The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve...The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.展开更多
JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essentia...JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essential for UV induced apoptosis. However, recent studies reveal that JNK can suppress apoptosis in IL-3-dependent hematopoietic cells via phosphorylation of the proapoptotic Bcl-2 family protein BAD. Thus, JNK has pro- or antiapoptotic functions, depend- ing on cell type, nature of the death stimulus, duration of its activation and the activity of other signaling pathways.展开更多
AIM: To observe the effect of resveratrol on nuclear factor Kappa-B (NF-κB) activation and the inflammatory response in sodium taurocholate-induced pancreatitis in rats. METHODS: Seventy-two male SD rats were randoml...AIM: To observe the effect of resveratrol on nuclear factor Kappa-B (NF-κB) activation and the inflammatory response in sodium taurocholate-induced pancreatitis in rats. METHODS: Seventy-two male SD rats were randomly divided into three groups: sham operation group (control), severe acute pancreatitis (SAP) group, and severe acute pancreatitis group treated with resveratrol (RES). A SAP model was established by injecting 4% sodium taurocholate 1 mL/kg through puncturing the pancreatic duct. In Res group, Res was given at 30 mg/kg b.m. intraperitoneally after the SAP model was successfully established. Eight animals from each group were sacrificed at 3, 6 and 12 h after modeling. The expression of NF-κB activation of pancreas was detected by irnmunohistochemical staining, whereas the levels of TNF-α and IL-8 in pancreatic tissues were estimated by radioimrnunoassay. The pathological changes of pancreas and lungs were examined microscopically. RESULTS: Much less hyperemia, edema, dust-colored necrotic focus and soaps were noticed in pancreas in RES group than in SAP group. In RES group, hemorrhage, exudates and infiltration of inflammatory cells in pancreas and interstitial edema, destruction of alveolar wall in lung were significantly less than in SAP group. In the SAP group, the activation of NF-κB in pancreatic tissues was enhanced significantly at any measure point compared with control group (64.23±10.72% vs 2.56±0.65%, 55.86±11.34% vs 2.32±0.42%, 36.23±2.30% vs 2.40±0.36%,P<0.01), TNF-α, IL-8 were also increased and reached their peak at 6 h and then declined. The activation of NF-κB and the levels of TNF-α and IL-8 in RES group were significantly lower than those in SAP group (P<0.01): activation (52.63±9.45% vs 64.23±10.72%, 40.52±8.40% vs 55.86±11.34%, 29.83±5.37% vs 36.23±2.30%), TNF-α (132.76±15.68 pg/mL vs 158.36±12.58 pg/mL, 220.32±23.57 pg/mL vs 247.67± 11.62 pg/mL, 175.68±18.43 pg/mL vs 197.35±12.57 pg/mL) and IL-8 (0.62±0.21 μg/L vs 0.83±0.10 μg/L, 1.10±0.124 μg/L vs1展开更多
AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT...AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT assay. Phase distribution of cell cyde was analyzed by flow cytometry. Expression of Cdc25C, p38, phosphorylation of p38 (pp38) were determined by Western blotting.RESULTS: MT1- assay showed that SB203580, a specific p38 MAPK inhibitor blocked DADS-induced growth inhibition.Flow cytometry analysis revealed that treatment of MGC803 cells with 30 mg/L DADS increased the percentage of cells in the G2/M phase from 9.3% to 39.4% (P<0.05), whereas inhibition of p38 activity by SB203580 abolished induction of G2/M arrest by DADS. Western blotting showed that phosphorylation of p38 was increased 3.52-fold following treatment of MGC803 cells with 30 mg/L DADS for 20 min(P<0.05), whereas Cdc25C was decreased 68% following treatment of MGCS03 cells with 30 mg/L DADS for 24 h(P<0.05). Decreased Cdc25C protein expression by DADS was attenuated by SB203580 (P<0.05).CONCLUSION: DADS-induced G2/M arrest of MGC803 cells involves activation of p38 MAP kinase pathways.Decreased Cdc25C protein expression by p38 MAPK played a crucial role in G2/M arrest after treatment with DADS.展开更多
AIM: To investigate the difference in activation of STAT3 signaling between two human stomach adenocarcinoma cell lines: 5-fluorouracil resistant cell line and its parental cell line, and to evaluate its relationship ...AIM: To investigate the difference in activation of STAT3 signaling between two human stomach adenocarcinoma cell lines: 5-fluorouracil resistant cell line and its parental cell line, and to evaluate its relationship with the expression of vascular endothelial growth factor (VEGF). METHODS: Western blot and electrophoretic mobility shift assay (EMSA) were used to detect the expression of phospho-STAT3 protein and constitutive activation of STAT3 in two human stomach adenocarcinoma cell lines, 5-fluorouracil resistant cell line SGC7901/R and its parental cell line SGC7901, respectively. The mRNA expression of VEGF was analysed by semi-quantitative RT-PCR. The expressive intensity of VEGF protein was measured by immunocytochemistry. RESULTS: The expressions of phospho-STATS protein and constitutive activation of STAT3 between two human stomach adenocarcinoma cell lines were different. Compared with the parental cell line SGC7901, the STAT3DNA binding activity and the expressive intensity of phospho-STAT3 protein were lower in the drug-resistant cell line SGC7901/R. The expression levels of VEGF mRNA and its encoded protein were also decreased in drugresistant cell line. CONCLUSION: Over-expression of VEGF may be correlated with elevated STAT3 activation in parental cell line. Lower VEGF expression may be correlated with decreased STAT3 activation in resistant cell line, which may have resulted from negative feedback regulation of STAT signaling.展开更多
文摘The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.
