Association of hyperuricemia with metabolic syndrome and its components in an adult population of Faisalabad, Pakistan.

BACKGROUND AND AIMS: The rising prevalence of metabolic syndrome (MetS) is a matter of serious concern worldwide. Hyperuricemia has been observed as an independent risk factor in the development of MetS and each of its individual components in different populations. This study aims to determine the association of hyperuricemia with MetS and its individual components in a Pakistani cohort. METHODS AND RESULTS: A cross-sectional study was performed in a public sector hospital in Faisalabad, Pakistan. Total 204 participants were studied along with their anthropometric measurements and blood sample analysis for clinically important parameters. MetS was defined according to the NCEP-criteria. Independent sample t-test, Binomial logistic regression and Linear regression analyses were used to determine the association between hyperuricemia and metabolic syndrome. The prevalence of MetS and hyperuricemia in our study was 42.6% and 31.9% respectively. As compared to the normo-uricemic group, the hyperuricemic group had a significantly higher systolic blood pressure, BMI and lower HDL-C level (p < 0.05). After adjusting for age, gender, BMI and LDL-C, hyperuricemia was observed to increase the risk of MetS, increased systolic blood pressure and reduce HDL-C respectively by 1.34, 1.23 and 1.20 folds respectively. CONCLUSION: In this study, a significant association between hyperuricemia and metabolic syndrome, systolic hypertension, blood glucose and decreased HDL-C was observed.

Pharmacogenetic study of CES1 gene and enalapril efficacy.

Enalapril is an orally administered angiotensin-converting enzyme inhibitor which is widely prescribed to treat hypertension, chronic kidney disease, and heart failure. It is an ester prodrug that needs to be activated by carboxylesterase 1 (CES1). CES1 is a hepatic hydrolase that in vivo biotransforms enalapril to its active form enalaprilat in order to produce its desired pharmacological impact. Several single nucleotide polymorphisms in CES1 gene are reported to alter the catalytic activity of CES1 enzyme and influence enalapril metabolism. G143E, L40T, G142E, G147C, Y170D, and R171C can completely block the enalapril metabolism. Some polymorphisms like Q169P, E220G, and D269fs do not completely block the CES1 function; however, they reduce the catalytic activity of CES1 enzyme. The prevalence of these polymorphisms is not the same among all populations which necessitate to consider the genetic panel of respective population before prescribing enalapril. These genetic variations are also responsible for interindividual variability of CES1 enzyme activity which ultimately affects the pharmacokinetics and pharmacodynamics of enalapril. The current review summarizes the CES1 polymorphisms which influence the enalapril metabolism and efficacy. The structure of CES1 catalytic domain and important amino acids impacting the catalytic activity of CES1 enzyme are also discussed. This review also highlights the importance of pharmacogenomics in personalized medicine.

Mass-spectrometric analysis of APOB polymorphism rs1042031 (G/T) and its influence on serum proteome of coronary artery disease patients: genetic-derived proteomics consequences.

Genetic polymorphisms of apolipoprotein B gene (APOB) may result into serum proteomic perturbance in Coronary Artery Disease (CAD). The current case-control cohort of Pakistani subjects was designed to analyze the genetic influence of APOB rs1042031, (G/T) genotype on serum proteome. Subjects were categorized into two groups: CAD patients (n = 480) and healthy individuals (n = 220). For genotyping, tetra ARMS-PCR was carried out and validated through sequencing, whereas LC/MS-based proteomic analysis of serum samples was performed through label-free quantification. In initial step of genotyping, the frequencies of each genotype GG, GT, and TT were 70%, 27%, and 30% in CAD patients, while in control group, the subjects were 52%, 43%, and 5%, respectively, in CAD patients. The genotypic frequencies in patients vs. control groups found significantly different (p = 0.004), and a strong association of dominant alleles GG with the CAD was observed in both dominant (OR: 2.4 (1.71-3.34), p = 0.001) and allelic genetic models (OR: 2.0 (1.45-2.86), p = 0.001). In second step of label-free quantitation, a total of 40 significant proteins were found with altered expression in CAD patients. The enriched Gene Ontology (GO) terms of molecular functions and pathways of these protein showed upregulated pathways as follows: chylomicron remodeling and assembly, complement cascade activation, plasma lipoprotein assembly, apolipoprotein-A receptor binding, and metabolism of fat-soluble vitamins in G allele carrier of rs1042031 (G > T) vs. mutant T-allele carriers. This study provides better understanding of CAD pathobiology by proteogenomics of APOB. It evidences the influence of APOB rs1042031-dominant (GG) genotype with CAD patients.

