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1.
Mol Cell ; 79(5): 836-845.e7, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32649884

RESUMO

The inactive X chromosome (Xi) is inherently susceptible to genomic aberrations. Replication stress (RS) has been proposed as an underlying cause, but the mechanisms that protect from Xi instability remain unknown. Here, we show that macroH2A1.2, an RS-protective histone variant enriched on the Xi, is required for Xi integrity and female survival. Mechanistically, macroH2A1.2 counteracts its structurally distinct and equally Xi-enriched alternative splice variant, macroH2A1.1. Comparative proteomics identified a role for macroH2A1.1 in alternative end joining (alt-EJ), which accounts for Xi anaphase defects in the absence of macroH2A1.2. Genomic instability was rescued by simultaneous depletion of macroH2A1.1 or alt-EJ factors, and mice deficient for both macroH2A1 variants harbor no overt female defects. Notably, macroH2A1 splice variant imbalance affected alt-EJ capacity also in tumor cells. Together, these findings identify macroH2A1 splicing as a modulator of genome maintenance that ensures Xi integrity and may, more broadly, predict DNA repair outcome in malignant cells.


Assuntos
Processamento Alternativo , Reparo do DNA , Epigênese Genética , Instabilidade Genômica , Histonas/fisiologia , Anáfase , Animais , Linhagem Celular , Instabilidade Cromossômica , Cromossomos Humanos X , Feminino , Histonas/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
2.
Mol Cell ; 69(1): 36-47.e7, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29249653

RESUMO

Recent integrative epigenome analyses highlight the importance of functionally distinct chromatin states for accurate cell function. How these states are established and maintained is a matter of intense investigation. Here, we present evidence for DNA damage as an unexpected means to shape a protective chromatin environment at regions of recurrent replication stress (RS). Upon aberrant fork stalling, DNA damage signaling and concomitant H2AX phosphorylation coordinate the FACT-dependent deposition of macroH2A1.2, a histone variant that promotes DNA repair by homologous recombination (HR). MacroH2A1.2, in turn, facilitates the accumulation of the tumor suppressor and HR effector BRCA1 at replication forks to protect from RS-induced DNA damage. Consequently, replicating primary cells steadily accrue macroH2A1.2 at fragile regions, whereas macroH2A1.2 loss in these cells triggers DNA damage signaling-dependent senescence, a hallmark of RS. Altogether, our findings demonstrate that recurrent DNA damage contributes to the chromatin landscape to ensure the epigenomic integrity of dividing cells.


Assuntos
Carcinogênese/genética , Cromatina/genética , Dano ao DNA/genética , Reparo do DNA/genética , Replicação do DNA/genética , Histonas/genética , Recombinação Homóloga/genética , Proteína BRCA1/metabolismo , Divisão Celular/genética , Células Cultivadas , Senescência Celular/genética , Instabilidade Genômica/fisiologia , Humanos , Transdução de Sinais/genética
3.
Plant Biotechnol J ; 22(5): 1402-1416, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38163285

RESUMO

Immunoglobulin G (IgG)-based fusion proteins have been widely exploited as a potential vaccine delivery platform but in the absence of exogenous adjuvants, the lack of robust immunity remains an obstacle. Here, we report on a key modification that overcomes that obstacle. Thus, we constructed an IgG-Fc vaccine platform for dengue, termed D-PCF, which in addition to a dengue antigen incorporates the cholera toxin non-toxic B subunit (CTB) as a molecular adjuvant, with all three proteins expressed as a single polypeptide. Following expression in Nicotiana benthamiana plants, the D-PCF assembled as polymeric structures of similar size to human IgM, a process driven by the pentamerization of CTB. A marked improvement of functional properties in vitro and immunogenicity in vivo over a previous iteration of the Fc-fusion protein without CTB [1] was demonstrated. These include enhanced antigen presenting cell binding, internalization and activation, complement activation, epithelial cell interactions and ganglioside binding, as well as more efficient polymerization within the expression host. Following immunization of mice with D-PCF by a combination of systemic and mucosal (intranasal) routes, we observed robust systemic and mucosal immune responses, as well as systemic T cell responses, significantly higher than those induced by a related Fc-fusion protein but without CTB. The induced antibodies could bind to the domain III of the dengue virus envelope protein from all four dengue serotypes. Finally, we also demonstrated feasibility of aerosolization of D-PCF as a prerequisite for vaccine delivery by the respiratory route.


Assuntos
Dengue , Vacinas , Animais , Camundongos , Humanos , Toxina da Cólera/química , Toxina da Cólera/metabolismo , Proteínas de Plantas , Adjuvantes Imunológicos , Peptídeos , Imunoglobulina G , Camundongos Endogâmicos BALB C
4.
J Gen Virol ; 104(12)2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38063292

RESUMO

The shortcomings of current direct-acting anti-viral therapy against human cytomegalovirus (HCMV) has led to interest in host-directed therapy. Here we re-examine the use of interferon proteins to inhibit HCMV replication utilizing both high and low passage strains of HCMV. Pre-treatment of cells with interferon alpha (IFNα) was required for robust and prolonged inhibition of both low and high passage HCMV strains, with no obvious toxicity, and was associated with an increased anti-viral state in HCMV-infected cells. Pre-treatment of cells with IFNα led to poor expression of HCMV immediate-early proteins from both high and low passage strains, which was associated with the presence of the anti-viral factor SUMO-PML. Inhibition of HCMV replication in the presence of IFNα involving ZAP proteins was HCMV strain-dependent, wherein a high passage HCMV strain was obviously restricted by ZAP and a low passage strain was not. This suggested that strain-specific combinations of anti-viral factors were involved in inhibition of HCMV replication in the presence of IFNα. Overall, this work further supports the development of strategies involving IFNα that may be useful to inhibit HCMV replication and highlights the complexity of the anti-viral response to HCMV in the presence of IFNα.


Assuntos
Citomegalovirus , Interferon-alfa , Humanos , Citomegalovirus/fisiologia , Interferon-alfa/farmacologia , Fatores de Transcrição/metabolismo , Replicação Viral , Antivirais/farmacologia , Antivirais/metabolismo
5.
PLoS Comput Biol ; 18(10): e1010495, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36197936

RESUMO

COVID-19 patients display a wide range of disease severity, ranging from asymptomatic to critical symptoms with high mortality risk. Our ability to understand the interaction of SARS-CoV-2 infected cells within the lung, and of protective or dysfunctional immune responses to the virus, is critical to effectively treat these patients. Currently, our understanding of cell-cell interactions across different disease states, and how such interactions may drive pathogenic outcomes, is incomplete. Here, we developed a generalizable and scalable workflow for identifying cells that are differentially interacting across COVID-19 patients with distinct disease outcomes and use this to examine eight public single-cell RNA-seq datasets (six from peripheral blood mononuclear cells, one from bronchoalveolar lavage and one from nasopharyngeal), with a total of 211 individual samples. By characterizing the cell-cell interaction patterns across epithelial and immune cells in lung tissues for patients with varying disease severity, we illustrate diverse communication patterns across individuals, and discover heterogeneous communication patterns among moderate and severe patients. We further illustrate patterns derived from cell-cell interactions are potential signatures for discriminating between moderate and severe patients. Overall, this workflow can be generalized and scaled to combine multiple scRNA-seq datasets to uncover cell-cell interactions.


Assuntos
COVID-19 , Comunicação Celular , Humanos , Leucócitos Mononucleares , SARS-CoV-2 , Fluxo de Trabalho
6.
Proc Natl Acad Sci U S A ; 117(8): 3953-3959, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32029591

RESUMO

Next-generation photonics envisions circuitry-free, rapidly reconfigurable systems powered by solitonic beams of self-trapped light and their particlelike interactions. Progress, however, has been limited by the need for reversibly responsive materials that host such nonlinear optical waves. We find that repeatedly switchable self-trapped visible laser beams, which exhibit strong pairwise interactions, can be generated in a photoresponsive hydrogel. Through comprehensive experiments and simulations, we show that the unique nonlinear conditions arise when photoisomerization of spiropyran substituents in pH-responsive poly(acrylamide-co-acrylic acid) hydrogel transduces optical energy into mechanical deformation of the 3D cross-linked hydrogel matrix. A Gaussian beam self-traps when localized isomerization-induced contraction of the hydrogel and expulsion of water generates a transient waveguide, which entraps the optical field and suppresses divergence. The waveguide is erased and reformed within seconds when the optical field is sequentially removed and reintroduced, allowing the self-trapped beam to be rapidly and repeatedly switched on and off at remarkably low powers in the milliwatt regime. Furthermore, this opto-chemo-mechanical transduction of energy mediated by the 3D cross-linked hydrogel network facilitates pairwise interactions between self-trapped beams both in the short range where there is significant overlap of their optical fields, and even in the long range--over separation distances of up to 10 times the beam width--where such overlap is negligible.

