Medical Pharmacology Commons^™

Astrovascular Decoupling In Awake 5×Fad Mice Is Associated With Reduced Astrocytic Calcium, Ruei-Lung Lin, Sophiya L. Sims, Nicholas A. Wright, Léopoldine B. Galopin, Blaine Weiss, Susan D. Kraner, Jacquelyn E. Rhinehart, Ting-Hsuan Lu, Pradoldej Sompol, Christopher M. Norris, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

INTRODUCTION

Evidence points to dysregulated Ca²⁺ in neurons and astrocytes in models of amyloidosis. While most of these data were obtained in vitro or in vivo under anesthesia, less work has investigated these variables in awake ambulating mice.

METHODS

Astrocytic Ca²⁺ fluctuations (GCaMP8f) were imaged concomitantly with vasoreactivity in S1 on a two-photon microscope during rest and ambulation. Single-cell resolution variables were extracted using continuous wavelet transform and traditional ΔF/F measures.

RESULTS

Along with increases in amyloid beta (Aβ) accumulation, we found significant reductions in measures of astrocyte functional connectivity, pairwise correlations, and network synchronicity in older 5×FAD …

Dysregulation Of Systemic Immunity In Aging And Dementia, Jenny Lutshumba, Barbara S. Nikolajczyk, Adam D. Bachstetter

Pharmacology and Nutritional Sciences Faculty Publications

Neuroinflammation and the tissue-resident innate immune cells, the microglia, respond and contribute to neurodegenerative pathology. Although microglia have been the focus of work linking neuroinflammation and associated dementias like Alzheimer’s Disease, the inflammatory milieu of brain is a conglomerate of cross-talk amongst microglia, systemic immune cells and soluble mediators like cytokines. Age-related changes in the inflammatory profile at the levels of both the brain and periphery are largely orchestrated by immune system cells. Strong evidence indicates that both innate and adaptive immune cells, the latter including T cells and B cells, contribute to chronic neuroinflammation and thus dementia. Neurodegenerative hallmarks …

Electrophysiological And Imaging Calcium Biomarkers Of Aging In Male And Female 5×Fad Mice, Adam O. Ghoweri, Lara Ouillette, Hilaree N. Frazier, Katie L. Anderson, Ruei-Lung Lin, John C. Gant, Rachel Parent, Shannon Moore, Geoffrey G. Murphy, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: In animal models and tissue preparations, calcium dyshomeostasis is a biomarker of aging and Alzheimer's disease that is associated with synaptic dysfunction, neuritic pruning, and dysregulated cellular processes. It is unclear, however, whether the onset of calcium dysregulation precedes, is concurrent with, or is the product of pathological cellular events (e.g., oxidation, amyloid-β production, and neuroinflammation). Further, neuronal calcium dysregulation is not always present in animal models of amyloidogenesis, questioning its reliability as a disease biomarker.

OBJECTIVE: Here, we directly tested for the presence of calcium dysregulation in dorsal hippocampal neurons in male and female 5×FAD mice on …

Neuronal Calcium Imaging, Excitability, And Plasticity Changes In The Aldh2-/- Mouse Model Of Sporadic Alzheimer's Disease, Adam O. Ghoweri, Peter Gagolewicz, Hilaree N. Frazier, John C. Gant, R. David Andrew, Brian M. Bennett, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Dysregulated signaling in neurons and astrocytes participates in pathophysiological alterations seen in the Alzheimer's disease brain, including increases in amyloid-β, hyperphosphorylated tau, inflammation, calcium dysregulation, and oxidative stress. These are often noted prior to the development of behavioral, cognitive, and non-cognitive deficits. However, the extent to which these pathological changes function together or independently is unclear.

OBJECTIVE: Little is known about the temporal relationship between calcium dysregulation and oxidative stress, as some reports suggest that dysregulated calcium promotes increased formation of reactive oxygen species, while others support the opposite. Prior work has quantified several key outcome measures associated with …

Neuroligin-1 Is Altered In The Hippocampus Of Alzheimer's Disease Patients And Mouse Models, And Modulates The Toxicity Of Amyloid-Beta Oligomers, Julien Dufort-Gervais, Chloé Provost, Laurence Charbonneau, Christopher M. Norris, Frédéric Calon, Valérie Mongrain, Jonathan Brouillette

Pharmacology and Nutritional Sciences Faculty Publications

Synapse loss occurs early and correlates with cognitive decline in Alzheimer’s disease (AD). Synaptotoxicity is driven, at least in part, by amyloid-beta oligomers (Aβo), but the exact synaptic components targeted by Aβo remain to be identified. We here tested the hypotheses that the post-synaptic protein Neuroligin-1 (NLGN1) is affected early in the process of neurodegeneration in the hippocampus, and specifically by Aβo, and that it can modulate Aβo toxicity. We found that hippocampal NLGN1 was decreased in patients with AD in comparison to patients with mild cognitive impairment and control subjects. Female 3xTg-AD mice also showed a decreased NLGN1 level …

Testosterone Replacement Therapy In Aging Males, Alexandra Dimit, Joelle Farano, Haley Armstrong, Michelle Musser

