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1.
Surg Radiol Anat ; 46(3): 271-283, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38374441

RESUMO

PURPOSE: Endoscopic third ventriculostomy (ETV) is a surgical procedure that can lead to complications and requires detailed preoperative planning. This study aimed to provide a more accurate understanding of the anatomy of the third ventricle and the location of important structures to improve the safety and success of ETV. METHODS: We measured the stereotactic coordinates of six points of interest relative to a predefined stereotactic reference point in 23 cadaver brain hemi-sections, 200 normal brain magnetic resonance imaging (MRI) scans, and 24 hydrocephalic brain MRI scans. The measurements were statistically analyzed, and comparisons were made. RESULTS: We found some statistically significant differences between genders in MRIs from healthy subjects. We also found statistically significant differences between MRIs from healthy subjects and both cadaver brains and MRIs with hydrocephalus, though their magnitude is very small and not clinically relevant. Some stereotactic points were more posteriorly and inferiorly located in cadaver brains, particularly the infundibular recess and the basilar artery. It was found that all stereotactic points studied were more posteriorly located in brains with hydrocephalus. CONCLUSION: The study describes periventricular structures in cadaver brains and MRI scans from healthy and hydrocephalic subjects, which can guide neurosurgeons in planning surgical approaches to the third ventricle. Overall, the study contributes to understanding ETV and provides insights for improving its safety and efficacy. The findings also support that practicing on cadaveric brains can still provide valuable information and is valid for study and training of neurosurgeons unfamiliar with the ETV technique.


Assuntos
Hidrocefalia , Neuroendoscopia , Terceiro Ventrículo , Humanos , Masculino , Feminino , Terceiro Ventrículo/diagnóstico por imagem , Terceiro Ventrículo/cirurgia , Neuroendoscopia/métodos , Encéfalo , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/cirurgia , Hidrocefalia/patologia , Ventriculostomia/métodos , Cadáver , Resultado do Tratamento , Estudos Retrospectivos
2.
J Foot Ankle Res ; 16(1): 80, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37957735

RESUMO

BACKGROUND: The heel is a complex anatomical region and is very often the source of pain complaints. The medial heel contains a number of structures, capable of compressing the main nerves of the region and knowing its anatomical topography is mandatory. The purpose of this work is to evaluate if tibial nerve (TN) and its main branches relate to the main anatomical landmarks of the ankle's medial side and if so, do they have a regular path after emerging from TN. METHODS: The distal part of the legs, ankles and feet of 12 Thiel embalmed cadavers were dissected. The pattern of the branches of the TN was registered and the measurements were performed according to the Dellon-McKinnon malleolar-calcaneal line (DML) and the Heimkes Triangle (HT). RESULTS: The TN divided proximal to DML in 87.5%, on top of the DML in 12,5% and distal in none of the feet. The Baxter's nerve (BN) originated proximally in 50%, on top of the DML in 12,5% and distally in 37.5% of the cases. There was a strong and significant correlation between the length of DML and the distance from the center of the medial malleolus (MM) to the lateral plantar nerve (LPN), medial plantar (MPN) nerve, BN and Medial Calcaneal Nerve (MCN) (ρ: 0.910, 0.866, 0.970 and 0.762 respectively, p <  0.001). CONCLUSIONS: In our sample the TN divides distal to DML in none of the cases. We also report a strong association between ankle size and the distribution of the MPN, LPN, BN and MCN. We hypothesize that location of these branches on the medial side of the ankle could be more predictable if we take into consideration the distance between the MM and the medial process of the calcaneal tuberosity.


Assuntos
Calcâneo , Síndrome do Túnel do Tarso , Humanos , Tornozelo , Pé/inervação , Calcâneo/anatomia & histologia , Calcanhar
3.
J Big Data ; 10(1): 83, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37274443

RESUMO

Big data has a substantial role nowadays, and its importance has significantly increased over the last decade. Big data's biggest advantages are providing knowledge, supporting the decision-making process, and improving the use of resources, services, and infrastructures. The potential of big data increases when we apply it in real-time by providing real-time analysis, predictions, and forecasts, among many other applications. Our goal with this article is to provide a viewpoint on how to build a system capable of processing big data in real-time, performing analysis, and applying algorithms. A system should be designed to handle vast amounts of data and provide valuable knowledge through analysis and algorithms. This article explores the current approaches and how they can be used for the real-time operations and predictions.

