Autophagy Attenuates Oxidative Stress-Induced Collagen Degradation in Vaginal Fibroblasts: Implications for Pelvic Organ Prolapse.

Abstract

Introduction and hypothesis: The relationship between autophagy and pelvic organ prolapse (POP) remains unknown. The aim of this novel experimental study, utilizing tissue samples derived from women undergoing gynecological surgery, is to investigate the role of autophagy in mitigating collagen degradation in human vaginal fibroblasts induced by oxidative stress, with particular emphasis on its implications in the pathogenesis of POP. Exploring the role of autophagy in protecting against collagen degradation and cellular senescence in human vaginal fibroblasts under oxidative stress may offer new insights into therapeutic strategies for conditions such as POP.

Methods: This study consists of laboratory-based experimental research that utilizes tissue samples collected from female patients undergoing gynecological surgery to analyze the role of autophagy in collagen degradation induced by oxidative stress. By treating with different concentrations of hydrogen peroxide (H₂O₂) and using rapamycin (RAPA) and 3-methyladenine (3-MA) as autophagy activators and inhibitors respectively, the effects on human vaginal fibroblasts (HVFs) were evaluated. Cell viability was determined using the Cell Counting Kit-8 test. Cellular senescence was determined with senescence-associated-β-galactosidase labeling and western blotting to identify the expression of p21 and p53. Reactive oxygen species (ROS) were determined with 2,7-dichlorofluorescin diacetate. Additionally, western blotting was used to establish collagen I, collagen III, microtubule-associated protein 1A/1B-light chain 3 (LC3), Beclin-1, and p62 and reverse transcription-quantitative polymerase chain reaction was used to determine the mRNA levels of COL3A1, COL1A1, TIMP1, MMP9, LC3, and Beclin-1 to investigate collagen metabolism and autophagic activity.

Results: The results showed that high-dose H₂O₂ significantly increased ROS levels, cell senescence, and collagen degradation in HVFs. The combined use of RAPA significantly reduced ROS levels, collagen degradation, and cell senescence, but this protective effect disappeared when 3-MA was added. Nevertheless, co-treatment of HVFs with RAPA, H₂O₂, and 3-MA abolished the positive impact of RAPA via boosting autophagy resistance.

Conclusions: Autophagy inhibits collagen degeneration and cellular senescence caused by oxidative stress.