Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 755
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Immunol ; 212(7): 1244-1253, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38334457

RESUMO

A variety of commercial platforms are available for the simultaneous detection of multiple cytokines and associated proteins, often employing Ab pairs to capture and detect target proteins. In this study, we comprehensively evaluated the performance of three distinct platforms: the fluorescent bead-based Luminex assay, the proximity extension-based Olink assay, and a novel proximity ligation assay platform known as Alamar NULISAseq. These assessments were conducted on human serum samples from the National Institutes of Health IMPACC study, with a focus on three essential performance metrics: detectability, correlation, and differential expression. Our results reveal several key findings. First, the Alamar platform demonstrated the highest overall detectability, followed by Olink and then Luminex. Second, the correlation of protein measurements between the Alamar and Olink platforms tended to be stronger than the correlation of either of these platforms with Luminex. Third, we observed that detectability differences across the platforms often translated to differences in differential expression findings, although high detectability did not guarantee the ability to identify meaningful biological differences. Our study provides valuable insights into the comparative performance of these assays, enhancing our understanding of their strengths and limitations when assessing complex biological samples, as exemplified by the sera from this COVID-19 cohort.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , Imunoensaio/métodos , Citocinas/metabolismo , Soro/metabolismo
2.
FASEB J ; 38(1): e23358, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38050671

RESUMO

MicroRNA (miRNA)-mediated mRNA regulation directs many homeostatic and pathological processes, but how miRNAs coordinate aberrant esophageal inflammation during eosinophilic esophagitis (EoE) is poorly understood. Here, we report a deregulatory axis where microRNA-155 (miR-155) regulates epithelial barrier dysfunction by selectively constraining tight junction CLDN7 (claudin-7). MiR-155 is elevated in the esophageal epithelium of biopsies from patients with active EoE and in cell culture models. MiR-155 localization using in situ hybridization (ISH) in patient biopsies and intra-epithelial compartmentalization of miR-155 show expression predominantly within the basal epithelia. Epithelial miR-155 activity was evident through diminished target gene expression in 3D organotypic cultures, particularly in relatively undifferentiated basal cell states. Mechanistically, generation of a novel cell line with enhanced epithelial miR-155 stable overexpression induced a functionally deficient epithelial barrier in 3D air-liquid interface epithelial cultures measured by transepithelial electrical resistance (TEER). Histological assessment of 3D esophageal organoid cultures overexpressing miR-155 showed notable dilated intra-epithelial spaces. Unbiased RNA-sequencing analysis and immunofluorescence determined a defect in epithelial barrier tight junctions and revealed a selective reduction in the expression of critical esophageal tight junction molecule, claudin-7. Together, our data reveal a previously unappreciated role for miR-155 in mediating epithelial barrier dysfunction in esophageal inflammation.


Assuntos
Claudinas , Esofagite Eosinofílica , MicroRNAs , Humanos , Claudinas/genética , Esofagite Eosinofílica/genética , Esofagite Eosinofílica/metabolismo , Esofagite Eosinofílica/patologia , Células Epiteliais/metabolismo , Hipóxia/metabolismo , Inflamação/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Junções Íntimas/metabolismo
3.
Mol Ther ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39108095

RESUMO

Clinical trials investigating the potential of mesenchymal stromal cells (MSCs) for the treatment of inflammatory diseases, such as acute respiratory distress syndrome (ARDS), have been disappointing; with less than 50% of patients responding to treatment. Licensed MSCs show enhanced therapeutic efficacy in response to cytokine-mediated activation signals. There are two distinct sub-phenotypes of ARDS: hypo- and hyper-inflammatory. We hypothesised that pre-licensing MSCs in a hyper-inflammatory ARDS environment would enhance their therapeutic efficacy in acute lung inflammation (ALI). Serum samples from ARDS patients were segregated into hypo- and hyper-inflammatory categories based on IL-6 levels. MSCs were licensed with pooled serum from hypo- or hyper-inflammatory ARDS patients or healthy serum controls. Our findings show that hyper-inflammatory ARDS pre-licensed MSC conditioned medium (MSC-CMHyper) led to a significant enrichment in tight junction expression and enhanced barrier integrity in lung epithelial cells in vitro and in vivo; in a VEGF-dependent manner. Importantly, while both MSC-CMHypo and MSC-CMHyper significantly reduced IL-6 and TNFα levels in the bronchoalveolar lavage fluid (BALF) of LPS-induced ALI mice, only MSC-CMHyper significantly reduced lung permeability and overall clinical outcomes including weight loss and clinical score. Thus the hypo- and hyper-inflammatory ARDS environment may differentially influence MSC cytoprotective and immunomodulatory functions.

