scholarly journals Angiotensin type 1A receptors (AT 1a ) and reactive oxygen species (ROS) mediate nuclear factor‐κ‐B (NF‐κB) activation in the subfornical organ (SFO) during slow‐pressor Angiotensin‐II (Ang‐II) hypertension

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Anfei Li ◽  
Colin N. Young ◽  
Robin L. Davisson
Keyword(s):  
Reactive Oxygen Species ◽  
Angiotensin Ii ◽  
Reactive Oxygen ◽  
Subfornical Organ ◽  
Nuclear Factor ◽  
Oxygen Species ◽  
Ang Ii ◽  
Nuclear Factor Κ B ◽  
Angiotensin Type

scholarly journals COX-1-derived PGE2 and PGE2 type 1 receptors are vital for angiotensin II-induced formation of reactive oxygen species and Ca2+ influx in the subfornical organ

2013 ◽  
Vol 305 (10) ◽  
pp. H1451-H1461 ◽  
Author(s):  
Gang Wang ◽  
Pallabi Sarkar ◽  
Jeffrey R. Peterson ◽  
Josef Anrather ◽  
Joseph P. Pierce ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Angiotensin Ii ◽  
Signaling Pathway ◽  
Reactive Oxygen ◽  
Subfornical Organ ◽  
Prostaglandin E ◽  
Oxygen Species ◽  
Ang Ii ◽  
Cox 1

Regulation of blood pressure by angiotensin II (ANG II) is a process that involves the reactive oxygen species (ROS) and calcium. We have shown that ANG-II type 1 receptor (AT1R) and prostaglandin E2 (PGE2) type 1 receptors (EP1R) are required in the subfornical organ (SFO) for ROS-mediated hypertension induced by slow-pressor ANG-II infusion. However, the signaling pathway associated with this process remains unclear. We sought to determine mechanisms underlying the ANG II-induced ROS and calcium influx in mouse SFO cells. Ultrastructural studies showed that cyclooxygenase 1 (COX-1) codistributes with AT1R in the SFO, indicating spatial proximity. Functional studies using SFO cells revealed that ANG II potentiated PGE2 release, an effect dependent on AT1R, phospholipase A2 (PLA2) and COX-1. Furthermore, both ANG II and PGE2 increased ROS formation. While the increase in ROS initiated by ANG II, but not PGE2, required the activation of the AT1R/PLA2/COX-1 pathway, both ANG II and PGE2 were dependent on EP1R and Nox2 as downstream effectors. Finally, ANG II potentiated voltage-gated L-type Ca2+ currents in SFO neurons via the same signaling pathway required for PGE2 production. Blockade of EP1R and Nox2-derived ROS inhibited ANG II and PGE2-mediated Ca2+ currents. We propose a mechanism whereby ANG II increases COX-1-derived PGE2 through the AT1R/PLA2 pathway, which promotes ROS production by EP1R/Nox2 signaling in the SFO. ANG II-induced ROS are coupled with Ca2+ influx in SFO neurons, which may influence SFO-mediated sympathoexcitation. Our findings provide the first evidence of a spatial and functional framework that underlies ANG-II signaling in the SFO and reveal novel targets for antihypertensive therapies.

scholarly journals Effect of Resveratrol on Reactive Oxygen Species-Induced Cognitive Impairment in Rats with Angiotensin II-Induced Early Alzheimer’s Disease

2018 ◽  
Author(s):  
Yu-Te Lin ◽  
Yi-Chung Wu ◽  
Gwo-Ching Sun ◽  
Chiu-Yi Ho ◽  
Tzyy-Yue Wong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cognitive Impairment ◽  
Angiotensin Ii ◽  
Nucleus Tractus Solitarius ◽  
Glycogen Synthase ◽  
Reactive Oxygen ◽  
Hippocampal Damage ◽  
Oxygen Species ◽  
Ang Ii

Recent studies have indicated that several anti-hypertensive drugs may delay the development and progression of Alzheimer’s disease (AD). However, the relationships among AD, hypertension, and oxidative stress remain to be elucidated. In the present study, we aimed to determine whether treatment with resveratrol reduces reactive oxygen species (ROS) generation in the brain, thereby reducing cognitive impairment in rats with angiotensin II (Ang-II)-induced early AD. Male WKY rats with Ang-II-induced AD were treated with losartan or resveratrol for 2 weeks. Our results revealed that treatment with resveratrol (10 mg/kg/day) decreased blood pressure, increased levels of brain-derived neurotrophic factor (BDNF) in the hippocampus, and decreased ROS production in the nucleus tractus solitarius (NTS) in the Ang-II groups. In addition, inhibition of TauT231 phosphorylation in the hippocampus using resveratrol significantly abolished Ang-II-induced expression of Ab precursors, active caspase 3, and glycogen synthase kinase 3b (GSK-3b)Y216 while increasing AktS473 phosphorylation. Notably, resveratrol reversed impairments in hippocampal-dependent contextual memory induced by deleting NADPH oxidase and NOX2. Overall, our results suggest that resveratrol exerts neuroprotective effects against memory impairment and hippocampal damage in a rat model of early stage AD by reducing oxidative stress. These novel findings indicate that resveratrol may represent a pharmacological option for patients with hypertension at a risk of AD during old age.

