The Lupus-derived Anti-double-stranded DNA IgG Contributes to Myofibroblast-like Phenotype in Mesangial Cells

Anti–double-stranded DNA (dsDNA) antibodies have been indicated to play a major role in the pathogenesis of lupus nephritis (LN), which is characterized by mesangial alterations, including phenotypic changes. To explore the effects of anti-dsDNA antibodies on the phenotype of mesangial cells (MCs), the anti-dsDNA IgG in sera and histological features of glomeruli were analyzed in the mice models of immune-complex glomerulonephritis. The MCs were cultured in vitro with the addition of anti-dsDNA or non-anti-dsDNA IgG. Compared to the anti-dsDNA-negative controls, the serum positive mice had increased extracellular matrix accumulation and higher alpha-smooth muscle actin expression in the mesangial region. The anti-dsDNA IgG enhanced the synthesis of transforming growth factor beta, alpha-smooth muscle actin, and fibronectin, and even induced the myofibroblast-like morphological features in cultured MCs. Our results indicated that anti-dsDNA antibodies contribute to the phenotypic changes in MCs, which suggests another mechanism of renal injuries in LN induced by anti-dsDNA antibodies.