The kinin receptor is expressed in the Malpighian tubule stellate cells in the mosquito Aedes aegypti (L.): A new model needed to explain ion transport?
Autor(es): Lu, Hsiao-Ling; Kersch, Cymon; Pietrantonio, Patricia V.
Resumo: It is known that insect kinins increase diuresis and fluid secretion in the Aedes aegypti Malpighian tubule, causing a rapid drop of the transepithelial resistance and increasing chloride conductance from the hemolymph towards the tubule lumen. The tubule is composed of both principal and stellate cells. The main route for increased chloride influx upon kinin treatment is proposed to be paracellular, with septate junctions acquiring increased chloride selectivity and conductance. Therefore, kinin treatment renders the Ae. aegypti tubule a "leaky epithelium", and under this model the kinin receptor is postulated to be expressed in principal cells. However, in another dipteran, the fruit fly Drosophila melanogaster, the main route for chloride transport is transcellular through stellate cells. In both the fruit fly and the mosquito Anopheles stephensi the kinin receptor has been immunolocalized in stellate cells, where it regulates transepithelial chloride permeability. Here we show that in Ae. aegypti, similarly, the stellate cells express the kinin receptor. This was confirmed through immunohistochemistry with two specific anti-kinin receptor antibodies and confocal analysis. The receptor is detected as a 75aakDa band in western blot. These results indicate that the currently accepted model for chloride transport must be re-evaluated in Ae. aegypti and suggest the kinin regulatory signals controlling intercellular junctions originate in the stellate cells. We provide evidence that the kinin receptor (AY596453) is expressed only in stellate cells in Malpighian (renal) tubules of females of the mosquito Aedes aegypti.
Palavras-Chave: Protein transport; Stellate cells; Malpighian tubules; Chloride transport; Renal tubules; Confocal microscopy; Diuresis; Chloride currents; Kinins; Aedes aegypti; Drosophila melanogaster; Anopheles stephensi
Imprenta: Insect Biochemistry and Molecular Biology, v. 41, n. 2, p. 135-140, 2011.
Descritores: Aedes aegypti - Cell ; Aedes aegypti - Proteins
Data de publicação: 2011
