PolyIC Induces Retinoic Acid-inducible Gene-I and Melanoma Differentiation-associated Gene 5 and Modulates Inflammation in Podocytes

Abstract

Background/aim: Viral infection often exacerbates proteinuria, which has been suggested to be due to antiviral responses of podocytes. We examined the effect of polyinosinic-polycytidylic acid (polyIC) on the expression of retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) in differentiated human podocytes in culture.

Materials and methods: The podocytes were treated with 2 ng/ml to 500 μg/ml of polyIC for 3 to 36 h, and also transfected with siRNA against RIG-I and MDA5. F-actin staining was performed to assess actin reorganization.

Results: PolyIC induced the expression of RIG-I and MDA5 in dose- and time-dependent manner, accompanied with interferon-β (IFN-β) and interleukin-6 (IL-6) up-regulation and actin reorganization. Temporal knockdown of RIG-I by siRNA decreased IFN-β expression, while MDA5 siRNA inhibited IFN-β and IL-6 expression. Actin reorganization was attenuated by RIG-I and MDA5 knockdown.

Conclusion: RIG-I and MDA5 may play a role in the antiviral responses of podocytes.

Keywords: MDA5; Podocyte; RIG-I; innate immunity; polyIC.