Treatment with 1.25% cholesterol enriched diet produces severe fatty liver disease characterized by advanced fibrosis and inflammation and impaired autophagy in mice.

Nonalcoholic fatty liver disease (NAFLD) is reaching pandemic proportions due to overnutrition. The understanding of advanced stages that recapitulate the human pathology is of great importance to get a better mechanistic insight. We hypothesized that feeding of WT (C57BL) mice with a diet containing a high content of fat (21%), sugar (41.5%) and 1.25% of cholesterol (called from now on high fat, sucrose and cholesterol diet, HFSCD) will reproduce the characteristics of disease severity. Analysis of 16 weeks HFSCD-fed mice demonstrated increased liver weight and plasmatic liver damage markers compared with control diet (CD)-fed mice. HFSCD-fed mice developed greater hepatic triglyceride, cholesterol and NEFA content, inflammation and NAFLD activity score (NAS) indicating an advanced disease. HFSCD-fed mice displayed augmented hepatic total CD3+ T and Th9 lymphocytes, as well as reduced Th2 lymphocytes and CD206 anti-inflammatory macrophages. Moreover, T cells and anti-inflammatory macrophages correlated positively and inversely, respectively, with intrahepatic cholesterol content. Consistently, circulating cytotoxic CD8+ T lymphocytes, Th1, and B cell levels were elevated in HFSCD-fed WT mice. Hepatic and adipose tissue expression analysis demonstrated changes in fibrotic and metabolic genes related with cholesterol, triglycerides, and fatty acid synthesis in HFSCD-fed WT. These mice also exhibited reduced antioxidant capacity and autophagy and elevated ERK signaling pathway activation and CHOP levels. Our results indicate that the feeding with a cholesterol-enriched diet in WT mice produces an advanced NAFLD stage with fibrosis, characterized by deficient autophagy and ER stress along with inflammasome activation partially via ERK pathway activation.

Light deficiency in Apoe-/-mice increases atheroma plaque size and vulnerability by modulating local immunity.

Previous research suggests a potential involvement of the cytokine LIGHT (TNFSF14) in atherosclerosis. In this study, the genetic inactivation of Light in Apolipoprotein E deficient mice (male and female C57BL) augmented plaque size and vulnerability while decreasing Treg cells. Human and mouse transcriptomic results demonstrated deranged immune pathways in human atheromas with low LIGHT expression levels and in Light-deficient murine atheromas. In agreement with this, in vitro LIGHT-treatment of human lymphocytes, induced an elevation of Treg cell prevalence while proteomic analysis showed a downregulation of apoptotic and leukocyte cytotoxic pathways. Consistently, Light-deficient mouse lesions displayed increased plaque apoptosis and detrimental adventitial T-lymphocyte aggregates. Altogether suggested that LIGHT could promote a Treg prevalence in the local immunity to prevent the generation of vulnerable plaques via decreased cytotoxic microenvironment and apoptosis. Light gene delivery in Apoe-/-Light-/- mice, through bone marrow transplantation approaches, consistently diminished lesion size and restored local plaque immunity. Altogether demonstrate that Light-deficiency promotes atheroma plaque progression, at least in part through local loss of immune homeostasis and increased apoptosis. This study suggest that therapies based on the local delivery of LIGHT within plaques might therefore prevent immune cell derangement and advanced atherosclerosis.

Association of carotid atheroma plaque with IL-18 levels and with polymorphisms in the IL-18 receptor gene in a Mediterranean population. / Asociación de la placa de ateroma carotídea con los niveles plasmáticos de IL-18 y con polimorfismos en el gen del receptor de la IL-18 en la población mediterránea.

BACKGROUND: Atherosclerosis is an inflammatory disease. Interleukin 18 (IL-18) is an inflammatory molecule that has been linked to the development of atherosclerosis and cardiovascular disease. OBJECTIVE: To evaluate the possible relationship between plasma levels of IL-18 and the presence of atherosclerosis evaluated at the carotid level, as well as to analyze the possible modulation by different polymorphisms in a Mediterranean population. MATERIAL AND METHODS: Seven hundred and forty-six individuals from the metropolitan area of Valencia were included, recruited over a period of 2 years. Hydrocarbon and lipid metabolism parameters were determined using standard methodology and IL-18 using ELISA. In addition, carotid ultrasound was performed and the genotype of four SNPs related to the IL-18 signaling pathway was analyzed. RESULTS: Patients with higher plasma levels of IL-18 had other associated cardiovascular risk factors. Elevated IL-18 levels were significantly associated with higher carotid IMT and the presence of atheromatous plaques. The genotype with the A allele of the SNP rs2287037 was associated with a higher prevalence of carotid atheromatous plaque. On the contrary, the genotype with the C allele of the SNP rs2293224 was associated with a lower prevalence of atheromatous plaque. CONCLUSIONS: High levels of IL-18 were significantly associated with a higher carotid IMT and the presence of atheromatous plaques, which appear to be influenced by genetic factors, as evidenced by associations between SNPs in the IL-18 receptor gene and the presence of atheroma plaque.

