RESUMO
The neutralization of tumor necrosis factor alpha (TNFα) with biopharmaceuticals is a successful therapy for inflammatory diseases. Currently, one of the main TNFα-antagonists is Etanercept, a dimeric TNF-R2 ectodomain. Considering that TNFα and its receptors are homotrimers, we proposed that a trimeric TNF-R2 ectodomain could be an innovative TNFα-antagonist. Here, the 3cTNFR2 protein was designed by the fusion of the TNF-R2 ectodomain with the collagen XV trimerization domain. 3cTNFR2 was produced in HEK293 cells and purified by immobilized metal affinity chromatography. Monomers, dimers, and trimers of 3cTNFR2 were detected. The interaction 3cTNFR2-TNFα was assessed. By microscale thermophoresis, the KD value for the interaction was 4.17 ± 0.88 nM, and complexes with different molecular weights were detected by size exclusion chromatography-high performance liquid chromatography. Moreover, 3cTNFR2 neutralized the TNFα-induced cytotoxicity totally in vitro. Although more studies are required to evaluate the anti-inflammatory effect, the results suggest that 3cTNFR2 could be a TNFα-antagonist agent.
Assuntos
Anti-Inflamatórios/farmacologia , Colágeno/genética , Endotoxinas/antagonistas & inibidores , Etanercepte/farmacologia , Receptores Tipo II do Fator de Necrose Tumoral/genética , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Colágeno/metabolismo , Endotoxinas/metabolismo , Endotoxinas/toxicidade , Etanercepte/química , Etanercepte/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Engenharia de Proteínas/métodos , Multimerização Proteica , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/toxicidadeRESUMO
Vascular endothelial growth factor (VEGF) has essential functions in angiogenesis, endothelial cell proliferation, migration, and tumor invasion. Different approaches have been developed to suppress tumor angiogenesis, which is considered a hallmark of cancer. Anti-VEGF monoclonal antibodies constitute an important strategy for cancer immunotherapy, which has been produced on several platforms. In this study, a novel single-chain anti-VEGF monoclonal antibody (scVEGFmAb) was produced in the goat mammary gland by adenoviral transduction. scVEGFmAb was purified by affinity chromatography. N-glycans were analyzed by exoglycosidase digestion and hydrophilic interaction ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry. The biological activity of scVEGFmAb was assessed by scratch and mouse aortic ring assays. scVEGFmAb was produced at 0.61 g/L in the goat milk, and its purification rendered 95 % purity. N-glycans attached to scVEGFmAb backbone were mainly neutral biantennary core fucosylated with Galß1,4GlcNAc motif, and charged structures were capped with Neu5Ac and Neu5Gc. The chimeric molecule significantly prevented cell migration and suppressed microvessel sprouting. These results demonstrated for the first time the feasibility of producing an anti-VEGF therapeutic antibody in the milk of non-transgenic goats with the potential to counteract tumor angiogenesis.
Assuntos
Leite , Fator A de Crescimento do Endotélio Vascular , Animais , Proliferação de Células , Cabras , Camundongos , Polissacarídeos , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
E-selectin is a cell-adhesion receptor with specific recognition capacity toward sialo-fucosylated Lewis carbohydrates present in leukocytes and tumor cells. E-selectin interactions mediate the progress of inflammatory processes and tumor metastasis, which aroused the interest in using this protein as a biomolecular target to design glycomimetic inhibitors for active targeting or therapeutic purposes. In this work, we report the rational discovery of two novel glycomimetic peptides targeting E-selectin based on mutations of the reference selectin-binding peptide IELLQAR. Sixteen single or double mutants at Ile1, Leu3, Leu4, and Arg7 residues were evaluated as potential candidates for E-selectin targeting using 50 ns molecular dynamics (MD) simulations. Nine peptides showing a stable association with the functional pocket were modified by adding a cysteine residue to the N-terminus to confer versatility for further chemical conjugation. Subsequent 50 ns MD simulations resulted in five cysteine-modified peptides with retained or improved E-selectin binding potential. Then, 300 ns accelerated MD (aMD) simulations were used to examine the binding properties of the best five cysteine-modified peptides. CIEELQAR and CIELFQAR exhibit the most selective association with the functional pocket of E-selectin, as revealed by potential of mean force profiles. Microscale thermophoresis experiments confirmed the E-selectin binding capacity of the selected peptides with KD values in the low micromolar range (CIEELQAR KD = 35.0 ± 1.4 µM; CIELFQAR KD = 16.4 ± 0.7 µM), which are 25-fold lower than the reported value for the native ligand sLex (KD = 878 µM). Our findings support the potential of CIEELQAR and CIELFQAR as novel E-selectin-targeting peptides with high recognition capacity and versatility for chemical conjugation, which are critical for enabling future applications in active targeting.
