Psychiatry related information on Per2

• Furthermore, the similar diurnal pattern of Per1 and Per2 expression in diurnal and nocturnal rodents suggests that the circadian organization of locomotor activity rhythms probably relies on differential cellular integration mechanisms downstream of the clock [1].

High impact information on Per2

• Here we demonstrate the role of the Rev-ErbA/ROR response element in gene expression during circadian night, which is in phase with Bmal1 and in antiphase to Per2 oscillations [2].
• The rhythm matured gradually; at P10, the amplitude of Per1, Per2, and Bmal1 mRNA rhythms was more pronounced than at P3 [3].
• Glucose down-regulates Per1 and Per2 mRNA levels and induces circadian gene expression in cultured Rat-1 fibroblasts [4].
• In the brain, we failed to detect the alteration of the clock gene expression with the exception of Per2, assuming that anesthesia perturbs circadian rhythms [5].
• In the reproductive tissues (uterus), biphasic rhythms in Per1 and Per2 mRNA were observed after E2 treatment [6].

Biological context of Per2

• By using rat-1 fibroblasts, a model cell system of the peripheral clock, we found that an exchange of the culture medium triggered circadian gene expression that was preceded by slow down-regulation of Per1 and Per2 mRNA levels [4].
• Phenotype of Per1- and Per2-expressing neurons in the suprachiasmatic nucleus of a diurnal rodent (Arvicanthis ansorgei): comparison with a nocturnal species, the rat [1].

Anatomical context of Per2

• Per2 is rhythmically expressed in the suprachiasmatic nucleus (SCN). Daily rhythm in Per2 expression was detected also in rostral and caudal ventrolateral medulla, nucleus of the solitary tract, hypothalamic paraventricular and dorsomedial nuclei, nucleus ambiguus, area postrema, anteroventral third ventricle, heart and kidney with its highest levels at the beginning of the night [7] [8].
• These results might suggest that the different responses to melatonin in the pineal gland during the light and dark periods was originated in the changes of Per2 in the PVN via SCN [9].
• Per1 and Per2, two clock genes rhythmically expressed in the suprachiasmatic nucleus (SCN), are implicated in the molecular mechanism of the circadian pacemaker and play a major role in its entrainment by light [10].
• Chronic administration of methamphetamine (8 mg/kg, i.p., for 10 days) caused increased Per2 protein expression in the hippocampus [11].

Associations of Per2 with chemical compounds

• In the PVN, Per2 decreased during the light period and increased during the dark period at 180 min after melatonin injection [9].
• A differential expression of somatostatin receptor SSTR2, not known to be a cocaine-responsive gene, as well as the clock gene Per2, were found by microarrays and confirmed by RNase protection assay [12].
• Norepinephrine (NE) induced AA-NAT and Per1, whereas its effect on Per2 was negligible [13].
• In the brain, E2 treatment advanced the peak of Per2 mRNA expression in the SCN; however, it failed to affect the rhythm of Per2 mRNA expression in the CX and Per1 mRNA expression in both the SCN and the CX [6].
• Estrogen differentially regulates expression of Per1 and Per2 genes between central and peripheral clocks and between reproductive and nonreproductive tissues in female rats [6].

Regulatory relationships of Per2

• These results suggest that the interaction of rPER2 with rTLP may influence the regulation of circadian clock components in nucleus after rPER2 is translocated into the nucleus [14].

Other interactions of Per2

• Light induced regulation of Per1 and Per2 mRNA expression have been suggested to take part in the clock resetting [15].
• The AA-NAT mRNA varied similar to the Per2 mRNA changes [9].

Analytical, diagnostic and therapeutic context of Per2

• With newly developed antisera, we substantiated the expression of Per1 and Per2 in these cells by single/double immunohistochemistry [16].
• Here we investigated the daily expression of the two core clock genes, Per1 and Per2, in the rat ovary using real-time RT-PCR, in situ hybridization histochemistry, and immunohistochemistry [16].

References