Hypertension-related Genes Research Articles

Personal Genetic-Hypertension Odyssey From Phenotypes to Genotypes and Targets.

Hypertension requires increased systemic vascular resistance. Thus far, Mendelian hypertension-related genes are related to salt retention, an indirect regulatory effect. With the identification of mutated, overactive, PDE3A (phosphodiesterase 3A), we have uncovered a more direct vasoconstrictive mechanism. The autosomal-dominant syndrome features another specific phenotype, brachydactyly type E. Hypertension and the bony phenotype invariably occur together. We distinguished between these phenotypes by examining individual pedigrees. We implicated the gene encoding the parathyroid hormone-related peptide in the brachydactyly. We identified the hypertensive mechanisms as involving regulatory-region, gain-of-function, exon 4 rare pathogenic variants, in the cAMP-cGMP-catabolizing enzyme, PDE3A. We generated rodent models that recapitulate all human phenotypes. Comparisons not only allowed pathogenic insights into the human condition but also provided intervention models. Moreover, we identified rare pathogenic variants in exon 13 encoding the enzymatic pocket. These patients had identical phenotypes, also corroborated in a rodent model, which produced the same human phenotypes. These data could allow the differentiation between a target organ and blood pressure phenotype. The research allows visualization of enzymatic processes at the intracellular nanodomain level. The scope of this project has elucidated genetic mechanisms important to cartilage development, possibly cancer metastases, and findings relevant to cardiovascular regulation via systemic vascular resistance. For our team, the project was an educational/scientific adventure over a professional lifetime.

Anti-hypertensive effect and potential mechanism of gastrodia-uncaria granules based on network pharmacology and experimental validation.

Hypertension has become a major contributor to the morbidity and mortality of cardiovascular diseases worldwide. Despite the evidence of the anti-hypertensive effect of gastrodia-uncaria granules (GUG) in hypertensive patients, little is known about its potential therapeutic targets as well as the underlying mechanism. GUG components were sourced from TCMSP and HERB, with bioactive ingredients screened. Hypertension-related targets were gathered from DisGeNET, OMIM, GeneCards, CTD, and GEO. The STRING database constructed a protein-protein interaction network, visualized by Cytoscape 3.7.1. Core targets were analyzed via GO and KEGG using R package ClusterProfiler. Molecular docking with AutodockVina 1.2.2 revealed favorable binding affinities. In vivo studies on hypertensive mice and rats validated network pharmacology findings. GUG yielded 228 active ingredients and 1190 targets, intersecting with 373 hypertension-related genes. PPI network analysis identified five core genes: AKT1, TNF-α, GAPDH, IL-6, and ALB. Top enriched GO terms and KEGG pathways associated with the anti-hypertensive properties of GUG were documented. Molecular docking indicated stable binding of core components to targets. In vivo study showed that GUG could improve vascular relaxation, alleviate vascular remodeling, and lower blood pressure in hypertensive animal models possibly through inhibiting inflammatory factors such as AKT1, mTOR, and CCND1. Integrated network pharmacology and in vivo experiment showed that GUG may exert anti-hypertensive effects by inhibiting inflammation response, which provides some clues for understanding the effect and mechanisms of GUG in the treatment of hypertension.

Uncovering the mechanism of Naoxintong capsule against hypertension based on network analysis and invitro experiments.

Naoxintong capsule (NXT) is a clinical drug for the treatment of cardiovascular diseases, but its pharmacological mechanism against hypertension remains unclear. Data concerning the compounds and targets of NXT were obtained from the TCMSP and DrugBank, whereas data concerning hypertension-related genes were obtained from DisGeNET. The network was analyzed and established by STRING and Cytoscape, and function enrichment was analyzed by GO and KEGG analysis. Molecular docking was performed to analyze the interaction between ingredients and targets, cellular activity was evaluated by MTT assay, and RT-qPCR and western blot were used to evaluate the expressions of related genes. The results showed that 146 active therapeutic components can target hypertension-related genes, and we found that core genes were mainly involved in the metabolism of lipids, lipopolysaccharides, the inflammatory signaling pathway, and the oxidative stress pathway. In addition, there was high affinity between the components of NXT and targets of hypertension, where the former can increase cell viability and reduce the expressions of NOX4, MCP-1, BAX, TNF-α and IL-1β. Moreover, NXT inhibited the expressions of IL-6 and Fis1, as well as increased the expression of MCL-1. These results revealed the active compounds, hypertension targets, signaling pathways, and molecular mechanisms of NXT for treating hypertension, offering references for the clinical application of NXT and the treatment of hypertension.

