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A physics-based model for predicting cell culture fluid properties inside a stirred tank bioreactor with embedded PID controller logic is presented. The model evokes a time-accurate solution to the fluid velocity field and overall volumetric mass transfer coefficient, as well as the ongoing effects of interfacial mass transfer, species mixing, and aqueous chemical reactions. The modeled system also includes a direct coupling between process variables and system control variables via embedded controller logic. Satisfactory agreement is realized between the model prediction and measured bioreactor data in terms of the steady-state operating conditions and the response to setpoint changes. Simulation runtimes are suitable for industrial research and design timescales.
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Reatores Biológicos , Oxigênio , Oxigênio/química , Técnicas de Cultura de Células , Simulação por Computador , Concentração de Íons de HidrogênioRESUMO
OBJECTIVE: Neutrophil infiltration into the synovial joint is a hallmark of rheumatoid arthritis (RA), a disease characterised by progressive bone erosion. However, the mechanisms by which neutrophils participate in bone destruction remain unclear. Carbamylation is a posttranslational modification linked to increased bone erosion in RA and we previously showed that carbamylation is present in RA neutrophil extracellular traps (NETs). However, it remains unclear whether NETs and their carbamylated protein cargo directly promote bone destruction and alter osteoclast biology. METHODS: NETs and carbamylated NETs (cNETs) were assessed for their capacity to induce osteoclast formation in CD14+ monocytes. Chemical inhibitors and neutralising antibodies were used to elucidate the pathway by which NETs induce osteoclastogenesis. HLA-DRB1*04:01 mice received intra-articular injection of cNETs for 4 weeks. Joints were isolated and assessed for osteoclast formation. Plasma and synovial fluid samples from patients with RA (n=32) were assessed for the presence of carbamylated histone, and correlations to disease specific outcomes were performed. RESULTS: We found that NETs, when cNETs, instruct monocytes to undergo rapid osteoclast formation. NET-mediated osteoclastogenesis appears to depend on Toll-like receptor 4 signalling and NET-associated proteins including histones and neutrophil elastase. In vivo, we identified that the number of osteoclasts increased following immunisation with cNETs in HLA-DRB1*04:01 transgenic mice. Furthermore, carbamylated histones are increased in plasma and synovial fluid from patients with RA and correlate with active bone resorption and inflammatory markers. CONCLUSIONS: Our results suggest that NETs have a direct role in RA-associated bone erosion by promoting osteoclast formation.
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Artrite Reumatoide , Armadilhas Extracelulares , Camundongos , Animais , Histonas , Osteoclastos , Armadilhas Extracelulares/metabolismo , Carbamilação de ProteínasRESUMO
OBJECTIVES: Premature cardiovascular events in systemic lupus erythematosus (SLE) contribute to morbidity and mortality, with no effective preventive strategies described to date. Immune dysregulation and metabolic disturbances appear to play prominent roles in the induction of vascular disease in SLE. The peroxisome proliferator activated receptor-gamma agonist pioglitazone (PGZ suppresses vascular damage and immune dysregulation in murine lupus and improves endothelial dysfunction in other inflammatory diseases. We hypothesised that PGZ could improve vascular dysfunction and cardiometabolic parameters in SLE. METHODS: Eighty SLE subjects with mild to severe disease activity were randomised to a sequence of PGZ followed by placebo for 3 months, or vice versa, in a double-blind, cross-over design with a 2-month wash-out period. Primary endpoints were parameters of endothelial function and arterial inflammation, measured by multimodal assessments. Additional outcome measures of disease activity, neutrophil dysregulation, metabolic disturbances and gene expression studies were performed. RESULTS: Seventy-two subjects completed the study. PGZ was associated with a significant reduction in Cardio-Ankle Vascular Index (a measure of arterial stiffness) compared with placebo. Various metabolic parameters improved with PGZ, including insulin resistance and lipoprotein profiles. Circulating neutrophil extracellular trap levels also significantly decreased with PGZ compared with placebo. Most adverse events experienced while on PGZ were mild and resolved with reduction in PGZ dose. CONCLUSION: PGZ was well tolerated and induced significant improvement in vascular stiffness and cardiometabolic parameters in SLE. The results suggest that PGZ should be further explored as a modulator of cardiovascular disease risk in SLE. TRIAL REGISTRATION NUMBER: NCT02338999.
