Correlation of PCSK9 gene polymorphism with cerebral ischemic stroke in Xinjiang Han and Uygur populations

Correlations of PCSK9 and LDLR Gene Polymorphisms and Serum PCSK9 Levels With Atherosclerosis and Lipid Metabolism in Patients on Maintenance Hemodialysis

This study is aimed at investigating the correlations of PCSK9 and LDLR gene polymorphisms as well as serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels with atherosclerosis and lipid metabolism in patients on maintenance hemodialysis (HD). A single nucleotide polymorphism at the E670G locus of the PCSK9 gene and the rs688 locus of the LDLR gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism. All study subjects' blood lipid (triglyceride [TG], total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], and low-density lipoprotein cholesterol [LDL-C]) concentrations and lipoprotein(a) and PCSK9 levels were measured. The differences in blood lipid levels between different genotypes of the E670G locus of the PCSK9 gene and the rs688 locus of the LDLR gene in patients on maintenance HD with atherosclerosis were compared. Patients on maintenance HD with atherosclerosis at the E670G locus of the PCSK9 gene AG + GG genotype had higher levels of TG, TC, LDL-C, and lipoprotein(a) than the AA genotype, and lower levels of HDL-C than the AA genotype. Patients on maintenance HD with atherosclerosis at the rs688 locus of the LDLR gene CT + TT genotype had higher levels of TG, TC, LDL-C, and lipoprotein(a) than the CC genotype, and lower levels of HDL-C than the CC genotype. Serum PCSK9 contents in patients on maintenance HD with atherosclerosis were positively correlated with lipid indices (TG, TC, LDL-C, and lipoprotein(a)) and carotid ultrasound indices (intima-media thickness and resistance index), and negatively correlated with HDL-C, maximum systolic blood flow velocity, and minimum diastolic blood flow velocity (all P < .05).

PCSK9 and the nervous system: a no-brainer?

In the past 20 years, PCSK9 has been shown to play a pivotal role in LDL cholesterol metabolism and cardiovascular health by inducing the lysosomal degradation of the LDL receptor. PCSK9 was discovered by the cloning of genes up-regulated after apoptosis induced by serum deprivation in primary cerebellar neurons, but despite its initial identification in the brain, the precise role of PCSK9 in the nervous system remains to be clearly established. The present article is a comprehensive review of studies published or in print before July 2023 that have investigated the expression pattern of PCSK9, its effects on lipid metabolism as well as its putative roles specifically in the central and peripheral nervous systems, with a special focus on cerebrovascular and neurodegenerative diseases.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) in the central nervous system

The gene encoding proprotein convertase subtilisin/kexin type 9 (PCSK9) and its protein product have been widely studied for their role in cholesterol and lipid metabolism. PCSK9 increases the rate of metabolic degradation of low-density lipoprotein receptors, preventing the diffusion of low-density lipoprotein (LDL) from plasma into cells and contributes to high lipoprotein-bound cholesterol levels in the plasma. While most research has focused on the regulation and disease relevance of PCSK9 to the cardiovascular system and lipid metabolism, there is a growing body of evidence that PCSK9 plays a crucial role in pathogenic processes in other organ systems, including the central nervous system. PCSK9's impact on the brain is not yet fully understood, though several recent studies have sought to illuminate its impact on various neurodegenerative and psychiatric disorders, as well as its connection with ischemic stroke. Cerebral PCSK9 expression is low but is highly upregulated during disease states. Among others, PCSK9 is known to play a role in neurogenesis, neural cell differentiation, central LDL receptor metabolism, neural cell apoptosis, neuroinflammation, Alzheimer's Disease, Alcohol Use Disorder, and stroke. The PCSK9 gene contains several polymorphisms, including both gain-of-function and loss-of-function mutations which profoundly impact normal PCSK9 signaling and cholesterol metabolism. Gain-of-function mutations lead to persistent hypercholesterolemia and poor health outcomes, while loss-of-function mutations generally lead to hypocholesterolemia and may serve as a protective factor against diseases of the liver, cardiovascular system, and central nervous system. Recent genomic studies have sought to identify the end-organ effects of such mutations and continue to identify evidence of a much broader role for PCSK9 in extrahepatic organ systems. Despite this, there remain large gaps in our understanding of PCSK9, its regulation, and its effects on disease risk outside the liver. This review, which incorporates data from a wide range of scientific disciplines and experimental paradigms, is intended to describe PCSK9's role in the central nervous system as it relates to cerebral disease and neuropsychiatric disorders, and to examine the clinical potential of PCSK9 inhibitors and genetic variation in the PCSK9 gene on disease outcomes, including neurological and neuropsychiatric disease.

