Distinct localization of prokineticin 2 and prokineticin receptor 2 mRNAs in the rat suprachiasmatic nucleus
Distinct localization of prokineticin 2 and prokineticin receptor 2 mRNAs in the rat suprachiasmatic nucleus
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DOI：
10.1111/j.1460-9568.2006.04834.x
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发表时间：
2006-06-01
影响因子：
3.4
通讯作者：
Shigeyoshi, Yasufumi
中科院分区：
文献类型：
--
作者：
Masumoto, Koh-hei;Nagano, Mamoru;Shigeyoshi, Yasufumi
视交叉上核（SCN）是调节哺乳动物生理和行为昼夜节律的主生物钟。前动力蛋白 2 (PK2) 在 SCN 中高表达，之前已有报道称其参与昼夜节律运动活动的产生。在本研究中，我们利用原位杂交方法研究了 PK2 和前动力蛋白受体 2 (PKR2)（PK2 的特异性受体）在大鼠 SCN 中的定位。在稳定的光：暗（L：D = 12：12 小时）和恒定的黑暗条件下，rPK2 mRNA 显示出强烈的昼夜节律振荡，峰值出现在白天。此外，在表达高峰期间，rPK2 mRNA 阳性神经元分散在背内侧和腹外侧 SCN 中，这是两个功能和形态上不同的亚区域。此外，双标记原位杂交实验表明，超过 50% 的含有 rPK2 mRNA 的神经元在 SCN 中共表达血管活性肠肽 (VIP)、胃泌素释放肽 (GRP) 或精氨酸加压素 (AVP)。相反，rPKR2 mRNA 水平没有显示出显着的昼夜变化。含有 rPKR2 mRNA 的神经元也聚集在 SCN 的背外侧部分，显示 rAVP、rVIP、rGRP 或 rPK2 转录本的标记可以忽略不计。此外，该区域表现出 rPer1 基因的延迟循环。这些结果表明 SCN 中表达 PKR2 的神经元具有内在的 PK2 神经传递和功能上不同的作用。
The suprachiasmatic nucleus (SCN) is the master circadian clock that regulates physiological and behavioral circadian rhythms in mammals. Prokineticin 2 (PK2) is highly expressed in the SCN, and its involvement in the generation of circadian locomotor activity has been reported previously. In the present study, using in situ hybridization methods, we investigated the localization of PK2 and prokineticin receptor 2 (PKR2), a specific receptor for PK2, in the rat SCN. In steady light : dark (L : D = 12 : 12 h) and constant dark conditions, rPK2 mRNA displayed a robust circadian oscillation with a peak occurring during the day. Moreover, during peak expression, the rPK2 mRNA-positive neurons were scattered in both the dorsomedial and ventrolateral SCN, which are two functionally and morphologically distinct subregions. Furthermore, double-labeling in situ hybridization experiments revealed that greater than 50% of the rPK2 mRNA-containing neurons co-expressed either vasoactive intestinal peptide (VIP), gastrin-releasing peptide (GRP) or arginine vasopressin (AVP) in the SCN. In contrast, the rPKR2 mRNA levels did not show significant diurnal alterations. rPKR2 mRNA-containing neurons were also clustered in the dorsolateral part of the SCN, which shows negligible labeling of either rAVP, rVIP, rGRP or rPK2 transcripts. In addition, this region exhibited a delayed cycling of the rPer1 gene. These results suggest an intrinsic PK2 neurotransmission and functionally distinct roles for PKR2-expressing neurons in the SCN.