miR­155 modulates high glucose­induced cardiac fibrosis via the Nrf2/HO­1 signaling pathway.

Cardiac fibrosis is a major pathological manifestation of diabetic cardiomyopathy, which is a leading cause of mortality in patients with diabetes. MicroRNA (miR)­155 is upregulated in cardiomyocytes in cardiac fibrosis, and the aim of the present study was to investigate if the inhibition of miR­155 was able to ameliorate cardiac fibrosis by targeting the nuclear factor erythroid­2­related factor 2 (Nrf2)/heme oxygenase­1 (HO­1) signaling pathway. H9C2 rat cardiomyocytes were cultured with high glucose (HG; 30 mM) to establish an in vitro cardiac fibrosis model that mimicked diabetic conditions; a miR­155 inhibitor and a miR­155 mimic were transfected into H9C2 cells. Following HG treatment, H9C2 cells exhibited increased expression levels of miR­155 and the fibrosis markers collagen I and α­smooth muscle actin (α­SMA). In addition, the expression levels of endonuclear Nrf2 and HO­1 were decreased, but the expression level of cytoplasmic Nrf2 was increased. Moreover, oxidative stress, mitochondrial damage and cell apoptosis were significantly increased, as indicated by elevated reactive oxygen species, malonaldehyde and monomeric JC­1 expression levels. In addition, superoxide dismutase expression was attenuated and there was an increased expression level of released cytochrome­c following HG treatment. Furthermore, it was demonstrated that expression levels of Bcl­2 and uncleaved Poly (ADP­ribose) polymerase were downregulated, whereas Bax, cleaved caspase­3 and caspase­9 were upregulated after HG treatment. However, the miR­155 inhibitor significantly restored Nrf2 and HO­1 expression levels, and reduced oxidative stress levels, the extent of mitochondrial damage and the number of cells undergoing apoptosis. Additionally, the miR­155 inhibitor significantly reversed the expression levels of collagen I and α­SMA, thus ameliorating fibrosis. Furthermore, the knockdown of Nrf2 reversed the above effects induced by the miR­155 inhibitor. In conclusion, the miR­155 inhibitor may ameliorate diabetic cardiac fibrosis by reducing the accumulation of oxidative stress­related molecules, and preventing mitochondrial damage and cardiomyocyte apoptosis by enhancing the Nrf2/HO­1 signaling pathway. This mechanism may facilitate the development of novel targets to prevent cardiac fibrosis in patients with diabetes.

Significance of ST-segment deviation in patients with acute pulmonary embolism and negative T waves.

BACKGROUND: Common electrocardiogram (ECG) manifestations in acute pulmonary em-bolism (APE) include ST-segment deviation (STDV) along with negative T-waves (NTW). STDV could occur in 3 typical ischemic patterns: (i) the left ventricular (LV) subendocardial ischemic pattern; (ii) the right ventricular (RV) transmural ischemic pattern; and (iii) the LV subendocardial plus RV transmural ischemic pattern. The purpose of this study was to evalu-ate the relationship of STDV and adverse clinical outcomes and to identify the relationship of relatively normal ECG and favorable clinical outcomes. METHODS: Retrospective analysis of electronic charts in APE patients was performed in a tertiary hospital. ECGs on admission were obtained and classified as with or without STDV. Adverse clinical outcomes were defined as need to intensify therapy and 30-day mortality. Relatively normal ECG was defined as without any STDV, abnormal QRS morphology in lead V1 and S1Q3T3. RESULTS: From a total of 210 patients with NTW, 131 had STDV ≥ 0.1 mV, while 79 did not. Patients with STDV had worse evolution: higher incidence of dyspnea, hypotension, cardiogen-ic shock, intensification of therapy, and death compared to patients without STDV (p = 0.001 for each variable). The majority (89%) of the patients with STDV presented with 1 of the 3 typical ischemic ECG patterns. LV subendocardial ischemic pattern (OR = 4.963, p = 0.004), RV transmural ischemic pattern (OR = 3.128, p = 0.021) and LV subendocardial plus RV transmural ischemic pattern (OR = 3.036, p = 0.017) independently predicted the need to intensify therapy. RV transmural ischemic pattern (OR = 4.227, p = 0.031) and LV subendocardial plus RV transmural ischemic pattern (OR = 4.022, p = 0.032) independently predicted 30-day mortality. Compared to the patients with abnormal ECG, the patients with relatively normal ECG had a significant lower incidence of death (0% vs. 16%; p = 0.001) and need to intensify therapy during hospitalization (6% vs. 30%; p = 0.002). CONCLUSIONS: Ischemic ECG patterns are common ECG manifestations of APE and predict worse evolution and 30-day mortality. Additionally, relatively normal ECGs may associate with favorable clinical outcomes.