Assuntos
Selectina E , Peptídeos , Adesão Celular , Ligantes , Antígeno Sialil Lewis XRESUMO
In Latin America, one of the key tasks of Community and Liberation Psychology has been to recover the memories of marginalized and excluded communities that have experienced multiple pasts marked by political violence. In Chile, researchers have focused on poor urban neighborhoods, where the question of how memories are transmitted in areas where conflicts and violence are still present has been overlooked. In this context, the following article aims to analyze the ways in which memories are transmitted in a neighborhood that has a long organizational history in the struggle against social inequalities; while at the same time being classified as a critical area by the state due to its current levels of violence and social conflict. The researchers led a 3-year case study from an ethnographic perspective, and applied a collaborative methodology that brought together the research team and the members of a territorial organization. The analysis is based on 72 interviews, 5 conversation groups and ethnographic observation. The data was analyzed using discourse analysis. The results revealed that the main form of memory transmission is not based on intergenerational narratives of the past, but rather on joint action; namely, dialogical practices among neighborhood residents that generate an ethos; a common way of life.
Assuntos
Características de Residência , Violência , Chile , Humanos , Fatores SocioeconômicosRESUMO
Glutamate exerts its actions through the activation of membrane receptors expressed in neurons and glia cells. The signaling properties of glutamate transporters have been characterized recently, suggesting a complex array of signaling transactions triggered by presynaptic released glutamate. In the cerebellar molecular layer, glutamatergic synapses are surrounded by Bergmann glia cells, compulsory participants of glutamate turnover and supply to neurons. Since a glutamate-dependent increase in cGMP levels has been described in these cells and the nitric oxide-cGMP signaling cascade increases their glutamate uptake activity, we describe here the Bergmann glia expression of neuronal nitric oxide synthetase. An augmentation of neuronal nitric oxide synthase was found upon glutamate exposure. This effect is mediated by glutamate transporters and is related to an increase in the stability of the enzyme. These results strengthen the notion of a complex regulation of glial glutamate uptake that supports neuronal glutamate signaling.
Assuntos
Cerebelo/metabolismo , Ácido Glutâmico/metabolismo , Neuroglia/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Células Cultivadas , Embrião de Galinha , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVE: Although clinical reports have described medial meniscal subluxation (MMS) in knee OA, few controlled studies have used dynamic US to examine the potential impact of MMS on OA. The aim of this study was to assess MMS in patients with knee OA and in asymptomatic controls by US in different weight-bearing positions. METHODS: In a cross-sectional controlled study, MMS was evaluated by US in 33 symptomatic OA knees and in 13 control knees in supine neutral and unipodal weight-bearing positions. The reproducibility of US in this setting was assessed and the US measurements were compared between patients and controls. RESULTS: MMS was observed more frequently in OA knees than in controls in the unipodal weight-bearing position both before (P = 0.014) and after (P = 0.035) walking 50 m. In both OA and control knees, an increase in MMS was observed in the unipodal weight-bearing positions compared with the supine neutral position, but this increase was greater in OA knees than in controls (P < 0.001). CONCLUSION: Our findings confirm clinical observations that the medial meniscus undergoes significant subluxation in knee OA. The degree of subluxation is greater in weight-bearing than in non-weight-bearing positions. Dynamic US is a reproducible method for the assessment of MMS.