子宮內膜異位症是一種婦產科常見的慢性發炎疾病，而深層浸潤型子宮內膜異 位症(DIE)則是近年來被新分類出來的子宮內膜異位症型態，他被定義為子宮內膜異 位組織浸潤到異位組織大於 5 毫米的深度。DIE 被廣為人知的特徵包含了:具有較 強的細胞增生能力與細胞侵襲特性，同時 DIE 病人會遭受到由發炎所誘導的神經性 疼痛症狀，因此 DIE 被認為是子宮內膜異位症中最嚴重的一種型態。然而，目前對 於 DIE 的了解還相當不足，為了去探討 DIE 的致病機轉，加上先前實驗室所發表的 研究曾在子宮內膜異位症中發現高度活化的 Notch 1 訊號傳遞，我們便假設:DIE 當 中或許由於高度活化的 Notch 1 訊號傳遞而加速了其致病進程。利用免疫組織染色 法，我們在臨床檢體中發現，比起正常與其他表層的子宮內膜異位症的檢體來說， Notch 1 訊號傳遞活化的標記蛋白 NICD 表現量在 DIE 組織中有顯著增加的情形，而 在細胞增生標記蛋白 Ki67 以及神經標記蛋白 PGP9.5 的染色結果中也一樣看到表現 量只有在 DIE 檢體中有顯著增加的情形。接著，我們利用生物資訊分析發現促發炎 因子介白素-17A (IL-17A)可能是調控 Notch 1 訊號傳遞與神經生長因子(NGF)在 DIE 組織中過度表現的可能蛋白質。因此透過免疫組織染色法的確認，我們證實了 IL- 17A 在 DIE 組織中確實存在，並發現 NGF 在 DIE 組織中也有高度表達。另外，在 子宮內膜原位細胞的實驗中，我們發現當給予 IL-17A 加藥處理後，NICD 表現量有 顯著增加的情形。這些研究結果代表了在 DIE 慢性發炎的微環境下，IL-17A 作為促 發炎因子可以藉由高度活化 Notch 1 訊號傳遞來加速 DIE 致病進程，並可能透過上 調 NGF 表現量來促進神經浸潤現象因而增強 DIE 病患的痛覺敏感度。我們的研究 還揭露了將 IL-17A、NICD 與 NGF 作為標靶治療的對象，或許在未來會成為有效治 療 DIE 的方式。

Deep infiltrating endometriosis (DIE), a newly classified type of endometriosis, is defined as ectopic lesions invading into tissues more than 5 mm deep. The well-known characteristics of DIE include high lesion activity, remarkable invasive ability and serious inflammation-associated neuropathic pain caused by nerves innervation, which make it the most severe type of endometriosis. Unfortunately, the pathological mechanisms of DIE remain poorly characterized. To investigate the etiology of DIE, we hypothesized that activation of Notch 1 signaling may facilitate the DIE pathological progression. Through immunohistochemical staining (IHC) of clinical specimens, we found that Notch 1 intracellular domain (NICD) expression was significantly increased in all DIE lesion sites (uterosacral-ligament, rectal wall, rectovaginal septum and ovary) compared to that in normal endometrium, superficial endometriosis and ovarian endometrioma. Concomitantly, cell proliferation maker, Ki67, and neuron marker, PGP9.5 were also significantly increased in DIE group compared to normal and other endometriosis groups. Based on literature report and bioinformatic analysis, we identified that interleukin-17A (IL-17A) is a likely candidate to regulate Notch 1 signaling activation, and nerve growth factor (NGF) is a mediator to attract nerve infiltration of DIE. Indeed, IHC results confirmed the existence of IL-17A in DIE lesions. NGF staining results also showed the strong positive signals in DIE lesions. Moreover, treatment with IL-17A on eutopic endometrial stromal cells increased NICD expressions. These results indicated that proinflammatory cytokine IL-17A promotes the proliferative ability of ectopic stromal cell in DIE through activating Notch 1 and may cause the nerve infiltration in DIE lesions via NGF overexpression. Taken together, our results demonstrate that aberrant expression of IL-17A contributes to the disease pathogenesis of DIE and suggest that targeting IL-17A and/or blocking Notch 1 signaling may be a novel therapeutic approach for DIE treatment in clinical application.

