Medicine and Health Sciences Commons^™

Calcium Imaging Of Central Amygdala Activity After Fentanyl Escalation, Samantha Malone

Theses and Dissertations--Psychology

Evidence suggests that rats given long access (LgA) sessions to self-administer (SA) opioids escalate their intake, while also showing greater withdrawal severity and drug-induced reinstatement compared to rats maintained on short access (ShA) daily SA sessions. Little is known about the neural changes that occur during opioid escalation that may impact withdrawal and relapse. Past work examining opioid SA using ShA sessions in rodents has identified the central amygdala (CeA) as an area of interest that becomes hyperactive in acute withdrawal and may be involved in the incubation of craving that occurs after protracted withdrawal. However, these studies have not …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations & Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

Severe Hypoxia Up-Regulates Gluconeogenesis In Daphnia, Morad C. Malek

Undergraduate Honors Theses

Hypoxia is a significant low oxygen state that has complex and diverse impacts on organisms. In aerobes, various adaptive responses to hypoxia are observed that vary depending on the level of oxygen depletion and previous adaptation, hence the continued attention to hypoxia as an important abiotic stressor. Adaptive responses to hypoxia are primarily governed by the hypoxia-inducible factors (HIFs), which activate downstream genetic pathways responsible for oxygen transport and metabolic plasticity. In aquatic habitats, oxygen availability can vary greatly over time and space. Therefore, aquatic organisms’ adaptation to hypoxia is likely pervasive, especially in genotypes originating from waterbodies prone to …

Effects Of Vitamin D Administration At The Beginning Of Lactation In Dairy Cows Oninflammatory Response And Liver Metabolism, Feyyaz Kaya, Hasan Batmaz

Turkish Journal of Veterinary & Animal Sciences

This study aimed to investigate the effect of vitamin D administered 24 h after calving of dairy cows on calcium-phosphorus metabolism, carbohydrate, lipid and liver metabolism, and inflammatory response. Twenty multiparous Holstein cows were randomly assigned to the experimental (EG) and control group (CG). The EG received 5,000,000 IU vitamin D3 (5 mL) 24 h after parturition intramuscularly, whereas the CG group received 5 mL of 0.9% NaCl. Blood samples were taken 24 h after parturition before treatments and at the 3rd, 7th, 14th, and 28th days of lactation. Serum NEFA, BHBA, haptoglobin, serum amyloid A (SAA), ceruloplasmin, calcium, phosphorus, …

Effects Of Dietary Calcium, Phosphorus And Microbial Phytase On Intestinal Morphologyin Laying Hens, Sabi̇re Güler, Ender Deni̇z Asmaz, Nuray Varol Kayapunar, İhsan İşbi̇li̇r, Şeri̇fe Şule Cengi̇z, Derya Yeşi̇lbağ, Ahmet Batuhan Şanli, Eyüp Eren Gültepe

Turkish Journal of Veterinary & Animal Sciences

Different challenges are being applied in the poultry industry in order to protect animal health and to increase immunity and production. The supplementation of microbial phytase is essential in terms of both reducing the inorganic phytase rate and contributing to the absorption of other minerals. In this study, a newly isolated microbial phytase was added at different concentrations to the diet together with calcium (Ca$^{2+}$) and available phosphorus (AP), and the effects of this supplementation on intestinal absorption capacity and Ca$^{2+}$ binding capacity were investigated via morphological measurements and immunohistochemical examination of the duodenum and ileum. For this purpose, 90 …

Calcaneal Ultrasound And Its Relation To Dietary And Lifestyle Factors, Anthropometry, And Vitamin D Deficiency In Young Medical Students, Lena Jafri, Hafsa Majid, Sibtain Ahmed, Ghazala Naureen, Aysha Habib Khan

Department of Pathology and Laboratory Medicine

Background: Bone quality and peak bone mass are greatly affected by lifestyle factors. The objective of the study was to investigate the relationships between anthropometry, dietary and caloric intake, body composition measurements, physical activity, and vitamin D status with quantitative ultrasound-based bone parameters among medical students.
Methods: Both male and female medical college students were included in this study. A detailed questionnaire was administered, collecting clinical, dietary, physical activity information, physical examination details, including body mass index (BMI). Body composition (total body fat, total body water, muscle mass, mean visceral fat mass, basal metabolic rate, bone mass using a bioelectrical …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

