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1.
Biochem Biophys Res Commun ; 711: 149914, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38608434

RESUMO

The steroid hormone ecdysone is essential for the reproduction and survival of insects. The hormone is synthesized from dietary sterols such as cholesterol, yielding ecdysone in a series of consecutive enzymatic reactions. In the insect orders Lepidoptera and Diptera a glutathione transferase called Noppera-bo (Nobo) plays an essential, but biochemically uncharacterized, role in ecdysteroid biosynthesis. The Nobo enzyme is consequently a possible target in harmful dipterans, such as disease-carrying mosquitoes. Flavonoid compounds inhibit Nobo and have larvicidal effects in the yellow-fever transmitting mosquito Aedes aegypti, but the enzyme is functionally incompletely characterized. We here report that within a set of glutathione transferase substrates the double-bond isomerase activity with 5-androsten-3,17-dione stands out with an extraordinary specific activity of 4000 µmol min-1 mg-1. We suggest that the authentic function of Nobo is catalysis of a chemically analogous ketosteroid isomerization in ecdysone biosynthesis.


Assuntos
Aedes , Aedes/enzimologia , Aedes/metabolismo , Animais , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Ecdisona/metabolismo , Proteínas de Insetos/metabolismo , Especificidade por Substrato , Esteroide Isomerases/metabolismo , Esteroide Isomerases/genética , Mosquitos Vetores/metabolismo , Cetosteroides/metabolismo , Cetosteroides/química
2.
PLoS Genet ; 20(3): e1011196, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38466721

RESUMO

Hematophagous mosquitoes require vertebrate blood for their reproductive cycles, making them effective vectors for transmitting dangerous human diseases. Thus, high-intensity metabolism is needed to support reproductive events of female mosquitoes. However, the regulatory mechanism linking metabolism and reproduction in mosquitoes remains largely unclear. In this study, we found that the expression of estrogen-related receptor (ERR), a nuclear receptor, is activated by the direct binding of 20-hydroxyecdysone (20E) and ecdysone receptor (EcR) to the ecdysone response element (EcRE) in the ERR promoter region during the gonadotropic cycle of Aedes aegypti (named AaERR). RNA interference (RNAi) of AaERR in female mosquitoes led to delayed development of ovaries. mRNA abundance of genes encoding key enzymes involved in carbohydrate metabolism (CM)-glucose-6-phosphate isomerase (GPI) and pyruvate kinase (PYK)-was significantly decreased in AaERR knockdown mosquitoes, while the levels of metabolites, such as glycogen, glucose, and trehalose, were elevated. The expression of fatty acid synthase (FAS) was notably downregulated, and lipid accumulation was reduced in response to AaERR depletion. Dual luciferase reporter assays and electrophoretic mobility shift assays (EMSA) determined that AaERR directly activated the expression of metabolic genes, such as GPI, PYK, and FAS, by binding to the corresponding AaERR-responsive motif in the promoter region of these genes. Our results have revealed an important role of AaERR in the regulation of metabolism during mosquito reproduction and offer a novel target for mosquito control.


Assuntos
Aedes , Receptores de Esteroides , Animais , Feminino , Humanos , Aedes/genética , Aedes/metabolismo , Ecdisona/metabolismo , Mosquitos Vetores/genética , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Homeostase/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
3.
J Cell Sci ; 137(5)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38323986

RESUMO

Migratory cells - either individually or in cohesive groups - are critical for spatiotemporally regulated processes such as embryonic development and wound healing. Their dysregulation is the underlying cause of formidable health problems such as congenital abnormalities and metastatic cancers. Border cell behavior during Drosophila oogenesis provides an effective model to study temporally regulated, collective cell migration in vivo. Developmental timing in flies is primarily controlled by the steroid hormone ecdysone, which acts through a well-conserved, nuclear hormone receptor complex. Ecdysone signaling determines the timing of border cell migration, but the molecular mechanisms governing this remain obscure. We found that border cell clusters expressing a dominant-negative form of ecdysone receptor extended ineffective protrusions. Additionally, these clusters had aberrant spatial distributions of E-cadherin (E-cad), apical domain markers and activated myosin that did not overlap. Remediating their expression or activity individually in clusters mutant for ecdysone signaling did not restore proper migration. We propose that ecdysone signaling synchronizes the functional distribution of E-cadherin, atypical protein kinase C (aPKC), Discs large (Dlg1) and activated myosin post-transcriptionally to coordinate adhesion, polarity and contractility and temporally control collective cell migration.


