Murine models to investigate the influence of diabetic metabolism on the development of atherosclerosis and restenosis

This is an, un-copyedited, author manuscript that has been accepted for publication in the Frontiers in BioscienceAtherosclerosis and related forms of cardiovascular disease (CVD) are associated with several genetic and environmental risk factors, including hypercholesterolemia, diabetes mellitus (DM), hypertension, obesity and smoking. Human DM is a multisystem disorder that results from progressive failure of insulin production and insulin resistance. Most diabetic patients die from complications of atherosclerosis and CVD, and DM is also associated with increased risk of restenosis post-angioplasty. Furthermore, the incidence of DM, particularly type 2-DM, is expected to increase significantly during the next decades owing to the unhealthy effects of modern life-style habits (e.g., obesity and lack of physical exercise). Thus, it is of utmost importance to develop novel preventive and therapeutic strategies to reduce the social and health-care burden of CVD and DM. Although a number of physiological alterations thought to promote atherosclerosis have been identified in diabetic patients, the precise molecular mechanisms that link DM and atherosclerosis are largely unknown. Thus, the aim of this review is to discuss current murine models of combined DM and atherosclerosis and to explore how these experimental systems are being utilized to gain mechanistic insights into diabetes-induced neointimal lesion development, as well as their potential use in evaluating the efficacy of new therapies. Our discussion includes models generated by streptozotocin treatment and those resulting from naturally occurring or targeted mutations in the mouse.Work in the laboratory of the authors is supported by grants from the Spanish Instituto de Salud Carlos III (Red Temática de Investigación Cooperativa en Enfermedades Cardiovasculares RECAVA, Red de Grupos G03/212), and from the Spanish Ministry of Education and Science and the European Regional Development Fund (SAF2004-03057, SAF2005-06058). H. G.-N. is supported by an European Union Marie Curie postdoctoral fellowship.Peer reviewe

Insulin Receptor Substrate-1 Expression Is Increased in Circulating Leukocytes of Patients with Acute Coronary Syndrome

The mechanisms underlying the increased risk of cardiovascular disease associated with diabetes mellitus (DM) are not fully defined. Insulin resistance in human metabolic syndrome patients is associated with decreased expression of the insulin receptor substrate-2- (Irs2-) AKT2 axis in mononuclear leukocytes (MLs). Moreover, acute coronary syndrome (ACS) has been linked through genome-wide association studies to the 2q36-q37.3 locus, which contains the Irs1 gene. Here, we investigated the expression of insulin-signaling pathway genes in MLs from patients with DM, ACS, and ACS plus DM. Quantitative real-time PCR expression studies showed no differences in the mRNA levels of Irs2, Akt2, and Akt1 among all patients. However, Irs1 mRNA expression was significantly increased in patients with ACS—diabetics and nondiabetics—compared with diabetic patients without ACS (P < .02 and P < .005, resp.). The present study reveals for the first time an association between increased Irs1 mRNA levels in MLs of patients with ACS which is not related to DM

Pathophysiology of the proatherothrombotic state in the metabolic syndrome

15 pages, 1 figure.--PMID: 20036940 [PubMed]The metabolic syndrome (MetS) is defined by the presence of at least three of the following abnormalities: glucose intolerance, hypertension, abdominal obesity, low HDL-cholesterol levels and hypertriglyceridemia. Obesity and insulin resistance are very frequently associated to the MetS and play a pivotal role in the development of type 2 diabetes mellitus (T2DM), which in turn increases the risk of cardiovascular disease. Although it varies among ethnic groups, the worldwide prevalence of MetS is 23% in young adults and increases with age. Remarkably, the prevalence of MetS is expected to increase during the next decades due in part to the acquisition of unhealthy life-style habits (e.g., sedentarism, smoking, unhealthy diet, etc). A major pathological alteration present in the MetS is a prothrombotic state as a result of endothelial dysfunction and hypercoagulability produced by a dysbalance of coagulation factors and proteins involved in the regulation of fibrinolysis. Although intensive research in recent years has permitted the identification of a number of prothrombotic alterations in MetS patients, a better understanding of the molecular mechanisms underlying the relationship between MetS and atherotrombosis is required to improve preventive and therapeutic strategies. In this review we discuss the main alterations in the endothelial function, coagulation cascade, fibrinolysis and platelet function that promote atherothrombosis in MetS patients. We also review available mouse models exhibiting alterations in atherothrombosis.Work in the authors’ laboratories is supported by grants from the Spanish Ministry of Science and Innovation and the European Regional Development Fund (SAF2007-62110), Instituto de Salud Carlos III (RECAVA grants RD06/0014/0004 and RD06/0014/0021), Generalitat Valenciana (GV/2007/164), Fundación Ramón Areces, Fina Biotech S.L., and Universidad de Talca (PIFRECV, Research Program of Cardiovascular Disease Risk).Peer reviewe

