Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 858
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Cell Biol ; 22(3): 297-309, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32066907

RESUMO

Non-centrosomal microtubule-organizing centres (ncMTOCs) have a variety of roles that are presumed to serve the diverse functions of the range of cell types in which they are found. ncMTOCs are diverse in their composition, subcellular localization and function. Here we report a perinuclear MTOC in Drosophila fat body cells that is anchored by the Nesprin homologue Msp300 at the cytoplasmic surface of the nucleus. Msp300 recruits the microtubule minus-end protein Patronin, a calmodulin-regulated spectrin-associated protein (CAMSAP) homologue, which functions redundantly with Ninein to further recruit the microtubule polymerase Msps-a member of the XMAP215 family-to assemble non-centrosomal microtubules and does so independently of the widespread microtubule nucleation factor γ-Tubulin. Functionally, the fat body ncMTOC and the radial microtubule arrays that it organizes are essential for nuclear positioning and for secretion of basement membrane components via retrograde dynein-dependent endosomal trafficking that restricts plasma membrane growth. Together, this study identifies a perinuclear ncMTOC with unique architecture that regulates microtubules, serving vital functions.


Assuntos
Membrana Basal/metabolismo , Núcleo Celular , Centro Organizador dos Microtúbulos/fisiologia , Actinas/fisiologia , Animais , Membrana Celular , Núcleo Celular/ultraestrutura , Centrossomo , Drosophila/metabolismo , Drosophila/ultraestrutura , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Dineínas/fisiologia , Endossomos/metabolismo , Corpo Adiposo/metabolismo , Corpo Adiposo/ultraestrutura , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas dos Microfilamentos/fisiologia , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/fisiologia , Centro Organizador dos Microtúbulos/ultraestrutura , Microtúbulos/fisiologia , Proteínas Musculares/metabolismo , Tubulina (Proteína)/fisiologia
2.
PLoS One ; 15(1): e0227685, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31935250

RESUMO

The acyl-CoA-binding proteins (ACBP) act by regulating the availability of acyl-CoA in the cytoplasm and must have essential functions in lipid metabolism. The genome of the kissing-bug Rhodnius prolixus encodes five proteins of this family, but little is known about them. In this study we investigated the expression and function of RpACBP-5. Feeding induced RpACBP-5 gene expression in the posterior midgut, and an increase of about four times was observed two days after the blood meal. However, the amount of protein, which was only detected in this organ, did not change during digestion. The RpACBP-5 gene was also highly expressed in pre-vitellogenic and vitellogenic oocytes. Recombinant RpACBP-5 was shown to bind to acyl-CoA of different lengths, and it exhibited nanomolar affinity to lauroyl-CoA in an isothermal titration assay, indicating that RpACBP-5 is a functional ACBP. RpACBP-5 knockdown by RNA interference did not affect digestion, egg laying and hatching, survival, or accumulation of triacylglycerol in the fat body and oocytes. Similarly, double knockdown of RpACBP-1 and RpACBP-5 did not alter egg laying and hatching, survival, accumulation of triacylglycerol in the fat body and oocytes, or the neutral lipid composition of the posterior midgut or hemolymph. These results show that RpACBP-5 is a functional ACBP but indicate that the lack of a detectable phenotype in the knockdown insects may be a consequence of functional overlap of the proteins of the ACBP family found in the insect.


Assuntos
Inibidor da Ligação a Diazepam/genética , Inibidor da Ligação a Diazepam/metabolismo , Rhodnius/genética , Acil Coenzima A/metabolismo , Animais , Proteínas de Transporte/metabolismo , Corpo Adiposo/metabolismo , Expressão Gênica/genética , Regulação da Expressão Gênica/genética , Hemolinfa/metabolismo , Proteínas de Insetos/genética , Metabolismo dos Lipídeos/genética , Oócitos/metabolismo , Oviposição , Interferência de RNA/fisiologia , Rhodnius/metabolismo , Triglicerídeos/metabolismo
3.
Insect Mol Biol ; 29(1): 66-76, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31301266