References
Acien, P. and I. Velasco, Endometriosis: a disease that remains enigmatic. ISRN Obstet Gynecol, 2013. 2013: p. 242149.
Zondervan, K.T., C.M. Becker, and S.A. Missmer, Endometriosis. N Engl J Med, 2020. 382(13): p. 1244-1256.
Robertson, D., G. Lefebvre, and C. Clinical Practice Gynaecology, Adhesion prevention in gynaecological surgery. J Obstet Gynaecol Can, 2010. 32(6): p. 598- 602.
Schliep, K.C., et al., Pain typology and incident endometriosis. Hum Reprod, 2015. 30(10): p. 2427-38.
Johnson, N.P., et al., World Endometriosis Society consensus on the classification of endometriosis. Hum Reprod, 2017. 32(2): p. 315-324.
Suginami, H., A reappraisal of the coelomic metaplasia theory by reviewing endometriosis occurring in unusual sites and instances. Am J Obstet Gynecol, 1991. 165(1): p. 214-8.
Gargett, C.E., R.W. Chan, and K.E. Schwab, Endometrial stem cells. Curr Opin Obstet Gynecol, 2007. 19(4): p. 377-83.
Jerman, L.F. and A.J. Hey-Cunningham, The role of the lymphatic system in endometriosis: a comprehensive review of the literature. Biol Reprod, 2015. 92(3): p. 64.
Sampson, J.A., Metastatic or Embolic Endometriosis, due to the Menstrual Dissemination of Endometrial Tissue into the Venous Circulation. Am J Pathol, 1927. 3(2): p. 93-110 43.
Halme, J., et al., Retrograde menstruation in healthy women and in patients with endometriosis. Obstet Gynecol, 1984. 64(2): p. 151-4.
Koninckx, P.R. and D. Martin, Treatment of deeply infiltrating endometriosis. Curr Opin Obstet Gynecol, 1994. 6(3): p. 231-41.
Yantiss, R.K., P.B. Clement, and R.H. Young, Endometriosis of the intestinal tract: a study of 44 cases of a disease that may cause diverse challenges in clinical and pathologic evaluation. Am J Surg Pathol, 2001. 25(4): p. 445-54.
Koninckx, P.R., et al., Suggestive evidence that pelvic endometriosis is a progressive disease, whereas deeply infiltrating endometriosis is associated with pelvic pain. Fertil Steril, 1991. 55(4): p. 759-65.
Chapron, C., et al., Deep infiltrating endometriosis: relation between severity of dysmenorrhoea and extent of disease. Hum Reprod, 2003. 18(4): p. 760-6.
Tuttlies, F., et al., [ENZIAN-score, a classification of deep infiltrating endometriosis]. Zentralbl Gynakol, 2005. 127(5): p. 275-81.
Ge, P., et al., Linaclotide treatment reduces endometriosis-associated vaginal hyperalgesia and mechanical allodynia through viscerovisceral cross-talk. Pain, 2019. 160(11): p. 2566-2579.
As-Sanie, S., et al., Functional Connectivity is Associated With Altered Brain Chemistry in Women With Endometriosis-Associated Chronic Pelvic Pain. J Pain, 2016. 17(1): p. 1-13.
Anaf, V., et al., Pain, mast cells, and nerves in peritoneal, ovarian, and deep infiltrating endometriosis. Fertil Steril, 2006. 86(5): p. 1336-43.
Anaf, V., et al., Relationship between endometriotic foci and nerves in rectovaginal endometriotic nodules. Hum Reprod, 2000. 15(8): p. 1744-50.
Liang, Y., et al., Perineural invasion in endometriotic lesions contributes to endometriosis-associated pain. J Pain Res, 2018. 11: p. 1999-2009. 

Tosti, C., et al., Pathogenetic Mechanisms of Deep Infiltrating Endometriosis. Reprod Sci, 2015. 22(9): p. 1053-9.
Reis, F.M., F. Petraglia, and R.N. Taylor, Endometriosis: hormone regulation and clinical consequences of chemotaxis and apoptosis. Hum Reprod Update, 2013. 19(4): p. 406-18.
Santulli, P., et al., Protein oxidative stress markers in peritoneal fluids of women with deep infiltrating endometriosis are increased. Hum Reprod, 2015. 30(1): p. 49-60.
