Biochemical Phenomena, Metabolism, and Nutrition Commons^™

Acetaminophen Prevents Aging-Associated Hyperglycemia In Aged Rats: Effect Of Aging-Associated Hyperactivation Of P38-Mapk And Erk1/2, Miaozong Wu, Devashish H. Desai, Sunil K. Kakarla, Anjaiah Katta, Satyanarayana Paturi, Anil K. Gutta, Kevin M. Rice, Ernest M. Walker Jr., Eric R. Blough

MIIR Faculty Research

Background

Aging-related hyperglycemia is associated with increased oxidative stress and diminished muscle glucose transporter-4 (Glut4) that may be regulated, at least in part, by the mitogen-activated protein kinases (MAPK).

Methods

To test the possibility that aging-related hyperglycemia can be prevented by pharmacological manipulation of MAPK hyperactivation, aged (27-month old) Fischer 344/NNiaHSD × Brown Norway/BiNia F1 (F344BN) rats were administered acetaminophen (30 mg/kg body weight/day) for 6 months in drinking water.

Results

Hepatic histopathology, serum aspartate aminotransferase and alanine aminotransferase analyses suggested that chronic acetaminophen did not cause hepatotoxicity. Compared with adult (6-month) and aged (27-month) rats, very aged rats (33-month) …

Identification And Characterization Of Novel Sir3/Mecp2-Chromatin Interactions, Nicholas L. Adkins

Theses, Dissertations and Capstones

The eukaryotic genome is packaged into chromosomes that are made up of a highly organized and heavily regulated structure called chromatin. The proteins involved in the compaction of DNA into this condensed state are mostly understood at the level of the structure of the nucleosome. The higher order arrangement of chromatin and how it effects gene regulation is only partially understood and characterized. The compaction of nucleosomal arrays into 30-nm and higher structures are partially the responsibility of architectural, or structural, chromatin associated proteins. The following dissertation analyzes the individual chromatin contributions of two well studied architectural proteins, the yeast …

Impact Of The Short-Term Consumption Of A Moderately High Fat Diet On Nitric Oxide Production And Bioavailibility, Kan Huang

Theses, Dissertations and Capstones

Nitric oxide (NO) plays an essential role in the regulation of numerous biological processes. Its bioavailability is assured by a well regulated balance between NO generation and NO removal. Disruptions in this balance contribute to the pathogenesis of various diseases, including hypertension, Alzheimer’s disease, diabetes mellitus and arthritis. Many factors contribute to the maintenance of NO bioavailability by controlling nitric oxide synthase (NOS) expression, NOS activity, the availability of substrates and cofactors involved in the generation of NO by NOS, levels of reactive oxygen species (ROS), and the formation and mobilization of NO reservoirs. Dietary factors have a significant impact …

Upregulation Of Heme Oxygenase-1 Combined With Increased Adiponectin Lowers Blood Pressure In Diabetic Spontaneously Hypertensive Rats Through A Reduction In Endothelial Cell Dysfunction, Apoptosis And Oxidative Stress, Jian Cao, George Drummond, Kazuyoshi Inoue, Komal Sodhi, Xiao Ying Li, Shinji Omura

Pharmaceutical Science and Research

This study was designed to investigate the effect of increased levels of HO-1 on hypertension exacerbated by diabetes. Diabetic spontaneously hypertensive rat (SHR) and WKY (control) animals were treated with streptozotocin (STZ) to induce diabetes and stannous chloride (SnCl2) to upregulate HO-1. Treatment with SnCl2 not only attenuated the increase of blood pressure (p<0.01), but also increased HO-1 protein content, HO activity and plasma adiponectin levels, decreased the levels of superoxide and 3-nitrotyrosine (NT), respectively. Reduction in oxidative stress resulted in the increased expression of Bcl-2 and AKT with a concomitant reduction in circulating endothelial cells (CEC) in the peripheral blood (p<0.005) and an improvement of femoral reactivity (response to acetylcholine). Thus induction of HO-1 accompanied with increased plasma adiponectin levels in diabetic hypertensive rats alters the phenotype through a reduction in oxidative stress, thereby permitting endothelial cells to maintain an anti-apoptotic environment and the restoration of endothelial responses thus preventing hypertension.

Suppression Of Implanted Mda-Mb 231 Human Breast Cancer Growth In Nude Mice By Dietary Walnut, W. Elaine Hardman, Gabriela Ion

Biochemistry and Microbiology

Walnuts contain components that may slow cancer growth including omega 3 fatty acids, phytosterols, polyphenols, carotenoids, and melatonin. A pilot study was performed to determine whether consumption of walnuts could affect growth of MDA-MB 231 human breast cancers implanted into nude mice. Tumor cells were injected into nude mice that were consuming an AIN-76A diet slightly modified to contain 10% corn oil. After the tumors reached 3 to 5 mm diameter, the diet of one group of mice was changed to include ground walnuts, equivalent to 56 g (2 oz) per day in humans. The tumor growth rate from Day …

Diabetes Alters Contraction-Induced Mitogen Activated Protein Kinase Activation In The Rat Soleus And Plantaris, Anjaiah Katta, Deborah L. Preston, Sunil K. Kakarla, Shinichi Asano, Sarath Meduru, Sriram P. Mupparaju, Ellie Yokochi, Kevin M. Rice, Devashish H. Desai, Eric R. Blough

MIIR Faculty Research

The prescription of anaerobic exercise has recently been advocated for the management of diabetes; however exercise-induced signaling in diabetic muscle remains largely unexplored. Evidence from exercise studies in nondiabetics suggests that the extracellular-signal-regulated kinases (Erk1/2), p38, and c-JUN NH2-terminal kinase (Jnk) mitogen-activated protein kinases (MAPKs) are important regulators of muscle adaptation. Here, we compare the basal and the in situ contraction-induced phosphorylation of Erk1/2- p38- and Jnk-MAPK and their downstream targets (p90rsk and MAPKAP-K2) in the plantaris and soleus muscles of normal and obese (fa/fa) Zucker rats. Compared to lean animals, the time course and magnitude of Erk1/2, p90rsk and …

Dietary Canola Oil Suppressed Growth Of Implanted Mda-Mb 231 Human Breast Tumors In Nude Mice, W. Elaine Hardman

Biochemistry and Microbiology

Long chain omega 3 (n-3) fatty acids, eicosapentaenoic (EPA) and/or docosahexaenoic acid (DHA), have been shown to suppress growth of most cancer cells. In vivo, alpha linolenic acid (ALA, 18:3n-3) can be converted to EPA or DHA. We hypothesized that substituting canola oil (10% ALA) for the corn oil (1% ALA) in the diet of cancer bearing mice would slow tumor growth by increasing n-3 fatty acids in the diet. Sixty nude mice received MDA-MB 231 human breast cancer cells and were fed a diet containing 8% w/w corn oil until the mean tumor volume was 60 mm ³ . …

Uniaxial Stretch-Induced Regulation Of Mitogen-Activated Protein Kinase, Akt And P70s6 Kinase In The Ageing Fischer 344 × Brown Norway Rat Aorta, Kevin M. Rice, Devashish H. Desai, Deborah L. Preston, Paulette S. Wehner, Eric R. Blough

MIIR Faculty Research

The effects of ageing on the cardiovascular system contribute to substantial alterations in cellular morphology and function. The variables regulating these changes are unknown; however, one set of signalling molecules that may be of particular importance in mediating numerous cellular responses, including control of cell growth, differentiation and adaptation, are the proteins associated with the mitogen-activated protein kinase (MAPK) signalling systems. The MAPKs, in conjunction with the p70 S6k signalling cascade, have emerged as critical components for regulating numerous mechanotransduction-related cellular responses. Here we investigate the ability of uniaxial stretch to activate the MAPK and p70 S6k pathways in adult …

