Since hematophagous insects ingest heme proteins in volumes of several times their body weight, they need multiple defense mechanisms to face the massive iron load. These mechanisms must work in conjunction with each other to ward off cytotoxic effects of free radicals resulting from the interaction between heme or free iron and oxygen. In other words, a leakage from one mechanism must be contained by other mechanisms. One means by which hematophagous insects handle the iron overload is by polymerizing heme into hemozoin as in the kissing bug, Rhodnius prolixus. The other is perhaps by the iron storage protein ferritin, an oligomer composed of two types of subunits called heavy- and light-chain. Vertebrate data suggest that ferritin is part of the constitutive antioxidant response. In this study, we examine the expression of the ferritin light-chain-homolog gene in Aedes aegypti cultured cells in response to iron, hydrogen peroxide, and hemin, as well as in different development stages of whole animals.
Acknowledgements: Fundings was provided by the National Institutes of Health, National Institute of General Medical Sciences (GM055866 and GM056812).
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