Medicine and Health Sciences Commons^™

Lat1 Protein Content Increases Following 12 Weeks Of Resistance Exercise Training In Human Skeletal Muscle, Paul A. Roberson, Christopher Brooks Mobley, Matthew A. Romero, Cody T. Haun, Shelby C. Osburn, Petey W. Mumford, Christopher G. Vann, Rory A. Greer, Arny A. Ferrando, Michael D. Roberts

Physiology Faculty Publications

Introduction: Amino acid transporters are essential for cellular amino acid transport and promoting protein synthesis. While previous literature has demonstrated the association of amino acid transporters and protein synthesis following acute resistance exercise and amino acid supplementation, the chronic effect of resistance exercise and supplementation on amino acid transporters is unknown. The purpose herein was to determine if amino acid transporters and amino acid metabolic enzymes were related to skeletal muscle hypertrophy following resistance exercise training with different nutritional supplementation strategies.

Methods: 43 college-aged males were separated into a maltodextrin placebo (PLA, n = 12), leucine (LEU, n = 14), …

Pkd1 Inhibits Ampk2 Through Phosphorylation Of Serine 491 And Impairs Insulin Signaling In Skeletal Muscle Cells, Kimberly A. Coughlan, Rudy J. Valentine, Bella S. Sudit, Katherine Allen, Yossi Dagon, Barbara B. Kahn, Neil B. Ruderman, Asish K. Saha

Rudy Valentine

Background: Diminished activity of the enzyme AMP-activated protein kinase (AMPK) is associated with impaired insulin signaling.

Results: Protein Kinase (PK)C/D1 activation inhibits AMPK2 via Ser491 phosphorylation; PKD1 inhibition prevents this in skeletal muscle cells.

Conclusion: PKD1 is a novel upstream AMPK-kinase that phosphorylates AMPK on Ser491 and regulates insulin signaling.

Significance: PKD1 inhibition may be a novel strategy for improving insulin sensitivity.

Imoxin Attenuates Lps‐Induced Inflammation And Murf1 Expression In Mouse Skeletal Muscle, Rudy J. Valentine, Matthew A. Jefferson, Marian L. Kohut, Hyeyoon Eo

Rudy Valentine

The double‐stranded RNA‐dependent protein kinase (PKR) contributes to inflammatory cytokine expression and disease pathogenesis in many conditions. Limited data are available on the efficacy of the PKR inhibitor imoxin to prevent lipopolysaccharide (LPS)‐induced inflammation in skeletal muscle in vivo. The aim of this study was to evaluate the effect of imoxin, a PKR inhibitor, on inflammatory and atrophy signaling in skeletal muscle in response to an acute inflammatory insult with LPS. Six‐week old C57BL/6J mice received vehicle (saline) or 0.5 mg/kg imoxin 24 and 2 h prior to induction of inflammation via 1 mg/kg LPS. Gastrocnemius muscles were collected 24 …

Acute Resistance Exercise Induces Sestrin2 Phosphorylation And P62 Dephosphorylation In Human Skeletal Muscle, Nina Zeng, Randall F. D'Souza, Vandre C. Figueiredo, James F. Markworth, Llion A. Roberts, Jonathan M. Peake, Cameron J. Mitchell, David Cameron-Smith

Center for Muscle Biology Faculty Publications

Sestrins (1, 2, 3) are a family of stress-inducible proteins capable of attenuating oxidative stress, regulating metabolism, and stimulating autophagy. Sequestosome1 (p62) is also a stress-inducible multifunctional protein acting as a signaling hub for oxidative stress and selective autophagy. It is unclear whether Sestrin and p62^Ser403 are regulated acutely or chronically by resistance exercise (RE) or training (RT) in human skeletal muscle. Therefore, the acute and chronic effects of RE on Sestrin and p62 in human skeletal muscle were examined through two studies. In Study 1, nine active men (22.1 ± 2.2 years) performed a bout of single-leg strength …

Exercise To The Rescue: An Analysis Of Altered Metabolic Gene Regulation Post-Exercise In Lean And Obese Individuals, Brandon Mudd

