Medical Physiology Commons^™

Redox-Sensitive Calcium/Calmodulin-Dependent Protein Kinase Iiα In Angiotensin Ii Intra-Neuronal Signaling And Hypertension, Urmi Basu, Adam J. Case, Jinxu Liu, Jun Tian, Yulong Li, Matthew C. Zimmerman

Journal Articles: Cellular & Integrative Physiology

Dysregulation of brain angiotensin II (AngII) signaling results in modulation of neuronal ion channel activity, an increase in neuronal firing, enhanced sympathoexcitation, and subsequently elevated blood pressure. Studies over the past two decades have shown that these AngII responses are mediated, in part, by reactive oxygen species (ROS). However, the redox-sensitive target(s) that are directly acted upon by these ROS to execute the AngII pathophysiological responses in neurons remain unclear. Calcium/calmodulin-dependent protein kinase II (CaMKII) is an AngII-activated intra-neuronal signaling protein, which has been suggested to be redox sensitive as overexpressing the antioxidant enzyme superoxide dismutase attenuates AngII-induced activation of …

Signaling Induced By Inflammatory Mediators In The Rodent Pulmonary Microvasculature, Rachel Escue Helms

Theses and Dissertations (ETD)

Acute lung inflammation (ALI), stemming from a disproportionate and detrimental immune response, may arise from or complicate other disease states, leading to the often-fatal acute respiratory distress syndrome (ARDS). Because of the many culpable factors and differing points of induction, pinning down the signaling mechanisms involved in the morbidity of this disorder as well as defining an effective treatment has proved problematic. However, the most detrimental characteristic of this condition is seen regardless of the development of the response: increased microvascular permeability. Because of the architecture and the size of the pulmonary microvascular network, the lungs have a resident, sequestered …

The Migration And Developmental Remodeling Of Intrinsic Interneurons In Visual Thalamus And The Role Of Retinal Signaling., Naomi E. Charalambakis

Electronic Theses and Dissertations

The dorsal lateral geniculate nucleus (dLGN) of the mouse is a model system to study the development of thalamic circuitry. While most studies focus on relay neurons of dLGN, little is known about the factors regulating the development of the other principal cell type, intrinsic interneurons. To date, the targeting and migratory path of dLGN interneurons as well as their morphological development remains unclear. Here we examined whether the migration, structure, and function of interneurons relies on retinal signaling. We took a loss-of-function approach and crossed GAD67-GFP mice, which express green fluorescent protein (GFP) in dLGN interneurons, with math5 nulls …

Distinct White Matter Changes Associated With Cerebrospinal Fluid Amyloid-Β1-42 And Hypertension, Omar M. Al-Janabi, Christopher A. Brown, Ahmed A. Bahrani, Erin L. Abner, Justin M. Barber, Brian T. Gold, Larry B. Goldstein, Richard R. Murphy, Peter T. Nelson, Nathan F. Johnson, Leslie M. Shaw, Charles D. Smith, John Q. Trojanowski, Donna M. Wilcock, Gregory A. Jicha

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Alzheimer's disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults.

OBJECTIVE: To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations.

METHODS: Clinical measures of cerebrovascular disease risk were collected from 62 participants in University of Kentucky Alzheimer's Disease Center studies who also had cerebrospinal fluid (CSF) sampling and MRI brain scans. CSF Aβ_1-42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess …

Effects Of Maternal Protein Restriction On The Pulmonary Surfactant System During The Early Life And Adulthood, Reza Khazaee

Electronic Thesis and Dissertation Repository

Fetal growth restriction (FGR) is defined by low birth weight and contributes to a variety of adult-onset diseases with different severities between males and females. However, the effects of FGR on the pulmonary surfactant are not fully elucidated. In this thesis, first, we investigated the FGR effects on the lung function and the surfactant system at the early postnatal life. It was hypothesized that FGR contributes to alterations of lung mechanics and the surfactant system during the neonatal period. Second, we assessed the FGR effects on the surfactant system in response to sepsis in adulthood. It was hypothesized that FGR …

Causality Analysis And Cell Network Modeling Of Spatial Calcium Signaling Patterns In Liver Lobules., Aalap Verma, Anil Noronha Antony, Babatunde A. Ogunnaike, Jan B. Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Dynamics as well as localization of Ca2+ transients plays a vital role in liver function under homeostatic conditions, repair, and disease. In response to circulating hormonal stimuli, hepatocytes exhibit intracellular Ca2+ responses that propagate through liver lobules in a wave-like fashion. Although intracellular processes that control cell autonomous Ca2+ spiking behavior have been studied extensively, the intra- and inter-cellular signaling factors that regulate lobular scale spatial patterns and wave-like propagation of Ca2+ remain to be determined. To address this need, we acquired images of cytosolic Ca2+ transients in 1300 hepatocytes situated across several mouse liver lobules over a period of …

Myocyte [Na+]I Dysregulation In Heart Failure And Diabetic Cardiomyopathy, Sanda Despa