4.
Adv Sci (Weinh) ; 10(24): e2300588, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37340602

RESUMO

Alterations of the glycosylation machinery are common events in cancer, leading to the synthesis of aberrant glycan structures by tumor cells. Extracellular vesicles (EVs) play a modulatory role in cancer communication and progression, and interestingly, several tumor-associated glycans have already been identified in cancer EVs. Nevertheless, the impact of 3D tumor architecture in the selective packaging of cellular glycans into EVs has never been addressed. In this work, the capacity of gastric cancer cell lines with differential glycosylation is evaluated in producing and releasing EVs when cultured under conventional 2D monolayer or in 3D culture conditions. Furthermore, the proteomic content is identified and specific glycans are studied in the EVs produced by these cells, upon differential spatial organization. Here, it is observed that although the proteome of the analyzed EVs is mostly conserved, an EV differential packaging of specific proteins and glycans is found. In addition, protein-protein interaction and pathway analysis reveal individual signatures on the EVs released by 2D- and 3D-cultured cells, suggesting distinct biological functions. These protein signatures also show a correlation with clinical data. Overall, this data highlight the importance of tumor cellular architecture when assessing the cancer-EV cargo and its biological role.


Assuntos
Vesículas Extracelulares , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/metabolismo , Proteômica , Vesículas Extracelulares/metabolismo , Linhagem Celular , Polissacarídeos/metabolismo
5.
J Perinat Med ; 51(7): 896-903, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37163520

RESUMO

OBJECTIVES: Analyze the diagnostic and prognostic value of the sFlt-1/PlGF ratio in pregnant women with at least one sign/symptom of suspected/diagnosed pre-eclampsia. METHODS: This retrospective observational study included 170 pregnant women with at least one sign/symptom of pre-eclampsia, who had sFlt-1/PlGF ratio values. The following information was evaluated: pregnant women's demographic data and clinical history; laboratory data (urine protein/creatinine ratio; sFlt-1/PlGF ratio); signs and symptoms presented; clinical outcome; fetal complications; data related to childbirth. Statistical analysis was performed by R Software Version 3.5.2. RESULTS: Among the 170 patients, 78 presented pre-eclampsia. The median sFlt-1/PlGF ratio was significantly higher [143.1 (2.2-2,927.1)] for women who presented pre-eclampsia than for women without pre-eclampsia [33.5 (0.8-400.2)]. The negative predictive value of sFlt-1/PlGF ratio <38 was 83.9 % (95 % CI, 71.7-92.4 %) and the positive predictive value of sFlt-1/PlGF ratio >85 or 110 (for late onset pre-eclampsia) was 76.4 % (95 % CI, 66.2-84.8 %). sFlt-1/PlGF >85 or 110 was associated with pre-eclampsia clinical development, fetal complications, shorter gestational age at birth, higher number of caesarean deliveries and lower birth weight. CONCLUSIONS: The sFlt-1/PlGF ratio, together with the standard diagnostic criteria, can be used to rule out pre-eclampsia, identify high-risk patients and predict the occurrence of adverse outcomes.


Assuntos
Pré-Eclâmpsia , Feminino , Humanos , Recém-Nascido , Gravidez , Biomarcadores/metabolismo , Obstetrícia , Fator de Crescimento Placentário , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/metabolismo , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular
6.
Proc Natl Acad Sci U S A ; 120(20): e2214853120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155874

RESUMO

Gastric cancer is a dominating cause of cancer-associated mortality with limited therapeutic options. Here, we show that syndecan-4 (SDC4), a transmembrane proteoglycan, is highly expressed in intestinal subtype gastric tumors and that this signature associates with patient poor survival. Further, we mechanistically demonstrate that SDC4 is a master regulator of gastric cancer cell motility and invasion. We also find that SDC4 decorated with heparan sulfate is efficiently sorted in extracellular vesicles (EVs). Interestingly, SDC4 in EVs regulates gastric cancer cell-derived EV organ distribution, uptake, and functional effects in recipient cells. Specifically, we show that SDC4 knockout disrupts the tropism of EVs for the common gastric cancer metastatic sites. Our findings set the basis for the molecular implications of SDC4 expression in gastric cancer cells and provide broader perspectives on the development of therapeutic strategies targeting the glycan-EV axis to limit tumor progression.


