Protease-activated receptor 2 deficiency in hematopoietic lineage protects against myocardial infarction through attenuated inflammatory response and fibrosis.

Ischaemic heart disease is one of the leading causes of death. Protease-activated receptor 2 (PAR2) is widely expressed within the cardiovascular system and is known to mediate inflammatory processes in various immunocytes, such as macrophages, mastocytes and neutrophils. Here, we investigated whether activating macrophage PAR2 modulates cardiac remodelling in a murine model of myocardial infarction. Myocardial infarction was produced by the permanent ligation of the left anterior descending coronary artery (LAD) in C57BL/6J background wild-type (WT) mice transplanted with bone marrow from WT or PAR2 knockout (PAR2 KO) mice. Hematopoietic deficiency of PAR2 had improvement of left ventricular systolic dysfunction and dilatation and decreased fibrosis deposition in remote zone at 1 week after LAD ligation. Inactivation of PAR2 also led to less recruitment of macrophages in myocardium, which was accompanied by decreased expression of pro-inflammatory cytokines. Furthermore, cultured cardiac fibroblasts (CFs) were activated and showed a fibrotic phenotype after being co-cultured in medium containing PAR2-activating macrophage, which enhances interferon-beta (INF-ß) expression. The beneficial effects of macrophages with INF-ß neutralisation or PAR2-deletion ameliorates the JAK/STAT3 pathway in CFs, which might be attributed to CF activation. These data suggest that macrophage-derived IFN-ß plays a crucial role in adverse cardiac remodelling after myocardial infarction, at least in part, through a PAR2-dependent mechanism.

miR-142 is a Sensitive Biomarker for the Diagnosis and Prognosis of Acute Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) is myocardial necrosis caused by acute and persistent ischemia and hypoxia of coronary arteries. AMI is one of the most common diseases in European countries and over 1.5 million AMI patients die of it in the United States annually. A collection of studies proposed that certain micro-RNAs play crucial roles in the onset and development of AMI. METHODS: Ninety-four AMI patients and 83 non-AMI healthy controls were recruited from Zhongda Hospital, Southeast University between July 2015 and September 2017. Serum samples were collected at admission and the expression of miR-142 was detected using real-time quantitative polymerase chain reaction (RT-qPCR) assays. RESULTS: miR-142 expression was markedly elevated in serum samples of AMI patients compared with the 83 non-AMI healthy controls. miR-142 expression was positively correlated with creatine kinase-KB (CK-MB; r = 0.6731, p = 0.0021) and troponin (r = 0.7138, p = 0.0013). The area under the curve (AUC) of miR-142, CK-MB, and troponin for the diagnosis of AMI were 0.9185, 0.8172, and 0.8717, respectively. Overall survival analysis implied that high miR-142 expression may predict poor survival (log-rank test, p = 0.0146). CONCLUSIONS: miR-142 may be a diagnostic and prognostic indicator for AMI, and therefore, it may contribute to AMI clinicopathologic prediction.

DNA methylation regulates α-smooth muscle actin expression during cardiac fibroblast differentiation.

Cardiac fibroblast (CF) differentiation to myofibroblasts expressing α-smooth muscle actin (α-SMA) plays a key role in cardiac fibrosis. Therefore, a study of the mechanism regulating α-SMA expression is a means to understanding the mechanism of fibroblast differentiation and cardiac fibrosis. Previous studies have shown that DNA methylation is associated with gene expression and is related to the development of tissue fibrosis. However, the mechanisms by which CF differentiation is regulated by DNA methylation remain unclear. Here, we explored the epigenetic regulation of α-SMA expression and its relevance in CF differentiation. In this study, we demonstrated that α-SMA was overexpressed and DNMT1 expression was downregulated in the infarct area after myocardial infarction. Treatment of CFs with transforming growth factor-ß1 (TGF-ß1 ) in vitro upregulated α-SMA expression via epigenetic modifications. TGF-ß1 also inhibited DNMT1 expression and activity during CF differentiation. In addition, α-SMA expression was regulated by DNMT1. Conversely, increasing DNMT1 expression levels rescued the TGF-ß1 -induced upregulation of α-SMA expression. Finally, TGF-ß1 regulated α-SMA expression by inhibiting the DNMT1-mediated DNA methylation of the α-SMA promoter. Taken together, our research showed that inhibition of the DNMT1-mediated DNA methylation of the α-SMA promoter plays an essential role in CF differentiation. In addition, DNMT1 may be a new target for the prevention and treatment of myocardial fibrosis.

