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1.
Anal Chem ; 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34817990

RESUMO

Alzheimer's disease (AD) has become highly relevant in aging societies, yet the fundamental molecular basis for AD is still poorly understood. New tools to study the undergoing structural conformation changes of amyloid beta (Aß) peptides, the pathogenic hallmark of AD, could play a crucial role in the understanding of the underlying mechanisms of misfolding and cytotoxicity of this peptide. It has been recently reported that Zn2+ interacts with Aß and changes its aggregation pathway away from less harmful fibrillar forms to more toxic species. Here, we present a versatile platform based on a set of sub-10 nm nanogap electrodes for the manipulation and sensing of biomolecules in the physiological condition at a low copy number, where molecules are trapped via dielectrophoresis (DEP) across the nanogap, which also serves as a surface-enhanced Raman spectroscopy hotspot. In this study, we demonstrate that our electrode nanogap platform can be used to study the structural difference between Aß40 and ZnAß40 peptides at different aggregation stages in the physiologically relevant concentration and in solution phase. The Raman spectroscopic signatures of the DEP-captured neuropeptides prove the device to be attractive as a label-free bioanalytical tool.

2.
iScience ; 24(10): 103056, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34755080

RESUMO

Impairment in the learning/memory behavior of bees is responsible for the massive disappearance of bee populations and its consequent agricultural economic losses. Such impairment might be because of o both pesticide exposure and pathogen infection, with a key contributor deformed wing virus (DWV). The present study found that sodium butyrate (NaB) significantly increased survival and reversed the learning/memory impairment of DWV-infected bees. A next-generation sequencing analysis showed that NaB affected the expression of genes involved in glycolytic processes and memory formation, which were suppressed by DWV infection. In addition, we performed a large-scale movement tracking experiment by using a wireless sensor network-based automatic real-time monitoring system and confirmed that NaB could improve the homing ability of DWV-infected bees. In short, we demonstrated the mechanism of how epigenetic regulation can resume the memory function of honeybees and suggest strategies for applying NaB to reduce the incidence of colony losses.

3.
Int J Mol Sci ; 22(21)2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34769266

RESUMO

Sublethal dosages of imidacloprid cause long-term destructive effects on honey bees at the individual and colony levels. In this review, the molecular effects of sublethal imidacloprid were integrated and reported. Several general effects have been observed among different reports using different approaches. Quantitative PCR approaches revealed that imidacloprid treatments during the adult stage are expressed as changes in immuneresponse, detoxification, and oxidation-reduction response in both workers and queens. In addition, transcriptomic approaches suggested that phototransduction, behavior, and somatic muscle development also were affected. Although worker larvae show a higher tolerance to imidacloprid than adults, molecular evidence reveals its potential impacts. Sublethal imidacloprid treatment during the larval stage causes gene expression changes in larvae, pupae, and adults. Transcriptome profiles suggest that the population and functions of affected differentially expressed genes, DEGs, vary among different worker ages. Furthermore, an early transcriptomic switch from nurse bees to foragers was observed, suggesting that precocious foraging activity may occur. This report comprehensively describes the molecular effects of sublethal dosages of imidacloprid on the honey bee Apis mellifera. The corresponding molecular pathways for physiological and neurological responses in imidacloprid-exposed honey bees were validated. Transcriptomic evidence suggests a global and sustained sublethal impact of imidacloprid on honey bee development.