MyD88 in myeloid cells promotes angiotensin II-induced vascular inflammation and is associated with all-cause mortality and incident heart failure in humans with arterial hypertension

Abstract Background Angiotensin II (AngII) causes hypertension and promotes vascular accumulation of inflammatory cells. We aimed to determine how myeloid factor of differentiation 88 (MyD88) contributes to vascular dysfunction and arterial hypertension in mice and humans. Methods Male C57BL/6 as well as MyD88-/-, LysMCre/wtMyD88LSL/LSL, LysMCre/wt, TLR2-/-, TLR4-/-, TLR7-/- and TLR9-/- were investigated in the AngII-model of hypertension (1 mg/kg/d for 7days). Biodata analyses were performed in the Gutenberg-Health Study (GHS), a population based cohort. In addition, we performed computational analyses of known hypertension-related genes from genome-wide association studies (GWAS) to investigate whether they preferentially interact with MyD88 in the human protein network. Results MyD88 deficiency attenuated AngII-induced blood pressure increase and endothelial dysfunction in conductance and resistance vessels. Vascular mRNA expression levels of vcam-1, nos2, nox2 were decreased in AngII-infused MyD88-/- mice compared to C57BL/6 controls. Flow cytometric analyses revealed that AngII-induced aortic accumulation of CD11b+Ly6Chi inflammatory monocytes was significantly dampened in MyD88-/- mice. AngII increased mRNA expression of cd62L, cd68 and ccl2, which was blocked in MyD88-/- mice, indicating a role of MyD88 for myeloid cell activation and differentiation. Additionally, aortic interferon-g+ NK cells and mRNA levels of interleukin-12 and interleukin-1b were reduced in AngII-treated MyD88-/- mice. Bone marrow transfer experiments demonstrated a vasoprotective effect of MyD88 deficiency in bone marrow-derived cells, and selective expression of MyD88 in LysMCre/wtMyD88LSL/LSL mice restored AngII-induced pathology, revealing that myelomonocytic cells drives vascular dysfunction in a MyD88-dependent manner. Furthermore, data from 1,274 individuals in the GHS indicated, that MyD88 mRNA expression was associated with all cause mortality and incident chronic heart failure after a median follow-up of 11.6 years. Computational analysis of the human protein interaction network demonstrated that MyD88 is significantly connected to proteins encoded by genetic loci associated with blood pressure traits in multiple GWAS. Conclusion We provide evidence, that MyD88 expressed by myelomonocytic cells promotes AngII-induced vascular dysfunction and arterial hypertension. MyD88 might be used as an inflammatory diagnostic marker for the risk of death in hypertensive patients.

Urinary extracellular vesicles carry valuable hints through mRNA for the understanding of endocrine hypertension.

Urinary extracellular vesicles (uEVs), released from cells of the urogenital tract organs, carry precious information about originating tissues. The study of molecules transported through uEVs such as proteins, lipids and nucleic acids provides a deeper understanding of the function of the kidney, an organ involved in the pathogenesis of hypertension and a target of hypertension-mediated organ damage. Molecules derived from uEVs are often proposed for the study of disease pathophysiology or as possible disease diagnostic and prognostic biomarkers. Analysis of mRNA loading within uEVs may be a unique and readily obtainable way to assess gene expression patterns of renal cells, otherwise achievable only by an invasive biopsy procedure. Interestingly, the only few studies investigating transcriptomics of hypertension-related genes through the analysis of mRNA from uEVs are inherent to mineralocorticoid hypertension. More specifically, it has been observed that perturbation in human endocrine signalling through mineralcorticoid receptors (MR) activation parallels changes of mRNA transcripts in urine supernatant. Furthermore, an increased copy number of uEVs-extracted mRNA transcripts of the 11β-hydroxysteroid dehydrogenase type 2 (HSD11B2) gene were detected among subjects affected by apparent mineralocorticoid excess (AME), a hypertension-inducing autosomal recessive disorder due to a defective enzyme function. Moreover, by studying uEVs mRNA, it was observed that the renal sodium chloride cotransporter (NCC) gene expression is modulated under different conditions related to hypertension. Following this perspective, we illustrate here the state of the art and the possible future of uEVs transcriptomics towards a deeper knowledge of hypertension pathophysiology and ultimately more tailored investigational, diagnostic-prognostic approaches.

