Zuocheng Yang

LY294002 and Rapamycin promote coxsackievirus-induced cytopathic effect and apoptosis via inhibition of PI3K/AKT/mTOR signaling pathway

Coxsackievirus B3 (CVB3) is a common human pathogen for acute myocarditis, pancreatitis, non-septic meningitis, and encephalitis; it induces a direct cytopathic effect (CPE) and apoptosis on infected cells. The Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT/PKB)/mammalian target of Rapamycin (mTOR) signaling pathway regulates several cellular processes and it is one of the most important pathways in human networks. However, the effect and mechanism of PI3K/AKT/mTOR signaling pathway in CVB3 infected cells are poorly understood. In this study, we demonstrate that inhibition of PI3K/AKT/mTOR signaling pathway increased CVB3-induced CPE and apoptosis in HeLa cells. The activity of downstream targets of PI3K and mTOR is attenuated after CVB3 infection and inhibitors of PI3K and mTOR made their activity to decrease more significantly. We further show that LY294002 and Rapamycin, the inhibitor of PI3K and mTOR respectively, promote CVB3-induced CPE and apoptosis. Taken together, these data illustrate a new and imperative role for PI3K/AKT/mTOR signaling in CVB3 infection in HeLa cells and suggest an useful approach for the therapy of CVB3 infection.

Both PI3K- and mTOR-Signaling Pathways Take Part in CVB3-Induced Apoptosis of HeLa Cells

This work illustrated the mechanism contributing to the process of Phosphatidylinostiol 3-kinase (PI3K)/protein kinase B (PKB)/mammalian target of rapamycin (mTOR) signaling pathway, which has been demonstrated to play an important role in virus-induced apoptosis, which contributes to the Viral Myocarditis (VMC) pathogeneses. We examined the expression of Bax, Bim, caspase-3, caspase-9, and viral replication after Coxsackievirus B3 (CVB3) infection using the mTOR inhibitor and PI3K inhibitor pretreated HeLa cells, respectively. Apoptosis in different groups was determined by flow cytometry. Bax, Bim, caspase-9, and caspase-3 were examined by semiquantitative polymerase chain reaction (PCR) and Western blot analysis. The expression of CVB3 mRNA and viral capsid protein VP1 were analyzed by semiquantitative PCR and Western blot analysis distinctively. We found that rapamycin and LY294002 promote CVB3-induced cytopathic effect (CPE) and apoptosis. CVB3 replication in host cells is mediated in mRNA and protein expression by rapamycin and LY294002. Moreover, comparing with controls, at 12 and 24 h of postinfection (p.i.), Bim and Bax expression increased in cells after treated with rapamycin or LY294002, which also stimulates the activation of procaspase-9, and the CVB3-induced caspase-3 self-cleavage. However, in the meantime, the mRNA expression of caspase-9 and caspase-3 did not have an obvious change. In summary, our results demonstrated that the mTOR-signaling pathway plays an important role in CVB3-induced CPE and apoptosis, which is indispensable in VMC, via regulating Bim, Bax, caspase-9, caspase-3, and viral replication. Our findings may provide a new perspective and a deeper understanding of the mechanism of CVB3-induced apoptosis which, in turn, may help with the development of new therapy for the CVB3 infection.

CD147 and Prostate Cancer: A Systematic Review and Meta-Analysis.

Background Prostate cancer is one of the most common non-cutaneous malignancies in men. We aimed to systemically evaluate the relationship between the expression of CD147 in tissues and the clinicopathological features of prostate cancer. Methods and Findings PubMed (1966–2016), EMBASE (1980–2016), the Cochrane Library (1996–2016), Web of Science (1945–2016), China National Knowledge Infrastructure (1982–2016), and the WanFang databases (1988–2016) were searched. Literature quality assessment was performed with the Newcastle-Ottawa Scale. Meta-analysis was performed by using Review Manager 5.3 and Stata 13.0. A total of 12591 prostate cancer patients from 14 studies were included. The results of the meta-analysis showed that there were significant differences in the positive expression rate in the following comparisons: prostatic cancer tissues vs. normal prostate tissues (odds ratio [OR] = 26.93, 95% confidence interval [CI] 7.95–91.20, P < 0.00001), prostatic cancer tissues vs. benign prostatic hyperplasia tissues (OR = 20.54, 95% CI 8.20–51.44, P < 0.00001), high Gleason score vs. low Gleason score (OR = 2.39, 95% CI 1.33–4.27, P = 0.03), TNM III to IV vs. TNM I to II (OR = 9.95, 95% CI 4.96–19.96, P < 0.00001), low or moderate differentiation vs. high differentiation (OR = 8.12, 95% CI 3.69–17.85, P < 0.00001), lymph node metastasis vs. non-lymph node metastasis (OR = 4.31, 95% CI 1.11–16.71, P = 0.03), and distant metastasis vs. non-distant metastasis (OR = 8.90, 95% CI 3.24–24.42, P < 0.00001). Conclusion The CD147 positive expression rate was closely related to the clinical characteristics of prostate cancer, but more research is needed to confirm the findings owing to the results of the subgroups.