Assuntos
Neoplasias Gástricas , Sindecana-4 , Humanos , Heparitina Sulfato/metabolismo , Invasividade Neoplásica , Neoplasias Gástricas/genética , Sindecana-4/genética , Sindecana-4/metabolismo
8.
Front Vet Sci ; 10: 1144227, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37035809

RESUMO

Four pet rabbits (Oryctolagus cuniculus cuniculus) diagnosed with a fatal infection by rabbit hemorrhagic disease virus (RHDV GI.2) were identified in the same week and further investigated. All animals lived in an urban environment (Lisbon, Portugal), were between 8 months and 2 years old and none had been vaccinated against RHDV2 (GI.2). Three animals arrived at the clinic and died shortly afterward and it was only possible to collect material for RT-qPCR (RHDV) test. These rabbits tested positive for RHDV2, with high viral loads. In the fourth case, additional clinical and post-mortem gross and histological evaluations were performed. This 8 month old intact female indoor pet rabbit was presented with apathy, tachypnea and tachycardia. Radiographic projections revealed no clinical revealed no clinical abnormalities. Serum biochemistry revealed a significant increase in AST and ALT with a small hypoglycemia. Abdominal ultrasound revealed an acute hepatitis. Despite hospitalization support, after 30 h of admission, the rabbit lost consciousness and developed anorexia and pyrexia in the last minutes before death. Post-mortem analysis and molecular testing by RT-qPCR, confirmed the diagnosis of RHDV2 (GI.2) infection also with high viral load. In conclusion, this paper reports a case series that demonstrates the severe infectious ability and the high mortality associated with RHDV even in rabbits from urban environments. Furthermore, it highlights the importance of always considering rabbit hemorrhagic disease (RHD) as a differential diagnosis in pet rabbits with non-specific clinical signs, and should warn veterinarians that pet rabbits living indoors can also be infected with a fatal outcome.

9.
10.
Front Pharmacol ; 13: 914886, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35910353

RESUMO

Soil-transmitted helminths are intestinal worm diseases transmitted through the soil. Available treatments are albendazole and/or ivermectin. The co-administration of existing drugs is an appropriate strategy. A fixed-dose combination adds practical advantages mainly considering mass drug administration. The aim is to characterize pharmacokinetics and to evaluate the comparative bioavailability of an innovative fixed-dose combination of ivermectin/albendazole 18/400 mg compared with the marketed references. Seventy-eight healthy volunteers were included in this laboratory-blinded, randomized, three-treatment, three-period crossover study. Each subject received a single dose of ivermectin/albendazole 18/400 mg (1 tablet); ivermectin 3 mg (6 tablets); and albendazole 400 mg (1 tablet). Serial blood samples for the pharmacokinetic analysis were obtained pre-dose and up to 72 h post-dose. Plasma concentrations of ivermectin H2B1a, ivermectin H2B1b, albendazole, and albendazole sulfoxide were analyzed by LC-MS/MS. Pharmacokinetic parameters were estimated by a non-compartmental analysis and bioavailability compared through a bioequivalence analysis. Safety and tolerability were assessed throughout the study. Main pharmacokinetic parameters of the fixed combination were estimated for both, ivermectin [Cmax (mean, confidence interval): 86.40 (30.42-39.23) ng/ml; AUC0-72 (mean, CI): 1,040 (530-1,678) ng·h/mL; tmax (median, min., and max.); 4.50 (2.50-5.50)] and albendazole [Cmax (mean, CI): 22.27 (1.89-111.78) ng/ml; AUC0-72 (mean, CI): 94.65 (11.65-507.78) ng·h/mL; tmax (median, min., and max.): 2.50 (1.00-12.00) h]. The 90% confidence interval of the geometric mean ratios demonstrated the bioequivalence in the case of ivermectin (Cmax: 110.68%-120.49%; AUC0-72: 110.46%-119.60%) but not in the case of albendazole (Cmax: 53.10%-70.34%; AUC0-72: 61.13%-76.54%). The pharmacokinetic profile of a new fixed-dose combination of ivermectin and albendazole was characterized. The bioequivalence versus the reference ivermectin was demonstrated, though bioequivalence versus albendazole was not shown. The three medications analyzed were well tolerated. The results allow the advancement to the next phase of the clinical program to demonstrate efficacy and safety in patients affected by soil-transmitted helminths. Clinical Trial Registration: https://www.clinicaltrialsregister.eu/ctr-search/search/, identifier Nr. 2020-003438-19.