Association study of PCSK9 SNPs (rs505151 & rs562556) and their haplotypes with CVDs in Indian population

BACKGROUND

Cardiovascular disease (CVD) has emerged as the most prevalent cause of death in India. Pro-protein Convertase Subtilisin/Kexin Type 9 (PCSK9) gene has been found to be associated with lipid levels and a biomarker for susceptibility of CVD.

AIM

To study the association of PCSK9 SNPs rs505151 & rs562556 and their haplotypes with CVDs in the Indian population.

SUBJECTS & METHODS

The present study comprised of 102 angiographically proven CVD patients & 100 healthy subjects. To study polymorphism, Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) method was used. Biochemical parameters were analysed by enzymatic methods or automated analysers. Haplotype analysis was done using SHEsis software.

RESULTS

The dominant genetic model with an odds ratio (confidence interval) of 4.71 (2.59 - 8.5), (p value = .0001), shows the risk of CVDs. However, rs562556 (I474V) variant was not found to be associated with clinical parameters and risk of CVDs (p value >.05). Out of four haplotypes, H3 (G-A) was found to be associated with the CVDs (OR- 3.137, p value = .0001).

CONCLUSION

This study concludes that G allele of rs505151 SNP (PCSK9) and the H3 (G-A) haplotype of rs505151 & rs562556 were found to be risk factors for CVDs in the Indian population.

Association Between Circulating Proprotein Convertase Subtilisin/Kexin Type 9 and Major Adverse Cardiovascular Events, Stroke, and All-Cause Mortality: Systemic Review and Meta-Analysis

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9), a pivotal protein in low-density lipoprotein cholesterol metabolism, has been validated to be an established target for cardiovascular (CV) risk reduction. Nevertheless, prospective studies concerning the associations between circulating PCSK9 and the risk of CV events and mortality have yielded, so far, inconsistent results. Herein, we conducted a meta-analysis to evaluate the association systemically.

Methods: Pertinent studies were identified from PubMed, EMBASE, and Cochrane Library database through July 2020. Longitudinal studies investigating the value of circulating PCSK9 for predicting major adverse cardiovascular events (MACEs) or stroke or all-cause mortally with risk estimates and 95% confidence intervals (CI) were included in the analyses. Dose-response meta-analysis was also applied to evaluate circulating PCSK9 and risk of MACEs in this study.

Results: A total of 22 eligible cohorts comprising 28,319 participants from 20 eligible articles were finally included in the study. The pooled relative risk (RR) of MACEs for one standard deviation increase in baseline PCSK9 was 1.120 (95% CI, 1.056–1.189). When categorizing subjects into tertiles, the pooled RR for the highest tertile of baseline PCSK9 was 1.252 (95% CI, 1.104–1.420) compared with the lowest category. This positive association between PCSK9 level and risk of MACEs persisted in sensitivity and most of the subgroup analyses. Twelve studies were included in dose-response meta-analysis, and a linear association between PCSK9 concentration and risk of MACEs was observed (x2 test for non-linearity = 0.31, P non-linearity = 0.575). No significant correlation was found either on stroke or all-cause mortality.

Conclusion: This meta-analysis added further evidence that high circulating PCSK9 concentration significantly associated with increased risk of MACEs, and a linear dose-response association was observed. However, available data did not suggest significant association either on stroke or all-cause mortality. Additional well-designed studies are warranted to further investigate the correlations between PCSK9 concentration and stroke and mortality.

