Trehalose is the major “blood sugar” of insects and it plays a crucial role in energy supply and as a stress protectant. The hydrolysis of trehalose occurs only under the enzymatic control of trehalase (Treh), which plays important roles in growth and development, energy supply, chitin biosynthesis, and abiotic stress responses. Previous reports have revealed that the vital hormone 20-hydroxyecdysone (20E) regulates Treh, but the detailed mechanism underlying 20E regulating Treh remains unclear. In this study, we investigated the function of HaTreh1 in Helicoverpa armigera larvae. Results showed that the transcript levels and enzymatic activity of HaTreh1 were elevated during molting and metamorphosis stages in the epidermis, midgut, and fat body, and that 20E upregulated the transcript levels of HaTreh1 through the classical nuclear receptor complex EcR-B1/USP1. HaTreh1 is a mitochondria protein.
We also found that knockdown of HaTreh1 in the fifth- or sixth- instar larvae resulted in weight loss and increased mortality. Yeast two-hybrid, Co-IP, and GST pull-down experiments demonstrated that HaTreh1 bound with ATP synthase subunit alpha (HaATPs-α) and that this binding increased under 20E treatment. In addition, 20E enhanced the transcript level of HaATPs-α and ATP content. Finally, the knockdown of HaTreh1 or HaATPs-α decreased the induction effect of 20E on ATP content. Altogether, these findings demonstrate that 20E controls ATP production by up-regulating the binding of HaTreh1 to HaATPs-α in H. armigera.
Ecdysone and 20-hydroxyecdysone are not required to activate glycolytic gene expression in Drosophila melanogaster embryos
Many of the Drosophila enzymes involved in carbohydrate metabolism are coordinately up-regulated approximately midway through embryogenesis. Previous studies have demonstrated that this metabolic transition is controlled by the Drosophila Estrogen-Related Receptor (dERR), which is stabilized and activated immediately prior to onset of glycolytic gene expression. The mechanisms that promote dERR activity, however, are poorly understood and other transcriptional regulators could control this metabolic transition, independent of dERR.
In this regard, the steroid hormone 20-hydroxyecdysone (20E) represents an intriguing candidate for regulating glycolytic gene expression in embryos – not only does the embryonic 20E pulse immediately precede transcriptional up-regulation of glycolytic metabolism, but 20E is also known to promote Lactate dehydrogenase gene expression. Here I test the hypothesis that embryonic 20E signaling is required to activate glycolytic gene expression. Using developmental northern blots, I demonstrate that the transcriptional up-regulation of glycolytic genes during embryogenesis still occurs in shadow mutants, which are unable to synthesize either ecdysone or 20E. My finding indicates that ecdysone and 20E signaling are not required for this mid-embryonic metabolic transition.
20-Hydroxyecdysone activates the protective arm of the RAAS via Mas receptor
20-Hydroxyecdysone (20E) is a steroid hormone that plays a key role in insect development through nuclear ecdysteroid receptors (EcR/RXR complex) and at least one membrane GPCR receptor (DopEcR). It also displays numerous pharmacological effects in mammals, where its mechanism of action is still debated, involving either an unidentified GPCR or the estrogen ERβ receptor. The goal of this study was to better understand 20E mechanism of action in mammals. A mouse myoblast cell line (C2C12) and the gene expression of myostatin (a negative regulator of muscle growth) was used as a reporter system of anabolic activity. Experiments using protein-bound 20E established the involvement of a membrane receptor. 20E-like effects were also observed with angiotensin-(1-7), the endogenous ligand of Mas.
Additionally, the effect on myostatin gene expression was abolished by Mas receptor knock-down using small interfering RNA (siRNA) or pharmacological inhibitors. 17β-Estradiol (E2) also inhibited myostatin gene expression, but protein-bound E2 was inactive, and E2 activity was not abolished by angiotensin-(1-7) antagonists. A mechanism involving cooperation between the Mas receptor and a membrane-bound palmitoylated estrogen receptor is proposed. The possibility to activate the Mas receptor with a safe steroid molecule is consistent with the pleiotropic pharmacological effects of ecdysteroids in mammals and, indeed, the proposed mechanism may explain the close similarity between angiotensin-(1-7)’s and 20E’s effects. Our findings open up many possible therapeutic developments involving stimulation of the protective arm of the renin-angiotensin-aldosterone system (RAAS) with 20E.
