DNA Synthesis during Endomitosis Is Stimulated by Insulin via the PI3K/Akt and TOR Signaling Pathways in the Silk Gland Cells of Bombyx mori

International Journal of Molecular Sciences

Yaofeng Li¹  Xiangyun Chen¹  Xiaofang Tang¹  Chundong Zhang¹  La Wang¹  Peng Chen¹  Minhui Pan¹  Cheng Lu¹ 

[1] State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; E-Mails:

关键词: Bombyx mori;    silk gland;    DNA synthesis;    insulin signaling;   

DOI  :  10.3390/ijms16036266

来源: mdpi

【 摘 要 】

Silk gland cells undergo multiple endomitotic cell cycles during silkworm larval ontogeny. Our previous study demonstrated that feeding is required for continued endomitosis in the silk gland cells of silkworm larvae. Furthermore, the insulin signaling pathway is closely related to nutritional signals. To investigate whether the insulin signaling pathway is involved in endomitosis in silk gland cells, in this study, we initially analyzed the effects of bovine insulin on DNA synthesis in endomitotic silk gland cells using 5-bromo-2'-deoxyuridine (BrdU) labeling technology, and found that bovine insulin can stimulate DNA synthesis. Insulin signal transduction is mainly mediated via phosphoinositide 3-kinase (PI3K)/Akt, the target of rapamycin (TOR) and the extracellular signal-regulated kinase (ERK) pathways in vertebrates. We ascertained that these three pathways are involved in DNA synthesis in endomitotic silk gland cells using specific inhibitors against each pathway. Moreover, we investigated whether these three pathways are involved in insulin-stimulated DNA synthesis in endomitotic silk gland cells, and found that the PI3K/Akt and TOR pathways, but not the ERK pathway, are involved in this process. These results provide an important theoretical foundation for the further investigations of the mechanism underlying efficient endomitosis in silk gland cells.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.