Nrf2 transcriptional upregulation of IDH2 to tune mitochondrial dynamics and rescue angiogenic function of diabetic EPCs
Xiaozhen Dai,
Kai Wang,
Jiawei Fan,
Hanjie Liu,
Xia Fan,
Qian Lin,
Yuhang Chen,
Hu Chen,
Yao Li,
Hairong Liu,
Oscar Chen,
Jing Chen,
Xiaohong Li,
Di Ren,
Ji Li,
Daniel J. Conklin,
Kupper A. Wintergerst,
Yu Li,
Lu Cai,
Zhongbin Deng,
Xiaoqing Yan,
Yi Tan
Affiliations
Xiaozhen Dai
School of Biosciences and Technology, Chengdu Medical College, Chengdu, Sichuan, China; Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA
Kai Wang
Department of Pediatrics, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
Jiawei Fan
School of Biosciences and Technology, Chengdu Medical College, Chengdu, Sichuan, China
Hanjie Liu
School of Laboratory Medicine, Chengdu Medical College, Chengdu, China
Xia Fan
Chinese-American Research Institute for Diabetic Complications, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
Qian Lin
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA
Yuhang Chen
School of Laboratory Medicine, Chengdu Medical College, Chengdu, China
Hu Chen
The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
Yao Li
The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
Hairong Liu
The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, China
Oscar Chen
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA
Jing Chen
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA
Xiaohong Li
Kentucky IDeA Network for Biomedical Research Excellence Bioinformatics Core, University of Louisville, Louisville, KY, USA
Di Ren
Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
Ji Li
Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
Daniel J. Conklin
Department of Medicine and Diabetes and Obesity Center, University of Louisville, Louisville, KY, USA
Kupper A. Wintergerst
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA; Division of Endocrinology, Department of Pediatrics, University of Louisville, Norton Children’s Hospital, Louisville, KY, USA; Wendy L. Novak Diabetes Care Center, Norton Children’s Hospital, Louisville, KY, USA
Yu Li
CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
Lu Cai
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA; Wendy L. Novak Diabetes Care Center, Norton Children’s Hospital, Louisville, KY, USA
Zhongbin Deng
Department of Surgery, Division of Immunotherapy, University of Louisville, Louisville, KY, USA
Xiaoqing Yan
Chinese-American Research Institute for Diabetic Complications, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China; Corresponding author. Chinese-American Research Institute for Diabetic Complications, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China.
Yi Tan
Pediatric Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY, USA; Wendy L. Novak Diabetes Care Center, Norton Children’s Hospital, Louisville, KY, USA; Corresponding author. Pediatric Research Institute, Department of Pediatrics of the University of Louisville School of Medicine, 570 South Preston Street, Baxter-I Building Suite 304E, Louisville, KY, 40202 USA.
Endothelial progenitor cells (EPCs) are reduced in number and impaired in function in diabetic patients. Whether and how Nrf2 regulates the function of diabetic EPCs remains unclear. In this study, we found that the expression of Nrf2 and its downstream genes were decreased in EPCs from both diabetic patients and db/db mice. Survival ability and angiogenic function of EPCs from diabetic patients and db/db mice also were impaired. Gain- and loss-of-function studies, respectively, showed that knockdown of Nrf2 increased apoptosis and impaired tube formation in EPCs from healthy donors and wild-type mice, while Nrf2 overexpression decreased apoptosis and rescued tube formation in EPCs from diabetic patients and db/db mice. Additionally, proangiogenic function of Nrf2-manipulated mouse EPCs was validated in db/db mice with hind limb ischemia. Mechanistic studies demonstrated that diabetes induced mitochondrial fragmentation and dysfunction of EPCs by dysregulating the abundance of proteins controlling mitochondrial dynamics; upregulating Nrf2 expression attenuated diabetes-induced mitochondrial fragmentation and dysfunction and rectified the abundance of proteins controlling mitochondrial dynamics. Further RNA-sequencing analysis demonstrated that Nrf2 specifically upregulated the transcription of isocitrate dehydrogenase 2 (IDH2), a key enzyme regulating tricarboxylic acid cycle and mitochondrial function. Overexpression of IDH2 rectified Nrf2 knockdown- or diabetes-induced mitochondrial fragmentation and EPC dysfunction. In a therapeutic approach, supplementation of an Nrf2 activator sulforaphane enhanced angiogenesis and blood perfusion recovery in db/db mice with hind limb ischemia. Collectively, these findings indicate that Nrf2 is a potential therapeutic target for improving diabetic EPC function. Thus, elevating Nrf2 expression enhances EPC resistance to diabetes-induced oxidative damage and improves therapeutic efficacy of EPCs in treating diabetic limb ischemia likely via transcriptional upregulating IDH2 expression and improving mitochondrial function of diabetic EPCs.
