Reconstruction and analysis of potential biomarkers for hypertrophic cardiomyopathy based on a competing endogenous RNA network.

Hypertrophic cardiomyopathy (HCM) is a common heritable cardiomyopath. Although considerable effort has been made to understand the pathogenesis of HCM, the mechanism of how long noncoding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) network result in HCM remains unknown. In this study, we acquired a total of 520 different expression profiles of lncRNAs (DElncRNAs) and 371 messenger RNAs (mRNA, DEGs) by microarray and 33 microRNAs (DEmiRNAs) by sequencing in plasma of patients with HCM and healthy controls. Then lncRNA-miRNA pairs were predicted using miRcode and starBase and crossed with DEmiRNAs. MiRNA-mRNA pairs were retrieved from miRanda and TargetScan and crossed with DEGs. Combined with these pairs, the ceRNA network with eight lncRNAs, three miRNAs, and 22 mRNAs was constructed. lncRNA RP11-66N24.4 and LINC00310 were among the top 10% nodes. The hub nodes were analyzed to reconstruct a subnetwork. Furthermore, quantitative real-time polymerase chain reaction results showed that LINC00310 was significantly decreased in patients with HCM. For LINC00310, GO analysis revealed that biological processes were enriched in cardiovascular system development, sprouting angiogenesis, circulatory system development, and pathway analysis in the cGMP-PKG signaling pathway. These results indicate that the novel lncRNA-related ceRNA network in HCM and LINC00310 may play a role in the mechanism of HCM pathogenesis, which could provide insight into the pathogenesis of HCM.

Identification of PA28ß as a potential novel biomarker in human esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is one of the most common and serious malignancies in China. However, the exact mechanisms of tumor formation and progression are unclear. As late diagnosis and poor therapeutic efficacy result in lower survival rates, identifying biomarkers for early detection, prognostic evaluation, and recurrence monitoring of ESCC is necessary. Here we analyzed 10 protein expression profiles of ESCC core tissues and paired normal esophageal epithelial tissues using two-dimensional gel electrophoresis. We excised 29 protein spots with two-fold or greater differential expression between cancer and normal tissues and identified them using matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry. The role of PA28ß in ESCC cell was confirmed using cell growth, colony formation and soft agar in TE-1 cells pre- and post- PA28ß transfection. Compared to their expression in the adjacent normal epithelia, 12 proteins, including transgelin (TAGLN), were upregulated in ESCC tissues; 17 proteins, including proteasome activator 28-beta subunit (PA28ß), were downregulated (p < 0.05). Western blotting and immunohistochemistry confirmed that PA28ß was significantly underexpressed in ESCC tissues. The functional assays demonstrate that PA28ß inhibited cell growth, proliferation and malignancy of TE-1 cells. Among the differentially expressed proteins, PA28ß is a potential tumor inhibitor.

Liraglutide prevents high glucose level induced insulinoma cells apoptosis by targeting autophagy.

BACKGROUND: The pathophysiology of type 2 diabetes is progressive pancreatic beta cell failure with consequential reduced insulin secretion. Glucotoxicity results in the reduction of beta cell mass in type 2 diabetes by inducing apoptosis. Autophagy is essential for the maintenance of normal islet architecture and plays a crucial role in maintaining the intracellular insulin content by accelerating the insulin degradation rate in beta cells. Recently more attention has been paid to the effect of autophagy in type 2 diabetes. The regulatory pathway of autophagy in controlling pancreatic beta cells is still not clear. The aim of our study was to evaluate whether liraglutide can inhibit apoptosis and modulate autophagy in vitro in insulinoma cells (INS-1 cells). METHODS: INS-1 cells were incubated for 24 hours in the presence or absence of high levels of glucose, liraglutide (a long-acting human glucagon-like peptide-1 analogue), or 3-methyadenine (3-MA). Cell viability was measured using the Cell Counting Kit-8 (CCK8) viability assay. Autophagy of INS-1 cells was tested by monodansylcadaverine (MDC) staining, an autophagy fluorescent compound used for the labeling of autophagic vacuoles, and by Western blotting of microtubule-associated protein I light chain 3 (LC3), a biochemical markers of autophagic initiation. RESULTS: The viability of INS-1 cells was reduced after treatment with high levels of glucose. The viability of INS-1 cells was reduced and apoptosis was increased when autophagy was inhibited. The viability of INS-1 cells was significantly increased by adding liraglutide to supplement high glucose level medium compared with the cells treated with high glucose levels alone. CONCLUSIONS: Apoptosis and autophagy were increased in rat INS-1 cells when treated with high level of glucose, and the viability of INS-1 cells was significantly reduced by inhibiting autophagy. Liraglutide protected INS-1 cells from high glucose level-induced apoptosis that is accompanied by a significant increase of autophagy, suggesting that liraglutide plays a role in beta cell apoptosis by targeting autophagy. Thus, autophagy may be a new target for the prevention or treatment of diabetes.

