Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Semin Cell Dev Biol ; 154(Pt C): 261-274, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36379848

RESUMO

Brain metastasis (BrM) is a major threat to the survival of melanoma, breast, and lung cancer patients. Circulating tumor cells (CTCs) cross the blood-brain barrier (BBB) and sustain in the brain microenvironment. Genetic mutations and epigenetic modifications have been found to be critical in controlling key aspects of cancer metastasis. Metastasizing cells confront inflammation and gradually adapt in the unique brain microenvironment. Currently, it is one of the major areas that has gained momentum. Researchers are interested in the factors that modulate neuroinflammation during BrM. We review here various epigenetic factors and mechanisms modulating neuroinflammation and how this helps CTCs to adapt and survive in the brain microenvironment. Since epigenetic changes could be modulated by targeting enzymes such as histone/DNA methyltransferase, deacetylases, acetyltransferases, and demethylases, we also summarize our current understanding of potential drugs targeting various aspects of epigenetic regulation in BrM.


Assuntos
Neoplasias Encefálicas , Neoplasias Pulmonares , Humanos , Epigênese Genética , Doenças Neuroinflamatórias , Neoplasias Encefálicas/genética , Inflamação/genética , Microambiente Tumoral/genética
2.
Development ; 150(6)2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36960827

RESUMO

The blood-brain barrier (BBB) is a vascular endothelial cell boundary that partitions the circulation from the central nervous system to promote normal brain health. We have a limited understanding of how the BBB is formed during development and maintained in adulthood. We used quantitative transcriptional profiling to investigate whether specific adhesion molecules are involved in BBB functions, with an emphasis on understanding how astrocytes interact with endothelial cells. Our results reveal a striking enrichment of multiple genes encoding laminin subunits as well as the laminin receptor gene Itga7, which encodes the alpha7 integrin subunit, in astrocytes. Genetic ablation of Itga7 in mice led to aberrant BBB permeability and progressive neurological pathologies. Itga7-/- mice also showed a reduction in laminin protein expression in parenchymal basement membranes. Blood vessels in the Itga7-/- brain showed separation from surrounding astrocytes and had reduced expression of the tight junction proteins claudin 5 and ZO-1. We propose that the alpha7 integrin subunit in astrocytes via adhesion to laminins promotes endothelial cell junction integrity, all of which is required to properly form and maintain a functional BBB.


Assuntos
Astrócitos , Barreira Hematoencefálica , Camundongos , Animais , Barreira Hematoencefálica/metabolismo , Laminina/metabolismo , Células Endoteliais/metabolismo , Integrinas/metabolismo , Junções Íntimas/metabolismo
3.
Semin Cancer Biol ; 86(Pt 3): 914-930, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34968667

RESUMO

Brain metastasis (BrM) is one of the major causes of death in cancer patients and is associated with an estimated 10-40 % of total cancer cases. The survival rate of brain metastatic patients has not improved due to intratumor heterogeneity, the survival adaptations of brain homing metastatic cells, and the lack of understanding of underlying molecular mechanisms that limit the availability of effective therapies. The heterogeneous population of immune cells and tumor-initiating cells or cancer stem cells in the tumor microenvironment (TME) release various factors, such as chemokines that upon binding to their cognate receptors enhance tumor growth at primary sites and help tumor cells metastasize to the brain. Furthermore, brain metastatic sites have unique heterogeneous microenvironment that fuels cancer cells in establishing BrM. This review explores the crosstalk of chemokines with the heterogeneous TME during the progression of BrM and recognizes potential therapeutic approaches. We also discuss and summarize different targeted, immunotherapeutic, chemotherapeutic, and combinatorial strategies (with chemo-/immune- or targeted-therapies) to attenuate chemokines mediated BrM.


