| Congresso Brasileiro de Microbiologia 2023 | Resumo: 957-1 | ||||
Resumo:Curcumin is a plant compound endowed with antioxidant, antiproliferative and antitumor activities, capable of chelating various metal ions such as iron and easily crossing membranes. It has antifungal activity against different species of fungi, such as Candida albicans, inhibiting the formation of hyphae and cell growth, as well as drug efflux pumps, leading to cell death by generation of reactive oxygen species, through the accumulation of biosynthetic precursors of ergosterol. However, the molecular mechanisms involved in the regulation of cell proliferation and fungal virulence by curcumin are not completely known. The fission yeast Schizosaccharomyces pombe (Ascomycota, Taphrinomycotina, Schizosaccharomycetes) has been widely used as a model in biomedical research to study several molecular and cellular processes. The goal of this work was to investigate the effects of curcumin on fungal cells using fission yeast as a model, with emphasis on cellular, vacuolar and mitochondrial morphology, as well as modulation of oxidative stress and H+-ATPases in vacuoles and plasma membrane. Wild type (wt) strains were cultured at pH 4.5 and 5.8 in the presence of 25 and 100 nM Concanamycin A and/or 50 µM curcumin (and/or 50 µM FeSO4) and analyzed by optical microscopy. Cells were also analyzed by fluorescence microscopy using mitochondrial and vacuolar markers Mitotracker Red FM and FM4-64, respectively, and the non-fluorescent probe H2DCFDA. To analyze the activity of P/V-H+-ATPases, cell fractionation was performed. We observed that the inhibitory effect of curcumin on cell growth was more evident at acidic extracellular pH. Treatments with Concanamycin A and curcumin resulted in the highest number of aberrant cells at pH 5.8 compared to pH 4.5. Cells grown with curcumin exhibited a reduction in the maximum amplitude of H+ transport mediated by P-H+-ATPases and V-ATPases in cell membranes. Curcumin treatment prevented the labeling of mitochondria with Mitotracker Red FM. Damaged mitochondria release signaling molecules, such as reactive oxygen species (ROS), which can lead to cell death. We demonstrated that curcumin induced ROS accumulation only in P5 Cta4 ATPase deficient mutant strain, evidencing the essential role of this membrane transporter for antioxidative defense and balance of ROS levels in cells under curcumin stress. The results show that curcumin interferes with the electrochemical H++-ATPases and with the mitochondrial membrane potential. The data indicate that curcumin disrupts cellular pH, causes mitochondrial and vacuolar/endosomal dysfunction, possibly impacting contact sites and interorganellar signaling and communication. Palavras-chave: antifungals, curcumin, H+-ATPase, membrane Agência de fomento:CAPES, CNPq, FAPERJ, UENF | |||||