mitoquinone and Necrosis

Sepsis is one of the main causes of death among critically ill patients. Sepsis pathogenesis includes infection by gram-negative and gram-positive bacteria, fungi, or both; exacerbated inflammatory response; hypotension, with potential to cause vasodilatory shock; and lesser delivery of oxygen to tissues due to impairment of oxygen utilization by cells. The participation of reactive species and/or free radicals such as nitric oxide (NO), peroxynitrite (ONOO

Topics: Adenosine Triphosphate; Animals; Antioxidants; Apoptosis; Humans; Melatonin; Mitochondria; Multiple Organ Failure; Necrosis; NF-kappa B; Organophosphorus Compounds; Oxidative Stress; Selenium; Sepsis; Ubiquinone; Vitamins

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