β-elemene reverses hepatocyte growth factor-induced resistance to gefitinib in PC-9 lung cancer cells via c-Met pathway

AIM: To investigate the effect of β-elemene on reversing hepatocyte growth factor (HGF)-induced resistance to gefitinib in PC-9 cells, and to explore its possible mechanisms. METHODS: The gefitinib-resistant PC-9 cells induced by HGF were treated with β-elemene or/and gefitinib. The cell activity was measured by MTT assay. The effect of β-elemene on the invasion ability in HGF-induced resistance to gefitinib in PC-9 cells was detected by Transwell migration assay. The protein levels of p-Met, c-Met, p-AKT and AKT in PC-9 cells of each group were determined by Western blot. RESULTS: The results of MTT assay showed that the cell activity of PC-9 cells was significantly inhibited by β-elemene (P<0.05). IC₅₀ of β-elemene for PC-9 cells was 169.31 mg/L. IC₅₀ of gefitinib for PC-9 cells was 0.30 μmol/L. Exogenously adding recombinant HGF induced significantly resistance to gefitinib in PC-9 cells. Moreover, SU11274 (an inhibitor of c-Met) significantly decreased the viability of the cells exposed to HGF and gefitinib (P<0.05). Combined treatment with β-elemene and gefitinib in the presence of HGF (50 μg/L) significantly decreased the viability of PC-9 cells as compared with the PC-9 cells treated with gefitinib alone in the presence of HGF (P<0.05), so did the result of the cell migration. The protein levels of p-Met and p-AKT were significantly up-regulated by HGF, while the protein levels of p-Met and p-AKT were markedly down-regulated in the cells treated with β-elemene and gefitinib compared with gefitinib alone in the presence of HGF. CONCLUSION: β-elemene reverses HGF-induced resistance to gefitinib in lung cancer PC-9 cells, likely due to the inhibition of HGF-induced activation of c-Met and its down streams signaling pathways (P<0.01).     

Reverse effect of shikonin on epithelial-mesenchymal transition induced by HGF in lung cancer cells

AIM:To investigate the effects of shikonin on the migration, invasion and epithelial-mesenchymal transition (EMT) in human non-small-cell lung cancer PC9 cells induced by hepatocyte growth factor (HGF). METHODS:The effect of shikonin on the viability of PC9 cells was measured by MTT assay. The cell migration and invasion abilities were analyzed by wound healing assay and Transwell method, respectively. The protein expression levels of E-cadherin, N-cadherin and vimentin in the PC9 cells were determined by Western blot. RESULTS:The viability of PC9 cells was significantly inhibited by shikonin in a dose-dependent manner (P<0.01), with IC₅₀ at 9.364 μmol/L. HGF significantly promoted the abilities of migration and invasion, and induced EMT in the PC9 cells. Shikonin significantly inhibited HGF-induced migration and invasion in the PC9 cells. The expression of E-cadherin was significantly down-regulated and the expression of N-cadherin and vimentin was significantly up-regulated in the presence of HGF (50 μg/L). However, shikonin reversed HGF-induced EMT, as indicated by up-regulation of E-cadherin and down-regulation of N-cadherin and vimentin (P<0.01). CONCLUSION:Shikonin reverses HGF-induced EMT in lung cancer PC9 cells.     

Effect of atorvastatin on cardiac function and HGF/c-Met signaling pathway after acute myocardial infarction in diabetic rats

AIM: To investigate the effect of atorvastatin on myocardial apoptosis, ventricular remodeling and cardiac function after acute myocardial infarction (AMI) in diabetic rats, and to explore whether the effect is mediated by hepatocyte growth factor (HGF)/c-Met signaling pathway. METHODS: Diabetes in 70 male SD rats was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg). After 8 weeks, AMI was induced by the ligation of the left anterior descending coronary artery in the diabetic rats, and 32 surviving rats were divided into AMI group (n=16) and AMI＋atorvastatin group (n=16, 20 mg·kg-1·d-1) at random. The similar surgical procedure was completed in sham group (n=11) without coronary ligation. Atorvastatin was given daily by gavage from the first day after AMI. Two weeks later, the cardiac function, pathological changes of myocardial tissues, myocardial apoptosis, and the expression of HGF and c-Met were compared among groups. RESULTS: AMI significantly reduced cardiac function, increased collagen volume fraction (CVF) and myocardial apoptotic index, and up-regulated the expression of HGF and c-Met at mRNA and protein levels in AMI control group (P<0.05). The cardiac function was improved, and CVF and myocardial apoptotic index were reduced by the treatment with atorvastatin, which also up-regulated the expression of HGF and c-Met (P<0.05). CONCLUSION: Atorvastatin significantly attenuates myocardial apoptosis and cardiac remodeling, and improves cardiac function after AMI in diabetic rats by further enhancing the activation of HGF/c-Met pathway.     

