Renin-angiotensin System Genes Research Articles

Polymorphism of genes involved in the regulation of blood pressure in elderly residents of the Arkhangelsk region

BACKGROUND: Living in the northern climate is associated with increased cardiovascular stress, which highlights the necessity for the study of candidate genes associated with the risk of cardiovascular diseases in both the native population and newcomers. Polymorphic loci of the renin-angiotensin system, NO-synthase, and endothelin-1 system genes have been identified as contributors to cardiovascular dysfunction and age-related blood pressure shifts. It is therefore crucial to assess the genetic polymorphism in the elderly population. AIM: To compare frequencies of gene alleles and genotypes involved in blood pressure regulation, including angiotensinogen AGT (rs699 and rs4762), angiotensin 2 type 1 receptor AGTR1 (rs5186), angiotensin converting enzyme ACE (rs4646994), endothelial NO synthase NOS3 and endothelin-1 EDN1 (rs5370) genes, in the native and non-native elderly population of the Arkhangelsk region. MATERIALS AND METHODS: A cross-sectional study was conducted in a random sample of Arkhangelsk residents between the ages of 60 and 74 years (N=604, with 36.4% of males). The molecular genetic analysis was conducted to determine the alleles and genotypes of six genes that are involved in blood pressure regulation. The Stata 18.0 software was used to assess the deviations of empirical genotype distributions from the predicted Hardy–Weinberg equilibrium and to compare the empirical distributions between the study groups. RESULTS: Alleles associated with the risk of cardiovascular diseases were minor in the study population. The genotype frequency distributions for the analyzed genetic variants were consistent with the Hardy–Weinberg principle, with the exception of the T704C variant of the AGT gene (rs699) in the native participants. The allele and genotype frequency distributions in the study sample were found to be similar to those reported worldwide and in European Russia. One exception was AGTR1 gene A1166C frequencies, with their 95% confidence intervals falling below the global level for both native and non-native elderly residents of the Arkhangelsk region. This may suggest that this allele is a selection variant associated with adaptation to the climate of the northern regions. CONCLUSION: The genetic polymorphism in blood pressure regulation was found to be similar between the native and non-native populations of the Arkhangelsk region. However, the AGTR1 gene A1166C frequency among the native population and newcomers was found to be lower than that observed globally.

Definitive Evidence for the Identification and Function of Renin-Expressing Cholinergic Neurons in the Nucleus Ambiguus.

The importance of the brain renin-angiotensin system in cardiovascular function is well accepted. However, not knowing the precise source of renin in the brain has been a limitation toward a complete understanding of how the brain renin-angiotensin system operates. Highly sensitive in situ hybridization techniques and conditional knockout mice were used to address the location and function of renin in the brainstem. We identified novel renin-expressing cholinergic neurons in the nucleus ambiguus (NuAm), a major vagal cardioinhibitory center in the brainstem. The expression of renin-angiotensin system genes was relatively abundant in the NuAm, implying that angiotensin II might mediate an important regulatory role in this nucleus and other regions with neural connectivity to the NuAm. Then, we generated conditional knockout mice lacking the classical renin isoform (Ren-aChAT-KO), specifically in cholinergic neurons. Ablation of Ren-a in cholinergic neurons abrogated renin expression in the NuAm. Moreover, studies using radiotelemetry, heart rate variability analyses, and pharmacological approaches revealed that the parasympathetic nervous system is depressed in Ren-aChAT-KO males while augmented in the Ren-aChAT-KO females. Subsequently, transcriptomic approaches were used to infer putative genes and signaling pathways regulated by renin within the NuAm. This study revealed that renin in cholinergic neurons plays a fundamental role in preserving autonomic balance and cardiovascular homeostasis in a sex-dependent manner. These findings define the NuAm as an endogenous, local source of renin with biological function and serve as conclusive evidence for the presence and functionality of the brain renin-angiotensin system.

Association between renin-angiotensin system gene polymorphism and cardio-ankle vascular index in patients with COVID-19

