TAKEDA-143242 increased survival via reduced cytokines in porcine peritonitis.

TAKEDA-143242 (TAK-242) is a small molecule shown to inhibit lipopolysaccharide-induced intracellular signaling and inflammation. In vitro studies demonstrated that TAK-242 can prevent release of TNF-α, IL-1ß, and IL-6 from activated macrophages of several species, including pigs. This study tested the hypothesis that TAK-242 would protect pigs from lethal gram-negative peritonitis via an anti-cytokine mechanism. A validated model of porcine gram-negative peritonitis, which employs chronically inplantated cardiac transducers and aortic and pulmonary artery catheters, was used. Pigs were pretreated with TAK-242 or its vehicle via a blinding procedure prior to intraperitoneal implantation of an LD(90) dose of E. coli 0111:B4 in a fibrin clot. Ten pigs were treated with TAK-242 and nine with its vehicle. All ten TAK-242 treated pigs survived, while three of the nine vehicle treated pigs survived (P = 0.01 χ(2) test). Pulmonary artery pressure increased markedly in vehicle pigs, and this elevation was significantly (two-way ANOVA) obviated in TAK-242 treated group. Circulating levels of cytokines in vehicle treated pigs showed increased expression (3930 ± 1770 at 1 h, 1007 ± 400 TNF-α at 2 h; 719 ± 308 of IL-1ß at 2-6 h; 33000 ± 1000 of IL-6 at 2-4 h [pg/mL, mean ± SEM]). Peak circulating levels of these cytokines were significantly reduced by pretreatment with TAK-242 (<25 pg/mL TNF-α ; <100 pg/mL IL-1ß; 0-1700 pg/mL IL-6, peak values). This study found that pretreatment with TAK-242 yielded significantly positive survival benefit in a lethal sepsis model that was associated with improved cardiovascular status and suppressed cytokine release.

Biphasic intra-thoracic pressure regulation augments cardiac index during porcine peritonitis: a feasibility study.

Preservation of cardiac output (CO) and pulmonary artery pressure (PAP) is vital to maintaining tissue oxygenation in sepsis. This feasibility study tested the hypothesis that therapeutic intra-thoracic pressure regulation (tIPR), delivered with a novel device, was designed to non-invasively enhance venous return by creating sub-atmospheric intra-thoracic pressure during the expiratory phase of mechanical ventilation, improves CO without fluid resuscitation in a porcine E. coli peritonitis model of sepsis. Seven pigs were intubated, anaesthetized and instrumented with a Swan-Ganz and femoral artery catheter. After a 30 min basal period, a fibrin clot containing 4-5 × 10(9) cfu kg(-1) E. coli O111.B4 was implanted in the peritoneum. One hour after clot implantation, tIPR was utilized for 30 min and then removed from the ventilator circuit for 30 min. This tIPR cycle was repeated 4-times. Changes in haemodynamic parameters were calculated by comparing pre-tIPR values to peak values during tIPR administration. Following peritonitis, tIPR significantly increased the peak cardiac index (mean ± SEM) (14.8 ± 2.6 vs 7.9 ± 2.3 ml kg(-1)) and mean arterial pressure (10.2 ± 1.5 vs 4.9 ± 1.1 mmHg) and simultaneously decreased PAP (-7.7 ± 1.5 vs -2.7 ± 0.8 mmHg). These results support the feasibility of the concept that therapeutic application of negative expiratory pressure may provide a non-invasive and complementary approach to increase cardiac output and organ perfusion in the setting of septic shock.

Targeting host E-selectin expression by antisense oligodeoxynucleotides as potential antiendotoxin therapy in vivo.

This study sought to determine if antisense oligodeoxynucleotides would inhibit E-selectin expression, which mediates leukocyte adhesion on endothelial cells, otherwise induced by in vivo endotoxin challenge. Six antisense phosphorothioate oligodeoxynucleotides calculated to bind porcine E-selectin mRNA were tested in porcine aortic endothelial cells. One, ISIS9481, exerted significant inhibition of E-selectin expression induced by tumor necrosis factor-α + endotoxin [lipopolysaccharide (LPS)]. Pigs were challenged with LPS (10 µg/kg) and treated with ISIS9481 (10 mg/kg) (n = 6). Two control groups were used, an antisense inactive in porcine aortic endothelial cells (n = 6) and saline (n = 5), and were combined as control (C = 11). Control pigs challenged with LPS expressed E-selectin in heart, lung, kidneys, and liver, whereas antisense-treated pigs expressed little E-selectin in these tissues. Cardiovascular data indicated that antisense treatment attenuated pathophysiological alterations induced by LPS. Specifically, in control pigs, LPS reduced cardiac output 32% from baseline, increased pulmonary (+116%) and systemic vascular resistances (+16%), and generated neutropenia (from 51,000 at basal to 18,000 polymorphonuclear neutrophils (PMN)/µL after LPS). In antisense-treated pigs, cardiac output decreased only 18%, pulmonary vascular resistance remained unchanged, whereas systemic vascular resistance decreased compared with basal values (-37%). PMN counts remained at 45,000-54,000/µL at 3-4 hours after LPS. These data demonstrate that antisense oligodeoxynucleotides, designed and tested in vitro to interact with 1 gene product, can be developed as either therapeutics or experimental tools in vivo.