Hiv Viral Rebound Due To A Possible Drug-Drug Interaction Between Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide And Calcium-Containing Products: Report Of 2 Cases, S. Lena Kang-Birken, Dena El-Sayed, John Prichard

School of Pharmacy Faculty Articles

Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) is a potent fixed-dose, once-daily regimen for HIV-1 treatment and has rare emergence of drug resistance. We report a potential drug-drug interaction in 2 female patients both receiving treatment for HIV and cerebral toxoplasmosis: one case between E/C/F/TAF with calcium carbonate and a second case involving leucovorin as calcium salt. Both cases resulted in rise in HIV RNA levels and emergence of M184 V mutation and resistance to elvitegravir and raltegravir. To the best of our knowledge, these 2 cases are the first reports of rapid emergence of mutation from coadministration of E/C/F/TAF and calcium.

Macrophage-Derived Netrin-1 Promotes Abdominal Aortic Aneurysm Formation By Activating Mmp3 In Vascular Smooth Muscle Cells, Tarik Hadi, Ludovic Boytard, Michele Silvestro, Dornazsadat Alebrahim, Samson Jacob, Jordyn Feinstein, Krista Barone, Wes Spiro, Susan Hutchison, Russell Simon, Debra L. Rateri, Florence Pinet, David Fenyo, Mark Adelman, Kathryn J. Moore, Holger K. Eltzschig, Alan Daugherty, Bhama Ramkhelawon

Physiology Faculty Publications

Abdominal aortic aneurysms (AAA) are characterized by extensive extracellular matrix (ECM) fragmentation and inflammation. However, the mechanisms by which these events are coupled thereby fueling focal vascular damage are undefined. Here we report through single-cell RNA-sequencing of diseased aorta that the neuronal guidance cue netrin-1 can act at the interface of macrophage-driven injury and ECM degradation. Netrin-1 expression peaks in human and murine aneurysmal macrophages. Targeted deletion of netrin-1 in macrophages protects mice from developing AAA. Through its receptor neogenin-1, netrin-1 induces a robust intracellular calcium flux necessary for the transcriptional regulation and persistent catalytic activation of matrix metalloproteinase-3 (MMP3) …

The Roles Of Primary Cilia In Cardiovascular Diseases, Rajasekharreddy Pala, Maha Jamal, Qamar Alshammari, Surya M. Nauli

Pharmacy Faculty Articles and Research

Primary cilia are microtubule-based organelles found in most mammalian cell types. Cilia act as sensory organelles that transmit extracellular clues into intracellular signals for molecular and cellular responses. Biochemical and molecular defects in primary cilia are associated with a wide range of diseases, termed ciliopathies, with phenotypes ranging from polycystic kidney disease, liver disorders, mental retardation, and obesity to cardiovascular diseases. Primary cilia in vascular endothelia protrude into the lumen of blood vessels and function as molecular switches for calcium (Ca2+) and nitric oxide (NO) signaling. As mechanosensory organelles, endothelial cilia are involved in blood flow sensing. Dysfunction in endothelial …

Amylin And Diabetic Cardiomyopathy – Amylin-Induced Sarcolemmal Ca2+ Leak Is Independent Of Diabetic Remodeling Of Myocardium, Miao Liu, Amanda Hoskins, Nirmal Verma, Donald M. Bers, Sanda Despa, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

Amylin is a pancreatic β-cell hormone co-secreted with insulin, plays a role in normal glucose homeostasis, and forms amyloid in the pancreatic islets of individuals with type-2 diabetes. Aggregated amylin is also found in blood and extra-pancreatic tissues, including myocardium. Myocardial amylin accumulation is associated with myocyte Ca²⁺ dysregulation in diabetic rats expressing human amylin. Whether deposition of amylin in the heart is a consequence of or a contributor to diabetic cardiomyopathy remains unknown. We used amylin knockout (AKO) mice intravenously infused with either human amylin (i.e, the aggregated form) or non-amyloidogenic (i.e., monomeric) rodent amylin to test the …

