Relja Borna, Weber Roxane, Maraslioglu Miriam, Wagner Nils, Borsello Tiziana, Jobin Christian, Marzi Ingo, Lehnert Mark
Department of Trauma, Hand and Reconstructive Surgery, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
Neuronal Death and Neuroprotection Unit, Instituto Di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
PLoS One. 2015 Sep 14;10(9):e0137875. doi: 10.1371/journal.pone.0137875. eCollection 2015.
Chronic ethanol (EtOH) abuse worsens pathophysiological derangements after hemorrhagic shock and resuscitation (H/R) that induce hepatic injury and strong inflammatory changes via JNK and NF-κB activation. Inhibiting JNK with a cell-penetrating, protease-resistant peptide D-JNKI-1 after H/R in mice with healthy livers ameliorated these effects. Here, we studied if JNK inhibition by D-JNKI-1 in chronically EtOH-fed mice after hemorrhagic shock prior to the onset of resuscitation also confers protection.
Male mice were fed a Lieber-DeCarli diet containing EtOH or an isocaloric control (ctrl) diet for 4 weeks. Animals were hemorrhaged for 90 min (32 ± 2 mm Hg) and randomly received either D-JNKI-1 (11 mg/kg, intraperitoneally, i. p.) or sterile saline as vehicle (veh) immediately before the onset of resuscitation. Sham animals underwent surgical procedures without H/R and were either D-JNKI-1 or veh treated. Two hours after resuscitation, blood samples and liver tissue were harvested.
H/R induced hepatic injury with increased systemic interleukin (IL)-6 levels, and enhanced local gene expression of NF-κB-controlled genes such as intercellular adhesion molecule (ICAM)-1 and matrix metallopeptidase (MMP)9. c-Jun and NF-κB phosphorylation were increased after H/R. These effects were further increased in EtOH-fed mice after H/R. D-JNKI-1 application inhibited the proinflammatory changes and reduced significantly hepatic injury after H/R in ctrl-fed mice. Moreover, D-JNKI-1 reduces in ctrl-fed mice the H/R-induced c-Jun and NF-κB phosphorylation. However, in chronically EtOH-fed mice, JNK inhibition did not prevent the H/R-induced hepatic damage and proinflammatory changes nor c-Jun and NF-κB phosphorylation after H/R.
These results indicate, that JNK inhibition is protective only in not pre-harmed liver after H/R. In contrast, the pronounced H/R-induced liver damage in mice being chronically fed with ethanol cannot be prevented by JNK inhibition after H/R and seems to be under the control of NF-κB.
慢性乙醇（EtOH）滥用会加重失血性休克和复苏（H/R）后的病理生理紊乱，H/R会通过激活JNK和NF-κB诱导肝损伤和强烈的炎症变化。在肝脏健康的小鼠中，H/R后用一种细胞穿透性、蛋白酶抗性肽D-JNKI-1抑制JNK可改善这些效应。在此，我们研究了在复苏开始前对慢性乙醇喂养的小鼠进行失血性休克后，D-JNKI-1抑制JNK是否也能提供保护作用。
雄性小鼠分别喂食含乙醇的Lieber-DeCarli饮食或等热量对照（ctrl）饮食4周。动物出血90分钟（32±2毫米汞柱），并在复苏开始前随机接受D-JNKI-1（11毫克/千克，腹腔注射，i.p.）或无菌生理盐水作为载体（veh）。假手术动物接受无H/R的手术操作，并接受D-JNKI-1或veh处理。复苏后两小时，采集血样和肝组织。
H/R诱导肝损伤，全身白细胞介素（IL）-6水平升高，并增强了NF-κB控制基因如细胞间粘附分子（ICAM）-1和基质金属肽酶（MMP）9的局部基因表达。H/R后c-Jun和NF-κB磷酸化增加。在H/R后的乙醇喂养小鼠中，这些效应进一步增强。应用D-JNKI-1可抑制ctrl喂养小鼠H/R后的促炎变化并显著减轻肝损伤。此外，D-JNKI-1可降低ctrl喂养小鼠H/R诱导的c-Jun和NF-κB磷酸化。然而，在慢性乙醇喂养的小鼠中，抑制JNK并不能预防H/R诱导的肝损伤和促炎变化，也不能预防H/R后c-Jun和NF-κB磷酸化。
这些结果表明，JNK抑制仅在H/R后未预先受损的肝脏中具有保护作用。相比之下，慢性乙醇喂养的小鼠中H/R诱导的明显肝损伤不能通过H/R后抑制JNK来预防，似乎受NF-κB控制。
