AUTHOR=Wang Yuan-Yuan , Zhang Xin-Yu , Mu Xue-Rui , Li Xian , Zhou Min , Song Yue-Hua , Xu Kang-Kang , Li Can 

TITLE=Insulin-Like ILP2 Regulates Trehalose Metabolism to Tolerate Hypoxia/Hypercapnia in Tribolium castaneum

JOURNAL=Frontiers in Physiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.857239

DOI=10.3389/fphys.2022.857239

ISSN=1664-042X

ABSTRACT=The insulin pathway regulates glucose metabolism, in response to hypoxic stress induced by high carbon dioxide in Tribolium castaneum. We used RNAi to downregulate the expression of insulin-like peptides (ILP2), with air-modulation, and high-concentration CO2 stress, in the larvae of Tribolium castaneum. We assessed the changes in carbohydrate-related content and the regulation of genes related to carbohydrate metabolism and the insulin pathway. Pupation, adult emergence, pupation rate, and mortality were assessed. There was a significant change in the expression of ILP and InR in T. castaneum, at a certain concentration of CO2. The expression of TRE1-1 and TRE1-4 was downregulated significantly. ILP2 RNAi did not alter the trehalose content significantly; however, the glycogen and glucose content increased significantly. High-concentration CO2 stress altered the trehalose content and reduced the glycogen and glucose content; however, the change in trehalose content was not significant, compared to that in the dsGFP group. Understanding the insulin pathway responses to hypoxic stress induced by a high concentration of CO2 would further elucidate the mechanisms underlying glucose metabolism in insects.