Aim. To assess the relationship between arterial stiffness and renin-angiotensin system (RAS) gene polymorphism in patients with COronaVIrus Disease 2019 (COVID-19).Material and methods: 100 patients (mean age of 58.1±11.98 years; 51% women, 49% men) were included in the cross-ectional study. This study included adult patients with laboratory-confirmed diagnosis of COVID-19 admitted to the University Hospital. All patients were evaluated for arterial stiffness using cardio-ankle vascular index (CAVI) by sphygmomanometry. Also alleles and genotypes of several polymorphic markers were identified by real-time polymerase chain reaction in human DNA preparations: rs4762 of angiotensinogen (AGT) gene, rs1799752 of angiotensin-converting enzyme type 1 gene (ACE1), rs5186 of angiotensin II type 1 receptor gene (ATP1), and rs1403543 of angiotensin II type 2 receptor gene (ATP2). The distributions of alleles and genotypes in groups with normal and elevated arterial stiffness (CAVI ≥9.5) were compared.Results. Elevated arterial stiffness (CAVI ≥9.5) was found in 29%. A significantly higher frequency of ATP1 rs5186 genotypes including the A allele, i.e., A/A+A/C versus C/C, was found in subjects with normal CAVI: 95.0% and 5.0% compared with 87.5% and 12.5% in those with CAVI ≥9.5 (χ2=3.907, p=0.049). A significantly higher frequency of genotypes involving the D allele (DD and ID) was detected in patients with increased stiffness: 95.0% compared to 81.3% in the group with normal stiffness (χ2=9.280, p<0.003), and a significantly higher frequency of genotypes including the A-allele: 68.7% and 31.3% compared to 55.0% and 45.0% in individuals with normal arterial stiffness (χ2=4.160, p=0.042). As a result, in patients hospitalized with COVID-19, the presence of increased arterial stiffness with a CAVI level ≥9.5 was associated with a higher frequency of adverse D/D genotype of ACE1 rs1799752, C/C genotype of ATP1 rs5186, A/A genotype and A allele of ATP2 rs1403543.Conclusion. Thus, the presence of certain unfavorable genotypes of ACE1, ATP1 and ATP2 may contribute to the formation of higher arterial stiffness in COVID-19 and be considered as a non-modifiable risk factor for increased vascular wall stiffness along with such a significant factor as age.

Neuronal ACE1 knockout disrupts the hippocampal renin angiotensin system leading to memory impairment and vascular loss in normal aging

Angiotensin I converting enzyme (ACE1) maintains blood pressure homeostasis by converting angiotensin I into angiotensin II in the renin-angiotensin system (RAS). ACE1 is expressed in the brain, where an intrinsic RAS regulates complex cognitive functions including learning and memory. ACE1 has been implicated in neurodegenerative disorders including Alzheimer's disease and Parkinson's disease, but the mechanisms remain incompletely understood. Here, we performed single-nucleus RNA sequencing to characterize the expression of RAS genes in the hippocampus and discovered that Ace is mostly expressed in CA1 region excitatory neurons. To gain a deeper understanding of the function of neuronal ACE1, we generated ACE1 conditional knockout (cKO) mice lacking ACE1 expression specifically in hippocampal and cortical excitatory neurons. ACE1 cKO mice exhibited hippocampus-dependent memory impairment in the Morris water maze, y-maze, and fear conditioning tests. Total ACE1 level was significantly reduced in the cortex and hippocampus of ACE1 cKO mice showing that excitatory neurons are the predominant cell type expressing ACE1 in the forebrain. Despite similar reductions in total ACE1 level in both the hippocampus and cortex, the RAS pathway was dysregulated in the hippocampus only. Importantly, ACE1 cKO mice exhibited age-related capillary loss selectively in the hippocampus. Here, we show selective vulnerability of the hippocampal microvasculature and RAS pathway to neuronal ACE1 knockout. Our results provide important insights into the function of ACE1 in the brain and demonstrate a connection between neuronal ACE1 and cerebrovascular function in the hippocampus.

Genetically conditioned interaction among microRNA-155, alpha-klotho, and intra-renal RAS in male rats: Link to CKD progression.

Incident chronic kidney disease (CKD) varies in populations with hypertension of similar severity. Proteinuria promotes CKD progression in part due to activation of plasminogen to plasmin in the podocytes, resulting in oxidative stress-mediated injury. Additional mechanisms include deficiency of renal alpha-klotho, that inhibits Wnt/beta-catenin, an up regulator of intra-renal renin angiotensin system (RAS) genes. Alpha-klotho deficiency therefore results in upregulation of the intra-renal RAS via Wnt/beta-catenin. In hypertensive, Dahl salt sensitive (DS) and spontaneously hypertensive rats (SHR), we investigated renal and vascular injury, miR-155, AT1R, alpha-klotho, and TNF-α. Hypertensive high salt DS (DS-HS), but not SHR developed proteinuria, plasminuria, and glomerulosclerosis. Compared to DS low salt (DS-LS), in hypertensive DS-HS alpha-klotho decreased 5-fold in serum and 2.6-fold in kidney, whereas serum mir-155 decreased 3.3-fold and AT1R increased 52% in kidney and 77% in aorta. AT1R, alpha-klotho, and miR-155 remained unchanged in prehypertensive and hypertensive SHR. TNF-α increased by 3-fold in serum and urine of DS-HS rats. These studies unveiled in salt sensitive DS-HS, but not in SHR, a genetically conditioned dysfunction of the intermolecular network integrated by alpha-klotho, RAS, miR-155, and TNF-α that is at the helm of their end-organ susceptibility while plasminuria may participate as a second hit.