MicroRNA-7b attenuates ischemia/reperfusion-induced H9C2 cardiomyocyte apoptosis via the hypoxia inducible factor-1/p-p38 pathway.

OBJECTIVE: MicroRNAs (miRNAs) have been shown to play crucial roles in the occurrence, development, and treatment of many cardiovascular diseases. Coronary heart disease (CAD)-related miRNAs are still a growing research area. miR-7b was reported to be downregulated in acute myocardial infarction (AMI) myocardium tissues. However, it remains largely unknown whether miR-7b is involved in the pathogenesis and progression of the AMI ischemia/reperfusion (I/R) injury. METHODS: Male C57BL/6 J mice and H9C2 cells were used as models in this study. Masson staining, real-time polymerase chain reaction, Western blot analysis, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling immunofluorescence staining assays were performed to detect the related indicators in the study. SPSS 17.0 software was used to calculate the experimental data. RESULTS: The results showed that miR-7b expression is downregulated after I/R in mice, and miR-7b could inhibit apoptosis in I/R-induced H9C2 cells via upregulating hypoxia-inducible factor 1a (HIF1a). The inhibitory effect of miR-7b on I/R-induced apoptosis in H9C2 cells was blocked by HIF1a silencing. In addition, our data suggested that the p-P38 pathway may be involved in the role of miR-7 in I/R-induced H9C2 cell apoptosis. CONCLUSION: We confirmed that the overexpression of miR-7b inhibits I/R-induced apoptosis in H9C2 cells by targeting the HIF1a/p-P38 pathway. Our findings not only demonstrate the potential role of miR-7b in attenuating I/R-induced apoptosis but also provide a new insight into the better prevention of the I/R injury by mediating HIF-1 and p-P38.

Baicalin Suppresses the Proliferation and Migration of Ox-LDL-VSMCs in Atherosclerosis through Upregulating miR-126-5p.

Atherosclerosis (AS) is a chronic inflammatory disease threatening human health, and vascular smooth muscle cells (VSMCs) are involved in AS processes. Baicalin is a flavonoid compound, which has anti-atherosclerotic effect. The aim of our study was to explore the molecular mechanism of baicalin on AS. The expression of miR-126-5p was measured in peripheral blood of AS patients and healthy control. We found miR-126-5p expression was decreased in AS. Then, high-mobility group box 1 (HMGB1) was verified as a target of miR-126-5p and its expression was increased in AS. Similarly, miR-126-5p and HMGB1 expression was downregulated and upregulated in oxidized low-density lipoprotein treated VSMCs (ox-LDL-VSMCs), respectively. Furthermore, baicalin upregulated miR-126-5p and downregulated HMGB1 expression. Functionally, baicalin significantly inhibited ox-LDL-VSMCs proliferation and migration, and miR-126-5p targets HMGB1 to enhance the inhibition induced by baicalin. Taken together, baicalin is able to prevent AS, which suppressed the proliferation and migration of ox-LDL-VSMCs through upregulating miR-126-5p by targeting HMGB1. These findings suggested that baicalin is an effective drug to alleviate AS, and miR-126-5p is a novel therapeutic target for AS.

Advanced glycation end products of bovine serum albumin affect the cell growth of human umbilical vein endothelial cells via modulation of MEG3/miR-93/p21 pathway.

Advanced glycation end products of BSA (AGE-BSA) contribute to the pathogenesis of diabetic vascular diseases. However, the roles and underlying mechanisms of AGE-BSA in diabetic vascular diseases remain largely unclear. Long non-coding RNAs (lncRNAs) are widely identified and known as gene regulators. However, the roles of lncRNAs in diabetic vascular disease are still vague. In this study, we sought to investigate the contributions of lncRNAs in human umbilical vein endothelial cells (HUVECs) treated with AGE-BSA. We first demonstrated that AGE-BSA reduced the cell viability and inhibited the cell proliferation of HUVECs. Then, we found that lncRNA MEG3 was up-regulated in HUVECs treated with AGE-BSA. Furthermore, inhibition of MEG3 restored the AGE-BSA-induced repression of cell viability and proliferation. In addition, our results revealed that MEG3 played its role via modulation of miR-93 expression in HUVECs treated with AGE-BSA. Furthermore, we illustrated that miR-93 played its role via regulation of p21 in HUVECs treated with AGE-BSA. Ultimately, our study displayed that AGE-BSA exerted its function via modulation of MEG3/miR-93/p21 pathway in HUVECs. Thus, for the first time, we identified the MEG3/miR-93/p21 axis in HUVECs treated with AGE-BSA, which might be a novel regulatory network in diabetic vascular cells, and possess the potential therapeutic value for diabetes mellitus.