Lean And Obese Zucker Rats Exhibit Different Patterns Of P70s6kinase Regulation In The Tibialis Anterior Muscle In Response To High Force Muscle Contraction, Anjaiah Katta

Theses, Dissertations and Capstones

Increased muscle loading results in phosphorylation of the 70 kDa ribosomal S6 kinase (p70s6k) signaling pathway and this event strongly correlates with degree of muscle adaptation following resistance exercise. Here, we compared the basal and contraction- induced phosphorylation of p70s6k, Akt and mTOR in tibialis anterior muscles of lean and obese Zucker rats. Immunoblotting demonstrated differences in level of basal p70S6k phosphorylation (Thr 389) in the normal and diabetic TA. HFES had an increase in p70S6k (Thr389) phosphorylation at 0-, 1- and 3-hr in lean TA and only at 3-hr in obese TA. mTOR (Ser 2448) Phosphorylation was elevated in …

Acetaminophen Protects Against Iron-Induced Cardiac Damage In Gerbils, Ernest M. Walker Jr., Christopher P. Epling, Cordel Parris, Silvestre Cansino, Protip Ghosh, Devashish H. Desai, Ryan G. Morrison, Gary L. Wright, Paulette Wehner, Elsa I. Mangiarua, Sandra M. Walker, Eric R. Blough

MIIR Faculty Research

There are few effective agents that safely remove excess iron from iron-overloaded individuals. Our goal was to evaluate the iron-removing effectiveness of acetaminophen given ip or orally in the gerbil iron-overload model. Male gerbils were divided into 5 groups: saline controls, iron-overloaded controls, iron-overloaded treated with ip acetaminophen, iron-overloaded treated with oral acetaminophen, and iron-overloaded treated with ipdeferoxamine. Iron dextran was injected iptwice/wk for 8 wk. Acetaminophen and deferoxamine treatments were given on Mondays, Wednesdays, and Fridays during the same 8 wk and continued for 4 wk after completion of iron-overloading. Echocardiograms were performed after completion of the iron-overloading and …

Diabetes Alters Vascular Mechanotransduction: Pressure-Induced Regulation Of Mitogen Activated Protein Kinases In The Rat Inferior Vena Cava, Kevin M. Rice, Devashish H. Desai, Sunil K. Kakarla, Anjaiah Katta, Deborah L. Preston, Paulette Wehner, Eric R. Blough

MIIR Faculty Research

Background

Diabetes mellitus is an important risk factor for increased vein graft failure after bypass surgery. However, the cellular and molecular mechanism(s) underlying vessel attrition in this population remain largely unexplored. Recent reports have suggested that the pathological remodeling of vein grafts may be mediated by mechanically-induced activation of the mitogen activated protein kinase (MAPK) signaling pathways and the MAPK-related induction of caspase-3 activity. On the basis of these findings, we hypothesized that diabetes may be associated with alterations in how veins "sense" and "respond" to altered mechanical loading.

Methods

Inferior venae cavae (IVC) from the non-diabetic lean (LNZ) and …

Mechanisms Of Growth Hormone Enhancement Of Excitatory Synaptic Transmission In Hippocampus, Ghada Saad Zaglool Ahmed Mahmoud

Theses, Dissertations and Capstones

Growth hormone (GH) deficiency is associated with impaired learning and memory. One possible target for GH effects on memory is the hippocampus, a brain region containing GH receptors (GHRs). To determine if GH acutely alters hippocampal function, recombinant human GH (rhGH) was applied to in vitro rat hippocampal brain slices. Extracellular recordings were used to assess effects of GH on the field EPSP (fEPSP) and long-term potentiation (LTP) of the fEPSP. GHR expression was measured in GH-treated and control rat hippocampal slices using RT-PCR. The GH signaling pathway was investigated by studying the effect of GH on the fEPSP after …

Roles Of Pkc Isozymes In Retinoic Acid-Induced B16 Mouse Melanoma Cell Growth Inhibition And Differentiation, Jianming Han

Theses, Dissertations and Capstones

Protein Kinase C (PKC) has been implicated in many cellular responses. Of the 11 isotypes in this family, seven are expressed in B16 mouse melanoma cells − PKCα, PKCδ, PKCε, PKCθ, PKCλ, PKCζ, and PKCµ.