Renin and CYP P450 gene variations significantly associated with essential hypertension: A prospective pharmacogenomics study

ObjectiveThis study aims to investigate the association between Renin-angiotensin aldosterone system (RAAS) and Cytochrome P450 gene polymorphisms in hypertension patients of the South Indian population using pharmacogenomics profile. MethodsHypertension cases (N = 147) and control subjects (n = 150) were collected from Tamil Nadu, India. A case-control association study was conducted to assess the involvement of RAAS gene polymorphisms (REN rs397514691, REN rs544315427, REN rs567667202) and CYP gene polymorphisms (CYP2D6 rs754164689, CYP2D6 rs1058172, CYP3A4 rs765598920) in essential hypertensive patients. Genotyping was performed using the PCR-RFLP method, and significant results were validated through RT-PCR analysis. ResultsThe genotype and allele distribution of REN rs397514691 and rs544315427 variants significantly associated with hypertensive patients (Variant Allele Frequency (VAF) = 0.11; VAF = 0.27, respectively). CYP2D6 polymorphisms rs754164689 and rs1058172 variant alleles were significantly associated with female hypertensive patients, suggesting a potential risk allele for essential hypertension in the South Indian population. REN and CYP3A4 variants, highly connected in pharmacology action, were validated through RT-PCR amplification studies, providing new insights into their role in the development of hypertension. Association confirmation was achieved through multifactor dimensionality reduction analysis. ConclusionThe genes associated with specific variants, particularly REN and CYP2D6, may serve as potential markers for the early diagnosis of hypertension and as new drug targets, particularly in the female population.

Abstract MP14: Identifying markers of Concentric Arterial and Arteriolar Hypertrophy (CAAH) Using Multiomics.

Experimental or spontaneous mutations of any of the renin-angiotensin system (RAS) genes or treatment with RAS inhibitors in mammals lead to kidney concentric arterial and arteriolar hypertrophy (CAAH). Despite the prevalent use of RAS inhibitors in children and adults, our knowledge of this disease is very limited. We assessed the hypothesis that mouse models of CAAH will produce identifiable and reproducible markers of early and progressive disease. We generated murine models that tracks the lineage of renin-producing cells with deletion ( Ren1 c-/- ;Ren1 cCre ;R26R mTmG , Ren1cKO) or an intact renin gene ( Ren1 c+/- ;Ren1 cCre ;R26R mTmG , control). Kidney cells expressing GFP and tdTomato were isolated by FACS and processed for scRNA-seq. Plasma and urine were collected for proteomics, metabolomics and lipidomics. To study kidney function and structure, we measured transdermal glomerular filtration rate (tGFR) and performed comprehensive three-dimensional (CUBIC) and immunohistochemical analyses. Ren1cKO mice presented with a decrease in the GFR (1.47±0.02 vs 0.40±0.06 mL/min/100g b.w ( n= 6; P <0.05)). They also had polydipsia (3.9±0.05 vs 9.6±0.09 mL/24h ( n= 6; P <0.05), polyuria (2.4±0.07 vs 5.9±0.09 mL/24h ( n= 6; P <0.05) and marked reduction in urinary osmolality (1384±92.09 vs 588±68.04 mOsm/kg ( n= 6; P <0.05). The wall thickness of the afferent arterioles in Ren1cKO mice was significantly increased when compared to controls (4.54 ± 0.17 μm vs 11.57 ± 0.91 μm, P <0.05). The hypertrophic arterioles were covered along their lengths with cells positive for renin. Plasma metabolites showed a significant increase in fatty acids and phosphatidylcholines ( P <0.05) in Ren1cKO mice. Collagens ( P <0.05), lymphocyte antigens ( P <0.05), Spink 1 ( P <0.05), and cadherin 13 were differentially abundant with cadherin 13 exclusively detected in Ren1cKO mice at 1 and 6 months. Our scRNA-seq data also found Spink 1 ( P Holm-adj .=0.00) and Cadherin 13 ( P Holm-adj .=5.49X10 3 ) significantly increased in renin null cells, corroborating the proteomic findings. 1) CAAH involves smooth muscle cell transdifferentiation to renin-expressing cells that exhibit a mesenchymal phenotype characterized by pro-inflammatory pathways, and deregulation of lipid-metabolic homeostasis. Further, the exclusive expression of Spink and Cadherin 13 suggest their involvement in the pathogenesis of these severe, and silent arteriolar disease. Those molecules may serve to mark the initiation and progression of CAAH.

Renin-Angiotensin System Genes Polymorphisms in Patients With COVID-19 and Its Relation to Severe Cases of SARS-CoV-2 Infection.

