The expression of nuclear 3,5,3′ triiodothyronine receptors is induced in Schwann cells by nerve transection

• Published in: Experimental neurology Vol. 116; no. 2; pp. 189 - 197
• Main Authors: Barakat-Walter, I., Duc, C., Sarlieve, L.L., Puymirat, J., Dussault, J.H., Droz, B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.05.1992; Elsevier
• Subjects: Animals; Biological and medical sciences; Blotting, Western; Cell Nucleus - metabolism; Cells, Cultured; Denervation; Ganglia, Spinal - metabolism; Medical sciences; Nervous system involvement in other diseases. Miscellaneous; Neurology; Rats; Rats, Inbred Strains; Receptors, Thyroid Hormone - metabolism; Schwann Cells - metabolism; Sciatic Nerve - metabolism; Spinal Cord - metabolism; Tissue Distribution; Triiodothyronine, Reverse - metabolism; Cell culture; Peripheral nerve; Nervous system diseases; Spinal cord; Monoclonal antibody; Section; Experimental disease; Schwann cell; Immunological investigation; Animal; Thyroid hormone; Sciatic nerve; Biological receptor
• ISSN: 0014-4886; 1090-2430
• DOI: 10.1016/0014-4886(92)90167-O

The effects of thyroid hormones on the nervous system are mediated by the presence of nuclear T 3 receptors (NT 3R). In this study, the expression of NT 3R was investigated in spinal cord, dorsal root ganglia (DRG), or sciatic nerve of adult rats after immunostaining with a 2B3-NT 3R monoclonal antibody which recognizes both α and β types of NT 3R. The specificity of this monoclonal antibody was confirmed by Western blots. The 2B3-NT 3R monoclonal antibody recognized one band corresponding to a molecular weight of 57 kDa in extract of spinal cord or DRG. No staining was observed on immunoblot of intact sciatic nerve. In the spinal cord, the nuclei of the neurons and glial cells including both astrocytes and oligodendrocytes exhibited 2B3-NT 3R immunoreactivity. While all the nuclei of the DRG sensory neurons expressed the NT 3R, all the nuclei of the satellite and Schwann cells were devoid of any immunoreaction. In the sciatic nerve, the nuclei of the Schwann cells also lacked 2B3-NT 3R-immunoreactivity. After sciatic nerve transection in vivo, Schwann cell nuclei, which never expressed NT 3R in intact nerves of adult rats, displayed a clear 2B3-NT 3R immunoreaction in proximal and distal stumps adjacent to the section. Double immunostaining with antibodies raised to 3-sulfogalactosylceramide or S100 confirmed that most of the NT 3R containing nuclei belong to Schwann cells. In dissociated cell cultures grown in vitro from sciatic nerves, Schwann cells exhibited 2B3-NT 3R immunoreactivity. These data suggest that the inhibition of NT 3R expression in Schwann cells ensheathing axons in intact nerve is reversed when the axons are degenerating or lacking. Thus Schwann cells which express 2B3-NT 3R in the absence of axonal contact could be responsive to T 3 in regenerating peripheral nerve.