The Yeast PNC1 Longevity Gene Is Up-Regulated by mRNA Mistranslation

Translation fidelity is critical for protein synthesis and to ensure correct cell functioning. Mutations in the protein synthesis machinery or environmental factors that increase synthesis of mistranslated proteins result in cell death and degeneration and are associated with neurodegenerative diseases, cancer and with an increasing number of mitochondrial disorders. Remarkably, mRNA mistranslation plays critical roles in the evolution of the genetic code, can be beneficial under stress conditions in yeast and in Escherichia coli and is an important source of peptides for MHC class I complex in dendritic cells. Despite this, its biology has been overlooked over the years due to technical difficulties in its detection and quantification. In order to shed new light on the biological relevance of mistranslation we have generated codon misreading in Saccharomyces cerevisiae using drugs and tRNA engineering methodologies. Surprisingly, such mistranslation up-regulated the longevity gene PNC1. Similar results were also obtained in cells grown in the presence of amino acid analogues that promote protein misfolding. The overall data showed that PNC1 is a biomarker of mRNA mistranslation and protein misfolding and that PNC1-GFP fusions can be used to monitor these two important biological phenomena in vivo in an easy manner, thus opening new avenues to understand their biological relevance

An optimized nanoparticle delivery system based on chitosan and chondroitin sulfate molecules reduces the toxicity of amphotericin B and is effective in treating tegumentary leishmaniasis

Amphotericin B (AmpB) is active against leishmaniasis, but its use is hampered due to its high toxicity observed in patients. In this study, a nanoparticles-delivery system for AmpB (NQC-AmpB), containing chitosan and chondroitin sulfate molecules, was evaluated in BALB/c mice against Leishmania amazonensis. An in vivo biodistribution study, including biochemical and toxicological evaluations, was performed to evaluate the toxicity of AmpB. Nanoparticles were radiolabeled with technetium-99m and injected in mice. The products presented a similar biodistribution in the liver, spleen, and kidneys of the animals. Free AmpB induced alterations in the body weight of the mice, which, in the biochemical analysis, indicated hepatic and renal injury, as well as morphological damage to the kidneys of the animals. In general, no significant organic alteration was observed in the animals treated with NQC-AmpB. Mice were infected with L. amazonensis and treated with the nanoparticles or free AmpB; then, parasitological and immunological analyses were performed. The NQC-AmpB group, as compared to the control groups, presented significant reductions in the lesion size and in the parasite burden in all evaluated organs. These animals presented significantly higher levels of IFN-γ and IL-12, and low levels of IL-4 and IL-10, when compared to the control groups. The NQC-AmpB system was effective in reducing the infection in the animals, and proved to be effective in diminishing the toxicity evoked by AmpB, which was observed when it was administered alone. In conclusion, NQC-AmpB could be considered a viable possibility for future studies in the treatment of leishmaniasisThis work was supported by grants from Pró-Reitoria de Pesquisa from UFMG (Edital 01/2014), Instituto Nacional de Ciência e Tecnologia em Nano-biofarmacêutica (INCT-Nanobiofar), FAPEMIG (CBB-APQ-00496-11 and CBB-APQ-00819-12), and CNPq (APQ-472090/2011-9 and APQ-482976/2012-8). MACF is a grant recipient of FAPEMIG/CAPES. EAFC, VNC, and AAGF are grant recipients of CNPq. Eduardo AF Coelho and André AG Faraco are co-senior authors of this stud

Sensitive and specific serodiagnosis of Leishmania infantum infection in dogs by using peptides selected from hypothetical proteins identified by an immunoproteomic approach

In Brazil, the percentage of infected dogs living in areas where canine visceral leishmaniasis (CVL) is endemic ranges from 10 to 62%; however, the prevalence of infection in dogs is probably higher than figures reported from serological studies. In addition, problems with the occurrence of false-positive or false-negative results in the serodiagnosis of CVL have been reported. The present work analyzed the potential of synthetic peptides mapped from hypothetical proteins for improvement of the serodiagnosis of Leishmania infantum infection in dogs. From 26 identified leishmanial proteins, eight were selected, considering that no homologies between these proteins and others from trypanosomatide sequence databases were encountered. The sequences of these proteins were mapped to identify linear B-cell epitopes, and 17 peptides were synthesized and tested in enzyme-linked immunosorbent assays (ELISAs) for the serodiagnosis of L. infantum infection in dogs. Of these, three exhibited sensitivity and specificity values higher than 75% and 90%, respectively, to differentiate L. infantum-infected animals from Trypanosoma cruziinfected animals and healthy animals. Soluble Leishmania antigen (SLA) showed poor sensitivity (4%) and specificity (36%) to differentiate L. infantum-infected dogs from healthy and T. cruzi-infected dogs. Lastly, the three selected peptides were combined in different mixtures and higher sensitivity and specificity values were obtained, even when sera from T. cruzi-infected dogs were used. The study’s findings suggest that these three peptides can constitute a potential tool for more sensitive and specific serodiagnosis of L. infantum infection in dogsThis work was supported by grants from the Pró-Reitoria de Pesquisa from UFMG (Edital 07/2012), Instituto Nacional de Ciência e Tecnologia em Nano-biofarmacêutica (INCT-NANOBIOFAR, Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (CBB-APQ-02364-08, CBB-APQ-00356-10, CBB-APQ-00496-11, and CBB-APQ-00819-12), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (APQ-472090/2011-9), and the Instituto Nacional de Ciência e Tecnologia em Vacinas (INCT-V). E.A.F.C. and A.P.F. are CNPq grant recipients. M.A.C.-F. is a FAPEMIG/CAPES grant recipient. This study was supported in Spain, in part, by grants from the Ministerio de Ciencia e Innovación (FIS/PI1100095)

