Título principal
Estudo dos mecanismos de tolerância do mosquito Aedes aegypti infectado com o Dengue vírus [recurso eletrônico] / Mariana Maraschin da Rocha ; orientador, José Henrique Maia Campos de Oliveira ; coorientador, Daniel Santos Mansur
Data de publicação
2024
Descrição física
73 p. : il.
Nota
Disponível somente em versão on-line.
Tese (doutorado) – Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia e Biociências, Florianópolis, 2024.
Inclui referências.
Estudo dos mecanismos de tolerância do mosquito Aedes aegypti infectado com o Dengue vírus [recurso eletrônico] / Mariana Maraschin da Rocha ; orientador, José Henrique Maia Campos de Oliveira ; coorientador, Daniel Santos Mansur
Data de publicação
2024
Descrição física
73 p. : il.
Nota
Disponível somente em versão on-line.
Tese (doutorado) – Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia e Biociências, Florianópolis, 2024.
Inclui referências.
Abstract: The Aedes aegypti mosquito consumes a large amount of blood as a nutrient source for egg production and simultaneously becomes infected with medically relevant arboviruses. This diet represents a metabolic/oxidative and immune challenge for the mosquito. As an adaptation to this challenge, mosquitoes have developed stress response mechanisms that protect the insect from potential tissue damage, ensuring its homeostasis. Aedes aegypti is the main vector of the dengue virus (DENV), and its ability to transmit the virus is directly related to its tolerance to the virus. Understanding the molecular relationship between the mosquito vector and the arboviruses it transmits is essential to comprehend its vector competence and thus develop strategies to block the transmission of arboviruses. Our hypothesis is that the antioxidant protection mechanisms triggered by blood feeding in the Aedes aegyptimosquito promote tolerance during dengue infection. We challenged the mosquitoes with two strains of DENV4: the TVP/360 strain, directly derived from a strain isolated in the Dominican Republic in 1981, and the LRV 13/422 strain, isolated in southern Brazil in 2013, and evaluated the fitness/adaptability of the mosquitoes through survival curves. Our results demonstrated that DENV infections did not negatively impact the lifespan of the mosquitoes. The infection intensity for the TVP/360 strain showed a prevalence of 89.28% on day 21 postinfection (dpi). For mosquitoes infected with the LRV 13/422 strain, an infection prevalence of 33.33% was observed on day 21 dpi. Next, we evaluated the expression profile of antioxidant and cellular stress response genes during blood feeding. Mosquitoes were infected with the TVP/360 strain, and gene expression was assessed at 24 hours postinfection (hpi), 4, and 7 dpi, in the gut and carcass. The Glutamine Synthetase 1 (GS1) gene (AAEL001887), essential in detoxifying excess amino groups derived from the proteinrich diet, showed a significant increase in mRNA in the mosquito gut epithelium 24 hours after feeding, regardless of the virus presence. The Nrf2 gene mRNA showed a 4fold increase in the infected group at 24 hpi. The GS1 and Nrf2 (AAEL019563) genes were selected for silencing using RNA interference (RNAi) technique in mosquitoes infected with the TVP/360 strain. We did not observe a change in viral load in the whole body of the insect 7 days after DENV challenge, suggesting that silencing these genes does not alter the resistance to the virus in Aedes aegypti. Ongoing experiments are evaluating the impact on mosquito physiology after reducing GS1 and Nrf2 expression, as well as the compensatory induction of other pathways associated with nitrogen metabolism in Aedes aegypti during DENV infection.