Tissue kallikrein-modified human endothelial progenitor cell implantation improves cardiac function via enhanced activation of akt and increased angiogenesis.

Endothelial progenitor cells (EPCs) have been shown to enhance angiogenesis not only by incorporating into the vasculature but also by secreting cytokines, thereby serving as an ideal vehicle for gene transfer. As tissue kallikrein (TK) has pleiotropic effects in inhibiting apoptosis and oxidative stress, and promoting angiogenesis, we evaluated the salutary potential of kallikrein-modified human EPCs (hEPCs; Ad.hTK-hEPCs) after acute myocardial infarction (MI). We genetically modified hEPCs with a TK gene and evaluated cell survival, engraftment, revascularization, and functional improvement in a nude mouse left anterior descending ligation model. hEPCs were manipulated to overexpress the TK gene. In vitro, the antiapoptotic and paracrine effects were assessed under oxidative stress. TK protects hEPCs from oxidative stress-induced apoptosis via inhibition of activation of caspase-3 and -9, induction of Akt phosphorylation, and secretion of vascular endothelial growth factor. In vivo, the Ad.hTK-hEPCs were transplanted after MI via intracardiac injection. The surviving cells were tracked after transplantation using near-infrared optical imaging. Left ventricular (LV) function was evaluated by transthoracic echocardiography. Capillary density was quantified using immunohistochemical staining. Engrafted Ad.hTK-hEPCs exhibited advanced protection against ischemia by increasing LV ejection fraction. Compared with Ad.Null-hEPCs, transplantation with Ad.hTK-hEPCs significantly decreased cardiomyocyte apoptosis in association with increased retention of transplanted EPCs in the myocardium. Capillary density and arteriolar density in the infarct border zone was significantly higher in Ad.hTK-hEPC-transplanted mice than in Ad.Null-hEPC-treated mice. Transplanted hEPCs were clearly incorporated into CD31(+) capillaries. These results indicate that implantation of kallikrein-modified EPCs in the heart provides advanced benefits in protection against ischemia-induced MI by enhanced angiogenesis and reducing apoptosis.

[Impact and related mechanisms of stromal cell-derived factor-1α on serum deprivation-induced cardiac stem cells apoptosis].

OBJECTIVE: To explore the impact and related mechanisms of stromal cell-derived factor-1α (SDF-1α) on serum deprivation-induced apoptosis of cardiac stem cells (CSCs). METHODS: CSCs were isolated from adult mouse heart tissue and cultured in vitro. Obtained cells were purified using magnetic-activated cell sorting (MACS) with c-kit magnetic beads. C-kit(+)CSCs were divided into five groups: normal control group, serum deprivation group, serum deprivation+SDF-1α group, serum deprivation+SDF-1α+AMD3100 group, serum deprivation+SDF-1α+LY294002 group. Cell apoptosis was assessed using the DeadEnd Colorimetric TUNEL System and flow cytometry analyses with an Annexin V-FITC Apoptosis Detection Kit. The viability of CSCs was assessed by CCK-8. The protein expression of Bcl-2 and phosphorylated Akt were detected by Western blot. The caspase-3 activity was determined using caspase-3 Colorimetric Assay Kit. RESULTS: After magnetic separation, more than 85% of cardiosphere derived cells were positive for c-kit expression. Compared with the normal control group, the apoptosis rate of serum deprivation group was significantly increased[(27.03 ± 0.80)% vs. (1.51 ± 0.54)%, P < 0.01], which could be significantly reduced by SDF-1α in a concentration dependent manner and peak effect was seen with 100 ng/ml SDF-1α[(10.67 ± 1.06)% vs. (27.03 ± 0.80)%, P < 0.01]. The expressions of p-Akt and Bcl-2 were significantly increased and the activity of caspase-3 was significantly decreased in serum deprivation+SDF-1α group compared to serum deprivation group (P < 0.01). Further more, the expression of p-Akt and Bcl-2 were significantly decreased and the activity of caspase-3 was increased in both serum deprivation+SDF-1α+AMD3100 group and serum deprivation+SDF-1α+LY294002 group compared to serum deprivation+SDF-1α group (P < 0.01). CONCLUSIONS: SDF-1α reduces serum deprivation induced CSCs apoptosis via modulating PI3K/Akt signaling pathway.

