Research article
Gene expression profile of rat left ventricles reveals persisting changes following chronic mild exercise protocol: implications for cardioprotection
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* Corresponding author: Betti Giusti betti.giusti@unifi.it
1 Department of Medical and Surgical Critical Care and Center of Research, Transfer and High Education, "DENOTHE", University of Florence, Florence, Italy
2 Department of Histology, Embryology and Applied Biology, University of Bologna, Bologna, Italy
3 S. Maria agli Ulivi, Don C. Gnocchi Foundation, Florence, Italy
4 Department of Medicine, Surgery and Dentistry, University of Milan, San Paolo Hospital, Milan, Italy
5 Department of Sport Sciences, Nutrition and Health, University of Milan, Milan, Italy
6 Center of Sport Medicine, Don C. Gnocchi Foundation, Milan, Italy
BMC Genomics 2009, 10:342 doi:10.1186/1471-2164-10-342
Published: 30 July 2009Abstract
Background
Epidemiological studies showed that physical exercise, specifically moderate lifelong training, is protective against cardiovascular morbidity and mortality. Most experimental work has focused into the effects and molecular mechanisms underlying intense, rather than mild exercise, by exploring the acute effect of training. Our study aims at investigating the cardioprotective effect of mild chronic exercise training and the gene expression profile changes at 48 hrs after the exercise cessation. Rats were trained at mild intensity on a treadmill: 25 m/min, 10%incline, 1 h/day, 3 days/week, 10 weeks; about 60% of the maximum aerobic power. By Affymetrix technology, we investigated the gene expression profile induced by exercise training in the left ventricle (LV) of trained (n = 10) and control (n = 10) rats. Cardioprotection was investigated by ischemia/reperfusion experiments (n = 10 trained vs. n = 10 control rats).
Results
Mild exercise did not induce cardiac hypertrophy and was cardioprotective as demonstrated by the decreased infarct size (p = 0.02) after ischemia/reperfusion experiments in trained with respect to control rats. Ten genes and 2 gene sets (two pathways) resulted altered in LV of exercised animals with respect to controls. We validated by real-time PCR the increased expression of four genes: similar to C11orf17 protein (RGD1306959), caveolin 3, enolase 3, and hypoxia inducible factor 1 alpha. Moreover, caveolin 3 protein levels were higher in exercised than control rats by immunohistochemistry and Western Blot analysis. Interestingly, the predicted gene similar to C11orf17 protein (RGD1306959) was significantly increased by exercise. This gene has a high homology with the human C11orf17 (alias: protein kinase-A interacting protein 1 or breast cancer associated gene 3). This is the first evidence that this gene is involved in the response to the exercise training.
Conclusion
Our data indicated that few, but significant, genes characterize the gene expression profile of the rat LV, when examined 48 hrs since the last training section and that mild exercise training determines cardioprotection without the induction of hypertrophy.