CCL17 and CCL22 chemokines are upregulated in human obesity and play a role in vascular dysfunction.

Background/Aims: Chemokines are known to play critical roles mediating inflammation in many pathophysiological processes. The aim of this study was to investigate the role of chemokine receptor CCR4 and its ligands CCL17 and CCL22 in human morbid obesity. Methods: Circulating levels of CCL17 and CCL22 were measured in 60 morbidly obese patients (mean age, 45 ± 1 years; body mass index/BMI, 44 ± 1 kg/m2) who had undergone bariatric bypass surgery, and 20 control subjects. Paired subcutaneous (SCAT) and visceral adipose tissue (VCAT) from patients were analysed to measure expression of CCR4 and its ligands by RT-PCR, western blot and immunohistochemical analysis. The effects of CCR4 neutralization ex vivo on leukocyte-endothelial cells were also evaluated. Results: Compared with controls, morbidly obese patients presented higher circulating levels of CCL17 (p=0.029) and CCL22 (p<0.001) and this increase was positively correlated with BMI (p=0.013 and p=0.0016), and HOMA-IR Index (p=0.042 and p< 0.001). Upregulation of CCR4, CCL17 and CCL22 expression was detected in VCAT in comparison with SCAT (p<0.05). Using the parallel-plate flow chamber model, blockade of endothelial CCR4 function with the neutralizing antibody anti-CCR4 in morbidly obese patients significantly reduced leucocyte adhesiveness to dysfunctional endothelium, a key event in atherogenesis. Additionally, CCL17 and CCL22 increased activation of the ERK1/2 mitogen-activated protein kinase signalling pathway in human aortic endothelial cells, which was significantly reduced by CCR4 inhibition (p=0.016 and p<0.05). Conclusion: Based on these findings, pharmacological modulation of the CCR4 axis could represent a new therapeutic approach to prevent adipose tissue dysfunction in obesity.

Vascular smooth muscle cell phenotype is modulated by ligands of the lymphotoxin beta receptor and the tumor necrosis factor receptor / El fenotipo de las células de músculo liso vascular es modulado por los ligandos del receptor de la linfotoxina beta y del receptor del factor de necrosis tumoral

Objective: Vascular smooth muscle cells (VSMCs) undergo a phenotypic-switching process during the generation of unstable atheroma plaques. In this investigation, the potential implication of the tumor necrosis factor superfamily (TNFSF) ligands, in the gene expression signature associated with VSMC plasticity was studied. Material and methods: Human aortic (ha)VSMCs were obtained commercially and treated with the cytokine TNFSF14, also called LIGHT, the lymphotoxin alpha (LTα), the heterotrimer LTα1β2 or with vehicle for 72h. The effect of the different treatments on gene expression was analyzed by quantitative PCR and included the study of genes associated with myofibroblast-like cell function, osteochondrogenesis, pluripotency, lymphorganogenesis and macrophage-like cell function. Results: HaVSMCs displayed a change in myofibroblast-like cell genes which consisted in reduced COL1A1 and TGFB1 mRNA levels when treated with LTα or LIGHT and with augmented MMP9 expression levels when treated with LTα. LTα and LIGHT treatments also diminished the expression of genes associated with osteochondrogenesis and pluripotency SOX9, CKIT, and KLF4. By contrary, all the above genes were no affected by the treatment with the trimer LTα1β2. In addition, haVSMC treatment with LTα, LTα1β2 and LIGHT altered lymphorganogenic cytokine gene expression which consisted of augmented CCL20 and CCL21 mRNA levels by LTα and a reduction in the gene expression of CCL21 and CXCL13 by LIGHT and LTα1β2 respectively. Neither, LTα or LIGHT or LTα1β2 treatments affected the expression of macrophage-like cell markers in haVSMC. Conclusions: Altogether, indicates that the TNFSF ligands through their interconnected network of signaling, are important in the preservation of VSMC identity against the acquisition of a genetic expression signature compatible with functional cellular plasticity.(AU)

