Leptin receptor mRNA in rat brain astrocytes.
We recently reported that mouse astrocytes express leptin receptors (ObR), and that obesity induces upregulation of astrocytic ObR. To provide further evidence of the importance of astrocytic ObR expression, we performed double-labeling fluorescent in situ hybridization (FISH) and immunohistochemistry in the rat hypothalamus. Laser confocal microscopic image analysis showed that ObR mRNA was present in glial fibrillary acidic protein (+) cells that show distinctive astrocytic morphology as well as in neurons. In addition to the presence of ObR mRNA, ObR protein was shown in both astrocytes and neurons in the rat hypothalamus by double-labeling immunohistochemistry. In cultured rat C6 astrocytoma cells treated with different doses of lipopolysaccharide for 6h, the mRNA for ObRa or ObRb did not show significant changes, as measured by quantitative RT-PCR. However, the protein expression of both ObRa and ObRb, determined by Western blotting, was increased after the C6 cells were treated with either lipopolysaccharide or tumor necrosis factor-alpha. The results indicate that astrocytic ObR expression is present in rats as well as mice, and that it probably plays a role in the neuroinflammatory response.
Hsuchou
Hung
H
Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
Pan
Weihong
W
Barnes
Maria J
MJ
Kastin
Abba J
AJ
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D045744:Cell Line, Tumor; D007031:Hypothalamus / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D054411:Receptors, Leptin / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D054411:Receptors, Leptin; D014409:Tumor Necrosis Factor-alpha