Identifying susceptibility genes for essential hypertension by transcriptome-wide association study

Hypertension is a leading risk factor of cardiovascular disease and mortality in the population worldwide. Recently, hundreds of genomic loci were reported for hypertension by GWAS, however, the most SNPs are located in intergenic regions of genome, where a functional cause is difficult to determine. In the current study, a TWAS of hypertension was conducted using 452,264 individuals including 84,640 patients. KEGG and GO enrichment analyses were performed for the hypertension-related genes identified via TWAS. PPI network analysis based on the STRING database was also performed to detect TWAS-identified genes in hypertension. We have identified 18,420 genes from the GWAS summary data, and of those 1010 non-overlapping genes expression were significantly associated with hypertension after FDR correction (PFDR <0.05) in four tissues (left heart ventricle, aorta, whole blood, and peripheral blood). The KEGG and GO terms were mostly related to autoimmune mechanisms, and the autoimmune-related pathways have also been enriched using GO analysis for PPI genes. We further performed Mendelian randomization analysis, and the results supported a significant association between autoimmunity and hypertension. Moreover, 15 novel hypertension-susceptible genes were identified in all tissues, and five of the genes (RBM6, HLA-DRB5, UHRF1BP1, LYZ, and TMEM116) were associated with autoimmune system, which provide further evidence supporting an autoimmune mechanism in hypertension. In summary, our study supports that an autoimmune mechanism plays an important role in the development of hypertension, and these findings will provide new biological insights that will assist in deciphering the molecular etiology of hypertension.

Genome-wide Meta-analysis Reveals New Gene Signatures and Potential Drug Targets of Hypertension.

The prevalence of hypertension reported around the world is increasing and is an important public health challenge. This study was designed to explore the disease’s genetic variations and to identify new hypertension-related genes and target proteins. We analyzed 22 publicly available Affymetrix cDNA datasets of hypertension using an integrated system-level framework involving differential expression genetic (DEG) analysis, data mining, gene enrichment, protein–protein interaction, microRNA analysis, toxicogenomics, gene regulation, molecular docking, and simulation studies. We found potential DEGs after screening out the extracellular proteins. We studied the functional role of seven shortlisted DEGs (ADM, EDN1, ANGPTL4, NFIL3, MSR1, CEBPD, and USP8) in hypertension after disease gene curation analysis. The expression profiling and cluster analysis showed significant variations and enriched GO terms. hsa-miR-365a-3p, hsa-miR-2052, hsa-miR-3065-3p, hsa-miR-603, hsa-miR-7113-3p, hsa-miR-3923, and hsa-miR-524-5p were identified as hypertension-associated miRNA targets for each gene using computational algorithms. We found functional interactions of source DEGs with target and important gene signatures including EGFR, AGT, AVP, APOE, RHOA, SRC, APOB, STAT3, UBC, LPL, APOA1, and AKT1 associated with the disease. These DEGs are mainly involved in fatty acid metabolism, myometrial pathways, MAPK, and G-alpha signaling pathways linked with hypertension pathogenesis. We predicted significantly disordered regions of 71.2, 48.8, and 45.4% representing the mutation in the sequence of NFIL3, USP8, and ADM, respectively. Regulation of gene expression was performed to find upregulated genes. Molecular docking analysis was used to evaluate Food and Drug Administration-approved medicines against the four DEGs that were overexpressed. For each elevated target protein, the three best drug candidates were chosen. Furthermore, molecular dynamics (MD) simulation using the target’s active sites for 100 ns was used to validate these 12 complexes after docking. This investigation establishes the worth of systems genetics for finding four possible genes as potential drug targets for hypertension. These network-based approaches are significant for finding genetic variant data, which will advance the understanding of how to hasten the identification of drug targets and improve the understanding regarding the treatment of hypertension.

Comprehensive molecular characterization of hypertension-related genes in cancer.

