Up-regulation of renal renin–angiotensin system and inflammatory mechanisms in the prenatal programming by low-protein diet: beneficial effect of the post-weaning losartan treatment

2018 ◽  
Vol 9 (5) ◽  
pp. 530-535 ◽  
Author(s):  
I. K. M. Watanabe ◽  
Z. P. Jara ◽  
R. A. Volpini ◽  
M. d. C. Franco ◽  
F. F. Jung ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Renin Angiotensin System ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Oxygen Species ◽  
Ang Ii ◽  
Prenatal Programming ◽  
Angiotensin System ◽  
Low Protein ◽  
Losartan Treatment

AbstractPrevious studies have shown that the renin–angiotensin system (RAS) is affected by adverse maternal nutrition during pregnancy. The aim of this study was to investigate the effects of a maternal low-protein diet on proinflammatory cytokines, reactive oxygen species and RAS components in kidney samples isolated from adult male offspring. We hypothesized that post-weaning losartan treatment would have beneficial effects on RAS activity and inflammatory and oxidative stress markers in these animals. Pregnant Sprague–Dawley rats were fed with a control (20% casein) or low-protein diet (LP) (6% casein) throughout gestation. After weaning, the LP pups were randomly assigned to LP and LP-losartan groups (AT1 receptor blockade: 10 mg/kg/day until 20 weeks of age). At 20 weeks of age, blood pressure levels were higher and renal RAS was activated in the LP group. We also observed several adverse effects in the kidneys of the LP group, including a higher number of CD3, CD68 and proliferating cell nuclear antigen-positive cells and higher levels of collagen and reactive oxygen species in the kidney. Further, our results revealed that post-weaning losartan treatment completely abolished immune cell infiltration and intrarenal RAS activation in the kidneys of LP rats. The prevention of augmentation of angiotensin (Ang II) concentration abolished inflammatory and fibrotic events, indicating that Ang II via the AT1 receptor is essential for pathological initiation. Our results suggest that the prenatal programming of hypertension is dependent on the up-regulation of local RAS and presence of immune cells in the kidney.

scholarly journals Renin Inhibition Attenuates Insulin Resistance, Oxidative Stress, and Pancreatic Remodeling in the Transgenic Ren2 Rat

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5643-5653 ◽  
Author(s):  
Javad Habibi ◽  
Adam Whaley-Connell ◽  
Melvin R. Hayden ◽  
Vincent G. DeMarco ◽  
Rebecca Schneider ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Renin Angiotensin System ◽  
Oxygen Species ◽  
Ang Ii ◽  
Angiotensin System ◽  
Nadph Oxidase Activity ◽  
Renin Inhibition

Emerging evidence indicates that pancreatic tissue expresses all components of the renin-angiotensin system. However, the functional role is not well understood. This investigation examined renin inhibition on pancreas structure/function in the transgenic Ren2 rat harboring the mouse renin gene, a model of tissue renin overexpression. Renin is the rate-limiting step in the generation of angiotensin II (Ang II), which stimulates the generation of reactive oxygen species in a variety of tissues. Overexpression of renin in Ren2 rats results in hypertension, insulin resistance, and cardiovascular and renal damage. Young (6–7 wk old) insulin-resistant male Ren2 and age-matched insulin sensitive Sprague Dawley rats were treated with the renin inhibitor, aliskiren (50 mg/kg·d by ip injection), or placebo for 21 d. At 21 d, the Ren2 demonstrated insulin resistance with increased islet insulin, Ang II, and reduced total insulin receptor substrate (IRS)-1, IRS-2, and Akt immunostaining. There was increased islet nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and subunits (p47phox and Rac1) as well as increased nitrotyrosine immunostaining (each P < 0.05). These functional abnormalities were associated with a disordered islet architecture; increased islet-exocrine interface, pericapillary fibrosis, and structurally abnormal mitochondria and content in endocrine and exocrine pancreas. In vivo treatment with aliskiren normalized systemic insulin resistance and islet insulin, Ang II, NADPH oxidase activity/subunits, and nitrotyrosine and improved total IRS-1 and Akt phosphorylation (each P < 0.05) as well as islet/exocrine structural abnormalities. Collectively, these data suggest that pancreatic functional/structural changes are driven, in part, by tissue renin-angiotensin system-mediated increases in NADPH oxidase and reactive oxygen species generation, abnormalities attenuated with direct renin inhibition.

scholarly journals Low-protein diet supplemented with ketoacids ameliorates proteinuria in 3/4 nephrectomised rats by directly inhibiting the intrarenal renin–angiotensin system

2016 ◽  
Vol 116 (9) ◽  
pp. 1491-1501 ◽  
Author(s):  
Jia-ying Zhang ◽  
Ying Yin ◽  
Li Ni ◽  
Quan Long ◽  
Li You ◽  
...  
Keyword(s):  
Mesangial Cells ◽  
Renin Angiotensin System ◽  
Renal Haemodynamics ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Low Protein ◽  
Ras Activation ◽  
Intrarenal Ras

