Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
J Neuroradiol ; 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37805126

RESUMO

INTRODUCTION: Functional magnetic resonance imaging is a powerful tool that has provided many insights into cognitive sciences. Yet, as its analysis is mostly based on the knowledge of an a priori canonical hemodynamic response function (HRF), its reliability in patients' applications has been questioned. There have been reports of neurovascular uncoupling in patients with glioma, but no specific description of the Hemodynamic Response Function (HRF) in glioma has been reported so far. The aim of this work is to describe the HRF in patients with glioma. METHODS: Forty patients were included. MR images were acquired on a 1.5T scanner. Activated clusters were identified using a fuzzy general linear model; HRFs were adjusted with a double-gamma function. Analyses were undertaken considering the tumor grade, age, sex, tumor location, and activated location. RESULTS: Differences are found in the occipital, limbic, insular, and sub-lobar areas, but not in the frontal, temporal, and parietal lobes. The presence of a glioma slows the time-to-peak and onset times by 5.2 and 3.8 % respectively; high-grade gliomas present 8.1 % smaller HRF widths than low-grade gliomas. DISCUSSION AND CONCLUSION: There is significant HRF variation due to the presence of glioma, but the magnitudes of the observed differences are small. Most processing pipelines should be robust enough for this magnitude of variation and little if any impact should be visible on functional maps. The differences that have been observed in the literature between functional mapping obtained with magnetic resonance vs. that obtained with direct electrostimulation during awake surgery are more probably due to the intrinsic difference in the mapping process: fMRI mapping detects all recruited areas while intra-surgical mapping indicates only the areas indispensable for the realization of a certain task. Surgical mapping might not be the gold standard to use when trying to validate the fMRI mapping process.

2.
Neurosurg Focus ; 53(6): E2, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36455268

RESUMO

OBJECTIVE: Noninvasive brain mapping with functional MRI (fMRI) and mapping with direct electrical stimulation (DES) are important tools in glioma surgery, but the evidence is inconclusive regarding the sensitivity and specificity of fMRI. The Human Connectome Project (HCP) proposed a new cortical parcellation that has not been thoroughly tested in a clinical setting. The main goal of this study was to evaluate the correlation of fMRI and DES mapping with HCP areas in a clinical setting, and to evaluate the performance of fMRI mapping in motor and language tasks in patients with glioma, using DES as the gold standard. METHODS: Forty patients with supratentorial gliomas were examined using preoperative fMRI and underwent awake craniotomy with DES. Functional activation maps were visualized on a 3D representation of the cortex, classified according to HCP areas, and compared with surgical mapping. RESULTS: Functional MRI was successful in identifying language and motor HCP areas in most cases, including novel areas such as 55b and the superior longitudinal fasciculus (SLF). Functional MRI had a sensitivity and specificity of 100% and 71%, respectively, for motor function in HCP area 4. Sensitivity and specificity were different according to the area and fMRI protocol; i.e., semantic protocols performed better in Brodmann area (BA) 55b/peri-sylvian language areas with 100% sensitivity and 20% specificity, and word production protocols in BAs 44 and 45 with 70% sensitivity and 80% specificity. Some compensation patterns could be observed, such as motor activation of the postcentral gyrus in precentral gliomas. CONCLUSIONS: HCP areas can be detected in clinical scenarios of glioma surgery. These areas appear relatively stable across patients, but compensation patterns seem to differ, allowing occasional resection of activating areas. Newly described areas such as 55b and SLF can act as critical areas in language networks. Surgical planning should account for these parcellations.


Assuntos
Conectoma , Glioma , Humanos , Imageamento por Ressonância Magnética , Glioma/diagnóstico por imagem , Glioma/cirurgia , Rede Nervosa , Estimulação Elétrica
3.
Int J Mol Sci ; 23(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36076972

RESUMO

The glucagon-like peptide-1 (GLP-1) is a pleiotropic hormone well known for its incretin effect in the glucose-dependent stimulation of insulin secretion. However, GLP-1 is also produced in the brain and displays a critical role in neuroprotection and inflammation by activating the GLP-1 receptor signaling pathways. Several studies in vivo and in vitro using preclinical models of neurodegenerative diseases show that GLP-1R activation has anti-inflammatory properties. This review explores the molecular mechanistic action of GLP-1 RAS in relation to inflammation in the brain. These findings update our knowledge of the potential benefits of GLP-1RAS actions in reducing the inflammatory response. These molecules emerge as a potential therapeutic tool in treating neurodegenerative diseases and neuroinflammatory pathologies.


