Enrichment of cardiac differentiation by a large starting number of embryonic stem cells in embryoid bodies is mediated by the Wnt11-JNK pathway.

Embryoid bodies (EBs) with large starting numbers of embryonic stem cells (ESCs) have a greater degree of cardiac differentiation than from low numbers of EBs. However, the biological roles of signaling molecules in these effects are not well understood. Here, we show that groups of EBs with different starting numbers of ESCs had differential gene expression patterns for Wnt5a and Wnt11. Wnt11 significantly increased the percentage of beating EBs by up-regulating the expression of the cardiac-specific genes. Wnt5a did not show these effects. Moreover, Wnt11 significantly increased the level of phosphorylated Jun N-terminal kinase. The inhibition of the JNK pathway by SP600125 blocked the effects of Wnt11. Thus, enrichment of cardiac differentiation in groups of EBs with a larger starting number of ESCs is mediated by the Wnt11-JNK pathway.

Time-dependent regulation of neuregulin-1ß/ErbB/ERK pathways in cardiac differentiation of mouse embryonic stem cells.

Neuregulin-1ß (NRG-1ß)/ErbB signaling plays crucial roles in the cardiac differentiation of mouse embryonic stem cells (ESCs), but its roles and the underlying mechanisms in cardiac differentiation are incompletely understood. This study showed that NRG-1ß significantly increased the percentage of beating embryoid bodies (EBs) and up-regulated the gene expressions of Nkx2.5, GATA4, α-actin, MLC-2v, and ANF in a time-dependent manner, with no effect on the gene expressions of HCN4 and Tbx3. Inhibition of ErbB receptors with AG1478 significantly decreased the percentage of beating EBs; down-regulated the gene expressions of Nkx2.5, GATA4, MLC-2v, ANF, and α-actin; and concomitantly up-regulated the gene expressions of HCN4 and Tbx3 in a time-dependent manner. Moreover, the up-regulation of transcripts for Nkx2.5 and GATA4 by NRG-1ß was blocked by the extracellular signal-related kinases (ERK) 1/2 inhibitor, U0126. However, U0126 could not inhibit the transcript up-regulations of MLC-2v and ANF by NRG-1ß. The protein quantitation results were consistent with those of gene quantitation. Our results suggest that NRG-1ß/ErbB signaling plays critical roles in the cardiac differentiation of mouse ESCs and in the subtype specification of cardiomyocytes in a time-dependent manner. The ERK1/2 pathway may be involved in the early cardiogenesis, but not in the subtype specification of cardiomyocytes.

MicroRNA-34a regulates high glucose-induced apoptosis in H9c2 cardiomyocytes.

Hyperglycemia is an important initiator of cardiovascular disease, contributing to the development of cardiomyocyte death and diabetic complications. The purpose of the present study was to investigate whether high glucose state could induce apoptosis of rat cardiomyocyte cell line H9c2 through microRNA-mediated Bcl-2 signaling pathway. The expression of miR-34a and Bcl-2 mRNA was detected by using real-time PCR. Western blotting was used to examine the changes in apoptosis-associated protein Bcl-2. Apoptosis of H9c2 cells was tested by using flow cytometry. The results showed that the expression of miR-34a was significantly elevated and that of Bcl-2 was strongly reduced, and apoptosis of cardiomyocytes was apparently increased in the high-glucose-treated H9c2 cells as compared with normal-glucose-treated controls. In addition, we identified Bcl-2 gene was the target of miR-34a. miR-34a mimics reduced the expression of Bcl-2 and increased glucose-induced apoptosis, but miR-34a inhibitor acted as the opposite mediator. Our data demonstrate that miR-34a contributes to high glucose-induced decreases in Bcl-2 expression and subsequent cardiomyocyte apoptosis.

C-reactive protein induces interleukin-6 and thrombospondin-1 protein and mRNA expression through activation of nuclear factor-ĸB in HK-2 cells.

BACKGROUND: Although C-reactive protein (CRP) is significantly increased in patients with diabetic nephropathy, whether CRP exerts direct proinflammatory effects on human renal tubular epithelial cells (HK-2 cells) is still unclear. METHODS: HK-2 cells were incubated with purified CRP at clinically relevant concentrations (0, 5, 10, 20 and 40 µg/ml). The protein and transcript levels of thrombospondin-1 (TSP-1) and interleukin-6 (IL-6) were determined by ELISA and RT-PCR. Phosphorylation of p38MAPK was investigated through Western blot analysis in HK-2 cells induced by CRP. The activation of nuclear factor-kappa B (NF-κB) was studied via EMSA. A specific p38MAPK inhibitor (SB203580) and an NF-κB inhibitor (PDTC; pyrrolidine dithiocarbamate) were used to analyze the signal transduction in CRP induction. To explore the direct or indirect role of CRP in HK-2 cells, IL-6 or TSP-1 antibodies were used. The expression of IL-6, TSP-1 and transforming growth factor-ß(1 )(TGF-ß(1)) were determined through Western blot analysis in HK-2 cells. RESULTS: In HK-2 cells, purified CRP significantly induced protein release and mRNA expression of IL-6 and TSP-1 in a dose- and time-dependent manner. TGF-ß(1) protein was overexpressed in HK-2 cells induced by CRP, which cannot be inhibited by IL-6 or TSP-1 antibodies. CRP triggered phosphorylation of p38MAPK and activation of NF-κB-mediated signal transduction. SB203580 (5 µM) and PDTC (50 µM) efficiently suppressed those effects of CRP in HK-2 cells. CONCLUSIONS: CRP induces IL-6 and TSP-1 protein release and mRNA expression from HK-2 cells via activation of the p38MAPK and NF-κB signaling pathways and TGF-ß(1) was highly expressed in HK-2 cells, suggesting that CRP plays an important role in the propagation and prolongation of inflammation in renal fibrosis.

