Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 547
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Immunity ; 49(5): 899-914.e6, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30413360

RESUMO

Interleukin-2 (IL-2) and downstream transcription factor STAT5 are important for maintaining regulatory T (Treg) cell homeostasis and function. Treg cells can respond to low IL-2 levels, but the mechanisms of STAT5 activation during partial IL-2 deficiency remain uncertain. We identified the serine-threonine kinase Mst1 as a signal-dependent amplifier of IL-2-STAT5 activity in Treg cells. High Mst1 and Mst2 (Mst1-Mst2) activity in Treg cells was crucial to prevent tumor resistance and autoimmunity. Mechanistically, Mst1-Mst2 sensed IL-2 signals to promote the STAT5 activation necessary for Treg cell homeostasis and lineage stability and to maintain the highly suppressive phosphorylated-STAT5+ Treg cell subpopulation. Unbiased quantitative proteomics revealed association of Mst1 with the cytoskeletal DOCK8-LRCHs module. Mst1 deficiency limited Treg cell migration and access to IL-2 and activity of the small GTPase Rac, which mediated downstream STAT5 activation. Collectively, IL-2-STAT5 signaling depends upon Mst1-Mst2 functions to maintain a stable Treg cell pool and immune tolerance.


Assuntos
Fator de Crescimento de Hepatócito/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores de Interleucina-2/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/metabolismo , Animais , Autoimunidade/genética , Autoimunidade/imunologia , Linhagem da Célula/genética , Fator de Crescimento de Hepatócito/genética , Via de Sinalização Hippo , Interleucina-2/metabolismo , Camundongos , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Serina-Treonina Quinase 3 , Linfócitos T Reguladores/imunologia , Proteínas rac de Ligação ao GTP/metabolismo
2.
Nature ; 591(7849): 306-311, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33627871

RESUMO

Regulatory T cells (Treg cells) are essential for immune tolerance1, but also drive immunosuppression in the tumour microenvironment2. Therapeutic targeting of Treg cells in cancer will therefore require the identification of context-specific mechanisms that affect their function. Here we show that inhibiting lipid synthesis and metabolic signalling that are dependent on sterol-regulatory-element-binding proteins (SREBPs) in Treg cells unleashes effective antitumour immune responses without autoimmune toxicity. We find that the activity of SREBPs is upregulated in intratumoral Treg cells. Moreover, deletion of SREBP-cleavage-activating protein (SCAP)-a factor required for SREBP activity-in these cells inhibits tumour growth and boosts immunotherapy that is triggered by targeting the immune-checkpoint protein PD-1. These effects of SCAP deletion are associated with uncontrolled production of interferon-γ and impaired function of intratumoral Treg cells. Mechanistically, signalling through SCAP and SREBPs coordinates cellular programs for lipid synthesis and inhibitory receptor signalling in these cells. First, de novo fatty-acid synthesis mediated by fatty-acid synthase (FASN) contributes to functional maturation of Treg cells, and loss of FASN from Treg cells inhibits tumour growth. Second, Treg cells in tumours show enhanced expression of the PD-1 gene, through a process that depends on SREBP activity and signals via mevalonate metabolism to protein geranylgeranylation. Blocking PD-1 or SREBP signalling results in dysregulated activation of phosphatidylinositol-3-kinase in intratumoral Treg cells. Our findings show that metabolic reprogramming enforces the functional specialization of Treg cells in tumours, pointing to new ways of targeting these cells for cancer therapy.


Assuntos
Metabolismo dos Lipídeos , Neoplasias/imunologia , Neoplasias/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Animais , Colesterol/metabolismo , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Ácido Mevalônico/metabolismo , Camundongos , Fosfatidilinositol 3-Quinase/metabolismo , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/antagonistas & inibidores , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo , Linfócitos T Reguladores/enzimologia , Regulação para Cima
3.
Proc Natl Acad Sci U S A ; 120(36): e2302342120, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37639589

