scholarly journals Skeletal muscle regeneration is altered in the R6/2 mouse model of Huntington's disease

2022 ◽  
Author(s):  
Sanzana Hoque ◽  
Marie Sjogren ◽  
Valerie Allamand ◽  
Kinga Gawlik ◽  
Naomi Franke ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Muscle Damage ◽  
Satellite Cell ◽  
Mouse Models ◽  
Satellite Cells ◽  
Muscle Fibers ◽  
Cag Repeat ◽  
Skeletal Muscle Regeneration

Huntington's disease (HD) is caused by CAG repeat expansion in the huntingtin (HTT) gene. Skeletal muscle wasting alongside central pathology is a well-recognized phenomenon seen in patients with HD and HD mouse models. HD muscle atrophy progresses with disease and affects prognosis and quality of life. Satellite cells, progenitors of mature skeletal muscle fibers, are essential for proliferation, differentiation, and repair of muscle tissue in response to muscle injury or exercise. In this study, we aim to investigate the effect of mutant HTT on the differentiation and regeneration capacity of HD muscle by employing in vitro mononuclear skeletal muscle cell isolation and in vivo acute muscle damage model in R6/2 mice. We found that, similar to R6/2 adult mice, neonatal R6/2 mice also exhibit a significant reduction in myofiber width and morphological changes in gastrocnemius and soleus muscles compared to WT mice. Cardiotoxin (CTX)-induced acute muscle damage in R6/2 and WT mice showed that the Pax7+ satellite cell pool was dampened in R6/2 mice at 4 weeks post-injection, and R6/2 mice exhibited an altered inflammatory profile in response to acute damage. Our results suggest that, in addition to the mutant HTT degenerative effects in mature muscle fibers, expression of mutant HTT in satellite cells might alter developmental and regenerative processes to contribute to the progressive muscle mass loss in HD. Taken together, the results presented here encourage further studies evaluating the underlying mechanisms of satellite cell dysfunction in HD mouse models.

Single-fiber isolation and maintenance of satellite cell quiescence

2005 ◽  
Vol 83 (5) ◽  
pp. 674-676 ◽  
Author(s):  
Ashley C Wozniak ◽  
Judy E Anderson
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Muscle Fibers ◽  
Single Fiber ◽  
Skeletal Muscle Regeneration ◽  
Mouse Muscle ◽  
Collagenase Digestion ◽  
Cell Quiescence ◽  
Gentle Agitation

The activity of satellite cells during myogenesis, development, or skeletal muscle regeneration is strongly modelled using cultures of single muscle fibers. However, there are variations in reported features of gene or protein expression as examined with single-fiber cultures. Here, we examined the potential differences in activation of satellite cells on normal mouse muscle fibers produced during a standard isolation protocol, with or without agitation during collagenase digestion. Activation was detected in satellite cells on fibers after 24 and 48 h of culture in basal growth medium using immunodetection of the incorporation of bromodeoxyuridine (BrdU) into DNA and quantification of the number of BrdU-positive cells per fiber. After 24 and 48 h in culture under nonactivating conditions, the number of activated (BrdU+) satellite cells was greater on fibers that had received gentle agitation during collagenase digestion than on those that were subject to digestion without agitation during isolation. The findings are interpreted to mean that at least some of the variation among published reports may derive from the application of various methods of fiber isolation. The information should be useful for maintaining satellite cell quiescence during studies of the regulatory steps that lead to satellite cell activation.Key words: activation, skeletal muscle, proliferation, single-fiber culture, myogenesis.

scholarly journals Juvenile Huntington’s Disease and Other PolyQ Diseases, Update on Neurodevelopmental Character and Comparative Bioinformatic Review of Transcriptomic and Proteomic Data

2021 ◽  
Vol 9 ◽  
Author(s):  
Karolina Świtońska-Kurkowska ◽  
Bart Krist ◽  
Joanna Delimata ◽  
Maciej Figiel
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Mouse Models ◽  
Muscular Atrophy ◽  
Expression Patterns ◽  
Cag Repeat ◽  
Human Cognition ◽  
Expression Data ◽  
Neuronal Stem Cell ◽  
Polyq Diseases