Protection Effect Of Exogenous Fibroblast Growth Factor 21 On The Kidney Injury In Vascular Calcification Rats, Yu-Chen Shi, Wei-Wei Lu, Yue-Long Hou, Kun Fu, Feng Gan, Shu-Juan Cheng, Shao-Ping Wang, Yong-Fen Qi, Jing-Hua Liu

Pharmacology and Nutritional Sciences Faculty Publications

Background: Chronic kidney disease (CKD) is closely related to the cardiovascular events in vascular calcification (VC). However, little has known about the characteristics of kidney injury caused by VC. Fibroblast growth factor 21 (FGF21) is an endocrine factor, which takes part in various metabolic actions with the potential to alleviate metabolic disorder diseases. Even FGF21 has been regarded as a biomarker in CKD, the role of FGF21 in CKD remains unclear. Therefore, in this study, we evaluate the FGF21 on the kidney injury in VC rats.

Methods: The male Sprague-Dawley rats were divided into three groups: (1) control group, (2) …

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 …

Primary Cilium-Dependent Signaling Mechanisms, Rajasekharreddy Pala, Nedaa Alomari, Surya M. Nauli

Pharmacy Faculty Articles and Research

Primary cilia are hair-like organelles and play crucial roles in vertebrate development, organogenesis, health, and many genetic disorders. A primary cilium is a mechano-sensory organelle that responds to mechanical stimuli in the micro-environment. A cilium is also a chemosensor that senses chemical signals surrounding a cell. The overall function of a cilium is therefore to act as a communication hub to transfer extracellular signals into intracellular responses. Although intracellular calcium has been one of the most studied signaling messengers that transmit extracellular signals into the cells, calcium signaling by various ion channels remains a topic of interest in the field. …

Carisbamate Blockade Of T-Type Voltage-Gated Calcium Channels, Do Young Kim, Fang-Xiong Zhang, Stan T. Nakanishi, Timothy Mettler, Ik-Hyun Cho, Younghee Ahn, Florian Hiess, Lina Chen, Patrick G. Sullivan, S. R. Wayne Chen, Gerald W. Zamponi, Jong M. Rho

Spinal Cord and Brain Injury Research Center Faculty Publications

Objectives

Carisbamate (CRS) is a novel monocarbamate compound that possesses antiseizure and neuroprotective properties. However, the mechanisms underlying these actions remain unclear. Here, we tested both direct and indirect effects of CRS on several cellular systems that regulate intracellular calcium concentration [Ca²⁺]_i.

Methods

We used a combination of cellular electrophysiologic techniques, as well as cell viability, Store Overload‐Induced Calcium Release (SOICR), and mitochondrial functional assays to determine whether CRS might affect [Ca²⁺]_i levels through actions on the endoplasmic reticulum (ER), mitochondria, and/or T‐type voltage‐gated Ca²⁺ channels.

Results

In CA3 pyramidal neurons, kainic …

Lactose Intolerance: An Overview Of The Facts And Their Implications, Noelle M. Yeo

Honors Theses

Lactose intolerance is often blamed for the symptoms such as bloating, diarrhea, gas, abdominal pain, and nausea, that ail many people. Patients often do not seek proper diagnosis from a physician and create their own treatment plans, severely restricting lactose intake, without professional guidance. Even those who do seek the care of a physician find that diagnosis is complicated by less-than ideal testing and confusion due to the symptoms common to many other conditions. The misconceptions and inability to confirm a diagnosis of lactose intolerance can cause nutrient deficiencies in these patients, as well as begin a pattern of unnecessary …

Calcium's Role As Nuanced Modulator Of Cellular Physiology In The Brain, Hilaree N. Frazier, Shaniya Maimaiti, Katie L. Anderson, Lawrence D. Brewer, John C. Gant, Nada M. Porter, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Publications

