Modulation of the unfolded protein response during hepatocyte and cardiomyocyte apoptosis in trauma/hemorrhagic shock.
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ABSTRACT:
SUBMITTER: Thacker SA
PROVIDER: S-EPMC3561621 | biostudies-other | 2013
REPOSITORIES: biostudies-other
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Project description:Trauma is a major cause of mortality in the United States. Death among those surviving the initial insult is caused by multiple organ failure (MOF) with the liver among the organs most frequently affected. We previously demonstrated in rodents that trauma complicated by hemorrhagic shock (trauma/HS) results in liver injury that can be prevented by IL-6 administration at the start of resuscitation; however, the contribution of the severity of HS to the extent of liver injury, whether or not resuscitation is required and the mechanism for the IL-6 protective effect have not been reported. In the experiments reported here, we demonstrated that the extent of liver apoptosis induced by trauma/HS depends on the duration of hypotension and requires resuscitation. We established that IL-6 administration at the start of resuscitation is capable of completely reversing liver apoptosis and is associated with increased Stat3 activation. Microarray analysis of the livers showed that the main effect of IL-6 was to normalize the trauma/HS-induced apoptosis transcriptome. Pharmacological inhibition of Stat3 activity within the liver blocked the ability of IL-6 to prevent liver apoptosis and to normalize the trauma/HS- induced liver apoptosis transcriptome. Genetic deletion of a Stat3beta, a naturally occurring, dominant-negative isoform of the Stat3, attenuated trauma/HS-induced liver apoptosis, confirming a role for Stat3, especially Stat3alpha, in preventing trauma/HS-mediated liver apoptosis. Thus, trauma/HS-induced liver apoptosis depends on the duration of hypotension and requires resuscitation. IL-6 administration at the start of resuscitation reverses HS-induced liver apoptosis, through activation of Stat3alpha, which normalizes the trauma/HS-induced liver apoptosis transcriptome.
| S-EPMC2581418 | biostudies-literature
Project description:Acute lung injury (ALI) occurs in up to 37% of patients following trauma/hemorrhagic shock (T/HS) and, in other settings, is due to alveolar epithelial cell (AEC) apoptosis. To determine if AEC apoptosis is a key contributor to ALI following T/HS and whether or not signal transducer and activator of translation (Stat)3 activation can prevent it, rats were pretreated with a Stat3 inhibitor or placebo and subjected to T/HS or sham protocol and resuscitated without or with interleukin (IL)-6. T/HS induced apoptosis in up to 15% of lung cells, 82% of which were AEC. Apoptosis increased with increasing duration of shock and required resuscitation. IL-6 treatment stimulated lung Stat3 activation and prevented AEC apoptosis. Pretreatment of rats with a Stat3 inhibitor blocked the antiapoptotic effect of IL-6. Mice deficient in Stat3 beta, a naturally occurring dominant negative isoform of Stat3, were resistant to T/HS-induced lung apoptosis. T/HS altered the expression of 87% of apoptosis-related genes. IL-6 treatment normalized expression of 75% of the genes altered by T/HS; Stat3 inhibition prevented normalization of 65% of the gene whose expression was normalized by IL-6. Thus, T/HS-induced AEC apoptosis, which depended on the duration of hypotension, required resuscitation and was prevented by IL-6-mediated activation of Stat3, which acted to normalize the apoptosis transcriptome.
