Search

Oxidative stress, inflammation, and aberrant activation of microglia in the retina are commonly observed in ocular pathologies. In glaucoma or age-related macular degeneration, the chronic activation of microglia affects retinal ganglion cells and photoreceptors, respectively, contributing to gradual vision loss. However, the molecular mechanisms that cause activation of microglia in the retina are not fully understood. Here we show that exposure of retinal pigment epithelial (RPE) cells to chronic low-level oxidative stress induces mitochondrial DNA (mtDNA)-specific damage, and the subsequent translocation of damaged mtDNA to the cytoplasm results in the binding and activation of intracellular DNA receptor Z-DNA-binding protein 1 (ZBP1). Activation of the mtDNA/ZBP1 pathway triggers the expression of proinflammatory markers in RPE cells. In addition, we show that the enhanced release of extracellular vesicles (EVs) containing fragments of mtDNA derived from the apical site of RPE cells induces a proinflammatory phenotype of microglia via activation of ZBP1 signaling. Collectively, our report establishes oxidatively damaged mtDNA as an important signaling molecule with ZBP1 as its intracellular receptor in the development of an inflammatory response in the retina. We propose that this novel mtDNA-mediated autocrine and paracrine mechanism for triggering and maintaining inflammation in the retina may play an important role in ocular pathologies. Therefore, the molecular mechanisms identified in this report are potentially suitable therapeutic targets to ameliorate development of ocular pathologies. [ABSTRACT FROM AUTHOR]

Abstract: Study Objective: To evaluate the survival of patients with advanced liver disease to determine if known exposure to general anesthesia within a 5-year period has a measurable effect on mortality. Design: Retrospective survival analysis of male veterans with advanced liver disease. Setting: Tertiary referral VA Medical Center and university-affiliated teaching hospital. Measurements: One hundred twenty-seven patients with a history of alcoholic cirrhosis and documented hepatitis C infection and stable platelet counts were identified and then divided into 3 groups. The 5-year survival rates in all 3 groups were compared using Kaplan-Meier survival curves. Main Results: Ninety patients had marked thrombocytopenia (<100000/mm3). Their survival rates with and without known exposure to general anesthesia were compared with those of control subjects with alcoholic cirrhosis and hepatitis C infection but with platelet counts greater than 100000/mm3. The 5-year survival rate of 57% in the group that received general anesthesia was comparable to the 58% rate observed in the group without this exposure. Both groups'' rates were statistically lower than the 5-year survival rate of 77% in the group with advanced liver disease but without thrombocytopenia. Conclusion: Comparably high mortality rates were observed in patients with advanced liver disease with or without exposure to general anesthesia. Higher survival rates were noted in patients with advanced liver disease who were not thrombocytopenic. [Copyright &y& Elsevier]