11.
Parasitol Res ; 121(9): 2463-2479, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35840730

RESUMO

Encephalitozoon cuniculi is a microsporidian parasite mostly associated with its natural host, the rabbit (Oryctolagus cuniculus). However, other animals can be infected, like other mammals, birds, and even humans. Although it usually causes subclinical infection, it can also lead to encephalitozoonosis, a clinical disease characterized by neurological, ocular, and/or renal signs that can be even fatal, especially in immunocompromised individuals. Therefore, this multidisciplinary review contributes with updated information about the E. cuniculi, deepening in its molecular and genetic characterization, its mechanisms of infection and transmission, and its prevalence among different species and geographic locations, in a One Health perspective. Recent information about the diagnostic and therapeutic approach in the main host species and the prophylaxis and infection control measures currently suggested are also discussed.


Assuntos
Encephalitozoon cuniculi , Encefalitozoonose , Saúde Única , Animais , Infecções Assintomáticas , Encephalitozoon cuniculi/genética , Encefalitozoonose/diagnóstico , Encefalitozoonose/epidemiologia , Encefalitozoonose/veterinária , Humanos , Hospedeiro Imunocomprometido , Mamíferos , Coelhos
12.
Acta Med Port ; 35(7-8): 588-590, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35612179

RESUMO

Angiotensin converting enzyme inhibitors (ACEi) are widely used for the treatment of multiple conditions such as hypertension, heart failure and chronic kidney disease. Angioedema is a rare but potentially fatal complication of ACEi use and unilateral tongue edema is a very rare presentation. We report a case of a 55-year-old man, with a history of hypertension, on enalapril for three years, who presented to the hospital with unilateral tongue swelling, without airway compromise. Other causes were excluded and the diagnosis of angioedema due to enalapril was established. The patient was discharged with discontinuation of ACEi with total resolution of symptoms and without relapse after several months. Although very rare, unilateral tongue swelling should be considered in the presentation of angioedema associated with ACEi. Tight surveillance is important to prevent fatal complications such as airway obstruction. ACEi discontinuation is crucial to avoid clinical relapse.


Os inibidores da enzima de conversão da angiotensina (iECAs) são amplamente usados no tratamento de várias patologias como a hipertensão arterial, insuficiência cardíaca e doença renal crónica. O angioedema é uma complicação rara mas potencialmente fatal desta medicação e o edema unilateral da língua é uma apresentação rara desta condição. Reportamos o caso de um homem de 55 anos com hipertensão, medicado há três anos com enalapril, que à admissão hospitalar apresentava edema unilateral da língua sem compromisso da via aérea. Outras etiologias foram excluídas, tendo-se assumido o diagnóstico de angioedema associado ao enalapril. Após suspensão do iECA os sintomas diminuíram progressivamente, sem recorrência do quadro após vários meses. Ainda que raro, o edema unilateral da língua deve ser considerado na apresentação do angioedema associado a iECA. É importante uma vigilância apertada para prevenir complicações fatais, tais como a obstrução da via aérea. A descontinuação do iECA é fundamental para evitar recidiva.


