Association of OLR1 gene polymorphisms with the risk of coronary artery disease: A systematic review and meta-analysis

Radical Oxygen Species, Oxidized Low-Density Lipoproteins, and Lectin-like Oxidized Low-Density Lipoprotein Receptor 1: A Vicious Circle in Atherosclerotic Process

Atherosclerosis is a complex condition that involves the accumulation of lipids and subsequent plaque formation in the arterial intima. There are various stimuli, cellular receptors, and pathways involved in this process, but oxidative modifications of low-density lipoprotein (ox-LDL) are particularly important in the onset and progression of atherosclerosis. Ox-LDLs promote foam-cell formation, activate proinflammatory pathways, and induce smooth-muscle-cell migration, apoptosis, and cell death. One of the major receptors for ox-LDL is LOX-1, which is upregulated in several cardiovascular diseases, including atherosclerosis. LOX-1 activation in endothelial cells promotes endothelial dysfunction and induces pro-atherogenic signaling, leading to plaque formation. The binding of ox-LDLs to LOX-1 increases the generation of reactive oxygen species (ROS), which can induce LOX-1 expression and oxidize LDLs, contributing to ox-LDL generation and further upregulating LOX-1 expression. This creates a vicious circle that is amplified in pathological conditions characterized by high plasma levels of LDLs. Although LOX-1 has harmful effects, the clinical significance of inhibiting this protein remains unclear. Further studies both in vitro and in vivo are needed to determine whether LOX-1 inhibition could be a potential therapeutic target to counteract the atherosclerotic process.

Association of the ESR1 (rs9340799), OLR1 (rs3736234), LIPC (rs2070895), VDR (rs2228570), and CETP (rs708272) Polymorphisms With Risk of Coronary Artery Disease in Iranian Patients

BACKGROUND

Coronary artery disease (CAD) is a devastating illness and a leading cause of death worldwide, primarily caused by atherosclerosis resulting from a genetic-environmental interaction. This study aimed to investigate the relationship between the ESR1 (rs9340799), OLR1 (rs3736234), LIPC (rs2070895), VDR (rs2228570), and CETP (rs708272) polymorphisms, lipid profile parameters, and CAD risk in a southeast Iranian population.

METHODS

A total of 400 subjects (200 CAD patients with hyperlipidemia and 200 healthy controls) were enrolled in this case-control study. Five selected polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique.

RESULTS

For all single nucleotide polymorphisms (SNPs), the population under study was in the Hardy-Weinberg equilibrium. The T-risk allele frequency of rs2228570 was associated with an increased risk of CAD. The TT and CT genotypes of rs2228570 had also been associated with the risk of CAD. Additionally, the TT genotype was associated with higher serum low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) levels. The GG genotype of the rs3736234 was associated with higher body mass index (BMI) and triglyceride (TG) levels, and the AA genotype of the rs708272 was associated with higher HDL-c levels. Based on these findings, we propose that the VDR (rs2228570) polymorphism was associated with serum HDL-c and LDL-c levels and may serve as potential risk factors for CAD within the Iranian population. Moreover, rs3736234 and rs708272 influence the concentrations of TG and HDL-c, respectively.

CONCLUSION

These findings provided insights into the complex interplay between genetic variations, cardiovascular risk, and lipid metabolism.

Associations of CKIP-1 and LOX-1 polymorphisms with the risk of type 2 diabetes mellitus with hypertension among Chinese adults

AIMS

Type 2 diabetes mellitus (T2DM) and hypertension are common high-incidence diseases, closely related, and have common pathogenic basis such as oxidative stress. Casein kinase 2 interacting protein-1 (CKIP-1) and low-density lipoprotein receptor (LOX-1) are considered to be important factors affect the level of oxidative stress in the body. The main purpose of this study was to explore the relationship between CKIP-1 (rs6693817 A > T, rs2306235 C > G) and LOX-1 (rs1050283 G > A, rs11053646 C > G) polymorphisms and the risk of hypertension and diabetes, and try to find new candidate genes for diabetes and diabetes with hypertension etiology in Chinese population.

