APLN and fibrosis: The results showed that glomerular fibrosis and expression of α-SMA and fibronectin in podocytes of STZ-treated β5iKO mice were decreased compared to STZ-treated C57/BL mice, and apelin could not alleviate the glomerular fibrosis and expression of α-SMA and fibronectin in STZ-treated β5iKO mice (Fig. 7).