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As a key enzyme for glycolysis, lactate dehydrogenase (LDH) remains as a topic of great interest in cancer study. Though a number of kinetic models have been applied to describe the dynamic behavior of LDH, few can reflect its actual mechanism, making it difficult to explain the observed substrate and competitor inhibitions at wide concentration ranges. A novel mechanistic kinetic model is developed based on the enzymatic processes and the interactive properties of LDH. Better kinetic simulation as well as new enzyme interactivity information and kinetic properties extracted from published articles via the novel model was presented. Case studies were presented to a comprehensive understanding of the effect of temperature, substrate, and inhibitor on LDH kinetic activities for promising application in cancer diagnosis, inhibitor evaluation, and adequate drug dosage prediction.
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Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Simulação de Dinâmica Molecular , Neoplasias/diagnóstico , Neoplasias/enzimologia , Inibidores Enzimáticos/química , Humanos , Cinética , L-Lactato Desidrogenase/metabolismo , Neoplasias/metabolismo , TemperaturaRESUMO
OBJECTIVE: Systemic lupus erythematosus (SLE) increases cardiovascular disease (CVD) risk, and this is not explained by traditional risk factors. Characterization of blood immunologic signatures that associate with subclinical CVD and predict its progression has been challenging and may help identify subgroups at risk. METHODS: Patients with SLE (n = 77) and healthy controls (HCs) (n = 27) underwent assessments of arterial stiffness, vascular wall inflammation, and coronary atherosclerosis burden with cardio-ankle vascular index (CAVI); fluorodeoxyglucose-positron emission tomography/computed tomography (CT) (target-to-background ratio [TBR]); and coronary CT angiography. Whole blood bulk RNA sequencing was performed in a subset of study participants (HC n = 10, SLE n = 20). In a partially overlapping subset (HC n = 24, SLE n = 64), serum inflammatory protein biomarkers were quantified with an Olink platform. RESULTS: CAVI, TBR, and noncalcified coronary plaque burden (NCB) were increased in patients with SLE compared to HCs. When comparing patients with SLE with high CAVI scores to those with low CAVI scores or to HCs, there was a down-regulation of genes in pathways involved in the cell cycle and differentially regulated pathways related to metabolism. Distinct serum proteins associated with increased CAVI (CCL23, colony-stimulating factor 1, latency-activating peptide transforming growth factor ß1, interleukin 33 [IL-33], CD8A, and IL-12B), NCB (monocyte chemotactic protein 4 and FMS-like tyrosine kinase 3 ligand [Flt3L]), and TBR (CD5, IL-1α, AXIN1, cystatin D [CST5], and tumor necrosis factor receptor superfamily 9; P < 0.05). CONCLUSION: Blood gene expression patterns and serum proteins that associate with worse vascular phenotypes suggest dysregulated immune and metabolic pathways linked to premature CVD. Cytokines and chemokines identified in associations with arterial stiffness, inflammation, and NCB in SLE may allow for characterization of new CVD biomarkers in lupus.
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Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disorder characterized by abscess-like nodules and boils resulting in fistulas and tissue scarring. We previously reported evidence of an autoimmune signature in HS, characterized by enhanced neutrophil extracellular trap (NET) infiltration in HS skin lesions and dysregulation of the adaptive immune system characterized by the presence of autoantibodies. Timely removal of NETs is critical for tissue homeostasis to prevent a dysregulated generation of modified autoantigens and tissue damage. DNases 1 and 1L3 play important roles in proper NET removal. We tested the hypothesis that NETs in patients with HS are not effectively cleared owing to the presence of antibodies against DNase 1 and DNase 1L3. We report that HS serum poorly degraded NETs. Addition of exogenous DNase 1 restored NET degradation capabilities in a subset of HS samples. DNase 1 activity was significantly decreased in HS sera. AntiâDNase 1 and âDNase 1L3 antibodies were detected in serum samples and skin lesions from patients with HS. Purified IgGs from HS decreased DNase 1 activity and NET degradation. Taken together, this identification of neutralizing antibodies against nucleases in HS expands the understanding of the pathogenesis of this disease to support an autoimmune mechanism in its underlying pathogenesis.
