Immunoelectron Microscopic Characterization of Human Dermal Lymphatic Microvascular Endothelial Cells: Differential Expression of CD31, CD34, and Type IV Collagen with Lymphatic Endothelial Cells vs Blood Capillary Endothelial Cells in Normal Human Skin, Lymphangioma, and Hemangioma In Situ

Abstract

We performed a comparative investigation of the immunomorphological characteristics of lymphatic and blood microvascular endothelial cells in normal human skin, cutaneous lymphangiomas, and hemangiomas, employing a pre-embedding immunogold electron microscopic technique. We stained for cell membrane proteins that are commonly used for light microscopic characterization of blood endothelial cells. With blood microvascular endothelial cells, we observed uniform labeling of the luminal cell membranes with monoclonal antibodies (MAbs) JC70 (CD31), EN-4 (CD31), BMA120, PAL-E, and QBEND-10 (CD34), and strong staining of the vascular basal lamina for Type IV collagen under normal and pathological conditions. In contrast, lymphatic microvascular endothelial cells in normal human skin and in lymphangiomas displayed, in addition to a luminal labeling, pronounced expression of CD31 and CD34 along the abluminal cell membranes. Moreover, CD31 was preferentially detected within intercellular junctions. The expression of CD34 was mostly confined to abluminal endothelial microprocesses and was upregulated in lymphangiomas and hemangiomas. Type IV collagen partially formed the luminal lining of initial lymphatics and occasionally formed bridges over interendothelial gaps. Our findings suggest a function of transmigration protein CD31 in recruitment of dendritic cells into the lymphatic vasculature. CD34 labeling may indicate early endothelial cell sprouting. The distribution of Type IV collagen also supports its role as a signal for migration and tube formation for lymphatic endothelial cells.

E7080 Suppresses Hematogenous Multiple Organ Metastases of Lung Cancer Cells with Nonmutated Epidermal Growth Factor Receptor

“…Double staining for CD31 and LYVE-1 showed that a small population of cells in the periphery was doubly positive for both (Fig. 4B), consistent with previous findings (26,27). Importantly, E7080 treatment dramatically inhibited the numbers of CD31-and LYVE-1-positive cells (Fig.…”

Mesenchymal cells with leukocyte and lymphendothelial characteristics in murine embryos

“…4A-C). CD31 (PECAM-1, platelet endothelial cell adhesion molecule-1) is a marker of both BECs and LECs, and is also present on leukocytes of the periphery (Sauter et al, 1998). The leukocyte common antigen CD45, a transmembrane glycoprotein with a molecular weight of 180 -220 kDa, is a marker for cells of hematopoietic origin except for erythrocytes.…”

Endothelial progenitor cells: Implications for cardiovascular disease

“…Several different negative controls are currently used in the different studies, ranging from isotype specific antibodies labeled with the same colors as the specific antibodies (8)(9)(10), addition of no antibodies at all to see the autofluorescence of the cells, to the fluorescence minus one (FMO) strategy [reviewed in (11)]. Another factor complicating the characterization of EPCs is the fact that the expression of the often used stem cell marker CD34 is not only restricted to stem cells, but is also expressed on mature microvascular endothelial cells (12,13). Therefore, CD133, a more immature hematopoietic stem cell marker that is absent on mature endothelial cells and monocytic cells (14) was introduced as a better marker for EPCs.…”