Causal association of cathepsins and endometriosis: A Mendelian randomization study

Causal association of cathepsins and endometriosis: A Mendelian randomization study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Causal association of cathepsins and endometriosis: A Mendelian randomization study Na Aru, Congyu Yang, Yuntian Chen, Jiaming Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3756621/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective Endometriosis is a prevalent reproductive disorder that affects a significant number of women globally. Cathepsins, which are lysosomal cysteine proteases, contribute to several physiological and pathological processes, including the attachment and invasion of endometrial tissue. Nevertheless, the causal relationship between cathepsins and endometriosis remains undetermined. The aim of this study was to explore the potential relationship between cathepsins and endometriosis using genetic polymorphisms. Methods We employed a two-sample Mendelian randomization (MR) analysis to investigate the causal association between nine cathepsins and endometriosis. Results The univariable MR analysis results indicate that Cathepsin H increases the risk of overall endometriosis (IVW: OR [95%]: 1.037 [1.007 to 1.067], p = 0.013), endometriosis of ovary (IVW: OR [95%]: 1.022 [1.001 to 1.042], p = 0.046), endometriosis of pelvic peritoneum OR [95%]: 1.046 [1.002 to 1.089], p = 0.047), and deep endometriosis (IVW: OR [95%]: 1.050 [1.002 to 1.099], p = 0.048). The multivariable MR analysis retained stable after adjusting for other types of cathepsins. And reverse MR analyses suggest that overall endometriosis may lead to increased Cathepsin H levels (IVW: OR [95%]: 1.017 [1.003, 1.073], p = 0.041). The results of the sensitivity analyses were consistent with the main findings. Conclusion Our MR analysis yields robust evidence supporting a causal relationship between Cathepsin H and the susceptibility to endometriosis, potentially inspiring directions in endometriosis diagnosis and treatment. Cathepsin causality endometriosis MR analysis SNP Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Endometriosis, a complex and debilitating gynecological condition, is characterized by a range of distressing symptoms, including dysmenorrhea, chronic pelvic pain, and dyspareunia ( 1 , 2 ). Globally, approximately 70 million women of reproductive age are affected by various forms of endometriosis ( 3 ). Interestingly, endometriosis shares certain characteristics with malignant neoplasms, such as the ability to invade tissues locally and metastasize to distant sites ( 4 ). The process of local invasion relies on enzymes that break down the extracellular matrix of surrounding connective tissue ( 5 ). The activity of the proteolytic system plays a crucial role in maintaining local homeostasis in both health and disease. However, the specific role of this group of enzymes in the development of endometriosis remains largely unknown. It is possible that the activity and altered expression of these enzymes contribute to the clinical profile of endometriosis ( 6 ). Cathepsins, which encompass a group of lysosomal proteolytic enzymes ( 7 ), are prominently found in humans and are part of the papain superfamily of cysteine proteases ( 8 ). These enzymes play crucial roles in numerous physiological and pathophysiological cellular processes. They are involved in protein and lipid metabolism, autophagy, antigen presentation, recycling of growth factor receptors, cellular stress signaling, degradation of the extracellular matrix, and lysosome-mediated cell death ( 9 ). Given their involvement in these essential processes, various cathepsins have been implicated in the development of different diseases, including endometriosis ( 10 ). Recent studies have shed light on the roles of several cathepsins in endometriosis. These include Cathepsin B ( 11 – 13 ), Cathepsin D ( 12 , 14 ), Cathepsin G ( 12 , 15 ), Cathepsin K ( 16 ), and Cathepsin L ( 16 ). However, there is still a lack of sufficient research exploring the causal relationship between specific types of cathepsins and the risk of different histological subtypes of endometriosis. Therefore, further investigation is necessary to better understand the causal associations between different cathepsins and the risk of specific endometriosis subtypes. With the advancements in genomics, there is growing evidence highlighting the role of heritability in the etiology of diseases ( 17 ). Mendelian randomization (MR) is an analytical method used in epidemiological studies to infer disease etiology based on the Mendelian independent distribution law. For MR to be considered valid, it is essential for the causal sequence to be plausible and supported by evidence ( 18 ). Previous observational studies have identified associations between cathepsin traits and endometriosis, suggesting a potential correlation between them. In this specific study, a comprehensive two-sample MR analysis was conducted to establish a causal link between specific cathepsin signatures and endometriosis. By utilizing this approach, the researchers aimed to provide stronger evidence for the causal relationship between cathepsins and the development of endometriosis. Materials and methods Study design In our study, we conducted a two-sample MR analysis to evaluate the causal relationship between cathepsins and endometriosis. To ensure reliable results, three key assumptions must be met when performing MR analysis: 1) a strong association between genetic variants and exposure factors, 2) no correlation between genetic variants and confounding variables, and 3) the influence of genetic variants on the outcome is solely mediated through the exposure factors, excluding other pathways. Genome-wide association study (GWAS) data sources for endometriosis All datasets were derived from the European population. The GWAS statistics for endometriosis were sourced from FinnGen Research's data release (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS.gz). The GWAS statistics encompassed 15,088 cases and 107,564 controls. Summary statistics for endometriosis of ovary were obtained from a comprehensive GWAS study conducted by FinnGen Research (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_OVARY.gz), involving a cohort of 5,867 cases and 107,564 controls. Summary statistics of endometriosis of pelvic peritoneum was derived from a GWAS encompassing a cohort of 5,628 cases and 107,564 controls of European ancestry (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_PELVICPERITONEUM.gz). Lastly, GWAS data for deep endometriosis was extracted from FinnGen Research (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_DEEP.gz), encompassing 2856 cases and 203,296 controls of European ancestry. Cathepsins GWAS data sources Genetic instruments for evaluating the levels of different cathepsins (µg/L) were obtained from the INTERVAL study, which involved 3,301 individuals of European descent ( 19 ). The summary data can be accessed at https://gwas.mrcieu.ac.uk . Selection of instrumental variables (IVs) A significance level of 5 × 10 − 6 was set for the instrumental variables (IVs) associated with each immune trait. To ensure reliable results, a threshold for strong linkage disequilibrium (LD) effect was applied (r 2 < 0.001) ( 20 ), with LD r 2 calculated using the 10,000 Genomes Project as a reference panel. The proportion of phenotypic variation explained (PVE) and the F statistic were calculated for each IV to assess the strength of the IVs and to avoid bias caused by weak instruments. Furthermore, to mitigate bias introduced by weak instruments, IVs with F statistics greater than 10 were considered strong instruments and included in the subsequent analysis. The exposure and outcome SNPs were harmonized to align effect estimates for the same effect allele. Palindromic SNPs with intermediate effect allele frequencies (EAFs > 0.42) or SNPs with incompatible alleles were excluded ( 21 ). Data analysis We performed various MR analyses, including MR Egger, weighted median, inverse-variance weighted (IVW), simple mode, weighted mode, and MR-PRESSO approaches. Among these, the IVW method is commonly used ( 22 ). To assess the presence of heterogeneity, we conducted heterogeneity tests using both the MR Egger and IVW methods. The Cochrane's Q value was used to