Different variants of single nucleotide polymorphisms (SNPs) of angiotensinogen (AGT), angiotensin-converting enzyme type 1 (ACE1), and angiotensin II receptors type 1 (AGTR1) and 2 (AGTR2) genes determine different susceptibility to cardiovascular disease (CVD) and hypertension, which can be considered as risk factors for fatal outcomes among coronavirus disease 2019 (COVID-19) patients. The objective of our study was to assess the relation between the frequency of SNPs of the renin-angiotensin system (RAS) components, and the severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The cross-sectional study included 100 patients with a laboratory-confirmed diagnosis of COVID-19 admitted to the hospital. Criteria for severe COVID-19 included respiratory rate (RR) > 30/min, blood oxygen saturation (SpO2) ≤ 93%, signs of unstable hemodynamics with systolic blood pressure (SBP) < 90 and/or diastolic blood pressure (DBP) < 60 mm Hg. All patients were identified with alleles and genotypes of the polymorphic markers rs4762 of the AGT gene, rs1799752 of the ACE1 gene, rs5186 of the AGTR1 gene and rs1403543 of the AGTR2 gene using the polymerase chain reaction method in human DNA preparations on real-time CFX96C1000 Touch, Bio-Rad equipment (Syntol, Russia). Statistical analysis was performed in R v.4.2. Patients were divided into groups with severe (n = 44) and moderate COVID-19 (n = 56). For ACE1 rs1799752, a significant deviation from the population distribution was detected in both studied subgroups. A higher frequency of the C allele SNP rs5186 AGTR1 gene was detected in the group with severe disease. More frequent A/A genotype of SNP rs1403543 AGTR2 was detected among females with severe COVID-19. Haplotype analysis revealed more common DCG haplotype among patients with severe COVID-19. The odds ratio for severe COVID-19 in the presence of the DCG haplotype was 3.996 (95% confidential interval: 1.080 -14.791, P < 0.05). Our data suggest that the SNP genes of the RAS components, may allow to identify groups of patients predisposed to a more severe course of COVID-19.

Sex and tissue-specific downregulation of miR410-3p in a mouse model of cardiometabolic diseases

The brain Renin-Angiotensin System (RAS) plays a pivotal role in controlling cardiometabolic homeostasis, fluid balance, and other functions including inflammation. Previous studies have shown that more than a thousand microRNA (miRNA) families regulate RAS genes expression, and their dysregulation has been associated with HTN, cardiac ischemia, and aging. Recently, we observed that hypercaloric diet (HCD) programming resulted in differentially expressed miRNA in the hypothalamus of only the male progeny, including miR-410-3p which is thought to target angiotensin-II type 1 receptors (AT1R). Here, we aimed to investigate whether miR-410-3p regulate AT1R expression in a mouse model of cardiometabolic disease (CMD) exhibiting hypertension, diabetes and obesity. C57BI/6J mice (3-week-old, both sexes, n=10) were fed a HCD (D12492. 60 kcal% Fat, Research Diets, USA) while weight and fasting blood glucose levels were measured weekly to ensure the acquisition of metabolic syndrome. At 12 weeks of age, the mice were infused subcutaneously (osmotic pump model 1004, Alzet) with Ang-II (600 ng/kg/min/4 weeks). Gene expression of miR-410-3p (QRT-PCR) was reduced in the hypothalamus of CMD male mice (0.5 ±0.1 vs.1.0 ±0.1, p&lt;0.05) but increased in females (1.6 ±0.4 vs.0.7 ±0.2, p&lt;0.001), while both sexes showed a reduction in the heart (Males: 0.2 ±0.0 vs.1.7 ±0.3; Females: 0.23 ±0.0 vs. 3.2 ±0.3, p&lt;0.01). AT1R protein expression (Capillary Western) was increased in the hypothalamus of CMD male (1.5 ±0.1 vs.1.0 ±0.2, p&lt;0.05) mice but not in females (1.0 ±0.1 vs.1.2 ±0.1, P&gt;0.05) while both sexes exhibited elevated levels in the heart (Males: 2.0 ±0.1 vs. 1.0 ±0.1; Females: 2.3 ±0.1 vs. 1.3 ±0.2, p&lt;0.05). Binding specificity (luciferase assay) was further assessed between miR-410-3p and the 3’UTR of AT1R. Binding was decreased in presence of miR410-3p mimic (0.9 ±0.0 vs. 2.1 ±0.0; p&lt;0.001) and enhanced by a miR410-3p inhibitor (2.5 ±0.1 vs. 2.1 ±0.0; p&lt;0.01), confirming that AT1R is a direct target of miR410-3p. Together, our data suggest that in CMD downregulation of miR410-3p is associated with the upregulation of AT1R both in the hypothalamus and heart, notably in males. This positions miR410-3p as a possible new therapeutic strategy to control RAS overactivity in CMD. This work was supported in part by a research grant from the National Institutes of Health (HL163588). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Upregulation of miR-361-3p Is Associated With Impaired AT2 Receptor Expression in Cardiometabolic Diseases

