The protective effect of 17 β-estradiol on human uterosacral ligament fibroblasts from postmenopausal women with pelvic organ prolapse

Abstract

This study aims to explore the protective effects of 17 β-estradiol on the human uterosacral ligament fibroblasts (hUSLFs) under static or stretched conditions. The experiments were performed on hUSLFs derived from pelvic organ prolapse (POP) and non-POP patients. Fibroblasts were cultured after collagenase digestion and identified by morphological observation and immunocytochemical methods. 17 β-estradiol (10−10 M and 10−9 M) and mechanical stress induced by the FX-5000 T-cell stress loading system under a loading strain of 1/2 sin waveform uniaxial cyclic stress with a tensile strain of 20% and a frequency of 0.5 Hz were either or both applied on hUSLFs. Cell proliferation was measured by CCK8, and cell apoptosis and death were detected using Annexin V/7-AAD staining and flow cytometric analysis. We found that the fibroblasts growth rate of POP patients was significantly lower than controls. The cell apoptosis and death rate increased as the mechanical load intensifying. After 20% mechanical stretching for 24 h, the dead cell rate was higher in POP than control. Notably, 17 β-estradiol treatment reversed mechanical stress induced hUSLFs apoptosis and death in both POP and Control cells. The protein and mRNA levels of anti-apoptotic PARP1 (poly-ADP-ribose polymerase) and Bcl-2 were increased by estrogen treatment. Meanwhile, expression of estrogen receptor α, a target of Poly-ADP-Ribosylation of PARP1, was also enhanced by 17 β-estradiol under the mechanical load. In conclusion, estrogen application ameliorates the mechanical strain induced cell apoptosis and death in hUSLFs from POP patients. PARP1 might be involved in this protective process, providing novel insights into the mechanical biology of and possible therapies for POP.

Potential of Estradiol‐Functionalized Polyisocyanide Hydrogels for Stimulating Tissue Regeneration of the Pelvic Floor

“…Soluble E2 treatment has been shown to either stimulate, [ 43 ] suppress, [ 44 ] or have no effect on POP‐derived primary fibroblasts. [ 45 ] E2‐releasing scaffolds either promote proliferation of ASCs [ 10,11 ] or have no effect on vaginal fibroblast proliferation. [ 12 ]…”

“…Besides the variation in E2 concentrations between studies, the ambiguous effects of E2 may find origin in a wide variety of culture conditions, particularly when realizing that serum contains estrogen and that phenol red is a weak estrogen mimic. [ 46 ] Reported culture medium compositions range from full medium (with estrogen‐containing serum), [ 10,11,38b ] phenol red‐free full medium, [ 12,45 ] starvation medium (estrogen‐free serum or serum‐free medium), [ 37,43 ] and phenol red‐free starvation medium. [ 26b,38a,40–42,44 ] Likewise, we also observed ambiguous effects of PIC‐E2 on ASCs when cultured in full versus starvation medium.…”

“…Soluble E2 treatment has been shown to either stimulate, [43] suppress, [44] or have no effect on POP-derived primary fibroblasts. [45] E2-releasing scaffolds either promote proliferation of ASCs [10,11] or have no effect on vaginal fibroblast proliferation. [12] Besides the variation in E2 concentrations between studies, the ambiguous effects of E2 may find origin in a wide variety of culture conditions, particularly when realizing that serum contains estrogen and that phenol red is a weak estrogen mimic.…”

An Improved Understanding of the Pathophysiology of Pelvic Organ Prolapse: A 3D In Vitro Model under Static and Mechanical Loading Conditions

“…[68] In the presence of mechanical loading, MKI67 is similarly expressed between non-POP and POP fibroblasts, which has also been previously reported. [17,20] FMT plays a key role during wound healing and tissue remodeling after POP surgery. [6] However, there is limited knowledge about the differences in FMT between POP and non-POP fibroblasts.…”

“…In recent years, several studies have investigated the differences between POP and non-POP fibroblasts in the presence of mechanical loading. [5,17,18,[20][21][22][23] However, these studies were solely performed in 2D cell cultures, which are an inferior representation of the native tissue microenvironment compared to 3D cell cultures. [24] Taken together, the limited and frequently inconclusive literature findings make it difficult to formulate a clear hypothesis on the behavior of POP versus non-POP fibroblasts.…”