In order to explore the expression of PI-3K in T lymphocytes of asthmatic rats and the relationship between PI-3K and activation of T lymphocytes, 24 Wistar rats were randomly divided into 4 groups： normal control gr...In order to explore the expression of PI-3K in T lymphocytes of asthmatic rats and the relationship between PI-3K and activation of T lymphocytes, 24 Wistar rats were randomly divided into 4 groups： normal control group, asthmatic one-week group, asthmatic two-week group and asthmatic four-week group. T cells were purified from blood of each rat and the expression of PI-3K was observed by immunocytochemical fluorescence staining, the serniquantitative fluorescence intensity was measured by HPIAS-2000 analytic software, and the expression of IL-4 in supernatants was detected by ELISA. The results showed that the fluorescence intensity of T lymphocytes in asthmatic groups was significantly higher than that in normal control （P〈0.001）, indicating that the expression of PI-3K in T lymphocytes of asthmatic rats was significantly higher than that in those of normal controls, and the difference between acute and chronic stage asthmatic groups was significant （P〈0.05）. The expression levels of IL-4 protein in supernatants of asthmatic T lymphocytes were significantly higher than those in the normal controls （P〈0.05）. There was a significant positive correlation between the expression of PI-3K in T lymphocytes and the IL-4 protein expression in supernatants （r=0.583, P〈0.01）. It was suggested that PI-3K signal pathway may participate in the processes of activation and other cytological effects of asthmatic T lymphocytes, thus may play an important roles in the pathogenesis of asthma.展开更多
Objective: To investigate the mechanism of inflammatory-mediated toll-like receptor 4(TLR4)-p38 mitogen-activated protein kinase(p38 MAPK) pathway in Kupffer cells(KCs) of non-alcoholic steatohepatitis(NASH) rats and ...Objective: To investigate the mechanism of inflammatory-mediated toll-like receptor 4(TLR4)-p38 mitogen-activated protein kinase(p38 MAPK) pathway in Kupffer cells(KCs) of non-alcoholic steatohepatitis(NASH) rats and the intervention effect of soothing Gan(Liver) and invigorating Pi(Spleen) recipes on this pathway. Methods: After 1 week of acclimatization, 120 Sprague-Dawley male rats were randomly divided into 8 groups using a random number table(n=15 per group): normal group, model group, low-dose Chaihu Shugan Powder(柴胡疏肝散, CHSG) group(3.2 g/kg), high-dose CHSG group(9.6 g/kg), low-dose Shenling Baizhu Powder(参苓白术散, SLBZ) group(10 g/kg), high-dose SLBZ(30 g/kg) group, and low-and highdose integrated recipe(L-IR, H-IR) groups. All rats in the model and treatment groups were fed with a high-fat diet(HFD). The treatments were administrated by gastrogavage once daily and lasted for 26 weeks. The liver tissues were detected with hematoxylin-eosin(HE) and oil red O staining. Levels of liver lipids, serum lipids and transaminases were measured. KCs were isolated from the livers of rats to evaluate the mRNA expressions of TLR4 and p38 MAPK by real-time fluorescence quantitative polymerase chain reaction, and proteins expressions of TLR4, p-p38 MAPK and p38 MAPK by Western blot. Levels of inflammatory cytokines including tumor necrosis factor α(TNF-α), interleukin(IL)-1 and IL-6 in KCs were measured by enzyme-linked immunosorbent assay. Results: After 26 weeks of HFD feeding, HE and oil red O staining showed that the NASH model rats successfully reproduced typical pathogenesis and histopathological features. Compared with the normal group, the model group exhibited significant increases in body weight, liver weight, liver index, serum levels of total cholesterol(TC), triglyceride(TG), low-density lipoprotein cholesterol, and aspartate aminotransferase as well as TC and TG levels in liver tissues, and significant decrease in serum level of high-density lipoprotein cholesterol(P<0.05 or P<0.01), while those indices were significantly ameliorated in the H-IR group(P<0.05 or P<0.01). Higher levels of TNF-α, IL-1 and IL-6 in KCs were observed in the model group compared with the normal group(P<0.01). Significant decreases in TNF-α, IL-1 and IL-6 were observed in the H-SLBZ, H-IR and L-IR groups compared with the model group(P<0.05 or P<0.01). The m RNA expressions of TLR4 and p38 MAPK and protein expressions of TLR4, p38 MAPK and p-p38 MAPK in KCs in the model group were significantly higher than the normal group(P<0.01), while those expression levels in the L-IR and H-IR groups were significantly lower than the model group(P<0.05 or P<0.01). Conclusions: Inflammation in KCs might play an important role in the pathogenesis of NASH in rats. The data demonstrated the importance of TLR4-p38 MAPK signaling pathway in KCs for the anti-inflammatory effect of soothing Gan and invigorating Pi recipes.展开更多
Insulin stimulates the production of PI(3,4,5)P3 in muscle cells, and this is required to stimulate GLUT4 fusion with the plasma membrane. Introduction of exogenous PI(3,4,5)P3 to muscle cells recapitulates insulin...Insulin stimulates the production of PI(3,4,5)P3 in muscle cells, and this is required to stimulate GLUT4 fusion with the plasma membrane. Introduction of exogenous PI(3,4,5)P3 to muscle cells recapitulates insulin's effects on GLUT4 fusion with the plasma membrane, but not glucose uptake. This study aims to explore the mechanism behind this difference. In L6-GLUT4myc muscle cells, the availability of the GLUT4 intracellular C-terminus and extracellular myc epitopes for immunoreactivity on plasma membrane lawns was detected with the corresponding antibody. The availability of the active site of GLUT4 from extracellular medium was assessed by affinity photolabeling with the cell impermeant compound Bio-LC-ATB-BMPA. 100nmol/L insulin and 10μmol/L PI(3,4,5)P3 caused myc signal gain on the plasma membrane lawns by 1.64-fold and 1.58-fold over basal, respectively. Insulin, but not PI(3,4,5)P3, increased photolabeling of GLUT4 and immunolabeling with C-terminus antibody by 2.47-fold and 2.04-fold over basal, respectively. Upon insulin stimulation, the C-terminus signal gain was greater than myc signal gain (2.04-fold vs. 1.64-fold over basal, respectively) in plasma membrane lawns. These results indicate that (i) PI(3,4,5)P3 does not make the active site of GLUT4 available from the extracellular surface despite causing GLUT4 fusion with the plasma membrane; (ii) the availability of the active site of GLUT4 from the extracellular medium and availability of the C-terminus from the cytosolic site are correlated; (iii) in addition to stimulating GLUT4 translocation, insulin stimulation displaces a protein which masks the GLUT4 C-terminus. We propose that a protein which masks the C-terminus also prevents the active site from being available for photolabelling and possibly glucose uptake after treatment with PI(3,4,5)P3.展开更多
文摘In order to explore the expression of PI-3K in T lymphocytes of asthmatic rats and the relationship between PI-3K and activation of T lymphocytes, 24 Wistar rats were randomly divided into 4 groups： normal control group, asthmatic one-week group, asthmatic two-week group and asthmatic four-week group. T cells were purified from blood of each rat and the expression of PI-3K was observed by immunocytochemical fluorescence staining, the serniquantitative fluorescence intensity was measured by HPIAS-2000 analytic software, and the expression of IL-4 in supernatants was detected by ELISA. The results showed that the fluorescence intensity of T lymphocytes in asthmatic groups was significantly higher than that in normal control （P〈0.001）, indicating that the expression of PI-3K in T lymphocytes of asthmatic rats was significantly higher than that in those of normal controls, and the difference between acute and chronic stage asthmatic groups was significant （P〈0.05）. The expression levels of IL-4 protein in supernatants of asthmatic T lymphocytes were significantly higher than those in the normal controls （P〈0.05）. There was a significant positive correlation between the expression of PI-3K in T lymphocytes and the IL-4 protein expression in supernatants （r=0.583, P〈0.01）. It was suggested that PI-3K signal pathway may participate in the processes of activation and other cytological effects of asthmatic T lymphocytes, thus may play an important roles in the pathogenesis of asthma.
