Similar results were obtained when H99 cells were pre-treated with FLC at 37°C (see Additional file 2). Figure 3 Cell wall integrity assays with H99 C. neoformans cells left untreated (H99) or exposed to FLC (H99F) at a sub-MIC

concentration Selleckchem CBL-0137 of 10 mg/l for 90 min at 30°C. Cells were grown at the same temperature for 48 h on YEPD supplemented with calcofluor white (CFW), Congo red, sodium dodecyl sulphate (SDS) and caffeine. Aliquots of cells were applied onto the agar surface with 10-fold serial dilutions. Effect of FLC on the susceptibility to H2O2 Because a number of FLC-responsive transcriptional changes was found to affect genes involved in the oxidative GSK690693 mw stress response (i.e. CTA1, GRE2), it seemed reasonable to examine whether FLC at sub-inhibitory concentrations could induce oxidative stress resistance in vitro. For this purpose, exponentially growing H99 cells that were treated with 10 mg/l FLC for 90 min were subjected to an additional challenge with 20 mM H2O2. The viable cells were next quantified on YEPD plates after 0.5, 1, 1.5 and 2 h of additional growth. As shown in Figure 4, while untreated cells showed a high degree of cell death, cells treated with FLC exhibited gained more viability upon oxidative

exposure at the endpoints of 1, 1.5 and 2 h. Tozasertib cost Similar results were obtained when H99 cells were pre-treated with FLC at 37°C (see Additional file 3). These findings indicate

that FLC exposure is able to generate protection against oxidative stress in vitro, possibly Demeclocycline as a result of a transcriptional adaptive response. Figure 4 Survival of C. neoformans after oxidative treatment. Exponentially growing cells were left untreated (H99) or exposed to 10 mg/l FLC (H99F) for 90 min at 30°C and then challenged with 20 mM H2O2 for 2 h. Aliquots were harvested at given time points and cell viability performed as described in Methods. Plotted values are means of three experiments Conclusions Although exposure to azoles has been already investigated in several other fungal species and the transcriptional profile of differentially expressed genes was obtained using a single FLC concentration and time point, our study reveals several interesting findings. First, we demonstrated that short-term exposure of C. neoformans to FLC resulted in a complex altered gene expression profile. These genes included not only genes commonly responding to diverse environmental stresses, such as oxidative and drug stresses, but also genes encoding virulence factors (i.e. Plb1, Sre1 and capsule). Second, we corroborated the potential of genome-wide transcriptional analyses to envisage alternative therapeutic strategies for cryptococcosis. Apart from ergosterol and its biosynthesis, there are yet few other targets to be exploited in anticryptococcal therapy.