Oliveira MF 2013 Abstract MiP2013

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Oliveira MF (2013) Comparative mitochondrial physiology in blood feeding insect vectors and parasites. Mitochondr Physiol Network 18.08.
Link:
Marcus F Oliveira
MiP2013, Book of Abstracts Open Access

Oliveira MF (2013)

Event: MiPNet18.08_MiP2013

Hematophagy poses a challenge to blood-feeding organisms since products of blood digestion can exert cellular deleterious effects. Mitochondria perform multiple roles in cell biology acting as the site of aerobic energy transducing pathways, and also an important source of reactive oxygen species (ROS), modulating redox metabolism. Our research group is currently investigating basic aspects of mitochondrial physiology in some hematophagous organisms that cause or transmit tropical diseases. The models currently investigated include the blood fluke Schistosoma mansoni, the mosquito Aedes aegypti and the kissing bug Rhodnius prolixus. In Aedes flight muscle mitochondria, we observed that blood intake caused a transient reduction in both oxygen consumption and hydrogen peroxide generation, which were parallel to blood digestion process, regardless of the mitochondrial metabolic state. In the kissing bug Rhodnius, a transient reduction on flight muscle oxygen consumption was observed along the blood digestion cycle, without affecting hydrogen peroxide generation. Interestingly in Rhodnius, both parameters were profoundly affected by aging, causing a 75% inhibition of respiration and hydrogen peroxide production in the OXPHOS state in old insects. Maximum hydrogen peroxide production was also specifically affected by blood intake but not plasma. Sexual differences in oxygen consumption in Aedes flight muscle were also identified, being significantly higher in females than in males, regardless of the substrate utilized. In this model, pyruvate and proline were the preferential substrates utilized to sustain oxygen consumption. Finally, in the blood fluke Schistosoma, where adult female worms digest ten times more blood than males, sexual differences in terms of respiratory capacity were also reported, where male worms exhibit higher mitochondrial oxygen consumption rates than females, regardless of the substrates utilized. Curiously, in female worms, hydrogen peroxide production was higher than in males, whereas females were more resistant to oxidative challenge promoted by menadione than males. Concluding, the blood-feeding habit promotes functional and structural remodeling in mitochondria from hematophagous organisms, which may represent an important adaptation to this exquisite dietary source.

Keywords: Aedes, Rhodnius, Schistosoma, insect flight muscle, Schistosoma mansoni, whole Aedes larva, insect cell lines Aag2, S2, C6/36, human platelet, Injuries & adaptation:trauma, haemorrhage, inflammation

O2k-Network Lab: BR Rio de Janeiro Oliveira MF


Labels: MiParea: Respiration, Comparative MiP;environmental MiP, Gender, Exercise physiology;nutrition;life style, mt-Medicine  Pathology: Aging;senescence, Infectious  Stress:Oxidative stress;RONS  Organism: Human, Drosophila, Hexapods, Other invertebrates  Tissue;cell: Skeletal muscle, Neuroblastoma  Preparation: Intact organism, Intact organ, Intact cells, Permeabilized cells, Permeabilized tissue, Homogenate 

Regulation: ADP, Flux control, mt-Membrane potential, Phosphate, Redox state, Threshold;excess capacity, Uncoupler  Coupling state: LEAK, ROUTINE, OXPHOS, ET  Pathway: F, N, S, Gp, CIV, ROX  HRR: Oxygraph-2k 

MiP2013 

Affiliations and acknowledgements

Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Brazil. - Email: maroli@bioqmed.ufrj.br

Financial support: CNPq, FAPERJ