Expression and immunolocalization of Gpnmb, a glioma-associated glycoprotein, in normal and inflamed central nervous systems of adult rats

This research investigates the role of Glycoprotein nonmetastatic melanoma B (Gpnmb) in the central nervous system of rats, both under normal conditions and when inflammation is present. Gpnmb is a protein that is highly expressed in glioblastoma cells and is considered a potential therapeutic target. The study found that Gpnmb mRNA is present in various regions of the rat brain and spinal cord. Furthermore, Gpnmb protein was found in specific cells within these regions, particularly in microglia and macrophages. These cells are involved in immune and inflammatory responses within the brain. The research also showed that when the rats were exposed to a bacterial endotoxin (LPS) to induce inflammation, there was an increase in the number of Gpnmb-expressing microglia and macrophages in a specific brain region called the area postrema. This suggests that Gpnmb plays a role in regulating immune and inflammatory responses in the brain.

• 1
  Gpnmb mRNA is expressed in the cerebrum, cerebellum, brain stem, and spinal cord of normal adult rats.
• 2
  Gpnmb-immunoreactive cells were widely distributed in the parenchyma of all brain regions examined, with the cells being most prevalent in the hippocampal dentate gyrus, cerebellar cortex, spinal dorsal horn, choroid plexus, ependyma, periventricular regions, and in layers II and III of the cerebral cortex.
• 3
  An intraperitoneal injection of bacterial endotoxin lipopolysaccharide increased the number of Gpnmb and OX42 double-positive cells in the area postrema, indicating infiltration of hematogenous macrophages.