Search results for "LIPOPROTEIN"

Clusterin gene expression in apoptotic MDCK cells is dependent on the apoptosis-inducing stimulus

1995

Abstract Clusterin (Apolipoprotein J, complement lysis inhibitor) is a widely expressed multifunctional glycoprotein. The expression of clusterin mRNA has been reported to be elevated in a broad spectrum of apoptotic or degenerative tissues. More recently, it was shown that within these tissues clusterin is expressed in the surviving rather than in the dying cells, and that clusterin gene expression is actually down-regulated in the apoptotic cells. We have studied the expression of the clusterin gene in apoptotic MDCK cells. Cell death was initiated by three different stimuli: application of the steroid hormone antagonist RU 486, activation of protein kinase C by the application of the pho…

Fatty acids liberated from low-density lipoprotein trigger endothelial apoptosis via mitogen-activated protein kinases.

2005

Enzymatic modification of low-density lipoprotein (LDL) as it probably occurs in the arterial intima drastically increases its cytotoxicity, which could be relevant for the progression of atherosclerotic lesions. LDL was treated with a protease and cholesterylesterase to generate a derivative similar to lesional LDL, with a high content of free cholesterol and fatty acids. Exposure of endothelial cells to the enzymatically modified lipoprotein (E-LDL), but not to native or oxidized LDL, resulted in programmed cell death. Apoptosis was triggered by apoptosis signal-regulating kinase 1 dependent phosphorylation of p38. Depletion and reconstitution experiments identified free fatty acids (FFA)…

Enzymatically modified LDL induces cathepsin H in human monocytes: potential relevance in early atherogenesis.

2003

Objective—Modification with proteases and cholesterylesterase transforms LDL to a moiety that resembles lipoproteins isolated from atherosclerotic lesions and possesses atherogenic properties. To identify changes in monocyte-derived foam cells laden with enzymatically modified LDL (E-LDL), we compared patterns of the most abundant transcripts in these cells after incubation with LDL or E-LDL.Methods and Results—Serial analyses of gene expression (SAGE) libraries were constructed from human monocytes after treatment with LDL or E-LDL. Several tags were differentially expressed in LDL-treated versus E-LDL–treated cells, whereby marked selective induction by E-LDL of cathepsin H was conspicuou…

The production of 85 kDa N-terminal fragment of apolipoprotein B in mutant HepG2 cells generated by targeted modification of apoB gene occurs by ALLN…

2010

Abstract To study the mechanism of low levels of full length and truncated apoB in individuals heterozygous for apoB truncation, a non-sense mutation was introduced in one of the three alleles of apob gene of HepG2 cells by homologous recombination. Despite very low levels of apoB-82 (1–2%) in the media, a prominent N-terminal apoB protein of 85 kDa (apoB-15) was secreted that fractionated at d > 1.065 in density gradient ultracentrifugation. The mechanism of production of this short protein was studied by 35S-methionine pulse–chase experiment. Oleate prevented presecretory degradation of apoB-100 in the cell and resulted in increased secretion of newly synthesized apoB-100 with decreases i…

Structural analysis of Borrelia burgdorferi periplasmic lipoprotein BB0365 involved in Lyme disease infection.

2019

The periplasmic lipoprotein BB0365 of the Lyme disease agent Borrelia burgdorferi is expressed throughout mammalian infection and is essential for all phases of Lyme disease infection; its function, however, remains unknown. In the current study, our structural analysis of BB0365 revealed the same structural fold as that found in the NqrC and RnfG subunits of the NADH:quinone and ferredoxin:NAD+ sodium-translocating oxidoreductase complexes, which points to a potential role for BB0365 as a component of the sodium pump. Additionally, BB0365 coordinated Zn2+ by the His51, His55, His140 residues, and the Zn2+ -binding site indicates that BB0365 could act as a potential metalloenzyme; therefore…

Human apolipoprotein A-I natural variants: molecular mechanisms underlying amyloidogenic propensity

2012

Human apolipoprotein A-I (apoA-I)-derived amyloidosis can present with either wild-type (Wt) protein deposits in atherosclerotic plaques or as a hereditary form in which apoA-I variants deposit causing multiple organ failure. More than 15 single amino acid replacement amyloidogenic apoA-I variants have been described, but the molecular mechanisms involved in amyloid-associated pathology remain largely unknown. Here, we have investigated by fluorescence and biochemical approaches the stabilities and propensities to aggregate of two disease-associated apoA-I variants, apoA-IGly26Arg, associated with polyneuropathy and kidney dysfunction, and apoA-ILys107-0, implicated in amyloidosis in severe…

Single tube optimisation of APOE genotyping based on melting curve analysis

2008

Objectives: To develop and validate a single-tube protocol for APOE genotyping using fluorescent probes. Design and methods: We have designed and validated a hybrid, single-tube, SimpleProbe/FRET probe protocol that takes advantage of the different probe wavelength emissions. Results: Our method offers high quality outcomes, minimum interferences between probe signals and is 100% concordant with the reference protocol. Conclusions: This method is cheaper, faster and more reliable and versatile than other alternatives proposed. © 2008 Elsevier Inc. All rights reserved.

N-acyl-homoserine-lactone quorum sensing in tomato phytopathogenic Pseudomonas spp. is involved in the regulation of lipodepsipeptide production

2012

Pseudomonas corrugata and Pseudomonas mediterranea are two closely related phytopathogenic bacteria both causal agents of tomato pith necrosis. P. corrugata produces phytotoxic and antimicrobial cationic lipodepsipeptides (LDPs) which are thought to act as major virulence factors. Previous studies have demonstrated that P. corrugata CFBP 5454 has an N-acyl homoserine lactone (AHL) quorum sensing (QS) system PcoI/PcoR and that LDP production occurs at high population densities. No molecular studies on virulence have thus far been reported for P. mediterranea. In this study, we show that P. mediterranea also produces LDPs as well as possessing an AHL-dependent QS system, designated PmeI/PmeR,…

A potential link between serum low-density lipoproteins and asthma

2015

Issues Affecting Quality of Life and Disease Burden in Lipoprotein Lipase Deficiency (Lpld) - First Step Towards a Pro Measure in Lpld

2015

Objectives: LPLD is an ultra-orphan genetic lipid disorder (prevalence 1-2/million). It is associated with severe hypertriglyceridemia and an increased risk of acute pancreatitis. Other manifestations include eruptive xanthoma, fatigue, difficulty with concentrating and cardiopulmonary symptoms. Associated symptoms, complications and the fat-restricted diet affect Quality of Life (QOL). Currently no disease-specific measure exists to assess QOL and the burden of LPLD. As part of post approval commitments of alipogene tiparvovec, regulatory bodies requested the development of a reliable measure of QOL in LPLD. This study evaluates existing EORTC questionnaires QLQ-C30 and QLQ-PAN26, and a ne…