The stress-response molecule NR4A1 resists ROS-induced pancreatic β-cells apoptosis via WT1.
Pancreatic β-cells often face endoplasmic reticulum stress and/or ROS-associated oxidative stress under adverse conditions. Our previous work has verified that NR4A1 protects pancreatic β-cells from ER-stress induced apoptosis. However, It remains unknown whether NR4A1 is able to protect pancreatic β-cells against ROS-associated oxidative stress. In the present study, our data showed that NR4A1 protein expression rapidly increased in MIN6 cells upon H2O2treatment, and overexpression of NR4A1 in MIN6 cells conferred resistance to cell apoptosis induced by H2O2. These results were further substantiated in isolated islets from mice infected with an adenovirus overexpressing NR4A1. 8-hydroxy-2'-deoxyguanosine (8-OHdG) was used as a biomarker for oxidative stress or a marker for ROS damage. We found that the 8-OHdG level in the islets from NR4A1 knockout mice fed with high-fat diet was much higher than that in the islets from parental control mice; and higher apoptotic rate was observed in the islets from NR4A1 KO mice compared to control mice. Further investigation of underlying mechanisms of NR4A1's protective effects showed that NR4A1 overexpression in MIN6 cells reduced Caspase 3 activation caused by H2O2, and increased expression of WT1 and SOD1. There is a putative NR4A1 binding site (-1118bp to -1111bp) in WT1 promoter; our data demonstrated that NR4A1 protein physically associates with the WT1 promoter, and enhanced WT1 promoter transactivation and knockdown of WT1 in MIN6 cells induced apoptosis. These findings suggest that NR4A1 protects pancreatic β-cells against H2O2mediated apoptosis by up-regulating WT1 expression.
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Chen
C
Zong
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Dandan
D
Qin
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Cong
C
Yu
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China; Department of Laboratory Medicine, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, Shandong, China.
Peng
P
Gao
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Jicui
J
Chen
Department of Laboratory Medicine, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, Shandong, China.
Sumei
S
Lu
Department of Endocrinology, Qingdao Municipal Hospital, Qingdao 266071, Shandong, China.
Yuchao
Y
Zhang
Department of Endocrinology, Qingdao Municipal Hospital, Qingdao 266071, Shandong, China.
Yuantao
Y
Liu
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Yingfeng
Y
Yang
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China.
Zeqing
Z
Pu
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China. Electronic address: lixia1666@sdu.edu.cn.
Xia
X
Li
The Department of Nutrition Sciences, University of Alabama at Birmingham, AL 35294, United States. Electronic address: yfu@uab.edu.
Yuchang
Y
Fu
Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, 250021, Shandong, China.
Qingbo
Q
Guan
Department of Cell Biology, Shandong University School of Medicine, Jinan 250012, Shandong, China; Key Laboratory of Protein Sciences for Chronic Degenerative Diseases in Universities of Shandong (Shandong University), Jinan 250012, Shandong, China. Electronic address: xdongw@sdu.edu.cn.
Xiangdong
X
Wang
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D059305:Diet, High-Fat; D059865:Endoplasmic Reticulum Stress / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000235:genetics*; D018384:Oxidative Stress / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000378:metabolism; D025721:WT1 Proteins / Q000235:genetics*
C539821:NR4A1 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D017382:Reactive Oxygen Species; D025721:WT1 Proteins; D000080242:8-Hydroxy-2'-Deoxyguanosine; D006861:Hydrogen Peroxide; D003849:Deoxyguanosine
Apoptosis; H(2)O(2); NR4A1; Pancreatic β-cells; WT1