Medical Physiology Commons^™

Nicotinamide Riboside And Beta-Hydroxybutyrate Activate Parallel Pathways For C. Elegans Lifespan Extension, Mckenzie Peters

Undergraduate Honors Theses

Supplementation with nicotinamide riboside (NR), a form of vitamin B3 and a precursor of nicotinamide adenine dinucleotide (NAD⁺) extends lifespan in the nematode C. elegans and delays aging-related pathologies in mammals. During aging, levels of NAD⁺ decline causing metabolic dysfunction and oxidative damage. Studies in C. elegans found that when NR was administered during larval development it induced the mitochondrial unfolded protein response (UPR^mt), which is frequently associated with lifespan extension. Both calorie restriction (CR) and ketogenic diets (KD) have been shown to extend lifespan, in part through increasing NAD⁺ and through increasing levels …

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 …

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 …

Gender- And Region-Specific Changes In Estrogen Signaling In Aging Rat Brain Mitochondria, Christopher M. Evola, Tanner L. Hudson, Luping Huang, Adrian M. Corbett, Debra A. Mayes

Neuroscience, Cell Biology & Physiology Faculty Publications

Recently epidemiological studies suggest females lose neuroprotection from neurodegenerative diseases as they go through menopause. It has been hypothesized that this neuroprotection is hormone‐dependent. The current study characterized cell signaling molecules downstream of estrogen receptor beta that are known to play a role in memory, PKC, ERK, and connexin‐43, in regions of the brain associated with memory decline in an attempt to elucidate significant changes that occur post‐estrus. Total whole cell lysates were compared to isolated mitochondrial protein because mitochondrial function is known to be altered during aging. As hypothesized, protein concentrations differed depending on age, gender, and brain region. …

Artificial Gravity As A Countermeasure To The Cardiovascular Deconditioning Of Spaceflight: Gender Perspectives, Joyce M. Evans, Charles F. Knapp, Nandu Goswami

Biomedical Engineering Faculty Publications

Space flight-induced physiological deconditioning resulting from decreased gravitational input, decreased plasma volume, and disruption of regulatory mechanisms is a significant problem in returning astronauts as well as in normal aging. Here we review effects of a promising countermeasure on cardiovascular systems of healthy men and women undergoing Earth-based models of space-flight. This countermeasure is produced by a centrifuge and called artificial gravity (AG). Numerous studies have determined that AG improves orthostatic tolerance (as assessed by various protocols) of healthy ambulatory men, of men deconditioned by bed rest or by immersion (both wet and dry) and, in one case, following spaceflight. …

Osteoarthritis, Cerebrovascular Dysfunction And The Common Denominator Of Inflammation: A Narrative Review, B. K. Al-Khazraji, C. T. Appleton, F. Beier, T. B. Birmingham, J. K. Shoemaker

Physiology and Pharmacology Publications

© 2018 The Author(s) Objective: Population-based cohort studies suggest an association between osteoarthritis (OA) and cerebrovascular disease, yet the mechanisms underlying vascular comorbidities in OA remain unclear. The purpose of this narrative review is to discuss the literature examining inflammation in OA with a focus on physiological mechanisms, and whether overlapping mechanisms exist in cerebrovascular dysfunction. Method: A literature search was conducted in PubMed using combinations of search terms: osteoarthritis, cerebrovascular (disease/dysfunction/risk), cardiovascular (disease/dysfunction/risk), aging/ageing, inflammation, inflammatory mediators, cytokine, c-reactive protein, interleukin, advanced glycation end-products, metabolic syndrome, reactive oxidative species, cognitive impairment, (vascular-related) dementia, small cerebral vessel disease, endothelial function, …

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

Pharmacology and Physiology Faculty Publications

No abstract provided.

Genetic Regulation Of Hematopoietic Stem Cell Aging, Erin J. Oakley

University of Kentucky Doctoral Dissertations

It is well documented that both quantitative and qualitative changes in the murine hematopoietic stem cell (HSC) population occur with age. In mice, the effect of aging on stem cells is highly strain-specific, thus suggesting genetic regulation plays a role in HSC aging. In C57BL/6 (B6) mice, the HSC population steadily increases with age, whereas in DBA/2 (D2) mice, this population declines. Our lab has previously mapped a quantitative trait locus (QTL) to murine chromosome 2 that is associated with the variation in frequency of HSCs between aged B6 and D2 mice. In these dissertation studies, I first aim to …

Molecular Mechanisms Of Olfactory Neurodegeneration, Radhika Anand Vaishnav

University of Kentucky Doctoral Dissertations

Olfactory sensory decline has been associated with normal aging as well as neurodegenerative disorders, yet the underlying mechanisms are unclear. The overall aim of this dissertation was to investigate the fundamental molecular and cellular mechanisms associated with olfactory neurodegeneration. This investigation uses an integrative approach, combining proteomics and gene expression analyses with cellular and tissuelevel characterization. Using these approaches, two model systems were investigated: 1) normally aging C57BL/6 mice of ages 1.5-, 6- and 20-months; and 2) a mouse model of elevated endogenous oxidative stress-associated neurodegeneration, namely, the Harlequin mutant mouse. The first specific aim was to test the hypothesis …

A Drosophila Deg/Enac Channel Subunit Is Required For Male Response To Female Pheromones, Heping Lin, Kevin J. Mann, Elena Starostina, Ronald D. Kinser, Claudio W. Pikielny

Dartmouth Scholarship

Odorants and pheromones as well as sweet- and bitter-tasting small molecules are perceived through activation of G protein-coupled chemosensory receptors. In contrast, gustatory detection of salty and sour tastes may involve direct gating of sodium channels of the DEG/ENaC family by sodium and hydrogen ions, respectively. We have found that ppk25, a Drosophila melanogaster gene encoding a DEG/ENaC channel subunit, is expressed at highest levels in the male appendages responsible for gustatory and olfactory detection of female pheromones: the legs, wings, and antennae. Mutations in the ppk25 gene reduce or even abolish male courtship response to females in the dark, …