Pepinsky, R.B., et al., Proteolytic processing of mullerian inhibiting substance produces a transforming growth factor-beta-like fragment. J Biol Chem, 1988. 263(35): p. 18961-4.
Carrarelli, P., et al., Increased expression of antimullerian hormone and its receptor in endometriosis. Fertil Steril, 2014. 101(5): p. 1353-8.
Jones, R.L., et al., Activin A and inhibin A differentially regulate human uterine matrix metalloproteinases: potential interactions during decidualization and trophoblast invasion. Endocrinology, 2006. 147(2): p. 724-32.
Ferreira, M.C., et al., Activin A increases invasiveness of endometrial cells in an in vitro model of human peritoneum. Mol Hum Reprod, 2008. 14(5): p. 301-7.
Artavanis-Tsakonas, S., M.D. Rand, and R.J. Lake, Notch signaling: cell fate control and signal integration in development. Science, 1999. 284(5415): p. 770-6.
Wharton, K.A., et al., Nucleotide sequence from the neurogenic locus notch implies a gene product that shares homology with proteins containing EGF-like repeats. Cell, 
1985. 43(3 Pt 2): p. 567-81.
Rebay, I., et al., Specific EGF repeats of Notch mediate interactions with Delta and Serrate: implications for Notch as a multifunctional receptor. Cell, 1991. 67(4): p. 687-99.
Fortini, M.E., Gamma-secretase-mediated proteolysis in cell-surface-receptor signalling. Nat Rev Mol Cell Biol, 2002. 3(9): p. 673-84.
Radtke, F. and K. Raj, The role of Notch in tumorigenesis: oncogene or tumour suppressor? Nat Rev Cancer, 2003. 3(10): p. 756-67.
Bray, S.J., Notch signalling: a simple pathway becomes complex. Nat Rev Mol Cell Biol, 2006. 7(9): p. 678-89.
Joutel, A., et al., Notch3 mutations in CADASIL, a hereditary adult-onset condition causing stroke and dementia. Nature, 1996. 383(6602): p. 707-10.
Gridley, T., Notch signaling in vertebrate development and disease. Mol Cell Neurosci, 1997. 9(2): p. 103-8.
Kimble, J. and P. Simpson, The LIN-12/Notch signaling pathway and its regulation. Annu Rev Cell Dev Biol, 1997. 13: p. 333-61.
Li, L., et al., Alagille syndrome is caused by mutations in human Jagged1, which encodes a ligand for Notch1. Nat Genet, 1997. 16(3): p. 243-51.
Louvi, A. and S. Artavanis-Tsakonas, Notch signalling in vertebrate neural development. Nat Rev Neurosci, 2006. 7(2): p. 93-102.
Jundt, F., et al., Activated Notch1 signaling promotes tumor cell proliferation and survival in Hodgkin and anaplastic large cell lymphoma. Blood, 2002. 99(9): p. 3398-403.
Li, H., et al., Cell cycle-linked MeCP2 phosphorylation modulates adult neurogenesis involving the Notch signalling pathway. Nat Commun, 2014. 5: p. 5601.
Wang, J., et al., Invasion of white matter tracts by glioma stem cells is regulated by a NOTCH1-SOX2 positive-feedback loop. Nat Neurosci, 2019. 22(1): p. 91-105. 

Luo, Y., et al., The role of miR-34c-5p/Notch in epithelial-mesenchymal transition (EMT) in endometriosis. Cell Signal, 2020. 72: p. 109666.
Song, Y., et al., Interleukin-6 (IL-6) Activates the NOTCH1 Signaling Pathway Through E-Proteins in Endometriotic Lesions. J Clin Endocrinol Metab, 2020. 
105(5).
Li, N., et al., Notch activity mediates oestrogen-induced stromal cell invasion in endometriosis. Reproduction, 2018. 157(4): p. 371-381.
Korbel, C., et al., Notch signaling controls sprouting angiogenesis of endometriotic lesions. Angiogenesis, 2018. 21(1): p. 37-46.
Patel, B.G., et al., Progesterone resistance in endometriosis: origins, consequences and interventions. Acta Obstet Gynecol Scand, 2017. 96(6): p. 623-632.
Brown, D.M., et al., Notch-1 Signaling Activation and Progesterone Receptor Expression in Ectopic Lesions of Women With Endometriosis. J Endocr Soc, 2018. 2(7): p. 765-778.
Su, R.W., et al., Decreased Notch pathway signaling in the endometrium of women with endometriosis impairs decidualization. J Clin Endocrinol Metab, 2015. 100(3): p. E433-42.
Amjadi, F., et al., Comparative evaluation of NOTCH signaling molecules in the endometrium of women with various gynecological diseases during the window of implantation. Iran J Basic Med Sci, 2019. 22(4): p. 426-431.
Veldhoen, M., et al., TGFbeta in the context of an inflammatory cytokine milieu supports de novo differentiation of IL-17-producing T cells. Immunity, 2006. 24(2): p. 179-89. 

Fossiez, F., et al., T cell interleukin-17 induces stromal cells to produce proinflammatory and hematopoietic cytokines. J Exp Med, 1996. 183(6): p. 2593- 603.
Gogacz, M., et al., Increased percentage of Th17 cells in peritoneal fluid is associated with severity of endometriosis. J Reprod Immunol, 2016. 117: p. 39-44.
Ahn, S.H., et al., IL-17A Contributes to the Pathogenesis of Endometriosis by Triggering Proinflammatory Cytokines and Angiogenic Growth Factors. J Immunol, 2015. 195(6): p. 2591-600.
Zhang, X., et al., Peritoneal fluid concentrations of interleukin-17 correlate with the severity of endometriosis and infertility of this disorder. BJOG, 2005. 112(8): p. 1153-5.
Wang, X., et al., Interleukin-17 activates and synergizes with the notch signaling pathway in the progression of pancreatic ductal adenocarcinoma. Cancer Lett, 2021. 508: p. 1-12.
Wang, C., et al., IL-17 induced NOTCH1 activation in oligodendrocyte progenitor cells enhances proliferation and inflammatory gene expression. Nat Commun, 2017. 8: p. 15508.
Keerthivasan, S., et al., Notch signaling regulates mouse and human Th17 differentiation. J Immunol, 2011. 187(2): p. 692-701.
Li, J., J.L. Casanova, and A. Puel, Mucocutaneous IL-17 immunity in mice and humans: host defense vs. excessive inflammation. Mucosal Immunol, 2018. 11(3): p. 581-589.
Wu, X.G., et al., Identification and Validation of the Signatures of Infiltrating Immune Cells in the Eutopic Endometrium Endometria of Women With Endometriosis. Front Immunol, 2021. 12: p. 671201.
Han, H., et al., Vascular Endothelial Growth Factor Mediates the Sprouted Axonogenesis of Breast Cancer in Rat. Am J Pathol, 2021. 191(3): p. 515-526.
Szubert, M., et al., Expression of nerve growth factor (NGF) in endometrium as a potential biomarker for endometriosis - Single tertiary care centre study. J Gynecol Obstet Hum Reprod, 2021. 50(3): p. 101895.
Liu, Y., et al., Effects of inhibiting the PI3K/Akt/mTOR signaling pathway on the pain of sciatic endometriosis in a rat model. Can J Physiol Pharmacol, 2019. 97(10): p. 963-970.
Efe, E., et al., Hormonal treatment for severe hydronephrosis caused by bladder endometriosis. Case Rep Urol, 2014. 2014: p. 891295.
Kolodziej, A., et al., Urinary Tract Endometriosis. Urol J, 2015. 12(4): p. 2213-7.
Mal, S., et al., Insight gamma-Secretase: Structure, Function, and Role in Alzheimer's Disease. Curr Drug Targets, 2021. 22(12): p. 1376-1403.
Kaushik, B., D. Pal, and S. Saha, Gamma Secretase Inhibitor: Therapeutic Target via NOTCH Signaling in T Cell Acute Lymphoblastic Leukemia. Curr Drug Targets, 2021. 22(15): p. 1789-1798.
Nisolle, M. and J. Donnez, Peritoneal endometriosis, ovarian endometriosis, and adenomyotic nodules of the rectovaginal septum are three different entities. Fertil Steril, 1997. 68(4): p. 585-96.