Assuntos
Encéfalo/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1 , Doenças Neurodegenerativas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Humanos , Inflamação/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico
4.
Rev Med Chil ; 150(3): 361-367, 2022 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-36156721

RESUMO

BACKGROUND: Neuropsychiatric symptoms can be part of the clinical spectrum of COVID-19 infections. AIM: To devise an evidence based clinical algorithm as a guide for clinicians, to identify and treat underlying clinical syndromes of psychomotor agitation, such as delirium, catatonia or substance withdrawal in patients who are hospitalized and infected with SARS-CoV-2. MATERIAL AND METHODS: A review of the literature about the pharmacological management of neuropsychiatric manifestations of COVID-19 at the general hospital, to develop a clinical protocol based on a consensus from an interdisciplinary expert panel at a Clinical Hospital. RESULTS: A consensual clinical algorithm for the management of delirium, catatonia, and substance withdrawal, manifested as psychomotor agitation in patients hospitalized with COVID-19, was developed as a clinical proposal for physicians at different levels of complexity in health services. CONCLUSIONS: Cooperation among different clinical units in the general hospital facilitated the implementation of a clinical algorithm for clinicians for the management of psychomotor agitation in COVID-19 patients.


Assuntos
COVID-19 , Catatonia , Delírio , Síndrome de Abstinência a Substâncias , COVID-19/complicações , Catatonia/tratamento farmacológico , Catatonia/etiologia , Delírio/tratamento farmacológico , Delírio/etiologia , Hospitais Gerais , Humanos , Agitação Psicomotora/tratamento farmacológico , Agitação Psicomotora/etiologia , SARS-CoV-2 , Síndrome de Abstinência a Substâncias/tratamento farmacológico
5.
Crit Rev Biotechnol ; 39(5): 665-679, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31030575

RESUMO

The continuous increase of approved biopharmaceutical products drives the development of more efficient recombinant protein expression systems. Chinese hamster ovary (CHO) cells are the mainstay for this purpose but have some drawbacks, such as low levels of expression. Several strategies have been applied to increase the productivity of CHO cells with different outcomes. Transcription factor (TF) engineering has emerged as an interesting and successful approach, as these proteins can act as master regulators; the expression and function of a TF can be controlled by small molecules, and it is possible to design tailored TFs and promoters with desired features. To date, the majority of studies have focused on the use of TFs with growth, metabolic, cell cycle or endoplasmic reticulum functions, although there is a trend to develop new, synthetic TFs. Moreover, new synthetic biological approaches are showing promising advances for the development of specific TFs, even with tailored ligand sensitivity. In this article, we summarize the strategies to increase recombinant protein expression by modulating and designing TFs and with advancements in synthetic biology. We also illustrate how this class of proteins can be used to develop more robust expression systems.


Assuntos
Fatores de Transcrição/metabolismo , Animais , Apoptose , Células CHO , Ciclo Celular , Cricetulus , Retículo Endoplasmático/metabolismo , Humanos , Regiões Promotoras Genéticas , Engenharia de Proteínas , Fatores de Transcrição/genética
6.
J Neuroinflammation ; 15(1): 337, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30518432