Cardiometabolic homeostasis has been shown to be regulated by the brain Renin-Angiotensin System (RAS), including via epigenetic mechanisms. MicroRNA (miRNA) regulation is one of the most common mechanisms controlling the expression of RAS genes and has previously been implicated in hypertension, cardiac ischemia, and aging. Recently, we observed that hypercaloric diet (HCD) programming resulted in differentially expressed miRNA in the hypothalamus of only the male progeny, including miR-361-3p which is thought to target angiotensin-II type 2 receptors (AT2R). Here, we aimed to investigate whether miR-361-3p regulate AT2R expression in a mouse model of cardiometabolic disease (CMD) exhibiting hypertension, diabetes and obesity. C57BI/6J mice (3-week-old, both sexes, n=10) were fed a HCD (D12492. 60 kcal% Fat, Research Diets, USA) while weight and fasting blood glucose levels were measured weekly to ensure the acquisition of metabolic syndrome. At 12 weeks of age, the mice were infused subcutaneously (osmotic pump model 1004, Alzet) with Ang-II (600 ng/kg/min/4 weeks). BP, food intake and glycemia were recorded weekly while intraperitoneal glucose (GTT), insulin (ITT) tolerance tests and body composition (EchoMRI) were assessed at the end of the study. Gene expression of miR-361-3p (QRT-PCR) was increased in the hypothalamus of CMD male mice (2.0 ±0.5 vs.1.2 ±0.2, p&lt;0.05) but not in females (2.7 ±0.8 vs.2.5 ±0.4, P&gt;0.05). However, both sexes showed an increase in the heart (Males: 2.0 ±0.5 vs.1.0 ±0.3; Females: 1.6 ±0.4 vs. 0.8 ±0.2, p&lt;0.05) which was associated with decreased AT2R cardiac expression (Capillary Western) in CMD male (0.9 ±0.0 vs.1.0 ±0.0, p&lt;0.05) and females (0.1 ±0.0 vs.0.6 ±0.1, p&lt;0.001). Together, our data suggest that in CMD, upregulation of miR-361-3p is associated with the decrease of AT2R in the heart, possibly contributing to impaired cardiac function in this model. This positions inhibitors of miR-361-3p as a possible new therapeutic strategy to control RAS overactivity in CMD. This work was supported in part by a research grant from the National Institutes of Health (HL163588). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sexually Dimorphic Gene Expression in Rat Proximal Tubules Suggests Activation of the Intrarenal Renin Angiotensin System and Elevated Transport Rates in Males

Introduction: Sexual dimorphism affects various organ systems, including renal and cardiovascular. The renin-angiotensin system (RAS) plays a pivotal role in regulating fluid homeostasis and blood pressure, with males being generally more sensitive to the hypertensive actions of angiotensin II (AngII). Proximal tubules (PT)s reabsorb 60-70% of filtered water, sodium, and bicarbonate and present sexually dimorphic biology. In addition, PTs are a key element of the intrarenal RAS and the production site of angiotensinogen ( Agt, AGT) and derived bioactive peptides. These peptides exert autocrine, as well as paracrine effects in distal portions of the nephron, regulating salt and water reabsorption. Hypothesis: We hypothesize that the increased sensitivity to the hypertensive actions of AngII in males is due to activation of the intrarenal RAS. Methods: We used 3 male and 3 female pools of whole kidney single-cell RNAseq transcriptomes to study gene expression differences across sexes in different segments of the nephron. Results: We identified sex-differentially expressed genes (DEGs) in all segments of the nephron, with the majority of DEG mapping to the PT. Analyzing all three PT segments together, we found 86 upregulated genes in females and 104 in males. Pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) highlighted pathways associated with glutathione biosynthesis and metabolism in females, while males presented greater expression of genes associated with the tricarboxylic acid cycle and mineral absorption, including the γ-subunit of the Na,K-ATPase ( Fxyd2). Differential expression of genes on each sub-segment of the PTs, namely S1, S2, and S3, showed the following number of upregulated genes: Females: 39, 37, and 73 in S1, S2, and S3, respectively; and Males: 67, 57, and 105 in S1, S2, and S3, respectively. This data indicates that S3 exhibits the largest sexually dimorphic transcriptomes. Pathway enrichment on S3 DEG in both males and females showed similar enrichment terms as in whole PTs. However, at this resolution, males also present upregulation of RAS genes, including Agt, and two proteases involved in the metabolism of angiotensin peptides: aminopeptidase A ( Enpep, APA) and prolyl endopeptidase ( Prep, PEP). APA and PEP can both cleave AngII to bioactive peptides AngIII and Ang(1-7), respectively. Conclusion: We conclude that the intrarenal RAS is upregulated in male PT.S3. The increase in AGT and proteases capable of metabolizing AngII suggest that this peptide may be elevated. Analyzing the expression of RAS genes alone does not allow us to infer a resultant effect on Na handling, as AngII, AngIII, and Ang(1-7) could exert both natriuretic and anti-natriuretic effects. However, enrichment terms associated with mineral transport and energy demands suggest active mineral transport prevails in males. Funding sources: This work was supported in part by CWRU BGT670107 and NIH-NIDDK DK128304 grants to AGV. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Angiotensin-converting enzyme I/D gene polymorphism and risk of type 2 diabetes mellitus in Iranian individuals