Tetra-ARMS-PCR assay development for genotyping of AGT rs699 T/C polymorphism, its comparison with PCR-RFLP and application in a case-control association study of cardiovascular disease patients.

Genetic variations in the AGT gene play a significant role in controlling the plasma concentration of angiotensinogen (precursor protein of bioactive octapeptide angiotensin II) and the efficacy of antihypertensive drugs. In the current study, Tetra-Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS-PCR) was developed for genotyping of AGT rs699 T/C polymorphism and validated through Sanger DNA sequencing. Its efficiency was also tested using 474 human DNA samples [control, n = 181; cardiovascular disease (CVD) patients, n = 293]. Results showed that T-ARMS-PCR is superior to the commonly used PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). Statistical analysis revealed that the AGT rs699 CC genotype is more prevalent in the CVD patient group (37% vs. 28%) and AGT rs699 C allele and CC genotype increased the risk of CVD by 1.4 and 1.9 fold, respectively. In summary, T-ARMS-PCR is the most suitable approach for quick and efficient genotyping of AGT rs699 T/C polymorphism in a large population in resource-limited countries, Furthermore, AGT rs699 T/C polymorphism is associated with the risk of CVD in the Punjabi Pakistani population.

Role of c-Src and reactive oxygen species in cardiovascular diseases.

Oxidative stress, caused by the over production of oxidants or inactivity of antioxidants, can modulate the redox state of several target proteins such as tyrosine kinases, mitogen-activated protein kinases and tyrosine phosphatases. c-Src is one such non-receptor tyrosine kinase which activates NADPH oxidases (Noxs) in response to various growth factors and shear stress. Interaction between c-Src and Noxs is influenced by cell type and primary messengers such as angiotensin II, which binds to G-protein coupled receptor and activates the intracellular signaling cascade. c-Src stimulated activation of Noxs results in elevated release of intracellular and extracellular reactive oxygen species (ROS). These ROS species disturb vascular homeostasis and cause cardiac hypertrophy, coronary artery disease, atherosclerosis and hypertension. Interaction between c-Src and ROS in the pathobiology of cardiac fibrosis is hypothesized to be influenced by cell type and stimuli. c-Src and ROS have a bidirectional relationship, thus increased ROS levels due to c-Src mediated activation of Noxs can further activate c-Src by promoting the oxidation and sulfenylation of critical cysteine residues. This review highlights the role of c-Src and ROS in mediating downstream signaling pathways underlying cardiovascular diseases. Furthermore, due to the central role of c-Src in activation of various signaling proteins involved in differentiation, migration, proliferation, and cytoskeletal reorganization of vascular cells, it is presented as therapeutic target for treating cardiovascular diseases except cardiac fibrosis.

Association of vitamin D receptor polymorphisms with cardiometabolic conditions in Pakistani population.

