Physical and inflammatory stressors elevate circadian clock gene mPer1 mRNA levels in the paraventricular nucleus of the mouse.
Stress induces secretion of corticosterone through activation of the hypothalamic-pituitary-adrenal axis. This corticosterone secretion is thought to be controlled by a circadian clock in the suprachiasmatic nucleus (SCN). The hypothalamic paraventricular nucleus (PVN) receives convergent information from both stress and the circadian clock. Recent reports demonstrate that mammalian orthologs (Per1, Per2, and Per3) of the Drosophila clock gene Period are expressed in the SCN, PVN, and peripheral tissues. In this experiment, we examined the effect of physical and inflammatory stressors on mPer gene expression in the SCN, PVN, and liver. Forced swimming, immobilization, and lipopolysaccharide injection elevated mPer1 gene expression in the PVN but not in the SCN or liver. A stress-induced increase in mPer1 expression was observed in the corticotropin-releasing factor-positive cells of the PVN; however, the stressors used in this study did not affect mPer2 expression in the PVN, SCN, or liver. The present study suggests that a stress-induced disturbance of circadian corticosterone secretion may be associated with the stress-induced expression of mPer1 mRNA in the PVN.
Takahashi
S
S
Department of Pharmacology and Brain Science, School of Human Sciences, Waseda University, Tokorozawa, Saitama, Japan 359-1192.
Yokota
S
S
Hara
R
R
Kobayashi
T
T
Akiyama
M
M
Moriya
T
T
Shibata
S
S
D000818:Animals; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000502:physiology; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D007103:Immobilization; D007249:Inflammation / Q000150:complications; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D056950:Period Circadian Proteins; D012333:RNA, Messenger / Q000378:metabolism*; D013312:Stress, Physiological / Q000209:etiology / Q000378:metabolism*; D013493:Suprachiasmatic Nucleus / Q000378:metabolism; D013550:Swimming; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D008070:Lipopolysaccharides; D009687:Nuclear Proteins; C539022:PER1 protein, human; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D003346:Corticotropin-Releasing Hormone