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| Status |
Public on Mar 08, 2006 |
| Title |
burde-affy-arabi-64764 |
| Organism |
Mus musculus |
| Experiment type |
Expression profiling by array
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| Summary |
In skeletal muscle, the pattern of electrical activity regulates the expression of proteins involved in synaptic transmission, contraction and metabolism. Disruptions in electrical activity, resulting from prolonged bed-rest, cast-immobilization or trauma, inevitably lead to muscle atrophy. The mechanisms that regulate muscle atrophy are poorly understood, but it seems likely that changes in gene expression play a key role in initiating and maintaining a muscle atrophy program. Previously, we found that Runx1, a transcription factor previously termed AML1, was substantially induced in muscle following denervation. More recently, we sought to determine whether this increase in Runx1 expression may be causally related to the morphological changes in skeletal muscle that accompany muscle disuse, notably muscle atrophy. We found that Runx1 is indeed required to sustain muscle and to minimize atrophy following denervation. Experiments described here are designed to identify the genes that are regulated by Runx1 in skeletal muscle with the particular goal of identifying genes that regulate muscle atrophy.
We propose to use microarray analysis to identify genes, expressed in skeletal muscle, that are mis-regulated in mice lacking Runx1.
We inactivated runx1 selectively in skeletal muscle and found that denervated myofibers in mutant mice atrophy far more (90% atrophy) than in wild-type mice (30% atrophy). We therefore reason that Runx1 activates and/or represses genes that are required to sustain muscle and to minimize atrophy.
We generated MCK::cre; runx1f/- and runx1f/- control mice. In normal mice, an increase in runx1 expression is detected by two days after denervation and is maximal by five days after denervation. Muscle atrophy is first evident between one and two weeks after denervation. As we wish to avoid detecting global changes in gene expression that are associated with late stages of muscle atrophy, we plan to denervate muscle for three or five days and to compare gene expression in dissected innervated and denervated muscles from mutant and control mice. We will generate thirty samples for comparison-5 replicates per condition: Samples 1-3 from runx1f/- control mice. (1) innervated tibialis anterior muscles (TA); (2) 3-day-denervated TA; (3) 5-day-denervated TA. Samples 4-6 from MCK::cre; runx1f/- mice. (4) innervated TA; (5) 3-day-denervated TA; (6) 5-day-denervated TA. We obtain sufficient total RNA (10 micrograms) from each dissected muscle to avoid pooling samples. We will analyze adult mice of the same age (~six weeks after birth; most will be littermates) and sex-male. It is difficult to anticipate how many genes will be identified in this screen, as few target genes for Runx1 have been identified in any cell type and none in skeletal muscle. Moreover, although we would prefer to focus our attention on genes that are strongly dependent upon Runx1 expression (e.g. more than 5-fold difference in expression in wild-type and mutant mice), we do not know the extent to which target gene expression will depend upon Runx1. For these reasons, in these experiments, we will analyze expression from five “identical” samples, so that we can be confident that even small (e.g. three-fold) differences in expression can be reliably determined. Importantly, in order to confirm results obtained from the microarray data, we will use other assays (RNase protection) to measure RNA expression of candidate genes in innervated and denervated muscles of wild-type and mutant mice.
Keywords: other
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| Contributor(s) |
Burden SJ |
| Citation(s) |
16024660 |
| Submission date |
Mar 08, 2006 |
| Last update date |
Feb 11, 2019 |
| Contact name |
Winnie Liang |
| E-mail(s) |
wliang@tgen.org
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| Organization name |
Translational Genomics
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| Street address |
445 N. Fifth Street
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| City |
Phoenix |
| State/province |
AZ |
| ZIP/Postal code |
85012 |
| Country |
USA |
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| Platforms (1) |
| GPL1261 |
[Mouse430_2] Affymetrix Mouse Genome 430 2.0 Array |
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| Samples (11)
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| GSM99421 |
skeletal muscle, tibialis anterior: Denervated 3-day Control 1_e1_le1 |
| GSM99422 |
skeletal muscle, tibialis anterior: Denervated 3-day Control 2_e1_le1 |
| GSM99423 |
skeletal muscle, tibialis anterior: Denervated 3-day Control 3_e1_le1 |
| GSM99424 |
skeletal muscle, tibialis anterior: Innverated MCK::cre 1_e1_le1 |
| GSM99425 |
skeletal muscle, tibialis anterior: Innervated MCK::cre 2_e1_le1 |
| GSM99426 |
skeletal muscle, tibialis anterior: Denervated 3-day MCK::cre 1_e1_le1 |
| GSM99427 |
skeletal muscle, tibialis anterior: Denervated 3-day MCK::cre 2_e1_le1 |
| GSM99428 |
skeletal muscle, tibialis anterior: Denervated 3-day MCK::cre 3_e1_le1 |
| GSM99429 |
skeletal muscle, tibialis anterior: Innvervated Control 1_e1_le1 |
| GSM99430 |
skeletal muscle, tibialis anterior: Innvervated Control 2_e1_le1 |
| GSM99431 |
skeletal muscle, tibialis anterior: Innvervated Control 3_e1_le1 |
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| Relations |
| BioProject |
PRJNA94643 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE4411_RAW.tar |
66.0 Mb |
(http)(custom) |
TAR (of CEL) |
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