基金Supported by the National Natural Science Foundation of China(No.30973694)
文摘Objective: To investigate the mechanism of inflammatory-mediated toll-like receptor 4(TLR4)-p38 mitogen-activated protein kinase(p38 MAPK) pathway in Kupffer cells(KCs) of non-alcoholic steatohepatitis(NASH) rats and the intervention effect of soothing Gan(Liver) and invigorating Pi(Spleen) recipes on this pathway. Methods: After 1 week of acclimatization, 120 Sprague-Dawley male rats were randomly divided into 8 groups using a random number table(n=15 per group): normal group, model group, low-dose Chaihu Shugan Powder(柴胡疏肝散, CHSG) group(3.2 g/kg), high-dose CHSG group(9.6 g/kg), low-dose Shenling Baizhu Powder(参苓白术散, SLBZ) group(10 g/kg), high-dose SLBZ(30 g/kg) group, and low-and highdose integrated recipe(L-IR, H-IR) groups. All rats in the model and treatment groups were fed with a high-fat diet(HFD). The treatments were administrated by gastrogavage once daily and lasted for 26 weeks. The liver tissues were detected with hematoxylin-eosin(HE) and oil red O staining. Levels of liver lipids, serum lipids and transaminases were measured. KCs were isolated from the livers of rats to evaluate the mRNA expressions of TLR4 and p38 MAPK by real-time fluorescence quantitative polymerase chain reaction, and proteins expressions of TLR4, p-p38 MAPK and p38 MAPK by Western blot. Levels of inflammatory cytokines including tumor necrosis factor α(TNF-α), interleukin(IL)-1 and IL-6 in KCs were measured by enzyme-linked immunosorbent assay. Results: After 26 weeks of HFD feeding, HE and oil red O staining showed that the NASH model rats successfully reproduced typical pathogenesis and histopathological features. Compared with the normal group, the model group exhibited significant increases in body weight, liver weight, liver index, serum levels of total cholesterol(TC), triglyceride(TG), low-density lipoprotein cholesterol, and aspartate aminotransferase as well as TC and TG levels in liver tissues, and significant decrease in serum level of high-density lipoprotein cholesterol(P<0.05 or P<0.01), while those indices were significantly ameliorated in the H-IR group(P<0.05 or P<0.01). Higher levels of TNF-α, IL-1 and IL-6 in KCs were observed in the model group compared with the normal group(P<0.01). Significant decreases in TNF-α, IL-1 and IL-6 were observed in the H-SLBZ, H-IR and L-IR groups compared with the model group(P<0.05 or P<0.01). The m RNA expressions of TLR4 and p38 MAPK and protein expressions of TLR4, p38 MAPK and p-p38 MAPK in KCs in the model group were significantly higher than the normal group(P<0.01), while those expression levels in the L-IR and H-IR groups were significantly lower than the model group(P<0.05 or P<0.01). Conclusions: Inflammation in KCs might play an important role in the pathogenesis of NASH in rats. The data demonstrated the importance of TLR4-p38 MAPK signaling pathway in KCs for the anti-inflammatory effect of soothing Gan and invigorating Pi recipes.
基金the National Natural Science Foundation of China (Grant No. 30570912)the National Natural Science Foundation of China (China-Canada Joint Health Research) (Grant No. 30611120532)+1 种基金the Foundation of Tianjin Education Bureau, China to Niu Wenyan (Grant No. 20040106)the Tianjin Municipal Science and Technology Commission, China (Grant Nos. 06YFGPSH03300 and 07JCZDJC07900)
文摘Insulin stimulates the production of PI(3,4,5)P3 in muscle cells, and this is required to stimulate GLUT4 fusion with the plasma membrane. Introduction of exogenous PI(3,4,5)P3 to muscle cells recapitulates insulin's effects on GLUT4 fusion with the plasma membrane, but not glucose uptake. This study aims to explore the mechanism behind this difference. In L6-GLUT4myc muscle cells, the availability of the GLUT4 intracellular C-terminus and extracellular myc epitopes for immunoreactivity on plasma membrane lawns was detected with the corresponding antibody. The availability of the active site of GLUT4 from extracellular medium was assessed by affinity photolabeling with the cell impermeant compound Bio-LC-ATB-BMPA. 100nmol/L insulin and 10μmol/L PI(3,4,5)P3 caused myc signal gain on the plasma membrane lawns by 1.64-fold and 1.58-fold over basal, respectively. Insulin, but not PI(3,4,5)P3, increased photolabeling of GLUT4 and immunolabeling with C-terminus antibody by 2.47-fold and 2.04-fold over basal, respectively. Upon insulin stimulation, the C-terminus signal gain was greater than myc signal gain (2.04-fold vs. 1.64-fold over basal, respectively) in plasma membrane lawns. These results indicate that (i) PI(3,4,5)P3 does not make the active site of GLUT4 available from the extracellular surface despite causing GLUT4 fusion with the plasma membrane; (ii) the availability of the active site of GLUT4 from the extracellular medium and availability of the C-terminus from the cytosolic site are correlated; (iii) in addition to stimulating GLUT4 translocation, insulin stimulation displaces a protein which masks the GLUT4 C-terminus. We propose that a protein which masks the C-terminus also prevents the active site from being available for photolabelling and possibly glucose uptake after treatment with PI(3,4,5)P3.
