内毒素诱导原代肝细胞表达FasL及其细胞毒效应

目的 探讨内毒素直接与间接致肝细胞凋亡在内毒素血症肝脏损伤中的病理机制。方法 采用低浓度胶原酶原位循环灌流法分离，培养肝细胞，经不同浓度内毒素（１、５、１０μｇ／ｍｌ）作用２４、４８ｈ后免疫组织化学法检测肝细胞膜性ＦａｓＬ（ｍＦａｓＬ）表达及ＴＵＮＥＬ试验检测内毒素直接与间接致肝细胞凋亡情况。结果 内毒素作用２４ｈ后肝细胞ｍＦａｓＬ表达阳性程度为＋＋－＋＋＋，对照组为阴性，内毒素直接作用２４ｈ后肝

Fas Ligand expression and apoptosis in primary rat hepatocytes induced by lipopolysaccharide

OBJECTIVE: To study hepatocyte apoptosis induced by lipopolysaccharide (LPS) directly and indirectly, and to elucidate the mechanisms of liver damage in endotoxemia. METHODS: Rat hepatocytes were isolated using collagenase perfusion, and cultured in RPMI 1640 medium. After 24h or 48 h of LPS treatment at various concentrations (1, 5, 10 mug/ml), membrane-bound Fas ligand (mFasL) expression in hepatocytes was determined by immunocytochemistry, and apoptosis was detected by TUNEL. In another set of experiments it was examined whether LPS-treated hepatocytes and its supernatants can stimulate apoptosis in LPS-untreated hepatocytes. RESULTS: LPS markedly stimulated mFasL expression and apoptosis in hepatocytes in a dose and time (24-48 h) dependent manner. In the co-culture system LPS-treated hepatocytes significantly induced LPS-untreated hepatocyte apoptosis. In contrast, there was no apoptotic cells observed in the supernatant stimulation system. CONCLUSION: LPS not only directly causes hepatocyte apoptosis, but also indirectly induces apoptosis of LPS-untreated hepatocytes by way of stimulating mFasL expression in hepatocytes.