Assuntos
Neoplasias Encefálicas , Humanos , Neoplasias Encefálicas/prevenção & controle , Quimiocinas , Células-Tronco Neoplásicas , Encéfalo , Microambiente Tumoral , Metástase Neoplásica
4.
Int J Mol Sci ; 24(9)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37175445

RESUMO

Stem-cell-based therapy is very promising for Alzheimer's disease (AD), yet has not become a reality. A critical challenge is the transplantation microenvironment, which impacts the therapeutic effect of stem cells. In AD brains, amyloid-beta (Aß) peptides and inflammatory cytokines continuously poison the tissue microenvironment, leading to low survival of grafted cells and restricted efficacy. It is necessary to create a growth-supporting microenvironment for transplanted cells. Recent advances in AD studies suggest that the asparaginyl endopeptidase (AEP) is a potential intervention target for modifying pathological changes. We here chose APP/PS1 mice as an AD model and employed pharmacological inhibition of the AEP for one month to improve the brain microenvironment. Thereafter, we transplanted neural stem cells (NSCs) into the hippocampus and maintained therapy for one more month. We found that inhibition of AEPs resulted in a significant decrease of Aß, TNF-α, IL-6 and IL-1ß in their brains. In AD mice receiving NSC transplantation alone, the survival of NSCs was at a low level, while in combination with AEP inhibition pre-treatment the survival rate of engrafted cells was doubled. Within the 2-month treatment period, implantation of NSCs plus pre-inhibition of the AEP significantly enhanced neural plasticity of the hippocampus and rescued cognitive impairment. Neither NSC transplantation alone nor AEP inhibition alone achieved significant efficacy. In conclusion, pharmacological inhibition of the AEP ameliorated brain microenvironment of AD mice, and thus improved the survival and therapeutic efficacy of transplanted stem cells.


Assuntos
Doença de Alzheimer , Células-Tronco Neurais , Animais , Camundongos , Doença de Alzheimer/terapia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Cisteína Endopeptidases , Modelos Animais de Doenças , Camundongos Transgênicos , Inibidores de Cisteína Proteinase
5.
Mol Cancer ; 21(1): 113, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538484

RESUMO

Brain metastasis (BrM) is a major problem associated with cancer-related mortality, and currently, no specific biomarkers are available in clinical settings for early detection. Liquid biopsy is widely accepted as a non-invasive method for diagnosing cancer and other diseases. We have reviewed the evidence that shows how the molecular alterations are involved in BrM, majorly from breast cancer (BC), lung cancer (LC), and melanoma, with an inception in how they can be employed for biomarker development. We discussed genetic and epigenetic changes that influence cancer cells to breach the blood-brain barrier (BBB) and help to establish metastatic lesions in the uniquely distinct brain microenvironment. Keeping abreast with the recent breakthroughs in the context of various biomolecules detections and identifications, the circulating tumor cells (CTC), cell-free nucleotides, non-coding RNAs, secretory proteins, and metabolites can be pursued in human body fluids such as blood, serum, cerebrospinal fluid (CSF), and urine to obtain potential candidates for biomarker development. The liquid biopsy-based biomarkers can overlay with current imaging techniques to amplify the signal viable for improving the early detection and treatments of occult BrM.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Células Neoplásicas Circulantes , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Feminino , Humanos , Biópsia Líquida/métodos , Células Neoplásicas Circulantes/patologia , Microambiente Tumoral
6.
Int J Mol Sci ; 22(1)2020 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-33375642

RESUMO

Neuroinflammation is an essential part of neurodegeneration. Yet, the current understanding of neuroinflammation-associated molecular events in distinct brain regions of prion disease patients is insufficient to lay the ground for effective treatment strategies targeting this complex neuropathological process. To address this problem, we analyzed the expression of 800 neuroinflammation-associated genes to create a profile of biological processes taking place in the frontal cortex and cerebellum of patients who suffered from sporadic Creutzfeldt-Jakob disease. The analysis was performed using NanoString nCounter technology with human neuroinflammation panel+. The observed gene expression patterns were regionally and sub-regionally distinct, suggesting a variable neuroinflammatory response. Interestingly, the observed differences could not be explained by the molecular subtypes of sporadic Creutzfeldt-Jakob disease. Furthermore, analyses of canonical pathways and upstream regulators based on differentially expressed genes indicated an overlap between biological processes taking place in different brain regions. This suggests that even smaller-scale spatial data reflecting subtle changes in brain cells' functional heterogeneity and their immediate pathologic microenvironments are needed to explain the observed differential gene expression in a greater detail.