BackgroundDuring cancer treatment, patients have a significantly higher risk of developing cardiovascular complications such as hypertension. In this study, we investigated the internal relationships between hypertension and different types of cancer.MethodsFirst, we comprehensively characterized the involvement of 10 hypertension-related genes across 33 types of cancer. The somatic copy number alteration (CNA) and single nucleotide variant (SNV) of each gene were identified for each type of cancer. Then, the expression patterns of hypertension-related genes were analyzed across 14 types of cancer. The hypertension-related genes were aberrantly expressed in different types of cancer, and some were associated with the overall survival of patients or the cancer stage. Subsequently, the interactions between hypertension-related genes and clinically actionable genes (CAGs) were identified by analyzing the co-expressions and protein–protein interactions.ResultsWe found that certain hypertension-related genes were correlated with CAGs. Next, the pathways associated with hypertension-related genes were identified. The positively correlated pathways included epithelial to mesenchymal transition, hormone androgen receptor, and receptor tyrosine kinase, and the negatively correlated pathways included apoptosis, cell cycle, and DNA damage response. Finally, the correlations between hypertension-related genes and drug sensitivity were evaluated for different drugs and different types of cancer. The hypertension-related genes were all positively or negatively correlated with the resistance of cancer to the majority of anti-cancer drugs. These results highlight the importance of hypertension-related genes in cancer.ConclusionsThis study provides an approach to characterize the relationship between hypertension-related genes and cancers in the post-genomic era.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40959-022-00136-z.

Quantitative Real-Time Analysis of Differentially Expressed Genes in Peripheral Blood Samples of Hypertension Patients.

Hypertension (HTN) is considered one of the most important and well-established reasons for cardiovascular abnormalities, strokes, and premature mortality globally. This study was designed to explore possible differentially expressed genes (DEGs) that contribute to the pathophysiology of hypertension. To identify the DEGs of HTN, we investigated 22 publicly available cDNA Affymetrix datasets using an integrated system-level framework. Gene Ontology (GO), pathway enrichment, and transcriptional factors were analyzed to reveal biological information. From 50 DEGs, we ranked 7 hypertension-related genes (p-value < 0.05): ADM, ANGPTL4, USP8, EDN, NFIL3, MSR1, and CEBPD. The enriched terms revealed significant functional roles of HIF-1-α transcription; endothelin; GPCR-binding ligand; and signaling pathways of EGF, PIk3, and ARF6. SP1 (66.7%), KLF7 (33.3%), and STAT1 (16.7%) are transcriptional factors associated with the regulatory mechanism. The expression profiles of these DEGs as verified by qPCR showed 3-times higher fold changes (2−ΔΔCt) in ADM, ANGPTL4, USP8, and EDN1 genes compared to control, while CEBPD, MSR1 and NFIL3 were downregulated. The aberrant expression of these genes is associated with the pathophysiological development and cardiovascular abnormalities. This study will help to modulate the therapeutic strategies of hypertension.

Unravelling the tangled web of hypertension and cancer.

Cardiovascular disease remains the primary cause of mortality globally, being responsible for an estimated 17 million deaths every year. Cancer is the second leading cause of death on a global level with roughly 9 million deaths per year being attributed to neoplasms. The two share multiple common risk factors such as obesity, poor physical exercise, older age, smoking and there exists rare monogenic hypertension syndromes. Hypertension is the most important risk factor for cardiovascular disease and affects more than a billion people worldwide and may also be a risk factor for the development of certain types of cancer (e.g. renal cell carcinoma (RCC)). The interaction space of the two conditions becomes more complicated when the well-described hypertensive effect of certain antineoplastic drugs is considered along with the extensive amount of literature on the association of different classes of antihypertensive drugs with cancer risk/prevention. The cardiovascular risks associated with antineoplastic treatment calls for efficient management of relative adverse events and the development of practical strategies for efficient decision-making in the clinic. Pharmacogenetic interactions between cancer treatment and hypertension-related genes is not to be ruled out, but the evidence is not still ample to be incorporated in clinical practice. Precision Medicine has the potential to bridge the gap of knowledge regarding the full spectrum of interactions between cancer and hypertension (and cardiovascular disease) and provide novel solutions through the emerging field of cardio-oncology. In this review, we aimed to examine the bidirectional associations between cancer and hypertension including pharmacotherapy.

