A systematic review of LDLR, PCSK9, and APOB variants in Asia

HIF-1α and VEGF Immunophenotypes as Potential Biomarkers in the Prognosis and Evaluation of Treatment Efficacy of Atherosclerosis: A Systematic Review of the Literature

BACKGROUND

Hypoxia-inducible factor 1 alpha (HIF-1α) and its related vascular endothelial growth factor (VEGF) may play a significant role in atherosclerosis and their targeting is a strategic approach that may affect multiple pathways influencing disease progression. This study aimed to perform a systematic review to reveal current evidence on the role of HIF-1α and VEGF immunophenotypes with other prognostic markers as potential biomarkers of atherosclerosis prognosis and treatment efficacy.

METHODS

We performed a systematic review of the current literature to explore the role of HIF-1α and VEGF protein expression along with the relation to the prognosis and therapeutic strategies of atherosclerosis. We used the terms {"Atherosclerosis" [OR] "Atheroma" [OR] "atheromatous plaque" [OR] "plaque atherosclerotic"} [AND] {"HIF-1α"} [AND] {"VEGF"} from 2009 up to May 2024 and the Medline/Embase/PubMed database. We used methodological approaches to assess unbiased data [ROBIS (Risk of Bias in Systematic) tool]. We used study eligibility criteria, and data were collected and evaluated from original articles by two independent teams, judged by an independent reviewer, and reported by PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) 2020.

RESULTS

We included 34 original studies investigating 650 human specimens, 21 different cell lines, and 9 animal models. Increased HIF-1α in vascular smooth muscle cells, macrophages, or endothelial cells, under hypoxia, chronic loss of nitric oxide (NO), or reduced micro ribonucleic acid (miRNA)-17 and miR-20, is associated with the upregulation of pro-inflammatory molecules, such as interleukin-1 beta (IL-1β) or tumor necrosis factor-alpha (TNF-α), increased migration inhibitory factor of macrophages, glycolytic flux, lipid accumulation, necroptosis via miR-383, and adverse effects in atherosclerosis and plaque vulnerability. However, increased HIF-1α in lymphocytes is associated with decreased interferon-gamma (IFN-γ) and a favorable prognosis. Increased VEGF in a coronary artery, activated macrophages, or chronic exposure to methamphetamine is associated with elevated levels of serum inflammatory cells (interleukin-18; IL18), p38 mitogen-activated protein kinase (MAPK) phosphorylation, lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF), and signal transducer and activator of transcription 6 isoform B (STAT6B) overexpression, leading to atherosclerosis progression and plaque break. However, VEGF overexpression in serum is marginally associated with an elevated risk for atherosclerosis. In contrast, stable overexpression of VEGF in macrophages correlates with reduced hyperplasia after arterial injury, reduced foam cell formation, and attenuation of atherosclerosis progression. HIF-1α/VEGF immunophenotypes reflect atherosclerosis treatment efficacy using, among others, HIF-inhibitors, statins, polyphenols, miR-497-5p, methylation modification, adenosine receptor antagonists, natural products, or glycosides.

CONCLUSION

We present an overview of HIF-1α/VEGF expression in chronic inflammatory-related atherosclerosis disease. Exploring pathogenetic mechanisms and therapeutic options, we included several studies using variable methods to evaluate HIF-1α/VEGF immunophenotypes with controversial and innovative results. Data limitations may include the use of different survival methods. Our data support HIF-1α/VEGF immunophenotypes as potential biomarkers of atherosclerosis prognosis and treatment efficacy.

Prevalence of genetically diagnosed familial hypercholesterolemia in Vietnamese patients with premature acute myocardial infarction

Familial hypercholesterolemia (FH) is a genetic disorder that results in elevated low-density lipoprotein cholesterol (LDL-C) levels, which manifest early in the first decades of life. It is a major cause of premature coronary artery disease worldwide, leading to significant public health challenges. The prevalence of genetically determined FH in patients with premature coronary artery disease remains underestimated, particularly in developing countries. This study aimed to assess the prevalence of genetically defined FH in Vietnamese patients with premature acute myocardial infarction (AMI) in the Vietnamese population. This cross-sectional study enrolled 218 consecutive patients diagnosed with premature AMI who underwent coronary angiography. The low-density lipoprotein receptor (LDLR), apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 genes were analyzed by next-generation sequencing. FH was diagnosed according to Dutch Lipid Clinic Network criteria. Among the patients with premature AMI who underwent coronary angiography, the mean age was 46.9 ± 6.1 years, with a predominance of males (83.9%). The prevalence of potential FH diagnosed using Dutch Lipid Clinic Network criteria was 14.7% (definite FH, 6.0%; probable FH, 8.7%). Pathogenic or likely pathogenic variants in LDLR, apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 were found in 9 of 218 patients (4.1%), all of which were causative mutations in LDLR. Patients with premature AMI and FH had significantly greater LDL-C levels (217.6 vs 125.7 mg/dL) and more severe coronary artery lesions, as assessed by the Gensini score (100.3 vs 60.5), than did those in the No FH group. The prevalence of genetically determined FH among Vietnamese patients with premature AMI is relatively high. Screening and diagnosis of hereditary conditions in patients with premature AMI are essential to improve early detection and management and reduce the burden of coronary artery disease in this population.