Assuntos
Biomarcadores , Encéfalo/metabolismo , Síndrome de Creutzfeldt-Jakob/etiologia , Síndrome de Creutzfeldt-Jakob/metabolismo , Expressão Gênica , Idoso , Encéfalo/patologia , Microambiente Celular/genética , Microambiente Celular/imunologia , Biologia Computacional/métodos , Síndrome de Creutzfeldt-Jakob/patologia , Suscetibilidade a Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Transcriptoma
7.
Rev Neurosci ; 34(1): 85-101, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35791032

RESUMO

Most of Alzheimer's disease (AD) cases are sporadic and occur after age 65. With prolonged life expectancy and general population aging, AD is becoming a significant public health concern. The immune system supports brain development, plasticity, and homeostasis, yet it is particularly vulnerable to aging-related changes. Aging of the immune system, called immunosenescence, is the multifaceted remodeling of the immune system during aging. Immunosenescence is a contributing factor to various age-related diseases, including AD. Age-related changes in brain immune cell phenotype and function, crosstalk between immune cells and neural cells, and neuroinflammation work together to promote neurodegeneration and age-related cognitive impairment. Although numerous studies have confirmed the correlation between systemic immune changes and AD, few studies focus on the immune state of brain microenvironment in aging and AD. This review mainly addresses the changes of brain immune microenvironment in aging and AD. Specifically, we delineate how various aspects of the brain immune microenvironment, including immune gateways, immune cells, and molecules, and the interplay between immune cells and neural cells, accelerate AD pathogenesis during aging. We also propose a theoretical framework of therapeutic strategies selectively targeting the different mechanisms to restore brain immune homeostasis.


Assuntos
Doença de Alzheimer , Imunossenescência , Humanos , Doença de Alzheimer/patologia , Encéfalo , Sistema Imunitário , Envelhecimento
8.
Cancer Treat Rev ; 114: 102521, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36736124

RESUMO

Brain metastases (BM) are a common and devastating manifestation of breast cancer (BC). BM are particularly frequent in the HER2-positive and triple-negative breast cancer phenotypes and usually occur following the metastatic spread to extracranial sites. Several genes mediating BM and biomarkers predicting their risk in BC have been reported in the past decade. These findings have advanced the understanding of BM pathobiology and paved the way for developing new therapeutic strategies but they still warrant a thorough clinical validation. Hence, a better understanding of the mechanistic aspects of BM and delineating the interactions of tumor cells with the brain microenvironment are of utmost importance. This review discusses the molecular basis of the metastatic cascade: the epithelial-mesenchymal transition, cancer, and tumor microenvironment interaction and intravasation, priming of the metastatic niche in the brain, and survival in the new site. We also outline the postulated mechanisms of BC cells' brain tropism. Finally, we discuss advances in the field of biomarkers (both tissue-based and liquid-based) that predict BM from BC.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Neoplasias de Mama Triplo Negativas , Humanos , Feminino , Neoplasias da Mama/patologia , Neoplasias de Mama Triplo Negativas/patologia , Biomarcadores , Neoplasias Encefálicas/secundário , Microambiente Tumoral
9.
Adv Sci (Weinh) ; 10(12): e2207238, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36808713

RESUMO

Finding effective disease-modifying treatment for Alzheimer's disease remains challenging due to an array of factors contributing to the loss of neural function. The current study demonstrates a new strategy, using multitargeted bioactive nanoparticles to modify the brain microenvironment to achieve therapeutic benefits in a well-characterized mouse model of Alzheimer's disease. The application of brain-penetrating manganese dioxide nanoparticles significantly reduces hypoxia, neuroinflammation, and oxidative stress; ultimately reducing levels of amyloid ß plaques within the neocortex. Analyses of molecular biomarkers and magnetic resonance imaging-based functional studies indicate that these effects improve microvessel integrity, cerebral blood flow, and cerebral lymphatic clearance of amyloid ß. These changes collectively shift the brain microenvironment toward conditions more favorable to continued neural function as demonstrated by improved cognitive function following treatment. Such multimodal disease-modifying treatment may bridge critical gaps in the therapeutic treatment of neurodegenerative disease.