Coming Back to Physiology: Extra Hepatic Functions of Proprotein Convertase Subtilisin/Kexin Type 9

Neuronal apoptosis regulated convertase-1 (NARC-1), now mostly known as proprotein convertase subtilisin/kexin type 9 (PCSK9), has received a lot of attention due to the fact that it is a key regulator of the low-density lipoprotein (LDL) receptor (LDL-R) and is therefore involved in hepatic LDL clearance. Within a few years, therapies targeting PCSK9 have reached clinical practice and they offer an additional tool to reduce blood cholesterol concentrations. However, PCSK9 is almost ubiquitously expressed in the body but has less well-understood functions and target proteins in extra hepatic tissues. As such, PCSK9 is involved in the regulation of neuronal survival and protein degradation, it affects the expression of the epithelial sodium channel (ENaC) in the kidney, it interacts with white blood cells and with cells of the vascular wall, and it modifies contractile activity of cardiomyocytes, and contributes to the regulation of cholesterol uptake in the intestine. Moreover, under stress conditions, signals from the kidney and heart can affect hepatic expression and thereby the plasma concentration of PCSK9 which then in turn can affect other target organs. Therefore, there is an intense relationship between the local (autocrine) and systemic (endocrine) effects of PCSK9. Although, PCSK9 has been recognized as a ubiquitously expressed modifier of cellular function and signaling molecules, its physiological role in different organs is not well-understood. The current review summarizes these findings.

Physiology and role of PCSK9 in vascular disease: Potential impact of localized PCSK9 in vascular wall

Proprotein convertase subtilisin/kexin type-9 (PCSK9), a member of the proprotein convertase family, is an important drug target because of its crucial role in lipid metabolism. Emerging evidence suggests a direct role of localized PCSK9 in the pathogenesis of vascular diseases. With this in our consideration, we reviewed PCSK9 physiology with respect to recent development and major studies (clinical and experimental) on PCSK9 functionality in vascular disease. PCSK9 upregulates low-density lipoprotein (LDL)-cholesterol levels by binding to the LDL-receptor (LDLR) and facilitating its lysosomal degradation. PCSK9 gain-of-function mutations have been confirmed as a novel genetic mechanism for familial hypercholesterolemia. Elevated serum PCSK9 levels in patients with vascular diseases may contribute to coronary artery disease, atherosclerosis, cerebrovascular diseases, vasculitis, aortic diseases, and arterial aging pathogenesis. Experimental models of atherosclerosis, arterial aneurysm, and coronary or carotid artery ligation also support PCSK9 contribution to inflammatory response and disease progression, through LDLR-dependent or -independent mechanisms. More recently, several clinical trials have confirmed that anti-PCSK9 monoclonal antibodies can reduce systemic LDL levels, total nonfatal cardiovascular events, and all-cause mortality. Interaction of PCSK9 with other receptor proteins (LDLR-related proteins, cluster of differentiation family members, epithelial Na⁺ channels, and sortilin) may underlie its roles in vascular disease. Improved understanding of PCSK9 roles and molecular mechanisms in various vascular diseases will facilitate advances in lipid-lowering therapy and disease prevention.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in the Brain and Relevance for Neuropsychiatric Disorders

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has long been studied in the liver due to its regulation of plasma low-density lipoprotein cholesterol (LDL-C) and its causal role in familial hypercholesterolemia. Although PCSK9 was first discovered in cerebellar neurons undergoing apoptosis, its function in the central nervous system (CNS) is less clear. PCSK9 has been shown to be involved in neuronal differentiation, LDL receptor family metabolism, apoptosis, and inflammation in the brain, but in vitro and in vivo studies offer contradictory findings. PCSK9 expression in the adult brain is low but is highly upregulated during disease states. Cerebral spinal fluid (CSF) PCSK9 concentrations are correlated with neural tube defects and neurodegenerative diseases in human patients. Epigenetic studies reveal that chronic alcohol use may modulate methylation of the PCSK9 gene and genetic studies show that patients with gain-of-function PCSK9 variants have higher LDL-C and an increased risk of ischemic stroke. Early safety studies of the PCSK9 inhibitors evolocumab and alirocumab, used to treat hypercholesterolemia, hinted that PCSK9 inhibition may negatively impact cognition but more recent, longer-term clinical trials found no adverse neurocognitive events. The purpose of this review is to elucidate the role of PCSK9 in the brain, particularly its role in disease pathogenesis.

Variations of the proprotein convertase subtilisin/kexin type 9 gene in coronary artery disease

Objective

Coronary artery disease (CAD) is the principal cause of mortality and morbidity worldwide. Studies have provided controversial results regarding whether variations in the proprotein convertase subtilisin/kexin type 9 gene (PCSK9) are risk factors for CAD. In this study, we evaluated the risk factors associated with PSCK9 genotypes and CAD in the Taiwanese population.