Apart from bone related effects, vitamin D has roles in immune modulation, hypertension, diabetes and cardiovascular diseases. Metabolic functions of vitamin D are mediated after binding with vitamin D receptor (VDR). VDR polymorphisms affect its physiological functions. Several VDR single nucleotide polymorphisms (SNPs) are reported previously. However, VDR polymorphisms causing influence on cardiovascular and metabolic disorders have not been investigated in Pakistani population so far. Therefore, present study was conducted to evaluate the role of VDR polymorphisms (rs2228570 and rs7975232) in the pathobiology of cardiometabolic disorders. In all, 400 cardiometabolic patients and 226 healthy control human adults were enrolled from Faisalabad, Pakistan. Biochemical parameters (serum glucose, liver function test, renal function test and lipid profile) were analyzed by standard kit methods. Genetic analysis was done by ARMS-PCR assay. Data was analyzed in SPSS v20. Regression analysis revealed that GG and AG genotypes of rs2228570 A>G polymorphism significantly increased the risk of hypertension in cardiovascular patients by 5.29 and 5.94 times respectively (GG: OR=5.29, 95% CI=1.63-17.2, p=0.005; AG: OR=5.94, 95% CI=1.70-20.7, p=0.005). However, rs7975232 C>A polymorphism was not correlated with cardiometabolic conditions. In conclusion, GG and AG genotypes of VDR SNP rs2228570 significantly contribute for hypertension in cardiovascular disease patients.

Genetic Association of Beta-Myosin Heavy-Chain Gene (MYH7) with Cardiac Dysfunction.

Cardiac dysfunction accelerates the risk of heart failure, and its pathogenesis involves a complex interaction between genetic and environmental factors. Variations in myosin affect contractile abilities of cardiomyocytes and cause structural and functional abnormalities in myocardium. The study aims to find the association of MYH7 rs121913642 (c.1594 T>C) and rs121913645 (c.667G>A) variants with cardiac dysfunction in the Punjabi Pakistani population. Patients with heart failure (n = 232) and healthy controls (n = 205) were enrolled in this study. MYH7 variant genotyping was performed using tetra ARMS-PCR. MYH7 rs121913642 TC genotype was significantly more prevalent in the patient group (p < 0.001). However, MYH7 rs121913645 genotype frequencies were not significantly different between the patient and control groups (p < 0.666). Regression analysis also revealed that the rs121913642 C allele increases the risk of cardiac failure by ~2 [OR:1.98, CI: 1.31−2.98, p < 0.001] in comparison to the T allele. High levels of the cardiac enzymes cardiac troponin I (cTnI) and CK-MB were observed in patients. There was also an increase in total cholesterol, LDL cholesterol, and uric acid in patients compared to the healthy control group (p < 0.001). In conclusion, the MYH7 gene variant rs121913642 is genetically associated with cardiac dysfunction and involved in the pathogenesis of HF.

Central role of c-Src in NOX5- mediated redox signalling in vascular smooth muscle cells in human hypertension.

AIMS: NOX-derived reactive oxygen species (ROS) are mediators of signalling pathways implicated in vascular smooth muscle cell (VSMC) dysfunction in hypertension. Among the numerous redox-sensitive kinases important in VSMC regulation is c-Src. However, mechanisms linking NOX/ROS to c-Src are unclear, especially in the context of oxidative stress in hypertension. Here, we investigated the role of NOX-induced oxidative stress in VSMCs in human hypertension focusing on NOX5, and explored c-Src, as a putative intermediate connecting NOX5-ROS to downstream effector targets underlying VSMC dysfunction. METHODS AND RESULTS: VSMC from arteries from normotensive (NT) and hypertensive (HT) subjects were studied. NOX1,2,4,5 expression, ROS generation, oxidation/phosphorylation of signalling molecules, and actin polymerization and migration were assessed in the absence and presence of NOX5 (melittin) and Src (PP2) inhibitors. NOX5 and p22phox-dependent NOXs (NOX1-4) were down-regulated using NOX5 siRNA and p22phox-siRNA approaches. As proof of concept in intact vessels, vascular function was assessed by myography in transgenic mice expressing human NOX5 in a VSMC-specific manner. In HT VSMCs, NOX5 was up-regulated, with associated oxidative stress, hyperoxidation (c-Src, peroxiredoxin, DJ-1), and hyperphosphorylation (c-Src, PKC, ERK1/2, MLC20) of signalling molecules. NOX5 siRNA reduced ROS generation in NT and HT subjects. NOX5 siRNA, but not p22phox-siRNA, blunted c-Src phosphorylation in HT VSMCs. NOX5 siRNA reduced phosphorylation of MLC20 and FAK in NT and HT. In p22phox- silenced HT VSMCs, Ang II-induced phosphorylation of MLC20 was increased, effects blocked by melittin and PP2. NOX5 and c-Src inhibition attenuated actin polymerization and migration in HT VSMCs. In NOX5 transgenic mice, vascular hypercontractilty was decreased by melittin and PP2. CONCLUSION: We define NOX5/ROS/c-Src as a novel feedforward signalling network in human VSMCs. Amplification of this system in hypertension contributes to VSMC dysfunction. Dampening the NOX5/ROS/c-Src pathway may ameliorate hypertension-associated vascular injury.

