Klotho Regulates the Extracellular Matrix Metabolism via TGF-β1/Wnt Signaling Pathway of Fibroblasts in Pelvic Organ Prolapse

Abstract

Pelvic organ prolapse (POP) is a gynecological disease frequently diagnosed in middle-aged and elderly women. Klotho is an antiaging protein. This study aimed to investigate the regulatory role and potential molecular mechanism of Klotho in the pathological process of POP. Random sampling was used to collect vaginal wall clinical samples from patients with POP (grade III or IV) and non-POP conditions (such as uterine fibroids and cervical precancerous lesions), with five cases in each group. Western blot was performed to detect the expression of Klotho and extracellular matrix (ECM) metabolism-related proteins. Primary fibroblasts were extracted and identified using immunocytochemistry. Fibroblast viability was assessed by MTT, and apoptosis levels were detected by flow cytometry. A POP fibroblast oxidative stress model was developed using H₂O₂, and qRT-PCR was utilized to determine the relative mRNA expression of Klotho. Klotho, Col-I, FN and CTGF proteins were low-expressed in POP patient samples, MMP2 protein was highly expressed in POP patient samples. After overexpression of Klotho, the expressions of Col-I, FN and CTGF proteins in fibroblasts were upregulated, the expressions of MMP2, β-catenin and TGF-β1 proteins were downregulated, the cell proliferation ability was increased, and the apoptosis level was reduced. However, the above results were reversed when further treated with the TGF-β1 signaling pathway activator SRI-011381. Klotho expression was suppressed by H₂O₂ treatment of POP fibroblasts. By regulating the TFG-β1/Wnt signaling pathway, Klotho affected ECM metabolism in POP fibroblasts to suppress the POP occurrence and development. Meanwhile, the expression of Klotho in POP fibroblasts could be affected by oxidative stress.