Musculoskeletal Diseases Commons^™

Unveiling The Impact Of Phosphate On Skeletal Muscle Dysfunction In Chronic Kidney Disease, Hiram Garcia, Sowmya Duddu, Erik Hinojosa, Model Zerfu, Nathaniel L. Alvarez, Mohammad Razzaque, Alex Zuo

Research Colloquium

Background: Chronic Kidney Disease (CKD) is characterized by progressive decline in renal function that ultimately culminates in the inability of the kidneys to effectively maintain homeostasis. The kidneys are a key regulator of phosphate, with other organs assisting in regulation including the skeletal system. In CKD, reduced kidney function leads to hyperphosphatemia. While its impact on the skeletal system is moderately studied, its effects on skeletal muscle are less reviewed. In our literature review, we aim to describe the effects of phosphate in the context of patients who have CKD while providing clinical context for this deserving population. We describe …

Autophagic Signaling Promotes Systems-Wide Remodeling In Skeletal Muscle Upon Oncometabolic Stress By D2-Hg, Yaqi Gao, Kyoungmin Kim, Heidi Vitrac, Rebecca L Salazar, Benjamin D Gould, Daniel Soedkamp, Weston Spivia, Koen Raedschelders, An Q Dinh, Anna G Guzman, Lin Tan, Stavros Azinas, David J R Taylor, Walter Schiffer, Daniel Mcnavish, Helen B Burks, Roberta A Gottlieb, Philip L Lorenzi, Blake M Hanson, Jennifer E Van Eyk, Heinrich Taegtmeyer, Anja Karlstaedt

Faculty, Staff and Student Publications

OBJECTIVES: Cachexia is a metabolic disorder and comorbidity with cancer and heart failure. The syndrome impacts more than thirty million people worldwide, accounting for 20% of all cancer deaths. In acute myeloid leukemia, somatic mutations of the metabolic enzyme isocitrate dehydrogenase 1 and 2 cause the production of the oncometabolite D2-hydroxyglutarate (D2-HG). Increased production of D2-HG is associated with heart and skeletal muscle atrophy, but the mechanistic links between metabolic and proteomic remodeling remain poorly understood. Therefore, we assessed how oncometabolic stress by D2-HG activates autophagy and drives skeletal muscle loss.

METHODS: We quantified genomic, metabolomic, and proteomic changes in …

Deletion Of Mipep In Adipocytes Protects Against Obesity And Insulin Resistance By Boosting Muscle Metabolism, Alexis Diaz-Vegas, Kristen C Cooke, Harry B Cutler, Belinda Yau, Stewart W C Masson, Dylan Harney, Oliver K Fuller, Meg Potter, Søren Madsen, Niamh R Craw, Yiju Zhang, Cesar L Moreno, Melkam A Kebede, G Gregory Neely, Jacqueline Stöckli, James G Burchfield, David E James

Faculty, Staff and Students Publications

Mitochondria facilitate thousands of biochemical reactions, covering a broad spectrum of anabolic and catabolic processes. Here we demonstrate that the adipocyte mitochondrial proteome is markedly altered across multiple models of insulin resistance and reveal a consistent decrease in the level of the mitochondrial processing peptidase miPEP.

OBJECTIVE: To determine the role of miPEP in insulin resistance.

METHODS: To experimentally test this observation, we generated adipocyte-specific miPEP knockout mice to interrogate its role in the aetiology of insulin resistance.

RESULTS: We observed a strong phenotype characterised by enhanced insulin sensitivity and reduced adiposity, despite normal food intake and physical activity. Strikingly, …

Mapping Sca1 Regional Vulnerabilities Reveals Neural And Skeletal Muscle Contributions To Disease, Lisa Duvick, W Michael Southern, Kellie A Benzow, Zoe N Burch, Hillary P Handler, Jason S Mitchell, Hannah Kuivinen, Udaya Gadiparthi, Praseuth Yang, Alyssa Soles, Carrie A Sheeler, Orion Rainwater, Shannah Serres, Erin B Lind, Tessa Nichols-Meade, Yun You, Brennon O'Callaghan, Huda Y Zoghbi, Marija Cvetanovic, Vanessa C Wheeler, James M Ervasti, Michael D Koob, Harry T Orr

