Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 115
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Neuroimage ; 295: 120639, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38796977

RESUMO

Data-based predictions of individual Cognitive Behavioral Therapy (CBT) treatment response are a fundamental step towards precision medicine. Past studies demonstrated only moderate prediction accuracy (i.e. ability to discriminate between responders and non-responders of a given treatment) when using clinical routine data such as demographic and questionnaire data, while neuroimaging data achieved superior prediction accuracy. However, these studies may be considerably biased due to very limited sample sizes and bias-prone methodology. Adequately powered and cross-validated samples are a prerequisite to evaluate predictive performance and to identify the most promising predictors. We therefore analyzed resting state functional magnet resonance imaging (rs-fMRI) data from two large clinical trials to test whether functional neuroimaging data continues to provide good prediction accuracy in much larger samples. Data came from two distinct German multicenter studies on exposure-based CBT for anxiety disorders, the Protect-AD and SpiderVR studies. We separately and independently preprocessed baseline rs-fMRI data from n = 220 patients (Protect-AD) and n = 190 patients (SpiderVR) and extracted a variety of features, including ROI-to-ROI and edge-functional connectivity, sliding-windows, and graph measures. Including these features in sophisticated machine learning pipelines, we found that predictions of individual outcomes never significantly differed from chance level, even when conducting a range of exploratory post-hoc analyses. Moreover, resting state data never provided prediction accuracy beyond the sociodemographic and clinical data. The analyses were independent of each other in terms of selecting methods to process resting state data for prediction input as well as in the used parameters of the machine learning pipelines, corroborating the external validity of the results. These similar findings in two independent studies, analyzed separately, urge caution regarding the interpretation of promising prediction results based on neuroimaging data from small samples and emphasizes that some of the prediction accuracies from previous studies may result from overestimation due to homogeneous data and weak cross-validation schemes. The promise of resting-state neuroimaging data to play an important role in the prediction of CBT treatment outcomes in patients with anxiety disorders remains yet to be delivered.


Assuntos
Transtornos de Ansiedade , Terapia Cognitivo-Comportamental , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Feminino , Masculino , Transtornos de Ansiedade/terapia , Transtornos de Ansiedade/diagnóstico por imagem , Transtornos de Ansiedade/fisiopatologia , Adulto , Terapia Cognitivo-Comportamental/métodos , Pessoa de Meia-Idade , Resultado do Tratamento , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Adulto Jovem , Terapia Implosiva/métodos
2.
Mol Ther ; 31(11): 3290-3307, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37641403

RESUMO

Type 4C Charcot-Marie-Tooth (CMT4C) demyelinating neuropathy is caused by autosomal recessive SH3TC2 gene mutations. SH3TC2 is highly expressed in myelinating Schwann cells. CMT4C is a childhood-onset progressive disease without effective treatment. Here, we generated a gene therapy for CMT4C mediated by an adeno-associated viral 9 vector (AAV9) to deliver the human SH3TC2 gene in the Sh3tc2-/- mouse model of CMT4C. We used a minimal fragment of the myelin protein zero (Mpz) promoter (miniMpz), which was cloned and validated to achieve Schwann cell-targeted expression of SH3TC2. Following the demonstration of AAV9-miniMpz.SH3TC2myc vector efficacy to re-establish SH3TC2 expression in the peripheral nervous system, we performed an early as well as a delayed treatment trial in Sh3tc2-/- mice. We demonstrate both after early as well as following late treatment improvements in multiple motor performance tests and nerve conduction velocities. Moreover, treatment led to normalization of the organization of the nodes of Ranvier, which is typically deficient in CMT4C patients and Sh3tc2-/- mice, along with reduced ratios of demyelinated fibers, increased myelin thickness and reduced g-ratios at both time points of intervention. Taken together, our results provide a proof of concept for an effective and potentially translatable gene replacement therapy for CMT4C treatment.