Neuroscientists studying normal brain aging, spinal cord injury, Alzheimer’s disease (AD) and other neurodegenerative diseases have focused considerable effort on carefully characterizing intracellular perturbations in calcium dynamics or levels. At the cellular level, calcium is known for controlling life and death and orchestrating most events in between. For many years, intracellular calcium has been recognized as an essential ion associated with nearly all cellular functions from cell growth to degeneration. Often the emphasis is on the negative impact of calcium dysregulation and the typical worse-case-scenario leading inevitably to cell death. However, even high amplitude calcium transients, when executed acutely can …

Feasibility Of Laser-Induced Breakdown Spectroscopy (Libs) As An At-Line Validation Tool For Calcium Determination In Infant Formula, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Patrick J. Cullen, Carl Sullivan

Articles

In this study, a 150 mJ laser-induced breakdown spectroscopy (LIBS) system was assessed to determine calcium content in infant formula (IF) samples. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers advantages over conventional methods such as real-time analyses, little to no sample preparation and ease of use. The aim of this work was to evaluate the feasibility of LIBS as an at-line tool for IF manufacturing. To this end, IF mixtures with varying content of calcium were prepared over a range (approx. 1.5–7 mg/g of calcium) selected to be in conformity with the guidelines provided by …

Regulation Of Amyloid Oligomer Binding To Neurons And Neurotoxicity By The Prion Protein-Mglur5 Complex, Flavio H. Beraldo, Valeriy G. Ostapchenko, Fabiana A. Caetano, Andre L. S. Guimaraes, Giulia D. S. Ferretti, Nathalie Daude, Lisa Bertram, Katiane O. P. C. Nogueira, Jerson L. Silva, David Westaway, Neil R. Cashman, Vilma R. Martins, Vania F. Prado, Marco A. M. Prado

Anatomy and Cell Biology Publications

The prion protein (PrPC) has been suggested to operate as a scaffold/receptor protein in neurons, participating in both physiological and pathological associated events. PrPC, laminin, and metabotropic glutamate receptor 5 (mGluR5) form a protein complex on the plasma membrane that can trigger signaling pathways involved in neuronal differentiation. PrPC and mGluR5 are co-receptors also for -amyloid oligomers (AOs) and have been shown to modulate toxicity and neuronal death in Alzheimer's disease. In the present work, we addressed the potential crosstalk between these two signaling pathways, laminin-PrPC-mGluR5 or AO-PrPC-mGluR5, as well as their interplay. Herein, we demonstrated that an existing complex …

Evaluation Of Negative Energy And Mineral Balance In Periparturient Holstein-Friesian Cattle, Ameer Ahmed Abdelhameed

Open Access Dissertations

Most cows experience a state of negative energy and mineral balance during the periparturient period. This imbalance is a major problem in the dairy industry and it is more frequently seen in multiparous cattle due to their high milk production. A large amount of fat and protein is mobilized in order to address the energy deficit during the periparturient period. The ability to accurately monitor energetics and electrolytes status using accurate, rapid, and low cost point-of-care instruments will assist in optimizing animal health and productivity.

This dissertation contains three studies that evaluated point-of-care instruments for measuring blood and plasma glucose, …

Blockade Of Astrocytic Calcineurin/Nfat Signaling Helps To Normalize Hippocampal Synaptic Function And Plasticity In A Rat Model Of Traumatic Brain Injury, Jennifer L. Furman, Pradoldej Sompol, Susan D. Kraner, Melanie M. Pleiss, Esther J. Putman, Jacob Dunkerson, Hafiz Mohmmad Abdul, Kelly N. Roberts, Stephen William Scheff, Christopher M. Norris

Pharmacology and Nutritional Sciences Faculty Publications

Increasing evidence suggests that the calcineurin (CN)-dependent transcription factor NFAT (Nuclear Factor of Activated T cells) mediates deleterious effects of astrocytes in progressive neurodegenerative conditions. However, the impact of astrocytic CN/NFAT signaling on neural function/recovery after acute injury has not been investigated extensively. Using a controlled cortical impact (CCI) procedure in rats, we show that traumatic brain injury is associated with an increase in the activities of NFATs 1 and 4 in the hippocampus at 7 d after injury. NFAT4, but not NFAT1, exhibited extensive labeling in astrocytes and was found throughout the axon/dendrite layers of CA1 and the dentate …

