TY - JOUR
T1 - Molecular mechanism regulating 24-hour rhythm of dopamine D3 receptor expression in mouse ventral striatums
AU - Ikeda, Eriko
AU - Matsunaga, Naoya
AU - Kakimoto, Keisuke
AU - Hamamura, Kengo
AU - Hayashi, Akane
AU - Koyanagi, Satoru
AU - Ohdo, Shigehiro
PY - 2013/5
Y1 - 2013/5
N2 - The dopamine D3 receptor (DRD3) in the ventral striatum is thought to influence motivation and motor functions. Although the expression of DRD3 in the ventral striatum has been shown to exhibit 24-hour variations, the mechanisms underlying the variation remain obscure. Here, we demonstrated that molecular components of the circadian clock act as regulators that control the 24-hour variation in the expression of DRD3. The transcription of DRD3 was enhanced by the retinoic acid-related orphan receptor a (RORa), and its activation was inhibited by the orphan receptor REV-ERBα, an endogenous antagonist of RORa. The serum or dexamethasone-induced oscillation in the expression of DRD3 in cells was abrogated by the downregulation or overexpression of REV-ERBα, suggesting that REV-ERBα functions as a regulator of DRD3 oscillations in the cellular autonomous clock. Chromatin immunoprecipitation assays of the DRD3 promoter indicated that the binding of the REVERBα protein to the DRD3 promoter increased in the early dark phase. DRD3 protein expression varied with higher levels during the dark phase. Moreover, the effects of the DRD3 agonist 7-hydroxy-N,N-dipropyl-2-aminotetralin (7-OHDPAT)- induced locomotor hypoactivity were significantly increased when DRD3 proteins were abundant. These results suggest that RORa and REV-ERBα consist of a reciprocating mechanism wherein RORa upregulates the expression of DRD3, whereas REV-ERBα periodically suppresses the expression at the time of day when REV-ERBα is abundant. Our present findings revealed that a molecular link between the circadian clock and the function of DRD3 in the ventral striatum acts as a modulator of the pharmacological actions of DRD3 agonists/antagonists.
AB - The dopamine D3 receptor (DRD3) in the ventral striatum is thought to influence motivation and motor functions. Although the expression of DRD3 in the ventral striatum has been shown to exhibit 24-hour variations, the mechanisms underlying the variation remain obscure. Here, we demonstrated that molecular components of the circadian clock act as regulators that control the 24-hour variation in the expression of DRD3. The transcription of DRD3 was enhanced by the retinoic acid-related orphan receptor a (RORa), and its activation was inhibited by the orphan receptor REV-ERBα, an endogenous antagonist of RORa. The serum or dexamethasone-induced oscillation in the expression of DRD3 in cells was abrogated by the downregulation or overexpression of REV-ERBα, suggesting that REV-ERBα functions as a regulator of DRD3 oscillations in the cellular autonomous clock. Chromatin immunoprecipitation assays of the DRD3 promoter indicated that the binding of the REVERBα protein to the DRD3 promoter increased in the early dark phase. DRD3 protein expression varied with higher levels during the dark phase. Moreover, the effects of the DRD3 agonist 7-hydroxy-N,N-dipropyl-2-aminotetralin (7-OHDPAT)- induced locomotor hypoactivity were significantly increased when DRD3 proteins were abundant. These results suggest that RORa and REV-ERBα consist of a reciprocating mechanism wherein RORa upregulates the expression of DRD3, whereas REV-ERBα periodically suppresses the expression at the time of day when REV-ERBα is abundant. Our present findings revealed that a molecular link between the circadian clock and the function of DRD3 in the ventral striatum acts as a modulator of the pharmacological actions of DRD3 agonists/antagonists.
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U2 - 10.1124/mol.112.083535
DO - 10.1124/mol.112.083535
M3 - Article
C2 - 23429911
AN - SCOPUS:84876574506
VL - 83
SP - 959
EP - 967
JO - Molecular Pharmacology
JF - Molecular Pharmacology
SN - 0026-895X
IS - 5
ER -