evaluate the variability of genetic instruments, where a p-value greater than 0.05 indicates no significant heterogeneity. To examine the presence of horizontal pleiotropy, we utilized the MR Egger regression equation, where a p-value above 0.05 suggests no evidence of horizontal pleiotropy ( 23 ). In addition, we employed multivariable MR, an extension of standard univariable MR, to consider multiple cathepsins when analyzing their causal effects on different subtypes of endometriosis. This approach also allowed us to estimate the direct causal effects of each exposure in a single analysis using the "MendelianRandomization" package ( 24 ). Reverse MR analyses, treating endometriosis as the exposure and cathepsins as the outcomes, were performed to evaluate reverse causality and explore bidirectional causality. To assess the potential impact of directional pleiotropy, we examined each SNP for potential associations with secondary phenotypes using the GWAS Catalog ( http://www.phenoscanner.medschl.cam.ac.uk/ ). Subsequently, we repeated the MR analyses, excluding SNPs associated with other phenotypes. Furthermore, we conducted leave-one-out sensitivity analyses on significant findings to determine if a single SNP was responsible for the observed causal relationship. The overall research design is illustrated in Fig. 1 . The MR analyses were conducted using the 'TwoSampleMR' package (version 0.5.7) in the R software environment ( 23 , 25 ). Results Exploration of the causal effect of cathepsins on endometriosis The findings of the univariable MR analysis revealed that genetically predicted Cathepsin H were positively correlated with the risk of overall endometriosis (OR [95%]: 1.037[1.007 to 1.067], p = 0.013) in the IVW method. Similar results were observed by using Weighted median (OR [95%]: 1.036 [1.005 to 1.068], p = 0.022), and Weighted mode (OR [95%]: 1.037 [1.005 to 1.069], p = 0.049). We noticed that Cathepsin H were suggestively associated with a higher risk of the rest of three histological subtypes of endometriosis in IVW method. OR [95%]: 1.022 [1.001 to 1.042], p = 0.046 for endometriosis of ovary; OR [95%]: 1.046 [1.002 to 1.089], p = 0.047 for endometriosis of pelvic peritoneum; OR [95%]: 1.050 [1.002 to 1.099], p = 0.048 for deep endometriosis (Fig. 2 ). No other types of cathepsins exhibited significant association with the risk of overall endometriosis or its different histological subtypes (Supplementary Table 1 and Fig. 3 ). Moreover, we conducted multivariable MR to assess the genetic predisposition involving cathepsins in relation to the risk of different histological subtypes of endometriosis. The results revealed that even after adjusting for other types of cathepsins, elevated Cathepsin H levels retained a robust association with an increased risk of overall endometriosis (IVW: OR [95%]: 1.034[1.002 to 1.066], p = 0.049), endometriosis of ovary (IVW: OR [95%]: 1.022 [1.005 to 1.039], p = 0.047), endometriosis of pelvic peritoneum (IVW: OR [95%]: 1.051[1.009 to 1.096], p = 0.042), and deep endometriosis (IVW: OR [95%]: 1.099[1.045 to 1.143], p = 0.043). However, no statistically significant causal association was observed between other types of cathepsins and overall endometriosis or its different histological subtypes (Supplementary Table 5 and Fig. 4 ). Exploration of the causal effect of endometriosis on cathepsins As detailed in Supplementary Tables 6, we evaluated the potential associations of cathepsins and endometriosis using the reverse MR analyses. Overall endometriosis was suggestively associated with increased Cathepsin H (IVW: OR [95%]: 1.017 [1.003, 1.073], p = 0.041). We did not find statistically significant associations between endometriosis and other types of cathepsins, the results were stable across sensitivity analyses, which are listed in Supplementary Table 7. Sensitivity analysis The MR-Egger intercept test and MR-PRESSO global test results indicated no evidence of heterogeneity or horizontal pleiotropy in the associations between cathepsins and endometriosis. These results are presented in Supplementary Tables 2. Furthermore, the leave-one-out analysis demonstrated the robustness of the MR results. Excluding any single SNP associated with cathepsins and endometriosis did not significantly alter the overall findings. To account for potential directional pleiotropy, we conducted an analysis using the GWAS Catalog to identify SNPs linked to cathepsins and endometriosis. Two SNPs were discovered to exhibit associations with other traits, as detailed in Supplementary Tables 3. After excluding these pleiotropic SNPs, the associations between cathepsins and endometriosis remained stable, as shown in Supplementary Table 4. Discussion Our analysis presents suggestive evidence that cathepsins may affect the risk of endometriosis based on a comprehensive genetic approach utilizing large-scale GWAS summary data. To the best of our knowledge, this is the first MR analysis to examine the causal relationship between multiple cathepsins and endometriosis. By using SNPs as instrumental variables and incorporating various two-sample MR methods, we confirmed a significant association between Cathepsin H and the risk of endometriosis. Additionally, in the reverse MR analysis, we observed a suggestive association between endometriosis and increased levels of Cathepsin H. Endometriosis is a severe reproductive system disorder often referred to as "benign cancer". Symptoms of endometriosis, such as dysmenorrhea, menorrhagia, and infertility, are likely a result of the abnormal implantation of endometrial tissues, leading to the formation of lesions on various sites including the peritoneal wall, uterus, and ovaries ( 26 , 27 ). While current treatments can alleviate moderate pain symptoms, their effectiveness in preventing lesion formation is inconsistent and varies among patients ( 28 ). The occurrence of retrograde menstruation, where endometrial fragments travel upward through the oviducts into the peritoneal cavity, is strongly associated with the development of the disease. However, this alone cannot explain the disorder since retrograde menstruation occurs in approximately 90% of women ( 29 ), whereas only 6–10% of women are diagnosed with endometriosis ( 30 ). The invasion of estrogen-dependent cells plays a central role in the formation of endometriosis lesions ( 31 ). Enzymes that degrade extracellular matrix proteins, such as collagen, fibronectin, and laminin, which constitute the peritoneal and uterine walls, may facilitate this invasion ( 32 , 33 ). Cathepsin H (CatH, EC 3.4.22.16) is a lysosomal cysteine protease that was initially discovered in rat liver lysosomes in 1976 and later isolated from human liver ( 34 , 35 ). Cysteine cathepsins are involved in regulating growth, migration, angiogenesis, and metastasis ( 36 – 38 ). In the context of endometrium, Cathepsin H expression is higher in the proliferative phase compared to the secretory phase, suggesting a potential link to estrogenic control, either directly or indirectly ( 39 ). Elevated levels of Cathepsin H have also been detected in the serum and tissue extracts of breast cancer patients, which is also tightly associated with estrogen ( 40 , 41 ). Cathepsin H plays multiple roles, including intracellular and extracellular proteolytic functions, as well as promoting cell proliferation and migration. It facilitates cell invasion through degradation of the extracellular matrix, both extracellularly and intracellularly ( 42 ) ( 43 ). However, its relatively weak endopeptidase activity suggests that Cathepsin H may not be a primary contributor to direct extracellular matrix degradation. While the exact role of Cathepsin H in cell progression remains unclear, it has been identified in early endosomes and implicated in talin processing within focal adhesions of migrating PC-3 cells, suggesting an intracellular proteolytic role in regulating cell migration ( 44 ). Additionally, upregulation of extracellular Cathepsin H mediated by T3 has been shown to activate MMPs or extracellular signal-regulated kinases, promoting cell migration and invasion ( 45 ). Estrogen-dependent cell invasion is central to endometriosis lesion establishment, and we believe that this might be the possible mechanism of Cathepsin H promoting endometriosis. Our findings provide evidence supporting a potential causal relationship