Hyperlipemia and oxidation of LDL induce vascular smooth muscle cell growth: an effect mediated by the HLH factor Id3

Loss of Id3 (Inhibitor of Differentiation 3) Increases the Number of IgM-Producing B-1b Cells in Ischemic Skeletal Muscle Impairing Blood Flow Recovery During Hindlimb Ischemia

OBJECTIVE

Neovascularization can maintain and even improve tissue perfusion in the setting of limb ischemia during peripheral artery disease. The molecular and cellular mechanisms mediating this process are incompletely understood. We investigate the potential role(s) for Id3 (inhibitor of differentiation 3) in regulating blood flow in a murine model of hindlimb ischemia (HLI). Approach and Results: HLI was modeled through femoral artery ligation and resection and blood flow recovery was quantified by laser Doppler perfusion imaging. Mice with global Id3 deletion had significantly impaired perfusion recovery at 14 and 21 days of HLI. Endothelial- or myeloid cell-specific deletion of Id3 revealed no effect on perfusion recovery while B-cell-specific knockout of Id3 (Id3BKO) revealed a significant attenuation of perfusion recovery. Flow cytometry revealed no differences in ischemia-induced T cells or myeloid cell numbers at 7 days of HLI, yet there was a significant increase in B-1b cells in Id3BKO. Consistent with these findings, ELISA (enzyme-linked immunoassay) demonstrated increases in skeletal muscle and plasma IgM. In vitro experiments demonstrated reduced proliferation and increased cell death when endothelial cells were treated with conditioned media from IgM-producing B-1b cells and tibialis anterior muscles in Id3BKO mice showed reduced density of total CD31+ and αSMA+CD31+ vessels.

CONCLUSIONS

This study is the first to demonstrate a role for B-cell-specific Id3 in maintaining blood flow recovery during HLI. Results suggest a role for Id3 in promoting blood flow during HLI and limiting IgM-expressing B-1b cell expansion. These findings present new mechanisms to investigate in peripheral artery disease pathogenesis.

Pantothenic acid promotes dermal papilla cell proliferation in hair follicles of American minks via inhibitor of DNA Binding 3/Notch signaling pathway

AIMS

Pantothenic acid (PA) has been applied to treat alopecia, but the underlying mechanism is still unclear. Our study aims to explore the underlying mechanism of PA in regulating hair follicle (HF) growth.

MAIN METHODS

Mink HFs and dermal papilla (DP) cells were isolated and cultured in vitro. HFs and DP cells were treated with 0, 10, 20, 40 μg/ml PA. The effect of PA on HF growth, DP cell proliferation, cell cycle distribution, cell migration, and insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) expressions in DP cells was measured. Moreover, the effect of PA on inhibitor of DNA binding 3 (ID3)/Notch signaling pathway was analyzed. Subsequently, ID3 was silenced to validate whether ID3/Notch signaling pathway was involved in regulating DP cell proliferation by PA.

KEY FINDINGS

Both 20 μg/ml and 40 μg/ml PA promoted HF growth, G1/S transition of DP cells and IGF-1 and VEGF expressions in DP cells, while only 20 μg/ml PA promoted cell viability and the migration of DP cells. Thus 20 μg/ml PA was chosen for the following experiments. PA treatment was found to up-regulate ID3 expression but down-regulate Notch receptor 1 (Notch1) and Notch signaling targets expressions. Furthermore, ID3 knockdown reversed PA-induced cell proliferation and inhibition of Notch1 and Notch signaling targets expressions, indicating that PA-induced DP cell proliferation and inhibition of Notch signaling were mediated via up-regulation of ID3.

SIGNIFICANCE

This study provides an underlying mechanism related to the effect of PA on stimulating DP cell proliferation.

Effect of Transcriptional Regulator ID3 on Pulmonary Arterial Hypertension and Hereditary Hemorrhagic Telangiectasia

Pulmonary arterial hypertension (PAH) can be discovered in patients who have a loss of function mutation of activin A receptor-like type 1 (ACVRL1) gene, a bone morphogenetic protein (BMP) type 1 receptor. Additionally, ACVRL1 mutations can lead to hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, an autosomal dominant inherited disease that results in mucocutaneous telangiectasia and arteriovenous malformations (AVMs). Transcriptional regulator Inhibitor of DNA-Binding/Differentiation-3 (ID3) has been demonstrated to be involved in both PAH and HTT; however, the role of its overlapping molecular mechanistic effects has yet to be seen. This review will focus on the existing understanding of how ID3 may contribute to molecular involvement and perturbations thus altering both PAH and HHT outcomes. Improved understanding of how ID3 mediates these pathways will likely provide knowledge in the inhibition and regulation of these diseases through targeted therapies.