RESUMO

Storage proteins are haemolymph-specific proteins in insects, mainly synthesized in the fat body, released into the haemolymph, and then selectively reabsorbed by the fat body before pupation. These storage proteins play an important role in insect metamorphosis and egg development. Some of these storage proteins are responsive to pathogen infection and can even suppress pathogen multiplication. However, the mechanisms of the physiological, biochemical and immune-responsive functions of storage proteins remain unclear. In this study, the expression patterns of Bombyx mori storage protein 1 (BmSP1) during the larval stage were analysed. Then, BmSP1 protein fused with enhanced green fluorescent protein (EGFP) was successfully expressed in a B. mori baculovirus vector expression system. Quantitative real-time PCR showed that the expression level of BmSP1 increased with the advance of instars and reached the highest level in the fifth instar, especially in the fat body. Recombinant BmSP1 expressed in silkworm larvae inhibited haemolymph melanization. Then, proteins that interact with BmSP1 were identified with EGFP used as an antigenic determinant by co-immunoprecipitation. A 30 kDa low molecular weight lipoprotein PBMHP-6 precursor (BmLP6) was shown to interact with BmSP1. Yeast two-hybrid experiments confirmed the interaction between BmSP1 and BmLP6. The results obtained in this study will be helpful for further study of the functions of BmSP1 and BmLP6 in the regulatory network of silkworm development and innate immunity.


Assuntos
Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Proteínas de Insetos/metabolismo , Animais , Bombyx/genética , Bombyx/imunologia , Linhagem Celular , Corpo Adiposo/metabolismo , Proteínas de Fluorescência Verde , Hemolinfa/imunologia , Imunidade Inata , Proteínas de Insetos/genética , Larva/genética , Larva/imunologia , Larva/metabolismo , Proteínas Recombinantes
4.
Insect Sci ; 27(2): 202-211, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30203565

RESUMO

Eusocial insects display a caste system in which different castes are morphologically and physiologically specialized for different tasks. Recent studies have revealed that epigenetic modifications, including DNA methylation and histone modification, mediate caste determination and differentiation, longevity, and polyethism in eusocial insects. Although there has been a growing interest in the relationship between epigenetic mechanisms and phenotypic plasticity in termites, there is little information about differential expression levels among castes and expression sites for these genes in termites. Here we show royal-tissue-specific expression of epigenetic modification genes in the termite Reticulitermes speratus. Using RNA-seq, we identified 74 genes, including three DNA methyltransferases, seven sirtuins, 48 Trithorax group proteins, and 16 Polycomb group proteins. Among these genes, 15 showed king-specific expression, and 52 showed age-dependent differential expression in kings and queens. Quantitative real-time PCR revealed that DNA methyltransferase 3 is expressed specifically in the king's testis and fat body, whereas some histone modification genes are remarkably expressed in the king's testis and queen's ovary. These findings imply that epigenetic modification plays important roles in the gamete production process in termite kings and queens.


Assuntos
Epigênese Genética , Isópteros/genética , Animais , Corpo Adiposo/metabolismo , Feminino , Isópteros/metabolismo , Masculino , Ovário/metabolismo , Caracteres Sexuais , Testículo/metabolismo , Transcriptoma
5.
Chemosphere ; 245: 125660, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31869670

RESUMO

A comparative transcriptome analysis was conducted to investigate the gene expression changes in the fat body of silkworm after treatment with different concentrations (50 µM and 200 µM) of selenium (Se). 912 differential expression genes (DEGs) (371 up-regulated and 541 down-regulated) and 1420 DEGs (1078 up-regulated and 342 down-regulated) were identified in silkworm fat body treated with 50 µM and 200 µM of Se, respectively. In case of 50 µM group, DEGs were mainly enriched in the peroxisome pathway and fatty acid metabolism pathway, and later were associated with antioxidant defense and nutrition regulation. After 200 µM Se-treatment, DEGs were mainly located in the glycerolipid metabolism and arachidonic acid metabolism pathways, which further encoded detoxification related genes. Furthermore, 32 candidate DEGs from these pathways had been selected to confirm the RNA-seq data. Among these DEGs, 14 genes were up-regulated in the 50 µM Se-treated group (only three genes in the 200 µM Se-treated group) which were involved in lipid metabolism and antioxidant defense, and 13 up-regulated genes (only two genes were up-regulated in the 50 µM Se-treated group) were involved in detoxification of the 200 µM Se-treated group. These changes showed that lower concentration of Se could regulate the nutrition and promote antioxidation pathways; whereas, high levels of Se promoted the detoxification of silkworm. These findings can be helpful to understand the possible mechanisms of Se action and detoxification in silkworm and other insects.


Assuntos
Bombyx/fisiologia , Selênio/metabolismo , Tecido Adiposo/metabolismo , Animais , Bombyx/genética , Bombyx/metabolismo , Regulação para Baixo , Corpo Adiposo/metabolismo , Corpo Adiposo/fisiologia , Perfilação da Expressão Gênica , Inativação Metabólica , Metabolismo dos Lipídeos , Transcriptoma
6.
Nat Commun ; 10(1): 5634, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822677

RESUMO

The blood-feeding behavior of Anopheles females delivers essential nutrients for egg development and drives parasite transmission between humans. Plasmodium growth is adapted to the vector reproductive cycle, but how changes in the reproductive cycle impact parasite development remains unclear. Here, we show that the bloodmeal-induced miR-276-5p fine-tunes the expression of branched-chain amino acid transferase to terminate the reproductive cycle. Silencing of miR-276 prolongs high rates of amino acid (AA) catabolism and increases female fertility, suggesting that timely termination of AA catabolism restricts mosquito investment into reproduction. Prolongation of AA catabolism in P. falciparum-infected females also compromises the development of the transmissible sporozoite forms. Our results suggest that Plasmodium sporogony exploits the surplus mosquito resources available after reproductive investment and demonstrate the crucial role of the mosquito AA metabolism in within-vector parasite proliferation and malaria transmission.


Assuntos
Anopheles/fisiologia , MicroRNAs/metabolismo , Plasmodium falciparum/crescimento & desenvolvimento , Aminoácidos/metabolismo , Animais , Anopheles/efeitos dos fármacos , Sequência de Bases , Ecdisona/farmacologia , Corpo Adiposo/metabolismo , Feminino , Inativação Gênica , MicroRNAs/genética , Modelos Biológicos , Reprodução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Esteroides/metabolismo , Transaminases/metabolismo
7.
PLoS One ; 14(12): e0226039, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31846465

RESUMO

The fat body, a multifunctional organ analogous to the liver and fat tissue of vertebrates, plays an important role in insect life cycles. The fat body is involved in protein storage, energy metabolism, elimination of xenobiotics, and production of immunity regulator-like proteins. However, the molecular mechanism of the fat body's physiological functions in the tephritid stem gall-forming fly, Procecidochares utilis, are still unknown. In this study, we performed transcriptome analysis of the fat body of P. utilis using Illumina sequencing technology. In total, 3.71 G of clean reads were obtained and assembled into 30,559 unigenes, with an average length of 539 bp. Among those unigenes, 21,439 (70.16%) were annotated based on sequence similarity to proteins in NCBI's non-redundant protein sequence database (Nr). Sequences were also compared to NCBI's non-redundant nucleotide sequence database (Nt), a manually curated and reviewed protein sequence database (SwissProt), and KEGG and gene ontology annotations were applied to better understand the functions of these unigenes. A comparative analysis was performed to identify unigenes related to detoxification, immunity and energy metabolism. Many unigenes involved in detoxification were identified, including 50 unigenes of putative cytochrome P450s (P450s), 18 of glutathione S-transferases (GSTs), 35 of carboxylesterases (CarEs) and 26 of ATP-binding cassette (ABC) transporters. Many unigenes related to immunity were identified, including 17 putative serpin genes, five peptidoglycan recognition proteins (PGRPs) and four lysozyme genes. In addition, unigenes potentially involved in energy metabolism, including 18 lipase genes, five fatty acid synthase (FAS) genes and six elongases of very long chain fatty acid (ELOVL) genes, were identified. This transcriptome improves our genetic understanding of P. utilis and the identification of a numerous transcripts in the fat body of P. utilis offer a series of valuable molecular resources for future studies on the functions of these genes.


Assuntos
Metabolismo Energético/genética , Corpo Adiposo/metabolismo , Imunidade/genética , Inativação Metabólica/genética , Tephritidae/genética , Transcriptoma , Transportadores de Cassetes de Ligação de ATP/classificação , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Hidrolases de Éster Carboxílico/classificação , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Sistema Enzimático do Citocromo P-450/classificação , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Bases de Dados Genéticas , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites , Filogenia , Análise de Sequência de DNA
8.
PLoS Genet ; 15(11): e1008487, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31725726

RESUMO

Maintenance of normal lipid homeostasis is crucial to heart function. On the other hand, the heart is now recognized to serve an important role in regulating systemic lipid metabolism; however, the molecular basis remains unclear. In this study, we identify the Drosophila Snail family of transcription factors (herein termed Sna TFs) as new mediators of the heart control of systemic lipid metabolism. Overexpression of Sna TF genes specifically in the heart promotes whole-body leanness whereas their knockdown in the heart promotes obesity. In addition, flies that are heterozygous for a snail deficiency chromosome also exhibit systemic obesity, and that cardiac-specific overexpression of Sna substantially reverses systemic obesity in these flies. We further show that genetically manipulating Sna TF levels in the fat body and intestine do not affect systemic lipid levels. Mechanistically, we find that flies bearing the overexpression or inhibition of Sna TFs in the postnatal heart only exhibit systemic lipid metabolic defects but not heart abnormalities. Cardiac-specific alterations of Sna TF levels also do not perturb cardiac morphology, viability, lipid metabolism or fly food intake. On the other hand, cardiac-specific manipulations of Sna TF levels alter lipogenesis and lipolysis gene expression, mitochondrial biogenesis and respiration, and lipid storage droplet 1 and 2 (Lsd-1 and Lsd-2) levels in the fat body. Together, our results reveal a novel and specific role of Sna TFs in the heart on systemic lipid homeostasis maintenance that is independent of cardiac development and function and involves the governance of triglyceride synthesis and breakdown, energy utilization, and lipid droplet dynamics in the fat body.


Assuntos
Metabolismo dos Lipídeos/genética , Miocárdio/metabolismo , Obesidade/genética , Fatores de Transcrição da Família Snail/genética , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Corpo Adiposo/metabolismo , Regulação da Expressão Gênica/genética , Coração/fisiologia , Humanos , Gotículas Lipídicas/metabolismo , Lipídeos/genética , Miocárdio/patologia , Obesidade/patologia , Biogênese de Organelas , Oxirredutases N-Desmetilantes/genética , Fatores de Transcrição/genética
9.
PLoS One ; 14(10): e0223456, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31600260

RESUMO

Expression of the Alzheimer's disease associated polypeptide Aß42 and the human polypeptide hormon islet amyloid polypeptide (hIAPP) and the prohormone precursor (hproIAPP) in neurons of Drosophila melanogaster leads to the formation of protein aggregates in the fat body tissue surrounding the brain. We determined the structure of these membrane-encircled protein aggregates using transmission electron microscopy (TEM) and observed the dissolution of protein aggregates after starvation. Electron tomography (ET) as an extension of transmission electron microscopy revealed that these aggregates were comprised of granular subunits having a diameter of 20 nm aligned into highly ordered structures in all three dimensions. The three dimensional (3D) lattice of hIAPP granules were constructed of two unit cells, a body centered tetragonal (BCT) and a triclinic unit cell. A 5-fold twinned structure was observed consisting of the cyclic twinning of the BCT and triclinic unit cells. The interaction between the two nearest hIAPP granules in both unit cells is not only governed by the van der Waals forces and the dipole-dipole interaction but potentially also by filament-like structures that can connect the nearest neighbors. Hence, our 3D structural analysis provides novel insight into the aggregation process of hIAPP in the fat body tissue of Drosophila melanogaster.


Assuntos
Drosophila melanogaster/metabolismo , Imageamento Tridimensional , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Animais , Cristalização , Drosophila melanogaster/ultraestrutura , Corpo Adiposo/metabolismo , Corpo Adiposo/ultraestrutura , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/ultraestrutura , Agregados Proteicos , Subunidades Proteicas/química
10.
Int J Biol Sci ; 15(10): 2170-2181, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31592097

RESUMO

Hyperproteinemia is a severe metabolic disease characterized by abnormally elevated plasma protein concentrations (PPC). However, there is currently no reliable animal model for PPC, and the pathological mechanism of hyperproteinemia thus remains unclear. In this study, we evaluated the effects of hyperproteinemia on reproductive development in an invertebrate silkworm model with a controllable PPC and no primary disease effects. High PPC inhibited the synthesis of vitellogenin and 30K protein essential for female ovarian development in the fat body of metabolic tissues, and inhibited their transport through the hemolymph to the ovary. High PPC also induced programmed cell death in testis and ovary cells, slowed the development of germ cells, and significantly reduced the reproductive coefficient. Furthermore, the intensities and mechanisms of high-PPC-induced reproductive toxicity differed between sexes in this silkworm model.


Assuntos
Apoptose/fisiologia , Proteínas Sanguíneas/metabolismo , Bombyx/metabolismo , Hemolinfa/metabolismo , Invertebrados/metabolismo , Animais , Corpo Adiposo/metabolismo , Feminino , Masculino , Ovário/metabolismo , Reprodução/fisiologia , Testículo/metabolismo , Vitelogeninas/metabolismo
11.
PLoS Genet ; 15(10): e1008443, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31661489

RESUMO

Arthropod-specific juvenile hormones control numerous essential functions in development and reproduction. In the dengue-fever mosquito Aedes aegypti, in addition to its role in immature stages, juvenile hormone III (JH) governs post-eclosion (PE) development in adult females, a phase required for competence acquisition for blood feeding and subsequent egg maturation. During PE, JH through its receptor Methoprene-tolerant (Met) regulate the expression of many genes, causing either activation or repression. Met-mediated gene repression is indirect, requiring involvement of intermediate repressors. Hairy, which functions downstream of Met in the JH gene-repression hierarchy, is one such factor. Krüppel-homolog 1, a zinc-finger transcriptional factor, is directly regulated by Met and has been implicated in both activation and repression of JH-regulated genes. However, the interaction between Hairy and Kr-h1 in the JH-repression hierarchy is not well understood. Our RNAseq-based transcriptomic analysis of the Kr-h1-depleted mosquito fat body revealed that 92% of Kr-h1 repressed genes are also repressed by Met, supporting the existence of a hierarchy between Met and Kr-h1 as previously demonstrated in various insects. Notably, 130 genes are co-repressed by both Kr-h1 and Hairy, indicating regulatory complexity of the JH-mediated PE gene repression. A mosquito Kr-h1 binding site in genes co-regulated by this factor and Hairy was identified computationally. Moreover, this was validated using electrophoretic mobility shift assays. A complete phenocopy of the effect of Met RNAi depletion on target genes could only be observed after Kr-h1 and Hairy double RNAi knockdown, suggesting a synergistic action between these two factors in target gene repression. This was confirmed using a cell-culture-based luciferase reporter assay. Taken together, our results indicate that Hairy and Kr-h1 not only function as intermediate downstream factors, but also act together in a synergistic fashion in the JH/Met gene repression hierarchy.


Assuntos
Aedes/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Repressoras/metabolismo , Aedes/crescimento & desenvolvimento , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Corpo Adiposo/metabolismo , Feminino , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Proteínas de Insetos/genética , Fatores de Transcrição Kruppel-Like/genética , Interferência de RNA , RNA-Seq , Proteínas Repressoras/genética
12.
Protein Pept Lett ; 26(12): 949-958, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31518216

RESUMO

BACKGROUND: Sulfakinins are arthropod neuropeptides that are structurally and functionally similar to vertebrate gastrin-cholecystokinin. Sulfakinins with sulfated tyrosine (sSK) or nonsulfated tyrosine (nSK) in the C-terminated heptapeptide XY(SO3H)GHMRFamide display different biological functions, including myotropic activity, inhibition of food intake, stimulation of digestive enzymes and regulation of carbohydrate and lipid content. OBJECTIVE: To reveal the mechanisms by which sulfakinin signalling modulates lipid homeostasis, we analysed the changes in the level and composition of fatty acids and organic compounds in the fat body and haemolymph of Tenebrio molitor larvae after nSK and sSK treatment. METHODS: Fatty acids in fat body and haemolymph of insects were analysed using Gas Chromatography - Mass Spectrometry (GC-MS). RESULTS: The direction of the changes observed for major fatty acids, 18:1 and 18:2, and the less abundant fatty acids, 16:0, 18:0, 16:1 and 14:0, was the same for unsaturated (UFAs) and saturated (SFAs) fatty acids, and elevated after nSK application in both analysed tissues. However, the action of sSK in fat body tissue evoked distinct effects and induced either significant decreases in individual fatty acids or UFAs and SFAs. Administration of nSK and sSK significantly increased the level of total organic compounds in the haemolymph, contrary to the effect of sSK in fat body, where the level of total organic compounds decreased, although changes differ between individual chemicals. CONCLUSION: Sulfakinins are engaged in the precise modulation of fatty acid levels and composition, but their action depends on the presence of sulfate group on the tyrosyl residue of the peptide what determines the different roles of these peptides in insect physiology.


Assuntos
Ácidos Graxos/metabolismo , Proteínas de Insetos/metabolismo , Neuropeptídeos/metabolismo , Tenebrio/metabolismo , Animais , Metabolismo Energético , Corpo Adiposo/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hemolinfa/metabolismo , Larva/metabolismo , Metabolismo dos Lipídeos , Transdução de Sinais
13.
Mol Biotechnol ; 61(11): 852-859, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31473916

RESUMO

To explore virus-like particles formation of dengue virus serotype type 2 (DENV-2) structural proteins of, C, prM, E were expressed in silkworm larvae using recombinant Bombyx mori nucleopolyhedroviruses (BmNPV). Each recombinant BmNPV bacmid coding the 2C-prM-E polypeptide and E protein fused with the signal peptide of bombyxin from B. mori was injected into silkworm larvae. The expressed proteins were collected from hemolymph and fat body, and purified using affinity chromatography. E protein was observed at 55 kDa. The DENV virus-like particles (DENV-LPs) with a diameter approximately 35 nm was observed using transmission electron microscopy (TEM) and immunogold-labelling TEM analysis. The binding of each partially purified proteins to heparin, one of receptors for DENV was confirmed. DENV-LPs were secreted in silkworm larval hemolymph even still low amount, but the E protein and heparin binding function were confirmed.


Assuntos
Proteínas do Capsídeo/metabolismo , Vírus da Dengue/genética , Nucleopoliedrovírus/genética , Proteínas do Envelope Viral/metabolismo , Proteínas Estruturais Virais/metabolismo , Vírion/genética , Animais , Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/isolamento & purificação , Vírus da Dengue/metabolismo , Corpo Adiposo/metabolismo , Expressão Gênica , Vetores Genéticos , Hemolinfa/metabolismo , Heparina/metabolismo , Larva/metabolismo , Nucleopoliedrovírus/metabolismo , Sinais Direcionadores de Proteínas/genética , Sorogrupo , Proteínas do Envelope Viral/biossíntese , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/isolamento & purificação , Proteínas Estruturais Virais/biossíntese , Proteínas Estruturais Virais/genética , Proteínas Estruturais Virais/isolamento & purificação , Vírion/ultraestrutura
14.
J Biotechnol ; 305: 35-42, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31493421

RESUMO

The cost of polyhydroxyalkanoates (PHAs) can be reduced by improving their productivity and recovery. In this study, we attempted to obtain a high cell density culture from a 13 L bioreactor and subsequently improved the recently developed biological recovery process using mealworms to obtain the PHA granules. A cell dry weight of 161 g/L containing 68-70 wt% P(3HB) was obtained. The freeze-dried cells contained a significant amount of mineral salts from the culture medium which reduced the cells' palatability for the mealworms. A simple washing procedure with water was sufficient to remove the residual mineral salts and this improved the cells' consumption by up to 12.5% of the mealworms' body weight. As a result, one kilogram of mealworms consumed 125 g of the washed cells daily and 87.2 g of feacal pellets were recovered, which was almost twice the weight of the unwashed cells. In addition, it also improved the purity of the PHA in the faecal pellets to a value <90% upon washing with water to remove the water-soluble compounds. This study has demonstrated a significant improvement in the production and recovery of PHA. In addition, the resulting mealworms showed a significant increase in protein content up to 79% and a decrease in fat content down to 8.3% of its dry weight.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Cupriavidus necator/crescimento & desenvolvimento , Poli-Hidroxialcanoatos/biossíntese , Tenebrio/crescimento & desenvolvimento , Animais , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Meios de Cultura/química , Cupriavidus necator/metabolismo , Corpo Adiposo/metabolismo , Fezes/microbiologia , Fermentação , Proteínas de Insetos/metabolismo , Tenebrio/metabolismo , Tenebrio/microbiologia
15.
J Insect Physiol ; 118: 103932, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31445957

RESUMO

Insulin-like peptides (ILPs) and the insulin/insulin-like growth factor 1 signaling (IIS) cascade regulate numerous physiological functions, including lifespan, reproduction, immunity, and metabolism, in diverse eukaryotes. We previously demonstrated that in female Anopheles stephensi and Aedes aegypti mosquitoes, activation of the IIS cascade in the fat body led to a significant increase in lifespan. In this work, we elucidated two putative mechanisms in A. stephensi behind the observed lifespan extension and assessed whether this lifespan extension confers an overall fitness advantage to the mosquito. Specifically, we demonstrated that increased Akt signaling in the mosquito fat body following a blood meal significantly suppressed the expression of ILP2 in the head. Moreover, overexpression of active Akt in the fat body altered the expression of a putative insulin binding protein ortholog, Imaginal morphogenesis protein-Late 2 (Imp-L2), in response to transgene expression. Combined, these two factors may act to reduce overall levels of circulating ILP2 or other ILPs in the mosquito, in turn conferring increased survival. We also examined the impact increased fat body IIS had on lifetime fecundity and demonstrated that transgenic female mosquito populations had higher lifetime fecundity relative to non-transgenic sibling controls. These studies provide new insights into the complex hormonal and molecular mechanisms regulating the interplay between IIS, aging, and reproduction in this important vector of human malaria parasites.


Assuntos
Anopheles/metabolismo , Corpo Adiposo/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Animais Geneticamente Modificados , Anopheles/genética , Anopheles/crescimento & desenvolvimento , Sangue , Feminino , Fertilidade/genética , Fertilidade/fisiologia , Humanos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Longevidade/genética , Longevidade/fisiologia , Transdução de Sinais
16.
J Insect Physiol ; 118: 103913, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302015

RESUMO

Silkworms are economically important insects because of the value of their silk. After finishing silk spinning, silkworms begin another important physiological process, vitellogenesis. In this study, we explored the relationship between silk spinning and vitellogenin (BmVg) expression in silkworms. In silkworms with the silk fibroin heavy chain gene knocked-out, the concentration of amino acids in the hemolymph was found to be significantly higher than that in the wild type, and the expression of BmVg was advanced at day 7 of the fifth instar stage and 0 h after spinning. Furthermore, through culturing fat body in vitro with different substances treatment including glucose, trehalose, amino acids, 20-hydroxyecdysone, and insulin, we found that only amino acids could induce BmVg expression. RNA interference of BmTOR1 in female silkworms could down-regulate BmVg transcription, resulting in shortened egg ducts and smaller eggs relative to the control. Therefore, these results showed that amino acids could induce BmVg expression through the TOR signaling pathway. Fat body cultured with amino acids in vitro and experiments involving amino acids injected into the silkworm showed that the majority of main amino acids of silk protein could induce BmVg expression. These results suggested that BmVg expression is related to silk spinning and this study would lay a foundation for elucidating the stage specificity expression of BmVg.


Assuntos
Aminoácidos/metabolismo , Bombyx/metabolismo , Vitelogeninas/metabolismo , Aminoácidos/farmacologia , Animais , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Corpo Adiposo/efeitos dos fármacos , Corpo Adiposo/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genitália Feminina/metabolismo , Hemolinfa/química , Proteínas de Insetos/metabolismo , Estágios do Ciclo de Vida , Interferência de RNA , Seda/química , Técnicas de Cultura de Tecidos , Vitelogeninas/genética
17.
Cell Host Microbe ; 26(2): 240-251.e8, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31350199

RESUMO

Interorgan immunological communication is critical to connect the local-systemic innate immune response and orchestrate a homeostatic host defense. However, the factors and their roles in this process remain unclear. We find Drosophila IMD response in guts can sequentially trigger a systemic IMD reaction in the fat body. Sugar alcohols of the polyol pathway are essential for the spatiotemporal regulation of gut-fat body immunological communication (GFIC). IMD activation in guts causes elevated levels of sorbitol and galactitol in hemolymph. Aldose reductase (AR) in hemocytes, the rate-limiting enzyme of the polyol pathway, is necessary and sufficient for the increase of plasma sugar alcohols. Sorbitol relays GFIC by subsequent activation of Metalloprotease 2, which cleaves PGRP-LC to activate IMD response in fat bodies. Thus, this work unveils how GFIC relies on the intermediate activation of the polyol pathway in hemolymph and demonstrates that AR provides a critical metabolic checkpoint in the global inflammatory response.


Assuntos
Alarminas/imunologia , Drosophila/imunologia , Imunidade Inata/fisiologia , Polímeros/metabolismo , Álcoois Açúcares/metabolismo , Aldeído Redutase/genética , Aldeído Redutase/metabolismo , Aldo-Ceto Redutases/genética , Animais , Animais Geneticamente Modificados , Proteínas de Transporte/metabolismo , Drosophila/genética , Corpo Adiposo/metabolismo , Galactitol/sangue , Galactitol/metabolismo , Hemolinfa/metabolismo , Humanos , Inflamação/imunologia , Masculino , Metaloproteases/metabolismo , Transdução de Sinais/imunologia , Sorbitol/sangue , Sorbitol/metabolismo , Álcoois Açúcares/sangue
18.
Dis Model Mech ; 12(6)2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31160313

RESUMO

The innate immune response is the first line of defence against microbial infections. In Drosophila, two major pathways of the innate immune system (the Toll- and Imd-mediated pathways) induce the synthesis of antimicrobial peptides (AMPs) within the fat body. Recently, it has been reported that certain cationic AMPs exhibit selective cytotoxicity against human cancer cells; however, little is known about their anti-tumour effects. Drosophila mxcmbn1 mutants exhibit malignant hyperplasia in a larval haematopoietic organ called the lymph gland (LG). Here, using RNA-seq analysis, we found many immunoresponsive genes, including those encoding AMPs, to be upregulated in these mutants. Downregulation of these pathways by either a Toll or imd mutation enhanced the tumour phenotype of the mxc mutants. Conversely, ectopic expression of each of five different AMPs in the fat body significantly suppressed the LG hyperplasia phenotype in the mutants. Thus, we propose that the Drosophila innate immune system can suppress the progression of haematopoietic tumours by inducing AMP gene expression. Overexpression of any one of the five AMPs studied resulted in enhanced apoptosis in mutant LGs, whereas no apoptotic signals were detected in controls. We observed that two AMPs, Drosomycin and Defensin, were taken up by circulating haemocyte-like cells, which were associated with the LG regions and showed reduced cell-to-cell adhesion in the mutants. By contrast, the AMP Diptericin was directly localised at the tumour site without intermediating haemocytes. These results suggest that AMPs have a specific cytotoxic effect that enhances apoptosis exclusively in the tumour cells.


