Efeito da variação de temperatura no bacterioma do intestino médio de Aedes aegypti e seu impacto na modulação da digestão de sangue
Data
2023-07-27
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Viçosa
Resumo
Sabe-se que a temperatura desempenha um papel na resistência/suscetibilidade dos mosquitos a infecções por patógenos, e em vários sistemas foi verificado um fenótipo resistente a baixas temperaturas. Estudos recentes mostraram que as bactérias do intestino médio parecem estimular o sistema imunológico do mosquito e, indiretamente, aumentar a proteção contra patógenos invasores. Em insetos hematófagos, não está claro como o repasto sanguíneo e a variação da temperatura ambiental afetam o bacterioma do inseto hospedeiro. Esse conhecimento é fundamental para compreender o impacto da temperatura na fisiologia do mosquito, a fim de buscar novas perspectivas de controle. Neste estudo, foram realizados experimentos no bacterioma intacto e reduzido para investigar a contribuição das bactérias intestinais na taxa de digestão do sangue em diferentes temperaturas (20, 28 e 36°C). Primeiramente, um coquetel de antibióticos (300 μg/ml) foi administrado às fêmeas do mosquito Aedes aegypti por 48 horas. Depois os mosquitos foram alimentados com sangue de camundongo e expostos às três temperaturas. O intestino médio foi dissecado 24 horas e 48 horas após a alimentação (ABF). Para obter taxas de digestão de proteínas em cada temperatura, foram determinados o conteúdo total de proteína e albumina, bem como a atividade de tripsina. Finalmente, para analisar as alterações na expressão gênica envolvida na resposta ao bacterioma intacto e reduzido, o RNA total foi extraído do intestino médio, dissecado 24 horas após a alimentação sanguínea, utilizando o RNeasy Mini Kit seguindo as instruções do fabricante. Nossos resultados demonstram que em um ambiente intestinal com carga bacteriana reduzida há menor teor de proteína e atividade enzimática a 28 e 36°C 24 horas após a alimentação sanguínea, demonstrando que o efeito da temperatura na digestão sanguínea depende do bacterioma intestinal. Além disso, a redução da carga bacteriana impactou na expressão dos transcritos, o que acarretou diminuição e aumento na expressão dos genes envolvidos na digestão sanguínea em 24 (ABF) nas três temperaturas. Embora sejam necessárias mais investigações para determinar os mecanismos moleculares destes processos, os nossos resultados indicam que a redução da carga bacteriana combinada com a variação da temperatura afeta a digestão sanguínea, bem como a expressão gênica associada a estes processos, o que por sua vez afeta a competência do vector. Palavras chaves: Aedes aegypti; temperatura; digestão do sangue; bacterioma intestinal; processos fisiológicos.
Temperature is known to play a role in the resistance/susceptibility of mosquitoes to pathogen infections, and in several systems a resistant phenotype has been verified at low temperatures. In hematophagous insects, it is unclear how blood meal and environmental temperature variation affect the bacteriome of the host insect. This knowledge is fundamental to understanding the impact of temperature on mosquito physiology in order to seek new control perspectives. In this study, experiments were conducted on the intact and reduced bacteriome to investigate the contribution of intestinal bacteria to the rate of blood digestion at different temperatures (20, 28 and 36°C). First, an antibiotic cocktail (300 μg/ml) was administered to female Aedes aegypti mosquitoes for 48h. After mosquitoes were fed with mice blood and exposed to the three temperatures. The midgut was dissected 24 hours and 48 hours after feeding (hpf). In order to obtain protein digestion rates at each temperature, total protein and albumin content as well trypsin activity were determined. Finally, to analyze the changes in gene expression involved in the response to intact and reduced bacteriome, total RNA was extracted from the midgut, dissected 24 hours after blood feeding, using the RNeasy Mini Kit following the manufacturer's instructions. Our results demonstrate that in an intestinal environment with reduced bacterial load there is a lower protein content and enzymatic activity at 28 and 36°C 24 hours after blood feeding, demonstrating that the effect of temperature on blood digestion depends on the intestinal bacteriome. Furthermore, the reduction in bacterial load impacted the expression of transcripts, there was a decrease and increase in the expression of genes involved in blood digestion at 24 (hpf) at the three temperatures. Although further investigation is needed to determine the molecular mechanisms of these processes, our results indicate that the reduction in bacterial load combined with temperature variation affects blood digestion, as well as the gene expression associated with these processes, which in turn affects the vector's competence. Keywords: Aedes aegypti; temperature; blood digestion; intestinal bacteriome; physiological processes.
Temperature is known to play a role in the resistance/susceptibility of mosquitoes to pathogen infections, and in several systems a resistant phenotype has been verified at low temperatures. In hematophagous insects, it is unclear how blood meal and environmental temperature variation affect the bacteriome of the host insect. This knowledge is fundamental to understanding the impact of temperature on mosquito physiology in order to seek new control perspectives. In this study, experiments were conducted on the intact and reduced bacteriome to investigate the contribution of intestinal bacteria to the rate of blood digestion at different temperatures (20, 28 and 36°C). First, an antibiotic cocktail (300 μg/ml) was administered to female Aedes aegypti mosquitoes for 48h. After mosquitoes were fed with mice blood and exposed to the three temperatures. The midgut was dissected 24 hours and 48 hours after feeding (hpf). In order to obtain protein digestion rates at each temperature, total protein and albumin content as well trypsin activity were determined. Finally, to analyze the changes in gene expression involved in the response to intact and reduced bacteriome, total RNA was extracted from the midgut, dissected 24 hours after blood feeding, using the RNeasy Mini Kit following the manufacturer's instructions. Our results demonstrate that in an intestinal environment with reduced bacterial load there is a lower protein content and enzymatic activity at 28 and 36°C 24 hours after blood feeding, demonstrating that the effect of temperature on blood digestion depends on the intestinal bacteriome. Furthermore, the reduction in bacterial load impacted the expression of transcripts, there was a decrease and increase in the expression of genes involved in blood digestion at 24 (hpf) at the three temperatures. Although further investigation is needed to determine the molecular mechanisms of these processes, our results indicate that the reduction in bacterial load combined with temperature variation affects blood digestion, as well as the gene expression associated with these processes, which in turn affects the vector's competence. Keywords: Aedes aegypti; temperature; blood digestion; intestinal bacteriome; physiological processes.
Descrição
Palavras-chave
Intestinos - Efeito da temperatura Aedes aegypti, Digestão, Sangue
Citação
PROFETA, Camila Aparecida. Efeito da variação de temperatura no bacterioma do intestino médio de Aedes aegypti e seu impacto na modulação da digestão de sangue. 2023. 55 f. Dissertação (Mestrado em Bioquímica Aplicada) - Universidade Federal de Viçosa, Viçosa. 2023.