Inhibitor of Differentiation-3 and Estrogenic Endocrine Disruptors: Implications for Susceptibility to Obesity and Metabolic Disorders

The rising global incidence of obesity cannot be fully explained within the context of traditional risk factors such as an unhealthy diet, physical inactivity, aging, or genetics. Adipose tissue is an endocrine as well as a metabolic organ that may be susceptible to disruption by environmental estrogenic chemicals. Since some of the endocrine disruptors are lipophilic chemicals with long half-lives, they tend to bioaccumulate in the adipose tissue of exposed populations. Elevated exposure to these chemicals may predispose susceptible individuals to weight gain by increasing the number and size of fat cells. Genetic studies have demonstrated that the transcriptional regulator inhibitor of differentiation-3 (ID3) promotes high fat diet-induced obesity in vivo. We have shown previously that PCB153 and natural estrogen 17β-estradiol increase ID3 expression. Based on our findings, we postulate that ID3 is a molecular target of estrogenic endocrine disruptors (EEDs) in the adipose tissue and a better understanding of this relationship may help to explain how EEDs can lead to the transcriptional programming of deviant fat cells. This review will discuss the current understanding of ID3 in excess fat accumulation and the potential for EEDs to influence susceptibility to obesity or metabolic disorders via ID3 signaling.

Contribution of Inhibitor of DNA Binding/Differentiation-3 and Endocrine Disrupting Chemicals to Pathophysiological Aspects of Chronic Disease

The overwhelming increase in the global incidence of obesity and its associated complications such as insulin resistance, atherosclerosis, pulmonary disease, and degenerative disorders including dementia constitutes a serious public health problem. The Inhibitor of DNA Binding/Differentiation-3 (ID3), a member of the ID family of transcriptional regulators, has been shown to play a role in adipogenesis and therefore ID3 may influence obesity and metabolic health in response to environmental factors. This review will highlight the current understanding of how ID3 may contribute to complex chronic diseases via metabolic perturbations. Based on the increasing number of reports that suggest chronic exposure to and accumulation of endocrine disrupting chemicals (EDCs) within the human body are associated with metabolic disorders, we will also consider the impact of these chemicals on ID3. Improved understanding of the ID3 pathways by which exposure to EDCs can potentiate complex chronic diseases in populations with metabolic disorders (obesity, metabolic syndrome, and glucose intolerance) will likely provide useful knowledge in the prevention and control of complex chronic diseases associated with exposure to environmental pollutants.

E Proteins and ID Proteins: Helix-Loop-Helix Partners in Development and Disease

The basic Helix-Loop-Helix (bHLH) proteins represent a well-known class of transcriptional regulators. Many bHLH proteins act as heterodimers with members of a class of ubiquitous partners, the E proteins. A widely expressed class of inhibitory heterodimer partners-the Inhibitor of DNA-binding (ID) proteins-also exists. Genetic and molecular analyses in humans and in knockout mice implicate E proteins and ID proteins in a wide variety of diseases, belying the notion that they are non-specific partner proteins. Here, we explore relationships of E proteins and ID proteins to a variety of disease processes and highlight gaps in knowledge of disease mechanisms.

Hyperlipidemia induces vascular smooth muscle cell proliferation involving Wnt/β-catenin signaling

Hyperlipidemia has been shown to stimulate vascular smooth muscle cell (VSMC) proliferation. Wnt signaling pathway plays a critical role in embryonic development and cell proliferation. In this study, Sprague-Dawley rats fed with high-fat or normal diet for 12 weeks were sacrificed, and the thoracic aorta was harvested to determine wnt3a, β-catenin, T-cell factor 4 (TCF4), and cyclin D1 expressions. VSMC proliferation within thoracic aorta and lipid accumulation within VSMCs were detected. Rat aortic VSMCs were cultured in serum from rats with hyperlipidemia or DKK-1; Wnt3a, β-catenin, TCF4, and cyclin D1 expressions, and cell cycle distribution were determined. The findings demonstrated that increased number of VSMCs, lipid droplets, and vacuoles within thoracic aorta in the high-fat-fed group. Compared with controls, VSMCs from high-fat-fed rats showed higher mRNA expressions of wnt3a, β-catenin, TCF4, and cyclin D1, as well as in VSMCs cultured with hyperlipidemic serum. After 24 h, VSMCs stimulated with hyperlipidemic serum showed significantly increased cell number and S-phase entry compared with cells exposed to normolipidemic serum. These effects were blocked by DKK-1. These results suggest that Wnt/β-catenin signaling plays an important role in hyperlipidemia-induced VSMC proliferation.

