angiotensinogen and Polycystic-Kidney--Autosomal-Dominant

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited disease of the kidneys and is marked by progressive cyst growth and decline in kidney function, resulting in end-stage renal disease (ESRD). Hypertension is thought to be a significant modifying factor in the progression of renal failure in ADPKD. A number of genetic variations involved in renin-angiotensin-aldosterone system (RAAS) pathway genes have clinical or physiological impacts on pathogenesis of hypertension-induced ESRD in ADPKD. Information on RAAS pathway gene polymorphisms and their association with ESRD and ADPKD, published till March 2013, was collected using MEDLINE search. The present review deals with RAAS gene polymorphisms focused on hypertension-induced ESRD in ADPKD in different populations. The results were inconclusive and limited by heterogeneity in the study designs and the population stratification. In lieu of applying next generation sequencing technologies to study complex diseases, it is also possible to apply the same to unravel the complexity of ESRD in ADPKD.

Topics: Angiotensinogen; Cytochrome P-450 CYP11B2; Humans; Hypertension; Kidney Failure, Chronic; Nitric Oxide Synthase Type III; Peptidyl-Dipeptidase A; Polycystic Kidney, Autosomal Dominant; Polymorphism, Genetic; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Renin; Renin-Angiotensin System

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder leading to deterioration of kidney function and end stage kidney disease (ESKD). A number of molecular processes are dysregulated in ADPKD but the exact mechanism of disease progression is not fully understood. We measured protein biomarkers being linked to ADPKD-associated molecular processes via ELISA in urine and serum in a cohort of ADPKD patients as well as age, gender and eGFR matched CKD patients and healthy controls. ANOVA and

Topics: Adult; Aged; Aged, 80 and over; Angiotensinogen; Apelin; Arginine Vasopressin; Biomarkers; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Polycystic Kidney, Autosomal Dominant; Vascular Endothelial Growth Factor A

The intrarenal renin angiotensin system (RAS) is activated in polycystic kidney disease. We have recently shown in the Pkd1 mouse that Gen 2 antisense oligonucleotide (ASO), which suppresses angiotensinogen (Agt) synthesis, is efficacious in slowing kidney cyst formation compared with lisinopril. The aim of this current study was to determine 1) if unilateral nephrectomy accelerates cystogenesis in Pkd1 mice (as previously shown in cilia knockout mice) and 2) whether Agt ASO can slow the progression in this accelerated cystic mouse model. Adult Pkd1 conditional floxed allele mice expressing cre were administered tamoxifen, resulting in global knockout of Pkd1. Three weeks after tamoxifen injection, mice underwent left unilateral nephrectomy. Mice were then treated with Agt ASO (75 mg/kg per week) or aliskiren (20 mg/kg per day)+Agt ASO or control for 8 wk. Unilateral nephrectomy accelerated kidney cyst formation compared with nonnephrectomized mice. Both Agt ASO and Aliskiren+Agt ASO treatments significantly reduced plasma and urinary Agt levels. Blood pressure was lowest in Aliskiren+Agt ASO mice among all treatment groups, and the control group had the highest blood pressure. All mice developed significant kidney cysts at 8 wk after nephrectomy, but Agt ASO and Aliskiren+Agt ASO groups had fewer kidney cysts than controls. Renal pAkt, pS6 levels, and apoptosis were significantly suppressed in those receiving Agt ASO compared with controls. These results indicate that suppressing Agt using an ASO slowed the progression of accelerated cystic kidney disease induced by unilateral nephrectomy in Pkd1 mice by suppressing intrarenal RAS, mammalian target of rapamycin pathway, and cell proliferation.

