Cloning and relative expression analysis of rat stromal cell derived factor-1 (SDF-1)1:: SDF-1 α mRNA is selectively induced in rat model of myocardial infarction

Stromal cell derived factor-1 (SDF-1) is a member of the non-ELR subfamily of CXC chemokines. SDF-1 and its receptor, CXCR4, are essential for cardiogenesis, hematopoiesis, and vasculogenesis during embryonic development, in addition to involvement in chemotaxis of leukocyte subsets and endothelial cells. In order to study SDF-1 expression in a rat model of myocardial infarction, we cloned and functionally expressed the rat SDF-1alpha orthologue. Rat SDF-1alpha is highly conserved, with >95% identity to its known human, feline, and murine counterparts. Constitutive expression of SDF-1 mRNA was observed in heart, brain, liver, and kidney. Significantly, apart from the SDF-1alpha and beta splice variants, expression of the recently identified SDF-1gamma was uniquely abundant in the heart. SDF-1alpha mRNA was selectively induced in permanent coronary artery occlusion model of myocardial infarction in rat, while SDF-1gamma remained unchanged. Such modulation of SDF-1alpha mRNA expression may be indicative of its role in the inflammatory events in cardiovascular disease.