171. IDENTIFICATION OF DECIDUALISATION- INDUCED PROTEIN CHANGES IN HUMAN ENDOMETRIAL STROMAL CELLS BY PROTEOMICS

Abstract

Decidualisation of human endometrial stromal cells (HESC) is pivotal for successful implantation and can be induced by cAMP analogues such as 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) and ligands to enhance cellular cAMP levels. The resulting decidualisation HESC is recognised by morphological changes and cellular products such as prolactin or insulin-like growth factors. The regulation of proteins during decidualisation HESC has yet to be clearly identified. The aim of this study was to identify proteins that are altered during decidualisation. HESC were isolated and decidualised with 500μM of 8-Br-cAMP for 72 hours. Decidualisation success was determined by prolactin assay. 2D differential in-gel electrophoresis (DIGE) was used to examine differentially expressed proteins between control and 8-Br-cAMP treated HESC. The proteins of interest were validated by Western blot and/or immunohistochemistry. A total of 88 differentially expressed proteins were identified by matrix assisted laser desorption/ionisation (MALDI) and/or liquid chromatography mass spectrometry (LC-MS). The proteins that were up regulated during decidualisation include insulin growth factor binding protein as well as caldesmon, tropomycin, actin, tubulin, SRC substrate cortactin and calponin-1 which contribute to the re-organisation of cell cytoskeletal restructuring and remodelling. Proteins associated with cellular growth and transformation such as annexin, nuclear migration factor protein and elongation factor 1B were also up regulated. These results suggest that the process of decidualisation is complicated requiring synergy and cross-talk between structural and cell growth proteins and pathways.