AIM: To develop an animal model of liver infection with Chlamydia pneumoniae (C. pneumoniae) in intraperito-neally infected mice for studying the presence of chlamy-diae in Kupffer cells and hepatocytes.METHODS: A tot...AIM: To develop an animal model of liver infection with Chlamydia pneumoniae (C. pneumoniae) in intraperito-neally infected mice for studying the presence of chlamy-diae in Kupffer cells and hepatocytes.METHODS: A total of 80 BALB/c mice were inoculated intraperitoneally with C. pneumoniae and sacrificed at various time points after infection. Chlamydiae were looked for in liver homogenates as well as in Kupffer cells and hepatocytes separated by liver perfusion with collagenase. C. pneumoniae was detected by both isola-tion in LLC-MK2 cells and fluorescence in situ hybridiza-tion (FISH). The releasing of TNFA-α by C. pneumoniae in vitro stimulated Kupffer cells was studied by enzyme-linked immunosorbent assay.RESULTS: C. pneumoniae isolation from liver homoge-nates reached a plateau on d 7 after infection when 6 of 10 animals were positive, then decreased, and became negative by d 20. C. pneumoniae isolation from sepa-rated Kupffer cells reached a plateau on d 7 when 5 of 10 animals were positive, and became negative by d 20. The detection of C. pneumoniae in separated Kupffer cells by FISH, confirmed the results obtained by culture. Isolated hepatocytes were always negative. Stimula-tion of Kupffer cells by alive C. pneumoniae elicited high TNF-α levels. CONCLUSION: A productive infection by C. pneumo-niae may take place in Kupffer cells and C. pneumoniae induces a local pro-inflammatory activity. C. pneumoniae is therefore, able to act as antigenic stimulus when local-ized in the liver. One could speculate that C. pneumoniaeinfection, involving cells of the innate immunity such as Kupffer cells, could also trigger pathological immune re-actions involving the liver, as observed in human patients with primary biliary cirrhosis.展开更多
Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models ...Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models were applied with 30 healthy male Xi＇ an canines which were randomly divided into a control group, simultaneous reperfusion（SR） group and HAI group, CD14 protein expression, Malonaldehyde （MDA） Contents in hepatic tissues and ALT values in serum were detected, and the pathological changes of hepatic tissues was investigated under the light microscopy. Results：The level of CD14 protein expression in SR and HAI group tended to be time-dependent and both higher than controls with statistical significance（P 〈 0.01）; The peak values of these two groups both occurred at 4 h, but the level in HAI group （11.94 ± 0.43） was evidently higher than that in SR group（3.04 ± 0.34）. MDA contents in liver tissue, ALT values in serum and pathological changes showed the same changing tendency as CD 14 expression. Conclusion：（1） Up-regulation of CD14 expression may be the receptor-mechanism of Kupffer cells（KCs） activation in liver transplantation. （2） HAI can upregulate CD14 expression after portal vein reperfusion, improve the activity of KCs further more, increase OFRs production and cooperate with portal reperfusion, and finally aggravate the grafts injury.展开更多
Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP ca...Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats.Method To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock+glycine group (glycine injected at the beginning of resuscitation) and shock+MP group (MP injected at the beginning of resuscitation).Results ① Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock+glycine and shock+MP groups were 77.8% and 80%, respectively. The difference was significant (P<0.05). ② Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. ③ Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock+glycine and shock+MP groups. The differences were significant (P<0.01). ④ There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-α) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P<0.01). Conclusion Glycine and MP reduce organ injury and mortality caused by hemorrhagic shock by preventing increase of intracellular calcium levels in Kupffer cell, suppressing Kupffer cell activation, decreasing the production of TNF-α by Kupffer cells, and blocking systemic inflammatory responses.展开更多
文摘AIM: To develop an animal model of liver infection with Chlamydia pneumoniae (C. pneumoniae) in intraperito-neally infected mice for studying the presence of chlamy-diae in Kupffer cells and hepatocytes.METHODS: A total of 80 BALB/c mice were inoculated intraperitoneally with C. pneumoniae and sacrificed at various time points after infection. Chlamydiae were looked for in liver homogenates as well as in Kupffer cells and hepatocytes separated by liver perfusion with collagenase. C. pneumoniae was detected by both isola-tion in LLC-MK2 cells and fluorescence in situ hybridiza-tion (FISH). The releasing of TNFA-α by C. pneumoniae in vitro stimulated Kupffer cells was studied by enzyme-linked immunosorbent assay.RESULTS: C. pneumoniae isolation from liver homoge-nates reached a plateau on d 7 after infection when 6 of 10 animals were positive, then decreased, and became negative by d 20. C. pneumoniae isolation from sepa-rated Kupffer cells reached a plateau on d 7 when 5 of 10 animals were positive, and became negative by d 20. The detection of C. pneumoniae in separated Kupffer cells by FISH, confirmed the results obtained by culture. Isolated hepatocytes were always negative. Stimula-tion of Kupffer cells by alive C. pneumoniae elicited high TNF-α levels. CONCLUSION: A productive infection by C. pneumo-niae may take place in Kupffer cells and C. pneumoniae induces a local pro-inflammatory activity. C. pneumoniae is therefore, able to act as antigenic stimulus when local-ized in the liver. One could speculate that C. pneumoniaeinfection, involving cells of the innate immunity such as Kupffer cells, could also trigger pathological immune re-actions involving the liver, as observed in human patients with primary biliary cirrhosis.
基金This work was supported by National Nature Science Fund(30571765)
文摘Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models were applied with 30 healthy male Xi＇ an canines which were randomly divided into a control group, simultaneous reperfusion（SR） group and HAI group, CD14 protein expression, Malonaldehyde （MDA） Contents in hepatic tissues and ALT values in serum were detected, and the pathological changes of hepatic tissues was investigated under the light microscopy. Results：The level of CD14 protein expression in SR and HAI group tended to be time-dependent and both higher than controls with statistical significance（P 〈 0.01）; The peak values of these two groups both occurred at 4 h, but the level in HAI group （11.94 ± 0.43） was evidently higher than that in SR group（3.04 ± 0.34）. MDA contents in liver tissue, ALT values in serum and pathological changes showed the same changing tendency as CD 14 expression. Conclusion：（1） Up-regulation of CD14 expression may be the receptor-mechanism of Kupffer cells（KCs） activation in liver transplantation. （2） HAI can upregulate CD14 expression after portal vein reperfusion, improve the activity of KCs further more, increase OFRs production and cooperate with portal reperfusion, and finally aggravate the grafts injury.
文摘Background Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats.Method To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock+glycine group (glycine injected at the beginning of resuscitation) and shock+MP group (MP injected at the beginning of resuscitation).Results ① Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock+glycine and shock+MP groups were 77.8% and 80%, respectively. The difference was significant (P<0.05). ② Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. ③ Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock+glycine and shock+MP groups. The differences were significant (P<0.01). ④ There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-α) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P<0.01). Conclusion Glycine and MP reduce organ injury and mortality caused by hemorrhagic shock by preventing increase of intracellular calcium levels in Kupffer cell, suppressing Kupffer cell activation, decreasing the production of TNF-α by Kupffer cells, and blocking systemic inflammatory responses.