Objetivo: La transición de placa de ateroma estable a placa inestable implica, entre otros procesos, un cambio fenotípico de las células del músculo liso vascular (CMLVs). En esta investigación, se estudió el posible papel de los ligandos de la superfamilia del factor de necrosis tumoral (TNFSF), en los cambios de expresión génica asociada a la plasticidad de las CMLVs. Materiales y métodos: Las CMLVs de aorta humana (CMLVah) se obtuvieron comercialmente y se trataron con la citoquina TNFSF14, también llamada LIGHT, la linfotoxina alfa (LTα), el heterotrímero LTα1β2 o con vehículo durante 72 horas. El efecto de los diferentes tratamientos se analizó mediante el estudio de la expresión génica por PCR cuantitativa e incluyó genes asociados con fenotipo miofibroblástico, osteocondrogénico, genes de pluripotencia, genes de linforganogénesis y genes característicos de macrófagos. Resultados: El estudio de genes asociados a fenotipo miofibroblástico en las CMLVah reveló una reducción de la expresión génica de COL1A1 y TGFB1 tras el tratamiento con LTα o LIGHT mientras que el tratamiento con LTα aumentó los niveles de mRNA de MMP9. LTα y LIGHT también disminuyeron la expresión de genes de osteocondrogénesis y pluripotencia como SOX9, CKIT y KLF4. Por el contrario, la expresión de los genes anteriores no se vio afectada por el tratamiento con el trímero LTα1β2. El tratamiento de las CMLVah con LTα, LTα1β2 y LIGHT alteró la expresión génica de citoquinas linforganogénicas con una expresión aumentada de los genes CCL20 y CCL21 por LTα y una reducción de los niveles de mRNA de CCL21 y CXCL13 por LIGHT y LTα1β2, respectivamente. Ninguno de los tres tratamientos alteró la expresión de genes típicos de macrófagos en las CMLVah. Conclusiones: La presente investigación indica que los ligandos de la familia de los TNFSF a través de su red de señalización...(AU)

Vascular smooth muscle cell phenotype is modulated by ligands of the lymphotoxin ß receptor and the tumor necrosis factor receptor.

OBJECTIVE: Vascular smooth muscle cells (VSMCs) undergo a phenotypic-switching process during the generation of unstable atheroma plaques. In this investigation, the potential implication of the tumor necrosis factor superfamily (TNFSF) ligands, in the gene expression signature associated with VSMC plasticity was studied. MATERIAL AND METHODS: Human aortic (ha)VSMCs were obtained commercially and treated with the cytokine TNFSF14, also called LIGHT, the lymphotoxin alpha (LTα), the heterotrimer LTα1ß2 or with vehicle for 72h. The effect of the different treatments on gene expression was analyzed by quantitative PCR and included the study of genes associated with myofibroblast-like cell function, osteochondrogenesis, pluripotency, lymphorganogenesis and macrophage-like cell function. RESULTS: HaVSMCs displayed a change in myofibroblast-like cell genes which consisted in reduced COL1A1 and TGFB1 mRNA levels when treated with LTα or LIGHT and with augmented MMP9 expression levels when treated with LTα. LTα and LIGHT treatments also diminished the expression of genes associated with osteochondrogenesis and pluripotency SOX9, CKIT, and KLF4. By contrary, all the above genes were no affected by the treatment with the trimer LTα1ß2. In addition, haVSMC treatment with LTα, LTα1ß2 and LIGHT altered lymphorganogenic cytokine gene expression which consisted of augmented CCL20 and CCL21 mRNA levels by LTα and a reduction in the gene expression of CCL21 and CXCL13 by LIGHT and LTα1ß2 respectively. Neither, LTα or LIGHT or LTα1ß2 treatments affected the expression of macrophage-like cell markers in haVSMC. CONCLUSIONS: Altogether, indicates that the TNFSF ligands through their interconnected network of signaling, are important in the preservation of VSMC identity against the acquisition of a genetic expression signature compatible with functional cellular plasticity.

Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone Peptide-Derived G Protein Coupled Receptor Agonists.