Discovery and study on potential effect of herbal pair of Uncariae Ramulus cum Uncis-Eucommiae Cortex on pregnancy hypertension based on network pharmacology and molecular docking

This study aimed to explore the optimal indications and mechanism of Uncariae Ramulus cum Uncis(UR)-Eucommiae Cortex(EC) in lowering blood pressure based on network pharmacology and molecular docking. Chemical constituents were collected and screened by TCMSP database. Swiss Target Prediction platform was used to predict the related targets of the drug. OMIM, TCMIP and GeneCards databases were used to collect hypertension-related genes, and the intersections were taken to obtain potential targets for anti-hypertensive treatment of UR-EC. FunRich software was used to enrich the clinical phenotype and expression site of potential target of lowering blood pressure to analyze and predict the optimal indications of UR-EC. STRING database was used for KEGG pathway enrichment analysis, and Cytoscape 3.7.2 was used to construct the network of &quot;composition-target-pathway&quot;. The key targets and their corresponding components in the network were analyzed and obtained, and then molecular docking was applied for preliminary verification. Twenty potential active components of UR and 24 potential active components of EC were respectively collected, and 92 anti-hypertensive potential targets of UR-EC were obtained. According to FunRich enrichment results, the optimal indication of UR-EC was pregnancy hypertension, which involved calcium signaling pathway, HIF-1 signaling pathway, neuroactive ligand receptor interaction, renin vascular tightening, VEGF signaling pathway, etc. In addition, AKT1, NOS2, ADRB2, F2, NOS3, SCN5 A, HTR2 A and JAK2 were considered as the key targets in the network. The molecular docking results showed that the screened potential active components had high binding activity with the key targets. This study preliminarily revealed that UR-EC may have therapeutic effects on pregnancy hypertension in terms of sedation, anti-hypertension, anti-inflammatory, anti-oxidation, improvement of vascular endothelial function and so on.

DNA methylation of hypertension-related genes and effect of riboflavin supplementation in adults stratified by genotype for the MTHFR C677T polymorphism

BackgroundThe interaction between genetic, epigenetic and environmental factors plays an important role in the aetiology of hypertension. GWAS and observational studies link the C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR) with hypertension, while riboflavin, the MTHFR cofactor, has been shown to reduce blood pressure and global DNA methylation in homozygous (TT genotype) individuals. It is currently unclear whether riboflavin modulates DNA methylation of other hypertension-related genes. ObjectivesTo compare DNA methylation of hypertension-related genes in adults stratified by MTHFR genotype and effect of riboflavin intervention in adults with the variant MTHFR 677TT genotype. MethodPyrosequencing was carried out for hypertension-related genes (ACE, AGTR1, GCK, GNA12, IGF2, MMP9 and NOS3) in blood samples from participants in previous trials (CC, n = 40; TT, n = 40). The effect of intervention with riboflavin (1.6 mg/d for16 weeks) or placebo on DNA methylation was investigated in adults with the variant MTHFR 677TT genotype (n = 80). ResultsIndividuals with the MTHFR 677TT v CC genotype had significantly higher average DNA methylation at NOS3 (+1.66%, P = 0.044). In response to riboflavin supplementation in TT individuals, there was an increase in average DNA methylation at IGF2 (+1.09%, P = 0.019) and a decrease at ACE (−0.44%, P = 0.021) in females only. Specific CpG sites were hypomethylated in GNA12 and hypermethylated in AGTR1. ConclusionThis study provides the first RCT evidence that riboflavin alters DNA methylation of hypertension-related genes in adults with the MTHFR 677TT genotype, providing some insight into mechanisms linking hypertension with the genotype-specific response of BP to riboflavin.

DNA methylation of hypertension-related genes is influenced by the MTHFR 677TT genotype and riboflavin supplementation