Polyglutamine (PolyQ) diseases are neurodegenerative disorders caused by the CAG repeat expansion mutation in affected genes resulting in toxic proteins containing a long chain of glutamines. There are nine PolyQ diseases: Huntington’s disease (HD), spinocerebellar ataxias (types 1, 2, 3, 6, 7, and 17), dentatorubral-pallidoluysian atrophy (DRPLA), and spinal bulbar muscular atrophy (SBMA). In general, longer CAG expansions and longer glutamine tracts lead to earlier disease presentations in PolyQ patients. Rarely, cases of extremely long expansions are identified for PolyQ diseases, and they consistently lead to juvenile or sometimes very severe infantile-onset polyQ syndromes. In apparent contrast to the very long CAG tracts, shorter CAGs and PolyQs in proteins seems to be the evolutionary factor enhancing human cognition. Therefore, polyQ tracts in proteins can be modifiers of brain development and disease drivers, which contribute neurodevelopmental phenotypes in juvenile- and adult-onset PolyQ diseases. Therefore we performed a bioinformatics review of published RNAseq polyQ expression data resulting from the presence of polyQ genes in search of neurodevelopmental expression patterns and comparison between diseases. The expression data were collected from cell types reflecting stages of development such as iPSC, neuronal stem cell, neurons, but also the adult patients and models for PolyQ disease. In addition, we extended our bioinformatic transcriptomic analysis by proteomics data. We identified a group of 13 commonly downregulated genes and proteins in HD mouse models. Our comparative bioinformatic review highlighted several (neuro)developmental pathways and genes identified within PolyQ diseases and mouse models responsible for neural growth, synaptogenesis, and synaptic plasticity.

scholarly journals PEDF-derived peptide promotes skeletal muscle regeneration through its mitogenic effect on muscle progenitor cells

2015 ◽  
Vol 309 (3) ◽  
pp. C159-C168 ◽  
Author(s):  
Tsung-Chuan Ho ◽  
Yi-Pin Chiang ◽  
Chih-Kuang Chuang ◽  
Show-Li Chen ◽  
Jui-Wen Hsieh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Cyclin D1 ◽  
Satellite Cell ◽  
Muscle Regeneration ◽  
Muscle Fibers ◽  
Skeletal Muscle Regeneration ◽  
Satellite Cell Proliferation

In response injury, intrinsic repair mechanisms are activated in skeletal muscle to replace the damaged muscle fibers with new muscle fibers. The regeneration process starts with the proliferation of satellite cells to give rise to myoblasts, which subsequently differentiate terminally into myofibers. Here, we investigated the promotion effect of pigment epithelial-derived factor (PEDF) on muscle regeneration. We report that PEDF and a synthetic PEDF-derived short peptide (PSP; residues Ser93-Leu112) induce satellite cell proliferation in vitro and promote muscle regeneration in vivo. Extensively, soleus muscle necrosis was induced in rats by bupivacaine, and an injectable alginate gel was used to release the PSP in the injured muscle. PSP delivery was found to stimulate satellite cell proliferation in damaged muscle and enhance the growth of regenerating myofibers, with complete regeneration of normal muscle mass by 2 wk. In cell culture, PEDF/PSP stimulated C2C12 myoblast proliferation, together with a rise in cyclin D1 expression. PEDF induced the phosphorylation of ERK1/2, Akt, and STAT3 in C2C12 myoblasts. Blocking the activity of ERK, Akt, or STAT3 with pharmacological inhibitors attenuated the effects of PEDF/PSP on the induction of C2C12 cell proliferation and cyclin D1 expression. Moreover, 5-bromo-2′-deoxyuridine pulse-labeling demonstrated that PEDF/PSP stimulated primary rat satellite cell proliferation in myofibers in vitro. In summary, we report for the first time that PSP is capable of promoting the regeneration of skeletal muscle. The signaling mechanism involves the ERK, AKT, and STAT3 pathways. These results show the potential utility of this PEDF peptide for muscle regeneration.

scholarly journals Satellite Cell Depletion Disrupts Transcriptional Coordination and Muscle Adaptation to Exercise

Function ◽  
2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Davis A Englund ◽  
Vandré C Figueiredo ◽  
Cory M Dungan ◽  
Kevin A Murach ◽  
Bailey D Peck ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Gene Networks ◽  
Wheel Running ◽  
Skeletal Muscle Regeneration ◽  
Rna Seq ◽  
Muscle Adaptation ◽  
Hypertrophic Growth ◽  
Adaptation To Exercise

Abstract Satellite cells are required for postnatal development, skeletal muscle regeneration across the lifespan, and skeletal muscle hypertrophy prior to maturity. Our group has aimed to address whether satellite cells are required for hypertrophic growth in mature skeletal muscle. Here, we generated a comprehensive characterization and transcriptome-wide profiling of skeletal muscle during adaptation to exercise in the presence or absence of satellite cells in order to identify distinct phenotypes and gene networks influenced by satellite cell content. We administered vehicle or tamoxifen to adult Pax7-DTA mice and subjected them to progressive weighted wheel running (PoWeR). We then performed immunohistochemical analysis and whole-muscle RNA-seq of vehicle (SC+) and tamoxifen-treated (SC−) mice. Further, we performed single myonuclear RNA-seq to provide detailed information on how satellite cell fusion affects myonuclear transcription. We show that while skeletal muscle can mount a robust hypertrophic response to PoWeR in the absence of satellite cells, growth, and adaptation are ultimately blunted. Transcriptional profiling reveals several gene networks key to muscle adaptation are altered in the absence of satellite cells.

