Tissue-dependent alteration of protease expression phenotype in murine peritoneal mast cells that were genetically labeled with green fluorescent protein

The changing process of protease expression phenotype was studied after tra nsplantation of peritoneal mast cells (PMCs). To pursue the fate of the tra nsplanted PMCs, we obtained PMCs from WBB6F(1)-c-kit(+)/c-kit(+) mice with a transgene encoding green fluorescent protein (GFP), A large (n = 10(4)) o r small (n = 500) number of PMCs was injected into the stomach wall of gene tically mast cell-deficient WBB6F(1)-c-kit(W)/c-kit(Wv) mice without the GF P transgene, The original PMCs expressed messenger (m) RNAs of both mast ce ll carboxypeptidase A (MC-CPA) and mouse mast cell protease (mMCP)-2. The M C-CPA(+)/mMCP-2(+) phenotype did not change in both the muscularis propria and mucosa when 10(4) PMCs were injected, In contrast, when 500 PMCs were i njected, the mast cells that developed in the muscularis propria showed MC- CPA(+)/mMICP-2(-) phenotype and those that appeared in the mucosa showed MC -CPA(-)/mMCP-2(+) phenotype. On day 1 after the injection of 500 PMCs, only similar to 20 GFP(+) cells mere detected in the muscularis propria and no GFP(+) cells in the mucosa, The proportion of Alcian blue(+) cells decrease d until day 7 and increased thereafter. The GFP+ but Alcian blue(-) cells w ere considered as degranulated PMCs, The remarkable decrease or degranulati on seemed to be necessary for the alteration of protease expression phenoty pe.