Assuntos
Proteínas de Drosophila , Animais , Proteínas de Drosophila/metabolismo , Ecdisona/metabolismo , Drosophila/metabolismo , Caderinas/genética , Caderinas/metabolismo , Movimento Celular/fisiologia , Miosinas/metabolismo , Drosophila melanogaster/metabolismo , Polaridade Celular/fisiologia , Adesão Celular
4.
Sci Adv ; 10(6): eadg8816, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38335295

RESUMO

To achieve a highly differentiated state, cells undergo multiple transcriptional processes whose coordination and timing are not well understood. In Drosophila embryonic epidermal cells, polished-rice (Pri) smORF peptides act as temporal mediators of ecdysone to activate a transcriptional program leading to cell shape remodeling. Here, we show that the ecdysone/Pri axis concomitantly represses the transcription of a large subset of cuticle genes to ensure proper differentiation of the insect exoskeleton. The repression relies on the transcription factor Ken and persists for several days throughout early larval stages, during which a soft cuticle allows larval crawling. The onset of these cuticle genes normally awaits the end of larval stages when the rigid pupal case assembles, and their premature expression triggers abnormal sclerotization of the larval cuticle. These results uncovered a temporal switch to set up distinct structures of cuticles adapted to the animal lifestyle and which might be involved in the evolutionary history of insects.


Assuntos
Proteínas de Drosophila , Ecdisona , Animais , Ecdisona/metabolismo , Drosophila/genética , Drosophila/metabolismo , Diferenciação Celular/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Peptídeos/metabolismo , Larva/genética , Insetos/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
5.
J Sci Food Agric ; 103(15): 7673-7682, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37431698

RESUMO

BACKGROUND: Cold storage has been widely used to maintain the quality of vegetables, but whether eating cold-stored vegetables affects health remains unknown. RESULTS: This study used silkworms as an animal model to evaluate the effects of nutrient changes in cold-stored mulberry leaves (CSML) on health. Compared with fresh mulberry leaves (FML), CSML contained lower vitamin C, soluble sugars and proteins, and higher H2 O2 , suggesting decreased antioxidant ability and nutrition. The CSML did not obviously affect larval survival rate, body weight or dry matter rate, cocoon shape, weight and size, or final rates of cluster and cocooning relative to the FML, suggesting CSML did not alter overall growth and development. However, the CSML increased the initial rates of cluster and cocooning and upregulated BmRpd3, suggesting CSML shortened larval lifespan and enhanced senescence. CSML upregulated BmNOX4, downregulated BmCAT, BmSOD and BmGSH-Px and increased H2 O2 in silkworms, suggesting CSML caused oxidative stress. CSML upregulated ecdysone biosynthesis and inactivation genes and elevated ecdysone concentration in silkworms, suggesting that CSML affected hormone homeostasis. CSML upregulated apoptosis-related genes, downregulated sericin and silk fibroin genes and decreased sericin content rate in silkworms, suggesting oxidative stress and protein deficiency. CONCLUSION: Cold storage reduced nutrition and antioxidant capability of mulberry leaves. CSML did not influence growth and development of silkworm larva, but affected health by causing oxidative stress and reducing protein synthesis. The findings show that the ingredient changes in CSML had negative effects on health of silkworms. © 2023 Society of Chemical Industry.