Celastrol protects TGF-ß1-induced endothelial-mesenchymal transition.

The endothelial-to-mesenchymal transition (EndMT) in endothelial cells contributes to the development of cardiac fibrosis, ultimately leading to cardiac remodeling. In this study, the effects and molecular mechanisms of celastrol (CEL) on transforming growth factor-ß1 (TGF-ß1)-induced EndMT in human umbilical vein endothelial (HUVEC-12) cells were investigated. The presented data demonstrated that CEL significantly blocked the morphology change of HUVEC-12 cells induced by TGF-ß1 without cell cytotoxicity. In accordance with these findings, CEL blocked TGF-ß1-induced EndMT as evidenced by the inhibition of the mesenchymal markers, including collagen I, III, α-SMA, fibronectin mRNA expression, and the increase in the mRNA expression of endothelial cell marker CD31. These changes were also confirmed by double immunofluorescence staining of CD31 and vimentin. The in vitro scratch assay showed that CEL inhibited the migration capacity of the transitioned endothelial cells induced by TGF-ß1. Further experiments showed that the beneficial effect of CEL on blocking the EndMT in HUVEC-12 cells was associated with the suppression of the TGF-ß1/Smads signalling pathway, which was also confirmed by the inhibition of its downstream transcription factor snail1, twist1, twist2, ZEB1 and ZEB2. These results indicate that CEL blocks TGF-ß1-induced EndMT through TGF-ß1/Smads signalling pathway and suggest that it may be a feasible therapy for cardiac fibrosis diseases.

Efficacy and safety analysis of new P2Y12 inhibitors versus clopidogrel in patients with percutaneous coronary intervention: a meta-analysis.

OBJECTIVE: New P2Y12 inhibitors, classified as oral (prasugrel and ticagrelor) and intravenous (cangrelor and elinogrel) drugs, have shown improved antithrombotic effects compared with clopidogrel in patients with acute coronary syndrome (ACS) or patients undergoing percutaneous coronary intervention (PCI) in landmark trials. The purpose of this study was to perform a meta-analysis of randomized trials that compared new P2Y12 inhibitors with clopidogrel to determine their efficacy and safety in patients undergoing PCI. METHODS: Randomized controlled trials of at least 4 weeks, comparing new P2Y12 inhibitors with clopidogrel in PCI, were identified using the electronic databases Cochrane Central Register of Controlled Trials, Medline, PubMed, Web of Science, and Google Scholar from January 1, 1980, to July 31, 2014. MAIN OUTCOME MEASURES: The primary efficacy endpoints were all-cause death and major adverse cardiovascular events (MACEs). The primary safety endpoint was thrombolysis in myocardial infarction (TIMI) major bleeding. RESULTS: Twelve studies including 71,097 patients met the inclusion criteria. New P2Y12 inhibitors significantly reduced all-cause death (odds ratio [OR]: 0.81; 95% confidence interval [CI] 0.73-0.90, p < 0.0001), MACEs (OR 0.81; 95% CI 0.73-0.90, p < 0.0001), stent thrombosis (OR 0.58; 95% CI 0.49-0.69, p < 0.00001), myocardial infarctions (OR 0.87; 95% CI 0.76-0.99, p = 0.03) and cardiovascular death (OR 0.82; 95% CI 0.73-0.92, p = 0.001) compared with clopidogrel. There were no significant differences between stroke (OR 0.87; 95% CI 0.72-1.05, p = 0.14) and major bleeding events (OR 1.22; 95% CI 0.99-1.52, p = 0.06) between the new P2Y12 inhibitor and clopidogrel groups. CONCLUSION: New P2Y12 inhibitors decreased death in patients undergoing PCI compared with clopidogrel with a considerable safety and tolerability profile; however, the risk/benefit ratio of ischemic and bleeding events should be further investigated.

Celastrol Protects TGF-β1-induced Endothelial-mesenchymal Transition / 华中科技大学学报（医学）（英德文版）

The endothelial-to-mesenchymal transition (EndMT) in endothelial cells contributes to the development of cardiac fibrosis,ultimately leading to cardiac remodeling.In this study,the effects and molecular mechanisms of celastrol (CEL) on transforming growth factor-β1 (TGF-β1)-induced EndMT in human umbilical vein endothelial (HUVEC-12) cells were investigated.The presented data demonstrated.that CEL significantly blocked the morphology change of HUVEC-12 cells induced by TGF-β1 without cell cytotoxicity.In accordance with these findings,CEL blocked TGF-β1-induced EndMT as evidenced by the inhibition of the mesenchymal markers,including collagen Ⅰ,Ⅲ,α-SMA,fibronectin mRNA expression,and the increase in the mRNA expression of endothelial cell marker CD31.These changes were also confirmed by double immunofluorescence staining of CD31 and vimentin.The in vitro scratch assay showed that CEL inhibited the migration capacity of the transitioned endothelial cells induced by TGF-β1.Further experiments showed that the beneficial effect of CEL on blocking the EndMT in HUVEC-12 cells was associated with the suppression of the TGF-β1/Smads signalling pathway,which was also confirmed by the inhibition of its downstream transcription factor snail1,twistl,twist2,ZEB1 and ZEB2.These results indicate that CEL blocks TGF-β1-induced EndMT through TGF-β1/Smads signalling pathway and suggest that it may be a feasible therapy for cardiac fibrosis diseases.