Effect of APOB polymorphism rs562338 (G/A) on serum proteome of coronary artery disease patients: a "proteogenomic" approach.

In the current study, APOB (rs1052031) genotype-guided proteomic analysis was performed in a cohort of Pakistani population. A total of 700 study subjects, including Coronary Artery Disease (CAD) patients (n = 480) and healthy individuals (n = 220) as a control group were included in the study. Genotyping was carried out by using tetra primer-amplification refractory mutation system-based polymerase chain reaction (T-ARMS-PCR) whereas mass spectrometry (Orbitrap MS) was used for label free quantification of serum samples. Genotypic frequency of GG genotype was found to be 90.1%, while 6.4% was for GA genotype and 3.5% was for AA genotypes in CAD patients. In the control group, 87.2% healthy subjects were found to have GG genotype, 11.8% had GA genotype, and 0.9% were with AA genotypes. Significant (p = 0.007) difference was observed between genotypic frequencies in the patients and the control group. The rare allele AA was found to be strongly associated with the CAD [OR: 4 (1.9-16.7)], as compared to the control group in recessive genetic model (p = 0.04). Using label free proteomics, altered expression of 60 significant proteins was observed. Enrichment analysis of these protein showed higher number of up-regulated pathways, including phosphatidylcholine-sterol O-acyltransferase activator activity, cholesterol transfer activity, and sterol transfer activity in AA genotype of rs562338 (G>A) as compared to the wild type GG genotype. This study provides a deeper insight into CAD pathobiology with reference to proteogenomics, and proving this approach as a good platform for identifying the novel proteins and signaling pathways in relation to cardiovascular diseases.

Biochemical investigation of rs1801282 variations in PPAR-γ gene and its correlation with risk factors of diabetes mellitus in coronary artery disease.

We aimed to investigate the association of single nucleotide polymorphism of Pro/Ala (rs1801282) in peroxisome proliferator-activated receptor-gamma (PPAR-γ) gene with risk factors of diabetes mellitus (DM) in cardiovascular disease (CVD) patients. We recruited 244 participants from Faisalabad Institute of Cardiology and Department of Cardiology, Sargodha District Head Quarter Teaching Hospital, Pakistan. Out of 244 participants, 144 cases were CVD patients and 100 were healthy controls. CVD patients were further divided into 111 coronary artery disease (CAD) and 33 cardiomyopathy (CMP) patients. Assessment of variant specific polymorphism/mutation of Pro/Pro and Pro/Ala genotypes was done through amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Further, serum biomarkers were measured to investigate the association among risk factors of DM and Pro/Ala polymorphism in PPAR-γ gene. About 31.5% Pro/Ala genotype was found in CVD patients out of which 22.5% were CAD patients and 9% were CMP patients. As a result, obesity, hypertension and smoking (35%, 23%, 21%, respectively) were observed to be the most critical risk factors accompanying Pro/Ala mutation in PPAR-γ particularly in CAD patients as compared to that in CMP patients. A similar pattern of association was observed among the elevated levels of glucose, cholesterol, triglyceride and ALT with Pro/Ala mutation in CAD patients. Further, CAD patients using ACE inhibitors (18%) and ß-blockers (13%) were found to be the carriers of Pro/Ala genotype and also showed significant increase in glucose level. This study suggests that hyperglycaemia in CAD patients particularly obese, smokers and hypertensives having Pro/Ala polymorphism in PPAR-γ gene are at high risk of developing DM as clearly observed by hyperglycaemia in CAD patients.