Changes of naturally occurring CD4(+)CD25(+) FOXP3(+) regulatory T cells in patients with acute coronary syndrome and the beneficial effects of atorvastatin treatment.

To determine the number and function of naturally occurring CD4(+)CD25(+)FOXP3(+) regulatory T cells (nTregs) in patients with acute coronary syndrome (ACS) and to determine the effects of a low dose of atorvastatin treatment (20 mg/day) on nTregs.Patients with ACS were randomly divided into a group receiving conventional therapy (n = 60) or conventional therapy supplemented with atorvastatin (20 mg/day) (n = 60). A group of healthy volunteers that did not suffer from ACS was used as controls (n = 60). T lymphocytes were isolated from ACS patients, both before and 4 weeks after treatment, or control patients and the percentage of nTregs was determined by flow cytometry. Serum levels of cytokines were determined by enzyme-linked immunosorbent assays. A mixed lymphocyte reaction was used to determine the ability of nTregs to inhibit proliferation of effector T cells. Quantitative PCR and Western blot were used to analyze (forkhead box P3) FOXP3 mRNA transcript levels and the expression of FOXP3 protein.In ACS patients, the percentage and inhibitory properties of nTregs were reduced, IFN-γ and hsCRP levels were increased, and IL-10 and TGF-ß1 levels were lowered. Atorvastatin treatment increased the percentage and inhibitory ability of nTregs, decreased serum IFN-γ and hsCRP levels, and decreased IL-10 and TGF-ß1 levels, as compared with the non-atorvastatin group.Our findings suggest that nTregs play an atheroprotective role in atherosclerosis. The inhibitory effects of atorvastatin on inflammation in ACS may be due to its beneficial effects on nTregs and restoration of immune homeostasis.

Mesenchymal stem cells alleviate atherosclerosis by elevating number and function of CD4(+)CD25 (+)FOXP3 (+) regulatory T-cells and inhibiting macrophage foam cell formation.

Atherosclerosis is a chronic inflammatory disease characterized by the formation of plaques inside arteries, leading to narrowing and blockage. Potential therapeutic strategies include expanding the population of regulatory T-cells (Tregs) to enhance atheroprotective immunity, and inhibiting the formation of macrophage foam cells. Here, we studied the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on atherosclerotic plaque formation in Apolipoprotein E(-/-) (ApoE-KO) mice, and elucidated the underlying mechanism. BM-MSCs isolated from 4 week-old ApoE-KO mice were evaluated by flow cytometry for expression of MSC-specific markers. Thirty eight week-old ApoE-KO mice were randomly divided into three experimental groups (n = 10 per group): 1. MSC group-received BM-MSCs intravenously; 2. Vehicle group-received DMEM; 3. Control group-did not receive any treatment. Administration of MSCs resulted in a marked decrease in the size of atherosclerotic plaques 3 months after treatment. In addition, the number and function of CD4(+)CD25(+)FOXP3(+) regulatory T-cells (Tregs) in cultured splenocytes, and the expression of FOXP3 at both mRNA and protein levels, was significantly increased in the MSC group. In vitro experiments further indicated that the formation of macrophage foam cells was inhibited by treatment with MSCs, accompanied by a significant downregulation in CD36 and scavenger receptor A (SRA). Our findings suggest that MSCs play an atheroprotective role by enhancing the number and function of Tregs and inhibiting the formation of macrophage foam cells. Hence, administration of MSCs to atherosclerotic patients might have significant clinical benefits.

Electrocardiogram patterns during hemodynamic instability in patients with acute pulmonary embolism.

