Multitissue Circadian Expression of Rat periodHomolog (rPer2) mRNA Is Governed by the Mammalian Circadian Clock, the Suprachiasmatic Nucleus in the Brain

Sakamoto, Katsuhiko; Nagase, Takahiro; Fukui, Hiromi; Horikawa, Kazumasa; Okada, Tetsuya; Tanaka, Hitoshi; Sato, Ken-iti; Miyake, Yoichi; Ohara, Osamu; Kako, Koichiro; Ishida, Norio

doi:10.1074/jbc.273.42.27039

Cited by 281 publications

(196 citation statements)

References 22 publications

Supporting

Mentioning

181

Contrasting

Unclassified

Order By: Relevance

“…There is evidence that SCN lesions might suppress rhythmic oscillation, but not the expression of rPer2 in the eye, brain, heart, lung, spleen, liver, and kidney (see Sakamoto et al, 1998), which is consistent with the concept of the circadian system being a hierarchical order of biological clocks.…”

Section: Peripheral Clocks Are Responsible For Overt Circadian Rhythmssupporting

confidence: 53%

The Circadian Timing System: Making Sense of day/night gene expression

et al. 2004

View full text Add to dashboard Cite

The circadian time-keeping system ensures predictive adaptation of individuals to the reproducible 24-h day/ night alternations of our planet by generating the 24-h (circadian) rhythms found in hormone release and cardiovascular, biophysical and behavioral functions, and others. In mammals, the master clock resides in the suprachiasmatic nucleus (SCN) of the hypothalamus. The molecular events determining the functional oscillation of the SCN neurons with a period of 24-h involve recurrent expression of several clock proteins that interact in complex transcription/translation feedback loops. In mammals, a glutamatergic monosynaptic pathway originating from the retina regulates the clock gene expression pattern in the SCN neurons, synchronizing them to the light:dark cycle. The emerging concept is that neural/humoral output signals from the SCN impinge upon peripheral clocks located in other areas of the brain, heart, lung, gastrointestinal tract, liver, kidney, fibroblasts, and most of the cell phenotypes, resulting in overt circadian rhythms in integrated physiological functions. Here we review the impact of day/night alternation on integrated physiology; the molecular mechanisms and input/output signaling pathways involved in SCN circadian function; the current concept of peripheral clocks; and the potential role of melatonin as a circadian neuroendocrine transducer.

show abstract

Section: Peripheral Clocks Are Responsible For Overt Circadian Rhythmssupporting

confidence: 53%

The Circadian Timing System: Making Sense of day/night gene expression

et al. 2004

View full text Add to dashboard Cite

show abstract

“…In addition, Circadian rhythms in CREB mRNA levels (A) and phosphorylated CREB (p-CREB) protein levels (B) detected in NK cells enriched from rat spleen at 6:00 a.m., 10:00 a.m., 2:00 p.m., 6:00 p.m., 10:00 p.m., and 2:00 a.m. These time points correspond with ZT 3,7,11,15,19, and 23, respectively. Total RNA from the enriched fraction was reverse transcribed to cDNA and then subjected to real-time PCR.…”

Section: Discussionmentioning

confidence: 99%

“…Rats were euthanized by decapitation at 6:00 a.m., 10:00 a.m., 2:00 p.m., 6:00 p.m., 10:00 p.m., and 2:00 a.m. These time points correspond with Zeitgeber times (ZT) 3 3,7,11,15,19, and 23, respectively. Spleens were immediately collected for enrichment of NK cells.…”

Section: Animals and Designmentioning

confidence: 99%

Circadian Oscillations of Clock Genes, Cytolytic Factors, and Cytokines in Rat NK Cells

Arjona

Sarkar

2005

The Journal of Immunology

192

141

View full text Add to dashboard Cite

A growing body of knowledge is revealing the critical role of circadian physiology in the development of specific pathological entities such as cancer. NK cell function participates in the immune response against infection and malignancy. We have reported previously the existence of a physiological circadian rhythm of NK cell cytolytic activity in rats, suggesting the existence of circadian mechanisms subjacent to NK cell function. At the cellular level, circadian rhythms are originated by the sustained transcriptional-translational oscillation of clock genes that form the cellular clock apparatus. Our aim in this study was to investigate the presence of molecular clock mechanisms in NK cells as well as the circadian expression of critical factors involved in NK cell function. For that purpose, we measured the circadian changes in the expression of clock genes (Per1, Per2, Bmal1, Clock), Dbp (a clock-controlled output gene), CREB (involved in clock signaling), cytolytic factors (granzyme B and perforin), and cytokines (IFN-γ and TNF-α) in NK cells enriched from the rat spleen. The results obtained from this study demonstrate for the first time the existence of functional molecular clock mechanisms in NK cells. Moreover, the circadian expression of cytolytic factors and cytokines in NK cells reported in this study emphasizes the circadian nature of NK cell function.

show abstract

“…In vivo, cependant, il semble que les NSC jouent un rôle d'oscillateur principal contrôlant les autres oscillateurs du système circadien [42]. En effet, la lésion des NSC entraîne une disparition apparente des rythmes dans les autres tissus [43,44]: les NSC, s'ils ne sont pas les seuls à exprimer une rythmicité, apparaissent donc indispensables à la fonction des autres oscillateurs. Ces oscillateurs subordonnés seraient moins robustes, et leur rythmicité moins soutenue que celle des NSC.…”

Section: Les Horloges Périphériquesunclassified