AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： I...AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： IEC were divided into control group, lipopolysaccharide （LPS） group, LPS＋ 50 μg/mL APS group, LPS＋ 100 μg/mL APS group, LPS＋ 200 μg/mL APS group, and LPS＋ 500 μg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor （TNF）-α and interleukin （IL）-8, were measured by reverse transcription-polymerase chain reaction. MAPK protein level was measured by Western blotting. RESULTS： The levels of TNF-α and IL-8 mRNAs were significantly higher in IEC with LPS-induced damage than in control cells. APS significantly abrogated the LPS-induced expression of the TNF-α and IL-8 genes. APS did not block the activation of extracellular signal- regulated kinase or c Jun amino-terminal kinase, but inhibited the activation of p38, suggesting that APS inhibits LPS-induced production of TNF-α and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.CONCLUSION： APS-modulated bacterial productmediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.展开更多
Objective To explore the role of the extracellular signal-regulated kinase （ERK）/cAMP response element binding protein （CREB） pathway in the induction of long-term potentiation （LTP） in the anterior cingulate co...Objective To explore the role of the extracellular signal-regulated kinase （ERK）/cAMP response element binding protein （CREB） pathway in the induction of long-term potentiation （LTP） in the anterior cingulate cortex （ACC） that may be implicated in pain-related negative emotion. Methods LTP of field potential was recorded in ACC slice and the expressions of phospho-ERK （pERK） and phospho-CREB （pCREB） were examined using immunohistochemistry method. Results LTP could be induced stably in ACC slice by high frequency stimulation （2-train, 100 Hz, 1 s）, while APv （an antagonist of NMDA receptor） could block the induction of LTP in the ACC, indicating that LTP in this experiment was NMDA receptor-dependent. Bath application of PD98059 （50 μmol/L）, a selective MEK inhibitor, at 30 min before tetanic stimulation could completely block the induction of LTP. Moreover, the protein level of pERK in the ACC was transiently increased after LTP induction, starting at 5 rain and returning to basal at 1 h after tetanic stimulation. The protein level of pCREB was also increased after LTP induction. The up-regulation in pERK and pCREB expressions could be blocked by pretreatment of PD98059. Double immunostaining showed that after LTP induction, most pERK was co-localized with pCREB. Conclusion NMDA receptor and ERK-CREB pathway are necessary for the induction of LTP in rat ACC and may play important roles in pain emotion.展开更多
文摘AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： IEC were divided into control group, lipopolysaccharide （LPS） group, LPS＋ 50 μg/mL APS group, LPS＋ 100 μg/mL APS group, LPS＋ 200 μg/mL APS group, and LPS＋ 500 μg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor （TNF）-α and interleukin （IL）-8, were measured by reverse transcription-polymerase chain reaction. MAPK protein level was measured by Western blotting. RESULTS： The levels of TNF-α and IL-8 mRNAs were significantly higher in IEC with LPS-induced damage than in control cells. APS significantly abrogated the LPS-induced expression of the TNF-α and IL-8 genes. APS did not block the activation of extracellular signal- regulated kinase or c Jun amino-terminal kinase, but inhibited the activation of p38, suggesting that APS inhibits LPS-induced production of TNF-α and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.CONCLUSION： APS-modulated bacterial productmediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.
基金supported by National Natural Science Fundation of China (No.30870835,30821002,and 30900444)National Basic Research Program of China (No. 2007CB512303,2007CB512502,and 2006CB500807)Postdoctoral Fundation of China (No.20080440578)
文摘Objective To explore the role of the extracellular signal-regulated kinase （ERK）/cAMP response element binding protein （CREB） pathway in the induction of long-term potentiation （LTP） in the anterior cingulate cortex （ACC） that may be implicated in pain-related negative emotion. Methods LTP of field potential was recorded in ACC slice and the expressions of phospho-ERK （pERK） and phospho-CREB （pCREB） were examined using immunohistochemistry method. Results LTP could be induced stably in ACC slice by high frequency stimulation （2-train, 100 Hz, 1 s）, while APv （an antagonist of NMDA receptor） could block the induction of LTP in the ACC, indicating that LTP in this experiment was NMDA receptor-dependent. Bath application of PD98059 （50 μmol/L）, a selective MEK inhibitor, at 30 min before tetanic stimulation could completely block the induction of LTP. Moreover, the protein level of pERK in the ACC was transiently increased after LTP induction, starting at 5 rain and returning to basal at 1 h after tetanic stimulation. The protein level of pCREB was also increased after LTP induction. The up-regulation in pERK and pCREB expressions could be blocked by pretreatment of PD98059. Double immunostaining showed that after LTP induction, most pERK was co-localized with pCREB. Conclusion NMDA receptor and ERK-CREB pathway are necessary for the induction of LTP in rat ACC and may play important roles in pain emotion.
