Caloric restriction induces H2O2 formation as a trigger of AMPK-eNOS-NO pathway in obese rats: Role for CAMKII
Caloric restriction induces H2O2 formation as a trigger of AMPK-eNOS-NO pathway in obese rats: Role for CAMKII
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DOI：
10.1016/j.freeradbiomed.2019.05.016
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发表时间：
2019-08-01
影响因子：
7.4
通讯作者：
Fernandez-Alfonso, Maria S.
中科院分区：
文献类型：
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作者：
Garcia-Prieto, Concha F.;Gil-Ortega, Marta;Fernandez-Alfonso, Maria S.
热量限制（CR）通过上调腺苷一磷酸活化蛋白激酶（AMPK）和内皮型一氧化氮合酶（eNOS）来改善内皮功能。此外，过氧化氢（H2 O2）在经历CR的酵母中上调。我们的目的是评估轻度短期CR是否增加血管H2 O2形成与AMPK和eNOS激活的联系。12周龄Zucker肥胖（fa/fa）和对照Zucker瘦雄性大鼠被喂食标准食物，自由采食（AL，n = 10）或20%CR（CR，n = 10）两周。CR显著改善了fa/fa大鼠对ACh的舒张，因为主动脉环中内源性H2 O2的产生增加（H2 O2水平（fa/faAL）= 0.5 +/- 0.05 nmol/mg vs. H2 O2水平（fa/faCR）= 0.76 +/- 0.07 nmol/mg蛋白质; p< 0.05）。fa/fa动物CR后主动脉线粒体超氧化物歧化酶（Mn-SOD）表达和总SOD活性增加。在培养的主动脉内皮细胞中，血清剥夺或2-脱氧-D-葡萄糖诱导：i）超氧阴离子和H2 O2水平，ii）p-AMPK/AMPK和p-eNOS/eNOS表达和iii）一氧化氮水平的显著增加。这种作用被过氧化氢酶减弱，并被Ca 2 +/钙调蛋白依赖性激酶II（CamkII）沉默强烈抑制。总之，我们认为轻度短期CR可能是通过增加H2 O2来保护血管壁的机制的触发因素，H2 O2然后激活AMPK和一氧化氮释放，从而改善内皮依赖性舒张。此外，我们证明了CAMK II通过H2 O2增加在介导CR诱导的AMPK活化中起关键作用。
Caloric restriction (CR) improves endothelial function through the upregulation of adenosine monophosphateactivated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). Moreover, hydrogen peroxide (H2O2) is upregulated in yeast subjected to CR. Our aim was to assess if mild short-term CR increases vascular H2O2 formation as a link with AMPK and eNOS activation.Twelve-week old Zucker obese (fa/fa) and control Zucker lean male rats were fed a standard chow either ad libitum (AL, n = 10) or with a 20% CR (CR, n = 10) for two weeks. CR significantly improved relaxation to ACh in fa/fa rats because of an enhanced endogenous production of H2O2 in aortic rings (H2O2 levels (fa/faAL)= 0.5 +/- 0.05 nmol/mg vs. H2O2 levels (fa/faCR)= 0.76 +/- 0.07 nmol/mg protein; p< 0.05). Expression of mitochondrial superoxide dismutase (Mn-SOD) and total SOD activity were increased in aorta from fa/fa animals after CR. In cultured aortic endothelial cells, serum deprivation or 2-deoxy-D-glucose induced a significant increase in: i) superoxide anion and H2O2 levels, ii) p-AMPK/AMPK and p-eNOS/eNOS expression and iii) nitric oxide levels. This effect was reduced by catalase and strongly inhibited by Ca2+/calmodulin-dependent kinase II (CamkII) silencing.In conclusion, we propose that mild short-term CR might be a trigger of mechanisms aimed at protecting the vascular wall by the increase of H2O2, which then activates AMPK and nitric oxide release, thus improving endothelium-dependent relaxation. In addition, we demonstrate that CAMKII plays a key role in mediating CR-induced AMPK activation through H2O2 increase.