Assuntos
Angioedema , Hipertensão , Doenças da Boca , Doenças da Língua , Masculino , Humanos , Pessoa de Meia-Idade , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Angioedema/induzido quimicamente , Angioedema/diagnóstico , Enalapril/efeitos adversos , Doenças da Língua/induzido quimicamente , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Língua , Recidiva , Edema/tratamento farmacológico
13.
Nat Commun ; 13(1): 1937, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35410423

RESUMO

In type II CRISPR systems, the guide RNA (gRNA) comprises a CRISPR RNA (crRNA) and a hybridized trans-acting CRISPR RNA (tracrRNA), both being essential in guided DNA targeting functions. Although tracrRNAs are diverse in sequence and structure across type II CRISPR systems, the programmability of crRNA-tracrRNA hybridization for Cas9 is not fully understood. Here, we reveal the programmability of crRNA-tracrRNA hybridization for Streptococcus pyogenes Cas9, and in doing so, redefine the capabilities of Cas9 proteins and the sources of crRNAs, providing new biosensing applications for type II CRISPR systems. By reprogramming the crRNA-tracrRNA hybridized sequence, we show that engineered crRNA-tracrRNA interactions can not only enable the design of orthogonal cellular computing devices but also facilitate the hijacking of endogenous small RNAs/mRNAs as crRNAs. We subsequently describe how these re-engineered gRNA pairings can be implemented as RNA sensors, capable of monitoring the transcriptional activity of various environment-responsive genomic genes, or detecting SARS-CoV-2 RNA in vitro, as an Atypical gRNA-activated Transcription Halting Alarm (AGATHA) biosensor.


Assuntos
Técnicas Biossensoriais , COVID-19 , Sistemas CRISPR-Cas/genética , Humanos , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , RNA Viral/genética , SARS-CoV-2/genética
14.
Life (Basel) ; 11(8)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34440483

RESUMO

Synthetic Biology (SynBio) is a multidisciplinary field that brings together science, technology and engineering to expedite the design, creation and modification of genetic materials to be applied in living organisms or in vitro systems [...].

15.
Adv Med Sci ; 66(2): 321-325, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34273746

RESUMO

PURPOSE: The T-box transcription factor brachyury has been demonstrated as a prognostic factor in a variety of cancer types and considered a novel oncotarget in solid tumors. Brachyury acts as a regulator of the epithelial-mesenchymal transition (EMT) process, leading to more aggressive behavior and poorer prognosis. However, recent literature evidence suggests a tumor suppressor role in other neoplasms. In the present study, we aimed to study brachyury expression and its prognostic impact in Ewing sarcoma, an aggressive neoplasm of young individuals. METHODS: We analyzed the expression of brachyury by immunohistochemistry in a series of 96 Ewing sarcomas in a tissue microarray and investigated the association of the protein expression with the clinical parameters and overall survival. RESULTS: More than half of the cases (51%, n â€‹= â€‹49) depicted positive nuclear brachyury expression, while a lack of expression was observed in 49% (n â€‹= â€‹47) of cases. Nuclear brachyury staining was significantly associated with non-white ethnicity (p â€‹= â€‹0.04) and axial localization (p â€‹= â€‹0.025). Importantly, lack of brachyury expression was significantly associated with lower overall survival in multivariate analyses (hazard ratio - HR: 2.227, p â€‹= â€‹0.008). CONCLUSIONS: Our findings indicate, that brachyury is an independent prognostic biomarker in Ewing sarcoma, which might suggest a tumor suppressor role and which yet to be fully elucidated.