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Armadilhas Extracelulares , Hidradenite Supurativa , Humanos , Hidradenite Supurativa/metabolismo , Desoxirribonucleases/metabolismo , Desoxirribonuclease I/metabolismo , Autoanticorpos/metabolismoRESUMO
The molecular mediators of cell death and inflammation in Alzheimer's disease (AD) have yet to be fully elucidated. Caspase-8 is a critical regulator of several cell death and inflammatory pathways; however, its role in AD pathogenesis has not yet been examined in detail. In the absence of caspase-8, mice are embryonic lethal due to excessive receptor interacting protein kinase 3-dependent (RIPK3-dependent) necroptosis. Compound RIPK3 and caspase-8 mutants rescue embryonic lethality, which we leveraged to examine the roles of these pathways in an amyloid ß-mediated (Aß-mediated) mouse model of AD. We found that combined deletion of caspase-8 and RIPK3, but not RIPK3 alone, led to diminished Aß deposition and microgliosis in the mouse model of AD carrying human presenilin 1 and amyloid precursor protein with 5 familial AD mutations (5xFAD). Despite its well-known role in cell death, caspase-8 did not appear to affect cell loss in the 5xFAD model. In contrast, we found that caspase-8 was a critical regulator of Aß-driven inflammasome gene expression and IL-1ß release. Interestingly, loss of RIPK3 had only a modest effect on disease progression, suggesting that inhibition of necroptosis or RIPK3-mediated cytokine pathways is not critical during midstages of Aß amyloidosis. These findings suggest that therapeutics targeting caspase-8 may represent a novel strategy to limit Aß amyloidosis and neuroinflammation in AD.
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Doença de Alzheimer , Amiloidose , Animais , Humanos , Camundongos , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Caspase 8/metabolismo , Modelos Animais de Doenças , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismoRESUMO
Systemic lupus erythematosus (SLE) often features extensive cardiovascular (CV) comorbidity and patients with SLE are at significantly increased risk of CV event occurrence and CV-related mortality. While the specific mechanisms leading to this increased cardiovascular disease (CVD) risk remain to be fully characterized, this heightened risk cannot be fully explained by traditional CV risk factors and is likely driven by immunologic and inflammatory features of SLE. Widespread innate and adaptive immune dysregulation characterize SLE, and factors including excessive type I interferon burden, inappropriate formation and ineffective clearance of neutrophil extracellular traps, and autoantibody formation have been linked to clinical and metabolic features impacting CV risk in SLE and may represent pathogenic drivers of SLE-related CVD. Indeed, functional and phenotypic aberrations in almost every immune cell type are present in SLE and may impact CVD progression. As understanding of the contribution of SLE-specific factors to CVD in SLE improves, improved screening and monitoring of CV risk alongside development of therapeutic treatments aimed at prevention of CVD in SLE patients are required and remain the focus of several ongoing studies and lines of inquiry.
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Doenças Cardiovasculares , Armadilhas Extracelulares , Lúpus Eritematoso Sistêmico , Autoanticorpos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Comorbidade , Humanos , Lúpus Eritematoso Sistêmico/complicações , Fatores de RiscoRESUMO
Objective: Antibodies against carbamylated proteins (anti-CarP) are associated with poor prognosis and the development of bone erosions in rheumatoid arthritis (RA). RA neutrophils externalize modified autoantigens through the formation of neutrophil extracellular traps (NETs). Increased levels of the cathelicidin LL37 have been documented in the synovium of RA patients, but the cellular source remains unclear. We sought to determine if post-translational modifications of LL37, specifically carbamylation, occur during NET formation, enhance this protein's autoantigenicity, and contribute to drive bone erosion in the synovial joint. Methods: ELISA and Western blot analyses were used to identify carbamylated LL37 (carLL37) in biological samples. Anti-carLL37 antibodies were measured in the serum of HLA-DRB1*04:01 transgenic mice and in human RA synovial fluid. Results: Elevated levels of carLL37 were found in plasma and synovial fluid from RA patients, compared to healthy controls. RA NETs release carLL37 and fibroblast-like synoviocytes (FLS) internalized NET-bound carLL37 and loaded it into their MHCII compartment. HLA-DRB1*04:01 transgenic mice immunized with FLS containing NETs developed autoantibodies against carLL37. Anti-carLL37 antibodies were present in RA sera and synovial fluid and they correlated with radiologic bone erosion scores of the hands and feet in RA patients. CarLL37-IgG immune complexes enhanced the ability of monocytes to differentiate into osteoclasts and potentiated osteoclast-mediated extracellular matrix resorption. Conclusions: NETs are a source of carLL37 leading to induction of anti-carbamylated autoantibody responses. Furthermore, carLL37-IgG immune complexes may be implicated in the bone damage characteristic of RA. These results support that dysregulated NET formation has pathogenic roles in RA.