4.
Mol Ther ; 32(1): 185-203, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38096818

RESUMO

Extracellular vesicles (EVs) released from healthy endothelial cells (ECs) have shown potential for promoting angiogenesis, but their therapeutic efficacy remains poorly understood. We have previously shown that transplantation of a human embryonic stem cell-derived endothelial cell product (hESC-ECP), promotes new vessel formation in acute ischemic disease in mice, likely via paracrine mechanism(s). Here, we demonstrated that EVs from hESC-ECPs (hESC-eEVs) significantly increased EC tube formation and wound closure in vitro at ultralow doses, whereas higher doses were ineffective. More important, EVs isolated from the mesodermal stage of the differentiation (hESC-mEVs) had no effect. Small RNA sequencing revealed that hESC-eEVs have a unique transcriptomic profile and are enriched in known proangiogenic microRNAs (miRNAs, miRs). Moreover, an in silico analysis identified three novel hESC-eEV-miRNAs with potential proangiogenic function. Differential expression analysis suggested that two of those, miR-4496 and miR-4691-5p, are highly enriched in hESC-eEVs. Overexpression of miR-4496 or miR-4691-5p resulted in increased EC tube formation and wound closure in vitro, validating the novel proangiogenic function of these miRNAs. In summary, we demonstrated that hESC-eEVs are potent inducers of EC angiogenic response at ultralow doses and contain a unique EV-associated miRNA repertoire, including miR-4496 and miR-4691-5p, with novel proangiogenic function.


Assuntos
Vesículas Extracelulares , MicroRNAs , Humanos , Animais , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Células Endoteliais/metabolismo , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Diferenciação Celular/genética , Células-Tronco/metabolismo
5.
Blood ; 140(24): 2626-2643, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36026606

RESUMO

S100A8/A9, also known as "calprotectin" or "MRP8/14," is an alarmin primarily secreted by activated myeloid cells with antimicrobial, proinflammatory, and prothrombotic properties. Increased plasma levels of S100A8/A9 in thrombo-inflammatory diseases are associated with thrombotic complications. We assessed the presence of S100A8/A9 in the plasma and lung autopsies from patients with COVID-19 and investigated the molecular mechanism by which S100A8/A9 affects platelet function and thrombosis. S100A8/A9 plasma levels were increased in patients with COVID-19 and sustained high levels during hospitalization correlated with poor outcomes. Heterodimeric S100A8/A9 was mainly detected in neutrophils and deposited on the vessel wall in COVID-19 lung autopsies. Immobilization of S100A8/A9 with collagen accelerated the formation of a fibrin-rich network after perfusion of recalcified blood at venous shear. In vitro, platelets adhered and partially spread on S100A8/A9, leading to the formation of distinct populations of either P-selectin or phosphatidylserine (PS)-positive platelets. By using washed platelets, soluble S100A8/A9 induced PS exposure but failed to induce platelet aggregation, despite GPIIb/IIIa activation and alpha-granule secretion. We identified GPIbα as the receptor for S100A8/A9 on platelets inducing the formation of procoagulant platelets with a supporting role for CD36. The effect of S100A8/A9 on platelets was abolished by recombinant GPIbα ectodomain, platelets from a patient with Bernard-Soulier syndrome with GPIb-IX-V deficiency, and platelets from mice deficient in the extracellular domain of GPIbα. We identified the S100A8/A9-GPIbα axis as a novel targetable prothrombotic pathway inducing procoagulant platelets and fibrin formation, in particular in diseases associated with high levels of S100A8/A9, such as COVID-19.


