ABSTRACT
Neuronal networks are balanced by mechanisms of homeostatic plasticity, which adjusts synaptic strength via molecular and morphological changes in the pre- and post-synapse. Here, we wondered whether the hyaluronic acid-based extracellular matrix (ECM) of the brain is involved in mechanisms of homeostatic plasticity. We hypothesized that the ECM, being rich in chondroitin sulfate proteoglycans such as brevican, which are suggested to stabilize synapses by their inhibitory effect on structural plasticity, must be remodelled to allow for structural and molecular changes during conditions of homeostatic plasticity. We found a high abundance of cleaved brevican fragments throughout the hippocampus and cortex and in neuronal cultures, with the strongest labelling in perineuronal nets on parvalbumin-positive interneurons. Using an antibody specific for a brevican fragment cleaved by the matrix metalloprotease ADAMTS4, we identified the enzyme as the main brevican-processing protease. Interestingly, we found ADAMTS4 largely associated with synapses. After inducing homeostatic plasticity in neuronal cell cultures by prolonged network inactivation, we found increased brevican processing at inhibitory as well as excitatory synapses, which is in line with the ADAMTS4 subcellular localization. Thus, the ECM is remodelled in conditions of homeostatic plasticity, which may liberate synapses to allow for a higher degree of structural plasticity.
Subject(s)
Brain/physiology , Extracellular Matrix/physiology , Homeostasis/physiology , Hyaluronic Acid/metabolism , Models, Neurological , Neuronal Plasticity/physiology , Synapses/physiology , ADAM Proteins/metabolism , ADAMTS4 Protein , Blotting, Western , Brain/metabolism , Brevican/metabolism , Cell Fractionation , HEK293 Cells , Humans , Image Processing, Computer-Assisted , Immunohistochemistry , Procollagen N-Endopeptidase/metabolismABSTRACT
A longitudinal, observational prospective panel cohort study of 61 patients lasting one year was undertaken. Explanatory variables included sociodemographic factors along with factors related to the underlying pathology as well as the protocol used and the type of treatment received. These variables were analyzed both individually and in combination to account for confounding effects and model interactions. A generalized estimating equation (GEE) model was constructed for each adverse effect. Associations were calculated as odds ratios (OR). Confounding variables related to drug tolerability were identified. Follitropin-alpha and cetrorelix exhibited the poorest safety profile. With respect to local adverse drug reactions (ADEs), the results obtained in our study point to statistically significant tolerability improvements for menotropin when administered in insemination. For gastrointestinal ADEs, ganirelix was the drug that showed the highest tolerability in in vitro treatments whereas follitropin-alpha showed the lowest tolerability in insemination treatments. Diverse factors related to assisted reproduction techniques (ART) influence the incidence of adverse effects. Each drug has a different safety profile with possible interactions depending on the type of assisted reproduction therapy used.
Subject(s)
Fertility Agents, Female/adverse effects , Reproductive Techniques, Assisted/adverse effects , Adult , Female , Humans , Logistic Models , Longitudinal Studies , Multivariate Analysis , Odds Ratio , Patient Safety , Prospective Studies , Risk Assessment , Risk Factors , Spain , Young AdultABSTRACT
As BMPs (Bone Morphogenetic Proteins) são membros da superfamília de proteínas TGF-β (Transforming Growth Factor β ), regulam o crescimento e diferenciação de vários tipos celulares em diversos tecidos, e algumas delas desempenham um papel crítico na diferenciação de células de origem mesenquimal em osteoblastos. Particularmente, rhBMP2 e rhBMP7, promovem osteoindução tanto /"in vitro/" como /"in vivo,/" sendo, ambas as proteínas utilizadas terapeuticamente em Ortopedia/Odontologia para reparo ósseo. A expressão diferencial de genes durante a osteodiferenciação de células C2C12 induzida por rhBMP2 e rhBMP7, foi analisada através de microarranjos de DNA, selecionando 31 genes, dos quais 24 foram validados por qPCR, 13 dos quais são relacionados à transcrição, quatro associados a algumas vias de sinalização celular e sete associados à matriz extracelular. Análise funcional destes genes permitirá conhecer, com maiores detalhes, os eventos moleculares que ocorrem durante a diferenciação osteoblástica de células C2C12 induzida por rhBMPs. Em paralelo, foi perseguida a super-expressão de rhBMP2 e rhBMP7 em células HEK293T, demonstrando-se a atividade de rhBMP7, induzindo osteodiferenciação /"in vitro/" e formação de osso /"in vivo/", demonstrando a viabilidade do objetivo de se produzir estas proteínas para futura aplicação como biofármacos no Brasil.
The BMPs (Bone Morphogenetic Proteins) are members of the TGF-β (Transforming Growth Factor β) superfamily of proteins, regulate growth and differentiation of various cell types in various tissues, and some play a critical role in differentiation of mesenchymal cells into osteoblasts. Particularly, rhBMP2 and rhBMP7, promote osteoinduction /"in vitro/" and /"in vivo/" and both proteins are used therapeutically in Orthopedics and Dentistry. The differential expression of genes during osteodifferentiation induced by rhBMP2 and rhBMP7 in C2C12 cells was analyzed through DNA microarrays, allowing the selection of 31 genes, of which 24 were validated by qPCR, 13 of which are related to transcription, four associated with cell signaling pathways and seven are associated with the extracellular matrix. Subsequent functional analysis of these genes should reveal more details on the molecular events which take place during C2C12 cells osteoblastic differentiation induced by rhBMPs In paralel, rhBMPs 2 and 7 were overexpressed in HEK293T cells and BMP7 activity to induce osteodifferentiation /"in vitro/" and bone formation /"in vivo/" was demonstrated, reinforcing the viability of our objective to produce these proteins for future application as biopharmaceuticals in Brazil
