Short-Chain Fatty Acids Ameliorate Diabetic Nephropathy via GPR43-Mediated Inhibition of Oxidative Stress and NF-κB Signaling

Figure 7

Interaction between β-arrestin-2 and I-κBα was induced by SCFAs via GPR43. (a) GMCs were treated with 30 mM high glucose for 6, 12, and 24 h. RT-PCR was performed to detect β-arrestin-2 and β-arrestin-1 mRNA levels. (b) The effects of indicated concentrations of SCFAs or an GPR43 agonist on β-arrestin-2 and β-arrestin-1 expression were analyzed by RT-PCR. (c) Western blot assay for the expression of β-arrestin-2 after 30 mM high glucose challenge for 6, 12, and 24 h. (d) High glucose-induced β-arrestin-2 expression was significantly reversed by SCFAs or GPR43 agonist. (e) The interaction between β-arrestin-2 and I-κBα under physiological conditions was detected by immunoprecipitation (IP) with anti-β-arrestin-2 antibody or normal mouse IgG antibody (negative control), followed by western blotting with an anti-I-κBα antibody. β-Arrestin-2 was conjugated with I-κBα in vitro. (f) The interaction between β-arrestin-2 and I-κBα was decreased by 30 mM high glucose but was reversed by 5 mM butyrate. And these butyrate-mediated effects were significantly reversed by siRNA-GPR43 but were facilitated by overexpressed GPR43. IgG-H marks the IgG heavy chain. But butyrate: compared with the NC group, ^# compared with the HG group, and ^& compared with the HG+But group. Ac: acetate; Pr: propionate.

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