Methods

A total of 501 patients diagnosed with CAD by angiography and 334 CAD-free controls were recruited. Two single nucleotide polymorphisms of PSCK9 (rs505151 and rs529787) were genotyped.

Results

The prevalence of a positive family history for CAD was significantly higher in individuals carrying the AG + GG genotype of the PSCK9 rs505151 polymorphism. Among CAD patients with a positive family history, the prevalence of diabetes mellitus was significantly higher in those carrying the AG + GG genotype of the PSCK9 rs505151 polymorphism (73.3%) than in those carrying the AA genotype (39.2%).

Conclusion

In CAD patients, the AG genotype of PSCK9 rs505151 is associated with diabetes and a positive family history of CAD.

Differential effects of PCSK9 variants on risk of coronary disease and ischaemic stroke

Aims

PCSK9 genetic variants that have large effects on low-density lipoprotein cholesterol (LDL-C) and coronary heart disease (CHD) have prompted the development of therapeutic PCSK9-inhibition. However, there is limited evidence that PCSK9 variants are associated with ischaemic stroke (IS).

Methods and results

Associations of the loss-of-function PCSK9 genetic variant (rs11591147; R46L), and five additional PCSK9 variants, with IS and IS subtypes (cardioembolic, large vessel, and small vessel) were estimated in a meta-analysis involving 10 307 IS cases and 19 326 controls of European ancestry. They were then compared with the associations of these variants with LDL-C levels (in up to 172 970 individuals) and CHD (in up to 60 801 CHD cases and 123 504 controls). The rs11591147 T allele was associated with 0.5 mmol/L lower LDL-C level (P = 9 × 10-143) and 23% lower CHD risk [odds ratio (OR): 0.77, 95% confidence interval (CI): 0.69-0.87, P = 7 × 10-6]. However, it was not associated with risk of IS (OR: 1.04, 95% CI: 0.84-1.28, P = 0.74) or IS subtypes. Information from additional PCSK9 variants also indicated consistently weaker effects on IS than on CHD.

Conclusion

PCSK9 genetic variants that confer life-long lower PCSK9 and LDL-C levels appear to have significantly weaker, if any, associations with risk of IS than with risk of CHD. By contrast, similar proportional reductions in risks of IS and CHD have been observed in randomized trials of therapeutic PCSK9-inhibition. These findings have implications for our understanding of when Mendelian randomization can be relied upon to predict the effects of therapeutic interventions.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Impact of Tag Single Nucleotide Polymorphisms (SNPs) in CCL11 Gene on Risk of Subtypes of Ischemic Stroke in Xinjiang Han Populations

BACKGROUND CCL11 is an important inflammatory cytokine associated with inflammation-related diseases such as atherosclerosis and stroke. The aim of this study was to investigate the relationship between CCL11 gene polymorphism with subtypes of ischemic stroke in Xinjiang Han populations. MATERIAL AND METHODS The improved multiple ligase detection reaction (iMLDR) method was used to analyze the genotypes of 6 tag SNPs in the CCL11 gene (rs1129844, rs17809012, rs1860183, rs1860184, rs4795898, and rs4795895) in a case-control study of 406 lacunar stroke patients, 214 large-artery atherosclerotic (LAA) stroke patients, and 425 controls. RESULTS We found the GG genotype of rs4795895 was significantly associated with increased risk of lacunar stroke (adjusted OR=1.676, 95%CI=1.117-2.515), and the GA genotype of rs17809012 was associated with a significant increase in risk of LAA stroke (adjusted OR=1.337, 95%CI=1.127-1.585). Hypertension stratification analyses showed that the GA genotype of rs17809012 was significantly associated with LAA stroke in the hypertensive group (adjusted OR=1.274, 95%CI=1.015-1.601). In the non-hypertensive group, the GA genotype of rs17809012 was significantly associated with LAA stroke (adjusted OR=1.361, 95%CI=1.041-1.780). The GG genotype of rs4795895 (adjusted OR=1.147, 95%CI=1.115-4.134) and the TT genotype of rs1860184 were significantly associated with lacunar stroke (adjusted OR=2.440, 95%CI=1.550-3.840). CONCLUSIONS This study demonstrates that the CCL11 gene could play an important role in the pathogenesis of lacunar stroke and LAA stroke in the Han population of China.

