ucf-101 and Sepsis

the pathogenesis of sepsis-associated encephalopathy (SAE) is multifactorial, involving neurotransmitter alterations, inflammatory cytokines, oxidative damage, mitochondrial dysfunction, apoptosis, and other factors. Mitochondria are major producers of reactive oxygen species, resulting in cellular injury. Omi/HtrA2 is a proapoptotic mitochondrial serine protease involved in caspase-dependent cell death; it is translocated from mitochondria to the cytosol after an apoptotic insult. We previously found that UCF-101, a specific inhibitor of Omi/HtrA2, has neuroprotective effects on cerebral oxidative injury and cognitive impairment in septic rats. In this study, the mechanisms and molecular pathways underlying these effects were investigated.. Male Sprague-Dawley rats were subjected to cecal ligation and puncture (CLP) or sham-operated laparotomy and were administered vehicle or UCF-101 (10 µmol/kg). The hippocampus was isolated for subsequent analysis. Omi/HtrA2 expression in the mitochondria or cytosol was evaluated by immunofluorescence or western blotting. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining was utilized to evaluate levels of apoptosis, and western blotting was used to evaluate apoptosis-related proteins, such as cleaved caspase-3, caspase-9, and poly (ADP-ribose) polymerase (PARP). Tight junction expression was assessed by immunofluorescence and western blotting. Mitochondrial function, inflammatory cytokines, and oxidative stress were also assayed. In addition, a wet/dry method was used to evaluate brain edema and Evans blue extravasation was used to evaluate blood-brain barrier (BBB) integrity.. After CLP treatment, the hippocampus exhibited a mild increase in Omi/HtrA2 expression; cytosolic Omi/HtrA2 expression increased significantly, whereas mitochondrial Omi/HtrA2 expression was reduced, indicating that CLP-induced oxidative stress resulted in the translocation of Omi/HtrA2 from mitochondria to the cytosol. Hippocampal cleaved caspase-3, caspase-9, and PARP levels were significantly higher in animals treated with CLP than in sham-operated animals, while XIAP expression was lower. Treatment with UCF-101 prevented the mobilization of Omi/HtrA2 from mitochondria to the cytosol, attenuated XIAP degradation, and decreased cleaved caspase-3, caspase-9, and PARP expression as well as apoptosis. UCF-101 also reversed the decreased mitochondrial complex I, II, and III respiration and the reduced ATP caused by CLP. In addition, UCF-101 treatment resulted in a significant improvement in BBB integrity, as demonstrated by increased occludin, claudin-5, and zonula occludens 1 levels and reduced Evans blue extravasation. No significant effects of UCF-101 on brain edema were found. Inflammatory cytokines and oxidative stress were significantly higher in the CLP-treated group than in the sham-operated group. However, the inhibition of Omi/HtrA2 by UCF-101 significantly alleviated these responses.. Our data indicated that Omi/ HtrA2 regulates a mitochondria-dependent apoptotic pathway in a murine model of septic encephalopathy. Inhibition of Omi/HtrA2 by UCF-101 leads to neuroprotection by inhibiting the cytosolic translocation of Omi/HtrA2 and antagonizing the caspase-dependent apoptosis pathway. Therapeutic interventions that inhibit Omi/HtrA2 translocation or protease activity may provide a novel method to treat SAE.

Topics: Animals; Apoptosis; Caspase 3; Cytosol; Disease Models, Animal; Dynamins; Electron Transport Chain Complex Proteins; GTP Phosphohydrolases; High-Temperature Requirement A Serine Peptidase 2; Hippocampus; Male; Malondialdehyde; Membrane Proteins; Mitochondria; Mitochondrial Proteins; Occludin; Poly(ADP-ribose) Polymerases; Pyrimidinones; Rats; Rats, Sprague-Dawley; Sepsis; Thiones; X-Linked Inhibitor of Apoptosis Protein

Omi/HtrA2 is a proapoptotic mitochondrial serine protease involved in caspase-dependent and caspase-independent cell apoptosis. It has been verified that Omi/HtrA2 is related to apoptosis due to oxidative stress, which may play an important role in the integrity of mitochondria. Ucf-101 is a specific inhibitor of Omi/HtrA2 and it has been demonstrated that Ucf-101 has organ protective effects in a variety of in vitro and in vivo studies. The aim of our study was to examine the neuroprotective effects of Ucf-101 on cerebral oxidative injury and cognitive impairment in septic rats.. Male Sprague Dawley rats are subjected to cecal ligation and puncture (CLP) or sham-operated laparotomy. Rats were divided into 4 groups: (1) a sham group plus normal saline (10 mL/kg); (2) a sham group plus Ucf-101 (10 umol/kg); (3) CLP plus normal saline (10 mL/kg); and (4) CLP plus Ucf-101 (10 umol/kg). Brain tumor necrosis factor (TNF)-α level, caspase-3 and caspase-9 activities, malondialdehyde (MDA) content and catalase (CAT) activities were examined. TUNEL staining was utilized to evaluate the amount of apoptosis and the cognitive function was evaluated by the MWM test. The study also assessed the clinical scores of animals and the survival time for the 7-day period.. CLP resulted in a poor survival rate, evidence of hippocampal oxidative injury, cell apoptosis and cognitive dysfunction as well as elevated TNF-α level and caspases activities, increased weight loss and clinical scores. Ucf-101 pre-treatment could significantly inhibit caspases activities and cell apoptosis, reduce TNF-α and MDA levels, slightly reverse CAT activities in the brain and attenuate this CLP effect on cognitive dysfunction. In addition, the survival rate and survival time was significantly improved by pre-treatment with Ucf-101.. The present results demonstrated that ucf-101 has the neuroprotective effects on cerebral oxidative injury and cognitive impairment in septic rats.

Topics: Animals; Apoptosis; Brain Diseases; Caspase 3; Caspase 9; Cognition Disorders; Lipid Peroxidation; Male; Malondialdehyde; Neuroprotective Agents; Oxidative Stress; Pyrimidinones; Rats; Rats, Sprague-Dawley; Sepsis; Thiones; Tumor Necrosis Factor-alpha