Mecanismos de sinalização celular envolvidos nos processos de proliferação e propagação de Ehrlichia canis in vitro

Abstract

Ehrlichia canis, etiologic agent of Canine Monocytic Ehrlichiosis, is an obligatory intracellular bacteria that lodges itself in monocytes and macrophages. In this study we analyzed the role of the cytoskeleton, specifically actin and microtubules, some components of the signaling pathway IP3/DAG: phospholipase C (PLC), protein kinase (PTK) and calcium channels as well as the role of iron in the processes of proliferation and propagation of E. canis in DH82 cells. For each of these components different inhibitory drugs were used: Cytochalasin D (inhibits actin polymerization), Nocodazole (inhibits microtubule polymerization), Neomycin (PLC inhibitor), Genistein (PTK inhibitor), Verapamil hydrochloride (blocker calcium channel) and Deferoxamine (iron chelator). Regarding to proliferation process, we observed a significant decrease in the total number of bacteria in treated cells. Except for Genistein (29.86%) and Nocodazole (38.53%), the percentage of infected cells was significantly lower compared with the control (33.23%). As for the propagation process, except for Nocodazole, there was a decrease in the total number of bacteria after treatment. In relation to infected cells percentage, no significant difference were seen in treated cells with Cytochalasin D (44.72%) and Deferoxamine (56.53%) when compared to controls (51.67%). Regarding Nocodazole was evidenced significant increase in the percentage of infected cells (64.75%). These results suggest that E. canis proliferation and spread are sensitive to tested drugs, demonstrating that actin filaments polymerization, compared to microtubules, as well as the components envelopment of signaling pathway IP3/DAG (PLC, PTK and calcium channels) analyzed and iron are essential to bacterial multiplication