Assuntos
Bombyx , Morus , Sericinas , Animais , Bombyx/genética , Bombyx/química , Seda/metabolismo , Seda/farmacologia , Morus/química , Larva , Antioxidantes/metabolismo , Ecdisona/metabolismo , Ecdisona/farmacologia , Fluormetolona/metabolismo , Fluormetolona/farmacologia
6.
PLoS Genet ; 19(6): e1010815, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37363926

RESUMO

In prostate cancer, loss of the tumour suppressor gene, Retinoblastoma (Rb), and consequent activation of transcription factor E2F1 typically occurs at a late-stage of tumour progression. It appears to regulate a switch to an androgen-independent form of cancer, castration-resistant prostate cancer (CRPC), which frequently still requires androgen receptor (AR) signalling. We have previously shown that upon mating, binucleate secondary cells (SCs) of the Drosophila melanogaster male accessory gland (AG), which share some similarities with prostate epithelial cells, switch their growth regulation from a steroid-dependent to a steroid-independent form of Ecdysone Receptor (EcR) control. This physiological change induces genome endoreplication and allows SCs to rapidly replenish their secretory compartments, even when ecdysone levels are low because the male has not previously been exposed to females. Here, we test whether the Drosophila Rb homologue, Rbf, and E2F1 regulate this switch. Surprisingly, we find that excess Rbf activity reversibly suppresses binucleation in adult SCs. We also demonstrate that Rbf, E2F1 and the cell cycle regulators, Cyclin D (CycD) and Cyclin E (CycE), are key regulators of mating-dependent SC endoreplication, as well as SC growth in both virgin and mated males. Importantly, we show that the CycD/Rbf/E2F1 axis requires the EcR, but not ecdysone, to trigger CycE-dependent endoreplication and endoreplication-associated growth in SCs, mirroring changes seen in CRPC. Furthermore, Bone Morphogenetic Protein (BMP) signalling, mediated by the BMP ligand Decapentaplegic (Dpp), intersects with CycD/Rbf/E2F1 signalling to drive endoreplication in these fly cells. Overall, our work reveals a signalling switch, which permits rapid growth of SCs and increased secretion after mating, independently of previous exposure to females. The changes observed share mechanistic parallels with the pathological switch to hormone-independent AR signalling seen in CRPC, suggesting that the latter may reflect the dysregulation of a currently unidentified physiological process.


Assuntos
Proteínas de Drosophila , Neoplasias de Próstata Resistentes à Castração , Humanos , Animais , Feminino , Masculino , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Endorreduplicação , Ecdisona/genética , Ecdisona/metabolismo , Fator de Transcrição E2F1/genética , Fatores de Transcrição/genética , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
7.
J Insect Sci ; 23(3)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37256698

RESUMO

The tachinid fly, Exorista sorbillans, is a notorious ovolarviparous endoparasitoid of the silkworm, Bombyx mori, causing severe damage to silkworm cocoon industry. Silkworm larvae show typically precocious wandering behavior after being parasitized by E. sorbillans; however, the underlying molecular mechanism remains unexplored. Herein, we investigated the changes in the levels of 20-hydroxyecdysone (20E) and juvenile hormone (JH) titer, and they both increased in the hemolymph of parasitized silkworms. Furthermore, we verified the expression patterns of related genes, which showed an upregulation of 20E signaling and biosynthesis genes but a significant downregulation of ecdysone oxidase (EO), a 20E inactivation enzyme, in parasitized silkworms. In addition, related genes of the JH signaling were activated in parasitized silkworms, while related genes of the JH degradation pathway were suppressed, resulting in an increase in JH titer. Notably, the precocious wandering behavior of parasitized silkworms was partly recoverable by silencing the transcriptions of BmCYP302A1 or BmCYP307A1 genes. Our findings suggest that the developmental duration of silkworm post parasitism could be shortened by regulation of 20E and JH titers, which may help silkworm to resist the E. sorbillans infestation. These findings provide a basis for deeper insight into the interplay between silkworms and E. sorbillans and may serve as a reference for the development of a novel approach to control silkworm myiasis.


Assuntos
Bombyx , Dípteros , Lepidópteros , Manduca , Animais , Dípteros/metabolismo , Larva , Ecdisona/metabolismo , Lepidópteros/metabolismo , Hormônios Juvenis/metabolismo
8.
Insect Biochem Mol Biol ; 154: 103909, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36693452

RESUMO

Glycogen synthase kinase 3ß (GSK3ß) plays important roles in gene transcription, metabolism, apoptosis, development, and signal transduction. However, its role in the regulation of pupal diapause remains unclear. In this paper, we find that low GSK3ß activity in brains of diapause-destined pupae of Helicoverpa armigera is caused by elevated AKT activity. In response to ROS, AKT phosphorylates GSK3ß to decrease its activity. In developing pupal brains, GSK3ß can activate the transcription factor Smad1, which binds to the promoter region of the ecdysone receptor (EcR) gene and increases its expression. In the presence of 20-hydroxyecdysone (20E), EcR can bind to USP and increase the expression of 20E-response genes, including HR3, for pupal-adult development. In contrast, high levels of ROS in brains of diapause-destined pupae up-regulate p-AKT, which in turn decreases GSK3ß activity. Low GSK3ß activity causes low expression of EcR/HR3 via down-regulation of Smad1 activity, leading to diapause initiation. These results suggest that low GSK3ß activity plays a key role in pupal diapause via ROS/AKT/GSK3ß/Smad/EcR/HR3 signaling.


Assuntos
Diapausa de Inseto , Mariposas , Receptores de Esteroides , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Regulação para Baixo , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Transdução de Sinais , Receptores de Esteroides/genética , Mariposas/genética , Ecdisona/metabolismo , Pupa
9.
Dev Biol ; 491: 113-125, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36100084

RESUMO

Epithelial cells form continuous membranous structures for organ formation, and these cells are classified into three major morphological categories: cuboidal, columnar, and squamous. It is crucial that cells transition between these shapes during the morphogenetic events of organogenesis, yet this process remains poorly understood. All three epithelial cell shapes can be found in the follicular epithelium of Drosophila egg chamber during oogenesis. Squamous cells (SCs) are initially restricted to the anterior terminus in cuboidal shape. They then rapidly become flattened to assume squamous shape by stretching and expansion in 12 â€‹h during midoogenesis. Previously, we reported that Notch signaling activated a zinc-finger transcription factor Broad (Br) at the end of early oogenesis. Here we report that ecdysone and JAK/STAT pathways subsequently converge on Br to serve as an important spatiotemporal regulator of this dramatic morphological change of SCs. The early uniform pattern of Br in the follicular epithelium is directly established by Notch signaling at stage 5 of oogenesis. Later, ecdysone and JAK/STAT signaling activities synergize to suppress Br in SCs from stage 8 to 10a, contributing to proper SC squamous shape. During this process, ecdysone signaling is essential for SC stretching, while JAK/STAT regulates SC clustering and cell fate determination. This study reveals an inhibitory role of ecdysone signaling in suppressing Br in epithelial cell remodeling. In this study we also used single-cell RNA sequencing data to highlight the shift in gene expression which occurs as Br is suppressed and cells become flattened.


Assuntos
Carcinoma de Células Escamosas , Proteínas de Drosophila , Animais , Carcinoma de Células Escamosas/genética , Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Ecdisona/metabolismo , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Oogênese/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zinco
10.
Insect Biochem Mol Biol ; 151: 103830, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36064128