4.
IUBMB Life ; 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34724333

RESUMO

Alzheimer's disease (AD) is the most prevalent and devastating neurodegenerative disease occurred in the elderly. One of the pathogenic hallmarks is senile plaques composed of amyloid-ß (Aß) fibrils. Single mutations resided in Aß were found in familial AD (FAD) patients that have early onset of the disease. The molecular details and properties of each FAD Aß variants are still elusive. Here, we employed collective spectroscopic techniques to examine the properties of various Aß40 fibrils. We generated fibrils of wild type (WT) and three FAD mutants on residue E22 including E22G, E22K, and E22Q. We monitored fibril formation by thioflavin T (ThT) assay, examined secondary structure by Fourier transform infrared and far-UV circular dichroism spectroscopy, imaged fibril morphology by transmission electron microscopy, and evaluated ThT-binding kinetics. In the thermal experiments, we found E22K fibrils resisted to high temperature and retained significant ß-sheet content than the others. E22K fibril seeds after high-temperature treatment still possess the seeding property, whereas WT fibril seeds are disturbed after the treatment. Therefore, in this study we demonstrated the mutation at E22K increases the thermal stability and seeding function of amyloid fibrils.

5.
Int J Mol Sci ; 22(20)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34681803

RESUMO

A neuropeptide (Sco-CHH-L), belonging to the crustacean hyperglycemic hormone (CHH) superfamily and preferentially expressed in the pericardial organs (POs) of the mud crab Scylla olivacea, was functionally and structurally studied. Its expression levels were significantly higher than the alternative splice form (Sco-CHH) in the POs, and increased significantly after the animals were subjected to a hypo-osmotic stress. Sco-CHH-L, but not Sco-CHH, significantly stimulated in vitro the Na+, K+-ATPase activity in the posterior (6th) gills. Furthermore, the solution structure of Sco-CHH-L was resolved using nuclear magnetic resonance spectroscopy, revealing that it has an N-terminal tail, three α-helices (α2, Gly9-Asn28; α3, His34-Gly38; and α5, Glu62-Arg72), and a π-helix (π4, Cys43-Tyr54), and is structurally constrained by a pattern of disulfide bonds (Cys7-Cys43, Cys23-Cys39, and Cys26-Cys52), which is characteristic of the CHH superfamily-peptides. Sco-CHH-L is topologically most similar to the molt-inhibiting hormone from the Kuruma prawn Marsupenaeus japonicus with a backbone root-mean-square-deviation of 3.12 Å. Ten residues of Sco-CHH-L were chosen for alanine-substitution, and the resulting mutants were functionally tested using the gill Na+, K+-ATPase activity assay, showing that the functionally important residues (I2, F3, E45, D69, I71, and G73) are located at either end of the sequence, which are sterically close to each other and presumably constitute the receptor binding sites. Sco-CHH-L was compared with other members of the superfamily, revealing a folding pattern, which is suggested to be common for the crustacean members of the superfamily, with the properties of the residues constituting the presumed receptor binding sites being the major factors dictating the ligand-receptor binding specificity.

6.
Front Genet ; 12: 665927, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220942

RESUMO

The environmental residue/sublethal doses of neonicotinoid insecticides are believed to generate a negative impact on pollinators, including honey bees. Here we report our recent investigation on how imidacloprid, one of the major neonicotinoids, affects worker bees by profiling the transcriptomes of various ages of bees exposed to different doses of imidacloprid during the larval stage. The results show that imidacloprid treatments during the larval stage severely altered the gene expression profiles and may induce precocious foraging. Differential expression of foraging regulators was found in 14-day-old treated adults. A high transcriptome similarity between larvae-treated 14-day-old adults and 20-day-old controls was also observed, and the similarity was positively correlated with the dose of imidacloprid. One parts per billion (ppb) of imidacloprid was sufficient to generate a long-term impact on the bee's gene expression as severe as with 50 ppb imidacloprid. The disappearance of nurse bees may be driven not only by the hive member constitution but also by the neonicotinoid-induced precocious foraging behavior.

