Marra F, DeFranco R, Grappone C, Parola M, Milani S, Leonarduzzi G, Pastacaldi S, Wenzel U O, Pinzani M, Dianzani M U, Laffi G, Gentilini P
Istituto di Medicina Interna, Università di Firenze Viale Morgagni, Florence, Italy.
J Investig Med. 1999 Jan;47(1):66-75.
Increased expression of monocyte chemotactic protein-1 (MCP-1) has been indicated as a mechanism underlying leukocyte recruitment after liver injury. In this study we examined the temporal relationship between MCP-1 expression and the appearance of monocyte infiltration during acute liver injury. In addition, we tested the effects of vitamin E, a well known antioxidant, on these parameters. Rats were intoxicated with a single intragastric administration of CCl4 with or without pretreatment with vitamin E (atocopherol).
Monocyte chemotactic protein-1 expression was analyzed by northern blotting and in situ hybridization and monocyte infiltration was determined by ED-1 immunostaining. The results were quantitated by computerized image analysis. Expression of MCP-1 mRNA was significantly increased as early as 12 hours following injury, and progressively increased thereafter. In contrast, a significant increase in the number of ED-1 positive cells, an index of monocyte infiltration, was observed only 24 and 48 hours after injury.
Vitamin E markedly reduced MCP-1 expression at the mRNA and protein levels, and caused a significant reduction in the number of monocyte/macrophages, indicating a role for oxidative stress in the induction of MCP-1 expression in vivo. Accordingly, in cultured hepatic stellate cells, different oxidative stress-related molecules increased MCP-1 mRNA.
These data suggest the existence of a direct relationship between MCP-1 expression and monocyte infiltration after acute liver injury, and that preventing the generation of oxidative stress-related molecules results in decreased expression and release of this chemokine.
单核细胞趋化蛋白-1（MCP-1）表达增加被认为是肝损伤后白细胞募集的潜在机制。在本研究中，我们检测了急性肝损伤期间MCP-1表达与单核细胞浸润出现之间的时间关系。此外，我们测试了著名的抗氧化剂维生素E对这些参数的影响。大鼠经单次胃内给予四氯化碳（CCl4），部分大鼠在给予CCl4前用维生素E（生育酚）预处理。
通过Northern印迹和原位杂交分析MCP-1表达，通过ED-1免疫染色确定单核细胞浸润情况。结果通过计算机图像分析进行定量。损伤后12小时，MCP-1 mRNA表达即显著增加，此后逐渐升高。相比之下，单核细胞浸润指标ED-1阳性细胞数量仅在损伤后24小时和48小时显著增加。
维生素E在mRNA和蛋白水平显著降低MCP-1表达，并导致单核细胞/巨噬细胞数量显著减少，表明氧化应激在体内诱导MCP-1表达中起作用。相应地，在培养的肝星状细胞中，不同的氧化应激相关分子可增加MCP-1 mRNA。
这些数据表明急性肝损伤后MCP-1表达与单核细胞浸润之间存在直接关系，并且防止氧化应激相关分子的产生会导致这种趋化因子的表达和释放减少。