RESUMO

BACKGROUND: Perinatal maternal malnutrition is related to altered growth of tissues and organs. The nervous system development is very sensitive to environmental insults, being the hippocampus a vulnerable structure, in which altered number of neurons and granular cells has been observed. Moreover, glial cells are also affected, and increased expression of proinflammatory mediators has been observed. We studied the effect of Glucagon-like peptide-1 receptor (GLP-1R) agonists, liraglutide, which have very potent metabolic and neuroprotective effects, in order to ameliorate/prevent the glial alterations present in the hippocampus of the pups from mothers with food restriction during pregnancy and lactation (maternal perinatal food restriction-MPFR). METHODS: Pregnant Sprague-Dawley rats were randomly assigned to 50% food restriction (FR; n = 12) or ad libitum controls (CT, n = 12) groups at day of pregnancy 12 (GD12). From GD14 to parturition, pregnant FR and CT rats were treated with liraglutide (100 µg/kg) or vehicle. At postnatal day 21 and before weaning, 48 males and 45 females (CT and MPFR) were sacrificed. mRNA expression levels of interleukin-1ß (IL1ß), interleukin-6 (IL-6), nuclear factor-κß, major histocompatibility complex-II (MHCII), interleukin 10 (IL10), arginase 1 (Arg1), and transforming growth factor (TGFß) were assessed in the hippocampus by quantitative real-time polymerase chain reaction. Iba1 and GFAP-immunoreactivity were assessed by immunocytochemistry. RESULTS: The mRNA expression IL1ß, IL6, NF-κB, and MHCII increased in the hippocampus of male but not in female pups from MPFR. In addition, there was an increase in the percentage of GFAP and Iba1-immupositive cells in the dentate gyrus compared to controls, indicating an inflammatory response in the brain. On the other hand, liraglutide treatment prevented the neuroinflammatory process, promoting the production of anti-inflammatory molecules such as IL10, TGFß, and arginase 1, and decreasing the number and reactivity of microglial cells and astrocytes in the hippocampus of male pups. CONCLUSION: Therefore, the GLP-1 analog, liraglutide, emerges as neuroprotective drug that minimizes the harmful effects of maternal food restriction, decreasing neuroinflammation in the hippocampus in a very early stage.


Assuntos
Anti-Inflamatórios/uso terapêutico , Privação de Alimentos , Hipocampo/metabolismo , Liraglutida/uso terapêutico , Efeitos Tardios da Exposição Pré-Natal/patologia , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Citocinas/metabolismo , Feminino , Idade Gestacional , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Proteínas dos Microfilamentos/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores Sexuais
7.
Physiol Plant ; 164(4): 378-384, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29572864

RESUMO

Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein-9 (CRISPR-Cas9) can be used as an efficient tool for genome editing in potato (Solanum tuberosum). From both a scientific and a regulatory perspective, it is beneficial if integration of DNA in the potato genome is avoided. We have implemented a DNA-free genome editing method, using delivery of CRISPR-Cas9 ribonucleoproteins (RNPs) to potato protoplasts, by targeting the gene encoding a granule bound starch synthase (GBSS, EC 2.4.1.242). The RNP method was directly implemented using previously developed protoplast isolation, transfection and regeneration protocols without further adjustments. Cas9 protein was preassembled with RNA produced either synthetically or by in vitro transcription. RNP with synthetically produced RNA (cr-RNP) induced mutations, i.e. indels, at a frequency of up to 9%, with all mutated lines being transgene-free. A mutagenesis frequency of 25% of all regenerated shoots was found when using RNP with in vitro transcriptionally produced RNA (IVT-RNP). However, more than 80% of the shoots with confirmed mutations had unintended inserts in the cut site, which was in the same range as when using DNA delivery. The inserts originated both from DNA template remnants from the in vitro transcription, and from chromosomal potato DNA. In 2-3% of the regenerated shoots from the RNP-experiments, mutations were induced in all four alleles resulting in a complete knockout of the GBSS enzyme function.


Assuntos
Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Ribonucleoproteínas/genética , Solanum tuberosum/genética , Protoplastos/metabolismo
8.
Can J Urol ; 24(4): 8932-8933, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28832314

RESUMO

Emphysematous cystitis is a rare type of urinary tract infection that is characterized by air pockets within the bladder wall and lumen, which come from gas that is mainly produced by gram-negative bacteria, notably Escherichia coli. This infection is more common in older women with poorly controlled diabetes. An abdominal computerized tomography (CT) scan is the gold standard method to make the diagnosis. The infection can be life-threatening, so prompt treatment is essential. We present a case of a 39-year-old woman with poorly controlled type 2 diabetes who developed emphysematous cystitis after a bilateral adrenalectomy. The infection was diagnosed by a CT scan that revealed gas in the bladder wall. A urine culture revealed 106 colonies/mL of Klebsiella pneumoniae. After a month of treatment with intravenous antibiotics (vancomycin plus meropenem plus colistin), bladder drainage, and strict glycemic control, the patient had a good outcome.


