Non-canonical NRF2 activation promotes a pro-diabetic shift in hepatic glucose metabolism
Pengfei Liu, Matthew Dodson, Hui Li, Cody J. Schmidlin, Aryatara Shakya, Yongyi Wei, Joe G. N. Garcia, Eli Chapman, Pawel R. Kiela, Qing-Yu Zhang, Eileen White, Xinxin Ding, Aikseng Ooi, Donna D. Zhang
Abstract
OBJECTIVE: NRF2, a transcription factor that regulates cellular redox and metabolic homeostasis, plays a dual role in human disease. While it is well known that canonical intermittent NRF2 activation protects against diabetes-induced tissue damage, little is known regarding the effects of prolonged non-canonical NRF2 activation in diabetes. The goal of this study was to determine the role and mechanisms of prolonged NRF2 activation in arsenic diabetogenicity. METHODS: mice exposed to arsenic in the drinking water for 20 weeks. RESULTS: In contrast to canonical oxidative/electrophilic activation, prolonged non-canonical NRF2 activation via p62-mediated sequestration of KEAP1 increases carbohydrate flux through the polyol pathway, resulting in a pro-diabetic shift in glucose homeostasis. This p62- and NRF2-dependent increase in liver fructose metabolism and gluconeogenesis occurs through the upregulation of four novel NRF2 target genes, ketohexokinase (Khk), sorbitol dehydrogenase (Sord), triokinase/FMN cyclase (Tkfc), and hepatocyte nuclear factor 4 (Hnf4A). CONCLUSION: We demonstrate that NRF2 and p62 are essential for arsenic-mediated insulin resistance and glucose intolerance, revealing a pro-diabetic role for prolonged NRF2 activation in arsenic diabetogenesis.