Assuntos
Plaquetas , COVID-19 , Calgranulina A , Calgranulina B , Complexo Glicoproteico GPIb-IX de Plaquetas , Animais , Camundongos , Plaquetas/metabolismo , Calgranulina A/metabolismo , COVID-19/metabolismo , Fibrina/metabolismo , Fosfatidilserinas/metabolismo , Agregação Plaquetária , Humanos , Calgranulina B/metabolismo , Autopsia , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo
6.
J Magn Reson Imaging ; 59(5): 1683-1694, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37540052

RESUMO

BACKGROUND: The role of neuroinflammation in psychiatric disorders is not well-elucidated. A noninvasive technique sensitive to low-level neuroinflammation may improve understanding of the pathophysiology of these conditions. PURPOSE: To test the ability of quantitative magnetization transfer (QMT) MR at 3 T for detection of low-level neuroinflammation induced by typhoid vaccine within a clinically reasonable scan time. STUDY TYPE: Randomized, crossover, placebo-controlled. SUBJECTS: Twenty healthy volunteers (10 males; median age 34 years). FIELD STRENGTH/SEQUENCE: Magnetization prepared rapid gradient-echo and MT-weighted 3D fast low-angle shot sequences at 3 T. ASSESSMENT: Participants were randomized to either vaccine or placebo first with imaging, then after a washout period received the converse with a second set of imaging. MT imaging, scan time, and blood-based inflammatory marker concentrations were assessed pre- and post-vaccine and placebo. Mood was assessed hourly using the Profile of Mood States questionnaire. QMT parameter maps, including the exchange rate from bound to free pool (kba) were generated using a two-pool model and then segmented into tissue type. STATISTICAL TESTS: Voxel-wise permutation-based analysis examined inflammatory-related alterations of QMT parameters. The threshold-free cluster enhancement method with family-wise error was used to correct voxel-wise results for multiple comparisons. Region of interest averages were fed into mixed models and Bonferroni corrected. Spearman correlations assessed the relationship between mood scores and QMT parameters. Results were considered significant if corrected P < 0.05. RESULTS: Scan time for the MT-weighted acquisition was approximately 11 minutes. Blood-based analysis showed higher IL-6 concentrations post-vaccine compared to post-placebo. Voxel-wise analysis found three clusters indicating an inflammatory-mediated increase in kba in cerebellar white matter. Cerebellar kba for white matter was negatively associated with vigor post-vaccine but not post-placebo. DATA CONCLUSION: This study suggested that QMT at 3 T may show some sensitivity to low-level neuroinflammation. Further studies are needed to assess the viability of QMT for use in inflammatory-based disorders. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.


Assuntos
Transtornos Mentais , Vacinas Tíficas-Paratíficas , Masculino , Humanos , Adulto , Estudos Cross-Over , Doenças Neuroinflamatórias , Imageamento por Ressonância Magnética/métodos
7.
Chromosome Res ; 31(3): 21, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37592171

RESUMO

Chromosome instability (CIN) is a cancer hallmark that drives tumour heterogeneity, phenotypic adaptation, drug resistance and poor prognosis. High-grade serous ovarian cancer (HGSOC), one of the most chromosomally unstable tumour types, has a 5-year survival rate of only ~30% - largely due to late diagnosis and rapid development of drug resistance, e.g., via CIN-driven ABCB1 translocations. However, CIN is also a cell cycle vulnerability that can be exploited to specifically target tumour cells, illustrated by the success of PARP inhibitors to target homologous recombination deficiency (HRD). However, a lack of appropriate models with ongoing CIN has been a barrier to fully exploiting disease-specific CIN mechanisms. This barrier is now being overcome with the development of patient-derived cell cultures and organoids. In this review, we describe our progress building a Living Biobank of over 120 patient-derived ovarian cancer models (OCMs), predominantly from HGSOC. OCMs are highly purified tumour fractions with extensive proliferative potential that can be analysed at early passage. OCMs have diverse karyotypes, display intra- and inter-patient heterogeneity and mitotic abnormality rates far higher than established cell lines. OCMs encompass a broad-spectrum of HGSOC hallmarks, including a range of p53 alterations and BRCA1/2 mutations, and display drug resistance mechanisms seen in the clinic, e.g., ABCB1 translocations and BRCA2 reversion. OCMs are amenable to functional analysis, drug-sensitivity profiling, and multi-omics, including single-cell next-generation sequencing, and thus represent a platform for delineating HGSOC-specific CIN mechanisms. In turn, our vision is that this understanding will inform the design of new therapeutic strategies.