Assuntos
Doença de Charcot-Marie-Tooth , Terapia Genética , Peptídeos e Proteínas de Sinalização Intracelular , Animais , Humanos , Camundongos , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/terapia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação , Células de Schwann/metabolismo
3.
Brief Bioinform ; 22(6)2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34009288

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is undeniably the most severe global health emergency since the 1918 Influenza outbreak. Depending on its evolutionary trajectory, the virus is expected to establish itself as an endemic infectious respiratory disease exhibiting seasonal flare-ups. Therefore, despite the unprecedented rally to reach a vaccine that can offer widespread immunization, it is equally important to reach effective prevention and treatment regimens for coronavirus disease 2019 (COVID-19). Contributing to this effort, we have curated and analyzed multi-source and multi-omics publicly available data from patients, cell lines and databases in order to fuel a multiplex computational drug repurposing approach. We devised a network-based integration of multi-omic data to prioritize the most important genes related to COVID-19 and subsequently re-rank the identified candidate drugs. Our approach resulted in a highly informed integrated drug shortlist by combining structural diversity filtering along with experts' curation and drug-target mapping on the depicted molecular pathways. In addition to the recently proposed drugs that are already generating promising results such as dexamethasone and remdesivir, our list includes inhibitors of Src tyrosine kinase (bosutinib, dasatinib, cytarabine and saracatinib), which appear to be involved in multiple COVID-19 pathophysiological mechanisms. In addition, we highlight specific immunomodulators and anti-inflammatory drugs like dactolisib and methotrexate and inhibitors of histone deacetylase like hydroquinone and vorinostat with potential beneficial effects in their mechanisms of action. Overall, this multiplex drug repurposing approach, developed and utilized herein specifically for SARS-CoV-2, can offer a rapid mapping and drug prioritization against any pathogen-related disease.


Assuntos
Antivirais/química , Tratamento Farmacológico da COVID-19 , Reposicionamento de Medicamentos , SARS-CoV-2/química , Antivirais/uso terapêutico , COVID-19/virologia , Humanos , Pandemias , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/patogenicidade
4.
Mol Psychiatry ; 27(11): 4464-4473, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35948661

RESUMO

Common variation in the gene encoding the neuron-specific RNA splicing factor RNA Binding Fox-1 Homolog 1 (RBFOX1) has been identified as a risk factor for several psychiatric conditions, and rare genetic variants have been found causal for autism spectrum disorder (ASD). Here, we explored the genetic landscape of RBFOX1 more deeply, integrating evidence from existing and new human studies as well as studies in Rbfox1 knockout mice. Mining existing data from large-scale studies of human common genetic variants, we confirmed gene-based and genome-wide association of RBFOX1 with risk tolerance, major depressive disorder and schizophrenia. Data on six mental disorders revealed copy number losses and gains to be more frequent in ASD cases than in controls. Consistently, RBFOX1 expression appeared decreased in post-mortem frontal and temporal cortices of individuals with ASD and prefrontal cortex of individuals with schizophrenia. Brain-functional MRI studies demonstrated that carriers of a common RBFOX1 variant, rs6500744, displayed increased neural reactivity to emotional stimuli, reduced prefrontal processing during cognitive control, and enhanced fear expression after fear conditioning, going along with increased avoidance behaviour. Investigating Rbfox1 neuron-specific knockout mice allowed us to further specify the role of this gene in behaviour. The model was characterised by pronounced hyperactivity, stereotyped behaviour, impairments in fear acquisition and extinction, reduced social interest, and lack of aggression; it provides excellent construct and face validity as an animal model of ASD. In conclusion, convergent translational evidence shows that common variants in RBFOX1 are associated with a broad spectrum of psychiatric traits and disorders, while rare genetic variation seems to expose to early-onset neurodevelopmental psychiatric disorders with and without developmental delay like ASD, in particular. Studying the pleiotropic nature of RBFOX1 can profoundly enhance our understanding of mental disorder vulnerability.


Assuntos
Transtorno do Espectro Autista , Transtorno Depressivo Maior , Transtornos Mentais , Animais , Camundongos , Humanos , Transtorno do Espectro Autista/genética , Transtorno Depressivo Maior/genética , Estudo de Associação Genômica Ampla , Transtornos Mentais/genética , Camundongos Knockout , Fatores de Processamento de RNA/genética
5.
Gene Ther ; 28(10-11): 659-675, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33692503

RESUMO

Mutations in the GJB1 gene, encoding the gap junction (GJ) protein connexin32 (Cx32), cause X-linked Charcot-Marie-Tooth disease (CMT1X), an inherited demyelinating neuropathy. We developed a gene therapy approach for CMT1X using an AAV9 vector to deliver the GJB1/Cx32 gene under the myelin protein zero (Mpz) promoter for targeted expression in Schwann cells. Lumbar intrathecal injection of the AAV9-Mpz.GJB1 resulted in widespread biodistribution in the peripheral nervous system including lumbar roots, sciatic and femoral nerves, as well as in Cx32 expression in the paranodal non-compact myelin areas of myelinated fibers. A pre-, as well as post-onset treatment trial in Gjb1-null mice, demonstrated improved motor performance and sciatic nerve conduction velocities along with improved myelination and reduced inflammation in peripheral nerve tissues. Blood biomarker levels were also significantly ameliorated in treated mice. This study provides evidence that a clinically translatable AAV9-mediated gene therapy approach targeting Schwann cells could potentially treat CMT1X.