between Cathepsin H and endometriosis. This discovery has implications for guiding prognosis and treatment decisions, as well as for the development of new drugs. However, it is important to acknowledge that endometriosis is a complex condition with multifaceted causes, and there are variations in clinical presentation among different histological subtypes. Therefore, a personalized treatment approach may be more effective than a one-size-fits-all approach. Further research is needed to delve into the intricate interplay between Cathepsin H and endometriosis, which will contribute to a deeper understanding of the condition and potentially lead to more targeted and efficient therapeutic interventions. It is essential to acknowledge the inherent limitations of our study, which should not be overlooked. Firstly, it is important to highlight that MR analysis, used in our study, cannot replace the need for clinical trials in establishing causality between exposure and outcome. MR analysis serves as a valuable tool for assessing potential causal relationships, but further investigations, including experimental studies and randomized controlled trials, are required to validate the association between Cathepsin H and the risk of endometriosis. Furthermore, it is crucial to recognize that our MR analysis was conducted exclusively within the European population due to limited availability of genetic data resources. Genetic heterogeneity exists among different ethnic groups, and therefore, it is possible that the results may vary in other populations. Future studies should consider conducting subgroup analyses that include diverse populations to obtain a more comprehensive and generalizable conclusion. In conclusion, while our findings offer valuable insights into the potential association between Cathepsin H and the risk of endometriosis using MR analysis, it is important to interpret the results in light of these limitations. Continued research efforts, involving different study designs and populations, are necessary to confirm and expand upon our findings. Conclusion On the basis of our study, Cathepsin H increases the risk of overall endometriosis, endometriosis of ovary, endometriosis of pelvic peritoneum, and deep endometriosis. Overall endometriosis may lead to increased Cathepsin H levels. Abbreviations GWAS, genome-wide association study; MR analysis, Mendelian randomization analysis; IVW method, inverse-variance weighted method. Declarations Acknowledgements The GWAS summary data were acquired from the publicly accessible online platform (https://gwas.mrcieu.ac.uk/). The analyses of the GWAS summary data were conducted using application R version 4.2.1. Funding This work was supported by Key research and development project of Sichuan Science and Technology Department (No.2023YFS0194), National Natural Science Foundation Youth Program (No.31801066) Competing interests The authors have no relevant financial or non-financial interests to disclose. Author Contributions N.A. led study design and prepared the manuscript. Y.C. and C.Y. performed the research and wrote the manuscript. J.L. provided the funding, helped the data analysis, and revised the manuscript. All authors contributed to the article and approved the submitted version. Ethics approval The GWAS summary data used in this study were all from the online public platform (https://gwas.mrcieu.ac.uk/). The study protocols were approved by respective local ethics committees, and participants have provided written informed consent. Data Availability Publicly available data were analyzed in this study, which can be found here: gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_OVARY.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_PELVICPERITONEUM.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_DEEP.gz. The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author. References Pant A, Moar K, K Arora T, Maurya P. Biomarkers of endometriosis. Clinica chimica acta; international journal of clinical chemistry. 2023;549:117563. Merli C, Cetera G, Caia C, Facchin F, Vercellini P. "The sound of silence" Giving voice to endometriosis-related positional dyspareunia. Archives of gynecology and obstetrics. 2023. Csirzó Á, Kovács DP, Szabó A, Fehérvári P, Jankó Á, Hegyi P, et al. Robot-assisted laparoscopy does not have demonstrable advantages over conventional laparoscopy in endometriosis surgery: a systematic review and meta-analysis. Surg Endosc. 2023. Thomas EJ, Campbell IG. Evidence that endometriosis behaves in a malignant manner. Gynecol Obstet Invest. 2000;50 Suppl 1:2-10. Sillem M, Prifti S, Neher M, Runnebaum B. Extracellular matrix remodelling in the endometrium and its possible relevance to the pathogenesis of endometriosis. Hum Reprod Update. 1998;4(5):730-5. Uzan C, Cortez A, Dufournet C, Fauvet R, Siffroi JP, Daraï E. Eutopic endometrium and peritoneal, ovarian and bowel endometriotic tissues express a different profile of matrix metalloproteinases-2, -3 and -11, and of tissue inhibitor metalloproteinases-1 and -2. Virchows Arch. 2004;445(6):603-9. Reiser J, Adair B, Reinheckel T. Specialized roles for cysteine cathepsins in health and disease. J Clin Invest. 2010;120(10):3421-31. Fonović M, Turk B. Cysteine cathepsins and extracellular matrix degradation. Biochim Biophys Acta. 2014;1840(8):2560-70. Conus S, Simon HU. Cathepsins: key modulators of cell death and inflammatory responses. Biochem Pharmacol. 2008;76(11):1374-82. Yadati T, Houben T, Bitorina A, Shiri-Sverdlov R. The Ins and Outs of Cathepsins: Physiological Function and Role in Disease Management. Cells. 2020;9(7). Kim CH, Lee YJ, Kim JB, Lee YJ, Ahn JW, Kim SH, et al. Cathepsin B in eutopic and ectopic endometrial tissues of patients with endometriosis. Dev Reprod. 2013;17(2):133-40. Laudanski P, Gorodkiewicz E, Ramotowska B, Charkiewicz R, Kuzmicki M, Szamatowicz J. Determination of cathepsins B, D and G concentration in eutopic proliferative endometrium of women with endometriosis by the surface plasmon resonance imaging (SPRI) technique. Eur J Obstet Gynecol Reprod Biol. 2013;169(1):80-3. Dietze R, Starzinski-Powitz A, Scheiner-Bobis G, Tinneberg HR, Meinhold-Heerlein I, Konrad L. Lysophosphatidic acid triggers cathepsin B-mediated invasiveness of human endometriotic cells. Biochim Biophys Acta Mol Cell Biol Lipids. 2018;1863(11):1369-77. Protopapas A, Markaki S, Mitsis T, Milingos D, Athanasiou S, Haidopoulos D, et al. Immunohistochemical expression of matrix metalloproteinases, their tissue inhibitors, and cathepsin-D in ovarian endometriosis: correlation with severity of disease. Fertil Steril. 2010;94(6):2470-2. Grzywa R, Gorodkiewicz E, Burchacka E, Lesner A, Laudański P, Łukaszewski Z, et al. Determination of cathepsin G in endometrial tissue using a surface plasmon resonance imaging biosensor with tailored phosphonic inhibitor. Eur J Obstet Gynecol Reprod Biol. 2014;182:38-42. Porter KM, Wieser FA, Wilder CL, Sidell N, Platt MO. Cathepsin Protease Inhibition Reduces Endometriosis Lesion Establishment. Reprod Sci. 2016;23(5):623-9. Brennan P, Hainaut P, Boffetta P. Genetics of lung-cancer susceptibility. Lancet Oncol. 2011;12(4):399-408. Davey Smith G, Hemani G. Mendelian randomization: genetic anchors for causal inference in epidemiological studies. Human molecular genetics. 2014;23:R89-98. Sun BB, Maranville JC, Peters JE, Stacey D, Staley JR, Blackshaw J, et al. Genomic atlas of the human plasma proteome. Nature. 2018;558(7708):73-9. Auton A, Brooks L, Durbin R, Garrison E, Kang H, Korbel J, et al. A global reference for human genetic variation. Nature. 2015;526(7571):68-74. Cai J, Li X, Wu S, Tian Y, Zhang Y, Wei Z, et al. Assessing the causal association between human blood metabolites and the risk of epilepsy. Journal of translational medicine. 2022;20(1):437. Wang X, Xu W, Wang F, Leng R, Yang X, Ling H, et al. Telomere Length and Development of Systemic Lupus Erythematosus: A Mendelian Randomization Study. Arthritis & rheumatology (Hoboken, NJ). 2022;74(12):1984-90. Hemani G, Zheng J, Elsworth B, Wade K, Haberland V, Baird D, et al. The MR-Base platform supports systematic causal inference across the human phenome. eLife. 2018;7. Yavorska OO, Burgess S. MendelianRandomization: an R package for performing Mendelian randomization analyses using summarized data. Int J Epidemiol. 2017;46(6):1734-9. Verbanck M, Chen C, Neale B, Do R. Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Nature genetics. 2018;50(5):693-8. Giudice LC. Clinical practice. Endometriosis. N Engl J Med. 2010;362(25):2389-98. Giudice LC, Kao LC. Endometriosis. Lancet. 2004;364(9447):1789-99. Soares SR, Martínez-Varea A, Hidalgo-Mora JJ, Pellicer A. Pharmacologic therapies in endometriosis: a systematic review. Fertil Steril. 2012;98(3):529-55. Halme J, Hammond MG, Hulka JF, Raj SG, Talbert LM. Retrograde menstruation in healthy women and in patients with endometriosis. Obstet Gynecol. 1984;64(2):151-4. Parazzini F, Esposito G, Tozzi L, Noli S, Bianchi S. Epidemiology of endometriosis and its comorbidities. Eur J Obstet Gynecol Reprod Biol. 2017;209:3-7. Burney RO, Giudice LC. Pathogenesis and pathophysiology of endometriosis. Fertil Steril. 2012;98(3):511-9. Witz CA, Montoya-Rodriguez IA, Cho S, Centonze VE, Bonewald LF, Schenken RS. Composition of the extracellular matrix of the peritoneum. J Soc Gynecol Investig. 2001;8(5):299-304. Sillem M, Hahn U, Coddington CC, 3rd, Gordon K, Runnebaum B, Hodgen GD. Ectopic growth of endometrium depends on its structural integrity and proteolytic activity in the cynomolgus monkey (Macaca fascicularis) model of endometriosis. Fertil Steril. 1996;66(3):468-73. Kirschke H, Langner J, Wiederanders B, Ansorge S, Bohley P, Broghammer U. [Intracellular protein breakdown. VII. Cathepsin L and H; two new proteinases from rat liver lysosomes]. Acta Biol Med Ger. 1976;35(3-4):285-99. Schwartz WN, Barrett AJ. Human cathepsin H. Biochem J. 1980;191(2):487-97. Turk B. Targeting proteases: successes, failures and future prospects. Nat Rev Drug Discov. 2006;5(9):785-99. Vasiljeva O, Reinheckel T, Peters C, Turk D, Turk V, Turk B. Emerging roles of cysteine cathepsins in disease and their potential as drug targets. Curr Pharm Des. 2007;13(4):387-403. Kramer L, Turk D, Turk B. The Future of Cysteine Cathepsins in Disease Management. Trends Pharmacol Sci. 2017;38(10):873-98. Allan G, Campen C, Hodgen G, Williams R, Charnock-Jones DS, Wan J, et al. Identification of genes with differential regulation in primate endometrium during the proliferative and secretory phases of the cycle. Endocr Res. 2003;29(1):53-65. Gabrijelcic D, Svetic B, Spaić D, Skrk J, Budihna M, Dolenc I, et al. Cathepsins B, H and L in human breast carcinoma. Eur J Clin Chem Clin Biochem. 1992;30(2):69-74. Gabrijelcic D, Svetic B, Spaić D, Skrk J, Budihna J, Turk V. Determination of cathepsins B, H, L and kininogen in breast cancer patients. Agents Actions Suppl. 1992;38 ( Pt 2):350-7. Gocheva V, Joyce JA. Cysteine cathepsins and the cutting edge of cancer invasion. Cell Cycle. 2007;6(1):60-4. Premzl A, Zavasnik-Bergant V, Turk V, Kos J. Intracellular and extracellular cathepsin B facilitate invasion of MCF-10A neoT cells through reconstituted extracellular matrix in vitro. Exp Cell Res. 2003;283(2):206-14. Jevnikar Z, Rojnik M, Jamnik P, Doljak B, Fonovic UP, Kos J. Cathepsin H mediates the processing of talin and regulates migration of prostate cancer cells. J Biol Chem. 2013;288(4):2201-9. Wu SM, Huang YH, Yeh CT, Tsai MM, Liao CH, Cheng WL, et al. Cathepsin H regulated by the thyroid hormone receptors associate with tumor invasion in human hepatoma cells. Oncogene. 2011;30(17):2057-69. Additional Declarations No competing interests reported. Supplementary Files Supplementarytables.xlsx Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3756621","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":259962136,"identity":"18db6e69-e6f6-4323-a09c-19eec1ad669f","order_by":0,"name":"Na Aru","email":"","orcid":"","institution":"West China Second University Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Na","middleName":"","lastName":"Aru","suffix":""},{"id":259962138,"identity":"6e913a98-e9e7-4188-8160-8a5050a95c2f","order_by":1,"name":"Congyu Yang","email":"","orcid":"","institution":"West China Second University Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Congyu","middleName":"","lastName":"Yang","suffix":""},{"id":259962139,"identity":"cddab739-78d8-45b7-a362-53b8c98a9c60","order_by":2,"name":"Yuntian Chen","email":"","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":false,"prefix":"","firstName":"Yuntian","middleName":"","lastName":"Chen","suffix":""},{"id":259962141,"identity":"002becd2-7e51-4213-a5c7-a15edc5137de","order_by":3,"name":"Jiaming Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsklEQVRIiWNgGAWjYBAC9hnpBw58qLDh4edvIFIL45w3iQ9nnEmTkZxxgFgt8x8YG/O2HbYxaEggVsvshDRp3rbzPAYMBxg/fMwhSkviMck5527zmDM3MEvO3EakLRJvym7zWDYcYGPmJUrLjAQzCR62czwGBxKI1CI4I8HYkKftAAlapCVyQIGczCM542AzcX7hkwBHpZ09P3/zwQ8fidGCBBgbSFM/CkbBKBgFowA3AAB+ADq1K+VicwAAAABJRU5ErkJggg==","orcid":"","institution":"West China Hospital of Sichuan University","correspondingAuthor":true,"prefix":"","firstName":"Jiaming","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2023-12-15 04:44:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3756621/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3756621/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":48488479,"identity":"32eb0bee-6136-41c8-bdd5-d090b248b5a1","added_by":"auto","created_at":"2023-12-19 20:06:21","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":51794,"visible":true,"origin":"","legend":"\u003cp\u003eResearch overview and design of Mendelian randomization analysis.\u003c/p\u003e","description":"","filename":"Fig11.png","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/699c6bc637bfeb904d165f0d.png"},{"id":48487410,"identity":"19167e9d-3e80-4cef-a02a-48226ba3733c","added_by":"auto","created_at":"2023-12-19 19:58:21","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":54209,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of Cathepsin H on overall endometriosis and its different histological subtypes by univariable Mendelian randomization analysis\u003c/p\u003e\n\u003cp\u003ensnp, number of single nucleotide polymorphisms; OR, odds ratio; CI, confidence interval.\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/433c5a5485eb4f9935d5ea7f.png"},{"id":48487413,"identity":"fb4d784f-5406-408c-8e04-5ac0c8003394","added_by":"auto","created_at":"2023-12-19 19:58:22","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":101079,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of cathepsins on endometriosis with IVW method by univariable Mendelian randomization analysis\u003c/p\u003e\n\u003cp\u003ensnp, number of single nucleotide polymorphisms; OR, odds ratio; CI, confidence interval.\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/5c753dfec030c5fbaabd33f5.png"},{"id":48488480,"identity":"51fa0a35-85c1-4841-8ec7-0ae1822333d7","added_by":"auto","created_at":"2023-12-19 20:06:22","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":956585,"visible":true,"origin":"","legend":"\u003cp\u003eThe effect of cathepsins on overall endometriosis and its different histological subtypes with IVW method by multivariable Mendelian randomization analysis\u003c/p\u003e\n\u003cp\u003eOR, odds ratio; CI, confidence interval.\u003c/p\u003e","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/3b57bf76b111a26800059aa8.png"},{"id":48489020,"identity":"9a21b0e0-676f-47aa-b35e-7f7f96d3b903","added_by":"auto","created_at":"2023-12-19 20:22:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1346924,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/1b1eef04-54b5-44fe-9c2d-62f3da38fa32.pdf"},{"id":48488481,"identity":"066e9e82-6182-446e-9d4e-993cc443bf13","added_by":"auto","created_at":"2023-12-19 20:06:22","extension":"xlsx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":69790,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarytables.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-3756621/v1/bab75cffe9556eed86f36c94.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Causal association of cathepsins and endometriosis: A Mendelian randomization study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEndometriosis, a complex and debilitating gynecological condition, is characterized by a range of distressing symptoms, including dysmenorrhea, chronic pelvic pain, and dyspareunia (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Globally, approximately 70\u0026nbsp;million women of reproductive age are affected by various forms of endometriosis (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Interestingly, endometriosis shares certain characteristics with malignant neoplasms, such as the ability to invade tissues locally and metastasize to distant sites (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). The process of local invasion relies on enzymes that break down the extracellular matrix of surrounding connective tissue (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). The activity of the proteolytic system plays a crucial role in maintaining local homeostasis in both health and disease. However, the specific role of this group of enzymes in the development of endometriosis remains largely unknown. It is possible that the activity and altered expression of these enzymes contribute to the clinical profile of endometriosis (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCathepsins, which encompass a group of lysosomal proteolytic enzymes (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), are prominently found in humans and are part of the papain superfamily of cysteine proteases (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). These enzymes play crucial roles in numerous physiological and pathophysiological cellular processes. They are involved in protein and lipid metabolism, autophagy, antigen presentation, recycling of growth factor receptors, cellular stress signaling, degradation of the extracellular matrix, and lysosome-mediated cell death (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Given their involvement in these essential processes, various cathepsins have been implicated in the development of different diseases, including endometriosis (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRecent studies have shed light on the roles of several cathepsins in endometriosis. These include Cathepsin B (\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), Cathepsin D (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e), Cathepsin G (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e), Cathepsin K (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e), and Cathepsin L (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). However, there is still a lack of sufficient research exploring the causal relationship between specific types of cathepsins and the risk of different histological subtypes of endometriosis. Therefore, further investigation is necessary to better understand the causal associations between different cathepsins and the risk of specific endometriosis subtypes.\u003c/p\u003e \u003cp\u003eWith the advancements in genomics, there is growing evidence highlighting the role of heritability in the etiology of diseases (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Mendelian randomization (MR) is an analytical method used in epidemiological studies to infer disease etiology based on the Mendelian independent distribution law. For MR to be considered valid, it is essential for the causal sequence to be plausible and supported by evidence (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Previous observational studies have identified associations between cathepsin traits and endometriosis, suggesting a potential correlation between them. In this specific study, a comprehensive two-sample MR analysis was conducted to establish a causal link between specific cathepsin signatures and endometriosis. By utilizing this approach, the researchers aimed to provide stronger evidence for the causal relationship between cathepsins and the development of endometriosis.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eIn our study, we conducted a two-sample MR analysis to evaluate the causal relationship between cathepsins and endometriosis. To ensure reliable results, three key assumptions must be met when performing MR analysis: 1) a strong association between genetic variants and exposure factors, 2) no correlation between genetic variants and confounding variables, and 3) the influence of genetic variants on the outcome is solely mediated through the exposure factors, excluding other pathways.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eGenome-wide association study (GWAS) data sources for endometriosis\u003c/h2\u003e \u003cp\u003eAll datasets were derived from the European population. The GWAS statistics for endometriosis were sourced from FinnGen Research's data release (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS.gz). The GWAS statistics encompassed 15,088 cases and 107,564 controls. Summary statistics for endometriosis of ovary were obtained from a comprehensive GWAS study conducted by FinnGen Research (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_OVARY.gz), involving a cohort of 5,867 cases and 107,564 controls. Summary statistics of endometriosis of pelvic peritoneum was derived from a GWAS encompassing a cohort of 5,628 cases and 107,564 controls of European ancestry (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_PELVICPERITONEUM.gz). Lastly, GWAS data for deep endometriosis was extracted from FinnGen Research (gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_DEEP.gz), encompassing 2856 cases and 203,296 controls of European ancestry.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eCathepsins GWAS data sources\u003c/h2\u003e \u003cp\u003eGenetic instruments for evaluating the levels of different cathepsins (\u0026micro;g/L) were obtained from the INTERVAL study, which involved 3,301 individuals of European descent (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). The summary data can be accessed at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://gwas.mrcieu.ac.uk\u003c/span\u003e\u003cspan address=\"https://gwas.mrcieu.ac.uk\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eSelection of instrumental variables (IVs)\u003c/h2\u003e \u003cp\u003eA significance level of 5 \u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e was set for the instrumental variables (IVs) associated with each immune trait. To ensure reliable results, a threshold for strong linkage disequilibrium (LD) effect was applied (r\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e), with LD r\u003csup\u003e2\u003c/sup\u003e calculated using the 10,000 Genomes Project as a reference panel. The proportion of phenotypic variation explained (PVE) and the F statistic were calculated for each IV to assess the strength of the IVs and to avoid bias caused by weak instruments. Furthermore, to mitigate bias introduced by weak instruments, IVs with F statistics greater than 10 were considered strong instruments and included in the subsequent analysis. The exposure and outcome SNPs were harmonized to align effect estimates for the same effect allele. Palindromic SNPs with intermediate effect allele frequencies (EAFs\u0026thinsp;\u0026gt;\u0026thinsp;0.42) or SNPs with incompatible alleles were excluded (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eData analysis\u003c/h2\u003e \u003cp\u003eWe performed various MR analyses, including MR Egger, weighted median, inverse-variance weighted (IVW), simple mode, weighted mode, and MR-PRESSO approaches. Among these, the IVW method is commonly used (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo assess the presence of heterogeneity, we conducted heterogeneity tests using both the MR Egger and IVW methods. The Cochrane's Q value was used to evaluate the variability of genetic instruments, where a p-value greater than 0.05 indicates no significant heterogeneity. To examine the presence of horizontal pleiotropy, we utilized the MR Egger regression equation, where a p-value above 0.05 suggests no evidence of horizontal pleiotropy (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn addition, we employed multivariable MR, an extension of standard univariable MR, to consider multiple cathepsins when analyzing their causal effects on different subtypes of endometriosis. This approach also allowed us to estimate the direct causal effects of each exposure in a single analysis using the \"MendelianRandomization\" package (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Reverse MR analyses, treating endometriosis as the exposure and cathepsins as the outcomes, were performed to evaluate reverse causality and explore bidirectional causality.