Molecular and biological effects of Cisplatin in Drosophila.

Cisplatin is widely used in cancer treatment and is one of the best cytostatic agents available for antitumor therapy. Drosophila melanogaster has one of the best annotated genomes and one of the best characterized sets of transposable elements (TE) sequences. This model organism is useful for analyzing the mode of action of several compounds in vivo and evaluating the behavioral consequences of treatments. The aim of our study was to increase the knowledge about the effects of Cisplatin in Drosophila by joining RNA-seq and biological assays. RNA-seq was followed by analyses of differential expression of genes (DEGs) and TEs (DETEs), and of pathways and ontology terms. DETEs were confirmed by qPCR. Cisplatin was evaluated at 50 and 100 µg/mL in Drosophila culture medium for 24 h. The fly locomotor assay, survival analysis, oviposition and development were used as biological assays. Cisplatin induced DEGs in a dose-dependent fashion, and four TEs were up-regulated. Most DEGs are related to DNA damage and detoxification processes. Cisplatin increases Drosophila locomotor activity and interrupts development. Genes and processes related to the assays were also identified. This is the first study to evaluate the effects of Cisplatin in flies using RNA-seq. Gene alteration was almost limited to drug metabolism and DNA damage, and the drug did not vastly affect Drosophila on the molecular level. Contrary to the hypothesis that stress dramatically alters TEs mobilization, only four TEs were up-regulated. Our study, together with previous knowledge, asserts Drosophila as a valuable organism in the study of chemotherapy drugs.

Metatranscriptomic analysis identifies different viral-like sequences in two neotropical Mansoniini mosquito species.

Mosquitoes interact with a wide range of viruses including both arboviruses and insect-specific viruses. This study aimed to characterize the RNA viruses that are interacting with Mansonia wilsoni and Coquillettidia hermanoi mosquito species. The total RNA extracted from mosquito pools were sequenced on a Ion torrent platform. Viral contigs were identified against viral databases and their evolutionary relationship were reconstructed. We identified a total of 107 viral sequences, 11 of which were assigned as endogenous viral elements, and at least six known viral families were identified. Phylogenetic reconstructions were performed for 4 viral families. All Mansoniini viruses investigated through phylogenetic analysis are closely related to insect-specific viruses found in other mosquito species although with considerable divergence at the amino acid level, suggesting that we have detected new viral lineages. This study enhanced our understanding about the virome of two sylvatic Mansoniini mosquitoes.

Modelo experimental de silicose pulmonar em camundongos / Experimental model of pulmonary silicosis in mice

Introdução: a silicose é uma doença crônica e difusa do pulmão, desenvolvida por trabalhadores expostos a inalação de partículas minerais de sílica cristalina. Depois da inalação, as partículas de sílica são fagocitadas por macrófagos alveolares (MA) que, quando ativados, irão liberar mediadores inflamatórios, espécies reativas de oxigênio, ácido aracdônico, quimiocinas ecitocinas. Outros tipos celulares também participam da patogênese da silicose, tais como, as células epiteliais bronquiolarese alveolares e os fibroblastos. Os modelos experimentais têm ajudado a elucidar as alterações celulares, moleculares e funcionais no pulmão. Nosso objetivo é mostrar os aspectos celulares da silicose, para ajudar no melhor entendimento dessa doença, utilizando um modelo experimental de silicose pulmonar em camundongos. Metodologia: foram utilizados 20 camundongos Swiss, levemente anestesiados, que receberam 50μl de salina (grupo salina) ou 20mg de sílica, diluídos em 50μl de salina estéril intratraqueal. Trinta dias após a instilação, os animais foram sacrificados, foi realizado o lavado broncoalveolar(LBA) e os pulmões foram retirados para análise histopatológica. Resultados: na coloração por Hematoxilina e Eosina, observamos um aumento no infiltrado inflamatório, com a formação de granulomas no parênquima pulmonar. Observamos, também, com a coloração por Picro-sírius, que houve um aumento signifi cativo de colágeno nos animais silicóticos. No LBA,os animais do grupo silicose apresentaram aumento significativo de leucócitos totais, monócitos e neutrófilos. Conclusão:nossos resultados mostram que o modelo de silicose pulmonar em camundongos pode ser utilizado para o melhor entendimento dessa enfermidade e em futuros estudos de tratamentos.