Assuntos
Transtornos Cromossômicos , Neoplasias Ovarianas , Humanos , Feminino , Proteína BRCA1/genética , Bancos de Espécimes Biológicos , Proteína BRCA2 , Neoplasias Ovarianas/genética , Translocação Genética , Instabilidade Cromossômica
8.
Ethn Health ; 29(3): 309-327, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38317577

RESUMO

OBJECTIVE: To solicit information/suggestions from prostate cancer survivors to improve survivorship experiences specific to work/workability. DESIGN: The study employed a qualitative/phenomenological approach. Black/African-American and white prostate cancer survivors who: (1) had prostatectomy or radiation therapy 6-36 months prior, (2) were working for pay within 30 days before having treatment, and (3) expected to be working for pay 6 months later (n = 45) were eligible for this study. Survivors were engaged in 60-to-90-minute structured interviews. Content analysis was used to ascertain prominent themes. RESULTS: Participants had the following recommendations for survivors: ask about research on treatment options and side effects; speak with other survivors about cancer diagnosis; and inform family/friends and employers about needed accommodations. Considerations for family/friends emphasized the significance of instrumental (e.g. help finding information) and emotional support (e.g. encouragement). Employer/co-worker considerations most often related to work-related accommodations/support and avoiding stigmatization of the survivor. Considerations for healthcare providers commonly included the provision of unbiased, plain-language communication about treatment options and side effects. No major differences existed by race. CONCLUSIONS: Needs of employed PrCA survivors, regardless of their race or treatment type, are commonly related to their desire for informational, instrumental, and/or emotional support from family/friends, employers/co-workers, and healthcare providers. The requested supports are most often related to the side effects of prostate cancer treatment.


Assuntos
Sobreviventes de Câncer , Neoplasias da Próstata , Humanos , Masculino , Negro ou Afro-Americano , Neoplasias da Próstata/terapia , Sobreviventes/psicologia , Sobrevivência , Brancos
9.
Am J Physiol Gastrointest Liver Physiol ; 325(1): G1-G13, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37129237

RESUMO

MicroRNAs (miRNAs) are a class of small endogenous RNA molecules between 18 and 25 nucleotides long. The primary function of miRNAs is in the posttranscriptional regulation of mRNA targets through RNA interference culminating in mRNA degradation or translational repression. MiRNAs are fundamental in physiological and pathological processes such as cell proliferation, differentiation, apoptosis, and inflammation. Among this includes the uncovered potential of miRNAs in overall esophageal disease with a focus on the clinicopathologic allergic disease eosinophilic esophagitis (EoE), gastroesophageal reflux disease (GERD), and the tumorigenic continuum from Barrett's esophagus (BE) toward esophageal adenocarcinoma (EAC). Although these pathologies are distinct from one another, they share pathophysiological elements such as an intense inflammatory milieu, esophageal dysfunction, and as presented in this review, an overlap in miRNA expression which contributes to overall esophageal disease. The overlap in the dysregulated miRNA transcriptome of these pathologies highlights the key role miRNAs play in contributing to esophageal disease progression. Owing to this notable dysregulation, there is an attractive utility for miRNAs as diagnostic and prognostic biomarkers in esophageal diseases that already require invasive endoscopies and biopsy retrieval. In this review miRNAs within EoE, GERD, BE, EAC, and esophageal achalasia are discussed, as well as reviewing a core set of miRNAs shared in the disease progression among some of these pathologies, along with the potential utility of targeting miRNAs as therapeutic options in overall esophageal disease.


Assuntos
Esôfago de Barrett , Esofagite Eosinofílica , Neoplasias Esofágicas , Refluxo Gastroesofágico , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Estudos de Casos e Controles , Neoplasias Esofágicas/metabolismo , Esôfago de Barrett/genética , Esôfago de Barrett/patologia , Refluxo Gastroesofágico/metabolismo , Esofagite Eosinofílica/genética , Esofagite Eosinofílica/terapia , Progressão da Doença
10.
Oncologist ; 28(5): 414-424, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36952230

