Myosin heavy chain isoform and ubiquitin protease mRNA expression after passive leg cycling in persons with spinal cord injury

Willoughby, Darryn S.; Priest, Joe W.; Jennings, R.

doi:10.1053/apmr.2000.0810157

Cited by 6 publications

(11 citation statements)

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“…Likewise, a combination of resistance exercises and aerobic exercises performed on opposing days, at an interval of once every 3 days, was able to prevent the increased protein expression of MuRF1 in soleus muscle and maintain fibre cross sectional area following 60-days bed rest[115]. These observations, in conjunction with reports that passive leg cycling in spinal cord injury patients significantly reduced mRNA levels of Ub, E2 and 20S[163], demonstrates that exercise is sufficient to blunt the UPS in human skeletal muscle following disuse atrophy. Whilst the significance of the exercise induced depression of UPSA C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT26 components on protein content is unknown, it is interesting to note its apparent relationship with the restoration of muscle mass.…”

supporting

confidence: 67%

The involvement of the ubiquitin proteasome system in human skeletal muscle remodelling and atrophy

Murton

Constantin²,

Greenhaff³

2008

Biochimica et Biophysica Acta (BBA) - Molecular Basis of Diseas

221

163

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Skeletal muscle exhibits great plasticity in response to altered activity levels, ultimately resulting in tissue remodelling and substantial changes in mass. Animal research would suggest that the ubiquitin proteasome system, in particular the ubiquitin ligases MAFbx/atrogin-1 and MuRF1, are instrumental to the processes underlying these changes. This review article therefore examines the role of proteasomal-mediated protein degradation in human skeletal muscle in health and disease. Specifically, the effects of exercise, disuse and inflammatory disease states on the ubiquitin proteasome system in human skeletal muscle are examined. The article also identifies several inconsistencies between published human studies and data obtained from animal models of muscle atrophy, highlighting the need for a more comprehensive examination of the molecular events responsible for modulating muscle mass in humans.

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supporting

confidence: 67%

The involvement of the ubiquitin proteasome system in human skeletal muscle remodelling and atrophy

Murton

Constantin²,

Greenhaff³

2008

Biochimica et Biophysica Acta (BBA) - Molecular Basis of Diseas

221

163

View full text Add to dashboard Cite

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“…Due to its consideration as being a constitutively expressed "housekeeping gene" [1], glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an external reference standard for detecting the relative change in the quantity of IL-6 mRNA using PCR [30,31]. For GAPDH mRNA (5¢ primer: bases 616 -636, 3¢ primer: bases 1189 -1169, GenEMBL AC NM 002 046), we have previously shown these primers to amplify a PCR fragment of 574 bp [30,31].…”

Section: Blood Samplingmentioning

confidence: 99%

Interleukin-6 Expression After Repeated Bouts of Eccentric Exercise

2003

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Plasma interleukin-6 (IL-6) is known to increase in response to eccentric exercise due to an acute-phase immune response. However, the severity of muscle injury is reduced with repeated bouts of eccentric exercise, possibly as a result of decreases in plasma IL-6. This study determined the response of IL-6 mRNA and IL-6, troponin-I (sTnI), muscle strength, and soreness as a result of repeated bouts of eccentric exercise. Eight males underwent two eccentric exercise bouts (3 wk apart) involving 7 sets of 10 repetitions at 150 % of the isotonic 1-RM of the dominant knee extensors. Blood samples were taken before, after and 2, 4, 6, 24, 48 and 96 h post-exercise. Strength and soreness ratings were assessed before and at 24, 48 and 96 h-post. Data were analyzed with 2 x 4 and 2 x 8 ANOVAs and the non-parametric Friedman test (p < 0.05). Both IL-6 mRNA and IL-6 underwent peak increases (p < 0.05) at 4 h-post and 6 h-post, respectively, but were not different between bouts. However, there were significant changes (p < 0.05) in sTnI, strength, and soreness that were greater after the first bout than the second, characteristic of the repeated bout effect. These results indicate that changes in sTnI, strength and soreness were less with the second eccentric exercise bout whereas the changes in both IL-6 mRNA and protein were not effected between bouts.

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“…However, this conclusion was based solely on either free ubiquitin levels in muscle (27) or proteasomal activities in muscle extracts (22). Others have shown a decrease in the mRNA levels of components of the ubiquitin-proteasome pathway in muscles from spinal cord injury patients after 12 wk of exercise training (31). In the present study, there was no effect of exercise training on muscle expression of ubiquitin, the 14-kDa E2 conjugating enzyme, or the ␤-1 subunit of the 20S proteasome in muscle 24 h postexercise.…”

Section: Discussionmentioning

confidence: 99%

“…For example, exercise has been shown to increase proteasome activity in rat muscle (22) and the expression of one component of this pathway (ubiquitin) in human muscle (27). However, in another study, the mRNA expression of components of the ubiquitin-proteasome pathway was reduced by passive leg cycling in spinal cord injury patients (31). Clearly, more extensive investigations are required to clarify the role of the ubiquitin-proteasome pathway in exercise-induced alterations in protein metabolism, particularly in the postexercise recovery period.…”

mentioning

confidence: 95%

IGF-I has no effect on postexercise suppression of the ubiquitin-proteasome system in rat skeletal muscle

Kee

Taylor

Carlsson

et al. 2002

Journal of Applied Physiology

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Both exercise and insulin-like growth factor I (IGF-I) are known to have major hypertrophic effects in skeletal muscle; however, the interactive effect of exogenous IGF-I and exercise on muscle protein turnover or the ubiquitin-proteasome pathway has not been reported. In the present study, we have examined the interaction between endurance exercise training and IGF-I treatment on muscle protein turnover and the ubiquitin-proteasome pathway in the postexercise period. Adult male rats (270-280 g) were randomized to receive 5 consecutive days of progressive treadmill exercise and/or IGF-I treatment (1 mg. kg body wt(-1). day(-1)). Twenty-four hours after the last bout of exercise, the rate of protein breakdown in incubated muscles was significantly reduced compared with that in unexercised rats. This was associated with a significant reduction in the chymotrypsin-like activity of the proteasome and the rate of ubiquitin-proteasome-dependent casein hydrolysis in muscle extracts from exercised compared with unexercised rats. In contrast, the muscle expression of the 20S proteasome subunit beta-1, ubiquitin, and the 14-kDa E2 ubiquitin-conjugating enzyme was not altered by exercise or IGF-I treatment 24 h postexercise. Exercise had no effect on the rates of total mixed muscle protein synthesis in incubated muscles 24 h postexercise. IGF-I treatment had no effect on muscle weights or the rates of protein turnover 24 h after endurance exercise. These results suggest that a suppression of the ubiquitin-proteasome proteolytic pathway after endurance exercise may contribute to the acute postexercise net protein gain.

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Myosin heavy chain isoform and ubiquitin protease mRNA expression after passive leg cycling in persons with spinal cord injury

Cited by 6 publications

References 0 publications

The involvement of the ubiquitin proteasome system in human skeletal muscle remodelling and atrophy

The involvement of the ubiquitin proteasome system in human skeletal muscle remodelling and atrophy

Interleukin-6 Expression After Repeated Bouts of Eccentric Exercise

IGF-I has no effect on postexercise suppression of the ubiquitin-proteasome system in rat skeletal muscle

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