Functional dissection of alternative secretory pathways in the yeast S. cerevisiae

Eukaryotic cells are characterized by having a subset of internal membrane compartments, each one with a specifi c identity, structure and function. Proteins destined to be targeted to the exterior of the cell need to enter and progress through the secretory pathway. Transport of secretory proteins from the endoplasmic reticulum (ER) to the Golgi takes place by the selective packaging of proteins into COPII-coated vesicles at the ER membrane. Taking advantage of the extensive genetic tools available for S. cerevisiae we found that Hsp150, a yeast secretory glycoprotein, selectively exited the ER in the absence of any of the three Sec24p family members. Sec24p has been thought to be an essential component of the COPII coat and thus indispensable for exocytic membrane traffic. Next we analyzed the ability of Hsp150 to be secreted in mutants, where post-Golgi transport is temperature sensitive. We found that Hsp150 could be selectively secreted under conditions where the exocyst component Sec15p is defective. Analysis of the secretory vesicles revealed that Hsp150 was packaged into a subset of known secretory vesicles as well as in a novel pool of secretory vesicles at the level of the Golgi. Secretion of Hsp150 in the absence of Sec15p function was dependent of Mso1p, a protein capable of interacting with vesicles intended to fuse with the plasma membrane, with the SNARE machinery and with Sec1p. This work demonstrated that Hsp150 is capable of using alternative secretory pathways in ER-to-Golgi and Golgi-to-plasma membrane traffi c. The sorting signals, used at both stages of the secretory pathway, for secretion of Hsp150 were different, revealing the highly dynamic nature and spatial organization of the secretory pathway. Foreign proteins usually misfold in the yeast ER. We used Hsp150 as a carrier to assist folding and transport of heterologous proteins though the secretory pathway to the culture medium in both S. cerevisiae and P. pastoris. Using this technique we expressed Hsp150Δ-HRP and developed a staining procedure, which allowed the visualization of the organelles of the secretory pathway of S. cerevisiae.Ei saatavill

Early-life exposure to mycotoxins: the contribution of MYCOMIX and earlyMYCO projects

Artigo baseado no original publicado em: Assunção R, Martins C, Vasco E, Jager A, Oliveira C, Cunha SC, Fernandes JO, Nunes B, Loureiro S, Alvito P. Portuguese children dietary exposure to multiple mycotoxins – An overview of risk assessment under MYCOMIX project. Food Chem Toxicol. 2018;118:399-408. https://doi.org/10.1016/j.fct.2018.05.040A exposição a contaminantes químicos nos primeiros 1000 dias de vida tem sido associada a alterações de saúde, constituindo um domínio emergente de pesquisa fundamental para o conhecimento do exposoma humano. As micotoxinas produzidas por fungos integram a lista de contaminantes químicos tóxicos presentes nos alimentos e têm efeitos carcinogénicos, nefrotóxicos, hepatotóxicos e imunossupressores. A mucosa intestinal é a primeira barreira biológica encontrada pelos alimentos contaminados por micotoxinas após a ingestão, sendo pouco conhecidos os potenciais efeitos decorrentes de uma exposição humana precoce a estes contaminantes. Estudos recentes obtidos no âmbito do projeto MYCOMIX evidenciaram que as crianças portuguesas até aos 3 anos estão expostas a múltiplas micotoxinas através do consumo de alimentos à base de cereais, o que constitui um risco potencial para a sua saúde. Este estudo revelou a ocorrência de ocratoxina A, zearalenona e deoxinivalenol em, respetivamente, 65%, 48% e 44% das amostras analisadas, confirmando a exposição das crianças a várias micotoxinas através da alimentação. Em virtude da toxicidade associada a estes contaminantes e à particular vulnerabilidade deste grupo populacional, estes resultados abrem novas perspetivas de investigação e reforçam a necessidade de avaliar a exposição precoce das crianças a micotoxinas e o seu potencial impacto na saúde, o que constitui o principal objetivo do projeto earlyMYCO.Exposure to hazardous chemicals during the first 1000 days of life has been linked to an increased risk of a number of health disorders. Early-life exposure to chemicals is an emerging research field that needs to be explored to contribute to the understanding of human exposome. Mycotoxins are food chemical contaminants, well known for their carcinogenic, nephrotoxic, hepatotoxic and immunosuppressive effects. Intestinal mucosa is the first biological barrier encountered by ingested mycotoxins and potential consequences of an early-life exposure to these compounds is poorly documented. Recent studies obtained under the MYCOMIX project showed that Portuguese children up to 3 years old are exposed to multiple mycotoxins through consumption of cereal-based foods, which constitutes a potential health threat. This study revealed the occurrence of ochratoxin A, zearalenone and deoxynivalenol in, respectively, 65%, 48% and 44% of the analyzed samples, confirming children exposure to several mycotoxins through food. Given the toxicity of these compounds and that children are a particularly vulnerable group, there is an urgent need to assess the impact of early-life exposure to mycotoxins and their potential impact on human health, which is the main goal of earlyMYCO project.Projeto MYCOMIX, financiado pela Fundação para a Ciência e a Tecnologia (PTDC/DTP-FT0/0417/2012). Este trabalho é financiado por fundos nacionais através da Fundação para a Ciência e a Tecnologia, no âmbito do projeto earlyMYCO (PTDC/MEDTOX/28762/2017) e do CESAM (UIDP/50017/2020+UIDB /50017/2020).info:eu-repo/semantics/publishedVersio