Pharmacy and Wellness Review

The U.S. Food and Drug Administration (FDA) cautions health care providers and patients regarding the use of testosterone replacement therapy products for the aging process, including a decrease in muscle strength, muscle mass, and lack of energy or sexual desire, due to an increased risk of heart attacks and strokes. Testosterone replacement therapy products are indicated for genetic defects, chemotherapy damage, or damage to the hypothalamus or pituitary gland, where testosterone is produced. A patient and his team of health care professionals must seriously consider the risks and benefits when using these products for other indications. Use of testosterone replacement …

Neuroimaging Biomarkers Of Mtor Inhibition On Vascular And Metabolic Functions In Aging Brain And Alzheimer’S Disease, Jennifer Lee, Lucille M. Yanckello, David Ma, Jared D. Hoffman, Ishita Parikh, Scott Thalman, Bjoern Bauer, Anika M. S. Hartz, Fahmeed Hyder, Ai-Ling Lin

Pharmacology and Nutritional Sciences Faculty Publications

The mechanistic target of rapamycin (mTOR) is a nutrient sensor of eukaryotic cells. Inhibition of mechanistic mTOR signaling can increase life and health span in various species via interventions that include rapamycin and caloric restriction (CR). In the central nervous system, mTOR inhibition demonstrates neuroprotective patterns in aging and Alzheimer’s disease (AD) by preserving mitochondrial function and reducing amyloid beta retention. However, the effects of mTOR inhibition for in vivo brain physiology remain largely unknown. Here, we review recent findings of in vivo metabolic and vascular measures using non-invasive, multimodal neuroimaging methods in rodent models for brain aging and AD. …

Fk506-Binding Protein 12.6/1b, A Negative Regulator Of [Ca2+], Rescues Memory And Restores Genomic Regulation In The Hippocampus Of Aging Rats, John C. Gant, Eric M. Blalock, Kuey-Chu Chen, Inga Kadish, Olivier Thibault, Nada M. Porter, Philip W. Landfield

Pharmacology and Nutritional Sciences Faculty Publications

Hippocampal overexpression of FK506-binding protein 12.6/1b (FKBP1b), a negative regulator of ryanodine receptor Ca²⁺ release, reverses aging-induced memory impairment and neuronal Ca²⁺ dysregulation. Here, we tested the hypothesis that FKBP1b also can protect downstream transcriptional networks from aging-induced dysregulation. We gave hippocampal microinjections of FKBP1b-expressing viral vector to male rats at either 13 months of age (long-term, LT) or 19 months of age (short-term, ST) and tested memory performance in the Morris water maze at 21 months of age. Aged rats treated ST or LT with FKBP1b substantially outperformed age-matched vector controls and performed similarly …

Development Of Activity In The Mouse Visual Cortex., Jing Shen, Matthew T Colonnese

Pharmacology and Physiology Faculty Publications

No abstract provided.

Ontogeny Of Hepatic Drug Transporters As Quantified By Lc-Ms/Ms Proteomics., B Prasad, Andrea Gaedigk, M Vrana, R Gaedigk, J Steven Leeder, L Salphati, X Chu, G Xiao, Ceca Hop, R Evers, L Gan, J D Unadkat

Manuscripts, Articles, Book Chapters and Other Papers

Protein expression of major hepatic uptake and efflux drug transporters in human pediatric (n = 69) and adult (n = 41) livers was quantified by liquid chromatography / tandem mass spectroscopy (LC-MS/MS). Transporter protein expression of OCT1, OATP1B3, P-gp, and MRP3 was age-dependent. Particularly, significant differences were observed in transporter expression (P < 0.05) between the following age groups: neonates vs. adults (OCT1, OATP1B3, P-gp), neonates or infants vs. adolescents and/or adults (OCT1, OATP1B3, and P-gp), infants vs. children (OATP1B3 and P-gp), and adolescents vs. adults (MRP3). OCT1 showed the largest increase, of almost 5-fold, in protein expression with age. Ontogenic expression of OATP1B1 was confounded by genotype and was revealed only in livers harboring SLCO1B1*1A/*1A. In livers >1 year, tissues harboring SLCO1B1*14/*1A showed 2.5-fold higher (P < 0.05) protein expression than SLCO1B1*15/*1A. Integration of these ontogeny data in physiologically based pharmacokinetic (PBPK) models will be a crucial step in predicting hepatic drug disposition in children.