Pharmacogenetic study of ACE, AGT, CYP11B1, CYP11B2 and eNOS gene variants in hypertensive patients from Faisalabad, Pakistan.

OBJECTIVE: To investigate the association of genetic variants of renin angiotensin aldosterone system, endothelial nitric oxide synthase and 11-beta-hydroxylase genes, and the drug efficacy of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker. METHODS: This two time-point study was conducted from April to November 2016 at Allied Hospital, Faisalabad and National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, and comprised of hypertensive patients taking angiotensin-converting enzyme inhibitor and angiotensin receptor blocker who were followed up for 12 weeks. Baseline and follow-up clinical and biochemical parameters were measured for all patients. Total 11 polymorphisms were genotyped by polymerase chain reaction, polymerase chain reaction-restriction fragment length polymorphism and amplification-refractory mutation system-polymerase chain reaction assays. Data was divided into baseline and follow-up groups, while the latter group was further divided into responding and non-responding subgroups on the basis of patient response to angiotensin-converting enzyme inhibitor and angiotensin receptor blocker drugs. Data was analysed using SPSS 20. RESULTS: Of the 45 patients, 25(55.5%) were females and 20(44.5%) were males. There was a significant reduction in the systolic blood pressure (p=0.004) and low-density lipoprotein cholesterol (p<0.001) from the baseline to the follow-up. Systolic blood pressure was significantly reduced in the responding group (p=0.003), while diastolic blood pressure (p=0.121) was not significantly different. There was no effect of angiotensin-converting enzyme, angiotensinogen, 11-beta-hydroxylase, aldosterone synthase and endothelial nitric oxide synthase gene polymorphisms on angiotensin converting enzyme inhibitor and angiotensin receptor blocker efficacy. CONCLUSIONS: Inter-individual response to angiotensin converting enzyme inhibitor and angiotensin receptor blocker was found to be independent of genetic polymorphisms in renin angiotensin aldosterone system, endothelial nitric oxide synthase and 11-beta-hydroxylase genes.

Association of ACE I/D Polymorphism with Risk of Diabetes in Cardiovascular Disease Patients.

Angiotensin converting enzyme (ACE), as part of renin angiotensin aldosterone system, is involved in blood pressure regulation and control several physiological functions. Insertion/Deletion (I/D) polymorphism of ACE has pronounced effects on development of metabolic diseases like diabetes, cardiovascular diseases (CVDs) and hypertension. However, association of I/D polymorphism with risk of diabetes in CVD patients is not known. The aim of present study was to check the association of ACE I/D polymorphism with risk of diabetes in subjects with CVD. For this, 531 subjects were sampled and divided into 3 groups; G1-H: (healthy controls, n=117), G2-CN: (cardiac patients without diabetes, n=271) and G3-CD: (cardiac patients with diabetes, n=143). Genotyping of ACE I/D polymorphism was done by polymerase chain reaction. Allelic and genotypic frequencies were in Hardy Weinberg Equilibrium (χ2=0.11, p>0.05) and revealed high prevalence of I allele (55%) among all groups. However, II genotype was more common (37%) in G3-CD: group. Level of glucose was also higher in subjects with II genotype than DD genotype (12.6±6.3 mmol/L vs. 9.7±5.1 mmol/L). Logistic regression analysis revealed that ACE II genotype increase the risk of diabetes in CVD patients by ~2 times [OR=1.94, CI: 1.24-3.01, p=0.03]; however, this association did not reach the significance level when adjusted for age and gender. In conclusion, ACE I/D polymorphism influence the risk of diabetes in CVD patients and ACE II increases this risk by ~2 fold.

