Physiology Commons^™

Evidence Of Myomir Regulation Of The Pentose Phosphate Pathway During Mechanical Load-Induced Hypertrophy, Taylor Valentino, Vandre C. Figueiredo, C. Brooks Mobley, John J. Mccarthy, Ivan J. Vechetti Jr.

Physiology Faculty Publications

Many of the molecular and cellular mechanisms discovered to regulate skeletal muscle hypertrophy were first identified using the rodent synergist ablation model. This model reveals the intrinsic capability and necessary pathways of skeletal muscle growth in response to mechanical overload (MOV). Reminiscent of the rapid cellular growth observed with cancer, we hypothesized that in response to MOV, skeletal muscle would undergo metabolic programming to sustain increased demands to support hypertrophy. To test this hypothesis, we analyzed the gene expression of specific metabolic pathways taken from transcriptomic microarray data of a MOV time course. We found an upregulation of genes involved …

Fusion And Beyond: Satellite Cell Contributions To Loading-Induced Skeletal Muscle Adaptation, Kevin A. Murach, Christopher S. Fry, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Center for Muscle Biology Faculty Publications

Satellite cells support adult skeletal muscle fiber adaptations to loading in numerous ways. The fusion of satellite cells, driven by cell-autonomous and/or extrinsic factors, contributes new myonuclei to muscle fibers, associates with load-induced hypertrophy, and may support focal membrane damage repair and long-term myonuclear transcriptional output. Recent studies have also revealed that satellite cells communicate within their niche to mediate muscle remodeling in response to resistance exercise, regulating the activity of numerous cell types through various mechanisms such as secretory signaling and cell–cell contact. Muscular adaptation to resistance and endurance activity can be initiated and sustained for a period of …

Chronic Muscle Weakness And Mitochondrial Dysfunction In The Absence Of Sustained Atrophy In A Preclinical Sepsis Model, Allison M. Owen, Samir P. Patel, Jeffrey D. Smith, Beverly K. Balasuriya, Stephanie F. Mori, Gregory S. Hawk, Arnold J. Stromberg, Naohide Kuriyama, Masao Kaneki, Alexander G. Rabchevsky, Timothy A. Butterfield, Karyn A. Esser, Charlotte A. Peterson, Marlene E. Starr, Hiroshi Saito

Physiology Faculty Publications

Chronic critical illness is a global clinical issue affecting millions of sepsis survivors annually. Survivors report chronic skeletal muscle weakness and development of new functional limitations that persist for years. To delineate mechanisms of sepsis-induced chronic weakness, we first surpassed a critical barrier by establishing a murine model of sepsis with ICU-like interventions that allows for the study of survivors. We show that sepsis survivors have profound weakness for at least 1 month, even after recovery of muscle mass. Abnormal mitochondrial ultrastructure, impaired respiration and electron transport chain activities, and persistent protein oxidative damage were evident in the muscle of …

Acute Treadmill Exercise Discriminately Improves The Skeletal Muscle Insulin-Stimulated Growth Signaling Responses In Mice Lacking Redd1, Cory M. Dungan, Bradley S. Gordon, David L Williamson

Physical Therapy Faculty Publications

A loss of the regulated in development and DNA damage 1 (REDD1) hyperactivates mechanistic Target of Rapamycin Complex 1 (mTORC1) reducing insulin‐stimulated insulin signaling, which could provide insight into mechanisms of insulin resistance. Although aerobic exercise acutely inhibits mTORC1 signaling, improvements in insulin‐stimulated signaling are exhibited. The goal of this study was to determine if a single bout of treadmill exercise was sufficient to improve insulin signaling in mice lacking REDD1. REDD1 wildtype (WT) and REDD1 knockout (KO) mice were acutely exercised on a treadmill (30 min, 20 m/min, 5% grade). A within animal noninsulin‐to‐insulin‐stimulated percent change in skeletal muscle …

The Effect Of Coronal Prosthetic Alignment Changes On Socket Reaction Moments, Spatiotemporal Parameters, And Perception Of Alignment During Gait In Individuals With Transtibial Amputation, Hiroshi Hashimoto, Toshiki Kobayashi, Fan Gao, Masataka Kataoka, Kuniharu Okuda

Kinesiology and Health Promotion Faculty Publications

Introduction: The alignment of a prosthesis is clinically determined based on observations by clinicians and the subjective perception of amputees during gait. However, this process has been reported to be unreliable. Socket reaction moment has been reported to be significantly impacted by alignment changes, but the impact of these alignment changes on other gait parameters is unclear. The aim of this study was to investigate the effects of coronal alignment changes of a transtibial prosthesis on socket reaction moment, spatiotemporal parameters, and perceptions of alignment during gait in amputees.

Methods: Nine individuals with transtibial amputation participated in this study. Socket …

Non-Invasive Detection Of Adeno-Associated Viral Gene Transfer Using A Genetically Encoded Cest-Mri Reporter Gene In The Murine Heart, Shelby Meier, Assaf A. Gilad, Jason Anthony Brandon, Chenghao Qian, Erhe Gao, Jose F. Abisambra, Moriel Vandsburger

Physiology Faculty Publications

Research into gene therapy for heart failure has gained renewed interest as a result of improved safety and availability of adeno-associated viral vectors (AAV). While magnetic resonance imaging (MRI) is standard for functional assessment of gene therapy outcomes, quantitation of gene transfer/expression relies upon tissue biopsy, fluorescence or nuclear imaging. Imaging of gene expression through the use of genetically encoded chemical exchange saturation transfer (CEST)-MRI reporter genes could be combined with clinical cardiac MRI methods to comprehensively probe therapeutic gene expression and subsequent outcomes. The CEST-MRI reporter gene Lysine Rich Protein (LRP) was cloned into an AAV9 vector and either …

Comparison Of Efficacy And Safety Between First And Second Generation Drug-Eluting Stents In Patients With Stable Coronary Artery Disease: A Single-Center Retrospective Study, Ru Liu, Fei Xiong, Yuan Wen, Yuan-Liang Ma, Yi Yao, Zhan Gao, Bo Xu, Yue-Jin Yang, Shu-Bin Qiao, Run-Lin Gao, Jin-Qing Yuan

Physiology Faculty Publications

Background: Lots of trials demonstrate that second-generation drug-eluting stents (G2-DES), with their improved properties, offer significantly superior efficacy and safety profiles compared to first generation DES (G1-DES) for patients with coronary artery disease (CAD) receiving percutaneous coronary intervention (PCI). This study aimed to verify the advantage of G2-DES over G1-DES in Chinese patients with stable CAD (SCAD).

Methods: For this retrospective observational analysis, 2709 SCAD patients with either G1-DES (n = 863) or G2-DES (n = 1846) were enrolled consecutively throughout 2013. Propensity score matching (PSM) was applied to control differing baseline factors. Two-year outcomes, including major adverse …

Differential Requirement For Satellite Cells During Overload-Induced Muscle Hypertrophy In Growing Versus Mature Mice, Kevin A. Murach, Sarah H. White, Yuan Wen, Angel Ho, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Physical Therapy Faculty Publications

Background: Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age.

Methods: Pax7^CreER-R26R^DTA mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day …

Neuromuscular Alterations After Ankle Sprains: An Animal Model To Establish Causal Links After Injury, Lindsey K. Lepley, Patrick O. Mckeon, Shane G. Fitzpatrick, Catherine L. Beckemeyer, Timothy L. Uhl, Timothy A. Butterfield

Physical Therapy Faculty Publications

Context: The mechanisms that contribute to the development of chronic ankle instability are not understood. Investigators have developed a hypothetical model in which neuromuscular alterations that stem from damaged ankle ligaments are thought to affect periarticular and proximal muscle activity. However, the retrospective nature of these studies does not allow a causal link to be established.

Objective: To assess temporal alterations in the activity of 2 periarticular muscles of the rat ankle and 2 proximal muscles of the rat hind limb after an ankle sprain.

Design: Controlled laboratory study.

Setting: Laboratory.

Patients or Other Participants: …

Cycle Training Modulates Satellite Cell And Transcriptional Responses To A Bout Of Resistance Exercise, Kevin A. Murach, R. Grace Walton, Christopher S. Fry, Sami L. Michaelis, Jason S. Groshong, Brian S. Finlin, Philip A. Kern, Charlotte A. Peterson

Physical Therapy Faculty Publications

This investigation evaluated whether moderate‐intensity cycle ergometer training affects satellite cell and molecular responses to acute maximal concentric/eccentric resistance exercise in middle‐aged women. Baseline and 72 h postresistance exercise vastus lateralis biopsies were obtained from seven healthy middle‐aged women (56 ± 5 years, BMI 26 ± 1, VO_2max 27 ± 4) before and after 12 weeks of cycle training. Myosin heavy chain (MyHC) I‐ and II‐associated satellite cell density and cross‐sectional area was determined via immunohistochemistry. Expression of 93 genes representative of the muscle‐remodeling environment was also measured via NanoString. Overall fiber size increased ~20% with cycle training ( …

Enhancement Of Aging Rat Laryngeal Muscles With Endogenous Growth Factor Treatment, Joseph C. Stemple, Richard D. Andreatta, Tanya S. Seward, Vrushali Angadi, Maria Dietrich, Colleen A. Mcmullen

Physical Therapy Faculty Publications

Clinical evidence suggests that laryngeal muscle dysfunction is associated with human aging. Studies in animal models have reported morphological changes consistent with denervation in laryngeal muscles with age. Life‐long laryngeal muscle activity relies on cytoskeletal integrity and nerve–muscle communication at the neuromuscular junction (NMJ). It is thought that neurotrophins enhance neuromuscular transmission by increasing neurotransmitter release. We hypothesized that treatment with neurotrophin 4 (NTF4) would modify the morphology and functional innervation of aging rat laryngeal muscles. Fifty‐six Fischer 344xBrown Norway rats (6‐ and 30‐mo age groups) were used to evaluate to determine if NTF4, given systemically (n = 32) …

Combination Therapy Of Hyaluronic Acid Mesotherapic Injections And Sclerotherapy For Treatment Of Lower Leg Telangiectasia Without Major Venous Insufficiency: A Preliminary Clinical Study, Tommaso Iannitti, Valentina Rottigni, Federica Torricelli, Beniamino Palmieri

Physiology Faculty Publications

Background. Telangiectasia is the dilation of dermal capillaries mainly due to hypertension and vein insufficiency. Treatments of choice for this condition are sclerotherapy with foam liquid or intradermal fiber optic laser energy delivery. Aim. The aim of this study was to assess the efficacy of a new therapeutic approach consisting in the use of polymerized hyaluronic acid mesotherapicinjections following sclerotherapy in the areas of the skin affected by telangiectasia in patients without major vein insufficiency. Materials and Methods. A total of 20 women, aged between 19 and 64 years, affected by recurrent lower leg telangiectasia, were included in this study. …