scholarly journals Effect of Resveratrol on Reactive Oxygen Species-Induced Cognitive Impairment in Rats with Angiotensin II-Induced Early Alzheimer’s Disease †

2018 ◽  
Vol 7 (10) ◽  
pp. 329 ◽  
Author(s):  
Yu-Te Lin ◽  
Yi-Chung Wu ◽  
Gwo-Ching Sun ◽  
Chiu-Yi Ho ◽  
Tzyy-Yue Wong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Reactive Oxygen Species ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Angiotensin Ii ◽  
Reactive Oxygen ◽  
Hippocampal Damage ◽  
Oxygen Species ◽  
Ang Ii

Recent studies have indicated that several anti-hypertensive drugs may delay the development and progression of Alzheimer’s disease (AD). However, the relationships among AD, hypertension, and oxidative stress remain to be elucidated. Here, we aimed to determine whether reactive oxygen species (ROS) reduction by resveratrol in the brain leads to cognitive impairment reduction in rats with angiotensin II (Ang-II)-induced early AD. Male Wistar Kyoto (WKY) rats with Ang-II-induced AD were treated with losartan or resveratrol for two weeks. Our results show decreased blood pressure, increased hippocampal brain-derived neurotrophic factor (BDNF) level, and decreased nucleus tractus solitarius (NTS) ROS production in the Ang-II groups with losartan (10 mg/kg), or resveratrol (10 mg/kg/day) treatment. Furthermore, losartan inhibition of hippocampal TauT231 phosphorylation activated AktS473 phosphorylation, and significantly abolished Ang-II-induced Aβ precursors, active caspase 3, and glycogen synthase kinase 3β (GSK-3β)Y216 expressions. Consistently, resveratrol showed similar effects compared to losartan. Both losartan and resveratrol restored hippocampal-dependent contextual memory by NADPH oxidase 2 (NOX2) deletion and superoxide dismutase 2 (SOD2) elevation. Our results suggest that both losartan and resveratrol exert neuroprotective effects against memory impairment and hippocampal damage by oxidative stress reduction in early stage AD rat model. These novel findings indicate that resveratrol may represent a pharmacological option similar to losartan for patients with hypertension at risk of AD during old age.

scholarly journals Angiotensin II-induced ERK1/ERK2 activation and protein synthesis are redox-dependent in glomerular mesangial cells

2004 ◽  
Vol 381 (1) ◽  
pp. 231-239 ◽  
Author(s):  
Yves GORIN ◽  
Jill M. RICONO ◽  
Brent WAGNER ◽  
Nam-Ho KIM ◽  
Basant BHANDARI ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Synthesis ◽  
Angiotensin Ii ◽  
Mesangial Cells ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ang Ii ◽  
Glomerular Mesangial Cells ◽  
Diphenylene Iodonium ◽  
Erk2 Activation

Angiotensin II (Ang II) stimulates hypertrophy of glomerular mesangial cells. The signalling mechanism by which Ang II exerts this effect is not precisely known. Downstream potential targets of Ang II are the extracellular-signal-regulated kinases 1 and 2 (ERK1/ERK2). We demonstrate that Ang II activates ERK1/ERK2 via the AT1 receptor. Arachidonic acid (AA) mimics the action of Ang II on ERK1/ERK2 and phospholipase A2 inhibitors blocked Ang II-induced ERK1/ERK2 activation. The antioxidant N-acetylcysteine as well as the NAD(P)H oxidase inhibitors diphenylene iodonium and phenylarsine oxide abolished both Ang II- and AA-induced ERK1/ERK2 activation. Moreover, dominant-negative Rac1 (N17Rac1) blocks activation of ERK1/ERK2 in response to Ang II and AA, whereas constitutively active Rac1 resulted in an increase in ERK1/ERK2 activity. Antisense oligonucleotides for Nox4 NAD(P)H oxidase significantly reduce activation of ERK1/ERK2 by Ang II and AA. We also show that protein synthesis in response to Ang II and AA is inhibited by N17Rac1 or MEK (mitogen-activated protein kinase/ERK kinase) inhibitor. These results demonstrate that Ang II stimulates ERK1/ERK2 by AA and Nox4-derived reactive oxygen species, suggesting that these molecules act as downstream signal transducers of Ang II in the signalling pathway linking the Ang II receptor AT1 to ERK1/ERK2 activation. This pathway involving AA, Rac1, Nox4, reactive oxygen species and ERK1/ERK2 may play an important role in Ang II-induced mesangial cell hypertrophy.

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