Low Density Lipoprotein Receptor Gene Research Articles

Determination of selected oxysterol levels, oxidative stress, and macrophage activation indicators in children and adolescents with familial hypercholesterolemia.

Elevated levels of cholesterol in the bloodstream, also referred to as hypercholesterolemia, pose a significant risk for the onset of cardiovascular and cerebrovascular diseases. Oxysterols, cholesterol-derived oxidized compounds that form enzymatically or non-enzymatically, contribute to the development of atherosclerosis and coronary artery disease. This study aimed to examine the critical oxysterol levels in children and adolescents with hypercholesterolemia and explore the correlation between these levels, oxidative stress, and atherosclerosis progression. The study included 20 patients with familial hypercholesterolemia (FH) and 20 healthy individuals aged between 6 and 18 years. Participants were categorized into children (6-9 years) and adolescents (10-18 years). Pediatric and adolescent patients were selected from among subjects with LDL-C ≥ 130mg/dL and diagnosed with heterozygous familial hypercholesterolemia (HeFH) based on the presence of mutations in the LDL receptor (LDL-R) gene. Patients with HeFH who were receiving regular atorvastatin therapy were included in the study. There were no notable differences in catalase and paraoxonase (PON1) activities among the groups. However, the patient group displayed substantially higher levels of malondialdehyde (MDA) (P = 0.0108) and superoxide dismutase (SOD) activity (P = 0.0103). Compared to the healthy control group, serum chitotriosidase (CHITO) activity (P = 0.037) and chitinase 3-like protein 1 (YKL-40) levels (P = 0.0027) were significantly elevated in the patient group. Furthermore, the carotid intima-media thickness (CIMT) measurements of the patient group were significantly greater than those of the healthy group (**P < 0.0001****). The patient group exhibited significantly elevated levels of 5,6-α-epoxycholesterol, Cholestane-3β,5α,6β-triol (C-triol), and 7-ketocholesterol (7-KC), whereas 27-hydroxycholesterol (27-OHC) was significantly more abundant in the healthy group. On the other hand, while 27-OHC/Total cholesterol (Total-C) levels were significantly higher in healthy individuals, the C-Triol/Total-C ratio was significantly higher in patients. No significant differences were found between the groups in terms of 7-KC/Total-C and 5,6-α-epoxycholesterol/Total-C levels. This study highlights the key roles of oxysterols, oxidative stress, and macrophage activation in the development of atherosclerosis in pediatric and adolescent patients with FH. Elevated C-Triol levels in FH patients, alongside increased CIMT, point to early vascular changes despite atorvastatin therapy. In contrast, higher 27-OHC levels in healthy controls suggest differential oxysterol regulation due to cholesterol-lowering treatments in FH patients. C-Triol and 27-OHC/Total-C ratios showed potential as biomarkers to distinguish patients with FH. These findings emphasize the need for therapies targeting oxidative stress and macrophage activation in addition to cholesterol-lowering interventions.

Striate palmoplantar keratoderma: a novel DSG1 mutation, combined with an LDLR mutation.

Palmoplantar keratoderma (PPK) is a heterogeneous group of disorders characterized by abnormal thickening of the skin on the palms and soles. Striate palmoplantar keratoderma (SPPK) is commonly caused by heterozygous mutations in the desmoglein-1 (DSG1) gene. This study aimed to report a case of a 36-year-old Chinese female patient with SPPK caused by a novel DSG1 gene mutation, along with her family history, and explore its potential relationship with other genetic variants. Whole-exome sequencing was performed on the patient and their family members to identify the pathogenic mutation, which was validated by Sanger sequencing. Histological and electron microscopy analyses were conducted to examine the pathological characteristics of skin tissue.of skin tissue. A frameshift mutation, c.1285del, in exon 10 of the DSG1 gene was identified, leading to a loss of protein function and resulting in SPPK. This mutation was also detected in two other family members with similar phenotypes. Additionally, a classical splicing variant, c.313+2dup, in the low-density lipoprotein receptor (LDLR) gene associated with hypercholesterolemia was identified in the patient; however, no direct association with SPPK was observed. This study was the first to report a novel mutation in the DSG1 gene associated with SPPK and suggested a potential role of the LDLR gene variant in SPPK patients, providing new insights for further research into the genetic mechanisms underlying SPPK.

Serum megalin levels in type-2 diabetes mellitus with and without cardiovascular disease

ABSTRACT Background: Low-density lipoprotein receptor-related protein-2 (LRP2), also called megalin, is a multi-ligand receptor of the LDL receptor gene family mediating reabsorption of ligands like Apo-A1. Type 2 diabetes mellitus (T2DM) may possibly disrupt megalin functions as it is found to be regulated by insulin. This might cause cardiovascular complications due to derangement in lipoprotein metabolism. The current study was carried out to assess the serum megalin levels among T2DM individuals with cardiovascular complications in the Indian population. Methods: This was a cross-sectional study involving 80 patients with T2DM. 40 T2DM patients with known cardiovascular disease were selected as cases and 40 of those without evidence of cardiovascular disease were selected as controls. Demographic details, DM duration and class of oral hypoglycemic agents (OHA) used were collected from medical records while details of lipid profile, fasting glucose, serum creatinine and urea were collected from laboratory information system. Serum megalin levels were estimated using left-over samples by ELISA. Results: The study groups showed no statistical significance in baseline laboratory parameters except for serum creatinine and low density lipoprotein cholesterol (LDL-c). Mean serum megalin levels were statistically insignificant between cases and controls (0.91 ± 0.78 ng/mL vs. 0.85 ± 0.69 ng/mL, P 0.74).The subgroup analysis of serum megalin levels based on OHA consumption among cases was also statistically insignificant (P 0.056). Pearson’s correlational analysis was statistically insignificant between serum megalin and lipid profile parameters among cases (P &gt; 0.05). Conclusion: Serum megalin alone may not serve as a biomarker for cardiovascular disease.

Variants that get straight to your heart – Cardiogenetic secondary findings in exome sequencing

BackgroundExome sequencing has been established as a fundamental tool in genetic diagnostics. It may also provide information about variants in genes unrelated to the primary purpose, so-called secondary findings. Especially, diagnoses of unnoticed inborn cardiac diseases are of high clinical relevance due to therapeutic options in context of prevention of sudden cardiac death. MethodsExome data of 9962 individuals was analysed for relevant cardiogenetic findings. Genes were selected according to ACMG recommendations for secondary findings (v.3.1). First, a filter for (likely) pathogenic variants, published in the ClinVar database, was used. Second, exome data was screened for loss of function (LoF) variants in genes in which LoF is a known disease pathomechanism. All variants were evaluated by geneticists regarding their pathogenicity. ResultsPathogenic or likely pathogenic variants were identified in 136 different individuals (136/9962, 1.4%), with the Low-Density Lipoprotein Receptor gene (LDLR, 24/136, 17.6%) and the Titin gene (TTN, 24/136, 17.6%), being the most frequently affected ones. 31.6% (43/136) of the identified variants had been reported beforehand, while 47.1% (64/136) had not been reported. The remaining cases (29/136, 21.3%) were part of research projects with no written reports. In 26.5% (36/136), the finding would have been missed, if only index patients and not their parents had been screened for secondary findings in case of trio ES. ConclusionAs demonstrated in our study, at least one or two out of one hundred people are likely to carry a pathogenic cardiogenetic variant. Counselling geneticist and clinicians need to be aware of these findings in exome and genome sequencing. Informed consent of the patient regarding the report of secondary findings should absolutely be obtained beforehand.

Analysis of low-density lipoprotein receptor gene mutations in a family with familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is a common monogenic autosomal dominant disorder, primarily mainly caused by pathogenic mutations in the low-density lipoprotein receptor (LDLR) gene. Through phenotypic-genetic linkage analysis, two LDLR pathogenic mutations were identified in FH families: c.G1027A (p.Gly343Ser) and c.G1879A (p.Ala627Thr). Whole exome sequencing was conducted on the proband with familial hypercholesterolemia to identify the target gene and screen for potential pathogenic mutations. The suspicious responsible mutation sites in 14 family members were analyzed using Sanger sequencing to assess genotype-phenotype correlations. Mutant and wild type plasmids were constructed and transfected into HEK293T cells to evaluate LDLR mRNA and protein expression. In parallel, bioinformatics tools were employed to predict structural and functional changes in the mutant LDLR. Immunofluorescence analysis revealed no significant difference in the intracellular localization of the p.Gly343Ser mutation, whereas protein expression of the p.Ala627Thr mutation was decreased and predominantly localized in the cytoplasm. Western blotting has showed that protein expression levels of the mutant variants were markedly declined in both cell lysates and supernatants. Enzyme linked immunosorbent assay has demonstrated that LDLR protein levels in the supernatant of cell culture medium was not significant different from those of the wild-type group. However, LDLR protein levels in the cell lysate of both the Gly343Ser and Ala627Thr variants groups were significantly lower than those in the wild-type group. Bioinformatic predictions further suggested that these mutations may affect post-translational modifications of the protein, providing additional insight into the mechanisms underlying the observed reduction in protein expression. In this study, we identified two heterozygous pathogenic variants in the LDLR gene, c.G1027A (p.Gly343Ser) and c.G1879A (p.Ala627Thr), in a family with familial hypercholesterolemia. We also conducted preliminary investigations into the mechanisms by which these mutations contribute to disease pathology.

Lipoprotein apheresis: an established therapeutic modality for homozygous familial hypercholesterolemia patients refractory to PCSK9 inhibitors: a case report and literature review

Homozygous familial hypercholesterolemia (HoFH), is a rare genetic disorder characterized by dual mutations in the low-density lipoprotein receptor (LDLR) gene, leading to dysfunctional or absent LDLRs, often accompanied by severe premature Atherosclerotic Cardiovascular Disease (ASCVD) and exhibiting refractoriness to aggressive pharmacological interventions. Double filtration plasmapheresis (DFPP), a form of lipoprotein apheresis (LA), has been effectively utilized as an adjunctive treatment modality to reduce serum LDL-C levels in refractory cases of HoFH. Here, we report a case of a 36-year-old female with HoFH who developed xanthomas on her limbs and waist at age 7. Despite maximum-tolerated doses of statins from age 32, combined with ezetimibe and evolocumab, her LDL-C levels remained critically elevated at 12–14 mmol/L. Her genetic testing confirmed a homozygous LDLR mutation. At 35 years old, she experienced exertional chest pain, and percutaneous coronary intervention revealed severe calcific left main stenosis, necessitating stent implantation. Subsequently, she initiated once every 1–2 months DFPP. Pre-DFPP, her LDL-C and total cholesterol (TC) levels were 13.82 ± 3.28 and 15.45 ± 0.78 mmol/L, respectively. Post-DFPP, her LDL-C and TC levels significantly decreased to 2.43 ± 0.33 mmol/L (81.76 ± 4.11% reduction) and 3.59 ± 0.41 mmol/L (76.76 ± 2.75% reduction), respectively. Lipoprotein (a) and triglycerides also decreased by 89.10 ± 1.39% and 42.29 ± 15.68%,respectively. Two years later, there was no progression of coronary artery disease, and her symptoms and xanthomas regressed significantly. Collectively, DFPP effectively reduces LDL-C levels in refractory cases of HoFH and contributes to delaying ASCVD progression, representing an efficacious adjunctive therapeutic modality.

Gene Mutation in Patients with Familial Hypercholesterolemia and Response to Alirocumab Treatment-A Single-Centre Analysis.

Background: Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by significantly elevated levels of low-density lipoprotein (LDL) cholesterol, which plays a major role in the progression of atherosclerosis and leads to a heightened risk of premature atherosclerotic cardiovascular disease. Methods: We have carried out an observational study on a group of 17 patients treated at the Outpatient Lipid Clinic from 2019 to 2024. Result: The most frequent mutation observed was found in the LDL receptor (LDLR) gene, which was identified in ten patients (58.8%). Five patients were identified to have a mutation in the apolipoprotein B (APOB) gene, whereas two patients had two points mutations, one in the LDLR, and the other in the APOB gene. The average age of patients with LDLR mutation was 54.8 (12.3); for APOB mutation it was 61.4 (9.3) and for patients with two points mutation it was 61.5 (14.8). The study results showed that at Week 12, individuals with LDLR-defective heterozygotes who were given alirocumab 150 mg every two weeks experienced a 63.0% reduction in LDL cholesterol levels. On the other hand, individuals with APOB heterozygotes experienced a 59% reduction in LDL cholesterol levels. However, in patients with double heterozygous for mutations in LDLR and APOB genes, there was a hyporesponsiveness to alirocumab, and the reduction in LDL-C was only by 23% in two individuals. Conclusions: In patients with a single mutation, there was a greater response to treatment with alirocumab in contrast to patients with double heterozygous mutation, who did not respond to treatment with PCSK9 inhibitors.

Molecular diagnostics of familial hypercholesterolemia in Russia: yesterday, today and tomorrow

Familial hypercholesterolemia is a severe hereditary disease leading to the development of atherosclerosis and its complications in the form of angina pectoris, myocardial infarction, cerebral stroke, or even leading to sudden death. Since the description of the disease, the concept of it has undergone significant evolution. First, it became clear that the prevalence of this disease was significantly higher than originally thought (1:300 for heterozygous familial hypercholesterolemia and not as 1:500 as estimated earlier). Secondly, it has been established that it is not based on the pathology of the low-density lipoprotein receptor gene alone, but includes at least four monogenic forms (defects of the APOB, PCSK9, ARH genes) and may also have a multigenic nature. Thirdly, with the development of DNA analysis methods from the initially available Southern hybridization to next generation DNA sequencing, the exceptional molecular heterogeneity of familial hypercholesterolemia became obvious and, accordingly, the need to establish national spectra of mutations leading to the development of familial hypercholesterolemia was established. Researchers have moved from characterizing individual mutations to creating national registries and databases. Finally, research into the genetics of familial hypercholesterolemia has led to the emergence of new classes of cholesterol-lowering drugs. In Russia, molecular diagnostics of familial hypercholesterolemia has also undergone significant changes since the beginning of the study of familial hypercholesterolemia in 1987 and to the present, consideration of these changes formed the basis of this review.

Familial Hypercholesterolaemia Patients with LDLR Mutation Among Asian Population in Southeast Asian Countries: Systematic Review

Familial hypercholesterolaemia (FH) is a genetic disorder associated with premature cardiovascular diseases; however, the majority of patients remain undertreated. This systematic review aimed to determine the prevalence of FH patients with low-density lipoprotein receptor (LDLR) gene pathogenic variants (PV) among the Asian population in Southeast Asian countries. Our search yielded 1,120 citations, with 28 deemed possibly suitable based on title and abstract screening. However, only six studies that utilised the Dutch Lipid Clinic Network (DLCN) or Simon Broome (SB) criteria were eligible to be included. These studies provided prevalence figures for clinically diagnosed FH patients, with a total of 17.1% (n=1,005/5,874); this rate was represented by three Malaysian studies, which estimated that 36–76% of clinically diagnosed FH patients had LDLR PV. Most patients reported having pre-existing cardiovascular disease, a family history of premature coronary artery disease and tendon xanthomata. This study found that the prevalence of LDLR PV among genetically confirmed FH patients in Southeast Asia is 20.5% (n=286/5,874). Genetically confirmed FH patients are at a higher risk of developing premature coronary artery disease, requiring more aggressive lipid-lowering treatment. Therefore, identifying LDLR PV among the population is essential for early FH diagnosis and treatment. KEYWORDS Arterial disease, autosomal dominant, LDL receptor, LDLR prevalence, pathogenic variants, premature CAD, Undertreated

Association between Ava II Polymorphism in LDL Receptor Gene and Hyperlipidemic Ischemic Stroke Patients

Association between Ava II Polymorphism in LDL Receptor Gene and Hyperlipidemic Ischemic Stroke Patients

Investigation of Cytotoxicity and Lipid-lowering Effects of Rivea hypocrateriformis Desr. Leaf Extracts on HepG2 Cells: An In Vitro Study

Background and Purpose Chronic diseases, such as cardiovascular disease as well as type 2 diabetes, are associated with hyperlipidemia, characterized by high blood lipid levels. HepG2 cells, a human liver cancer cell line, have become a popular model for evaluating the effectiveness of drugs in treating hyperlipidemia. These cells are preferred due to their ability to mimic liver cell physiology and easy maintenance in culture. Methods In this study, HEP, HEC, HEA, and HEE extracts of Rivea hypocrateriformis were tested on HepG2 cells for cytotoxicity using the MTT assay. The IC50 values of the extracts were determined and compared to analyze their toxicity. Microscopic images of the cell lines were also examined to observe any structural changes induced by the extracts. Results and Conclusion The results showed that both HEC and HEE extracts exhibited significant toxicity on HepG2 cells at the highest concentration of 500 µg/ml. Gradual decreases in concentration led to a gradual rise in % cell viability. The IC50 values of HEC and HEE were calculated to be 61.49 µg/ml and 87.08 µg/ml, respectively, indicating that HEC was slightly more toxic than HEE. According to the results obtained using the vanilla method, HEC and HEE extracts markedly reduced lipid content compared to the oleic acid-induced group. The gene expression regulation of AMPK, FAS, LDL receptor, and HMG-CoA was investigated using the RT-PCR method. The results showed that the extract-treated groups exhibited higher AMPK and LDL receptor gene expression. In contrast, the HEE extract showed higher activity than HEC in suppressing the FAS gene. Overall, the findings suggest that HEC and HEE extracts have potential as anticancer and lipid-lowering agents. Detailed research is needed to understand how the active constituents work.

Familiar Hypercholesterolemia, Overview: A Lethal Hereditary Disorder with Simple Diagnosis and Affordable Treatment.

Familial hypercholesterolemia (FH) is an underdiagnosed disorder characterized by high concentration of low- density lipoprotein (c-LDL) from birth, and if left untreated, causes premature cardiovascular morbidity and mortality. An effective and inexpensive method for detecting FH is to determine c-LDL, and genetic study reveals asymptomatic relatives. The most frequent mutations occur in the LDL receptor gene (RLDL) and the least frequent are in apolipoprotein B100 (ApoB 100), apoprotein convertase subtilisin/kexin 9 (PCSK9) and LDL receptor adaptor 1 (RLDLAP1). Patients with heterozygous FH (HFHe) have c-LDL levels above 190 mg/dL; homozygous patients (HFHo) have the most severe form, with c-LDL above 500 mg/dL. Treatment is a low-fat diet and lipid-lowering drugs, mainly statins in combination with cholesterol absorption inhibitors (ezetimibe). In HFHo or severe heterozygotes resistant to treatment, the use of anti-PCSK9 monoclonal antibodies and c-LDL apheresis is considered, however, this is not available in countries such as Mexico. Even the lack of governmental programs for the systematic detection of FH is frequent. Therefore, this panoramic review shows the generalities, genetic basis, diagnosis, clinical characteristics, and treatment of FH, with the purpose of informing and calling the attention of health professionals, legislators, and the population at large.

Association of LDLR Gene Polymorphism with the Risk of Cardiovascular Disease in End-Stage Kidney Disease Patients on Maintenance Hemodialysis

Background The low-density lipoprotein receptor (LDLR) is essential for regulating intracellular cholesterol levels. Mutations in the LDLR gene can cause a increase in LDL cholesterol levels in the blood, elevating the vulnerability to cardiovascular disease (CVD). This study evaluated the correlation between the LDLR rs688 polymorphism and CVD risk in chronic kidney disease (CKD). Materials and Methods Polymorphism in this case-control study was genotyped using the TaqMan real-time polymerase chain reaction in a cohort of 100 CKD patients (Group I) and 100 healthy controls (Group II). We examined the LDLR rs688 allele and genotype distribution in 50 CKD cases with CVD and 50 cases without CVD. Results There was a significantly greater frequency of CT variant of LDL SNP rs688 in Group I than in Group II (p = 0.006). CT and TT genotypes were significantly higher in CKD patients with CVD, with odds ratios (ORs) (95% CI) of 4.3 (1.6–11.8, p = 0.004) and 7.6 (2.3–24.8, p = 0.001), respectively. Conclusion SNP rs688 C&gt;T detection in the LDLR gene showed that CT and TT genotypes are associated with elevated CVD risk in CKD.

Development of DNA-Based Lateral Flow Assay for Detection of LDLR Gene Mutation for Familial Hypercholesterolemia.

The techniques for detecting single nucleotide polymorphisms (SNP) require lengthy and complex experimental procedures and expensive instruments that may only be available in some laboratories. Thus, a deoxyribonucleic acid (DNA)-based lateral flow assay (LFA) was developed as a point-of-care test (POCT) diagnostic tool for genotyping. In this study, single nucleotide variation (E101K) in the low-density lipoprotein receptor (LDLR) gene leading to familial hypercholesterolemia (FH) was chosen as a model. Hypercholesterolemic individuals (n = 103) were selected from the Malaysian Cohort project (UKM Medical Molecular Biology Institute) while the control samples were selected from the Biobank (UKM Medical Molecular Biology Institute). The DNA samples were isolated from whole blood. Polymerase chain reaction (PCR) amplification process was performed using bifunctional labelled primers specifically designed to correspond to the variant that differentiates wild-type and mutant DNA for visual detection on LFA. The variant was confirmed using Sanger sequencing, and the sensitivity and specificity of the LFA detection method were validated using the Agena MassARRAY® technique. Out of 103 hypercholesterolemic individuals, 5 individuals (4.8%) tested positive for E101K, LDLR mutation and the rest, including healthy control individuals, tested negative. This result was concordant with Sanger sequencing and Agena MassARRAY®. These five individuals could be classified as Definite FH, as the DNA diagnosis was confirmed. The sensitivity and specificity of the variant detection by LFA is 100% compared to results using the genotyping method using Agena MassARRAY®. The developed LFA can potentially be used in the POC setting for detecting the E101K variant in the LDLR gene. This LFA can also be used to screen family members with E101K variant in the LDLR gene and is applicable for other SNP's detection.

Chenodeoxycholic Acid-Modified Polyethyleneimine Nano-Composites Deliver Low-Density Lipoprotein Receptor Genes for Lipid-Lowering Therapy by Targeting the Liver.

Lipid-lowering drugs, especially statins, are extensively utilized in clinical settings for the prevention of hyperlipidemia. Nevertheless, prolonged usage of current lipid-lowering medications is associated with significant adverse reactions. Therefore, it is imperative to develop novel therapeutic agents for lipid-lowering therapy. In this study, a chenodeoxycholic acid and lactobionic acid double-modified polyethyleneimine (PDL) nanocomposite as a gene delivery vehicle for lipid-lowering therapy by targeting the liver, are synthesized. Results from the in vitro experiments demonstrate that PDL exhibits superior transfection efficiency compared to polyethyleneimine in alpha mouse liver 12 (AML12) cells and effectively carries plasmids. Moreover, PDL can be internalized by AML12 cells and rapidly escape lysosomal entrapment. Intravenous administration of cyanine5.5 (Cy5.5)-conjugated PDL nanocomposites reveals their preferential accumulation in the liver compared to polyethyleneimine counterparts. Systemic delivery of low-density lipoprotein receptor plasmid-loaded PDL nanocomposites into mice leads to reduced levels of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TC) in the bloodstream without any observed adverse effects on mouse health or well-being. Collectively, these findings suggest that low-density lipoprotein receptor plasmid-loaded PDL nanocomposites hold promise as potential therapeutics for lipid-lowering therapy.

LDLR variant classification for improved cardiovascular risk prediction in familial hypercholesterolemia

Background and aimsFamilial hypercholesterolemia (FH) is a genetic disorder marked by high LDL cholesterol and an increased premature coronary artery disease (CAD) risk. Current dichotomous classification of LDL receptor gene (LDLR) variants may inadequately capture patient variability in LDL cholesterol levels and CAD risk. This study assessed a novel approach for determining LDLR variant severity using variant-specific LDL cholesterol percentiles. MethodsParticipants of the Dutch FH cascade screening program were screened for 456 LDLR variants. For each LDLR variant carrier, a sex- and age-specific LDL cholesterol percentile was derived from the LDL cholesterol level measured at study entry, i.e. generally from the blood drawn for DNA analysis. These percentiles were used to calculate the mean LDL cholesterol percentile for each variant. Based on the variant-specific LDL cholesterol percentiles, carriers were grouped into the following LDL cholesterol strata: <75th, 75th-88th, 88th-92nd, 92nd-96.5th, 96.5th-98th, and ≥98th percentile. Additionally, variants were categorized into class 1 (LDLR deficient) and non-class 1 (often LDLR defective) variants. CAD risk between carriers in the different LDL cholesterol strata and non-carriers was compared using a Cox proportional hazard model. ResultsOut of 35,067 participants, 12,485 (36 %) LDLR variant carriers (mean age 38.0 ± 20.0 years, 47.7 % male) were identified. Carriers had a 5-fold higher CAD risk compared with non-carriers. Hazard ratios for CAD increased gradually from 2.2 (95%CI 0.97–5.0) to 12.0 (95%CI 5.5–24.8) across the LDL cholesterol strata. A 7.3-fold and 3.9-fold increased CAD risk was observed in carriers of class 1 and non-class 1 LDLR variants, respectively. ConclusionsThis study presents a refined approach for classifying LDLR variants based on their impact on LDL cholesterol levels, allowing for more precise, genotype-specific CAD risk estimation in FH patients compared with traditional methods.

Generation of two familial hypercholesterolemia patient-specific induced pluripotent stem cell lines harboring heterozygous mutations in the LDLR gene

Familial hypercholesterolemia (FH) is a genetic disorder affecting the metabolism of lipoprotein, characterized by elevated levels of plasma concentrations of low-density lipoprotein cholesterol (LDLC). The most common FH cause is mutations within the gene that encodes for the LDL receptor (LDLR) protein. Two induced pluripotent stem cell (iPSC) lines were generated from patients with FH, each carrying a single heterozygous mutation in the LDLR gene, one is a missense mutation, c.631C > T, and the other is a splice-site mutation, c.313 + 1G > A. Both iPSC lines exhibited strong expression of pluripotency markers, demonstrated the ability to differentiate into derivatives of the three germ layers, and maintained normal karyotypes. These derived iPSC lines represent powerful tools for in vitro modeling FH and offer a promising platform for therapeutic development.

POLYMORPHISM OF LIPID METABOLISM GENES IN TATARSTAN-TYPE COWS

POLYMORPHISM OF LIPID METABOLISM GENES IN TATARSTAN-TYPE COWS

Impact of LDLR polymorphisms on lipid levels and atorvastatin’s efficacy in a northern Chinese adult Han cohort with dyslipidemia

BackgroundDyslipidemia, a significant risk factor for atherosclerotic cardiovascular disease (ASCVD), is influenced by genetic variations, particularly those in the low-density lipoprotein receptor (LDLR) gene. This study aimed to elucidate the effects of LDLR polymorphisms on baseline serum lipid levels and the therapeutic efficacy of atorvastatin in an adult Han population in northern China with dyslipidemia.MethodsIn this study, 255 Han Chinese adults receiving atorvastatin therapy were examined and followed up. The 3’ untranslated region (UTR) of the LDLR gene was sequenced to identify polymorphisms. The associations between gene polymorphisms and serum lipid levels, as well as changes in lipid levels after intervention, were evaluated using the Wilcoxon rank sum test, with a P < 0.05 indicating statistical significance. Assessment of linkage disequilibrium patterns and haplotype structures was conducted utilizing Haploview.ResultsEleven distinct polymorphisms at LDLR 3’ UTR were identified. Seven polymorphisms (rs1433099, rs14158, rs2738466, rs5742911, rs17249057, rs55971831, and rs568219285) were correlated with the baseline serum lipid levels (P < 0.05). In particular, four polymorphisms (rs14158, rs2738466, rs5742911, and rs17249057) were in strong linkage disequilibrium (r2 = 1), and patients with the AGGC haplotype had higher TC and LDL-C levels at baseline. Three polymorphisms (rs1433099, rs2738467, and rs7254521) were correlated with the therapeutic efficacy of atorvastatin (P < 0.05). Furthermore, carriers of the rs2738467 T allele demonstrated a significantly greater reduction in low-density lipoprotein cholesterol (LDL-C) levels post-atorvastatin treatment (P = 0.03), indicating a potentially crucial genetic influence on therapeutic outcomes. Two polymorphisms (rs751672818 and rs566918949) were neither correlated with the baseline serum lipid levels nor atorvastatin’s efficacy.ConclusionsThis research outlined the complex genetic architecture surrounding LDLR 3’ UTR polymorphisms and their role in lipid metabolism and the response to atorvastatin treatment in adult Han Chinese patients with dyslipidemia, highlighting the importance of genetic profiling in enhancing tailored therapeutic strategies. Furthermore, this investigation advocates for the integration of genetic testing into the management of dyslipidemia, paving the way for customized therapeutic approaches that could significantly improve patient care.Trial registrationThis multicenter study was approved by the Ethics Committee of Xiangya Hospital Central South University (ethics number K22144). It was a general ethic. In addition, this study was approved by The First Hospital of Hebei Medical University (ethics number 20220418).

Abstract 4448: Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples

Abstract Introduction: Clinically active KRASG12C inhibitors have represented a key research breakthrough and led to novel treatment options for lung, colorectal and other cancer patients harboring this mutation. While treatment with KRASG12C inhibitors are clinically active in the majority of patients, the depth and duration of response is variable and most patients ultimately progress. This variation in therapeutic response highlights the need for a better understanding of drug mechanism of action and the identification of rational combination strategies. Oncogenic KRAS mutations hyperactivate the MAPK pathway, create an immunosuppressive tumor microenvironment, and promote glycolysis even in the presence of oxygen commonly known as the Warburg effect. This altered metabolic state is marked by increased glucose uptake and lactate production, providing necessary substrates for rapid tumor growth. Results: Pharmacological inhibition of KRASG12C with a potent and selective KRASG12C inhibitor, adagrasib, revealed marked alterations of metabolic gene expression programs in tumor samples collected from mouse xenograft studies and repeat biopsies provided by patients enrolled on adagrasib clinical trials. Upregulation of genes involved in reverse cholesterol transport including ApoE, NR1H3 (LXRa) and ABCA1 was observed across both preclinical tumor xenografts and patient samples following adagrasib treatment. Additionally, decreased expression of Glut1 and low-density lipoprotein receptor (LDLR) genes were also observed in both tumor models and patients suggesting that adagrasib treatment results in an extensive shift in uptake and utilization of cholesterol, lipid, and glucose. The impact of adagrasib treatment on circulating metabolic parameters in tumor xenograft-bearing mice were investigated in follow up studies. Conclusions: Taken together, these data suggest adagrasib modulates cholesterol efflux, glucose and lipid pathways and alters tumor and systemic metabolic regulation. Additional research may yield a targetable collateral vulnerability and rational combinatorial strategy. Citation Format: Fabiola Shelton, Natalie Hoffman, David Trinh, Xousaen M. Helu, Andrew Calinisan, Allan Hebbert, Larry Yan, David M. Briere, Laura Hover, Julio Fernandez-Benet, Kenna Anderes, James G. Christensen, Jill Hallin, Peter Olson. Effects of adagrasib on cholesterol, lipid and glucose gene expression regulation in tumor xenograft models and patient samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4448.