Pharmacology and Nutritional Sciences Faculty Publications

By controlling the function of various sarcolemmal and mitochondrial ion transporters, intracellular Na⁺ concentration ([Na⁺]_i) regulates Ca²⁺ cycling, electrical activity, the matching of energy supply and demand, and oxidative stress in cardiac myocytes. Thus, maintenance of myocyte Na⁺ homeostasis is vital for preserving the electrical and contractile activity of the heart. [Na⁺]_i is set by the balance between the passive Na⁺ entry through numerous pathways and the pumping of Na⁺ out of the cell by the Na⁺/K⁺-ATPase. This equilibrium is perturbed in heart failure, …

Propofol Inhibits The Voltage-Gated Sodium Channel Nachbac At Multiple Sites., Yali Wang, Elaine Yang, Marta M. Wells, Vasyl Bondarenko, Kellie Woll, Vincenzo Carnevale, Daniele Granata, Michael L. Klein, Roderic G. Eckenhoff, William P. Dailey, Manuel Covarrubias, Pei Tang, Yan Xu

Department of Neuroscience Faculty Papers

Voltage-gated sodium (Na_V) channels are important targets of general anesthetics, including the intravenous anesthetic propofol. Electrophysiology studies on the prokaryotic Na_V channel NaChBac have demonstrated that propofol promotes channel activation and accelerates activation-coupled inactivation, but the molecular mechanisms of these effects are unclear. Here, guided by computational docking and molecular dynamics simulations, we predict several propofol-binding sites in NaChBac. We then strategically place small fluorinated probes at these putative binding sites and experimentally quantify the interaction strengths with a fluorinated propofol analogue, 4-fluoropropofol. In vitro and in vivo measurements show that 4-fluoropropofol and propofol have similar effects …

High Fat Diet Upregulates Fatty Acid Oxidation And Ketogenesis Via Intervention Of Ppar-Γ., Kunal Sikder, Sanket Kumar Shukla, Neel Patel, Harpreet Singh, Khadija Rafiq

Center for Translational Medicine Faculty Papers

BACKGROUND/AIMS: Systemic hyperlipidemia and intracellular lipid accumulation induced by chronic high fat diet (HFD) leads to enhanced fatty acid oxidation (FAO) and ketogenesis. The present study was aimed to determine whether activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) by surplus free fatty acids (FA) in hyperlipidemic condition, has a positive feedback regulation over FAO and ketogenic enzymes controlling lipotoxicity and cardiac apoptosis.

METHODS: 8 weeks old C57BL/6 wild type (WT) or PPAR-γ-/- mice were challenged with 16 weeks 60% HFD to induce obesity mediated type 2 diabetes mellitus (T2DM) and diabetic cardiomyopathy. Treatment course was followed by echocardiographic measurements, glycemic and …

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. …

Spinal Control Of Locomotion: Individual Neurons, Their Circuits And Functions, Marie-Pascale Côté, Lynda M. Murray, Maria Knikou

Publications and Research

Systematic research on the physiological and anatomical characteristics of spinal cord interneurons along with their functional output has evolved for more than one century. Despite significant progress in our understanding of these networks and their role in generating and modulating movement, it has remained a challenge to elucidate the properties of the locomotor rhythm across species. Neurophysiological experimental evidence indicates similarities in the function of interneurons mediating afferent information regarding muscle stretch and loading, being affected by motor axon collaterals and those mediating presynaptic inhibition in animals and humans when their function is assessed at rest. However, significantly different muscle …

Gene Delivery Of Adenoviral-Tmbim6 Vector Protects The Neonatal Brain After Hypoxic-Ischemic Injury, Desislava Doycheva

Loma Linda University Electronic Theses, Dissertations & Projects

Neonatal hypoxia ischemia (HI) is an injury caused to the immature brain due to reduced cerebral blood flow which is associated with life-long neurological impairments. HI causes oxidative protein folding in the endoplasmic reticulum (ER), which results in ER stress. Generation of reactive oxygen species (ROS), from cytochrome P450 members (CYP) and NADPH-P450 reductases (NPR), in combination with activation of the unfolded protein response (UPR) are two major consequences of ER stress that cause oxidative damage and cell death. Herein we identified the role of Bax Inhibitor-1 (BI-1), an evolutionary conserved protein encoded by the Transmembrane Bax inhibitor Motif Containing …

Changes In The Morphology Of Hypoglossal Motor Neurons In The Brainstem Of Developing Rats, Paul Allen Williams

Loma Linda University Electronic Theses, Dissertations & Projects

The autonomic brainstem generates and modifies breathing rhythm by integrating inputs from chemo- and mechanosensors in the viscera while coordinating descending outputs from higher CNS structures. Hypoglossal motoneurons (XII MNs) receive inputs from respiratory premotor neurons in the medulla. Previous studies in rodents have demonstrated significant changes in breathing control during the first three weeks of life, with a sensitive period at 10 to 13 days post-birth (P10–P13) characterized by pronounced changes in neurotransmitters, receptors, excitation-inhibition balance, and breathing. However, age-dependent morphological changes of XII MNs during the first three weeks post-birth and especially during this sensitive period, have not …