RESUMO

BACKGROUND: Talazoparib is a poly (adenosine diphosphate-ribose) polymerase inhibitor approved for the treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm), HER2-negative, locally advanced or metastatic breast cancer (LA/mBC), with approval based on the EMBRACA trial. To date, there are no published data on talazoparib use in the real-world United States (USA) setting. PATIENTS AND METHODS: Characteristics, treatment patterns, and clinical outcomes of real-world US patients with gBRCAm HER2-negative LA/mBC treated with talazoparib monotherapy were collected via retrospective chart review and summarized using descriptive statistics. RESULTS: Among 84 eligible patients, 35.7% had hormone receptor-positive tumors and 64.3% had triple-negative LA/mBC (TNBC). At talazoparib initiation, 29.8% had ECOG PS of ≥2 and 19.0% had brain metastasis. Mutations in gBRCA1 or 2 were detected among 64.3% and 35.7% of patients, respectively. Talazoparib was given as 1st-line therapy in 14.3% of patients, 2nd-line in 40.5%, and 3rd- or 4th-line in 45.2%. Median time to talazoparib treatment failure was 8.5 months (95% CI, 8.0-9.7), median progression-free survival was 8.7 months (95% CI, 8.0-9.9), the median time from initiation to chemotherapy was 12.2 months (95% CI, 10.5-20.1), and the overall response rate was 63.1%. No differences in clinical outcomes were observed between patients with HR-positive/HER2-negative LA/mBC and patients with TNBC by using unadjusted statistical comparisons. Brain metastasis and ECOG PS ≥2 at talazoparib initiation were associated with treatment failure and progression or mortality. CONCLUSION: Overall, talazoparib clinical outcomes in this real-world population are consistent with findings from EMBRACA.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , Adulto , Humanos , Estados Unidos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Estudos Retrospectivos
11.
Immunol Cell Biol ; 101(6): 556-577, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36967673

RESUMO

CO2 is produced during aerobic respiration. Normally, levels of CO2 in the blood are tightly regulated but pCO2 can rise (hypercapnia, pCO2 > 45 mmHg) in patients with lung diseases, for example, chronic obstructive pulmonary disease (COPD). Hypercapnia is a risk factor in COPD but may be of benefit in the context of destructive inflammation. The effects of CO2 per se, on transcription, independent of pH change are poorly understood and warrant further investigation. Here we elucidate the influence of hypercapnia on monocytes and macrophages through integration of state-of-the-art RNA-sequencing, metabolic and metabolomic approaches. THP-1 monocytes and interleukin 4-polarized primary murine macrophages were exposed to 5% CO2 versus 10% CO2 for up to 24 h in pH-buffered conditions. In hypercapnia, we identified around 370 differentially expressed genes (DEGs) under basal and about 1889 DEGs under lipopolysaccharide-stimulated conditions in monocytes. Transcripts relating to both mitochondrial and nuclear-encoded gene expression were enhanced in hypercapnia in basal and lipopolysaccharide-stimulated cells. Mitochondrial DNA content was not enhanced, but acylcarnitine species and genes associated with fatty acid metabolism were increased in hypercapnia. Primary macrophages exposed to hypercapnia also increased activation of genes associated with fatty acid metabolism and reduced activation of genes associated with glycolysis. Thus, hypercapnia elicits metabolic shifts in lipid metabolism in monocytes and macrophages under pH-buffered conditions. These data indicate that CO2 is an important modulator of monocyte transcription that can influence immunometabolic signaling in immune cells in hypercapnia. These immunometabolic insights may be of benefit in the treatment of patients experiencing hypercapnia.


Assuntos
Hipercapnia , Doença Pulmonar Obstrutiva Crônica , Humanos , Animais , Camundongos , Hipercapnia/etiologia , Hipercapnia/metabolismo , Dióxido de Carbono , Monócitos/metabolismo , Genes Mitocondriais , Lipopolissacarídeos , Doença Pulmonar Obstrutiva Crônica/complicações , Expressão Gênica , Ácidos Graxos
12.
Genet Med ; 25(3): 100344, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36729052

RESUMO

This review aimed to update the clinical practice guidelines for managing adults with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society recruited expert clinicians worldwide to revise the original clinical practice guidelines for adults in a stepwise process according to best practices: (1) a systematic literature search (1992-2021), (2) study selection and synthesis by clinical experts from 8 countries, covering 24 subspecialties, and (3) formulation of consensus recommendations based on the literature and further shaped by patient advocate survey results. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text review, with 2318 meeting inclusion criteria (clinical care relevance to 22q11.2DS) including 894 with potential relevance to adults. The evidence base remains limited. Thus multidisciplinary recommendations represent statements of current best practice for this evolving field, informed by the available literature. These recommendations provide guidance for the recognition, evaluation, surveillance, and management of the many emerging and chronic 22q11.2DS-associated multisystem morbidities relevant to adults. The recommendations also address key genetic counseling and psychosocial considerations for the increasing numbers of adults with this complex condition.


