Role of transient receptor potential cation channel 6 (TRPC6) channel in mouse podocyte injury induced by TGF-β1

Abstract

Objective To investigate the effects of transient receptor potential cation channel 6 (TRPC6) on the expression of nephrin, desmin and caspase 9 and on the apoptosis of podocytes in a mouse model of podocyte injury induced by TGF-β1. Methods Conditionally immortalized mouse podocytes were cultured in vitro and divided into four groups: control, TGF-β1 treatment, TGF-β1+ PGPU6/GFP/Neo-TRPC6-mus-581 (TRPC6 knockdown) and TGF-β1+ PGPU6/GFP/Neo-NC (negative control). Real-time RT-PCR and Western blot analysis were performed to detect the expression of nephrin, desmin and caspase 9 at mRNA and protein levels, respectively. Flow cytometry was used to analyze the apoptotic rate of podocytes. DAPI fluorescent staining was used to observe the morphological changes of apoptotic podocytes. Results Green fluorescent protein (GFP)-expressing podocytes at 48 hours after transfection were significantly more than those at 24 hours after transfection. The level of TRPC6 in mouse podocytes transfected with PGPU6/GFP/Neo-TRPC6-mus-581 was significantly decreased as compared with that of the control group (P 0.05). More apoptotic cells with typical morphological features of apoptosis were observed after exposure to TGF-β1 for 48 hours. Conclusion TGF-β1 could induce the apoptosis of podocytes, inhibit the expression of nephrin and enhance the expression of caspase 9 and desmin, the possible mechanisms of which may be related to TRPC6 signal pathway. These changes in TGF-β1-treated podocytes could be alleviated by inhibiting the expression of TRPC6, which might have a protective effect on podocyte injury. Key words: Podocyte; TGF-β1; Apoptosis; Desmin; Nephrin; Caspase 9