Role and mechanism of Angiotensin II-induced ChemR23 in podocyte injury

Abstract

Objective To observe the expression of ChemR23 induced by Angiotensin Ⅱ (AngⅡ) in podocyte and its role in renal injury. Methods Conditionally immortalized mice podocytes were cultured in vitro. Immunofluorescence was used to observe the sub-cellular location of ChemR23. The expressions of ChemR23, Nephrin and Podocin stimulated by different concentrations of AngⅡ were detected by qRT-PCR and Western blotting. Lentivirus targeting ChemR23 was used. The expressions of Nephrin and Podocin and the phosphorylation state of NF-κB P65 were detected by Western Blot. The inhibitor of NF-κB P65 was added to the cultural medium for 2 h before AngⅡ stimulation. The effect of NF-κB P65 inhibitor on AngⅡ-induced expression of Nephrin and Podocin was detected by Western Blot. Results It is showed that ChemR23 was located in cytosol and membrane. Compared with the normal control, the expression of ChemR23 was significantly increased by AngⅡ in mRNA and protein level, while the expressions of Nephrin and Podocin were decreased (P<0.05). When using Lentivirus vector to interfere the expression of ChemR23, AngⅡ-repressed expressions of Nephrin and Podocin were restored (P<0.05). Western Blot showed the level of phosphorylated NF-κB P65 was significantly increased by AngⅡ stimulation (P<0.05), which could be inhibited by interfering the expression of ChemR23. When adding the NF-κB P65 inhibitor, the low expression of Nephrin and Podocin induced by AngⅡ stimulation was restored (P<0.05). Conclusions AngⅡ can induce ChemR23 expression, which activates NF-κB P65 signaling pathway, and then inhibits the expressions of Nephrin and Podocin. Targeting ChemR23 is a potential way to alleviate podocyte injury caused by AngⅡ. Key words: AngiotensinⅡ; Podocyte; Cell injury; ChemR23; NF-κB