Protective effect of the glucagon-like peptide-1 analogue liraglutide on carbon tetrachloride-induced acute liver injury in mice.

Acute liver injury seriously endangers human health. Liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, has antioxidative effects in addition to being widely used in the treatment of type 2 diabetes and was reported to ameliorate liver diseases. The aim of this study was to evaluate the hepatoprotective effects of liraglutide on carbon tetrachloride (CCl4)-induced acute liver injury in mice and to investigate the mechanisms involved in this protective effect. Male BALB/c mice were pre-treated with liraglutide (200 µg/kg/day) by hypodermic injection for 3 days before a 0.1% (v/v) CCl4 (10 ml/kg, dissolved in olive oil) intraperitoneal injection, or post-treated with liraglutide once immediately after a CCl4 intraperitoneal injection. The experimental data showed that liraglutide treatment significantly decreased the serum ALT and AST levels and ameliorated the liver histopathological changes induced by CCl4. In addition, liraglutide pre-treatment dramatically increased the number of proliferating cell nuclear antigen (PCNA)-positive hepatocytes and significantly reduced hepatocyte apoptosis after CCl4 treatment. As a consequence, liraglutide pre-treatment significantly prevented CCl4-induced malondialdehyde (MDA) production and increased the activity of the antioxidant superoxide dismutase (SOD) enzyme. In addition, liraglutide pre-treatment significantly ameliorated mitochondrial respiratory functions and ultrastructural features. Furthermore, liraglutide pre-treatment enhances the activation of the NRF2/HO-1 signaling pathway. In summary, liraglutide protects against CCl4-induced acute liver injury by protecting mitochondrial functions and inhibiting oxidative stress, which may partly involve the activation of NRF2/HO-1 signaling pathway.

Fecal microbiota transplantation alleviates myocardial damage in myocarditis by restoring the microbiota composition.

Myocarditis can be caused by several infectious and noninfectious causes. Treatment for myocarditis is still a difficult task in clinical practice. The gut microbiota is related to cardiovascular diseases such as atherosclerosis and hypertension. However, little is known about the role of the gut microbiota in myocarditis. In our study, we tested the hypothesis that gut dysbiosis is associated with myocarditis. We focused on whether fecal microbiota transplantation (FMT) can be used as an effective treatment for myocarditis. We used an experimental autoimmune myocarditis (EAM) mouse model. Fecal samples were isolated from the control and EAM groups for bacterial genome analysis. We observed an increase in microbial richness and diversity in the myocarditis mice. These changes were accompanied by an increased Firmicutes/Bacteroidetes ratio. We also evaluated the efficacy of FMT for the treatment of myocarditis. EAM mouse guts were repopulated with fecal contents from an untreated male mouse donor. We found that myocardial injury was improved by diminished inflammatory infiltration, showing that IFN-γ gene expression in the heart tissue and CD4+IFN-γ+ cells in the spleen were decreased after FMT in EAM mice. We also found that FMT was able to rebalance the gut microbiota by restoring the Bacteroidetes population and reshaping the microbiota composition. Myocarditis is associated with gut microbiota dysbiosis and characterized by an increased F/B ratio. FMT treatment can rebalance the gut microbiota and attenuate myocarditis. Thus, FMT may be a potential therapeutic strategy for the treatment of myocarditis.

Down-regulation of Helios Expression in Tregs from Patients with Hypertension.

Regulatory T cells (Tregs) play a pivotal role in the pathological development of hypertension. Helios, a transcription factor from the Ikaros family, was recently reported to be a bona fide marker for natural Tregs or activated Tregs with suppression function, however, little has been known about its role in hypertension. This study was aimed to find whether Helios+ Tregs really play a vital role in hypertension. A total of 60 hypertension patients, and 46 normotension subjects were enrolled in this study. Frequencies of different Tregs subsets in peripheral blood were measured by flow cytometry. Plasma cytokine level was determined by ELISA. The mRNA expression of Foxp3 and Helios in purified CD4+ T cells was detected by RT-PCR. Proportion of CD4+Foxp3+Helios+ Tregs was decreased significantly in patients with hypertension (62.52%±1.18% vs. 71.89%±1.03%, P<0.01), and it was correlated with plasma level of IL-10 positively (a=0.505, P<0.05) and plasma level of IFN-gamma negatively (r=-0.551, P<0.05). The mRNA expression of Foxp3 (7.23±1.00 vs. 10.58±0.54, P<0.05) and Helios (8.47±0.95 vs. 15.52±2.0, P<0.05) was decreased in CD4+ T cells from patients with hypertension. Helios+ Tregs were decreased in patients with hypertension and may play a protective role in hypertension progression.

