Versican is induced in infiltrating monocytes in myocardial infarction

Versican, a large chondroitin sulfate proteoglycan, plays a role in conditions such as wound healing and tissue remodelling. To test the hypothesis that versican expression is transiently upregulated and plays a role in the infarcted heart, we examined its expression in a rat model of myocardial infarction. Northern blot analysis demonstrated increased expression of versican mRNA. Quantitative real-time RT-PCR analysis revealed that versican mRNA began to increase as early as 6 h and reached its maximal level 2 days after coronary artery ligation. Versican mRNA then gradually decreased, while the mRNA of decorin, another small proteoglycan, increased thereafter. Versican mRNA was localized in monocytes, as indicated by CD68-positive staining, around the infarct tissue. The induction of versican mRNA was accelerated by ischemia/reperfusion (I/R), which was characterized by massive cell infiltration and enhanced inflammatory response. To examine the alteration of versican expression in monocytes/macrophages, we isolated human peripheral blood mononuclear cells and stimulated them with granulocyte/macrophage colony-stimulating factor (GM-CSF). Stimulation of mononuclear cells with GM-CSF increased the expression of versican mRNA as well as cytokine induction. The production of versican by monocytes in the infarct area represents a novel finding of the expression of an extracellular matrix gene by monocytes in the infarcted heart. We suggest that upregulation of versican in the infarcted myocardium may have a role in the inflammatory reaction, which mediates subsequent chemotaxis in the infarcted heart.

Digital Object Identifer:10.1007/s11010-005-8051-4
Published with permission from the copyright holder. This is the author's copy, as published in Molecular and Cellular Biochemistry, December 2005, Volume 280, Issue 1-2, Pages 47-56.
Publisher URL:http://dx.doi.org/10.11997 The Roya007/s11010-005-8051-4
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