Expression of the receptor for pituitary adenylate cyclase-activating polypeptide (PAC1-R) in reactive astrocytes.
We generated transgenic mice that express an enhanced green fluorescent protein (EGFP) under the control of the mouse glial fibrillary acidic protein (GFAP) promoter. In one of the transgenic lines, the green fluorescence of EGFP was undetectable in almost all of the brain regions, including the neocortex, in untreated animals. However, when reactive astrogliosis was induced by cortical stab wounding, the strong fluorescence of EGFP was observed around the needle track but was not found in the corresponding area of the contralateral hemisphere. The EGFP-expressing cells had the morphological features of reactive astrocytes such as thick processes. The EGFP-expressing cells were found to overlap with the astroglial marker GFAP, but not with the microglial marker CD11b or the neuronal marker NeuN. Furthermore, there were some EGFP-expressing cells that expressed vimentin-like immunoreactivity, the specific marker for reactive astrocytes. These results strongly suggest that the EGFP-expressing cells are reactive astrocytes, but not resting astrocytes. Using these transgenic mice, immunostaining for the PAC1 receptor (PAC1-R) was performed. PAC1-R, which is a pituitary adenylate cyclase-activating polypeptide (PACAP)-specific receptor, binds PACAP, which is known to have a wide variety of functions. An immunohistochemical study revealed the localization of PAC1-R in reactive astrocytes visualized with EGFP around the needle track at 5 days postsurgery.
Suzuki
Ryusuke
R
Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Arata
Satoru
S
Nakajo
Shigeo
S
Ikenaka
Kazuhiro
K
Kikuyama
Sakae
S
Shioda
Seiji
S
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D015415:Biomarkers; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000293:injuries* / Q000378:metabolism* / Q000503:physiopathology; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D005911:Gliosis / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D049452:Green Fluorescent Proteins; D007150:Immunohistochemistry; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009479:Neuropeptides / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011401:Promoter Regions, Genetic / Q000235:genetics; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone / Q000378:metabolism*; D019076:Transgenes / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
C495402:Adcyap1 protein, mouse; C495504:Adcyap1r1 protein, mouse; D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D008164:Luminescent Proteins; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone; D049452:Green Fluorescent Proteins