scholarly journals Striatal Circuit Development and Its Alterations in Huntington’s Disease

2020 ◽  
Author(s):  
Margaux Lebouc ◽  
Quentin Richard ◽  
Maurice Garret ◽  
Jérôme Baufreton
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Mouse Models ◽  
Neurodegenerative Disorder ◽  
Repeat Expansion ◽  
Cag Repeat ◽  
Rodent Models ◽  
Network Development ◽  
Cag Repeat Expansion ◽  
Circuit Development

Huntington's disease (HD) is an inherited neurodegenerative disorder that usually starts during midlife with progressive alterations of motor and cognitive functions. The disease is caused by a CAG repeat expansion within the huntingtin gene leading to severe striatal neurodegeneration. Recent studies conducted on pre-HD children highlight early striatal developmental alterations starting as soon as 6 years old, the earliest age assessed. These findings, in line with data from mouse models of HD, raise the question of when during development do the first disease-related striatal alterations emerge or whether they contribute to the later appearance of the neurodegenerative features of the disease. In this review we will describe the different stages of striatal network development and then discuss recent evidence for its alterations in rodent models of the disease. We argue that a better understanding of the striatum’s development should help in assessing aberrant neurodevelopmental processes linked to the HD mutation.

scholarly journals Altered Ca2+ signaling in skeletal muscle fibers of the R6/2 mouse, a model of Huntington’s disease

2014 ◽  
Vol 144 (5) ◽  
pp. 393-413 ◽  
Author(s):  
Peter Braubach ◽  
Murat Orynbayev ◽  
Zoita Andronache ◽  
Tanja Hering ◽  
Georg Bernhard Landwehrmeyer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Voltage Clamp ◽  
Trinucleotide Repeat ◽  
Transport Model ◽  
Muscle Fibers ◽  
Muscle Pathology ◽  
Release Flux ◽  
Inward Currents

Huntington’s disease (HD) is caused by an expanded CAG trinucleotide repeat within the gene encoding the protein huntingtin. The resulting elongated glutamine (poly-Q) sequence of mutant huntingtin (mhtt) affects both central neurons and skeletal muscle. Recent reports suggest that ryanodine receptor–based Ca2+ signaling, which is crucial for skeletal muscle excitation–contraction coupling (ECC), is changed by mhtt in HD neurons. Consequently, we searched for alterations of ECC in muscle fibers of the R6/2 mouse, a mouse model of HD. We performed fluorometric recordings of action potentials (APs) and cellular Ca2+ transients on intact isolated toe muscle fibers (musculi interossei), and measured L-type Ca2+ inward currents on internally dialyzed fibers under voltage-clamp conditions. Both APs and AP-triggered Ca2+ transients showed slower kinetics in R6/2 fibers than in fibers from wild-type mice. Ca2+ removal from the myoplasm and Ca2+ release flux from the sarcoplasmic reticulum were characterized using a Ca2+ binding and transport model, which indicated a significant reduction in slow Ca2+ removal activity and Ca2+ release flux both after APs and under voltage-clamp conditions. In addition, the voltage-clamp experiments showed a highly significant decrease in L-type Ca2+ channel conductance. These results indicate profound changes of Ca2+ turnover in skeletal muscle of R6/2 mice and suggest that these changes may be associated with muscle pathology in HD.

scholarly journals Necdin mediates skeletal muscle regeneration by promoting myoblast survival and differentiation

2007 ◽  
Vol 179 (2) ◽  
pp. 305-319 ◽  
Author(s):  
Daniela Deponti ◽  
Stéphanie François ◽  
Silvia Baesso ◽  
Clara Sciorati ◽  
Anna Innocenzi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Transgenic Mice ◽  
Satellite Cell ◽  
Muscle Regeneration ◽  
Muscle Injury ◽  
Muscle Fibers ◽  
Skeletal Muscle Regeneration ◽  
Muscle Degeneration ◽  
Wild Type ◽  
Cell Type