BACKGROUND: We have previously described new electrocardiogram (ECG) findings for massive pulmonary embolism, namely ST-segment elevation in lead aVR with ST-segment depression in leads I and V4 -V6 . However, the ECG patterns of patients with acute pulmonary embolism during hemodynamic instability are not fully described. METHODS: We compared the differences between the ECG at baseline and after deterioration during hemodynamic instability in twenty patients with acute pulmonary embolism. RESULTS: Compared with the ECG at baseline, three ischemic ECG patterns were found during clinical deterioration with hemodynamic instability: ST-segment elevation in lead aVR with concomitant ST-segment depression in leads I and V4 -V6 , ST-segment elevation in leads V1 -V3 /V4 , and ST-segment elevation in leads III and/or V1 /V2 with concomitant ST-segment depression in leads V4 /V5 -V6 . Ischemic ECG patterns with concomitant S1Q3 and/or abnormal QRS morphology in lead V1 were more common (90%) during hemodynamic instability than at baseline (5%) (P = 0.001). CONCLUSIONS: Hemodynamic instability in acute pulmonary embolism is reflected by signs of myocardial ischemia combined with the right ventricular strain pattern in the 12-lead ECG.

[Effects of MSCs on the progression of atherosclerosis plaque in ApoE-knock out mice].

AIM: To explore the effects of mesenchymal stem cells in the formation of atherosclerosis plaque in hypercholesterolemic apoliprotein (apo) E -/ - mice. METH-ODS: ApoE -- mice mesenchymal stem cells (MSCs)were isolated and identified. Thirty ApoE -/ - mice were divided into negative control group (Neg, n = 10), positive control group (Pos, n = 10) and MSCs group ( n = 10).MSCs were injected through caudal vein into the body ofPos and MSCs groups. The plaque area of all subjects were compared, the percentage of CD4 CD25' regulatory T cells in different tissues were analyzed by FACS, proliferation response of splenocytes to mesenchymal stem cells and cyto-kines in the supernatant were determined by ELISA. RE-SULTS: Compared with controls, MSCs resulted in a significant decrease of the atherosclerotic plaques size (P <0.05), and a significant increase of CD4 CD25 regulatory T cells in spleen (P<0.05). Specific proliferation response of CD4' CD25' regulatory T cells in splenocytes to MSCswas significantly suppressed. The supernatant levels ofTGF-f3 and IL-10 in MSCs group were increased while IFN-y decreased significantly. CONCLUSION: MSCs play an important role in regulating the inflammatory response and may significantly inhibit the formation of the atherosclerosis plaque in ApoE-'- mice.

Electrocardiographic characteristics in angiographically documented occlusion of the dominant left circumflex artery with acute inferior myocardial infarction: limitations of ST elevation III/II ratio and ST deviation in lateral limb leads.

BACKGROUND: The prognosis of dominant left circumflex artery (LCx) occlusion-related inferior acute myocardial infarction (AMI) patients is poor, but the electrocardiographic (ECG) characteristics of this AMI entity have not been described. METHODS: One hundred thirty-five patients with first dominant right coronary artery (RCA) or dominant LCx-related inferior AMI were included. The characteristics of ECG obtained on admission for 55 patients with culprit lesions proximal to the first major right ventricular (RV) branch of dominant RCA (group proximal dominant RCA), 62 patients with culprit lesions distal to the first major RV branch of dominant RCA (group distal dominant RCA), and 18 patients with culprit lesions in dominant LCx (group dominant LCx) were compared. RESULTS: There were no significant differences among the 3 groups in the prevalence regarding an S/R ratio greater than 1:3 in aVL, ST elevation in aVR (ST upward arrow(aVR)), ST depression in aVR (ST downward arrow(aVR)) of 1 mm or more, and atrioventricular block. Greater ST elevation in lead III than in II and greater ST depression in aVL than I showed specificity of 17% and 44% to identify dominant RCA as culprit lesion, respectively. All 3 groups could be distinguished on the basis of ST upward arrow(V4R), ST downward arrow(V4R), ST downward arrow(V3)/ST upward arrow(III) of 1.2 or less, and ST downward arrow(V3)/ST upward arrow(III) of more than 1.2. CONCLUSIONS: Greater ST elevation in lead III than in II, greater ST depression in aVL than I, and an S/R ratio of greater than 1:3 in aVL were not useful to discriminate between dominant RCA and dominant LCx occlusion-related inferior AMI. ST-segment deviation in lead V(4)R and the ratio of ST downward arrow(V3)/ST upward arrow(III) were useful in predicting the dominant artery occlusion-related inferior AMI.

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.