Berberine Attenuates Cardiac Hypertrophy Through Inhibition of mTOR Signaling Pathway.

PURPOSE: Berberine was reported to exert beneficial effects on cardiac hypertrophy. However, its cellular and molecular mechanisms still remained unclear. METHODS: Cardiac hypertrophy was induced in male Sprague-Dawley (SD) rats by transverse aorta constriction (TAC), with or without 6-week treatment of berberine. Echocardiography was performed to evaluate cardiac function. Rats were then sacrificed for histological assay, with detection for proteins and mRNA. H9c2 cells were pretreated with berberine of different concentrations (0, 1 µM, and 10 µM), followed by treatment with 2 µM norepinephrine (NE). Cells of different groups were measured for cell surface area, with mRNA detected by qRT-PCR and proteins by western blot. RESULTS: Compared with the sham group, rats of the TAC group showed significantly increased cardiac hypertrophy and fibrosis, which could be ameliorated by treatment with berberine. Western blot showed that mammalian target of rapamycin (mTOR) signaling-related protein expressions, including phospho-mTOR, phospho-4EBP1, and phospho-p70 S6K (Thr389), but not phospho-p70 S6K (Ser371), were significantly increased in the TAC group, which were inhibited by berberine treatment. H9c2 cells were treated with NE to induce hypertrophy with increased cell surface area and mRNA expressions of anp and bnp. Berberine of 10 µM, but not 1 µM, significantly ameliorated NE-induced hypertrophy and inhibited protein expressions of mTOR signaling pathway similar to those in the rat model. CONCLUSIONS: Berberine can exert cardioprotective effects on both pressure-overloaded cardiac hypertrophy and failure in vivo and NE-induced hypertrophy in vitro. Our results suggest berberine could be a potential treatment for patients with cardiac hypertrophy and failure.

Serum prealbumin is a predictive biomarker for stroke-associated infection after an ischemic stroke.

BACKGROUND: Several prior studies have linked serum prealbumin (PA) as a predictor for perioperative infection. However, whether peripheral blood PA levels can be used as an indicator of stroke-associated infection (SAI) is still unclear. In this study, we attempt to find whether serum PA is a meaningful predictor in SAI after an ischemic stroke, so as to provide theoretical basis for clinical treatment. METHODS: Consecutive patients with acute ischemic stroke who were admitted to our hospital were enrolled and serum PA was collected. A prospective study was conducted to observe the predictive value of PA in the SAI incident in ischemic stroke patients. RESULTS: Of 104 patients, 29 (27.9%) developed an SAI after 7 d of follow-up. The stroke with SAI group had significantly lower PA levels than the stroke without SAI group ( p < 0.05). The optimal cutoff value for predicting SAI was PA ≤ 191 mg/L, with sensitivity and specificity of 58.62% and 81.33%, respectively. Kaplan-Meier survival analysis showed that stroke patients with low serum PA level (PA ≤ 191 mg/L) had a higher SAI rates (log-rank test, χ2 = 16.870, p < 0.001). Cox regression analysis showed that PA ≤ 191 mg/L (hazard ratio = 3.207; 95% CI, 1.430-7.190, p = 0.005) was an independent risk factor for SAI. CONCLUSIONS: Early detection of serum PA during the acute phase of ischemic stroke may help us to identify at-risk SAI patients, and hence rapidly guide the intervention to prevent SAI.

Erythropoietin modulates imbalance of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in doxorubicin-induced cardiotoxicity.

BACKGROUND: Doxorubicin (DOX) is a highly effective anti-cancer drug with limited clinical use due to its serious cardiotoxicity. Recent studies reported that erythropoietin (EPO) could exert a cardioprotective effect by non-erythropoietic effects. This study was to investigate fibrosis of DOX-induced cardiotoxicity and determine mechanisms of EPO against extracellular matrix (ECM) remodelling. METHODS: Rats were grouped as the control group, the DOX group and the DOX+EPO group. DOX (2.5 mg/kg/dose, six doses for two weeks) was administered to induce cardiotoxicity by intraperitoneal injections in the DOX group and the DOX+EPO group, and EPO (2500U/kg/dose, six doses for two weeks) was administered simultaneously in the DOX+EPO group. Two weeks after the last administration, rats were killed with cardiac tissues used for histological analyses and immunological detections for matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2). RESULTS: Rats treated with DOX showed degenerative changes with cardiac fibrosis. Compared to the control group, the expression of MMP-2 was up-regulated whereas that of TIMP-2 was down-regulated in the DOX group. EPO administration improved cardiac fibrosis, decreased MMP-2 expression, increased TIMP-2 expression and ameliorated imbalance of MMP-2/TIMP-2 ratio. CONCLUSIONS: The present study suggests that EPO can exert a cardioprotective effect on DOX-induced cardiotoxicity which may be associated with improving MMP-2/TIMP-2 imbalance.

[Tanshinone IIA attenuates hydrogen peroxide-induced senescence of human umbilical vein endothelial cells through activating SIRT1/eNOS pathway].