This study aimed to examine the relationship between type 2 diabetes mellitus (T2DM) and renin-angiotensin system gene polymorphisms in the Iranian population. Additionally, we performed a straightforward meta-analysis of the present articles to better understand this role. A total of 100 Iranian individuals, 50 patients with T2DM, and 50 age-matched healthy individuals were included in this study. DNA was extracted using the salting-out approach, polymerase chain reaction was used to amplify the angiotensin-converting enzyme (ACE) gene, electrophoresis techniques were used, and genotyping was performed. We also searched PubMed, Web of Science, Scopus, and Google Scholar databases for papers published in 2023. We found a significantly higher frequency of I/D genotype in the patient group than in the control group, and the risk of T2DM was 10 times higher in individuals with the I/D genotype (OR, 10 [95% CI, 3.7 to 27]; p < 0.0001) and also 2.85 time higher in individuals with the D allele OR, 2.85 [95% CI, 1.55 to 5.24]; p < 0.001). The ACE polymorphism alleles D and I/D genotypes may increase the risk of developing T2DM in an Iranian population.

Upregulation of the Renin-Angiotensin System Is Associated with Patient Survival and the Tumour Microenvironment in Glioblastoma.

Glioblastoma is a highly aggressive disease with poor survival outcomes. An emerging body of literature links the role of the renin-angiotensin system (RAS), well-known for its function in the cardiovascular system, to the progression of cancers. We studied the expression of RAS-related genes (ATP6AP2, AGTR1, AGTR2, ACE, AGT, and REN) in The Cancer Genome Atlas (TCGA) glioblastoma cohort, their relationship to patient survival, and association with tumour microenvironment pathways. The expression of RAS genes was then examined in 12 patient-derived glioblastoma cell lines treated with chemoradiation. In cases of glioblastoma within the TCGA, ATP6AP2, AGTR1, ACE, and AGT had consistent expressions across samples, while AGTR2 and REN were lowly expressed. High expression of AGTR1 was independently associated with lower progression-free survival (PFS) (p = 0.01) and had a non-significant trend for overall survival (OS) after multivariate analysis (p = 0.095). The combined expression of RAS receptors (ATP6AP2, AGTR1, and AGTR2) was positively associated with gene pathways involved in hypoxia, microvasculature, stem cell plasticity, and the molecular characterisation of glioblastoma subtypes. In patient-derived glioblastoma cell lines, ATP6AP2 and AGTR1 were upregulated after chemoradiotherapy and correlated with an increase in HIF1A expression. This data suggests the RAS is correlated with changes in the tumour microenvironment and associated with glioblastoma survival outcomes.

Renin-angiotensin system gene polymorphism and aging

A personalized healthy aging program, aimed at preservation of functional capacities in old ages, should consider genetic (hereditary) factors that determine the structure and functions of body organs and systems, and their age-related changes. Individual genetic characteristics of a person can influence the aging process. For this reason, recent research focuses on identifying genetic mechanisms of aging and longevity associated with multifactorial diseases. Renin-angiotensin system (RAS) contributes to the development of pathological conditions leading to cardiovascular diseases, cognitive changes, disorders of auditory and visual analyzers, and may determine the preservation of functional capacities in older adults. We present a literature review of the role of the RAS gene polymorphisms in the aging processes. The results of the synthesis of Russian and international literature indicated the contribution of polymorphic variants of the angiotensinogen (AGT), angiotensin-converting enzyme (ACE), and angiotensin II receptor type 1 (AGTR1) genes to the development of pathological conditions and the associated decreases in functional capacities of an elderly person. Testing for these polymorphisms can be of a practical importance for personified health assessment and development of timely preventive interventions aimed at improving life expectancy and quality of life among older adults.

Transcriptomics-based analysis reveals the nephrotoxic effects of triphenyltin (TPT) on SD rats by affecting RAS, AQPs and lipid metabolism

Triphenyltin (TPT) is a class of organotin compounds that are extensively used in industry and agriculture. They have endocrine-disrupting effects and cause severe environmental contamination. Pollutants may accumulate in the kidneys and cause pathological complications. However, the mechanism of TPT's toxicological effects on the kidney remains unclear. This study aimed to investigate the toxic effects and mechanism of action of TPT exposure on renal impairment in rats. Male SD rats were divided into four groups: the Ctrl group (control group), TPT-L group (0.5 mg/kg/d), TPT-M group (1 mg/kg/d), and TPT-H group (2 mg/kg/d). After 28 days of exposure to TPT, we observed the morphology and structure of kidney tissue using HE, PASM, and Masson staining. We also detected serum biochemical indexes, performed transcriptome sequencing of rat kidney tissue using RNA-seq. Furthermore, protein expression levels were measured through immunohistochemistry and gene expression levels were determined using RT-qPCR. The study results indicated a decrease in kidney weight and relative kidney weight after 28 days of exposure to TPT. Additionally, TPT caused damage to kidney structure and function, as evidenced by HE staining, PASM staining, and serum biochemical tests. Transcriptomics identified 352 DEGs, and enrichment analyses revealed that TPT exposure primarily impacted the renin-angiotensin system (RAS). The expression levels of water channel proteins were reduced, and the expression levels of RAS and lipid metabolism-related genes (Mme, Ace, Fasn, Cyp4a8, Cpt1b and Ppard) were significantly decreased in the TPT-treated group. In summary, exposure to TPT may impair renal structure and function in rats by affecting RAS, AQPs, and lipid metabolism.

