Angiotensin-(1–7) in kidney disease: a review of the controversies

2012 ◽  
Vol 123 (6) ◽  
pp. 333-346 ◽  
Author(s):  
Danielle Zimmerman ◽  
Kevin D. Burns
Keyword(s):  
Angiotensin Ii ◽  
Kidney Disease ◽  
Kidney Diseases ◽  
Biological Effects ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Biologically Active ◽  
Renal Vasculature ◽  
Experimental Conditions ◽  
Enzymatic Pathways

Ang-(1–7) [angiotensin-(1–7)] is a biologically active heptapeptide component of the RAS (renin–angiotensin system), and is generated in the kidney at relatively high levels, via enzymatic pathways that include ACE2 (angiotensin-converting enzyme 2). The biological effects of Ang-(1–7) in the kidney are primarily mediated by interaction with the G-protein-coupled receptor Mas. However, other complex effects have been described that may involve receptor–receptor interactions with AT1 (angiotensin II type 1) or AT2 (angiotensin II type 2) receptors, as well as nuclear receptor binding. In the renal vasculature, Ang-(1–7) has vasodilatory properties and it opposes growth-stimulatory signalling in tubular epithelial cells. In several kidney diseases, including hypertensive and diabetic nephropathy, glomerulonephritis, tubulointerstitial fibrosis, pre-eclampsia and acute kidney injury, a growing body of evidence supports a role for endogenous or exogenous Ang-(1–7) as an antagonist of signalling mediated by AT1 receptors and thereby as a protector against nephron injury. In certain experimental conditions, Ang-(1–7) appears to paradoxically exacerbate renal injury, suggesting that dose or route of administration, state of activation of the local RAS, cell-specific signalling or non-Mas receptor-mediated pathways may contribute to the deleterious responses. Although Ang-(1–7) has promise as a potential therapeutic agent in humans with kidney disease, further studies are required to delineate its signalling mechanisms in the kidney under physiological and pathophysiological conditions.

scholarly journals Hypoxia and Hypoxia-Inducible Factors in Kidney Injury and Repair

Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 207 ◽  
Author(s):  
Shaoqun Shu ◽  
Ying Wang ◽  
Meiling Zheng ◽  
Zhiwen Liu ◽  
Juan Cai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Kidney Disease ◽  
Target Genes ◽  
Kidney Diseases ◽  
Kidney Injury ◽  
Hypoxia Inducible Factors ◽  
Experimental Conditions ◽  
Chronic Kidney Diseases ◽  
Kidney Fibrosis ◽  
Injury And Repair

Acute kidney injury (AKI) is a major kidney disease characterized by an abrupt loss of renal function. Accumulating evidence indicates that incomplete or maladaptive repair after AKI can result in kidney fibrosis and the development and progression of chronic kidney disease (CKD). Hypoxia, a condition of insufficient supply of oxygen to cells and tissues, occurs in both acute and chronic kidney diseases under a variety of clinical and experimental conditions. Hypoxia-inducible factors (HIFs) are the “master” transcription factors responsible for gene expression in hypoxia. Recent researches demonstrate that HIFs play an important role in kidney injury and repair by regulating HIF target genes, including microRNAs. However, there are controversies regarding the pathological roles of HIFs in kidney injury and repair. In this review, we describe the regulation, expression, and functions of HIFs, and their target genes and related functions. We also discuss the involvement of HIFs in AKI and kidney repair, presenting HIFs as effective therapeutic targets.

Anti-Hypertensive Potential and Epigenetics of Angiotensin II type 2 Receptor (AT2R)

2020 ◽  
Vol 16 ◽  
Author(s):  
Mayank Chaudhary
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Blood Pressure Regulation ◽  
Biologically Active ◽  
Pressure Regulation ◽  
Tissue Remodelling ◽  
Critical Pathway

