Search results for "LDL receptor"
showing 10 items of 62 documents
Evaluation of clinical diagnosis criteria of familial ligand defective apoB 100 and lipoprotein phenotype comparison between LDL receptor gene mutati…
2007
Familial hypercholesterolemia (FH) and familial defective apoB 100 (FDB) are characterized by increased plasma low-density lipoprotein cholesterol (LDLc) levels and risk of coronary heart disease (CHD). FDB is clinically indistinguishable from FH. The aims of this study were to evaluate clinical diagnosis criteria for FDB and to compare the lipoprotein phenotype between carriers of LDL receptor (LDLR) gene mutations that affect the ligand-binding domain and subjects with the R3500Q mutation in apoB gene. We studied 213 subjects (113 probands) with FH and 19 heterozygous FDB subjects. Genetic diagnosis was determined by following a protocol based on Southern blot and polymerase chain reactio…
Autosomal recessive hypercholesterolemia in a Sicilian kindred harboring the 432insA mutation of the ARH gene
2003
Abstract We describe a Sicilian family presenting a recessive form of hypercholesterolemia harboring a mutation of the autosomal recessive hypercholesterolemia (ARH) gene. In two of the three sibs, a 26-year-old male and a 22-year-old female, a severe hypercholesterolemia was diagnosed with very high levels of plasma cholesterol (15.9 and 12.2 mmol/l, respectively); tendon xanthomatas and xanthelasms were present and in the male proband was documented a diffuse coronary atherosclerotic disease with a rapid and fatal progression. Both the parents had normal or slightly increased levels of plasma cholesterol. All causes of secondary hypercholesterolemia were ruled out as well as an involvemen…
Six novel mutations of the LDL receptor gene in FH kindred of Sicilian and Paraguayan descent
2006
Familial hypercholesterolemia (FH) is an autosomal dominant inherited disease caused by mutations in the gene coding for the low density lipoprotein receptor (LDL-R). It is characterized by a high concentration of low density lipoprotein (LDL), which frequently gives rise to premature coronary artery disease. We studied the probands of five FH Sicilian families with 'definite' FH and one proband of Paraguayan descent with homozygous FH who has been treated with an effective living-donor liver transplantation. In order to seek the molecular defect in these six families, we used direct sequencing to define the molecular defects of the LDL-R gene responsible for the disease. We described three…
A new PCSK9 gene promoter variant affects gene expression and causes autosomal dominant hypercholesterolemia.
2008
Autosomal dominant hypercholesterolemia (ADH) is a genetic disorder characterized by increased low-density lipoprotein (LDL)-cholesterol levels, leading to high risk of premature cardiovascular disease. More than 900 mutations in LDL receptor, six in APOB and 10 in PCSK9 have been identified as a cause of the disease in different populations. All known mutations in PCSK9 causing hypercholesterolemia produce an increase in the enzymatic activity of this protease. Up to now, there are data about the implication of PCSK9 in ADH in a low number of populations, not including a Spanish population.The objective of the study was to study the prevalence of PCSK9 mutations in ADH Spanish population.W…
Spectrum of mutations and phenotypic expression in patients with autosomal dominant hypercholesterolemia identified in Italy.
2013
Abstract Objective To determine the spectrum of gene mutations and the genotype–phenotype correlations in patients with Autosomal Dominant Hypercholesterolemia (ADH) identified in Italy. Methods The resequencing of LDLR , PCSK9 genes and a selected region of APOB gene were conducted in 1018 index subjects clinically heterozygous ADH and in 52 patients clinically homozygous ADH. The analysis was also extended to 1008 family members of mutation positive subjects. Results Mutations were detected in 832 individuals: 97.4% with LDLR mutations, 2.2% with APOB mutations and 0.36% with PCSK9 mutations. Among the patients with homozygous ADH, 51 were carriers of LDLR mutations and one was an LDLR / …
Functional Role of Lipoprotein Receptors in Alzheimers Disease
2008
The LDL receptor gene family constitutes a class of structurally closely related cell surface receptors fulfilling diverse functions in different organs, tissues, and cell types. The LDL receptor is the prototype of this family, which also includes the VLDLR, ApoER2/LRP8, LRP1 and LRP1B, as well as Megalin/GP330, SorLA/LR11, LRP5, LRP6 and MEGF7. Recently several lines of evidence have positioned the LDL receptor gene family as one of the key players in Alzheimer's disease (AD) research. Initially this receptor family was of high interest due to its key function in cholesterol/apolipoprotein E (ApoE) uptake, with the epsilon4 allele of ApoE as the strongest genetic risk factor for late-onse…
Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.
2012
Background The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. Methodology/Principal Findings In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytome…
Functional role of the low-density lipoprotein receptor-related protein in Alzheimer's disease.
2006
Alzheimer’s disease (AD) is the most common age-related neurodegenerative disorder, characterized by neuronal loss, neurofibrillary tangle formation and the extracellular deposition of amyloid-β (Aβ) plaques. The amyloid precursor protein (APP) and the enzymes responsible for Aβ generation seem to be the base elements triggering the destructive processes. Initially, the low-density lipoprotein receptor-related protein (LRP) was genetically linked to AD and later it emerged to impact on many fundamental events related to this disease. LRP is not only involved in Aβ clearance but is also the major receptor of several AD-associated ligands, e.g. apolipoprotein E and α<sub>2</sub>-m…
Genetic polymorphisms affecting the phenotypic expression in familial hypercholesterolemia
2004
The clinical expression of heterozygous familial hypercholesterolemia (FH) is highly variable even in patients carrying the same LDL receptor (LDL-R) gene mutation. This variability might be due to environmental factors as well as to modifying genes affecting lipoprotein metabolism. We investigated Apo E (2, 3, 4), MTP (-493G/T), Apo B (-516C/T), Apo A-V (-1131T/C), HL (-514C/T and -250G/A), FABP-2 (A54T), LPL (D9N, N291S, S447X) and ABCA1 (R219K) polymorphisms in 221 unrelated FH index cases and 349 FH relatives with defined LDL-R gene mutations. We found a significant and independent effect of the following polymorphisms on: (i) plasma LDL-C (Apo E, MTP and Apo B); (ii) plasma HDL-C (HL, …
Effects of PCSK9 variants on common carotid artery intima media thickness and relation to ApoE alleles.
2009
BACKGROUND: PCSK9 plays a key role in plasma cholesterol metabolism by modulating the expression of LDL receptors. OBJECTIVE AND METHODS: In this study we investigated the effects of two common polymorphism of the PCSK9 gene (E670G and I474V) on the intima media thickness of the common carotid artery and the possible relation with polymorphisms of apolipoprotein E in 1541 middle aged subjects selected from the general population enrolled in the PLIC study and confirmed the major findings in a second free-living population enrolled in the Ventimiglia study. RESULTS: 670G carriers showed significantly increased plasma total cholesterol, LDL-cholesterol, and Apo levels B while no significant d…