Biochemical Phenomena, Metabolism, and Nutrition Commons^™

Regulation Of Iron-Related Molecules In The Rat Hippocampus: Sex- And Age-Associated Differences, Srinivasarao Thulluri, Miaozong Wu, Eric R. Blough, Nandini D.P.K. Manne, Ashley B. Litchfield, Bin Wang

MIIR Faculty Research

Iron accumulation, especially that of free oxidized ferrous iron, has been shown to induce tissue oxidative damage and contribute to brain aging and the development of neurodegenerative disease. Here we examine whether sex and advanced age affect the expression of iron-related molecules that participate in regulating free iron levels (heme oxygenase I (HOI), iron-regulatory protein I (IRPI), and ferritin heavy chain (FTH)) and whether changes in the expression of these molecules are associated with differences in the expression of alpha-synuclein (ASN) which is thought to be a critical regulator in the pathogenesis of neurodegeneration. Using a well-established aging animal model, …

Acetaminophen Improves Protein Translational Signaling In Aged Skeletal Muscle, Miaozong Wu, Hua Liu, Jacqueline Fannin, Anjaiah Katta, Yeling Wang, Ravi Kumar Arvapalli, Satyanarayana Paturi, Sunil K. Karkala, Kevin M. Rice, Eric R. Blough

MIIR Faculty Research

Background: Age-related muscle atrophy is characterized by increased oxidative stress, diminished Akt enzymatic function, and reduced phosphorylation of the mammalian target of rapamycin (mTOR), which can be attenuated by chronic acetaminophen ingestion. Here we hypothesize that age-related impairments in Akt/ mTOR function are associated with reduced protein translational signaling, and that these changes, if present, can be attenuated by acetaminophen treatment.

Results: Compared to 6- and 27-month old animals, the expression of the mTOR-complex proteins raptor and GbL and the phosphorylation of tuberin/TSC2 (Thr1462) were reduced in the soleus muscles of very aged rats (33 months old). These changes in …

Fluprostenol-Induced Mapk Signaling Is Independent Of Aging In Fischer 344/Nniahsd X Brown Norway/Binia Rat Aorta, Kevin M. Rice, Ernest M. Walker, Sunil K. Kakarla, Satyanarayana Paturi, Miaozong Wu, Sumit Narula, Eric R. Blough

MIIR Faculty Research

The factors that regulate vascular mechanotransduction and how this process may be altered with aging are poorly understood and have not been widely studied. Recent data suggest that increased tissue loading can result in the release of prostaglandin F2 alpha (PGF2α) and other reports indicate that aging diminishes the ability of the aged aorta to activate mitogen activated protein kinase (MAPK) signaling in response to increased loading. Using ex vivo incubations, here we investigate whether aging affects the ability of the aorta to induce phosphorylation of extracellular signal-regulated kinase 1/2 (ERK½-MAPK), p38-MAPK, and Jun N-terminal kinase (JNK-MAPK) activation following stimulation …

Lean And Obese Zucker Rats Exhibit Different Patterns Of P70s6 Kinase Regulation In The Tibialis Anterior Muscle In Response To High-Force Muscle Contraction, Anjaiah Katta, Sunil K. Karkala, Miaozong Wu, Sarath Meduru, Devashish H. Desai, Kevin M. Rice, Eric R. Blough

MIIR Faculty Research

Increased phosphorylation of the 70-kDa ribosomal S6 kinase (p70S6k) signaling is strongly correlated with the degree of muscle adaptation following exercise. Herein we compare the phosphorylation of p70S6k, Akt, and mammalian target of rapamycin (mTOR) in the tibialis anterior (TA) muscles of lean and obese Zucker rats following a bout of eccentric exercise. Exercise increased p70S6k (Thr389) phosphorylation immediately after (33.3 ± 7.2%) and during [1 h (24.0 ± 14.9%) and 3 h (24.6 ± 11.3%)] recovery in the lean TA and at 3 h (33.5 ± 8.0%) in the obese TA Zucker rats. mTOR (Ser2448) phosphorylation was elevated in …

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) …

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 …

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 …

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 …