Regeneration of muscle fibers that are lost during pathological muscle degeneration or after injuries is sustained by the production of new myofibers. An important cell type involved in muscle regeneration is the satellite cell. Necdin is a protein expressed in satellite cell–derived myogenic precursors during perinatal growth. However, its function in myogenesis is not known. We compare transgenic mice that overexpress necdin in skeletal muscle with both wild-type and necdin null mice. After muscle injury the necdin null mice show a considerable defect in muscle healing, whereas mice that overexpress necdin show a substantial increase in myofiber regeneration. We also find that in muscle, necdin increases myogenin expression, accelerates differentiation, and counteracts myoblast apoptosis. Collectively, these data clarify the function and mechanism of necdin in skeletal muscle and show the importance of necdin in muscle regeneration.

scholarly journals Canonical NF-κB signaling regulates satellite stem cell homeostasis and function during regenerative myogenesis

2018 ◽  
Vol 11 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Alex R Straughn ◽  
Sajedah M Hindi ◽  
Guangyan Xiong ◽  
Ashok Kumar
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Cell Function ◽  
Skeletal Muscle Regeneration ◽  
Cell Homeostasis ◽  
Adult Skeletal Muscle ◽  
Adult Mice ◽  
And Function

Abstract Skeletal muscle regeneration in adults is attributed to the presence of satellite stem cells that proliferate, differentiate, and eventually fuse with injured myofibers. However, the signaling mechanisms that regulate satellite cell homeostasis and function remain less understood. While IKKβ-mediated canonical NF-κB signaling has been implicated in the regulation of myogenesis and skeletal muscle mass, its role in the regulation of satellite cell function during muscle regeneration has not been fully elucidated. Here, we report that canonical NF-κB signaling is induced in skeletal muscle upon injury. Satellite cell-specific inducible ablation of IKKβ attenuates skeletal muscle regeneration in adult mice. Targeted ablation of IKKβ also reduces the number of satellite cells in injured skeletal muscle of adult mice, potentially through inhibiting their proliferation and survival. We also demonstrate that the inhibition of specific components of the canonical NF-κB pathway causes precocious differentiation of cultured satellite cells both ex vivo and in vitro. Finally, our results highlight that the constitutive activation of canonical NF-κB signaling in satellite cells also attenuates skeletal muscle regeneration following injury in adult mice. Collectively, our study demonstrates that the proper regulation of canonical NF-κB signaling is important for the regeneration of adult skeletal muscle.

scholarly journals A mouse model of Huntington’s disease shows altered ultrastructure of transverse tubules in skeletal muscle fibers

2021 ◽  
Vol 153 (4) ◽  
Author(s):  
Shannon H. Romer ◽  
Sabrina Metzger ◽  
Kristiana Peraza ◽  
Matthew C. Wright ◽  
D. Scott Jobe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Muscle Fibers ◽  
Membrane Capacitance ◽  
Mrna Levels ◽  
Primary Role ◽  
Ec Coupling ◽  
Skeletal Muscle Fibers

Huntington’s disease (HD) is a fatal and progressive condition with severe debilitating motor defects and muscle weakness. Although classically recognized as a neurodegenerative disorder, there is increasing evidence of cell autonomous toxicity in skeletal muscle. We recently demonstrated that skeletal muscle fibers from the R6/2 model mouse of HD have a decrease in specific membrane capacitance, suggesting a loss of transverse tubule (t-tubule) membrane in R6/2 muscle. A previous report also indicated that Cav1.1 current was reduced in R6/2 skeletal muscle, suggesting defects in excitation–contraction (EC) coupling. Thus, we hypothesized that a loss and/or disruption of the skeletal muscle t-tubule system contributes to changes in EC coupling in R6/2 skeletal muscle. We used live-cell imaging with multiphoton confocal microscopy and transmission electron microscopy to assess the t-tubule architecture in late-stage R6/2 muscle and found no significant differences in the t-tubule system density, regularity, or integrity. However, electron microscopy images revealed that the cross-sectional area of t-tubules at the triad were 25% smaller in R6/2 compared with age-matched control skeletal muscle. Computer simulation revealed that the resulting decrease in the R6/2 t-tubule luminal conductance contributed to, but did not fully explain, the reduced R6/2 membrane capacitance. Analyses of bridging integrator-1 (Bin1), which plays a primary role in t-tubule formation, revealed decreased Bin1 protein levels and aberrant splicing of Bin1 mRNA in R6/2 muscle. Additionally, the distance between the t-tubule and sarcoplasmic reticulum was wider in R6/2 compared with control muscle, which was associated with a decrease in junctophilin 1 and 2 mRNA levels. Altogether, these findings can help explain dysregulated EC coupling and motor impairment in Huntington’s disease.

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