The regulatory relationship between RagA and Nprl2 in Drosophila gut development / 生物工程学报

The gastrointestinal tract is the largest digestive organ and the largest immune organ and detoxification organ, which is vital to the health of the body. Drosophila is a classic model organism, and its gut is highly similar to mammalian gut in terms of cell composition and genetic regulation, therefore can be used as a good model for studying gut development. target of rapmaycin complex 1 (TORC1) is a key factor regulating cellular metabolism. Nprl2 inhibits TORC1 activity by reducing Rag GTPase activity. Previous studies have found that nprl2 mutated Drosophila showed aging-related phenotypes such as enlarged foregastric and reduced lifespan, which were caused by over-activation of TORC1. In order to explore the role of Rag GTPase in the developmental defects of the gut of nprl2 mutated Drosophila, we used genetic hybridization combined with immunofluorescence to study the intestinal morphology and intestinal cell composition of RagA knockdown and nprl2 mutated Drosophila. The results showed that RagA knockdown alone could induce intestinal thickening and forestomach enlargement, suggesting that RagA also plays an important role in intestinal development. Knockdown of RagA rescued the phenotype of intestinal thinning and decreased secretory cells in nprl2 mutants, suggesting that Nprl2 may regulate the differentiation and morphology of intestinal cells by acting on RagA. Knockdown of RagA did not rescue the enlarged forestomach phenotype in nprl2 mutants, suggesting that Nprl2 may regulate forestomach development and intestinal digestive function through a mechanism independent of Rag GTPase.

Resveratrol and Sir2 Reverse Sleep and Memory Defects Induced by Amyloid Precursor Protein / 神经科学通报·英文版

Resveratrol (RES), a natural polyphenolic phytochemical, has been suggested as a putative anti-aging molecule for the prevention and treatment of Alzheimer's disease (AD) by the activation of sirtuin 1 (Sirt1/Sir2). In this study, we tested the effects of RES and Sirt1/Sir2 on sleep and courtship memory in a Drosophila model by overexpression of amyloid precursor protein (APP), whose duplications and mutations cause familial AD. We found a mild but significant transcriptional increase of Drosophila Sir2 (dSir2) by RES supplementation for up to 17 days in APP flies, but not for 7 days. RES and dSir2 almost completely reversed the sleep and memory deficits in APP flies. We further demonstrated that dSir2 acts as a sleep promotor in Drosophila neurons. Interestingly, RES increased sleep in the absence of dSir2 in dSir2-null mutants, and RES further enhanced sleep when dSir2 was either overexpressed or knocked down in APP flies. Finally, we showed that Aβ aggregates in APP flies were reduced by RES and dSir2, probably via inhibiting Drosophila β-secretase (dBACE). Our data suggest that RES rescues the APP-induced behavioral deficits and Aβ burden largely, but not exclusively, via dSir2.

Direction Selectivity of TmY Neurites in Drosophila / 神经科学通报·英文版

The perception of motion is an important function of vision. Neural wiring diagrams for extracting directional information have been obtained by connectome reconstruction. Direction selectivity in Drosophila is thought to originate in T4/T5 neurons through integrating inputs with different temporal filtering properties. Through genetic screening based on synaptic distribution, we isolated a new type of TmY neuron, termed TmY-ds, that form reciprocal synaptic connections with T4/T5 neurons. Its neurites responded to grating motion along the four cardinal directions and showed a variety of direction selectivity. Intriguingly, its direction selectivity originated from temporal filtering neurons rather than T4/T5. Genetic silencing and activation experiments showed that TmY-ds neurons are functionally upstream of T4/T5. Our results suggest that direction selectivity is generated in a tripartite circuit formed among these three neurons-temporal filtering, TmY-ds, and T4/T5 neurons, in which TmY-ds plays a role in the enhancement of direction selectivity in T4/T5 neurons.

Neuroprotective effect of ginsenoside Re on drosophila model of Parkinson's disease / 中国中药杂志

This study aims to explore the neuroprotective mechanism of ginsenoside Re(GS-Re) on drosophila model of Parkinson's disease(PD) induced by rotenone(Rot). To be specific, Rot was used to induce PD in drosophilas. Then the drosophilas were grouped and respectively treated(GS-Re: 0.1, 0.4, 1.6 mmol·L~(-1); L-dopa: 80 μmol·L~(-1)). Life span and crawling ability of drosophilas were determined. The brain antioxidant activity [content of catalase(CAT), malondialdehyde(MDA), reactive oxygen species(ROS), superoxide dismutase(SOD)], dopamine(DA) content, and mitochondrial function [content of adenosine triphosphate(ATP), NADH:ubiquinone oxidoreductase subunit B8(NDUFB8) Ⅰ activity, succinate dehydrogenase complex, subunit B(SDHB) Ⅱ activity] were detected by enzyme-linked immunosorbent assay(ELISA). The number of DA neurons in the brains of drosophilas was measured with the immunofluorescence method. The levels of NDUFB8 Ⅰ, SDHB Ⅱ, cytochrome C(Cyt C), nuclear factor-E2-related factor 2(Nrf2), heme oxygenase-1(HO-1), B-cell lymphoma/leukemia 2(Bcl-2)/Bcl-2-assaciated X protein(Bax), and cleaved caspase-3/caspase-3 in the brain were detected by Western blot. The results showed that model group [475 μmol·L~(-1) Rot(IC_(50))] demonstrated significantly low survival rate, obvious dyskinesia, small number of neurons and low DA content in the brain, high ROS level and MDA content, low content of SOD and CAT, significantly low ATP content, NDUFB8 Ⅰ activity, and SDHB Ⅱ activity, significantly low expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax, large amount of Cyt C released from mitochondria to cytoplasm, low nuclear transfer of Nrf2, and significantly high expression of cleaved caspase-3/caspase-3 compared with the control group. GS-Re(0.1, 0.4, and 1.6 mmol·L~(-1)) significantly improved the survival rate of PD drosophilas, alleviated the dyskinesia, increased DA content, reduced the loss of DA neurons, ROS level, and MDA content in brain, improved content of SOD and CAT and antioxidant activity in brain, maintained mitochondrial homeostasis(significantly increased ATP content and activity of NDUFB8 Ⅰ and SDHB Ⅱ, significantly up-regulated expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax), significantly reduced the expression of Cyt C, increased the nuclear transfer of Nrf2, and down-regulated the expression of cleaved caspase-3/caspase-3. In conclusion, GS-Re can significantly relieve the Rot-induced cerebral neurotoxicity in drosophilas. The mechanism may be that GS-Re activates Keap1-Nrf2-ARE signaling pathway by maintaining mitochondrial homeostasis, improves antioxidant capacity of brain neurons, then inhibits mitochondria-mediated caspase-3 signaling pathway, and the apoptosis of neuronal cells, thereby exerting the neuroprotective effect.

Estudo do potencial de reposicionamento do composto auranofina no controle de infecções por Candida albicans / Study on the potential for the repositioning of auranofin in the control of Candida albicans infections