With mouse age comes wisdom : a review and suggestions of relevant mouse models for age-related conditions

Ageing is a complex multifactorial process that results in many changes in physiological changes processes that ultimately increase susceptibility to a wide range of diseases. As such an ageing population is resulting in a pressing need for more and improved treatments across an assortment of diseases. Such treatments can come from a better understanding of the pathogenic pathways which, in turn, can be derived from models of disease. Therefore the more closely the model resembles the disease situation the more likely relevant the data will be that is generated from them. Here we review the state of knowledge of mouse models of a range of diseases and aspects of an ageing physiology that are all germane to ageing. We also give recommendations on the most common mouse models on their relevance to the clinical situations occurring in aged patients and look forward as to how research in ageing models can be carried out. As we continue to elucidate the pathophysiology of disease, often through mouse models, we also learn what is needed to refine these models. Such factors can include better models, reflecting the ageing patient population, or a better phenotypic understanding of existing models

Increased dosage of Ink4/Arf protects against glucose intolerance and insulin resistance associated with aging

Recent genome-wide association studies have linked type-2 diabetes mellitus to a genomic region in chromosome 9p21 near the Ink4/Arf locus, which encodes tumor suppressors that are up-regulated in a variety of mammalian organs during aging. However, it is unclear whether the susceptibility to type-2 diabetes is associated with altered expression of the Ink4/Arf locus. In the present study, we investigated the role of Ink4/Arf in age-dependent alterations of insulin and glucose homeostasis using Super-Ink4/Arf mice which bear an extra copy of the entire Ink4/Arf locus. We find that, in contrast to age-matched wild-type controls, Super-Ink4/Arf mice do not develop glucose intolerance with aging. Insulin tolerance tests demonstrated increased insulin sensitivity in Super-Ink4/Arf compared with wild-type mice, which was accompanied by higher activation of the insulin receptor substrate (IRS)-PI3K-AKT pathway in liver, skeletal muscle and heart. Glucose uptake studies in Super-Ink4/Arf mice showed a tendency toward increased (18)F-fluorodeoxyglucose uptake in skeletal muscle compared with wild-type mice (P = 0.079). Furthermore, a positive correlation between glucose uptake and baseline glucose levels was observed in Super-Ink4/Arf mice (P < 0.008) but not in wild-type mice. Our studies reveal a protective role of the Ink4/Arf locus against the development of age-dependent insulin resistance and glucose intolerance.Work supported by grants from the Spanish Ministry of Economy and Competiveness (MINECO) and European Regional Development Fund (SAF2007-62110, SAF2010-16044, SAF2008-0011, SAF2011-23777), and from the Instituto de Salud Carlos III (FIS: PI-CP10/00555, RECAVA: RD06/0014/0021, and EMER07-12). H.G.-N. is an investigator from ‘Miguel Servet’ programme (CP10/00555) and A.V. from MINECO. The Centro Nacional de Investigaciones Cardiovasculares (CNIC) is supported by the MINECO and the Pro-CNIC Foundation.S

Unidad Técnica de Biblioteca y Documentación de la Estación Experimental de Aula Dei (CSIC) (Z-EEAD)

2 Pag. A-3, 1 Fot., 1 Map.Información actualizada de la Unidad Técnica de Biblioteca y Documentación (UTBD) de la Estación Experimental de Aula Dei (EEAD-CSIC), una de las 78 Bibliotecas que conforman la Red de Bibliotecas CSIC, en consonancia con la proporcionada en reciente Plan Estratégico CSIC 2010-2013. Incluye relación de Prestaciones de servicio ofrecidas para el período 2010-2013.Peer reviewe

Type 1 diabetic mellitus patientswith increased atherosclerosisriskdisplay decreased CDKN2A/2B/2BAS gene expression in leukocytes

Background: Type 1 diabetes mellitus (T1DM) patients display increased risk of cardiovascular disease (CVD) and are characterized by a diminished regulatory T (Treg) cell content or function. Previous studies have shown an association between decreased CDKN2A/2B/2BAS gene expression and enhanced CVD. In the present study the potential relationship between CDKN2A/2B/2BAS gene expression, immune cell dysfunction and increased cardiovascular risk in T1DM patients was explored. Methods: A cross-sectional study was performed in 90 subjects divided into controls and T1DM patients. Circulating leukocyte subpopulations analysis by flow cytometry, expression studies on peripheral blood mononuclear cell by qPCR and western blot and correlation studies were performed in both groups of subjects. Results: Analysis indicated that, consistent with the described T cell dysfunction, T1DM subjects showed decreased circulating CD4+CD25+CD127- Treg cells. In addition, T1DM subjects had lower mRNA levels of the transcription factors FOXP3 and RORC and lower levels of IL2 and IL6 which are involved in Treg and Th17 cell differentiation, respectively. T1DM patients also exhibited decreased mRNA levels of CDKN2A (variant 1 p16Ink4a), CDKN2A (p14Arf, variant 4), CDKN2B (p15Ink4b) and CDKN2BAS compared with controls. Notably, T1DM patients had augmented pro-atherogenic CD14++CD16+-monocytes, which predict cardiovascular acute events and enhanced common carotid intima-media thickness (CC-IMT). Conclusions: Decreased expression of CDKN2A/2B/2BAS in leukocytes associates with increased CC-IMT atherosclerosis surrogate marker and proatherogenic CD14++CD16+ monocytes in T1DM patients. These results suggest a potential role of CDKN2A/2B/2BAS genes in CVD risk in T1DM

Novel Immune Features of the Systemic Inflammation Associated with Primary Hypercholesterolemia: Changes in Cytokine/Chemokine Profile, Increased Platelet and Leukocyte Activation

Primary hypercholesterolemia (PH) is associated with a low grade systemic inflammation that is likely the main driver of premature atherosclerosis. Accordingly, we characterized the immune cell behaviour in PH and its potential consequences. Whole blood from 22 PH patients and 21 age-matched controls was analysed by flow cytometry to determine the percentage of leukocyte immunophenotypes, activation, and platelet-leukocyte aggregates. Plasma markers were determined by Enzyme-Linked ImmunoSorbent Assay (ELISA). The adhesion of platelet-leukocyte aggregates to tumor necrosis factor-α (TNFα)-stimulated arterial endothelium was investigated using the dynamic model of the parallel-plate flow chamber. PH patients presented greater percentage of Mon 3 monocytes, Th2 and Th17 lymphocytes, activated platelets, and leukocytes than controls. The higher percentages of circulating platelet-neutrophil, monocyte and lymphocyte aggregates in patients caused increased platelet-leukocyte adhesion to dysfunctional arterial endothelium. Circulating CXCL8, CCL2, CX3CL1, and IL-6 levels positively correlated with key lipid features of PH, whereas negative correlations were found for IL-4 and IL-10. We provide the first evidence that increased platelet and leukocyte activation leads to elevated platelet-leukocyte aggregates in PH and augmented arterial leukocyte adhesiveness, a key event in atherogenesis. Accordingly, modulation of immune system behavior might be a powerful target in the control of further cardiovascular disease in PH