RESUMO

The insect steroid hormone ecdysone plays a critical role in insect development. Several recent studies have shown that ecdysone enters cells through Organic Anion Transporting Polypeptides (OATPs) in insects such as flies and mosquitoes. However, the conservation of this mechanism across other arthropods and the role of this transporter in canonical ecdysone pathways are less well studied. Herein we functionally characterized the putative ecdysone importer (EcI) from two major agricultural moth pests: Helicoverpa armigera (cotton bollworm) and Spodoptera frugiperda (fall armyworm). Phylogenetic analysis of OATP transporters across the superphylum Ecdysozoa revealed that EcI likely appeared only at the root of the arthropod lineage. Partial disruption of EcI in S. frugiperda decreased embryo hatching rate and larval survival, suggesting that this gene is essential for development in vivo. Depletion and re-expression of EcI in the lepidoptera cell line RP-HzGUT-AW1(MG) demonstrated this protein's ability to control ecdysone mediated signaling in gene regulation, its role in ecdysone mediated cell death, and its sensitivity to rifampicin, a well-known organic anion transporter inhibitor. Overall, this work sheds light on ecdysone uptake mechanisms across insect species and broadens our knowledge of the physiological roles of OATPs in the transportation of endogenous substrates.


Assuntos
Mariposas , Transportadores de Ânions Orgânicos , Animais , Ecdisona/metabolismo , Filogenia , Larva , Spodoptera/genética , Spodoptera/metabolismo , Transportadores de Ânions Orgânicos/genética , Insetos/metabolismo
11.
Proc Natl Acad Sci U S A ; 119(25): e2202932119, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35696563

RESUMO

The primary insect steroid hormone ecdysone requires a membrane transporter to enter its target cells. Although an organic anion-transporting polypeptide (OATP) named Ecdysone Importer (EcI) serves this role in the fruit fly Drosophila melanogaster and most likely in other arthropod species, this highly conserved transporter is apparently missing in mosquitoes. Here we report three additional OATPs that facilitate cellular incorporation of ecdysone in Drosophila and the yellow fever mosquito Aedes aegypti. These additional ecdysone importers (EcI-2, -3, and -4) are dispensable for development and reproduction in Drosophila, consistent with the predominant role of EcI. In contrast, in Aedes, EcI-2 is indispensable for ecdysone-mediated development, whereas EcI-4 is critical for vitellogenesis induced by ecdysone in adult females. Altogether, our results indicate unique and essential functions of these additional ecdysone importers in mosquito development and reproduction, making them attractive molecular targets for species- and stage-specific control of ecdysone signaling in mosquitoes.


Assuntos
Aedes , Ecdisona , Proteínas de Insetos , Transportadores de Ânions Orgânicos , Aedes/crescimento & desenvolvimento , Aedes/fisiologia , Animais , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Feminino , Proteínas de Insetos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Vitelogênese
12.
Proc Natl Acad Sci U S A ; 119(5)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35086929

RESUMO

In Drosophila melanogaster, loss of regenerative capacity in wing imaginal discs coincides with an increase in systemic levels of the steroid hormone ecdysone, a key coordinator of their developmental progression. Regenerating discs release the relaxin hormone Dilp8 (Drosophila insulin-like peptide 8) to limit ecdysone synthesis and extend the regenerative period. Here, we describe how regenerating tissues produce a biphasic response to ecdysone levels: lower concentrations of ecdysone promote local and systemic regenerative signaling, whereas higher concentrations suppress regeneration through the expression of broad splice isoforms. Ecdysone also promotes the expression of wingless during both regeneration and normal development through a distinct regulatory pathway. This dual role for ecdysone explains how regeneration can still be completed successfully in dilp8- mutant larvae: higher ecdysone levels increase the regenerative activity of tissues, allowing regeneration to reach completion in a shorter time. From these observations, we propose that ecdysone hormone signaling functions to coordinate regeneration with developmental progression.


