Social and Behavioral Sciences Commons^™

Elevated Stearoyl-Coa Desaturase In Brains Of Patients With Alzheimer's Disease, Giuseppe Astarita, Kwang-Mook Jung, Vitaly Vasilevko, Nicholas V. Dipatrizio, Sarah K. Martin, David H. Cribbs, Elizabeth Head, Carl W. Cotman, Daniele Piomelli

Sanders-Brown Center on Aging Faculty Publications

The molecular bases of Alzheimer's disease (AD) remain unclear. We used a lipidomic approach to identify lipid abnormalities in the brains of subjects with AD (N = 37) compared to age-matched controls (N = 17). The analyses revealed statistically detectable elevations in levels of non-esterified monounsaturated fatty acids (MUFAs) and mead acid (20:3n-9) in mid-frontal cortex, temporal cortex and hippocampus of AD patients. Further studies showed that brain mRNAs encoding for isoforms of the rate-limiting enzyme in MUFAs biosynthesis, stearoyl-CoA desaturase (SCD-1, SCD-5a and SCD-5b), were elevated in subjects with AD. The monounsaturated/saturated fatty acid ratio ('desaturation index')--displayed a strong …

Epigenetic Silencing Of Nucleolar Rrna Genes In Alzheimer's Disease, Maciej Pietrzak, Grzegorz Rempala, Peter T. Nelson, Jing-Juan Zheng, Michal Hetman

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Ribosomal deficits are documented in mild cognitive impairment (MCI), which often represents an early stage Alzheimer's disease (AD), as well as in advanced AD. The nucleolar rRNA genes (rDNA), transcription of which is critical for ribosomal biogenesis, are regulated by epigenetic silencing including promoter CpG methylation.

METHODOLOGY/PRINCIPAL FINDINGS: To assess whether CpG methylation of the rDNA promoter was dysregulated across the AD spectrum, we analyzed brain samples from 10 MCI-, 23 AD-, and, 24 age-matched control individuals using bisulfite mapping. The rDNA promoter became hypermethylated in cerebro-cortical samples from MCI and AD groups. In parietal cortex, the rDNA promoter …

Microglial P38Α Mapk Is A Key Regulator Of Proinflammatory Cytokine Up-Regulation Induced By Toll-Like Receptor (Tlr) Ligands Or Beta-Amyloid (Aβ), Adam D. Bachstetter, Bin Xing, Lucia De Almeida, Edgardo R. Dimayuga, D. Martin Watterson, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Overproduction of proinflammatory cytokines from activated microglia has been implicated as an important contributor to pathophysiology progression in both acute and chronic neurodegenerative diseases. Therefore, it is critical to elucidate intracellular signaling pathways that are significant contributors to cytokine overproduction in microglia exposed to specific stressors, especially pathways amenable to drug interventions. The serine/threonine protein kinase p38α MAPK is a key enzyme in the parallel and convergent intracellular signaling pathways involved in stressor-induced production of IL-1β and TNFα in peripheral tissues, and is a drug development target for peripheral inflammatory diseases. However, much less is known about the quantitative …

Common And Distinct Mechanisms Of Cognitive Flexibility In Prefrontal Cortex, Chobok Kim, Nathan F. Johnson, Sara E. Cilles, Brian T. Gold

Neuroscience Faculty Publications

The human ability to flexibly alternate between tasks represents a central component of cognitive control. Neuroimaging studies have linked task switching with a diverse set of prefrontal cortex (PFC) regions, but the contributions of these regions to various forms of cognitive flexibility remain largely unknown. Here, subjects underwent functional brain imaging while they completed a paradigm that selectively induced stimulus, response, or cognitive set switches in the context of a single task decision performed on a common set of stimuli. Behavioral results indicated comparable reaction time costs associated with each switch type. Domain-general task-switching activation was observed in the inferior …