Kupffer cells are a dominant site of uncoupling protein 2 expression in rat liver.
The mechanisms underlying thermogenesis in liver are not well understood. They may involve proteins related to the mitochondrial uncoupling protein (UCP1) of brown adipocytes. In this paper, it is demonstrated that UCP1 is not expressed in any liver cell type of rat while UCP2, a recently cloned homologue of UCP1, is expressed at a very high level in Kupffer cells but not in hepatocytes. This high level of expression of UCP2 in Kupffer cells allowed cross immunoreactivity with antibodies directed against UCP1. This cross reactivity was confirmed by the detection of UCP2 with anti-UCP1 antibody, in western blotting analysis of transfected yeasts expressing rat UCP2. The high level expression of UCP2 in Kupffer cells suggests a particular function of UCP2 in macrophages.
Larrouy
D
D
CNRS/UPRESA 5018, Université Paul Sabatier, Hôpital Rangueil, Toulouse, France.
Laharrague
P
P
Carrera
G
G
Viguerie-Bascands
N
N
Levi-Meyrueis
C
C
Fleury
C
C
Pecqueur
C
C
Nibbelink
M
M
André
M
M
Casteilla
L
L
Ricquier
D
D
D000818:Animals; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000032:analysis / Q000096:biosynthesis; D003001:Cloning, Molecular; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007473:Ion Channels; D007728:Kupffer Cells / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis; D026901:Membrane Transport Proteins; D051379:Mice; D024101:Mitochondrial Proteins; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae; D014158:Transcription, Genetic; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2
D002352:Carrier Proteins; D007473:Ion Channels; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C000604372:Ucp1 protein, mouse; C000604373:Ucp1 protein, rat; C000604390:Ucp2 protein, mouse; C000604391:Ucp2 protein, rat; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2