Dystrophin deficiency disrupts muscle clock expression and mitochondrial quality control in mdx mice

2021 ◽  
Author(s):  
Justin P. Hardee ◽  
Marissa K. Caldow ◽  
Audrey S.M. Chan ◽  
Stuart K. Plenderleith ◽  
Jennifer Trieu ◽  
...  
Keyword(s):  
Quality Control ◽  
Mrna Expression ◽  
Tibialis Anterior ◽  
Oxidative Capacity ◽  
Mdx Mice ◽  
Dark Cycle ◽  
Mitochondrial Quality Control ◽  
The Core ◽  
Dystrophin Deficiency ◽  
Diurnal Regulation

Impaired oxidative capacity and mitochondrial function contribute to the dystrophic pathology in muscles of Duchenne muscular dystrophy (DMD) patients and in relevant mouse models of the disease. Emerging evidence suggests an association between disrupted core clock expression and mitochondrial quality control, but this has not been established in muscles lacking dystrophin. We examined the diurnal regulation of muscle core clock and mitochondrial quality control expression in dystrophin-deficient C57BL/10ScSn-Dmdmdx (mdx) mice, an established model of DMD. Male C57BL/10 (BL/10; n=18) and mdx mice (n=18) were examined every 4 hours beginning at the dark cycle. Throughout the entire light-dark cycle, extensor digitorum longus (EDL) muscles from mdx mice had decreased core clock mRNA expression (Arntl, Cry1, Cry2, Nr1d2; p<0.05) and disrupted mitochondrial quality control mRNA expression related to biogenesis (decreased; Ppargc1a, Esrra; p<0.05), fission (increased; Dnm1l; p<0.01), fusion (decreased; Opa1, Mfn1; p<0.05) and autophagy/mitophagy (decreased: Bnip3; p<0.05; increased: Becn1; p<0.05). Cosinor analysis revealed a decrease in the rhythmicity parameters mesor and amplitude for Arntl, Cry1, Cry2, Per2, and Nr1d1 (p<0.001) in mdx mice. Diurnal oscillations in Esrra, Sirt1, Map1lc3b and Sqstm1 were absent in mdx mice, along with decreased mesor and amplitude of Ppargc1a mRNA expression (p<0.01). The expression of proteins involved in mitochondrial biogenesis (decreased: PPARGC1A, p<0.05) and autophagy/mitophagy (increased: MAP1LC3BII, SQSTM1, BNIP3; p<0.05) were also dysregulated in tibialis anterior muscles of mdx mice. These findings suggest that dystrophin deficiency in mdx mice impairs the regulation of the core clock and mitochondrial quality control, with relevance to DMD and related disorders.

scholarly journals Disruptions to the limb muscle core molecular clock coincide with changes in mitochondrial quality control following androgen depletion

2019 ◽  
Vol 317 (4) ◽  
pp. E631-E645 ◽  
Author(s):  
Michael L. Rossetti ◽  
Karyn A. Esser ◽  
Choogon Lee ◽  
Robert J. Tomko ◽  
Alexey M. Eroshkin ◽  
...  
Keyword(s):  
Quality Control ◽  
Muscle Atrophy ◽  
Molecular Clock ◽  
Tibialis Anterior ◽  
Expression Patterns ◽  
Limb Muscle ◽  
Mitochondrial Quality Control ◽  
The Core ◽  
Expression Of Genes ◽  
Androgen Depletion

Androgen depletion in humans leads to significant atrophy of the limb muscles. However, the pathways by which androgens regulate limb muscle mass are unclear. Our laboratory previously showed that mitochondrial degradation was related to the induction of autophagy and the degree of muscle atrophy following androgen depletion, implying that decreased mitochondrial quality contributes to muscle atrophy. To increase our understanding of androgen-sensitive pathways regulating decreased mitochondrial quality, total RNA from the tibialis anterior of sham and castrated mice was subjected to microarray analysis. Using this unbiased approach, we identified significant changes in the expression of genes that compose the core molecular clock. To assess the extent to which androgen depletion altered the limb muscle clock, the tibialis anterior muscles from sham and castrated mice were harvested every 4 h throughout a diurnal cycle. The circadian expression patterns of various core clock genes and known clock-controlled genes were disrupted by castration, with most genes exhibiting an overall reduction in phase amplitude. Given that the core clock regulates mitochondrial quality, disruption of the clock coincided with changes in the expression of genes involved with mitochondrial quality control, suggesting a novel mechanism by which androgens may regulate mitochondrial quality. These events coincided with an overall increase in mitochondrial degradation in the muscle of castrated mice and an increase in markers of global autophagy-mediated protein breakdown. In all, these data are consistent with a novel conceptual model linking androgen depletion-induced limb muscle atrophy to reduced mitochondrial quality control via disruption of the molecular clock.

