Life Sciences Commons^™

Nox2 Inhibition Regulates Stress Response And Mitigates Skeletal Muscle Fiber Atrophy During Simulated Microgravity, John M. Lawler, Jeffrey M. Hord, Pat Ryan, Dylan Holly, Mariana Janini Gomes, Dinah Rodriguez, Vinicius Guzzoni

Health & Human Performance Faculty Publications and Presentations

Insufficient stress response and elevated oxidative stress can contribute to skeletal muscle atrophy during mechanical unloading (e.g., spaceflight and bedrest). Perturbations in heat shock proteins (e.g., HSP70), antioxidant enzymes, and sarcolemmal neuronal nitric oxidase synthase (nNOS) have been linked to unloading-induced atrophy. We recently discovered that the sarcolemmal NADPH oxidase-2 complex (Nox2) is elevated during unloading, downstream of angiotensin II receptor 1, and concomitant with atrophy. Here, we hypothesized that peptidyl inhibition of Nox2 would attenuate disruption of HSP70, MnSOD, and sarcolemmal nNOS during unloading, and thus muscle fiber atrophy. F344 rats were divided into control (CON), hindlimb unloaded (HU), …

Frontotemporal Dementia Nonsense Mutation Of Progranulin Rescued By Aminoglycosides, Lisha Kuang, Kei Hashimoto, Eric J. Huang, Matthew S. Gentry, Haining Zhu

Molecular and Cellular Biochemistry Faculty Publications

Frontotemporal dementia (FTD) is an early onset dementia and is characterized by progressive atrophy of the frontal and/or temporal lobes. FTD is highly heritable with mutations in progranulin accounting for 5-26% of cases in different populations. Progranulin is involved in endocytosis, secretion and lysosomal processes, but its function under physiological and pathological conditions remains to be defined. Many FTD-causing nonsense progranulin mutations contain a premature termination codon (PTC), thus progranulin haploinsufficiency has been proposed as a major disease mechanism. Currently, there is no effective FTD treatment or therapy.

Aminoglycosides are a class of antibiotics that possess a less known function …

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 …

Frequency Of Precancerous Lesions In Endoscopic Gastric Biopsies In Chronic Gastritis, Saroona Haroon, Naveen Faridi, Faisal Rashid Lodhi, Shafaq Mujtaba

Department of Pathology and Laboratory Medicine

Objective:
To determine the frequency of precancerous lesions in endoscopic gastric biopsies of patients with chronic gastritis.STUDY Design: A case series.
Place and duration of study:
Department of Histopathology, Liaquat National Hospital, Karachi, from July 2008 to January 2009.METHODOLOGY: Over 6 months, 375 endoscopic gastric biopsies of patients with age group of 15-65 years having endoscopic chronic gastritis were included. From final biopsy report, basic information like patient demographics and presence of precancerous lesions i.e. activity (chronic active gastritis), atrophy (atrophic gastritis), intestinal metaplasia and dysplasia were recorded on proforma. Results were described as proportions and frequency.
Results:
The frequency …

Multimodal Imaging Evidence For Axonal And Myelin Deterioration In Amnestic Mild Cognitive Impairment, Brian T. Gold, Yang Jiang, David K. Powell, Charles D. Smith

Neuroscience Faculty Publications

White matter (WM) microstructural declines have been demonstrated in Alzheimer's disease and amnestic mild cognitive impairment (aMCI). However, the pattern of WM microstructural changes in aMCI after controlling for WM atrophy is unknown. Here, we address this issue through joint consideration of aMCI alterations in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity, as well as macrostructural volume in WM and gray matter compartments. Participants were 18 individuals with aMCI and 24 healthy seniors. Voxelwise analyses of diffusion tensor imaging data was carried out using tract-based spatial statistics (TBSS) and voxelwise analyses of high-resolution structural data was conducted using …

Functional And Structural Adaptations Of Skeletal Muscle To Microgravity, Robert Fitts, Danny R. Riley, Jeffrey J. Widrick

Biological Sciences Faculty Research and Publications

Our purpose is to summarize the major effects of space travel on skeletal muscle with particular emphasis on factors that alter function. The primary deleterious changes are muscle atrophy and the associated decline in peak force and power. Studies on both rats and humans demonstrate a rapid loss of cell mass with microgravity. In rats, a reduction in muscle mass of up to 37% was observed within 1 week. For both species, the antigravity soleus muscle showed greater atrophy than the fast-twitch gastrocnemius. However, in the rat, the slow type I fibers atrophied more than the fast type II fibers, …