Expression Of Tyrosine Kinase Receptor B In Eutopic Endometrium Of Women With Adenomyosis

Background and Objectives:Adenomyosis is characterized by the presence of ectopic endometrial glands and stroma in the myometrium. It can result in progressive dysmenorrhea and abnormal bleeding. Despite numerous studies on adenomyosis, its etiology, pathogenesis and the better conservative treatment are still not clear to date. Previous studies demonstrated that endometrial cells from women with endometriotic foci exhibit reduced apoptosis. To the best of our knowledge, it is still unclear whether TrkB plays a role in the pathogenesis of adenomyosis. The purpose of our present study was:(1) to examine if there was distinctive expression of TrkB in endometrium between women with and without adenomyosis. (2) to determine whether TrkB expression in human endometrium was associated with serum CA125 and VAS of dysmenorrhea. Methods:We collected endometrial tissues from 31 women with adenomyosis and 30 adenomyosis-free women undergoing surgery for benign indications. TrkB expression was assessed by immunohistochemistry (IHC) and reverse-transcription polymerase chain reaction (RT-PCR)Results:1. Immunoreactive staining for TrkB were present in the cytoplasm and membrane of epithelial and stromal cells in endometrium. The immunostaining intensity was more noticeable in the glandular epithelium. The average level of TrkB protein (quantitation of immunostaining intensity) in secretory endometrial samples of women with adenomyosis was siginificantly higher than that in controls (p<0.01).2. The average level of TrkB messenger RNA(mRNA) expression of women with adenomyosis was significantly higher than that of controls at secretory phase (p<0.01).3. The serum CA125 concentrations were significantly elevated in patients with adenomyosis comparison to the controls (p<0.01). The VAS scores of dysmenorrhea were significantly increased in adenomyosis patients comparison to the control group(p<0.01).4. The immunostaining quantitation of TrkB protein in human endometrium was positively correlated with the serum CA125 and VAS scores of dysmenorrhea. TrkB mRNA expression in human endometrium was positively correlated with the serum CA125 and VAS scores of dysmenorrhea.Conclusion:Our study revealed elevation of TrkB protein and mRNA expression in the secretory endometrium of women with adenomyosis. Furthermore, TrkB expression was positively correlated with the serum CA125 and VAS scores of dysmenorrhea. TrkB might contribute to the pathogenesis and progression of adenomyosis.