Anthocyanins from Chinese bayberry extract activate transcription factor Nrf2 in β cells and negatively regulate oxidative stress-induced autophagy.
Islet replacement is a promising cure for insulin-dependent diabetes but is limited by a massive early cell death following transplantation. Overburden oxidative stress is one of the major factors causing cell damage. We have shown previously that anthocyanins in Chinese bayberry extract protected β cells (INS-1) from hydrogen peroxide (H₂O₂)-induced apoptosis and decreased grafts' apoptosis after transplantation partially through heme oxygenase-1 (HO-1) up-regulation. In the present study, we observed that H₂O₂ stimulation induced autophagy in β cells. Inhibition of autophagy increased cell viability and decreased cell death. Anthocyanin pretreatment attenuated oxidative stress-mediated autophagic cell death. Anthocyanins activated antioxidant transcription factor Nrf2 in INS-1 cells, and Nrf2/HO-1 negatively regulated autophagy process. Furthermore, we here demonstrate that autophagy also took place in β cell grafts during the early post-transplantation phase. β Cells pretreated with anthocyanins displayed decreased extent of autophagy after transplantation. Taken together, these findings further supported the conclusion that anthocyanins could serve as a protective agent of β cells and suggested that autophagy might play a role in β cells during transplantation.
Department of Surgery (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University , No. 88 Jiefang Road, Hangzhou, Zhejiang Province 310009, People's Republic of China.
Bo
B
Zhang
Miranbieke
M
Buya
Wenjie
W
Qin
Chongde
C
Sun
Haolei
H
Cai
Qiuping
Q
Xie
Bing
B
Xu
Yulian
Y
Wu
D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000637:transplantation; D051379:Mice; D008813:Mice, Inbred ICR; D031641:Myrica / Q000737:chemistry*; D051267:NF-E2-Related Factor 2 / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D015854:Up-Regulation / Q000187:drug effects
D000872:Anthocyanins; D004365:Drugs, Chinese Herbal; D051267:NF-E2-Related Factor 2