Safadi Rifaat, Zigmond Ehud, Pappo Orit, Shalev Zvi, Ilan Yaron
Liver Unit, Department of Medicine, Haassah Medical Center, Jerusalem, Israel.
Int Immunol. 2007 Aug;19(8):1021-9. doi: 10.1093/intimm/dxm069. Epub 2007 Aug 13.
While CD8 lymphocytes possess pro-fibrogenic properties and NK (non-T) cells are anti-fibrogenic, the role of NKT lymphocytes in liver fibrosis is still unclear. Beta-glucosylceramide (GC), a naturally occurring glycolipid, exerts modulatory effects on these cells.
To explore the role of NKT cells in hepatic fibrosis via GC.
Hepatic fibrosis was induced by biweekly intra-peritoneal (IP) carbon tetrachloride (CCl(4)) administrations for 7 weeks in 5 groups (A-E) of male C57Bl/6 mice. Mice were treated with daily IP GC injections in groups A and C, or daily oral doses in groups B and D. GC was administered either for the duration of the study period (in groups A and B), or for the last 3 weeks of CCl(4) induction (groups C and D). GC-treated mice were compared with non-treated fibrotic controls (group E) and naive rodents (group F). Liver fibrosis, injury parameters and FACS analysis of lymphocytes were assessed.
Marked amelioration (P < 0.0001) of hepatic fibrosis observed in all GC-treated mice without altering reactive oxygen species production. As determined by Sirius red-stained liver tissue sections and measured by Bioquant morphometry; all CCl(4)-administered groups significantly (P < 0.0001) increased the relative fibrosis area compared with naive animals. The increases were 14.4 +/- 1.03-fold in group A, 7.9 +/- 0.37-fold in group B, 5.2 +/- 0.2-fold in group C, 10.3 +/- 0.4-fold in group D and 23.8 +/- 1.9-fold in group E. Western blot analysis for alpha smooth muscle actin from liver extracts followed a similar pattern, increasing in groups A-E. A significant decrease in liver damage was observed in all GC-treated groups, as noted by a decrease in transaminase serum levels (P < 0.005). The beneficial effect of GC was associated with a significant decrease in the intra-hepatic NKT and CD8 lymphocytes as well as their attenuation of both T(h)1 and T(h)2 cytokines.
Administration of GC had a significant anti-fibrotic effect following CCl(4) administration. This effect was associated with an altered NKT and CD8 lymphocyte distribution and a cytokine shift. Immune modulation using GC may have a role in the treatment of fibrosis and other immune-mediated disorders.
虽然CD8淋巴细胞具有促纤维化特性，而自然杀伤（非T）细胞具有抗纤维化作用，但NKT淋巴细胞在肝纤维化中的作用仍不清楚。β-葡萄糖神经酰胺（GC）是一种天然存在的糖脂，对这些细胞具有调节作用。
通过GC探讨NKT细胞在肝纤维化中的作用。
将5组（A - E）雄性C57Bl/6小鼠每两周腹腔注射四氯化碳（CCl₄）7周诱导肝纤维化。A组和C组小鼠每天腹腔注射GC，B组和D组小鼠每天口服GC。GC在整个研究期间给药（A组和B组），或在CCl₄诱导的最后3周给药（C组和D组）。将接受GC治疗的小鼠与未治疗的纤维化对照组（E组）和未处理的正常小鼠（F组）进行比较。评估肝纤维化、损伤参数及淋巴细胞的流式细胞术分析。
所有接受GC治疗的小鼠肝纤维化均有明显改善（P < 0.0001），且不改变活性氧的产生。通过天狼星红染色的肝组织切片并经Bioquant形态测量法测定；与正常动物相比，所有给予CCl₄的组肝纤维化相对面积均显著增加（P < 0.0001）。A组增加14.4 ± 1.03倍，B组增加7.9 ± 0.37倍，C组增加5.2 ± 0.2倍，D组增加10.3 ± 0.4倍，E组增加23.8 ± 1.9倍。肝提取物中α平滑肌肌动蛋白的蛋白质印迹分析呈现类似模式，在A - E组中均增加。所有接受GC治疗的组肝损伤均显著降低，血清转氨酶水平下降表明了这一点（P < 0.005）。GC的有益作用与肝内NKT和CD8淋巴细胞显著减少以及Th1和Th2细胞因子的减弱有关。
给予GC在CCl₄给药后具有显著的抗纤维化作用。这种作用与NKT和CD8淋巴细胞分布改变及细胞因子转变有关。使用GC进行免疫调节可能在纤维化及其他免疫介导疾病的治疗中发挥作用。