Topics: Amides; Angiotensinogen; Animals; Apoptosis; Cell Proliferation; Disease Models, Animal; Disease Progression; ErbB Receptors; Female; Fumarates; Genetic Predisposition to Disease; Kidney; Male; Mice, Knockout; Nephrectomy; Oligonucleotides, Antisense; Phenotype; Polycystic Kidney, Autosomal Dominant; Renin; Renin-Angiotensin System; Time Factors; TOR Serine-Threonine Kinases; TRPP Cation Channels

In autosomal dominant polycystic kidney disease (ADPKD), activation of the renin-angiotensin aldosterone system (RAAS) may contribute to hypertension and disease progression. Although previous studies have focused on circulating RAAS components, preliminary evidence suggests that APDKD may increase urinary RAAS components. Therefore, our aim was to analyze circulating and urinary RAAS components in ADPKD. We cross-sectionally compared 60 patients with ADPKD with 57 patients with non-ADPKD chronic kidney disease (CKD). The two groups were matched by sex, estimated glomerular filtration rate (eGFR), blood pressure, and RAAS inhibitor use. Despite similar plasma levels of angiotensinogen and renin, urinary angiotensinogen and renin excretion were five- to sixfold higher in ADPKD (

Topics: Adult; Aged; Angiotensinogen; Biomarkers; Cross-Sectional Studies; Female; Glomerular Filtration Rate; Humans; Kidney; Male; Middle Aged; Organ Size; Polycystic Kidney, Autosomal Dominant; Renal Insufficiency, Chronic; Renin; Renin-Angiotensin System

Autosomal dominant polycystic kidney disease (ADPKD) is a multisystemic and progressive disorder characterized by cyst formation and kidney enlargement and ultimately renal failure. Reduction of CKD progression in the ADPKD by pharmacological blockade of the renin-angiotensin-aldosterone system (RAAS) using ACE inhibitors indicated the involvement of RAAS pathway in the progression of CKD. The aim of the present study is to investigate the role of angiotensinogen tag-single nucleotide polymorphisms (AGT tag-SNPs) in progression of CKD.. Twelve AGT tag-SNPs were genotyped in 102 ADPKD patients and 106 non-ADPKD subjects using FRET-based KASPar method. Genotypes and haplotypes were compared between ADPKD and controls. The effect of genotypes and hypertension on CKD progression was assessed using univariate and multivariate logistic regression. Mantel-Haenszel (M-H) stratified analysis was performed to study the interaction between CKD stages and hypertension.. Of the twelve tag-SNPs analyzed, only rs11122578 SNP deviated Hardy-Weinberg equilibrium in controls. Significant association between two AGT polymorphisms (rs11122577 and rs4762) and ADPKD was observed. Analysis of linkage disequilibrium revealed two haplotype blocks and haplotypes are not associated with ADPKD. The univariate analysis revealed that the age, hypertension, family history of diabetes and AGT rs4762 contributed to the progression of CKD in ADPKD. The modifier effect of these factors remained even after controlling other variables in multivariate analysis.. The results of our study suggest significant association between Thr207Met polymorphism of AGT and CKD progression and acts as an effect modifier of renal disease progression in ADPKD.

Topics: Adult; Angiotensinogen; Case-Control Studies; Disease Progression; Female; Humans; Male; Middle Aged; Polycystic Kidney, Autosomal Dominant; Polymorphism, Single Nucleotide; Renal Insufficiency, Chronic

Renal cyst enlargement is associated with the activation of both the circulating and intrarenal renin-angiotensin systems. Angiotensinogen (AGT) is the substrate for renin. The aim of the present study was to determine the effect of AGT inhibition on renal cyst enlargement. An AGT antisense oligonucleotide (ASO) that selectively inhibits AGT mRNA was injected once weekly in PKD2WS25 mice [an orthologous model of human autosmal dominant polycystic kidney disease (PKD) involving mutation of the Pkd2 gene] from 4 to 16 wk of age. The AGT ASO resulted in a 40% decrease in AGT RNA in the kidney, a 60% decrease in AGT RNA in the liver, and a significant decrease in AGT protein in the kidney and serum. The AGT ASO resulted in a significant decrease in kidney size, cyst volume density, and blood urea nitrogen. The AGT ASO resulted in a significant decrease in transforming growth factor-β and interstitial fibrosis in the kidney. Mice treated with the AGT ASO had a significant decrease in proinflammatory cytokines [chemokine (C-X-C motif) ligand (CXCL)1 and IL-12] in the kidney. Cluster of differentiation (CD)36 is a scavenger receptor found on tubular cells that can activate the renin-angiotensin system. Administration of a CD36 ASO had no effect on PKD and kidney function, suggesting that the effect of the AGT ASO is independent of CD36. In summary, AGT inhibition resulted in significant decreases in kidney size and cyst volume and an improvement in kidney function in PKD mice. The AGT ASO resulted in a decrease in transforming growth factor-β, interstitial fibrosis, and the proinflammatory cytokines CXCL1 and IL-12 in the kidney.

