (\u003cem\u003ep=\u003c/em\u003e0.002), UPDRS-III (\u003cem\u003ep=\u003c/em\u003e0.014). Beta oxidation of very long chain fatty acids was relevant to UPDRS (\u003cem\u003ep=\u003c/em\u003e0.033), UPDRS-III (\u003cem\u003ep=\u003c/em\u003e0.033). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 2-Table S9)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eHIP2\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;mRNA levels\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe control group showed tendency of downregulation of \u003cem\u003eHIP2\u003c/em\u003e mRNA (\u003cem\u003ep\u003c/em\u003e = 0.697). Compared with controls, the\u003cem\u003e\u0026nbsp;HIP2\u003c/em\u003e mRNA level was elevated after Tai Chi training since 6 months (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.001) and lasted to 12 months (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.001). Tai Chi training seemed to be better in upregulating \u003cem\u003eHIP2\u003c/em\u003e mRNA level than brisk walking (\u003cem\u003ep\u003c/em\u003e=0.277). \u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003eAdditional File 3-Figure S7)\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe found that the difference of UPDRS and UPDRS-III was associated with the change of \u003cem\u003eHIP2\u003c/em\u003e mRNA level after Bonferroni correction (p\u0026lt;0.005). Association between the difference of BBS and the change of \u003cem\u003eHIP2\u003c/em\u003e mRNA level was also detected, but it did not survive after Bonferroni correction. \u003cstrong\u003e(Additional File 2-Table S10)\u003c/strong\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eLong-term beneficial effects of Tai Chi on improving balance, and other motor symptoms in PD were found in our study. Tai Chi improved BBS, UPDRS, TUG, step width, indicating its beneficial effects on motor symptoms (including gait and balance). Tai Chi had more advantages in improving BBS, step width than brisk walking.\u003c/p\u003e \u003cp\u003eMore importantly, we want to explore the mechanisms of Tai Chi in improving the motor symptoms of PD. By using fMRI testing, we found the association between changes of BBS and the switch of VN. Relationship between improvement of UPDRS and the function of DMN was also positive. Plasma cytokines IL-1β, IL-5, IL-7, IL-9, IL-13, MCP-1, MIP-1a, MIP-1β were relatively downregulated and GM-CSF were upregulated after Tai Chi training. Among them, downregulation of IL-1β were positively related to improved BBS scores. Decreased L-malic acid and 3-phosphoglyceric acid, and increased adenosine were associated with changes of UPDRS in PD after Tai Chi training, while downregulation of L-malic acid, upregulation of L-fucose and pipecolic acid were related to changes of UPDRS-III. Arginine biosynthesis, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids were also affected by Tai Chi. The \u003cem\u003eHIP2\u003c/em\u003e mRNA levels were significantly elevated after Tai Chi training, and its change was correlated with the changes of UPDRS and UPDRS-III in PD by Tai Chi.\u003c/p\u003e \u003cp\u003eOur study found significant improvement of motor function (especially gait and balance) in PD patients after Tai Chi training, which was consistent with the results of previous studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The mechanism of Tai Chi\u0026rsquo;s beneficial effects might be associated with the improved brain networks function in PD patients. Our results indicated association between enhanced VN function and improved BBS scores. The VN was composed by bilateral striate and extrastriate visual areas [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Visual-proprioceptive sensory conflict could influence gait and balance [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The visual cue lessens the vestibular noise and improves personal balance in environment [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. PD patients with freezing of gait displayed reduced network connections in VN [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Thus, improved VN function might explain for the better performance of BBS in PD after Tai Chi training. We also observed change of DMN was related to improvement in UPDRS and UPDRS-III. The DMN included the hippocampus, parahippocampal, fusiform and angular gyrus, the precuneus and the middle temporal gyrus [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Precuneus is one of the functional hub regions of DMN, and its interactions with sensorimotor network were positively associated with motor performances [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Thus, improvement of DMN could explain the improved motor function in PD after Tai Chi training since connection of precuneus to motor areas might be associated to processes of motor mental imagery and planning [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eProinflammatory cytokines were downregulated after Tai Chi training. Among them, decreased IL-1β was correlated with improved BBS score. Inflammation plays an important role in the pathogenesis and disease progression of PD [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Meta-analysis of inflammatory cytokines in PD demonstrated significantly higher blood levels of IL-1β compared with healthy controls [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. IL-1β plays an important role in different neurobiological processes, such as neuroinflammation, neurotoxicity, and host defense. Therefore, this cytokine has been linked to both acute and chronic neurodegenerative conditions [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. PD symptoms were observed in IL-1β wild-type animals, IL-1β may contribute to the initiation or progression of PD [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Decreased IL-1β, indicating reduced inflammation, might explain for the improved BBS in PD patients after Tai Chi training.