T cell-specific overexpression of TGFß1 fails to influence atherosclerosis in ApoE-deficient mice

T Cells in Atherosclerosis in Ldlr-/- and Apoe-/- Mice

Atherosclerosis is the underlying basis for most cardiovascular diseases. It is a chronic inflammation affecting the arterial intima and is promoted by hypercholesterolemia. Cells of both the innate and adaptive immune systems contribute to this inflammation with macrophages and T cells being the most abundant immune cells in the atherosclerotic plaques. In this review, we discuss the studies that examined the role of T cells and T cell subsets in Apoe-/- and Ldlr-/- murine models of atherosclerosis. While there is a general consensus that Th1 cells are pro-atherogenic and regulatory T cells are atheroprotective, the role of other subsets is more ambiguous. In addition, the results in the two models of atherosclerosis do not always yield similar results. Additional studies in the two murine models using cell specific gene manipulations are needed.

Protein transduction therapy into cochleae via the round window niche in guinea pigs

Cell-penetrating peptides (CPPs) are short sequences of amino acids that facilitate the penetration of conjugated cargoes across mammalian cell membranes, and as such, they may provide a safe and effective method for drug delivery to the inner ear. Simple polyarginine peptides have been shown to induce significantly higher cell penetration rates among CPPs. Herein, we show that a peptide consisting of nine arginines ("9R") effectively delivered enhanced green fluorescent protein (EGFP) into guinea pig cochleae via the round window niche without causing any deterioration in auditory function. A second application, 24 hours after the first, prolonged the presence of EGFP. To assess the feasibility of protein transduction using 9R-CPPs via the round window, we used "X-linked inhibitor of apoptosis protein" (XIAP) bonded to a 9R peptide (XIAP-9R). XIAP-9R treatment prior to acoustic trauma significantly reduced putative hearing loss and the number of apoptotic hair cells loss in the cochleae. Thus, the topical application of molecules fused to 9R-CPPs may be a simple and promising strategy for treating inner ear diseases.

Cytokines: roles in atherosclerosis disease progression and potential therapeutic targets

Atherosclerosis, the primary cause of cardiovascular disease (CVD), is a chronic inflammatory disorder in the walls of medium and large arteries. CVD is currently responsible for about one in three global deaths and this is expected to rise in the future due to an increase in the prevalence of obesity and diabetes. Current therapies for atherosclerosis mainly modulate lipid homeostasis and while successful at reducing the risk of a CVD-related death, they are associated with considerable residual risk and various side effects. There is, therefore, a need for alternative therapies aimed at regulating inflammation in order to reduce atherogenesis. This review will highlight the key role cytokines play during disease progression as well as potential therapeutic strategies to target them.

Polymorphisms of TGFβ-1 and TGFBR2 in relation to coronary artery disease in a Chinese population

BACKGROUND AND AIM

TGF-β1 has been previously reported to be involved in the pathogenesis of atherosclerosis. The aim of the present study was to assess whether functional gene polymorphisms of TGF-β1 and its key receptor TGF-β receptor type II (TGFBR2) contribute as risk factors to the onset and severity of atherosclerotic coronary artery disease (CAD).

DESIGN AND METHODS

A total of 605 patients who underwent angiography for suspected CAD were prospectively recruited to this study. Coronary stenosis severity was assessed by the number of narrowed coronary vessels and the Gensini score. Among them, 502 patients had documented CAD, and 103 patients without documented CAD served as non-CAD controls. All patients were genotyped for one TGF-β1 polymorphism (rs1800470 (+T29C)) and two TGFBR2 polymorphisms (rs6785385 (-3779A/G), rs764522 (-1444C/G)) by polymerase chain reaction-restriction fragment length polymorphism and confirmed by direct sequencing.

RESULTS

No significant difference in the frequency for either polymorphism was found between CAD and control patients. Neither TGFBR2 rs6785385 (-3779A/G) nor rs764522 (-1444C/G) gene polymorphisms were associated with the severity of CAD (P>0.05). In male CAD patients, polymorphisms at TGF-β1 rs1800470 (+T29C) were, however, associated with the severity of CAD. The T allele frequency was significantly and positively correlated with the number of narrowed coronary arteries (three or more vessels: 49.3%, two vessels: 44.1%, one vessel: 36.9%) (P=0.039). Gensini scores in patients with the TT, CT, and CC genotype were 34.33±2.23, 32.06±4.79, and 26.90±3.83, respectively (P<0.05). In multiple linear regression analysis, the T allele of TGF-β1 polymorphism was independently correlated with the Gensini score (β=0.131).

CONCLUSION

TGF-β1 T29C gene polymorphism may be associated with severity of CAD in male patients. TGFBR2 polymorphisms may not determine the genetic susceptibility to CAD.

Cytokines in atherosclerosis: Key players in all stages of disease and promising therapeutic targets

Atherosclerosis, a chronic inflammatory disorder of the arteries, is responsible for most deaths in westernized societies with numbers increasing at a marked rate in developing countries. The disease is initiated by the activation of the endothelium by various risk factors leading to chemokine-mediated recruitment of immune cells. The uptake of modified lipoproteins by macrophages along with defective cholesterol efflux gives rise to foam cells associated with the fatty streak in the early phase of the disease. As the disease progresses, complex fibrotic plaques are produced as a result of lysis of foam cells, migration and proliferation of vascular smooth muscle cells and continued inflammatory response. Such plaques are stabilized by the extracellular matrix produced by smooth muscle cells and destabilized by matrix metalloproteinase from macrophages. Rupture of unstable plaques and subsequent thrombosis leads to clinical complications such as myocardial infarction. Cytokines are involved in all stages of atherosclerosis and have a profound influence on the pathogenesis of this disease. This review will describe our current understanding of the roles of different cytokines in atherosclerosis together with therapeutic approaches aimed at manipulating their actions.