7.
Int J Mol Sci ; 24(24)2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38139385

RESUMO

The culture confirmation of Mycobacterium tuberculosis (MTB) remains the gold standard for the diagnosis of Tuberculosis (TB) with culture conversion representing proof of cure. However, over 40% of TB samples fail to isolate MTB even though many patients remain infectious due to the presence of viable non-culturable forms. Previously, we have shown that two short cationic peptides, T14D and TB08L, induce a hormetic response at low concentrations, leading to a stimulation of growth in MTB and the related animal pathogen Mycobacterium bovis (bTB). Here, we examine these peptides showing they can influence the mycobacterial membrane integrity and function through membrane potential reduction. We also show this disruption is associated with an abnormal reduction in transcriptomic signalling from specific mycobacterial membrane sensors that normally monitor the immediate cellular environment and maintain the non-growing phenotype. We observe that exposing MTB or bTB to these peptides at optimal concentrations rapidly represses signalling mechanisms maintaining dormancy phenotypes, which leads to the promotion of aerobic metabolism and conversion into a replicative phenotype. We further show a practical application of these peptides as reagents able to enhance conventional routine culture methods by stimulating mycobacterial growth. We evaluated the ability of a peptide-supplemented sample preparation and culture protocol to isolate the MTB against a gold standard routine method tested in parallel on 255 samples from 155 patients with suspected TB. The peptide enhancement increased the sample positivity rate by 46% and decreased the average time to sample positivity of respiratory/faecal sampling by seven days. The most significant improvements in isolation rates were from sputum smear-negative low-load samples and faeces. The peptide enhancement increased sampling test sensitivity by 19%, recovery in samples from patients with a previously culture-confirmed TB by 20%, and those empirically treated for TB by 21%. We conclude that sample decontamination and culture enhancement with D-enantiomer peptides offer good potential for the much-needed improvement of the culture confirmation of TB.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Mycobacterium tuberculosis/genética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Tuberculose/diagnóstico , Técnicas de Cultura , Escarro/microbiologia , Sensibilidade e Especificidade
8.
J Med Internet Res ; 24(10): e36134, 2022 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-36315229

RESUMO

BACKGROUND: This is a systematic review of randomized controlled trials and a meta-analysis comparing smart technology with face-to-face physical activity (PA) interventions in community-dwelling older adults (mean age 60 years). OBJECTIVE: This study aims to determine the effect of interventions including smart technology components compared with face-to-face PA interventions on PA and physical function in older adults. The secondary outcomes are depression, anxiety, and health-related quality of life. METHODS: We searched MEDLINE, Embase, CINAHL, and AMED electronic databases from inception to February 2021. Two independent reviewers screened titles, abstracts, and full texts and performed data extraction and risk of bias assessments using the Cochrane risk of bias tool. The Grading of Recommendations Assessment, Development and Evaluation was used to evaluate the quality of the evidence. We provided a narrative synthesis on all included studies and, where possible, performed meta-analyses for similar outcomes. RESULTS: This review included 19 studies with a total of 3455 participants. Random effects meta-analyses showed that interventions with smart technology components resulted in improved step count (mean difference 1440 steps, 95% CI 500-2390) and total PA (standardized mean difference 0.17, 95% CI 0.02-0.32) compared with face-to-face alone. There was no difference between groups in terms of the measures of physical function. Smart technology alone did not show significant differences between groups in any outcome. The quality of the evidence was very low based on the Grading of Recommendations Assessment, Development and Evaluation criteria. CONCLUSIONS: Interventions that include smart technology may improve daily step counts by an average of 1440 steps in community-dwelling older adults; however, the quality of the evidence was very low. Future studies are needed to improve the certainty of these results. TRIAL REGISTRATION: PROSPERO CRD42020135232; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=135232.


