Myoneural interactions affect diaphragm muscle adaptations to inactivity

Miyata, Hirofumi; Zhan, Wang; Prakash, Y.S.; Sieck, Gary C.

doi:10.1152/jappl.1995.79.5.1640

Cited by 124 publications

(256 citation statements)

References 0 publications

Supporting

Mentioning

229

Contrasting

Order By: Relevance

“…8,9,11,12,14,21 Briefly, the cervical spinal cord was exposed with a bilateral dorsal laminectomy at C2, and the right anterolateral cord was transected at C2 (i.e., involving the lateral and ventral funiculi, and preserving the dorsal funiculus). All animals were observed daily after surgery, and intramuscular buprenorphine and oral acetaminophen were administered for the first 3 days.…”

Section: Shmentioning

confidence: 99%

“…All SH animals displayed gross deficits related to the cervical spinal cord injury such as altered movements of the rib cage and abdomen consistent with hemidiaphragm paralysis. 8,9 Histological evidence of transplanted MSCs survival…”

Section: Intraspinal Injectionmentioning

confidence: 99%

“…5,6 SH involves a unilateral transection of anterolateral funiculi at C2, which removes premotor drive to phrenic motoneurons, paralyzing the ipsilateral diaphragm muscle. [7][8][9][10][11][12][13][14] Following SH, there is gradual recovery of rhythmic diaphragm activity ipsilateral to injury, [15][16][17][18][19][20][21] suggesting neuroplasticity and strengthening of spared contralateral synaptic inputs to phrenic motoneurons. Importantly, recovery of ipsilateral diaphragm activity after SH can be enhanced by intrathecal delivery of BDNF at the level of the phrenic motor nucleus.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Localized Delivery of Brain-Derived Neurotrophic Factor-Expressing Mesenchymal Stem Cells Enhances Functional Recovery following Cervical Spinal Cord Injury

Gransee

Zhan

Sieck

et al. 2015

Journal of Neurotrauma

116

View full text Add to dashboard Cite

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are important in modulating neuroplasticity and promoting recovery after spinal cord injury. Intrathecal delivery of BDNF enhances functional recovery following unilateral spinal cord hemisection (SH) at C2, a well-established model of incomplete cervical spinal cord injury. We hypothesized that localized delivery of BDNF-expressing mesenchymal stem cells (BDNF-MSCs) would promote functional recovery of rhythmic diaphragm activity after SH. In adult rats, bilateral diaphragm electromyographic (EMG) activity was chronically monitored to determine evidence of complete SH at 3 days post-injury, and recovery of rhythmic ipsilateral diaphragm EMG activity over time post-SH. Wild-type, bone marrow-derived MSCs (WT-MSCs) or BDNF-MSCs (2 · 10 5 cells) were injected intraspinally at C2 at the time of injury. At 14 days post-SH, green fluorescent protein (GFP) immunoreactivity confirmed MSCs presence in the cervical spinal cord. Functional recovery in SH animals injected with WT-MSCs was not different from untreated SH controls (n = 10; overall, 20% at 7 days and 30% at 14 days). In contrast, functional recovery was observed in 29% and 100% of SH animals injected with BDNF-MSCs at 7 days and 14 days post-SH, respectively (n = 7). In BDNF-MSCs treated SH animals at 14 days, root-mean-squared EMG amplitude was 63 -16% of the pre-SH value compared with 12 -9% in the control/WT-MSCs group. We conclude that localized delivery of BDNF-expressing MSCs enhances functional recovery of diaphragm muscle activity following cervical spinal cord injury. MSCs can be used to facilitate localized delivery of trophic factors such as BDNF in order to promote neuroplasticity following spinal cord injury.

show abstract

Section: Shmentioning

confidence: 99%

Section: Intraspinal Injectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Localized Delivery of Brain-Derived Neurotrophic Factor-Expressing Mesenchymal Stem Cells Enhances Functional Recovery following Cervical Spinal Cord Injury

Gransee

Zhan

Sieck

et al. 2015

Journal of Neurotrauma

116

View full text Add to dashboard Cite

show abstract

“…However, the efficacy of force generation and shortening would be impaired. Accordingly, it was observed that following denervation of the rat diaphragm muscle specific force was reduced and Vmax was slowed [52].…”

Section: Myhc-iixmentioning

confidence: 99%

Cross-bridge kinetics in respiratory muscles

Sieck¹,

Prakash²

1997

Eur Respir J

View full text Add to dashboard Cite

In respiratory muscles, force generation and shortening depend on the cyclical interaction of actin and myosin (cross-bridge cycling). During crossbridge cycling, adenosine triphosphate (ATP) is hydrolysed. The globular head region of the myosin heavy chain (MyHC) possesses both the binding site to actin and the site for ATP hydrolysis. Therefore, the MyHC is both a structural and enzymatic protein.Different isoforms of MyHC are expressed in skeletal muscle fibres, and these MyHC isoforms provide mechanical and metabolic diversity. In the present study, the relationships between MyHC isoform expression in single rat diaphragm muscle fibres and their mechanical and energetic properties were evaluated. The expression of MyHC isoforms in single diaphragm muscle fibres was identified using electrophoretic and immunohistochemical techniques. Cross-bridge cycling kinetics in diaphragm muscle fibres clearly depend on MyHC isoform expression, and these differences are interpreted in the context of Huxley's two-state crossbridge model.It is concluded that the unique mechanical and energetic properties of myosin heavy chain isoforms are designed to accomplish different motor behaviours of the diaphragm muscle, and that, as a result of these unique properties, a selective recruitment of diaphragm muscle fibres is essential to avoid fatigue. Eur Respir J 1997; 10: 2147-2158 In respiratory muscles, as in other skeletal muscles, mechanical action results from the cyclical interaction between two contractile proteins, actin and myosin, which is regulated by Ca 2+ release from the sarcoplasmic reticulum (SR) and binding to troponin C. The myosin molecule, a hexameric protein, comprises two myosin heavy chains (MyHC) and four myosin light chains (MyLC). Different isoforms of MyHC exist in skeletal muscle, and the pattern of expression of MyHC isoforms provides the underlying basis for classification of different muscle fibre types. The expression of different MyHC isoforms also provides the underlying basis for the varying mechanical properties of muscle fibres.The dependence of muscle fibre mechanical and energetic properties on MyHC isoform expression stems from the fact that each MyHC contains the binding site of the myosin molecule to actin for cross-bridge formation, as well as the site for the hydrolysis of adenosine triphosphate (ATP) (actomyosin adenosine triphosphatase (ATPase)) during cross-bridge cycling [1][2][3]. Indeed, a smaller proteolytic fragment of the MyHC, comprising the globular head region (subfragment 1), possesses both the actin-binding site and the site for ATP hydrolysis [4]. This review will focus on the mechanical and energetic significance of MyHC isoform expression in diaphragm muscle fibres. Myosin heavy chain expression in skeletal muscle fibresThe genetic regulation of MyHC isoform expression in skeletal muscle fibres is responsive to a number of intrinsic factors, including preprogrammed embryonic and postnatal development, hormonal influences and the pattern of innervation, as well a...

show abstract

“…In our previous studies 23) , after 2 weeks of unilateral diaphragm muscle paralysis induced by SPH, there was only a small decrease in muscle-specific force, and no change in the maximum unloaded shortening velocity. In contrast, after DNV or TTX blockade, there was a marked decrease in specific force and a substantial slowing of maximum unloaded shortening velocity in the diaphragm muscle.…”

Section: Inactivity-related Changes In Diaphragm Musclementioning

confidence: 71%

Age and activity-related changes in the respiratory motor system

Miyata

2013

JPFSM

View full text Add to dashboard Cite

The ability of the respiratory motor system to adapt to various functional demands is very important for maintaining human lifestyles. Age-related changes in the system have been studied in several animals. Furthermore, many kinds of models of altered use have been developed to examine activity-related changes in the system. In this review, the plasticity of the respiratory motor system, including spinal phrenic motoneurons and endplates on muscle fibers are discussed, mainly relating to inactivity and over-activity models in rat diaphragm muscle.

show abstract

Myoneural interactions affect diaphragm muscle adaptations to inactivity

Cited by 124 publications

References 0 publications

Localized Delivery of Brain-Derived Neurotrophic Factor-Expressing Mesenchymal Stem Cells Enhances Functional Recovery following Cervical Spinal Cord Injury

Localized Delivery of Brain-Derived Neurotrophic Factor-Expressing Mesenchymal Stem Cells Enhances Functional Recovery following Cervical Spinal Cord Injury

Cross-bridge kinetics in respiratory muscles

Age and activity-related changes in the respiratory motor system

Contact Info

Product

Resources

About