17β-estradiol facilitates the proliferation, migration, and collagen production in uterosacral ligament fibroblasts from patients with pelvic organ prolapse by activating HOXA13/TIMP1 axis

Abstract

Local estrogen therapy is clinically employed for pelvic organ prolapse (POP) management, demonstrating efficacy in promoting collagen synthesis and maintaining pelvic connective tissue integrity. This study aimed to investigate the roles and mechanisms of estrogen 17β-estradiol (E2) in regulating proliferation, migration, and collagen production of human uterosacral ligament fibroblasts (hUSLFs) from POP patients. Primary hUSLFs from POP patients and controls were isolated and treated with 10^− 7, 10^− 8, 10^− 9 M E2, respectively. Cell proliferation, migration, apoptosis, collagen I/III levels, and matrix metalloproteinase 2 (MMP2)/MMP9 expression were examined. Homeobox A13 (HOXA13) levels were measured in clinical uterosacral ligament (USL) tissues and E2-treated hUSLFs. Gain- and loss-of-function experiments were conducted to investigate the role of HOXA13 in hUSLFs. Chromatin immunoprecipitation (ChIP) and luciferase assays verified HOXA13-mediated transcription regulation of tissue inhibitor of metalloproteinase 1 (TIMP1) in hUSLFs. Rescue experiments was conducted to investigate the roles of E2/HOXA13/TIMP1 axis in hUSLF functions. E2 remarkably promoted proliferation, migration, and collagen production while inhibiting apoptosis and MMP2/MMP9 expression in hUSLFs. The concentration at 10^− 8 M showed the optimal efficacy. HOXA13 was downregulated in USL tissues of POP patients compared with controls. HOXA13 overexpression promoted proliferation, migration, and collagen production while reducing apoptosis in hUSLFs. Whereas HOXA13 knockdown showed the opposite results. E2 treatment upregulated HOXA13 expression in hUSLFs. HOXA13 knockdown abrogated E2-mediated functional enhancement of hUSLFs. Moreover, HOXA13 transcriptionally activated TIMP1 expression. TIMP1 knockdown reversed the positive effects of HOXA13 on the proliferation, migration, and collagen production of hUSLFs. E2 facilitates proliferation, migration, and collagen production of hUSLFs from POP patients through upregulating the HOXA13/TIMP1 axis. Our findings provide important mechanistic insights into the protective effects of estrogen on POP fibroblasts and identify HOXA13 as a potential therapeutic target worthy of further investigation.