AbstractIntroduction:The C677T polymorphism in the folate metabolising enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with hypertension. Riboflavin acts as a cofactor for MTHFR in one-carbon metabolism which generates methyl groups for utilisation in important biological reactions such as DNA methylation. Supplementation with riboflavin has previously been shown to lower blood pressure in individuals with the MTHFR 677TT genotype. The mechanism regulating this gene-nutrient interaction is currently unknown but may involve aberrant DNA methylation which has been implicated hypertension.Objectives:The aims of this study were to examine DNA methylation of hypertension-related genes in adults stratified by MTHFR C677T genotype and the effect of riboflavin supplementation on DNA methylation of these genes in individuals with the MTHFR 677TT genotype.Materials and Methods:We measured DNA methylation using pyrosequencing in a set of candidate genes associated with hypertension including angiotensin II receptor type 1 (AGTR1), G nucleotide binding protein subunit alpha 12 (GNA12), insulin-like growth factor 2 (IGF2) and nitric oxide synthase 3 (NOS3). Stored peripheral blood leukocyte samples from participants previously screened for the MTHFR C677T genotype who participated in targeted randomised controlled trials (1.6mg/d riboflavin or placebo for 16 weeks) at Ulster University were accessed for this analysis (n = 120).Results:There were significant differences in baseline average methylation between MTHFR CC and TT genotypes at NOS3 (p = 0.026) and AGTR1 (p = 0.045) loci. Riboflavin supplementation in the TT genotype group resulted in altered average methylation at IGF2 (p = 0.025) and CpG site-specific alterations at the AGTR1 and GNA12 loci.Conclusion:DNA methylation at genes related to hypertension were significantly different in individuals stratified by MTHFR genotype group. Furthermore, in MTHFR 677TT genotype individuals, there were concurrent alterations in DNA methylation at genes linked to hypertension in response to riboflavin supplementation. This is the largest study to date to demonstrate an interaction between DNA methylation of hypertension-related genes and riboflavin supplementation in adults with the MTHFR 677TT genotype. Further work using a genome-wide approach is required to better understand the role of riboflavin in altering DNA methylation in these genetically at-risk individuals.

Characteristic analysis of the pathway-based weighted network of hypertension-related genes

Complex network is an effective approach for analyzing the complex interactions in diseases. Hypertension is a complex multifactorial disease involving multiple biological pathways and interactions between genetic and environmental factors. By combining network approach with biological knowledge, this study constructs a pathway-based weighted network model of hypertension-related genes of the salt-sensitive rat to explore the interrelationships between genes; in this network model a weight is assigned to each edge in terms of the number of the same pathways in which the two nodes (genes) connected to the edge are involved. Analysis of statistical and topological characteristics shows that the edge weights are correlated to the network topology, and the edge weight distribution decays as a power-law. The disparity of the weights indicates that the edge weight distribution for the nodes with the same degree is of approximately equal weights; and the edges with the larger weights tend to connect with the higher degree nodes. By introducing an integrated ranking index that comprehensively reflect the contribution of the three indices of nodes (strength, degree, and number of pathways), eight key hub genes are identified by the threshold of integrated ranking index larger than 0.60: Jun, Cdk4, RT1-Da, Pdgfra, Fn1, Actg1, Cycs, and Creb3l2. These genes can be regarded as candidate genes or drug targets for further biological and medical research on their functions. This study provides a new strategy for exploring the underlying mechanisms of hypertension, and further evidences again that complex network is an excellent tool for the study of complex diseases.

New pathogenic variant of BMPR2 in pulmonary arterial hypertension.

The aim of this study was to evaluate the variant frequency of pulmonary arterial hypertension-related genes and provide theoretical basis for genetic screening of patients with pulmonary arterial hypertension further. Ten genes associated with pulmonary arterial hypertension were sequenced in 7 cases of idiopathic pulmonary arterial hypertension and 34 cases of congenital heart disease (CHD) associated with pulmonary arterial hypertension by next-generation high-throughput sequencing. Function prediction and gene variant amino acid conservation were carried out by bioinformatics software. Family study was performed on the patients with the variant. A new bone morphogenetic protein receptor type 2(BMPR2) variant (c.344T&gt;C, p. F115S) was discovered in a girl who was diagnosed with idiopathic pulmonary arterial hypertension. Her second aunt and third aunt carried the same variant and were confirmed as patients with pulmonary arterial hypertension as well. No variants or single nucleotide polymorphisms were found in other pulmonary arterial hypertension-associated genes. BMPR2 variant is the most common variant of pulmonary arterial hypertension. Genetic screening of BMPR2 variant and family survey in patients with pulmonary arterial hypertension is suggested for the sake of definite cause and better treatment.

Puerarin Reduces Blood Pressure in Spontaneously Hypertensive Rats by Targeting eNOS.