Genetic Variations of Angiotensinogen, Angiotensin Converting Enzyme, and Angiotensin Type 1 Receptor with the Risk of Pulmonary Tuberculosis.

There is little data regarding the impact of renin-angiotensin system (RAS) gene polymorphisms on tuberculosis. The current study designed to survey the possible association between RAS polymorphisms and the risk of pulmonary tuberculosis (PTB) in a sample of the southeast Iranian population. This case-control study was done on 170 PTB patients and 170 healthy subjects. The AGT rs699 C&gt;T, ACE rs4341 C&gt;G and AT1R rs5186 C&gt;A variants were genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and ACE rs4646994 (287bp I/D) variant by PCR method. Regarding AT1R rs5186 A&gt;C polymorphism, the findings revealed that AC genotype and C allele significantly decreased the risk of PTB (OR=0.39, 95% CI=0.22-0.67, p=0.001, and OR=0.53, 95% CI=0.25-0.72, p=0.002, C vs. A, respectively). The TC genotype and C allele of AGT rs699 T&gt;C significantly associated with decreased the risk of PTB (OR=0.45, 95% CI=0.28-0.74, p=0.002, TC vs. TT and OR=0.51, 95% CI=0.32-0.80, p=0.005, C vs. T, respectively). The ID genotype of ACE 287bp I/D significantly increased the risk of PTB (OR=1.88, 95% CI=1.12-3.17, p=0.017). Our finding did not support an association between ACE rs4341 C&gt;G variant and the risk of PTB. In summary, the findings revealed an association between AT1R rs5186 A&gt;C, AGT rs699 T&gt;C and ACE 287bp I/D polymorphisms and the risk of PTB in a sample of the southeast Iranian population. Further investigation with higher sample sizes and diverse ethnicities are required to confirm our findings.

Survival and Predictive Factors of Lethality in Hemodyalisis: D/I Polymorphism of The Angiotensin I-Converting Enzyme and of the Angiotensinogen M235T Genes

Background: End-stage kidney disease patients continue to have markedly increased cardiovascular disease morbidity and mortality. Analysis of genetic factors connected with the renin–angiotensin system that influences the survival of the patients with end-stage kidney disease supports the ongoing search for improved outcomes. Objective: To assess survival and its association with the polymorphism of renin-angiotensin system genes: angiotensin I-converting enzyme insertion/deletion and angiotensinogen M235T in patients undergoing hemodialysis. Methods: Our study was designed to examine the role of renin-angiotensin system genes. It was an observational study. We analyzed 473 chronic hemodialysis patients in four dialysis units in the state of Rio de Janeiro. Survival rates were calculated by the Kaplan–Meier method and the differences between the curves were evaluated by Tarone–Ware, Peto-Prentice, and log rank tests. We also used logistic regression analysis and the multinomial model. A p value  0.05 was considered to be statistically significant. The local medical ethics committee gave their approval to this study. Results: The mean age of patients was 45.8 years old. The overall survival rate was 48% at 11 years. The major causes of death were cardiovascular diseases (34%) and infections (15%). Logistic regression analysis found statistical significance for the following variables: age (p = 0.000038), TT angiotensinogen (p = 0.08261), and family income greater than five times the minimum wage (p = 0.03089), the latter being a protective factor. Conclusions: The survival of hemodialysis patients is likely to be influenced by the TT of the angiotensinogen M235T gene. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0).

Altered Gene Expression Within the Renin-Angiotensin System in Normal Aging and Dementia.