Mahurin Honors College Capstone Experience/Thesis Projects

The skeletal muscle of obese individuals exhibits a depressed ability to metabolize fats. Exercise training is thought to rescue this dampened ability to metabolize fats; mediated by a coordinated increase in the expression of a network of genes that regulate metabolism and fuel utilization. The purpose of this study is to determine the exercise-induced regulation of metabolically important genes in lean and obese individuals. Muscle biopsies (one pre-exercise/baseline and one immediately post-exercise) were obtained from 4 lean (BF% 24.4 ± 5.5; 23.5 yrs ± 1.9) and 13 obese (BF% 39.7 ± 2.4; 26.1 yrs ± 2.3), age-matched, relatively young subjects, …

Individual Responses For Muscle Activation, Repetitions, And Volume During Three Sets To Failure Of High- (80% 1rm) Versus Low-Load (30% 1rm) Forearm Flexion Resistance Exercise, Nathaniel D. M. Jenkins, Terry J. Housh, Samuel L. Buckner, Haley C. Bergstrom, Kristen C. Cochrane, Cory M. Smith, Ethan C. Hill, Richard J. Schmidt, Joel T. Cramer

Kinesiology and Health Promotion Faculty Publications

This study compared electromyographic (EMG) amplitude, the number of repetitions completed, and exercise volume during three sets to failure of high- (80% 1RM) versus low-load (30% 1RM) forearm flexion resistance exercise on a subject-by-subject basis. Fifteen men were familiarized, completed forearm flexion 1RM testing. Forty-eight to 72 h later, the subjects completed three sets to failure of dumbbell forearm flexion resistance exercise with 80% (n = 8) or 30% (n = 7) 1RM. EMG amplitude was calculated for every repetition, and the number of repetitions performed and exercise volume were recorded. During sets 1, 2, and 3, one …

Short-Term, High-Fat Diet Accelerates Disuse Atrophy And Protein Degradation In A Muscle-Specific Manner In Mice, Steven L. Roseno, Patrick R. Davis, Lance M. Bollinger, Jonathan J. S. Powell, Carol A. Witczak, Jeffrey J. Brault

Kinesiology and Health Promotion Faculty Publications

BACKGROUND: A short-term high-fat diet impairs mitochondrial function and the ability of skeletal muscle to respond to growth stimuli, but it is unknown whether such a diet alters the ability to respond to atrophy signals. The purpose of this study was to determine whether rapid weigh gain induced by a high-fat (HF) diet accelerates denervation-induced muscle atrophy.

METHODS: Adult, male mice (C57BL/6) were fed a control or HF (60 % calories as fat) diet for 3 weeks (3wHF). Sciatic nerve was sectioned unilaterally for the final 5 or 14 days of the diet. Soleus and extensor digitorum longus …

High-Intensity Tasks With External Load In Military Applications: A Review, Eric K. O'Neal, Jared H. Hornsby, Kyle J. Kelleran

Human Movement Sciences & Special Education Faculty Publications

This article provides a synopsis of the limited investigations examining the impact of external load (EL) on performance of high-intensity tasks under load (HITL), EL training intervention effects on HITL performance, and injuries from EL training. Repetitive lifting tasks and initiation of locomotion, such as rapidly moving from a prone position to sprinting appear to be more hindered by EL than maximal sprinting velocity and may explain why training with EL does not improve obstacle course or prolonged (200-300 yard shuttle) drills. EL training appears to offer very little if any benefit for HITL in lesser trained populations. This contrast …

Invited Review: Heat Shock Proteins And Exercise: A Primer, Earl Noble, Kevin Milne, C.W. Melling

Jamie Melling

Heat shock proteins (HSPs) are, in general, prosurvival molecules within the cellular environment, and the overexpression of even just 1 family of HSPs can lead to protection against and improvements after a variety of stressors. Not surprisingly, a fertile area of study has grown out of effors to exploit the innate biologic behaviour of HSPs. Exercise, because of the inherent physiologic stresses associated with it, is but 1 stimulus that can result in a robust increase in various HSPs in several tissues, not the least of which happen to be the heart and skeletal muscle. The purpose of this review …