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1.
Chem Commun (Camb) ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916042

RESUMO

A polycyclic aromatic hydrocarbon displaying twelve edge nitrogen centers for a 42 π-electron system is reported. This compound was synthesized via Sonogashira coupling of pyrimidine precursors, [2+2+2] cycloaddition of bis(aryl) alkynes, and anionic cyclodehydrogenation. Spectroscopy, electrochemistry, and computational results suggest a narrowing of the HOMO-LUMO gap compared to the N-free analogue. Metal coordination affects the optical properties of the extended π system.

3.
Nat Commun ; 15(1): 3602, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684700

RESUMO

Glioblastoma (GBM) is a highly lethal type of cancer. GBM recurrence following chemoradiation is typically attributed to the regrowth of invasive and resistant cells. Therefore, there is a pressing need to gain a deeper understanding of the mechanisms underlying GBM resistance to chemoradiation and its ability to infiltrate. Using a combination of transcriptomic, proteomic, and phosphoproteomic analyses, longitudinal imaging, organotypic cultures, functional assays, animal studies, and clinical data analyses, we demonstrate that chemoradiation and brain vasculature induce cell transition to a functional state named VC-Resist (vessel co-opting and resistant cell state). This cell state is midway along the transcriptomic axis between proneural and mesenchymal GBM cells and is closer to the AC/MES1-like state. VC-Resist GBM cells are highly vessel co-opting, allowing significant infiltration into the surrounding brain tissue and homing to the perivascular niche, which in turn induces even more VC-Resist transition. The molecular and functional characteristics of this FGFR1-YAP1-dependent GBM cell state, including resistance to DNA damage, enrichment in the G2M phase, and induction of senescence/stemness pathways, contribute to its enhanced resistance to chemoradiation. These findings demonstrate how vessel co-option, perivascular niche, and GBM cell plasticity jointly drive resistance to therapy during GBM recurrence.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Camundongos , Quimiorradioterapia/métodos , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Tolerância a Radiação , Proteínas de Sinalização YAP/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Proteômica
4.
Nat Commun ; 14(1): 7432, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973846

RESUMO

Spatial resolution of the T cell repertoire is essential for deciphering cancer-associated immune dysfunction. Current spatially resolved transcriptomic technologies are unable to directly annotate T cell receptors (TCR). We present spatially resolved T cell receptor sequencing (SPTCR-seq), which integrates optimized target enrichment and long-read sequencing for highly sensitive TCR sequencing. The SPTCR computational pipeline achieves yield and coverage per TCR comparable to alternative single-cell TCR technologies. Our comparison of PCR-based and SPTCR-seq methods underscores SPTCR-seq's superior ability to reconstruct the entire TCR architecture, including V, D, J regions and the complementarity-determining region 3 (CDR3). Employing SPTCR-seq, we assess local T cell diversity and clonal expansion across spatially discrete niches. Exploration of the reciprocal interaction of the tumor microenvironmental and T cells discloses the critical involvement of NK and B cells in T cell exhaustion. Integrating spatially resolved omics and TCR sequencing provides as a robust tool for exploring T cell dysfunction in cancers and beyond.


Assuntos
Receptores de Antígenos de Linfócitos T , Linfócitos T , Receptores de Antígenos de Linfócitos T/genética , Regiões Determinantes de Complementaridade/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Perfilação da Expressão Gênica , Receptores de Antígenos de Linfócitos T alfa-beta/genética
5.
J Mol Recognit ; 36(11): e3056, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37696759

RESUMO

Thrombosis, or the formation of blood clots, can lead to serious medical conditions such as stroke, heart attack, and deep vein thrombosis. The purinoreceptor P2Y12 plays a critical role in the thrombotic pathway and is targeted for therapy to prevent clot formation. However, it is essential to balance the regulation of thrombosis to avoid adverse situations. This study focuses on the P2Y12 receptor and aims to discern the protein residue network and differentiate residues based on their intramolecular interactions. The study utilized a statistical analysis to characterize the significant residues involved in ligand interaction, which helps to identify critical residues that are essential for the function of the receptor. A parametric analysis of interactions of residues in the intraprotein interaction was conducted, which revealed significant residue-based contacts that facilitate protein interactions. By examining the interactions between residues, the mechanisms underlying protein interactions were studied and the importance of specific residues in facilitating these interactions was determined. This research provides important information on P2Y12, and the findings based on the network based significance of interacting residues may contribute to the development of new therapies that target the receptor to prevent clot formation while maintaining a balance in thrombosis regulation to avoid adverse outcomes. Ultimately, this study could lead to improved treatments for thrombotic disorders and better patient outcomes.

