The Adhesion GPCR GPR125 is specifically expressed in the choroid plexus and is upregulated following brain injury.
BACKGROUND
GPR125 belongs to the family of Adhesion G protein-coupled receptors (GPCRs). A single copy of GPR125 was found in many vertebrate genomes. We also identified a Drosophila sequence, DmCG15744, which shares a common ancestor with the entire Group III of Adhesion GPCRs, and also contains Ig, LRR and HBD domains which were observed in mammalian GPR125.


RESULTS
We found specific expression of GPR125 in cells of the choroid plexus using in situ hybridization and protein-specific antibodies and combined in situ/immunohistochemistry co-localization using cytokeratin, a marker specific for epithelial cells. Induction of inflammation by LPS did not change GPR125 expression. However, GPR125 expression was transiently increased (almost 2-fold) at 4 h after traumatic brain injury (TBI) followed by a decrease (approximately 4-fold) from 2 days onwards in the choroid plexus as well as increased expression (2-fold) in the hippocampus that was delayed until 1 day after injury.


CONCLUSIONS
These findings suggest that GPR125 plays a functional role in choroidal and hippocampal response to injury.
Pickering
Chris
C
Uppsala University, Department of Neuroscience, Functional Pharmacology, BMC, Box 593, SE-75124, Uppsala, Sweden. chris.pickering@neuro.uu.se
Hägglund
Maria
M
Szmydynger-Chodobska
Joanna
J
Marques
Fernanda
F
Palha
Joana A
JA
Waller
Linn
L
Chodobski
Adam
A
Fredriksson
Robert
R
Lagerström
Malin C
MC
Schiöth
Helgi B
HB
D000818:Animals; D001483:Base Sequence; D001930:Brain Injuries / Q000139:chemically induced / Q000503:physiopathology*; D002831:Choroid Plexus / Q000378:metabolism / Q000473:pathology*; D020869:Gene Expression Profiling; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology; D007633:Keratins / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides; D008297:Male; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D019038:Platelet Glycoprotein GPIb-IX Complex; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation / Q000235:genetics
C523437:GPR125 protein, mouse; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D019038:Platelet Glycoprotein GPIb-IX Complex; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C094990:adhesion receptor; D007633:Keratins