Tanshinone IIA alleviates lipopolysaccharide-induced renal tubular epithelial cell apoptosis by inhibiting RIP3/FUNDC1 signaling pathway

Abstract

To investigate the effect of tanshinone IIA pretreatment on acute renal injury in lipopolysaccharide (LPS)-induced septic mice and explore the possible mechanism. Thirty C57BL/6 mice were randomized for treatment with saline (control), 10 mg/kg LPS for 24 h, or 10 mg/kg tanshinone IIA 15 min before LPS treatment. After the treatments, serum creatinine and blood urea nitrogen levels of the mice were detected, renal pathologies were observed with PAS staining, and renal expressions of RIP3, cleaved caspase-3 and p18-FUNDC1 were detected with Western blotting. In the cell experiment, cultured normal human renal tubular epithelial cells (HK-2) were treated with LPS (10 mg/mL), LPS+ siNC, LPS+ siRIP3, or LPS+tanshinone IIA (10 mg/L), and the changes in cell apoptosis were examined with TUNEL staining; Western blotting was performed to detect the expression levels of RIP3, cleaved caspase-3 and p18-FUNDC1, and qRT-PCR was used to detect the expression of RIP3 mRNA. LPS challenge for 24 h significantly increased serum creatinine and blood urea nitrogen levels in the mice, caused obviously damages in the proximal renal tubules, and increased renal expressions of RIP3, cleaved caspase-3 and p18-FUNDC1 proteins. Tanshinone IIA pretreatment significantly improved LPS-induced renal injury in the mice, alleviated apoptosis of the renal cells, and inhibited the expressions of RIP3, cleaved caspase-3 and p18-FUNDC1 proteins. In HK-2 cells, LPS stimulation significantly increased the protein expressions of RIP3, cleaved caspase-3 and p18-FUNDC1 and induced obvious cell apoptosis. Pretreatment with tanshinone IIA strongly inhibited the expression of RIP3 and p18-FUNDC1 and reduced LPS-induced apoptosis of HK-2 cells. Tanshinone IIA can reduce LPS-induced apoptosis of renal tubular epithelial cells by inhibiting RIP3/FUNDC1 signal pathway.