Reeves H L, Burt A D, Wood S, Day C P
Department of Medicine, Medical School, University of Newcastle upon Tyne, UK.
J Hepatol. 1996 Nov;25(5):677-83. doi: 10.1016/s0168-8278(96)80238-8.
BACKGROUND/AIMS: There is now overwhelming evidence that hepatic stellate cells are the principal cells involved in hepatic fibrogenesis. In several different forms of liver injury it has been demonstrated that they proliferate and undergo phenotypic transformation (activation) into matrix-producing, myofibroblast-like cells in response to necroinflammation, mediated in part, by Kupffer cell-derived factors. In alcoholic liver disease, however, the observation that fibrosis can occur in the absence of alcoholic hepatitis has cast doubt on necroinflammation being an absolute pre-requisite for alcohol-related hepatic stellate cells proliferation/activation and subsequent fibrogenesis.
Evidence for hepatic stellate cells activation has been sought in liver biopsies from 38 well-documented alcoholic patients with no evidence of alcoholic hepatitis or cirrhosis and eight normal controls. Activated hepatic stellate cells were identified immunohistochemically using a specific monoclonal antibody to detect cytoplasmic alpha smooth muscle actin (alpha-SMA), which is not present in quiescent cells. Kupffer cells were detected with the monoclonal antibody KP1 and collagen was stained using Sirius red. Immunoreactive cells and the amount of fibrosis were quantified, using a Kontron Vidas Image Analyser. Steatosis was graded from 0 (none-few hepatocytes containing fat) to 3 (> 2/3 hepatocyte containing fat).
Biopsies from alcoholic patients contained significantly greater numbers of activated hepatic stellate cells (alpha-SMA+ve) than control biopsies (average cell counts: 84 +/- 11/mm2 versus 23 +/- 5/mm2, p < 0.0001). There was no correlation between numbers of activated hepatic stellate cells and either numbers of Kupffer cells or amount of fibrosis. There was, however, a significant correlation between hepatic stellate cells activation and steatosis (grade 0, 15 +/- 7 cells/unit area (n = 4), grade 1, 56 +/- 16 (n = 13), grade 2, 85 +/- 20 (n = 9), grade 3, 137 +/- 19 (n = 12); p = 0.002, ANOVA).
These results suggest that neither necroinflammation nor an increase in Kupffer cells is an absolute prerequisite for hepatic stellate cells proliferation/activation and subsequent fibrogenesis in alcoholic liver disease. The correlation between alcohol-induced hepatic stellate cells activation and severity of steatosis is likely to reflect that both are attributable in part to the metabolic consequences of ethanol metabolism, namely increased concentrations of acetaldehyde and lipid peroxidation.
背景/目的：目前有大量证据表明肝星状细胞是参与肝纤维化形成的主要细胞。在几种不同形式的肝损伤中，已证实它们会增殖并发生表型转化（激活），以响应坏死性炎症，转变成产生基质的肌成纤维细胞样细胞，这部分是由库普弗细胞衍生的因子介导的。然而，在酒精性肝病中，在没有酒精性肝炎的情况下也会发生纤维化这一观察结果，让人怀疑坏死性炎症是否是酒精相关肝星状细胞增殖/激活及随后纤维化形成的绝对先决条件。
在38例有充分记录的无酒精性肝炎或肝硬化证据的酒精性患者及8例正常对照者的肝活检组织中寻找肝星状细胞激活的证据。使用特异性单克隆抗体通过免疫组织化学方法鉴定激活的肝星状细胞，以检测细胞质α平滑肌肌动蛋白（α-SMA），静止细胞中不存在该蛋白。用单克隆抗体KP1检测库普弗细胞，并用天狼星红对胶原蛋白进行染色。使用Kontron Vidas图像分析仪对免疫反应性细胞和纤维化程度进行定量。脂肪变性从0级（无-少数肝细胞含脂肪）到3级（>2/3肝细胞含脂肪）进行分级。
酒精性患者的活检组织中激活的肝星状细胞（α-SMA阳性）数量明显多于对照活检组织（平均细胞计数：84±11/mm²对23±5/mm²，p<0.0001）。激活的肝星状细胞数量与库普弗细胞数量或纤维化程度之间均无相关性。然而，肝星状细胞激活与脂肪变性之间存在显著相关性（0级，15±7个细胞/单位面积（n = 4），1级，56±16（n = 13），2级，85±20（n = 9），3级，137±19（n = 12）；p = 0.002，方差分析）。
这些结果表明，坏死性炎症和库普弗细胞增加均不是酒精性肝病中肝星状细胞增殖/激活及随后纤维化形成的绝对先决条件。酒精诱导的肝星状细胞激活与脂肪变性严重程度之间的相关性可能反映出两者部分归因于乙醇代谢的代谢后果，即乙醛浓度增加和脂质过氧化。
