ABSTRACT
BACKGROUND: Coronary artery disease (CAD) remains the single most important cause of mortality worldwide. Many candidate and GWAS genetic variants have been identified in the recent years. In the current study, we selected six SNPs from various genes that have originally been identified in GWAS studies and examined the association of SNPs individually and as a genetic risk score (GRS) with CAD and blood lipid levels in the Pakistani subjects. METHODS: Six hundred twenty-four (404 cases and 219 controls) subjects were genotyped for variants rs10757274 in CDKN2A gene, rs17465637 in MIA3 gene, rs7025486 in DAB2IP gene, rs17228212 in SMAD3 gene, rs981887 in MRAS gene and rs1746048 in CXCL12 gene, by TaqMan and KASPar allele discrimination techniques. Serum lipid parameters were measured using commercially available kits. Statistical analyses were done using SPSS version 22. RESULTS: Individually, the single SNPs were not associated with CAD (p < 0.05). However, the combined GRS of 6 SNPs was significantly higher in cases than controls (4.89 ± 0.11 vs 4.58 ± 0.08, p = 0.024). Among blood lipids, GRS showed significant positive association with serum triglycerides levels (p = 0.022). CONCLUSION: The GRS was quantitatively associated with CAD risk and showed association with serum triglycerides levels, suggesting that the mechanism of these variants is likely to be in part at least through creating an atherogenic lipid profile in subjects carrying high numbers of risk alleles.
Subject(s)
Aryl Hydrocarbon Receptor Nuclear Translocator/genetics , Chemokine CXCL12/genetics , Coronary Artery Disease/genetics , Cyclin-Dependent Kinase Inhibitor p18/genetics , Polymorphism, Single Nucleotide , Smad3 Protein/genetics , ras GTPase-Activating Proteins/genetics , ras Proteins/genetics , Adult , Alleles , Aryl Hydrocarbon Receptor Nuclear Translocator/blood , Case-Control Studies , Chemokine CXCL12/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Coronary Artery Disease/blood , Coronary Artery Disease/pathology , Cyclin-Dependent Kinase Inhibitor p16 , Cyclin-Dependent Kinase Inhibitor p18/blood , Female , Gene Expression , Gene Frequency , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Male , Middle Aged , Pakistan , Risk , Smad3 Protein/blood , Triglycerides/blood , ras GTPase-Activating Proteins/blood , ras Proteins/bloodABSTRACT
Besides genetic abnormalities in MPN patients, several studies have reported alterations in protein expression that could contribute towards the clinical phenotype. However, little is known about protein modifications in Ph- MPN erythrocytes. In this context, we used a quantitative mass spectrometry proteomics approach to study the MPN erythrocyte proteome. LC-MS/MS (LTQ Orbitrap) analysis led to the identification of 51 and 86 overexpressed proteins in Polycythemia Vera and Essential Thrombocythemia respectively, compared with controls. Functional comparison using pathway analysis software showed that the Rho GTPase family signaling pathways were deregulated in MPN patients. In particular, IQGAP1 was significantly overexpressed in MPNs compared with controls. Additionally, Western-blot analysis not only confirmed IQGAP1 overexpression, but also showed that IQGAP1 levels depended on the patient's genotype. Moreover, we found that in JAK2V617F patients IQGAP1 could bind RhoA, Rac1 and Cdc42 and consequently recruit activated GTP-Rac1 and the cytoskeleton motility protein PAK1. In CALR(+) patients, IQGAP1 was not overexpressed but immunoprecipitated with RhoGDI. In JAK2V617F transduced Ba/F3 cells we confirmed JAK2 inhibitor-sensitive overexpression of IQGAP1/PAK1. Altogether, our data demonstrated alterations of IQGAP1/Rho GTPase signaling in MPN erythrocytes dependent on JAK2/CALR status, reinforcing the hypothesis that modifications in erythrocyte signaling pathways participate in Ph- MPN pathogenesis.
