Medicine and Health Sciences Commons^™

Manufactured Aluminum Oxide Nanoparticles Decrease Expression Of Tight Junction Proteins In Brain Vasculature, Lei Chen, Robert A. Yokel, Bernhard Hennig, Michal Toborek

Pharmaceutical Sciences Faculty Publications

Manufactured nanoparticles of aluminum oxide (nano-alumina) have been widely used in the environment; however, their potential toxicity provides a growing concern for human health. The present study focuses on the hypothesis that nano-alumina can affect the blood-brain barrier and induce endothelial toxicity. In the first series of experiments, human brain microvascular endothelial cells (HBMEC) were exposed to alumina and control nanoparticles in dose- and time-responsive manners. Treatment with nano-alumina markedly reduced HBMEC viability, altered mitochondrial potential, increased cellular oxidation, and decreased tight junction protein expression as compared to control nanoparticles. Alterations of tight junction protein levels were prevented by cellular …

Aluminum Bioavailability From Tea Infusion, Robert A. Yokel, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

The objective was to estimate oral Al bioavailability from tea infusion in the rat, using the tracer ²⁶Al. ²⁶Al citrate was injected into tea leaves. An infusion was prepared from the dried leaves and given intra-gastrically to rats which received concurrent intravenous ²⁷Al infusion. Oral Al bioavailability (F) was calculated from the area under the ²⁶Al, compared to ²⁷Al, serum concentration × time curves. Bioavailability from tea averaged 0.37%; not significantly different from water (F = 0.3%), or basic sodium aluminum phosphate (SALP) in cheese (F = 0.1 to 0.3%), but greater than acidic SALP …

Focus On Rna Isolation: Obtaining Rna For Microrna (Mirna) Expression Profiling Analyses Of Neural Tissue, Wang-Xia Wang, Bernard R. Wilfred, Donald A. Baldwin, R. Benjamin Isett, Na Ren, Arnold J. Stromberg, Peter T. Nelson

Sanders-Brown Center on Aging Faculty Publications

MicroRNAs (miRNAs) are present in all known plant and animal tissues and appear to be somewhat concentrated in the mammalian nervous system. Many different miRNA expression profiling platforms have been described. However, relatively little research has been published to establish the importance of 'upstream' variables in RNA isolation for neural miRNA expression profiling. We tested whether apparent changes in miRNA expression profiles may be associated with tissue processing, RNA isolation techniques, or different cell types in the sample. RNA isolation was performed on a single brain sample using eight different RNA isolation methods, and results were correlated using a conventional …

Focal Cerebral Ischemia In The Tnfalpha-Transgenic Rat, L. Creed Pettigrew, Mark S. Kindy, Stephen W. Scheff, Joe E. Springer, Richard J. Kryscio, Yizhao Li, David S. Grass

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: To determine if chronic elevation of the inflammatory cytokine, tumor necrosis factor-alpha (TNFalpha), will affect infarct volume or cortical perfusion after focal cerebral ischemia.

METHODS: Transgenic (TNFalpha-Tg) rats overexpressing the murine TNFalpha gene in brain were prepared by injection of mouse DNA into rat oocytes. Brain levels of TNFalpha mRNA and protein were measured and compared between TNFalpha-Tg and non-transgenic (non-Tg) littermates. Mean infarct volume was calculated 24 hours or 7 days after one hour of reversible middle cerebral artery occlusion (MCAO). Cortical perfusion was monitored by laser-Doppler flowmetry (LDF) during MCAO. Cortical vascular density was quantified by stereology. …

Aluminum Bioavailability From Basic Sodium Aluminum Phosphate, An Approved Food Additive Emulsifying Agent, Incorporated In Cheese, Robert A. Yokel, Clair L. Hicks, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

Oral aluminum (Al) bioavailability from drinking water has been previously estimated, but there is little information on Al bioavailability from foods. It was suggested that oral Al bioavailability from drinking water is much greater than from foods. The objective was to further test this hypothesis. Oral Al bioavailability was determined in the rat from basic [26Al]-sodium aluminum phosphate (basic SALP) in a process cheese. Consumption of approximately 1g cheese containing 1.5% or 3% basic SALP resulted in oral Al bioavailability (F) of approximately 0.1% and 0.3%, respectively, and time to maximum serum 26Al concentration (Tmax) of 8-9h. These Al bioavailability …

Pioglitazone Inhibition Of Lipopolysaccharide-Induced Nitric Oxide Synthase Is Associated With Altered Activity Of P38 Map Kinase And Pi3k/Akt, Bin Xing, Tao Xin, Randy Lee Hunter, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Previous studies have suggested that peroxisome proliferator activated receptor-gamma (PPAR-gamma)-mediated neuroprotection involves inhibition of microglial activation and decreased expression and activity of inducible nitric oxide synthase (iNOS); however, the underlying molecular mechanisms have not yet been well established. In the present study we explored: (1) the effect of the PPAR-gamma agonist pioglitazone on lipopolysaccharide (LPS)-induced iNOS activity and nitric oxide (NO) generation by microglia; (2) the differential role of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun NH(2)-terminal kinase (JNK), and phosphoinositide 3-kinase (PI3K) on LPS-induced NO generation; and (3) the regulation of p38 MAPK, JNK, and PI3K by pioglitazone. …