\u003c/p\u003e \u003cp\u003eTo assess the potential impact of directional pleiotropy, we examined each SNP for potential associations with secondary phenotypes using the GWAS Catalog (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://www.phenoscanner.medschl.cam.ac.uk/\u003c/span\u003e\u003cspan address=\"http://www.phenoscanner.medschl.cam.ac.uk/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e). Subsequently, we repeated the MR analyses, excluding SNPs associated with other phenotypes. Furthermore, we conducted leave-one-out sensitivity analyses on significant findings to determine if a single SNP was responsible for the observed causal relationship. The overall research design is illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The MR analyses were conducted using the 'TwoSampleMR' package (version 0.5.7) in the R software environment (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003eExploration of the causal effect of cathepsins on endometriosis\u003c/h2\u003e\n \u003cp\u003eThe findings of the univariable MR analysis revealed that genetically predicted Cathepsin H were positively correlated with the risk of overall endometriosis (OR [95%]: 1.037[1.007 to 1.067], p\u0026thinsp;=\u0026thinsp;0.013) in the IVW method. Similar results were observed by using Weighted median (OR [95%]: 1.036 [1.005 to 1.068], p\u0026thinsp;=\u0026thinsp;0.022), and Weighted mode (OR [95%]: 1.037 [1.005 to 1.069], p\u0026thinsp;=\u0026thinsp;0.049). We noticed that Cathepsin H were suggestively associated with a higher risk of the rest of three histological subtypes of endometriosis in IVW method. OR [95%]: 1.022 [1.001 to 1.042], p\u0026thinsp;=\u0026thinsp;0.046 for endometriosis of ovary; OR [95%]: 1.046 [1.002 to 1.089], p\u0026thinsp;=\u0026thinsp;0.047 for endometriosis of pelvic peritoneum; OR [95%]: 1.050 [1.002 to 1.099], p\u0026thinsp;=\u0026thinsp;0.048 for deep endometriosis (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). No other types of cathepsins exhibited significant association with the risk of overall endometriosis or its different histological subtypes (Supplementary Table 1 and Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eMoreover, we conducted multivariable MR to assess the genetic predisposition involving cathepsins in relation to the risk of different histological subtypes of endometriosis. The results revealed that even after adjusting for other types of cathepsins, elevated Cathepsin H levels retained a robust association with an increased risk of overall endometriosis (IVW: OR [95%]: 1.034[1.002 to 1.066], p\u0026thinsp;=\u0026thinsp;0.049), endometriosis of ovary (IVW: OR [95%]: 1.022 [1.005 to 1.039], p\u0026thinsp;=\u0026thinsp;0.047), endometriosis of pelvic peritoneum (IVW: OR [95%]: 1.051[1.009 to 1.096], p\u0026thinsp;=\u0026thinsp;0.042), and deep endometriosis (IVW: OR [95%]: 1.099[1.045 to 1.143], p\u0026thinsp;=\u0026thinsp;0.043). However, no statistically significant causal association was observed between other types of cathepsins and overall endometriosis or its different histological subtypes (Supplementary Table 5 and Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003eExploration of the causal effect of endometriosis on cathepsins\u003c/h2\u003e\n \u003cp\u003eAs detailed in Supplementary Tables\u0026nbsp;6, we evaluated the potential associations of cathepsins and endometriosis using the reverse MR analyses. Overall endometriosis was suggestively associated with increased Cathepsin H (IVW: OR [95%]: 1.017 [1.003, 1.073], p\u0026thinsp;=\u0026thinsp;0.041). We did not find statistically significant associations between endometriosis and other types of cathepsins, the results were stable across sensitivity analyses, which are listed in Supplementary Table\u0026nbsp;7.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eSensitivity analysis\u003c/h2\u003e\n \u003cp\u003eThe MR-Egger intercept test and MR-PRESSO global test results indicated no evidence of heterogeneity or horizontal pleiotropy in the associations between cathepsins and endometriosis. These results are presented in Supplementary Tables\u0026nbsp;2. Furthermore, the leave-one-out analysis demonstrated the robustness of the MR results. Excluding any single SNP associated with cathepsins and endometriosis did not significantly alter the overall findings.\u003c/p\u003e\n \u003cp\u003eTo account for potential directional pleiotropy, we conducted an analysis using the GWAS Catalog to identify SNPs linked to cathepsins and endometriosis. Two SNPs were discovered to exhibit associations with other traits, as detailed in Supplementary Tables\u0026nbsp;3. After excluding these pleiotropic SNPs, the associations between cathepsins and endometriosis remained stable, as shown in Supplementary Table\u0026nbsp;4.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur analysis presents suggestive evidence that cathepsins may affect the risk of endometriosis based on a comprehensive genetic approach utilizing large-scale GWAS summary data. To the best of our knowledge, this is the first MR analysis to examine the causal relationship between multiple cathepsins and endometriosis. By using SNPs as instrumental variables and incorporating various two-sample MR methods, we confirmed a significant association between Cathepsin H and the risk of endometriosis. Additionally, in the reverse MR analysis, we observed a suggestive association between endometriosis and increased levels of Cathepsin H.\u003c/p\u003e \u003cp\u003eEndometriosis is a severe reproductive system disorder often referred to as \"benign cancer\". Symptoms of endometriosis, such as dysmenorrhea, menorrhagia, and infertility, are likely a result of the abnormal implantation of endometrial tissues, leading to the formation of lesions on various sites including the peritoneal wall, uterus, and ovaries (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). While current treatments can alleviate moderate pain symptoms, their effectiveness in preventing lesion formation is inconsistent and varies among patients (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). The occurrence of retrograde menstruation, where endometrial fragments travel upward through the oviducts into the peritoneal cavity, is strongly associated with the development of the disease. However, this alone cannot explain the disorder since retrograde menstruation occurs in approximately 90% of women (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e), whereas only 6\u0026ndash;10% of women are diagnosed with endometriosis (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). The invasion of estrogen-dependent cells plays a central role in the formation of endometriosis lesions (\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e). Enzymes that degrade extracellular matrix proteins, such as collagen, fibronectin, and laminin, which constitute the peritoneal and uterine walls, may facilitate this invasion (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCathepsin H (CatH, EC 3.4.22.16) is a lysosomal cysteine protease that was initially discovered in rat liver lysosomes in 1976 and later isolated from human liver (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e). Cysteine cathepsins are involved in regulating growth, migration, angiogenesis, and metastasis (\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). In the context of endometrium, Cathepsin H expression is higher in the proliferative phase compared to the secretory phase, suggesting a potential link to estrogenic control, either directly or indirectly (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). Elevated levels of Cathepsin H have also been detected in the serum and tissue extracts of breast cancer patients, which is also tightly associated with estrogen (\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). Cathepsin H plays multiple roles, including intracellular and extracellular proteolytic functions, as well as promoting cell proliferation and migration. It facilitates cell invasion through degradation of the extracellular matrix, both extracellularly and intracellularly (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e) (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). However, its relatively weak endopeptidase activity suggests that Cathepsin H may not be a primary contributor to direct extracellular matrix degradation. While the exact role of Cathepsin H in cell progression remains unclear, it has been identified in early endosomes and implicated in talin processing within focal adhesions of migrating PC-3 cells, suggesting an intracellular proteolytic role in regulating cell migration (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e). Additionally, upregulation of extracellular Cathepsin H mediated by T3 has been shown to activate MMPs or extracellular signal-regulated kinases, promoting cell migration and invasion (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e). Estrogen-dependent cell invasion is central to endometriosis lesion establishment, and we believe that this might be the possible mechanism of Cathepsin H promoting endometriosis.