Temporal patterns of picoplankton abundance and metabolism on the western coast of the equatorial Atlantic Ocean

Picoplankton are central global carbon (C) cycling players and often dominate the ocean plankton communities, especially in low latitudes. Therefore, evaluating picoplankton temporal dynamics is critical to understanding microbial stocks and C fluxes in tropical oceans. However, the lack of studies on low-latitude picoplankton communities translates into a common conception that there is an absence of seasonality. Herein, we studied the temporal variation in abundance (measured by flow cytometry), and carbon flux (taking bacterial production and respiration as proxies) of the picoplanktonic community for the first time, as well as their environmental drivers in a low-latitude (05° 59’ 20.7″S 035° 05’ 14.6″W) Atlantic coastal station. We performed monthly samplings between February 2013 and August 2016 in a novel microbial observatory – hereafter called the Equatorial Atlantic Microbial Observatory – established on the northeastern Brazilian Atlantic coast. Our results revealed stability in temporal dynamics of picoplankton, despite a considerable inter-annual variation, with some related to the El Niño (ENSO) event in 2015. However, weak environmental relationships found were not enough to explain the variation in picoplankton’s abundance, which suggests that other factors such as biological interactions may lead to picoplankton abundance variation over time. Heterotrophic bacteria dominated picoplankton during the entire study period and between photosynthetic counterparts, and Synechococcus showed greater relative importance than picoeukaryotes. These results bring a novel perspective that picoplankton may exhibit more pronounced fluctuations in the tropical region when considering inter-annual intervals, and is increasing prokaryotic contribution to carbon cycling towards the equator.Fil: Menezes, Maiara. Universidade Federal do Rio Grande do Norte; BrasilFil: Junger, Pedro C.. Universidade Federal do São Carlos; BrasilFil: Kavagutti, Vinicius S.. Universidade Federal do São Carlos; BrasilFil: Wanderley, Bruno. Universidade Federal do Rio Grande do Norte; BrasilFil: Cabral, Anderson de Souza. Universidade Federal do Rio de Janeiro; BrasilFil: Paranhos, Rodolfo. Universidade Federal do Rio de Janeiro; BrasilFil: Unrein, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; ArgentinaFil: Amado, André M.. Universidade Federal do Rio Grande do Norte; Brasil. Universidade Federal de Juiz de Fora; BrasilFil: Sarmento, Hugo. Universidade Federal do São Carlos; Brasi

Role of metformin and other metabolic drugs in the prevention and therapy of endocrine-related cancers

Metabolic syndrome is associated with chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. This review summarizes the current evidence on the antitumor effects of some relevant drugs currently used to manage metabolic-related pathologies (i.e. insulin and its analogs, metformin, statins, etc.) in endocrine-related cancers including breast cancer, prostate cancer, pituitary cancer, ovarian cancer, and neuroendocrine neoplasms. Although current evidence does not provide a clear antitumor role of several of these drugs, metformin seems to be a promising chemopreventive and adjuvant agent in cancer management, modulating tumor cell metabolism and microenvironment, through both AMP-activated protein kinase-dependent and -independent mechanisms. Moreover, its combination with statins might represent a promising therapeutic strategy to tackle the progression of endocrine-related tumors. However, further studies are needed to endorse the clinical relevance of these drugs as adjuvants for cancer chemotherapy.Ministerio de Ciencia e Innovación de España. PID2019- 105564RB-I00/FPU16-05059Fondo Europeo de Desarrollo Regional (FEDER) y Fondo Social Europeo (FSE). PI20/01301Instituto de Salud Carlos III de España. SCIII-AES-2019/002525Junta de Andalucía. PI-0152-2019, PI-0094-2020, PI-0038/2019, RH-0084-2020 y BIO-013

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Regulação do sistema adrenérgico no tecido adiposo na obesidade