The increasing prevalence of obesity and type 2 diabetes (T2DM) is provoking an important socioeconomic burden mainly in the form of cardiovascular disease (CVD). One successful strategy is the so-called metabolic surgery whose beneficial effects are beyond dietary restrictions and weight loss. One key underlying mechanism behind this surgery is the cooperative improved action of the preproglucagon-derived hormones, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) which exert their functions through G protein-coupled receptors (GPCR). Great success has been reached with therapies based on the GLP-1 receptor monoagonism; therefore, a logical and rational approach is the use of the dual and triagonism of GCPC to achieve complete metabolic homeostasis. The present review describes novel findings regarding the complex biology of the preproglucagon-derived hormones, their signaling, and the drug development of their analogues, especially those acting as dual and triagonists. Moreover, the main investigations into animal models and ongoing clinical trials using these unimolecular dual and triagonists are included which have demonstrated their safety, efficacy, and beneficial effects on the CV system. These therapeutic strategies could greatly impact the treatment of CVD with unprecedented benefits which will be revealed in the next years.

Dissecting Abdominal Aortic Aneurysm Is Aggravated by Genetic Inactivation of LIGHT (TNFSF14).

Abdominal aortic aneurysm (AAA), is a complex disorder characterized by vascular vessel wall remodeling. LIGHT (TNFSF14) is a proinflammatory cytokine associated with vascular disease. In the present study, the impact of genetic inactivation of Light was investigated in dissecting AAA induced by angiotensin II (AngII) in the Apolipoprotein E-deficient (Apoe-/-) mice. Studies in aortic human (ah) vascular smooth muscle cells (VSMC) to study potential translation to human pathology were also performed. AngII-treated Apoe-/-Light-/- mice displayed increased abdominal aorta maximum diameter and AAA severity compared with Apoe-/- mice. Notably, reduced smooth muscle α-actin+ area and Acta2 and Col1a1 gene expression were observed in AAA from Apoe-/-Light-/- mice, suggesting a loss of VSMC contractile phenotype compared with controls. Decreased Opn and augmented Sox9 expression, which are associated with detrimental and non-contractile osteochondrogenic VSMC phenotypes, were also seen in AngII-treated Apoe-/-Light-/- mouse AAA. Consistent with a role of LIGHT preserving VSMC contractile characteristics, LIGHT-treatment of ahVSMCs diminished the expression of SOX9 and of the pluripotency marker CKIT. These effects were partly mediated through lymphotoxin ß receptor (LTßR) as the silencing of its gene ablated LIGHT effects on ahVSMCs. These studies suggest a protective role of LIGHT through mechanisms that prevent VSMC trans-differentiation in an LTßR-dependent manner.

Overexpression of glucose 6 phosphate dehydrogenase preserves mouse pancreatic beta cells function until late in life.

NAD(P)H donates electrons for reductive biosynthesis and antioxidant defense across all forms of life. Glucose-6-phosphate dehydrogenase (G6PD) is a critical enzyme to provide NADPH. G6PD deficiency is present in more than 400 million people worldwide. This enzymopathy provides protection against malaria but sensitizes cells to oxidative stressors. Oxidative stress has been involved in the pathogenesis of the diabetic complications and several studies have provided evidences of a link between G6PD deficiency and type 2 diabetes (T2D). We hypothesized that a moderate overexpression of G6PD (G6PD-Tg) could protect ß-cells from age-associated oxidative stress thus reducing the risk of developing T2D. Here we report, that G6PD-Tg mice show an improved glucose tolerance and insulin sensitivity when compared to old age-matched Wild Type (WT) ones. This is accompanied by a decrease in oxidative damage and stress markers in the pancreas of the old Tg animals (20-24month-old). Pancreatic ß-cells progress physiologically towards a state of reduced responsiveness to glucose. In pancreatic islets isolated from G6PD-Tg and WT animals at different ages, and using electrophysiological techniques, we demonstrate a wider range of response to glucose in the G6PD-Tg cells that may explain the improvements in glucose tolerance and insulin sensitivity. Together, our results show that overexpression of G6PD maintains pancreatic ß-cells from old mice in a "juvenile-like" state and points to the G6PD dependent generation of NADPH as an important factor to improve the natural history of diabetes.

Therapies for the Treatment of Cardiovascular Disease Associated with Type 2 Diabetes and Dyslipidemia.

