title: Mitochondrial physiology in the major arbovirus vector Aedes aegypti: substrate preferences and sexual differences define respiratory capacity and superoxide production.
abstract: Adult females of Aedes aegypti are facultative blood sucking insects and vectors of Dengue and yellow fever viruses. Insect dispersal plays a central role in disease transmission and the extremely high energy demand posed by flight is accomplished by a very efficient oxidative phosphorylation process, which take place within flight muscle mitochondria. These organelles play a central role in energy metabolism, interconnecting nutrient oxidation to ATP synthesis, but also represent an important site of cellular superoxide production. Given the importance of mitochondria to cell physiology, and the potential contributions of this organelle for A. aegypti biology and vectorial capacity, here, we conducted a systematic assessment of mitochondrial physiology in flight muscle of young adult A. aegypti fed exclusively with sugar. This was carried out by determining the activities of mitochondrial enzymes, the substrate preferences to sustain respiration, the mitochondrial bioenergetic efficiency and capacity, in both mitochondria-enriched preparations and mechanically permeabilized flight muscle in both sexes. We also determined the substrates preferences to promote mitochondrial superoxide generation and the main sites where it is produced within this organelle. We observed that respiration in A. aegypti mitochondria was essentially driven by complex I and glycerol 3 phosphate dehydrogenase substrates, which promoted distinct mitochondrial bioenergetic capacities, but with preserved efficiencies. Respiration mediated by proline oxidation in female mitochondria was strikingly higher than in males. Mitochondrial superoxide production was essentially mediated through proline and glycerol 3 phosphate oxidation, which took place at sites other than complex I. Finally, differences in mitochondrial superoxide production among sexes were only observed in male oxidizing glycerol 3 phosphate, exhibiting higher rates than in female. Together, these data represent a significant step towards the understanding of fundamental mitochondrial processes in A. aegypti, with potential implications for its physiology and vectorial capacity.
authors: Laboratório de Bioquímica de Resposta ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil; Laboratório de Inflamação e Metabolismo, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem (INBEB), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Juliana B R Correa
authors: JB
authors: Soares
authors: Laboratório de Bioquímica de Resposta ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil; Laboratório de Inflamação e Metabolismo, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem (INBEB), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Alessandro
authors: A
authors: Gaviraghi
authors: Laboratório de Bioquímica de Resposta ao Estresse, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil; Laboratório de Inflamação e Metabolismo, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem (INBEB), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors: Marcus F
authors: MF
authors: Oliveira
mesh_terms: D000330:Aedes / Q000033:anatomy & histology / Q000502:physiology* / Q000821:virology; D000818:Animals; D001103:Arboviruses / Q000302:isolation & purification*; D049628:Body Size; D045304:Cytochromes c / Q000378:metabolism; D003715:Dengue / Q000635:transmission; D042967:Electron Transport Complex I / Q000378:metabolism; D005260:Female; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D006801:Humans; D019476:Insect Proteins / Q000378:metabolism; D007303:Insect Vectors / Q000502:physiology* / Q000821:virology; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011392:Proline / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D012727:Sex Characteristics; D013481:Superoxides / Q000378:metabolism*
chemical_list: D005994:Glycerophosphates; D019476:Insect Proteins; D009243:NAD; D013481:Superoxides; D019289:Pyruvic Acid; D045304:Cytochromes c; D011392:Proline; C029620:alpha-glycerophosphoric acid; D005993:Glycerolphosphate Dehydrogenase; D042967:Electron Transport Complex I