A ocorrência crescente de resistência antifúngica, a toxicidade, além do pequeno espectro de ação dos antifúngicos convencionais, limita o número de alternativas terapêuticas para doenças causadas por leveduras do gênero Candida. Uma das frentes de pesquisa é a proposta de novos usos para drogas existentes chamada de reposicionamento, que diminui o tempo e esforço na busca de novos compostos eficazes. Neste contexto, o presente estudo tem como objetivo avaliar o potencial antifúngico e os mecanismos de ação do composto auranofina contra a espécie Candida albicans, além da toxicidade in vivo. Foram utilizadas cepas padrões de C. albicans (SC5314, ATCC 18804) e as concentrações inibitória mínima (CIM) e fungicida mínima (CFM) foram determinadas. Os mecanismos de ação dos compostos foram avaliados sobre a estrutura celular de C. albicans, com verificação de alterações na morfologia, na parede celular, sobre os fatores de virulência de C. albicans, como transição levedura-hifa e produção de exoenzimas, além do efeito do composto sobre o metabolismo de C. albicans e efeito antifúngico sob condições de estresse osmótico. Para avaliação da toxicidade das concentrações efetivas de auranofina in vivo, foi utilizado o modelo invertebrado, Drosophila melanogaster. Os dados obtidos no ensaio de transição levedura-hifa foram avaliados pelos testes ANOVA e de Tukey e os testes Kruskal-Wallis e de Dunn. foram utilizados na análise do efeito de auranofina sobre o metabolismo fúngico. O nível de significância para todos os testes foi de 5%. Foram verificadas concentrações inibitória e fungicida de auranofina sobre C. albicans. Apesar da ausência de efeitos sobre fatores de virulência, auranofina causou redução no metabolismo fúngico e no crescimento fúngico sob estresse osmótico, sugerindo, nesse caso, um possível efeito direto ou indireto na membrana celular fúngica. Além disso, nas concentrações efetivas não foi observada toxicidade relevante in vivo. Os resultados demonstraram, portanto, que auranofina tem potencial para seu reposicionamento como antifúngico, no entanto, mais estudos são necessários para mais esclarecimentos e utilização adequada do medicamento (AU).

The increasing occurrence of antifungal resistance, toxicity, in addition to the small spectrum of action of conventional antifungals, limits the number of therapeutic alternatives for diseases caused by yeasts of the genus Candida. One of the research fronts is the proposal of new uses for existing drugs called repositioning, which reduces the time and effort in the search for new effective compounds. In this context, the present study aims to evaluate the antifungal potential and mechanisms of action of the auranofin compound against Candida albicans, in addition to in vivo toxicity. Standard strains of C. albicans (SC5314, ATCC 18804) were used and minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined. The mechanisms of action of the compounds were evaluated on the cellular structure of C. albicans, with verification of changes in morphology, in the cell wall, on the virulence factors of C. albicans, such as yeast-hypha transition and production of exoenzymes, in addition to the effect of the compound on the metabolism of C. albicans and antifungal effect under osmotic stress conditions. To evaluate the toxicity of effective concentrations of auranofin in vivo, the invertebrate model, Drosophila melanogaster, was used. The data obtained in the yeast-hypha transition assay were evaluated by the ANOVA and Tukey tests and the KruskalWallis and Dunn tests. were used to analyze the effect of auranofin on fungal metabolism. The significance level for all tests was 5%. Inhibitory and fungicidal concentrations of auranofin were verified on C. albicans. Despite the absence of effects on virulence factors, auranofin caused a reduction in fungal metabolism and fungal growth under osmotic stress, suggesting, in this case, a possible direct or indirect effect on the fungal cell membrane. Furthermore, at effective concentrations, no relevant in vivo toxicity was observed. The results showed, therefore, that auranofin has the potential for its repositioning as an antifungal, however, more studies are needed for further clarification and proper use of the drug (AU).

Infestation index of Drosophila suzukii (Diptera: Drosophilidae) in small fruit in southern Brazil / Índice de infestação de Drosophila suzukii (Diptera: Drosophilidae) em pequenas frutas no sul do Brasil

The spotted-wing drosophila, Drosophila suzukii Matsumura, is considered the main insect pest of small fruit in the world. Identifying susceptible hosts is essential to develop management strategies. The aim of this study was to verify the level of D. suzukii infestation in blackberry, blueberry, strawberry, cattley guava and Surinam cherry fruits cultivated in the southern region in Brazil, and to determine the infestation index (II) per fruit. The studies were carried out during two harvests (2015/16 and 2016/17) in three areas with organic cultivation of small fruit. The highest level of D. suzukii natural infestation was observed in blackberry (40 to 65% infestation), and strawberry (approximately 30% infestation) fruits. In contrast, blueberries were less preferred (< 7% infestation). For native fruit of the region (cattley guava and Surinam cherry), it was also verified infestation of the fly, demonstrating they are hosts for multiplication in the off-season periods of the other crops. In relation to II, blackberry and Surinam cherry provided a higher average number of insects per gram of fruit (≈ 1.6 adults of D. suzukii). In contrast, blueberries and cattley guava had the lowest insect ratio per gram of fruit (≈ 0.7 adults per gram). The period between late spring to mid-autumn was considered ideal for the pest occurrence in the field. The knowledge of natural infestation levels is essential for understanding the behavior of the pest in the field, which will assist in the design of management strategies.(AU)

A drosófila-da-asa-manchada, Drosophila suzukii Matsumura, é considerada o principal inseto-praga de pequenos frutos no mundo. A identificação de hospedeiros suscetíveis é essencial para o desenvolvimento de estratégias de manejo. O objetivo deste estudo foi verificar o nível de infestação de D. suzukii em frutos de amoreira-preta, mirtileiro, morangueiro, araçazeiro e pitangueira cultivados na região no sul do Brasil e determinar os índices de infestação (II) por fruto. Os estudos foram realizados durante duas safras (2015/16 e 2016/17) em três áreas com cultivo orgânico de pequenas frutas. O maior nível de infestação natural de D. suzukii foi observado em amora-preta (40 a 65% de infestação) e morango (aproximadamente 30% de infestação). Em contraste, o mirtilo foi menos preferido (< 7% de infestação). Para as frutas nativas da região (araçá e pitanga), também ocorreu infestação da mosca, demonstrando serem hospedeiros potenciais para a multiplicação da praga nos períodos de entressafras. Em relação ao II, amoras e pitangas proporcionaram um maior número médio de insetos por grama de fruto (≈ 1,6 adultos de D. suzukii). Por outro lado, mirtilos e araçás apresentaram a menor relação de insetos emergidos por gramas de frutos (≈ 0,7 adultos por grama). O período entre final da primavera até meados do outono foi considerado ideal para a ocorrência da praga no campo. O conhecimento dos níveis de infestação natural é fundamental para o entendimento do comportamento da praga no campo, o que auxiliará no delineamento de estratégias de manejo.(AU)

Does the surrounding vegetation influence the fruit fly assemblage in guava orchards? / A vegetação do entorno influencia a assembléia de moscas-das- frutas em pomares de goiabeira?

This study aimed to evaluate how the surrounding vegetation affects the assemblage of fruit flies. For this, flies were collected in guava orchards with distinct types of surrounding vegetation (exotic pasture, native forest and fruit tree intercropping). The experiment was conducted in Itaporã and Dourados, State of Mato Grosso do Sul, Brazil. Weekly samples were collected from March to April 2015. McPhail traps were baited with 5% hydrolyzed corn protein. Species richness, diversity index and abundance were evaluated for each orchard, as well as the species composition of fruit fly between the environments surrounding the orchard and, finally, the sex ratio. A total of 579 individuals were collected of the species Anastrepha fraterculus, A. montei, A. obliqua, A. sororcula, A. striata, A. turpiniae and A. zenildae. The orchard surrounded by native forest had the highest species richness and Shannon diversity. The species composition differed between environments, with the formation of three distinct groups. The environment surrounding the guava orchard influences the richness, diversity, abundance and sex ratio of fruit flies, indicating that the native forest may provide more resources for the maintenance of these insects.

Este estudo teve como objetivo avaliar como a vegetação do entorno dos pomares afeta a assembleia de moscas-das-frutas. Para isto, foram coletadas moscas em pomares de goiabeiras com distintos tipos de vegetação no entorno (pastagens exóticas, mata nativa e fruticultura). O experimento foi conduzido em Itaporã e Dourados, Estado do Mato Grosso do Sul, Brasil. Amostras semanais foram coletadas de março a abril de 2015. As armadilhas McPhail foram iscadas com 5% de proteína hidrolisada de milho. A riqueza de espécies, o índice de diversidade e a abundância foram avaliados para cada pomar, assim como a composição de espécies de moscas-das-frutas entre os ambientes do entorno do pomar e razão sexual. Um total de 579 indivíduos foram coletados das espécies Anastrepha fraterculus, A. montei, A. obliqua, A. sororcula, A. striata, A. turpiniae e A. zenildae. O pomar cercado por mata nativa apresentou maior riqueza de espécies e diversidade de Shannon. A composição das espécies diferiu entre os ambientes, com a formação de três grupos distintos. O ambiente do entorno do pomar de goiabeira influencia a riqueza, diversidade, abundância e razão sexual das moscas-das-frutas, indicando que a mata nativa pode fornecer mais recursos para a manutenção desses insetos.