Vasculoprotective effects of rosiglitazone through modulating renin-angiotensin system in vivo and vitro.

BACKGROUND: The peroxisome proliferator-activated receptor-γ (PPARγ) agonist rosiglitazone has been suggested to exert cardiovascular protection through the improvement of lipid metabolism, anti-inflammation, anti-proliferation etc. However, whether renin-angiotensin system (RAS) is involved in the vascular protective effects of PPARγ agonists is not fully understood. The present study aimed to investigate the effects of the renin-angiotensin system in vascular protection mediated by PPARγ agonists. OBJECTIVE: To investigate the actions of the renin-angiotensin system in vascular protection mediated by activation of PPARγ in vivo and in vitro. METHODS: Rats were fed a regular diet (n = 8), a cholesterol-rich diet plus methylthiouracil (80 mg/Kg/day, n = 10), a cholesterol-rich diet plus methylthiouracil and rosiglitazone (4 mg/kg/day, n = 10). The rosiglitazone treatment was started from one month after the start of cholesterol-rich diet plus methylthiouracil, and lasted five months. Cultured vascular smooth muscle cells (VSMCs) were pretreated with 1 µmol/L angiotensin II (ANG II) for 6 h and randomly divided into the control group; the ANG II group (1 µmol/L ANG II); the groups respectively treated with different concentration rosiglitazone (20, 30, 50) µmol/L for 12 h; the groups treated with 30 µmol/L rosiglitazone for (6, 12, 24) h. Morphology changes of the aortic tissues were observed by hematoxylin and eosin stain. The VSMC growth was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Angiotensin II and expression of angiotensin receptors were determined by radioimmunoassay, reverse transcription polymerase chain reaction (RT-PCR), western blot, and immunohistochemistry. RESULTS: After 6 months, lipid deposition, VSMC proliferation and migration toward intima were observed in aortic tissues in the rats on a cholesterol-rich diet plus methylthiouracil, while these pathological changes induced by the cholesterol-rich diet were significantly suppressed by rosiglitazone. In addition, VSMC proliferation induced by ANG II was markedly inhibited by rosiglitazone. Rosiglitazone markedly down-regulated expression of angiotensin type 1 receptor (AT1R) and up-regulated expression of angiotensin type 2 receptor (AT2R) in the aortic tissues and ANG II-treated VSMCs. CONCLUSIONS: The present study demonstrated that PPARγ agonist rosiglitazone suppressed ANG II-induced VSMC proliferation in vitro and early atherosclerotic formation evoked by cholesterol-rich diet in vivo. These vasculoprotective effects of rosiglitazone were mediated at least partially by reduction in local tissue ANG II concentration, down-regulation of AT1R expression and up-regulation of AT2R expression both at the mRNA and protein levels.

PTBP1 Targets ILK to Regulate the Hypoxia-Induced Phenotypic Transformation of Pulmonary Artery Smooth Muscle Cells.

PURPOSE: Pulmonary hypertension (PH) is a pathological process mainly characterized by the progressive increase in pulmonary vascular resistance. The degradation of pulmonary artery smooth muscle cells (PASMCs) from contractile/differentiated phenotype to synthetic/dedifferentiated phenotype is a key factor for hypoxic pulmonary hypertension. MATERIALS AND METHODS: In this study, qPCR was performed to evaluate the gene expression of mRNAs. Western blot, immunofluorescence and RNA pull down were used to detect gene expression levels. RESULTS: We found that the gene expression of polypyrimidine tract-binding protein1 (PTBP1) was increased significantly in a time-dependent manner in rats PA tissues and PASMCs after hypoxia. PTBP1 knockdown can inhibit the phenotypic transition of PASMCs. PTBP1 inhibits the phenotypic transition of PASMCs. In addition, PTBP1 inhibits the integrin-linked kinase (ILK) expression under hypoxic conditions, thereby down-regulating the expression of downstream proteins. It inhibits the phenotypic transition of PASMCs and alleviates pulmonary hypertension. CONCLUSION: In conclusion, PTBP1/ILK axis promotes the development of PH via inducing phenotypic transition of PASMCs. This may provide a novel therapy for PH.

The inhibitory effects of rosiglitazone on cardiac hypertrophy through modulating the renin-angiotensin system in diet-induced hypercholesterolemic rats.