Assuntos
Cistite/microbiologia , Enfisema/microbiologia , Infecções por Klebsiella , Klebsiella pneumoniae , Adulto , Cistite/complicações , Enfisema/complicações , Feminino , Humanos
11.
Rev Med Chil ; 145(10): 1330-1335, 2017 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-29488574

RESUMO

At the end of May 2017, the third version of the Latin American Conference on Resident Education, LACRE, was held in Chile; it convened 433 people from 14 regional countries. Chronic stress and emotional exhaustion of residents was one of the topics discussed. Reports from different countries documented that about half of residents suffer from burnout. This is, they are emotionally drained, indifferent towards their patients and with a sense of low personal fulfillment at work. This article describes the contributions presented in LACRE about interventions or institutional programs designed to reduce burnout and promote self-care of residents. The relevance of these initiatives is discussed in the current global context, considering the available evidence on the effectiveness of interventions to promote well-being among residents. International experts are making renewed and eloquent calls to medical educators and organizations to get involved in the solution of the erosion of resident wellbeing during the residence.


Assuntos
Esgotamento Profissional/prevenção & controle , Internato e Residência/tendências , Corpo Clínico/psicologia , Carga de Trabalho/psicologia , Humanos , América Latina , Qualidade de Vida , Fatores de Risco
12.
Age Ageing ; 43(3): 346-51, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24064236

RESUMO

BACKGROUND: delirium is frequently under diagnosed in older hospitalised patients. Predictive models have not been widely incorporated in clinical practice. OBJECTIVE: to develop and validate a predictive score for incident delirium. DESIGN AND SETTING: two consecutive observational prospective cohorts (development and validation) in a university affiliated hospital. SUBJECTS: inpatients 65 years and older. METHODS: in the development cohort patients were assessed within the first 48 h of admission, and every 48 h thereafter, using the confusion assessment method to diagnose delirium and data were collected on comorbidity, illness severity, functional status and laboratory. Delirium predictive score (DPS) was constructed in the development cohort using variables associated with incident delirium in the multivariate analysis (P < 0.05), and then tested in a validation cohort of comparable patients, admitted without delirium. Receiver operating characteristic (ROC) analysis and likelihood ratio (LR) were calculated. RESULTS: the development cohort included 374 patients, incident delirium occurred in 25. After multivariate analysis incident delirium was independently associated with lower functional status (Barthel Index) and a proxy for dehydration (elevated urea to creatinine ratio). Using these variables, DPS was constructed with a performance in the ROC curve area of 0.86 (95% CI: 0.82-0.91) and (-) LR = 0.16 and (+) LR = 3.4. The validation cohort included 104 patients and the performance of the score was ROC 0.78 (95% CI: 0.66-0.90). CONCLUSIONS: This simple predictive model highlights functional status and a proxy for dehydration as a useful tool for identifying older patients that may benefit from close monitoring and preventive care for early diagnosis of delirium.


Assuntos
Atividades Cotidianas/psicologia , Desidratação , Delírio/diagnóstico , Idoso , Chile/epidemiologia , Comorbidade , Técnicas de Apoio para a Decisão , Desidratação/sangue , Desidratação/complicações , Desidratação/psicologia , Delírio/sangue , Delírio/epidemiologia , Delírio/etiologia , Delírio/fisiopatologia , Feminino , Avaliação Geriátrica/métodos , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Medição de Risco/métodos , Fatores de Risco , Índice de Gravidade de Doença
13.
J Acad Consult Liaison Psychiatry ; 65(2): 136-147, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37806639