Duncan NRI Faculty and Staff Publications

Spinocerebellar ataxia type 1 (SCA1) is a fatal neurodegenerative disease caused by an expanded polyglutamine tract in the widely expressed ataxin-1 (ATXN1) protein. To elucidate anatomical regions and cell types that underlie mutant ATXN1-induced disease phenotypes, we developed a floxed conditional knockin mouse (f-ATXN1146Q/2Q) with mouse Atxn1 coding exons replaced by human ATXN1 exons encoding 146 glutamines. f-ATXN1146Q/2Q mice manifested SCA1-like phenotypes including motor and cognitive deficits, wasting, and decreased survival. Central nervous system (CNS) contributions to disease were revealed using f-ATXN1146Q/2Q;Nestin-Cre mice, which showed improved rotarod, open field, and Barnes maze performance by 6-12 weeks of age. In contrast, …

Estrogen-Related Receptor Signaling In Skeletal Muscle Fitness, Danesh Sopariwala, Hao Nguyen, Vihang Narkar

Faculty, Staff and Student Publications

Skeletal muscle is a highly plastic tissue that can alter its metabolic and contractile features, as well as regenerative potential in response to exercise and other conditions. Multiple signaling factors including metabolites, kinases, receptors, and transcriptional factors have been studied in the regulation of skeletal muscle plasticity. Recently, estrogen-related receptors (ERRs) have emerged as a critical transcriptional hub in control of skeletal muscle homeostasis. ERRα and ERRγ - the two highly expressed ERR sub-types in the muscle respond to various extracellular cues such as exercise, hypoxia, fasting and dietary factors, in turn regulating gene expression in the skeletal muscle. On …

Innately Expressed Estrogen-Related Receptors In The Skeletal Muscle Are Indispensable For Exercise Fitness, Danesh H Sopariwala, Andrea S Rios, Guangsheng Pei, Anirban Roy, Meiricris Tomaz Da Silva, Hao Thi Thu Nguyen, Addison Saley, Rachel Van Drunen, Anastasia Kralli, Kristin Mahan, Zhongming Zhao, Ashok Kumar, Vihang A Narkar

Faculty, Staff and Student Publications

Transcriptional determinants in the skeletal muscle that govern exercise capacity, while poorly defined, could provide molecular insights into how exercise improves fitness. Here, we have elucidated the role of nuclear receptors, estrogen-related receptor alpha and gamma (ERRα/γ) in regulating myofibrillar composition, contractility, and exercise capacity in skeletal muscle. We used muscle-specific single or double (DKO) ERRα/γ knockout mice to investigate the effect of ERRα/γ deletion on muscle and exercise parameters. Individual knockout of ERRα/γ did not have a significant impact on the skeletal muscle. On the other hand, DKO mice exhibit pale muscles compared to wild-type (WT) littermates. RNA-seq analysis …

Effects Of Gabapentin And Pregabalin On Calcium Homeostasis: Implications For Physical Rehabilitation Of Musculoskeletal Tissues, Perla C Reyes Fernandez, Christian S Wright, Stuart J Warden, Julia Hum, Mary C Farach-Carson, William R Thompson

Faculty, Staff and Student Publications

Purpose of review: In this review, we discuss the mechanism of action of gabapentinoids and the potential consequences of long-term treatment with these drugs on the musculoskeletal system.

Recent findings: Gabapentinoids, such as gabapentin (GBP) and pregabalin (PGB) were designed as antiepileptic reagents and are now commonly used as first-line treatment for neuropathic pain and increasingly prescribed off-label for other pain disorders such as migraines and back pain. GBP and PGB exert their analgesic actions by selectively binding the α2δ1 auxiliary subunit of voltage-sensitive calcium channels, thereby inhibiting channel function. Numerous tissues express the α2δ1 subunit where GBP and PGB …

Mir-486 Is Essential For Muscle Function And Suppresses A Dystrophic Transcriptome, Adrienne Samani, Rylie M Hightower, Andrea L Reid, Katherine G English, Michael A Lopez, J Scott Doyle, Michael J Conklin, David A Schneider, Marcas M Bamman, Jeffrey J Widrick, David K Crossman, Min Xie, David Jee, Eric C Lai, Matthew S Alexander

