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Series GSE15117 Query DataSets for GSE15117
Status Public on Jul 01, 2009
Title Temporal pattern of skeletal muscle gene expression following endurance exercise in Alaskan sled dogs
Organism Canis lupus familiaris
Experiment type Expression profiling by array
Summary Background: Muscle responses to exercise are complex, and potentially include acute responses to exercise-induced injury as well as longer-term adaptive training responses. Using Alaskan sled dogs as an experimental model, changes in muscle gene expression were analyzed to better understand the temporal changes that occur after severe exercise.
Methods: Dogs were randomly assigned to undertake in a 160 km run (n=9), or to remain at rest (n=4). Biceps femoris muscle was obtained by needle biopsy from the unexercised dogs and two dogs at each of 2, 6 and 12 hours after the exercise and from 3 dogs 24 hours after exercise. RNA was extracted and microarray analysis used to define gene transcriptional changes.
Results: Nine hundred sixty three transcripts exhibited statistically significant change over time after exercise as compared to the unexercised dogs. The changes in gene expression after exercise occurred in a clear temporal pattern and included transcripts with increased expression 2 hours after exercise with a return towards resting levels by 6 hours after exercise. Other transcripts demonstrated increased expression which peaked at six hours after exercise, while other transcripts showed sustained induction or repression over the 24 hours after exercise. Increases in a number of known transcriptional regulators, including PPAR-α, CERM and CEBPD, were observed 2-hours after exercise. Pathway analysis demonstrated coordinated changes in expression of genes with known functional relationships, including genes involved in muscle remodeling and growth, intermediary metabolism and immune regulation.
Conclusion: Sustained endurance exercise by Alaskan sled dogs induces coordinated changes in gene expression with a clear temporal pattern. RNA expression profiling has the potential to identify novel regulatory mechanisms and responses to exercise stimuli.
 
Overall design Subjects were 13 Alaskan sled dogs aged 4.5 + 2.5 years (mean + SD) and weighing 23.3 + 2.5 kg. Dogs were randomly assigned to two groups – one group of 9 dogs subsequently ran 160 km in 24 hours as 2 sessions of 80 km, separated by a 6 hour rest period. The second group consisted of four dogs housed in unheated kennels, their usual housing, for the duration of the experiment. All dogs were from the same kennel. Dogs were fed a commercial kibble (Eukanuba, Iams Company, Dayton, OH) supplemented with frozen meat during the 8 weeks preceding the study and throughout the study period. The dog’s diet was consistent before, during and after the exercise bout. All dogs had completed 1590 + 100 km of training runs in the 3 months before the study. The dogs had not exercised for 72 hors before the start of this study.
Dogs in the exercise group ran as a team pulling a lightly laden sled and driver over packed snow. Ambient temperatures were -20o to -10o C with no wind. Dogs completed the two 80 km runs in 23 hours, including the 6 hour rest period.
Blood samples were collected by jugular venepuncture from all dogs the day before exercise, and within a 10 minute window at 2, 6, 12, and 24 hours after completing the second run. Samples were collected into evacuated glass tubes containing a clot enhancer.
Muscle samples were collected from each of two dogs within a 10 minute window at 2, 6 and 12 hours after completing exercise and from three dogs 24 hours after completing exercise. Muscle samples were collected from each of the four unexercised dogs within two hours of the other dogs initiating their exercise bout. Each dog had only one biopsy procedure performed. Muscle samples were collected from the biceps femoris muscle using a needle biopsy that yielded approximately 40-60 mg of muscle. The biopsy was performed after clipping and aseptic preparation of the skin overlying the biopsy site. The dog was anesthetized with propofol (6 mg/kg, IV, maintained as necessary with 2 mg/kg additional boluses), a cuffed orotracheal tube placed and the dog ventilated with a hand-held ventilation bag. When adequate anesthesia had been obtained a 5 mm incision was made in the skin. A sterile biopsy needle (12 g PGI EZ Core, Products group International, Inc. Lyons, CO) was then inserted through the incision and a sample of muscle collected. If necessary, repeated collections of muscle were made until a minimum of 40 mg of muscle has been collected from an individual dog. The skin incision was closed with tissue glue and an antibiotic ointment applied. The dog was monitored closely until recovery from anesthesia was complete. Carprofen (4.4 mg/kg, orally) was administered when the dog had recovered sufficiently from anesthesia to have a gag reflex.
 
Citation(s) 19498091
Submission date Mar 04, 2009
Last update date Mar 21, 2012
Contact name Olivia Fong
E-mail(s) olivia.fong@merck.com
Organization name Merck & Co.
Department Molecular Profiling
Lab Merck Research Laboratories
Street address P.O. Box 2000
City Rahway
State/province NJ
ZIP/Postal code 07065
Country USA
 
Platforms (1)
GPL6800 Rosetta/Merck Dog 50k v2.0 Array 1 microarray
Samples (13)
GSM377775 Dog Biceps femoris Unexercised Control Pool (n=4) vs. Biceps femoris; 0000 min (Not Exercised); Dog #01
GSM377776 Dog Biceps femoris Unexercised Control Pool (n=4) vs. Biceps femoris; 0000 min (Not Exercised); Dog #02
GSM377777 Dog Biceps femoris Unexercised Control Pool (n=4) vs. Biceps femoris; 0000 min (Not Exercised); Dog #03
Relations
BioProject PRJNA114867

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE15117_RAW.tar 4.6 Mb (http)(custom) TAR (of TXT)
Processed data included within Sample table
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