| S-EPMC5350783 | biostudies-literature
Project description:BackgroundPatients suffering from severe trauma experience substantial immunological stress. Lung injury is a known risk factor for the development of posttraumatic complications, but information on the long-term course of the pulmonary inflammatory response and treatment with mild hypothermia are scarce.AimTo investigate the pulmonary inflammatory response to multiple trauma and hemorrhagic shock in a porcine model of combined trauma and to assess the immunomodulatory properties of mild hypothermia.MethodsFollowing induction of trauma (blunt chest trauma, liver laceration, tibia fracture), two degrees of hemorrhagic shock (45 and 50%) over 90 (n = 30) and 120 min. (n = 20) were induced. Animals were randomized to hypothermia (33°C) or normothermia (38°C). We evaluated bronchoalveolar lavage (BAL) fluid and tissue levels of cytokines and investigated changes in microRNA- and gene-expression as well as tissue apoptosis.ResultsWe observed a significant induction of Interleukin (IL) 1β, IL-6, IL-8, and Cyclooxygenase-2 mRNA in lung tissue. Likewise, an increased IL-6 protein concentration could be detected in BAL-fluid, with a slight decrease of IL-6 protein in animals treated with hypothermia. Lower IL-10 protein levels in normothermia and higher IL-10 protein concentrations in hypothermia accompanied this trend. Tissue apoptosis increased after trauma. However, intervention with hypothermia did not result in a meaningful reduction of pro-inflammatory biomarkers or tissue apoptosis.ConclusionWe observed signs of a time-dependent pulmonary inflammation and apoptosis at the site of severe trauma, and to a lower extent in the trauma-distant lung. Intervention with mild hypothermia had no considerable effect during 48 hours following trauma.
| S-EPMC9728855 | biostudies-literature
Project description:Adverse outcomes following severe traumatic injury are frequently attributed to a state of immunological dysfunction acquired during treatment and recovery. Recent genomic evidence however, suggests that the trajectory toward development of multiple organ dysfunction syndrome (MODS) is already in play at admission (<2 h following injury). Improved understanding of the molecular events during the hyper-acute immunological response to trauma, <2 h following injury, may reveal opportunities to ameliorate organ injury and expedite recovery. Lymphocytes have not previously been considered key participants in this early response; however, two observations in human trauma patients namely, raised populations of circulating NKT and NK cells during the hyper-acute phase and persistent lymphopenia beyond 48 h show association with the development of MODS during recovery. These highlight the need for greater understanding of lymphocyte function in the hyper-acute phase of inflammation. An exploratory study was therefore conducted in a well-established murine model of trauma and hemorrhagic shock (T&HS) to investigate (1) the development of lymphopenia in the murine model and (2) the phenotypic and functional changes of three innate-like lymphocyte subsets, NK1.1+ CD3-, NK1.1+ CD3+, γδTCR+ CD3+ cells, focusing on the first 6 h following injury. Rapid changes in phenotype and function were demonstrated in these cells within blood and spleen, but responses in lung tissue lagged behind. This study describes the immediacy of the innate-like lymphocyte response to trauma in different body compartments and considers new lines for further investigation to develop our understanding of MODS pathogenesis.
| S-EPMC6638190 | biostudies-literature
Project description:We previously demonstrated in rodents that T/HS results in liver injury that can be prevented by IL-6 administration at the start of resuscitation, however the mechanism(s) for the IL-6 protective effect is not fully known. We used microarrays to detail the global gene expression in response to T/HS and the effect of IL-6 on this model with and without pharmacologic blockade of Stat3-mediated IL-6 and identified distinct members of the inflammasome de-regulated during T/HS that normalized with IL-6 administration during resuscitation.
2011-03-16 | GSE27978 | GEO
Project description:The PT , PT + PP, and CLP murine models have unique transcriptomic respones 2 hrs, 1 and 3 days after injury
2016-07-10 | GSE69345 | GEO
Project description:Porcine deltacoronavirus (PDCoV) is an emerging enteropathogenic coronavirus that has the potential for cross-species infection. Many viruses have been reported to induce endoplasmic reticulum stress (ERS) and activate the unfolded protein response (UPR). To date, little is known about whether and, if so, how the UPR is activated by PDCoV infection. Here, we investigated the activation state of UPR pathways and their effects on viral replication during PDCoV infection. We found that PDCoV infection induced ERS and activated all three known UPR pathways (inositol-requiring enzyme 1 [IRE1], activating transcription factor 6 [ATF6], and PKR-like ER kinase [PERK]), as demonstrated by IRE1-mediated XBP1 mRNA cleavage and increased mRNA expression of XBP1s, ATF4, CHOP, GADD34, GRP78, and GRP94, as well as phosphorylated eIF2α expression. Through pharmacologic treatment, RNA interference, and overexpression experiments, we confirmed the negative role of the PERK-eIF2α pathway and the positive regulatory role of the ATF6 pathway, but found no obvious effect of IRE1 pathway, on PDCoV replication. Taken together, our results characterize, for the first time, the state of the ERS response during PDCoV infection and identify the PERK and ATF6 pathways as potential antiviral targets.