Cardiovascular disease (CVD) is the leading cause of death worldwide and is the clinical manifestation of the atherosclerosis. Elevated LDL-cholesterol levels are the first line of therapy but the increasing prevalence in type 2 diabetes mellitus (T2DM) has positioned the cardiometabolic risk as the most relevant parameter for treatment. Therefore, the control of this risk, characterized by dyslipidemia, hypertension, obesity, and insulin resistance, has become a major goal in many experimental and clinical studies in the context of CVD. In the present review, we summarized experimental studies and clinical trials of recent anti-diabetic and lipid-lowering therapies targeted to reduce CVD. Specifically, incretin-based therapies, sodium-glucose co-transporter 2 inhibitors, and proprotein convertase subtilisin kexin 9 inactivating therapies are described. Moreover, the novel molecular mechanisms explaining the CVD protection of the drugs reviewed here indicate major effects on vascular cells, inflammatory cells, and cardiomyocytes, beyond their expected anti-diabetic and lipid-lowering control. The revealed key mechanism is a prevention of acute cardiovascular events by restraining atherosclerosis at early stages, with decreased leukocyte adhesion, recruitment, and foam cell formation, and increased plaque stability and diminished necrotic core in advanced plaques. These emergent cardiometabolic therapies have a promising future to reduce CVD burden.

Postprandial triglyceridaemia is modulated by insulin resistance but not by grade of obesity in abdominal and morbid obese subjects.

BACKGROUND: Obesity is associated with high cardiovascular risk. Postprandial lipidaemia has been associated with cardiovascular disease risk. Our aim was to identify whether anthropometric parameters, insulin resistance (IR) and/or fasting plasma triglycerides may determine postprandial changes in lipoprotein concentrations in abdominal and morbid obese subjects. METHODS: We have studied 20 non-diabetic, normolipidaemic subjects with abdominal obesity, 20 morbid obese subjects and 20 healthy individuals, that have similar age and gender. In all of them a standardised oral fat load test (OFLT) with unsaturated fat was performed. RESULTS: During the OFLT, the postprandial triglycerides response was significantly higher in subjects with abdominal obesity compared with morbid obese subjects (4 hours triglycerides pick value and AUC of triglycerides). Both obese groups showed significantly higher postprandial triglycerides response compared with healthy subjects. Dividing the obesity group according to the presence of IR, we found that IR was an important factor related with postprandial lipaemia but not BMI or waist circumference. In addition, postprandial glycaemia and insulinaemia significantly decreased in all studied subjects, being the highest decrease in morbid obese subjects and in subjects with IR. Postprandial triglyceridaemia significantly correlated with IR parameters and not with anthropometric parameters in AO and MO subjects. CONCLUSION: In subjects with AO and MO, postprandial triglycerides values are higher than healthy individuals and independently predicted by fasting IR parameters. Furthermore, unsaturated fat improved IR state.

Dapagliflozin Does Not Modulate Atherosclerosis in Mice with Insulin Resistance.

Type 2 diabetes mellitus (T2DM) increases morbimortality in humans via enhanced susceptibility to cardiovascular disease (CVD). Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are drugs designed for T2DM treatment to diminish hyperglycaemia by reducing up to 90% of renal tube glucose reabsorption. Clinical studies also suggest a beneficial action of SGLT2i in heart failure and CVD independent of its hypoglycaemiant effect. In the present study, we explored the effect of SGLT2i dapagliflozin (DAPA) in the metabolism and atherosclerosis in Apoe-/-Irs2+/- mice, which display accelerated atherosclerosis induced by insulin resistance. DAPA treatment of Apoe-/-Irs2+/- mice, which were fed a high-fat, high-cholesterol diet, failed to modify body weight, plasma glucose or lipid. Carbohydrate metabolism characterisation showed no effect of DAPA in the glucose tolerance test (GTT) despite augmented insulin levels during the test. In fact, decreased C-peptide levels in DAPA-treated mice during the GTT suggested impaired insulin release. Consistent with this, DAPA treatment of Apoe-/-Irs2+/- isolated islets displayed lower glucose-stimulated insulin secretion compared with vehicle-treated islets. Moreover, insulin-signalling experiments showed decreased pAKT activation in DAPA-treated adipose tissue indicating impaired insulin signalling in this tissue. No changes were seen in lesion size, vulnerability or content of macrophages, vascular smooth muscle cells, T cells or collagen. DAPA did not affect circulating inflammatory cells or cytokine levels. Hence, this study indicates that DAPA does not protect against atherosclerosis in insulin-resistant mice in hypercholesterolemic conditions.

TET2-Loss-of-Function-Driven Clonal Hematopoiesis Exacerbates Experimental Insulin Resistance in Aging and Obesity.