Assuntos
Síndrome de DiGeorge , Adulto , Humanos , Relevância Clínica , Consenso , Síndrome de DiGeorge/genética , Síndrome de DiGeorge/terapia , Aconselhamento Genético , Inquéritos e Questionários
13.
Genet Med ; 25(3): 100338, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36729053

RESUMO

This review aimed to update the clinical practice guidelines for managing children and adolescents with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society, the international scientific organization studying chromosome 22q11.2 differences and related conditions, recruited expert clinicians worldwide to revise the original 2011 pediatric clinical practice guidelines in a stepwise process: (1) a systematic literature search (1992-2021), (2) study selection and data extraction by clinical experts from 9 different countries, covering 24 subspecialties, and (3) creation of a draft consensus document based on the literature and expert opinion, which was further shaped by survey results from family support organizations regarding perceived needs. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text reviews, including 1545 meeting criteria for potential relevance to clinical care of children and adolescents. Informed by the available literature, recommendations were formulated. Given evidence base limitations, multidisciplinary recommendations represent consensus statements of good practice for this evolving field. These recommendations provide contemporary guidance for evaluation, surveillance, and management of the many 22q11.2DS-associated physical, cognitive, behavioral, and psychiatric morbidities while addressing important genetic counseling and psychosocial issues.


Assuntos
Síndrome de DiGeorge , Adolescente , Humanos , Criança , Síndrome de DiGeorge/genética , Síndrome de DiGeorge/terapia , Aconselhamento Genético , Inquéritos e Questionários
14.
Blood ; 137(24): 3443-3453, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-33512486

RESUMO

Glycoprotein VI (GPVI) is the major signaling receptor for collagen on platelets. We have raised 54 nanobodies (Nb), grouped into 33 structural classes based on their complementary determining region 3 loops, against recombinant GPVI-Fc (dimeric GPVI) and have characterized their ability to bind recombinant GPVI, resting and activated platelets, and to inhibit platelet activation by collagen. Nbs from 6 different binding classes showed the strongest binding to recombinant GPVI-Fc, suggesting that there was not a single dominant class. The most potent 3, Nb2, 21, and 35, inhibited collagen-induced platelet aggregation with nanomolar half maximal inhibitory concentration (IC50) values and inhibited platelet aggregation under flow. The binding KD of the most potent Nb, Nb2, against recombinant monomeric and dimeric GPVI was 0.6 and 0.7 nM, respectively. The crystal structure of monomeric GPVI in complex with Nb2 revealed a binding epitope adjacent to the collagen-related peptide (CRP) binding groove within the D1 domain. In addition, a novel conformation of GPVI involving a domain swap between the D2 domains was observed. The domain swap is facilitated by the outward extension of the C-C' loop, which forms the domain swap hinge. The functional significance of this conformation was tested by truncating the hinge region so that the domain swap cannot occur. Nb2 was still able to displace collagen and CRP binding to the mutant, but signaling was abolished in a cell-based NFAT reporter assay. This demonstrates that the C-C' loop region is important for GPVI signaling but not ligand binding and suggests the domain-swapped structure may represent an active GPVI conformation.


Assuntos
Complexo Antígeno-Anticorpo , Plaquetas , Glicoproteínas da Membrana de Plaquetas , Multimerização Proteica , Anticorpos de Domínio Único , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/metabolismo , Plaquetas/química , Plaquetas/metabolismo , Humanos , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/genética , Glicoproteínas da Membrana de Plaquetas/química , Glicoproteínas da Membrana de Plaquetas/genética , Glicoproteínas da Membrana de Plaquetas/metabolismo , Domínios Proteicos , Multimerização Proteica/efeitos dos fármacos , Multimerização Proteica/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/farmacologia
15.
Glob Chang Biol ; 29(6): 1423-1436, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36537002