Animal models of sepsis.

In this review, we start with a general discussion of relevant factors that can determine the validity of a sepsis animal model. We briefly review some of the currently used animal models of sepsis (small animal models and large animal models). We discuss the clinical relevance of animal models in sepsis research today and address potential reasons for the apparent underperformance of animal models in predicting therapeutic success of novel drugs in clinical trials.

Protective effect of a novel, potent inhibitor of poly(adenosine 5'-diphosphate-ribose) synthetase in a porcine model of severe bacterial sepsis.

OBJECTIVE: To determine whether activation of the nuclear enzyme poly(adenosine 5'-diphosphate [ADP]-ribose) synthetase (PARS) contributes to mortality rate, myocardial dysfunction, and cardiovascular collapse in a porcine model of sepsis induced by implantation of an infected clot. DESIGN: Prospective, random animal study. SETTING: Research laboratory at Rush Presbyterian St. Luke's Medical Center. SUBJECTS: Twenty pigs were chronically instrumented with intracardiac transducers to measure left ventricular pressure, sonomicrometer crystals in the left ventricle to measure short axis diameter, an ultrasonic flow meter to measure cardiac output, and catheters in the pulmonary artery and aorta to measure blood pressures and collect samples. INTERVENTIONS: By using a randomized study design, we administered either the novel potent PARS inhibitor PJ34 (10 mg/kg for 1 hr, 2 mg x kg(-1) x hr(-1) for 96 hrs) or vehicle to pigs immediately before intraperitoneal implantation of Escherichia coli 0111.B4 (2.3 +/- 0.1 x 10(10) colony-forming units/kg)-laden fibrin clots to produce peritonitis and bacteremia. MEASUREMENTS AND MAIN RESULTS: In vehicle-treated pigs, 12% survival was recorded at 24 hrs, whereas 83% and 66% survival was recorded in the PJ34-treated animals at 24 and 96 hrs, respectively (p <.05). PJ34 treatment attenuated bacteremia-induced increases in systemic and pulmonary vascular resistances. In controls, peritonitis induced rapid increase in plasma tumor necrosis factor-alpha. PJ34 treatment significantly attenuated this cytokine response. The formation of peroxynitrite and the activation of PARS were confirmed in hearts and lungs of the septic pigs by the immunohistochemical detection of nitrotyrosine and poly(ADP-ribose), respectively. Inhibition of PARS with PJ34 abolished poly(ADP-ribose) formation in septic animals. CONCLUSIONS: Treatment with a potent PARS inhibitor improved survival and cardiovascular status and attenuated an important mediator component of the inflammatory response in a lethal porcine model of sepsis.

Protein-free phospholipid emulsion treatment improved cardiopulmonary function and survival in porcine sepsis.

Lipoprotein phospholipid (PL) plays a major role in neutralization of endotoxin. This study tested the hypothesis that prophylactic administration of a PL-enriched emulsion (PRE), which augments PL content of serum lipoproteins and neutralizes endotoxin in vitro, would preserve cardiovascular function and improve survival in porcine septic peritonitis. A control group was compared with low-, mid-, and high-dose treatment groups that received PRE by primed continuous infusion for 48 h. A fibrin clot containing live Escherichia coli 0111.B4 was implanted intraperitoneally 30 min after the priming dose. Survival increased in a dose-dependent manner and was correlated with serum PL. Infused PL was associated with high-density lipoprotein in the low-dose group and all serum lipoproteins at higher doses. Treatment significantly lowered serum endotoxin and tumor necrosis factor (TNF)-alpha, preserved cardiac output and ejection fraction, and attenuated increases in systemic and pulmonary vascular resistances. This study demonstrated that augmentation of lipoprotein PL via administration of PRE improved survival and offered a novel therapeutic approach to sepsis.