Evaluating the Impact of Omega-3 Fatty Acid (SolowaysTM) Supplementation on Lipid Profiles in Adults with PPARG Polymorphisms: A Randomized, Double-Blind, Placebo-Controlled Trial

Emerging evidence suggests that PPARG gene polymorphisms may influence lipid metabolism and cardiovascular risk, with omega-3 fatty acids proposed to modulate these effects. This study aims to assess the effects of fish oil supplementation on cardiovascular markers among adults with PPARG gene polymorphisms in a randomized, double-blind, placebo-controlled trial. A cohort of 102 patients with LDL-C 70-190 mg/dL was randomized to receive either 2000 mg of omega-3 fatty acids or a placebo daily for 90 days. In the omega-3 group with PPARG polymorphisms, LDL-C was reduced by 15.4% (95% CI: -19.8% to -11.0%), compared with a 2.6% decrease in the placebo group (95% CI: -4.1% to -1.1%; p < 0.01). In the omega-3 group without PPARG polymorphisms, LDL-C was reduced by 3.7% (95% CI: -6.9% to -0.6%), not significantly different from the placebo group's reduction of 2.9% (95% CI: -5.1% to -0.8%; p = 0.28). The reduction in LDL-C was notably 11.7% greater in those with PPARG polymorphisms than in those without (95% CI: -19.3% to -4.0%; p < 0.01). Triglycerides decreased by 21.3% in omega-3 recipients with PPARG polymorphisms (95% CI: -26.5% to -16.2%; p < 0.01), with no significant changes in HDL-C, total cholesterol, or hsCRP levels in any groups. Minor allele frequencies and baseline characteristics were comparable, ensuring a balanced genetic representation. Omega-3 fatty acids significantly reduce LDL-C and triglycerides in carriers of PPARG polymorphisms, underlining the potential for genetic-driven personalization of cardiovascular interventions.

Expanding the genetic spectrum for Chinese familial hypercholesterolemia population with six genetic mutations identified using a next-generation sequencing-based laboratory-developed screening test

BACKGROUND

This study was to reveal the prevalence of definite familial hypercholesterolemia (FH) in the hospital-visiting population, determine the pathogenic mutation detection rate in clinically diagnosed definite FH patients, and expand the FH mutation spectrum in China.

METHODS

Blood lipid profiles of 41,803 patients visiting the hospital were investigated and 4967 patients with clinical diagnoses of other metabolic diseases were excluded. One hundred and seventy-three (0.41%) received a definite diagnosis of FH according to the Dutch Lipid Clinical Network Criteria-Chinese Revised Version (DLCN-CRV), and 18 patients subsequently agreed to undergo genetic testing. A next-generation sequencing (NGS)-based laboratory-developed test covering the exonic regions of 24 lipid metabolism-related genes was conducted alongside in silico analyses to identify possible FH mutations in 16 definite FH patients, according to the American College of Medical Genetics and Genomics (ACMG) criteria. Sanger sequencing was used to confirm mutations, and SWISS-MODEL was used to simulate the molecular structures of the confirmed protein-carrying mutations.

RESULTS

The FH prevalence was 0.41% for the 41,803 individuals (DLCN-CRV grade >8) and 25% of definite FH patients carried six FH pathogenic mutations (≥ACMG Class 4). All genetic variants were confirmed by Sanger sequencing. Five pathogenic variants on the LDLR gene (NM_000527: c.C1783T: p.R595W, c.T493G: p.W165G, c.G1879A: p.A627T, c.G682T: p.E228X, and exon10: c.G1432A: p.G478R) and one pathogenic variant on APOB (NM_000384: c.C10579T: p.R3527W) in 25% of the identified definite FH patients. Two pathogenic mutations, c.T493G (p.W165G) and c.C1783T (p.R595W), were added to the current genetic spectrum of FH in China.

CONCLUSION

This study contributes to improving the current FH detection rate and genetic screening strategies; it provides new directions for treatment, management, and drug development.

Relationship between Brain Metabolic Disorders and Cognitive Impairment: LDL Receptor Defect

The low-density-lipoprotein receptor (LDLr) removes low-density lipoprotein (LDL), an endovascular transporter that carries cholesterol from the bloodstream to peripheral tissues. The maintenance of cholesterol content in the brain, which is important to protect brain function, is affected by LDLr. LDLr co-localizes with the insulin receptor and complements the internalization of LDL. In LDLr deficiency, LDL blood levels and insulin resistance increase, leading to abnormal cholesterol control and cognitive deficits in atherosclerosis. Defects in brain cholesterol metabolism lead to neuroinflammation and blood–brain-barrier (BBB) degradation. Moreover, interactions between endoplasmic reticulum stress (ER stress) and mitochondria are induced by ox-LDL accumulation, apolipoprotein E (ApoE) regulates the levels of amyloid beta (Aβ) in the brain, and hypoxia is induced by apoptosis induced by the LDLr defect. This review summarizes the association between neurodegenerative brain disease and typical cognitive deficits.

Development of an Optimized Tetra-Amplification Refractory Mutation System PCR for Detection of 12 Pathogenic Familial Hypercholesterolemia Variants in the Asian Population

Early detection of genetic diseases such as familial hypercholesterolemia (FH), and the confirmation of related pathogenic variants, are crucial in reducing the risk for premature coronary artery disease. Currently, next-generation sequencing is used for detecting FH-related candidate genes but is expensive and time-consuming. There is a lack of kits suitable for the detection of the common FH-related variants in the Asia-Pacific region. Thus, this study addressed that need with the development of an optimized tetra-amplification mutation system (T-ARMS) PCR-based assay for the detection of 12 pathogenic variants of FH in the Asian population. The two important parameters for T-ARMS PCR assay performance-annealing temperature and the ratio of outer/inner primer concentrations-were optimized in this study. The optimal annealing temperature of all 12 T-ARMS PCR reactions was 64.6°C. The ideal ratios of outer/inner primer concentrations with each pathogenic variant were: A1, 1:2; A2, 1:4; L1, 1:10; L2, 1:1; L3, 1:2; L4, 1:8; L5, 1:1; L6, 1:2; L7, 1:8; L8, 1:8; L9, 1:2; and L10, 1:8. The lowest limit of detection using DNA extracted from patients was 0.1 ng. The present article highlights the beneficial findings on T-ARMS PCR as part of the development of a PCR-based detection kit for use in detecting FH in economically developing countries in Asia with a greater prevalence of FH.

Identification and Functional Characterization of a Low-Density Lipoprotein Receptor Gene Pathogenic Variant in Familial Hypercholesterolemia

We report a single-point variant of low-density lipoprotein receptor (LDLR) in a Chinese proband with a clinical diagnosis of familial hypercholesterolemia (FH) with a comprehensive functional analysis. Target exome capture-based next-generation sequencing was used for sequencing and identification of genomic variants in the LDLR gene. The expression, cellular location, and function of the mutant LDLR were analyzed. Sequencing of LDLR in FH patients indicated a point variant of single-base substitution (G < A) at a position of 2389 in the 16th exon, which led to a loss of the 16th exon in the LDLR messenger RNA. This genomic variant was found to cause exon 16 deletion in the mutant LDLR protein. Subsequent functional analyses showed that the mutant LDLR was retained in the Golgi apparatus and rarely expressed in the cellular membranes of HepG2 cells. Accordingly, the intake ability of HepG2 cells with the mutant LDLR was significantly reduced (P < 0.05). In conclusion, our results suggest that a mutant with a single-base substitution (c. 2389G > A) in the 16th exon of the LDLR gene was associated with miscleavage of messenger RNA and the retention of mutant LDLR in the Golgi apparatus, which revealed a pathogenic variant in LDLR underlying the pathogenesis of FH.

The Spectrum of Low-Density Lipoprotein Receptor Mutations in a Large Turkish Cohort of Patients with Familial Hypercholesterolemia

Background: Monogenic hypercholesterolemia with Mendelian inheritance is a heterogeneous group of diseases that are characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C) levels, and the most common form of this disorder is autosomal-dominant familial hypercholesterolemia (FH). Methods: A total of 104 index cases with the clinical diagnosis of FH were included in this study. Low-density lipoprotein receptor (LDLR) was sequenced using the Sanger sequencing method. Results: Pathogenic/likely pathogenic variants were detected in LDLR in 55 of the 104 cases (mutation detection rate = 52.8%). Thirty different variants were detected in LDLR, three of which were novel. The total cholesterol and LDL-C values of the patients in the group of premature termination codon (PTC) mutation carriers were significantly higher than those of the patients in the group of non-PTC mutation carriers. A total of 87 patients (17 pediatric and 70 adult cases) were diagnosed with cascade genetic screening. Statin treatment was recommended to all 87 patients and was accepted and initiated in 70 of these patients. Conclusions: This study is the largest patient cohort that evaluated FH cases in the Turkish population. Herein, we revealed the LDLR mutation spectrum for a Turkish population and compared the cases in the context of genotype-phenotype correlation. Genetic screening of individuals with suspected FH not only helps to establish their diagnosis, but also facilitates early diagnosis and treatment initiation in other family members through cascade screening.