Assuntos
Doença de Alzheimer , Encéfalo , Nanopartículas Metálicas , Animais , Camundongos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Hipóxia Celular , Sistemas de Liberação de Medicamentos , Lipídeos/química , Nanopartículas Metálicas/química , Estresse Oxidativo , Polímeros/química , Encéfalo/metabolismo
10.
Front Oncol ; 13: 976945, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36793608

RESUMO

Organotypic cultures of murine brain slices are well-established tools in neuroscience research, including electrophysiology studies, modeling neurodegeneration, and cancer research. Here, we present an optimized ex vivo brain slice invasion assay that models glioblastoma multiforme (GBM) cell invasion into organotypic brain slices. Using this model, human GBM spheroids can be implanted with precision onto murine brain slices and cultured ex vivo to allow tumour cell invasion into the brain tissue. Traditional top-down confocal microscopy allows for imaging of GBM cell migration along the top of the brain slice, but there is limited resolution of tumour cell invasion into the slice. Our novel imaging and quantification technique involves embedding stained brain slices into an agar block, re-sectioning the slice in the Z-direction onto slides, and then using confocal microscopy to image cellular invasion into the brain tissue. This imaging technique allows for the visualization of invasive structures beneath the spheroid that would otherwise go undetected using traditional microscopy approaches. Our ImageJ macro (BraInZ) allows for the quantification of GBM brain slice invasion in the Z-direction. Importantly, we note striking differences in the modes of motility observed when GBM cells invade into Matrigel in vitro versus into brain tissue ex vivo highlighting the importance of incorporating the brain microenvironment when studying GBM invasion. In summary, our version of the ex vivo brain slice invasion assay improves upon previously published models by more clearly differentiating between migration along the top of the brain slice versus invasion into the slice.

11.
Phytomedicine ; 109: 154613, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36610112

RESUMO

BACKGROUND: Small cell lung cancer (SCLC) is an aggressive tumor with high brain metastasis (BM) potential. There has been no significant progress in the treatment of SCLC for more than 30 years. Cordycepin has shown the therapeutic potential for cancer by modulating multiple cellular signaling pathways. However, the effect and mechanism of cordycepin on anti-SCLC BM remain unknown. PURPOSE: In this study, we focused on the anti-SCLC BM effect of cordycepin in the zebrafish model and its potential mechanism. STUDY DESIGN AND METHODS: A SCLC xenograft model based on zebrafish embryos and in vitro cell migration assay were established. Cordycepin was administrated by soaking and microinjection in the zebrafish model. RNA-seq assay was performed to analyze transcriptomes of different groups. Geno Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were performed to reveal the underlying mechanism. Real-time qPCR was used to verify the effects of cordycepin on the key genes. RESULTS: Cordycepin showed lower cytotoxicity in vitro compared with cisplatin, anlotinib and etoposide, but showed comparable anti-proliferation and anti-BM effects in zebrafish SCLC xenograft model. Cordycepin showed significant anti-SCLC BM effects when administrated by both soaking and microinjection. RNA-seq demonstrated that cordycepin was involved in vitamin D metabolism, lipid transport, and proteolysis in cellular protein catabolic process pathways in SCLC BM microenvironment in zebrafish, and was involved in regulating the expressions of key genes such as cyp24a1, apoa1a, ctsl. The anti-BM effect of cordycepin in SCLC was mediated by reversing the expression of these genes. CONCLUSION: Our work is the first to describe the mechanism of cordycepin against SCLC BM from the perspective of regulating the brain microenvironment, providing new evidence for the anti-tumor effect of cordycepin.


Assuntos
Neoplasias Encefálicas , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Animais , Humanos , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/patologia , Peixe-Zebra , Neoplasias Pulmonares/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Microambiente Tumoral
12.
Front Mol Biosci ; 10: 1141994, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37056723

RESUMO

The incidence of brain metastases (BrM) has become a growing concern recently. It is a common and often fatal manifestation in the brain during the end-stage of many extracranial primary tumors. Increasing BrM diagnoses can be attributed to improvements in primary tumor treatments, which have extended patients' lifetime, and allowed for earlier and more efficient detection of brain lesions. Currently, therapies for BrM encompass systemic chemotherapy, targeted therapy, and immunotherapy. Systemic chemotherapy regimens are controversial due to their associated side effects and limited efficacy. Targeted and immunotherapies have garnered significant attention in the medical field: they target specific molecular sites and modulate specific cellular components. However, multiple difficulties such as drug resistance and low permeability of the blood-brain barrier (BBB) remain significant challenges. Thus, there is an urgent need for novel therapies. Brain microenvironments consist of cellular components including immune cells, neurons, endothelial cells as well as molecular components like metal ions, nutrient molecules. Recent research indicates that malignant tumor cells can manipulate the brain microenvironment to change the anti-tumoral to a pro-tumoral microenvironment, both before, during, and after BrM. This review compares the characteristics of the brain microenvironment in BrM with those in other sites or primary tumors. Furthermore, it evaluates the preclinical and clinical studies of microenvironment-targeted therapies for BrM. These therapies, due to their diversity, are expected to overcome drug resistance or low permeability of the BBB with low side effects and high specificity. This will ultimately lead to improved outcomes for patients with secondary brain tumors.