Expression of low-density lipoprotein receptor after exposure to hepatocyte growth factor in human Tenon's capsule fibroblasts

AIM: To study the dynamic alteration of low-density lipoprotein receptor (LDLr) expression after exposure to hepatocyte growth factor (HGF) in human Tenon's capsule fibroblasts (HTFs).METHODS: HTFs were stimulated with HGF at different concentrations (0, 10, 20, 40, 80 and 160 μg/L) for 12, 24, and 48 h. The viability of HTFs was analyzed by MTT assay. The expression of LDLr at mRNA and protein levels were analyzed by real-time PCR and Western blot.RESULTS: The expression of LDLr at mRNA and protein levels was positively correlated with the viability of HTFs. HGF promoted the viability of HTFs in a time-and concentration-dependent manner. At the same time, HGF promoted the expression of LDLr in the same manner.CONCLUSION: Exposure of HTFs to HGF induces LDLr expression at high level, suggesting that over-expression of LDLr on the HTFs may be a target receptor for controlled drug delivery, particularly in anti-scarring therapy after glaucoma filtration surgery.     

Effect of exogenous HGF gene transfection on pulmonary perfusion and pressure in pulmonary artery hypertension in rabbits

AIM: To investigate the feasibility of exogenous hepatocyte growth factor (HGF) gene transfection to promote pulmonary collateral angiogenesis, improve pulmonary perfusion and reduce pulmonary artery pressure in the rabbit model of pulmonary artery hypertension (PAH). METHODS: The model rabbits of PAH were randomly divided into control group, empty vector group and HGF gene transfection group. The rabbits in HGF gene transfection group were transfected with Ad-HGF via intratracheal instillation. Pulmonary hemodynamic indicators were monitored in the 4th week after HGF gene transfection. Density of pulmonary vessels was examined with double-labeling immunofluorescence (endothelial cells were labeled with anti-FⅧ and vascular smooth muscle cells were marked with anti-α-SMA). Double-labeling immunofluorescence of FITC-lectin and anti-α-SMA was also performed to evaluate the pulmonary blood perfusion. RESULTS: Four weeks after transfection, the density of pulmonary arterioles of the rabbits in HGF gene transfection group was higher than that in control group and empty vector group (P<0.05), which was confirmed by double-labeling immunofluorescence. Pulmonary blood perfusion in HGF group was significantly increased compared with that in the other two groups, in which pulmonary arterial stenosis and occlusion were observed. The mean pulmonary artery pressure in HGF transfection group was much lower than that in control group and empty vector group (P<0.05). CONCLUSION: Four weeks after intratracheal adenoviral-mediated HGF gene transfection, pulmonary collateral vessels and pulmonary perfusion increase, and the pulmonary artery pressure is effectively reduced.     

碳水化合物反应元件结合蛋白的研究进展

糖脂代谢是人和动物正常生长发育的能源基础,这将直接影响着动物的脂质性状,因此糖脂代谢目前已经成为培育优质畜禽品种的切入点。近年来,发现碳水化合物反应元件结合蛋白(carbohydrate response element binding protein,ChREBP)在调控动物糖脂代谢中具有重要的作用,特别在糖脂代谢的主要场所——肝脏中对糖脂代谢发挥着关键作用。作者就ChREBP的结构特征、组织分布、葡萄糖应答机制、生物学功能、表达调控等方面作一综述,以期为今后的研究提供理论依据。     

Capsosiphon fulvescens extracts improve obesity‐associated metabolic disorders and hepatic steatosis in high‐fat diet‐induced obese mice