Identification and Functional Analysis of G Protein-Coupled Receptors in 20-Hydroxyecdysone Signaling From the Helicoverpa armigera Genome
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors in animals and humans, which transmit various signals from the extracellular environment into cells. Studies have reported that several GPCRs transmit the same signal; however, the mechanism is unclear. In the present study, we identified all 122 classical GPCRs from the genome of Helicoverpa armigera, a lepidopteran pest species. Twenty-four GPCRs were identified as upregulated at the metamorphic stage by comparing the transcriptomes of the midgut at the metamorphic and feeding stages.Nine of them were confirmed to be upregulated at the metamorphic stage. RNA interference in larvae revealed the prolactin-releasing peptide receptor (PRRPR), smoothened (SMO), adipokinetic hormone receptor (AKHR), and 5-hydroxytryptamine receptor (HTR) are involved in steroid hormone 20-hydroxyecdysone (20E)-promoted pupation. Frizzled 7 (FZD7) is involved in growth, while tachykinin-like peptides receptor 86C (TKR86C) had no effect on growth and pupation.
Via these GPCRs, 20E regulated the expression of different genes, respectively, including Pten (encoding phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase), FoxO (encoding forkhead box O), BrZ7 (encoding broad isoform Z7), Kr-h1 (encoding Krüppel homolog 1), Wnt (encoding Wingless/Integrated) and cMyc, with hormone receptor 3 (HHR3) as their common regulating target. PRRPR was identified as a new 20E cell membrane receptor using a binding assay. These data suggested that 20E, via different GPCRs, regulates different gene expression to integrate growth and development.
20-Hydroxyecdysone, 90% |
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| GP0436-1G | Glentham Life Sciences | 1 g | 122.4 EUR |
20-Hydroxyecdysone, 90% |
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| GP0436-250MG | Glentham Life Sciences | 250 mg | 74.4 EUR |
20-Hydroxyecdysone, 97% |
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| GP9112-100MG | Glentham Life Sciences | 100 mg | 303.6 EUR |
20-Hydroxyecdysone, 97% |
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| GP9112-25MG | Glentham Life Sciences | 25 mg | 132 EUR |
CRAB 20-Hydroxyecdysone |
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| QY-E160051 | Qayee Biotechnology | 96T | 573.6 EUR |
20-Hydroxyecdysone Standard, 200UL |
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| C240-200UL | Arbor Assays | 200UL | 272.4 EUR |
20-Hydroxyecdysone Standard, 40UL |
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| C240-40UL | Arbor Assays | 40UL | 147.6 EUR |
20-hydroxyecdysone 3-acetate |
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| TBW01415 | ChemNorm | 10mg | Ask for price |
2-O-Acetyl-20-hydroxyecdysone |
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| HY-N6640 | MedChemExpress | 10mg | 768 EUR |
DetectX® 20-Hydroxyecdysone Conjugate, 13ML |
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| C239-13ML | Arbor Assays | 13ML | 1252.8 EUR |
DetectX® 20-Hydroxyecdysone Conjugate, 3ML |
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| C239-3ML | Arbor Assays | 3ML | 357.6 EUR |
20-Hydroxyecdysone EIA Kit (One Plate) |
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| K066-H1 | Arbor Assays | 1x96 well plate | 613.2 EUR |
20-Hydroxyecdysone EIA Kit (Five Plate) |
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| K066-H5 | Arbor Assays | 5x96 well plate | 2343.6 EUR |
Activation of the ROS/CncC and 20-Hydroxyecdysone Signaling Pathways Is Associated with Xanthotoxin-Induced Tolerance to λ-Cyhalothrin in Spodoptera litura
Adaptation to phytochemicals in herbivorous insects can influence tolerance to insecticides. However, it is unclear how insects use phytochemicals as cues to activate their metabolic detoxification systems. In this study, we found that dietary exposure to xanthotoxin enhanced tolerance of Spodoptera litura larvae to λ-cyhalothrin. Xanthotoxin ingestion significantly elevated the mRNA levels of 35 detoxification genes as well as the transcription factors Cap ‘n’ collar isoform-C (CncC) and its binding factor small muscle aponeurosis fibromatosis isoform-K (MafK). Additionally, xanthotoxin exposure increased the levels of reactive oxygen species (ROS), while ROS inhibitor N-acetylcysteine (NAC) treatment blocked xanthotoxin-induced expression of CncC, MafK, and detoxification genes and also prevented xanthotoxin-enhanced larval tolerance to λ-cyhalothrin. The 20-hydroxyecdysone (20E) signaling pathway was effectively activated by xanthotoxin, while blocking of 20E signaling transduction prevented xanthotoxin-enhanced larval tolerance to λ-cyhalothrin.
Application of 20E induced the expression of multiple xanthotoxin-induced detoxification genes and enhanced λ-cyhalothrin tolerance in S. litura. NAC treatment blocked xanthotoxin-induced 20E synthesis, while the CncC agonist curcumin activated the 20E signaling pathway. These results indicate that the ROS/CncC pathway controls the induction of metabolic detoxification upon exposure to xanthotoxin, at least in part, through its regulation of the 20E signaling pathway.