7.
Environ Pollut ; 281: 116944, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33813192

RESUMO

Artificial light at night (ALAN) is a major driver of firefly population declines, but its physiological effects are not well understood. To investigate the impact of ALAN on firefly development, we exposed larval Aquatica ficta fireflies to ALAN for two weeks. High larval mortality was observed in the periods of 1-68 days and 106-134 days post-treatment, which may represent the short- and long-term impacts of ALAN. We then profiled the transcriptome of larval Aquatica ficta fireflies following two weeks of ALAN exposure. A total of 1262 (1.67% out of 75777 unigenes) were differentially expressed in the treatment group: 1157 were down-regulated, and 105 were up-regulated. Up-regulated unigenes were related to regulation of hormone levels, ecdysteroid metabolic process, and response to stimulus; down-regulated unigenes were related to negative regulation of insulin receptor signaling, germ cell development, oogenesis, spermatid development, and regulation of neuron differentiation. Transcriptome results suggest that the endocrine, reproductive, and neural development of firefly larvae could be impaired by even relatively brief period of ALAN exposure. This report contributes a much-needed molecular perspective to the growing body of research documenting the fitness impacts of ALAN on bioluminescent fireflies.


Assuntos
Vaga-Lumes , Luz , Animais , Expressão Gênica , Larva , Reprodução
8.
Langmuir ; 37(1): 516-523, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33352048

RESUMO

The onset or progression of numerous neurodegenerative diseases occurs due to aggregation of proteins that ultimately form fibrils. The assembly and morphology of fibrils are susceptible to environmental factors. In this work, we used atomic force microscopy (AFM) to investigate the effects of dissolved nitrogen and oxygen molecules on the morphology of fibrils formed by a hydrophobic amyloid peptide implicated in amyotrophic lateral sclerosis, 15 repeats of glycine-alanine, on a highly oriented pyrolytic graphite substrate. We started with preformed fibril solutions that were then diluted with buffers of different gas conditions, resulting in the aggregation of the fibrils into different morphologies that were revealed by AFM after adsorption on the substrate. Straight fibrils were observed in both degassed and ambient buffers, but a stronger lateral association was seen in degassed buffers. Smaller and softer fibrils were observed in O2-supersaturated buffers, and plaque-like fibril aggregates of considerably large size were evident in N2-supersaturated buffers. In overnight incubation experiments, we observed changes in both the morphology and height of the fibril aggregates, and their evolution varied with different gas conditions. These findings indicate that the gas type and concentration affect the aggregation of amyloid fibrils and may facilitate the development of biomaterial applications and treatments for amyloid-related diseases.

9.
Nat Commun ; 11(1): 5950, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230138

RESUMO

TDP-43 inclusions are found in many Alzheimer's disease (AD) patients presenting faster disease progression and greater brain atrophy. Previously, we showed full-length TDP-43 forms spherical oligomers and perturbs amyloid-ß (Aß) fibrillization. To elucidate the role of TDP-43 in AD, here, we examined the effect of TDP-43 in Aß aggregation and the attributed toxicity in mouse models. We found TDP-43 inhibited Aß fibrillization at initial and oligomeric stages. Aß fibrillization was delayed specifically in the presence of N-terminal domain containing TDP-43 variants, while C-terminal TDP-43 was not essential for Aß interaction. TDP-43 significantly enhanced Aß's ability to impair long-term potentiation and, upon intrahippocampal injection, caused spatial memory deficit. Following injection to AD transgenic mice, TDP-43 induced inflammation, interacted with Aß, and exacerbated AD-like pathology. TDP-43 oligomers mostly colocalized with intracellular Aß in the brain of AD patients. We conclude that TDP-43 inhibits Aß fibrillization through its interaction with Aß and exacerbates AD pathology.


Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Amiloide/metabolismo , Animais , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Hipocampo/patologia , Hipocampo/fisiopatologia , Humanos , Potenciação de Longa Duração , Transtornos da Memória/patologia , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Placa Amiloide/patologia , Agregação Patológica de Proteínas/patologia , Ligação Proteica , Domínios Proteicos
10.
Biochem Biophys Res Commun ; 529(3): 714-719, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32736697

RESUMO

Obesity is associated with metabolic disorders. Fibroblast growth factor 21 (FGF21) has been recognized as important in metabolism. Glucosamine (GLN) has been demonstrated to perform diverse beneficial functions. This study aimed to reveal whether and how GLN would modulate FGF21 production in relation to metabolism. With in vivo model of normal diet (ND) and high-fat diet (HFD) mice receiving GLN injection and in vitro model of mouse AML12 liver cells and differentiated 3T3L1 adipocytes challenged with GLN, GLN appeared to improve the glucose metabolism in HFD and ND mice and to elevate FGF21 protein expression in HFD liver and to increase both FGF21 protein and mRNA levels in WAT from HFD and ND mice and it also upregulated FGF21 expression in both AML12 and differentiated 3T3L1 cells. By using inhibitors against various signaling pathways, p38, Akt, NF-κB, and PKA appeared potentially involved in GLN-mediated FGF21 production in AML12 cells; GLN was able to mediate activation of NF-κB, p38 or PKA/CREB signaling. Our accumulated findings suggest that GLN may potentially improve the metabolic performance by inducing FGF21 production in liver and adipose tissues and such induction in liver cells may act in part due to GLN induction of the NF-κB, p38 and PKA pathways.


Assuntos
Tecido Adiposo/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Glucosamina/metabolismo , Fígado/metabolismo , Células 3T3-L1 , Animais , Fatores de Crescimento de Fibroblastos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Regulação para Cima
11.
J Hum Genet ; 65(7): 619-625, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32246049

RESUMO

The Fabry disease-causing mutation, the GLA IVS4+919G>A (designated GLA IVS4), is very prevalent in patients with hypertrophic cardiomyopathy in Taiwan. This X-linked mutation has also been found in patients in Kyushu, Japan and Southeast Asia. To investigate the age and the possible ancestral origin of this mutation, a total of 33 male patients with the GLA IVS4+919G>A mutation, born in Taiwan, Japan, Singapore, Malaysia, Vietnam, and the Fujian and Guangdong provinces of China, were studied. Peripheral bloods were collected, and the Ilumina Infinium CoreExome-24 microarray was used for dense genotyping. A mutation-carrying haplotype was discovered which was shared by all 33 patients. This haplotype does not exist in 15 healthy persons without the mutation. Rather, a wide diversity of haplotypes was found in the vicinity of the mutation site, supporting the existence of a single founder of the GLA IVS4 mutation. The age of the founder mutation was estimated by the lengths of the mutation-carrying haplotypes based on the linkage-disequilibrium decay theory. The first, second, and third quartile of the age estimates are 800.7, 922.6, and 1068.4 years, respectively. We concluded that the GLA IVS4+919G>A mutation originated from a single mutational event that occurred in a Chinese chromosome more than 800 years ago.


Assuntos
Cardiomiopatia Hipertrófica Familiar/genética , Doença de Fabry/genética , alfa-Galactosidase/genética , Adulto , Cardiomiopatia Hipertrófica Familiar/epidemiologia , Cardiomiopatia Hipertrófica Familiar/patologia , China/epidemiologia , Doença de Fabry/epidemiologia , Doença de Fabry/patologia , Genes Ligados ao Cromossomo X/genética , Genótipo , Haplótipos/genética , Humanos , Japão/epidemiologia , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mutação/genética , Taiwan/epidemiologia
12.
Brain ; 143(2): 430-440, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32040555