What is the impact of PCSK9 rs505151 and rs11591147 polymorphisms on serum lipids level and cardiovascular risk: a meta-analysis

Background

PCSK9 rs505151 and rs11591147 polymorphisms are identified as gain- and loss-of-function mutations, respectively. The effects of these polymorphisms on serum lipid levels and cardiovascular risk remain to be elucidated.

Methods

In this meta-analysis, we explored the association of PCSK9 rs505151 and rs11591147 polymorphisms with serum lipid levels and cardiovascular risk by calculating the standardized mean difference (SMD) and odds ratios (OR) with 95% confidence intervals (CI).

Results

Pooled results analyzed under a dominant genetic model indicated that the PCSK9 rs505151 G allele was related to higher levels of triglycerides (SMD: 0.14, 95% CI: 0.02 to 0.26, P = 0.021, I² = 0) and low-density lipoproteins cholesterol (LDL-C) (SMD: 0.17, 95% CI: 0.00 to 0.35, P = 0.046, I² = 75.9%) and increased cardiovascular risk (OR: 1.50, 95% CI: 1.19 to 1.89, P = 0.0006, I² = 48%). The rs11591147 T allele was significantly associated with lower levels of total cholesterol (TC) and LDL-C (TC, SMD: -0.45, 95% CI: -0.57 to −0.32, P = 0.000, I² = 0; LDL-C, SMD: -0.44, 95% CI: -0.55 to −0.33, P = 0.000, I² = 0) and decreased cardiovascular risk (OR: 0.77, 95% CI: 0.60 to 0.98, P = 0.031, I² = 59.9) in Caucasians.

Conclusions

This study indicates that the variant G allele of PCSK9 rs505151 confers increased triglyceride (TG) and LDL-C levels, as well as increased cardiovascular risk. Conversely, the variant T allele of rs11591147 protects carriers from cardiovascular disease susceptibility and lower TC and LDL-C levels in Caucasians. These findings provide useful information for researchers interested in the fields of PCSK9 genetics and cardiovascular risk prediction not only for designing future studies, but also for clinical and public health applications.

Association and differences in genetic polymorphisms in PCSK9 gene in subjects with lacunar infarction in the Han and Uygur populations of Xinjiang Uygur Autonomous Region of China

Polymorphisms in the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene are associated with severe hypercholesterolemia and stroke. Here, we investigated the relationship between single nucleotide polymorphisms in PCSK9 and stroke in 237 patients with lacunar infarction in the Uygur and Han populations in Xinjiang Uygur Autonomous Region of China. Using the SNaPshot single-base terminal extension method, four PCSK9 gene polymorphisms were analyzed. We found a significantly strong relationship between the PCSK9 rs17111503 (G > A) polymorphism and increased susceptibility to lacunar infarction by variant homozygote comparison, and using the dominant and recessive models in the Han population but not in the Uygur population. Low triglyceride levels were found in AA carriers (rs17111503, G > A) in the Han population but not in the Uygur population. Association analysis revealed that the rs17111503 (G > A) polymorphism was not significantly associated with smoking, alcohol drinking, history of hypertension or diabetes in the Han or Uygur lacunar infarction patients. rs11583680, rs483462 and rs505151 were not associated with risk of lacunar infarction in the Han or Uygur populations. Our findings suggest that the PCSK9 rs17111503 (G > A) polymorphism is associated with susceptibility to lacunar infarction in the Han population but not in the Uygur population.

A meta-analysis of adiponectin gene rs22411766 T>G polymorphism and ischemic stroke susceptibility

Several studies have investigated the correlation between adiponectin gene rs22411766 T>G polymorphism and ischemic stroke risk. However, the results were not conclusive with each other. Therefore, to overcome this obstacle, we performed this meta-analysis to further explicate the adiponectin gene rs22411766 T>G polymorphism and ischemic stroke susceptibility. Case-control or cohort studies focused on adiponectin gene rs22411766 T>G polymorphism and ischemic stroke risk were electronic searched in the databases of Medline, Pubmed, Cochrane library, Excerpta Medica database(EMBASE) and China National Knowledge Infrastructure (CNKI). All the potentially relevant studies were included in this meta-analysis. The association between adiponectin gene rs22411766 T>G polymorphism and ischemic stroke was expressed by odds ratio with its confidence interval. Publication bias has been assessed by begg's funnel plot. All the analyses have been performed by Revman 5.1 statistical software. Finally, a total of six studies with 1,345 cases and 1,421 controls were included in this meta-analysis. Our results demonstrated that there was a significant association between adiponectin gene rs22411766 T>G polymorphism and ischemic stroke risk (p<0.05). People with G single nucleotide of adiponectin gene have the increased risk of developing ischemic stroke compared to T single nucleotide.