Background:: Renin angiotensin system (RAS) is a critical pathway involved in blood pressure regulation. Octapeptide, angiotensin II (Ang aII), is biologically active compound of RAS pathway which mediates its action by binding to either angiotensin II type 1 receptor (AT1R) or angiotensin II type 2 receptor (AT2R). Binding of Ang II to AT1R facilitates blood pressure regulation whereas AT2R is primarily involved in wound healing and tissue remodelling. Objective:: Recent studies have highlighted additional role of AT2R to counter balance detrimental effects of AT1R. Activation of angiotensin II type 2 receptor using AT2R agonist has shown effect on natriuresis and release of nitric oxide. Additionally, AT2R activation has been found to inhibit angiotensin converting enzyme (ACE) and enhance angiotensin receptor blocker (ARB) activity. These findings highlight the potential of AT2R as novel therapeutic target against hypertension. Conclusion:: The potential role of AT2R highlights the importance of exploring additional mechanisms that might be crucial for AT2R expression. Epigenetic mechanisms including DNA methylation and histone modification have been explored vastly with relation to cancer but role of such mechanisms on expression of AT2R has recently gained interest.

scholarly journals AT1 and AT2 receptors modulate renal tubular cell necroptosis in angiotensin II-infused renal injury mice

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yongjun Zhu ◽  
Hongwang Cui ◽  
Jie Lv ◽  
Haiqin Liang ◽  
Yanping Zheng ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Renal Injury ◽  
Critical Role ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Tubular Cell ◽  
Tubular Damage ◽  
Renal Tubular Cell ◽  
Ang Ii ◽  
Renal Tubular

AbstractAbnormal renin-angiotensin system (RAS) activation plays a critical role in the initiation and progression of chronic kidney disease (CKD) by directly mediating renal tubular cell apoptosis. Our previous study showed that necroptosis may play a more important role than apoptosis in mediating renal tubular cell loss in chronic renal injury rats, but the mechanism involved remains unknown. Here, we investigate whether blocking the angiotensin II type 1 receptor (AT1R) and/or angiotensin II type 2 receptor (AT2R) beneficially alleviates renal tubular cell necroptosis and chronic kidney injury. In an angiotensin II (Ang II)-induced renal injury mouse model, we found that blocking AT1R and AT2R effectively mitigates Ang II-induced increases in necroptotic tubular epithelial cell percentages, necroptosis-related RIP3 and MLKL protein expression, serum creatinine and blood urea nitrogen levels, and tubular damage scores. Furthermore, inhibition of AT1R and AT2R diminishes Ang II-induced necroptosis in HK-2 cells and the AT2 agonist CGP42112A increases the percentage of necroptotic HK-2 cells. In addition, the current study also demonstrates that Losartan and PD123319 effectively mitigated the Ang II-induced increases in Fas and FasL signaling molecule expression. Importantly, disruption of FasL significantly suppressed Ang II-induced increases in necroptotic HK-2 cell percentages, and necroptosis-related proteins. These results suggest that Fas and FasL, as subsequent signaling molecules of AT1R and AT2R, might involve in Ang II-induced necroptosis. Taken together, our results suggest that Ang II-induced necroptosis of renal tubular cell might be involved both AT1R and AT2R and the subsequent expression of Fas, FasL signaling. Thus, AT1R and AT2R might function as critical mediators.

scholarly journals CD73 Overexpression in Podocytes: A Novel Marker of Podocyte Injury in Human Kidney Disease

2021 ◽  
Vol 22 (14) ◽  
pp. 7642
Author(s):  
Zoran V. Popovic ◽  
Felix Bestvater ◽  
Damir Krunic ◽  
Bernhard K. Krämer ◽  
Raoul Bergner ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Kidney Diseases ◽  
Kidney Injury ◽  
Membranous Glomerulonephritis ◽  
Human Kidney ◽  
Protective Role ◽  
Control Group ◽  
Podocyte Injury ◽  
Ccr2 Expression ◽  
Cd73 Expression

The CD73 pathway is an important anti-inflammatory mechanism in various disease settings. Observations in mouse models suggested that CD73 might have a protective role in kidney damage; however, no direct evidence of its role in human kidney disease has been described to date. Here, we hypothesized that podocyte injury in human kidney diseases alters CD73 expression that may facilitate the diagnosis of podocytopathies. We assessed the expression of CD73 and one of its functionally important targets, the C-C chemokine receptor type 2 (CCR2), in podocytes from kidney biopsies of 39 patients with podocytopathy (including focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), membranous glomerulonephritis (MGN) and amyloidosis) and a control group. Podocyte CD73 expression in each of the disease groups was significantly increased in comparison to controls (p < 0.001–p < 0.0001). Moreover, there was a marked negative correlation between CD73 and CCR2 expression, as confirmed by immunohistochemistry and immunofluorescence (Pearson r = −0.5068, p = 0.0031; Pearson r = −0.4705, p = 0.0313, respectively), thus suggesting a protective role of CD73 in kidney injury. Finally, we identify CD73 as a novel potential diagnostic marker of human podocytopathies, particularly of MCD that has been notorious for the lack of pathological features recognizable by light microscopy and immunohistochemistry.

