Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Proteome Res ; 23(3): 939-955, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38364797

RESUMO

N-Linked glycosylation is one of the most essential post-translational modifications of proteins. However, N-glycan structural determination remains challenging because of the small differences in structures between isomers. In this study, we constructed a database containing collision-induced dissociation MSn mass spectra and chromatograms of high-performance liquid chromatography for the rapid identification of high-mannose and paucimannose N-glycan isomers. These N-glycans include isomers by breaking of arbitrary numbers of glycosidic bonds at arbitrary positions of canonical Man9GlcNAc2 N-glycans. In addition, some GlcMannGlcNAc2 N-glycan isomers were included in the database. This database is particularly useful for the identification of the N-glycans not in conventional N-glycan standards. This study demonstrated the application of the database to structural assignment for high-mannose N-glycans extracted from bovine whey proteins, soybean proteins, human mammary epithelial cells, and human breast carcinoma cells. We found many N-glycans that are not expected to be generated by conventional biosynthetic pathways of multicellular eukaryotes.


Assuntos
Mama , Manose , Humanos , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Bases de Dados Factuais , Polissacarídeos
2.
Nat Methods ; 18(9): 1013-1026, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34446922

RESUMO

Extracellular vesicles (EVs) are nano-sized lipid bilayer vesicles released by virtually every cell type. EVs have diverse biological activities, ranging from roles in development and homeostasis to cancer progression, which has spurred the development of EVs as disease biomarkers and drug nanovehicles. Owing to the small size of EVs, however, most studies have relied on isolation and biochemical analysis of bulk EVs separated from biofluids. Although informative, these approaches do not capture the dynamics of EV release, biodistribution, and other contributions to pathophysiology. Recent advances in live and high-resolution microscopy techniques, combined with innovative EV labeling strategies and reporter systems, provide new tools to study EVs in vivo in their physiological environment and at the single-vesicle level. Here we critically review the latest advances and challenges in EV imaging, and identify urgent, outstanding questions in our quest to unravel EV biology and therapeutic applications.


Assuntos
Vesículas Extracelulares , Microscopia/métodos , Animais , Corantes/química , Epitopos , Vesículas Extracelulares/química , Vesículas Extracelulares/patologia , Vesículas Extracelulares/fisiologia , Corantes Fluorescentes/química , Humanos
3.
Anal Chem ; 95(23): 8789-8797, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37235553

RESUMO

N-linked glycosylation is one of the most important post-translational modifications of proteins. Current knowledge of multicellular eukaryote N-glycan biosynthesis suggests high mannose N-glycans are generated in the endoplasmic reticulum and Golgi apparatus through conserved biosynthetic pathways. According to conventional biosynthetic pathways, four Man7GlcNAc2 isomers, three Man6GlcNAc2 isomers, and one Man5GlcNAc2 isomer are generated during this process. In this study, we applied our latest mass spectrometry method, logically derived sequence tandem mass spectrometry (LODES/MSn), to re-examine high mannose N-glycans extracted from various multicellular eukaryotes which are not glycosylation mutants. LODES/MSn identified many high mannose N-glycan isomers previously unreported in plantae, animalia, cancer cells, and fungi. A database consisting of retention time and CID MSn mass spectra was constructed for all possible MannGlcNAc2 (n = 5, 6, 7) isomers that include the isomers by removing arbitrary numbers and positions of mannose from canonical N-glycan, Man9GlcNAc2. Many N-glycans in this database are not found in current N-glycan mass spectrum libraries. The database is useful for rapid high mannose N-glycan isomeric identification.