\u003c/p\u003e \u003cp\u003eAs for the results of metabolomics analysis, dysregulation of metabolites and metabolic pathways in PD were revealed, which were mainly associated with amino acid metabolism (pipecolic acid, L-fucose, arginine biosynthesis), energy metabolism (L-malic, 3-phosphoglyceric acid, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids) and neurotransmitters metabolism (adenosine) [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. L-arginine, which participated in the synthesis of nitric oxide, could affect oxidative stress and energy metabolism playing a key role in the pathogenesis of PD [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Deficiency of TCA cycle enzymes and dysfunction of mitochondria, which regulated neuroinflammation and neurodegeneration, were also observed in PD [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The coupling of adenosine with its specific receptors acts as an upstream neuromodulator for neurotransmitters such as acetylcholine, glutamate, g-amino-butyric acid (GABA), and dopamine that is implicated in the modulation of multiple body functions [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Our results indicated improved amino acid metabolism, energy metabolism and neurotransmitters metabolism in PD patients after Tai Chi training.\u003c/p\u003e \u003cp\u003e \u003cem\u003eHIP2\u003c/em\u003e is an E2 ubiquitin-conjugating enzyme via UPS pathway related to protein cleavage [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Impaired UPS system is related with protein aggregation, causing inflammation and abnormal oxidation [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Reduction of the \u003cem\u003eHIP2\u003c/em\u003e expression led to spontaneous motor function impairment and increased vulnerability to dopaminergic degeneration in PD models [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In our previous study, the \u003cem\u003eHIP2\u003c/em\u003e mRNA level was found downregulated in 20 PD patients and then elevated after one-year Tai Chi training accompanying improved motor function [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Our present study further confirmed that Tai Chi could reverse the downregulation of \u003cem\u003eHIP2\u003c/em\u003e mRNA in a larger PD cohort, and linked its change with the improvement of motor function in PD patients after Tai Chi training, indicating Tai Chi\u0026rsquo;s role in decreasing the vulnerability to dopaminergic degeneration in PD.\u003c/p\u003e \u003cp\u003eBased on the above evidence from fMRI and blood biomarkers, we found enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration in PD after Tai Chi training.\u003c/p\u003e"},{"header":"Limitations","content":"\u003cp\u003eThere were some limitations in our study. First, the number of subjects in our study is not enough. Because of the small sample, validity might be lost, therefore, larger sized cohort studies are warranted. The dropout is inevitable in the long-time visit, causing the relatively small sample amount. Second, the dropout rate of brisk walking and control could not be ignored. Since Tai Chi was monitored in fixed Tai Chi class, it was much easier to keep training than brisk walking. Besides, patients in the Tai Chi class were willing to stick to Tai Chi training since they had benefited from it.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eOur study revealed that long-term Tai Chi training improves PD patients with motor function, especially in gait and balance. Enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration might be the mechanisms of Tai Chi effects.\u003c/p\u003e"},{"header":"List Of Abbreviations","content":"\u003cp\u003eANOVA, analysis of variance; BBN, Bayesian belief network; BBS, Berg Balance scale; DMN, default mode network; FDR, false discovery rate; fMRI, functional magnetic resonance imaging; GEE, generalized estimating equations; GM-CSF, granulocyte-macrophage colony stimulating factor; \u003cem\u003eHIP2\u003c/em\u003e, Huntingtin interaction protein 2; IL, interleukin; LASSO, least absolute shrinkage and selection operator; LEDD, levodopa equivalent daily dosage; MCP1, monocyte chemotactic protein 1; MIP, macrophage inflammatory protein; PD, Parkinson's disease; PDGF, platelet derived growth factor; TCA, tricarboxylic acid cycle; TUG, Timed Up and Go test; UPDRS, Unified Parkinson's Disease Rating Scale; UPS, ubiquitin proteasome; VN, visual network.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by Ruijin Hospital Ethic Committee of Shanghai Jiao Tong University School, and all participants have given written informed consents.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by grants from the National Natural Science Foundation of China (grant numbers 81430022, 91332107, 81371407, 81801267), Shanghai Municipal Science and Technology Major Project (2018SHZDZX05) and Shanghai Municipal Education Commission (2017NKX001).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGL and PH performed clinical assessment, run the statistical analysis and drafted the manuscript. SSC, YCH and XS performed clinical assessment. QYJ performed fMRI scan. PH performed gait assessment. GYH and BYL made fMRI analysis. YXL made fMRI data management. JX and ZW joined the study design. SDC and YYT performed patient recruitment and diagnosis. SDCn designed the study, supervised the study, double-checked the statistical analysis and revised the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank all the coaches of Sino Taiji of Fuxing International for their Tai Chi training courses to PD patients. We also thank all the patients who participated in this study, and the technical support of cytokine test from Wayen company.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKalia LV, Lang AE. Parkinson's disease. Lancet. 2015;386:896\u0026ndash;912.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAshburn A, Stack E, Pickering RM, Ward CD. 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Science. 2001;292:1552\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"translational-neurodegeneration","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tneu","sideBox":"Learn more about [Translational Neurodegeneration](http://translationalneurodegeneration.