13.
ACS Appl Mater Interfaces ; 15(1): 200-219, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36468535

RESUMO

Brain organoids are self-assembled three-dimensional aggregates with brain-like cell types and structures and have emerged as new model systems that can be used to investigate human neurodevelopment and neurological disorders. However, brain organoids are not as mature and functional as real human brains due to limitations of the culture system with insufficient developmental patterning signals and a lack of components that are important for brain development and function, such as the non-neural population and vasculature. In addition, establishing the desired brain-like environment and monitoring the complex neural networks and physiological functions of the brain organoids remain challenging. The current protocols to generate brain organoids also have problems with heterogeneity and batch variation due to spontaneous self-organization of brain organoids into complex architectures of the brain. To address these limitations of current brain organoid technologies, various engineering platforms, such as extracellular matrices, fluidic devices, three-dimensional bioprinting, bioreactors, polymeric scaffolds, microelectrodes, and biochemical sensors, have been employed to improve neuronal development and maturation, reduce structural heterogeneity, and facilitate functional analysis and monitoring. In this review, we provide an overview of the latest engineering techniques that overcome these limitations in the production and application of brain organoids.


Assuntos
Encéfalo , Organoides , Humanos , Encéfalo/metabolismo , Modelos Biológicos , Tecnologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-35596258

RESUMO

Brain diseases, including neurodegenerative diseases, acute ischemic stroke and brain tumors, have become a major health problem and a huge burden on society with high morbidity and mortality. However, most of the current therapeutic drugs can only relieve the symptoms of brain diseases, and it is difficult to achieve satisfactory therapeutic effects fundamentally. Extensive studies have shown that the therapeutic effects of brain diseases are mainly affected by two factors: the conservation of the blood-brain barrier (BBB) and the complexity of the brain micro-environment. Brain-targeting drug delivery systems provide new possibilities for overcoming these barriers with versatility. In this review, it provides an overview of BBB alteration and discusses targeting delivery strategies for brain diseases therapy. Furthermore, delivery systems which are designed to modulate the brain micro-environment with synergistic effects were also highlighted. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.


Assuntos
Neoplasias Encefálicas , AVC Isquêmico , Barreira Hematoencefálica , Encéfalo , Sistemas de Liberação de Medicamentos , Humanos , Microambiente Tumoral
15.
Cancer Lett ; 540: 215726, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35589002

RESUMO

Mechanisms underlying breast cancer brain metastasis (BCBM) are still unclear. In this study, we observed that extracellular vesicles (EVs) secreted from breast cancer cells with increased expression of tGLI1, a BCBM-promoting transcription factor, strongly activated astrocytes. EV-derived microRNA/miRNA microarray revealed tGLI1-positive breast cancer cells highly secreted miR-1290 and miR-1246 encapsulated in EVs. Genetic knockin/knockout studies established a direct link between tGLI1 and both miRNAs. Datamining and analysis of patient samples revealed that BCBM patients had more circulating EV-miRs-1290/1246 than those without metastasis. Ectopic expression of miR-1290 or miR-1246 strongly activated astrocytes whereas their inhibitors abrogated the effect. Conditioned media from miR-1290- or miR-1246-overexpressing astrocytes promoted mammospheres. Furthermore, miRs-1290/1246 suppressed expression of FOXA2 transcription repressor, leading to CNTF cytokine secretion and subsequent activation of astrocytes. Finally, we conducted a mouse study to demonstrate that astrocytes overexpressing miR-1290, but not miR-1246, enhanced intracranial colonization and growth of breast cancer cells. Collectively, our findings demonstrate, for the first time, that breast cancer EV-derived miR-1290 and miR-1246 activate astrocytes in the brain metastatic microenvironment and that EV-derived miR-1290 promotes progression of brain metastases through the novel EV-miR-1290→FOXA2→CNTF signaling axis.