The promoter activity of human Mfn2 depends on Sp1 in vascular smooth muscle cells

AIMS: Mitofusin-2 (Mfn2) expression is dysregulated in vascular proliferative disorders and its overexpression attenuates the proliferation of vascular smooth muscle cells (VSMCs) and neointimal lesion development after balloon angioplasty. We sought to gain insight into the mechanisms that control Mfn2 expression in VSMCs. METHODS AND RESULTS: We cloned and characterized 2 kb of the 5'-flanking region of the human Mfn2 gene. Its TATA-less promoter contains a CpG island. In keeping with this, 5'-rapid amplification of cDNA ends revealed six transcriptional start sites (TSSs), of which TSS2 and TSS5 were the most frequently used. The strong CpG island was found to be non-methylated under conditions characterized by large differences in Mfn2 gene expression. The proximal Mfn2 promoter contains six putative Sp1 motifs. Sp1 binds to the Mfn2 promoter and its overexpression activates the Mfn2 promoter in VSMCs. Chemical inhibition of Sp1 reduced Mfn2 expression, and Sp1 silencing reduced transcriptional activity of the Mfn2 promoter. In keeping with this view, Sp1 and Mfn2 mRNA levels were down-regulated in the aorta early after an atherogenic diet in apolipoprotein E-knockout mice or in VSMCs cultured in the presence of low serum. CONCLUSION: Sp1 is a key factor in maintaining basal Mfn2 transcription in VSMCs. Given the anti-proliferative actions of Mfn2, Sp1-induced Mfn2 transcription may represent a mechanism for prevention of VSMC proliferation and neointimal lesion and development

Effects of HCV Eradication on Bone mineral density in HIV/HCV Coinfected Patients

Little is known about the effects of eradication of HCV on bone mineral density (BMD) and biomarkers of bone remodeling in HIV/HCV coinfected patients. We prospectively assessed standardized BMD (sBMD) at the lumbar spine and femoral neck, World Health Organization (WHO) BMD categories at both sites, and plasma concentrations of soluble receptor activator of nuclear factor-kappaβ ligand (sRANKL), and osteoprotegerin (OPG) at baseline (the date of initiation of anti-HCV therapy) and at 96 weeks. A total of 238 patients were included, median age 49.5 years, 76.5% males, 48.3% with cirrhosis, 98.3% on antiretroviral therapy, median CD4+ cell count 527 cells/mm 3, 86.6% with HIV-1 RNA < 50 copies/mL. The prevalence of osteoporosis at baseline at the lumbar spine (LS) and femoral neck (FN) was 17.6% and 7.2%, respectively. Anti-HCV therapy comprised pegylated interferon and ribavirin (PegIFN-RBV) plus one direct-acting antiviral in 53.4%, PegIFN-RBV in 34.5%, and sofosbuvir/RBV in 12.2%. A total of 145 (60.9%) patients achieved sustained viral response (SVR). No significant effect of SVR was observed on sBMD for the interaction between time and SVR either in the LS (P=0.801) or the FN (P=0.911). Likewise, no significant effect of SVR was observed in plasma levels of sRANKL (P=0.205), OPG (P=0.249), and sRANKL/OPG ratio (P=0.123) for the interaction between time and SVR. No significant correlation was found between fibrosis by transient elastography, and LS and FN sBMD, at baseline, and week 96. SVR was not associated with significant changes in BMD nor biomarkers of bone remodeling in HIV/HCV-coinfected persons.This study was supported by Instituto de Salud Carlos III (ISCII), grant numbers PI11/01556, PI14/01094, PI14/01581, and PI14CIII/00011, and by Ministerio de Sanidad, Servicios Sociales e Igualdad, grant number EC11-241. The study was also funded by the RD16/0025/0017, RD16/0025/0018 and RD16CIII/0002/0002 projects as part of the Plan Nacional R + D + I and cofunded by ISCIII-Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER).S