Interação de células endoteliais isoladas da veia umbilical humana (HUVECs) com cepas de Aspergillus fumigatus deficientes em galactosaminogalactana

• Autor(a) principal: Virginio, Emylli Dias
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16114
• topic: A. fumigatus; HUVECs; Galactosaminogalactan; ∆; uge3 mutant; gt4c mutant; ugm1 mutant; Coagulation; Homeostasis; Apoptosis; Platelet activation; Aspergillus fumigatus-; Mutação (Biologia); A. fumigatus; HUVECs; Galactosaminogalactana; Mutante ∆; uge3; Mutante ∆; gt4c; Mutante ∆; ugm1; Coagulação; Homeostase; Apoptose; Ativação de plaquetas; Cordão umbilical; Células Endoteliais da Veia Umbilical Humana; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::QUIMICA DE MACROMOLECULAS

The cell surface of Aspergillus fumigatus is the first structure of the fungus to get in contact with host constituents. Recent studies have shown that glycoconjugates of A. fumigatus cell surface are involved in the host adhesion processes. Among these surface carbohydrates, a galactosaminogalactan (GAG) was characterized for its key role at the adhesion of the fungus. The GAG synthesis process and its transportation to the cell wall is not fully understood. However, it is known that the UGE3 and GT4C genes encodes, respectively, an UDP-glucose-4-epimerase and a glycosyl transferase that are essentials for the production of A. fumigatus GAG. In this context, this work aimed to elucidate the role of GAG molecule at endothelial activation end to uncover which endothelial biological processes were regulated because of this activation. To achieve this objective, we used the primary culture of human umbilical vein endothelial cells model (HUVECs) challenged with wild type and mutant strains of A. fumigatus. The mutant strains used were: (i) two strains deficient at GAG synthesis (∆uge3 e ∆gt4c) and; (ii) one mutant strain wich super express GAG at cell surface (∆ugm1). After HUVECs interaction with each A. fumigatus strains, we evaluated the adhesion profile to endothelial cells, the HUVECs viability and the secretion of cytokines in the conditioned media. Besides, a comparative and quantitative proteomic study was performed, to elucidate the biological processes modulated by GAG. The results of this study indicated that the mutant strains ∆uge3 and ∆gt4c had a hypo-adherent profile to HUVECS when compared to the AF293 e Ku80 wild type strains, also, a significant decrease at TNF-α secretion was observed. In contrast, the ∆ugm1 strain showed a hyper-adherent profile to HUVECs, when compared to the wild type strains. Corroborating previous data of our group, the ∆ugm1 strain induced a significant increase of TNF-α secretion. The HUVECs infected with the ∆uge3 e ∆gt4c mutants showed a reduction of the pro-inflammatory IL-6 and the TNF-α secretion profile when compared to the wild type strains. The proteomic data indicated that GAG is related with the modulation of HUVECs proteins involved in biological processes that are important in the physiopathology of invasive aspergillosis, such as: adhesion and cellular movement, regulation of angiogenesis and coagulation, oxidative stress, cellular homeostasis, platelet activation and apoptosis.