Bradham C A, Schemmer P, Stachlewitz R F, Thurman R G, Brenner D A
Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Liver Transpl Surg. 1999 Jul;5(4):282-93. doi: 10.1002/lt.500050401.
Reperfusion after liver transplantation results in the induction of tumor necrosis factor-alpha (TNFalpha) as well as activation of the stress-associated signaling proteins, c-Jun N-terminal kinase (JNK), activating protein-1 (AP-1), and nuclear factor-kappaB (NF-kappaB). To test the hypothesis that Kupffer cells are involved in the activation of signal transduction cascades during rat liver transplantation, Kupffer cells were depleted from donor liver using gadolinium chloride (GdCl3), and then the activation of JNK, AP-1, and NF-kappaB were assessed after transplantation. The results showed that GdCl3 treatment did not inhibit the activation of these stress signals, although transplanted livers were depleted of Kupffer cells and partially protected from reperfusion injury. Interleukin-6 (IL-6) and IL-10 messenger RNAs (mRNAs) were induced by transplantation, and the induction was suppressed by Kupffer cell depletion. The induction of TNFalpha mRNA and serum protein during liver transplantation was unaffected by GdCl3. These results show that Kupffer cells are not a major source of TNFalpha production after liver transplantation and that stress-signaling protein activation occurs independently of Kupffer cells. Transplantation strongly activates the transcription factor NF-kappaB, which blocks TNFalpha-mediated apoptosis in hepatocytes in vitro. To assess the role of NF-kappaB activation during liver transplantation, the IkappaBalpha superrepressor was expressed in donor livers using adenoviral-mediated gene transfer. Inhibition of NF-kappaB resulted in increased serum alanine aminotransferase levels after 3 hours of transplantation. In addition, the blockade of NF-kappaB resulted in increased histological tissue injury and increased hepatic terminal deoxyribonucleotide transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) staining, indicating apoptosis. These results show that NF-kappaB activation has a protective role in the transplanted liver.
肝移植后的再灌注会导致肿瘤坏死因子-α（TNFα）的诱导以及应激相关信号蛋白c-Jun氨基末端激酶（JNK）、活化蛋白-1（AP-1）和核因子-κB（NF-κB）的激活。为了验证库普弗细胞在大鼠肝移植过程中参与信号转导级联激活的假说，使用氯化钆（GdCl3）从供体肝脏中清除库普弗细胞，然后在移植后评估JNK、AP-1和NF-κB的激活情况。结果显示，尽管移植肝脏中的库普弗细胞被清除且部分免受再灌注损伤，但GdCl3处理并未抑制这些应激信号的激活。白细胞介素-6（IL-6）和白细胞介素-10信使核糖核酸（mRNA）通过移植被诱导，而这种诱导通过清除库普弗细胞受到抑制。肝移植期间TNFα mRNA和血清蛋白的诱导不受GdCl3影响。这些结果表明，库普弗细胞不是肝移植后TNFα产生的主要来源，应激信号蛋白的激活独立于库普弗细胞发生。移植强烈激活转录因子NF-κB，其在体外可阻断TNFα介导的肝细胞凋亡。为了评估NF-κB激活在肝移植过程中的作用，使用腺病毒介导的基因转移在供体肝脏中表达IκBα超阻遏物。抑制NF-κB导致移植3小时后血清丙氨酸氨基转移酶水平升高。此外，阻断NF-κB导致组织学组织损伤增加以及肝末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记（TUNEL）染色增加，表明发生凋亡。这些结果表明，NF-κB激活在移植肝脏中具有保护作用。