Human aging is frequently accompanied by the acquisition of somatic mutations in the hematopoietic system that induce clonal hematopoiesis, leading to the development of a mutant clone of hematopoietic progenitors and leukocytes. This somatic-mutation-driven clonal hematopoiesis has been associated with an increased incidence of cardiovascular disease and type 2 diabetes, but whether this epidemiological association reflects a direct, causal contribution of mutant hematopoietic and immune cells to age-related metabolic abnormalities remains unexplored. Here, we show that inactivating mutations in the epigenetic regulator TET2, which lead to clonal hematopoiesis, aggravate age- and obesity-related insulin resistance in mice. This metabolic dysfunction is paralleled by increased expression of the pro-inflammatory cytokine IL-1ß in white adipose tissue, and it is suppressed by pharmacological inhibition of NLRP3 inflammasome-mediated IL-1ß production. These findings support a causal contribution of somatic TET2 mutations to insulin resistance and type 2 diabetes.

Srebf2 Locus Overexpression Reduces Body Weight, Total Cholesterol and Glucose Levels in Mice Fed with Two Different Diets.

Macronutrients represent risk factors for hyperlipidemia or diabetes. Lipid alterations and type 2 diabetes mellitus are global health problems. Overexpression of sterol regulatory element-binding factor (Srebf2) in transgenic animals is linked to elevated cholesterol levels and diabetes development. We investigated the impact of increased Srebf2 locus expression and the effects of control and high-fat, high-sucrose (HFHS) diets on body weight, glucose and lipid metabolisms in transgenic mice (S-mice). Wild type (WT) and S-mice were fed with both diets for 16 weeks. Plasma glucose, insulin and lipids were assessed (n = 25). Immunostainings were performed in liver, pancreas and fat (N = 10). Expression of Ldlr and Hmgcr in liver was performed by RT-PCR (N = 8). Control diet: S-mice showed reduced weight, insulin, total and HDL cholesterol and triglycerides (TG). HFHS diet widened differences in weight, total and HDL cholesterol, insulin and HOMA index but increased TG in S-mice. In S-mice, adipocyte size was lower while HFHS diet produced lower increase, pancreatic ß-cell mass was lower with both diets and Srebf2, Ldlr and Hmgcr mRNA levels were higher while HFHS diet produced a rise in Srebf2 and Hmgcr levels. Srebf2 complete gene overexpression seems to have beneficial effects on metabolic parameters and to protect against HFHS diet effects.

Impact of Cholesterol Metabolism in Immune Cell Function and Atherosclerosis.

Cholesterol, the most important sterol in mammals, helps maintain plasma membrane fluidity and is a precursor of bile acids, oxysterols, and steroid hormones. Cholesterol in the body is obtained from the diet or can be de novo synthetized. Cholesterol homeostasis is mainly regulated by the liver, where cholesterol is packed in lipoproteins for transport through a tightly regulated process. Changes in circulating lipoprotein cholesterol levels lead to atherosclerosis development, which is initiated by an accumulation of modified lipoproteins in the subendothelial space; this induces significant changes in immune cell differentiation and function. Beyond lesions, cholesterol levels also play important roles in immune cells such as monocyte priming, neutrophil activation, hematopoietic stem cell mobilization, and enhanced T cell production. In addition, changes in cholesterol intracellular metabolic enzymes or transporters in immune cells affect their signaling and phenotype differentiation, which can impact on atherosclerosis development. In this review, we describe the main regulatory pathways and mechanisms of cholesterol metabolism and how these affect immune cell generation, proliferation, activation, and signaling in the context of atherosclerosis.

Terapias antiinflamatorias para la enfermedad cardiovascular: vías de señalización y mecanismos / Anti-inflammatory therapies for cardiovascular disease: signaling pathways and mechanisms