Cardiac hypertrophy is not only an adaptational state before heart failure but also is an independent risk factor for ischemia, arrhythmia, and sudden death. However, the direct effects of hypercholesterolemia on the myocardium and mechanisms are not completely understood. It has been demonstrated that peroxisome proliferator-activated receptor-gamma (PPARgamma) ligand agonists attenuate cardiac hypertrophy through anti-inflammatory effects. The present study investigated the effects of PPARgamma agonists on hypercholesterolemia-dependent, renin-angiotensin-system-related cardiac hypertrophy. The findings showed that left ventricular hypertrophy, eminent cardiomyocyte hypertrophy, and lipid deposits in myocardium were observed in the rats fed a cholesterol-rich diet for 6 months, while these characteristic pathological alterations and the increase in angiotensin II (ANG II) level and over-expression of angiotensin II type 1 receptor (AT(1)R) in the left ventricular tissues induced by the cholesterol-rich diet were significantly suppressed to equal extents by rosiglitazone and irbesartan. In contrast, expression of angiotensin II type 2 receptor (AT(2)R) was upregulated by these two drugs. In addition, lipid metabolism was markedly improved. The above findings suggest that the cardioprotection of the PPARgamma agonist against cardiac hypertrophy evoked by hypercholesterolemia in rats is mediated partially by the improvement of lipid profile, the reduction of ANG II level in the local tissue along with the downregulation of AT(1)R expression, and upregulation of AT(2)R expression.

MSCs Contribute to the Conversion of Ly6Chigh Monocytes into Ly6Clow Subsets under AMI.

BACKGROUND: Ly6Chigh monocytes are inflammatory cells that accumulate in an infarcted myocardium, and Ly6Clow monocytes are believed to be reparative and curb myocardial remodeling. NR4A1 is a novel target for modulating the inflammatory phenotype of monocytes during atherogenesis. OBJECTIVES: We aimed to investigate whether MSCs can contribute to the heterogeneity of Ly6Chigh monocytes differentiated into Ly6Clow monocytes and whether this regulation is related to nuclear receptor NR4A1. METHODS: Ly6Chigh/low monocytes were first cocultured with MSCs. C57BL/6CX3CR1-/- mice and C57BL/6 wild-type mice were then used to construct AMI models, and survival functions in the two groups were further compared. Ly6Chigh/low monocytes in circulation and in MI tissue of C57BL/6CX3CR1-/- AMI mice with or without MSC transplantation were determined by flow cytometry at day 1 and day 3. NR4A1 expression was further determined by Western blot. Apoptosis of cardiac myocytes in the infarct border zone at day 3 and day 7 was identified by TUNEL kits. Angiogenesis in the AMI heart at day 7 and day 21 was determined through immunohistochemistry by CD31. RESULTS: We first demonstrated that the percentage of Ly6Clow monocytes increased greatly after 3 days of coculture with MSCs (12.8% ± 3.77% vs. 3.69% ± 0.74%, p < 0.001). The expression of NR4A1 in Ly6Chigh/low monocytes was also significantly elevated at that time (1.81 ± 0.46 vs. 0.43 ± 0.09, p < 0.001). Following AMI, the percentage of circulating Ly6Clow monocytes in C57BL/6CX3CR1-/- mice was significantly lower than that in C57BL/6 wild-type mice (4.36% ± 1.27% vs. 12.17% ± 3.81%, p < 0.001). The survival rate of C57BL/6CX3CR1-/- mice (25%) was significantly lower than that of C57BL/6 wild-type mice (56.3%) after AMI (χ 2 = 4.343, p = 0.037). After MSCs were transplanted, we observed a significant increase in Ly6Clow monocytes both in circulation (16.7% ± 3.67% vs. 3.22% ± 0.44%, p < 0.001) and in the MI heart (3.31% ± 0.69% vs. 0.42% ± 0.21%, p < 0.001) of C57BL/6CX3CR1-/- mice. Western blot analysis further showed that the expression level of NR4A1 in the MI hearts of C57BL/6CX3CR1-/- mice increased significantly under MSC transplantation (0.39 ± 0.10 vs. 0.11 ± 0.04, p < 0.001). We also found significantly decreased TUNEL+ cardiac myocytes (15.45% ± 4.42% vs. 22.78% ± 6.40%, p < 0.001) in mice with high expression levels of NR4A1 compared to mice with low expression levels. Meanwhile, we further identified increased capillary density in the infarct zones of mice with high expression levels of NR4A1 (0.193 ± 0.036 vs. 0.075 ± 0.019, p < 0.001) compared to mice with low expression levels 21 days after AMI. CONCLUSIONS: MSCs can control the heterogeneity of Ly6Chigh monocyte differentiation into Ly6Clow monocytes and further reduce inflammation after AMI. The underlying mechanism might be that MSCs contribute to the increased expression of NR4A1 in Ly6Chigh/low monocytes.

LncRNA-LUNAR1 Levels Are Closely Related to Coronary Collaterals in Patients with Chronic Total Coronary Occlusion.

Coronary collaterals can effectively improve myocardial blood supply to the area of CTO (chronic total coronary occlusion) and can, thus, reduce infarct size. LUNAR1(leukemia-induced noncoding activator RNA-1) is a specific LncRNA regulated by Notch signaling that not only can enhance the expression of IGFR-1 but also can promote angiogenesis and cell survival. Here, we investigated the relationship between LncRNA-LUNAR1 levels in peripheral plasma and the formation of coronary collaterals. In total, 172 patients with CTO were enrolled and followed up for 12 months. Coronary collaterals were scored according to the Rentrop scoring system. Preclinical tests of tube formation were used to address the mechanisms behind the association between LncRNA-LUNAR1 and development of collaterals. Clinical data and inflammatory factors, including comorbidity, CD14++CD16- monocytes, and CCL2 (chemokine motif ligand 2), were compared and analyzed. Real-time PCR was used to detect the expression of LncRNA-LUNAR1 in peripheral blood plasma. The Rentrop score was positively correlated with LncRNA-LUNAR1 levels in patients with CTO (R = 0.47, p < 0.001). Tube formation assay proved the direct association between LncRNA-LUNAR1 and development of collaterals (p = 0.011). The univariate Kaplan-Meier analysis revealed that patients with low LncRNA-LUNAR1 expression exhibited worse clinical outcomes than those with high LncRNA-LUNAR1 levels (p = 0.008). Receiver operating characteristic (ROC) curve and correlation analysis further confirmed that LncRNA-LUNAR1 expression was closely related to chronic inflammatory diseases, especially diabetes (area = 0.644, p = 0.001; 95% CI, 0.562-0.726). Furthermore, both CD14++CD16- monocytes (r = - 0.37; p < 0.001) and CCL2 levels (r = - 0.35; p < 0.001) negatively affected the expression of LncRNA-LUNAR1. LncRNA-LUNAR1 expression was positively correlated with coronary collaterals in patients with CTO. Inflammatory factors, including CD14++CD16- monocytes and CCL2, may be risk factors affecting LncRNA-LUNAR1 expression.

miR-17 regulates the proliferation and apoptosis of endothelial cells in coronary heart disease via targeting insulin-like-growth factor 1.

Coronary heart disease (CHD) is one of the main risks of death, which is mainly caused by coronary arteries arteriosclerosis. The present study aims to investigate the potential roles of miR-17 in CHD. In the present study, Human umbilical vascular endothelial cells (HUVECs) were treated with oxidized low density lipoprotein (ox-LDL). qRT-PCR and western blot were used to examine the mRNA and protein levels, respectively. CCK-8 and flow cytomtry were conducted to determine the proliferation and apoptosis of ox-LDL treated HUVECs. Moreover, luciferase assay was performed to confirm whether insulin-like Growth Factor-1 (IGF-1) was a target of miR-17. The results showed that miR-17 was upregulated in ox-LDL treated HUVECs, while IGF-1 was downregulated. The luciferase activity of ox-LDL treated HUVECs was decreased after the treatment of miR-17 mimics and IGF-1 3'UTR WT. Moreover, overexpressed miR-17 promoted the cell viability and inhibited the apoptosis of ox-LDL treated HUVECs, which was more potent after the treatment of IGF-1 siRNA. Furthermore, the expression of Bax and Caspase3 was decreased, and Bcl-2 was increased in ox-LDL treated HUVECs transfected with miR-17 mimics, which was further decreased after transfection with IGF-1 siRNA. Taken together, miR-17 may regulate the proliferation and apoptosis of ox-LDL treated HUVECs. miR-17 may be a promising biomarker for CHD.

Tetramethylprazine attenuates myocardial ischemia/reperfusion injury through modulation of autophagy.