The double-edged effect of autophagy in pancreatic beta cells and diabetes.

Autophagy is an intracellular catabolic system, which enables cells to capture cytoplasmic components for degradation within lysosomes. Autophagy is involved in development, differentiation and tissue remodeling in various organisms, and is also implicated in certain diseases. Recent studies demonstrate that autophagy is necessary to maintain architecture and function of pancreatic beta cells. Altered autophagy is also involved in pancreatic beta cell death. Whether autophagy plays a protective or harmful role in diabetes is still not clear. In this review, we will summarize the current knowledge about the role of autophagy in pancreatic beta cell and diabetes.

Selenium inhibits high glucose-induced cyclooxygenase-2 and P-selectin expression in vascular endothelial cells.

Selenium as a component of glutathione peroxidase may be beneficial in insulin resistance, hence potentially may modify the risk of diabetes and cardiovascular disease. The aim of our study was to evaluate whether selenium can also alter high glucose (HG), advanced glycation end products (AGE), high insulin (HI) and H2O2-induced expression of cyclooxygenase (COX)-2 and P-selectin. Human umbilical vein endothelial cells (HUVECs) were pretreated with selenium and stimulated by HG, AGE, HI and H2O2. Selenium significantly inhibited HG, AGE, HI and H2O2-induced expression of COX-2 and P-selectin. Moreover, selenium also inhibited HG, AGE, HI and H2O2-induced activation of p38 mitogen-activated protein kinase (p38 MAPK), which indicated that the preventive effects of selenium on COX-2 and P-selectin may be associated with p38. Our results indicated that selenium supplementation can reduce HG, AGE, HI and H2O2-induced expression of COX-2 and P-selectin by inhibition of the p38 pathway.

[Role of PKC in regulation of CD73 by lysophosphatidylcholine in human endothelial cells].

OBJECTIVE: To discuss the effect of protein kinase C (PKC) on regulation of ecto-5'-nucleotidase activity by lysophosphatidylcholine(LPC) in human umbilical endothelial cells (HUVEC). METHODS: Experiments were conducted in HUVEC grown on dishes which were divided into 4 groups (n=15): (1) Control group in which only eAMP (5 micromol/L) was added; (2) LPC group in which HUVEC were incubated with LPC (10 micromol/L) before eAMP was added; (3) Chelerythrine group in which cells were pre-incubated with the PKC inhibitor chelerythrine (100 micromol/L) before LPC and eAMP were added; (4) alpha, beta-Methyladenosine-5'-Diphosphate (AOPCP) group in which cells were incubated with AOPCP (10 micromol/L) before eAMP was added. Etheno-adenosine production was detected at 15th, 30th, 45th min with high performance liquid chromatography(HPLC) respectively. RESULTS: Comparing to the control group LPC significantly increased etheno-adenosine production at three time points respectively (P < 0.05). Furthermore, PKC inhibitor chelerythrine abolished this effect of LPC and the ethenoadenosine production at three time points were at the same level of control group (P > 0.05). CD73 inhibitor AOPCP significantly decreased the etheno-adenosine production compared to the other three groups (P < 0.01). CONCLUSION: Ecto-5'-nucleotidase can be modulated within minutes following exposure of HUVEC to LPC and this response may be mediated by PKC in HUVEC.

[Effect of selenium on expression of P38 mitogen-activated protein kinase and monocyte chemoattractant protein-1 in diabetic endothelial cells].

AIM: To study the relationship between P38MAPK and MCP-1 in diabetic HUVEC and the mechanism of anti-atherosclerosis of selenium. METHODS: HUVEC were treated with high concentration of glucose, advanced glycosylation end products (AGE), high concentration of insulin or H(2)O(2) with or without pre-treatment with SB203580 (P38MAPK specific inhibitor) or selenium. The expression of phospho-P38MAPK and MCP-1 in HUVEC was detected by Western blot or RT-PCR, respectively. RESULTS: High concentration of glucose, AGE, high concentration of insulin and H(2)O(2) can activate P38MAPK and increase the expression of MCP-1 in HUVEC. The expression of MCP-1 was inhibited by SB203580. Selenium inhibited the activation of P38MAPK and reduced the expression of MCP-1. CONCLUSION: P38MAPK is an upstream signaling molecule of MCP-1. P38MAPK may be one of the initiating signals of diabetic atherosclerosis. Selenium can inhibit the expression of MCP-1 by repressing P38MAPK signaling pathway and therefore prevent the development of atherosclerosis.