| S-EPMC9192130 | biostudies-literature
Project description:The etiology of trauma-hemorrhage shock-induced acute lung injury has been difficult to elucidate due, at least in part, to the inability of in vivo studies to separate the non-injurious pulmonary effects of trauma-hemorrhage from the tissue injurious ones. To circumvent this in vivo limitation, we utilized a model of trauma-hemorrhagic shock (T/HS) in which T/HS-lung injury was abrogated by dividing the mesenteric lymph duct. In this way, it was possible to separate the pulmonary injurious response from the non-injurious systemic response to T/HS by comparing the pulmonary molecular response of rats subjected to T/HS which did and did not develop lung injury as well as to non-shocked rats. Utilizing high-density oligonucleotide arrays and treatment group comparisons of whole lung tissue collected at 3 hours after the end of the shock or sham-shock period, 139 of the 8,799 assessed genes were differentially expressed. Keywords: Treatment response to shock
2007-07-25 | GSE6332 | GEO
Project description:The early use of fresh frozen plasma as a resuscitative agent after hemorrhagic shock has been associated with improved survival, but the mechanism of protection is unknown. Hemorrhagic shock causes endothelial cell dysfunction and we hypothesized that fresh frozen plasma would restore endothelial integrity and reduce syndecan-1 shedding after hemorrhagic shock. A prospective, observational study in severely injured patients in hemorrhagic shock demonstrated significantly elevated levels of syndecan-1 (554±93 ng/ml) after injury, which decreased with resuscitation (187±36 ng/ml) but was elevated compared to normal donors (27±1 ng/ml). Three pro-inflammatory cytokines, interferon-?, fractalkine, and interleukin-1?, negatively correlated while one anti-inflammatory cytokine, IL-10, positively correlated with shed syndecan-1. These cytokines all play an important role in maintaining endothelial integrity. An in vitro model of endothelial injury then specifically examined endothelial permeability after treatment with fresh frozen plasma orlactated Ringers. Shock or endothelial injury disrupted junctional integrity and increased permeability, which was improved with fresh frozen plasma, but not lactated Ringers. Changes in endothelial cell permeability correlated with syndecan-1 shedding. These data suggest that plasma based resuscitation preserved endothelial syndecan-1 and maintained endothelial integrity, and may help to explain the protective effects of fresh frozen plasma after hemorrhagic shock.
| S-EPMC3158765 | biostudies-literature
Project description:Trauma complicated by hemorrhagic shock (T/HS) is the leading cause of morbidity and mortality in the United States for individuals under the age of 44 years. Initial survivors are susceptible to developing multiple organ failure (MOF), which is thought to be caused, at least in part, by excessive or maladaptive activation of inflammatory pathways. We previously demonstrated in rodents that T/HS results in liver injury that can be prevented by IL-6 administration at the start of resuscitation; however, the contribution of the severity of HS to the extent of liver injury, whether or not resuscitation is required, and the mechanism(s) for the IL-6 protective effect have not been reported. In the experiments described here, we demonstrated that the extent of liver inflammation induced by T/HS depends on the duration of hypotension and requires resuscitation. We established that IL-6 administration at the start of resuscitation is capable of completely reversing liver inflammation and is associated with increased Stat3 activation. Global assessment of the livers showed that the main effect of IL-6 was to normalize the T/HS-induced inflammation transcriptome. Pharmacological inhibition of Stat3 activity within the liver blocked the ability of IL-6 to prevent liver inflammation and to normalize the T/HS-induced liver inflammation transcriptome. Genetic deletion of a Stat3?, a naturally occurring, dominant-negative isoform of the Stat3, attenuated T/HS-induced liver inflammation, confirming a role for Stat3, especially Stat3?, in preventing T/HS-mediated liver inflammation. Thus, T/HS-induced liver inflammation depends on the duration of hypotension and requires resuscitation; IL-6 administration at the start of resuscitation reverses T/HS-induced liver inflammation, through activation of Stat3?, which normalized the T/HS-induced liver inflammation transcriptome.
| S-EPMC3127578 | biostudies-literature