6.
STAR Protoc ; 4(3): 102383, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37393609

RESUMO

Single-cell RNA-sequencing (scRNA-seq) is becoming a ubiquitous method in profiling the cellular transcriptomes of both malignant and non-malignant cells from the human brain. Here, we present a protocol to isolate viable tumor cells from human ex vivo glioblastoma cultures for single-cell transcriptomic analysis. We describe steps including surgical tissue collection, sectioning, culturing, primary tumor cells inoculation, growth tracking, fluorescence-based cell sorting, and population-enriched scRNA-seq. This comprehensive methodology empowers in-depth understanding of brain tumor biology at the single-cell level. For complete details on the use and execution of this protocol, please refer to Ravi et al.1.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/genética , Perfilação da Expressão Gênica , Neoplasias Encefálicas/genética , Encéfalo , Transcriptoma/genética
7.
Neuro Oncol ; 25(2): 290-302, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-35802605

RESUMO

BACKGROUND: Recent efforts have described the evolution of glioblastoma from initial diagnosis to post-treatment recurrence on a genomic and transcriptomic level. However, the evolution of the proteomic landscape is largely unknown. METHODS: Sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) was used to characterize the quantitative proteomes of two independent cohorts of paired newly diagnosed and recurrent glioblastomas. Recurrence-associated proteins were validated using immunohistochemistry and further studied in human glioma cell lines, orthotopic xenograft models, and human organotypic brain slice cultures. External spatial transcriptomic, single-cell, and bulk RNA sequencing data were analyzed to gain mechanistic insights. RESULTS: Although overall proteomic changes were heterogeneous across patients, we identified BCAS1, INF2, and FBXO2 as consistently upregulated proteins at recurrence and validated these using immunohistochemistry. Knockout of FBXO2 in human glioma cells conferred a strong survival benefit in orthotopic xenograft mouse models and reduced invasive growth in organotypic brain slice cultures. In glioblastoma patient samples, FBXO2 expression was enriched in the tumor infiltration zone and FBXO2-positive cancer cells were associated with synaptic signaling processes. CONCLUSIONS: These findings demonstrate a potential role of FBXO2-dependent glioma-microenvironment interactions to promote tumor growth. Furthermore, the published datasets provide a valuable resource for further studies.


Assuntos
Neoplasias Encefálicas , Proteínas F-Box , Glioblastoma , Glioma , Humanos , Animais , Camundongos , Glioblastoma/patologia , Proteômica , Camundongos Knockout , Glioma/patologia , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Proteínas , Microambiente Tumoral , Proteínas de Neoplasias , Proteínas do Tecido Nervoso , Proteínas de Ciclo Celular , Proteínas F-Box/genética
8.
Brain ; 146(2): 549-560, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-35978480