The Role Of Glucocorticoid Signaling In Prostate Cancer Health Disparities, Leanne W. Burnham

Loma Linda University Electronic Theses, Dissertations & Projects

African-American men are more likely to develop aggressive prostate cancer (PCa) and die from the disease than other ethnic groups. Glucocorticoid signaling is a contributing biological factor to worse PCa prognosis, and is emerging as a key driver of PCa progression in the absence of androgens. The mechanism involves glucocorticoids binding to glucocorticoid receptor (GR) and bypassing the androgen receptor (AR) signaling pathway to activate AR-target genes that promote tumor aggressiveness and therapy-resistance. This is problematic as African-American men have hypersensitive GR signaling and chronically-elevated levels of glucocorticoids linked to cumulative stressful life events. To explore the role of glucocorticoid …

Systematic Pan-Cancer Analysis Of Somatic Allele Frequency., Liam Spurr, Muzi Li, Nawaf Alomran, Qianqian Zhang, Paula Restrepo, Mercedeh Movassagh, Chris Trenkov, Nerissa Tunnessen, Tatiyana Apanasovich, Keith A Crandall, Nathan Edwards, Anelia Horvath

Pharmacology and Physiology Faculty Publications

Imbalanced expression of somatic alleles in cancer can suggest functional and selective features, and can therefore indicate possible driving potential of the underlying genetic variants. To explore the correlation between allele frequency of somatic variants and total gene expression of their harboring gene, we used the unique data set of matched tumor and normal RNA and DNA sequencing data of 5523 distinct single nucleotide variants in 381 individuals across 10 cancer types obtained from The Cancer Genome Atlas (TCGA). We analyzed the allele frequency in the context of the variant and gene functional features and linked it with changes in …

Effect Of Exercise And Hypoxia On Plasma Telomerase, Charli D. Aguilar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Telomerase reverse transcriptase (TERT) is the enzyme that adds telomeric sequences to the end of linear chromosomes. Exercise has shown to upregulate acutely leukocyte TERT after just 30 minutes of running on a treadmill at 80% of VO2max (Denham et al., 2016). Hypoxia inducible factor 1 (HIF-1) is also a mediator of TERT in in vitro (Nishi et al., 2004). Moderate acute exposure to hypoxia was associated with substantial increases in plasma TERT in a recent study on rats (Wang et al., 2014). The specific aim of the current study was to identify if acute hypoxia upregulates plasma TERT …

Disruption Of Neonatal Cardiomyocyte Physiology Following Exposure To Bisphenol-A., Manelle Ramadan, Meredith Sherman, Rafael Jaimes, Ashika Chaluvadi, Luther Swift, Nikki Gillum Posnack

Pharmacology and Physiology Faculty Publications

Bisphenol chemicals are commonly used in the manufacturing of polycarbonate plastics, polyvinyl chloride plastics, resins, and thermal printing applications. Humans are inadvertently exposed to bisphenols through contact with consumer products and/or medical devices. Recent reports have shown a link between bisphenol-a (BPA) exposure and adverse cardiovascular outcomes; although these studies have been limited to adult subjects and models. Since cardiac physiology differs significantly between the developing and adult heart, we aimed to assess the impact of BPA exposure on cardiac function, using a neonatal cardiomyocyte model. Neonatal rat ventricular myocytes were monitored to assess cell viability, spontaneous beating rate, beat …

Protein Trafficking Of Bk Channel Β1 Subunits In Cerebral Artery Myocytes, Xue Zhai

Theses and Dissertations (ETD)

Rationale: Large-conductance calcium (Ca²⁺)-activated potassium channels (BK) are expressed in arterial myocytes to control arterial contractility. It is composed of pore- forming BKα and auxiliary β1 subunits. Auxiliary β1 subunits associate with BKα which modulate Ca²⁺ sensitivity of BK channel. Previous data showed that BKα locates at cell membrane, whereas β1 subunits are primarily intracellular which regulated by Rab11A- positive recycling endosomes. Endothelin-1 (ET-1), a vasoconstrictor, induces contraction of myocytes. ET-1 inhibits BK channel but mechanisms are not fully understood. It is unclear that vasoconstrictors regulate the cellular distribution of BK channels. Furthermore, BK channels are involved …

Characterization Of The Hepatotoxicity Of Rifampicin And Isoniazid, Christopher T. Brewer

Theses and Dissertations (ETD)

In a mouse model, rifampicin and isoniazid combination treatment results in cholestatic liver injury that is associated with an increase of protoporphyrin ix (PPIX), the penultimate heme precursor. Excess PPIX is believed to bind to bile acids, precipitate in bile canaliculi, and form bile plugs leading to cholestasis fol owed by liver injury. Both ferrochelatase (FECH/Fech) and aminolevulinic acid synthase 1 (ALAS1/Alas1) are crucial enzymes in regulating heme biosynthesis. Isoniazid has recently been reported to up-regulate Alas1 but down-regulate Fech protein levels in mice; however the mechanism of isoniazid mediated heme synthesis …