Can ants contribute to the conservative biological control of the south american fruit fly? / Formigas podem contribuir para o controle biológico conservativo da mosca-das-frutas sul-americana?

Ants (Hymenoptera, Formicidae) are an efficient group of insects as predators of various arthropods. Based on records of the predatory ant activity, a survey was carried out on the efficiency in predation of Anastrepha fraterculus (Diptera: Tephritidae) larvae, considering the percentage of removal of larvae using the variables of soil density and moisture content and their effect on the larvae burying. For this, A. fraterculus larvae were released to the soil and observed for 10 min while burying or removed by the ants in a peach (Prunus persica, Rosaceae) orchard. Eight ant species were recorded removing 32.70% of the larvae. Solenopsis saevissima was the most efficient species, with 42.86% of larvae removal. There were no significant correlations between the predation by ants with soil density and soil moisture content. Despite this, the study pointed out that ants belong to genera Pachycondyla, Pheidole, Pogonomyrmex and Solenopsis can be predators on A. fraterculus larvae, with emphasis on the S. saevissima. These ants can contribute as important agents of conservative biological control of the population of A. fraterculus in peach orchard and their conservation becomes interesting to use of combined control methods aiming to reduce insecticides and aggressive soil management methods.

Formigas (Hymenoptera, Formicidae) são eficientes como predadores de diversos artrópodes. Baseado nos registros de atividade predatória de formigas, um levantamento da eficiência na predação de larvas de Anastrepha fraterculus (Diptera: Tephritidae) considerando a porcentagem na remoção das larvas pelas formigas frente às variáveis de densidade e teor de umidade do solo e o seu efeito sobre o tempo de enterramento das larvas, foi realizado. Larvas de A. fraterculus foram liberadas ao solo e observadas por 10 min enquanto enterravam-se ou eram removidas pelas formigas em um pomar de pessegueiro (Prunus persica, Rosaceae). Oito espécies de formigas foram registradas removendo 32.7% das larvas oferecidas. Solenopsis saevissima foi a espécie mais eficiente com 42.9% da remoção de larvas. Não ocorreram correlações significativas entre os registros de predação por formigas com a densidade e o teor de umidade do solo. Apesar disso, o estudo apontou que as formigas pertencentes aos gêneros Pachycondyla, Pheidole, Pogonomyrmex e Solenopsis podem ser predadoras de larvas de A. fraterculus, com ênfase na espécie S. saevissima, podem contribuir como importantes agentes de controle biológico conservativo da população de A. fraterculus em pomar de pessegueiro e que sua conservação torna-se interessante frente ao uso de métodos de controle combinados visando a redução de inseticidas e de métodos agressivos de manejo do solo.

Lonchaeidae (Diptera) species and their host plants in the Cerrado biome in the state of Piauí, Brazil / Espécies de Lonchaeidae (Diptera) e seus hospedeiros no bioma Cerrado no estado do Piauí, Brasil

Some species of Lonchaeidae (Diptera) are considered frugivorous and polyphagous pests, and are widely distributed in Neotropical regions. The relationship between a fly and its host plant is important for studies on behavior and distribution of frugivorous flies. The objective of this work was to identify the Lonchaeidae fly species and their host plants in the Cerrado biome, specifically in the state of Piauí, Brazil. Eighty-one adults (33 ♀ and 48 ♂) from the genus Neosilba McAlpine (Lonchaeidae), represented by the species Neosilba inesperata Strikis & Prado, Neosilba pendula Bezzi, and Neosilba zadolicha McAlpine, were collected from fruit samples. Oranges [Citrus sinensis (L.) Osbeck] and guava (Psidium guajava L.) had the highest frequencies of infestation. A Neosilba species was considered a primary invader in orange. These results are the first ones reported of Lonchaeidae species and their host plants in the state of Piauí.(AU)

Algumas espécies de Lonchaeidae (Diptera) são consideradas pragas frugívoras e polífagas, com ampla distribuição geográfica em regiões neotropicais. A relação mosca/planta hospedeira é de grande valor para estudos de comportamento e distribuição de moscas frugívoras. O objetivo deste trabalho foi identificar as espécies de Lonchaeidae e suas plantas hospedeiras no bioma Cerrado, especificamente no estado do Piauí, Brasil. Oitenta e um adultos (33 ♀ e 48 ♂) do gênero Neosilba McAlpine (Lonchaeidae), pertencentes às espécies Neosilba inesperata Strikis & Prado, Neosilba pendula Bezzi e Neosilba zadolicha McAlpine, foram coletados de amostras de frutas, sendo a laranja [Citrus sinensis (L.) Osbeck] e a goiaba (Psidium guajava L.) as de maiores frequências de infestação. Uma espécie de Neosilba foi considerada um invasor primário em laranjas. Esses resultados são os primeiros relatos de espécies de Lonchaeidae e suas plantas hospedeiras no estado do Piauí.(AU)

Targeted Downregulation of kdm4a Ameliorates Tau-engendered Defects in Drosophila melanogaster

BACKGROUND: Tauopathies, a class of neurodegenerative diseases that includes Alzheimer's disease (AD), are characterized by the deposition of neurofibrillary tangles composed of hyperphosphorylated tau protein in the human brain. As abnormal alterations in histone acetylation and methylation show a cause and effect relationship with AD, we investigated the role of several Jumonji domain-containing histone demethylase (JHDM) genes, which have yet to be studied in AD pathology. METHODS: To examine alterations of several JHDM genes in AD pathology, we performed bioinformatics analyses of JHDM gene expression profiles in brain tissue samples from deceased AD patients. Furthermore, to investigate the possible relationship between alterations in JHDM gene expression profiles and AD pathology in vivo, we examined whether tissue-specific downregulation of JHDM Drosophila homologs (kdm) can affect tauR406W-induced neurotoxicity using transgenic flies containing the UAS-Gal4 binary system. RESULTS: The expression levels of JHDM1A, JHDM2A/2B, and JHDM3A/3B were significantly higher in postmortem brain tissue from patients with AD than from non-demented controls, whereas JHDM1B mRNA levels were downregulated in the brains of patients with AD. Using transgenic flies, we revealed that knockdown of kdm2 (homolog to human JHDM1), kdm3 (homolog to human JHDM2), kdm4a (homolog to human JHDM3A), or kdm4b (homolog to human JHDM3B) genes in the eye ameliorated the tauR406W-engendered defects, resulting in less severe phenotypes. However, kdm4a knockdown in the central nervous system uniquely ameliorated tauR406W-induced locomotion defects by restoring heterochromatin. CONCLUSION: Our results suggest that downregulation of kdm4a expression may be a potential therapeutic target in AD.

Anticancer Activity of Tubulosine through Suppression of Interleukin-6-Induced Janus Kinase 2/Signal Transducer and Activation of Transcription 3 Signaling / 한국유방암학회지