RESUMO

Inhibition of overexpressed enzymes is among the most promising approaches for targeted cancer treatment. However, many cancer-expressed enzymes are "nonlethal," in that the inhibition of the enzymes' activity is insufficient to kill cancer cells. Conventional antibody-based therapeutics can mediate efficient treatment by targeting extracellular nonlethal targets but can hardly target intracellular enzymes. Herein, we report a cancer targeting and treatment strategy to utilize intracellular nonlethal enzymes through a combination of selective cancer stem-like cell (CSC) labeling and Click chemistry-mediated drug delivery. A de novo designed compound, AAMCHO [N-(3,4,6-triacetyl- N-azidoacetylmannosamine)-cis-2-ethyl-3-formylacrylamideglycoside], selectively labeled cancer CSCs in vitro and in vivo through enzymatic oxidation by intracellular aldehyde dehydrogenase 1A1. Notably, azide labeling is more efficient in identifying tumorigenic cell populations than endogenous markers such as CD44. A dibenzocyclooctyne (DBCO)-toxin conjugate, DBCO-MMAE (Monomethylauristatin E), could next target the labeled CSCs in vivo via bioorthogonal Click reaction to achieve excellent anticancer efficacy against a series of tumor models, including orthotopic xenograft, drug-resistant tumor, and lung metastasis with low toxicity. A 5/7 complete remission was observed after single-cycle treatment of an advanced triple-negative breast cancer xenograft (~500 mm3).


Assuntos
Aldeído Desidrogenase , Anticorpos , Humanos , Azidas , Carcinogênese , Química Click , Família Aldeído Desidrogenase 1 , Retinal Desidrogenase
4.
Nature ; 573(7775): 614, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31554976

RESUMO

This Article has been retracted; see accompanying Retraction Note.

5.
Nature ; 565(7737): 101-105, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30568299

RESUMO

A defining feature of adaptive immunity is the development of long-lived memory T cells to curtail infection. Recent studies have identified a unique stem-like T-cell subset amongst exhausted CD8-positive T cells in chronic infection1-3, but it remains unclear whether CD4-positive T-cell subsets with similar features exist in chronic inflammatory conditions. Amongst helper T cells, TH17 cells have prominent roles in autoimmunity and tissue inflammation and are characterized by inherent plasticity4-7, although how such plasticity is regulated is poorly understood. Here we demonstrate that TH17 cells in a mouse model of autoimmune disease are functionally and metabolically heterogeneous; they contain a subset with stemness-associated features but lower anabolic metabolism, and a reciprocal subset with higher metabolic activity that supports transdifferentiation into TH1-like cells. These two TH17-cell subsets are defined by selective expression of the transcription factors TCF-1 and T-bet, and by discrete levels of CD27 expression. We also identify signalling via the kinase complex mTORC1 as a central regulator of TH17-cell fate decisions by coordinating metabolic and transcriptional programmes. TH17 cells with disrupted mTORC1 signalling or anabolic metabolism fail to induce autoimmune neuroinflammation or to develop into TH1-like cells, but instead upregulate TCF-1 expression and acquire stemness-associated features. Single-cell RNA sequencing and experimental validation reveal heterogeneity in fate-mapped TH17 cells, and a developmental arrest in the TH1 transdifferentiation trajectory upon loss of mTORC1 activity or metabolic perturbation. Our results establish that the dichotomy of stemness and effector function underlies the heterogeneous TH17 responses and autoimmune pathogenesis, and point to previously unappreciated metabolic control of plasticity in helper T cells.


Assuntos
Transdiferenciação Celular , Células-Tronco/citologia , Células-Tronco/metabolismo , Células Th17/citologia , Células Th17/metabolismo , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Modelos Animais de Doenças , Feminino , Memória Imunológica/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Proteína Regulatória Associada a mTOR/deficiência , Proteína Regulatória Associada a mTOR/genética , Análise de Sequência de RNA , Transdução de Sinais , Análise de Célula Única , Células-Tronco/imunologia , Fator 1 de Transcrição de Linfócitos T/biossíntese , Fator 1 de Transcrição de Linfócitos T/metabolismo , Proteínas com Domínio T/biossíntese , Proteínas com Domínio T/metabolismo , Células Th17/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
6.
Nature ; 563(7729): 105-108, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30382201

RESUMO

The ocean is the main source of thermal inertia in the climate system1. During recent decades, ocean heat uptake has been quantified by using hydrographic temperature measurements and data from the Argo float program, which expanded its coverage after 20072,3. However, these estimates all use the same imperfect ocean dataset and share additional uncertainties resulting from sparse coverage, especially before 20074,5. Here we provide an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2)-levels of which increase as the ocean warms and releases gases-as a whole-ocean thermometer. We show that the ocean gained 1.33 ± 0.20  × 1022 joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.83 ± 0.11 watts per square metre of Earth's surface. We also find that the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks. Our result-which relies on high-precision O2 measurements dating back to 19916-suggests that ocean warming is at the high end of previous estimates, with implications for policy-relevant measurements of the Earth response to climate change, such as climate sensitivity to greenhouse gases7 and the thermal component of sea-level rise8.

7.
Nature ; 558(7708): 141-145, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29849151

RESUMO

Dendritic cells orchestrate the crosstalk between innate and adaptive immunity. CD8α+ dendritic cells present antigens to CD8+ T cells and elicit cytotoxic T cell responses to viruses, bacteria and tumours 1 . Although lineage-specific transcriptional regulators of CD8α+ dendritic cell development have been identified 2 , the molecular pathways that selectively orchestrate CD8α+ dendritic cell function remain elusive. Moreover, metabolic reprogramming is important for dendritic cell development and activation3,4, but metabolic dependence and regulation of dendritic cell subsets are largely uncharacterized. Here we use a data-driven systems biology algorithm (NetBID) to identify a role of the Hippo pathway kinases Mst1 and Mst2 (Mst1/2) in selectively programming CD8α+ dendritic cell function and metabolism. Our NetBID analysis reveals a marked enrichment of the activities of Hippo pathway kinases in CD8α+ dendritic cells relative to CD8α- dendritic cells. Dendritic cell-specific deletion of Mst1/2-but not Lats1 and Lats2 (Lats1/2) or Yap and Taz (Yap/Taz), which mediate canonical Hippo signalling-disrupts homeostasis and function of CD8+ T cells and anti-tumour immunity. Mst1/2-deficient CD8α+ dendritic cells are impaired in presentation of extracellular proteins and cognate peptides to prime CD8+ T cells, while CD8α- dendritic cells that lack Mst1/2 have largely normal function. Mechanistically, compared to CD8α- dendritic cells, CD8α+ dendritic cells exhibit much stronger oxidative metabolism and critically depend on Mst1/2 signalling to maintain bioenergetic activities and mitochondrial dynamics for their functional capacities. Further, selective expression of IL-12 by CD8α+ dendritic cells depends on Mst1/2 and the crosstalk with non-canonical NF-κB signalling. Our findings identify Mst1/2 as selective drivers of CD8α+ dendritic cell function by integrating metabolic activity and cytokine signalling, and highlight that the interplay between immune signalling and metabolic reprogramming underlies the unique functions of dendritic cell subsets.


Assuntos
Antígenos CD8/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Algoritmos , Animais , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Apresentação Cruzada/imunologia , Células Dendríticas/citologia , Via de Sinalização Hippo , Homeostase , Interleucina-12/imunologia , Interleucina-12/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Serina-Treonina Quinase 3 , Proteínas Supressoras de Tumor
8.
Cryo Letters ; 45(3): 177-184, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709189

RESUMO

BACKGROUND: Ovarian tissue cryopreservation for fertility preservation carries a risk of malignant cell re-seeding. Artificial ovary is a promising method to solve such a problem. However, ovary decellularization protocols are limited. Hence, further studies are necessary to get better ovarian decellularization techniques for the construction of artificial ovary scaffolds. OBJECTIVE: To establish an innovative decellularization technique for whole porcine ovaries by integrating liquid nitrogen with chemical agents to reduce the contact time between the scaffolds and chemical reagents. MATERIALS AND METHODS: Porcine ovaries were randomly assigned to three groups: novel decellularized group, conventional decellularized group and fresh group. The ovaries in the novel decellularized group underwent three cycles of freezing by liquid nitrogen and thawing at temperatures around 37 degree C before decellularization. The efficiency of the decellularization procedure was assessed through histological staining and DNA content analysis. The maintenance of ovarian decellularized extracellular matrix(ODECM) constituents was determined by analyzing the content of matrix proteins. Additionally, we evaluated the biocompatibility of the decellularized extracellular matrix(dECM) by observing the growth of granulosa cells on the ODECM scaffold in vitro. RESULTS: Hematoxylin and eosin staining, DAPI staining and DNA quantification techniques collectively confirm the success of the novel decellularization methods in removing cellular and nuclear components from ovarian tissue. Moreover, quantitative assessments of ODECM contents revealed that the novel decellularization technique preserved more collagen and glycosaminoglycan compared to the conventional decellularized group (P<0.05). Additionally, the novel decellularized scaffold exhibited a significantly higher number of granulosa cells than the conventional scaffold during in vitro co-culture (P<0.05). CONCLUSION: The novel decellularized method demonstrated high efficacy in eliminating DNA and cellular structures while effectively preserving the extracellular matrix. As a result, the novel decellularized method holds significant promise as a viable technique for ovarian decellularization in forthcoming studies. Doi.org/10.54680/fr24310110212.


Assuntos
Criopreservação , Matriz Extracelular Descelularizada , Nitrogênio , Ovário , Alicerces Teciduais , Animais , Feminino , Nitrogênio/química , Suínos , Ovário/citologia , Alicerces Teciduais/química , Criopreservação/métodos , Matriz Extracelular Descelularizada/química , Engenharia Tecidual/métodos , Células da Granulosa/citologia , Preservação da Fertilidade/métodos , Matriz Extracelular/química , DNA/análise , DNA/química
9.
Dig Dis Sci ; 68(8): 3413-3420, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37115362

RESUMO

BACKGROUND: Primary and secondary non-response to anti-tumor necrosis factor (TNF) therapy is common in patients with Crohn's disease (CD), yet limited research has compared the effectiveness of subsequent biological therapy. OBJECTIVE: We sought to compare the effectiveness of vedolizumab and ustekinumab in anti-TNF-experienced patients with CD, focusing on patient-prioritized patient-reported outcomes (PROs). METHODS: We conducted a prospective, internet-based cohort study nested within IBD Partners. We identified anti-TNF-experienced patients initiating with CD vedolizumab or ustekinumab and analyzed PROs reported approximately 6 months later (minimum 4 months, maximum 10 months). Co-primary outcomes were Patient-Reported Outcome Measurement Information System (PROMIS) domains of Fatigue and Pain Interference. Secondary outcomes included patient-reported short Crohn's disease activity index (sCDAI), treatment persistence, and corticosteroid use. Inverse probability of treatment weighting (IPTW) was used to control for a number of potential confounders and incorporated into linear and logistic regression models for continuous and categorical outcomes, respectively. RESULTS: Overall, 141 vedolizumab and 219 ustekinumab initiators were included in our analysis. After adjustment, we found no differences between treatment groups in our primary outcomes of Pain Interference or Fatigue or the secondary outcome of sCDAI. However, vedolizumab was associated with lower treatment persistence (OR 0.4, 95% CI 0.2-0.6) and higher corticosteroid use at follow-up assessment (OR 1.7, 95% CI 1.1-2.6). DISCUSSION: Among anti-TNF experienced patients with CD, Pain Interference or Fatigue was not significantly different 4-10 months after starting ustekinumab or vedolizumab. However, reduced steroid use and increased persistence suggest superiority of ustekinumab for non-PRO outcomes.


Assuntos
Doença de Crohn , Ustekinumab , Humanos , Ustekinumab/efeitos adversos , Doença de Crohn/diagnóstico , Doença de Crohn/tratamento farmacológico , Doença de Crohn/induzido quimicamente , Inibidores do Fator de Necrose Tumoral , Estudos de Coortes , Estudos Prospectivos , Corticosteroides , Resultado do Tratamento , Estudos Retrospectivos
10.
Beijing Da Xue Xue Bao Yi Xue Ban ; 55(3): 521-529, 2023 Jun 18.
Artigo em Zh | MEDLINE | ID: mdl-37291929

