OBJECTIVE: To analyze variant of LDLR gene in a patient with familial hypercholesterolemia (FH) in order to provide a basis for the clinical diagnosis and genetic counseling. METHODS: A patient who had visited the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University in June 2020 was selected as the study subject. Clinical data of the patient was collected. Whole exome sequencing (WES) was applied to the patient. Candidate variant was verified by Sanger sequencing. Conservation of the variant site was analyzed by searching the UCSC database. RESULTS: The total cholesterol level of the patient was increased, especially low density lipoprotein cholesterol. A heterozygous c.2344A>T (p.Lys782*) variant was detected in the LDLR gene. Sanger sequencing confirmed that the variant was inherited from the father. CONCLUSION The heterozygous c.2344A>T (p.Lys782*) variant of the LDLR gene probably underlay the FH in this patient. Above finding has provided a basis for genetic counseling and prenatal diagnosis for this family.
Humans ; Cholesterol, LDL/genetics* ; Heterozygote ; Hyperlipoproteinemia Type II/genetics* ; Mutation ; Pedigree ; Phenotype ; Receptors, LDL/genetics*

OBJECTIVE: To explore the correlation between clinical phenotypes and pathogenic variants in two patients with familial hypercholesterolemia. METHODS: Both patients were subjected to whole exome sequencing (WES) with a focus on the analysis of genes associated with dyslipidemia. Candidate variants were verified by Sanger sequencing of the patients and their family members. RESULTS: WES revealed that the proband 1 has harbored two heterozygous variants of the LDLR gene, namely c.1360G>A (p.D454N) and c.292G>A (p.G98S), whilst proband 2 has harbored a heterozygous c.321T>G (p.C107W) variant of the LDLR gene. Based on the guidelines from the American College of Medical Genetic and Genomics (ACMG), the above variants were respectively predicted to be likely pathogenic (PM1+PM2+PP2+PP3+PP4+PP5), variant of unknown significance (PM1+PP2+PP3), and likely pathogenic (PM1+PM2+PP2+PP4+PP5). Treatment with PCSK9 inhibitor has attained a significant effect in proband 1 but no apparent effect in proband 2. CONCLUSION Variants of the LDLR gene probably underlay the familial hypercholesterolemia in the two pedigrees. The difference in the severity of the clinical phenotypes and response to PCSK9 inhibitor treatment between the two probands may be attributed to the different genotypes of the LDLR gene. Genetic testing not only can provide a basis for clinical diagnosis, but also facilitate the choice of lipid-lowering drugs.
Humans ; China ; Hyperlipoproteinemia Type II/genetics* ; Phenotype ; Receptors, LDL/genetics*

This study explores the regulatory effect of astragaloside Ⅳ on miR-17-5 p and its downstream proprotein convertase subtillisin/kexin type 9(PCSK9)/very low density lipoprotein receptor(VLDLR) signal pathway, aiming at elucidating the mechanism of astragaloside Ⅳ against atherosclerosis(AS). In cell experiment, oxidized low-density lipoprotein(ox-LDL) was used for endothelial cell injury modeling with vascular smooth muscle cells(VSMCs). Then cells were classified into the model group, miR-17-5 p inhibitor group, blank serum group, and astragaloside Ⅳ-containing serum group based on the invention. Afterward, cell viability and the expression of miR-17-5 p, VLDLR, and PCSK9 mRNA and protein in cells in each group were detected. In animal experiment, 15 C57 BL/6 mice were used as the control group, and 45 ApoE~(-/-) mice were classified into the model group, miR-17-5 p inhibitor group, and astragaloside Ⅳ group, with 15 mice in each group. After 8 weeks of intervention, the peripheral serum levels of interleukin-6(IL-6), interleukin-10(IL-10), and tumor necrosis factor-α(TNF-α), and the expression of miR-17-5 p, VLDLR, and PCSK9 mRNA in the aorta of mice were detected. The pathological changes of mice in each group were observed. According to the cell experiment, VSMC viability in the miR-17-5 p inhibitor group and the astragaloside Ⅳ-containing serum group was higher than that in the model group(P<0.05). The mRNA and protein expression of miR-17-5 p and VLDLR in VSMCs in the miR-17-5 p inhibitor group and the astragaloside Ⅳ-containing serum group was lower than that in the model group(P<0.05), but the mRNA and protein expression of PCSK9 was higher than that in the model group(P<0.05). As for the animal experiment, the levels of IL-6 and TNF-α in the peripheral serum of the miR-17-5 p inhibitor group and the astragaloside Ⅳ group were lower(P<0.05) and the serum level of IL-10 was higher(P<0.05) than that of the model group. The mRNA expression of miR-17-5 p and VLDLR in the aorta in the miR-17-5 p inhibitor group and the astragaloside Ⅳ group was lower(P<0.05), and PCSK9 mRNA expression was higher(P<0.05) than that in the model group. Pathological observation showed mild AS in the miR-17-5 p inhibitor group and the astragaloside Ⅳ group. In summary, astragaloside Ⅳ can prevent the occurrence and development of AS. The mechanism is that it performs targeted regulation of miR-17-5 p, further affecting the PCSK9/VLDLR signal pathway, inhibiting vascular inflammation, and thus alleviating endothelial cell injury.
Animals ; Atherosclerosis/genetics* ; Lipoproteins, LDL/metabolism* ; Mice ; MicroRNAs/metabolism* ; Proprotein Convertase 9/metabolism* ; Receptors, LDL/metabolism* ; Saponins ; Signal Transduction ; Triterpenes