Assuntos
Doença de Charcot-Marie-Tooth , Células de Schwann , Animais , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/metabolismo , Doença de Charcot-Marie-Tooth/terapia , Conexinas/genética , Conexinas/metabolismo , Terapia Genética/métodos , Camundongos , Camundongos Knockout , Células de Schwann/metabolismo , Distribuição Tecidual
6.
Neuroimage ; 237: 118157, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34020017

RESUMO

Adapting threat-related memories towards changing environments is a fundamental ability of organisms. One central process of fear reduction is suggested to be extinction learning, experimentally modeled by extinction training that is repeated exposure to a previously conditioned stimulus (CS) without providing the expected negative consequence (unconditioned stimulus, US). Although extinction training is well investigated, evidence regarding process-related changes in neural activation over time is still missing. Using optimized delayed extinction training in a multicentric trial we tested whether: 1) extinction training elicited decreasing CS-specific neural activation and subjective ratings, 2) extinguished conditioned fear would return after presentation of the US (reinstatement), and 3) results are comparable across different assessment sites and repeated measures. We included 100 healthy subjects (measured twice, 13-week-interval) from six sites. 24 h after fear acquisition training, extinction training, including a reinstatement test, was applied during fMRI. Alongside, participants had to rate subjective US-expectancy, arousal and valence. In the course of the extinction training, we found decreasing neural activation in the insula and cingulate cortex as well as decreasing US-expectancy, arousal and negative valence towards CS+. Re-exposure to the US after extinction training was associated with a temporary increase in neural activation in the anterior cingulate cortex (exploratory analysis) and changes in US-expectancy and arousal ratings. While ICCs-values were low, findings from small groups suggest highly consistent effects across time-points and sites. Therefore, this delayed extinction fMRI-paradigm provides a solid basis for the investigation of differences in neural fear-related mechanisms as a function of anxiety-pathology and exposure-based treatment.


Assuntos
Adaptação Fisiológica/fisiologia , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Adulto , Córtex Cerebral/diagnóstico por imagem , Feminino , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
7.
Depress Anxiety ; 38(11): 1169-1181, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34293223

RESUMO

BACKGROUND: The need to optimize exposure treatments for anxiety disorders may be addressed by temporally intensified exposure sessions. Effects on symptom reduction and public health benefits should be examined across different anxiety disorders with comorbid conditions. METHODS: This multicenter randomized controlled trial compared two variants of prediction error-based exposure therapy (PeEx) in various anxiety disorders (both 12 sessions + 2 booster sessions, 100 min/session): temporally intensified exposure (PeEx-I) with exposure sessions condensed to 2 weeks (n = 358) and standard nonintensified exposure (PeEx-S) with weekly exposure sessions (n = 368). Primary outcomes were anxiety symptoms (pre, post, and 6-months follow-up). Secondary outcomes were global severity (across sessions), quality of life, disability days, and comorbid depression. RESULTS: Both treatments resulted in substantial improvements at post (PeEx-I: dwithin = 1.50, PeEx-S: dwithin = 1.78) and follow-up (PeEx-I: dwithin = 2.34; PeEx-S: dwithin = 2.03). Both groups showed formally equivalent symptom reduction at post and follow-up. However, time until response during treatment was 32% shorter in PeEx-I (median = 68 days) than PeEx-S (108 days; TRPeEx-I = 0.68). Interestingly, drop-out rates were lower during intensified exposure. PeEx-I was also superior in reducing disability days and improving quality of life at follow-up without increasing relapse. CONCLUSIONS: Both treatment variants focusing on the transdiagnostic exposure-based violation of threat beliefs were effective in reducing symptom severity and disability in severe anxiety disorders. Temporally intensified exposure resulted in faster treatment response with substantial public health benefits and lower drop-out during the exposure phase, without higher relapse. Clinicians can expect better or at least comparable outcomes when delivering exposure in a temporally intensified manner.