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease caused by motor neuron loss, resulting in muscle wasting, paralysis and eventual death. A key pathological feature of ALS is cytoplasmically mislocalized and aggregated TDP-43 protein in >95% of cases, which is considered to have prion-like properties. Historical studies have predominantly focused on genetic forms of ALS, which represent ∼10% of cases, leaving the remaining 90% of sporadic ALS relatively understudied. Additionally, the role of astrocytes in ALS and their relationship with TDP-43 pathology is also not currently well understood. We have therefore used highly enriched human induced pluripotent stem cell (iPSC)-derived motor neurons and astrocytes to model early cell type-specific features of sporadic ALS. We first demonstrate seeded aggregation of TDP-43 by exposing human iPSC-derived motor neurons to serially passaged sporadic ALS post-mortem tissue (spALS) extracts. Next, we show that human iPSC-derived motor neurons are more vulnerable to TDP-43 aggregation and toxicity compared with their astrocyte counterparts. We demonstrate that these TDP-43 aggregates can more readily propagate from motor neurons into astrocytes in co-culture paradigms. We next found that astrocytes are neuroprotective to seeded aggregation within motor neurons by reducing (mislocalized) cytoplasmic TDP-43, TDP-43 aggregation and cell toxicity. Furthermore, we detected TDP-43 oligomers in these spALS spinal cord extracts, and as such demonstrated that highly purified recombinant TDP-43 oligomers can reproduce this observed cell-type specific toxicity, providing further support to a protein oligomer-mediated toxicity hypothesis in ALS. In summary, we have developed a human, clinically relevant, and cell-type specific modelling platform that recapitulates key aspects of sporadic ALS and uncovers both an initial neuroprotective role for astrocytes and the cell type-specific toxic effect of TDP-43 oligomers.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Astrócitos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios Motores/metabolismo , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Morte Celular/genética , Citoplasma/metabolismo , Humanos , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Medula Espinal/metabolismo , Medula Espinal/patologia
13.
Acta Neuropathol Commun ; 8(1): 3, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31964415

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal, adult-onset degenerative disorder of motor neurons. The diseased spinal cord motor neurons of more than 95% of amyotrophic lateral sclerosis (ALS) patients are characterized by the mis-metabolism of the RNA/DNA-binding protein TDP-43 (ALS-TDP), in particular, the presence of cytosolic aggregates of the protein. Most available mouse models for the basic or translational studies of ALS-TDP are based on transgenic overexpression of the TDP-43 protein. Here, we report the generation and characterization of mouse lines bearing homologous knock-in of fALS-associated mutation A315T and sALS-associated mutation N390D, respectively. Remarkably, the heterozygous TDP-43 (N390D/+) mice but not those heterozygous for the TDP-43 (A315T/+) mice develop a full spectrum of ALS-TDP-like pathologies at the molecular, cellular and behavioral levels. Comparative analysis of the mutant mice and spinal cord motor neurons (MN) derived from their embryonic stem (ES) cells demonstrates that different ALS-associated TDP-43 mutations possess critical ALS-causing capabilities and pathogenic pathways, likely modified by their genetic background and the environmental factors. Mechanistically, we identify aberrant RNA splicing of spinal cord Bcl-2 pre-mRNA and consequent increase of a negative regulator of autophagy, Bcl-2, which correlate with and are caused by a progressive increase of TDP-43, one of the early events associated with ALS-TDP pathogenesis, in the spinal cord of TDP-43 (N390D/+) mice and spinal cord MN derived from their ES cells. The TDP-43 (N390D/+) knock-in mice appear to be an ideal rodent model for basic as well as translational studies of ALS- TDP.


Assuntos
Esclerose Amiotrófica Lateral , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Esclerose Amiotrófica Lateral/patologia , Animais , Autofagia , Linhagem Celular , Células-Tronco Embrionárias , Feminino , Técnicas de Introdução de Genes , Masculino , Camundongos Transgênicos , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(6): 1845-1849, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31839048

RESUMO

OBJECTIVE: To investigate the clinical significance of bone marrow unclassifiable cells in diagnosis of fever of unknown origin(FUO). METHODS: The clinical data of 60 patients with FUO admitted in the first affiliated hospital of Xi'an Jiaotong university from June 2014 to May 2016 were collected, and 60 patients with FUO were divided into 2 group: group A(30 cases) in which the unclassifiable cells in bone marrow were observed by bone marrow examination, and group B(30 cases) in which the unclassifiable cells in bone marrow not were found by bone marrow examination. The clinical characteristics, bone marrow features, immunophenotypes of bone marrow cells and prognosis of patients in 2 groups were analyzed retrospectively. RESULTS: Out of 30 patients in group A, 18 were diagnosed as malignant tumors including 12 cases of lymphoma, while out of 30 patients in group B, 5 cases were diagnosed as malignant tumor, including 3 cases of lymphoma. For the patients with non-tumor diseases, the bone marrow unclassifiable cells disappeared after the patients condition was improved. CONCLUSION: The bone marrow examination including the smear and biopsy shonld be performed routinely for the patients with FUO. If the unclassifiable cells are observed morphologically in bone marrow of patients with FUO, the disease of patients should be considered as malignant tumor, especially, lymphoma.


Assuntos
Medula Óssea , Febre de Causa Desconhecida , Células da Medula Óssea , Exame de Medula Óssea , Humanos , Estudos Retrospectivos
15.
Insect Biochem Mol Biol ; 112: 103209, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31422154

RESUMO

Insecticidal proteins from Bacillus thuringiensis (Bt) are the primary recombinant proteins expressed in transgenic crops (Bt-crops) to confer insect resistance. Development of resistance to Bt toxins in insect populations threatens the sustainable application of Bt-crops in agriculture. The Bt toxin Cry2Ab is a major insecticidal protein used in current Bt-crops, and resistance to Cry2Ab has been selected in several insects, including the cabbage looper, Trichoplusia ni. In this study, the Cry2Ab resistance gene in T. ni was mapped to Chromosome 17 by genetic linkage analyses using a whole genome resequencing approach, and was then finely mapped using RNA-seq-based bulked segregant analysis (BSA) and amplicon sequencing (AmpSeq)-based fine linkage mapping to a locus containing two genes, ABCA1 and ABCA2. Mutations in ABCA1 and ABCA2 in Cry2Ab resistant T. ni were identified by both genomic DNA and cDNA sequencing. Analysis of the expression of ABCA1 and ABCA2 in T. ni larvae indicated that ABCA2 is abundantly expressed in the larval midgut, but ABCA1 is not a midgut-expressed gene. The mutation in ABCA2 in Cry2Ab resistant T. ni was identified to be an insertion of a transposon Tntransib in ABCA2. For confirmation of ABCA2 as the Cry2Ab-resistance gene, T. ni mutants with frameshift mutations in ABCA1 and ABCA2 were generated by CRISPR/Cas9 mutagenesis. Bioassays of the T. ni mutants with Cry2Ab verified that the mutations of ABCA1 did not change larval susceptibility to Cry2Ab, but the ABCA2 mutants were highly resistant to Cry2Ab. Genetic complementation test of the ABCA2 allele in Cry2Ab resistant T. ni with an ABCA2 mutant generated by CRISPR/Cas9 confirmed that the ABCA2 mutation in the Cry2Ab resistant strain confers the resistance. The results from this study confirmed that ABCA2 is essential for the toxicity of Cry2Ab in T. ni and mutation of ABCA2 confers the resistance to Cry2Ab in the resistant T. ni strain derived from a Bt resistant greenhouse population.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Resistência a Inseticidas/genética , Mariposas/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Bacillus thuringiensis , Toxinas Bacterianas/toxicidade , Endotoxinas/toxicidade , Expressão Gênica , Ligação Genética , Proteínas Hemolisinas/toxicidade , Inseticidas , Larva/efeitos dos fármacos , Larva/genética , Larva/metabolismo , Mariposas/efeitos dos fármacos , Mariposas/metabolismo , Mutação
16.
Brief Bioinform ; 20(3): 976-984, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-29194477

RESUMO

The development of disease involves a systematic disturbance inside cells and is associated with changes in the interactions or regulations among genes forming biological networks. The bridges inside a network are critical in shortening the distances between nodes. We observed that, inside the human gene regulatory network, one strongly connected core bridged the whole network. Other regulations outside the core formed a weakly connected component surrounding the core like a peripheral structure. Furthermore, the regulatory feedback loops (FBLs) inside the core compose an interface-like structure between the core and periphery. We then denoted the regulatory FBLs as the interface core. Notably, both the cancer-associated and essential biomolecules and regulations were significantly overrepresented in the interface core. These results implied that the interface core is not only critical for the network structure but central in cellular systems. Furthermore, the enrichment of the cancer-associated and essential regulations in the interface core might be attributed to its bridgeness in the network. More importantly, we identified one regulatory FBL between HNF4A and NR2F2 that possesses the highest bridgeness in the interface core. Further investigation suggested that the disturbance of the HNF4A-NR2F2 FBL might protect tumor cells from apoptotic processes. Our results emphasize the relevance of the regulatory network properties to cellular systems and might reveal a critical role of the interface core in cancer.


Assuntos
Carcinogênese/genética , Redes Reguladoras de Genes , Humanos , Neoplasias/genética
17.
Commun Biol ; 1: 178, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30393775

RESUMO

Defective arginine synthesis, due to the silencing of argininosuccinate synthase 1 (ASS1), is a common metabolic vulnerability in cancer, known as arginine auxotrophy. Understanding how arginine depletion kills arginine-auxotrophic cancer cells will facilitate the development of anti-cancer therapeutic strategies. Here we show that depletion of extracellular arginine in arginine-auxotrophic cancer cells causes mitochondrial distress and transcriptional reprogramming. Mechanistically, arginine starvation induces asparagine synthetase (ASNS), depleting these cancer cells of aspartate, and disrupting their malate-aspartate shuttle. Supplementation of aspartate, depletion of mitochondria, and knockdown of ASNS all protect the arginine-starved cells, establishing the causal effects of aspartate depletion and mitochondrial dysfunction on the arginine starvation-induced cell death. Furthermore, dietary arginine restriction reduced tumor growth in a xenograft model of ASS1-deficient breast cancer. Our data challenge the view that ASNS promotes homeostasis, arguing instead that ASNS-induced aspartate depletion promotes cytotoxicity, which can be exploited for anti-cancer therapies.

18.
Nat Plants ; 4(10): 784-791, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30250279

RESUMO

Fleshy fruits using ethylene to regulate ripening have developed multiple times in the history of angiosperms, presenting a clear case of convergent evolution whose molecular basis remains largely unknown. Analysis of the fruitENCODE data consisting of 361 transcriptome, 71 accessible chromatin, 147 histone and 45 DNA methylation profiles reveals three types of transcriptional feedback circuits controlling ethylene-dependent fruit ripening. These circuits are evolved from senescence or floral organ identity pathways in the ancestral angiosperms either by neofunctionalisation or repurposing pre-existing genes. The epigenome, H3K27me3 in particular, has played a conserved role in restricting ripening genes and their orthologues in dry and ethylene-independent fleshy fruits. Our findings suggest that evolution of ripening is constrained by limited hormone molecules and genetic and epigenetic materials, and whole-genome duplications have provided opportunities for plants to successfully circumvent these limitations.


Assuntos
Frutas/genética , Genoma de Planta/genética , Evolução Biológica , Cromatina/metabolismo , Metilação de DNA , Etilenos/metabolismo , Perfilação da Expressão Gênica , Histonas/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Proteínas de Domínio MADS/metabolismo , Malus/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Pyrus/crescimento & desenvolvimento
19.
Eur J Med Chem ; 158: 393-404, 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30227353