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Artrite Reumatoide/etiologia , Artrite Reumatoide/patologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Reabsorção Óssea/imunologia , Reabsorção Óssea/patologia , Catelicidinas/imunologia , Animais , Artrite Reumatoide/metabolismo , Reabsorção Óssea/metabolismo , Armadilhas Extracelulares/imunologia , Humanos , Camundongos , Osteoclastos/imunologia , Osteoclastos/metabolismo , Líquido Sinovial/imunologia , Sinoviócitos/imunologia , Sinoviócitos/metabolismo , Sinoviócitos/patologiaRESUMO
Process intensification has shown great potential to increase productivity and reduce costs in biomanufacturing. This case study describes the evolution of a manufacturing process from a conventional processing scheme at 1000-L scale (Process A, n = 5) to intensified processing schemes at both 1000-L (Process B, n = 8) and 2000-L scales (Process C, n = 3) for the production of a monoclonal antibody by a Chinese hamster ovary cell line. For the upstream part of the process, we implemented an intensified seed culture scheme to enhance cell densities at the seed culture step (N-1) prior to the production bioreactor (N) by using either enriched N-1 seed culture medium for Process B or by operating the N-1 step in perfusion mode for Process C. The increased final cell densities at the N-1 step allowed for much higher inoculation densities in the production bioreactor operated in fed-batch mode and substantially increased titers by 4-fold from Process A to B and 8-fold from Process A to C, while maintaining comparable final product quality. Multiple changes were made to intensify the downstream process to accommodate the increased titers. New high-capacity resins were implemented for the Protein A and anion exchange chromatography (AEX) steps, and the cation exchange chromatography (CEX) step was changed from bind-elute to flow-through mode for the streamlined Process B. Multi-column chromatography was developed for Protein A capture, and an integrated AEX-CEX pool-less polishing steps allowed semi-continuous Process C with increased productivity as well as reductions in resin requirements, buffer consumption, and processing times. A cost-of-goods analysis on consumables showed 6.7-10.1 fold cost reduction from the conventional Process A to the intensified Process C. The hybrid-intensified process described here is easy to implement in manufacturing and lays a good foundation to develop a fully continuous manufacturing with even higher productivity in the future.
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Anticorpos Monoclonais/metabolismo , Reatores Biológicos/economia , Biotecnologia/organização & administração , Animais , Biotecnologia/economia , Células CHO , Técnicas de Cultura de Células , Proliferação de Células , Custos e Análise de Custo , Cricetinae , Cricetulus , Eficiência , Humanos , Invenções , Modelos EconômicosRESUMO
Increasing cell culture productivity of recombinant proteins via process improvements is the primary focus for research groups within biologics manufacturing. Any recommendations to improve a manufacturing process obviously must be effective, but also be robust, scalable, and with product quality comparable to the original process. In this study, we report that three different GS-/- CHO cell lines developed in media containing a standard concentration of the selection agent methionine sulfoximine (MSX), but then exposed to increased MSX concentrations during seed train expansion, achieved titer increases of 10-19%. This result was observed in processes already considerably optimized. Expanding the cells with a higher MSX concentration improved cell line production stability with increased culture age. Production cultures in 500-L and 1000-L bioreactors replicated laboratory results using 5-L bioreactors, demonstrating process robustness and scalability. Furthermore, product quality attributes of the final drug substance using the higher MSX process were comparable with those from cells expanded in media with the standard selection MSX concentration. Subsequent mechanistic investigations confirmed that the cells were not altered at the genetic level in terms of integration profiles or gene copy number, nor transcriptional levels of glutamine synthetase, heavy chain, or light chain genes. This study provides an effective and applicable strategy to improve the productivity of therapeutic proteins for biologics manufacturing.
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Although process intensification by continuous operation has been successfully applied in the chemical industry, the biopharmaceutical industry primarily uses fed-batch, rather than continuous or perfusion methods, to produce stable monoclonal antibodies (mAbs) from Chinese hamster ovary (CHO) cells. Conventional fed-batch bioreactors may start with an inoculation viable cell density (VCD) of ~0.5 × 106 cells/mL. Increasing the inoculation VCD in the fed-batch production bioreactor (referred to as N stage bioreactor) to 2-10 × 106 cells/mL by introducing perfusion operation or process intensification at the seed step (N-1 step) prior to the production bioreactor has recently been used because it increases manufacturing output by shortening cell culture production duration. In this study, we report that increasing the inoculation VCD significantly improved the final titer in fed-batch production within the same 14-day duration for 3 mAbs produced by 3 CHO GS cell lines. We also report that other non-perfusion methods at the N-1 step using either fed batch or batch mode with enriched culture medium can similarly achieve high N-1 final VCD of 22-34 × 106 cells/mL. These non-perfusion N-1 seeds supported inoculation of subsequent production fed-batch production bioreactors at increased inoculation VCD of 3-6 × 106 cells/mL, where these achieved titer and product quality attributes comparable to those inoculated using the perfusion N-1 seeds demonstrated in both 5-L bioreactors, as well as scaled up to 500-L and 1000-L N-stage bioreactors. To operate the N-1 step using batch mode, enrichment of the basal medium was critical at both the N-1 and subsequent intensified fed-batch production steps. The non-perfusion N-1 methodologies reported here are much simpler alternatives in operation for process development, process characterization, and large-scale commercial manufacturing compared to perfusion N-1 seeds that require perfusion equipment, as well as preparation and storage vessels to accommodate large volumes of perfusion media. Although only 3 stable mAbs produced by CHO cell cultures are used in this study, the basic principles of the non-perfusion N-1 seed strategies for shortening seed train and production culture duration or improving titer should be applicable to other protein production by different mammalian cells and other hosts at any scale biologics facilities.