Assuntos
Exercício Físico , Qualidade de Vida , Humanos , Idoso , Pessoa de Meia-Idade , Vida Independente , Ansiedade , Tecnologia
9.
J Neurochem ; 159(3): 574-589, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34482548

RESUMO

A contributing factor to the development of obesity is the consumption of a diet high in saturated fatty acids, such as palmitate. These fats induce hypothalamic neuroinflammation, which dysregulates neuronal function and induces orexigenic neuropeptide Y (Npy) to promote food intake. An inflammatory cytokine array identified multiple candidates that could mediate palmitate-induced up-regulation of Npy mRNA levels. Of these, visfatin or nicotinamide phosphoribosyltransferase (NAMPT), macrophage migratory inhibitory factor (MIF), and IL-17F were chosen for further study. Direct treatment of the neuropeptide Y/agouti-related peptide (NPY/AgRP)-expressing mHypoE-46 neuronal cell line with the aforementioned cytokines demonstrated that visfatin could directly induce Npy mRNA expression. Preventing the intracellular metabolism of palmitate through long-chain acyl-CoA synthetase (ACSL) inhibition was sufficient to block the palmitate-mediated increase in Npy gene expression. Furthermore, thin-layer chromatography revealed that in neurons, palmitate is readily incorporated into ceramides and defined species of phospholipids. Exogenous C16 ceramide, dipalmitoyl-phosphatidylcholine, and dipalmitoyl-phosphatidylethanolamine were sufficient to significantly induce Npy expression. This study suggests that the intracellular metabolism of palmitate and elevation of metabolites, including ceramide and phospholipids, are responsible for the palmitate-mediated induction of the potent orexigen Npy. Furthermore, this suggests that the regulation of Npy expression is less reliant on inflammatory cytokines per se than palmitate metabolites in a model of NPY/AgRP neurons. These lipid species likely induce detrimental downstream cellular signaling events ultimately causing an increase in feeding, resulting in an overweight phenotype and/or obesity.


Assuntos
Citocinas/farmacologia , Neuropeptídeo Y/biossíntese , Palmitatos/farmacologia , Acil Coenzima A/metabolismo , Animais , Linhagem Celular , Ceramidas/metabolismo , Meios de Cultivo Condicionados , Dieta Hiperlipídica , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Nicotinamida Fosforribosiltransferase/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
10.
J Gen Virol ; 102(11)2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34816792

RESUMO

Several viruses, including human cytomegalovirus (HCMV), are thought to replicate in the placenta. However, there is little understanding of the molecular mechanisms involved in HCMV replication in this tissue. We investigated replication of HCMV in the extravillous trophoblast cell line SGHPL-4, a commonly used model of HCMV replication in the placenta. We found limited HCMV protein expression and virus replication in SGHPL-4 cells. This was associated with a lack of trophoblast progenitor cell protein markers in SGHPL-4 cells, suggesting a relationship between trophoblast differentiation and limited HCMV replication. We proposed that limited HCMV replication in trophoblast cells is advantageous to vertical transmission of HCMV, as there is a greater opportunity for vertical transmission when the placenta is intact and functional. Furthermore, when we investigated the replication of other vertically transmitted viruses in SGHPL-4 cells we found some limitation to replication of Zika virus, but not herpes simplex virus. Thus, limited replication of some, but not all, vertically transmitted viruses may be a feature of trophoblast cells.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/fisiologia , Trofoblastos/virologia , Replicação Viral , Linhagem Celular , Citomegalovirus/genética , Infecções por Citomegalovirus/transmissão , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Placenta/virologia , Gravidez
11.
Carcinogenesis ; 41(3): 313-325, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31621840

RESUMO

Metastasis is the primary cause of treatment failures and mortality in most cancers. Triple-negative breast cancer (TNBC) is refractory to treatment and rapidly progresses to disseminated disease. We utilized an orthotopic mouse model that molecularly and phenotypically resembles human TNBC to study the effects of exogenous, daily tissue inhibitor of metalloproteinase-2 (TIMP-2) treatment on tumor growth and metastasis. Our results demonstrated that TIMP-2 treatment maximally suppressed primary tumor growth by ~36-50% and pulmonary metastasis by >92%. Immunostaining assays confirmed disruption of the epithelial to mesenchymal transition (EMT) and promotion of vascular integrity in primary tumor tissues. Immunostaining and RNA sequencing analysis of lung tissue lysates from tumor-bearing mice identified significant changes associated with metastatic colony formation. Specifically, TIMP-2 treatment disrupts periostin localization and critical cell-signaling pathways, including canonical Wnt signaling involved in EMT, as well as PI3K signaling, which modulates proliferative and metastatic behavior through p27 phosphorylation/localization. In conclusion, our study provides evidence in support of a role for TIMP-2 in suppression of triple-negative breast cancer growth and metastasis through modulation of the epithelial to mesenchymal transition, vascular normalization, and signaling pathways associated with metastatic outgrowth. Our findings suggest that TIMP-2, a constituent of the extracellular matrix in normal tissues, may have both direct and systemic antitumor and metastasis suppressor effects, suggesting potential utility in the clinical management of breast cancer progression.