Role Of The Calcium Plateau In The Neuronal Injury And Behavioral Morbidities Following Organophosphate Intoxication, Laxmikant S. Deshpande, Robert E. Blair, Kristin F. Phillips, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) chemicals include nerve agents and pesticides, and there is a growing concern of OP based chemical attacks against civilians. Current antidotes are essential in limiting immediate mortality associated with OP exposure. However, further research is needed to identify molecular mechanisms underlying long-term neurological deficits following survival of OP toxicity in order to develop effective therapeutics. We have developed rat survival models of OP induced status epilepticus (SE) that mimic chronic mortality and morbidity following OP intoxication. We have observed significant elevations in hippocampal calcium levels after OP SE that persisted for weeks following initial survival. Drugs inhibiting intracellular …

Pharmacological Blockade Of The Calcium Plateau Provides Neuroprotection Following Organophosphate Paraoxon Induced Status Epilepticus In Rats, Laxmikant S. Deshpande, Robert E. Blair, Beverly A. Huang, Kristin F. Phillips, Robert J. Delorenzo

Neurology Publications

Organophosphate (OP) compounds which include nerve agents and pesticides are considered chemical threat agents. Currently approved antidotes are crucial in limiting OP mediated acute mortality. However, survivors of lethal OP exposure exhibit delayed neuronal injury and chronic behavioral morbidities. In this study, we investigated neuroprotective capabilities of dantrolene and carisbamate in a rat survival model of paraoxon (POX) induced status epilepticus (SE). Significant elevations in hippocampal calcium levels were observed 48-h post POX SE survival, and treatment with dantrolene (10 mg/kg, i.m.) and carisbamate (90 mg/kg, i.m.) lowered these protracted calcium elevations. POX SE induced delayed neuronal injury …

Gating Mechanisms Of The Canonical Trp Channel Isoform Trpc4, Dhananjay P. Thakur

Dissertations & Theses (Open Access)

Non-selective cation channels formed by Transient Receptor Potential Canonical (TRPC) proteins play important roles in regulatory and pathophysiological processes. These channels are known to be activated downstream from phospholipase C (PLC) signaling. However, the mechanism by which the PLC pathway activates TRPC4/C5 remains unclear. Uniquely, TRPC4 is maximally activated only when two separate G protein pathways, G_q/11 and G_i/o, are co-stimulated, making it a coincidence detector of G_q/11- and G_i/o -coupled receptor activation. Using HEK293 cells co-expressing mouse TRPC4β and selected G protein-coupled receptors, I observed that coincident stimulation of G_i/o proteins and …

Hippocalcin Response To Calcium: Do Conserved Tryptophans – W30 Or W103 – Matter?, Sunkesula K. Sagar

Graduate School of Biomedical Sciences Theses and Dissertations

Changes in intracellular calcium levels play a very important role in cell signaling, in turn, affecting neuronal functions such as memory, learning and cell death. A class of proteins called Neuronal Calcium Sensor (NCS) proteins serves to modulate the functioning of the neuronal cells in response to changes in calcium levels, and prevent neuronal apoptosis. Structurally, all NCS proteins have 4 calcium-binding EF hand motifs, although EF1 does not bind to calcium in many members. All NCS proteins have an acyl modification at the N- terminus – where a myristoyl group is added post-translationally. Hippocalcin (HPCA) is an NCS protein, …

Mechanisms Of Nanosecond Pulsed Electric Field (Nspef)-Induced Cell Death In Cells And Tumors, Stephen J. Beebe

Bioelectrics Publications

The evolution of pulse power technology from high power physics to biology and medicine places nanosecond pulsed electric fields (nsPEFs) in positions for in vitro and in vivo applications as non-ligand agonists that not only bypass plasma membrane receptors for induction of intracellular signaling pathways, but also bypass intracellular oncogenic impasses to induce cell death by regulated mechanisms. Based on work reviewed here, a likely scenario for cell and tumor demise includes nsPEF-induced permeabilization of the plasma membrane, Ca2+ influx, dissipation of the mitochondrial membrane potential, which is likely due to events beyond permeabilization of the inner mitochondrial membrane, cytochrome …

