title: The role of CHOP messenger RNA expression in the link between oxidative stress and apoptosis.
abstract: Low expression of antioxidant enzymes makes pancreatic beta-cells susceptible to cell damage by oxidative stress. Pancreatic beta-cell loss caused by endoplasmic reticulum stress is associated with the onset of diabetes mellitus. The present studies were undertaken to investigate a possible involvement of proapoptotic gene CHOP in pancreatic beta-cells damage by oxidative stress. The induction of CHOP messenger RNA and apoptosis were investigated in betaHC-9 cells after the oxidative stress by hydrogen peroxide and ribose. Latter was examined after the suppression of CHOP by small interfering RNA. For in vivo study, the pancreatic beta-cells were examined in CHOP-knockout (KO) mice after multiple low-dose streptozotocin (MLDS) administration. In betaHC-9 cells, both hydrogen peroxide and ribose obviously increased apoptotic cells, accompanied with enhanced CHOP messenger RNA expression. However, the number of apoptotic cells by those stimulations was significantly reduced by the addition of small interfering RNA against CHOP. In vivo study also showed that CHOP-KO mice were less susceptible to diabetes after MLDS administration. Although the oxidative stress marker level was similar to that of MLDS-treated wild type, the pancreatic beta-cell area was maintained in CHOP-KO mice. The present studies showed that CHOP should be important in pancreatic beta-cell injury by oxidative stress and indicate that CHOP may play a role in the development of pancreatic beta-cell damage on the onset of diabetes mellitus.
authors.affiliation: Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Ariyama
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimizu
authors.forename: Kenju
authors.initials: K
authors.lastname: Shimomura
authors.forename: Shuichi
authors.initials: S
authors.lastname: Okada
authors.forename: Tsugumichi
authors.initials: T
authors.lastname: Saito
authors.forename: Eijiro
authors.initials: E
authors.lastname: Yamada
authors.forename: Seiichi
authors.initials: S
authors.lastname: Oyadomari
authors.forename: Masataka
authors.initials: M
authors.lastname: Mori
authors.forename: Masatomo
authors.initials: M
authors.lastname: Mori
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism / Q000502:physiology; D034741:RNA, Small Interfering / Q000494:pharmacology; D012266:Ribose / Q000378:metabolism; D013311:Streptozocin; D051742:Transcription Factor CHOP / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*
chemical_list: C497250:Ddit3 protein, mouse; D007328:Insulin; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051742:Transcription Factor CHOP; D013311:Streptozocin; D012266:Ribose; D006861:Hydrogen Peroxide