Search results for "Lipoproteins."

Oxidative stress leads to cholesterol accumulation in vascular smooth muscle cells.

1999

The transformation of macrophages and smooth muscle cells into foam cells by modified low-density lipoproteins (LDL) is one of the key events of atherogenesis. Effects of free radicals have mainly been studied in LDL, and other than toxicity, data dealing with direct action of free radicals on cells are scarce. This study focused on the direct effects of free radicals on cholesterol metabolism of smooth muscle cells. A free radical generator, azobis-amidinopropane dihydrochloride, was used, and conditions for a standardized oxidative stress were set up in vascular smooth muscle cells. After free radical action, the cells presented an accumulation of cholesterol that appeared to be the resul…

Insulin resistance aggravates atherosclerosis by reducing vascular smooth muscle cell survival and increasing CX3CL1/CX3CR1 axis.

2014

Aims Insulin resistance (IR) is a major risk factor for cardiovascular disease and atherosclerosis. Life-threatening acute events are mainly due to rupture of unstable plaques, and the role of vascular smooth muscle cells (VSMCs) in this process in IR, Type 2 diabetes mellitus, and metabolic syndrome (T2DM/MetS) has not been fully addressed. Therefore, the role of VSMC survival in the generation of unstable plaques in T2DM/MetS and the involvement of inflammatory mediators was investigated. Methods and results Defective insulin receptor substrate 2 (IRS2)-mediated signalling produced insulin-resistant VSMCs with reduced survival, migration, and higher apoptosis than control cells. Silencing…

Changes in serum lipid and lipoprotein concentrations and compositions at birth and after 1 month of life in macrosomic infants of insulin-dependent …

1999

The aim of this study was to determine whether macrosomia related to maternal diabetes alters lipoprotein metabolism and whether these abnormalities still persist or regress after 1 month of life. Serum lipoprotein compositions and concentrations as well as serum lipid fatty acid compositions were investigated in macrosomic infants (birth weight = 4840 +/- 105 g at term) of insulin-dependent diabetic mothers at birth and after 1 month of life, and were compared to those of control infants (birth weight = 3400 +/- 198 g at term) of healthy mothers. Compared to controls, at birth, macrosomic newborns had higher serum lipids, apolipoprotein A-I and B-100, and lipoprotein (very low density lipo…

A targeted apoB38.9 mutation in mice is associated with reduced hepatic cholesterol synthesis and enhanced lipid peroxidation.

2006

Familial hypobetalipoproteinemia (FHBL) due to truncation-specifying mutations of apolipoprotein B (apoB), which impair hepatic lipid export in very low-density lipoprotein (VLDL) particles, is associated with fatty liver. In an FHBL-like mouse with the apoB38.9 mutation, fatty liver develops despite reduced hepatic fatty acid synthesis. However, hepatic cholesterol contents in apoB38.9 mice are normal. We found that cholesterogenic enzymes (3-hydroxy-3-methylglutaryl-coenzyme A reductase, sterol-C5-desaturase, and 7-dehydrocholesterol reductase) were consistently downregulated in two separate expression-profiling experiments using a total of 19 mice ( n = 7 each for apob+/+and apob+/38.9, …

In vivo metabolism of LDL subfractions in patients with heterozygous FH on statin therapy

2004

LDL can be subfractionated into buoyant (1.020-1.029 g/ml(-1)), intermediate (1.030-1.040 g/ml(-1)), and dense (1.041-1.066 g/ml(-1)) LDLs. We studied the rebound of these LDL-subfractions after LDL apheresis in seven patients with heterozygous familial hypercholesterolemia (FH) regularly treated by apheresis (58 +/- 9 years, LDL-cholesterol = 342 +/- 87 mg/dl(-1), triglycerides = 109 +/- 39 mg/dl(-1)) and high-dose statins. Apolipoprotein B (apoB) concentrations were measured in LDL subfractions immediately after and on days 1, 2, 3, 5, and 7 after apheresis. Compartmental models were developed to test three hypotheses: 1) that dense LDLs are derived from the delipidation of buoyant and in…

Dietary cholate increases plasma levels of apolipoprotein B in mice by posttranscriptional mechanisms

2001

To induce atherogenesis in mice, a high fat (HF) diet is supplemented with cholic acid (CA), which increases apoB-containing particles and lower apoA-I-containing particles. HF diet without CA increases levels of both HDL and LDL, suggesting that CA may be responsible for the elevation of LDL and lowering of HDL. The mechanism of dietary CA-induced lowering of apoA-I-containing particles has recently been reported. In this study, we examined the mechanism of CA- and HF-induced elevation of apoB-containing lipoproteins in mice. Mice were fed the following four diets: control chow (C), high fat high cholesterol, (HF), control and 0.5% cholate (CA), and HF + CA. Dietary CA increased the plasma…

THE ATHEROGENIC LIPOPROTEIN PHENOTYPE AS PREDICTOR OF CARDIOVASCULAR EVENTS IN PATIENTS WITH NON-CORONARY FORMS OF ATHEROSCLEROSIS

2008

Effects of statins on low-density-lipoproteins size: a new role in cardiovascular prevention ?

2006

Cardiovascular diseases still represent the first cause of death in most of the industrialized countries. An effective prevention includes the treatment of a series of risk factors: smoking, hypertension, diabetes, obesity and dyslipidemia.1 Statins represent a class of cholesterol-lowering drugs as inhibitors of the hydroxymethylglutaryl-coenzyme A reductase enzyme which catalyzes one of the first steps of the cholesterol metabolic pathway. This class of drugs has been used in a very large number of patients, in both primary and secondary cardiovascular prevention, for its ability to reduce clinical events linked to atherosclerosis, including acute myocardial infarction, unstable angina, c…

P1502Open-label ODYSSEY APPRISE study: interim data from the first 843 participants

2017

Gestational diabetes and the metabolic syndrome: Can obesity and small, dense low density lipoproteins be key mediators of this association?

2013

Gestational diabetes mellitus (GDM) represents a condition of glucose intolerance with first appearance or recognition at the time of a pregnancy, associated with an inadequate pancreatic response to the advanced insulin resistance of the later stages of pregnancy, and accompanied by enhancing β-cell mass and secretion of insulin. Women who had GDM exhibit a higher risk for later advent of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). Additionally, previous GDM has been proposed as independently correlated with higher risk for development of atherosclerosis in a healthy population, similar to the metabolic syndrome (MetS) and independently of the presence of established…