METHODS

574 T2DM patients and 597 controls frequently matched by age and sex were selected for genotyping of CKIP-1 (rs6693817 A > T, rs2306235 C > G) and LOX-1 gene (rs1050283 G > A, rs11053646 C > G). Logistic regression was used to analyze the correlation between different genotypes and the risk of T2DM and T2DM with hypertension, and the results were expressed as odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

We found that the risk of T2DM in the AA + AT genotype of rs6693817 was higher than that in the TT genotype in Chinese population (OR = 1.318, 95%CI: 1.011-1.717, P = 0.041), and the difference was still significant after adjustment (OR = 1.370, 95%CI: 1.043-1.799, Padjusted = 0.024), the difference of heterozygotes (AT vs TT: OR = 1.374, 95%CI: 1.026-1.840, Padjusted = 0.033) was statistically significant. But after Bonferroni correction, the significance of the above sites disappeared. And rs6693817 was associated with the risk of T2DM combined with hypertension before and after adjustment in dominant model (OR = 1.424, 95% CI: 1.038-1.954, P = 0.028; OR = 1.460, 95% CI: 1.057-2.015, Padjusted = 0.021, respectively) and in heterozygote model (OR = 1.499, 95% CI: 1.069-2.102, P = 0.019; OR = 1.562, 95% CI: 1.106-2.207, Padjusted = 0.011, respectively). However, only the statistical significance of the heterozygous model remained after Bonferroni correction. rs2306235, rs1050283 and rs11053646 were not significantly correlated with T2DM and T2DM combined with hypertension risk (P > 0.05).

CONCLUSIONS

The results suggest that CKIP-1 rs6693817 is related to the susceptibility of Chinese people to T2DM with hypertension, providing a new genetic target for the treatment of diabetes with hypertension with in the future.

LOX-1 variants modulate the severity of cardiovascular disease: state of the art and future directions

Atherosclerosis is one of the major causes of cerebral infarction and many other ischemic cardio-cerebrovascular diseases. Although large randomized clinical trials have highlighted the impressive benefits of lipid-lowering therapies, the 50-70% of patients who have achieved their lipid-lowering goal remain at high cardiovascular disease risk. For this reason, there is a need to investigate other markers of atherosclerosis progression. LOX-1 is a scavenger receptor that accepts oxidized low-density lipoproteins as major ligand and internalizes it by endocytosis favoring its retention in subendothelial layer and triggering a wide variety of proatherogenic events. However, other factors such as cytokines, shear stress, and advanced glycation end-products can upregulate LOX-1. LOX-1 is encoded by the OLR1 gene, located in the p12.3-p13 region of chromosome 12. OLR1 gene has different isoforms induced by splicing, or single-nucleotide polymorphisms (SNPs). According to some authors, the expression of these isoforms induces a different effect on atherosclerosis and cardiovascular disease. In particular, LOXIN, an isoform lacking part of the functional domain, exerts an important role in atherosclerosis protection. In other cases, studies on SNPs showed an association with more severe forms, like in the case of 3'UTR polymorphisms. The knowledge of these variants can give rise to the development of new preventive therapies and can lead to the identification of subjects at greater risk of cardiovascular event. In this review, we reported the state of the art regarding SNPs with known effects on OLR1 splicing and how LOX-1 variants modulate the severity of cardiovascular disease.

A novel nonsynonymous SNP in the OLR1 gene associated with litter size in Guizhou white goats

Oxidized low-density lipoprotein receptor-1 (OLR1) encodes a low-density lipoprotein receptor belonging to the C-type lectin superfamily, which is closely related to reproduction. OLR1 is associated with fecundity in Awassi sheep. However, its effect on litter size has not been investigated in goats. In this study, OLR1 sequences and their mRNA expression levels in the gonadal axis of Guizhou white goats were evaluated to investigate the relationship between gene polymorphisms and litter size. In addition, the potential effects of a nonsynonymous substitution were evaluated using a bioinformatics approach. The expression levels of OLR1 were highest in the uterus of mothers with multiple kids and highest in the ovaries of mothers with single kids. OLR1 mRNA expression levels in the ovaries of mothers with single kids were two times higher than in the ovaries of mothers with multiple kids. The sequencing results revealed five SNPs in OLR1; however, only g.294 T > A, g.2260 T > C, and g.2268 C > T were significantly associated with litter size (P < 0.05). Linkage disequilibrium was detected between g.2260 T > C and g.2268 C > T (r² = 0.322, D' = 0.6). Additionally, goats with the Hap 1/1 diplotype had a greater litter size than others (P < 0.05). g.2260 T > C was a nonsynonymous mutation that resulted in the replacement of valine with alanine at the amino acid residue 54 of the OLR1 protein. Bioinformatic analyses revealed that the p.V54A locus was relatively conserved in cloven-hoofed species. Mutations at this locus could change the local conformation and reduce the stability of OLR1, affecting its half-life and the litter size of the nanny goat. These findings confirm that OLR1 affects goat kidding traits and provide a novel insight into the regulatory mechanism underlying the effect of OLR1 on litter size.

Identification of Key Genes as Early Warning Signals of Acute Myocardial Infarction Based on Weighted Gene Correlation Network Analysis and Dynamic Network Biomarker Algorithm

Purpose

The specific mechanisms and biomarkersunderlying the progression of stable coronary artery disease (CAD) to acute myocardial infarction (AMI) remain unclear. The current study aims to explore novel gene biomarkers associated with CAD progression by analyzing the transcriptomic sequencing data of peripheral blood monocytes in different stages of CAD.

Material and Methods

A total of 24 age- and sex- matched patients at different CAD stages who received coronary angiography were enrolled, which included 8 patients with normal coronary angiography, 8 patients with angiographic intermediate lesion, and 8 patients with AMI. The RNA from peripheral blood monocytes was extracted and transcriptome sequenced to analyze the gene expression and the differentially expressed genes (DEG). A Gene Oncology (GO) enrichment analysis was performed to analyze the biological function of genes. Weighted gene correlation network analysis (WGCNA) was performed to classify genes into several gene modules with similar expression profiles, and correlation analysis was carried out to explore the association of each gene module with a clinical trait. The dynamic network biomarker (DNB) algorithm was used to calculate the key genes that promote disease progression. Finally, the overlapping genes between different analytic methods were explored.

Results

WGCNA analysis identified a total of nine gene modules, of which two modules have the highest positive association with CAD stages. GO enrichment analysis indicated that the biological function of genes in these two gene modules was closely related to inflammatory response, which included T-cell activation, cell response to inflammatory stimuli, lymphocyte activation, cytokine production, and the apoptotic signaling pathway. DNB analysis identified a total of 103 genes that may play key roles in the progression of atherosclerosis plaque. The overlapping genes between DEG/WGCAN and DNB analysis identified the following 13 genes that may play key roles in the progression of atherosclerosis disease: SGPP2, DAZAP2, INSIG1, CD82, OLR1, ARL6IP1, LIMS1, CCL5, CDK7, HBP1, PLAU, SELENOS, and DNAJB6.

Conclusions

The current study identified a total of 13 genes that may play key roles in the progression of atherosclerotic plaque and provides new insights for early warning biomarkers and underlying mechanisms underlying the progression of CAD.

Etiologic Puzzle of Coronary Artery Disease: How Important Is Genetic Component?

In the modern era, coronary artery disease (CAD) has become the most common form of heart disease and, due to the severity of its clinical manifestations and its acute complications, is a major cause of morbidity and mortality worldwide. The phenotypic variability of CAD is correlated with the complex etiology, multifactorial (caused by the interaction of genetic and environmental factors) but also monogenic. The purpose of this review is to present the genetic factors involved in the etiology of CAD and their relationship to the pathogenic mechanisms of the disease. Method: we analyzed data from the literature, starting with candidate gene-based association studies, then continuing with extensive association studies such as Genome-Wide Association Studies (GWAS) and Whole Exome Sequencing (WES). The results of these studies revealed that the number of genetic factors involved in CAD etiology is impressive. The identification of new genetic factors through GWASs offers new perspectives on understanding the complex pathophysiological mechanisms that determine CAD. In conclusion, deciphering the genetic architecture of CAD by extended genomic analysis (GWAS/WES) will establish new therapeutic targets and lead to the development of new treatments. The identification of individuals at high risk for CAD using polygenic risk scores (PRS) will allow early prophylactic measures and personalized therapy to improve their prognosis.