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Anticorpos Monoclonais/biossíntese , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , Animais , Células CHO , Cricetulus , HumanosRESUMO
OBJETIVO: Analisar a tomografia computadorizada e a broncoscopia no diagnóstico do câncer pulmonar e verificar a eficácia destas técnicas perante a presença desta doença. Os parâmetros idade, gênero, hábitos tabágicos, tipos histológicos, estadiamento e terapêutica foram, igualmente, analisados. MATERIAIS E MÉTODOS: Foram analisados 70 pacientes do Serviço de Pneumologia do Hospital Distrital da Figueira da Foz, Coimbra, Portugal, que realizaram ambas as técnicas em estudo, tendo-se confirmado ou não a presença de câncer pulmonar. RESULTADOS: Diagnosticaram-se 37 tumores pulmonares, 23 casos no gênero masculino e 14 no feminino. Histologicamente, 40,54 por cento eram adenocarcinomas, seguido do carcinoma escamoso (32,43 por cento dos casos) e do carcinoma de pequenas células (18,92 por cento). O estadiamento mostrou 6,70 por cento no estádio IB, 23,30 por cento no estádio IIIA comparativamente ao IIIB com 36,70 por cento, encontrando-se 33,30 por cento dos doentes no estádio IV. A quimioterapia isolada foi efetuada em 75,7 por cento dos doentes. A sensibilidade da broncoscopia foi de 83,8 por cento, a especificidade, de 81,8 por cento, e a precisão, de 82,8 por cento. A sensibilidade da tomografia computadorizada foi de 81,1 por cento, a especificidade, de 63,6 por cento, e a precisão, de 72,8 por cento. CONCLUSÃO: Os resultados da broncoscopia confirmaram a sua importância no diagnóstico do câncer pulmonar, pela dependência deste no exame anatomopatológico do tecido ou células, obtido por várias técnicas de biópsia. A tomografia computadorizada apresentou boa sensibilidade, de 81,1 por cento, contudo, a sua especificidade, de apenas 63,6 por cento, resulta do número de falso-positivos (36,4 por cento).
OBJECTIVE: To analyze the role of computed tomography and bronchoscopy in the diagnosis of lung cancer, evaluating the effectiveness of these techniques in the presence of this disease. Parameters such as age, gender, smoking habits, histological types, staging and treatment were also analyzed. MATERIALS AND METHODS: The sample of the present study included 70 patients assisted at the Department of Pneumology of Hospital Distrital da Figueira da Foz, Coimbra, Portugal, who were submitted to both diagnostic methods, namely, computed tomography and bronchoscopy, to confirm the presence or the absence of lung cancer. RESULTS: Thirty-seven patients (23 men and 14 women) were diagnosed with lung cancer. Histologically 40.54 percent were adenocarcinoma, followed by squamous carcinoma (32.43 percent cases) and small-cell lung cancer (18.92 percent). Staging showed 6.70 percent stage IB disease, 23.30 percent stage IIIA and 36.70 percent stage IIIB, and 33.30 percent stage IV. Chemotherapy alone was the first treatment of choice for 75.7 percent of patients. Bronchoscopy sensitivity was 83.8 percent, specificity 81.8 percent, and accuracy 82.8 percent. Computed tomography sensitivity was 81.1 percent, specificity 63.6 percent, and accuracy 72.8 percent. CONCLUSION: Bronchoscopy results corroborated the relevance of the method in the diagnosis of lung cancer, considering its dependence on the anatomopathological study of tissue or cells obtained through different biopsy techniques. Computed tomography presented good sensitivity (81.1 percent), however the specificity of only 63.6 percent is related to the rate of false-positive results (36.4 percent).