Interaction of thyroid state and denervation on skeletal myosin heavy chain expression

Haddad, Fadia; Arnold, Christopher; Zeng, Ming; Baldwin, Kenneth M.

doi:10.1002/(sici)1097-4598(199712)20:12<1487::aid-mus2>3.0.co;2-4

Cited by 44 publications

(55 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The fiber type transformation seen in rabbit muscles did not differ from that in rat muscles examined at an earlier stage of denervation (5,23,25,34,56,59). In one of those studies, coexpression of the different isoforms showed that the switch occurred within individual fibers and not by replacement with fibers of another type (34).…”

Section: Discussionmentioning

confidence: 58%

See 1 more Smart Citation

Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year

Ashley¹,

Sutherland²,

Lanmüller³

et al. 2007

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

JC. Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year. Am J Physiol Cell Physiol 292: C440 -C451, 2007; doi:10.1152/ajpcell.00085.2006.-Our understanding of the effects of long-term denervation on skeletal muscle is heavily influenced by an extensive literature based on the rat. We have studied physiological and morphological changes in an alternative model, the rabbit. In adult rabbits, tibialis anterior muscles were denervated unilaterally by selective section of motor branches of the common peroneal nerve and examined after 10, 36, or 51 wk. Denervation reduced muscle mass and cross-sectional area by 50 -60% and tetanic force by 75%, with no apparent reduction in specific force (force per cross-sectional area of muscle fibers). The loss of mass was associated with atrophy of fast fibers and an increase in fibrous and adipose connective tissue; the diameter of slow fibers was preserved. Within fibers, electron microscopy revealed signs of ultrastructural disorganization of sarcomeres and tubular systems. This, rather than the observed transformation of fiber type from IIx to IIa, was probably responsible for the slow contractile speed of the muscles. The muscle groups denervated for 10, 36, or 51 wk showed no significant differences. At no stage was there any evidence of necrosis or regeneration, and the total number of fibers remained constant. These changes are in marked contrast to the necrotic degeneration and progressive decline in mass and force that have previously been found in long-term denervated rat muscles. The rabbit may be a better choice for a model of the effects of denervation in humans, at least up to 1 yr after lesion.force; shortening velocity; electron microscopy; histochemistry MUCH OF OUR KNOWLEDGE of the effects of long-term denervation of mammalian skeletal muscle comes from experimental studies of total sciatic section in the rat (7,32,54). The mass of the affected muscles falls rapidly within 5-7 days of axotomy (11,18,22,25,55,57,58) and declines further to 30 -50% of control weight in succeeding weeks (1,5,11,14,23,41,60). After several months, muscle weight stabilizes at ϳ5-20% of control (1,13,45).Within the muscles, individual fibers show a reduction of ϳ70% in cross-sectional area (CSA) over a period of months (5,14,21,37), and over 90% (1,21,45) in the longer term. Initially, fast (type II) fibers are more susceptible to atrophy than slow (type I) fibers (5,7,32,38,48,54,59), but over more prolonged periods the fiber types atrophy to a similar extent (6, 54). Corresponding to this reduction in fiber CSA, there is a striking and progressive increase in interstitial collagen and fat (32). At the ultrastructural level, atrophic muscle fibers show evidence of disorganization, including loss or misalignment of sarcomeres, dissociation of the T system and sarcoplasmic reticulum (SR), and changes in the sarcomeric location of mitochondria (32, 51, 52).The major physiological correlate of these morphological changes is a loss of force-generati...