Reversal Of Aging-Related Neuronal Ca2+ Dysregulation And Cognitive Impairment By Delivery Of A Transgene Encoding Fk506-Binding Protein 12.6/1b To The Hippocampus, John C. Gant, Kuey-Chu Chen, Inga Kadish, Eric M. Blalock, Olivier Thibault, Nada M. Porter, Philip W. Landfield

Pharmacology and Nutritional Sciences Faculty Publications

Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca(2+)-dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca(2+) channel activity and ryanodine receptor (RyR)-mediated Ca(2+) release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca(2+) release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer's disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca(2+) responses. …

Efficacy Of Female Rat Models In Translational Cardiovascular Aging Research, Kevin M. Rice, J. C. Fannin, C. Gillette, Eric Blough

Pharmaceutical Science and Research

Cardiovascular disease is the leading cause of death in women in the United States. Aging is a primary risk factor for the development of cardiovascular disease as well as cardiovascular-related morbidity and mortality. Aging is a universal process that all humans undergo; however, research in aging is limited by cost and time constraints. Therefore, most research in aging has been done in primates and rodents; however it is unknown how well the effects of aging in rat models translate into humans. To compound the complication of aging gender has also been indicated as a risk factor for various cardiovascular diseases. …

Frontal White Matter Integrity In Adults With Down Syndrome With And Without Dementia, David K. Powell, Allison Caban-Holt, Greg A. Jicha, William C. Robertson, Roberta Davis, Brian T. Gold, Frederick A. Schmitt, Elizabeth Head

Magnetic Resonance Imaging and Spectroscopy Center Faculty Publications

Adults with Down syndrome (DS) are at high risk for developing Alzheimer's disease after the age of 40 years. To detect white matter (WM) changes in the brain linked to dementia, fractional anisotropy (FA) from diffusion tensor imaging was used. We hypothesized that adults with DS without dementia (DS n = 10), DS with dementia (DSAD n = 10) and age matched non-DS subjects (CTL n = 10) would show differential levels of FA and an association with scores from the Brief Praxis Test and the Severe Impairment Battery. WM integrity differences in DS compared with CTL were found predominantly …

Aged Rats Are Hypo-Responsive To Acute Restraint: Implications For Psychosocial Stress In Aging, Heather M. Buechel, Jelena Popovic, Kendra Staggs, Katie L. Anderson, Olivier Thibault, Eric M. Blalock

Pharmacology and Nutritional Sciences Faculty Publications

Cognitive processes associated with prefrontal cortex and hippocampus decline with age and are vulnerable to disruption by stress. The stress/stress hormone/allostatic load hypotheses of brain aging posit that brain aging, at least in part, is the manifestation of life-long stress exposure. In addition, as humans age, there is a profound increase in the incidence of new onset stressors, many of which are psychosocial (e.g., loss of job, death of spouse, social isolation), and aged humans are well-understood to be more vulnerable to the negative consequences of such new-onset chronic psychosocial stress events. However, the mechanistic underpinnings of this age-related shift …

Inhibition Of Soluble Tumor Necrosis Factor Ameliorates Synaptic Alterations And Ca2+ Dysregulation In Aged Rats, Diana M. Sama, Hafiz Mohmmad Abdul, Jennifer L. Furman, Irina A. Artiushin, David E. Szymkowski, Stephen W. Scheff, Christopher M. Norris

Graduate Center for Gerontology Faculty Publications

The role of tumor necrosis factor α (TNF) in neural function has been investigated extensively in several neurodegenerative conditions, but rarely in brain aging, where cognitive and physiologic changes are milder and more variable. Here, we show that protein levels for TNF receptor 1 (TNFR1) are significantly elevated in the hippocampus relative to TNF receptor 2 (TNFR2) in aged (22 months) but not young adult (6 months) Fischer 344 rats. To determine if altered TNF/TNFR1 interactions contribute to key brain aging biomarkers, aged rats received chronic (4-6 week) intracranial infusions of XPro1595: a soluble dominant negative TNF that preferentially inhibits …

Aging And Down Syndrome, Elizabeth Head, Wayne Silverman, David Patterson, Ira T. Lott

Pharmacology and Nutritional Sciences Faculty Publications

No abstract provided.

Biomarkers For Aging, Philip W. Landfield, Eric M. Blalock, Kuey-Chu Chen, Thomas S. Foster

Pharmacology and Nutritional Sciences Faculty Patents

A statistical and functional correlation strategy to identify changes in cellular pathways specifically linked to impaired cognitive function with aging. Analyses using the strategy identified multiple groups of genes expressed in the hippocampi of mammals, where the genes were expressed at different levels for several ages. The aging changes in expression began before mid-life. Many of the genes were involved in specific neuronal and glial pathways with previously unrecognized relationships to aging and/or cognitive decline. These identified genes and the proteins they encode can be used as novel biomarkers of brain aging and as targets for developing treatment methods against …

Expansion Of The Calcium Hypothesis Of Brain Aging And Alzheimer's Disease: Minding The Store, Olivier Thibault, John C. Gant, Philip W. Landfield

Pharmacology and Nutritional Sciences Faculty Publications

Evidence accumulated over more than two decades has implicated Ca2+ dysregulation in brain aging and Alzheimer's disease (AD), giving rise to the Ca2+ hypothesis of brain aging and dementia. Electrophysiological, imaging, and behavioral studies in hippocampal or cortical neurons of rodents and rabbits have revealed aging-related increases in the slow afterhyperpolarization, Ca2+ spikes and currents, Ca2+transients, and L-type voltage-gated Ca2+ channel (L-VGCC) activity. Several of these changes have been associated with age-related deficits in learning or memory. Consequently, one version of the Ca2+ hypothesis has been that increased L-VGCC activity drives many of the other Ca2+-related biomarkers of hippocampal aging. …