{"paper_id":"91287832-2606-4989-9c77-a2463574a6ce","body_text":"Abstract\nEndometriosis is a gynecological condition characterized by the uncontrolled growth of endometrial-like tissue outside the uterine cavity. Although highly prevalent, the biological mechanisms of endometriosis are poorly understood, and the disease is often misdiagnosed due to the unavailability of pre-operative diagnostic methods. Thus, better characterization of molecular markers of endometriosis is critical to improve our understanding of the disease and management of patients. Here, we used matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) imaging to investigate protein and N-glycan molecular signatures in eutopic endometrium and endometriosis lesions from tissues prospectively collected from patients. MALDI MS imaging of intact proteins revealed neutrophil defensins detected at higher relative abundances in regions of endometriosis lesions, providing evidence that immune/inflammatory processes may be associated with endometriosis. Various alterations in N-glycan molecular profiles were also observed when comparing endometriosis lesions and eutopic endometrium, including a significantly higher detection of fucosylated N-glycans and increased levels of branching from biantennary to tri- and tetra-antennary structures in endometriosis lesions. These results provide evidence that alterations in N-glycosylation machinery are involved in dysregulation of cellular and signaling processes and may contribute to endometriosis development. A co-localization analysis identified several tryptic peptides detected within regions of endometriosis lesions, suggesting extracellular matrix (ECM) proteins such as collagen may contribute to the development of endometriosis lesions. Overall, by characterizing molecular alterations in proteins and N-glycans, the results of this study provide novel insights into potential mechanisms involved in endometriosis pathogenesis.\nGraphical Abstract\nSimilar content being viewed by others\nData availability\nAll data from this study are deposited and available at Dataverse (https://dataverse.org/).\nReferences\nWheeler J. Epidemiology of endometriosis-associated infertility. J Reprod Med. 1989;34(1):41–6.\nCanis M, Donnez JG, Guzick DS, Halme JK, Rock JA, Schenken RS, et al. Revised American society for reproductive medicine classification of endometriosis: 1996. Fertil Steril. 1997;67(5):817–21.\nLeyland N, Casper R, Laberge P, Singh SS, Allen L, Arendas K, et al. Endometriosis: diagnosis and management. J Endometr. 2010;2(3):107–34.\nSimoens S, Dunselman G, Dirksen C, Hummelshoj L, Bokor A, Brandes I, et al. 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We are thankful for Brooke Lasher, Elizabeth Davis, Hitakshi Modi, and Stephanie Nutt for their assistance with sample collection procedures.\nFunding\nThis research was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (R01 HD101560-03) and the Cancer Prevention and Research Institute of Texas (CPRIT, Grant No. RP190617).\nAuthor information\nAuthors and Affiliations\nContributions\nM.L., M.T.B., and L.S.E. initiated the project and planned experiments. M.L. and E.H.S. performed experiments. M.L. processed and analyzed the data and generated figures. S.L. performed pathological evaluation of tissues. C.S. and M.T.B. obtained the tissue samples. M.L. and L.S.E. wrote the paper with input and edits from other authors. All authors read and approved the final paper.\nCorresponding author\nEthics declarations\nEthics approval\nThis study was performed under approved IRB protocols at UT Austin (protocol #2017080087) and Baylor College of Medicine (protocol #H-50480).\nConflict of interest\nThe authors declare no competing interests.\nAdditional information\nPublisher's Note\nSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\nSupplementary Information\nBelow is the link to the electronic supplementary material.\nRights and permissions\nSpringer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.\nAbout this article\nCite this article\nLin, M., Seeley, E.H., Ledet, S. et al. Mass spectrometry imaging reveals alterations in protein and N-glycan molecular signatures in endometriosis tissues. Anal Bioanal Chem 417, 4133–4145 (2025). https://doi.org/10.1007/s00216-025-05930-z\nReceived:\nRevised:\nAccepted:\nPublished:\nVersion of record:\nIssue date:\nDOI: https://doi.org/10.1007/s00216-025-05930-z","source_license":"CC0","license_restricted":false}