The conditioned medium of human mesenchymal stromal cells reduces irradiation-induced damage in cardiac fibroblast cells.

Recently, multipotent mesenchymal stromal cell (MSC) treatment has attracted special attention as a new alternative strategy for stimulating regeneration. Irradiation myocardial fibrosis (IMF) is a major complication associated with total body irradiation for hematopoietic stem cell transplantation, nuclear accidents, and thoracic radiotherapy for lung cancer, esophageal cancer, proximal gastric cancer, breast cancer, thymoma, and lymphoma. The aim of the present study was to assess the therapeutic paracrine effects of human umbilical cord-derived mesenchymal stromal cells (UC-MSCs) in the cell model of IMF. For this purpose, primary human cardiac fibroblasts (HCF) cells were irradiated and cultured with the conditioned medium of UC-MSCs (MSCCM). MSCCM promoted cell viability, reduced collagen deposition as measured by Sircol assay and qPCR (Col1A1 and Col1A2), prevented oxidative stress and increased antioxidant status (as measured by malondialdehyde content and the activities and mRNA levels of antioxidant enzymes), and reduced pro-fibrotic TGF-ß1, IL-6 and IL-8 levels (as examined by ELISA kit and qPCR). Pretreatment with inhibitor of NF-κB led to a decrease in the levels of TGF-ß1 in cell lysate of HCF cells by ELISA kit. Furthermore, we also found that MSCCM prevented NF-κB signaling pathway activation for its proinflammatory actions induced by irradiation. Taken together, our data suggest that MSCCM could reduce irradiation-induced TGF-ß1 production through inhibition of the NF-κB signaling pathway. These data provide new insights into the functional actions of MSCCM on irradiation myocardial fibrosis.

Cardioprotective Effects of Malvidin Against Isoproterenol-Induced Myocardial Infarction in Rats: A Mechanistic Study.

BACKGROUND Malvidin (alvidin-3-glucoside) is a polyphenol that belongs to the class of natural anthocyanin, which is abundantly found in red wines, colored fruits, and the skin of red grapes. Therefore, the current investigation was intended to evaluate the effect of malvidin against myocardial infarction induced by isoproterenol in the rats. MATERIAL AND METHODS The cardioprotective effects was assessed by determining the effect of malvidin on the activities of endogenous antioxidants - catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) - and on the levels of lipid peroxidation and serum marker enzymes. The serum levels of IL-6 and TNF-α were also determined using an enzyme-linked immunosorbent assay (ELISA) kit. RESULTS The present study demonstrated a significant cardioprotective effect of malvidin by restoring the defensive activities of endogenous antioxidants - catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) - and by reducing the levels of lipid peroxidation and serum marker enzymes lactate dehydrogenase (LD) and creatine kinase (CK). Malvidin significantly ameliorated the histopathological changes and impaired mitochondria in the cardiac necrosis stimulated with isoproterenol. Additionally, the results also demonstrated that nuclear translocation of Nrf-2 and subsequent HO-1 expression might be associated with nuclear factor kappa B (NF-κB) pathway activation. CONCLUSIONS Our findings suggest that malvidin exerts cardioprotective effects that might be due to possible strong antioxidant and anti-inflammatory activities. Therefore, this study provides the basis for the development of malvidin as a safe and effective treatment of myocardial infarction.

Activated Circulating Myeloid-Derived Suppressor Cells in Patients with Dilated Cardiomyopathy.