Bioinformatics approach to evaluate differential gene expression of M1/M2 macrophage phenotypes and antioxidant genes in atherosclerosis

Atherosclerosis is a pro-inflammatory process intrinsically related to systemic redox impairments. Macrophages play a major role on disease development. The specific involvement of classically activated, M1 (pro-inflammatory), or the alternatively activated, M2 (anti-inflammatory), on plaque formation and disease progression are still not established. Thus, based on meta-data analysis of public micro-array datasets, we compared differential gene expression levels of the human antioxidant genes (HAG) and M1/M2 genes between early and advanced human atherosclerotic plaques, and among peripheric macrophages (with or without foam cells induction by oxidized low density lipoprotein, oxLDL) from healthy and atherosclerotic subjects. Two independent datasets, GSE28829 and GSE9874, were selected from gene expression omnibus (http://www.ncbi.nlm.nih.gov/geo/) repository. Functional interactions were obtained with STRING (http://string-db.org/) and Medusa (http://coot.embl.de/medusa/). Statistical analysis was performed with ViaComplex(®) (http://lief.if.ufrgs.br/pub/biosoftwares/viacomplex/) and gene score enrichment analysis (http://www.broadinstitute.org/gsea/index.jsp). Bootstrap analysis demonstrated that the activity (expression) of HAG and M1 gene sets were significantly increased in advance compared to early atherosclerotic plaque. Increased expressions of HAG, M1, and M2 gene sets were found in peripheric macrophages from atherosclerotic subjects compared to peripheric macrophages from healthy subjects, while only M1 gene set was increased in foam cells from atherosclerotic subjects compared to foam cells from healthy subjects. However, M1 gene set was decreased in foam cells from healthy subjects compared to peripheric macrophages from healthy subjects, while no differences were found in foam cells from atherosclerotic subjects compared to peripheric macrophages from atherosclerotic subjects. Our data suggest that, different to cancer, in atherosclerosis there is no M1 or M2 polarization of macrophages. Actually, M1 and M2 phenotype are equally induced, what is an important aspect to better understand the disease progression, and can help to develop new therapeutic approaches.

Id proteins in the vasculature: from molecular biology to cardiopulmonary medicine

The inhibitors of differentiation (Id) proteins belong to the helix-loop-helix group of transcription factors and regulate cell differentiation and proliferation. Recent studies have reported that Id proteins play important roles in cardiogenesis and formation of the vasculature. We have also demonstrated that heritable pulmonary arterial hypertension (HPAH) patients have dysregulated Id gene expression in pulmonary artery smooth muscle cells. The interaction between bone morphogenetic proteins and other growth factors or cytokines regulates Id gene expression, which impacts on pulmonary vascular cell differentiation and proliferation. Exploration of the roles of Id proteins in vascular remodelling that occurs in PAH and atherosclerosis might provide new insights into the molecular basis of these diseases. In addition, current progress in identification of the interactors of Id proteins will further the understanding of the function of Ids in vascular cells and enable the identification of novel targets for therapy in PAH and other cardiovascular diseases.