Assuntos
Terapia Implosiva , Qualidade de Vida , Ansiedade/terapia , Transtornos de Ansiedade/epidemiologia , Transtornos de Ansiedade/terapia , Comorbidade , Humanos , Resultado do Tratamento
8.
Brain ; 142(5): 1227-1241, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30907403

RESUMO

Charcot-Marie-Tooth disease type 4C is the most common recessively inherited demyelinating neuropathy that results from loss of function mutations in the SH3TC2 gene. Sh3tc2-/- mice represent a well characterized disease model developing early onset progressive peripheral neuropathy with hypo- and demyelination, slowing of nerve conduction velocities and disturbed nodal architecture. The aim of this project was to develop a gene replacement therapy for treating Charcot-Marie-Tooth disease type 4C to rescue the phenotype of the Sh3tc2-/- mouse model. We generated a lentiviral vector LV-Mpz.SH3TC2.myc to drive expression of the human SH3TC2 cDNA under the control of the Mpz promoter specifically in myelinating Schwann cells. The vector was delivered into 3-week-old Sh3tc2-/- mice by lumbar intrathecal injection and gene expression was assessed 4-8 weeks after injection. Immunofluorescence analysis showed presence of myc-tagged human SH3TC2 in sciatic nerves and lumbar roots in the perinuclear cytoplasm of a subset of Schwann cells, in a dotted pattern co-localizing with physiologically interacting protein Rab11. Quantitative PCR analysis confirmed SH3TC2 mRNA expression in different peripheral nervous system tissues. A treatment trial was initiated in 3 weeks old randomized Sh3tc2-/- littermate mice which received either the full or mock (LV-Mpz.Egfp) vector. Behavioural analysis 8 weeks after injection showed improved motor performance in rotarod and foot grip tests in treated Sh3tc2-/- mice compared to mock vector-treated animals. Moreover, motor nerve conduction velocities were increased in treated Sh3tc2-/- mice. On a structural level, morphological analysis revealed significant improvement in g-ratios, myelin thickness, and ratios of demyelinated fibres in lumbar roots and sciatic nerves of treated Sh3tc2-/- mice. Finally, treated mice also showed improved nodal molecular architecture and reduction of blood neurofilament light levels, a clinically relevant biomarker for axonal injury/degeneration. This study provides a proof of principle for viral gene replacement therapy targeted to Schwann cells to treat Charcot-Marie-Tooth disease type 4C and potentially other similar demyelinating inherited neuropathies.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/terapia , Modelos Animais de Doenças , Terapia Genética/métodos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Animais , Doença de Charcot-Marie-Tooth/metabolismo , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Camundongos , Camundongos Knockout , Camundongos Transgênicos
9.
Molecules ; 25(3)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31979348

RESUMO

In our work, we developed the synthesis of new polyfunctional pegylated trehalose derivatives and evaluated their cryoprotective effect using flow cytometry. We showed that new compounds (modified trehaloses) bound to appropriate extracellular polymeric cryoprotectants could be helpful as a chemical tool for the evaluation of their potential toxic cell membrane influences. Our aim was to form a chemical tool for the evaluation of cryoprotectant cell membrane influences, which are still not easily predicted during the freezing/thawing process. We combined two basic cryoprotectants: polyethyleneglycols (PEGs) and trehalose in the new chemical compounds-pegylated trehalose hybrids. If PEG and trehalose are chemically bound and trehalose is adsorbed on the cell surface PEGs molecules which are, due to the chemical bonding with trehalose, close to the cell surface, can remove the cell surface hydration layer which destabilizes the cell membrane. This was confirmed by the comparison of new material, PEG, trehalose, and their mixture cryoprotective capabilities.


Assuntos
Membrana Celular/efeitos dos fármacos , Crioprotetores/farmacologia , Polietilenoglicóis/farmacologia , Trealose/síntese química , Trealose/farmacologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Química Click , Criopreservação , Dimetil Sulfóxido/farmacologia , Citometria de Fluxo , Congelamento , Humanos , Polietilenoglicóis/química , Trealose/análogos & derivados , Trealose/química
10.
Verhaltenstherapie ; 30(2): 141-155, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34305358