Topics: Angiotensinogen; Animals; Blood Urea Nitrogen; CD36 Antigens; Cells, Cultured; Chemokine CXCL1; Disease Models, Animal; Down-Regulation; Female; Fibrosis; Genetic Therapy; Interleukin-12; Kidney; Male; Mice, Inbred C57BL; Mice, Mutant Strains; Mutation; Oligonucleotides, Antisense; Polycystic Kidney, Autosomal Dominant; Recovery of Function; RNA, Messenger; Transforming Growth Factor beta; TRPP Cation Channels

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary kidney diseases that frequently result in renal failure. In this cross-sectional observational cohort study, we evaluated urinary angiotensinogen (AGT) as a potential biomarker to assess renal function in ADPKD.. Urinary AGT was measured in 233 ADPKD patients and its association with estimated glomerular filtration rate (eGFR) and height-adjusted total kidney volume (htTKV) were evaluated. The localization of AGT and other renin-angiotensin system (RAS)-related molecules were identified using immunohistochemistry in human ADPKD tissues.. Baseline urinary AGT/Cr was negatively correlated with CKD-EPI eGFR (r(2) = 0.162, P < 0.001) and positively correlated with htTKV (r(2) = 0.107, P < 0.001). Both urinary AGT/Cr and plasma renin activity levels were significantly elevated in hypertensive ADPKD patients. Among hypertensive subjects, urinary AGT/Cr was significantly increased in the advanced CKD stages (III-V) compared to early CKD stages (I-II) (28.6 ± 60.3 vs. 93.2 ± 139.3 μg/g, P < 0.001). Immunohistochemical study showed strong expression of AGT along the cyst-lining epithelial cells as well as the nearby compressed tubular epithelial cells.. Our results suggested that urinary AGT/Cr may be a valuable biomarker for renal damage in ADPKD since intrarenal ischemic insults induced by cyst growth and subsequent intrarenal RAS activation may play a potential role in the development of hypertension and renal dysfunction in ADPKD.

Topics: Adult; Angiotensinogen; Biomarkers; Cohort Studies; Creatinine; Cross-Sectional Studies; Epithelial Cells; Female; Glomerular Filtration Rate; Humans; Hypertension; Immunohistochemistry; Kidney; Kidney Tubules; Male; Middle Aged; Organ Size; Polycystic Kidney, Autosomal Dominant; Renal Insufficiency, Chronic; Renin; Severity of Illness Index

Although several lines of evidence suggest that renin angiotensin system (RAS) proteins are synthesized by cyst epithelium and dilated tubules, role of intrarenal RAS in the progression of otozomal dominant polycystic kidney disease (ADPKD) is not well known. We aimed to study the levels and clinical correlations of urinary angiotensinogen (UAGT) in normotensive ADPKD patients compared with age- and sex-matched healthy subjects.. The study included 20 normotensive ADPKD patients (F/M: 11/9) and 20 age and sex matched healthy controls (F/M: 9/11). Diagnosis of ADPKD was made based on Ravine criteria. Twenty-four hours ambulatory blood pressure monitoring (ABPM) was performed. Serum concentrations of creatinine, Na, K, uric acid, and urinary concentrations of Na, K, uric acid, creatinine, protein and albumin were measured. UAGT were measured via commercially available ELISA kit.. ADPKD patients had higher urinary albumin:creatinine ratio (UAIb/UCrea) than healthy controls (p < 0.01). UAGT/UCrea levels significantly positively correlated with urinary protein: creatinine ratio (UPro/UCrea) (r = 0.785, p = 0.01), and UAIb/UCrea (r = 0.681, p = 0.01) in normotensive ADPKD patients.. This pilot study demonstrates that UAGT levels tend to be elevated and are correlated with proteinuria and albuminuria in normotensive ADPKD patients during relatively early stages of the disease.