Endothelin-1 downregulates Mas receptor expression in human cardiomyocytes

Endothelin-1 (ET-1) and the renin-angiotensin system (RAS) are involved in the pathogenesis of cardiac dysfunction. The Mas receptor is a functional binding site for angiotensin (Ang)‑(1-7), which is now considered a critical component of the RAS and exerts cardioprotective effects. To the best of our knowledge, the present study aimed to examine, for the first time, the effects of ET-1 on Mas expression in cultured human cardiomyocytes. Human cardiomyocytes were treated with ET-1 at different concentrations (1, 5, 10, 20 and 30 nM) for varied time periods (0.5, 1.5, 3, 4.5 or 6 h) with or without the transcription inhibitor actinomycin D, endothelin A (ETA) receptor blocker BQ123 and ETB receptor blocker BQ788, or different kinase inhibitors. ET-1 decreased the Mas mRNA level in a statistically significant dose- and time-dependent manner within 4.5 h, which was reflected in the dose-dependent downregulation of Mas promoter activity, Mas protein levels and Ang-(1-7) binding on the cell membrane. Actinomycin D (1 mg/ml), BQ123 (1 µM), p38 mitogen-activated protein kinase (MAPK) siRNA and inhibitor PD169316 (25 µM), completely eliminated the inhibitory effects of ET-1 on Mas expression in human cardiomyocytes. In conclusion, the present study demonstrated that ET-1 downregulates Mas expression at the transcription level in human cardiomyocytes via the ETA receptor by a p38 MAPK‑dependent mechanism. This study provides novel insights into the function of ET-1 and the Ang‑(1-7)/Mas axis in cardiac pathophysiology.

A plasma mir-125a-5p as a novel biomarker for Kawasaki disease and induces apoptosis in HUVECs

Background Kawasaki disease (KD) is a childhood systemic vasculitis that exhibits a specific preference for the coronary arteries. The aetiology remains unknown and there are no especially diagnostic tests. microRNAs (miRNAs) are 18 to 23 nucleotides non-coding RNAs that are negative regulator of gene expression and play a crucial role in the regulatory network of the genome. Recently, circulating miRNAs have been found presentation in human plasma and displayed some characteristics of the ideal biomarker. However, few researches explored differentially expressed miRNAs in the plasma of KD patients. Our study is to identify circulating miRNAs in KD plasma which can serve as potential biomarkers of KD diagnosis. Materials and methods The total of five pairs of acute KD and normal plasma samples were analyzed using ABI miRNAs TLDA Assay chip. Differentially expression of miR-125a-5p in plasma were confirmed by quantitative real-time PCR (qRT-PCR) in independent cohort (acute KD = 30, convalescent KD = 30 and healthy control = 32). After bioinformatics prediction, miR-125a-5p vector and inhibitor were transfected into HUVECs respectively, to observe MKK7 expression as a potential target gene. Flow cytometry was used to analyze apoptosis. The mRNA and protein levels of desired genes including MKK7, Caspase-3, Bax and Bcl2 were detected by qRT-PCR and western blotting. Results Eighteen miRNAs were differentially expressed in acute KD’s plasma compared with healthy control. miR-125a-5p was significantly increased in plasma of KD patients (p = 0.000), but no variation between acute and convalescent KD (p = 0.357). Moreover, the results from the gain and loss functions of miR-125a-5p in HUVECs have shown that miR-125a-5p remarkably suppressed MKK7 expression, as a novel target gene. Importantly, miR-125a-5p also induced apoptosis in HUVECs through inhibition MKK7 levels to regulate Bax/Bcl2 pathway resulting to activate Caspase-3. Conclusion Our study indicated that the circulating miR-125a-5p levels in KD’s plasma have remarkably evaluated compared with healthy individuals. miR-125a-5p might play a role in the development of KD by regulating target gene MKK7 to induce apoptosis in vascular endothelial cells. Therefore, our findings have suggested that detected miR-125a-5p levels in plasma could be used as a potential biomarker in early KD diagnosis.

