mitoquinone and Acute-Disease

To investigate the effects of autophagy on exocrine function of pancreas in rats with acute sepsis, and to determine whether the mitochondrial coenzyme Q (Mito Q) can prevent exocrine dysfunction of pancreas mediated by autophagy.. Experiment I: 30 Sprague-Dawley (SD) rats were randomly divided into three groups, with 10 rats in each group. All the rats were given lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally, and Wortmannin (2 mg/kg), the specific inhibitor of autophagy (LPS + Wortmannin group), Mito Q (6.5 μmol/kg, LPS + Mito Q group), or the same volume of normal saline (LPS group) was respectively injected via the tail vein 1 hour later. Survival rate was assessed within 12 hours after LPS injection. Experiment II: another 100 male SD rats were randomly divided into ten groups with 10 rats in each group: namely control 4, 6 and 12 hours groups, LPS 4, 6 and 12 hours groups, and LPS + Wortmannin 4 hours group, Wortmannin 4 hours group, LPS + Mito Q 6 hours group, and Mito Q 6 hours group. The protocols of model reproduction and drug administration were the same as in the experiment I. Blood samples were collected at each time point, and the amylase content was determined with the velocity method. The levels of reactive oxygen species (ROS) in the pancreases were measured with enzyme-linked immunosorbent assay (ELISA). The expression of the autophagy-related protein LC3 was determined with Western Blot. The pathological changes in the pancreas were observed with microscopy.. (1) The survival time in the LPS + Wortmannin group was significantly shorter than that in the LPS group (hours: 7.50±0.64 vs. 11.90±0.13, χ (2) = 19.847, P = 0.001). There was no significant difference in the survival time between LPS + Mito Q and LPS groups (hours: 11.60±0.24 vs. 11.90±0.13, χ (2) = 1.055, P = 0.137). (2) The serum amylase in the LPS 6 hours, LPS + Wortmannin 4 hours, and LPS + Mito Q 6 hours groups were significantly higher than those in the control group at the same time points (U/L: 2 881.00±550.12 vs. 2 099.20±249.57, 3 672.00±779.24 vs. 2 081.36±245.18, 2 975.20±687.03 vs. 2 099.20±249.57, all P < 0.05), and were significantly lowered in LPS 12 hours group (U/L: 794.00±218.71 vs. 2 086.80±261.75, P < 0.01). The pancreatic ROS in the LPS 6 hours and 12 hours groups, LPS + Wortmannin 4 hours group, and LPS + Mito Q 6 hours group were significantly higher than those of the control group at the same time points (kU/L: 3.18±1.06 vs. 1.78±0.37, 3.63±1.08 vs. 1.85±0.41, 3.14±0.98 vs. 1.65±0.34, 3.17±1.03 vs. 1.78±0.37, all P < 0.05). The serum amylase and pancreatic ROS in LPS + Wortmannin 4 hours group were significantly higher than those of the LPS group at the same time points (U/L: 3 672.00±779.24 vs. 2 432.20±442.85, kU/L: 3.14±0.98 vs. 1.87±0.42, both P < 0.05), but there were no differences in above two parameters between LPS + Mito Q 6 hours group and LPS group (U/L: 2 975.20±687.03 vs. 2 881.00±550.12, kU/L: 3.17±1.03 vs. 3.18±1.06, both P > 0.05). Light microscopy showed that obvious pathological changes were found in the pancreas in the LPS 6 hours and 12 hours groups, LPS + Wortmannin 4 hours group, and LPS + Mito Q 6 hours group. Electron microscopy showed that the number of autophagic vacuoles increased 6 hours after LPS administration. There was no difference at any time point in the number of autophagic vacuoles between LPS + Mito Q 6 hours group and LPS 6 hours group, and the autophagic vacuoles were not found after Wortmannin intervention. It was demonstrated by Western Blot that the levels of LC3 protein in the LPS 6 hours and 12 hours groups, and LPS + Mito Q 6 hours group were significantly higher than those of the control group at the same time points (A value: 0.34±0.02 vs. 0.17±0.02, 0.37±0.03 vs. 0.18±0.04, 0.36±0.02 vs. 0.17±0.02, all P < 0.05), but there were no differences between LPS 12 hours group or LPS + Mito Q 6 hours group and LPS 6 hours group (both P > 0.05).. Autophagy prevents exocrine dysfunction of pancreas in septic rats, and the autophagic capacity or autophagosome-formation rate may determine the development of exocrine pancreatic dysfunction. The mitochondria-targeted antioxidant Mito Q does not prevent exocrine dysfunction of pancreas.

