ephrinBexpressing

EphrinBexpressing refers to cells that display ephrin-B family ligands on their surface, primarily EFNB1, EFNB2, and EFNB3. These transmembrane ligands bind to Eph receptors on neighboring cells, enabling contact-dependent bidirectional signaling. Forward signaling occurs in the Eph receptor–expressing cell, while reverse signaling occurs in the ephrin-B–expressing cell.

Reverse signaling requires phosphorylation of the ephrin-B intracellular domain, typically by Src family kinases, and interactions with PDZ-domain proteins. This signaling can trigger cytoskeletal rearrangements and changes in cell adhesion and migration, contributing to coordinated tissue patterning and boundary formation.

Biological roles of ephrin-B signaling are broad and include neural development, axon guidance, neural crest cell migration, and vascular remodeling. Ephrin-B signaling influences the formation of tissue boundaries and interfaces between different cell populations, as well as synaptic development and plasticity in the nervous system. In the vascular system, ephrin-Bs contribute to endothelial cell interactions and angiogenic processes.

Expression patterns of ephrin-B ligands vary by tissue and developmental stage. Detection methods include in situ hybridization, immunohistochemistry, and transcript analysis. Dysregulation of ephrin-B signaling has been linked to developmental disorders, such as craniofrontonasal syndrome associated with EFNB1, and to pathological processes in cancer and angiogenesis, where altered cell migration and vessel formation can occur.