The effects of glucocorticoids on extracellular matrix and cell surface molecules in mouse embryonic tissues from different embryonic stages

Organogenesis during embryonic development constitutes a series of intricate processes that include differentiation and proliferation of the cells. Normal morphogenesis and differentiation depend on the coordination of cell-cell and cell-extracellular matrix interactions. The extracellular matrix has profound structural and biological effects on morphogenetic processes. The large number of extracellular matrix molecules and their interactions with each other define unique biological matrices important in morphogenesis. Glucocorticoid hormones are known to play pivotal roles in the development of a wide variety of tissues through modulating some developmental processes such as cell proliferation, differentiation and apoptosis. This study?s purpose was to elucidate the changes in extracellular matrix components during the embryonic development of normal or antenatally dexamethasone treated mice. For this purpose, we tested the glycosaminoglycans, fibronectins, cadherins and catenins in some tissues such as lung, heart, liver, eye, spinal cord and bone from normal and antenally dexamethasone treated mouse embryos between E12-E15. Generally, we found that, carboxylated and sulphated glycosaminoglycans were main glycosaminoglycan structures in fetal tissues. Further, the localizations fibronectin, cadherin and catenin molecules were differently in tissues tested. The effect of antenatal glucocorticoids on the extracellular matrix components was very slightly. We concluded that extracellular matrix components expressions were regionally and developmentally regulated with or without dexamethasone treatments and these expressions are very important in morphogenesis. Key words: Extracellular Matrix, Embryo, Dexamethasone, Morphogenesis