PURPOSE: The chemical structure of tubulosine has been known since the mid-1960s. However, little is known about its biological and pharmacological functions. The aim of this study was to investigate the novel functions of tubulosine in cancer treatment, specifically in breast cancer. METHODS: An Unpaired (Upd)-induced Drosophila cell line and interleukin (IL)-6-stimulated human breast cancer cell lines were used to investigate the biological and pharmacological activities of tubulosine in vitro. To investigate the activities of tubulosine, we performed molecular and cellular experiments such as Western blot and reverse transcription polymerase chain reaction analyses, immunoprecipitation and terminal deoxynucleotidyl transferase dUTP nick end labeling assays, and immunofluorescence staining using breast cancer cell lines. RESULTS: Tubulosine exhibited anticancer activity in IL-6-stimulated human breast cancer cells. Moreover, tubulosine reduced the tyrosine phosphorylation level and transcriptional activity of signal transducer and activator of transcription (STAT) protein at 92E in Upd-induced Drosophila cells. Additionally, tubulosine suppressed IL-6-induced Janus kinase 2 (JAK2)/STAT3 signaling, resulting in decreased viability and induction of apoptotic cell death in breast cancer cells. Interestingly, inhibition of IL-6-induced JAK2/STAT3 signaling by tubulosine was associated with the blocking of IL-6 receptor (IL-6R) and glycoprotein 130 (gp130) binding. CONCLUSION: Tubulosine exhibits anticancer activity through functional inhibition of IL-6-induced JAK2/STAT3 signaling by targeting IL-6Rα/gp130 binding in breast cancer cells. These findings suggest that tubulosine may hold promise for the treatment of inflammation-associated cancers, including breast cancer.

Adzuki bean (Vigna angularis) extract reduces amyloid-β aggregation and delays cognitive impairment in Drosophila models of Alzheimer's disease

BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein (Aβ) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of Aβ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined. MATERIALS/METHODS: First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on Aβ42 aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, Aβ42-overexpressing Drosophila were used. In these flies, overexpression of Aβ42 induced the formation of Aβ42 aggregates in the brain, decreased motor function, and resulted in cognitive impairment. RESULTS: Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of Aβ42 aggregates in a concentration-dependent manner. When Aβ42-overexpressing flies were fed regular medium containing adzuki extract, the Aβ42 level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in Aβ42-overexpressing flies fed regular medium with adzuki extract. CONCLUSIONS: The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.

Taurine Transporter dEAAT2 is Required for Auditory Transduction in Drosophila / 神经科学通报·英文版

Drosophila dEAAT2, a member of the excitatory amino-acid transporter (EAAT) family, has been described as mediating the high-affinity transport of taurine, which is a free amino-acid abundant in both insects and mammals. However, the role of taurine and its transporter in hearing is not clear. Here, we report that dEAAT2 is required for the larval startle response to sound stimuli. dEAAT2 was found to be enriched in the distal region of chordotonal neurons where sound transduction occurs. The Ca imaging and electrophysiological results showed that disrupted dEAAT2 expression significantly reduced the response of chordotonal neurons to sound. More importantly, expressing dEAAT2 in the chordotonal neurons rescued these mutant phenotypes. Taken together, these findings indicate a critical role for Drosophila dEAAT2 in sound transduction by chordotonal neurons.

Hierarchical Control of Drosophila Sleep, Courtship, and Feeding Behaviors by Male-Specific P1 Neurons / 神经科学通报·英文版

Animals choose among sleep, courtship, and feeding behaviors based on the integration of both external sensory cues and internal states; such choices are essential for survival and reproduction. These competing behaviors are closely related and controlled by distinct neural circuits, but whether they are also regulated by shared neural nodes is unclear. Here, we investigated how a set of male-specific P1 neurons controls sleep, courtship, and feeding behaviors in Drosophila males. We found that mild activation of P1 neurons was sufficient to affect sleep, but not courtship or feeding, while stronger activation of P1 neurons labeled by four out of five independent drivers induced courtship, but only the driver that targeted the largest number of P1 neurons affected feeding. These results reveal a common neural node that affects sleep, courtship, and feeding in a threshold-dependent manner, and provide insights into how competing behaviors can be regulated by a shared neural node.

