封闭枯否细胞对LPS诱导激活丝裂原活化蛋白激酶的影响

目的： 利用小鼠LPS血症模型，探讨封闭枯否细胞（KCs）对LPS诱导MAPK信号转导通路的影响。方法： 雄性昆明种小鼠在注射LPS（5 mg/kg）前48 h及24 h，分别静脉注射GdCl₃（10 mg/kg）或等量的生理盐水，于LPS或生理盐水注射后30 min，分别取出肝脏或分离KCs；体外培养小鼠KCs经GdCl₃（100 μmol/L）预处理1 h，加入含LPS（100 μg/L）的DMEM培养基继续孵育30 min，分别检测肝脏及体内外KCs ERK1/2、p38MAPK蛋白表达和磷酸化水平，及GdCl₃对KCs吞噬、分泌功能的影响。结果： GdCl₃可抑制LPS 诱导KCs活化和TNF-α分泌，但不能抑制LPS诱导KCs或肝脏ERK1/2、p38MAPK磷酸化，也不能影响ERK1/2、p38MAPK蛋白表达，KCs 经GdCl₃单独短时间处理（1 h），可使其少量分泌TNF-α。结论： 封闭KCs并不能通过调节细胞内ERK1/2、p38MAPK信号转导途径，抑制LPS诱导的KCs活化及TNF-α释放，而可能是通过其它信号转导途径（JNK、NF-кB、GPCR等）间的相互作用减轻肝损伤。

Effect of Kupffer cell blockade on activation of mitogen-activated protein kinases in response to lipopolysaccharide

AIM: Using the mouse model of lipopolysaccharide(LPS) attack,we study the effect of Kupffer cell (KC) blockade on the activation of mitogen-activated protein kinases(MAPKs) signal transduction pathway induced by LPS.METHODS: GdCl₃ (10 mg/kg) or the same volume of NS was continually injected intravenously at 48 h and 24 h before LPS (5 mg/kg) was injected into the male mice of Kunming species.The liver was then took out and KCs were isolated 30 minute after LPS was injected.The KCs isolated from the mice were cultured,and pretreated with GdCl₃ (100 μmol/L) for 1 h.The culture medium containing LPS (100 μg/L) was added and continuously incubated for 30 minute.The protein expression and phosphorylation level of ERK1/2 and p38MAPK in liver or KCs were assayed in vivo and in vitro,and effect of GdCl₃ on the phagocytosis function was observed,respectively.RESULTS: LPS induced the protein phosphorylation of ERK1/2 and p38MAPK in KCs or liver,no effect on the protein expression was observed.GdCl₃ treatment inhibited LPS-induced KCs activation and secretion of TNF-α,however,it had no effect on ERK1/2 and p38MAPK in KCs or liver,neither at the protein expression nor the phosphorylation.KCs secreted a few TNF-α with short time treatment with GdCl₃ alone in vitro.CONCLUSION: KC blockade with GdCl₃ alleviates LPS-induced KCs activation and the release of TNF-α not through modulating intracellular ERK1/2 or p38MAPK signal transduction pathways.We presume that GdCl₃ might reduce liver injury through cross talk of other intracellular signal transduction pathways (JNK,NF-кB,GPCR,etc).