Proteasome Composition in Cytokine-Treated Neurons and Astrocytes is Determined Mainly by Subunit Displacement.

In this study, we investigated if subunit displacement and/or alterations in proteasome biosynthesis are responsible for the changes in the levels of constitutive proteasomes (c-20S), immunoproteasomes (i-20S) and the activators PA28 and PA700 in neurons and astrocytes cultured with a cytokine mixture (IFN-γ/TNF-α/IL-1β). Exposure of both cell types to cytokines for 24 h increases mRNA and protein expression of the i-20S-specific subunit β5i and PA28α/β, and leads to a decline in the amount of the c-20S-specific subunit β5. Since β5 mRNA levels are unchanged by the cytokine treatment, it is fair to conclude that displacement of constitutive β-subunits with inducible β5i subunits is likely the mechanism underlying the decrease in c-20S.

Decreased levels of constitutive proteasomes in experimental autoimmune encephalomyelitis may be caused by a combination of subunit displacement and reduced Nfe2l1 expression.

The goal of this study was to determine if subunit displacement and/or alterations in proteasome biosynthesis could explain the changes observed in the levels of constitutive proteasomes (c-20S) and immunoproteasomes (i-20S) in the spinal cords of mice with experimental autoimmune encephalomyelitis (EAE). To this end, EAE was induced in C57BL/6 mice by immunization with MOG peptide. Spinal cords were collected at different times during the disease course and used for western blotting, RNA analysis, and immunohistochemistry.

Reduced expression of the ferroptosis inhibitor glutathione peroxidase-4 in multiple sclerosis and experimental autoimmune encephalomyelitis.

Glutathione peroxidase 4 (GPx4) is the only enzyme capable of reducing toxic lipid hydroperoxides in biological membranes to the corresponding alcohols using glutathione as the electron donor. GPx4 is the major inhibitor of ferroptosis, a non-apoptotic and iron-dependent programmed cell death pathway, which has been shown to occur in various neurological disorders with severe oxidative stress. In this study, we investigate whether GPx4 expression is altered in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE).

The Role of Calpain and Proteasomes in the Degradation of Carbonylated Neuronal Cytoskeletal Proteins in Acute Experimental Autoimmune Encephalomyelitis.

The present study was designed to investigate the role of calpain and the proteasome in the removal of oxidized neuronal cytoskeletal proteins in myelin basic protein-induced experimental autoimmune encephalomyelitis (EAE). To this end, EAE rats received a single intrathecal injection of calpeptin or epoxomicin at the first sign of clinical disease. Forty-eight hours later, animals were sacrificed and lumbar spinal cord segments were dissected and used for biochemical analyses.

Mechanism of Protein Carbonylation in Glutathione-Depleted Rat Brain Slices.

This study was conducted to further our understanding about the link between lipid peroxidation and protein carbonylation in rat brain slices incubated with the glutathione (GSH)-depletor diethyl maleate. Using this in vitro system of oxidative stress, we found that there is a significant lag between the appearance of carbonylated proteins and GSH depletion, which seems to be due to the removal of oxidized species early on in the incubation by the mitochondrial Lon protease. Upon acute GSH depletion, protein carbonyls accumulated mostly in mitochondria and to a lesser degree in other subcellular fractions that also contain high levels of polyunsaturated lipids.

Nrf2-dysregulation correlates with reduced synthesis and low glutathione levels in experimental autoimmune encephalomyelitis.

This study investigates the possible mechanism(s) underlying glutathione (GSH) deficiency in the mouse spinal cord during the course of myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of multiple sclerosis. Using the classical enzymatic recycling method and a newly developed immunodot assay, we first demonstrated that total GSH levels (i.e.

Type 5 adenylyl cyclase increases oxidative stress by transcriptional regulation of manganese superoxide dismutase via the SIRT1/FoxO3a pathway.

Background: For reasons that remain unclear, whether type 5 adenylyl cyclase (AC5), 1 of 2 major AC isoforms in heart, is protective or deleterious in response to cardiac stress is controversial. To reconcile this controversy we examined the cardiomyopathy induced by chronic isoproterenol in AC5 transgenic (Tg) mice and the signaling mechanisms involved.

Methods And Results: Chronic isoproterenol increased oxidative stress and induced more severe cardiomyopathy in AC5 Tg, as left ventricular ejection fraction fell 1.

Adenylyl cyclase type 5 protein expression during cardiac development and stress.

Adenylyl cyclase (AC) types 5 and 6 (AC5 and AC6) are the two major AC isoforms expressed in the mammalian heart that mediate signals from beta-adrenergic receptor stimulation. Because of the unavailability of isoform-specific antibodies, it is difficult to ascertain the expression levels of AC5 protein in the heart. Here we demonstrated the successful generation of an AC5 isoform-specific mouse monoclonal antibody and studied the expression of AC5 protein during cardiac development in different mammalian species.

Genetic analysis of attractin homologs.

Attractin (ATRN) and Attractin-like 1 (ATRNL1) are highly similar type I transmembrane proteins. Atrn null mutant mice have a pleiotropic phenotype including dark fur, juvenile-onset spongiform neurodegeneration, hypomyelination, tremor, and reduced body weight and adiposity, implicating ATRN in numerous biological processes. Bioinformatic analysis indicated that Atrn and Atrnl1 arose from a common ancestral gene early in vertebrate evolution.

Cell cycle progression and activation of Akt kinase are required for insulin-like growth factor I-mediated suppression of apoptosis in granulosa cells.

Ovarian follicle development is dependent on growth factors that stimulate cell proliferation and act as survival factors to prevent apoptosis of follicle cells. We examined the mechanism of the protective effect of IGF-I against Fas ligand-induced apoptosis of granulosa cells and its relationship to cell proliferation. IGF-I activated both the phosphoinositide 3'-OH kinase (PI3K) and the MAPK pathways.