Toll-like receptor 2 promotes neurogenesis from the dentate gyrus after photothrombotic cerebral ischemia in mice

The subgranular zone (SGZ) of hippocampal dentate gyrus (HDG) is a primary site of adult neurogenesis. Toll-like receptors (TLRs), are involved in neural system development of Drosophila and innate immune response of mammals. TLR2 is expressed abundantly in neurogenic niches such as adult mammalian hippocampus. It regulates adult hippocampal neurogenesis. However, the role of TLR2 in adult neurogenesis is not well studied in global or focal cerebral ischemia. Therefore, this study aimed to investigate the role of TLR2 in adult neurogenesis after photochemically induced cerebral ischemia. At 7 days after photothrombotic ischemic injury, the number of bromodeoxyuridine (BrdU)-positive cells was increased in both TLR2 knock-out (KO) mice and wild-type (WT) mice. However, the increment rate of BrdU-positive cells was lower in TLR2 KO mice compared to that in WT mice. The number of doublecortin (DCX) and neuronal nuclei (NeuN)-positive cells in HDG was decreased after photothrombotic ischemia in TLR2 KO mice compared to that in WT mice. The survival rate of cells in HDG was decreased in TLR2 KO mice compared to that in WT mice. In contrast, the number of cleaved-caspase 3 (apoptotic marker) and the number of GFAP (glia marker)/BrdU double-positive cells in TLR2 KO mice were higher than that in WT mice. These results suggest that TLR2 can promote adult neurogenesis from neural stem cell of hippocampal dentate gyrus through increasing proliferation, differentiation, and survival from neural stem cells after ischemic injury of the brain.

A De Novo RAPGEF2 Variant Identified in a Sporadic Amyotrophic Lateral Sclerosis Patient Impairs Microtubule Stability and Axonal Mitochondria Distribution

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is frequently linked to microtubule abnormalities and mitochondrial trafficking defects. Whole exome sequencing (WES) of patient-parent trios has proven to be an efficient strategy for identifying rare de novo genetic variants responsible for sporadic ALS (sALS). Using a trio-WES approach, we identified a de novo RAPGEF2 variant (c.4069G>A, p.E1357K) in a patient with early-onset sALS. To assess the pathogenic effects of this variant, we have used patient-derived skin fibroblasts and motor neuron-specific overexpression of the RAPGEF2-E1357K mutant protein in Drosophila. Patient fibroblasts display reduced microtubule stability and defective microtubule network morphology. The intracellular distribution, ultrastructure, and function of mitochondria are also impaired in patient cells. Overexpression of the RAPGEF2 mutant in Drosophila motor neurons reduces the stability of axonal microtubules and disrupts the distribution of mitochondria to distal axons and neuromuscular junction (NMJ) synapses. We also show that the recruitment of the pro-apoptotic protein BCL2-associated X (BAX) to mitochondria is significantly increased in patient fibroblasts compared with control cells. Finally, increasing microtubule stability through pharmacological inhibition of histone deacetylase 6 (HDAC6) rescues defects in the intracellular distribution of mitochondria and BAX. Overall, our data suggest that the RAPGEF2 variant identified in this study can drive ALS-related pathogenic effects through microtubule dysregulation.

Repeated Failure in Reward Pursuit Alters Innate Drosophila Larval Behaviors / 神经科学通报·英文版

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown, although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit (RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference, which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tβh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tβh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.

Protective effect of luteolin on the transgenic Drosophila model of Parkinson's disease

In the present study we have studied the effect of 25, 50, 75 and 100 µM of luteolin on the transgenic Drosophila expressing human alpha synuclein. The doses of luteolin were established in diet and the PD flies were allowed to feed on it for 24 days. After 24 days of exposure the flies were assayed for climbing assay, oxidative stress markers, caspase-3 & 9 activity and dopamine content. The immunohistochemistry was also performed on the brain sections for the activity of tyrosine hydroxylase. The exposure of luteolin showed a dose dependent delay in the loss of climbing ability and activity, reduction in oxidative stress markers, caspase-3&9 activities and results in an increase in the dopamine content. The results obtained for the immunohistochemistry also supports the protective role of luteolin against the damage of the dopaminergic neurons