Biology subjects

Pereira, M. D.

Publications and source records attributed to Pereira, M. D..

3 recordsLinked to original sources

bioRxiv2021

Urine proteomics as a non-invasive approach to monitor exertional rhabdomyolysis during military training

Exertional rhabdomyolysis (ERM), a condition often associated with strenuous exercise, a common practice in the military activities, can be defined as the process of injury and rupture of muscle cell membranes, with leakage of its components into the blood stream. Creatine kinase (CK) has been extensively used for ERM diagnosis, albeit several studies reported the discrepancy between CK levels and clinical signs or symptoms. In this study, we analyzed the biochemical profile of the blood, and the urinary proteome of ten marine soldiers in a special training course. The samples were collected in two periods, M1 and M2, which correspond to the lowest and highest CK levels during training, respectively. Quantitative urinary proteome profile of M1 and M2 was determined showing changes with highest significance in immune system and cell adhesion-related pathways after strenuous physical exercise. Changes in the abundance of several proteins was observed in individuals carrying genetic polymorphisms related to greater risk for muscle damage. Remarkably, we identified a panel of proteins (CTSH, PIK3IP1, DEFB1, ITGB1, BCAN, and TNFRSF10C) that present high correlation with three classical blood biochemical markers of ERM and AGT MET235Thr and ACE I/D polymorphisms. These proteins represent potential urine markers of muscle damage due to intense physical conditions such as military training activities.

biochemistry↗

bioRxiv2021

Extracellular vesicles regulate yeast growth, biofilm formation, and yeast-to-hypha differentiation in Candida albicans

The ability to undergo morphological changes during adaptation to distinct environments is exploited by Candida albicans and has a direct impact on virulence. In this study, we investigated the influence of fungal extracellular vesicles (EVs) during yeast growth, biofilm formation, and morphogenesis in C. albicans. Addition of C. albicans EVs (Ca EVs) to the culture medium positively affected yeast growth. Using crystal violet staining and scanning electron microscopy (SEM), we demonstrated that Ca EVs inhibited biofilm formation by C. albicans in vitro. By time-lapse microscopy and SEM, we showed that Ca EV-treatment stops filamentation promoting pseudohyphae formation with multiple sites for yeast budding. The ability of Ca EVs to regulate dimorphism was further compared to EVs isolated from different C. albicans strains, Saccharomyces cerevisiae, and Histoplasma capsulatum. Ca EVs from distinct strains robustly inhibited yeast-to-hyphae differentiation with morphological changes occurring in less than 4 hours. A minor inhibitory effect was promoted by EVs from S. cerevisiae and H. capsulatum only after 24 hours of incubation. The inhibitory effect of Ca EVs was promoted by a combination of lipid compounds identified by gas chromatography-tandem mass spectrometry analysis as sesquiterpenes, diterpenes, and fatty acids. Remarkably, Ca EVs were also able to reverse filamentation, transforming hyphal growth to yeast forms. Transcriptomic analysis demonstrated that treatment with Ca EVs modified the expression of more than 300 genes. The most effectively upregulated pathways were related to DNA metabolism. The downregulated genes were mostly associated with extracellular and adhesion proteins. Finally, yeast cells treated with Ca EVs for 24 hours lost their agar invasive ability and were avirulent when inoculated in Galleria mellonella larvae. In summary, our results indicate that fungal EVs can profoundly modify C. albicans growth and regulate yeast-to-hypha differentiation inhibiting biofilm formation and virulence.

microbiology↗

bioRxiv2019

Muropeptides Stimulate Growth Resumption from Stationary Phase in Escherichia coli

When nutrients run out, bacteria enter a dormant metabolic state. This low or undetectable metabolic activity helps bacteria to preserve their scant reserves for future, but also diminishes their ability to trace the environment for new growth-promoting substrates. However, neighboring microbial growth is a sure indicator of favorable environment and thus, can serve as a cue for exiting the dormancy. Here we report that for Escherichia coli this cue is the basic peptidoglycan unit (i.e. muropeptide). We show that several forms of muropeptides can stimulate growth resumption of dormant E. coli cells, but the sugar - peptide bond is crucial for activity. We also demonstrate that muropeptides from several different species can induce growth resumption of E. coli and also Pseudomonas aeruginosa. These results, together with the previous identification of muropeptides as germination signal for bacterial spores, makes muropeptides rather universal cue for bacterial growth.

microbiology↗