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Gene expression responses over 24 h to lengthening and shortening contractions in human muscle: major changes in CSRP3, MUSTN1, SIX1, and FBXO32.

Authors :
Kostek MC
Chen YW
Cuthbertson DJ
Shi R
Fedele MJ
Esser KA
Rennie MJ
Source :
Physiological genomics [Physiol Genomics] 2007 Sep 19; Vol. 31 (1), pp. 42-52. Date of Electronic Publication: 2007 May 22.
Publication Year :
2007

Abstract

Resistance training using lengthening (eccentric) contractions induces greater increases in muscle size than shortening (concentric) contractions, but the underlying molecular mechanisms are not clear. Using temporal expression profiling, we compared changes in gene expression within 24 h of an acute bout of each type of contractions conducted simultaneously in the quadriceps of different legs. Five healthy young men performed shortening contractions with one leg while the contralateral leg performed lengthening contractions. Biopsies were taken from both legs before exercise and 3, 6, and 24 h afterwards, in the fed state. Expression profiling (n = 3) was performed using a custom-made Affymetrix MuscleChip containing probe sets of approximately 3,300 known genes and expressed sequence tags expressed in skeletal muscle. We identified 51 transcripts differentially regulated between the two exercise modes. Using unsupervised hierarchical clustering, we identified four distinct clusters, three of which corresponded to unique functional categories (protein synthesis, stress response/early growth, and sarcolemmal structure). Using quantitative RT-PCR (n = 5), we verified expression changes (lengthening/shortening) in SIX1 (3 h, -1.9-fold, P < 0.001), CSRP3 (6 h, 2.9-fold, P < 0.05), and MUSTN1 (24 h, 4.3-fold, P < 0.05). We examined whether FBXO32/atrogin-1/MAFbx, a known regulator of protein breakdown and of muscle atrophy was differentially expressed: the gene was downregulated after lengthening contractions (3 h, 2.7-fold, P < 0.05; 6 h, 3.3-fold, P < 0.05; 24 h, 2.3-fold, P < 0.05). The results suggested that lengthening and shortening contractions activated distinct molecular pathways as early as 3 h postexercise. The molecular differences might contribute to mechanisms underlying the physiological adaptations seen with training using the two modes of exercise.

Details

Language :
English
ISSN :
1531-2267
Volume :
31
Issue :
1
Database :
MEDLINE
Journal :
Physiological genomics
Publication Type :
Academic Journal
Accession number :
17519359
Full Text :
https://doi.org/10.1152/physiolgenomics.00151.2006