Faculty, Staff and Student Publications

miR-486 is a muscle-enriched microRNA, or “myomiR,” that has reduced expression correlated with Duchenne muscular dystrophy (DMD). To determine the function of miR-486 in normal and dystrophin-deficient muscles and elucidate miR-486 target transcripts in skeletal muscle, we characterized mir-486 knockout mice (mir-486 KO). mir-486 KO mice developed disrupted myofiber architecture, decreased myofiber size, decreased locomotor activity, increased cardiac fibrosis, and metabolic defects were exacerbated in mir-486 KO:mdx5cv (DKO) mice. To identify direct in vivo miR-486 muscle target transcripts, we integrated RNA sequencing and chimeric miRNA eCLIP sequencing to identify key transcripts and pathways that contribute towards mir-486 …

Small Rna Signatures Of Acute Ischemic Stroke In L1cam Positive Extracellular Vesicles, Michael A Lopez, Ying Si, Xianzhen Hu, Valentyna Williams, Fuad Qushair, Jackson Carlyle, Lyndsy Alesce, Michael Conklin, Shawn Gilbert, Marcas M Bamman, Matthew S Alexander, Peter H King

Faculty, Staff and Student Publications

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease characterized by skeletal muscle instability, progressive muscle wasting, and fibrosis. A major driver of DMD pathology stems from aberrant upregulation of transforming growth factor β (TGFβ) signaling. In this report, we investigated the major transducers of TGFβ signaling, i.e., receptor Smads (R-Smads), in DMD patient skeletal muscle and observed a 48-fold increase in Smad8 mRNA. Smad1, Smad2, Smad3, and Smad5 mRNA were only minimally increased. A similar pattern was observed in the muscle from the mdx5cv mouse. Western blot analysis showed upregulation of phosphorylated Smad1, Smad5, and Smad8 …

Pediatric Nemaline Myopathy: A Systematic Review Using Individual Patient Data, Briana Christophers, Michael A Lopez, Vandana A Gupta, Hannes Vogel, Mary Baylies

Faculty, Staff and Student Publications

Nemaline myopathy is a skeletal muscle disease that affects 1 in 50 000 live births. The objective of this study was to develop a narrative synthesis of the findings of a systematic review of the latest case descriptions of patients with NM. A systematic search of MEDLINE, Embase, CINAHL, Web of Science, and Scopus was performed using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the keywords pediatric, child, NM, nemaline rod, and rod myopathy. Case studies focused on pediatric NM and published in English between January 1, 2010, and December 31, …

Feasibility And Efficacy Of Bisphosphonate Use For The Prevention Of Bone And Muscle Loss, Laura E. Flores

Theses & Dissertations

Loss of bone and muscle mass often occurs in tandem, increasing the risk of fragility fractures. Whereas many drugs are approved for the treatment of bone loss, there are few treatments available for the concomitant loss of bone and muscle. Identification of a treatment to mitigate pathologic bone and muscle atrophy has the potential to impact countless populations and influence approaches for healthy aging. Bisphosphonates have emerged as a potential treatment for both bone and muscle loss in cellular, murine, and observational human studies. Our findings of modest weight maintenance in postmenopausal women treated with 12-months of risedronate, relative to …

Dermatomyositis, Sandi Watts

ASA Multidisciplinary Research Symposium

Dermatomyositis is a rare disease which affects the skin and muscles. This disease can manifest in children or not present until one is older. Since this disease is so rare, most individuals who are diagnosed with it will have a team of physicians who work together to help treat the patient.

Structural Studies Of The Ig58 Domain Of The Giant Muscle Protein Obscurin, Matthew C. Oehler

Senior Honors Projects, 2010-2019

Obscurin (720-900 kD) is a giant sarcomeric signaling protein that is the only known link

between the cytoskeleton and the surrounding membrane structure. Mutations to obscurin

and to obscurin binding partners have been linked to human muscle diseases such as

hypertrophic cardiomyopathies and muscular dystrophy. These diseases likely occur due

to the abrogation of specific molecular interactions necessary for suitable function. To

more fully understand how specific mutations lead to disease, here we solve the highresolution

structure of obscurin Ig58. The literature shows that an Arg8Gln mutation to

the Ig58 domain of obscurin is associated with hypertrophic cardiomyopathy (HCM).

Chemical …