miR-133 inhibits proliferation and promotes apoptosis by targeting LASP1 in lupus nephritis.

Lupus nephritis (LN) is a chronic autoimmune disease. Recently, microRNA (miR)-133 has been demonstrated to play an important role in renal cell carcinoma. Our current study was designed to test the role of miR-133 and its potential target in LN. First, significant correlation of LASP1 and miR-133 levels was observed in the human LN tissue. Modification of miR-133 level in the human mesangial cells (HMCs) by either overexpression or knockdown demonstrated a suppressive role of miR-133 in cell proliferation and an inductive role in cell apoptosis. Modification of LASP1 level in the HMCs demonstrated the opposing effects of LASP1 to miR-133 on proliferation and apoptosis. In addition, luciferase assay showed miR-133 directly regulates LASP1 expression through its binding site in the 3'UTR of LASP1. At last, our data showed that the changes in properties, such as suppression in proliferation and induction in apoptosis, induced by overexpression of miR-133 were restored by additional expression of LASP1. In summary, our obtained data demonstrated that miR-133 suppresses proliferation and promotes apoptosis through its binding with LASP1 in human mesangial cells. This study revealed a new mechanism involving the interaction of miR-133 and LASP1 in the pathogenesis of LN.