Dados do Trabalho

Título

The relevance of lipophagy throughout the digestive cycle in the insect vector Rhodnius Prolixus

Introdução

Rhodnius prolixus, a vector of Chagas disease, is an obligatory hematophagous insect. Autophagy is a conserved cellular mechanism that acts in response to nutrient starvation, when organelles are sequestered by the autophagosome, which eventually fuses with the lysosome for degradation. Lipophagy refers to the specific degradation of lipid droplets by autophagy. There are over 40 genes that code proteins described as part of autophagy pathway including Atg6, which is a component of a PI3K complex, responsible for generating PIP3, a recruitment signal for other ATGs to assemble the autophagosome. Atg8 encodes a protein present in the membrane of the autophagosome, and is it the main molecular marker.

Objetivo (s)

In this study, Atg6 and Atg8, were silenced in adult females of Rhodnius prolixus to investigate the role of autophagy in the mobilization of lipids during the digestive cycle.

Material e Métodos

RNAi and qPCR were used to test expression levels and gene silencing. Triacylglycerol (TAG) was measured colorimetrically and lipid droplets (LDs) were analyzed by fluorescence confocal microscopy. Flight capacity was evaluated using a wind tunnel.

Resultados e Conclusão

The knockdown of Atg6 or Atg8 did not affect TAG content in the fat body or flight muscle on the 5th and 10th days after feeding. The knockdown females had higher gene expression of Brummer lipase (orthologous to Atgl), indicating a connection between lipophagy and lipolysis, pathways of lipid degradation. In the fat body, the LDs were larger, and the flight capacity of the silenced insects was reduced. Conclusions: Our data suggest that the inhibition of the autophagy machinery during the blood meal digestion affected the lipid metabolism of these insects, and resulted in changes in physiological parameters.

Palavras-chave

Lipophagy, ATG6, ATG8, Insect, Rhodnius prolixus.

Agradecimentos

CAPES, FAPERJ, CNPq