The Influence of OLR1 and PCSK9 Gene Polymorphisms on Ischemic Stroke: Evidence from a Meta-Analysis

Both OLR1 and PCSK9 genes are associated with atherosclerosis, cardiovascular disease and ischemic stroke. The overall prevalence of PCSK9 rs505151 and OLR1 rs11053646 variants in ischemic stroke were 0.005 and 0.116, respectively. However, to date, association between these polymorphisms and ischemic stroke remains inconclusive. Therefore, this first meta-analysis was carried out to clarify the presumed influence of these polymorphisms on ischemic stroke. All eligible case-control and cohort studies that met the search terms were retrieved in multiple databases. Demographic and genotyping data were extracted from each study, and the meta-analysis was performed using RevMan 5.3 and Metafor R 3.2.1. The pooled odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using both fixed- and random-effect models. Seven case-control studies encompassing 1897 cases and 2119 controls were critically evaluated. Pooled results from the genetic models indicated that OLR1 rs11053646 dominant (OR = 1.33, 95%  CI:1.11–1.58) and co-dominant models (OR = 1.24, 95%  CI:1.02–1.51) were significantly associated with ischemic stroke. For the PCSK9 rs505151 polymorphism, the OR of co-dominant model (OR = 1.36, 95%  CI:1.01–1.58) was found to be higher among ischemic stroke patients. In conclusion, the current meta-analysis highlighted that variant allele of OLR1 rs11053646 G > C and PCSK9 rs505151 A > G may contribute to the susceptibility risk of ischemic stroke.

Angiotensinogen polymorphism and ischemic stroke risk

The angiotensinogen M235T polymorphism was associated with ischemic stroke risk. However, the results were controversial. Thus, a meta-analysis was conducted. NCBI, Medline, Web of Science and Embase databases were systematically searched. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using random-effects models. There was a significant association between angiotensinogen M235T polymorphism and ischemic stroke risk (OR = 1.69; 95% CI, 1.35-2.11; P < 0.001). In the stratified analysis by ethnicity, we found that this polymorphism was significantly associated with ischemic stroke in Asian (OR = 1.85; 95% CI, 1.45-2.35; P < 0.001). In the age subgroup, we found that angiotensinogen M235T polymorphism could increase both early-onset ischemic stroke risk (OR = 1.88; 95% CI, 1.33-2.43; P < 0.001) and late-onset ischemic stroke risk (OR = 1.20; 95% CI, 1.01-1.39; P = 0.04). This meta-analysis suggested that angiotensinogen M235T polymorphism was associated with ischemic stroke.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) in lipid metabolism, atherosclerosis and ischemic stroke

Proprotein convertase subtilisin/kexin 9 (PCSK9) is the ninth member of the proprotein convertase family. It is an important regulator of cholesterol metabolism. PCSK9 can bind to low-density lipoprotein receptors (LDLRs) and induce the degradation of these receptors through the endosome/lysosome pathway, thus decreasing the LDLR levels on the cell surface of hepatocytes, resulting in increased serum low-density lipoprotein cholesterol (LDL-C) concentrations. Recent studies have found that gene polymorphisms of PCSK9 are associated with hypercholesterolemia, risk of atherosclerosis, and ischemic stroke. Furthermore, monoclonal antibodies, peptide mimetics, small molecule inhibitors and gene silencing agents that are associated with PCSK9 are some of the newer pharmaceutical therapeutic strategies and approaches for lowering serum LDL-C levels. In this review, we will discuss recent advances in PCSK9 research, which show that PCSK9 is correlated with lipid metabolism, atherosclerosis, and, in particular, ischemic stroke. We will also discuss the current state of PCSK9 therapeutics and their potential in modulating these diseases.