RESUMO

OBJECTIVE: To analyze the clinicopathological features, molecular changes and prognostic factors in angioimmunoblastic T-cell lymphoma (AITL). METHODS: Sixty-one cases AITL diagnosed by Department of Pathology of Peking University Cancer Hospital were collected with their clinical data. Morphologically, they were classified as typeⅠ[lymphoid tissue reactive hyperplasia (LRH) like]; typeⅡ[marginal zone lymphoma(MZL)like] and type Ⅲ [peripheral T-cell lymphoma, not specified (PTCL-NOS) like]. Immunohistochemical staining was used to evaluate the presence of follicular helper T-cell (TFH) phenotype, proliferation of extra germinal center (GC) follicular dendritic cells (FDCs), presence of Hodgkin and Reed-Sternberg (HRS)-like cells and large B transformation. The density of Epstein-Barr virus (EBV) + cells was counted with slides stained by Epstein-Barr virus encoded RNA (EBER) in situ hybridization on high power field (HPF). T-cell receptor / immunoglobulin gene (TCR/IG) clonality and targeted exome sequencing (TES) test were performed when necessary. SPSS 22.0 software was used for statistical analysis. RESULTS: Morphological subtype (%): 11.4% (7/61) cases were classified as type Ⅰ; 50.8% (31/61) as type Ⅱ; 37.8% (23/61) as type Ⅲ. 83.6% (51/61) cases showed classical TFH immunophenotype. With variable extra-GC FDC meshwork proliferation (median 20.0%); 23.0% (14/61) had HRS-like cells; 11.5% (7/61) with large B transformation. 42.6% (26/61) of cases with high counts of EBV. 57.9% (11/19) TCR+/IG-, 26.3% (5/19) TCR+/IG+, 10.5% (2/19) were TCR-/IG-, and 5.3% (1/19) TCR-/IG+. Mutation frequencies by TES were 66.7% (20/30) for RHOA, 23.3% (7/30) for IDH2 mutation, 80.0% (24/30) for TET2 mutation, and 33.3% (10/30) DNMT3A mutation. Integrated analysis divided into four groups: (1) IDH2 and RHOA co-mutation group (7 cases): 6 cases were type Ⅱ, 1 case was type Ⅲ; all with typical TFH phenotype; HRS-like cells and large B transformation were not found; (2) RHOA single mutation group (13 cases): 1 case was type Ⅰ, 6 cases were type Ⅱ, 6 cases were type Ⅲ; 5 cases without typical TFH phenotype; 6 cases had HRS-like cells, and 2 cases with large B transformation. Atypically, 1 case showed TCR-/IG-, 1 case with TCR-/IG+, and 1 case with TCR+/IG+; (3) TET2 and/or DNMT3A mutation alone group (7 cases): 3 cases were type Ⅱ, 4 cases were type Ⅲ, all cases were found with typical TFH phenotype; 2 cases had HRS-like cells, 2 cases with large B transformation, and atypically; (4) non-mutation group (3 cases), all were type Ⅱ, with typical TFH phenotype, with significant extra-GC FDC proliferation, without HRS-like cells and large B transformation. Atypically, 1 case was TCR-/IG-. Univariate analysis confirmed that higher density of EBV positive cell was independent adverse prognostic factors for both overall survival (OS) and progression free survival(PFS), (P=0.017 and P=0.046). CONCLUSION: Pathological diagnoses of ALTL cases with HRS-like cells, large B transformation or type Ⅰ are difficult. Although TCR/IG gene rearrangement test is helpful but still with limitation. TES involving RHOA, IDH2, TET2, DNMT3A can robustly assist in the differential diagnosis of those difficult cases. Higher density of EBV positive cells counts in tumor tissue might be an indicator for poor survival.


Assuntos
Infecções por Vírus Epstein-Barr , Linfadenopatia Imunoblástica , Linfoma de Células T Periférico , Humanos , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/genética , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Auxiliares-Indutores/patologia , Linfadenopatia Imunoblástica/genética , Linfadenopatia Imunoblástica/patologia , Linfoma de Células T Periférico/genética , Linfoma de Células T Periférico/metabolismo , Linfoma de Células T Periférico/patologia , Receptores de Antígenos de Linfócitos T
11.
Zhonghua Gan Zang Bing Za Zhi ; 31(5): 551-555, 2023 May 20.
Artigo em Zh | MEDLINE | ID: mdl-37365035

RESUMO

Relevant research in recent years has demonstrated that the atrial fibrillation occurrence rate is significantly higher in patients with cirrhosis. The most common indication for long-term anticoagulant therapy is chronic atrial fibrillation. The use of anticoagulant therapy greatly reduces the incidence rate of ischemic stroke. Patients with cirrhosis combined with atrial fibrillation have an elevated risk of bleeding and embolism during anticoagulant therapy due to cirrhotic coagulopathy. At the same time, the liver of such patients will go through varying levels of metabolism and elimination while consuming currently approved anticoagulant drugs, thereby increasing the complexity of anticoagulant therapy. This article summarizes the clinical studies on the risks and benefits of anticoagulant therapy in order to provide a reference for patients with cirrhosis combined with atrial fibrillation.