Id proteins: small molecules, mighty regulators

The family of inhibitor of differentiation (Id) proteins is a group of evolutionarily conserved molecules, which play important regulatory roles in organisms ranging from Drosophila to humans. Id proteins are small polypeptides harboring a helix-loop-helix (HLH) motif, which are best known to mediate dimerization with other basic HLH proteins, primarily E proteins. Because Id proteins do not possess the basic amino acids adjacent to the HLH motif necessary for DNA binding, Id proteins inhibit the function of E protein homodimers, as well as heterodimers between E proteins and tissue-specific bHLH proteins. However, Id proteins have also been shown to have E protein-independent functions. The Id genes are broadly but differentially expressed in a variety of cell types. Transcription of the Id genes is controlled by transcription factors such as C/EBPβ and Egr as well as by signaling pathways triggered by different stimuli, which include bone morphogenic proteins, cytokines, and ligands of T cell receptors. In general, Id proteins are capable of inhibiting the differentiation of progenitors of different cell types, promoting cell-cycle progression, delaying cellular senescence, and facilitating cell migration. These properties of Id proteins enable them to play significant roles in stem cell maintenance, vasculogenesis, tumorigenesis and metastasis, the development of the immune system, and energy metabolism. In this review, we intend to highlight the current understanding of the function of Id proteins and discuss gaps in our knowledge about the mechanisms whereby Id proteins exert their diverse effects in multiple cellular processes.

Targeting Wnt-Frizzled signaling in cardiovascular diseases

Wnts are secreted glycoproteins implicated in biological processes ranging from embryonic cardiac development to uncontrolled cell proliferation in diseased conditions. Cardiovascular disease is a major cause of morbidity and mortality worldwide. Phenotypic modulation of vascular smooth muscle cells, migration and proliferation in intimal layer and increased extracellular matrix production are some of the known hallmarks of cardiovascular pathologies. Heterogeneity associated with the binding of Wnts to their transmembrane receptors, Frizzled, and coreceptors low density lipoprotein-receptor-related protein is indeed intriguing. Nuclear-cytoplasmic shuttling of beta-catenin and activation of transcriptional factors, lymphoid enhancer factor and T cell activation factor leading to target gene activation has remained elusive. Our review highlights the emerging role of Wnt-Frizzled signaling in cardiovascular diseases. Overall, the pathway appears to be an attractive therapeutic target in identifying susceptible individuals at risk of developing restenosis/other vascular pathologies in the near future.

Daming capsule restores endothelial dysfunction induced by high-fat diet

BACKGROUND

Daming capsule (DMC), a traditional Chinese formula, has a lipid-modulating action with reduced adverse side effects as compared with other lipid lowering compounds. Since endothelial dysfunction often accompanies the hyperlipidemic state, we hypothesize that DMC might restore endothelial dysfunction produced by a high-fat (HF) diet. Importantly, we also investigate possible mechanisms involved in mediating the effects of DMC on vascular reactivity.

METHODS

Rats were divided into four groups: control, HF diet, HF mixed DMC diet, HF mixed atorvastatin (ATV) diet. After 30 days, the thoracic cavity was exposed to remove the thoracic aorta for (i) histological examination; (ii) measurement of endothelial nitric oxide synthase (eNOS) by western blot; and (iii) tension study of thoracic aortic ring.

RESULTS

HF diet induced significant attenuation in the contraction and relaxation of rat aortic rings. Treatment with DMC significantly improved the relaxation of the aortic rings as compared with those from HF rats (P < 0.05), which was abolished by a nonspecific NOS inhibitor L-NAME. Moreover DMC significantly restored the decrease in eNOS expression induced by HF diet. Similar results were found in histopathologic changes. DMC failed to restore the loss of vasocontraction of aorta explained by an impairment of ATP-sensitive K+ channels (KATP) on the structure and/or function. DMC exerted the same protective effect as ATV, a positive control drug, on vascular injury produced by HF diet.

CONCLUSION

DMC partially protects the aorta from HF-induced endothelial dysfunction via upregulation of the expression of eNOS.

Overexpression of Id3 induces apoptosis of A549 human lung adenocarcinoma cells

OBJECTIVES

Inhibitor of differentiation 3 (Id3) protein has been implicated in the control of multiple cell death signalling pathways and in aetiology of numerous diseases. The aims of this study were to construct a recombinant eukaryotic expression vector (pEGFP/Id3), containing human Id3 (hId3) fused with enhanced green fluorescent protein (EGFP), and to determine effects of ectopic Id3 overexpression, on human lung adenocarcinoma cell (A549) proliferation.

MATERIALS AND METHODS

Human Id3 cDNA was inserted into pEGFP-N1 vector to yield the recombinant eukaryotic expression vector pEGFP/Id3. Cells were transfected with pEGFP or pEGFP/Id3, and proliferation of EGFP-expressing cells was monitored by flow cytometry (FCM) and confocal fluorescence microscopy. RT-PCR, immunoblotting and immunocytochemistry were used to assess Id3 mRNA transcription and protein expression. Apoptosis was evaluated by Annexin V/7-AAD staining and FCM, while nuclear morphology of apoptotic cells was examined using Hoechst 33258 staining.

