Life Sciences Commons^™

Nfatc2 Modulates Microglial Activation In The Aβpp/Ps1 Mouse Model Of Alzheimer's Disease, Gunjan D. Manocha, Atreyi Ghatak, Kendra L. Puig, Susan D. Kraner, Christopher M. Norris, Colin K. Combs

Pharmacology and Nutritional Sciences Faculty Publications

Alzheimer’s disease (AD) brains are characterized by fibrillar amyloid-β (Aβ) peptide containing plaques and associated reactive microglia. The proinflammatory phenotype of the microglia suggests that they may negatively affect disease course and contribute to behavioral decline. This hypothesis predicts that attenuating microglial activation may provide benefit against disease. Prior work from our laboratory and others has characterized a role for the transcription factor, nuclear factor of activated T cells (NFAT), in regulating microglial phenotype in response to different stimuli, including Aβ peptide. We observed that the NFATc2 isoform was the most highly expressed in murine microglia cultures, and inhibition or …

Neuroinflammation And Neurologic Deficits In Diabetes Linked To Brain Accumulation Of Amylin, Sarah Srodulski, Savita Sharma, Adam B. Bachstetter, Jennifer M. Brelsfoard, Conrado Pascual, Xinmin Simon Xie, Kathryn E. Saatman, Linda J. Van Eldik, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: We recently found that brain tissue from patients with type-2 diabetes (T2D) and cognitive impairment contains deposits of amylin, an amyloidogenic hormone synthesized and co-secreted with insulin by pancreatic β-cells. Amylin deposition is promoted by chronic hypersecretion of amylin (hyperamylinemia), which is common in humans with obesity or pre-diabetic insulin resistance. Human amylin oligomerizes quickly when oversecreted, which is toxic, induces inflammation in pancreatic islets and contributes to the development of T2D. Here, we tested the hypothesis that accumulation of oligomerized amylin affects brain function.

METHODS: In contrast to amylin from humans, rodent amylin is neither amyloidogenic nor cytotoxic. …

Cardioprotection By Controlling Hyperamylinemia In A "Humanized" Diabetic Rat Model, Sanda Despa, Savita Sharma, Todd R. Harris, Hua Dong, Ning Li, Nipavan Chiamvimonvat, Heinrich Taegtmeyer, Kenneth B. Margulies, Bruce D. Hammock, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Chronic hypersecretion of the pancreatic hormone amylin is common in humans with obesity or prediabetic insulin resistance and induces amylin aggregation and proteotoxicity in the pancreas. We recently showed that hyperamylinemia also affects the cardiovascular system. Here, we investigated whether amylin aggregates interact directly with cardiac myocytes and whether controlling hyperamylinemia protects the heart.

METHODS AND RESULTS: By Western blot, we found abundant amylin aggregates in lysates of cardiac myocytes from obese patients, but not in controls. Aggregated amylin was elevated in failing hearts, suggesting a role in myocyte injury. Using rats overexpressing human amylin in the pancreas (HIP …

Reversal Of Glial And Neurovascular Markers Of Unhealthy Brain Aging By Exercise In Middle-Aged Female Mice, Caitlin S. Latimer, James L. Searcy, Michael T. Bridges, Lawrence D. Brewer, Jelena Popović, Eric M. Blalock, Philip W. Landfield, Olivier Thibault, Nada M. Porter

Pharmacology and Nutritional Sciences Faculty Publications

Healthy brain aging and cognitive function are promoted by exercise. The benefits of exercise are attributed to several mechanisms, many which highlight its neuroprotective role via actions that enhance neurogenesis, neuronal morphology and/or neurotrophin release. However, the brain is also composed of glial and vascular elements, and comparatively less is known regarding the effects of exercise on these components in the aging brain. Here, we show that aerobic exercise at mid-age decreased markers of unhealthy brain aging including astrocyte hypertrophy, a hallmark of brain aging. Middle-aged female mice were assigned to a sedentary group or provided a running wheel for …

Deep Sleep And Parietal Cortex Gene Expression Changes Are Related To Cognitive Deficits With Age, Heather M. Buechel, Jelena Popovic, James L. Searcy, Nada M. Porter, Olivier Thibault, Eric M. Blalock

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Age-related cognitive deficits negatively affect quality of life and can presage serious neurodegenerative disorders. Despite sleep disruption's well-recognized negative influence on cognition, and its prevalence with age, surprisingly few studies have tested sleep's relationship to cognitive aging.

METHODOLOGY: We measured sleep stages in young adult and aged F344 rats during inactive (enhanced sleep) and active (enhanced wake) periods. Animals were behaviorally characterized on the Morris water maze and gene expression profiles of their parietal cortices were taken.

PRINCIPAL FINDINGS: Water maze performance was impaired, and inactive period deep sleep was decreased with age. However, increased deep sleep during the …