The renin-angiotensin system (RAS) is dysregulated in Alzheimer's disease (AD). In this study, we have explored the hypothesis that an -age--related imbalance in brain RAS is a trigger for RAS dysregulation in AD. We characterized RAS gene expression in the frontal cortex from (i) a cohort of normal aging (n = 99, age range = 19-96 years) and (ii) a case-control cohort (n = 209) including AD (n = 66), mixed dementia (VaD + AD; n = 50), pure vascular dementia (VaD; n = 42), and age-matched controls (n = 51). The AD, mixed dementia, and age-matched controls were further stratified by Braak tangle stage (BS): BS0-II (n = 48), BSIII-IV (n = 44), and BSV-VI (n = 85). Gene expression was calculated by quantitative PCR (qPCR) for ACE1, AGTR1, AGTR2, ACE2, LNPEP, and MAS1 using the 2-∆∆Cq method, after adjustment for reference genes (RPL13 and UBE2D2) and cell-specific calibrator genes (NEUN, GFAP, PECAM). ACE1 and AGTR1, markers of classical RAS signaling, and AGTR2 gene expression were elevated in normal aging and gene expression in markers of protective downstream regulatory RAS signaling, including ACE2, MAS1, and LNPEP, were unchanged. In AD and mixed dementia, AGTR1 and AGTR2 gene expression were elevated in BSIII-IV and BSV-VI, respectively. MAS1 gene expression was reduced at BSV-VI and was inversely related to parenchymal Aβ and tau load. LNPEP gene expression was specifically elevated in VaD. These data provide novel insights into RAS signaling in normal aging and dementia.

Abstract P216: Multiomics Approach To Unravel The Molecular Mechanisms Responsible For Kidney Concentric Arterial And Arteriolar Hypertrophy

Introduction: Experimental or spontaneous mutations of any of the renin-angiotensin system (RAS) genes or treatment with RAS inhibitors in mammals -including humans- lead to kidney concentric arterial and arteriolar hypertrophy (CAAH), a silent, progressive, and severe thickening of the intrarenal arterial tree. Therefore, it is crucial to comprehend the identity and fate changes of the vascular smooth muscle cells (VSMCs) as they switch their phenotype to renin-producing cells (RPC) during the progression of the arteriolar disease. Objective: Using new mouse models and single-cell ‘omic’ approaches available in our lab to assess the chromatin landscape of the RPCs and VSMCs, we aim to identify the genomic hotspots that determine the initiation, evolution, and ultimate fate of the diseased cells. Methods: We generated two murine models. In the first model ( Ren1 c-/- ;Ren1 cCre ;R26R mTmG ) the renin gene is deleted while the cells (renin null cells) are labeled green (GFP+) from embryonic life. In the second model ( SMMHC CreERt2 ; R26R tdTomato ; Ren1 cYFP ) VSMCs are labeled red (tdTomato+) upon tamoxifen injection whereas cells currently expressing renin are labeled yellow (YFP+). Kidney cells expressing the different fluorophores were isolated by Fluorescence Activated Cell Sorting and processed for Single Cell Multiome ATAC (Assay for Transposase-Accessible Chromatin) + Gene Expression, using 10X Genomics Chromium technology. Results: The wall thickness of the afferent arterioles in Ren1 C KO mice was significantly increased when compared to control (4.54 ± 0.17 μm vs 11.57 ± 0.91 μm, P &lt;0.0001). The hypertrophic arterioles were covered along their lengths with cells positive for renin, suggesting that renin cells were involved in the hypertrophy. As the mice got older, SMCs accumulate inwardly and concentrically, obstructing the vessels lumens, leading to focal fibrosis. Conclusion: Our studies showed that deletion of the renin gene led to CAAH. Experiments involving transcriptomics and epigenomics are ongoing to understand the evolution of the CAAH and identify and transcriptional profile changes that occur at the single-cell level.

Altered renin-angiotensin system gene expression in airways of antigen-challenged mice: ACE2 downregulation and unexpected increase in angiotensin 1–7

ObjectiveEvidence suggest that the renin-angiotensin system (RAS) is activated in people with asthma, although its pathophysiological role is unclear. Angiotensin-converting enzyme 2 (ACE2) is the major enzyme that converts angiotensin II to angiotensin 1–7 (Ang-1–7), and is also known as a receptor of SARS-CoV-2. The current study was conducted to identify the change in RAS-related gene expression in airways of a murine asthma model. MethodsThe ovalbumin (OA)-sensitized mice were repeatedly challenged with aerosolized OA to induce asthmatic reaction. Twenty-four hours after the last antigen challenge, the main bronchial smooth muscle (BSM) tissues were isolated. ResultsThe KEGG pathway analysis of differentially expressed genes in our published microarray data revealed a significant change in the RAS pathway in the antigen-challenged mice. Quantitative RT-PCR analyses showed significant increases in the angiotensin II-generating enzymes (Klk1, Klk1b3 and Klk1b8) and a significant decrease in Ace2. Surprisingly, ELISA analyses revealed a significant increase in Ang-1–7 levels in bronchoalveolar lavage (BAL) fluids of the antigen-challenged animals, while no significant change in angiotensin II was observed. Application of Ang-1–7 to the isolated BSMs had no effect on their isometrical tension. ConclusionThe expression of Ace2 was downregulated in the BSMs of OA-challenged mice, while Klk1, Klk1b3 and Klk1b8 were upregulated. Despite the downregulation of ACE2, the level of its enzymatic product, Ang-1–7, was increased in the inflamed airways, suggesting the existence of an unknown ACE2-independent pathway for Ang-1–7 production. The functional role of Ang-1–7 in the airways remains unclear.