RESUMO

BACKGROUND: Delirium is the most prevalent neuropsychiatric syndrome experienced by patients admitted to inpatient clinical units, occurring in at least 20% of medically hospitalized patients and up to 85% of those admitted to critical care units. Although current guidelines recommend the implementation of universal prevention strategies, the use of management strategies largely depends on constant surveillance and screening. This allows for the timely diagnosis and correction of its underlying causes and implementation of management strategies. OBJECTIVE: It was to adapt and analyze the Spanish adaptation of the Stanford Proxy Test for Delirium (S-PTDsv) instrument for its use among Spanish-speaking populations. The S-PTD is an instrument consisting of 13 observational items to be completed by a clinician observer, usually the patient's nurse. The completion of the questionnaire takes about 1 minute and does not require the active participation of the person evaluated, which has important clinical advantages compared to other available instruments (e.g., the Confusion Assessment Method). METHODS: The psychometric properties of the S-PTDsv were evaluated in a population of 123 patients using a quantitative, cross-sectional design. All subjects were over 18 years of age and hospitalized in various inpatient medico-surgical and intensive care unit services, either at the Barcelona Clinical Hospital (Barcelona, Spain) or the UC-Christus Health Network Clinical Hospital (Santiago, Chile, S.A.). The ultimate diagnosis of delirium was made by a member of the Psychiatry Consult Service by means of an independent neuropsychiatric evaluation based on the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, published in 2013, which is the latest version of the diagnostic manual. All study tests were performed by study personnel who were blinded to each other's test results within an hour of each other. RESULTS: In the receiver operator characteristic (ROC) curve analysis, the S-PTDsv demonstrated excellent classification qualities when compared with the DSM-5 as the classification reference standard. Using a cutoff point of ≥3, the S-PTDsv had a sensitivity of 94% and a specificity of 97%. The area under the curve indicator was equal to 0.95, suggesting the S-PTDsv has an excellent overall performance in accurately identifying cases of delirium. Accordingly, the S-PTDsv's positive predictive value = 0.93, and the negative predictive value = 0.97. The internal reliability measured with Cronbach's alpha was 0.96. Confirmatory factor analysis revealed a 1-dimensional structure with high loadings (>0.72), demonstrating that all items similarly contribute to the total diagnostic dimension, suggesting adequate construct validity. This provided evidence of convergent validity. CONCLUSIONS: The performance of the S-PTDsv, as compared to a blinded neuropsychiatric assessment based on DSM-5, indicates that it is an effective instrument for the detection of delirium, in the Spanish-speaking populations. These results are comparable and consistent with previously published studies in the English language version.

14.
Neural Regen Res ; 19(8): 1671-1677, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38103230

RESUMO

The glucagon-like peptide 1 is a pleiotropic hormone that has potent insulinotropic effects and is key in treating metabolic diseases such as diabetes and obesity. Glucagon-like peptide 1 exerts its effects by activating a membrane receptor identified in many tissues, including different brain regions. Glucagon-like peptide 1 activates several signaling pathways related to neuroprotection, like the support of cell growth/survival, enhancement promotion of synapse formation, autophagy, and inhibition of the secretion of proinflammatory cytokines, microglial activation, and apoptosis during neural morphogenesis. The glial cells, including astrocytes and microglia, maintain metabolic homeostasis and defense against pathogens in the central nervous system. After brain insult, microglia are the first cells to respond, followed by reactive astrocytosis. These activated cells produce proinflammatory mediators like cytokines or chemokines to react to the insult. Furthermore, under these circumstances, microglia can become chronically inflammatory by losing their homeostatic molecular signature and, consequently, their functions during many diseases. Several processes promote the development of neurological disorders and influence their pathological evolution: like the formation of protein aggregates, the accumulation of abnormally modified cellular constituents, the formation and release by injured neurons or synapses of molecules that can dampen neural function, and, of critical importance, the dysregulation of inflammatory control mechanisms. The glucagon-like peptide 1 receptor agonist emerges as a critical tool in treating brain-related inflammatory pathologies, restoring brain cell homeostasis under inflammatory conditions, modulating microglia activity, and decreasing the inflammatory response. This review summarizes recent advances linked to the anti-inflammatory properties of glucagon-like peptide 1 receptor activation in the brain related to multiple sclerosis, Alzheimer's disease, Parkinson's disease, vascular dementia, or chronic migraine.

15.
Nat Commun ; 15(1): 7191, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39168995

RESUMO

Quantum spin liquids (QSLs) have become a key area of research in magnetism due to their remarkable properties, such as long-range entanglement, fractional excitations, and topologically protected phenomena. Recently, the search for QSLs has expanded into the three-dimensional world, despite the suppression of quantum fluctuations due to high dimensionality. A new candidate material, K2Ni2(SO4)3, belongs to the langbeinite family and consists of two interconnected trillium lattices. Although magnetically ordered, it exhibits a highly dynamical and correlated state. In this work, we combine inelastic neutron scattering measurements with density functional theory (DFT), pseudo-fermion functional renormalization group (PFFRG), and classical Monte Carlo (cMC) calculations to study the magnetic properties of K2Ni2(SO4)3, revealing a high level of agreement between experiment and theory. We further reveal the origin of the dynamical state in K2Ni2(SO4)3 to be centred around a magnetic network composed of tetrahedra on a trillium lattice.