BACKGROUNDFamilial hypercholesterolemia (FH), caused by low density lipoprotein (LDL) receptor (LDL-R) gene mutations, is associated with increased risk of premature coronary heart disease. Until now, limited molecular data concerning FH are available in China. The present study described the clinical profiles and cell biological defects of a Chinese FH kindred with novel LDL-R gene mutation.

METHODSThe patient's LDL-R gene coding region was sequenced. The patient's lymphocytes were isolated and the LDL-R expression, binding and up-take functions were observed by immunohistochemistry staining and flow cytometry detection. The patient's heart and the major large vessels were detected by vessel ultrasound examination and myocardial perfusion imaging (MPI).

RESULTSThe patient's LDL-R expression, LDL binding and up-take functions were significantly lower than normal control (39%, 63% and 76% respectively). A novel homozygous 1439 C-->T mutation of the LDL-R gene was detected in the patient and his family. ECG showed atypical angina pectoris. Echocardiogram showed stenosis of the coronary artery and calcification of the aortic valve and its root. Blood vessel ultrasound examination showed the thickness of large vessel intima, and the vessel lumen was narrowed by 71%. MPI showed ischemic changes.

CONCLUSIONSThe LDL-R synthesis dysfunction of FH patients leads to arterial stenosis and calcification, which are the major phenotype of the clinical disorder. The mutation of the LDL-R gene is determined. These data increase the mutational spectrum of FH in China.

Adult ; Child, Preschool ; Homozygote ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Middle Aged ; Mutation ; Receptors, LDL ; genetics ; physiology

Genetic Testing ; Humans ; Hyperlipoproteinemia Type II/genetics* ; Pedigree ; Receptors, LDL/genetics*

OBJECTIVE: To screen for LDLR gene mutations in 9 patients with familial hypercholesterolemia (FH). METHODS: All exons of the LDLR gene and flanking intronic sequences were amplified by PCR and subjected to automatic DNA sequencing. For patients with homozygous or compound heterozygous mutations, parental DNA sequencing or T cloning sequencing was carried out to determine the parental origin of the mutant alleles. RESULTS: Direct sequencing of PCR products revealed 8 LDLR variants in 7 patients, which included c.259T>G, c.513delC, c.530C>T, c.682G>T, c.763C>T, c.1187-10G>A, c.1948delG, and c.1730G>A, among which c.1948delG was novel. Four patients have carried heterozygous mutations, two carried homozygous mutations, and one carried compound heterozygous mutations. The patients with biallelic mutations presented with a more severe phenotype compared those carrying heterozygous mutations. CONCLUSION LDLR mutations were identified in 7 out of 9 patients with FH. Among the 8 identified LDLR mutations, c.1948delG was firstly reported. Above findings have expanded the mutation spectrum of LDLR gene.
DNA Mutational Analysis ; Genetic Testing ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Mutation ; Phenotype ; Receptors, LDL ; genetics

OBJECTIVE: To investigate the effect of reinioside C (RC) on the expression of lectin-like oxidized low density lipoprotein receptor (LOX)-1 mRNA and LOX-1 protein induced by oxidized low density lipoprotein (ox-LDL) in cultured human umbilical vein endothelial cells (HUVEC). METHODS: HUVECs were cultured with ox-LDL (50 mg/L) for 24 h in the absence or presence of RC (1, 3, and 10 micromol/L). The expressions of LOX-1 mRNA and LOX-1 protein were examined by RT-PCR and Western-blot. RESULTS: Incubation with ox-LDL (50 mg/L) significantly raised the expression of LOX-1 mRNA and LOX-1 protein,which was concentration-dependent. CONCLUSION RC can inhibit the increased expression of LOX-1 mRNA and LOX-1 protein induced by ox-LDL in HUVECs.
Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Endothelium, Vascular ; Humans ; Lipoproteins, LDL ; pharmacology ; Polygala ; chemistry ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, LDL ; biosynthesis ; genetics ; Saponins ; pharmacology ; Umbilical Veins ; cytology ; metabolism

OBJECTIVETo investigate if inflammatory stress enhances liver lipid accumulation via SREBPs mediated dysregulation of low density protein receptor (LDLr) expression in apolipoprotein E, scavenger receptors class A and CD36 triple knockout (ApoE/SRA/CD36 KO) mice.

METHODS16 Male ApoE/SRA/CD36 KO mice were subcutaneously injected with 0.5 ml 10% casein or PBS. The mice were fed a Western diet (Harlan, TD88137) containing 21% fat and 0.15% of cholesterol for 14 weeks. Animals were sacrificed and blood samples were collected. The serum amyloid A (SAA), IL-6, total cholesterol (TC), LDL and high density protein (HDL) were assayed. The lipid accumulation in liver was evaluated by Oil Red O staining. The mRNA and protein expression of SREBP-2, SREBPs cleavage activating protein (SCAP) and LDLr were analyzed by Real-Time Polymerase Chain Reaction (RT-PCR) and immunohistochemistry staining.

RESULTSBlood levels of SAA [(26.60+/-3.24) ng/ml vs (14.35+/-1.73) ng/ml, P < 0.01] and IL-6 [(36.37+/-2.20) pg/ml vs (18.02+/-4.87) pg/ml, P < 0.01] were higher, while TC [(7.72+/-1.70) mmol/L vs (13.23+/-3.61)mmol/L, P less than 0.01], LDL-cholesterol [(2.94+/-0.44) mmol/L vs (9.28+/-3.66) mmol/L, P less than 0.01] and HDL cholesterol [(2.24+/-0.63) mmol/L vs (4.13+/-0.42) mmol/L, P less than 0.01] were lower in inflamed mice compared to controls. ORO staining showed that lipid accumulation in the liver was more extensive in inflamed group despite lower blood lipid levels. Meanwhile, Real Time PCR data showed inflammation induced the expression of LDLr (4.56 fold), SCAP (3.14 fold) and SREBP-2 (14.72 fold) in liver. Immunohistochemical staining also indicated increased proteins expression in the liver, which was consistent with mRNA data.

CONCLUSIONSInflammation causes lipid accumulation in liver via disrupting SREBP-2 and LDLr expression.

Animals ; Apolipoproteins E ; genetics ; Cholesterol, LDL ; metabolism ; Fatty Liver ; metabolism ; Inflammation ; metabolism ; Liver ; metabolism ; Male ; Mice ; Mice, Knockout ; Receptors, LDL ; metabolism ; Sterol Regulatory Element Binding Protein 2 ; metabolism

OBJECTIVE To investigate the relationship between the Nco I, Ava II polymorphism of low density lipoprotein receptor (LDL-R) gene in patients with the occurrence of atherosclerotic cerebral infarction (ACI) among the Han nationality in Liaoning province. METHODS The polymerase chain reaction technique was used to study the polymorphisms of LDL-R gene and allele frequencies in 77 patients with ACI and in 113 age-matched Chinese healthy controls. The levels of the lipid and lipoproteins were also compared among the cases with ACI and the controls. RESULTS A(+) frequencies of LDL-R gene in healthy controls and ACI group were 0.230 and 0.125 respectively, while the N(+) frequencies of healthy control and ACI group was 0.667 and 0.662 respectively. In case of the coexistence of A(-) A(-) and N(+) N(+), the relative risk (RR) of ACI was 5.56(P<0.001), while the RR of the increase of serum levels TG, TC, LDL-C, LP(a) were 4.29, 7.67, 9.33 and 3.09(P<0.05), respectively. CONCLUSION The coexistence of A(-) A(-) and N(+) N(+) can affect the concentration of lipid and lipoprotein and is in close relationship with the occurrence of ACI.
Apolipoprotein A-I ; blood ; Apolipoproteins B ; blood ; Binding Sites ; genetics ; Cerebral Infarction ; blood ; genetics ; Cholesterol ; blood ; Cholesterol, LDL ; blood ; DNA ; genetics ; metabolism ; Deoxyribonucleases, Type II Site-Specific ; metabolism ; Genotype ; Humans ; Intracranial Arteriosclerosis ; blood ; genetics ; Lipoproteins ; blood ; Receptors, LDL ; genetics ; Triglycerides ; blood

OBJECTIVE: To investigate the effect of miR-590-5p on the expression of lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) in apoptotic human umbilical vein endothelial cells (HUVECs) induced by ox-LDL, and to explore the role of miR-590-5p in modulating HUVECs apoptosis. METHODS: HUVECs were exposed to ox-LDL (50 μg/mL) for 0 to 48 h. Apoptosis was detected by Annexin V-FITC stain and was distinguished from necrosis by propidium iodide (PI) staining. The relative expression level of miR-590-5p in HUVECs was analyzed using real-time quantitative PCR (RT-qPCR). HUVECs were transfected with miR-590-5p mimics or miRNA mimics control followed by 50 μg/mL ox-LDL stimulation for 48 h. LOX-1 mRNA and protein were measured by RT-qPCR and Western blot, and apoptosis in HUVECs was analyzed by flow ctyometry after Annexin V-FITC/PI double stain. RESULTS: Incubation of HUVECs with 50 μg/mL ox-LDL for 0 to 48 h resulted in a time-dependent induction of apoptotic cell death and down-regulation of miR-590-5p. Transfection of miR-590-5p mimics suppressed LOX-1 expression at both mRNA and protein levels, leading to a reduction of ox-LDL-induced apoptosis in HUVECs. CONCLUSION MiR-590-5p protects endothelial cells from ox-LDL induced apoptosis by inhibiting the expression of LOX-1.
Apoptosis ; genetics ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Lipoproteins, LDL ; pharmacology ; MicroRNAs ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Scavenger Receptors, Class E ; genetics ; metabolism ; Transfection