Mestrado em BioquímicaThe prevalence of obesity is dramatically increasing worldwide, and is associated with an increased risk of cardiovascular disease and metabolic disorders. Adipose tissue is recognized as a major endocrine and secretory organ, producing a variety of adipokines which modulate energy homeostasis, lipid physiology, inflammation and immune function. It has been recently highlighted that the pattern of adipose tissue distribution (visceral or subcutaneous) might be a predictive of health risk. Visceral obesity is considered to be more pro-inflammatory and more strongly associated with cardiometabolic risk. The catecholamines (CA), adrenaline (AD) and noradrenaline (NA) are the major regulators of lipidic metabolism in adipocytes, also affecting the differentiation and proliferation of these cells and the secretion of adipokines. The recent finding that adipocytes are able to produce CA opens a new perspective about the role of these amines in obesity. The aim of this study was to investigate the localization and expression of two of the most important enzymes involved in CA synthesis, tyrosine hydroxylase (TH) and phenylethanolamine N-methyltrasnferase (PNMT), in metabolically distinct adipose tissue depots, using C57BL6 mice as dietary-induced obesity model. Two groups of male and female C57BL/6 mice with about 22-23 g were used. During 12 or 16 weeks, one group was fed with a high-fat diet (HFD, 45% lipids, 20% proteins and 35% carbohydrates) and the other with a standard diet (SD, 13% lipids, 20% proteins and 67% carbohydrates). After 12 and 16 weeks, mice were respectively overweighed or obese (15% and 45% of weight gain, respectively). All the animals were sacrificed and visceral and subcutaneous adipose tissues (VAT and SAT) collected after diet interventions. The number of adipocytes producing TH or PNMT, and cellular localization of these enzymes were evaluated by immunhistochemistry. mRNA levels of both enzymes were assessed by quantitative real-time PCR. In this study, animals fed with the HFD showed an increase of adipocyte areas in both VAT and SAT, compared with those fed with a standard diet (SD). In addition, contrary to subcutaneous, visceral adipocyte areas significantly increased after 16 weeks in comparison with 12 weeks of dietary treatments. The immunohistochemistry assays showed that both TH and PNMT are cytoplasmic enzymes, being located in the perinuclear area and along the cell membrane. Protein levels of these two enzymes were differently affected by the type of diet. The number of adipocytes expressing TH decreased with the HFD, whereas those expressing PNMT increased, in comparison with the SD. Protein TH levels were only significantly modified by global comparison between VAT and SAT, regardless of the diet. Indeed, in these conditions, SAT presented a higher number of TH expressing adipocytes than VAT. On the other hand, whereas the two adipose tissues expressed similar PNMT mRNA levels, VAT presented lower values of TH mRNA than SAT. In conclusion, results obtained with this study showed that the expression of both TH and PNMT in adipose tissue is differently modulated on visceral and subcutaneous adipose depots and is dependent on the diet type.A prevalência da obesidade está a aumentar dramaticamente em todo o mundo, estando associada ao aumento do risco de doenças cardiovasculares e metabólicas. O tecido adiposo é considerado um importante órgão endócrino e secretor, produzindo uma variedade de adipocinas que modulam a homeostasia energética, fisiologia lipídica, inflamação e função imunológica. Recentemente, tem sido salientado que o padrão de distribuição do tecido adiposo (visceral ou subcutâneo) pode ser um preditor de risco para a saúde. A obesidade visceral é considerada mais pró-inflamatória e mais fortemente associada ao risco cardiometabólico. As catecolaminas (CA), adrenalina (AD) e noradrenalina (NA), são os principais reguladores do metabolismo lipídico nos adipócitos, afetando igualmente a diferenciação e proliferação destas células e a secreção de adipocinas. A recente descoberta de que os adipócitos são capazes de produzir CA proporciona uma nova perspetiva sobre o papel destas aminas na obesidade. O objetivo deste estudo foi investigar a localização e expressão de duas das mais importantes enzimas envolvidas na síntese de CA, a tirosina hidroxilase (TH) e a feniletanolamina N- metiltransferase (PNMT), em locais de tecido adiposo metabolicamente diferentes, usando os ratos C57BL6 como modelo de obesidade induzida pela dieta. Dois grupos de machos e fêmeas C57BL6 com cerca de 22-23 g foram incluídos no estudo. Durante 12 ou 16 semanas, um grupo foi alimentado com uma dieta rica em gordura (HFD, 45 % de lípidos, 20 % de proteínas e 35 % de hidratos de carbono) e o outro grupo com uma dieta padrão (SD, 13 % de lípidos, 20 % de proteínas e 67 % de hidratos de carbono). Depois de 12 e 16 semanas, os animais apresentavam, respetivamente, sobrepeso ou obesidade (15% e 45% de ganho de peso, respetivamente). Todos os animais foram sacrificados no final das intervenções dietéticas, sendo os tecidos adiposo visceral e subcutâneo (TAV e SAT) recolhidos para posterior análise. O número de adipócitos produtores de TH ou PNMT e a localização celular destas enzimas foram avaliados por imunohistoquímica. Os níveis de mRNA de ambas as enzimas foram avaliados por PCR quantitativo em tempo real. Neste estudo, os animais alimentados com a HFD apresentavam um aumento das áreas dos adipócitos nos tecidos VAT e SAT, em comparação com os alimentados com uma dieta padrão (SD). Além disso, ao contrário dos adipócitos subcutâneos, as áreas dos adipócitos viscerais aumentaram significativamente depois das 16 semanas, em comparação com as 12 semanas de tratamento dietético. Os ensaios de imunohistoquímica mostraram que tanto a TH como a PNMT são enzimas citoplasmáticas, estando localizadas na área perinuclear e ao longo da membrana celular. Os níveis proteicos destas duas enzimas foram afetados de forma diferente dependendo do tipo de dieta. O número de adipócitos que expressam TH diminuiu com a HFD, enquanto que o número de adipócitos que expressam PNMT aumentou, em comparação com o grupo da SD. Os níveis de proteína da TH apenas apresentaram diferenças significativas quando foi feita uma comparação global entre o VAT e o SAT, independentemente da dieta. De fato, nessas condições, o SAT apresentou um maior número de adipócitos que expressam TH em relação ao VAT. Por outro lado, enquanto que os dois tecidos adiposos expressaram níveis semelhantes de mRNA da PNMT, o VAT apresentou valores significativamente mais baixos de mRNA da TH em relação ao SAT. Em conclusão, os resultados obtidos com o presente estudo mostram que a expressão de ambas as enzimas, TH e PNMT, no tecido adiposo é dependente do tipo de dieta e é modulada de forma distinta nos tecidos adiposo visceral e subcutâneo