Puerarin is an isoflavonoid isolated from the root of Pueraria lobata (Gegen in Chinese) that has been widely used to treat cardiovascular and cerebrovascular diseases in China. Here, we investigated the hypotensive effects and mechanisms of puerarin in spontaneously hypertensive rats. The qPCR array technique was used to determine the expression of hypertension-related genes. Then, the differentially expressed genes were analyzed using the STRING database. The systolic blood pressure and diastolic blood pressure of rats decreased after the administration of puerarin for nine weeks. Puerarin, but not losartan, also slowed the heart rate of rats. NO and cGMP levels were improved by puerarin. Eighteen differentially expressed hypertension-related genes were identified by comparing the model group with the control group and the high-dose puerarin group with the model group. NO and cGMP levels were increased by high-dose puerarin. High-dose puerarin increased the levels of the phosphorylated eNOS protein and decreased AT1 and Cav1 levels. Based on our results, eNOS was a key target in the mechanism by which puerarin reduced blood pressure, and puerarin represents a potential antihypertensive agent.

ALPHA-ADDUCIN POLYMORPHISM'S INFLUENCE ON ISCHEMIC STROKES

Objective: rs4961 Gly460Trp variant of the alpha adducin gene (ADD1) has been associated with renal sodium retention and salt sensitive hypertension. Previous studies indicated that carriers of the 460Trp allele have a higher risk of hypertension and cardiovascular (CV) diseases compared to wild-type homozygotes (Gly460Gly). The aim of this study is to assess whether there is a correlation between this ADD1 variant and the development of ischemic strokes in an Italian population. Design and method: 212 patients with ischemic stroke (IS) were recruited from the Stroke Unit of San Raffaele Hospital in Milan and divided into four categories according to Oxford Classification. These patients were compared to a cohort of elder general population (EGP, 128 patients) and a cohort of hypertensive patients (HYP, 2404 patients), both with no history of strokes. All patients analysed were genotyped for adducin family (ADD1, ADD2, ADD3) and other hypertension-related genes. Scientific data: in IS group mean age at strokes’ diagnosis was 72.34 ± 11.9, 61% men, 39% women. The incidence of CV risk factors was: hypertension 66%, diabetes 22%, hypercholesterolemia 40% and hypertriglyceridemia 13%, previous stroke 14%. Mean creatinine value was 1.07 ± 0.66 mg/dL. Two comparable populations were selected with similar age (71.28 ± 6.9 years for EGP) and with the same incidence of risk factors (for HYP population). Notably, the presence of subjects homozygous for ADD1 mutated allele (rs4961 TrpTrp) is more than double in patients bearing ischemic stroke than in the two other (6.1% IS vs. 2.3% EP, p = 0.049; 6.1% IS vs. 2.2 HYP, p = 0.009; fig. 1). There was no statistically difference among the various types of stroke. No other significant associations were identified with other gene variations. Results: These data suggest a correlation between mutated alpha-Adducin and the increased incidence of all types of ischemic stroke. No correlation was found with the other hypertension-related genes analysed. Conclusions: rs4961 alpha-Adducin polymorphism should be considered as an independent risk factor for ischemic strokes. Furthermore, ischemic stroke does not appear directly linked to hypertension. Finally, alpha-Adducin polymorphism itself might be a candidate gene in the pathogenesis of stroke.

Abstract P327: Stress Overload and Methylation of Hypertension Related Genes

Background: Nearly 30% of U.S. adults are hypertensive with a high prevalence existing among Black Americans (42%). Exposure to psychosocial stress has been identified as a risk factor for hypertension and may explain part of the observed racial disparities. One pathway through which stress exposure may mechanistically alter biological functioning in a manner that affects risk of hypertension is via epigenetic modifications in hypertension-related genes, but this area remains understudied. Aims and Hypothesis: In the present study, we investigate the relationship between stress exposure and methylation of 25 genes that have been associated with blood pressure in Blacks in previous genetic research. We hypothesize that stress exposure is associated with DNA methylation of blood pressure related genes. Methods: We conducted an epigenetic association study using data from the ongoing InterGEN Study, a longitudinal investigation of the psychological, environmental, and genetic factors that contribute to hypertension risk in African American mothers (n=74) and their young children. Stress exposure was measured using the 24-item Stress Overload Scale (α=0.95), and a summary score was calculated by summing the Likert scale responses. Methylation was measured using the Illumina Infinium MethylationEPIC Beadchip, and M-values (i.e. log2 ratio of the intensities of methylated probe versus unmethylated probe) were calculated for association analysis. Linear regression was employed to assess the association between stress exposure and methylation in the a priori defined genes. Results: At p&lt;0.05, we identified 45 methylation sites associated with stress overload. These sites represented 17 of the 25 investigated genes. The most statistically significant sites were related to the genes: insulin like growth factor binding protein 3 ( IGFBP3 ), calcium voltage-gated channel subunit alpha1 H ( CACNA1H ), and solute carrier family 4 member 5 ( SLC4A5 ) (p=0.001, p=0.002, and p=0.006, respectively). Conclusion: This study provides biological insight into DNA methylation as a mechanism whereby exposure to psychosocial stress affects risk of hypertension in Black women. Additional replication studies with a larger sample size and includes men are needed to validate and generalize the findings. Future research should further investigate the biological mediators between DNA methylation and hypertension manifestation.