BACKGROUND/AIMS: Myeloid-derived suppressor cells (MDSCs) are increased in inflammatory and autoimmune disorders. This study aims to evaluate the significance of MDSCs in dilated cardiomyopathy (DCM) patients. METHODS: In total, 42 newly hospitalized DCM patients and 39 healthy controls were enrolled in the study. The frequencies of circulating CD14+HLA-DR-/low MDSCs were determined by flow cytometry. Then, the functional properties of MDSCs in suppressing T cell proliferation and interferon-gamma (IFN-x03B3;) production were measured in a co-culture model. Then, mRNA expression levels of various important molecules in peripheral blood mononuclear cells were measured by real time polymerase chain reaction. Furthermore, correlation analyses between MDSC frequencies and cardiac function parameters were also performed. RESULTS: The frequencies of circulating CD14+HLA-DR-/low MDSCs were significantly elevated in DCM patients compared with healthy controls. It showed that MDSCs from DCM patients more effectively suppressed T cell proliferation and IFN-x03B3; production compared with those from healthy controls, which was partially mediated by arginase-1 (Arg-1). In addition, the correlation analysis suggested that MDSC frequencies were negatively correlated with left ventricular ejection fraction (LVEF), while positively with N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with DCM. CONCLUSIONS: Circulating activated MDSCs might play significant immunomodulatory roles in the pathogenesis of DCM.

Association of IL33/ST2 signal pathway gene polymorphisms with myocardial infarction in a Chinese Han population.

This study investigated the relationship between IL-33/ST2 signal pathway gene polymorphisms and myocardial infarction (MI) in Han Chinese. A case-control association analysis was performed on a total of 490 MI patients (MI group) and 929 normal subjects (NC group). Sequenom Mass Array and Taqman genotyping technique were used to analyze the tag single nucleotide polymorphisms (SNPs) in the genes encoding IL-33, ST2, and IL-1RaP (rs11792633, rs1041973 and rs4624606). The results showed that the frequencies of rs4624606 genotypes AA, TT, AT were 0.031, 0.647, 0.322 in MI group and 0.026, 0.712, 0.263 in NC group, and the allele frequencies of A and T were 0.192, 0.808 in MI group and 0.157, 0.843 in NC group. There were significant differences in rs4624606 genotypes and allele frequencies between MI group and NC group (P<0.05). For rs11792633, the allele frequencies of C and T were 0.45, 0.55 in MI group and 0.454, 0.546 in NC group with no significant differences found between the two groups. Compared with genotype CC+TC, rs11792633 genotype TT had an increased risk of hypertension (P<0.05). However, there were no significant differences in the frequencies of rs11792633 genotypes between the two groups. No significant differences were noted in the frequencies of rs1041973 genotype and allele between the two groups. Logistic regression analysis showed that rs4624606 genotypes AT and AA+AT were both significantly associated with MI (AT: OR=1.325, P=0.029, 95% CI=1.03-1.705; AA+AT: OR=1.316, P=0.028, 95% CI=1.03-1.681) after factors such as age, gender, smoking, drinking, body mass index (BMI), triglyceride (TG) and cholesterol were adjusted. Those carrying rs4624606 genotype AT or AA+AT had an increased risk of MI. No associations were found between the polymorphisms of the other two loci with MI. It was concluded that, in the IL33/ST2 signal pathway, the A allele of rs4624606 polymorphism of IL-1RaP gene is a potential independent risk factor for MI, and the genotypes AA+AT and AT are associated with the incidence of MI.

Expansion of myeloid-derived suppressor cells in patients with acute coronary syndrome.

AIM: The aim of this study was to explore whether the circulating frequency and function of myeloid-derived suppressor cells (MDSCs) are altered in patients with acute coronary syndrome (ACS). METHODS: The frequency of MDSCs in peripheral blood was determined by flow cytometry, and mRNA expression in purified MDSCs was analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR). The suppressive function of MDSCs isolated from different groups was also determined. The plasma levels of certain cytokines were determined using Bio-Plex Pro™ Human Cytokine Assays. RESULTS: The frequency of circulating CD14(+)HLA-DR(-/low) MDSCs; arginase-1 (Arg-1) expression; and plasma levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α, and IL-33 were markedly increased in ACS patients compared to stable angina (SA) or control patients. Furthermore, MDSCs from ACS patients were more potent suppressors of T-cell proliferation and IFN-γ production than those from the SA or control groups at ratios of 1:4 and 1:2; this effect was partially mediated by Arg-1. In addition, the frequency of MDSCs was positively correlated with plasma levels of IL-6, IL-33, and TNF-α. CONCLUSIONS: We observed an increased frequency and suppressive function of MDSCs in ACS patients, a result that may provide insights into the mechanisms involved in ACS.