RESUMO

One of the pathologic hallmarks in Alzheimer's disease (AD) is extracellular senile plaques composed of amyloid-ß (Aß) fibrils. Blocking Aß self-assembly or disassembling Aß aggregates by small molecules would be potential therapeutic strategies to treat AD. In this study, we synthesized a series of rationally designed divalent compounds and examined their effects on Aß fibrillization. A divalent amide (2) derived from two molecules of caffeic acid with a propylenediamine linker of ∼5.0 Šin length, which is close to the distance of adjacent ß sheets in Aß fibrils, showed good potency to inhibit Aß(1-42) fibrillization. Furthermore, compound 2 effectively dissociated the Aß(1-42) preformed fibrils. The cytotoxicity induced by Aß(1-42) aggregates in human neuroblastoma was reduced in the presence of 2, and feeding 2 to Aß transgenic C. elegans rescued the paralysis phenotype. In addition, the binding and stoichiometry of 2 to Aß(1-40) were demonstrated by using electrospray ionization-traveling wave ion mobility-mass spectrometry, while molecular dynamic simulation was conducted to gain structural insights into the Aß(1-40)-2 complex.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacologia , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer/tratamento farmacológico , Amidas/química , Amidas/farmacologia , Amidas/uso terapêutico , Peptídeos beta-Amiloides/ultraestrutura , Animais , Caenorhabditis elegans , Ácidos Cafeicos/uso terapêutico , Humanos , Modelos Moleculares , Fragmentos de Peptídeos/ultraestrutura , Multimerização Proteica/efeitos dos fármacos
20.
J Virol ; 92(23)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30209166

RESUMO

The baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a large double-stranded DNA (dsDNA) virus that encodes approximately 156 genes and is highly pathogenic to a variety of larval lepidopteran insects in nature. Oral infection of larval midgut cells is initiated by the occlusion-derived virus (ODV), while secondary infection of other tissues is mediated by the budded virus (BV). Global viral gene expression has been studied in detail in BV-infected cell cultures, but studies of ODV infection in the larval midgut are limited. In this study, we examined expression of the ∼156 AcMNPV genes in Trichoplusia ni midgut tissue using a transcriptomic approach. We analyzed expression profiles of viral genes in the midgut and compared them with profiles from a T. ni cell line (Tnms42). Several viral genes (p6.9, orf76, orf75, pp31, Ac-bro, odv-e25, and odv-ec27) had high expression levels in the midgut throughout the infection. Also, the expression of genes associated with occlusion bodies (polh and p10) appeared to be delayed in the midgut in comparison with the cell line. Comparisons of viral gene expression profiles revealed remarkable similarities between the midgut and cell line for most genes, although substantial differences were observed for some viral genes. These included genes associated with high level BV production (fp-25k), acceleration of systemic infection (v-fgf), and enhancement of viral movement (arif-1/orf20). These differential expression patterns appear to represent specific adaptations for virus infection and transmission through the polarized cells of the lepidopteran midgut.IMPORTANCE Baculoviruses such as AcMNPV are pathogens that are natural regulators of certain insect populations. Baculovirus infections are biphasic, with a primary phase initiated by oral infection of midgut epithelial cells by occlusion-derived virus (ODV) virions and a secondary phase in which other tissues are infected by budded-virus (BV) virions. While AcMNPV infections in cultured cells have been studied extensively, comparatively little is known regarding primary infection in the midgut. In these studies, we identified gene expression patterns associated with ODV-mediated infection of the midgut in Trichoplusia ni and compared those results with prior results from BV-infected cultured cells, which simulate secondary infection. These studies provide a detailed analysis of viral gene expression patterns in the midgut, which likely represent specific viral strategies to (i) overcome or avoid host defenses in the gut and (ii) rapidly move infection from the midgut, into the hemocoel to facilitate systemic infection.


Assuntos
Sistema Digestório/metabolismo , Perfilação da Expressão Gênica , Larva/genética , Nucleopoliedrovírus/genética , RNA Viral/genética , Spodoptera/genética , Proteínas Virais/genética , Animais , Sistema Digestório/virologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Larva/metabolismo , Larva/virologia , Nucleopoliedrovírus/metabolismo , Spodoptera/metabolismo , Spodoptera/virologia , Proteínas Virais/metabolismo
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