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1.
Cell ; 184(3): 827-839.e14, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33545036

RESUMO

Ahmed and colleagues recently described a novel hybrid lymphocyte expressing both a B and T cell receptor, termed double expresser (DE) cells. DE cells in blood of type 1 diabetes (T1D) subjects were present at increased numbers and enriched for a public B cell clonotype. Here, we attempted to reproduce these findings. While we could identify DE cells by flow cytometry, we found no association between DE cell frequency and T1D status. We were unable to identify the reported public B cell clone, or any similar clone, in bulk B cells or sorted DE cells from T1D subjects or controls. We also did not observe increased usage of the public clone VH or DH genes in B cells or in sorted DE cells. Taken together, our findings suggest that DE cells and their alleged public clonotype are not enriched in T1D. This Matters Arising paper is in response to Ahmed et al. (2019), published in Cell. See also the response by Ahmed et al. (2021), published in this issue.


Assuntos
Diabetes Mellitus Tipo 1 , Linfócitos B , Células Clonais , Diabetes Mellitus Tipo 1/genética , Citometria de Fluxo , Humanos , Receptores de Antígenos de Linfócitos T
2.
Mol Cell ; 83(3): 393-403, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36599353

RESUMO

The positive transcription elongation factor b (P-TEFb) is composed of cyclins T1 or T2 and cyclin-dependent kinase 9 that regulate the elongation phase of transcription by RNA polymerase II. By antagonizing negative elongation factors and phosphorylating the C-terminal domain of RNA polymerase II, P-TEFb facilitates the elongation and co-transcriptional processing of nascent transcripts. This step is critical for the expression of most eukaryotic genes. In growing cells, P-TEFb is regulated negatively by its reversible associations with HEXIM1/2 in the 7SK snRNP and positively by a number of transcription factors, as well as the super elongation complex. In resting cells, P-TEFb falls apart, and cyclin T1 is degraded by the proteasome. This complex regulation of P-TEFb has evolved for the precise temporal and spatial regulation of gene expression in the organism. Its dysregulation contributes to inflammatory and neoplastic conditions.


Assuntos
Fator B de Elongação Transcricional Positiva , RNA Polimerase II , Humanos , Fator B de Elongação Transcricional Positiva/genética , Fator B de Elongação Transcricional Positiva/metabolismo , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Células HeLa , Quinase 9 Dependente de Ciclina/genética , Quinase 9 Dependente de Ciclina/metabolismo , Ciclina T/genética , Ciclina T/metabolismo , Transcrição Gênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
Mol Cell ; 81(3): 530-545.e5, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33382982

RESUMO

Transcription factors regulate gene networks controlling normal hematopoiesis and are frequently deregulated in acute myeloid leukemia (AML). Critical to our understanding of the mechanism of cellular transformation by oncogenic transcription factors is the ability to define their direct gene targets. However, gene network cascades can change within minutes to hours, making it difficult to distinguish direct from secondary or compensatory transcriptional changes by traditional methodologies. To overcome this limitation, we devised cell models in which the AML1-ETO protein could be quickly degraded upon addition of a small molecule. The rapid kinetics of AML1-ETO removal, when combined with analysis of transcriptional output by nascent transcript analysis and genome-wide AML1-ETO binding by CUT&RUN, enabled the identification of direct gene targets that constitute a core AML1-ETO regulatory network. Moreover, derepression of this gene network was associated with RUNX1 DNA binding and triggered a transcription cascade ultimately resulting in myeloid differentiation.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , RNA Neoplásico/biossíntese , Proteína 1 Parceira de Translocação de RUNX1/metabolismo , Transcrição Gênica , Acetilação , Sítios de Ligação , Ligação Competitiva , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Autorrenovação Celular , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Sangue Fetal/citologia , Regulação Leucêmica da Expressão Gênica , Redes Reguladoras de Genes , Células HEK293 , Células-Tronco Hematopoéticas/patologia , Histonas/metabolismo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Células-Tronco Neoplásicas/patologia , Proteínas de Fusão Oncogênica/genética , Ligação Proteica , Proteólise , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA Neoplásico/genética , Proteína 1 Parceira de Translocação de RUNX1/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Tempo , Transcriptoma
4.
Development ; 151(20)2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619327

RESUMO

Tissue morphogenesis is intimately linked to the changes in shape and organisation of individual cells. In curved epithelia, cells can intercalate along their own apicobasal axes, adopting a shape named 'scutoid' that allows energy minimization in the tissue. Although several geometric and biophysical factors have been associated with this 3D reorganisation, the dynamic changes underlying scutoid formation in 3D epithelial packing remain poorly understood. Here, we use live imaging of the sea star embryo coupled with deep learning-based segmentation to dissect the relative contributions of cell density, tissue compaction and cell proliferation on epithelial architecture. We find that tissue compaction, which naturally occurs in the embryo, is necessary for the appearance of scutoids. Physical compression experiments identify cell density as the factor promoting scutoid formation at a global level. Finally, the comparison of the developing embryo with computational models indicates that the increase in the proportion of scutoids is directly associated with cell divisions. Our results suggest that apico-basal intercalations appearing immediately after mitosis may help accommodate the new cells within the tissue. We propose that proliferation in a compact epithelium induces 3D cell rearrangements during development.


Assuntos
Proliferação de Células , Embrião não Mamífero , Morfogênese , Animais , Epitélio , Embrião não Mamífero/citologia , Contagem de Células , Estrelas-do-Mar/embriologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Divisão Celular
5.
Proc Natl Acad Sci U S A ; 121(40): e2321928121, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39331407

RESUMO

Convergent extension of epithelial tissue is a key motif of animal morphogenesis. On a coarse scale, cell motion resembles laminar fluid flow; yet in contrast to a fluid, epithelial cells adhere to each other and maintain the tissue layer under actively generated internal tension. To resolve this apparent paradox, we formulate a model in which tissue flow in the tension-dominated regime occurs through adiabatic remodeling of force balance in the network of adherens junctions. We propose that the slow dynamics within the manifold of force-balanced configurations is driven by positive feedback on myosin-generated cytoskeletal tension. Shifting force balance within a tension network causes active cell rearrangements (T1 transitions) resulting in net tissue deformation oriented by initial tension anisotropy. Strikingly, we find that the total extent of tissue deformation depends on the initial cellular packing order. T1s degrade this order so that tissue flow is self-limiting. We explain these findings by showing that coordination of T1s depends on coherence in local tension configurations, quantified by a geometric order parameter in tension space. Our model reproduces the salient tissue- and cell-scale features of germ band elongation during Drosophila gastrulation, in particular the slowdown of tissue flow after approximately twofold elongation concomitant with a loss of order in tension configurations. This suggests local cell geometry contains morphogenetic information and yields experimentally testable predictions. Defining biologically controlled active tension dynamics on the manifold of force-balanced states may provide a general approach to the description of morphogenetic flow.


Assuntos
Modelos Biológicos , Animais , Células Epiteliais/fisiologia , Células Epiteliais/metabolismo , Células Epiteliais/citologia , Morfogênese/fisiologia , Epitélio/fisiologia , Epitélio/metabolismo , Gastrulação/fisiologia , Drosophila/fisiologia , Junções Aderentes/metabolismo , Junções Aderentes/fisiologia , Drosophila melanogaster , Fenômenos Biomecânicos , Citoesqueleto/metabolismo , Citoesqueleto/fisiologia , Miosinas/metabolismo
6.
Cereb Cortex ; 34(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39183364

RESUMO

47,XXX (Triple X syndrome) is a sex chromosome aneuploidy characterized by the presence of a supernumerary X chromosome in affected females and is associated with a variable cognitive, behavioral, and psychiatric phenotype. The effect of a supernumerary X chromosome in affected females on intracortical microstructure is currently unknown. Therefore, we conducted 7 Tesla structural MRI and compared T1 (ms), as a proxy for intracortical myelin (ICM), across laminae of 21 adult women with 47,XXX and 22 age-matched typically developing females using laminar analyses. Relationships between phenotypic traits and T1 values in 47,XXX were also investigated. Adults with 47,XXX showed higher bilateral T1 across supragranular laminae in the banks of the superior temporal sulcus, and in the right inferior temporal gyrus, suggesting decreases of ICM primarily within the temporal cortex in 47,XXX. Higher social functioning in 47,XXX was related to larger inferior temporal gyrus ICM content. Our findings indicate an effect of a supernumerary X chromosome in adult-aged women on ICM across supragranular laminae within the temporal cortex. These findings provide insight into the role of X chromosome dosage on ICM across laminae. Future research is warranted to further explore the functional significance of altered ICM across laminae in 47,XXX.


Assuntos
Imageamento por Ressonância Magnética , Bainha de Mielina , Humanos , Feminino , Adulto , Bainha de Mielina/metabolismo , Imageamento por Ressonância Magnética/métodos , Adulto Jovem , Aberrações dos Cromossomos Sexuais , Pessoa de Meia-Idade , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/metabolismo , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genética , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/diagnóstico por imagem , Cromossomos Humanos X/genética , Trissomia/genética , Córtex Cerebral/diagnóstico por imagem
7.
Nano Lett ; 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38588382

RESUMO

Nitrogen vacancy (NV) center-based magnetometry has been proven to be a versatile sensor for various classes of magnetic materials in broad temperature and frequency ranges. Here, we use the longitudinal relaxation time T1 of single NV centers to investigate the spin dynamics of nanometer-thin flakes of α-RuCl3 at room temperature. We observe a significant reduction in the T1 in the presence of α-RuCl3 in the proximity of NVs, which we attribute to paramagnetic spin noise confined in the 2D hexagonal planes. Furthermore, the T1 time exhibits a monotonic increase with an applied magnetic field. We associate this trend with the alteration of the spin and charge noise in α-RuCl3 under an external magnetic field. These findings suggest that the influence of the spin dynamics of α-RuCl3 on the T1 of the NV center can be used to gain information about the material itself and the technique to be used on other 2D materials.

8.
Nano Lett ; 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39400054

RESUMO

Traditional macromolecules or nanoscale Mn2+ chelate-based magnetic resonance imaging (MRI) contrast agents (CAs) suffer from complicated and laborious synthesis processes, relatively low kinetic stability and T1 relaxivity, limiting their clinical applications. Herein, we fabricated a series of kinetically inert Mn2+ chelate-backboned polymers, P(MnL-PEG), through a facile and one-pot polymerization process. Particularly, P(MnL-PEG)-3 demonstrates a significantly higher T1 relaxivity of 23.9 Mn mM-1 s-1 at 1.5 T than that of previously reported small molecules and macromolecules or nanoscale Mn2+ chelate-based CAs. Due to its high T1 relaxivity, extended blood circulation, hepatocyte-specific uptake, and kidneys metabolism, P(MnL-PEG)-3 presents significantly enhanced contrast in blood vessel, liver, and kidneys imaging compared to clinical Gd3+-based CAs (Gd-EOB-DTPA and Gd-DOTA) at a dosage of 0.05 mmol Mn/Gd kg-1 BW, and can accurately diagnose orthotopic H22 liver tumors in vivo in animal models. We anticipate that this work will promote the development of clinically relevant MRI CAs.

9.
Nano Lett ; 24(30): 9406-9414, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39036992

RESUMO

Extremely small iron oxide nanoparticle (ESIONP)-based stimuli-responsive switchable MRI contrast agents (CAs) show great promise for accurate detection of tumors due to their outstanding advantages of high specificity and low background signal. However, currently developed ESIONP-based switchable CAs often suffer single-biomarker-induced responses, which lack absolute specificity to pathological tissues, potentially diminishing diagnostic accuracy. In this study, weak acidity and hypoxia, two of the most remarkable characteristics of tumors, are introduced as dual biomarker stimuli to construct an ESIONP-based switchable MRI CA (DKL-CA), with its signal switch controlled by a "dual-key-and-lock" strategy. Only when DKL-CA is exposed to a coexisting weakly acidic and hypoxic environment can monodispersed ESIONPs form nanoclusters, thereby realizing a switch from the T1 to T2 contrast. Moreover, DKL-CA exhibits favorable biosafety and the capacity for precise tumor diagnosis in tumor-bearing mice. Overall, DKL-CA paves the way for designing highly accurate ESIONP-based MRI CAs for tumor diagnosis.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Neoplasias , Meios de Contraste/química , Imageamento por Ressonância Magnética/métodos , Animais , Camundongos , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/diagnóstico , Nanopartículas Magnéticas de Óxido de Ferro/química , Linhagem Celular Tumoral
10.
J Neurosci ; 43(12): 2168-2177, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36804738

RESUMO

Sleep loss pervasively affects the human brain at multiple levels. Age-related changes in several sleep characteristics indicate that reduced sleep quality is a frequent characteristic of aging. Conversely, sleep disruption may accelerate the aging process, yet it is not known what will happen to the age status of the brain if we can manipulate sleep conditions. To tackle this question, we used an approach of brain age to investigate whether sleep loss would cause age-related changes in the brain. We included MRI data of 134 healthy volunteers (mean chronological age of 25.3 between the age of 19 and 39 years, 42 females/92 males) from five datasets with different sleep conditions. Across three datasets with the condition of total sleep deprivation (>24 h of prolonged wakefulness), we consistently observed that total sleep deprivation increased brain age by 1-2 years regarding the group mean difference with the baseline. Interestingly, after one night of recovery sleep, brain age was not different from baseline. We also demonstrated the associations between the change in brain age after total sleep deprivation and the sleep variables measured during the recovery night. By contrast, brain age was not significantly changed by either acute (3 h time-in-bed for one night) or chronic partial sleep restriction (5 h time-in-bed for five continuous nights). Together, the convergent findings indicate that acute total sleep loss changes brain morphology in an aging-like direction in young participants and that these changes are reversible by recovery sleep.SIGNIFICANCE STATEMENT Sleep is fundamental for humans to maintain normal physical and psychological functions. Experimental sleep deprivation is a variable-controlling approach to engaging the brain among different sleep conditions for investigating the responses of the brain to sleep loss. Here, we quantified the response of the brain to sleep deprivation by using the change of brain age predictable with brain morphologic features. In three independent datasets, we consistently found increased brain age after total sleep deprivation, which was associated with the change in sleep variables. Moreover, no significant change in brain age was found after partial sleep deprivation in another two datasets. Our study provides new evidence to explain the brainwide effect of sleep loss in an aging-like direction.


Assuntos
Privação do Sono , Sono , Masculino , Feminino , Humanos , Adulto , Adulto Jovem , Privação do Sono/diagnóstico por imagem , Privação do Sono/psicologia , Sono/fisiologia , Encéfalo/diagnóstico por imagem , Vigília/fisiologia , Fatores de Tempo
11.
J Biol Chem ; 299(6): 104802, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37172727

RESUMO

Lactate serves as the major glucose alternative to an energy substrate in the brain. Lactate level is increased in the fetal brain from the middle stage of gestation, indicating the involvement of lactate in brain development and neuronal differentiation. Recent reports show that lactate functions as a signaling molecule to regulate gene expression and protein stability. However, the roles of lactate signaling in neuronal cells remain unknown. Here, we showed that lactate promotes the all stages of neuronal differentiation of SH-SY5Y and Neuro2A, human and mouse neuroblastoma cell lines, characterized by increased neuronal marker expression and the rates of neurites extension. Transcriptomics revealed many lactate-responsive genes sets such as SPARCL1 in SH-SY5Y, Neuro2A, and primary embryonic mouse neuronal cells. The effects of lactate on neuronal function were mainly mediated through monocarboxylate transporters 1 (MCT1). We found that NDRG family member 3 (NDRG3), a lactate-binding protein, was highly expressed and stabilized by lactate treatment during neuronal differentiation. Combinative RNA-seq of SH-SY5Y with lactate treatment and NDRG3 knockdown shows that the promotive effects of lactate on neural differentiation are regulated through NDRG3-dependent and independent manners. Moreover, we identified TEA domain family member 1 (TEAD1) and ETS-related transcription factor 4 (ELF4) are the specific transcription factors that are regulated by both lactate and NDRG3 in neuronal differentiation. TEAD1 and ELF4 differently affect the expression of neuronal marker genes in SH-SY5Y cells. These results highlight the biological roles of extracellular and intracellular lactate as a critical signaling molecule that modifies neuronal differentiation.


Assuntos
Diferenciação Celular , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular , Ácido Láctico , Neurônios , Animais , Humanos , Camundongos , Diferenciação Celular/fisiologia , Linhagem Celular , Regulação da Expressão Gênica/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia , Neuroblastoma/genética , Neurônios/citologia , Neurônios/metabolismo , Transdução de Sinais
12.
Neuroimage ; 288: 120523, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38278427

RESUMO

Although manganese (Mn) is a trace metal essential for humans, chronic exposure to Mn can cause accumulation of this metal ion in the brain leading to an increased risk of neurological and neurobehavioral health effects. This is a concern for welders exposed to Mn through welding fumes. While brain Mn accumulation in occupational settings has mostly been reported in the basal ganglia, several imaging studies also revealed elevated Mn in other brain areas. Since Mn functions as a magnetic resonance imaging (MRI) T1 contrast agent, we developed a whole-brain MRI approach to map in vivo Mn deposition differences in the brains of non-exposed factory controls and exposed welders. This is a cross-sectional analysis of 23 non-exposed factory controls and 36 exposed full-time welders from the same truck manufacturer. We collected high-resolution 3D MRIs of brain anatomy and R1 relaxation maps to identify regional differences using voxel-based quantification (VBQ) and statistical parametric mapping. Furthermore, we investigated the associations between excess Mn deposition and neuropsychological and motor test performance. Our results indicate that: (1) Using whole-brain MRI relaxometry methods we can generate excess Mn deposition maps in vivo, (2) excess Mn accumulation due to occupational exposure occurs beyond the basal ganglia in cortical areas associated with motor and cognitive functions, (3) Mn likely diffuses along white matter tracts in the brain, and (4) Mn deposition in specific brain regions is associated with exposure (cerebellum and frontal cortex) and motor metrics (cerebellum and hippocampus).


Assuntos
Manganês , Ferreiros , Humanos , Estudos Transversais , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Mapeamento Encefálico
13.
Neuroimage ; 296: 120666, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38830440

RESUMO

Direct imaging of semi-solid lipids, such as myelin, is of great interest as a noninvasive biomarker of neurodegenerative diseases. Yet, the short T2 relaxation times of semi-solid lipid protons hamper direct detection through conventional magnetic resonance imaging (MRI) pulse sequences. In this study, we examined whether a three-dimensional ultrashort echo time (3D UTE) sequence can directly acquire signals from membrane lipids. Membrane lipids from red blood cells (RBC) were collected from commercially available blood as a general model of the myelin lipid bilayer and subjected to D2O exchange and freeze-drying for complete water removal. Sufficiently high MR signals were detected with the 3D UTE sequence, which showed an ultrashort T2* of ∼77-271 µs and a short T1 of ∼189 ms for semi-solid RBC membrane lipids. These measurements can guide designing UTE-based sequences for direct in vivo imaging of membrane lipids.


Assuntos
Membrana Eritrocítica , Imageamento por Ressonância Magnética , Lipídeos de Membrana , Bainha de Mielina , Humanos , Imageamento por Ressonância Magnética/métodos , Bainha de Mielina/química , Membrana Eritrocítica/química , Membrana Eritrocítica/metabolismo , Lipídeos de Membrana/química , Liofilização , Eritrócitos/metabolismo
14.
Breast Cancer Res ; 26(1): 104, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918836

RESUMO

BACKGROUND: Immune-positron emission tomography (PET) imaging with tracers that target CD8 and granzyme B has shown promise in predicting the therapeutic response following immune checkpoint blockade (ICB) in immunologically "hot" tumors. However, immune dynamics in the low T-cell infiltrating "cold" tumor immune microenvironment during ICB remain poorly understood. This study uses molecular imaging to evaluate changes in CD4 + T cells and CD8 + T cells during ICB in breast cancer models and examines biomarkers of response. METHODS: [89Zr]Zr-DFO-CD4 and [89Zr]Zr-DFO-CD8 radiotracers were used to quantify changes in intratumoral and splenic CD4 T cells and CD8 T cells in response to ICB treatment in 4T1 and MMTV-HER2 mouse models, which represent immunologically "cold" tumors. A correlation between PET quantification metrics and long-term anti-tumor response was observed. Further biological validation was obtained by autoradiography and immunofluorescence. RESULTS: Following ICB treatment, an increase in the CD8-specific PET signal was observed within 6 days, and an increase in the CD4-specific PET signal was observed within 2 days in tumors that eventually responded to immunotherapy, while no significant differences in CD4 or CD8 were found at the baseline of treatment that differentiated responders from nonresponders. Furthermore, mice whose tumors responded to ICB had a lower CD8 PET signal in the spleen and a higher CD4 PET signal in the spleen compared to non-responders. Intratumoral spatial heterogeneity of the CD8 and CD4-specific PET signals was lower in responders compared to non-responders. Finally, PET imaging, autoradiography, and immunofluorescence signals were correlated when comparing in vivo imaging to ex vivo validations. CONCLUSIONS: CD4- and CD8-specific immuno-PET imaging can be used to characterize the in vivo distribution of CD4 + and CD8 + T cells in response to immune checkpoint blockade. Imaging metrics that describe the overall levels and distribution of CD8 + T cells and CD4 + T cells can provide insight into immunological alterations, predict biomarkers of response to immunotherapy, and guide clinical decision-making in those tumors where the kinetics of the response differ.


Assuntos
Neoplasias da Mama , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Modelos Animais de Doenças , Inibidores de Checkpoint Imunológico , Tomografia por Emissão de Pósitrons , Microambiente Tumoral , Animais , Microambiente Tumoral/imunologia , Feminino , Camundongos , Linfócitos T CD8-Positivos/imunologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/imunologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Humanos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linhagem Celular Tumoral , Zircônio , Compostos Radiofarmacêuticos , Radioisótopos
15.
Br J Haematol ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39191510

RESUMO

Wilms' tumour 1 (WT1) can function as an oncogene or a tumour suppressor. Our previous clinical cohort studies showed that low WT1 expression at diagnosis independently predicted poor outcomes in acute myeloid leukaemia (AML) with RUNX1::RUNX1T1, whereas it had an opposite role in AML with non-favourable cytogenetic risk (RUNX1::RUNX1T1-deficient). The molecular mechanism by which RUNX1::RUNX1T1 affects the prognostic significance of WT1 in AML remains unknown. In the present study, first we validated the prognostic significance of WT1 expression in AML. Then by using the established transfected cell lines and xenograft tumour model, we found that WT1 suppresses proliferation and enhances effect of cytarabine in RUNX1::RUNX1T1(+) AML but has opposite functions in AML cells without RUNX1::RUNX1T1. Furthermore, as a transcription factor, WT1 physically interacts with RUNX1::RUNX1T1 and acts as a co-factor together with RUNX1::RUNX1T1 to activate the expression of its target gene DUSP6 to dampen extracellular signal-regulated kinase (ERK) activity. When RUNX1::RUNX1T1-deficient, WT1 can activate the mitogen-activated extracellular signal-regulated kinase/ERK axis but not through targeting DUSP6. These results provide a mechanism by which WT1 together with RUNX1::RUNX1T1 suppresses cell proliferation through WT1/DUSP6/ERK axis in AML. The current study provides an explanation for the controversial prognostic significance of WT1 expression in AML patients.

16.
Immunogenetics ; 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39276210

RESUMO

This study aimed to investigate the prevalence of insulin autoantibody (IAA), glutamic acid decarboxylase antibody (GADA), and insulinoma-associated antigen-2 antibody (IA-2A) in type 1 diabetes (T1D) children based on the presence of predisposing HLA-II alleles. Additionally, to assess the sequence homology between autoantigens of islet cells and selected proteins derived from gut bacteria in terms of their binding capacities to HLA risk alleles, HLA-DRB1/DQB1 alleles were determined by PCR-SSOP in 111 T1D children (probands) along with 222 parents and 133 siblings. Autoantibodies were measured by ELISA, and in silico analysis was run as follows: protein extraction, homology and epitope prediction, peptide alignment, and HLA-peptide docking. Higher significant frequencies of DRB1*03:01, DQB1*02:01, and DQB1*03:02 alleles and DRB1*03:01 ~ DQB1*02:01 haplotype and lower frequencies of DRB1*11:01, DRB1*14:01, and DQB1*03:01 alleles were found in probands compared to parents and siblings. DRB1*11:01 ~ DQB1*03:01, DRB1*14:01 ~ DQB1*05:03, and DRB1*15:01-DQB1*06:02 haplotypes were significantly less frequent in the probands compared to parents. Out of 111 probands, 21 were seronegative, 90 tested positive for one autoantibody, and 15 showed the concurrent presence of three autoantibodies. Logistic regression analysis revealed that DRB1*04 ~ DQB1*03:02 haplotype was associated with the induction of GADA and IA-2A, while DRB1*11:01 ~ DQB1*03:01 was associated with seronegativity. Epitopes derived from GAD and gut bacteria showed strong binding capacities to HLA risk alleles. Due to the sequence similarities between gut bacteria-derived proteins and islet cell autoantigens and their potential for binding to HLA risk alleles, dysbiosis of gut microbiota can be considered another risk factor for the development of T1D, especially in genetically susceptible individuals.

17.
BMC Med ; 22(1): 357, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39227839

RESUMO

BACKGROUND: Our previous genome­wide association studies (GWAS) have suggested rs912304 in 14q12 as a suggestive risk variant for type 1 diabetes (T1D). However, the association between this risk region and T1D subgroups and related clinical risk features, the underlying causal functional variant(s), putative candidate gene(s), and related mechanisms are yet to be elucidated. METHODS: We assessed the association between variant rs912304 and T1D, as well as islet autoimmunity and islet function, stratified by the diagnosed age of 12. We used epigenome bioinformatics analyses, dual luciferase reporter assays, and expression quantitative trait loci (eQTL) analyses to prioritize the most likely functional variant and potential causal gene. We also performed functional experiments to evaluate the role of the causal gene on islet function and its related mechanisms. RESULTS: We identified rs912304 as a risk variant for T1D subgroups with diagnosed age ≥ 12 but not < 12. This variant is associated with residual islet function but not islet-specific autoantibody positivity in T1D individuals. Bioinformatics analysis indicated that rs912304 is a functional variant exhibiting spatial overlaps with enhancer active histone marks (H3K27ac and H3K4me1) and open chromatin status (ATAC-seq) in the human pancreas and islet tissues. Luciferase reporter gene assays and eQTL analyses demonstrated that the biallelic sites of rs912304 had differential allele-specific enhancer activity in beta cell lines and regulated STXBP6 expression, which was defined as the most putative causal gene based on Open Targets Genetics, GTEx v8 and Tiger database. Moreover, Stxbp6 was upregulated by T1D-related proinflammatory cytokines but not high glucose/fat. Notably, Stxbp6 over-expressed INS-1E cells exhibited decreasing insulin secretion and increasing cell apoptosis through Glut1 and Gadd45ß, respectively. CONCLUSIONS: This study expanded the genomic landscape regarding late-onset T1D risk and supported islet function mechanistically connected to T1D pathogenesis.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Adolescente , Animais , Criança , Feminino , Humanos , Masculino , Idade de Início , Citocinas/genética , Citocinas/metabolismo , Diabetes Mellitus Tipo 1/genética , Regulação da Expressão Gênica , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Ilhotas Pancreáticas/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas , Proteínas de Transporte/genética
18.
BMC Med ; 22(1): 37, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273326

RESUMO

BACKGROUND: This study investigates the association between socioeconomic status (SES) and glycemic control in individuals with type 1 diabetes (T1D) using flash glucose monitoring (FGM) devices within a public health system where these technologies are freely available and utilized according to recommended guidelines. METHODS: A follow-up study of 1060 adults (mean age 47.4 ± 15.0 years, 49.0% women) with T1D, receiving care at three Spanish university hospitals that regularly employ the FGM system. SES was assessed using the Spanish Deprivation Index and the average annual net income per person. Glycemic data were collected over a 14-day follow-up period, including baseline glycated hemoglobin (HbA1c) levels prior to sensor placement, the last available HbA1c levels, and FGM-derived glucose metrics. Individuals with sensor usage time < 70% were excluded. Chronic micro and macrovascular complications related to diabetes were documented. Regression models, adjusted for clinical variables, were employed to determine the impact of SES on optimal sensor control (defined as time in range (TIR) ≥ 70% with time below range < 4%) and disease complications. RESULTS: The average follow-up was of 2 years. The mean TIR and the percentage of individuals with optimal control were higher in individuals in the highest SES quartile (64.9% ± 17.8% and 27.9%, respectively) compared to those in the lowest SES quartile (57.8 ± 17.4% and 12.1%) (p < 0.001). Regression models showed a higher risk of suboptimal control (OR 2.27, p < 0.001) and ischemic heart disease and/or stroke (OR 3.59, p = 0.005) in the lowest SES quartile. No association was observed between SES and the risk of diabetic nephropathy and retinopathy. FGM system improved HbA1c levels across all SES quartiles. Although individuals in the highest SES quartile still achieved a significantly lower value at the end of the follow-up 55 mmol/mol (7.2%) compared to those in the lowest SES quartile 60 mmol/mol (7.6%) (p < 0.001), the significant disparities in this parameter between the various SES groups were significantly reduced after FGM technology use. CONCLUSIONS: Socioeconomic status plays a significant role in glycemic control and complications in individuals with T1D, extending beyond access to technology and its proper utilization. The free utilization of FGM technology helps alleviate the impact of social inequalities on glycemic control.


Assuntos
Diabetes Mellitus Tipo 1 , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/epidemiologia , Seguimentos , Glicemia , Hemoglobinas Glicadas , Glucose , Automonitorização da Glicemia , Classe Social
19.
Small ; 20(29): e2309842, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38431935

RESUMO

Triple negative breast cancer (TNBC) cells have a high demand for oxygen and glucose to fuel their growth and spread, shaping the tumor microenvironment (TME) that can lead to a weakened immune system by hypoxia and increased risk of metastasis. To disrupt this vicious circle and improve cancer therapeutic efficacy, a strategy is proposed with the synergy of ferroptosis, immunosuppression reversal and disulfidptosis. An intelligent nanomedicine GOx-IA@HMON@IO is successfully developed to realize this strategy. The Fe release behaviors indicate the glutathione (GSH)-responsive degradation of HMON. The results of titanium sulfate assay, electron spin resonance (ESR) spectra, 5,5'-Dithiobis-(2-nitrobenzoic acid (DTNB) assay and T1-weighted magnetic resonance imaging (MRI) demonstrate the mechanism of the intelligent iron atom (IA)-based cascade reactions for GOx-IA@HMON@IO, generating robust reactive oxygen species (ROS). The results on cells and mice reinforce the synergistic mechanisms of ferroptosis, immunosuppression reversal and disulfidptosis triggered by the GOx-IA@HMON@IO with the following steps: 1) GSH peroxidase 4 (GPX4) depletion by disulfidptosis; 2) IA-based cascade reactions; 3) tumor hypoxia reversal; 4) immunosuppression reversal; 5) GPX4 depletion by immunotherapy. Based on the synergistic mechanisms of ferroptosis, immunosuppression reversal and disulfidptosis, the intelligent nanomedicine GOx-IA@HMON@IO can be used for MRI-guided tumor therapy with excellent biocompatibility and safety.


Assuntos
Ferroptose , Imageamento por Ressonância Magnética , Ferroptose/efeitos dos fármacos , Imageamento por Ressonância Magnética/métodos , Animais , Humanos , Linhagem Celular Tumoral , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Terapia de Imunossupressão , Microambiente Tumoral/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/diagnóstico por imagem , Feminino , Glutationa/metabolismo
20.
Small ; : e2401422, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39118560

RESUMO

Silica-supported amine absorbents, including materials produced by tethering aminosilanes or infusion of poly(ethyleneimine), represent a promising class of materials for CO2 capture applications, including direct air and point source capture. Various silica surface treatments and functionalization strategies are explored to enhance stability and CO2 uptake in amine-based solid sorbent systems. Here, the synthesis and characterization of novel vinyltrimethoxysilane-treated Santa Barbara Amorphous-15 (SBA-15) supports and the corresponding enhancement in CO2 uptake compared to various SBA-15-based control supports are presented. The relationship between CO2 diffusion and amine efficiency in these systems is explored using a previously reported kinetic model. The synthesized materials are characterized with CO2 and H2O isotherms, diffuse reflectance infrared Fourier transform spectroscopy, 1H T1-T2 relaxation correlation NMR, and rapid thermal cycling experiments. The novel support materials are shown to enable high amine efficiencies, approaching a fourfold improvement over standard SBA-15-supported amines, while simultaneously exhibiting excellent stability when cycled rapidly under humid conditions. As the poly(ethyleneimine) loadings are held constant across the various samples, enhancements in CO2 uptake are attributed to differences in the way the poly(ethyleneimine) interacts with the support surface.

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