Inhibition of C-Jun N-Terminal Kinase After Hemorrhage but Before Resuscitation Mitigates Hepatic Damage and Inflammatory Response in Male Rats

Abstract

Inhibition of c-Jun N-terminal kinase (JNK) by a cell-penetrating, protease-resistant JNK peptide (D-JNKI-1) before hemorrhage and resuscitation (H/R) ameliorated the H/R-induced hepatic injury and blunted the proinflammatory changes. Here we tested the hypothesis if JNK inhibition at a later time point-after hemorrhagic shock but before the onset of resuscitation-in a rat model of H/R also confers protection. Twenty-four male Sprague-Dawley rats (250 - 350 g) were randomly divided into 4 groups: 2 groups of shock animals were hemorrhaged to a MAP of 32 to 37 mmHg for 60 min and randomly received either D-JNKI-1 (11 mg/kg i.p.) or sterile saline as vehicle immediately before the onset of resuscitation. Two groups of sham-operated animals underwent surgical procedures without H/R and were either D-JNKI-1 or vehicle treated. Rats were killed 2 h later. Serum activity of alanine aminotransferase and serum lactate dehydrogenase after H/R increased 3.5-fold in vehicle-treated rats as compared with D-JNKI-1-treated rats. Histopathological analysis revealed that hepatic necrosis and apoptosis (hematoxylin-eosin, TUNEL, and M30, respectively) were significantly inhibited in D-JNKI-1-treated rats after H/R. Hepatic oxidative (4-hydroxynonenal) and nitrosative (3-nitrotyrosine) stress as well as markers of inflammation (hepatic and serum IL-6 levels and hepatic infiltration with polymorphonuclear leukocytes) were also reduced in D-JNKI-1-treated rats. LPS-stimulated TNF-alpha release from whole blood from hemorrhaged and resuscitated animals was higher in vehicle-treated rats as compared with D-JNKI-1-treated rats. c-Jun N-terminal kinase inhibition after hemorrhage before resuscitation resulted in a reduced activation of c-Jun. Taken together, these results indicate that D-JNKI-1 application after hemorrhagic shock before resuscitation blunts hepatic damage and proinflammatory changes during resuscitation. Hence, JNK inhibition is even protective when initiated after blood loss before resuscitation. These experimental results indicate that the JNK pathway may be a possible treatment option for the harmful consequences of H/R.

Immune–neural connections: how the immune system’s response to infectious agents influences behavior

“…It is not known if the activation of JNK by TNF, as a prerequisite for sickness, occurs within neurons or within glia through TNF-R2 (Fig.5). Attenuation of glia activation by the inhibition of JNK could act to decrease the net inflammatory response (Relja et al, 2009) and thus decrease the ability of the brain to express cytokines, which could then act on neurons. In any case, it is clear that proinflammatory cytokines act by at least two pathways to fully induce sickness.…”

Acute alcohol intoxication reduces mortality, inflammatory responses and hepatic injury after haemorrhage and resuscitationin vivo

“…Constant pressure was maintained by further withdrawal of small volumes of blood as necessary for 60 min. Then, rats were resuscitated by transfusion of 60% of the shed blood plus a volume of lactated Ringer's solution corresponding to 50% of the shed blood volume with a syringe pump over 30 min via the left jugular vein (Relja et al, 2009). After the end of resuscitation, catheters were removed, the vessels were occluded and the wounds were closed.…”

“…The increase of proinflammatory cytokines is strongly associated with an increased mortality in a model of H/R (Cai et al, 2009). Furthermore, elevated cytokine levels contribute to the up-regulation of adhesion molecules, apoptotic and/or necrotic changes of endothelial, parenchymal and immune cells and accompany compromised organ function after H/R, notably in the liver (Yamakawa et al, 2000;Cockerill et al, 2001;Liaw et al, 2005;Shimizu et al, 2007;Lehnert et al, 2008;Relja et al, 2009;2010). NF-kB is involved in the regulation of inflammatory and immune processes, and is activated in the liver following H/R (Meng et al, 2001).…”

Plant polyphenols attenuate hepatic injury after hemorrhage/resuscitation by inhibition of apoptosis, oxidative stress, and inflammation via NF-kappaB in rats

“…With regard to the liver, JNK activation promotes organ damage in models of I/R, rat liver transplantation, partial hepatectomy, and H/R [12,30,36,38,39]. Furthermore, JNK activation is linked to the expression of several inflammatory genes, production of pro-inflammatory molecules, such as IL-6 and apoptosis after H/R and hypoxia [40][41][42].…”

“…ROS and RNS, derived from hepatocytes, activated macrophages and the infiltrating neutrophils induce lipid peroxidation of cellular membranes, oxidation of DNA, protein nitrosylation, necrosis and apoptosis, and therefore play a crucial role in the induction and in the progression of liver injury after H/R [9][10][11]. Moreover, H/R is accompanied by enhanced hepatic and serum IL-6 levels [12]. IL-6-deficient mice were protected from pro-inflammatory changes, hepatic necrosis, enhanced nuclear factor-kappaB (NF-kappaB) activity, and organ damage as observed in wild-type mice after H/R [13].…”