Assuntos
Antibacterianos/uso terapêutico , Antineoplásicos/uso terapêutico , Proteínas de Drosophila/genética , Drosophila melanogaster/imunologia , Neoplasias Hematológicas/tratamento farmacológico , Imunidade Inata/efeitos dos fármacos , Mutação/genética , Peptídeos/uso terapêutico , Proteínas Supressoras de Tumor/genética , Animais , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Corpo Adiposo/efeitos dos fármacos , Corpo Adiposo/metabolismo , Hemizigoto , Hemócitos/efeitos dos fármacos , Hiperplasia , Larva/efeitos dos fármacos , Linfonodos/efeitos dos fármacos , Linfonodos/metabolismo , Peptídeos/farmacologia , Fenótipo , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
19.
Mol Genet Genomics ; 294(6): 1375-1383, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31214765

RESUMO

Forkhead box O (FoxO) is a downstream transcription factor of the insulin-signaling pathway, which plays vital roles in the growth and metabolism of organisms. In this study, BmFoxO was overexpressed in BmE cells, in which proliferation was inhibited and apoptosis was increased. The transgenic vector overexpressing BmFoxO was constructed, and the transgenic silkworm line A4FoxO was generated via embryonic microinjection. The body size of A4FoxO silkworm was smaller than that of non-transgenic silkworm (WT). The quantitative polymerase chain reaction results revealed that the insulin pathway was enhanced and the growth-related TOR pathway was suppressed. Furthermore, the translation of proteins in the fat body of A4FoxO silkworm was inhibited. The expression level of genes involved in the glucose synthesis and lipolysis pathways was increased, whereas that of genes involved in fat synthesis was decreased. Oil red O staining revealed that the amount of lipid droplets was reduced in A4FoxO silkworms compared with WT. Further analysis showed that the content of triglyceride and glycogen was significantly decreased in fat body, but the content of glucose and trehalose was increased in the hemolymph of A4FoxO silkworms. These results suggest that the enhanced expression of BmFoxO disturbs glycolipid metabolism and affects silkworm growth.


Assuntos
Bombyx/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Glucose/biossíntese , Proteínas de Insetos/metabolismo , Lipólise , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Bombyx/embriologia , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Linhagem Celular , Proliferação de Células , Corpo Adiposo/metabolismo , Fatores de Transcrição Forkhead/genética , Proteínas de Insetos/genética , Larva/crescimento & desenvolvimento , Metabolismo dos Lipídeos/genética , Lipólise/genética , Açúcares/metabolismo , Triglicerídeos/metabolismo
20.
Biochemistry (Mosc) ; 84(4): 435-440, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31228935

RESUMO

Active skeletal muscles produce lactate. H+ is generated during lactate neutralization in the Cori cycle, which leads to muscle acidosis and soreness (the so-called Delayed Onset Muscle Soreness, DOMS) in vertebrates. The aim of the study was to determine the activities/concentrations of compounds involved in the Cori cycle in worker and forager bees. Muscles, fat bodies, and hemolymph from 1- and 14-day-old workers and foragers were collected and assayed for the protein, lactate, glucose, NAD+, and NADH concentrations and lactate dehydrogenase (LDH) activity. Both lactate concentration and LDH activity in the hemolymph, muscles, and fat bodies increased with age. The concentrations of NAD+ and NADH in the tissues decreased with ageing/senescence, whereas protein concentrations increased until day 14 of bee's life and then decreased in foragers. The concentration of glucose decreased in the hemolymph and muscles and increased in the fat bodies. Elevated lactate concentrations in foragers may indicate transition from the aerobic to the anaerobic phase and development of metabolic acidosis that may eventually lead to muscle damage/soreness and shorter lifespan. When analyzing flight dynamics, load mass, and bee behavior, changes in the concentrations of Cori cycle compounds should be taken into account.


Assuntos
L-Lactato Desidrogenase/metabolismo , Músculo Esquelético/enzimologia , Animais , Abelhas , Corpo Adiposo/enzimologia , Corpo Adiposo/metabolismo , Hemolinfa/enzimologia , Hemolinfa/metabolismo , Ácido Láctico/metabolismo , Músculo Esquelético/metabolismo , Mialgia/patologia , Mialgia/veterinária , NAD/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA