Microscopy suggests that glutathione S-transferase is stored in large granules of myeloid cells in bone marrow and sparse granulocytes of the regenerating tail of lizard

Abstract

Microscopy suggests that glutathione S-transferase is stored in large granules of myeloid cells in bone marrow and sparse granulocytes of the regenerating tail of lizard. Acta Zoologica (Stockolm). Tail regeneration in lizards occurs after an immune-privileged blastema and is formed where various immunosuppressive cells and biomolecules keep inflammation low. Molecules that limit inflammation may include glutathione and glutathione S-transferase (GST). These molecules reduce reactive oxidative species (ROS) and detoxify extraneous molecules. In the present study, the presence of GST has been analysed in the early phases of tail regeneration in the lizard Podarcis muralis. Using a rabbit polyclonal antibody directed against epitopes present in GST of P. muralis, a light and electron microscopy immunohistochemical and Western blotting study has been done. The study detected proteins of 25 and 32 kDa in pale-medium electron-dense and large granules present in promyelocytes and myelocytes of likely basophilic or eosinophilic fate that is present in the bone marrow of tail vertebrae. These cells are still proliferating and give rise to basophilic or eosinophilic granulocytes that also migrate into the regenerating tail. The enzyme stored in granules of promyelocytes and myelocytes is also localized in the cytoplasm of granulocytes present in the regenerating blastema-cone, basophilic or/and eosinophilic. It is suggested that these granulocytes in the blastema reduce ROS and detoxify potentially inflammatory metabolites, contributing with other molecules to limit inflammation and favour regeneration.