Evaluation of new therapies and biomarkers in paracoccidioidomycosis: antifungal activity of alkyl gallates in alternative models and mice and identification of circulating microRNAs

Abstract

The search for new therapies and new biomarkers are needed in fungal diseases such as paracoccidioidomycosis (PCM). The PCM is a systemic mycosis caused by fungi of the genus Paracoccidioides and appears endemic in Central and South America. Despite the good efficacy of antifungal agents against P. brasiliensis and P. lutzii, some of them such as amphotericin B can be toxic to the host cells. Furthermore, it was described the occurrence of P. brasiliensis isolates resistant to ketoconazole. In this context, the search for natural products with improved antifungal efficacy and safety have increased. Additionally, alternative models as Galleria mellonella and Caenorhabditis elegans have been used to study the fungus-host interaction and for search of new therapies in a simple way and on large scale. In this work, G. mellonella and C. elegans will be infected by different concentrations of Paracoccidioides spp. and efficacy of drugs amphotericin B, itraconazole and esters of gallic acid derivatives will be evaluated. For such purpose the survival and fungal burden in these models will be evaluated and subsequently the compound with best activity in alternative models will be evaluated for efficacy, toxicology and pharmacokinetics in mice. Another important aspect of this work relates to the search for new biomarkers such as circulating microRNAs. MicroRNAs are small non-coding RNAs that play critical roles in most biological processes and also in the pathophysiology of diseases. Thus, it will be performed the identification of RNAs in serum of patients and mice with PCM and subsequent screening of microRNAs by quantitative PCR. The search for genes and pathways related to microRNAs will be identified by bioinformatics. Statistical analysis of all results will be made at Graph Pad Prism 5. (AU)