show abstract

Section: Discussionmentioning

confidence: 58%

“…The mass of the affected muscles falls rapidly within 5-7 days of axotomy (11,18,22,25,55,57,58) and declines further to 30 -50% of control weight in succeeding weeks (1,5,11,14,23,41,60). After several months, muscle weight stabilizes at ϳ5-20% of control (1,13,45).…”

mentioning

confidence: 98%

Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year

Ashley¹,

Sutherland²,

Lanmüller³

et al. 2007

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

show abstract

“…Thyroid hormones act by repressing or activating the genes coding for the different myosin isoforms, and all members of the MyHC multigene family respond to changes in 3,5,3Ј-triiodo-L-thyronine (T 3 ) levels, although the mode of response is determined in a highly muscle and fiber type-specific manner (20,40). Both fast-and slow-twitch muscles respond rapidly to both hyper-and hypothyroidism at the MyHC mRNA level (1,2,4,10,14,20). The response at the protein level is slower and partially different from that at the mRNA level.…”

mentioning

confidence: 99%

Aberrant expression of myosin isoforms in skeletal muscles from mice lacking therev-erbAαorphan receptor gene

Pircher¹,

Chomez²,

Yu³

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Aberrant expression of myosin isoforms in skeletal muscles from mice lacking the rev-erbA␣ orphan receptor gene. Am J Physiol Regul Integr Comp Physiol 288: R482-R490, 2005. First published September 16, 2004; doi:10.1152/ajpregu.00690.2003.-The rev-erbA␣ orphan protein belongs to the steroid nuclear receptor superfamily. No ligand has been identified for this protein, and little is known of its function in development or physiology. In this study, we focus on 1) the distribution of the rev-erbA␣ protein in adult fast-and slow-twitch skeletal muscles and muscle fibers and 2) how the rev-erbA␣ protein influences myosin heavy chain (MyHC) isoform expression in mice heterozygous (ϩ/Ϫ) and homozygous (Ϫ/Ϫ) for a rev-erbA␣ protein null allele. In the fast-twitch extensor digitorum longus muscle, rev-erbA␣ protein expression was linked to muscle fiber type; however, MyHC isoform expression did not differ between wild-type, ϩ/Ϫ, or Ϫ/Ϫ mice. In the slow-twitch soleus muscle, the link between rev-erbA␣ protein and MyHC isoform expression was more complex than in the extensor digitorum longus. Here, a significantly higher relative amount of the ␤/slow (type I) MyHC isoform was observed in both rev-erbA␣ Ϫ/Ϫ and ϩ/Ϫ mice vs. that shown in wild-type controls. A role for the ratio of thyroid hormone receptor proteins ␣ 1 to ␣2 in modulating MyHC isoform expression can be ruled out because no differences were seen in MyHC isoform expression between thyroid hormone receptor ␣ 2-deficient mice (heterozygous and homozygous) and wild-type mice. Therefore, our data are compatible with the rev-erbA␣ protein playing an important role in the regulation of skeletal muscle MyHC isoform expression. orphan nuclear receptors; thyroid hormone; fast-and slow-twitch muscle THE VARIABLE EXPRESSION OF myofibrillar protein isoforms is a major determinant of the contractile properties and ATPase activities of skeletal and myocardial fibers (3, 50). The myosin heavy chain (MyHC) molecule is the most abundant myofibrillar protein and is encoded by a multigene family consisting of several members (35). Several isoforms have now been described in rodent skeletal muscles, including one slow isoform (type I or ␤/slow), three fast (IIa, IIx/d, and IIb), and two developmental (embryonic and neonatal/perinatal/fetal) isoforms, which are all coded by distinct genes (50). Four other MyHC isoforms, slow tonic, superfast IIm, ␣-cardiac-like, and extraocular myosin, are expressed in a few specialized muscles (7, 50). Despite their similarity in primary structure, the expression of different MyHC isoforms is precisely regulated in a tissue-specific and developmental stage-specific manner (50, 52). In addition, innervation patterns (33, 45, 46), altered physiological stimuli (34, 46), and various hormones (19) are known to have a significant impact on MyHC isoform expression.Skeletal muscle is a major target for hormone action. Thyroid hormone is one of the most potent regulators of skeletal muscle MyHC isoform expression in mammals, and it has been suggested...