16.
Am J Physiol Endocrinol Metab ; 304(10): E1105-17, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23531615

RESUMO

Exendin-4 (Ex-4) is a natural agonist of the glucagon-like peptide-1 (GLP-1) receptor, currently being used as a treatment for type 2 diabetes mellitus due to its insulinotropic properties. Previous studies have revealed that acute administration of both GLP-1 and, in particular, Ex-4 potently stimulates hypothalamic-pituitary-adrenal (HPA) axis activity. In this work, the effects of prolonged Ex-4 exposure on HPA function were explored. To this end, Sprague-Dawley rats were subjected to a daily regimen of two Ex-4 injections (5 µg/kg sc) for a minimum of 7 days. We found that subchronic Ex-4 administration produced a number of effects that resemble chronic stress situations, including hyperactivation of the HPA axis during the trough hours, disruption of glucocorticoid circadian secretion, hypertrophy of the adrenal gland, decreased adrenal gland sensitivity, impaired pituitary-adrenal stress responses, and reductions in both food intake and body weight. In addition, a threefold increase in diuresis was observed followed by a 1.5-fold increase in water intake; these latter effects were abolished by adrenalectomy. Together, these findings indicate that Ex-4 induces a profound dysregulation of HPA axis activity that may also affect renal function.


Assuntos
Glândulas Suprarrenais/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Peptídeos/farmacologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Peçonhas/farmacologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Glândulas Suprarrenais/fisiologia , Hormônio Adrenocorticotrópico/sangue , Animais , Peso Corporal/fisiologia , Ritmo Circadiano/fisiologia , Corticosterona/sangue , Ingestão de Alimentos/fisiologia , Exenatida , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Sistema Hipófise-Suprarrenal/fisiologia , Ratos , Ratos Sprague-Dawley , Estresse Fisiológico/fisiologia
17.
Methods Mol Biol ; 2653: 333-361, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36995636

RESUMO

Cultivated potato (Solanum tuberosum L.) is one of the most important staple food crops worldwide. Its tetraploid and highly heterozygous nature poses a great challenge to its basic research and trait improvement through traditional mutagenesis and/or crossbreeding. The establishment of the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) as a gene editing tool has allowed the alteration of specific gene sequences and their concomitant gene function, providing powerful technology for potato gene functional analysis and improvement of elite cultivars. This technology relies on a short RNA molecule called single guide RNA (sgRNA) that directs the Cas9 nuclease to induce a site-specific double-stranded break (DSB). Further, repair of the DSB by the error-prone non-homologous end joining (NHEJ) mechanism leads to the introduction of targeted mutations, which can be used to produce the loss of function of specific gene(s). In this chapter, we describe experimental procedures to apply the CRISPR/Cas9 technology for potato genome editing. First, we provide strategies for target selection and sgRNA design and describe a Golden Gate-based cloning system to obtain a sgRNA/Cas9-encoding binary vector. We also describe an optimized protocol for ribonucleoprotein (RNP) complex assembly. The binary vector can be used for both Agrobacterium-mediated transformation and transient expression in potato protoplasts, while the RNP complexes are intended to obtain edited potato lines through protoplast transfection and plant regeneration. Finally, we describe procedures to identify the gene-edited potato lines. The methods described here are suitable for potato gene functional analysis and breeding.


Assuntos
Sistemas CRISPR-Cas , Solanum tuberosum , Sistemas CRISPR-Cas/genética , Solanum tuberosum/genética , Melhoramento Vegetal , Edição de Genes/métodos , Genômica
18.
Blood Adv ; 7(1): 73-86, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35895513

RESUMO

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that originate in the bone marrow (BM) and have immunoregulatory functions. MDSCs have been implicated in the pathogenesis of several autoimmune diseases but have not been investigated in immune aplastic anemia (AA). We examined the roles of granulocytic-MDSCs (G-MDSCs) in murine models of human AA and BM failure (BMF). As both prophylaxis and therapy, BM-derived G-MDSCs improved pancytopenia and BM cellularity and suppressed BM T-cell infiltration in major histocompatibility complex (MHC)-matched C.B10 BMF mice. These effects were not obtained in the MHC-mismatched CByB6F1 AA model, likely because of MHC disparity between G-MDSCs and donor T cells. Single-cell RNA sequencing demonstrated that G-MDSCs downregulated cell cycle-related genes in BM-infiltrated T cells, consistent with suppression of T-cell proliferation by G-MDSCs through reactive oxygen species pathways. Clearance of G-MDSCs in the MHC-mismatched CByB6F1 model using anti-Ly6G antibody facilitated T cell-mediated BM destruction, suggesting an intrinsic immunosuppressive property of G-MDSCs. However, the same anti-Ly6G antibody in the MHC-matched C.B10 AA model mildly mitigated BMF, associated with expansion of an intermediate Ly6G population. Our results demonstrate that G-MDSC eradication and therapeutic efficacy are immune context-dependent.


Assuntos
Anemia Aplástica , Células Supressoras Mieloides , Pancitopenia , Humanos , Animais , Camundongos , Granulócitos , Células Mieloides , Transtornos da Insuficiência da Medula Óssea/metabolismo , Anemia Aplástica/terapia
19.
Front Immunol ; 14: 1137069, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37346047

RESUMO

Molecular characterization of antibody immunity and human antibody discovery is mainly carried out using peripheral memory B cells, and occasionally plasmablasts, that express B cell receptors (BCRs) on their cell surface. Despite the importance of plasma cells (PCs) as the dominant source of circulating antibodies in serum, PCs are rarely utilized because they do not express surface BCRs and cannot be analyzed using antigen-based fluorescence-activated cell sorting. Here, we studied the antibodies encoded by the entire mature B cell populations, including PCs, and compared the antibody repertoires of bone marrow and spleen compartments elicited by immunization in a human immunoglobulin transgenic mouse strain. To circumvent prior technical limitations for analysis of plasma cells, we applied single-cell antibody heavy and light chain gene capture from the entire mature B cell repertoires followed by yeast display functional analysis using a cytokine as a model immunogen. We performed affinity-based sorting of antibody yeast display libraries and large-scale next-generation sequencing analyses to follow antibody lineage performance, with experimental validation of 76 monoclonal antibodies against the cytokine antigen that identified three antibodies with exquisite double-digit picomolar binding affinity. We observed that spleen B cell populations generated higher affinity antibodies compared to bone marrow PCs and that antigen-specific splenic B cells had higher average levels of somatic hypermutation. A degree of clonal overlap was also observed between bone marrow and spleen antibody repertoires, indicating common origins of certain clones across lymphoid compartments. These data demonstrate a new capacity to functionally analyze antigen-specific B cell populations of different lymphoid organs, including PCs, for high-affinity antibody discovery and detailed fundamental studies of antibody immunity.


Assuntos
Medula Óssea , Plasmócitos , Camundongos , Animais , Humanos , Camundongos Transgênicos , Baço , Saccharomyces cerevisiae , Anticorpos Monoclonais , Receptores de Antígenos de Linfócitos B/genética , Formação de Anticorpos , Citocinas
20.
Sci Rep ; 13(1): 8011, 2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37198258

RESUMO

Adoptive immune therapies based on the transfer of antigen-specific T cells have been used successfully to treat various cancers and viral infections, but improved techniques are needed to identify optimally protective human T cell receptors (TCRs). Here we present a high-throughput approach to the identification of natively paired human TCRα and TCRß (TCRα:ß) genes encoding heterodimeric TCRs that recognize specific peptide antigens bound to major histocompatibility complex molecules (pMHCs). We first captured and cloned TCRα:ß genes from individual cells, ensuring fidelity using a suppression PCR. We then screened TCRα:ß libraries expressed in an immortalized cell line using peptide-pulsed antigen-presenting cells and sequenced activated clones to identify the cognate TCRs. Our results validated an experimental pipeline that allows large-scale repertoire datasets to be annotated with functional specificity information, facilitating the discovery of therapeutically relevant TCRs.


Assuntos
Receptores de Antígenos de Linfócitos T , Linfócitos T , Humanos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Clonagem Molecular , Antígenos , Peptídeos/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA