CXCR4 antagonist alleviates proliferation and collagen synthesis of cardiac fibroblasts induced by TGF-β1.

Abstract

We aimed to investigate the effects of CX-C chemokine receptor type 4 (CXCR4) on transforming growth factor (TGF)-β1-induced cardiac fibrosis in Human cardiac fibroblasts (HCFs). HCFs were stimulated with TGF-β1, and the level of α-smooth muscle actin (α-SMA) was assessed by immunofluorescence assay. The expression of CXCR4 was detected by Western blotting. Then the cells were incubated with CXCR4 antagonist AMD 3465. Cell viability was measured by CCK-8 assay. The expression of α-SMA, proliferating cell nuclear antigen (PCNA) and Ki67 were examined. Collagen synthesis was detected by sirius red staining. Moreover, the expression of phpspho-Smad2 (p-Smad2) and p-Smad3 were determined. We found that the level of α-SMA was increased after induction with TGF-β1. The expression of CXCR4 was upregulated in TGF-β1-treated HCFs. Following treatment with AMD 3465, cell proliferation was inhibited coupled with a decrease in PCNA and Ki67 expression. Additionally, the expression of α-SMA was decreased after being intervened with AMD 3465. Concurrently, the levels of collagen were reduced accompanied by downregulation of Collagen I and III. Furthermore, AMD 3465 treatment decreased the expression of p-Smad2 and p-Smad3. Our findings suggested that CXCR4 antagonist AMD 3465 could alleviate cardiac fibrosis via blocking TGF-β1-induced activation of Smad2/3 in HCFs.