RESUMO

EINLEITUNG: Voraussetzung für die Approbation im Rahmen der neuen Psychotherapeutenausbildung ist u.a. das Bestehen einer anwendungsorientierten Parcoursprüfung. Da diese Prüfung von Lehrenden und Studierenden als Herausforderung angesehen wird, wurde eine Kurzform der Parcoursprüfung im Rahmen einer Modulprüfung des MSc-Studiengangs Psychologie eingeführt und evaluiert. METHODE: Für die 15-minütige Parcoursprüfung wurden 9 Kompe-tenzbereiche basierend auf praxisorientierten Psychotherapieseminaren entwickelt, von denen 2 jeweils geprüft wurden. Zur Standardisierung der Benotung wurde ein Bewertungsbogen konzipiert. Eine Mitarbeiterin erhielt ein Training als Simulationspatientin. Für die Evaluation wurde ein Fragebogen entwickelt, welcher u.a. die Umsetzbarkeit und das subjektive Erleben dieses Prüfungsformats aus der Sicht der an der Prüfung beteiligten Personen erfasst. ERGEBNISSE: 14 Prüfungskandidierende ließen sich durch 3 Prüfende prüfen. Die Gesamtdurchschnittsnote betrug 1,19 (Bereich: 1,0-2,3). Die Auswertung der Fragebögen zeigte, dass alle drei Gruppen die Prüfung als geeignet, die praktischen Fertigkeiten abzubilden, objektiv und praxisnah empfanden. Von den Prüfungskandidierenden gaben 50% an, dass die Prüfung sie gestresst habe, während die Simulationspatientin sich nie und die Prüfenden sich gar nicht (78%) oder kaum (22%) gestresst fühlten. DISKUSSION: Die Ergebnisse dieser Pilotstudie weisen auf eine gute Umsetzbarkeit der Parcoursprüfung hin, wenngleich sie auch mit Stress für die Prüfungskandidierenden verbunden war. Die Pilotstudie wird limitiert durch eine kleine und wahrscheinlich verzerrte Stichprobe (motivierte Studierende) ohne Vergleichsgruppe. Abschließend werden die Vor- und Nachteile dieses Prüfungsmodells kritisch diskutiert.


INTRODUCTION: One of the requirements for the approbation as part of the new psychotherapist studies is, among other things, passing an objective structured clinical ex-amination (OSCE) involving simulating patients. Since teachers and students regard this new format as a challenge, a short form of the OSCE was implemented in the module examination of the current master's degree in psychology and evaluated by a pilot study. METHOD: For the 15-min course examination, 9 areas of competences were developed based on practice-oriented psychotherapy seminars, 2 of which were tested. In order to standardize the grading, a standardized evaluation form was developed. A colleague received training to simulate a patient. For evaluation, a questionnaire was conceptualized which measured, among other things, the feasibility and subjective experiences of and during the new format as rated by the persons involved in the exam. RESULTS: 14 examination candidates chose to be examined in this new format by 3 auditors. The overall averaged grade was 1.19 (range: 1.0­3). The evaluation of the questionnaire showed that all three groups rated the exam to be suitable for displaying practical skills, objective and close to the practical application. Of the examination candidates, 50% reported feelings of stress, while the simulating patient never and the auditors did not at all (78%) or rarely felt stressed (22%) during the different examinations. DISCUSSION: Overall, the results of this pilot study indicate a good feasibility of the OSCE, although the examination candidates rated it to be stressful at the same time. The pilot study is limited by the small and probably biased sample (motivated students) without a comparison group. To conclude, pros and cons of this examination format will be critically discussed.

11.
Eur Arch Psychiatry Clin Neurosci ; 269(2): 161-170, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28712090

RESUMO

Although cognitive behavioral therapy (CBT) is highly effective in the treatment of anxiety disorders, many patients still do not benefit. This study investigates whether a history of traumatic event experience is negatively associated with outcomes of CBT for panic disorder. The moderating role of the monoamine oxidase A (MAOA) gene and depression symptoms as well as the association between trauma history and fear reactivity as a potential mechanism are further analyzed. We conducted a post-hoc analysis of 172 male and 60 female patients with panic disorder treated with CBT in a multi-center study. Treatment outcome was assessed at post-treatment using self-report and clinician rating scales. Fear reactivity before treatment was assessed via heart rate and self-reported anxiety during a behavioral avoidance test. Among females, we did not find any differences in treatment response between traumatized and non-traumatized individuals or any two-way interaction trauma history × MAOA genotype. There was a significant three-way interaction trauma history × MAOA genotype × depression symptoms on all treatment outcomes indicating that in traumatized female patients carrying the low-activity allele, treatment effect sizes decreased with increasing depression symptoms at baseline. No such effects were observed for males. In conclusion, we found no evidence for a differential treatment response in traumatized and non-traumatized individuals. There is preliminary evidence for poorer treatment outcomes in a subgroup of female traumatized individuals carrying the low-active variant of the MAOA gene. These patients also report more symptoms of depression symptomatology and exhibit a dampened fear response before treatment which warrants further investigation.