scholarly journals Cigarette smoke inhalation aggravates diabetic kidney injury in rats

2019 ◽  
Vol 8 (6) ◽  
pp. 964-971 ◽  
Author(s):  
Songling Jiang ◽  
Do Van Quan ◽  
Jae Hyuck Sung ◽  
Moo-Yeol Lee ◽  
Hunjoo Ha
Keyword(s):  
Kidney Disease ◽  
Cigarette Smoke ◽  
Density Lipoprotein ◽  
Kidney Injury ◽  
Diabetic Rats ◽  
Smoke Inhalation ◽  
Lipoprotein Cholesterol ◽  
Sprague Dawley ◽  
Experimental Conditions ◽  
Diabetic Kidney

Abstract Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease. Epidemiological studies have demonstrated that cigarette smoke or nicotine is a risk factor for the progression of chronic kidney injury. The present study analyzed the kidney toxicity of cigarette smoke in experimental rats with DKD. Experimental diabetes was induced in 7-week-old Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin (60 mg kg−1). Four weeks after the induction of diabetes, rats were exposed to cigarette smoke (200 μg L−1), 4 h daily, and 5 days per week for 4 weeks. Cigarette smoke did not affect the levels of plasma glucose, hemoglobin A1c, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol or non-esterified fatty acids in both control and diabetic rats under the experimental conditions. Cigarette smoke, however, significantly increased diabetes-induced glomerular hypertrophy and urinary kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) excretion, suggesting exacerbation of diabetic kidney injury. Cigarette smoke promoted macrophage infiltration and fibrosis in the diabetic kidney. As expected, cigarette smoke increased oxidative stress in both control and diabetic rats. These data demonstrated that four weeks of exposure to cigarette smoke aggravated the progression of DKD in rats.

Renin-angiotensin system and aldosterone secretion during aortic constriction in the rat

1977 ◽  
Vol 232 (5) ◽  
pp. F434-F437 ◽  
Author(s):  
R. H. Freeman ◽  
J. O. Davis ◽  
W. S. Spielman
Keyword(s):  
Angiotensin Ii ◽  
Perfusion Pressure ◽  
Renin Angiotensin System ◽  
Renal Perfusion ◽  
Bilateral Nephrectomy ◽  
Aortic Constriction ◽  
Aldosterone Secretion ◽  
Experimental Conditions ◽  
Angiotensin System ◽  
Renin Angiotensin

Suprarenal aortic constriction sufficient to reduce renal perfusion pressure by approximately 50% increased aldosterone secretion in anesthetized rats pretreated with dexamethasone. Bilateral nephrectomy under the same experimental conditions blocked the aldosterone response. Additionally, [1-sarcosine, 8-alanine]angiotensin II blocked the response in aldosterone secretion to aortic constriction in dexamethasone-treated rats. Finally, in rats hypophysectomized to exclude the influence of ACTH, the aldosterone response to aortic constriction was blocked by [1-sarcosine, 8-alanine]angiotensin II. The results indicate that angiotensin II increased aldosterone secretion during aortic constriction in the rat. These observations, along with those reported previously in sodium-depleted rats, point to an important overall role for the renin-angiotensin system in the control of aldosterone secretion in the rat.

Abstract 016: Profound and Sustained Amplification of Circulating ACE2 Activity Does Not Protect Diabetic Mice from Kidney Disease

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Jan Wysocki ◽  
Minghao Ye ◽  
Ahmed M Khattab ◽  
Yashpal Kanwar ◽  
Mark Osborn ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Diabetic Mice ◽  
Diabetic Kidney ◽  
Over Expression ◽  
Akita Mice

ACE2 is a monocarboxypeptidase that by converting AngII to Ang1-7 should down-regulate the renin-angiotensin system and therefore provide a means to therapeutically target diabetic kidney disease, a condition where the kidney RAS is overactive. Previous work indicated that soluble human recombinant (r)ACE2 administration for 4 weeks attenuated kidney injury in diabetic Akita mice. Whether such effect of rACE2 can be confirmed and attributed to augmented ACE2 activity is uncertain because chronic use of human rACE2 in mice induces immunogenicity and the development of antibodies that neutralize serum ACE2 activity. To examine the effect of chronic amplification of circulating ACE2 on kidney injury caused by STZ-induced diabetes and to circumvent the immunogenicity arising from xenogeneic ACE2, ACE2 of mouse origin was administered to mice using either daily i.p. injections (1 mg/kg) of mrACE2 for 4 weeks or after 20 weeks of ACE2 mini-circle (MC) (10-30ug/mouse) administration. MC provides a form of gene delivery that is resistant to gene silencing and, in addition, greatly optimizes long-term in vivo overexpression of proteins of interest. ACE2MC resulted in a profound and sustained increase in serum ACE2 activity (2.4±0.3 vs. 497±135 RFU/ul/hr, p<0.01) but kidney ACE2 activity was unchanged (17.4±1.3 vs. 19.0±0.8 RFU/ug prot/hr). mACE2-treated mice injected with STZ developed diabetes similar to sham mice injected with STZ. Systolic BP was not different between non-diabetic mice, sham STZ-mice, and STZ-mice receiving mACE2 by either i.p. mrACE2 or ACE2MC. Urinary albumin was similarly increased in sham STZ-mice and in STZ-mice receiving mACE2. Glomerular mesangial score and glomerular cellularity were both increased to a similar extent in sham STZ-mice and in STZ-mice with mACE2 administration, as compared to non-diabetic controls. In conclusion, profound and long-term augmentation of ACE2 activity confined to the circulation is not sufficient to attenuate glomerular pathology and albuminuria in STZ-induced diabetic kidney disease probably because of lack of kidney delivery of ACE2. Strategies to achieve over-expression of ACE2 at the kidney level are needed to demonstrate a beneficial effect of this enzyme on diabetic kidney disease.

scholarly journals Circular RNAs as Novel Diagnostic Biomarkers and Therapeutic Targets in Kidney Disease

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianwen Yu ◽  
Danli Xie ◽  
Naya Huang ◽  
Qin Zhou
Keyword(s):  
Kidney Disease ◽  
Kidney Diseases ◽  
Expression Patterns ◽  
Therapeutic Targets ◽  
Kidney Injury ◽  
Renal Diseases ◽  
Circular Rnas ◽  
Specific Expression ◽  
Glomerular Diseases ◽  
Diagnosis And Prognosis

Circular RNAs (circRNAs) are a novel type of non-coding RNAs that have aroused growing attention in this decade. They are widely expressed in eukaryotes and generally have high stability owing to their special closed-loop structure. Many circRNAs are abundant, evolutionarily conserved, and exhibit cell-type-specific and tissue-specific expression patterns. Mounting evidence suggests that circRNAs have regulatory potency for gene expression by acting as microRNA sponges, interacting with proteins, regulating transcription, or directly undergoing translation. Dysregulated expression of circRNAs were found in many pathological conditions and contribute to the pathogenesis and progression of various disorders, including renal diseases. Recent studies have revealed that circRNAs may serve as novel reliable biomarkers for the diagnosis and prognosis prediction of multiple kidney diseases, such as renal cell carcinoma (RCC), acute kidney injury (AKI), diabetic kidney disease (DKD), and other glomerular diseases. Furthermore, circRNAs expressed by intrinsic kidney cells are shown to play a substantial role in kidney injury, mostly reported in DKD and RCC. Herein, we review the biogenesis and biological functions of circRNAs, and summarize their roles as promising biomarkers and therapeutic targets in common kidney diseases.

scholarly journals SARS-CoV-2 infection in hospitalized pediatric patients with kidney disease

2020 ◽  
Vol 10 (3) ◽  
Author(s):  
Flávia Silveira ◽  
Káthia Zuntini ◽  
Márcia Silveira ◽  
Lohanna Tavares ◽  
Juliana Mendes ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Pediatric Patients ◽  
Kidney Diseases ◽  
Pediatric Population ◽  
Transplant Rejection ◽  
Kidney Injury ◽  
Underlying Disease ◽  
Great Divergence ◽  
Stage 1