The current study aimed to investigate the effects of tetramethylprazine (TMP) on myocardial ischemia/reperfusion (MI/R) injury and its underlying mechanisms. MI/R rat model and hypoxia/reoxygenation (H/R) cardiomyocytes model were established. CK level and LDH activity were detected to evaluate MI/R and H/R injury. Cell viability was determined by cell counting kit-8 (CCK-8) assay. Cell apoptosis were identified by flow cytometry and autophagy were detected by western blot. Treatment with TMP significantly reduced CK level and LDH activity and decreased myocardial infarct size in MI/R rats. TMP reduced autophagy dysfunction induced by MI/R. Moreover, TMP treatment decreased H/R-induced injury and attenuated autophagy dysfunction in cardiomyocytes. Inhibiting autophagic flux with chloroquine (CQ) decreased the cardioprotection exerted by TMP in vivo and in vitro. Additionally, the effects of TMP on the modulation of autophagy were inhibited by LY294002 (a PI3K inhibitor) in H/R cardiomyocytes. Our findings suggested TMP exerted cardioprotection against MI/R injury by decreasing Beclin-1 associated autophagy dysfunction through PI3K pathway.

Kallistatin Inhibits Atherosclerotic Inflammation by Regulating Macrophage Polarization.

Kallistatin (KS) has been recognized as a plasma protein with anti-inflammatory functions. Macrophages are the primary inflammatory cells in atherosclerotic plaques. However, it is unknown whether KS plays a role in macrophage development and the pathogenesis of atherosclerosis. This study investigated the role of KS in macrophage development, a key pathological process in atherosclerosis. An atherosclerosis model was established in ApoE-/- mice via partial left carotid artery (PLCA) ligation. An adenovirus vector (Ad. HKS) containing the human KS gene was delivered via the tail vein before PLCA ligation. The mice were divided into two groups: the PLCA + Ad. HKS and PLCA + adenovirus vector (Ad. Null) groups and followed for 2 and 4 weeks. Human KS was expressed in the mice after KS gene delivery. In addition, KS significantly inhibited plaque formation and reduced inflammation in the plaques and liver 4 weeks after gene delivery. Moreover, KS gene delivery significantly increased the expression of interleukin-10 and Arginase 1, which are M2 macrophage markers, and reduced the expression of inducible nitric oxide synthase and monocyte chemotactic protein 1, which are M1 macrophage markers. Furthermore, in cultured RAW 264.7 macrophages, KS significantly stimulated M2 marker expression and differentiation and decreased M1 marker expression, as determined by flow cytometry and real-time polymerase chain reaction. These effects were blocked by Krüppel-like factor 4 small-interfering RNA oligonucleotides. These findings demonstrate that KS inhibits atherosclerotic plaque formation and regulates M1/M2 macrophage polarization via Krüppel-like factor 4 activation.

TWEAK promotes endothelial progenitor cell vasculogenesis to alleviate acute myocardial infarction via the Fn14-NF-κB signaling pathway.

Acute myocardial infarction (AMI) remains one of the leading causes of mortality worldwide; however, endothelial progenitor cell (EPC) transplantation has been proposed as a promising treatment strategy for EPC. High levels of tumor necrosis factor-related weak inducer of apoptosis (TWEAK) have been reported in AMI, although its effect on EPCs has not been reported. In the present study, immunofluorescence and flow cytometry were performed to assess the effect of TWEAK in isolated mouse EPCs. Echocardiography was used to evaluate the cardiac function of murine hearts following EPC treatment in the AMI model, while collagen synthesis within the heart tissue was assessed using Masson's trichrome staining. A tube formation assay and Transwell migration assay were performed to investigate the effects of TWEAK on vessel formation and EPC migration in vitro. Angiogenesis and arteriogenesis were assessed in vivo using immunohistochemistry and western blotting was performed to determine the effect of TWEAK-mediated nuclear factor (NF)-κB pathway activation in EPCs. The results revealed that TWEAK promotes EPC migration, tube formation and viability in vitro. Furthermore, TWEAK treatment resulted in improved cardiac function, decreased heart collagen and vasculogenesis in mice with AMI, which was mediated by the TWEAK- fibroblast growth factor-inducible 14 (Fn14)-NF-κB signaling pathway, as determined using Fn14 small interfering (si)RNA and Bay 11-7082 (an NF-κB inhibitor). In summary, the results of the present study suggest that activation of the TWEAK-Fn14-NF-κB signaling pathway exerts a beneficial effect on EPCs for the treatment of AMI.

Transplantation of bradykinin-preconditioned human endothelial progenitor cells improves cardiac function via enhanced Akt/eNOS phosphorylation and angiogenesis.