Assuntos
Ecdisona/metabolismo , Regeneração/fisiologia , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Expressão Gênica/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Hormônios Esteroides Gonadais/metabolismo , Discos Imaginais/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Larva/crescimento & desenvolvimento , Neurônios/metabolismo , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo , Asas de Animais/metabolismo , Proteína Wnt1/metabolismo
13.
Dis Model Mech ; 15(1)2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34842272

RESUMO

Development involves tightly paced, reproducible sequences of events, yet it must adjust to conditions external to it, such as resource availability and organismal damage. A major mediator of damage-induced immune responses in vertebrates and insects is JAK/STAT signaling. At the same time, JAK/STAT activation by the Drosophila Upd cytokines is pleiotropically involved in normal development of multiple organs. Whether inflammatory and developmental JAK/STAT roles intersect is unknown. Here, we show that JAK/STAT is active during development of the prothoracic gland (PG), which controls metamorphosis onset through ecdysone production. Reducing JAK/STAT signaling decreased PG size and advanced metamorphosis. Conversely, JAK/STAT hyperactivation by overexpression of pathway components or SUMOylation loss caused PG hypertrophy and metamorphosis delay. Tissue damage and tumors, known to secrete Upd cytokines, also activated JAK/STAT in the PG and delayed metamorphosis, at least in part by inducing expression of the JAK/STAT target Apontic. JAK/STAT damage signaling, therefore, regulates metamorphosis onset by co-opting its developmental role in the PG. Our findings in Drosophila provide insights on how systemic effects of damage and cancer can interfere with hormonally controlled development and developmental transitions.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais/fisiologia
14.
Dev Cell ; 56(19): 2741-2751.e7, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34610327

RESUMO

Cancer cachexia is associated with many types of tumors and is characterized by a combination of anorexia, loss of body weight, catabolic alterations, and systemic inflammation. We developed a tumor model in Drosophila larvae that causies cachexia-like syndrome, and we found that cachectic larvae show reduced levels of the circulating steroid ecdysone (Ec). Artificially importing Ec in the tumor through the use of the EcI/Oatp74D importer aggravated cachexia, whereas feeding animals with Ec rescued cachectic defects. This suggests that a steroid sink induced by the tumor promotes catabolic alterations in healthy tissues. We found that Oatp33Eb, a member of the Oatp transporter family, is specifically induced in tumors promoting cachexia. The overexpression of Oatp33Eb in noncachectic tumors induced cachexia, whereas its inhibition in cachectic tumors restored circulating Ec and reversed cachectic alterations. Oatp transporters are induced in several types of hormone-dependent tumors, and this result suggests that a similar sink effect could modify hormonal balance in cachectic cancer patients.


Assuntos
Caquexia/metabolismo , Ecdisona/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Animais , Peso Corporal , Caquexia/fisiopatologia , Proteínas de Drosophila , Drosophila melanogaster , Larva/metabolismo , Neoplasias , Transportadores de Ânions Orgânicos/fisiologia , Esteroides/metabolismo
15.
Cell Rep ; 36(9): 109644, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34469735

RESUMO

In holometabolous insects, metamorphic timing and body size are controlled by a neuroendocrine axis composed of the ecdysone-producing prothoracic gland (PG) and its presynaptic neurons (PGNs) producing PTTH. Although PTTH/Torso signaling is considered the primary mediator of metamorphic timing, recent studies indicate that other unidentified PGN-derived factors also affect timing. Here, we demonstrate that the receptor tyrosine kinases anaplastic lymphoma kinase (Alk) and PDGF and VEGF receptor-related (Pvr), function in coordination with PTTH/Torso signaling to regulate pupariation timing and body size. Both Alk and Pvr trigger Ras/Erk signaling in the PG to upregulate expression of ecdysone biosynthetic enzymes, while Alk also suppresses autophagy by activating phosphatidylinositol 3-kinase (PI3K)/Akt. The Alk ligand Jelly belly (Jeb) is produced by the PGNs and serves as a second PGN-derived tropic factor, while Pvr activation mainly relies on autocrine signaling by PG-derived Pvf2 and Pvf3. These findings illustrate that a combination of juxtacrine and autocrine signaling regulates metamorphic timing, the defining event of holometabolous development.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Glândulas Endócrinas/enzimologia , Metamorfose Biológica , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Animais Geneticamente Modificados , Comunicação Autócrina , Tamanho Corporal , Proteínas de Drosophila/genética , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Ecdisona/metabolismo , Glândulas Endócrinas/embriologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , IMP Desidrogenase/genética , IMP Desidrogenase/metabolismo , Janus Quinases/genética , Janus Quinases/metabolismo , Mutação , Receptores Proteína Tirosina Quinases/genética , Receptores de Peptídeos de Invertebrados/genética , Receptores de Peptídeos de Invertebrados/metabolismo , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Crescimento do Endotélio Vascular/genética , Fatores de Crescimento do Endotélio Vascular/metabolismo
16.
Cell Rep ; 36(5): 109466, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34348164

RESUMO

The evolutionarily conserved Nrf2-Keap1 pathway is a key antioxidant response pathway that protects cells/organisms against detrimental effects of oxidative stress. Impaired Nrf2 function is associated with cancer and neurodegenerative diseases in humans. However, the function of the Nrf2-Keap1 pathway in the developing nervous systems has not been established. Here we demonstrate a cell-autonomous role of the Nrf2-Keap1 pathway, composed of CncC/Nrf2, Keap1, and MafS, in governing neuronal remodeling during Drosophila metamorphosis. Nrf2-Keap1 signaling is activated downstream of the steroid hormone ecdysone. Mechanistically, the Nrf2-Keap1 pathway is activated via cytoplasmic-to-nuclear translocation of CncC in an importin- and ecdysone-signaling-dependent manner. Moreover, Nrf2-Keap1 signaling regulates dendrite pruning independent of its canonical antioxidant response pathway, acting instead through proteasomal degradation. This study reveals an epistatic link between the Nrf2-Keap1 pathway and steroid hormone signaling and demonstrates an antioxidant-independent but proteasome-dependent role of the Nrf2-Keap1 pathway in neuronal remodeling.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Plasticidade Neuronal , Transdução de Sinais , Esteroides/metabolismo , Animais , Antioxidantes/metabolismo , Sequência de Bases , Núcleo Celular/metabolismo , Dendritos/metabolismo , Proteínas de Drosophila/química , Ecdisona/metabolismo , Carioferinas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Proteólise
17.
PLoS Genet ; 17(2): e1009362, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33556132

RESUMO

During the development of a holometabolous insect such as Drosophila, specific group of cells in the larva survive during metamorphosis, unlike the other larval cells, and finally give rise to the differentiated adult structures. These cells, also known as Adult Progenitor Cells (APCs), maintain their multipotent capacity, differentially respond to hormonal and nutritional signals, survive the intrinsic and environmental stress and respond to the final differentiation cues. However, not much is known about the specific molecular mechanisms that account for their unique characteristics. Here we show that a specific Drosophila APC gene, headcase (hdc), has a dual role in the normal development of these cells. It acts at a systemic level by controlling the hormone ecdysone in the prothoracic gland and at the same time it acts locally as a tissue growth suppressor in the APC clusters, where it modulates the activity of the TOR pathway and promotes their survival by contributing in the regulation of the Unfolded Protein Response. We also show that hdc provides protection against stress in the APCs and that its ectopic expression in cells that do not usually express hdc can confer these cells with an additional stress protection. Hdc is the founding member of a group of homolog proteins identified from C. elegans to humans, where has been found associated with cancer progression. The finding that the Drosophila hdc is specifically expressed in progenitor cells and that it provides protection against stress opens up a new hypothesis to be explored regarding the role of the human Heca and its contribution to carcinogenesis.