\u003c/p\u003e \u003cp\u003eOur findings provide evidence supporting a potential causal relationship between Cathepsin H and endometriosis. This discovery has implications for guiding prognosis and treatment decisions, as well as for the development of new drugs. However, it is important to acknowledge that endometriosis is a complex condition with multifaceted causes, and there are variations in clinical presentation among different histological subtypes. Therefore, a personalized treatment approach may be more effective than a one-size-fits-all approach. Further research is needed to delve into the intricate interplay between Cathepsin H and endometriosis, which will contribute to a deeper understanding of the condition and potentially lead to more targeted and efficient therapeutic interventions.\u003c/p\u003e \u003cp\u003eIt is essential to acknowledge the inherent limitations of our study, which should not be overlooked. Firstly, it is important to highlight that MR analysis, used in our study, cannot replace the need for clinical trials in establishing causality between exposure and outcome. MR analysis serves as a valuable tool for assessing potential causal relationships, but further investigations, including experimental studies and randomized controlled trials, are required to validate the association between Cathepsin H and the risk of endometriosis. Furthermore, it is crucial to recognize that our MR analysis was conducted exclusively within the European population due to limited availability of genetic data resources. Genetic heterogeneity exists among different ethnic groups, and therefore, it is possible that the results may vary in other populations. Future studies should consider conducting subgroup analyses that include diverse populations to obtain a more comprehensive and generalizable conclusion. In conclusion, while our findings offer valuable insights into the potential association between Cathepsin H and the risk of endometriosis using MR analysis, it is important to interpret the results in light of these limitations. Continued research efforts, involving different study designs and populations, are necessary to confirm and expand upon our findings.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOn the basis of our study, Cathepsin H increases the risk of overall endometriosis, endometriosis of ovary, endometriosis of pelvic peritoneum, and deep endometriosis. Overall endometriosis may lead to increased Cathepsin H levels.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eGWAS, genome-wide association study; MR analysis, Mendelian randomization analysis; IVW method, inverse-variance weighted method.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe GWAS summary data were acquired from the publicly accessible online platform (https://gwas.mrcieu.ac.uk/). The analyses of the GWAS summary data were conducted using application R version 4.2.1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Key research and development project of Sichuan Science and Technology Department (No.2023YFS0194), National Natural Science Foundation Youth Program (No.31801066)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eN.A. led study design and prepared the manuscript.\u003c/p\u003e\n\u003cp\u003eY.C. and C.Y. performed the research and wrote the manuscript.\u003c/p\u003e\n\u003cp\u003eJ.L. provided the funding, helped the data analysis, and revised the manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the article and approved the submitted version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe GWAS summary data used in this study were all from the online public platform (https://gwas.mrcieu.ac.uk/). The study protocols were approved by respective local ethics committees, and participants have provided written informed consent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePublicly available data were analyzed in this study, which can be found here: gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_OVARY.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_PELVICPERITONEUM.gz, gs://finngen-public-data-r9/summary_stats/finngen_R9_N14_ENDOMETRIOSIS_DEEP.gz. The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ePant A, Moar K, K Arora T, Maurya P. Biomarkers of endometriosis. Clinica chimica acta; international journal of clinical chemistry. 2023;549:117563.\u003c/li\u003e\n\u003cli\u003eMerli C, Cetera G, Caia C, Facchin F, Vercellini P. \u0026quot;The sound of silence\u0026quot; Giving voice to endometriosis-related positional dyspareunia. Archives of gynecology and obstetrics. 2023.\u003c/li\u003e\n\u003cli\u003eCsirz\u0026oacute; \u0026Aacute;, Kov\u0026aacute;cs DP, Szab\u0026oacute; A, Feh\u0026eacute;rv\u0026aacute;ri P, Jank\u0026oacute; \u0026Aacute;, Hegyi P, et al. Robot-assisted laparoscopy does not have demonstrable advantages over conventional laparoscopy in endometriosis surgery: a systematic review and meta-analysis. Surg Endosc. 2023.\u003c/li\u003e\n\u003cli\u003eThomas EJ, Campbell IG. Evidence that endometriosis behaves in a malignant manner. Gynecol Obstet Invest. 2000;50 Suppl 1:2-10.\u003c/li\u003e\n\u003cli\u003eSillem M, Prifti S, Neher M, Runnebaum B. Extracellular matrix remodelling in the endometrium and its possible relevance to the pathogenesis of endometriosis. Hum Reprod Update. 1998;4(5):730-5.\u003c/li\u003e\n\u003cli\u003eUzan C, Cortez A, Dufournet C, Fauvet R, Siffroi JP, Dara\u0026iuml; E. Eutopic endometrium and peritoneal, ovarian and bowel endometriotic tissues express a different profile of matrix metalloproteinases-2, -3 and -11, and of tissue inhibitor metalloproteinases-1 and -2. Virchows Arch. 2004;445(6):603-9.\u003c/li\u003e\n\u003cli\u003eReiser J, Adair B, Reinheckel T. Specialized roles for cysteine cathepsins in health and disease. J Clin Invest. 2010;120(10):3421-31.\u003c/li\u003e\n\u003cli\u003eFonović M, Turk B. Cysteine cathepsins and extracellular matrix degradation. Biochim Biophys Acta. 2014;1840(8):2560-70.\u003c/li\u003e\n\u003cli\u003eConus S, Simon HU. Cathepsins: key modulators of cell death and inflammatory responses. Biochem Pharmacol. 2008;76(11):1374-82.\u003c/li\u003e\n\u003cli\u003eYadati T, Houben T, Bitorina A, Shiri-Sverdlov R. The Ins and Outs of Cathepsins: Physiological Function and Role in Disease Management. Cells. 2020;9(7).\u003c/li\u003e\n\u003cli\u003eKim CH, Lee YJ, Kim JB, Lee YJ, Ahn JW, Kim SH, et al. Cathepsin B in eutopic and ectopic endometrial tissues of patients with endometriosis. Dev Reprod. 2013;17(2):133-40.\u003c/li\u003e\n\u003cli\u003eLaudanski P, Gorodkiewicz E, Ramotowska B, Charkiewicz R, Kuzmicki M, Szamatowicz J. Determination of cathepsins B, D and G concentration in eutopic proliferative endometrium of women with endometriosis by the surface plasmon resonance imaging (SPRI) technique. Eur J Obstet Gynecol Reprod Biol. 2013;169(1):80-3.\u003c/li\u003e\n\u003cli\u003eDietze R, Starzinski-Powitz A, Scheiner-Bobis G, Tinneberg HR, Meinhold-Heerlein I, Konrad L. Lysophosphatidic acid triggers cathepsin B-mediated invasiveness of human endometriotic cells. Biochim Biophys Acta Mol Cell Biol Lipids. 2018;1863(11):1369-77.\u003c/li\u003e\n\u003cli\u003eProtopapas A, Markaki S, Mitsis T, Milingos D, Athanasiou S, Haidopoulos D, et al. Immunohistochemical expression of matrix metalloproteinases, their tissue inhibitors, and cathepsin-D in ovarian endometriosis: correlation with severity of disease. Fertil Steril. 2010;94(6):2470-2.\u003c/li\u003e\n\u003cli\u003eGrzywa R, Gorodkiewicz E, Burchacka E, Lesner A, Laudański P, Łukaszewski Z, et al. Determination of cathepsin G in endometrial tissue using a surface plasmon resonance imaging biosensor with tailored phosphonic inhibitor. Eur J Obstet Gynecol Reprod Biol. 2014;182:38-42.\u003c/li\u003e\n\u003cli\u003ePorter KM, Wieser FA, Wilder CL, Sidell N, Platt MO. Cathepsin Protease Inhibition Reduces Endometriosis Lesion Establishment. Reprod Sci. 2016;23(5):623-9.