show abstract

“…They typically function as weight-bearing and postural muscles. In the soleus, a slow muscle in the hindlimb, ϳ90% of fibers express the ␤-form of MHC (13,16). The relationship between weight-bearing activity and the expression of ␤-MHC in soleus muscle is demonstrated by removing the factor of load in experimental animal models.…”

mentioning

confidence: 99%

Functional overload increases β-MHC promoter activity in rodent fast muscle via the proximal MCAT (βe3) site

Giger

Haddad

Qin

et al. 2002

American Journal of Physiology-Cell Physiology

Self Cite

View full text Add to dashboard Cite

. Functional overload increases ␤-MHC promoter activity in rodent fast muscle via the proximal MCAT (␤e3) site. Am J Physiol Cell Physiol 282: C518-C527, 2002. First published October 24, 2001 10.1152/ ajpcell.00444.2001 of the rat plantaris muscle by the removal of synergistic muscles induces a shift in the myosin heavy chain (MHC) isoform expression profile from the fast isoforms toward the slow type I, or, ␤-MHC isoform. Different length rat ␤-MHC promoters were linked to a firefly luciferase reporter gene and injected in control and OL plantaris muscles. Reporter activities of Ϫ3,500, Ϫ914, Ϫ408, and Ϫ215 bp promoters increased in response to 1 wk of OL. The smallest Ϫ171 bp promoter was not responsive to OL. Mutation analyses of putative regulatory elements within the Ϫ171 and Ϫ408 bp region were performed. The Ϫ408 bp promoters containing mutations of the ␤e1, distal muscle CAT (MCAT; ␤e2), CACC, or A/T-rich (GATA), were still responsive to OL. Only the proximal MCAT (␤e3) mutation abolished the OL response. Gel mobility shift assays revealed a significantly higher level of complex formation of the ␤e3 probe with nuclear protein from OL plantaris compared with control plantaris. These results suggest that the ␤e3 site functions as a putative OL-responsive element in the rat ␤-MHC gene promoter. gel mobility shift assay; plantaris muscle; direct gene transfer; dual luciferase; ␤-myosin heavy chain SKELETAL MUSCLE FIBERS have the potential to adapt their phenotypic properties to meet different functional demands. The ␤-myosin heavy chain (MHC) isoform is typically expressed in "slow" muscles, which are characterized by a relatively slow speed of shortening but exhibit fatigue resistance and thus are able to maintain contractile activity for long periods of time. They typically function as weight-bearing and postural muscles. In the soleus, a slow muscle in the hindlimb, ϳ90% of fibers express the ␤-form of MHC (13, 16). The relationship between weight-bearing activity and the expression of ␤-MHC in soleus muscle is demonstrated by removing the factor of load in experimental animal models. This is achieved by subjecting the animal to either the microgravity environment of spaceflight (14) or through the ground-based model of hindlimb suspension (4) such that the leg extensor muscles bear little or no weight. When these manipulations are imposed, the expression of ␤-MHC is significantly reduced along with a shift toward increased expression of faster MHC isoforms (4,14).At the other extreme, functional overload induces the expression of ␤-MHC in the plantaris, a fast-twitch ankle extensor muscle that normally expresses the fast MHC isoforms, IIb and IIx, which account for Ͼ80% of the MHC pool (28). In this model, the overload stress is induced by the removal of synergistic muscles along with normal weight-bearing activity, which collectively causes compensatory hypertrophy of muscle fibers (1,26). Adaptation to the overload stimulus also prompts a shift in the fiber-type profile toward a slow fiber-type patte...

show abstract

Interaction of thyroid state and denervation on skeletal myosin heavy chain expression

Cited by 44 publications

References 40 publications

Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year

Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year

Aberrant expression of myosin isoforms in skeletal muscles from mice lacking therev-erbAαorphan receptor gene

Functional overload increases β-MHC promoter activity in rodent fast muscle via the proximal MCAT (βe3) site

Contact Info

Product

Resources

About