LAMPs and ABH histo-blood group antigens in granulation tissue.

Endothelial cells are major participants in angiogenic processes accompanying wound repair. The functions of ABH histo-blood group antigens (HBGAs) and lysosome-associated membrane proteins LAMP-1 and LAMP-2 in endothelial cells of granulation tissue are currently unkown. Here we hypothesize that HBGAs and LAMPs enrich the phenotypic characteristics of endothelial cells and might be implicated in the plasticity of granulation tissue. Immunohistochemistry revealed permanent expression of HBGAs in the cytoplasm of endothelial cells of all sprouting capillaries regardless of the organ examined. A modulation in both the localization and the intensity of the signal for LAMPs was observed. Interestingly, LAMP-1 showed a more intensive staining compared to LAMP-2. LAMP-1 was found in the cytoplasm, as well as on plasma membranes of endothelial cells. We present the first comparative immunohistochemical study of the expression of HBGA and LAMPs in endothelial cells of granulation tissue. Novel evidence for modulating LAMP reactivity is reported. Our results suggest that both glycoconjugates might contribute to the process of neoangiogenesis and tissue remodeling in wound healing.