文摘JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essential for UV induced apoptosis. However, recent studies reveal that JNK can suppress apoptosis in IL-3-dependent hematopoietic cells via phosphorylation of the proapoptotic Bcl-2 family protein BAD. Thus, JNK has pro- or antiapoptotic functions, depend- ing on cell type, nature of the death stimulus, duration of its activation and the activity of other signaling pathways.
基金Supported by the National Natural Science Foundation of China, No.30371398
文摘AIM: To observe the effect of resveratrol on nuclear factor Kappa-B (NF-κB) activation and the inflammatory response in sodium taurocholate-induced pancreatitis in rats. METHODS: Seventy-two male SD rats were randomly divided into three groups: sham operation group (control), severe acute pancreatitis (SAP) group, and severe acute pancreatitis group treated with resveratrol (RES). A SAP model was established by injecting 4% sodium taurocholate 1 mL/kg through puncturing the pancreatic duct. In Res group, Res was given at 30 mg/kg b.m. intraperitoneally after the SAP model was successfully established. Eight animals from each group were sacrificed at 3, 6 and 12 h after modeling. The expression of NF-κB activation of pancreas was detected by irnmunohistochemical staining, whereas the levels of TNF-α and IL-8 in pancreatic tissues were estimated by radioimrnunoassay. The pathological changes of pancreas and lungs were examined microscopically. RESULTS: Much less hyperemia, edema, dust-colored necrotic focus and soaps were noticed in pancreas in RES group than in SAP group. In RES group, hemorrhage, exudates and infiltration of inflammatory cells in pancreas and interstitial edema, destruction of alveolar wall in lung were significantly less than in SAP group. In the SAP group, the activation of NF-κB in pancreatic tissues was enhanced significantly at any measure point compared with control group (64.23±10.72% vs 2.56±0.65%, 55.86±11.34% vs 2.32±0.42%, 36.23±2.30% vs 2.40±0.36%,P<0.01), TNF-α, IL-8 were also increased and reached their peak at 6 h and then declined. The activation of NF-κB and the levels of TNF-α and IL-8 in RES group were significantly lower than those in SAP group (P<0.01): activation (52.63±9.45% vs 64.23±10.72%, 40.52±8.40% vs 55.86±11.34%, 29.83±5.37% vs 36.23±2.30%), TNF-α (132.76±15.68 pg/mL vs 158.36±12.58 pg/mL, 220.32±23.57 pg/mL vs 247.67± 11.62 pg/mL, 175.68±18.43 pg/mL vs 197.35±12.57 pg/mL) and IL-8 (0.62±0.21 μg/L vs 0.83±0.10 μg/L, 1.10±0.124 μg/L vs1
基金Supported by the Natural Science Foundation of Hunan Province,No.02JJY2026,01JJY2146 and the Foundation of Hunan ProvinceEducation Department,No.01A016
文摘AIM: To determine the role of p38 MAP kinase signal transduction pathways in diallyl disulfide (DADS)-induced G2/M arrest in human gastric cancer MGC803 cells.METHODS: MGC803 cell growth inhibition was measured by MTT assay. Phase distribution of cell cyde was analyzed by flow cytometry. Expression of Cdc25C, p38, phosphorylation of p38 (pp38) were determined by Western blotting.RESULTS: MT1- assay showed that SB203580, a specific p38 MAPK inhibitor blocked DADS-induced growth inhibition.Flow cytometry analysis revealed that treatment of MGC803 cells with 30 mg/L DADS increased the percentage of cells in the G2/M phase from 9.3% to 39.4% (P<0.05), whereas inhibition of p38 activity by SB203580 abolished induction of G2/M arrest by DADS. Western blotting showed that phosphorylation of p38 was increased 3.52-fold following treatment of MGC803 cells with 30 mg/L DADS for 20 min(P<0.05), whereas Cdc25C was decreased 68% following treatment of MGCS03 cells with 30 mg/L DADS for 24 h(P<0.05). Decreased Cdc25C protein expression by DADS was attenuated by SB203580 (P<0.05).CONCLUSION: DADS-induced G2/M arrest of MGC803 cells involves activation of p38 MAP kinase pathways.Decreased Cdc25C protein expression by p38 MAPK played a crucial role in G2/M arrest after treatment with DADS.
基金Supported by Shanghai Education Committee Foundation, No.024119114
文摘AIM: To investigate the difference in activation of STAT3 signaling between two human stomach adenocarcinoma cell lines: 5-fluorouracil resistant cell line and its parental cell line, and to evaluate its relationship with the expression of vascular endothelial growth factor (VEGF). METHODS: Western blot and electrophoretic mobility shift assay (EMSA) were used to detect the expression of phospho-STAT3 protein and constitutive activation of STAT3 in two human stomach adenocarcinoma cell lines, 5-fluorouracil resistant cell line SGC7901/R and its parental cell line SGC7901, respectively. The mRNA expression of VEGF was analysed by semi-quantitative RT-PCR. The expressive intensity of VEGF protein was measured by immunocytochemistry. RESULTS: The expressions of phospho-STATS protein and constitutive activation of STAT3 between two human stomach adenocarcinoma cell lines were different. Compared with the parental cell line SGC7901, the STAT3DNA binding activity and the expressive intensity of phospho-STAT3 protein were lower in the drug-resistant cell line SGC7901/R. The expression levels of VEGF mRNA and its encoded protein were also decreased in drugresistant cell line. CONCLUSION: Over-expression of VEGF may be correlated with elevated STAT3 activation in parental cell line. Lower VEGF expression may be correlated with decreased STAT3 activation in resistant cell line, which may have resulted from negative feedback regulation of STAT signaling.