Study on the biological basis of hypertension and syndrome with liver-fire hyperactivity based on data mining technology

Objective: To construct gene co-occurrence network of hypertension and liver-fire hyperactivity syndrome, to investigate the biological basis of hypertension and liver-fire hyperactivity syndrome and the characteristics of the molecular network from gene level. Materials and Methods: Applying GenCLip 2.0 online platform to retrieve the up-to-date literature referred to essential hypertension from PubMed database, cluster the abnormal expression of essential hypertension-related genes and analyze their function, combining Kyoto encyclopedia of genes and genomes-pathway analysis to investigate the closely related genes and the signaling molecules. Based on the genes closely related to hypertension, standard diagnostic symptoms of liver-fire hyperactivity were used as keywords to conduct hypertension liver-fire hyperactivity-related gene cluster analysis. Results: The top 1000 genes of essential hypertension were retrieved from GenCLip 2.0 online platform, which mainly clustered in the regulation of ambulatory blood pressure, regulation of renin-angiotensin-aldosterone system (RAAS), and sympathetic nervous system activity, as well as endothelial dysfunction; the closely related genes of hypertension with liver-fire hyperactivity are related to RAAS, gene REN, angiotensin converting enzyme, angiotensinogen, and cytochrome P450 family CYP2D6. Conclusion: A combination of literature mining and data mining can construct the gene network of hypertension and the syndrome-related genes, which provides a new method for the study of the biological basis of hypertension from the genetic level.

PP.30.25] EFFECT OF MAGNESIUM DEPRIVATION ON HYPERTENSION RELATED GENE EXPRESSION PROFILES IN HUMAN HEART

Objective: While we well understand that nutritional Mg2+-deprivation may lead to increased blood pressure and numerous cellular dysfunctions, the effects of extracellular Mg2+-concentrations on molecular pathways and processes has not been studied as yet. Characterising these Mg2+-dependent intracellular molecular pathways may well constitute a further step towards understanding the effects of magnesium on myocardial function as well as blood pressure control. Design and method: Using molecular profiling technique, we look at over to 20 000 different gene expressions in the presence and absence of extracellular Mg2+, thus identifying the specific molecular signature of myocardial Mg2+-deprivation. This allows us to demonstrate its effects at the molecular level in resting human atrial myocardium. Using PANTHER software (Applied Biosystems) we assess up- and down-regulation of gene expression associated with biological processes and pathways. Results: Myocardial gene expression after exposure of 30 minutes to Mg2+-free solution is massively altered compared to control experiments. We find a complex de-regulation of gene expression secondary to Mg2+ deficiency, several accociated with hypertension-related genes. It can be seen that gene-expression associated with clusters of immunity- and defence-processes, protein metabolism and signal transduction as well as nucleoside, nucleotide and nucleic metabolism are significantly down-regulated. Similarly, biological processes involved in transcription, protein biosynthesis and cell communication, nucleoside, nucleotide and nucleic metabolism as well as signal transduction and protein metabolism are effected by up-regulation. Clusters of pathways down-regulated by Mg2+ deficiency are: various signalling pathways, T-cell activation, apoptosis and angiogenesis. Clusters of up-regulated pathways are mainly different groups of signalling. Conclusions: In summary, experimental myocardial Mg2+-deprivation leads to complex changes in the expression profile of biological processes and molecular pathways. Furthermore, one can deduce from earlier observations that Mg2+i is well buffered and remains relatively uninfluenced by extracellular manoeuvres. The interdependence of intracellular and extracellular Mg2+, however, appears once more difficult to understand, but may well effect the development of arterial hypertension. Further studies are certainly needed in order to firmly establish the mechanisms of extracellular Mg2+ influencing intracellular processes and pathways that may affect blood pressure and myocardial function.