Regulatory T cells protect fine particulate matter-induced inflammatory responses in human umbilical vein endothelial cells.

OBJECTIVE: To investigate the role of CD4(+)CD25(+) T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms. METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm(2)) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4(+)CD25(-) T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined. RESULTS: Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF- κ B activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF- κ B activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors. CONCLUSIONS: Tregs could attenuate fine particles-induced inflammatory responses and NF- κ B activation in HUVECs.

GABA and topiramate inhibit the formation of human macrophage-derived foam cells by modulating cholesterol-metabolism-associated molecules.

AIMS: γ-aminobutyric acid (GABA), the principal inhibitory neurotransmitter, acts on GABA receptors to play an important role in the modulation of macrophage functions. The present study examined the effects of GABA and a GABA receptor agonist on modulating cholesterol-metabolism-associated molecules in human monocyte-derived macrophages (HMDMs). METHODS: ORO stain, HPLC, qRT-PCR, Western blot and EMSA were carried out using HMDMs exposed to ox-LDL with or without GABAergic agents as the experimental model. RESULTS: GABA and topiramate reduced the percentage of cholesterol ester in lipid-laden HMDMs by down-regulating SR-A, CD36 and LOX-1 expression and up-regulating ABCA1, ABCG1 and SR-BI expression in lipid-laden HMDMs. The production of TNF-α was decreased in GABA-and topiramate-treated lipid-laden HMDMs, and levels of interleukin (IL)-6 did not change. The activation of two signaling pathways, p38MAPK and NF-κB, was repressed by GABA and topiramate in lipid-laden HMDMs. CONCLUSION: GABA and topiramate inhibit the formation of human macrophage-derived foam cells and may be a possibility for macrophage targeted therapy of atherosclerotic lesions.

Inhibitory role for GABA in atherosclerosis.

γ-Aminobutyric acid (GABA), the classical inhibitory neurotransmitter in the nervous system, has a parallel inhibitory role in the immune system. It affects a variety of functional properties of the immune cells like monocyte migration, macrophage cholesterol efflux, regulatory T cell proliferation and inflammatory cytokine secretion. All of these are the main pathologic processes of atherosclerosis, a chronic inflammatory disease involving both innate and adaptive immune responses in the artery wall. Moreover, GABA has neuroprotective effects in brain ischemic injury, which is one of the serious complications of atherosclerosis. Therefore, we hypothesize GABA may be a prospect immune cell targeting therapy in atherosclerosis.

Specific Kv1.3 blockade modulates key cholesterol-metabolism-associated molecules in human macrophages exposed to ox-LDL.

Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions.

Blocking of the human ether-à-go-go-related gene channel by imatinib mesylate.

Imatinib mesylate (IM), a widely prescribed powerful tyrosine kinase inhibitor, has been associated with increased risk of heart failure and is known to induce cell apoptosis and death in isolated cardiomyocytes. In addition to acquired long QT syndrome, pharmacological inhibition of human ether-à-go-go-related gene (HERG) channel has been reported to involve in apoptosis. The present study was undertaken to characterize the biophysical properties of IM on HERG and the molecular determinants of HERG blockade using mutant channels (Y652A and F656A). Wild type (WT) and mutant HERG channels were expressed in HEK-293 cells and Xenopus oocytes and the currents (I(HERG)) were measured using patch-clamp and two-microelectrode voltage-clamp techniques. IM inhibited WT I(HERG) in a concentration-dependent manner with an IC(50) of 19.51±2.50 µmol/L and 44.76±1.54 µmol/L in HEK-293 cells and Xenopus oocytes, respectively. The IM-induced inhibition of WT I(HERG) followed a voltage- and time-dependent manner. The blockade was enhanced by further activation of currents, which were in accordance with an open-channel blockade. The V(1/2) for steady-state activation shifted from -15.48±1.21 to -26.66±2.98 mV (p<0.05, n=6). The inactivation kinetics and voltage dependence of steady-state inactivation of the WT HERG channel were not significantly altered by IM. Two S6 domain mutants, F652A and Y656A, attenuated IM-induced inhibition of WT I(HERG). Therefore, IM preferentially blocked the open HERG channel through F652 and Y656, providing a molecular mechanism for the cardiac side effects during the clinical administration of IM.