This study determines whether preconditioning (PC) of human endothelial progenitor cells (hEPCs) with bradykinin promotes infarcted myocardium repair via enhanced activation of B2 receptor (B2R)-dependent Akt/eNOS and increased angiogenesis. hEPCs with or without bradykinin preconditioning (BK-PC) were transplanted into a nude mouse model of acute myocardial infarction. Survival of transplanted cells was assessed using DiD-labeled hEPCs. Infarct size, cardiac function, and angiogenesis were measured 10 d after transplantation. Akt, eNOS, and vascular endothelial growth factor (VEGF) expressions in cardiac tissues were detected by western blotting, and NO production was determined using an NO assay kit. The cell migration and tube formation in cultured hEPCs were determined using transwell chamber and matrigel tube formation assays, respectively. The VEGF levels in the cell supernatant were measured using an enzyme-linked immunosorbent assay kit. BK-PC-hEPCs improved cardiac function, decreased infarct size, and promoted neovascularization 10 d following transplantation. PC increased Akt and eNOS phosphorylation, VEGF expression, and NO production in the ischemic myocardium. The effects of BK-PC were abrogated by HOE140 (B2R antagonist) and LY294002 (Akt antagonist). PC increased hEPC migration, tube formation, and VEGF levels in vitro. Activation of B2R-dependent Akt/eNOS phosphorylation by BK-PC promotes hEPC neovascularization and improves cardiac function following transplantation.

Transplantation of bradykinin-preconditioned human endothelial progenitor cells improves cardiac function via enhanced Akt/eNOS phosphorylation and angiogenesis.

This study determines whether preconditioning (PC) of human endothelial progenitor cells (hEPCs) with bradykinin promotes infarcted myocardium repair via enhanced activation of B2 receptor (B2R)-dependent Akt/eNOS and increased angiogenesis. hEPCs with or without bradykinin preconditioning (BK-PC) were transplanted into a nude mouse model of acute myocardial infarction. Survival of transplanted cells was assessed using DiD-labeled hEPCs. Infarct size, cardiac function, and angiogenesis were measured 10 d after transplantation. Akt, eNOS, and vascular endothelial growth factor (VEGF) expressions in cardiac tissues were detected by western blotting, and NO production was determined using an NO assay kit. The cell migration and tube formation in cultured hEPCs were determined using transwell chamber and matrigel tube formation assays, respectively. The VEGF levels in the cell supernatant were measured using an enzyme-linked immunosorbent assay kit. BK-PC-hEPCs improved cardiac function, decreased infarct size, and promoted neovascularization 10 d following transplantation. PC increased Akt and eNOS phosphorylation, VEGF expression, and NO production in the ischemic myocardium. The effects of BK-PC were abrogated by HOE140 (B2R antagonist) and LY294002 (Akt antagonist). PC increased hEPC migration, tube formation, and VEGF levels in vitro. Activation of B2R-dependent Akt/eNOS phosphorylation by BK-PC promotes hEPC neovascularization and improves cardiac function following transplantation.

Long term prognosis of acute coronary syndrome with chronic renal dysfunction treated in different therapy units at department of cardiology: a retrospective cohort study.

Coronary care unit is common in hospitals and clinical centers which offer intensive care and therapy for severe coronary artery disease patients. However, if coronary care unit could improve the long term prognosis of acute coronary syndrome patients with renal dysfunction remain unknown. Accordingly, we designed this study to evaluate the differences of incidence of major adverse cardiovascular events for acute coronary syndromes patients with renal dysfunction who treated in coronary care unit or normal unit. The primary end point was all cause mortality. A total of 414 acute coronary syndromes patients with renal dysfunction involved in the study. The results showed that during 12-48 months follow-up, death of any cause occurred in 1.8% patients (4 of 247) in coronary care unit group, as compared with 1.8% in the normal group (3 of 167) (hazard ratio, 1.098; 95% confidence interval, 0.246 to 4.904; P=0.903). Kaplan-Meier survival analysis showed that there were no significant differences between the two groups with respect to the risk of death (P=0.903), revascularization (P=0.948), stroke (P=0.542), heart failure (P=0.198). This trial firstly revealed that acute coronary syndromes patients with renal dysfunction treated in coronary care unit and normal units. Our study showed that acute coronary syndromes patients with renal dysfunction treated in coronary care unit obtained no significant benefits compared with patients in normal units, although there was a declining tendency of the risk of major adverse cardiovascular effectswith patients in coronary care unit.