Autophagy and mitochondrial alterations in human retinal pigment epithelial cells induced by ethanol: implications of 4-hydroxy-nonenal.

Retinal pigment epithelium has a crucial role in the physiology and pathophysiology of the retina due to its location and metabolism. Oxidative damage has been demonstrated as a pathogenic mechanism in several retinal diseases, and reactive oxygen species are certainly important by-products of ethanol (EtOH) metabolism. Autophagy has been shown to exert a protective effect in different cellular and animal models. Thus, in our model, EtOH treatment increases autophagy flux, in a concentration-dependent manner. Mitochondrial morphology seems to be clearly altered under EtOH exposure, leading to an apparent increase in mitochondrial fission. An increase in 2',7'-dichlorofluorescein fluorescence and accumulation of lipid peroxidation products, such as 4-hydroxy-nonenal (4-HNE), among others were confirmed. The characterization of these structures confirmed their nature as aggresomes. Hence, autophagy seems to have a cytoprotective role in ARPE-19 cells under EtOH damage, by degrading fragmented mitochondria and 4-HNE aggresomes. Herein, we describe the central implication of autophagy in human retinal pigment epithelial cells upon oxidative stress induced by EtOH, with possible implications for other conditions and diseases.

Neuroprotection of lipoic acid treatment promotes angiogenesis and reduces the glial scar formation after brain injury.

After trauma brain injury, a large number of cells die, releasing neurotoxic chemicals into the extracellular medium, decreasing cellular glutathione levels and increasing reactive oxygen species that affect cell survival and provoke an enlargement of the initial lesion. Alpha-lipoic acid is a potent antioxidant commonly used as a treatment of many degenerative diseases such as multiple sclerosis or diabetic neuropathy. Herein, the antioxidant effects of lipoic acid treatment after brain cryo-injury in rat have been studied, as well as cell survival, proliferation in the injured area, gliogenesis and angiogenesis. Thus, it is shown that newborn cells, mostly corresponded with blood vessels and glial cells, colonized the damaged area 15 days after the lesion. However, lipoic acid was able to stimulate the synthesis of glutathione, decrease cell death, promote angiogenesis and decrease the glial scar formation. All those facts allow the formation of new neural tissue. In view of the results herein, lipoic acid might be a plausible pharmacological treatment after brain injury, acting as a neuroprotective agent of the neural tissue, promoting angiogenesis and reducing the glial scar formation. These findings open new possibilities for restorative strategies after brain injury, stroke or related disorders.

Brain mitochondrial alterations after chronic alcohol consumption

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The aim of this study was to demonstrate the existence of alterations in glutathione and cholesterol homeostasis in brain mitochondria from alcoholic rats. Glutathione concentration decreased, whereas oxidized glutathione and cholesterol contents increased in these organelles, suggesting the ethanol-induced generation of reactive oxygen species, and the impairment of mitochondrial uptake of glutathione, possibly due to the increase in cholesterol deposition. The release of apoptogenic proteins was increased after stimulating mitochondria from the brain of alcoholic rats with atractyloside. As a conclusion, chronic alcohol consumption might sensitize brain mitochondria to apoptotic stimuli, and promote the subsequent release of apoptotic proteins (AU)

Brain mitochondrial alterations after chronic alcohol consumption.

The aim of this study was to demonstrate the existence of alterations in glutathione and cholesterol homeostasis in brain mitochondria from alcoholic rats. Glutathione concentration decreased, whereas oxidized glutathione and cholesterol contents increased in these organelles, suggesting the ethanol-induced generation of reactive oxygen species, and the impairment of mitochondrial uptake of glutathione, possibly due to the increase in cholesterol deposition. The release of apoptogenic proteins was increased after stimulating mitochondria from the brain of alcoholic rats with atractyloside. As a conclusion, chronic alcohol consumption might sensitize brain mitochondria to apoptotic stimuli, and promote the subsequent release of apoptotic proteins.

Persistence of müllerian derivatives, lymphangiectasis, hepatic failure, postaxial polydactyly, renal and craniofacial anomalies.

We describe 3 unrelated newborn males with a previously unreported constellation of congenital anomalies. All 3 died neonatally of hepatic failure. Clinically, they presented with a pattern of malformations characterized by prenatal linear growth deficiency, hypertrophied alveolar ridges, redundant nuchal skin, and postaxial polydactyly. All 3 cases had male external genitalia with cryptorchidism, and 2 of them, a small penis. Necropsies showed similar internal anomalies, consisting of müllerian duct remnants, lymphangiectasis, and renal anomalies. The karyotypes were normal (46, XY) in skin fibroblasts (Case 1) and in peripheral blood lymphocytes (Case 3). Although this pattern of congenital anomalies must be differentiated from several other lethal syndromes, to our knowledge, no similar cases have been described previously. Cause of this syndrome is unknown. Because Case 2 had a previous brother with similar anomalies, we suspect that this new entity probably is an autosomal recessive or X-linked trait.