Assuntos
Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/epidemiologia , Anticoagulantes/uso terapêutico , Hemorragia , Cirrose Hepática/complicações , Cirrose Hepática/tratamento farmacológico , Fatores de Risco
12.
Geophys Res Lett ; 49(5): e2021GL096990, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35859935

RESUMO

The reflection-by-sheath mechanism of 5 kHz narrowband emissions (NB) at Saturn is confirmed by Cassini observations during several crossings of the magnetopause, which show that the 5 kHz NB can be prevented from escaping Saturn's magnetosphere. The L-O mode 5 kHz NB remained visible in areas of low plasma density but disappeared in regions of high plasma density. In three cases, NB disappeared immediately after the crossings of Saturn's magnetopause. A possible reflected NB event observed near the magnetosheath is discussed. This mechanism can help explain the 5 kHz NB observed at low latitudes outside the Enceladus plasma torus and their upper frequency limit variations. This mechanism significantly improves the current understanding of the 5 kHz NB.

13.
Geophys Res Lett ; 49(16): e2022GL099237, 2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36249464

RESUMO

A new radio component namely Saturn Anomalous Myriametric Radiation (SAM) is reported. A total of 193 SAM events have been identified by using all the Cassini Saturn orbital data. SAM emissions are L-O mode radio emission and occasionally accompanied by a first harmonic in R-X mode. SAM's intensities decrease with increasing distance from Saturn, suggesting a source near Saturn. SAM has a typical central frequency near 13 kHz, a bandwidth greater than 8 kHz and usually drifts in frequency over time. SAM's duration can extend to near 11 hr and even longer. These features distinguish SAM from the regular narrowband emissions observed in the nearby frequency range, hence the name anomalous. The high occurrence rate of SAM after low frequency extensions of Saturn Kilometric Radiation and the SAM cases observed during compressions of Saturn's magnetosphere suggest a special connection to solar wind dynamics and magnetospheric conditions at Saturn.

14.
Proc Natl Acad Sci U S A ; 116(18): 8709-8714, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30975744

RESUMO

Developing highly active, multivalent ligands as therapeutic agents is challenging because of delivery issues, limited cell permeability, and toxicity. Here, we report intrinsically cell-penetrating multivalent ligands that target the trinucleotide repeat DNA and RNA in myotonic dystrophy type 1 (DM1), interrupting the disease progression in two ways. The oligomeric ligands are designed based on the repetitive structure of the target with recognition moieties alternating with bisamidinium groove binders to provide an amphiphilic and polycationic structure, mimicking cell-penetrating peptides. Multiple biological studies suggested the success of our multivalency strategy. The designed oligomers maintained cell permeability and exhibited no apparent toxicity both in cells and in mice at working concentrations. Furthermore, the oligomers showed important activities in DM1 cells and in a DM1 liver mouse model, reducing or eliminating prominent DM1 features. Phenotypic recovery of the climbing defect in adult DM1 Drosophila was also observed. This design strategy should be applicable to other repeat expansion diseases and more generally to DNA/RNA-targeted therapeutics.


Assuntos
Distrofia Miotônica/tratamento farmacológico , Proteínas de Ligação a RNA/metabolismo , Repetições de Trinucleotídeos , Animais , DNA , Proteínas de Ligação a DNA , Drosophila melanogaster , Células HeLa , Humanos , Ligantes , Fígado/metabolismo , Camundongos , Mioblastos/fisiologia , Distrofia Miotônica/genética , Proteínas com Motivo de Reconhecimento de RNA , Proteínas de Ligação a RNA/química
15.
J Assist Reprod Genet ; 39(7): 1423-1431, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35653042

RESUMO

In recent years, researchers have successfully generated many human and mammalian organoid models, including organoids representing the intestine, prostate, ovary, bladder, liver, and brain. Therefore, organoids have become an important research model in the fields of regenerative medicine, drug research, and gene therapy, acting as a bridge between in vivo and in vitro experiments. In addition, testicular organoids (TOs) represent the highest level of in vitro culture of spermatogenic cells in a simulated testicular environment. However, the generation of TOs is still in the early stages, and there is still much room for improvement in dealing with the many challenges and prospects to achieve the goal of TOs that simulate the testicular microenvironment in vitro or even reconstruct the process of spermatogenesis without the need to reconstruct seminiferous tubules. We review the brief history of TO generation and some major strategies for functional applications of TOs, which are the main concerns of our clinicians and laboratory researchers.