Curcumin serves as a human kv1.3 blocker to inhibit effector memory T lymphocyte activities.

Curcumin, the principal active component of turmeric, has long been used to treat various diseases in India and China. Recent studies show that curcumin can serve as a therapeutic agent for autoimmune diseases via a variety of mechanisms. Effector memory T cells (T(EM), CCR7⁻ CD45RO⁺ T lymphocyte) have been demonstrated to play a crucial role in the pathogenesis of T cell-mediated autoimmune diseases, such as multiple sclerosis (MS) or rheumatoid arthritis (RA). Kv1.3 channels are predominantly expressed in T(EM) cells and control T(EM) activities. In the present study, we examined the effect of curcumin on human Kv1.3 (hKv1.3) channels stably expressed in HEK-293 cells and its ability to inhibit proliferation and cytokine secretion of T(EM) cells isolated from patients with MS or RA. Curcumin exhibited a direct blockage of hKv1.3 channels in a time-dependent and concentration-dependent manner. Moreover, the activation curve was shifted to a more positive potential, which was consistent with an open-channel blockade. Paralleling hKv1.3 inhibition, curcumin significantly inhibited proliferation and interferon-γ secretion of T(EM) cells. Our findings demonstrate that curcumin is able to inhibit proliferation and proinflammatory cytokine secretion of T(EM) cells probably through inhibition of hKv1.3 channels, which contributes to the potency of curcumin for the treatment of autoimmune diseases. This is probably one of pharmacological mechanisms of curcumin used to treat autoimmune diseases.

Impaired thymic export and increased apoptosis account for regulatory T cell defects in patients with non-ST segment elevation acute coronary syndrome.

Regulatory T (Treg) cells play a protective role against the development of atherosclerosis. Previous studies have revealed Treg cell defects in patients with non-ST elevation acute coronary syndrome (NSTACS), but the mechanisms underlying these defects remain unclear. In this study, we found that the numbers of peripheral blood CD4(+)CD25(+)CD127(low) Treg cells and CD4(+)CD25(+)CD127(low)CD45RA(+)CD45RO(-) naive Treg cells were lower in the NSTACS patients than in the chronic stable angina (CSA) and the chest pain syndrome (CPS) patients. However, the number of CD4(+)CD25(+)CD127(low)CD45RA(-)CD45RO(+) memory Treg cells was comparable in all of the groups. The frequency of CD4(+)CD25(+)CD127(low)CD45RO(-)CD45RA(+)CD31(+) recent thymic emigrant Treg cells and the T cell receptor excision circle content of purified Treg cells were lower in the NSTACS patients than in the CSA patients and the CPS controls. The spontaneous apoptosis of Treg cells (defined as CD4(+)CD25(+)CD127(low)annexin V(+)7-AAD(-)) was increased in the NSTACS patients compared with the CSA and CPS groups. Furthermore, oxidized LDL could induce Treg cell apoptosis, and the oxidized LDL levels were significantly higher in the NSTACS patients than in the CSA and CPS groups. In accordance with the altered Treg cell levels, the concentration of TNF-α was increased in the NSTACS patients, resulting in a decreased IL-10/TNF-α ratio. These findings indicate that the impaired thymic output of Treg cells and their enhanced susceptibility to apoptosis in the periphery were responsible for Treg cell defects observed in the NSTACS patients.

The antibody targeting the E314 peptide of human Kv1.3 pore region serves as a novel, potent and specific channel blocker.