Estudo da marcha em idosos: resultados preliminares

The objectives of this pilot study, were the evaluation of, time-spatial, parameters of Brazilian elderly gait and to compare comfortable gait speed’s value with foreign reference data (from Oberg). Methods: Subjects were 15 healthy volunteers (8 men, 7 women) 60 to 79 years of age. The measurements were made in theirs building playground. Gait was timed over a 6 m distance; step length, stride width and foot angle were measured from footprints. Cadence was calculated from velocity and step length. Results: mean comfortable speed was ranged from 1,05 + 0,14 m/s for women in their sixties to 1,10 + 0,13 m/s for men in their seventies. Mean step length, stride width, cadence and foot angle were respectively 52,1 + 8,75 cm; 11,2 + 3,49 cm; 119,4 + 11,07 step/min and 13,5 + 8,53 degree for men and 46,6 + 8,08 cm; 6,75 + 7,07cm; 137,4 + 22,64 step/min and 7,5 + 5,1 degree for women. Conclusion: The lowest elderly’s gait speed obtained despite the sample’s small number in confronting with Oberg data, suggest the importance of comprehensive studies to supply the lack of normative gait data for the Brazilian population.Os objetivos foram avaliar parâmetros tempo-espaciais da marcha de idosos brasileiros e comparar o valor médio da velocidade confortável da marcha com um banco de dados estrangeiro (de Oberg) de parâmetros básicos da marcha. Metodo: Foram estudados 15 voluntários saudáveis (8 homens, 7 mulheres) dos 60 aos 79 anos de idade. As medidas foram realizadas no playgroung dos prédios onde residiam. A velocidade da marcha foi medida para uma distância de 6 m; o comprimento do passo, a largura da passada e o ângulo dos pés foram medidos a partir de impressões plantares. A cadência foi calculada a partir da velocidade da marcha e do comprimento do passo. Resultados: O valor médio da velocidade confortável da marcha variou de 1,05 + 0,14 m/s para mulheres da faixa etária de 60 anos a 1,10 + 0,13 m/s para homens da faixa etária de 70 anos. Os valores médios do comprimento do passo, da largura da passada, do ângulo dos pés e da cadência foram respectivamente 52,1 + 8,75 cm; 11,2 + 3,49 cm; 119,4 + 11,07 passos/min e 13,5 + 8,53 graus para os homens e 46,6 + 8,08 cm; 6,75 + 7,07cm; 137,4 + 22,64 passos/min e 7,5 + 5,1 graus para as mulheres. Conclusão: O menor valor da velocidade da marcha encontrado para os nossos idosos (apesar da casuística pequena), quando confrontado com os dados de Oberg, sugere a importância de estudos completos para suprir a falta de dados normativos de parâmetros da marcha para a população brasileira

Whole-genome sequencing of 1,171 elderly admixed individuals from Brazil

As whole-genome sequencing (WGS) becomes the gold standard tool for studying population genomics and medical applications, data on diverse non-European and admixed individuals are still scarce. Here, we present a high-coverage WGS dataset of 1,171 highly admixed elderly Brazilians from a census-based cohort, providing over 76 million variants, of which ~2 million are absent from large public databases. WGS enables identification of ~2,000 previously undescribed mobile element insertions without previous description, nearly 5 Mb of genomic segments absent from the human genome reference, and over 140 alleles from HLA genes absent from public resources. We reclassify and curate pathogenicity assertions for nearly four hundred variants in genes associated with dominantly-inherited Mendelian disorders and calculate the incidence for selected recessive disorders, demonstrating the clinical usefulness of the present study. Finally, we observe that whole-genome and HLA imputation could be significantly improved compared to available datasets since rare variation represents the largest proportion of input from WGS. These results demonstrate that even smaller sample sizes of underrepresented populations bring relevant data for genomic studies, especially when exploring analyses allowed only by WGS