Objective To explore the effect of tanshinone IIA (TSA) on hydrogen peroxide (H2O2)-induced senescence of human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. Methods HUVECs were cultured in vitro and divided into the control group, model group and TSA group. The cells in the TSA group were pre-treated with TSA for 24 hours. H2O2 was used to induce cell senescence in the model and TSA groups. Transfection with SIRT1 siRNA was used for the knockdown of SIRT1 in HUVECs. CCK-8 assay was performed to detect cell viability. The expression levels of senescence-related proteins (P21 and P26), SIRT1, phosphorylated endothelial nitric oxide synthase (p-eNOS), and eNOS were detected by Western blot analysis. Senescence-associated ß-galactosidase (SA-ß-gal) staining was performed to evaluate cell senescence. Results Pretreatment with TSA at low concentrations (10, 20 and 40 µg/mL) for 24 hours did not affect cell viability, while high concentrations (80, 160 and 320 µg/mL) decreased cell viability significantly. In addition, 10, 20 and 40 µg/mL of TSA promoted H2O2-mediated cell viability of HUVECs in a concentration-dependent manner. Compared with the control group, the positive rate of SA-ß-gal staining in the model group increased, while the positive rate in the TSA group was significantly lower than that in the model group. The expression levels of P21 and P16 protein in the model group were higher than those in the control group, while SIRT1 and p-eNOS/eNOS were lower than those in the control group. Conversely, the expression of P21 and P16 proteins in the TSA group were lower than those in the model group, and SIRT1 and p-eNOS/eNOS were higher in the TSA group than those in the model group. Transfected with SIRT1 siRNA significantly down-regulated the expression of SIRT1 in HUVECs and the positive rate of SA-ß-gal staining was notably raised when SIRT1 was silenced in TSA-treated HUVECs. Conclusion TSA attenuates H2O2-induced endothelial cell senescence by activating SIRT1/eNOS signaling pathway.

Histone deacetylase inhibitors induce human renal cell carcinoma cell apoptosis through p-JNK activation.

OBJECTIVE: To study the effect of histone deacetylase inhibitors trichostatin A (TSA) and LBH589 on the growth of human renal cell carcinoma OS-RC-2 cells in vitro and explore the underlying molecular mechanism. METHODS: OS-RC-2 cells were treated with LBH589 or TSA with or without SP600125 pretreatment, and the cell viability was measured by MTT assay. The changes of cell cycle distribution and apoptosis of OS-RC-2 cells were examined by flow cytometry, and the expressions of c-Jun, p-c-Jun, Bcl-2, and Bax were quantified by Western blotting. RESULTS: TSA and LBH589 both inhibited the growth of OS-RC-2 cells in a dose- and time-dependent manner. TSA at 1 µnmol/L and LBH589 at 50 nmol/L caused obvious cell cycle arrest in G2/M phase and cell apoptosis, and significantly increased the protein levels of phosphorylated c-Jun. TSA treatment obviously increased Bax expression but decreased Bcl2 expression in the cells. The growth inhibitory effect of TSA was attenuated by the JNK inhibitor SP600125 in OS-RC-2 cells. TSA-induced phosphorylation of c-Jun and Bax upregulation was partially counteracted by SP600125. CONCLUSION: TSA and LBH589 can cause cell cycle arrest and induce apoptosis in OS-RC-2 cells, in which process P-JNK pathway plays an important role.

Induction of the liver cancer-down-regulated long noncoding RNA uc002mbe.2 mediates trichostatin-induced apoptosis of liver cancer cells.

Differential expression of long non-coding RNAs (lncRNAs) plays critical roles in hepatocarcinogenesis. Considerable attention has focused on the antitumor effect of histone deacetylase inhibitor (Trichostatin A, TSA) as well as the coding gene expression-induced apoptosis of cancer cells. However, it is not known whether lncRNA has a role in TSA-induced apoptosis of human hepatocellular carcinoma (HCC) cells. The global expression of lncRNAs and coding genes was analyzed with the Human LncRNA Array V2.0 after 24 h treatment. Expression was verified in cell lines and tissues by quantitative real-time PCR. The data showed that 4.8% (959) of lncRNA and 6.1% (1849) of protein coding gene were significantly differentially expressed. The differential expressions of lncRNA and protein coding genes had distinguishable hierarchical clustering expression profiling pattern. Among these differentially expressed lncRNAs, the greatest change was noted for uc002mbe.2, which had more than 300 folds induction upon TSA treatment. TSA selectively induced uc002mbe.2 in four studied HCC cell lines. Compared with normal human hepatocytes and adjacent noncancerous tissues, uc002mbe.2 expression level was significantly lower in the HCC cell lines and liver cancer tissues. The TSA-induced uc002mbe.2 expression was positively correlated with the apoptotic effect of TSA in HCC cells. In addition, knockdown the expression of uc002mbe.2 significantly reduced TSA-induced apoptosis of Huh7cells. Therefore, TSA-induced apoptosis of HCC cells is uc002mbe.2 dependent and reduced expression of uc002mbe.2 may be associated with liver carcinogenesis.