RESUMO

Fire seasons have become increasingly variable and extreme due to changing climatological, ecological, and social conditions. Earth observation data are critical for monitoring fires and their impacts. Herein, we present a whole-system framework for identifying and synthesizing fire monitoring objectives and data needs throughout the life cycle of a fire event. The four stages of fire monitoring using Earth observation data include the following: (1) pre-fire vegetation inventories, (2) active-fire monitoring, (3) post-fire assessment, and (4) multi-scale synthesis. We identify the challenges and opportunities associated with current approaches to fire monitoring, highlighting four case studies from North American boreal, montane, and grassland ecosystems. While the case studies are localized to these ecosystems and regional contexts, they provide insights for others experiencing similar monitoring challenges worldwide. The field of remote sensing is experiencing a rapid proliferation of new data sources, providing observations that can inform all aspects of our fire monitoring framework; however, significant challenges for meeting fire monitoring objectives remain. We identify future opportunities for data sharing and rapid co-development of information products using cloud computing that benefits from open-access Earth observation and other geospatial data layers.


Assuntos
Incêndios , Incêndios Florestais , Ecossistema , Florestas
16.
Immunity ; 41(1): 36-48, 2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25035952

RESUMO

Chronic, low-grade adipose tissue inflammation is a key etiological mechanism linking the increasing incidence of type 2 diabetes (T2D) and obesity. It is well recognized that the immune system and metabolism are highly integrated, and macrophages, in particular, have been identified as critical effector cells in the initiation of inflammation and insulin resistance. Recent advances have been made in the understanding of macrophage recruitment and retention to adipose tissue and the participation of other immune cell populations in the regulation of this inflammatory process. Here we discuss the pathophysiological link between macrophages, obesity, and insulin resistance, highlighting the dynamic immune cell regulation of adipose tissue inflammation. We also describe the mechanisms by which inflammation causes insulin resistance and the new therapeutic targets that have emerged.


Assuntos
Tecido Adiposo/imunologia , Diabetes Mellitus Tipo 2/imunologia , Resistência à Insulina/imunologia , Macrófagos/imunologia , Obesidade/imunologia , Tecido Adiposo/citologia , Animais , Citocinas/imunologia , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Fígado/citologia , Fígado/imunologia , Ativação de Macrófagos/imunologia , Camundongos , Músculo Esquelético/citologia , Músculo Esquelético/imunologia , Obesidade/tratamento farmacológico , Obesidade/fisiopatologia , Transdução de Sinais/imunologia
17.
J Exp Biol ; 226(12)2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37282982

RESUMO

Recent studies of in vivo muscle function in guinea fowl revealed that distal leg muscles rapidly modulate force and work to stabilize running in uneven terrain. Previous studies focused on running only, and it remains unclear how muscular mechanisms for stability differ between walking and running. Here, we investigated in vivo function of the lateral gastrocnemius (LG) during walking over obstacles. We compared muscle function in birds with intact (iLG) versus self-reinnervated LG (rLG). Self-reinnervation results in proprioceptive feedback deficit due to loss of monosynaptic stretch reflex. We tested the hypothesis that proprioceptive deficit results in decreased modulation of EMG activity in response to obstacle contact, and a delayed obstacle recovery compared with that for iLG. We found that total myoelectric intensity (Etot) of iLG increased by 68% in obstacle strides (S 0) compared with level terrain, suggesting a substantial reflex-mediated response. In contrast, Etot of rLG increased by 31% in S 0 strides compared with level walking, but also increased by 43% in the first post-obstacle (S +1) stride. In iLG, muscle force and work differed significantly from level walking only in the S 0 stride, indicating a single-stride recovery. In rLG, force increased in S 0, S +1 and S +2 compared with level walking, indicating three-stride obstacle recovery. Interestingly, rLG showed little variation in work output and shortening velocity in obstacle terrain, indicating a shift towards near-isometric strut-like function. Reinnervated birds also adopted a more crouched posture across level and obstacle terrains compared with intact birds. These findings suggest gait-specific control mechanisms in walking and running.


Assuntos
Galliformes , Caminhada , Animais , Fenômenos Biomecânicos , Caminhada/fisiologia , Músculo Esquelético/fisiologia , Marcha/fisiologia , Galliformes/fisiologia
18.
PLoS Comput Biol ; 18(11): e1010708, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36441766

RESUMO

The clustering of platelet glycoprotein receptors with cytosolic YxxL and YxxM motifs, including GPVI, CLEC-2 and PEAR1, triggers activation via phosphorylation of the conserved tyrosine residues and recruitment of the tandem SH2 (Src homology 2) domain effector proteins, Syk and PI 3-kinase. We have modelled the clustering of these receptors with monovalent, divalent and tetravalent soluble ligands and with transmembrane ligands based on the law of mass action using ordinary differential equations and agent-based modelling. The models were experimentally evaluated in platelets and transfected cell lines using monovalent and multivalent ligands, including novel nanobody-based divalent and tetravalent ligands, by fluorescence correlation spectroscopy. Ligand valency, receptor number, receptor dimerisation, receptor phosphorylation and a cytosolic tandem SH2 domain protein act in synergy to drive receptor clustering. Threshold concentrations of a CLEC-2-blocking antibody and Syk inhibitor act in synergy to block platelet aggregation. This offers a strategy for countering the effect of avidity of multivalent ligands and in limiting off-target effects.


Assuntos
Glicoproteínas da Membrana de Plaquetas , Domínios de Homologia de src , Simulação por Computador
19.
Analyst ; 148(21): 5366-5379, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37702052

RESUMO

Paracetamol overdose is a leading cause of acute liver failure that can prove fatal. Establishing paracetamol concentration accurately and quickly is critical. Current detection methods are invasive, time-consuming and/or expensive. Non-invasive, rapid and cost-effective techniques are urgently required. To address this challenge, a novel approach, called Paper-Arrow Mass Spectrometry (PA-MS) has been developed. This technique combines sample collection, extraction, enrichment, separation and ionisation onto a single paper strip, and the entire analysis process, from sample to result, can be carried out in less than 10 min requiring only 2 µL of raw human saliva. PA-MS achieved a LOQ of 185 ng mL-1, mean recovery of 107 ± 7%, mean accuracy of 11 ± 8% and precision ≤5% using four concentrations, and had excellent linearity (r2 = 0.9988) in the range of 0.2-200 µg mL-1 covering the treatment concentration range, surpassing the best-in-class methods currently available for paracetamol analysis. Furthermore, from a panel of human saliva samples, inter-individual variability was found to be <10% using this approach. This technique represents a promising tool for rapid and accurate emergency diagnosis.

20.
Med J Aust ; 219(11): 535-541, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37940105

RESUMO

OBJECTIVE: To quantify the value of maternity health care - the relationship of outcomes to costs - in Queensland during 2012-18. STUDY DESIGN: Retrospective observational study; analysis of Queensland Perinatal Data Collection data linked with the Queensland Health Admitted Patient, Non-Admitted Patient, and Emergency Data Collections, and with the Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (PBS) databases. SETTING, PARTICIPANTS: All births in Queensland during 1 July 2012 - 30 June 2018. MAIN OUTCOME MEASURES: Maternity care costs per birth (reported in 2021-22 Australian dollars), both overall and by funder type (public hospital funders, MBS, PBS, private health insurers, out-of-pocket costs); value of care, defined as total cost per positive birth outcome (composite measure). RESULTS: The mean cost per birth (all funders) increased from $20 471 (standard deviation [SD], $17 513) during the second half of 2012 to $30 000 (SD, $22 323) during the first half of 2018; the annual total costs for all births increased from $1.31 billion to $1.84 billion, despite a slight decline in the total number of births. In a mixed effects linear analysis adjusted for demographic, clinical, and birth characteristics, the mean total cost per birth in the second half of 2018 was $9493 higher (99.9% confidence interval, $8930-10 056) than during the first half of 2012. The proportion of births that did not satisfy our criteria for a positive birth outcome increased from 27.1% (8404 births) during the second half of 2012 to 30.5% (9041 births) during the first half of 2018. CONCLUSION: The costs of maternity care have increased in Queensland, and many adverse birth outcomes have become more frequent. Broad clinical collaboration, effective prevention and treatment strategies, as well as maternal health services focused on all dimensions of value, are needed to ensure the quality and viability of maternity care in Australia.


Assuntos
Serviços de Saúde Materna , Obstetrícia , Idoso , Feminino , Gravidez , Humanos , Queensland/epidemiologia , Austrália , Programas Nacionais de Saúde
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA