Twist-related protein 1 induces epithelial-mesenchymal transition and renal fibrosis through the upregulation of complement 3.

Abstract

We have demonstrated that complement 3 (C3) is upregulated and induces epithelial-mesenchymal transition (EMT) phenomenon and renal fibrosis in unilateral ureteral obstruction (UUO) kidney. We investigated roles of twist-related protein 1 (TWIST1) in EMT phenomenon and renal fibrosis through C3 upregulation in a mouse UUO model with gene silencer pyrrole-imidazole (PI) polyamides targeting TWIST1. We designed and synthesized PI polyamides targeting TWIST1 binding site on mouse pre-pro C3 promoter. Increased expression C3 mRNA with interferon-γ was significantly inhibited with PI polyamide in nephrotubular epithelial cells. Immunofluorescence showed suppression of E-cadherin and enhancement of α-smooth muscle actin (α-SMA) stainings as EMT phenomena in UUO kidney. TWIST1 and C3 expression was significantly increased in UUO kidney versus contralateral unobstructed kidney (CUK). Expression of transforming growth factor-β1 (TGF-β1), α-SMA and renin mRNAs was increased in UUO kidney versus CUK. Systemic administration of TWIST1 PI polyamide significantly suppressed increased C3 expression in UUO kidney versus CUK. PI polyamide administration also suppressed the increased expression of TGF-β1, α-SMA and renin mRNAs and histologically improved renal fibrosis in UUO kidney. These findings indicate that TWIST1 induces EMT phenomenon and renal fibrosis by TGF-β1 upregulation of C3 in mouse UUO model and that TWIST1 PI polyamide may be a novel medicine for renal fibrosis.