Selective blockade of Kv1.3 channels in effector memory T (T(EM)) cells was validated to ameliorate autoimmune or autoimmune-associated diseases. We generated the antibody directed against one peptide of human Kv1.3 (hKv1.3) extracellular loop as a novel and possible Kv1.3 blocker. One peptide of hKv1.3 extracellular loop E3 containing 14 amino acids (E314) was chosen as an antigenic determinant to generate the E314 antibody. The E314 antibody specifically recognized 63.8KD protein stably expressed in hKv1.3-HEK 293 cell lines, whereas it did not recognize or cross-react to human Kv1.1(hKv1.1), Kv1.2(hKv1.2), Kv1.4(hKv1.4), Kv1.5(hKv1.5), KCa3.1(hKCa3.1), HERG, hKCNQ1/hKCNE1, Nav1.5 and Cav1.2 proteins stably expressed in HEK 293 cell lines or in human atrial or ventricular myocytes by Western blotting analysis and immunostaining detection. By the technique of whole-cell patch clamp, the E314 antibody was shown to have a directly inhibitory effect on hKv1.3 currents expressed in HEK 293 or Jurkat T cells and the inhibition showed a concentration-dependence. However, it exerted no significant difference on hKv1.1, hKv1.2, hKv1.4, hKv1.5, hKCa3.1, HERG, hKCNQ1/hKCNE1, L-type Ca(2+) or voltage-gated Na(+) currents. The present study demonstrates that the antibody targeting the E314 peptide of hKv1.3 pore region could be a novel, potent and specific hKv1.3 blocker without affecting a variety of closely related K(v)1 channels, KCa3.1 channels and functional cardiac ion channels underlying central nervous system (CNS) disorders or drug-acquired arrhythmias, which is required as a safe clinic-promising channel blocker.

[Study on the correlation of the levels of serum IFN-γ and RANTES and rabbit vulnerable atherosclerotic plaque].

AIM: To investigate the correlation between the levels of serum IFN-γ and RANTES (regulated upon on activation on normal T cell expressed and secreted) and rabbit atherosclerotic plaque stability. METHODS: 30 male New Zealand rabbits were randomly divided into three groups: control group, stable atherosclerotic plaque group(AS group) and vulnerable atherosclerotic plaque group(VAP group), with 10 rabbits in a group. The control group was given normal diet while the AS group and the VAP group were given high-fat diet for 12 weeks. According to literature method pharmacological triggers inducing the vulnerable atherosclerotic plaque formation in the VAP group. Fasting blood was extracted from ear medium artery about 2 mL at week-0 and the 12th week, serum total cholesterol, triglyceride and high density lipoprotein cholesterol were detected by enzymatic method, and low density lipoprotein cholesterol was calculated by Friedwald formula. All animals were executed after they were fed by injected excessive Phenobarbital sodium at ear vein for 12 weeks. Before executed, ear medium artery blood was taken to detect the levels of serum IFN-γ and RANTES by ELISA.The corrected plaque area and vulnerability index were calculated by Masson staining and its correlation coefficient with inflammatory factors were measured. RESULTS: The level of serum IFN-γ at the AS group and the VAP group, compared with the control group, was significantly increased(all P<0.01), at the same time, the level of serum IFN-γ in the VAP group was significantly higher than in the AS group(P<0.01). About the level of serum RANTES there was no obvious difference when the AS group was compared with the control group(P>0.05). The level of serum RANTES in the VAP group was higher than in the AS group and the control group(all P<0.01). Regarding corrected plaque area and vulnerability Index, the VAP group was significantly higher than the AS group (P<0.01). In the AS group and the VAP group, the serum concentrations of IFN-γand RANTES exhibited a positive correlation with corrected plaque area and vulnerability Index (P<0.05). CONCLUSION: IFN-γ and RANTES may be inflammatory marker about atherosclerotic vulnerable plaque, and their serum concentration can be used to evaluate the atherosclerotic plaque instability.

The role of RANTES as a crucial downstream cytokine in calcineurin-dependent VSMC apoptosis stimulated by INFgamma and CD40L.