Assuntos
Terapia Cognitivo-Comportamental , Depressão/fisiopatologia , Medo/fisiologia , Monoaminoxidase/genética , Avaliação de Resultados em Cuidados de Saúde , Transtorno de Pânico/terapia , Trauma Psicológico/terapia , Adulto , Comorbidade , Depressão/epidemiologia , Depressão/genética , Feminino , Humanos , Masculino , Transtorno de Pânico/epidemiologia , Transtorno de Pânico/genética , Trauma Psicológico/epidemiologia , Trauma Psicológico/genética , Fatores Sexuais
12.
Proc Natl Acad Sci U S A ; 113(17): E2421-9, 2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27035961

RESUMO

Inherited demyelinating peripheral neuropathies are progressive incurable diseases without effective treatment. To develop a gene therapy approach targeting myelinating Schwann cells that can be translatable, we delivered a lentiviral vector using a single lumbar intrathecal injection and a myelin-specific promoter. The human gene of interest, GJB1, which is mutated in X-linked Charcot-Marie-Tooth Disease (CMT1X), was delivered intrathecally into adult Gjb1-null mice, a genetically authentic model of CMT1X that develops a demyelinating peripheral neuropathy. We obtained widespread, stable, and cell-specific expression of connexin32 in up to 50% of Schwann cells in multiple lumbar spinal roots and peripheral nerves. Behavioral and electrophysiological analysis revealed significantly improved motor performance, quadriceps muscle contractility, and sciatic nerve conduction velocities. Furthermore, treated mice exhibited reduced numbers of demyelinated and remyelinated fibers and fewer inflammatory cells in lumbar motor roots, as well as in the femoral motor and sciatic nerves. This study demonstrates that a single intrathecal lentiviral gene delivery can lead to Schwann cell-specific expression in spinal roots extending to multiple peripheral nerves. This clinically relevant approach improves the phenotype of an inherited neuropathy mouse model and provides proof of principle for treating inherited demyelinating neuropathies.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Doenças Desmielinizantes/genética , Animais , Terapia Genética , Humanos , Bainha de Mielina/metabolismo , Células de Schwann/metabolismo
13.
Brain ; 140(3): 599-616, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28100454

RESUMO

Pelizaeus-Merzbacher-like disease or hypomyelinating leukodystrophy-2 is an autosomal recessively inherited leukodystrophy with childhood onset resulting from mutations in the gene encoding the gap junction protein connexin 47 (Cx47, encoded by GJC2). Cx47 is expressed specifically in oligodendrocytes and is crucial for gap junctional communication throughout the central nervous system. Previous studies confirmed that a cell autonomous loss-of-function mechanism underlies hypomyelinating leukodystrophy-2 and that transgenic oligodendrocyte-specific expression of another connexin, Cx32 (GJB1), can restore gap junctions in oligodendrocytes to achieve correction of the pathology in a disease model. To develop an oligodendrocyte-targeted gene therapy, we cloned the GJC2/Cx47 gene under the myelin basic protein promoter and used an adeno-associated viral vector (AAV.MBP.Cx47myc) to deliver the gene to postnatal Day 10 mice via a single intracerebral injection in the internal capsule area. Lasting Cx47 expression specifically in oligodendrocytes was detected in Cx47 single knockout and Cx32/Cx47 double knockout mice up to 12 weeks post-injection, including the corpus callosum and the internal capsule but also in more distant areas of the cerebrum and in the spinal cord. Application of this oligodendrocyte-targeted somatic gene therapy at postnatal Day 10 in groups of double knockout mice, a well characterized model of hypomyelinating leukodystrophy-2, resulted in significant improvement in motor performance and coordination at 1 month of age in treated compared to mock-treated mice, as well as prolonged survival. Furthermore, immunofluorescence and morphological analysis revealed improvement in demyelination, oligodendrocyte apoptosis, inflammation, and astrogliosis, all typical features of this leukodystrophy model in both brain and spinal cord. Functional dye transfer analysis confirmed the re-establishment of oligodendrocyte gap junctional connectivity in treated as opposed to untreated mice. These results provide a significant advance in the development of oligodendrocyte-cell specific gene therapy. Adeno-associated viral vectors can be used to target therapeutic expression of a myelin gene to oligodendrocytes. We show evidence for the first somatic gene therapy approach to treat hypomyelinating leukodystrophy-2 preclinically, providing a potential treatment for this and similar forms of leukodystrophies.