RESULTS

Over 4 days transfection with pEGFP, the proportion of EGFP-positive A549 cells peaked at approximately 60% by 48 h and remained stable over the next 48 h. In contrast, the proportion of EGFP-positive cells in cultures transfected with pEGFP/Id3 decreased from a peak of 60% at 48 h to <5% at 96 h, suggesting that Id3 expression inhibited cell proliferation or survival. Annexin V/7-AAD and Hoechst 33258 staining revealed significantly higher rates of apoptosis in pEGFP/Id3-transfected cells.

CONCLUSION

Overexpression of Id3 triggered apoptosis in A549 human lung adenocarcinoma cells, implicating Id3 in negative control of tumour growth. These Id3-induced pro-apoptotic signalling pathways require further study, but this preliminary investigation suggests that Id3 regulation could be exploited in anti-tumour therapies.

Inhibitor of differentiation-3 mediates high fat diet-induced visceral fat expansion

OBJECTIVE

Inhibitor of differentiation-3 (Id3) has been implicated in promoting angiogenesis, a key determinant of high-fat diet (HFD)-induced visceral adiposity. Yet the role of Id3 in HFD-induced angiogenesis and visceral adipose expansion is unknown.

METHODS AND RESULTS

Id3(-/-) mice demonstrated a significant attenuation of HFD-induced visceral fat depot expansion compared to wild type littermate controls. Importantly, unlike other Id proteins, loss of Id3 did not affect adipose depot size in young mice fed chow diet or differentiation of adipocytes in vitro or in vivo. Contrast enhanced ultrasound revealed a significant attenuation of visceral fat microvascular blood volume in HFD-fed mice null for Id3 compared to wild type controls. HFD induced Id3 and VEGFA expression in the visceral stromal vascular fraction and Id3(-/-) mice had significantly lower levels of VEGFA protein in visceral adipose tissue compared to wild type. Furthermore, HFD-induced VEGFA expression in visceral adipose tissue was completely abolished by loss of Id3. Consistent with this effect, Id3 abolished E12-mediated repression of VEGFA promoter activity.

CONCLUSIONS

Results identify Id3 as an important regulator of HFD-induced visceral adipose VEGFA expression, microvascular blood volume, and depot expansion. Inhibition of Id3 may have potential as a therapeutic strategy to limit visceral adiposity.

B-cell aortic homing and atheroprotection depend on Id3

RATIONALE

B cells are abundant in the adventitia of normal and diseased vessels. Yet, the molecular and cellular mechanisms mediating homing of B cells to the vessel wall and B-cell effects on atherosclerosis are poorly understood. Inhibitor of differentiation-3 (Id3) is important for atheroprotection in mice and polymorphism in the human ID3 gene has been implicated as a potential risk marker of atherosclerosis in humans. Yet, the role of Id3 in B-cell regulation of atherosclerosis is unknown.

OBJECTIVE

To determine if Id3 regulates B-cell homing to the aorta and atheroprotection and identify molecular and cellular mechanisms mediating this effect.

METHODS AND RESULTS

Loss of Id3 in Apoe(-/-) mice resulted in early and increased atherosclerosis. Flow cytometry revealed a defect in Id3(-/-) Apoe(-/-) mice in the number of B cells in the aorta but not the spleen, lymph nodes, and circulation. Similarly, B cells transferred from Id3(-/-) Apoe(-/-) mice into B-cell-deficient mice reconstituted spleen, lymph node, and blood similarly to B cells from Id3(+/+) Apoe(-/-) mice, but aortic reconstitution and B-cell-mediated inhibition of diet-induced atherosclerosis was significantly impaired. In addition to retarding initiation of atherosclerosis, B cells homed to regions of existing atherosclerosis, reduced macrophage content in plaque, and attenuated progression of disease. The chemokine receptor CCR6 was identified as an important Id3 target mediating aortic homing and atheroprotection.

CONCLUSIONS

Together, these results are the first to identify the Id3-CCR6 pathway in B cells and demonstrate its role in aortic B-cell homing and B-cell-mediated protection from early atherosclerosis.