Many studies have suggested that VSMC (vascular smooth muscle cell) apoptosis plays a key role in destabilization and rupture of atherosclerotic plaques. Therefore protection for VSMCs from apoptosis is a promising approach to stabilize 'vulnerable' lesions. However, the mechanisms as to why VSMCs in the fibrous cap often appear as profilerated in early stages, but turn apoptotic in advanced stages, are still unknown. In the present study, using RNAi (RNA interference) technology and a CaN (calcineurin) antagonist, the correlation between CaN and RANTES (regulated upon activation, normal T-cell expressed and secreted) in cultured rat apoptotic VSMCs stimulated by IFNgamma (interferon gamma; 20 ng/ml) and CD40L (CD40 ligand; 100 ng/ml) was investigated. RANTES released from VSMCs in each group was measured by ELISA and its mRNA in VSMCs was determined by RT (reverse transcription)-PCR. The total activity and expression of CaN in VSMCs were detected by the zymochemistry method and Western blot analysis respectively. From the results of the present study it can be hypothesized that an elevated CaN concentration in endochylema, by the CD40-CD40L signal pathway, induces VSMC apoptosis accomplished by the overexpression of RANTES. Therefore RANTES is a potential target for treating vulnerable atherosclerotic plaques owing to its crucial downstream regulating role in CaN-dependent VSMC apoptosis.

In rats with myocardial infarction, interference by simvastatin with the TLR4 signal pathway attenuates ventricular remodelling.

OBJECTIVE: The objective of this study was to investigate the effect of simvastatin on TLR4,TNF-alpha and IL-6 expression in the myocardium and its relation to left ventricular (LV) remodelling in a rat model of myocardial infarction (MI) and to investigate the mechanism by which simvastatin improves LV remodelling in rats after MI. METHODS AND RESULTS: The rat MI models were established by ligation of the left anterior descending coronary artery and divided into three groups: (I) an untreated MI group; (2) a group treated with simvastatin [40 mg/(kg/d)] for 4 weeks; (3) the sham group. Cardiac geometry and function were determined by echocardiography and infarct size was determined by the histomorphometric analysis; the expression ofTLR4 in the myocardium was measured by RT-PCR and western blotting;TNF-alpha and IL-6 levels in myocardial homogenate and serum were measured by ELISA. LVEDD and LVESD significantly increased and fractional shortening (FS) markedly decreased in the MI group. It was clear that simvastatin inhibited LV dilation and improved LV function after MI without affecting infarct size. The expression of TLR4, TNF-alpha and IL-6 in the myocardium significantly increased in the MI group and simvastatin markedly inhibits the expression of TLR4, TNF-alpha, and IL-6 in the myocardium after MI. Serum TNF-alpha and IL-6 levels between the MI group and the simvastatin group remained unchanged. Both in the MI group and the simvastatin group,TLR4 protein positively related to LVEDD and to the levels of TNF-alpha and IL-6 in the myocardium, respectively. CONCLUSION: Amelioration of LV remodelling in rats after MI by simvastatin might be associated with its effect on the TLR4-mediated signalling pathway in the myocardium.

[Study on the association of -689C/T polymorphism in the PPARgamma2 promoter with myocardial infarction].

OBJECTIVE: To investigate the association of -689C/T polymorphism in the peroxisome proliferator-activated receptor-gamma2 (PPARgamma2) promoter with myocardial infarction (MI). METHODS: This is a case-control study, which included 194 subjects with MI and 693 subjects without MI in nondiabetic Han population in Wuhan. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the -689C-->T substitution. RESULTS: The CC,CT, and TT genotype frequencies of -689C/T polymorphism were 88.1%,11.9%,and 0.0 in MI patients and 93.1%,6.6%,and 0.3% in controls, respectively (CC vs. CT+TT, P=0.025). The -689T allele was an independent risk factor for MI (OR=2.125, 95%CI: 1.206-3.744, P=0.009) after adjusting for age,sex,waist circumference,body mass index, smoking, alcohol drinking, physical activities, systolic blood pressure, diastolic blood pressure, fasting blood glucose, total cholesterol, triglyceride, level. The -689T allele carriers had significantly higher TC levels than noncarriers [(5.05+/-1.16) mmol/L vs. (4.78+/-1.05) mmol/L, P=0.004] in the total population. CONCLUSION: The PPARgamma2 promoter -689C/T polymorphism is associated with an increased risk of MI.