Ultra-Processed Food Consumption Is Related to Higher Trans Fatty Acids, Sugar Intake and Micronutrient-Impaired Status in Schoolchildren of Bahia, Brazil

Ultra-processed food (UPF) consumption impacts nutrient intake and plays an important role in non-communicable diseases (NCD), even among schoolchildren. This cross-sectional study aimed to characterize the food consumption of this population and its relationship with laboratory and anthropometric aspects. A sample of 190 subjects aged 5 to 19 y was randomly selected for dietary, laboratory, and anthropometric assessment. Statistical inference was calculated using Spearman’s correlation. Excess weight was observed in 34%, a high Waist-to-Height Ratio in 9%, and hypertriglyceridemia in 17% of the subjects, higher among those from urban schools (45%, p = 0.011; 15%, p = 0.015; 24%, p = 0.026, respectively). UPF consumption represented 21% of caloric intake and showed a positive correlation with trans fatty acids (r = 0.70) and sugar (r = 0.59) intake. Unprocessed food consumption showed a weak, but significant, correlation with Body Mass Index (r = 0.22) and Waist Circumference (r = 0.23), while processed meat showed a negative correlation with serum ferritin (r = −0.16) and vitamins D (r = −0.20) and B12 (r = −0.15). These findings highlight the need for public policies to promote Food and Nutritional Security for schoolchildren to prevent NCD and nutritional deficiencies

Avaliação in vitro de quimioterápicos e fitoterápicos no controle de argulus sp / Vitro evaluation of chemotherapy and phytotherapy in the control of argulus sp

O presente estudo teve como objetivo avaliar a eficácia in vitro da utilização de quimioterápicos e fitoterápicos no controle de Argulus sp. O experimento foi realizado na Base de Piscicultura Carlos Eduardo Matiazze e no Laboratório de Produção Animal (LAPA), da Universidade Federal de Rondônia (UNIR), campus de Presidente Médici- RO. Foram analisados 480 indivíduos de Argulus sp. coletados em ambiente de cultivo, sendo testados 15 tratamentos (1 controle, 8 produtos fitoterápicos e 6 produtos quimioterápicos). Cada tratamento continha três repetições, com 10 parasitos/placa, contendo 10 ml de solução preparada com os produtos, na concentração de 100 mg/L. A eficácia antiparasitária dos produtos foi analisada a cada 15 minutos, com a contagem dos parasitos mortos. Os testes tiveram uma duração de 180 min. Neste ensaio in vitro, os resultados foram satisfatórios ao testar o efeito inibitório de quatro tratamentos com produtos quimioterápicos e dois tratamentos com fitoterápicos sobre os Argulus sp., onde as soluções com permanganato de potássio, Neguvon® e formaldeído apresentaram 100% de eficácia nos primeiros quinze minutos de experimento. E, os produtos cal, extrato de nem e copaíba apresentaram 100%, 100% e 80%, respectivamente, aos cento e oitenta minutos, tempo final de avaliação experimental. Os demais produtos conseguiram atingir a eficácia de 30%, 26,7%, 26,7%, 13,3%, 6,7%, 3,3%, 0% e 0% para mamão, alho, mastruz, gengibre e albendazol, babosa, sal e cravo, respectivamente. Estes resultados evidenciam que os produtos naturais são factíveis, economicamente viáveis e ambientalmente corretos para a piscicultura, contribuindo com a sustentabilidade, por diminuir a utilização de produtos químicos, como por exemplo em estações de reprodução de peixes, para controle de matrizes e reprodutores. As substâncias de origem vegetal podem ser apresentadas como fonte alternativa para o uso direto ou no desenvolvimento de anti-parasitários fitoterápicos, requerendo avanço nos estudos para tratamento in vivo, substituindo-se o de produtos químicos por naturais. Os resultados encontrados possibilitam ainda um maior embasamento quanto ao controle do parasito Argulus sp., nos direcionando ao desenvolvimento de novas pesquisas, tanto in vitro como in vivo, levando à difusão das mesmas e, futuramente, à aplicação destas nos ambientes de cultivo.