Assuntos
Eucariotos , Manose , Humanos , Manose/química , Eucariotos/metabolismo , Vias Biossintéticas , Polissacarídeos/química , Espectrometria de Massas em Tandem/métodos
4.
Nucleic Acids Res ; 48(17): e100, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32797168

RESUMO

Tracking DNA double strand break (DSB) repair is paramount for the understanding and therapeutic development of various diseases including cancers. Herein, we describe a multiplexed bioluminescent repair reporter (BLRR) for non-invasive monitoring of DSB repair pathways in living cells and animals. The BLRR approach employs secreted Gaussia and Vargula luciferases to simultaneously detect homology-directed repair (HDR) and non-homologous end joining (NHEJ), respectively. BLRR data are consistent with next-generation sequencing results for reporting HDR (R2 = 0.9722) and NHEJ (R2 = 0.919) events. Moreover, BLRR analysis allows longitudinal tracking of HDR and NHEJ activities in cells, and enables detection of DSB repairs in xenografted tumours in vivo. Using the BLRR system, we observed a significant difference in the efficiency of CRISPR/Cas9-mediated editing with guide RNAs only 1-10 bp apart. Moreover, BLRR analysis detected altered dynamics for DSB repair induced by small-molecule modulators. Finally, we discovered HDR-suppressing functions of anticancer cardiac glycosides in human glioblastomas and glioma cancer stem-like cells via inhibition of DNA repair protein RAD51 homolog 1 (RAD51). The BLRR method provides a highly sensitive platform to simultaneously and longitudinally track HDR and NHEJ dynamics that is sufficiently versatile for elucidating the physiology and therapeutic development of DSB repair.


Assuntos
Genes Reporter , Luciferases/genética , Reparo de DNA por Recombinação , Animais , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Copépodes/enzimologia , Reparo do DNA por Junção de Extremidades , Feminino , Células HEK293 , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Luciferases/metabolismo , Camundongos , Camundongos Nus , Reação em Cadeia da Polimerase Multiplex/métodos , Imagem Óptica/métodos , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Análise de Sequência de DNA/métodos
5.
Cytotherapy ; 23(5): 373-380, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33934807

RESUMO

Mesenchymal stromal/stem cells (MSCs) have been widely tested against many diseases, with more than 1000 registered clinical trials worldwide. Despite many setbacks, MSCs have been approved for the treatment of graft-versus-host disease and Crohn disease. However, it is increasingly clear that MSCs exert their therapeutic functions in a paracrine manner through the secretion of small extracellular vesicles (sEVs) of 50-200 nm in diameter. Unlike living cells that can persist long-term, sEVs are non-living and non-replicative and have a transient presence in the body. Their small size also renders sEV preparations highly amenable to sterilization by filtration. Together, acellular MSC-sEV preparations are potentially safer and easier to translate into the clinic than cellular MSC products. Nevertheless, there are inherent challenges in the development of MSC-sEV drug products. MSC-sEVs are products of living cells, and living cells are sensitive to changes in the external microenvironment. Consequently, quality control metrics to measure key identity and potency features of MSC-sEV preparations have to be specified during development of MSC-sEV therapeutics. The authors have previously described quantifiable assays to define the identity of MSC-sEVs. Here the authors discuss requirements for prospective potency assays to predict the therapeutic effectiveness of the drug substance in accordance with International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. Although potency assays should ideally reflect the mechanism of action (MoA), this is challenging because the MoA for the reported efficacy of MSC-sEV preparations against multiple diseases of diverse underlying pathology is likely to be complex and different for each disease and difficult to fully elucidate. Nevertheless, robust potency assays could be developed by identifying the EV attribute most relevant to the intended biological activity in EV-mediated therapy and quantifying the EV attribute. Specifically, the authors highlight challenges and mitigation measures to enhance the manufacture of consistent and reproducibly potent sEV preparations, to identify and select the appropriate EV attribute for potency assays despite a complex "work-in-progress" MoA and to develop assays likely to be compliant with regulatory guidance for assay validation.


Assuntos
Vesículas Extracelulares , Doença Enxerto-Hospedeiro , Células-Tronco Mesenquimais , Humanos , Estudos Prospectivos
6.
J Neuroeng Rehabil ; 18(1): 150, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635141

RESUMO

BACKGROUND: Falls are more prevalent in stroke survivors than age-matched healthy older adults because of their functional impairment. Rapid balance recovery reaction with adequate range-of-motion and fast response and movement time are crucial to minimize fall risk and prevent serious injurious falls when postural disturbances occur. A Kinect-based Rapid Movement Training (RMT) program was developed to provide real-time feedback to promote faster and larger arm reaching and leg stepping distances toward targets in 22 different directions. OBJECTIVE: To evaluate the effectiveness of the interactive RMT and Conventional Balance Training (CBT) on chronic stroke survivors' overall balance and balance recovery reaction. METHODS: In this assessor-blinded randomized controlled trial, chronic stroke survivors were randomized to receive twenty training sessions (60-min each) of either RMT or CBT. Pre- and post-training assessments included clinical tests, as well as kinematic measurements and electromyography during simulated forward fall through a "lean-and-release" perturbation system. RESULTS: Thirty participants were recruited (RMT = 16, CBT = 14). RMT led to significant improvement in balance control (Berg Balance Scale: pre = 49.13, post = 52.75; P = .001), gait control (Timed-Up-and-Go Test: pre = 14.66 s, post = 12.62 s; P = .011), and motor functions (Fugl-Meyer Assessment of Motor Recovery: pre = 60.63, post = 65.19; P = .015), which matched the effectiveness of CBT. Both groups preferred to use their non-paretic leg to take the initial step to restore stability, and their stepping leg's rectus femoris reacted significantly faster post-training (P = .036). CONCLUSION: The RMT was as effective as conventional balance training to provide beneficial effects on chronic stroke survivors' overall balance, motor function and improving balance recovery with faster muscle response. TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov ( https://clinicaltrials.gov/ct2/show/NCT03183635 , NCT03183635) on 12 June 2017.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Acidentes por Quedas/prevenção & controle , Idoso , Humanos , Equilíbrio Postural , Acidente Vascular Cerebral/complicações , Estudos de Tempo e Movimento
7.
J Neuroeng Rehabil ; 18(1): 19, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514393

RESUMO

BACKGROUND: Wearable ankle robotics could potentially facilitate intensive repetitive task-specific gait training on stair environment for stroke rehabilitation. A lightweight (0.5 kg) and portable exoskeleton ankle robot was designed to facilitate over-ground and stair training either providing active assistance to move paretic ankle augmenting residual motor function (power-assisted ankle robot, PAAR), or passively support dropped foot by lock/release ankle joint for foot clearance in swing phase (swing-controlled ankle robot, SCAR). In this two-center randomized controlled trial, we hypothesized that conventional training integrated with robot-assisted gait training using either PAAR or SCAR in stair environment are more effective to enhance gait recovery and promote independency in early stroke, than conventional training alone. METHODS: Sub-acute stroke survivors (within 2 months after stroke onset) received conventional training integrated with 20-session robot-assisted training (at least twice weekly, 30-min per session) on over-ground and stair environments, wearing PAAR (n = 14) or SCAR (n = 16), as compared to control group receiving conventional training only (CT, n = 17). Clinical assessments were performed before and after the 20-session intervention, including functional ambulatory category as primary outcome measure, along with Berg balance scale and timed 10-m walk test. RESULTS: After the 20-session interventions, all three groups showed statistically significant and clinically meaningful within-group functional improvement in all outcome measures (p < 0.005). Between-group comparison showed SCAR had greater improvement in functional ambulatory category (mean difference + 0.6, medium effect size 0.610) with more than 56% independent walkers after training, as compared to only 29% for CT. Analysis of covariance results showed PAAR had greater improvement in walking speed than SCAR (mean difference + 0.15 m/s, large effect size 0.752), which was in line with the higher cadence and speed when wearing the robot during the 20-session robot-assisted training over-ground and on stairs. CONCLUSIONS: Robot-assisted stair training would lead to greater functional improvement in gait independency and walking speed than conventional training in usual care. The active powered ankle assistance might facilitate users to walk more and faster with their paretic leg during stair and over-ground walking. TRIAL REGISTRATION: ClinicalTrials.gov NCT03184259. Registered on 12 June 2017.


Assuntos
Exoesqueleto Energizado , Recuperação de Função Fisiológica , Robótica/métodos , Reabilitação do Acidente Vascular Cerebral/instrumentação , Adulto , Idoso , Articulação do Tornozelo/fisiopatologia , Feminino , Transtornos Neurológicos da Marcha/reabilitação , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/fisiopatologia , Reabilitação do Acidente Vascular Cerebral/métodos
8.
Nano Lett ; 20(2): 1089-1100, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-31884787

RESUMO

Biomolecules that respond to different external stimuli enable the remote control of genetically modified cells. We report herein a sonogenetic approach that can manipulate target cell activities by focused ultrasound stimulation. This system requires an ultrasound-responsive protein derived from an engineered auditory-sensing protein prestin. Heterologous expression of mouse prestin containing two parallel amino acid substitutions, N7T and N308S, that frequently exist in prestins from echolocating species endowed transfected mammalian cells with the ability to sense ultrasound. An ultrasound pulse of low frequency and low pressure efficiently evoked cellular calcium responses after transfecting with prestin(N7T, N308S). Moreover, pulsed ultrasound can also noninvasively stimulate target neurons expressing prestin(N7T, N308S) in deep regions of mouse brains. Our study delineates how an engineered auditory-sensing protein can cause mammalian cells to sense ultrasound stimulation. Moreover, our sonogenetic tools will serve as new strategies for noninvasive therapy in deep tissues.


Assuntos
Encéfalo/metabolismo , Audição/genética , Proteínas Motores Moleculares/genética , Neurônios/metabolismo , Animais , Ecolocação , Audição/fisiologia , Humanos , Camundongos , Proteínas Motores Moleculares/química , Neurônios/química , Engenharia de Proteínas/métodos , Ondas Ultrassônicas
9.
J Neuroinflammation ; 17(1): 120, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32299465

RESUMO

BACKGROUND: Glioblastomas are the most common and lethal primary brain tumors. Microglia, the resident immune cells of the brain, survey their environment and respond to pathogens, toxins, and tumors. Glioblastoma cells communicate with microglia, in part by releasing extracellular vesicles (EVs). Despite the presence of large numbers of microglia in glioblastoma, the tumors continue to grow, and these neuroimmune cells appear incapable of keeping the tumor in check. To understand this process, we analyzed gene expression in microglia interacting with glioblastoma cells. METHODS: We used RNASeq of isolated microglia to analyze the expression patterns of genes involved in key microglial functions in mice with glioblastoma. We focused on microglia that had taken up tumor-derived EVs and therefore were within and immediately adjacent to the tumor. RESULTS: We show that these microglia have downregulated expression of genes involved in sensing tumor cells and tumor-derived danger signals, as well as genes used for tumor killing. In contrast, expression of genes involved in facilitating tumor spread was upregulated. These changes appear to be in part EV-mediated, since intracranial injection of EVs in normal mice led to similar transcriptional changes in microglia. We observed a similar microglial transcriptomic signature when we analyzed datasets from human patients with glioblastoma. CONCLUSION: Our data define a microgliaGlioblastoma specific phenotype, whereby glioblastomas have hijacked gene expression in the neuroimmune system to favor avoiding tumor sensing, suppressing the immune response, clearing a path for invasion, and enhancing tumor propagation. For further exploration, we developed an interactive online tool at http://www.glioma-microglia.com with all expression data and additional functional and pathway information for each gene.


Assuntos
Neoplasias Encefálicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Microglia/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Vesículas Extracelulares/genética , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , Feminino , Técnicas de Introdução de Genes/métodos , Glioblastoma/genética , Glioblastoma/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/patologia , Carga Tumoral/fisiologia
10.
Hong Kong Physiother J ; 40(1): 63-73, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32489241

RESUMO

OBJECTIVE: To compare the effectiveness of mobile video-guided home exercise program and standard paper-based home exercise program. METHODS: Eligible participants were randomly assigned to either experimental group with mobile video-guided home exercise program or control group with home exercise program in a standard pamphlet for three months. The primary outcome was exercise adherence. The secondary outcomes were self-efficacy for exercise by Self-Efficacy for Exercise (SEE) Scale; and functional outcomes including mobility level by Modified Functional Ambulatory Category (MFAC) and basic activities of daily living (ADL) by Modified Barthel Index (MBI). All outcomes were captured by phone interviews at 1 day, 1 month and 3 months after the participants were discharged from the hospitals. RESULTS: A total of 56 participants were allocated to the experimental group ( n = 27 ) and control group ( n = 29 ) . There were a significant between-group differences in 3-months exercise adherence (experimental group: 75.6%; control group: 55.2%); significant between-group differences in 1-month SEE (experimental group: 58.4; control group: 43.3) and 3-month SEE (experimental group: 62.2; control group: 45.6). For functional outcomes, there were significant between-group differences in 3-month MFAC gain (experimental group: 1.7; control group: 1.0). There were no between-group differences in MBI gain. CONCLUSION: The use of mobile video-guided home exercise program was superior to standard paper-based home exercise program in exercise adherence, SEE and mobility gain but not basic ADL gain for patients recovering from stroke.

11.
Proteomics ; 19(1-2): e1800162, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30334355

RESUMO

Extracellular vesicles (EVs) including exosomes and microvesicles are lipid bilayer-encapsulated nanoparticles released by cells, ranging from 40 nm to several microns in diameter. Biological cargoes including proteins, RNAs, and DNAs can be ferried by EVs to neighboring and distant cells via biofluids, serving as a means of cell-to-cell communication under normal and pathological conditions, especially cancers. On the other hand, EVs have been investigated as a novel "information capsule" for early disease detection and monitoring via liquid biopsy. This review summarizes current advancements in EV subtype characterization, cancer EV capture, proteomic analysis technologies, as well as possible EV-based multiomics for cancer diagnostics.


Assuntos
Vesículas Extracelulares/metabolismo , Neoplasias/diagnóstico , Neoplasias/metabolismo , Proteômica/métodos , Micropartículas Derivadas de Células/metabolismo , Exossomos/metabolismo , Humanos
12.
J Biomed Sci ; 25(1): 91, 2018 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-30580764

RESUMO

Extracellular vesicles (EVs) are lipid bilayer-enclosed nanoparticles released by cells. They range from 30 nm to several micrometers in diameter, and ferry biological cargos such as proteins, lipids, RNAs and DNAs for local and distant intercellular communications. EVs have since been found to play a role in development, as well as in diseases including cancers. To elucidate the roles of EVs, researchers have established different methods to visualize and study their spatiotemporal properties. However, since EV are nanometer-sized, imaging them demands a full understanding of each labeling strategy to ensure accurate monitoring. This review covers current and emerging strategies for EV imaging for prospective studies.


Assuntos
Diagnóstico por Imagem/métodos , Vesículas Extracelulares/fisiologia , Microscopia Eletrônica/métodos , Diagnóstico por Imagem/instrumentação , Vesículas Extracelulares/ultraestrutura , Microscopia Eletrônica/instrumentação
13.
Clin Rehabil ; 32(4): 462-472, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29019274

RESUMO

OBJECTIVE: To investigate whether a comprehensive exercise program was effective in improving physical function among institutionalized older adults and whether adding whole-body vibration to the program conferred additional therapeutic benefits. DESIGN: A single-blinded randomized controlled trial was conducted. SETTING: This study was carried out in residential care units. PARTICIPANTS: In total, 73 older adults (40 women, mean age: 82.3 ± 7.3 years) were enrolled into this study. INTERVENTIONS: Participants were randomly allocated to one of the three groups: strength and balance program combined with whole-body vibration, strength and balance program without whole-body vibration, and social and recreational activities consisting of upper limb exercises only. All participants completed three training sessions per week for eight weeks. OUTCOME MEASURES: Assessment of mobility, balance, lower limb strength, walking endurance, and self-perceived balance confidence were conducted at baseline and immediately after the eight-week intervention. Incidences of falls requiring medical attention were recorded for one year after the end of the training period. RESULTS: A significant time × group interaction was found for lower limb strength (five-times-sit-to-stand test; P = 0.048), with the exercise-only group showing improvement (pretest: 35.8 ± 16.1 seconds; posttest: 29.0 ± 9.8 seconds), compared with a decline in strength among controls (pretest: 27.1 ± 10.4 seconds; posttest: 28.7 ± 12.3 seconds; P = 0.030). The exercise with whole-body vibration group had a significantly better outcome in balance confidence (pretest: 39.2 ± 29.0; posttest: 48.4 ± 30.6) than the exercise-only group (pretest: 35.9 ± 24.8; posttest: 38.2 ± 26.5; P = 0.033). CONCLUSION: The exercise program was effective in improving lower limb strength among institutionalized older adults but adding whole-body vibration did not enhance its effect. Whole-body vibration may improve balance confidence without enhancing actual balance performance.


Assuntos
Acidentes por Quedas/prevenção & controle , Envelhecimento/fisiologia , Terapia por Exercício/métodos , Equilíbrio Postural/fisiologia , Vibração/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Avaliação da Deficiência , Feminino , Seguimentos , Avaliação Geriátrica/métodos , Hong Kong , Humanos , Masculino , Instituições Residenciais , Método Simples-Cego , Resultado do Tratamento
14.
Cell Mol Neurobiol ; 36(3): 417-27, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27017608

RESUMO

Extracellular vesicles present an attractive delivery vehicle for therapeutic proteins. They intrinsically contain many proteins which can provide information to other cells. Advantages include reduced immune reactivity, especially if derived from the same host, stability in biologic fluids, and ability to target uptake. Those from mesenchymal stem cells appear to be intrinsically therapeutic, while those from cancer cells promote tumor progression. Therapeutic proteins can be loaded into vesicles by overexpression in the donor cell, with oligomerization and membrane sequences increasing their loading. Examples of protein delivery for therapeutic benefit in pre-clinical models include delivery of: catalase for Parkinson's disease to reduce oxidative stress and thus help neurons to survive; prodrug activating enzymes which can convert a prodrug which crosses the blood-brain barrier into a toxic chemotherapeutic drug for schwannomas and gliomas; and the apoptosis-inducing enzyme, caspase-1 under a Schwann cell specific promoter for schwannoma. This therapeutic delivery strategy is novel and being explored for a number of diseases.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Vesículas Extracelulares/metabolismo , Glioma/tratamento farmacológico , Neurilemoma/tratamento farmacológico , Doença de Parkinson/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Glioma/metabolismo , Glioma/patologia , Humanos , Neurilemoma/metabolismo , Neurilemoma/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia
15.
Neurobiol Dis ; 82: 22-31, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26019056

RESUMO

We examined the potential benefit of gene therapy in a mouse model of tuberous sclerosis complex (TSC) in which there is embryonic loss of Tsc1 (hamartin) in brain neurons. An adeno-associated virus (AAV) vector (serotype rh8) expressing a tagged form of hamartin was injected into the cerebral ventricles of newborn pups with the genotype Tsc1(cc) (homozygous for a conditional floxed Tsc1 allele) SynI-cre(+), in which Tsc1 is lost selectively in neurons starting at embryonic day 12. Vector-treated Tsc1(cc)SynIcre(+) mice showed a marked improvement in survival from a mean of 22 days in non-injected mice to 52 days in AAV hamartin vector-injected mice, with improved weight gain and motor behavior in the latter. Pathologic studies showed normalization of neuron size and a decrease in markers of mTOR activation in treated as compared to untreated mutant littermates. Hence, we show that gene replacement in the brain is an effective therapeutic approach in this mouse model of TSC1. Our strategy for gene therapy has the advantages that therapy can be achieved from a single application, as compared to repeated treatment with drugs, and that AAV vectors have been found to have minimal to no toxicity in clinical trials for other neurologic conditions. Although there are many additional issues to be addressed, our studies support gene therapy as a useful approach in TSC patients.


Assuntos
Encéfalo/patologia , Terapia Genética/métodos , Esclerose Tuberosa/terapia , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/uso terapêutico , Animais , Modelos Animais de Doenças , Camundongos , Mutação , Neurônios/patologia , Fenótipo , Resultado do Tratamento , Esclerose Tuberosa/genética , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa
16.
Bioscience ; 65(8): 783-797, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26955082

RESUMO

The release of extracellular vesicles (EVs), including exosomes and microvesicles, is a phenomenon shared by many cell types as a means of communicating with other cells and also potentially removing cell contents. The cargo of EVs includes the proteins, lipids, nucleic acids, and membrane receptors of the cells from which they originate. EVs released into the extracellular space can enter body fluids and potentially reach distant tissues. Once taken up by neighboring and/or distal cells, EVs can transfer functional cargo that may alter the status of recipient cells, thereby contributing to both physiological and pathological processes. In this article, we will focus on EV composition, mechanisms of uptake, and their biological effects on recipient cells. We will also discuss established and recently developed methods used to study EVs, including isolation, quantification, labeling and imaging protocols, as well as RNA analysis.

17.
PLoS One ; 19(4): e0301773, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38593167

RESUMO

Respiratory syncytial virus (RSV) is the leading viral cause of bronchiolitis and pneumonia in infants and toddlers, but there currently is no licensed pediatric vaccine. A leading vaccine candidate that has been evaluated for intranasal immunization in a recently completed phase 1/2 clinical trial is an attenuated version of RSV strain A2 called RSV/ΔNS2/Δ1313/I1314L (hereafter called ΔNS2). ΔNS2 is attenuated by deletion of the interferon antagonist NS2 gene and introduction into the L polymerase protein gene of a codon deletion (Δ1313) that confers temperature-sensitivity and is stabilized by a missense mutation (I1314L). Previously, introduction of four amino acid changes derived from a second RSV strain "line 19" (I79M, K191R, T357K, N371Y) into the F protein of strain A2 increased the stability of infectivity and the proportion of F protein in the highly immunogenic pre-fusion (pre-F) conformation. In the present study, these four "line 19" assignments were introduced into the ΔNS2 candidate, creating ΔNS2-L19F-4M. During in vitro growth in Vero cells, ΔNS2-L19F-4M had growth kinetics and peak titer similar to the ΔNS2 parent. ΔNS2-L19F-4M exhibited an enhanced proportion of pre-F protein, with a ratio of pre-F/total F that was 4.5- to 5.0-fold higher than that of the ΔNS2 parent. The stability of infectivity during incubation at 4°C, 25°C, 32°C and 37°C was greater for ΔNS2-L19F-4M; for example, after 28 days at 32°C, its titer was 100-fold greater than ΔNS2. ΔNS2-L19F-4M exhibited similar levels of replication in human airway epithelial (HAE) cells as ΔNS2. The four "line 19" F mutations were genetically stable during 10 rounds of serial passage in Vero cells. In African green monkeys, ΔNS2-L19F-4M and ΔNS2 had similar growth kinetics, peak titer, and immunogenicity. These results suggest that ΔNS2-L19F-4M is an improved live attenuated vaccine candidate whose enhanced stability may simplify its manufacture, storage and distribution, which merits further evaluation in a clinical trial in humans.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vacinas contra Vírus Sincicial Respiratório , Vírus Sincicial Respiratório Humano , Animais , Humanos , Chlorocebus aethiops , Criança , Vacinas contra Vírus Sincicial Respiratório/genética , Células Vero , Anticorpos Antivirais , Proteínas Virais de Fusão/genética , Vírus Sincicial Respiratório Humano/genética , Anticorpos Neutralizantes , Mutação de Sentido Incorreto
18.
Disabil Rehabil ; : 1-8, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711228

RESUMO

PURPOSE: To examine whether the Upper Extremity Functional Index (UEFI) score independently contributes to the Stroke Impact Scale (SIS) score and quantified its relative contribution to SIS scores in chronic stroke survivors. MATERIALS AND METHODS: A cross-sectional study in a university-based rehabilitation centre with people with chronic stroke (N = 95) aged ≥ 50 years. The outcome measures included paretic hand grip strength, Fugl-Meyer Upper Extremity Assessment (FMA-UE), Wolf Motor Function Test (WMFT), UEFI, and SIS. RESULTS: Correlation analysis revealed that paretic hand grip strength, FMA-UE, UEFI, and WMFT scores exhibited a significant moderate positive correlation with SIS scores (r = 0.544-0.687, p < 0.001). The results of a regression model indicated that after adjustment for demographic factors and stroke-related impairments, the UEFI scores remained independently associated with SIS scores, accounting for 18.8% of the variance. The entire model explained 60.3% of the variance in SIS scores. CONCLUSIONS: Self-perceived UE motor function is a crucial component to be included in rehabilitation programmes aimed at enhancing quality of life and participation among chronic stroke survivors.


Observation-based outcome measures, e.g., Fugl­Meyer Assessment for Upper Extremity (FMA-UE), Wolf Motor Function Test (WMFT) could not predict the health-related quality of life (Stroke Impact scale (SIS)) in chronic stroke survivors in our study, which was contradictory with current studies.A self-perceived outcome measure to evaluate upper extremity function (Upper Extremity Functional Index (UEFI)) could independently predict the health-related quality of life (SIS), accounting for 18.8% of the variance.Our study demonstrated that self-perceived UE motor function would be an important component to optimize the rehabilitation programmes aimed at enhancing quality of life and social participation among chronic stroke survivors.

19.
Disabil Rehabil ; : 1-16, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38334111

RESUMO

PURPOSE: To provide updated evidence about the effects of MT with ES for recovering upper extremities motor function in people with stroke. METHODS: Systematic review and meta-analysis were completed. Methodological quality was assessed using the version 2 of the Cochrane risk-of-bias tool. The GRADE approach was employed to assess the certainty of evidence. RESULTS: A total of 16 trials with 773 participants were included in this review. The results demonstrated that MT with ES was more effective than sham (standardized mean difference [SMD], 1.89 [1.52-2.26]) and ES alone (SMD, 0.42 [0.11-0.73]) with low quality of evidence, or MT alone (SMD, 0.47[0.04-0.89]) with low quality of evidence for improving upper extremity motor control assessed using Fugl-Meyer Assessment. MT with ES had significant improvement of (MD, 6.47 [1.92-11.01]) the upper extremity gross gripping function assessed using the Action Research Arm Test compared with MT alone with low quality of evidence. MT combined with ES was more effective than sham group (SMD, 1.17 [0.42-1.93) for improving the ability to perform activities of daily living with low quality of evidence assessed using Motor Activity Log. CONCLUSION: MT with ES may be effective in improving upper limb motor recovery in people with stroke.


Combining Mirror Therapy (MT) and Electrical Stimulation (ES) modality could improve upper limb motor control, gross gripping function, and performance in ADLs based on ICF for people with stroke.Those individuals with subacute stroke are recommended as the optimal target group for the combined MT and ES.

20.
J Biol Chem ; 287(11): 8407-16, 2012 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-22267745

RESUMO

Pannexin 1 (Panx1) is a novel gap junction protein shown to have tumor-suppressive properties. To model its in vivo role in the intratumor biomechanical environment, we investigated whether Panx1 channels modulate the dynamic assembly of multicellular C6 glioma aggregates. Treatment with carbenoxolone and probenecid, which directly and specifically block Panx1 channels, respectively, showed that Panx1 is involved in accelerating aggregate assembly. Experiments further showed that exogenous ATP can reverse the inhibitive effects of carbenoxolone and that aggregate compaction is sensitive to the purinergic antagonist suramin. With a close examination of the F-actin microfilament network, these findings show that Panx1 channels act as conduits for ATP release that stimulate the P(2)X(7) purinergic receptor pathway, in turn up-regulating actomyosin function. Using a unique three-dimensional scaffold-free method to quantify multicellular interactions, this study shows that Panx1 is intimately involved in regulating intercellular biomechanical interactions pivotal in the progression of cancer.


Assuntos
Citoesqueleto de Actina/metabolismo , Conexinas/metabolismo , Glioma/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Transdução de Sinais , Citoesqueleto de Actina/genética , Actomiosina/genética , Actomiosina/metabolismo , Trifosfato de Adenosina/antagonistas & inibidores , Trifosfato de Adenosina/farmacologia , Animais , Antiulcerosos/farmacologia , Carbenoxolona/antagonistas & inibidores , Carbenoxolona/farmacologia , Linhagem Celular Tumoral , Conexinas/genética , Antagonismo de Drogas , Glioma/genética , Camundongos , Proteínas de Neoplasias/genética , Proteínas do Tecido Nervoso/genética , Probenecid/antagonistas & inibidores , Probenecid/farmacologia , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2X7/metabolismo , Uricosúricos/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA