Thyroid Hormone and the Neuroglia: Both Source and Target

Figure 3

Expression of crucial elements of the D2 ubiquitination machinery in glial cells in the rat brain. (a,b) mRNA of WSB1, the D2 ubiquitin ligase is expressed in tanycytes lining the wall of the third ventricle (3V). WSB1 expression (arrows) extended from the anterior lower part (not shown) to the lower two thirds of the wall of the third ventricle in more caudal regions. Neuronal cells also express WSB1. (c,d) Hybridization signal of the USP33 D2 deubiquitinase was also detected over tanycytes and ependymal cells lining all regions of the wall of the third ventricle (arrows). Neuronal cells also express USP33. (e) WSB1 in situ hybridization signal (arrows) is observed over the majority of GFAP-expressing astrocytes (brown immunoreactivity) demonstrated here in the hippocampal dentate gyrus. (f) The mRNA of USP33 was absent from GFAP-expressing astrocytes (brown) in the hippocampus, but it was expressed in granular neurons. The sense probes for WSB1 or USP33 did not produce any signal (not shown). Mol, molecular layers of the dentate gyrus; GrDG, granular layer of the dentate gyrus; PoDG, polymorph layer of the dentate gyrus. Reprinted with permission from Fekete et al. [181] The Endocrine Society.