title: Circadian expression of clock genes in human peripheral leukocytes.
abstract: In mammals, behavioral and physiological processes display 24-h rhythms that are regulated by a circadian system. In the present study, we investigated the possibility that the expression of clock genes in peripheral leukocytes can be used to assess the circadian clock system. We found that Per1 and Per2 exhibit circadian oscillations in mRNA expression in mouse peripheral leukocytes. Furthermore, the rhythms of Per1 and Per2 mRNA expression in peripheral leukocytes are severely blunted in homozygous Cry1/2 double-deficient mice that are known to have an abolished biological clock. We have examined the circadian expression of clock genes in human leukocytes and found that Per1 mRNA exhibits a robust circadian expression while Per2 and Bmal1 mRNA showed weak rhythm. These observations suggest that monitoring Per1 mRNA expression in human leukocytes may be useful for investigating the function of the circadian system in physiological and pathophysiological states.
authors.affiliation: Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fukuya
authors.forename: Noriaki
authors.initials: N
authors.lastname: Emoto
authors.forename: Hidemi
authors.initials: H
authors.lastname: Nonaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yagita
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yokoyama
mesh_terms: D056930:ARNTL Transcription Factors; D000328:Adult; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics*; D002940:Circadian Rhythm; D056931:Cryptochromes; D005420:Flavoproteins / Q000235:genetics; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D056950:Period Circadian Proteins; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D018797:Cell Cycle Proteins; D056931:Cryptochromes; D005420:Flavoproteins; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C538960:BMAL1 protein, human; C538961:Bmal1 protein, mouse; C538963:CRY1 protein, human; C538964:Cry1 protein, mouse; C539022:PER1 protein, human; C421902:PER2 protein, human; C539023:Per1 protein, mouse