Assuntos
Sarcoma de Ewing , Biomarcadores Tumorais , Proteínas Fetais , Humanos , Prognóstico , Proteínas com Domínio T
16.
Cancers (Basel) ; 13(6)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809543

RESUMO

Biglycan (BGN gene), an extracellular proteoglycan, has been described to be associated with cancer aggressiveness. The purpose of this study was to clarify the clinical value of biglycan as a biomarker in multiple independent GC cohorts and determine the in vitro and in vivo role of biglycan in GC malignant features. We found that BGN is commonly over-expressed in all analyzed cohorts, being associated with disease relapse and poor prognosis in patients with advanced stages of disease. In vitro and in vivo experiments demonstrated that biglycan knock-out GC cells display major phenotypic changes with a lower cell survival, migration, and angiogenic potential when compared with biglycan expressing cells. Biglycan KO GC cells present increased levels of PARP1 and caspase-3 cleavage and a decreased expression of mesenchymal markers. Importantly, biglycan deficient GC cells that were supplemented with exogenous biglycan were able to restore biological features, such as survival, clonogenic and migratory capacities. Our in vitro and in vivo findings were validated in human GC samples, where BGN expression was associated with several oncogenic gene signatures that were associated with apoptosis, cell migration, invasion, and angiogenesis. This study provided new insights on biglycan role in GC that should be taken in consideration as a key cellular regulator with major impact in tumor progression and patients' clinical outcome.

17.
Biotechnol Bioeng ; 118(6): 2202-2219, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33624859

RESUMO

Serological assays are valuable tools to study SARS-CoV-2 spread and, importantly, to identify individuals that were already infected and would be potentially immune to a virus reinfection. SARS-CoV-2 Spike protein and its receptor binding domain (RBD) are the antigens with higher potential to develop SARS-CoV-2 serological assays. Moreover, structural studies of these antigens are key to understand the molecular basis for Spike interaction with angiotensin converting enzyme 2 receptor, hopefully enabling the development of COVID-19 therapeutics. Thus, it is urgent that significant amounts of this protein became available at the highest quality. In this study, we produced Spike and RBD in two human derived cell hosts: HEK293-E6 and Expi293F™. We evaluated the impact of different and scalable bioprocessing approaches on Spike and RBD production yields and, more importantly, on these antigens' quality attributes. Using negative and positive sera collected from human donors, we show an excellent performance of the produced antigens, assessed in serologic enzyme-linked immunosorbent assay (ELISA) tests, as denoted by the high specificity and sensitivity of the test. We show robust Spike productions with final yields of approx. 2 mg/L of culture that were maintained independently of the production scale or cell culture strategy. To the best of our knowledge, the final yield of 90 mg/L of culture obtained for RBD production, was the highest reported to date. An in-depth characterization of SARS-CoV-2 Spike and RBD proteins was performed, namely the antigen's oligomeric state, glycosylation profiles, and thermal stability during storage. The correlation of these quality attributes with ELISA performance show equivalent reactivity to SARS-CoV-2 positive serum, for all Spike and RBD produced, and for all storage conditions tested. Overall, we provide straightforward protocols to produce high-quality SARS-CoV-2 Spike and RBD antigens, that can be easily adapted to both academic and industrial settings; and integrate, for the first time, studies on the impact of bioprocess with an in-depth characterization of these proteins, correlating antigen's glycosylation and biophysical attributes to performance of COVID-19 serologic tests.


Assuntos
Antígenos Virais/biossíntese , Glicosilação , Glicoproteína da Espícula de Coronavírus/biossíntese , Temperatura Baixa , Ensaio de Imunoadsorção Enzimática/normas , Congelamento , Células HEK293 , Humanos , Conformação Proteica , Estabilidade Proteica , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/normas , SARS-CoV-2 , Testes Sorológicos/normas , Glicoproteína da Espícula de Coronavírus/normas
18.
Front Bioeng Biotechnol ; 9: 821075, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35071221