Las enfermedades cardiovasculares (ECV) son una manifestación clínica de la ateroesclerosis, una enfermedad inflamatoria que se agrava en presencia de diferentes factores de riesgo como la dislipemia o la diabetes mellitus tipo 2. Los eventos cardiovasculares agudos son resultado de un proceso inflamatorio crónico no resuelto que facilita la rotura de placas inestables. Los tratamientos existentes reducen los factores de riesgo, pero no previenen los eventos isquémicos recurrentes en pacientes con riesgo residual inflamatorio caracterizado por altas concentraciones de proteína C reactiva. Una mejor comprensión del papel de la inmunidad innata y adaptativa en la ateroesclerosis ha llevado a la investigación de tratamientos antiinflamatorios para la ECV. Algunos ensayos clínicos consisten en la evaluación de dosis bajas de fármacos diseñados para otras enfermedades inflamatorias sistémicas con alto riesgo de ECV, como la artritis reumatoide y la soriasis. Otras investigaciones son estudios restrospectivos y metanálisis de la incidencia de ECV en ensayos clínicos que han evaluado diferentes fármacos en las enfermedades. Otras terapia, sin embargo, se basan en ensayos preclínicos, como las vacunas. En este manuscrito se resumen las principales estrategias antiinflamatorias y los mecanismos moleculares asociados que se están evaluando en ensayos clínicos o preclínicos

Cardiovascular diseases (CVD) are the clinical manifestation of atherosclerosis, a chronic inflammatory disease promoted by several risk factors such as dyslipidemia, type 2 diabetes mellitus, hypertension, and smoking. Acute CVD events are the result of an unresolved inflammatory chronic state that promotes the rupture of unstable plaque lesions. Of note, the existing intensive therapies modify risk factors but do not prevent life-threatening recurrent ischemic events in high-risk patients, who have a residual inflammatory risk displayed by increased C-reactive protein (CRP) levels. Better understanding of the role of innate and adaptive immunity in plaque development and rupture has led to intensive investigation of anti-inflammatory strategies for CVD. Some of them are being tested in specific clinical trials and use lower doses of existing medications originally developed for other inflammatory diseases such as rheumatoid arthritis and psoriasis, which have high CVD risk. Other investigations are retrospective and meta-analyses of existing clinical trials that evaluate the incidence of CVD in these inflammatory diseases. Others are based on preclinical testing such as vaccines. In this article, we summarize the main anti-inflammatory strategies and associated molecular mechanisms that are being evaluated in preclinical or clinical CVD studies

Genetic inactivation of the LIGHT (TNFSF14) cytokine in mice restores glucose homeostasis and diminishes hepatic steatosis.

AIMS/HYPOTHESIS: Non-alcoholic fatty liver disease (NAFLD) is frequently associated with type 2 diabetes mellitus. Progression of NAFLD is mediated, among other things, by activation of inflammatory pathways. In the present study, the role of the proinflammatory cytokine LIGHT (TNFSF14) was explored in NAFLD and type 2 diabetes mellitus in mice deficient for the cytokine. METHODS: Light-deficient (Light-/-) mice and WT controls were fed a regular chow diet (RCD) or a high-fat high-cholesterol diet (HFHCD) for 16 weeks. The expression of LIGHT and its receptors, herpes virus entry mediator (HVEM) and lymphotoxin ß receptor (LTßR), was investigated in both dietary regimens. Glucose tolerance, insulin sensitivity, non-alcoholic fatty liver (NAFL), systemic and tissue inflammation, and metabolic gene expression were explored in Light-/- and WT mice fed an RCD and an HFHCD. The effect of Light deficiency was also evaluated in hepatic tissue and in inflammation in HFHCD-fed Irs2+/- mice with impaired insulin signalling. RESULTS: Light deficiency did not have an effect on metabolism, in NAFL or in tissue and systemic inflammation, in RCD-fed WT mice. HVEM and LTßR were markedly increased in livers of HFHCD-fed WT mice compared with RCD-fed WT controls. In WT mice under HFHCD, Light deficiency improved glucose tolerance and insulin sensitivity. Non-alcoholic fatty liver disease activity (NAS) score, hepatic CD3+ T lymphocytes and F4/80+ macrophages were decreased in HFHCD-fed Light-/- mice compared with HFHCD-fed WT controls. Consistent with a potential role of adipose tissue in hepatic homeostasis, Light-/- mice exhibited augmented anti-inflammatory F4/80+CD206+ adipose tissue macrophages and reduced proinflammatory F4/80+CD11c+ adipose tissue macrophages. Moreover, adipose tissue explants from Light-/- mice showed diminished secretion of monocyte chemoattractant protein 1 (MCP1), TNF-α and IL-17 cytokines. Circulating Light-/- leucocytes consistently displayed augmented levels of the patrolling Ly6Clow monocytes, decreased Th9 T cell subset and diminished plasma TNF-α and IL-6 levels. Similarly, Light deficiency in Irs2+/- mice, which display impaired insulin signalling, also reduced NAFL as well as systemic and adipose tissue inflammation. Analysis of hepatic gene expression in Light-/- mouse livers showed reduced levels of Zbtb16, the transcription factor essential for natural killer T (NKT) cell function, and two genes related to NAFLD and fibrosis, Klf6 and Tlr4. CONCLUSIONS/INTERPRETATION: These results indicate that Light deficiency in HFHCD improves hepatic glucose tolerance, and reduces hepatic inflammation and NAFL. This is accompanied by decreased systemic inflammation and adipose tissue cytokine secretion and by changes in the expression of key genes such as Klf6 and Tlr4 involved in NAFLD. These results suggest that therapies to block LIGHT-dependent signalling might be useful to restore hepatic homeostasis and to restrain NAFLD.