Assuntos
Neoplasias Encefálicas , Neoplasias da Mama , Fator Neurotrófico Ciliar , Vesículas Extracelulares , Fator 3-beta Nuclear de Hepatócito , MicroRNAs , Animais , Astrócitos/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Fator Neurotrófico Ciliar/metabolismo , Vesículas Extracelulares/metabolismo , Feminino , Fator 3-beta Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Transcrição/metabolismo , Microambiente Tumoral
16.
J Biol Eng ; 16(1): 14, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35698088

RESUMO

BACKGROUND: The brain extracellular environment is involved in many critical processes associated with neurodevelopment, neural function, and repair following injury. Organization of the extracellular matrix and properties of the extracellular space vary throughout development and across different brain regions, motivating the need for platforms that provide access to multiple brain regions at different stages of development. We demonstrate the utility of organotypic whole hemisphere brain slices as a platform to probe regional and developmental changes in the brain extracellular environment. We also leverage whole hemisphere brain slices to characterize the impact of cerebral ischemia on different regions of brain tissue. RESULTS: Whole hemisphere brain slices taken from postnatal (P) day 10 and P17 rats retained viable, metabolically active cells through 14 days in vitro (DIV). Oxygen-glucose-deprivation (OGD), used to model a cerebral ischemic event in vivo, resulted in reduced slice metabolic activity and elevated cell death, regardless of slice age. Slices from P10 and P17 brains showed an oligodendrocyte and microglia-driven proliferative response after OGD exposure, higher than the proliferative response seen in DIV-matched normal control slices. Multiple particle tracking in oxygen-glucose-deprived brain slices revealed that oxygen-glucose-deprivation impacts the extracellular environment of brain tissue differently depending on brain age and brain region. In most instances, the extracellular space was most difficult to navigate immediately following insult, then gradually provided less hindrance to extracellular nanoparticle diffusion as time progressed. However, changes in diffusion were not universal across all brain regions and ages. CONCLUSIONS: We demonstrate whole hemisphere brain slices from P10 and P17 rats can be cultured up to two weeks in vitro. These brain slices provide a viable platform for studying both normal physiological processes and injury associated mechanisms with control over brain age and region. Ex vivo OGD impacted cortical and striatal brain tissue differently, aligning with preexisting data generated in in vivo models. These data motivate the need to account for both brain region and age when investigating mechanisms of injury and designing potential therapies for cerebral ischemia.

17.
Front Oncol ; 12: 1003715, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36248975

RESUMO

Brain metastasis of a cancer is a malignant disease with high mortality, but the cause and the molecular mechanism remain largely unknown. Using the samples of primary tumors of 22 cancer types in the TCGA database, we have performed a computational study of their transcriptomic data to investigate the drivers of brain metastases at the basic physics and chemistry level. Our main discoveries are: (i) the physical characteristics, namely electric charge, molecular weight, and the hydrophobicity of the extracellular structures of the expressed transmembrane proteins largely affect a primary cancer cell's ability to cross the blood-brain barrier; and (ii) brain metastasis may require specific functions provided by the activated enzymes in the metastasizing primary cancer cells for survival in the brain micro-environment. Both predictions are supported by published experimental studies. Based on these findings, we have built a classifier to predict if a given primary cancer may have brain metastasis, achieving the accuracy level at AUC = 0.92 on large test sets.

18.
Front Oncol ; 12: 914156, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936750

RESUMO

Integrins are heterodimeric transmembrane glycoproteins resulting from the non-covalent association of an α and ß chain. The major integrin receptor for collagen/laminin, α2ß1 is expressed on a wide variety of cell types and plays an essential role in the adhesion of normal and tumor cells to the extracellular matrix. Integrin-triggered signaling pathways promote the invasion and survival of glioma cells by modifying the brain microenvironment. In this study, we investigated the association of a specific genetic polymorphism of integrin α2ß1 with the incidence of diffusely infiltrating astrocytoma and the progression of these tumors. Single-nucleotide polymorphism in intron 7 of the integrin ITGA2 gene was examined in 158 patients and 162 controls using polymerase chain reaction and restriction enzyme analysis. The ITGA2 genotype +/+ (with a BglII restriction site in both alleles) exhibited higher frequency in grade II astrocytoma compared to control (P = 0.02) whereas the genotype -/- (lacking the BglII site) correlated with the poorest survival rate (P = 0.04). In addition, in silico analyses of ITGA2 expression from low-grade gliomas (LGG, n = 515) and glioblastomas (GBM, n = 159) indicated that the higher expression of ITGA2 in LGG was associated with poor overall survival (P < 0.0001). However, the distribution of integrin ITGA2 BglII genotypes (+/+, +/-, -/-) was not significantly different between astrocytoma subgroups III and IV (P = 0.65, 0.24 and 0.33; 0.29, 0.48, 0.25, respectively) compared to control. These results suggest a narrow association between the presence of this SNP and indicate that further studies with larger samples are warranted to analyze the relation between tumor grade and overall survival, highlighting the importance of determining these polymorphisms for prognosis of astrocytomas.

19.
Adv Healthc Mater ; 11(22): e2201150, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36074801

RESUMO

Stroke patients with diabetes have worse neurological outcomes than non-diabetic stroke patients, and treatments beneficial for non-diabetic stroke patients are not necessarily effective for diabetic stroke patients. While stem cell-derived extracellular vesicles (EVs) show potential for treating stroke, the results remain unsatisfactory due to the lack of approaches for retaining and controlling EVs released into the brain. Herein, a glucose/reactive oxygen species dual-responsive hydrogel showing excellent injectability, biocompatibility, and self-healing capability is introduced as an EVs-loading vehicle and an intelligent EVs sustained releasing system in the brain. These EVs-hydrogels are developed via crosslinking of phenylboronic acid-modified hyaluronic acid and Poly vinyl alcohol, and fusion with neural stem cell-derived EVs. The results show EVs are stably incorporated into the hydrogels and can be controllably released in response to the brain microenvironment after stroke in type 2 diabetic mice. The EVs-hydrogels exert an excellent angiogenic effect, increasing the migration and tube formation of human umbilical vein endothelial cells. In addition, injection of EVs-hydrogels into the ischemic mouse brain enhances EVs retention and facilitates sustained release, promotes angiogenesis, and improves neurobehavioral recovery. These results suggest such a microenvironment responsive and sustained release EVs-hydrogel system offers a safe, and efficient therapy for diabetic stroke.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Vesículas Extracelulares , Acidente Vascular Cerebral , Animais , Camundongos , Humanos , Hidrogéis/farmacologia , Preparações de Ação Retardada , Células Endoteliais da Veia Umbilical Humana , Encéfalo , Acidente Vascular Cerebral/terapia
20.
J Tradit Chin Med ; 41(2): 276-283, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33825408

RESUMO

OBJECTIVE: To compare and observe the effects of three kinds of cephalic acupuncture therapies commonly used in the clinic on promoting nerve function rehabilitation in the brain microenvironment of rats with cerebral palsy. METHODS: A negative control group, positive control group, and three cephalic acupuncture groups based on the administration of three cephalic acupuncture therapies were established. Ten experimental rats were selected from each group at 1, 2, and 3 weeks after modeling. Neuromotor function after treatment was rated according to the Basso, Beattie, and Bresnahan method. White matter fiber bundles were evaluated by head diffusion tensor imaging. The expression levels of neuron-specific enolase, microtubule-associated protein 2, and myelin basic protein in the brain tissue extract were detected by Western blot analysis and the activities of ATPases were determined using a fixed phosphorus method. RESULTS: The pathological changes in brain tissue were restored and motor function scores were increased in the mice in each cephalic acupuncture group, and the expression of neuronal growth-related proteins in the brain tissue extract was significantly increased. Additionally, the activities of ATPases in the lesion area were significant enhanced (P < 0.05). Diffusion tensor imaging revealed that the white matter fiber bundles of mice in each cephalic acupuncture group gradually increased and recovered. The nervous system structure was significantly improved. CONCLUSIONS: All three acupuncture methods promoted the rehabilitation of nerve function damaged by cerebral palsy. These effects are likely related to the improved expression of nerve growth-related proteins, enhancement of ATPase activities, and regulation of the brain microenvironment.


Assuntos
Terapia por Acupuntura , Paralisia Cerebral/terapia , Pontos de Acupuntura , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Paralisia Cerebral/diagnóstico por imagem , Paralisia Cerebral/fisiopatologia , Paralisia Cerebral/reabilitação , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA