All primers and probes (see Additional file 1) were designed with Beacon Designer 2 (version 2.06) software (Premier Biosoft International, Palo Alto, CA, USA) and synthesized by MWG Biotech (Florence, Italy). qRT-PCRs were carried out as previously described [23]. The annealing temperature used for all primers
was 65°C. Each reaction was run in triplicate on three separate occasions. For relative quantification of target gene expression, ACT1 was used as a www.selleckchem.com/products/Thiazovivin.html normalizer https://www.selleckchem.com/products/mek162.html gene [23]. Changes (n-fold) in gene expression relative to that of the control were determined from mean ACT1-normalized expression levels. Oxidative stress and cell wall inhibitor assays Susceptibilities to hydrogen peroxide (H2O2) and cell wall inhibitors were measured with exponentially growing cells in liquid YEPD at 30°C or 37°C pre-treated or not with
FLC (10 mg/l) for 90 min as described elsewhere with modifications [26, 27]. The cells were next washed with sterile PBS and diluted to an OD650 of 1.0 in PBS. For the oxidative stress 4EGI-1 concentration assays, aliquots of the cell suspensions were transferred to Eppendorf tubes where H2O2 (Sigma, Milan, Italy) was added to 20 mM and incubated at 30°C or 37°C for 2 h. Viability was determined after appropriate dilution of the samples with PBS by plating 100 μl in triplicate on solid YEPD. The CFU were counted after incubation for 72 h at 30°C or 37°C. For the cell wall inhibitor assays, dilutions Celecoxib of the cell suspensions were made in PBS and 5 μl of these were grown on YEPD plates containing 0.5% Congo red (Sigma, C-6767), 0.5, 1.0 and 1.5 mg ml-1 calcofluor white (Sigma, F-3543), 0.01%, 0.03% and 0.06% SDS (Sigma) and 0.2, 0.5 and 1.0 mg ml-1 caffeine (Sigma, C-0750). Plates were incubated for 48 h at 30°C or 37°C and photographed. Results
and Discussion Experimental design and global gene expression results The transcript profiles of C. neoformans H99 cells exposed to 10 mg/l of FLC (1/2 × MIC) for one doubling time (90 min) at 30°C were compared with profiles of untreated cells. A total of 476 genes were found responsive to FLC treatment under the test conditions, consisting of a single concentration and a single time point as described elsewhere [28–30]. The threshold value used in the present analysis was at least a twofold difference of gene expression between the experimental conditions, which is a value generally accepted in fungal genome-wide expression profiling [31]. Given that approximately 95% of the genes (6434/6823) spotted on the microarrays gave validated data, the above mentioned number indicate that 7.4% of the total number of genes in the C. neoformans H99 genome exhibited transcriptional changes, with 231 genes being upregulated and 245 downregulated upon FLC treatment.