Development and application of low-cost T-ARMS-PCR assay for AGT and CYP11B1 gene polymorphisms.

Angiotensin II (Ang II: a truncated octapeptide of angiotensinogen, AGT) and 11-ß-hydroxylase influence regulation of blood pressure. Dysregulation of Ang II and 11-ß-hydroxylase can lead to hypertension and elevate aldosterone levels. Polymorphisms in AGT (encodes AGT) and CYP11B1 (encodes 11-ß-hydroxylase) shift the paradigm from physiological to pathological. Currently, various high-throughput techniques are used to genotype these polymorphisms. These techniques require expensive infrastructure and reagents. However, in developing countries, where cost is the main limiting factor, it is not feasible to use expensive techniques. So, the aim of current study was to develop efficient low-cost method for genotyping of cardiovascular disease and hypertension associated polymorphisms of AGT (rs4762, rs5051) and CYP11B1 (rs6410). For this, tetra amplification-refractory mutation system-polymerase chain reaction (T-ARMS-PCR) method was developed and optimized for aforementioned AGT and CYP11B1 gene polymorphisms. Efficiency of T-ARMS-PCR was tested by genotyping 776 human samples. These T-ARMS-PCR assays were also validated by Sanger DNA sequencing, where 100% concordance was found, allowing the efficient use of these T-ARMS-PCR assays for polymorphism genotyping in AGT and CYP11B1 in resource limited settings. T-ARMS-PCR is low-cost, efficient and reliable assay for genotyping of AGT and CYP11B1 gene polymorphisms.

A case control association study of ACE gene polymorphism (I/D) with hypertension in Punjabi population from Faisalabad, Pakistan.

Angiotensin converting enzyme (ACE) is a key component of renin angiotensin aldosterone system. It converts angiotensin I to angiotensin II. Insertion/deletion (I/D) polymorphism of ACE gene is found associated with several complications. However, its association with hypertension and related metabolic diseases is still controversial. So, the aim of the present study was to check this association for Punjabi population from Faisalabad, Pakistan. For this purpose, blood samples (patients = 100, controls = 48) were collected and several biochemical parameters were measured. Genotyping for ACE (I/D) polymorphism was performed by polymerase chain reaction (PCR) assay. ID genotype is found prevalent in the studied population as 41% in control subjects and 61% in patients. Furthermore, chi-square analysis showed significant (p = 0.005) difference for genotypic frequencies between both groups. One-way ANOVA for association of II, ID, and DD genotypes with anthropometric, clinical, and biochemical parameters showed that in patient group, DD genotype is significantly (p = 0.041) associated with systolic blood pressure (SBP). Moreover, ID genotype is found associated with the presence of cardiovascular diseases. This study concludes that DD genotype is strongly associated with higher SBP in hypertensive patients.

Hypertension regulating angiotensin peptides in the pathobiology of cardiovascular disease.

Renin angiotensin system (RAS) is an endogenous hormone system involved in the control of blood pressure and fluid volume. Dysregulation of RAS has a pathological role in causing cardiovascular diseases through hypertension. Among several key components of RAS, angiotensin peptides, varying in amino acid length and biological function, have important roles in preventing or promoting hypertension, cardiovascular diseases, stroke, vascular remodeling etc. These peptides are generated by the metabolism of inactive angiotensinogen or its derived peptides by hydrolyzing action of certain enzymes. Angiotensin II, angiotensin (1-12), angiotensin A and angiotensin III bind primarily to angiotensin II type 1 receptor and cause vasoconstriction, accumulation of inflammatory markers to sub-endothelial region of blood vessels and activate smooth muscle cell proliferation. Moreover, when bound to angiotensin II type 2 receptor, angiotensin II works as cardio-protective peptide and halt pathological cell signals. Other peptides like angiotensin (1-9), angiotensin (1-7), alamandine and angiotensin IV also help in protecting from cardiovascular diseases by binding to their respective receptors.