Assuntos
Organoides , Testículo , Animais , Humanos , Masculino , Mamíferos , Espermatogênese/genética
16.
Osteoarthritis Cartilage ; 29(8): 1203-1212, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34023528

RESUMO

OBJECTIVE: Characterization of a novel human placental tissue-derived biologic, PTP-001, which is in development as a candidate therapeutic for the treatment of osteoarthritis symptoms and pathophysiology. METHODS: Human placental tissues from healthy donors were prepared as a particulate formulation, PTP-001. PTP-001 extracts were assayed for the presence of disease-relevant biofactors which could have beneficial effects in treating osteoarthritis. PTP-001 eluates were tested in human chondrocyte cultures to determine effects on the production of a key collagen-degrading matrix metalloproteinase, MMP-13. PTP-001 eluates were also assessed for anti-inflammatory potential in human monocyte/macrophage cultures, as well as for growth-stimulating anabolic effects in human synoviocytes. The in vivo effects of PTP-001 on joint pain and histopathology were evaluated in a rat model of osteoarthritis induced surgically by destabilization of the medial meniscus. RESULTS: PTP-001 was found to contain an array of beneficial growth factors, cytokines and anti-inflammatory molecules. PTP-001 eluates dose-dependently inhibited the production of chondrocyte MMP-13, and the secretion of proinflammatory cytokines from monocyte/macrophage cultures. PTP-001 eluates also promoted proliferation of cultured synovial cells. In a rat osteoarthritis model, PTP-001 significantly reduced pain responses throughout 6 weeks post-dosing. The magnitude and duration of pain reduction following a single intraarticular treatment with PTP-001 was comparable to that observed for animals treated with a corticosteroid (active control). For rats dosed twice with PTP-001, significant reductions in cartilage histopathology scores were observed. CONCLUSIONS: PTP-001 represents a promising biologic treatment for osteoarthritis, with a multi-modal mechanism of action that may contribute to symptom management and disease modification.


Assuntos
Produtos Biológicos/farmacologia , Osteoartrite/tratamento farmacológico , Animais , Artralgia/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Condrócitos/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Metaloproteinase 13 da Matriz/metabolismo , Placenta/química , Gravidez , Ratos , Membrana Sinovial/citologia
17.
Biochemistry ; 59(37): 3463-3472, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32856901

RESUMO

There are few methods available for the rapid discovery of multitarget drugs. Herein, we describe the template-assisted, target-guided discovery of small molecules that recognize d(CTG) in the expanded d(CTG·CAG) sequence and its r(CUG) transcript that cause myotonic dystrophy type 1. A positive cross-selection was performed using a small library of 30 monomeric alkyne- and azide-containing ligands capable of producing >5000 possible di- and trimeric click products. The monomers were incubated with d(CTG)16 or r(CUG)16 under physiological conditions, and both sequences showed selectivity in the proximity-accelerated azide-alkyne [3+2] cycloaddition click reaction. The limited number of click products formed in both selections and the even smaller number of common products suggests that this method is a useful tool for the discovery of single-target and multitarget lead therapeutic agents.


Assuntos
DNA/antagonistas & inibidores , Distrofia Miotônica/tratamento farmacológico , Distrofia Miotônica/genética , RNA/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Expansão das Repetições de Trinucleotídeos/efeitos dos fármacos , Células Cultivadas , DNA/genética , DNA/metabolismo , Humanos , Distrofia Miotônica/patologia , RNA/genética , RNA/metabolismo , Expansão das Repetições de Trinucleotídeos/genética
18.
Biochem Biophys Res Commun ; 529(3): 773-777, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32736706

RESUMO

Nesfatin-1, a pleotropic peptide, was recently implicated in the regulation of anxiety and depression-like behavior in rats. However, the underlying mechanisms remain unclear so far. Thus, this study aimed to investigate the role of endogenous nesfatin-1 in the mediation of anxiety and depression-like behavior induced by corticotropin-releasing factor (CRF). Therefore, normal weight male intracerebroventricularly (icv) cannulated Sprague Dawley rats received two consecutive icv injections of anti-nesfatin-1 antibody or IgG control antibody followed by CRF or saline, before being exposed to a behavioral test. In the elevated zero maze test, assessing anxiety and explorative behavior, blockade of nesfatin-1 using an anti-nesfatin-1 antibody under basal conditions increased the number of entries into the open arms compared to control antibody/vehicle (1.6-fold, p < 0.05) and the time in open arms compared to the other groups (p < 0.05). Control antibody/CRF-treated animals tended to spend less time in the open arms compared to control antibody/vehicle (0.7-fold, p = 0.17), an effect not altered by the nesfatin-1 antibody (control antibody/CRF-treated animals vs. nesfatin-1 antibody/CRF group, p = 1.00). In the novelty-induced hypophagia test, assessing anhedonia as part of depression-like behavior, no significant differences were observed between the four groups for the latency to the first bout, number of bouts and the amount of palatable snack eaten (p > 0.05). In summary, CRF tended to increase anxiety and explorative behavior an effect not altered by blockade of nesfatin-1, whereas no significant effect of CRF on anhedonia was observed. Blockade of endogenous nesfatin-1 significantly decreased anxiety-like behavior giving rise to a physiological role of brain nesfatin-1 in the mediation of anxiety.


Assuntos
Ansiolíticos/uso terapêutico , Anticorpos/uso terapêutico , Ansiedade/induzido quimicamente , Ansiedade/tratamento farmacológico , Hormônio Liberador da Corticotropina , Nucleobindinas/antagonistas & inibidores , Animais , Ansiedade/prevenção & controle , Depressão/induzido quimicamente , Depressão/tratamento farmacológico , Depressão/prevenção & controle , Masculino , Ratos Sprague-Dawley
19.
Herz ; 44(4): 354-362, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29181563

RESUMO

BACKGROUND: The efficacy of final kissing balloon (FKB) inflation in one-stent techniques for bifurcation lesions is controversial. The goal of the present study was to investigate the impact of FKB on long-term clinical outcomes in one-stent strategies. METHODS: A literature search of the PubMed, Embase, and Cochrane Library databases was undertaken through August 2017. The primary outcome was major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, and target lesion revascularization. Overall hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using the random-effects model. RESULTS: Ten studies comprising 7364 patients treated with a one-stent technique were included in the analysis. Overall, FKB did not demonstrate a significant reduction in MACE compared with non-FKB in both randomized trials (HR: 1.13; 95% CI: 0.65-1.98) and observational studies (HR: 0.86; 95% CI: 0.61-1.20). The risk of cardiac death (HR: 0.89; 95% CI: 0.53-1.49), myocardial infarction (HR: 0.76; 95% CI: 0.53-1.09), and target lesion revascularization (HR: 0.96; 95% CI: 0.74-1.23) was also similar in both groups. CONCLUSION: FKB may not be mandatory and a selective FKB strategy might be more justified in one-stent techniques for bifurcation lesions.


Assuntos
Doença da Artéria Coronariana , Infarto do Miocárdio , Stents , Idoso , Angiografia Coronária , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/prevenção & controle , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Resultado do Tratamento
20.
Diabet Med ; 35(12): 1686-1692, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30175547

RESUMO

AIM: Attending routine outpatient clinic appointments is a central self-management behaviour of individuals living with Type 1 diabetes. A large number of young adults with Type 1 diabetes disengage from diabetes services, which may contribute to poor psychosocial and diabetes outcomes. The aim of this study is to elicit preferences from young adults with Type 1 diabetes regarding clinic-related services to inform service delivery. METHODS: A discrete choice experiment was developed to understand the preferences of young adults with Type 1 diabetes for clinic-related services. RESULTS: Young adults recruited from young adult Type 1 diabetes clinics in 2016 completed the experiment (n = 105). Young adults with Type 1 diabetes showed a preference for shorter waiting times, seeing a nurse and a consultant, relative to a nurse alone, and a flexible booking system compared with fixed appointment times. Results suggest no preference for a nurse and a doctor, relative to a nurse alone, or other optional services (e.g. seeing dietitians or psychologists), type of HbA1c test and digital blood glucose diaries over paper-based diaries. CONCLUSION: This study highlights aspects of routine clinic appointments that are valued by young adults living with Type 1 diabetes, namely shorter waiting times at clinic, the option to see both a nurse and consultant at each visit and a flexible clinic appointment booking system. These findings suggest young adults with Type 1 diabetes value convenience and should help services to restructure their clinics to be more responsive to the needs of young adults.


Assuntos
Comportamento de Escolha , Diabetes Mellitus Tipo 1/terapia , Preferência do Paciente , Adolescente , Adulto , Instituições de Assistência Ambulatorial , Glicemia/análise , Automonitorização da Glicemia/instrumentação , Automonitorização da Glicemia/métodos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/psicologia , Feminino , Grupos Focais , Humanos , Masculino , Preferência do Paciente/psicologia , Preferência do Paciente/estatística & dados numéricos , Satisfação do Paciente/estatística & dados numéricos , Relações Profissional-Paciente , Inquéritos e Questionários , Fatores de Tempo , Listas de Espera , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA