Hipkaeo Wiphawi, Chomphoo Surang, Pakkarato Sawetree, Sakaew Waraporn, Sawatpanich Tarinee, Hozumi Yasukazu, Polsan Yada, Hipkaeo Damrong, Goto Kaoru, Kondo Hisatake
Nanomorphology-Based Apply Research Group and Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand,
Histochem Cell Biol. 2015 Aug;144(2):185-93. doi: 10.1007/s00418-015-1328-0. Epub 2015 May 8.
The present immunohistochemical study was attempted to localize in the submandibular glands of mice at various postnatal stages a diacylglycerol kinase (DGK) isoform termed DGKζ which is characterized by a nuclear localization signal and a nuclear export signal. This attempt was based on following facts: the continuous postnatal differentiation of glandular cells in the rodent submandibular gland, the regulatory role of DGK in the activity of protein kinase C (PKC) through attenuation of diacylglycerol (DAG), and the possible involvement of PKC in various cellular activities including the saliva secretion as well as the cell differentiation. As a result, a selective localization of immunoreactivity for DGKζ was detected in terminal tubule (TT) cells which comprise a majority of the newborn acinar structure and differentiate into the intercalated duct cells and/or the acinar cells. The immunoreactivity was deposited in portions of the cytoplasm lateral and basal to the nucleus, but not in the nuclei themselves. Although the immunoreactive TT cells remained until later stages in female specimen than in male, they eventually disappeared in both sexes by young adult stages. The present finding suggests that the regulatory involvement of DGKζ in PKC functions via control of DAG is exerted in the differentiation of the TT cells. In addition, another possible involvement of DGKζ in the regulation of secretion of the TT cells as well as its functional significance of its nuclear localization in the submandibular ganglion cells was also discussed.
本免疫组织化学研究试图在小鼠出生后不同阶段的颌下腺中定位一种名为二酰基甘油激酶（DGK）ζ的同工型，其特征在于具有核定位信号和核输出信号。该尝试基于以下事实：啮齿动物颌下腺中腺细胞的出生后持续分化、DGK通过二酰基甘油（DAG）的衰减对蛋白激酶C（PKC）活性的调节作用，以及PKC可能参与包括唾液分泌和细胞分化在内的各种细胞活动。结果，在构成大多数新生腺泡结构并分化为闰管细胞和/或腺泡细胞的终末小管（TT）细胞中检测到了DGKζ免疫反应性的选择性定位。免疫反应性沉积在细胞核外侧和基部的部分细胞质中，而不在细胞核本身。尽管免疫反应性TT细胞在雌性标本中比在雄性标本中保留到更晚阶段，但它们最终在两性的年轻成年阶段消失。本研究结果表明，DGKζ通过控制DAG对PKC功能的调节作用在TT细胞的分化中发挥作用。此外，还讨论了DGKζ在TT细胞分泌调节中的另一种可能作用及其在颌下神经节细胞中核定位的功能意义。