AbstractLow-protein diet plus ketoacids (LPD+KA) has been reported to decrease proteinuria in patients with chronic kidney diseases (CKD). However, the mechanisms have not been clarified. As over-activation of intrarenal renin–angiotensin system (RAS) has been shown to play a key role in the progression of CKD, the current study was performed to investigate the direct effects of LPD+KA on intrarenal RAS, independently of renal haemodynamics. In this study, 3/4 subtotal renal ablated rats were fed 18 % normal-protein diet (Nx-NPD), 6 % low-protein diet (Nx-LPD) or 5 % low-protein diet plus 1 % ketoacids (Nx-LPD+KA) for 12 weeks. Sham-operated rats fed NPD served as controls. The level of proteinuria and expression of renin, angiotensin II (AngII) and its type 1 receptors (AT1R) in the renal cortex were markedly higher in Nx-NPD group than in the sham group. LPD+KA significantly decreased the proteinuria and inhibited intrarenal RAS activation. To exclude renal haemodynamic impact on intrarenal RAS, the serum samples derived from the different groups were added to the culture medium of mesangial cells. It showed that the serum from Nx-NPD directly induced higher expression of AngII, AT1R, fibronectin and transforming growth factor-β1 in the mesangial cells than in the control group. Nx-LPD+KA serum significantly inhibited these abnormalities. Then, proteomics and biochemical detection suggested that the mechanisms underlying these beneficial effects of LPD+KA might be amelioration of the nutritional metabolic disorders and oxidative stress. In conclusion, LPD+KA could directly inhibit the intrarenal RAS activation, independently of renal haemodynamics, thus attenuating the proteinuria in CKD rats.

Counter-regulatory effects played by the ACE – Ang II – AT1 and ACE2 – Ang-(1–7) – Mas axes on the reactive oxygen species-mediated control of vascular function: perspectives to pharmacological approaches in controlling vascular complications

VASA ◽  
2014 ◽  
Vol 43 (6) ◽  
pp. 404-414 ◽  
Author(s):  
Laena Pernomian ◽  
Larissa Pernomian ◽  
Carolina Baraldi Araújo Restini
Keyword(s):  
Reactive Oxygen Species ◽  
Vascular Tone ◽  
Vascular Dysfunction ◽  
Reactive Oxygen ◽  
Renin Angiotensin System ◽  
Electrolyte Balance ◽  
Oxygen Species ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin

The Renin-Angiotensin system plays an important role in the regulation of systemic blood pressure as well as in fluid and electrolyte balance. It is divided into two described axes, the ACE – Ang II – AT1 receptor, with Ang II as the main mediator, and the ACE2 – Ang-(1–7) – Mas receptor, with Ang-(1–7) responsible for the main effects. The main vascular effect induced by Ang II is contraction, while Ang-(1–7) includes relaxation in several vascular beds. Ang II also activates several cytokines that are important in the genesis of vascular inflammation and hypertrophy. In this context, Ang-(1–7) seems to have a protective role. Both AT1 and Mas receptors modulate, in different ways, the generation of, which are involved in the control of vascular tone and the genesis of vascular dysfunction triggered by several diseases, including diabetes mellitus, arterial hypertension and atherosclerosis. Thereby, this review presents an overview of the modulation played by the whole Renin-Angiotensin system on the reactive oxygen species-mediated control of vascular tone and the oxidative stress-elicited vascular dysfunction.

Erythropoietin in COVID-19-Induced Neuroinflammation; EPO Plus Losartan Might be Promising

2020 ◽  
Author(s):  
Reza Nejat ◽  
Ahmad Shahir Sadr ◽  
David Najafi
Keyword(s):  
Inflammatory Mediators ◽  
Renin Angiotensin System ◽  
Oxygen Species ◽  
Ang Ii ◽  
Angiotensin System ◽  
Intracellular Messengers ◽  
The Central Nervous System ◽  
Harmful Effects

Introduction: Neuroinflammation is the inflammatory reaction in the central nervous system (CNS) provoked by diverse insults. This phenomenon results in a cascade of release of inflammatory mediators and intracellular messengers such as reactive oxygen species. The elicited responses are the cause of many neurological and neurodegenerative disorders. Erythropoietin (EPO) has been considered effective in attenuating this inflammatory process in the CNS, yet its administration in COVID-19 needs meticulously designed studies. Discussion: Neuroinflammation in COVID-19 due to probable contribution of renin-angiotensin system dysregulation resulting in surplus of Ang II and owing to the synergistic interaction between this octapeptide and EPO needs special consideration. Both of these compounds increase intracellular Ca2+ which may induce release of cytokine and inflammatory mediators leading to aggravation of neuroinflammation. In addition, Ang II elevates HIF even in normoxia which by itself increases EPO. It is implicated that EPO and HIF may likely increase in patients with COVID-19 which makes administration of EPO to these patients hazardous. Furthermore, papain-like protease of SARS-CoV2 as a deubiquitinase may also increase HIF. Conclusion: It is hypothesized that administration of EPO to patients with COVID-19-induced neuroinflammation may not be safe and in case EPO is needed for any reason in this disease adding of losartan may block AT1R-mediated post-receptor harmful effects of Ang II in synergism with EPO. Inhibition of papain-like protease might additionally decrease HIF in this disease. More in vitro, in vivo and clinical studies are needed to validate these hypotheses.

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