Bankey P, Prager M, Geldon D, Taylor S, McIntyre K
Department of Surgery, University of Texas, Southwestern Medical Center, Dallas.
Arch Surg. 1994 Nov;129(11):1166-71. doi: 10.1001/archsurg.1994.01420350064008.
Overproduction of liver sinusoidal cell (LCS) mediators in response to endotoxemia or gram-negative infection that follows tissue injury may contribute to hepatic dysfunction.
To better define the role of hepatocyte-derived acute-phase reactants in the regulation of sinusoidal cell mediator production following sequential insults, we tested the hypothesis that interleukin-6 (IL-6) prestimulation alters hepatocyte regulation of lipopolysaccharide (LPS)-stimulated sinusoidal cell tumor necrosis factor (TNF), IL-6, and nitric oxide production.
Hepatocytes and LSCs were isolated from Wistar rats, and in vitro responses were compared between LSCs alone and hepatocyte-LSC cocultures. Cocultures and LSCs alone were sequentially stimulated with IL-6 (5000 U/mL) then LPS (dose-response), and culture supernatants were analyzed for TNF (L929 cytolysis), IL-6 (7TD1 proliferation), and nitric oxide (Griess reaction). Induction of acute-phase protein synthesis by the stimulation of hepatocytes with IL-6 and dexamethasone (0.1 mumol/L) was assayed by methionine radiolabeling and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Coculture levels of messenger RNA for TNF-alpha and IL-6 were examined by RNA extraction and reverse transcriptase polymerase chain reaction with specific primers.
Interleukin-6 and dexamethasone signal hepatocyte acute-phase protein synthesis. Prestimulation of cocultures, but not of LSCs alone, with IL-6 inhibits LPS-stimulated IL-6 and nitric oxide production significantly. Bioactivity of TNF is reduced to a lesser extent. Polymerase chain reaction analysis demonstrated similar levels of TNF and IL-6 message following sequential stimulation.
Interleukin-6-stimulated acute-phase hepatocytes limit LPS-stimulated coculture cytokine bioactivity and nitric oxide production. This hepatocyte response may provide a local counterregulatory mechanism to limit LSC-mediated injury.
内毒素血症或组织损伤后革兰氏阴性菌感染会导致肝窦状细胞（LCS）介质过度产生，这可能会导致肝功能障碍。
为了更好地确定肝细胞衍生的急性期反应物在相继损伤后对肝窦状细胞介质产生的调节作用，我们验证了白细胞介素-6（IL-6）预刺激会改变肝细胞对脂多糖（LPS）刺激的肝窦状细胞肿瘤坏死因子（TNF）、IL-6和一氧化氮产生的调节这一假设。
从Wistar大鼠中分离出肝细胞和肝窦状细胞（LSCs），比较单独培养的LSCs和肝细胞-LSCs共培养物的体外反应。共培养物和单独的LSCs先用IL-6（5000 U/mL）然后用LPS（剂量反应）进行顺序刺激，分析培养上清液中的TNF（L929细胞溶解）、IL-6（7TD1增殖）和一氧化氮（Griess反应）。用蛋氨酸放射性标记和SDS-PAGE（十二烷基硫酸钠-聚丙烯酰胺凝胶电泳）检测IL-6和地塞米松（0.1 μmol/L）刺激肝细胞对急性期蛋白合成的诱导作用。通过RNA提取和用特异性引物进行逆转录聚合酶链反应检测共培养物中TNF-α和IL-6信使RNA的水平。
白细胞介素-6和地塞米松可诱导肝细胞急性期蛋白合成。用IL-6预刺激共培养物而非单独的LSCs，可显著抑制LPS刺激的IL-6和一氧化氮产生。TNF的生物活性降低程度较小。聚合酶链反应分析显示顺序刺激后TNF和IL-6信使水平相似。
白细胞介素-6刺激的急性期肝细胞会限制LPS刺激的共培养细胞因子生物活性和一氧化氮产生。这种肝细胞反应可能提供一种局部负调节机制以限制肝窦状细胞介导的损伤。
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