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/tneu/default.aspx","title":"Translational Neurodegeneration","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Parkinson’s disease, Tai Chi, Motor symptoms, Mechanism, Brain network.","lastPublishedDoi":"10.21203/rs.3.rs-884753/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-884753/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTai Chi has been shown to improve motor symptoms in Parkinson\u0026rsquo;s disease (PD), but its long-term effects was not clear and the related mechanism was not elucidated. Therefore, we investigated the mechanism of long-term Tai Chi training on improving motor symptoms in PD.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e95 early-stage PD patients were enrolled and randomly divided into Tai Chi (N\u0026thinsp;=\u0026thinsp;32), brisk walking (N\u0026thinsp;=\u0026thinsp;31) and no-exercise group (N\u0026thinsp;=\u0026thinsp;32). All subjects were assessed at baseline, 6 months and 12 months after one-year intervention. Motor symptoms were evaluated by Berg balance scale (BBS), Unified PD rating scale (UPDRS), Timed Up and Go test (TUG) and 3D gait analysis. Functional MRI, plasma cytokine and metabolomics, blood Huntingtin interaction protein 2 (\u003cem\u003eHIP2\u003c/em\u003e) mRNA levels were analyzed to investigate the mechanisms of Tai Chi training at macro and molecular level. The longitudinal effects of self-changes were calculated using repeated measures ANOVA. Generalized estimating equations (GEE) was used to assess the association of longitudinal data of rating scales. Switch rates were used into the fMRI analysis. False discovery rate (FDR) correction was used to perform multiple correction.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eTai Chi group had better performance in BBS, UPDRS, TUG and step width. Besides, Tai Chi had more advantages in improving BBS, step width than brisk walking. Improved BBS was correlated with enhanced visual network function and downregulation of IL-1β. Improvements in UPDRS were associated with enhanced default mode network function, decreased L-malic acid and 3-phosphoglyceric acid, increased adenosine and \u003cem\u003eHIP2\u003c/em\u003e mRNA levels. In addition, arginine biosynthesis, urea cycle, TCA cycle and beta oxidation of very long chain fatty acids were also improved by Tai Chi.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eLong-term Tai Chi training improved motor function, especially gait and balance, in PD. Enhanced brain network function, reduced inflammation, improved amino acid metabolism, energy metabolism and neurotransmitters metabolism, decreased vulnerability to dopaminergic degeneration might be the mechanisms of Tai Chi effects.\u003c/p\u003e\u003ch2\u003eTrial registration:\u003c/h2\u003e \u003cp\u003eThis study is registered at Chinese Clinical Trial Registry (Registration number: ChiCTR-OPC-16008074; Registration date: March 8, 2016).\u003c/p\u003e","manuscriptTitle":"Mechanisms of Motor Symptom Improvement by Long-Term Tai Chi Training in Parkinson's Disease Patients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-09-29 15:51:02","doi":"10.21203/rs.3.rs-884753/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2021-11-15T00:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2021-11-12T00:00:00+00:00","index":4,"fulltext":"Recommendation: Reviewer's comments unavailable due to the journal's policy.\n"},{"type":"editorInvitedReview","content":"","date":"2021-11-07T00:00:00+00:00","index":3,"fulltext":"Recommendation: Reviewer's comments unavailable due to the journal's policy.\n"},{"type":"editorInvitedReview","content":"","date":"2021-11-05T00:00:00+00:00","index":2,"fulltext":"Recommendation: Reviewer's comments unavailable due to the journal's policy.\n"},{"type":"editorInvitedReview","content":"","date":"2021-11-01T13:50:32+00:00","index":0,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2021-11-01T01:00:00+00:00","index":4,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2021-11-01T00:00:00+00:00","index":3,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2021-10-02T00:00:00+00:00","index":2,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2021-09-28T02:18:34+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2021-09-27T00:00:00+00:00","index":1,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2021-09-27T00:00:00+00:00","index":1,"fulltext":"Recommendation: Reviewer's comments unavailable due to the journal's policy.\n"},{"type":"editorAssigned","content":"","date":"2021-09-15T00:37:18+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2021-09-13T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2021-09-13T23:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Translational Neurodegeneration","date":"2021-09-07T10:56:37+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"translational-neurodegeneration","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tneu","sideBox":"Learn more about [Translational Neurodegeneration](http://translationalneurodegeneration.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/tneu/default.aspx","title":"Translational Neurodegeneration","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"38bb6a7b-0008-45a6-a0a8-1b9bf73c8a40","owner":[],"postedDate":"September 29th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":7519566,"name":"Translational Medicine"},{"id":7519567,"name":"Neurology"}],"tags":[],"updatedAt":"2022-02-07T14:19:03+00:00","versionOfRecord":{"articleIdentity":"rs-884753","link":"https://doi.org/10.1186/s40035-022-00280-7","journal":{"identity":"translational-neurodegeneration","isVorOnly":false,"title":"Translational Neurodegeneration"},"publishedOn":"2022-02-07 14:19:03","publishedOnDateReadable":"February 7th, 2022"},"versionCreatedAt":"2021-09-29 15:51:02","video":"","vorDoi":"10.1186/s40035-022-00280-7","vorDoiUrl":"https://doi.org/10.1186/s40035-022-00280-7","workflowStages":[]},"version":"v1","identity":"rs-884753","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-884753","identity":"rs-884753","version":["v1"]},"buildId":"ApUGefWb6u5IBVtyqm6d5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}