Expressions of sugar transporters/trehalases in relation to PTTH-stimulated ecdysteroidogenesis in the silkworm, Bombyx mori.

Autor: Gu SH; Department of Biology, National Museum of Natural Science, 1 Kuan-Chien Road, Taichung 404, Taiwan, ROC. Electronic address: gu330@mail.nmns.edu.tw., Lin PL; Department of Biology, National Museum of Natural Science, 1 Kuan-Chien Road, Taichung 404, Taiwan, ROC., Chang CH; Department of Biology, National Museum of Natural Science, 1 Kuan-Chien Road, Taichung 404, Taiwan, ROC.
Jazyk: angličtina
Zdroj: Journal of insect physiology [J Insect Physiol] 2024 Sep; Vol. 157, pp. 104672. Date of Electronic Publication: 2024 Jul 07.
DOI: 10.1016/j.jinsphys.2024.104672
Abstrakt: The prothoracic gland (PG) is the source of ecdysteoids in larval insects. Although numerous studies have been conducted on signaling networks involved in prothoracicotropic hormone (PTTH)-stimulated ecdysteroidogenesis in PGs, less is known about regulation of metabolism in PGs. In the present study, we investigated correlations between expressions of sugar transporter (St)/trehalase (Treh) genes and PTTH-stimulated ecdysteroidogenesis in Bombyx mori PGs. Our results showed that in vitro PTTH treatment stimulated expression of the St1 gene, but not other transporter genes. Expression of the Treh1 gene was also stimulated by PTTH treatment. An immunoblotting analysis showed that St1 protein levels in Bombyx PGs increased during the later stage of the last larval instar and were not affect by PTTH treatment. PTTH treatment enhanced Treh enzyme activity in a time-dependent manner. Blocking either extracellular signal-regulated kinase (ERK) signaling with U0126 or phosphatidylinositol 3-kinase (PI3K) signaling with LY294002 decreased PTTH-stimulated Treh enzyme activity, indicating a link from the ERK and PI3K signaling pathways to Treh activity. Treatment with the Treh inhibitor, validamycin A, blocked PTTH-stimulated Treh enzyme activity and partially inhibited PTTH-stimulated ecdysteroidogenesis. Treatment with either a sugar transport inhibitor (cytochalasin B) or a specific glycolysis inhibitor (2-deoxy-D-glucose, 2-DG) partially inhibited PTTH-stimulated ecdysteroidogenesis. Taken together, these results indicate that increased expressions of St1/Treh1 and Treh activity, which lie downstream of PTTH signaling, are involved in PTTH stimulation in B. mori PGs.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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