The cytotoxicity of coxsackievirus B3 is associated with a blockage of autophagic flux mediated by reduced syntaxin 17 expression

Coxsackievirus B3 (CVB3) is an important human pathogen linked to cardiac arrhythmias and acute heart failure. CVB3 infection has been reported to induce the formation of autophagosomes that support the viral replication in host cells. Interestingly, our study shows that the accumulation of autophagosomes during CVB3 infection is caused by a blockage of autophagosome–lysosome fusion rather than the induction of autophagosome biogenesis. Moreover, CVB3 decreases the transcription and translation of syntaxin 17 (STX17), a SNARE (soluble N-ethylmaleimide-sensitive factor activating protein receptor) protein involved in autophagosome–lysosome fusion. Overexpression of STX17 restored the autophagic flux, alleviated the virus-induced lysosomal dysfunction, and decreased the apoptosis induced by CVB3 infection in HeLa cells. Taken together, our results suggest that CVB3 infection impairs the autophagic flux by blocking autophagosome–lysosome fusion. These findings thus point to potential new therapeutic strategies targeting STX17 or autophagosome–lysosome fusion for treating CVB3-associated diseases.

Association of PECAM-1 Gene Polymorphisms with Kawasaki Disease in Chinese Children

Kawasaki disease (KD) is an acute systemic vasculitis complicated by development of coronary artery lesions. PECAM-1 is a kind of cell adhesion molecule, which plays an important role in coronary artery disease. The relationship between PECAM-1 gene polymorphisms and their susceptibility to Kawasaki diseases (KD) is still unclear. In our study, we examined the PECAM-1 gene polymorphisms in 44 KD patients and 59 healthy children and revealed the correlation of PECAM-1 gene polymorphisms in KD children with and without coronary artery lesions (CAL).

Cardiac progenitor cell‑derived exosomes promote H9C2 cell growth via Akt/mTOR activation

Exosomes are cell-derived vesicles released from a variety of mammalian cells that are involved in cell-to-cell signalling. It has been reported that cardiac progenitor cells (CPCs) derived from an adult heart are one of the most promising stem cell types for cardioprotection and repair. The mammalian target of rapamycin (mTOR) signalling pathway is a pivotal regulator in CPCs, therefore, CPC-derived exosomes were used in the present study to investigate whether it can promote H9C2 cell growth through the protein kinase B (PKB, or Akt)/mTOR signalling pathway. The CPCs were isolated from Sprague-Dawley hearts. Following treatment with a specific medium, the exosomes were purified and identified by electron micrograph and western blot assays, using CD63 and CD81 as markers. The methyl-thiazolyl-tetrazolium and 5-ethynyl-2′-deoxyuridine methods were used to detect H9C2 cell growth. The expression of Akt and mTOR were detected by western blot analysis following treatment with 200 or 400 µg/ml of exosomes for 24 or 48 h, respectively. It was found that, compared with higher concentrations of exosomes, prolonging the duration of exposure promoted cell growth. Accordingly, CPC-derived exosomes stimulated the expression of Akt to a marked degree; groups treated with exosomes for 48 h showed higher expression of Akt than those treated for 24 h at the same concentration. mTOR was also stimulated by CPC-derived exosomes. The activation of mTOR increased in accordance with the treatment time at an exosome concentration of 200 µg/ml and decreased with treatment time at an exosome concentration of 400 µg/ml. In conclusion, the present study demonstrated that CPC-derived exosomes promoted H9C2 cell growth via the activation of Akt/mTOR in a time-dependent manner at a relatively low exosome concentration, which may provide a novel therapy for cardiovascular disease.