Short term intensified training temporarily impairs mitochondrial respiratory capacity in elite endurance athletes

2021 ◽  
Author(s):  
Daniele A. Cardinale ◽  
Kasper D. Gejl ◽  
Kristine Grøsfjeld Petersen ◽  
Joachim Nielsen ◽  
Niels Ørtenblad ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Quality Control ◽  
Oxidative Capacity ◽  
Endurance Athletes ◽  
Training Period ◽  
Moderate Intensity ◽  
Mitochondrial Quality Control ◽  
Quality Control Program ◽  
Mitochondrial Oxidative Capacity ◽  
Mitochondrial Respiratory

Aim: The maintenance of healthy and functional mitochondria is the result of a complex mitochondrial turnover and herein quality-control program which includes both mitochondrial biogenesis and autophagy of mitochondria. The aim of this study was to examine the effect of an intensified training load on skeletal muscle mitochondrial quality control in relation to changes in mitochondrial oxidative capacity, maximal oxygen consumption and performance in highly trained endurance athletes. Methods: 27 elite endurance athletes performed high intensity interval exercise followed by moderate intensity continuous exercise 3 days per week for 4 weeks in addition to their usual volume of training. Mitochondrial oxidative capacity, abundance of mitochondrial proteins, markers of autophagy and antioxidant capacity of skeletal muscle were assessed in skeletal muscle biopsies before and after the intensified training period. Results: The intensified training period increased several autophagy markers suggesting an increased turnover of mitochondrial and cytosolic proteins. In permeabilized muscle fibers, mitochondrial respiration was ~20 % lower after training although some markers of mitochondrial density increased by 5-50%, indicative of a reduced mitochondrial quality by the intensified training intervention. The antioxidative proteins UCP3, ANT1, and SOD2 were increased after training, whereas we found an inactivation of aconitase. In agreement with the lower aconitase activity, the amount of mitochondrial LON protease that selectively degrades oxidized aconitase, was doubled. Conclusion: Together, this suggests that mitochondrial respiratory function is impaired during the initial recovery from a period of intensified endurance training while mitochondrial quality control is slightly activated in highly trained skeletal muscle.

Resistance Exercise Improves Mitochondrial Quality Control in a Rat Model of Sporadic Inclusion Body Myositis

Gerontology ◽  
2019 ◽  
Vol 65 (3) ◽  
pp. 240-252 ◽  
Author(s):  
Jung-Hoon Koo ◽  
Eun-Bum Kang ◽  
Joon-Yong Cho
Keyword(s):  
Quality Control ◽  
Rat Model ◽  
Mitochondrial Function ◽  
Inclusion Body Myositis ◽  
Oxidative Capacity ◽  
Control Group ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Oxidative Capacity ◽  
Sporadic Inclusion Body Myositis ◽  
Muscle Impairment