Topics: Acute Disease; Androstadienes; Animals; Autophagy; Lipopolysaccharides; Male; Mitochondria; Organophosphorus Compounds; Pancreas, Exocrine; Rats; Rats, Sprague-Dawley; Sepsis; Ubiquinone; Wortmannin

Although oxidative stress has been strongly implicated in the development of acute pancreatitis (AP), antioxidant therapy in patients has so far been discouraging. The aim of this study was to assess potential protective effects of a mitochondria-targeted antioxidant, MitoQ, in experimental AP using in vitro and in vivo approaches. MitoQ blocked H2O2-induced intracellular ROS responses in murine pancreatic acinar cells, an action not shared by the control analogue dTPP. MitoQ did not reduce mitochondrial depolarisation induced by either cholecystokinin (CCK) or bile acid TLCS, and at 10 µM caused depolarisation per se. Both MitoQ and dTPP increased basal and CCK-induced cell death in a plate-reader assay. In a TLCS-induced AP model MitoQ treatment was not protective. In AP induced by caerulein hyperstimulation (CER-AP), MitoQ exerted mixed effects. Thus, partial amelioration of histopathology scores was observed, actions shared by dTPP, but without reduction of the biochemical markers pancreatic trypsin or serum amylase. Interestingly, lung myeloperoxidase and interleukin-6 were concurrently increased by MitoQ in CER-AP. MitoQ caused biphasic effects on ROS production in isolated polymorphonuclear leukocytes, inhibiting an acute increase but elevating later levels. Our results suggest that MitoQ would be inappropriate for AP therapy, consistent with prior antioxidant evaluations in this disease.

Topics: Acinar Cells; Acute Disease; Animals; Antioxidants; Apoptosis; Ceruletide; Cholecystokinin; Disease Models, Animal; Inflammation; Male; Membrane Potential, Mitochondrial; Mice; Mitochondria; Necrosis; Organophosphorus Compounds; Oxidative Stress; Pancreas; Pancreatitis; Reactive Oxygen Species; Taurolithocholic Acid; Ubiquinone

Sepsis-induced organ failure is the major cause of death in critical care units, and is characterized by a massive dysregulated inflammatory response and oxidative stress. We investigated the effects of treatment with antioxidants that protect mitochondria (MitoQ, MitoE, or melatonin) in a rat model of lipopolysaccharide (LPS) plus peptidoglycan (PepG)-induced acute sepsis, characterized by inflammation, mitochondrial dysfunction and early organ damage.. Anaesthetized and ventilated rats received an i.v. bolus of LPS and PepG followed by an i.v. infusion of MitoQ, MitoE, melatonin, or saline for 5 h. Organs and blood were then removed for determination of mitochondrial and organ function, oxidative stress, and key cytokines.. MitoQ, MitoE, or melatonin had broadly similar protective effects with improved mitochondrial respiration (P<0.002), reduced oxidative stress (P<0.02), and decreased interleukin-6 levels (P=0.0001). Compared with control rats, antioxidant-treated rats had lower levels of biochemical markers of organ dysfunction, including plasma alanine amino-transferase activity (P=0.02) and creatinine concentrations (P<0.0001).. Antioxidants that act preferentially in mitochondria reduce mitochondrial damage and organ dysfunction and decrease inflammatory responses in a rat model of acute sepsis.

Topics: Acute Disease; Animals; Antioxidants; Biomarkers; Cytokines; Escherichia coli; Interleukin-6; Kidney Function Tests; Lipopolysaccharides; Liver Function Tests; Male; Melatonin; Mitochondria; Multiple Organ Failure; Organophosphorus Compounds; Oxidative Stress; Oxygen Consumption; Rats; Rats, Sprague-Dawley; Sepsis; Staphylococcus aureus; Ubiquinone