http://homepages.gac.edu/~jwotton2/PSY385/Neuroplasticity.pdf

Stress, Depression, and Neuroplasticity: A Convergence of Mechanisms

Hypertension 66 (20.3%) 24 (24.2%) 30 (16.3%) NS Diabetes 20 (6.2%) 7 (7.1%) 10 (5.4%) NS Excess weight 78 (24%) 27 (27.3%) 44 (23.9%) NS Smokers 64 (19.7%) 17 (17.2%) 35 (19.0%) NS Age >50 years 137 (42.2%) 54 (54.5%) 67 (36.4%) <0.02 Kidney disease 7 (2.2%) 1 (1%) 5 (2.7%) NS Family history, DM 102 (31.4%) 28 (28.3%) 66 (35.9%) NS

Conflict of interest statement. None declared.

Mounting evidence suggests that acute and chronic stress, especially the stress-induced release of glucocorticoids, induces changes in glutamate neurotransmission in the prefrontal cortex and the hippocampus, thereby influencing some aspects of cognitive processing. In addition, dysfunction of glutamatergic neurotransmission is increasingly considered to be a core feature of stress-related mental illnesses. Recent studies have shed light on the mechanisms by which stress and glucocorticoids affect glutamate transmission, including effects on glutamate release, glutamate receptors and glutamate clearance and metabolism. This new understanding provides insights into normal brain functioning, as well as the pathophysiology and potential new treatments of stress-related neuropsychiatric disorders.

/pdf/the-stressed-synapse-the-impact-of-stress-and-28jxfa3vve.pdf

The stressed synapse: the impact of stress and glucocorticoids on glutamate transmission

Towards a glutamate hypothesis of depression: an emerging frontier of neuropsychopharmacology for mood disorders.

Major reactive oxygen species (ROS)-producing systems in vascular wall include NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase, xanthine oxidase, the mitochondrial electron transport chain, and uncoupled endothelial nitric oxide (NO) synthase. ROS at moderate concentrations have important signaling roles under physiological conditions. Excessive or sustained ROS production, however, when exceeding the available antioxidant defense systems, leads to oxidative stress. Animal studies have provided compelling evidence demonstrating the roles of vascular oxidative stress and NO in atherosclerosis. All established cardiovascular risk factors such as hypercholesterolemia, hypertension, diabetes mellitus, and smoking enhance ROS generation and decrease endothelial NO production. Key molecular events in atherogenesis such as oxidative modification of lipoproteins and phospholipids, endothelial cell activation, and macrophage infiltration/activation are facilitated by vascular oxidative stress and inhibited by endothelial NO. Atherosclerosis develops preferentially in vascular regions with disturbed blood flow (arches, branches, and bifurcations). The fact that these sites are associated with enhanced oxidative stress and reduced endothelial NO production is a further indication for the roles of ROS and NO in atherosclerosis. Therefore, prevention of vascular oxidative stress and improvement of endothelial NO production represent reasonable therapeutic strategies in addition to the treatment of established risk factors (hypercholesterolemia, hypertension, and diabetes mellitus).

Roles of Vascular Oxidative Stress and Nitric Oxide in the Pathogenesis of Atherosclerosis

http://www.jbc.org/content/280/41/34924.full.pdf

Differential Promotion of Glutamate Transporter Expression and Function by Glucocorticoids in Astrocytes from Various Brain Regions

http://www.jbc.org/content/285/32/24398.full.pdf

One enzyme, two functions: PON2 prevents mitochondrial superoxide formation and apoptosis independent from its lactonase activity

Recent studies provide evidence that wild-type Cu/Zn-superoxide dismutase (SOD1(hWT)) might be an important factor in mutant SOD1-mediated amyotrophic lateral sclerosis (ALS). In order to investigate its functional role in the pathogenesis of ALS, we designed fusion proteins of two SOD1 monomers linked by a polypeptide. We demonstrated that wild-type-like mutants, but not SOD1(G85R) homodimers, as well as mutant heterodimers including SOD1(G85R)-SOD1(hWT) display dismutase activity. Mutant homodimers showed an increased aggregation compared with the corresponding heterodimers in cell cultures and transgenic Caenorhabditis elegans, although SOD1(G85R) heterodimers are more toxic in functional assays. Our data show that (i) toxicity of mutant SOD1 is not correlated to its aggregation potential; (ii) dismutase-inactive mutants form dismutase-active heterodimers with SOD1(hWT); (iii) SOD1(hWT) can be converted to contribute to disease by forming active heterodimers. Therefore, we conclude that toxicity of mutant SOD1 is at least partially mediated through heterodimer formation with SOD1(hWT) in vivo and does not correlate with the aggregation potential of individual mutants.

Heterodimer formation of wild-type and amyotrophic lateral sclerosis-causing mutant Cu/Zn-superoxide dismutase induces toxicity independent of protein aggregation

Wild-type Cu/Zn superoxide dismutase (SOD1) does not facilitate, but impedes the formation of protein aggregates of amyotrophic lateral sclerosis causing mutant SOD1.

Heidrun Witan

Papers

Differential Promotion of Glutamate Transporter Expression and Function by Glucocorticoids in Astrocytes from Various Brain Regions

One enzyme, two functions: PON2 prevents mitochondrial superoxide formation and apoptosis independent from its lactonase activity

Heterodimer formation of wild-type and amyotrophic lateral sclerosis-causing mutant Cu/Zn-superoxide dismutase induces toxicity independent of protein aggregation

Wild-type Cu/Zn superoxide dismutase (SOD1) does not facilitate, but impedes the formation of protein aggregates of amyotrophic lateral sclerosis causing mutant SOD1.