Background: Mitochondrial dysfunction is implicated in the pathogenesis of multiple muscular diseases, including sporadic inclusion body myositis (s-IBM), the most common aging-related muscle disease. However, the factors causing mitochondrial dysfunction in s-IBM are unknown. Objective: We hypothesized that resistance exercise (RE) may alleviate muscle impairment by improving mitochondrial function via reducing amyloid-beta (Aβ) accumulation. Methods: Twenty-four male Wistar rats were randomized to a saline-injection control group (sham, n = 8), a chloroquine (CQ) control group (CQ-CON, n = 8), and a CQ plus RE group (CQ-RE, n = 8) in which rats climbed a ladder with weight attached to their tails 9 weeks after starting CQ treatment. Results: RE markedly inhibited soleus muscle atrophy and muscle damage. RE reduced CQ-induced Aβ accumulation, which resulted in decreased formation of rimmed vacuoles and mitochondrial-mediated apoptosis. Most importantly, the decreased Aβ accumulation improved both mitochondrial quality control (MQC) through increased mitochondrial biogenesis and mitophagy, and mitochondrial dynamics. Furthermore, RE-mediated reduction of Aβ accumulation elevated mitochondrial oxidative capacity by upregulating superoxide dismutase-2, catalase, and citrate synthase via activating sirtuin 3 signaling. Conclusion: RE enhances mitochondrial function by improving MQC and mitochondrial oxidative capacity via reducing Aβ accumulation, thereby inhibiting CQ-induced muscle impairment, in a rat model of s-IBM.

scholarly journals Molecular Biomarkers of the Mitochondrial Quality Control Are Differently Affected by Hypoxia-Reoxygenation Stress in Marine Bivalves Crassostrea gigas and Mytilus edulis

2020 ◽  
Vol 7 ◽  
Author(s):  
Jennifer B. M. Steffen ◽  
Halina I. Falfushynska ◽  
Helen Piontkivska ◽  
Inna M. Sokolova
Keyword(s):  
Quality Control ◽  
Mrna Expression ◽  
Mytilus Edulis ◽  
Crassostrea Gigas ◽  
Hypoxia Tolerance ◽  
Marker Genes ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Functions ◽  
Marine Bivalves ◽  
Hypoxia Reoxygenation

Coastal environments commonly experience strong oxygen fluctuations. Resulting hypoxia/reoxygenation stress can negatively affect mitochondrial functions, since oxygen deficiency impairs ATP generation, whereas a surge of oxygen causes mitochondrial damage by oxidative stress. Marine intertidal bivalves are adapted to fluctuating oxygen conditions, yet the underlying molecular mechanisms that sustain mitochondrial integrity and function during oxygen fluctuations are not yet well understood. We used targeted mRNA expression analysis to determine the potential involvement of the mitochondrial quality control mechanisms in responses to short-term hypoxia (24 h at &lt;0.01% O2) and subsequent reoxygenation (1.5 h at 21% O2) in two hypoxia-tolerant marine bivalves, the Pacific oysters Crassostrea gigas and the blue mussels Mytilus edulis. We hypothesized that the genes involved in the mitochondrial quality control will be upregulated during hypoxia, and the less hypoxia-tolerant of the two studied species (M. edulis) will show a stronger dependence on transcriptional upregulation of these pathways than C. gigas. To test these hypotheses, mRNA expression of 17 (C. gigas) and 11 (M. edulis) marker genes involved in mitochondrial fusion, fission, proteolysis and mitophagy was analyzed in the digestive gland of M. edulis and C. gigas in normoxia and during hypoxia-reoxygenation (H/R) stress. In the mussels, the mRNA expression of the transcripts related to mitochondrial dynamics and quality control was strongly altered during H/R stress showing a shift toward fission, suppression of fusion, an increase in mitochondrial proteolysis and onset of mitophagy. These changes indicate that H/R stress induces mitochondrial injury in M. edulis requiring upregulation of the protective mechanisms to segregate the dysfunctional mitochondria by fission and degrade the oxidative damaged proteins and/or organelles. Unlike mussels, the transcript levels of all studied genes in the oysters remained at the baseline (normoxic) levels during H/R stress. This muted transcriptional response of C. gigas is in agreement with earlier findings showing better ability to maintain cellular homeostasis and higher resistance to apoptosis during H/R stress in the oysters compared with the mussels. The revealed species-specific differences in the expression of the mitochondrial quality control pathways shed light on the potentially important mechanisms of mitochondrial protection against H/R-induced damage that might contribute to hypoxia tolerance in marine bivalves.

scholarly journals Mitophagy and Mitochondria Biogenesis Are Differentially Induced in Rat Skeletal Muscles during Immobilization and/or Remobilization

2020 ◽  
Vol 21 (10) ◽  
pp. 3691
Author(s):  
Christiane Deval ◽  
Julie Calonne ◽  
Cécile Coudy-Gandilhon ◽  
Emilie Vazeille ◽  
Daniel Bechet ◽  
...  
Keyword(s):  
Quality Control ◽  
Muscle Mass ◽  
Tibialis Anterior ◽  
Skeletal Muscles ◽  
Mitochondrial Quality Control ◽  
Dynamic Movement ◽  
Mitochondria Biogenesis ◽  
Muscle Groups

Mitochondria alterations are a classical feature of muscle immobilization, and autophagy is required for the elimination of deficient mitochondria (mitophagy) and the maintenance of muscle mass. We focused on the regulation of mitochondrial quality control during immobilization and remobilization in rat gastrocnemius (GA) and tibialis anterior (TA) muscles, which have very different atrophy and recovery kinetics. We studied mitochondrial biogenesis, dynamic, movement along microtubules, and addressing to autophagy. Our data indicated that mitochondria quality control adapted differently to immobilization and remobilization in GA and TA muscles. Data showed i) a disruption of mitochondria dynamic that occurred earlier in the immobilized TA, ii) an overriding role of mitophagy that involved Parkin-dependent and/or independent processes during immobilization in the GA and during remobilization in the TA, and iii) increased mitochondria biogenesis during remobilization in both muscles. This strongly emphasized the need to consider several muscle groups to study the mechanisms involved in muscle atrophy and their ability to recover, in order to provide broad and/or specific clues for the development of strategies to maintain muscle mass and improve the health and quality of life of patients.

scholarly journals Mitochondria Homeostasis and Oxidant/Antioxidant Balance in Skeletal Muscle—Do Myokines Play a Role?

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 179
Author(s):  
Brian Pak Shing Pang ◽  
Wing Suen Chan ◽  
Chi Bun Chan
Keyword(s):  
Skeletal Muscle ◽  
Quality Control ◽  
Control System ◽  
Energy Content ◽  
Mitochondrial Dynamics ◽  
Critical Role ◽  
Oxidative Capacity ◽  
Quality Control System ◽  
Mitochondrial Quality Control ◽  
Tissue Mass

Mitochondria are the cellular powerhouses that generate adenosine triphosphate (ATP) to substantiate various biochemical activities. Instead of being a static intracellular structure, they are dynamic organelles that perform constant structural and functional remodeling in response to different metabolic stresses. In situations that require a high ATP supply, new mitochondria are assembled (mitochondrial biogenesis) or formed by fusing the existing mitochondria (mitochondrial fusion) to maximize the oxidative capacity. On the other hand, nutrient overload may produce detrimental metabolites such as reactive oxidative species (ROS) that wreck the organelle, leading to the split of damaged mitochondria (mitofission) for clearance (mitophagy). These vital processes are tightly regulated by a sophisticated quality control system involving energy sensing, intracellular membrane interaction, autophagy, and proteasomal degradation to optimize the number of healthy mitochondria. The effective mitochondrial surveillance is particularly important to skeletal muscle fitness because of its large tissue mass as well as its high metabolic activities for supporting the intensive myofiber contractility. Indeed, the failure of the mitochondrial quality control system in skeletal muscle is associated with diseases such as insulin resistance, aging, and muscle wasting. While the mitochondrial dynamics in cells are believed to be intrinsically controlled by the energy content and nutrient availability, other upstream regulators such as hormonal signals from distal organs or factors generated by the muscle itself may also play a critical role. It is now clear that skeletal muscle actively participates in systemic energy homeostasis via producing hundreds of myokines. Acting either as autocrine/paracrine or circulating hormones to crosstalk with other organs, these secretory myokines regulate a large number of physiological activities including insulin sensitivity, fuel utilization, cell differentiation, and appetite behavior. In this article, we will review the mechanism of myokines in mitochondrial quality control and ROS balance, and discuss their translational potential.

scholarly journals Parkin drives pS65-Ub turnover independently of canonical autophagy in Drosophila

2021 ◽  
Author(s):  
Joanne L Usher ◽  
Juliette J Lee ◽  
Alvaro Sanchez-Martinez ◽  
Alexander J Whitworth
Keyword(s):  
Parkinson’S Disease ◽  
Cell Culture ◽  
Parkinson's Disease ◽  
Quality Control ◽  
Common Pathway ◽  
Mitochondrial Quality Control ◽  
The Core ◽  
Mitochondrial Turnover ◽  
Related Proteins

Parkinson's disease-related proteins, PINK1 and parkin, act in a common pathway to maintain mitochondrial quality control. While the PINK1-parkin pathway can promote autophagic mitochondrial turnover (mitophagy) in cell culture, recent studies have questioned whether they contribute to mitophagy in vivo, and alternative PINK1- and parkin-dependent mitochondrial quality control pathways have been proposed. To determine the mechanisms by which the Pink1-parkin pathway operates in vivo, we developed methods to detect Ser65-phosphorylated ubiquitin (pS65-Ub) in Drosophila. Exposure to the oxidant paraquat led to robust, Pink1-dependent pS65-Ub production. Surprisingly, parkin-null flies displayed strikingly elevated basal levels of pS65-Ub, suggestive of disrupted flux through the Pink1-parkin pathway. Depletion of the core autophagy proteins Atg1, Atg5 and Atg8a did not cause pS65-Ub accumulation to the same extent as loss of parkin, and overexpression of parkin was able to reduce both basal and paraquat-induced pS65-Ub levels in an Atg5-null background. Taken together, these results suggest that the Pink1-parkin pathway is able to promote mitochondrial turnover independently of canonical autophagy in vivo.

Fine structure of early degenerating myofibers in the tibialis anterior of young ‘MDX’ mouse

1988 ◽  
Vol 46 ◽  
pp. 322-323
Author(s):  
H.D. Geissinger ◽  
C.K. McDonald-Taylor
Keyword(s):  
Fine Structure ◽  
Muscle Regeneration ◽  
Tibialis Anterior ◽  
Genetic Defect ◽  
Mdx Mouse ◽  
Mdx Mice ◽  
Histopathological Changes ◽  
Electron Microscopic ◽  
Dystrophic Mouse ◽  
Preliminary Study

A new strain of mice, which had arisen by mutation from a dystrophic mouse colony was designated ‘mdx’, because the genetic defect, which manifests itself in brief periods of muscle destruction followed by episodes of muscle regeneration appears to be X-linked. Further studies of histopathological changes in muscle from ‘mdx’ mice at the light microscopic or electron microscopic levels have been published, but only one preliminary study has been on the tibialis anterior (TA) of ‘mdx’ mice less than four weeks old. Lesions in the ‘mdx’ mice vary between different muscles, and centronucleation of fibers in all muscles studied so far appears to be especially prominent in older mice. Lesions in young ‘mdx’ mice have not been studied extensively, and the results appear to be at variance with one another. The degenerative and regenerative aspects of the lesions in the TA of 23 to 26-day-old ‘mdx’ mice appear to vary quantitatively.

Regenerating myofibers in tibialis anterior muscles of young ‘MDX’ mice

1987 ◽  
Vol 45 ◽  
pp. 726-727
Author(s):  
H. D. Geissinge ◽  
L.D. Rhodes
Keyword(s):  
Muscular Dystrophy ◽  
Mouse Model ◽  
Tibialis Anterior ◽  
Physiological Activity ◽  
Mdx Mice ◽  
Mode Of Inheritance

A recently discovered mouse model (‘mdx’) for muscular dystrophy in man may be of considerable interest, since the disease in ‘mdx’ mice is inherited by the same mode of inheritance (X-linked) as the human Duchenne (DMD) muscular dystrophy. Unlike DMD, which results in a situation in which the continual muscle destruction cannot keep up with abortive regenerative attempts of the musculature, and the sufferers of the disease die early, the disease in ‘mdx’ mice appears to be transient, and the mice do not die as a result of it. In fact, it has been reported that the severely damaged Tibialis anterior (TA) muscles of ‘mdx’ mice seem to display exceptionally good regenerative powers at 4-6 weeks, so much so, that these muscles are able to regenerate spontaneously up to their previous levels of physiological activity.

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