Intracellular lipid accumulation, low-density lipoprotein receptor-related protein expression, and cell survival in vascular smooth muscle cells derived from normal and atherosclerotic human coronaries.
ABSTRACT Vascular smooth muscle cell (VSMC) regulation during atherosclerotic plaque progression is determinant for plaque stability.
To study lipid accumulation, low-density lipoprotein receptor-related protein (LRP) expression, and cell survival in VSMCs isolated from nonatherosclerotic areas (normal VSMCs) and advanced atherosclerotic plaques (plaque-VSMCs) of human coronaries.
Normal or plaque-VSMCs were obtained from the intima by modification of the explant technique.
Aggregated low-density lipoprotein (agLDL) (100 micro g mL(-1)) internalization induced higher intracellular cholesteryl ester (CE) accumulation in plaque-VSMC compared with normal VSMCs (89.28 +/- 6.1 vs. 60.34 +/- 4.1 micro g CE mg(-1) of protein; P < 0.05). This internalization was associated with LRP expression, as plaque-VSMCs show higher levels of LRP mRNA (6.06 +/- 0.55 vs. 3.87 +/- 0.28; P < 0.05) and LRP protein expression than normal VSMCs. However, plaque-VSMCs showed a lower proliferative response than normal VSMCs (6536 +/- 636 vs. 11151 +/- 815 c.p.m. [(3)H]thymidine; P < 0.05) and did not respond to platelet-derived growth factor BB (PDGF-BB) stimulus. In agreement, the Bcl(2)/BAX ratio was significantly lower in plaque-VSMCs compared with normal VSMCs (0.14 +/- 0.05 vs. 0.51 +/- 0.07; P < 0.05) and it was independent of lipid loading.
These results indicate that higher intracellular lipid deposition in plaque-VSMCs is related to higher LRP expression levels. However, LRP-mediated agLDL internalization is not directly related to the reduced survival of plaque-VSMCs.
Article: Alterations of specific biomarkers of metabolic pathways in vascular tree from patients with Type 2 diabetes.[show abstract] [hide abstract]
ABSTRACT: The aims of this study were to check whether different biomarkers of inflammatory, apoptotic, immunological or lipid pathways had altered their expression in the occluded popliteal artery (OPA) compared with the internal mammary artery (IMA) and femoral vein (FV) and to examine whether glycemic control influenced the expression of these genes. The study included 20 patients with advanced atherosclerosis and type 2 diabetes mellitus, 15 of whom had peripheral arterial occlusive disease (PAOD), from whom samples of OPA and FV were collected. PAOD patients were classified based on their HbA1c as well (HbA1c ≤ 6.5) or poorly (HbA1c > 6.5) controlled patients. Controls for arteries without atherosclerosis comprised 5 IMA from patients with ischemic cardiomyopathy (ICM). mRNA, protein expression and histological studies were analyzed in IMA, OPA and FV. After analyzing 46 genes, OPA showed higher expression levels than IMA or FV for genes involved in thrombosis (F3), apoptosis (MMP2, MMP9, TIMP1 and TIM3), lipid metabolism (LRP1 and NDUFA), immune response (TLR2) and monocytes adhesion (CD83). Remarkably, MMP-9 expression was lower in OPA from well-controlled patients. In FV from diabetic patients with HbA1c ≤6.5, gene expression levels of BCL2, CDKN1A, COX2, NDUFA and SREBP2 were higher than in FV from those with HbA1c >6.5. The atherosclerotic process in OPA from diabetic patients was associated with high expression levels of inflammatory, lipid metabolism and apoptotic biomarkers. The degree of glycemic control was associated with gene expression markers of apoptosis, lipid metabolism and antioxidants in FV. However, the effect of glycemic control on pro-atherosclerotic gene expression was very low in arteries with established atherosclerosis.Cardiovascular Diabetology 07/2012; 11:86. · 3.35 Impact Factor
Article: LDL-cholesterol versus HDL-cholesterol in the atherosclerotic plaque: inflammatory resolution versus thrombotic chaos.[show abstract] [hide abstract]
ABSTRACT: Atherosclerosis is a complex disease in which many processes contribute to lesion development. Yet, it is well accepted that high serum levels of low-density lipoproteins (LDL) play a main role in the initiation and progression of atherosclerosis. Despite currently available optimal LDL-lowering therapies, a worrisome number of clinical events still occur. The protective effect of high-density lipoproteins (HDL) in atherosclerosis, either by suppressing vascular-LDL accumulation, inflammation, oxidation, endothelial damage, and thrombosis, has supported the need of the use of HDL-raising therapies to address this residual risk. Results obtained in some studies, however, have shown that HDL quality, rather than quantity, should be the target of future pharmacological therapies. Here, we will first explore the mechanism by which excess LDL is fundamental in the development of atherosclerosis and its thrombotic complications, behaving as a factor that introduces chaos in the vascular wall. Afterwards, we will explore how functional HDL, through various cellular and molecular mechanisms, facilitates the resolution of this vascular chaos by suppression of atherosclerosis progression and induction of regression.Annals of the New York Academy of Sciences 04/2012; 1254:18-32. · 3.15 Impact Factor
Article: LDL-induced impairment of human vascular smooth muscle cells repair function is reversed by HMG-CoA reductase inhibition.[show abstract] [hide abstract]
ABSTRACT: Growing human atherosclerotic plaques show a progressive loss of vascular smooth muscle cells (VSMC) becoming soft and vulnerable. Lipid loaded-VSMC show impaired vascular repair function and motility due to changes in cytoskeleton proteins involved in cell-migration. Clinical benefits of statins reducing coronary events have been related to repopulation of vulnerable plaques with VSMC. Here, we investigated whether HMG-CoA reductase inhibition with rosuvastatin can reverse the effects induced by atherogenic concentrations of LDL either in the native (nLDL) form or modified by aggregation (agLDL) on human VSMC motility. Using a model of wound repair, we showed that treatment of human coronary VSMC with rosuvastatin significantly prevented (and reversed) the inhibitory effect of nLDL and agLDL in the repair of the cell depleted areas. In addition, rosuvastatin significantly abolished the agLDL-induced dephosphorylation of myosin regulatory light chain as demonstrated by 2DE-electrophoresis and mass spectrometry. Besides, confocal microscopy showed that rosuvastatin enhances actin-cytoskeleton reorganization during lipid-loaded-VSMC attachment and spreading. The effects of rosuvastatin on actin-cytoskeleton dynamics and cell migration were dependent on ROCK-signalling. Furthermore, rosuvastatin caused a significant increase in RhoA-GTP in the cytosol of VSMC. Taken together, our study demonstrated that inhibition of HMG-CoA reductase restores the migratory capacity and repair function of VSMC that is impaired by native and aggregated LDL. This mechanism may contribute to the stabilization of lipid-rich atherosclerotic plaques afforded by statins.PLoS ONE 01/2012; 7(6):e38935. · 4.09 Impact Factor