Possible role of parathyroid hormone-related protein as a proinflammatory cytokine in atherosclerosis

Parathyroid hormone-related protein (PTHrP) is a vasodilator peptide. In addition, PTHrP appears to affect vascular growth and to be a mediator of inflammation in rheumatic and brain disorders. We examined the possible role of PTHrP in the inflammatory process in atherosclerosis We immunohistochemically analyzed the cellular localization of PTHrP, the type 1 PTH/PTHrP receptor (PTH1R), and monocyte chemoattractant protein-1 (MCP-1) in 26 human carotid atherosclerotic plaques. The inflammatory region of plaques was characterized by high PTHrP, PTH1R, and MCP-1 immunostaining in relation to the cap (0.75+/-0.1 versus 0.29+/-0.04, 0.5+/-0.1 versus 0.25+/-0.05, 0.72+/-0.2 versus 0.29+/-0.05, respectively; P