Treatment of B16 cells with retinoic acid (RA) results in growth inhibition and differentiation. Simultaneously, RA induces a 6-8 fold increase of PKC α protein level, but only about 2-fold increase of PKC enzyme activity. The over- expression of wild type PKCα in B16 cells mimicked the action of RA. The over- expression of enzymatically inactive PKCα, either open or closed conformation, also inhibited B16 …

Regulation Of Retinoic Acid Receptor Α By Protein Kinase C In B16 Mouse Melanoma Cells, Goran Boskovic, Dinakar Desai, Richard M. Niles

Biochemistry and Microbiology

We have previously found that retinoic acid stimulates the expression of protein kinase Cα (PKC) in B16 mouse melanoma cells. Because it has been reported that PKC can phosphorylate retinoic acid receptor (RAR) and alter its function, we determined whether changes in the level and/or activity of PKC could affect the expression or function of the RAR in B16 melanoma. Using in vivophosphorylation and band shift techniques, we could not demonstrate that altering PKC activity and/or protein level changed thein vivo phosphorylation of RARα. However activation of PKC resulted in increased RARα protein. Increased receptor protein correlated with …

Role Of Lipid Peroxidation And Antioxidant Enzymes In Omega 3 Fatty Acids Induced Suppression Of Breast Cancer Xenograft Growth In Mice, W. Elaine Hardman, Jesus Munoz Jr., Ivan L. Cameron

Biochemistry and Microbiology

Background:

Supplementing mice with high levels of dietary n-3 polyunsaturated fatty acids (PUFAs) increases the n-3 PUFAs in cell membranes, increases the susceptibility of the cells for lipid peroxidation (LPO) and decreases the growth rate of mammary and other tumors. However, the results of an earlier study indicated that a factor in addition to LPO was involved in the reduction in tumor growth in n-3 PUFAs fed mice. Athymic mice bearing MDA-MB-231 human breast carcinoma xenografts, were fed fish oil concentrate (FOC) or control diets, with and without supplemental Vitamin E (2000 IU /kg diet) and were sacrificed both before …

Vitamin A And Cancer, Richard M. Niles

Biochemistry and Microbiology

Vitamin A, its physiological metabolites and synthetic derivatives (retinoids) have been shown to have protective effects against the development of certain types of cancer. In addition, pharmacological amounts of retinoids have been used with some success in the treatment of a few human tumors. The chemoprevention effect of retinoids is most likely exerted at the tumor promotion phase of carcinogenesis. Retinoids block tumor promotion by either inhibiting proliferation, inducing apoptosis, inducing differentiation, or a combination of these actions. Clinically, isotretinoin (13-cis-retinoic acid) significantly decreases the incidence of second primary tumors in patients with head and neck cancer and also reduces …

Dietary Fish Oil Sensitizes A549 Lung Xenografts To Doxorubicin Chemotherapy, W. Elaine Hardman, Mary Pat Moyer, Ivan L. Cameron

Biochemistry and Microbiology

A549 xenografts were allowed to grow in nude mice to about 5 mm in diameter, then diets were changed to modified AIN-76 diets containing 19% wt/wt. fish oil (FO) or 20% wt./wt. com oil (CO). Ten days later dietary ferric citrate (0.3% wt./dry wt.) was added and doxoribicin (DOX) treatment (3.6 mg/kg i.v. each of the 5 days for 18 days) commenced. Treatment with DOX halted the growth of tumors in the CO fed mice. However, in those mice, which consumed FO or FO with ferric citrate, treatment with DOX caused significant tumor regression.