Id3 is a novel atheroprotective factor containing a functionally significant single-nucleotide polymorphism associated with intima-media thickness in humans

RATIONALE

The gene encoding the helix-loop-helix transcription factor Id3 (inhibitor of differentiation-3) is located within atherosclerosis susceptibility loci of both mice and humans, yet its influence on atherosclerosis is not known.

OBJECTIVE

The present study sought to determine whether polymorphisms in the ID3 gene were associated with indices of atherosclerosis in humans and if loss of Id3 function modulated atherogenesis in mice.

METHODS AND RESULTS

Six tagging single-nucleotide polymorphisms (SNPs) (tagSNPs) in the human ID3 gene were assessed in participants of the Diabetes Heart Study. One tagSNP, rs11574, was independently associated with carotid intima-media thickness (IMT). The human ID3 variant at rs11574 results in an alanine to threonine substitution in the C terminus. To determine the effect of this polymorphism on the basic function of Id3, site-directed mutagenesis of the human ID3 gene at rs11574 was performed. Results demonstrated a significant reduction in coimmunoprecipitation of the known E-protein partner, E12, with Id3 when it contains the sequence encoded by the risk allele (Id3105T). Further, Id3105T had an attenuated ability to modulate E12-mediated transcriptional activation compared to Id3 containing the ancestral allele (Id3105A). Microarray analysis of vascular smooth muscle cells from WT and Id3(-/-) mice revealed significant modulation of multiple gene pathways implicated in atherogenesis. Moreover, Id3(-/-)ApoE(-/-) mice developed significantly more atherosclerosis in response to 32 weeks of Chow or Western diet feeding than Id3(+/+)ApoE(-/-) mice.

CONCLUSIONS

Taken together, results provide novel evidence that Id3 is an atheroprotective factor and link a common SNP in the human ID3 gene to loss of Id3 function and increased IMT.

Topical mitogen-activated protein kinases inhibition reduces intimal hyperplasia in arterialized vein grafts

OBJECTIVE

Vein graft arterialization results in activation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinases-1 and -2 (ERK1/2), which have been implicated in cell proliferation, migration, and apoptosis. The goal of our study was to characterize the effect of MAPK inhibition on intimal hyperplasia (IH) in arterialized vein grafts in hypercholesterolemic rabbits.

METHODS

Reversed bilateral jugular vein to common carotid artery interposition grafts were constructed in 16 New Zealand White rabbits. The veins were incubated for 30 min prior to grafting with either the synthetic ERK1/2 activation inhibitor UO126 or the control vehicle. Vein graft and control jugular vein were harvested 3 h, 1 d, and 28 d after arterialization for histological and biochemical analyses.

RESULTS

Treatment with UO126 was associated with 31% reduction in mean intimal area (1.68 +/- 0.78 mm(2)versus 2.44 +/- 1.65 mm(2); mean +/- SD; P = 0.036) relative to controls. The intima-to-media ratio of UO126-treated vein grafts decreased by 29% (0.53 +/- 0.04 versus 0.74 +/- 0.06; mean +/- SD; P < 0.01) compared to controls, vehicle-treated vein grafts. There was also significant increase in apoptosis in UO126-treated vein graft medial cell layer at 1 d.

CONCLUSION

Topical administration of UO126 before vein grafting significantly decreases IH in arterialized vein grafts in hypercholesterolemic rabbits. These results may have significant implications for the development of strategies aimed at blocking or reducing IH in bypass grafts. Therefore, further evaluation of this simple strategy to improve vein graft patency following coronary artery or peripheral vascular bypass surgery is warranted.

Arterial smooth muscle cells dysfunction in hyperglycaemia and hyperglycaemia associated with hyperlipidaemia: from causes to effects

Given the important role of smooth muscle cells in arterial wall dysfunction in diabetes, as well as in diabetes associated with accelerated atherosclerosis, we provide a brief review of the recent achievements in identification of signalling molecules underlying their altered cellular responses, and examine the consequences of these pathological insults on smooth muscle cells properties. The original results emerging from the Golden Syrian hamster model (rendered diabetic or simultaneously hyperlipidaemic-diabetic) and from human aortic smooth muscle cells cultured in 25 mM glucose (to mimic diabetic condition) or sera of obese type 2 diabetic patients (to mimic the metabolic syndrome condition) are presented in this context. We conclude this review with several open issues disclosed by the most recent literature that deserve essential attention for targeting the translational medicine.