RESUMEN
The fungal pathogen Paracoccidioides lutzii causes systemic mycosis Paracoccidioidomycosis (PCM), which presents a broad distribution in Latin America. Upon infection, the fungus undergoes a morphological transition to yeast cells and provokes an inflammatory granulomatous reaction with a high number of neutrophils in the lungs. In this work, we employed proteomic analysis to investigate the in vitro response of the fungus to the interaction with human neutrophils. Proteomic profiling of P. lutzii yeast cells harvested at 2 and 4 h post interaction with human polymorphonuclear cells allowed the identification of 505 proteins differentially accumulated. The data indicated that P. lutzii yeast cells underwent a shift in metabolism from glycolysis to Beta oxidation, increasing enzymes of the glyoxylate cycle and upregulating enzymes related to the detoxification of oxidative and heat shock stress. To our knowledge, this is the first study employing proteomic analysis in the investigation of the response of a member of the Paracoccidioides genus to the interaction with neutrophils.
RESUMEN
Background: Paracoccidioidomycosis is a neglected mycosis with a high socioeconomic impact that requires long-term treatment with antifungals that have limitations in their use. The development of antifungals targeting essential proteins that are present exclusively in the fungus points to a potentially promising treatment. Methods: The inhibitor of the enzyme homoserine dehydrogenase drove the synthesis of N'-(2-hydroxybenzylidene)-4-methoxy-1-naphthohydrazide (AOS). This compound was evaluated for its antifungal activity in different species of Paracoccidioides and the consequent alteration in the proteomic profile of Paracoccidioides brasiliensis. Results: The compound showed a minimal inhibitory concentration ranging from 0.75 to 6.9 µM with a fungicidal effect on Paracoccidioides spp. and high selectivity index. AOS differentially regulated proteins related to glycolysis, TCA, the glyoxylate cycle, the urea cycle and amino acid metabolism, including homoserine dehydrogenase. In addition, P. brasiliensis inhibited protein synthesis and stimulated reactive oxygen species in the presence of AOS. Conclusions: AOS is a promising antifungal agent for the treatment of PCM, targeting important metabolic processes of the fungus.
RESUMEN
Cutaneous melanoma has an aggressive clinical presentation, showing rapid rate of growth and metastatic dissemination due to the permanence of cancer stem cells. The present study was to evaluate the expression of the self-renewal regulatory factor and the clinical significance of the transcription factor OCT4 in melanoma. Melanoma tissues were stained by immunohistochemistry and the correlation between the expression of this marker was determined through clinical-pathological variables and survival outcomes. Positive expression of nuclear and cytoplasmic OCT4 was observed in 49% and 41.2% of cases, respectively. The positive expression of nuclear OCT4 in melanoma was significantly associated with prognostic factors, such as Breslow depth, Clark's level, ulceration and metastasis. Survival of patients was 56% compared to positive nuclear OCT4 expression and 94.2% when compared to the low expression of the gene. Nuclear OCT4 positive genotype indicated aggressive tumor behavior with a worse clinical outcome, which indicates OCT4 as a useful biomarker in the prognosis of melanoma.