RESUMO

Among compatible solutes, glycine betaine has various applications in the fields of nutrition, pharmaceuticals, and cosmetics. Currently, this compound can be extracted from sugar beet plants or obtained by chemical synthesis, resulting in low yields or high carbon footprint, respectively. Hence, in this work we aimed at exploring the production of glycine betaine using the unicellular cyanobacterium Synechocystis sp. PCC 6803 as a photoautotrophic chassis. Synechocystis mutants lacking the native compatible solutes sucrose or/and glucosylglycerol-∆sps, ∆ggpS, and ∆sps∆ggpS-were generated and characterized. Under salt stress conditions, the growth was impaired and accumulation of glycogen decreased by ∼50% whereas the production of compatible solutes and extracellular polymeric substances (capsular and released ones) increased with salinity. These mutants were used as chassis for the implementation of a synthetic device based on the metabolic pathway described for the halophilic cyanobacterium Aphanothece halophytica for the production of the compatible solute glycine betaine. Transcription of ORFs comprising the device was shown to be stable and insulated from Synechocystis' native regulatory network. Production of glycine betaine was achieved in all chassis tested, and was shown to increase with salinity. The introduction of the glycine betaine synthetic device into the ∆ggpS background improved its growth and enabled survival under 5% NaCl, which was not observed in the absence of the device. The maximum glycine betaine production [64.29 µmol/gDW (1.89 µmol/mg protein)] was reached in the ∆ggpS chassis grown under 3% NaCl. Taking into consideration this production under seawater-like salinity, and the identification of main key players involved in the carbon fluxes, this work paves the way for a feasible production of this, or other compatible solutes, using optimized Synechocystis chassis in a pilot-scale.

19.
Nat Commun ; 11(1): 5961, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33235249

RESUMO

Versatile tools for gene expression regulation are vital for engineering gene networks of increasing scales and complexity with bespoke responses. Here, we investigate and repurpose a ubiquitous, indirect gene regulation mechanism from nature, which uses decoy protein-binding DNA sites, named DNA sponge, to modulate target gene expression in Escherichia coli. We show that synthetic DNA sponges can be designed to reshape the response profiles of gene circuits, lending multifaceted tuning capacities including reducing basal leakage by >20-fold, increasing system output amplitude by >130-fold and dynamic range by >70-fold, and mitigating host growth inhibition by >20%. Further, multi-layer DNA sponges for decoying multiple regulatory proteins provide an additive tuning effect on the responses of layered circuits compared to single-layer sponges. Our work shows synthetic DNA sponges offer a simple yet generalizable route to systematically engineer the performance of synthetic gene circuits, expanding the current toolkit for gene regulation with broad potential applications.


Assuntos
Proteínas de Ligação a DNA , DNA/síntese química , Escherichia coli , Regulação Bacteriana da Expressão Gênica , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Redes Reguladoras de Genes , Biologia Sintética/métodos , Fatores de Transcrição/metabolismo
20.
Neurotherapeutics ; 17(4): 2015-2027, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32785847

RESUMO

Glioblastomas (GBMs) are the most aggressive tumor type of the central nervous system, mainly due to their high invasiveness and innate resistance to radiotherapy and chemotherapy, with temozolomide (TMZ) being the current standard therapy. Recently, brachyury was described as a novel tumor suppressor gene in gliomas, and its loss was associated with increased gliomagenesis. Here, we aimed to explore the role of brachyury as a suppressor of glioma invasion, stem cell features, and resistance to TMZ. Using gene-edited glioma cells to overexpress brachyury, we found that brachyury-positive cells exhibit reduced invasive and migratory capabilities and stem cell features. Importantly, these brachyury-expressing cells have increased expression of differentiation markers, which corroborates the results from human glioma samples and in vivo tumors. Glioma cells treated with retinoic acid increased the differentiation status with concomitant increased expression of brachyury. We then selected TMZ-resistant (SNB-19) and TMZ-responsive (A172 and U373) cell lines to evaluate the role of brachyury in the response to TMZ treatment. We observed that both exogenous and endogenous brachyury activation, through overexpression and retinoic acid treatment, are associated with TMZ sensitization in glioma-resistant cell lines. In this study, we demonstrate that brachyury expression can impair aggressive glioma features associated with treatment resistance. Finally, we provide the first evidence that brachyury can be a potential therapeutic target in GBM patients who do not respond to conventional chemotherapeutic drugs.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proteínas Fetais/biossíntese , Glioma/metabolismo , Proteínas com Domínio T/biossíntese , Temozolomida/uso terapêutico , Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proteínas Fetais/genética , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Proteínas com Domínio T/genética , Temozolomida/farmacologia
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