Topics: Adult; Angiotensinogen; Blood Pressure; Case-Control Studies; Female; Humans; Male; Pilot Projects; Polycystic Kidney, Autosomal Dominant; Young Adult

Early onset of hypertension and its consequences account for the great majority of deaths in patients with autosomal dominant polycystic kidney disease (ADPKD). Renin-angiotensin system (RAS) components have been shown in ADPKD kidneys independent of systemic RAS. Thus, we examined the urinary angiotensinogen (UAGT) levels as a biomarker of intrarenal RAS status in ADPKD patients with/without hypertension and healthy subjects.. Eighty-four ADPKD patients (43 with hypertension and 41 without hypertension) and 40 healthy controls were studied cross-sectionally. Patients with glomerular filtration rate <60 ml/min were excluded from the study. Hypertension was diagnosed with ambulatory blood pressure monitoring. Urinary and plasma concentration of angiotensinogen, spot urine microprotein and creatinine (UCre) levels were recorded for each participant.. UAGT/UCre levels were higher in hypertensive ADPKD patients (23.7 ± 8.4) compared with normotensive ADPKD patients (16.6 ± 5.2) and healthy controls (6.9 ± 3.3; p < 0.001). In univariate analysis, UAGT correlated with systolic blood pressure, diastolic blood pressure (DBP) and proteinuria. The independence of these correlations was analyzed in a regression model, and UAGT was shown to be significantly predicted by proteinuria and DBP.. Intrarenal RAS activation which is monitored by UAGT levels clinically may be a harbinger of hypertension and kidney disease in ADPKD patients.

Topics: Adult; Angiotensinogen; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Case-Control Studies; Cohort Studies; Creatinine; Cross-Sectional Studies; Female; Glomerular Filtration Rate; Humans; Hypertension; Male; Middle Aged; Polycystic Kidney, Autosomal Dominant; Proteinuria; Regression Analysis; Renin-Angiotensin System

Hypertension is a common complication of autosomal dominant polycystic kidney disease (ADPKD), often present before the onset of renal failure. A role for the renin-angiotensin system (RAS) has been proposed, but studies of systemic RAS have failed to show a correlation between plasma renin activity and blood pressure in ADPKD. Ectopic renin expression by cyst epithelium was first reported in 1992 (Torres VE, Donovan KA, Sicli G, Holley KE, Thibodeau ST, Carretero OA, Inagami T, McAteer JA, and Johnson CM. Kidney Int 42: 364-373, 1992). It is not known, however, whether other RAS components are also expressed by cysts in ADPKD. We show that, in addition to renin, angiotensinogen (AGT) is produced by some cysts and dilated tubules. Angiotensin-converting enzyme, ANG II type 1 receptor, and ANG II peptide are also present within cysts and in many tubules; and some cyst fluids contain high ANG II concentrations. Additionally, cyst-derived cells in culture continue to express the components of the RAS at both the protein and mRNA levels. We further show that renin is expressed primarily in cysts of distal tubule origin and in cyst-derived cells with distal tubule characteristics, whereas AGT is expressed primarily in cysts of proximal tubule origin and in cyst-derived cells with proximal tubule characteristics. Renin production by cyst-derived cells appears to be regulated by extracellular Na+ concentration. Based on these observations, we propose a model of an autocrine/paracrine RAS in polycystic kidney disease, whereby overactivity of the intrarenal system results in sustained increases in intratubular ANG II concentrations.