The Effect Of Different Body Weight Categories On Plasma Macromineral Levels In Four Close-Bred Flocks Of Adult Japanese Quails (Coturnix Coturnix Japonica), Ahmed Sultan Jatoi, Abdul Waheed Sahota, Muhammad Akram, Khalid Javed, Muhammad Hayat Jaspal, Jibran Hussain, Shahid Mehmood, Yassar Abbas, Amjad Hussain Mirani, Hafiz Muhammad Ishaq

Turkish Journal of Veterinary & Animal Sciences

The present study was conducted to investigate plasma macrominerals (Ca, P, Na, K, and Mg) in adult male and female quails according to different body weights in four close-bred flocks of Japanese quails (Coturnix coturnix japonica) maintained at the Avian Research and Training Center of the University of Veterinary and Animal Sciences, Lahore. The results showed that mean plasma Na concentration was significantly (P < 0.05) different in female quails with respect to body size categories. The interaction between flocks and body size for plasma Ca levels was significant (P < 0.05) in both sexes of quails, whereas plasma Na was significant (P < 0.05) in female quails. The mean plasma P and K levels in imported and local flocks of Japanese quails were significantly (P < 0.05) different in female quails, whereas plasma Mg was significantly (P < 0.05) different in male quails. However, with respect to body size categories, plasma P, K, and Mg were significantly (P < 0.05) different in female quails only. The interaction between flocks and body size was significant for K and P in female quails and for plasma Mg levels in both sexes of quails.

Cardioprotection By Controlling Hyperamylinemia In A "Humanized" Diabetic Rat Model, Sanda Despa, Savita Sharma, Todd R. Harris, Hua Dong, Ning Li, Nipavan Chiamvimonvat, Heinrich Taegtmeyer, Kenneth B. Margulies, Bruce D. Hammock, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Chronic hypersecretion of the pancreatic hormone amylin is common in humans with obesity or prediabetic insulin resistance and induces amylin aggregation and proteotoxicity in the pancreas. We recently showed that hyperamylinemia also affects the cardiovascular system. Here, we investigated whether amylin aggregates interact directly with cardiac myocytes and whether controlling hyperamylinemia protects the heart.

METHODS AND RESULTS: By Western blot, we found abundant amylin aggregates in lysates of cardiac myocytes from obese patients, but not in controls. Aggregated amylin was elevated in failing hearts, suggesting a role in myocyte injury. Using rats overexpressing human amylin in the pancreas (HIP …

Coupling S100a4 To Rhotekin Alters Rho Signaling Output In Breast Cancer Cells, Min Chen, Anne R. Bresnick, Kathleen L. O'Connor

Markey Cancer Center Faculty Publications

Rho signaling is increasingly recognized to contribute to invasion and metastasis. In this study, we discovered that metastasis-associated protein S100A4 interacts with the Rho-binding domain (RBD) of Rhotekin, thus connecting S100A4 to the Rho pathway. Glutathione S-transferase pull-down and immunoprecipitation assays demonstrated that S100A4 specifically and directly binds to Rhotekin RBD, but not the other Rho effector RBDs. S100A4 binding to Rhotekin is calcium-dependent and uses residues distinct from those bound by active Rho. Interestingly, we found that S100A4 and Rhotekin can form a complex with active RhoA. Using RNA interference, we determined that suppression of both S100A4 and …

Role Of Neurogranin In The Regulation Of Calcium Binding To Calmodulin, Anuja Chandrasekar

Dissertations & Theses (Open Access)

Role of Neurogranin in the regulation of calcium binding to Calmodulin

Anuja Chandrasekar, B.S

Advisor: M. Neal Waxham, Ph.D

The overall goal of my project was to gain a quantitative understanding of how the interaction between two proteins neurogranin (RC3) and calmodulin (CaM) alters a fundamental property of CaM. CaM, has been extensively studied for more than four decades due to its seminal role in almost all biological functions as a calcium signal transducer. Calcium signals in cardiac and neuronal cells are exquisitely precise and enable activation of some processes while down-regulating others. CaM, with its four calcium binding sites, …