Stimulation of vascular smooth muscle cell migration by macrophage migration inhibitory factor.

Macrophage migration inhibitory factor (MIF) is a well known proinflammatory factor that influences the migration and proliferation of various cell types, predominantly monocytes and macrophages. Recent evidence suggests an important role for MIF in the progression of atherosclerosis and restenosis. For this reason, we studied the effect of MIF on platelet-derived growth factor-BB (PDGF-BB)-induced migration and PDGF receptor protein expression in vascular smooth muscle cells (VSMCs). Furthermore, the possibility of MIF influencing the migration of VSMCs was investigated. Our results show that short-term incubation of MIF is able to enhance PDGF-BB-induced migration. Long-term incubation decreases PDGF-BB-induced migration, but preserves a short-term stimulatory effect. These effects are not regulated at the level of PDGF receptor protein expression. MIF also acts as a chemoattractant for VSMCs, with a maximum response at 15 ng/ml. In contrast, the proliferation of VSMCs was unaffected by MIF. We conclude that MIF has a biphasic effect on VSMC migration. It remains unclear whether this effect is direct or involves the secretion of unidentified promigratory factors. Exogenous MIF does not stimulate VSMC proliferation; however, a role for MIF in proliferation cannot be fully ruled out. In view of the known key contributions of macrophage-derived MIF and VSMCs, the observed effects may well play a role in the progression of atherosclerosis and restenosis.

Methods in molecular cardiology: the polymerase chain reaction.

Several polymerase chain reaction (PCR) techniques are described in this review to give insight into the potential applications for cardiovascular research. Although PCR can be performed in several ways, all applications are based on the same general principle, the amplification of DNA or RNA by the enzyme polymerase. This amplification provides the opportunity to detect, identify and multiply a single copy of DNA or RNA, in or outside the cell. This powerful technique can be used in several directions of DNA and RNA research resulting in the ability to specifically detect the presence and activity of genes. The use of these techniques in cardiovascular research is discussed here.

Methods in molecular cardiology: protein analysis.

Several protein analysis techniques are described in this review to give insight into the potential applications for research. Protein analysis can be performed in several ways. All techniques are derived from the same general principle, the migration of charged particles in an electrical field. Electrophoresis of biomolecules, like proteins, provides the possibility to identify and characterise the molecules based upon different chemical properties. Immobilisation of the proteins after electrophoresis on paper is necessary to allow easy handling of the materials (blotting). These techniques also provide information on the state of a protein, whether it is activated or inactivated. To show the use of the described techniques in cardiology, two applications are provided in this review.