Topics: Angiotensin II; Angiotensinogen; Animals; Antibodies; Blotting, Western; Cells, Cultured; Humans; Hypertension, Renal; Kidney; Peptidyl-Dipeptidase A; Polycystic Kidney, Autosomal Dominant; Rabbits; Receptor, Angiotensin, Type 1; Renin; Renin-Angiotensin System; RNA, Messenger

Glomerular filtration rate decline (GFRd) is variable in autosomic dominant polycystic kidney disease (ADPKD). In 88 ADPKD patients, GFRd was assessed by 1/S(Cr) and compared with the association to AT1A1166C (AT1R), AGTM235T (angiotensinogen) and ecNOSGlu298Asp (NO endothelial synthase) polymorphisms. Age at S(Cr) values of 2 and 6 mg/dl were assumed as beginning of progressive phase (A2) and end-stage-renal disease (A6), respectively. Polymorphisms were studied by PCR-RFLP. The group as a whole showed GFRd (ml/min/year) of 6.9+/-0.5; A2 and A6 of 48.9+/-1.3 and 55.0+/-1.4 years and mean arterial pressure of 111.2+/-1.2 mmHg. When A6 was considered, two populations were defined (< or = and > 55 years). In < or = 55 (assumed as PKD1 phenotype) (n=42), A2 and A6 of the AT1 1166CC genotype were 36.0+/-1.2 and 41.4+/-0.9 years vs AA-AC (42.8+/-1.0 and 47.5+/-0.8, p<0.001). A2 and A6 of the ecNOS298Asp/Asp genotype were 34.8+/-1.5 and 41.1+/-0.6 years vs. Glu/Glu-Glu/Asp (42.4+/-0.9 and 47.1+/-0.8, p<0.02). In AGT235TT genotype, GFRd was 12.4+/-2.2 ml/min/year vs MM-MT (7.9+/-0.7, p<0.03). This difference was also observed when all ADPKD patients were considered (TT: 11.02+/-1.5 vs. MM-MT: 6.44+/-0.5 ml/ min/year, p<0.003). AT1 1166CC and ecNOS 298Asp/Asp are associated with earlier A2 and A6 whereas AGT 235TT induce twofold increase in GFRd, suggesting that RAS and ecNOS are involved in ADPKD progression.

Topics: Adult; Angiotensinogen; Animals; Disease Progression; Genotype; Glomerular Filtration Rate; Humans; Kidney Failure, Chronic; Mice; Middle Aged; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Phenotype; Polycystic Kidney, Autosomal Dominant; Polymorphism, Genetic; Regression Analysis; Renin-Angiotensin System

Autosomal dominant polycystic kidney disease (ADPKD), a common genetic disease, is characterized by the development of hypertension and end stage renal disease. An increase in the activity of the renin-angiotensin system, due to a renal ischemia caused by cyst expansion, contributes to the development of hypertension and renal failure in ADPKD. Recently, the angiotensinogen (AGT) gene, M235T, and angiotensin II type 1 receptor (ATR) gene, A1166C, polymorphisms have been associated with the susceptibility to develop hypertension and renal disease. We hypothesized that the AGT M235T and ATR A1166C polymorphisms could account for some of the variability in the progression of ADPKD. Genotyping was performed in 108 adult patients with ADPKD, and 105 normotensive healthy controls, using PCR and restriction digestion. We analyzed the effects of the AGT M235T and ATR A1166C polymorphisms on hypertension and age at the end stage renal disease (ESRD). Of the 108 patients with ADPKD, 64 (59%) had hypertension and 24 (22%) reached the ESRD. The prevalence of hypertension were; [MM+MT], [TT] genotypes, 60%, 59% (p=1.00); [AA], [AC+CC] genotypes, 60%, 50% respectively (p=0.54). The ages at the onset of ESRD were; [MM+MT], [TT] genotypes, 50 +/- 9 years, 56 +/- 8 years (p=0.07); [AA], [AC+CC] genotypes, 54 +/- 8 years, 52 +/- 14 years, respectively (p=0.07). There were no differences in the prevalence of hypertension and the ages at the ESRD in relation to the AGT M235T and ATR A1166C polymorphisms. We suggest that the AGT and ATR gene polymorphisms would not have an effect on hypertension or the ESRD in ADPKD.

Topics: Adult; Age of Onset; Angiotensinogen; Disease Progression; Female; Humans; Hypertension; Kidney Failure, Chronic; Male; Middle Aged; Polycystic Kidney, Autosomal Dominant; Polymorphism, Genetic; Prevalence; Receptor, Angiotensin, Type 1; Receptors, Angiotensin