Study of anabolic effect of human parathyroid hormone (1-340 in culture of osteoblasts induced to apoptosis

Orientadores: Silvana Pereira Barros, Decio dos Santos Pinto JuniorTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Muitas pesquisas a respeito do paratormônio (PTH) têm demonstrado que o efeito anabólico (neoformativo) desse peptídeo sobre o tecido ósseo, quando administrado de um modo intermitente, resulta na indução de nódulos de mineralização em cultura de osteoblastos, deposição óssea e aumento da resistência a fraturas em todo o esqueleto. Frente a esses possíveis benefícios, o PTH foi aprovado recentemente pela US Food & Drug Administration (FDA) com o nome genérico de Teriparatide e com o nome comercial de Forteo® (Lilly) que já está sendo comercializado para o tratamento da osteoporose, mas, no entanto ainda vem suscitando grande interesse na comunidade científica, uma vez que o seu complexo mecanismo de ação não está totalmente esclarecido. Relatos científicos indicam que parte do anabolismo do PTH se deve a diferenciação e proliferação dos osteoblastos, aumentando significativamente o número destas células, e parte a um efeito inibidor da apoptose nos osteoblastos. O presente estudo investigou in vitro a capacidade anti-apoptótica do hPTH(1-34) em osteoblastos induzidos à apoptose pelo TNF-a, elegendo como modelo de estudo o cultivo de osteoblastos de calvária de rato. As células foram cultivadas em MEM- a, suplementado com SFB, ácido ascórbico, ß-glicerofosfato e gentamicina, e foram divididas em grupos experimentais que receberam tratamentos diferentes. No grupo I, as células foram induzidas à apoptose, recebendo tratamento com o TNF-a; no grupo II, as células não foram induzidas à apoptose e receberam tratamento intermitente com o hPTH(1-34); no grupo III, as células foram induzidas à apoptose e receberam tratamento com o hPTH(1-34); e no grupo IV, as células não foram induzidas à apoptose e não receberam tratamento com o PTH (controle). Para a detecção da apoptose foram empregados os métodos de exclusão por marcação com o corante azul de Trypan (câmara de Neubauer) e a citometria de fluxo (FACSCalibur). Os resultados obtidos foram submetidos à análise estatística que demonstrou que o tratamento intermitente com o PTH inibiu a apoptose em torno de 60% nos osteoblastos induzidos pelo TNF-a, aumentando, desta forma, o número de osteoblastosAbstract: It is still not clear why sustained elevation of parathyroid hormone (PTH) stimulates bone resorption, whereas intermittent administration stimulates bone formation. Intermittent PTH administration was recently approved by the United States Food and Drug Administration as the first form of osteoporosis therapy that increases bone mass de novo, reverses the bone deficit, providing a proof-of-principle that osteoblast-targeted (anabolic) agents can effectively reduce osteoporotic fractures. Considering indications that attenuation of osteoblast apoptosis by daily injections of PTH in mice should account for the increased number of osteoblasts and, thereby, the increased bone formation produced by this treatment regimen, in the present study we aimed to investigate the anti-apoptotic ability of hPTH (1-34) in cultured osteoblastic cells through induction by TNF-a in association with PTH anabolic treatment using a calvariaderived osteoblastic cell line. Cells were cultured in MEM-a, supplemented with FBS, ascorbic acid, ß-glycerphosphate and gentamicin, and were divided in experimental groups that received different treatments. In group I, cells were induced to apoptosis, receiveing treatment with TNF-a; in group II, cells were not induced to apoptosis and received intermittent treatment with hPTH(1-34); in group III, cells were induced to apoptosis and received intermittent treatment with hPTH(1-34); and in group IV, cells were not induced to apoptosis and didn¿t receive intermittent treatment with hPTH(1-34) (control). For determination of cell death, two methods were used: staining with Trypan Blue and flow cytometry. The results were statistically analyzed and demonstrated that intermittent treatment with hPTH(1-34) was able to inhibit apoptosis induction by 60%, thereby increasing osteoblast number even in the presence of TNF-aDoutoradoHistologia e EmbriologiaDoutor em Biologia Buco-Denta

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora