Renal ischemia–reperfusion injury (IRI) is a major cause of acute kidney injury (AKI). Twist-related protein 2 (Twist2) is a basic helix/loop/helix transcription factor. However, the underlying effects of Twist2 in IRI remain to be elucidated. Herein, we found that the expression of Twist2 was significantly upregulated in renal tissues of mice induced by ischemia/reperfusion (I/R) and in human renal tubular epithelial cell HK-2 exposed to hypoxia–reoxygenation. We silenced Twist2 with RNAi technology. Twist2 knockdown alleviated renal pathological damage in mice. Twist2 depletion ameliorated IRI-induced mitochondrial dysfunction, such as increasing ATP content and mitochondrial DNA copy number and restoring mitochondrial membrane potential in the kidneys of mice , and similar results were observed in in vitro experiments. Twist2 interference increased the expression of LC3B and decreased the expression of p62 and mitochondrial membrane proteins TIMM23 and TOMM20 both in vivo and in vitro. Electron microscope and the co-localization of LC3B and mitotracker DsRed suggested the induction of autophagy and mitophagy after Twist2 knockdown in kidneys or cells. Mechanism studies revealed that Twist2 exerted a direct inhibitory effect on BCL2 interacting protein 3 (Bnip3) transcriptional activity by targeting the Bnip3 promoter. In hypoxia/reoxygenation-induced renal tubular epithelial cells, the interference of Bnip3 reversed the effect of Twist2 depletion on mitochondrial function and mitophagy. In conclusion, our findings suggest that the depletion of Twist2 exerts renoprotective effect in I/R-induced AKI. Twist2 regulates mitochondrial function and mitophagy in part by targeting and downregulating Bnip3. Our study provides new insights into the pathological mechanisms of I/R-induced AKI.
Run Ling,Xin Yin,Liyao Ma,Yan Zhang,Yidan Ma,Rufei Gao,Yanqing Geng,Xinyi Mu,Xuemei Chen,Fangfang Li,Junlin He
Decabromodiphenyl ethane (DBDPE) is a brominated flame retardant widely used for its high flame retardancy and low bioavailability. However, DBDPE exhibits bioaccumulative potential. The placental vasculature, critical for the exchange between maternal and fetal circulation, is susceptible to environmental factors. We aimed to understand the potential toxicity of DBDPE to the placental vasculature. Gestational CD-1 mice and human umbilical vein endothelial cells (HUVECs) were exposed to 0, 0.5, 5, 50 mg/kg·bw·day or 0, 6.25, 12.5, 25, 50 μmol/L DBDPE, respectively. DBDPE exposure impaired placental angiogenesis and inhibited the proliferation and invasion of HUVECs by activating the endothelial-to-mesenchymal transition (EndMT) through the TGF-β1/Smad pathway, in vivo and in vitro . DBDPE upregulated the transcription factor TWIST2 and mRNA acetyltransferase NAT10. Knockdown or overexpression of TWIST2 reversed the vascular dysfunction and EndMT mechanism. DBDPE facilitated the recruitment of NAT10 by TWIST2, promoting N4-acetylcytidine (ac4C) RNA modifications and stabilizing the TGF-β1 mRNA. NAT10 inhibition rescued the effects caused by DBDPE. These findings uncover molecular mechanisms linking DBDPE exposure to adverse pregnancy outcomes, highlighting potential risks to pregnant women.