OBJECTIVES: This study aims to present the confirmed cases of SARS-CoV-2 infection in pediatric patients with chronic and acute kidney diseases admitted to a tertiary pediatric hospital. METHODS: Descriptive and retrospective observational study with all children hospitalized between March and June 2020 who had, simultaneously, SARS-CoV-2 infection and renal pathologies. Of this total of patients, those who had another underlying disease besides the renal disease were excluded. RESULTS: During the period, nine children with kidney disease were admitted to the hospital and had infection confirmed by the new coronavirus through positive RT-PCR. Regarding the underlying disease, seven had only kidney disease, three of whom had stage 5 chronic kidney disease; one, with stage 1 chronic kidney disease; one, with cortic-sensitive nephrotic syndrome; and two, with acute kidney injury. Two patients in this study had already undergone kidney transplantation, used immunosuppressants and had their doses reduced due to the infectious condition. Only one required oxygen therapy and transfer to the intensive care unit, but was not intubated and returned to the ward within 24 hours. CONCLUSIONS: According to the cases described, the pediatric population with kidney disease, including those using immunosuppressants due to acute transplant rejection, seems to evolve without severe COVID-19, therefore there is no great divergence in relation to the population of the same healthy age group.

Abstract 188: Loss of Renal Prolyl Carboxypeptidase in Mice With Chronic Kidney Disease

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Orly Leiva ◽  
Khalid M Elased ◽  
Mariana Morris ◽  
Nadja Grobe
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Protein Expression ◽  
Western Blot ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Left Renal Artery ◽  
Renal Tubules ◽  
Ang Ii ◽  
Chronic Kidney Injury

There are 26 million adults with chronic kidney disease (CKD) in the U.S. and the incidence continues to increase. It is well documented that the activation of the renin angiotensin system and the elevated formation of angiotensin (Ang) II both contribute to renal pathophysiology in CKD. Emerging evidence suggests that the Ang II degrading protease prolyl carboxypeptidase (PCP) is renoprotective. Thus, we investigated protein expression and activity of renal PCP using immunofluorescence, western blot and mass spectrometry in a mouse model of CKD. Renal injury in male C57Bl6 mice was caused by constriction of the left renal artery using silver clips (2K1C-method). Blood pressure measurements by radiotelemetry revealed a significant increase of 36.1 ± 3.9 mm Hg in 2K1C animals compared with control animals 1 week after clip placement (p<0.0001). Using immunofluorescence and confocal microscopy, PCP was localized in the Bowman’s capsule of the glomerulus and in proximal and distal renal tubules. Western blot analysis showed PCP was significantly reduced in clipped 2K1C kidneys compared to unclipped kidneys of the 2K1C mice or compared to control mice (clipped 0.04 ± 0.02 vs unclipped 0.58 ± 0.16 vs control 0.65 ± 0.18, p < 0.05). In addition, renal PCP enzyme activity was found to be markedly reduced in 2K1C kidneys as assessed by mass spectrometric based enzyme assays (clipped 37.1 ± 4.3 pmol Ang-(1-7)/h/μg vs unclipped 77.3 ± 12.3 pmol Ang-(1-7)/h/μg vs control 120.7 ± 14.7 pmol Ang-(1-7)/h/μg, p < 0.01). In contrast, protein expression of prolyl endopeptidase, another enzyme capable of converting Ang II into Ang-(1-7), was not affected. Notably, renal pathologies were exacerbated in the 2K1C model as revealed by a significant increase in mesangial expansion (clipped 34.6 ± 3.1 vs unclipped 52.1 ± 4.0 vs control 1.2 ± 2.1, p < 0.0001) and renal fibrosis (clipped 57.5 ± 0.9 vs unclipped 33.0 ± 0.7 vs control 3.3 ± 0.2, p < 0.0001). Results suggest that PCP is suppressed in chronic kidney injury and that this downregulation may attenuate renoprotective effects via impaired Ang II degradation by PCP. Therefore, Ang II processing by PCP may have clinical implications in patients with renal pathologies.

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