RESUMO

Drug-resistant mesial-temporal lobe epilepsy is a devastating disease with seizure onset in the hippocampal formation. A fraction of hippocampi samples from epilepsy-surgical procedures reveals a peculiar histological pattern referred to as 'gliosis only' with unresolved pathogenesis and enigmatic sequelae. Here, we hypothesize that 'gliosis only' represents a particular syndrome defined by distinct clinical and molecular characteristics. We curated an in-depth multiparameter integration of systematic clinical, neuropsychological as well as neuropathological analysis from a consecutive cohort of 627 patients, who underwent hippocampectomy for drug-resistant temporal lobe epilepsy. All patients underwent either classic anterior temporal lobectomy or selective amygdalohippocampectomy. On the basis of their neuropathological exam, patients with hippocampus sclerosis and 'gliosis only' were characterized and compared within the whole cohort and within a subset of matched pairs. Integrated transcriptional analysis was performed to address molecular differences between both groups. 'Gliosis only' revealed demographics, clinical and neuropsychological outcome fundamentally different from hippocampus sclerosis. 'Gliosis only' patients had a significantly later seizure onset (16.3 versus 12.2 years, P = 0.005) and worse neuropsychological outcome after surgery compared to patients with hippocampus sclerosis. Epilepsy was less amendable by surgery in 'gliosis only' patients, resulting in a significantly worse rate of seizure freedom after surgery in this subgroup (43% versus 68%, P = 0.0001, odds ratio = 2.8, confidence interval 1.7-4.7). This finding remained significant after multivariate and matched-pairs analysis. The 'gliosis only' group demonstrated pronounced astrogliosis and lack of significant neuronal degeneration in contrast to characteristic segmental neuron loss and fibrillary astrogliosis in hippocampus sclerosis. RNA-sequencing of gliosis only patients deciphered a distinct transcriptional programme that resembles an innate inflammatory response of reactive astrocytes. Our data indicate a new temporal lobe epilepsy syndrome for which we suggest the term 'Innate inflammatory gliosis only'. 'Innate inflammatory gliosis only' is characterized by a diffuse gliosis pattern lacking restricted hippocampal focality and is poorly controllable by surgery. Thus, 'innate inflammatory gliosis only' patients need to be clearly identified by presurgical examination paradigms of pharmacoresistant temporal lobe epilepsy patients; surgical treatment of this subgroup should be considered with great precaution. 'Innate inflammatory gliosis only' requires innovative pharmacotreatment strategies.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Esclerose Hipocampal , Humanos , Epilepsia do Lobo Temporal/patologia , Gliose/patologia , Esclerose/patologia , Hipocampo/patologia , Lobo Temporal/patologia , Epilepsia Resistente a Medicamentos/complicações , Resultado do Tratamento
9.
EMBO Mol Med ; 14(12): e15343, 2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36278433

RESUMO

Lactate is a central metabolite in brain physiology but also contributes to tumor development. Glioblastoma (GB) is the most common and malignant primary brain tumor in adults, recognized by angiogenic and invasive growth, in addition to its altered metabolism. We show herein that lactate fuels GB anaplerosis by replenishing the tricarboxylic acid (TCA) cycle in absence of glucose. Lactate dehydrogenases (LDHA and LDHB), which we found spatially expressed in GB tissues, catalyze the interconversion of pyruvate and lactate. However, ablation of both LDH isoforms, but not only one, led to a reduction in tumor growth and an increase in mouse survival. Comparative transcriptomics and metabolomics revealed metabolic rewiring involving high oxidative phosphorylation (OXPHOS) in the LDHA/B KO group which sensitized tumors to cranial irradiation, thus improving mouse survival. When mice were treated with the antiepileptic drug stiripentol, which targets LDH activity, tumor growth decreased. Our findings unveil the complex metabolic network in which both LDHA and LDHB are integrated and show that the combined inhibition of LDHA and LDHB strongly sensitizes GB to therapy.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Lactato Desidrogenases , Animais , Camundongos , Ácido Láctico , Metabolômica , Glioblastoma/enzimologia , Glioblastoma/patologia , Neoplasias Encefálicas/enzimologia , Neoplasias Encefálicas/patologia
10.
J Parasit Dis ; 46(3): 613-616, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36091291

RESUMO

The nematode parasite Calodium hepaticum (Capillaria hepatica) has a global distribution and is commonly reported in rodents (definitive host), dogs, cats and wild animals. Humans especially children are more susceptible to the parasitic infection. This paper documents an incidental finding of hepatic calodiosis with cirrhosis in a stray dog and discusses the zoonotic implications. A non descript dog was brought for necropsy examination to the Department of Veterinary Pathology, Madras Veterinary College, Tamil Nadu, India. Liver appeared dark brown, mottled with multifocal random variably sized, grey white flat firm areas. Histopathologically, liver tissue revealed multiple random encysted large collection of eggs surrounded by mild inflammation with a few lymphocytes, macrophages and fine fibrosis. The eggs had characteristic barrel shape, bipolar ends, bilayered wall, cross striations between the walls, and yolk. Periodic acid Schiff stain demonstrated the glycolic wall of ova. Marked portal to portal fibrosis was demonstrated by Masson's trichrome (for collagen) and by Warthin-Starry (for reticulin) stains. The stage of parasitic infection was diagnosed as intermediate to chronic due to fibrosis. A need to study the prevalence of the disease in rodents, human and animals is emphasized. Improper burial of carcasses of rodents and dogs may contribute to spread of infection. Pets and stray animals may transmit infection to human and pose health risk.

11.
Clin Cancer Res ; 28(21): 4747-4756, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36037304

RESUMO

PURPOSE: Most chimeric antigen receptor (CAR) T-cell strategies against glioblastoma have demonstrated only modest therapeutic activity and are based on persistent gene modification strategies that have limited transgene capacity, long manufacturing processes, and the risk for uncontrollable off-tumor toxicities. mRNA-based T-cell modifications are an emerging safe, rapid, and cost-effective alternative to overcome these challenges, but are underexplored against glioblastoma. EXPERIMENTAL DESIGN: We generated mouse and human mRNA-based multifunctional T cells coexpressing a multitargeting CAR based on the natural killer group 2D (NKG2D) receptor and the proinflammatory cytokines IL12 and IFNα2 and assessed their antiglioma activity in vitro and in vivo. RESULTS: Compared with T cells that either expressed the CAR or cytokines alone, multifunctional CAR T cells demonstrated increased antiglioma activity in vitro and in vivo in three orthotopic immunocompetent mouse glioma models without signs of toxicity. Mechanistically, the coexpression of IL12 and IFNα2 in addition to the CAR promoted a proinflammatory tumor microenvironment and reduced T-cell exhaustion as demonstrated by ex vivo immune phenotyping, cytokine profiling, and RNA sequencing. The translational potential was demonstrated by image-based single-cell analyses of mRNA-modified T cells in patient glioblastoma samples with a complex cellular microenvironment. This revealed strong antiglioma activity of human mRNA-based multifunctional NKG2D CAR T cells coexpressing IL12 and IFNα2 whereas T cells that expressed either the CAR or cytokines alone did not demonstrate comparable antiglioma activity. CONCLUSIONS: These data provide a robust rationale for future clinical studies with mRNA-based multifunctional CAR T cells to treat malignant brain tumors.


Assuntos
Glioblastoma , Receptores de Antígenos Quiméricos , Humanos , Camundongos , Animais , Glioblastoma/genética , Glioblastoma/terapia , Glioblastoma/patologia , Imunoterapia Adotiva , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , RNA Mensageiro/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral , Receptores de Antígenos Quiméricos/genética , Linfócitos T , Citocinas , Interleucina-12 , Microambiente Tumoral/genética
12.
Cancer Cell ; 40(6): 639-655.e13, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35700707

RESUMO

Glioblastomas are malignant tumors of the central nervous system hallmarked by subclonal diversity and dynamic adaptation amid developmental hierarchies. The source of dynamic reorganization within the spatial context of these tumors remains elusive. Here, we characterized glioblastomas by spatially resolved transcriptomics, metabolomics, and proteomics. By deciphering regionally shared transcriptional programs across patients, we infer that glioblastoma is organized by spatial segregation of lineage states and adapts to inflammatory and/or metabolic stimuli, reminiscent of the reactive transformation in mature astrocytes. Integration of metabolic imaging and imaging mass cytometry uncovered locoregional tumor-host interdependence, resulting in spatially exclusive adaptive transcriptional programs. Inferring copy-number alterations emphasizes a spatially cohesive organization of subclones associated with reactive transcriptional programs, confirming that environmental stress gives rise to selection pressure. A model of glioblastoma stem cells implanted into human and rodent neocortical tissue mimicking various environments confirmed that transcriptional states originate from dynamic adaptation to various environments.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Humanos , Metabolômica/métodos
13.
J Am Chem Soc ; 144(14): 6493-6503, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35360899

RESUMO

Barocaloric effects─thermal changes in a material induced by applied hydrostatic pressure─offer promise for creating solid-state refrigerants as alternatives to conventional volatile refrigerants. To enable efficient and scalable barocaloric cooling, materials that undergo high-entropy, reversible phase transitions in the solid state in response to a small change in pressure are needed. Here, we report that pressure-induced spin-crossover (SCO) transitions in the molecular iron(II) complex Fe[HB(tz)3]2 (HB(tz)3- = bis[hydrotris(1,2,4-triazol-1-yl)borate]) drive giant and reversible barocaloric effects at easily accessible pressures. Specifically, high-pressure calorimetry and powder X-ray diffraction studies reveal that pressure shifts as low as 10 bar reversibly induce nonzero isothermal entropy changes, and a pressure shift of 150 bar reversibly induces a large isothermal entropy change (>90 J kg-1 K-1) and adiabatic temperature change (>2 K). Moreover, we demonstrate that the thermodynamics of the SCO transition can be fine-tuned through systematic deuteration of the tris(triazolyl)borate ligand. These results provide new insights into pressure-induced SCO transitions and further establish SCO materials as promising barocaloric materials.

14.
Nat Commun ; 13(1): 925, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177622

RESUMO

Despite recent advances in cancer immunotherapy, certain tumor types, such as Glioblastomas, are highly resistant due to their tumor microenvironment disabling the anti-tumor immune response. Here we show, by applying an in-silico multidimensional model integrating spatially resolved and single-cell gene expression data of 45,615 immune cells from 12 tumor samples, that a subset of Interleukin-10-releasing HMOX1+ myeloid cells, spatially localizing to mesenchymal-like tumor regions, drive T-cell exhaustion and thus contribute to the immunosuppressive tumor microenvironment. These findings are validated using a human ex-vivo neocortical glioblastoma model inoculated with patient derived peripheral T-cells to simulate the immune compartment. This model recapitulates the dysfunctional transformation of tumor infiltrating T-cells. Inhibition of the JAK/STAT pathway rescues T-cell functionality both in our model and in-vivo, providing further evidence of IL-10 release being an important driving force of tumor immune escape. Our results thus show that integrative modelling of single cell and spatial transcriptomics data is a valuable tool to interrogate the tumor immune microenvironment and might contribute to the development of successful immunotherapies.


Assuntos
Neoplasias Encefálicas/imunologia , Glioblastoma/imunologia , Interleucina-10/metabolismo , Células Mieloides/metabolismo , Linfócitos T/imunologia , Adulto , Idoso , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Comunicação Celular/imunologia , Linhagem Celular Tumoral , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Voluntários Saudáveis , Heme Oxigenase-1/metabolismo , Humanos , Imunoterapia/métodos , Inibidores de Janus Quinases/farmacologia , Inibidores de Janus Quinases/uso terapêutico , Janus Quinases/antagonistas & inibidores , Janus Quinases/metabolismo , Masculino , Pessoa de Meia-Idade , Neocórtex/citologia , Neocórtex/imunologia , Neocórtex/patologia , Cultura Primária de Células , RNA-Seq , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Análise de Célula Única , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Técnicas de Cultura de Tecidos , Evasão Tumoral , Microambiente Tumoral/imunologia
15.
Nat Neurosci ; 25(1): 20-25, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34811521

RESUMO

Microglia appear activated in the vicinity of amyloid beta (Aß) plaques, but whether microglia contribute to Aß propagation into unaffected brain regions remains unknown. Using transplantation of wild-type (WT) neurons, we show that Aß enters WT grafts, and that this is accompanied by microglia infiltration. Manipulation of microglia function reduced Aß deposition within grafts. Furthermore, in vivo imaging identified microglia as carriers of Aß pathology in previously unaffected tissue. Our data thus argue for a hitherto unexplored mechanism of Aß propagation.


Assuntos
Peptídeos beta-Amiloides , Microglia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Humanos , Microglia/metabolismo , Neurônios/metabolismo , Placa Amiloide/patologia
16.
Cell Death Dis ; 12(8): 723, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34290229

RESUMO

Glioblastoma (GBM), the most malignant tumor of the central nervous system, is marked by its dynamic response to microenvironmental niches. In particular, this cellular plasticity contributes to the development of an immediate resistance during tumor treatment. Novel insights into the developmental trajectory exhibited by GBM show a strong capability to respond to its microenvironment by clonal selection of specific phenotypes. Using the same mechanisms, malignant GBM do develop intrinsic mechanisms to resist chemotherapeutic treatments. This resistance was reported to be sustained by the paracrine and autocrine glutamate signaling via ionotropic and metabotropic receptors. However, the extent to which glutamatergic signaling modulates the chemoresistance and transcriptional profile of the GBM remains unexplored. In this study we aimed to map the manifold effects of glutamate signaling in GBM as the basis to further discover the regulatory role and interactions of specific receptors, within the GBM microenvironment. Our work provides insights into glutamate release dynamics, representing its importance for GBM growth, viability, and migration. Based on newly published multi-omic datasets, we explored the and characterized the functions of different ionotropic and metabotropic glutamate receptors, of which the metabotropic receptor 3 (GRM3) is highlighted through its modulatory role in maintaining the ability of GBM cells to evade standard alkylating chemotherapeutics. We addressed the clinical relevance of GRM3 receptor expression in GBM and provide a proof of concept where we manipulate intrinsic mechanisms of chemoresistance, driving GBM towards chemo-sensitization through GRM3 receptor inhibition. Finally, we validated our findings in our novel human organotypic section-based tumor model, where GBM growth and proliferation was significantly reduced when GRM3 inhibition was combined with temozolomide application. Our findings present a new picture of how glutamate signaling via mGluR3 interacts with the phenotypical GBM transcriptional programs in light of recently published GBM cell-state discoveries.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Glioblastoma/tratamento farmacológico , Receptores de Glutamato Metabotrópico/metabolismo , Aminoácidos/farmacologia , Antineoplásicos Alquilantes/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Glioblastoma/patologia , Ácido Glutâmico/metabolismo , Humanos , Cinética , Terapia Neoadjuvante , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Microambiente Tumoral/efeitos dos fármacos , Xantenos/farmacologia
17.
Neuro Oncol ; 23(11): 1885-1897, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33864086

RESUMO

BACKGROUND: Glioblastoma cells assemble to a syncytial communicating network based on tumor microtubes (TMs) as ultra-long membrane protrusions. The relationship between network architecture and transcriptional profile remains poorly investigated. Drugs that interfere with this syncytial connectivity such as meclofenamate (MFA) may be highly attractive for glioblastoma therapy. METHODS: In a human neocortical slice model using glioblastoma cell populations of different transcriptional signatures, three-dimensional tumor networks were reconstructed, and TM-based intercellular connectivity was mapped on the basis of two-photon imaging data. MFA was used to modulate morphological and functional connectivity; downstream effects of MFA treatment were investigated by RNA sequencing and fluorescence-activated cell sorting (FACS) analysis. RESULTS: TM-based network morphology strongly differed between the transcriptional cellular subtypes of glioblastoma and was dependent on axon guidance molecule expression. MFA revealed both a functional and morphological demolishment of glioblastoma network architectures which was reflected by a reduction of TM-mediated intercellular cytosolic traffic as well as a breakdown of TM length. RNA sequencing confirmed a downregulation of NCAM and axon guidance molecule signaling upon MFA treatment. Loss of glioblastoma communicating networks was accompanied by a failure in the upregulation of genes that are required for DNA repair in response to temozolomide (TMZ) treatment and culminated in profound treatment response to TMZ-mediated toxicity. CONCLUSION: The capacity of TM formation reflects transcriptional cellular heterogeneity. MFA effectively demolishes functional and morphological TM-based syncytial network architectures. These findings might pave the way to a clinical implementation of MFA as a TM-targeted therapeutic approach.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Ácido Meclofenâmico/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Glioblastoma/tratamento farmacológico , Humanos , Técnicas In Vitro
18.
Nanoscale Adv ; 3(14): 4207-4215, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-36132832

RESUMO

The polyhedron-structured NiSe2@MoSe2 (NMS) were magnificently produced through hydrothermal method, which makes the active electrode very effective in accessing the redox active sites in the charge/discharge process in supercapacitor applications. Systematic studies of the structural and morphological features of the unique polyhedron NMS were performed. Laser Raman spectra reported the vibrational and rotational modes of NMS. NMS exhibited a maximum 1000 F g-1 (138.8 mA h g-1) specific capacitance at 1 A g-1 and attained a capacity retention of 77.67% for 5000 stable cycles at 10 A g-1 using 1 M KOH as an electrolyte. The well assembled asymmetric supercapacitor NMS hydrolyzed for 18 h//AC demonstrated an outstanding electrochemical performance with an improved 305 F g-1 specific capacitance attained at 1 A g-1 with a good cycle life of 87.35% and a capacity retention of over 5000 cycles. Herein, the combined contribution of both the Ni and Mo ions offers a richer redox chemistry, which is beneficial to a higher electrochemical activity. The experimental results indicate that the NMS electrode could be used as a high-performance electrode.

19.
Mol Biochem Parasitol ; 238: 111291, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32479776

RESUMO

In free-living and parasitic nematodes, the methylation of phosphoethanolamine to phosphocholine provides a key metabolite to sustain phospholipid biosynthesis for growth and development. Because the phosphoethanolamine methyltransferases (PMT) of nematodes are essential for normal growth and development, these enzymes are potential targets of inhibitor design. The pine wilt nematode (Bursaphelenchus xylophilus) causes extensive damage to trees used for lumber and paper in Asia. As a first step toward testing BxPMT1 as a potential nematicide target, we determined the 2.05 Å resolution x-ray crystal structure of the enzyme as a dead-end complex with phosphoethanolamine and S-adenosylhomocysteine. The three-dimensional structure of BxPMT1 served as a template for site-directed mutagenesis to probe the contribution of active site residues to catalysis and phosphoethanolamine binding using steady-state kinetic analysis. Biochemical analysis of the mutants identifies key residues on the ß1d-α6 loop (W123F, M126I, and Y127F) and ß1e-α7 loop (S155A, S160A, H170A, T178V, and Y180F) that form the phosphobase binding site and suggest that Tyr127 facilitates the methylation reaction in BxPMT1.


Assuntos
Etanolaminas/química , Proteínas de Helminto/química , Metiltransferases/química , Nematoides/enzimologia , Pinus/parasitologia , Doenças das Plantas/parasitologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Etanolaminas/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Cinética , Metiltransferases/genética , Metiltransferases/metabolismo , Modelos Moleculares , Nematoides/genética , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Termodinâmica
20.
RSC Adv ; 10(33): 19410-19418, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35515465

RESUMO

So far, numerous metal oxides and metal hydroxides have been reported as an electrode material, a critical component in supercapacitors that determines the operation window of the capacitor. Among them, nickel and cobalt-based materials are studied extensively due to their high capacitance nature. However, the pure phase of hydroxides does not show a significant effect on cycle life. The observed XRD results revealed the phase structures of the obtained Ni(OH)2 and Co-Ni(OH)2 hydroxides. The congruency of the peak positions of Ni(OH)2 and Co-Ni(OH)2 is attributed to the homogeneity of the physical and chemical properties of the as-prepared products. The obtained results from XPS analysis indicated the presence of Co and the chemical states of the as-prepared composite active electrode materials. The SEM analysis revealed that the sample had the configuration of agglomerated particle nature. Moreover, the morphology and structure of the hydroxide materials impacted their charge storage properties. Thus, in this study, Ni(OH)2 and Co-Ni(OH)2 composite materials were produced via a hydrothermal method to obtain controllable morphology. The electrochemical properties were studied. It was observed that both the samples experienced a pseudocapacitive behavior, which was confirmed from the CV curves. For the electrode materials Ni(OH)2 and Co-Ni(OH)2, the specific capacitance (C s) of about 1038 F g-1 and 1366 F g-1, respectively, were observed at the current density of 1.5 A g-1. The Ni-Co(OH)2 composite showed high capacitance when compared with Ni(OH)2. The cycle index was determined for the electrode materials and it indicated excellent stability. The stability of the cell was investigated up to 2000 cycles, and the cell showed excellent retention of 96.26%.

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