Adrenomedullin gene delivery reduces testicular Interstitial fibrosis via activation of the GSK-3β/β-catenin/TCF-4 signaling pathway.

This study was designed to assess whether adrenomedullin (ADM) can alleviate testicular interstitial fibrosis by triggering the GSK-3β/β-catenin/TCF-4 cascade, consequently reducing the levels of connective tissue growth factor (CTGF), fibronectin, and type I collagen. Primary Leydig cells underwent treatment with lipopolysaccharide (LPS) followed by transduction using an adeno-associated virus engineered to express ADM (Ad-ADM). Cell viability was subsequently measured employing the CCK-8 assay. Additionally, the gene and protein expression levels of fibronectin, CTGF, and collagen type I were systematically determined. Treatment with Ad-ADM effectively restored Leydig cell viability and significantly decreased the mRNA and protein expression of CTGF, collagen type I, and fibronectin. Additionally, Ad-ADM inhibited the phosphorylation of GSK-3β and suppressed the activation of β-catenin, which interacts with TCF-4 in LPS-exposed Leydig cells. ADM may thus reduce fibrosis-related factor production in LPS-exposed Leydig cells, ameliorating testicular interstitial fibrosis via activation of the GSK-3β/β-catenin/TCF-4 pathway.