The Anti-Senescence Effect and Mechanism of 17β-estradiol on Pelvic Organ Prolapse Derived Fibroblasts

Abstract

Abstract Background: Recently, low estrogen and the age at menopause as independent risk factors for Pelvic Organ Prolapse (POP) were attracting high attention. In clinical practice, pre-/post-operative Local Estrogen Therapy (LET) shown effectiveness in alleviating POP symptoms. However, there is lack of scientific evidence to support the validity of these claims. Therefore, this study aimed to investigate the anti-senescence effect and mechanism of 17β-estradiol on POP derived fibroblasts. Methods: The primary fibroblasts cells were isolated and cultured form surgical POP samples (n = 8, age from 50–75), the passage-0 cells confluence at 80% takes about 15 days and the passage 3–5 cells were used for further test. Immunocytochemistry was used to characterize the primary fibroblasts, CCK8 assay was used to test the cell proliferative capacity and the Senescence-Associated β-Galactosidase (SA-β Gal) Staining was tested to calculate the senescence rate of fibroblasts. Moreover, western blotting was used to detect the expression of COL-I, COL-III, p16INK4A, p21, p-53, SIRT-1 and LC3-I/II protein. In addition, Transmission Electron Microscope (TEM) was used to observe the ultrastructure of fibroblasts. Results: The results showed that 17β-estradiol (E2) significantly promoted the POP derived-fibroblasts proliferation and reduced the staining rate of senescence-associated-β-galactosidase (SA-β-Gal), markedly enhanced the extracellular matrix protein COL-I and COL-III accompanied by the inhibition of senescent protein P16INK4a, as well as improved the cells autophagy and metabolic activity. In addition, E2 significantly up-regulated the anti-aging protein SIRT1 and markedly down-regulated p53 and p21, indicating the anti-senescence mechanism of E2 through mediated the Sirt1/p53/p21 axis pathway. Conclusion: We provide preliminary evidence that anti-aging effect and mechanism of estrogen on POP fibroblasts, hoping to provide a theoretical basis for estrogen against POP senescence, guide the clinical application and local administration of estrogen on POP treatment, thereby improve long-term maintenance and rejuvenation of the pelvic floor connective tissue.