Assuntos
Células-Tronco Adultas/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Estresse Fisiológico/genética , Animais , Animais Geneticamente Modificados , Diferenciação Celular/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Larva/citologia , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Metamorfose Biológica/genética , Microscopia Confocal , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
18.
Curr Biol ; 31(4): 840-852.e5, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33340458

RESUMO

In the germarium of the Drosophila ovary, developing germline cysts are surrounded by a population of somatic escort cells that are known to function as the niche cells for germline differentiation;1 however, the underlying molecular mechanisms of this niche function remain poorly understood. Through single-cell gene expression profiling combined with genetic analyses, we here demonstrate that the escort cells can be spatially and functionally divided into two successive domains. The anterior escort cells (aECs) specifically produce ecdysone, which acts on the cystoblast to promote synchronous cell division, whereas the posterior escort cells (pECs) respond to ecdysone signaling and regulate soma-germline cell adhesion to promote the transition from 16-cell cyst-to-egg chamber formation. The patterning of the aEC and pEC domains is independent of the germline but is dependent on JAK/STAT signaling activity, which emanates from the posterior. Thus, a heterogeneous population of escort cells constitutes a stepwise niche environment to orchestrate cystoblast division and differentiation toward egg chamber formation.


Assuntos
Cistos , Proteínas de Drosophila , Ecdisona , Animais , Diferenciação Celular , Drosophila , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Ecdisona/metabolismo , Feminino , Células Germinativas , Ovário , Células-Tronco
19.
Proc Natl Acad Sci U S A ; 117(50): 31935-31944, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33257577

RESUMO

The stereotyped dimensions of animal bodies and their component parts result from tight constraints on growth. Yet, the mechanisms that stop growth when organs reach the right size are unknown. Growth of the Drosophila wing-a classic paradigm-is governed by two morphogens, Decapentaplegic (Dpp, a BMP) and Wingless (Wg, a Wnt). Wing growth during larval life ceases when the primordium attains full size, concomitant with the larval-to-pupal molt orchestrated by the steroid hormone ecdysone. Here, we block the molt by genetically dampening ecdysone production, creating an experimental paradigm in which the wing stops growing at the correct size while the larva continues to feed and gain body mass. Under these conditions, we show that wing growth is limited by the ranges of Dpp and Wg, and by ecdysone, which regulates the cellular response to their signaling activities. Further, we present evidence that growth terminates because of the loss of two distinct modes of morphogen action: 1) maintenance of growth within the wing proper and 2) induced growth of surrounding "pre-wing" cells and their recruitment into the wing. Our results provide a precedent for the control of organ size by morphogen range and the hormonal gating of morphogen action.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Ecdisona/metabolismo , Asas de Animais/crescimento & desenvolvimento , Proteína Wnt1/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Larva/citologia , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Tamanho do Órgão/genética , Asas de Animais/citologia
20.
Elife ; 92020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32773037

RESUMO

Developmental studies revealed fundamental principles on how organ size and function is achieved, but less is known about organ adaptation to new physiological demands. In fruit flies, juvenile hormone (JH) induces intestinal stem cell (ISC) driven absorptive epithelial expansion balancing energy uptake with increased energy demands of pregnancy. Here, we show 20-Hydroxy-Ecdysone (20HE)-signaling controlling organ homeostasis with physiological and pathological implications. Upon mating, 20HE titer in ovaries and hemolymph are increased and act on nearby midgut progenitors inducing Ecdysone-induced-protein-75B (Eip75B). Strikingly, the PPARγ-homologue Eip75B drives ISC daughter cells towards absorptive enterocyte lineage ensuring epithelial growth. To our knowledge, this is the first time a systemic hormone is shown to direct local stem cell fate decisions. Given the protective, but mechanistically unclear role of steroid hormones in female colorectal cancer patients, our findings suggest a tumor-suppressive role for steroidal signaling by promoting postmitotic fate when local signaling is deteriorated.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Ecdisona/metabolismo , Células-Tronco/metabolismo , Fatores de Transcrição/metabolismo , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Intestinos/crescimento & desenvolvimento , Hormônios Juvenis/metabolismo , PPAR gama/metabolismo , Transdução de Sinais
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