Screening of differentially expressed genes associated with Kawasaki disease by microarray analysis

Kawasaki disease (KD) is an autoimmune disorder that can induce coronary artery aneurysms, particularly in the case of delayed diagnosis and/or treatment. Early diagnosis is important for treatment and reduces the risk of heart injury. The aim of the present study was to identify differentially expressed genes by comparing the levels of gene expression in human umbilical vein endothelial cells following treatment with plasma from healthy individuals and patients with acute or convalescent KD. Following comparison of the control and acute KD groups, 385 up-regulated and 537 down-regulated genes were identified in the acute KD group. In the convalescent group, 505 and 879 genes were up-regulated and down-regulated, respectively, relative to the control group. Genes involved in the immune system and cell growth factors were up-regulated, while genes functioning in methylation were down-regulated, following treatment with KD plasma. In addition, five potential candidate molecular markers of KD, C-X-C motif chemokine ligand 2 (CXCL2), interleukin (IL) 8, tripartite motif containing 58 (TRIM58), immunoglobulin superfamily member 3 (IGSF3) and runt related transcription factor 1 (RUNX1) were identified by microarray analysis and verified using quantitative polymerase chain reaction. A significant positive correlation was identified between the neutrophil polys and expression levels of four of these candidate genes, including CXCL2, IL8, TRIM58, and IGSF3 (all P<0.01; R2≥0.64). However, only CXCL2 expression was significantly positively correlated with neutrophil polys (P=0.01; R2=0.64) and neutrophil bands (P<0.001; R2=0.73). These results indicate that CXCL2 serves a crucial role in the injury of endothelial cells by KD plasma.

Association of miR-146a Gene Polymorphism at loci rs2910164 G/C, rs57095329 A/G, and rs6864584 T/C with Susceptibility to Kawasaki Disease in Chinese Children

ObjectiveTo investigate the genetic association of miR-146a gene polymorphisms at loci rs2910164 G/C, rs57095329 A/G, and rs6864584 T/C in patients with Kawasaki disease (KD) and coronary artery lesions (CAL).MethodsThere were 120 patients with KD and 126 healthy subjects in this study. The genotype of loci rs2910164 G/C, rs57095329 A/G, and rs6864584 T/C of miR-146a gene were detected by polymerase chain reaction-sequence-based typing.ResultsFor miR-146a gene polymorphisms at loci rs2910164 G/C, rs57095329 A/G, and rs6864584 T/C, there were no significant difference of genotype frequencies and allele frequencies between KD group and healthy control group, or between the IVIG-resistant group and IVIG-sensitive group (P > 0.05). In KD with coronary artery lesions (KD-CAL) group, the genotype frequencies of GG were higher than that in KD without coronary artery lesion (KD-WO) group at locus rs2910164 G/C polymorphisms of miR-146a gene (χ2 = 6.660, P = 0.036), patients with KD carried genotype of GG were at 3.636 times higher risk of getting coronary artery lesions than those of non-carriers (χ2 = 6.455, P = 0.018, OR = 3.636, 95%CI = 1.280–10.262). While there was no significant difference of allele frequency of G and C between KD-CAL group and KD-WO group (P > 0.05). In KD-CAL group, the allele frequency of A was higher than that in KD-WO group at locus rs57095329 A/G polymorphisms of miR-146a gene (χ2 = 4.745, P = 0.035), carriers with allele A were at 2.422 times higher risk of getting coronary artery lesions than those of non-carriers (χ2 = 4.745, P = 0.035, OR = 2.422, 95%CI = 1.073–5.465), while there was no significant difference of genotype frequency of AA, AG, and GG types between KD-CAL group and KD-WO group (P > 0.05). There was no significant difference of genotype frequencies of TT, TC, and CC types and allele frequencies of T and C types between KD-CAL group and KD-WO group at locus rs6864584 T/C polymorphisms of miR-146a gene (P > 0.05).ConclusionsThe significant association has been found between the genotype and allele frequency of the miR-146a gene loci rs2910164 G/C and rs57095329 A/G, the genotype GG of rs2910164 G/C, and allele A of rs57095329 A/G were risk factors for getting coronary artery lesions.