Georg Birgitte, Jørgensen Henrik L, Hannibal Jens
Department of Clinical Biochemistry, Bispebjerg University Hospital, 2400 Copenhagen, Denmark.
Department of Clinical Biochemistry, Amager and Hvidovre Hospital, 2650 Copenhagen, Denmark.
Int J Mol Sci. 2024 Dec 3;25(23):13006. doi: 10.3390/ijms252313006.
Many endocrine glands exhibit circadian rhythmicity, but the interplay between the central circadian clock in the suprachiasmatic nucleus (SCN), the peripheral endocrine clock, and hormones is sparsely understood. We therefore studied the cellular localizations of the clock protein PER1, parathyroid hormone (PTH) and calcitonin (CT) in the parathyroid and thyroid glands, respectively. Thyroid glands, including the parathyroids, were dissected at different time-points from rats housed in 12 h:12 h light-darkness cycles, and were double-immunostained for PER1 and PTH or CT. Sera were analyzed for PTH, CT, phosphate, and calcium. In both glands, PER1 expression peaked late at night, while limited staining was seen during the daytime. High-resolution microscopy revealed cytosolic PER1 at zeitgeber time (ZT)12, and nucleic staining at ZT24 in both PTH and CT cells. PTH peaked at Z12-ZT16, while neither CT staining nor serum CT oscillated during the daily cycle. Serum PTH was significantly higher at ZT12 than ZT24, but only phosphate was found to exhibit significant diurnal oscillation. The staining of the calcium-sensitive receptor (CSR) did not demonstrate circadian oscillation. In conclusion, PER1 expression peaked late at night/early in the morning in hormone-producing cells of both the thyroid and parathyroid glands. In the parathyroids, this was preceded by a PTH peak, while neither CT nor CRS were found to oscillate.
许多内分泌腺都表现出昼夜节律性，但视交叉上核（SCN）中的中枢昼夜节律钟、外周内分泌钟和激素之间的相互作用却鲜为人知。因此，我们分别研究了时钟蛋白PER1、甲状旁腺激素（PTH）和降钙素（CT）在甲状旁腺和甲状腺中的细胞定位。从处于12小时光照-12小时黑暗周期饲养的大鼠中，在不同时间点解剖包括甲状旁腺在内的甲状腺，并对PER1和PTH或CT进行双重免疫染色。分析血清中的PTH、CT、磷酸盐和钙。在这两种腺体中，PER1表达在深夜达到峰值，而在白天染色有限。高分辨率显微镜显示，在授时时间（ZT）12时，PTH和CT细胞的胞质中有PER1，在ZT24时有核染色。PTH在ZT12-ZT16达到峰值，而CT染色和血清CT在每日周期中均未出现振荡。血清PTH在ZT12时显著高于ZT24，但仅发现磷酸盐有显著的昼夜振荡。钙敏感受体（CSR）的染色未显示昼夜振荡。总之，PER1表达在甲状腺和甲状旁腺的激素产生细胞中在深夜/清晨达到峰值。在甲状旁腺中，在此之前有一个PTH峰值，而未发现CT和CRS有振荡。
