BACKGROUND: Pelvic organ prolapse (POP) is due to age-related atrophy and the weakening of the tissues of the pelvic floor, with degradation of collagen and extracellular matrix (ECM) by metalloproteinases (MMPs). This study aimed to investigates the role of the age-related enzyme klotho, encoded by the KL gene, in cultured fibroblasts obtained from patients with POP and the levels of reactive oxygen species (ROS), interleukin-6 (IL-6), and MMPs.
MATERIAL AND METHODS: Pelvic floor fibroblasts were obtained from connective tissue from three patients with POP and three normal subjects. Cell proliferation and ROS production were measured using a cell counting kit-8 (CCK-8) assay and flow cytometry. Levels of interleukin-6 (IL-6), klotho, metalloproteinase-1 (MMP-1), MMP-3, extracellular signal-regulated kinases 1/2 (ERK1/2), and p-ERK1/2 were measured by enzyme-linked immunoassay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot.
RESULTS: In cultured pelvic floor fibroblasts from patients with POP, the expression of klotho protein and klotho mRNA were significantly down-regulated in fibroblasts from patients with POP compared with normal fibroblasts. Klotho supplementation in cultured fibroblasts for patients with POP included increased cell growth, reduced expression of ROS reduction, and reduced the secretion of IL-6. Using qRT-PCR and Western blot, klotho supplementation of fibroblasts from patients with POP increased cell growth and reduced the levels of IL-6 and ROS in a dose-dependent way.
CONCLUSIONS: Klotho protein reduced the expression of MMP-1 and MMP-3 in fibroblasts from patients with POP by down-regulating the phosphorylation of ERK1/2.

Keywords: MAP Kinase Signaling System, Matrix Metalloproteinases, pelvic organ prolapse