Forest disturbance and growth processes are reflected in the geographical distribution of large canopy gaps across the Brazilian Amazon

Canopy gaps are openings in the forest canopy resulting from branch fall and tree mortality events. The geographical distribution of large canopy gaps may reflect underlying variation in mortality and growth processes. However, a lack of data at the appropriate scale has limited our ability to study this relationship until now. We detected canopy gaps using a unique LiDAR dataset consisting of 650 transects randomly distributed across 2500 km(2) of the Brazilian Amazon. We characterized the size distribution of canopy gaps using a power law and we explore the variation in the exponent, alpha. We evaluated how the alpha varies across the Amazon, in response to disturbance by humans and natural environmental processes that influence tree mortality rates. We observed that South-eastern forests contained a higher proportion of large gaps than North-western, which is consistent with recent work showing greater tree mortality rates in the Southeast than the Northwest. Regions characterized by strong wind gust speeds, frequent lightning and greater water shortage also had a high proportion of large gaps, indicating that geographical variation in alpha is a reflection of underlying disturbance processes. Forests on fertile soils were also found to contain a high proportion of large gaps, in part because trees grow tall on these sites and create large gaps when they fall; thus, canopy gap analysis picked up differences in growth as well as mortality processes. Finally, we found that human-modified forests had a higher proportion of large gaps than intact forests, as we would expect given that these forests have been disturbed. Synthesis. The proportion of large gaps in the forest canopy varied substantially over the Brazilian Amazon. We have shown that the trends can be explained by geographical variation in disturbance and growth. The frequency of extreme weather events is predicted to increase under climate change, and changes could lead to greater forest disturbance, which should be detectable as an increased proportion of large gaps in intact forests.Peer reviewe

Cartilage restoration of patellofemoral lesions: a systematic review

Purpose This study aimed to systematically analyze the postoperative clinical, functional, and imaging outcomes, complications, reoperations, and failures following patellofemoral cartilage restoration surgery. Methods This review was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed, EMBASE, and Cochrane Library databases were searched up to August 31, 2018, to identify clinical studies that assessed surgical outcomes of patellofemoral cartilage restoration surgery. The Methodological Index for Non-Randomized Studies (MINORS) was used to assess study quality. Results Forty-two studies were included comprising 1,311 knees (mean age of 33.7 years and 56% males) and 1,309 patellofemoral defects (891 patella, 254 trochlear, 95 bipolar, and 69 multiple defects, including the patella or trochlea) at a mean follow-up of 59.2 months. Restoration techniques included autologous chondrocyte implantation (56%), particulated juvenile allograft cartilage (12%), autologous matrix-induced chondrogenesis (9%), osteochondral autologous transplantation (9%), and osteochondral allograft transplantation (7%). Significant improvement in at least one score was present in almost all studies and these surpassed the minimal clinically important difference threshold. There was a weighted 19%, 35%, and 6% rate of reported complications, reoperations, and failures, respectively. Concomitant patellofemoral surgery (51% of patients) mostly did not lead to statistically different postoperative outcomes. Conclusion Numerous patellofemoral restoration techniques result in significant functional improvement with a low rate of failure. No definitive conclusions could be made to determine the best surgical technique since comparative studies on this topic are rare, and treatment choice should be made according to specific patient and defect characteristics