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Role of the mTOR signalling pathway in salivary gland development
Author(s) -
Sakai Manabu,
Fukumoto Moe,
Ikai Kazuki,
Ono Minagi Hitomi,
Inagaki Shinobu,
Kogo Mikihiko,
Sakai Takayoshi
Publication year - 2019
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14937
Subject(s) - pi3k/akt/mtor pathway , mtorc1 , mtorc2 , salivary gland , biology , p70 s6 kinase 1 , microbiology and biotechnology , kinase , protein kinase b , ribosomal protein s6 , rptor , signal transduction , medicine , endocrinology , biochemistry
Development of the salivary gland is characterized by extensive branching morphogenesis. Although various molecules have been implicated in salivary gland development, the role of the mammalian target of rapamycin (mTOR) signalling pathway, including both mTOR complexes 1 and 2 (mTORC1 and 2), in salivary gland development is unknown. Here, we examined protein expression levels related to the mTOR signalling pathway using an ex vivo submandibular salivary gland (SMG) organ culture. We showed that branching buds in the salivary glands were substantially decreased and phosphorylation of mTORC1 signalling pathway related proteins (mTOR, p70 ribosomal protein S6 kinase 1 and eukaryotic initiation factor 4E‐binding protein 1) was inhibited by rapamycin (an mTOR inhibitor). In addition, AKT, which is an upstream protein kinase of mTORC1 and is downstream of mTORC2, is inhibited by LY294002 (a phosphatidylinositol 3‐kinase inhibitor), but not by rapamycin. Moreover, rapamycin‐treated ICR neonatal mice exhibited a reduction in both body weight and salivary glands compared with vehicle‐treated neonatal mice. The present data indicate that the mTOR signalling pathway, including both mTORC1 and mTORC2, plays a critical role in salivary gland development both in ex vivo SMG organ culture and ICR neonatal mice in vivo .