[Aging and circadian clock gene expression in peripheral tissues in rats].
Aging is associated with alterations of the circadian rhythms (shortened amplitude and phase-advance). We studied by quantitative RT-PCR the influence of aging on the expression of circadian clock genes (Clock, Bmal1, Cry1,2, Per1-3) in peripheral tissues (liver and heart) of middle-aged (13 months) and old (27 months) rats of the Wag/Rij strain exposed to a 12 hours light/12 hours dark cycle. Rats were killed at the light-dark transition (8 am and 8 pm). In the liver, Per, Cry et Bmal1 genes showed a morning/evening difference of expression; in addition, old rats exhibited a significant decrease of Per gene expression in the evening vs middle-aged rats. The heart showed similar profiles with only a tendency toward a decrease of Per expression and an increased Bmal1 expression in the evening in old rats. These results show that aging is associated with circadian gene expression changes.
Claustrat
F
F
Service de radioanalyse, hôpital cardiologique, 59, boulevard Pinel, 69677 Bron cedex, France. francine.claustrat@chu-lyon.fr
Fournier
I
I
Geelen
G
G
Brun
J
J
Corman
B
B
Claustrat
B
B
D000375:Aging / Q000502:physiology*; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D056931:Cryptochromes; D005260:Female; D005420:Flavoproteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
C538965:Cry1 protein, rat; D056931:Cryptochromes; D005420:Flavoproteins