\u003c/li\u003e\n\u003cli\u003eBrennan P, Hainaut P, Boffetta P. Genetics of lung-cancer susceptibility. Lancet Oncol. 2011;12(4):399-408.\u003c/li\u003e\n\u003cli\u003eDavey Smith G, Hemani G. Mendelian randomization: genetic anchors for causal inference in epidemiological studies. Human molecular genetics. 2014;23:R89-98.\u003c/li\u003e\n\u003cli\u003eSun BB, Maranville JC, Peters JE, Stacey D, Staley JR, Blackshaw J, et al. Genomic atlas of the human plasma proteome. Nature. 2018;558(7708):73-9.\u003c/li\u003e\n\u003cli\u003eAuton A, Brooks L, Durbin R, Garrison E, Kang H, Korbel J, et al. A global reference for human genetic variation. Nature. 2015;526(7571):68-74.\u003c/li\u003e\n\u003cli\u003eCai J, Li X, Wu S, Tian Y, Zhang Y, Wei Z, et al. Assessing the causal association between human blood metabolites and the risk of epilepsy. Journal of translational medicine. 2022;20(1):437.\u003c/li\u003e\n\u003cli\u003eWang X, Xu W, Wang F, Leng R, Yang X, Ling H, et al. Telomere Length and Development of Systemic Lupus Erythematosus: A Mendelian Randomization Study. Arthritis \u0026amp; rheumatology (Hoboken, NJ). 2022;74(12):1984-90.\u003c/li\u003e\n\u003cli\u003eHemani G, Zheng J, Elsworth B, Wade K, Haberland V, Baird D, et al. The MR-Base platform supports systematic causal inference across the human phenome. eLife. 2018;7.\u003c/li\u003e\n\u003cli\u003eYavorska OO, Burgess S. MendelianRandomization: an R package for performing Mendelian randomization analyses using summarized data. Int J Epidemiol. 2017;46(6):1734-9.\u003c/li\u003e\n\u003cli\u003eVerbanck M, Chen C, Neale B, Do R. Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Nature genetics. 2018;50(5):693-8.\u003c/li\u003e\n\u003cli\u003eGiudice LC. Clinical practice. Endometriosis. N Engl J Med. 2010;362(25):2389-98.\u003c/li\u003e\n\u003cli\u003eGiudice LC, Kao LC. Endometriosis. Lancet. 2004;364(9447):1789-99.\u003c/li\u003e\n\u003cli\u003eSoares SR, Mart\u0026iacute;nez-Varea A, Hidalgo-Mora JJ, Pellicer A. Pharmacologic therapies in endometriosis: a systematic review. Fertil Steril. 2012;98(3):529-55.\u003c/li\u003e\n\u003cli\u003eHalme J, Hammond MG, Hulka JF, Raj SG, Talbert LM. Retrograde menstruation in healthy women and in patients with endometriosis. Obstet Gynecol. 1984;64(2):151-4.\u003c/li\u003e\n\u003cli\u003eParazzini F, Esposito G, Tozzi L, Noli S, Bianchi S. Epidemiology of endometriosis and its comorbidities. Eur J Obstet Gynecol Reprod Biol. 2017;209:3-7.\u003c/li\u003e\n\u003cli\u003eBurney RO, Giudice LC. Pathogenesis and pathophysiology of endometriosis. Fertil Steril. 2012;98(3):511-9.\u003c/li\u003e\n\u003cli\u003eWitz CA, Montoya-Rodriguez IA, Cho S, Centonze VE, Bonewald LF, Schenken RS. Composition of the extracellular matrix of the peritoneum. J Soc Gynecol Investig. 2001;8(5):299-304.\u003c/li\u003e\n\u003cli\u003eSillem M, Hahn U, Coddington CC, 3rd, Gordon K, Runnebaum B, Hodgen GD. Ectopic growth of endometrium depends on its structural integrity and proteolytic activity in the cynomolgus monkey (Macaca fascicularis) model of endometriosis. Fertil Steril. 1996;66(3):468-73.\u003c/li\u003e\n\u003cli\u003eKirschke H, Langner J, Wiederanders B, Ansorge S, Bohley P, Broghammer U. [Intracellular protein breakdown. VII. Cathepsin L and H; two new proteinases from rat liver lysosomes]. Acta Biol Med Ger. 1976;35(3-4):285-99.\u003c/li\u003e\n\u003cli\u003eSchwartz WN, Barrett AJ. Human cathepsin H. Biochem J. 1980;191(2):487-97.\u003c/li\u003e\n\u003cli\u003eTurk B. Targeting proteases: successes, failures and future prospects. Nat Rev Drug Discov. 2006;5(9):785-99.\u003c/li\u003e\n\u003cli\u003eVasiljeva O, Reinheckel T, Peters C, Turk D, Turk V, Turk B. Emerging roles of cysteine cathepsins in disease and their potential as drug targets. Curr Pharm Des. 2007;13(4):387-403.\u003c/li\u003e\n\u003cli\u003eKramer L, Turk D, Turk B. The Future of Cysteine Cathepsins in Disease Management. Trends Pharmacol Sci. 2017;38(10):873-98.\u003c/li\u003e\n\u003cli\u003eAllan G, Campen C, Hodgen G, Williams R, Charnock-Jones DS, Wan J, et al. Identification of genes with differential regulation in primate endometrium during the proliferative and secretory phases of the cycle. Endocr Res. 2003;29(1):53-65.\u003c/li\u003e\n\u003cli\u003eGabrijelcic D, Svetic B, Spaić D, Skrk J, Budihna M, Dolenc I, et al. Cathepsins B, H and L in human breast carcinoma. Eur J Clin Chem Clin Biochem. 1992;30(2):69-74.\u003c/li\u003e\n\u003cli\u003eGabrijelcic D, Svetic B, Spaić D, Skrk J, Budihna J, Turk V. Determination of cathepsins B, H, L and kininogen in breast cancer patients. Agents Actions Suppl. 1992;38 ( Pt 2):350-7.\u003c/li\u003e\n\u003cli\u003eGocheva V, Joyce JA. Cysteine cathepsins and the cutting edge of cancer invasion. Cell Cycle. 2007;6(1):60-4.\u003c/li\u003e\n\u003cli\u003ePremzl A, Zavasnik-Bergant V, Turk V, Kos J. Intracellular and extracellular cathepsin B facilitate invasion of MCF-10A neoT cells through reconstituted extracellular matrix in vitro. Exp Cell Res. 2003;283(2):206-14.\u003c/li\u003e\n\u003cli\u003eJevnikar Z, Rojnik M, Jamnik P, Doljak B, Fonovic UP, Kos J. Cathepsin H mediates the processing of talin and regulates migration of prostate cancer cells. J Biol Chem. 2013;288(4):2201-9.\u003c/li\u003e\n\u003cli\u003eWu SM, Huang YH, Yeh CT, Tsai MM, Liao CH, Cheng WL, et al. Cathepsin H regulated by the thyroid hormone receptors associate with tumor invasion in human hepatoma cells. Oncogene. 2011;30(17):2057-69.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cathepsin, causality, endometriosis, MR analysis, SNP","lastPublishedDoi":"10.21203/rs.3.rs-3756621/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3756621/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eEndometriosis is a prevalent reproductive disorder that affects a significant number of women globally. Cathepsins, which are lysosomal cysteine proteases, contribute to several physiological and pathological processes, including the attachment and invasion of endometrial tissue. Nevertheless, the causal relationship between cathepsins and endometriosis remains undetermined. The aim of this study was to explore the potential relationship between cathepsins and endometriosis using genetic polymorphisms.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe employed a two-sample Mendelian randomization (MR) analysis to investigate the causal association between nine cathepsins and endometriosis.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe univariable MR analysis results indicate that Cathepsin H increases the risk of overall endometriosis (IVW: OR [95%]: 1.037 [1.007 to 1.067], p\u0026thinsp;=\u0026thinsp;0.013), endometriosis of ovary (IVW: OR [95%]: 1.022 [1.001 to 1.042], p\u0026thinsp;=\u0026thinsp;0.046), endometriosis of pelvic peritoneum OR [95%]: 1.046 [1.002 to 1.089], p\u0026thinsp;=\u0026thinsp;0.047), and deep endometriosis (IVW: OR [95%]: 1.050 [1.002 to 1.099], p\u0026thinsp;=\u0026thinsp;0.048). The multivariable MR analysis retained stable after adjusting for other types of cathepsins. And reverse MR analyses suggest that overall endometriosis may lead to increased Cathepsin H levels (IVW: OR [95%]: 1.017 [1.003, 1.073], p\u0026thinsp;=\u0026thinsp;0.041). The results of the sensitivity analyses were consistent with the main findings.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eOur MR analysis yields robust evidence supporting a causal relationship between Cathepsin H and the susceptibility to endometriosis, potentially inspiring directions in endometriosis diagnosis and treatment.\u003c/p\u003e","manuscriptTitle":"Causal association of cathepsins and endometriosis: A Mendelian randomization study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-12-19 19:58:17","doi":"10.21203/rs.3.rs-3756621/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"97155cc3-6b0e-49b0-bc3f-00ddfa8f3498","owner":[],"postedDate":"December 19th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-01T09:42:34+00:00","versionOfRecord":[],"versionCreatedAt":"2023-12-19 19:58:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3756621","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3756621","identity":"rs-3756621","version":["v1"]},"buildId":"B-jG_2CBjPDmsCi4Wdhf-","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}