SGLT-2 (Sodium-Glucose Cotransporter 2) Inhibition Reduces Ang II (Angiotensin II)-Induced Dissecting Abdominal Aortic Aneurysm in ApoE (Apolipoprotein E) Knockout Mice.

OBJECTIVE: Abdominal aortic aneurysm (AAA) is a pathological condition of permanent vessel dilatation that predisposes to the potentially fatal consequence of aortic rupture. SGLT-2 (sodium-glucose cotransporter 2) inhibitors have emerged as powerful pharmacological tools for type 2 diabetes mellitus treatment. Beyond their glucose-lowering effects, recent studies have shown that SGLT-2 inhibitors reduce cardiovascular events and have beneficial effects on several vascular diseases such as atherosclerosis; however, the potential effects of SGLT-2 inhibition on AAA remain unknown. This study evaluates the effect of oral chronic treatment with empagliflozin-an SGLT-2 inhibitor-on dissecting AAA induced by Ang II (angiotensin II) infusion in apoE (apolipoprotein E)-/- mice. Approach and Results: Empagliflozin treatment significantly reduced the Ang II-induced increase in maximal suprarenal aortic diameter in apoE-/- mice independently of blood pressure effects. Immunohistochemistry analysis revealed that empagliflozin diminished Ang II-induced elastin degradation, neovessel formation, and macrophage infiltration at the AAA lesion. Furthermore, Ang II infusion resulted in a marked increase in the expression of chemokines (CCL-2 [chemokine (C-C motif) ligand 2] and CCL-5 [chemokine (C-C motif) ligand 5]), VEGF (vascular endothelial growth factor), and MMP (matrix metalloproteinase)-2 and MMP-9 in suprarenal aortic walls of apoE-/- mice, and all were reduced by empagliflozin cotreatment. Western blot analysis revealed that p38 MAPK (p38 mitogen-activated protein kinase) and NF-κB (nuclear factor-κB) activation was also reduced in the suprarenal aortas of apoE-/- mice cotreated with empagliflozin. Finally, in vitro studies in human aortic endothelial cells and macrophages showed that empagliflozin inhibited leukocyte-endothelial cell interactions and release of proinflammatory chemokines. CONCLUSIONS: Pharmacological inhibition of SGLT-2 by empagliflozin inhibits AAA formation. SGLT-2 inhibition might represent a novel promising therapeutic strategy to prevent AAA progression.

Type 1 diabetic mellitus patients with increased atherosclerosis risk display 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.

Anti-inflammatory Therapies for Cardiovascular Disease: Signaling Pathways and Mechanisms.

Cardiovascular diseases (CVD) are the clinical manifestation of atherosclerosis, a chronic inflammatory disease promoted by several risk factors such as dyslipidemia, type 2 diabetes mellitus, hypertension, and smoking. Acute CVD events are the result of an unresolved inflammatory chronic state that promotes the rupture of unstable plaque lesions. Of note, the existing intensive therapies modify risk factors but do not prevent life-threatening recurrent ischemic events in high-risk patients, who have a residual inflammatory risk displayed by increased C-reactive protein (CRP) levels. Better understanding of the role of innate and adaptive immunity in plaque development and rupture has led to intensive investigation of anti-inflammatory strategies for CVD. Some of them are being tested in specific clinical trials and use lower doses of existing medications originally developed for other inflammatory diseases such as rheumatoid arthritis and psoriasis, which have high CVD risk. Other investigations are retrospective and meta-analyses of existing clinical trials that evaluate the incidence of CVD in these inflammatory diseases. Others are based on preclinical testing such as vaccines. In this article, we summarize the main anti-inflammatory strategies and associated molecular mechanisms that are being evaluated in preclinical or clinical CVD studies.