Therapeutic Collateral Growth Investigations In An Experimental Model Of Femoral Artery Ligation In Mice

Background and objective Apart from their crucial role in pathogen recognition and initiation of the immune defense system, Toll-like receptors (TLRs) are known to be involved in various physiological and pathological vascular processes. The aim of this study was to investigate the potential of the lipopeptide and TLR2/6 ligand macrophage-activating lipoprotein of 2 kDa (MALP-2) to promote blood flow recovery by collateral growth after experimental ligation of the femoral artery in mice. Materials and methods In this study BALB/c mice 10-14 weeks old were subjected to experimental microsurgical ligation of the left femoral artery with simultaneous intravenous application of MALP-2 (1 mu g). Muscles (adductor muscles and gastrocnemius muscles) were harvested 3 and 7 days after surgery for subsequent histological and morphometric analyses. Results The use of MALP-2 significantly improved the diameter and wall thickness of collateral vessels in the adductor muscles. This was accompanied by proliferation of intimal endothelial cells and accumulation of macrophages in perivascular tissue. In addition, injection of MALP-2 promoted angiogenesis through an increased capillary density in lower hindlimbs (gastrocnemius muscle). Conclusion The application of MALP-2 in this experimental animal model showed promising results for the therapeutic use of the TLR2/6 ligand to promote reperfusion of the extremities by the growth of collateral blood vessels.