Assuntos
Carcinogênese/genética , Proliferação de Células/genética , Inibidor Tecidual de Metaloproteinase-2/genética , Neoplasias de Mama Triplo Negativas/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Metástase Neoplásica , Fosfatidilinositol 3-Quinases , Análise de Sequência de RNA , Neoplasias de Mama Triplo Negativas/patologia , Via de Sinalização Wnt/genética , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Angew Chem Int Ed Engl ; 59(1): 226-231, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31663249

RESUMO

Responsive photonic crystals have potential applications in mechanical sensors and soft displays; however, new materials are constantly desired to provide new innovations and improve on existing technologies. To address this, we report stretchable chiral nematic cellulose nanocrystal (CNC) elastomer composites that exhibit reversible visible color upon the application of mechanical stress. When stretched (or compressed) the colorless materials maintain their chiral nematic structure but the helical pitch is reduced into the visible region, resulting in coloration of the CNC-elastomer composite. By increasing the percentage elongation of the material (ca. 50-300 %), the structural color can be tuned from red to blue. The color of the materials was characterized by reflectance optical microscopy and reflectance circular dichroism to confirm the wavelength and polarization of the reflected light. We also probed the mechanism of the structural color using 2D-X-ray diffraction. Finally, by either water-patterning the starting CNC film, or by forming a CNC film with gradient color, through masked evaporation, we were able to prepare encoded stretchable chiral nematic CNC-elastomers.

13.
Langmuir ; 34(2): 646-652, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-29286246

RESUMO

The self-assembly process in cellulose nanocrystal (CNC) film formation was studied as a function of evaporation time. It is known that the total evaporation time of CNC dispersions affects the structure of the film obtained, but the extension of different phases of the evaporation has not been explored. By extending the evaporation time of CNC suspensions after the onset of liquid crystallinity, the homogeneity of the resulting films could be improved as observed by polarized optical microscopy and scanning electron microscopy. Here, we show that an intermediate stage of self-assembly, between phase separation and gel vitrification, called tactoid annealing, helps explain the discrepancies in order for chiral nematic CNC films dried at varying evaporation times. This intermediate stage of self-assembly may be useful for designing highly ordered and homogenous CNC-based materials.

14.
Nucleic Acids Res ; 44(7): e64, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-26687720

RESUMO

DNA double-strand breaks (DSBs) and their repair can cause extensive epigenetic changes. As a result, DSBs have been proposed to promote transcriptional and, ultimately, physiological dysfunction via both cell-intrinsic and cell-non-autonomous pathways. Studying the consequences of DSBs in higher organisms has, however, been hindered by a scarcity of tools for controlled DSB induction. Here, we describe a mouse model that allows for both tissue-specific and temporally controlled DSB formation at ∼140 defined genomic loci. Using this model, we show that DSBs promote a DNA damage signaling-dependent decrease in gene expression in primary cells specifically at break-bearing genes, which is reversed upon DSB repair. Importantly, we demonstrate that restoration of gene expression can occur independently of cell cycle progression, underlining its relevance for normal tissue maintenance. Consistent with this, we observe no evidence for persistent transcriptional repression in response to a multi-day course of continuous DSB formation and repair in mouse lymphocytes in vivo Together, our findings reveal an unexpected capacity of primary cells to maintain transcriptome integrity in response to DSBs, pointing to a limited role for DNA damage as a mediator of cell-autonomous epigenetic dysfunction.


Assuntos
Quebras de DNA de Cadeia Dupla , Transcriptoma , Animais , Células Cultivadas , Endodesoxirribonucleases , Loci Gênicos , Camundongos , Camundongos Transgênicos , Transdução de Sinais
15.
Am J Surg ; 229: 106-110, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37968147

RESUMO

BACKGROUND: Rising incidence of papillary thyroid microcarcinomas (PTMC) has raised concerns for overdiagnosis. Utility of the American Thyroid Association Risk Stratification System (ATA-RSS) 2015 in predicting risk of disease recurrence in patients with PTMC was assessed. METHODS: Electronic health records of patients who underwent total thyroidectomy were queried. ATA-RSS 2015 risk stratification was performed on those with PTMC, and validity for predicting disease recurrence was calculated. RESULTS: With 10-year median follow up, recurrence was higher in PTMC patients with high/intermediate vs low ATA risk (33 â€‹% vs 4 â€‹%, p â€‹= â€‹0.002). Sensitivity of ATA-RSS for detecting recurrence was 60 â€‹%, specificity 90 â€‹%, PPV 33.3 â€‹%, NPV 96.6 â€‹%, and accuracy 88 â€‹%. When microscopic extrathyroidal extension (ETE) was excluded as an intermediate risk criterion, PPV improved to 50 â€‹% and accuracy improved to 92.5 â€‹% CONCLUSIONS: ATA-RSS 2015 predicts recurrence in PTMC with high NPV but low PPV. Exclusion of microscopic ETE improved PPV, which may help prevent overtreatment.


Assuntos
Carcinoma Papilar , Recidiva Local de Neoplasia , Neoplasias da Glândula Tireoide , Humanos , Valor Preditivo dos Testes , Recidiva Local de Neoplasia/epidemiologia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Tireoidectomia , Estudos Retrospectivos , Medição de Risco
16.
Mol Cell Endocrinol ; 586: 112179, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38387703

RESUMO

Neuropeptide Y (Npy) is an abundant neuropeptide expressed in the central and peripheral nervous systems. NPY-secreting neurons in the hypothalamic arcuate nucleus regulate energy homeostasis, and Npy mRNA expression is regulated by peripheral nutrient and hormonal signals like leptin, interleukin-6 (IL-6), and fatty acids. This study demonstrates that IL-6, which phosphorylates tyrosine 705 (Y705) of STAT3, decreased Npy mRNA in arcuate immortalized hypothalamic neurons. In parallel, inhibitors of STAT3-Y705 phosphorylation, stattic and cucurbitacin I, robustly upregulated Npy mRNA. Chromatin-immunoprecipitation showed high baseline total STAT3 binding to multiple regulatory regions of the Npy gene, which are decreased by IL-6 exposure. The STAT3-Npy interaction was further examined in obesity-related pathologies. Notably, in four different hypothalamic neuronal models where palmitate potently stimulated Npy mRNA, Socs3, a specific STAT3 activity marker, was downregulated and was negatively correlated with Npy mRNA levels (R2 = 0.40, p < 0.001), suggesting that disrupted STAT3 signaling is involved in lipotoxicity-mediated dysregulation of Npy. Finally, human NPY SNPs that map to human obesity or body mass index were investigated for potential STAT3 binding sites. Although none of the SNPs were linked to direct STAT3 binding, analysis show that rs17149106 (-602 G > T) is located on an upstream enhancer element of NPY, where the variant is predicted to disrupt validated binding of KLF4, a known inhibitory cofactor of STAT3 and downstream effector of leptin signaling. Collectively, this study demonstrates that STAT3 signaling negatively regulates Npy transcription, and that disruption of this interaction may contribute to metabolic disorders.


Assuntos
Leptina , Neuropeptídeo Y , Humanos , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Leptina/farmacologia , Leptina/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Hipotálamo/metabolismo , Obesidade/metabolismo , Núcleo Arqueado do Hipotálamo/metabolismo , Neurônios/metabolismo , RNA Mensageiro/genética , Fator de Transcrição STAT3/metabolismo
17.
NPJ Vaccines ; 9(1): 123, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956057

RESUMO

The Mycobacterial growth inhibition assay (MGIA) is an ex-vivo assay used to measure the overall functional immune response elicited by infection or vaccination. In tuberculosis (TB) vaccine development, MGIA is a potentially important tool for preclinical evaluation of early-stage vaccine candidates to complement existing assays, and to potentially reduce the need for lengthy and costly pathogenic Mycobacterium tuberculosis (Mtb) animal challenge experiments. The conventional method of MGIA in mice entails directly infecting mixed cell cultures, most commonly splenocytes, from immunised mice with mycobacteria. However, this direct infection of mixed cell populations may yield unreliable results and lacks sufficient sensitivity to discriminate well between different vaccines due to the low number of mycobacteria-permissive cells. Here, we modified the assay by inclusion of mycobacteria-infected congenic murine macrophage cell lines as the target cells, and by measuring the total number of killed cells rather than the relative reduction between different groups. Thus, using splenocytes from Mycobacterium bovis BCG immunised mice, and J774 and MH-S (BALB/c background) or BL/6-M (C57Bl/6 background) macrophage cell lines, we demonstrated that the modified assay resulted in at least 26-fold greater mycobacterial killing per set quantity of splenocytes as compared to the conventional method. This increased sensitivity of measuring mycobacterial killing was confirmed using both the standard culture forming unit (CFU) assay and luminescence readings of luciferase-tagged virulent and avirulent mycobacteria. We propose that the modified MGIA can be used as a highly calibrated tool for quantitating the killing capacity of immune cells in preclinical evaluation of vaccine candidates for TB.

18.
Can J Vet Res ; 88(3): 87-93, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988333

RESUMO

There is a knowledge gap regarding the effect of extracorporeal shockwave treatment (ESWT) on the stress response and immunomodulatory and anti-inflammatory properties of equine umbilical cord blood mesenchymal stromal cells (CB-MSCs). The objective of this study was to investigate the presence of cellular oxidative stress, inflammatory response, and production of growth factors in CB-MSCs after treatment with ESWT. We hypothesized that CB-MSCs treated with ESWT will experience higher levels of cellular stress and increased production of anti-inflammatory cytokines and growth factors compared to untreated CB-MSCs.


Il existe un manque de connaissances concernant l'effet du traitement extracorporel par ondes de choc (ESWT) sur la réponse au stress et les propriétés immunomodulatrices et anti-inflammatoires des cellules stromales mésenchymateuses du sang de cordon ombilical équin (CB-MSCs). L'objectif de cette étude était d'étudier la présence de stress oxydatif cellulaire, de réponse inflammatoire et de production de facteurs de croissance dans les CB-MSCs après un traitement par ESWT. Nous avons émis l'hypothèse que les CB-MSCs traitées par ESWT connaîtront des niveaux plus élevés de stress cellulaire et une production accrue de cytokines anti-inflammatoires et de facteurs de croissance par rapport aux CB-MSCs non traitées.(Traduit par Docteur Serge Messier).


Assuntos
Sangue Fetal , Células-Tronco Mesenquimais , Animais , Cavalos , Sangue Fetal/citologia , Tratamento por Ondas de Choque Extracorpóreas/métodos , Citocinas/metabolismo , Células Cultivadas
19.
Methods Mol Biol ; 2813: 309-320, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38888786

RESUMO

Nanoparticle carriers enable the multivalent delivery of nucleic acids to cells and protect them from degradation. In this chapter, we present a comprehensive overview of four methodologies: electrophoretic mobility shift assay (EMSA), alamarBlue/CFDA-AM cell viability dyes, fluorescence microscopy, and antiviral assays, which collectively are tools to explore interactions between nucleic acids and nanoparticles, and their biological efficacy. These assays provide insights into binding potential, cytotoxicity, and antiviral efficacy of nucleic acid-based nanoparticle treatments furthering the development of effective antiviral therapeutics.


Assuntos
Antivirais , Nanopartículas , Ácidos Nucleicos , Nanopartículas/química , Antivirais/farmacologia , Humanos , Ácidos Nucleicos/química , Ensaio de Desvio de Mobilidade Eletroforética/métodos , Cátions/química , Sobrevivência Celular/efeitos dos fármacos , Microscopia de Fluorescência , Portadores de Fármacos/química , Animais
20.
Sci Rep ; 14(1): 4248, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38378802

RESUMO

In the enduring challenge against disease, advancements in medical technology have empowered clinicians with novel diagnostic platforms. Whilst in some cases, a single test may provide a confident diagnosis, often additional tests are required. However, to strike a balance between diagnostic accuracy and cost-effectiveness, one must rigorously construct the clinical pathways. Here, we developed a framework to build multi-platform precision pathways in an automated, unbiased way, recommending the key steps a clinician would take to reach a diagnosis. We achieve this by developing a confidence score, used to simulate a clinical scenario, where at each stage, either a confident diagnosis is made, or another test is performed. Our framework provides a range of tools to interpret, visualize and compare the pathways, improving communication and enabling their evaluation on accuracy and cost, specific to different contexts. This framework will guide the development of novel diagnostic pathways for different diseases, accelerating the implementation of precision medicine into clinical practice.


Assuntos
Comunicação , Medicina de Precisão , Processos Mentais
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