International Journal of Oral Biology

The Korean Academy of Oral Biology (대한구강생물학회)
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Homer2 regulates amylase secretion via physiological calcium oscillations in mouse parotid gland acinar cells

  • Kang, Namju (Department of Oral Biology, Yonsei University College of Dentistry) ;
  • Kang, Jung Yun (Department of Oral Biology, Yonsei University College of Dentistry) ;
  • Shin, Dong Min (Department of Oral Biology, Yonsei University College of Dentistry) ;
  • Yang, Yu-Mi (Department of Oral Biology, Yonsei University College of Dentistry)
  • Received : 2020.04.27
  • Accepted : 2020.05.13
  • Published : 2020.06.30
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Abstract

The salivary glands secrete saliva, which plays a role in the maintenance of a healthy oral environment. Under physiological conditions, saliva secretion within the acinar cells of the gland is regulated by stimulation of specific calcium (Ca2+) signaling mechanisms such as increases in the intracellular Ca2+ concentration ([Ca2+]i) via storeoperated Ca2+ entry, which involves components such as Orai1, transient receptor potential (TRP) canonical 1, stromal interaction molecules, and inositol 1,4,5-triphosphate (IP3) receptors (IP3Rs). Homer proteins are scaffold proteins that bind to G protein-coupled receptors, IP3Rs, ryanodine receptors, and TRP channels. However, their exact role in Ca2+ signaling in the salivary glands remains unknown. In the present study, we investigated the role of Homer2 in Ca2+ signaling and saliva secretion in parotid gland acinar cells under physiological conditions. Deletion of Homer2 (Homer2-/-) markedly decreased the amplitude of [Ca2+]i oscillations via the stimulation of carbachol, which is physiologically concentrated in parotid acinar cells, whereas the frequency of [Ca2+]i oscillations showed no difference between wild-type and Homer2-/- mice. Homer2-/- mice also showed a significant decrease in amylase release by carbachol in the parotid gland in a dose-dependent manner. These results suggest that Homer2 plays a critical role in maintaining [Ca2+]i concentration and secretion of saliva in mouse parotid gland acinar cells.

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References

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