Herbal dietary supplements have attracted more and more attention owing to their relative effectiveness in obesity ‐related metabolic disorders and diseases. This study investigated the therapeutic effects and underlying mechanisms of Capsosiphon fulvescens (CF) extracts on obesity, their associated metabolic disorders and hepatic steatosis in high‐fat diet (HFD)‐induced obese mice. Male C57BL/6 mice were fed with normal, HFD/Vehicle and HFD/CF (orally 300 mg/kg/day for CF). After 12 weeks, CF blocked HFD‐induced body weight, food intake, liver weight, hepatic triglyceride (TG), fat mass (weight of abdominal subcutaneous fat and epididymal adipose tissue) and biochemical parameters (total cohlesterol, glucose, TG, creatinine, high‐density lipoproteins cholesterol and low‐density lipoprotein cholesterol) of serum. CF also had improved serum levels of adiponectin, leptin and insulin‐like growth factor‐1 in HFD/CF mice. Moreover, CF ameliorated the hepatic steatosis‐reducing size of white adipose tissue. These results indicate that CF have anti‐obesity effects and are effective for reducing metabolic risk and hepatic steatosis.     

The new seed cells for hepatocyte transplantation

The prospect of liver disease treatment by hepatocyte transplantation is broad, but it is difficult to apply it in clinic therapy due to the restriction of source and proliferation of donor hepatocyte. The hematopoietic stem cell plasticity of trans-differentiation to hepatocyte provides a new source of seed cells for hepatocyte transplantation. In this review, we focus on advances in the seed cells for hepatocyte transplantation.     

Application of ESC-derived hepatic stem cells in therapeutic liver repo pulation

AIM: To study the proliferation, differentiation and the capacity of forming teratomas of ESC-derived hepatic stem cells in mouse pre-treated with retrorsine and 70% partial hepatotomy. METHODS: The ESC-derived hepatic stem cells, labelled with CFDA SE, were transplanted into BALB/c mouse liver. The distribution, incorperation and proliferation of transplanted cells were observed under fluorescent microscopy. Hepatic function was assayed by detecting albumin level in serum. The situation of forming teratomas in vivo was also evaluated.RESULTS: 1 week post-transplantation, some scattered region was green under fluorescent microscopy. The aera of green region increased apparently in 2 weeks, and cord-like structure was observed. Immunofluorescent staining of albumin demonstrated some positve cells, but there was no significant difference for albumin level in serum (P>0.05). No teratoma was formed in the experimental group, while a large teratoma was observed in control group in 6 weeks post-transplantation.CONCLUSION: The ESC-derived hepatic stem cells are normally incorporated into mouse liver parenchymal structure, proliferate and differentiate further in vivo and possess some hepatic functions without forming teratomas.     

A Nutraceutical Formulation Containing Brown Algae Reduces Hepatic Lipid Accumulation by Modulating Lipid Metabolism and Inflammation in Experimental Models of NAFLD and NASH

Recently, some preclinical and clinical studies have demonstrated the ability of brown seaweeds in reducing the risk factors for metabolic syndrome. Here, we analyzed the beneficial effect of a nutraceutical formulation containing a phytocomplex extracted from seaweeds and chromium picolinate in animal models of liver steatosis of differing severities (rats with non-alcoholic fatty liver disease (NAFLD) and its complication, non-alcoholic steatohepatitis (NASH)). This treatment led to a significant drop in hepatic fat deposition in both models (p < 0.01 vs. untreated animals), accompanied by a reduction in plasma inflammatory cytokines, such as interleukin 6, tumor necrosis factor α, and C reactive protein, and myeloperoxidase expression in liver tissue. Furthermore, a modulation of the molecular pathways involved in lipid metabolism and storage was demonstrated, since we observed the significant reduction of the mRNA levels of fatty acid synthase, diacylglycerol acyltransferases, the sterol-binding protein SREBP-1, and the lipid transporter perilipin-2, in both treated NAFLD and NASH rats in comparison to untreated ones. In conclusion, this nutraceutical product was effective in reducing liver steatosis and showed further beneficial effects on hepatic inflammation and glycemic control, which were particularly evident in rats characterized by a more severe condition, thus representing a therapeutic option for the treatment of NAFLD and NASH patients.