IDENTIFICATION OF PROTEINS DIFFERENTIALLY SECRETED BY HEPG2 CELLS INFECTED WITH DENGUE VIRUS THROUGH A PROTEOMIC APPROACH
1HIGA, L.M.; 1CANELLAS, F.; 1CARUSO, M.B.; 2CHAPEAUROUGE, A.; 1OLIVEIRA-CARVALHO, A.L.; 2PERALES, J.; 1ZINGALI, R.B.; 1DA POIAN, A.T.
1Instituto de Bioquímica Médica, UFRJ; 2Departamento de Fisiologia e Farmacodinâmica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz; Rede Proteômica do Rio de Janeiro.
The diseases caused by the dengue virus, the classical dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), pose a serious public health hazard. The symptoms of DHF/DSS include hemorrhage, abrupt onset of vascular leakage, and shock, accompanied by severe thrombocytopenia, massive complement activation and the production of potentially cytotoxic cytokines that contribute to and exacerbate the cascade of inflammatory events. Several experimental evidences suggest that the liver is an important site of virus replication, at least in severe, fatal cases of dengue virus infection. The liver secretes cytokines and the acute phase proteins involved in the inflammatory response. Thus, studies about the effects of dengue virus infection on the physiology of the hepatic cells might contribute to the identification of cellular proteins involved in the viral replication and in the pathogenesis of the disease. In order to identify differentially secreted proteins from HepG2 cells (an human hepatoma cell lineage), infected or not with the dengue virus serotype 2, a proteomic approach was used. Samples from control and infected cells were applied to 2D electrophoresis gels. Matching of these gels was performed revealing at least 93 proteins exclusively secreted by control cells, 63 proteins exclusively secreted by infected cells and 80 proteins appeared in both gels. The proteins were excised from the gels, digested with trypsin and then submitted to MALDI-TOF/TOF Mass Spectrometry analysis, and about 20 proteins were identified. Among them, the NS1 protein, a non-structural protein of the dengue virus, was found in the dimeric and monomeric forms. In addition, differential expression of some secreted proteins was also observed, among them an increase in the enzyme superoxide dismutase and a decrease in heparan sulfate proteoglycan. The results obtained so far show that a proteomic approach has revealed to be a useful tool to study the effects of infection on target cells.
Financial support: CAPES, CNPq/MCT, FAPERJ, ICGEB.
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