Involvement of E-cadherin in the Development of Erythroid Cells; Subject Heading.
The cadherins represent a large family of structurally and functionally related cell adhesion molecules involved in morphogenesis of multicellular organisms and maintenance of solid tissues. In the hematopoietic system, however, almost nothing was known about the involvement of this family. PCR screening of RNA of human bone marrow mononuclear cells with specific primers for different classical cadherins revealed that members of this family are also expressed by bone marrow cells. Here we report that E-cadherin, which is mainly expressed by cells of epithelial origin, plays a critical role in the development of human erythrocytes. FACS analysis with human E-cadherin-specific antibodies and the use of immunoaffinity columns revealed that expression of E-cadherin is restricted to defined maturation stages of the erythropoietic cell lineage. Erythroblasts and normoblasts express E-cadherin, but mature erythrocytes do not. Lymphoid and all the other myeloid cell lineages do not express E-cadherin at any developmental stage. The differentiation of the erythroid lineage in vitro could be influenced by addition of anti-E-cadherin antibodies in a concentration dependent manner indicating a direct involvement of this cell adhesion molecule in the differentiation process. In line with these in vitro data is the finding that E-cadherin is down regulated during erythroleukemia on the developing erythroid cells. Our results suggest an unanticipated function of E-cadherin in the hematopoietic system.
Armeanu
Sorin
S
Medical University Clinic, Section for Transplantation Immunology and Immunohematology, 72072 Tübingen, FRG.
MÜller
Claudia A.
CA
Klein
Gerd
G