Assuntos
Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Terapia Genética/métodos , Leucoencefalopatias , Oligodendroglia/metabolismo , Animais , Animais Recém-Nascidos , Antígenos CD/metabolismo , Apoptose/genética , Conexinas/deficiência , Conexinas/genética , Dependovirus/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Leucoencefalopatias/genética , Leucoencefalopatias/terapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transtornos dos Movimentos/etiologia , Proteína Básica da Mielina/genética , Proteína Básica da Mielina/metabolismo , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Desempenho Psicomotor/fisiologia , Proteína beta-1 de Junções Comunicantes
14.
J Biol Chem ; 291(8): 3694-704, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26555263

RESUMO

The enzyme-catalyzed phosphorylation of glucose to glucose-6-phosphate is a reaction central to the metabolism of all life. ADP-dependent glucokinase (ADPGK) catalyzes glucose-6-phosphate production, utilizing ADP as a phosphoryl donor in contrast to the more well characterized ATP-requiring hexokinases. ADPGK is found in Archaea and metazoa; in Archaea, ADPGK participates in a glycolytic role, but a function in most eukaryotic cell types remains unknown. We have determined structures of the eukaryotic ADPGK revealing a ribokinase-like tertiary fold similar to archaeal orthologues but with significant differences in some secondary structural elements. Both the unliganded and the AMP-bound ADPGK structures are in the "open" conformation. The structures reveal the presence of a disulfide bond between conserved cysteines that is positioned at the nucleotide-binding loop of eukaryotic ADPGK. The AMP-bound ADPGK structure defines the nucleotide-binding site with one of the disulfide bond cysteines coordinating the AMP with its main chain atoms, a nucleotide-binding motif that appears unique to eukaryotic ADPGKs. Key amino acids at the active site are structurally conserved between mammalian and archaeal ADPGK, and site-directed mutagenesis has confirmed residues essential for enzymatic activity. ADPGK is substrate inhibited by high glucose concentration and shows high specificity for glucose, with no activity for other sugars, as determined by NMR spectroscopy, including 2-deoxyglucose, the glucose analogue used for tumor detection by positron emission tomography.


Assuntos
Glucoquinase/química , Glucose/química , Dobramento de Proteína , Motivos de Aminoácidos , Animais , Glucoquinase/genética , Humanos , Camundongos , Ressonância Magnética Nuclear Biomolecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade
15.
Ann Neurol ; 78(2): 303-16, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26010264

RESUMO

OBJECTIVE: X-linked Charcot-Marie-Tooth disease (CMT1X) is a common inherited neuropathy caused by mutations in the GJB1 gene encoding the gap junction protein connexin32 (Cx32). Clinical studies and disease models indicate that neuropathy mainly results from Schwann cell autonomous, loss-of-function mechanisms; therefore, CMT1X may be treatable by gene replacement. METHODS: A lentiviral vector LV.Mpz-GJB1 carrying the GJB1 gene under the Schwann cell-specific myelin protein zero (Mpz) promoter was generated and delivered into the mouse sciatic nerve by a single injection immediately distal to the sciatic notch. Enhanced green fluorescent protein (EGFP) reporter gene expression was quantified and Cx32 expression was examined on a Cx32 knockout (KO) background. A gene therapy trial was performed in a Cx32 KO model of CMT1X. RESULTS: EGFP was expressed throughout the length of the sciatic nerve in up to 50% of Schwann cells starting 2 weeks after injection and remaining stable for up to 16 weeks. Following LV.Mpz-GJB1 injection into Cx32 KO nerves, we detected Cx32 expression and correct localization in non-compact myelin areas where gap junctions are normally formed. Gene therapy trial by intraneural injection in groups of 2-month-old Cx32 KO mice, before demyelination onset, significantly reduced the ratio of abnormally myelinated fibers (p = 0.00148) and secondary inflammation (p = 0.0178) at 6 months of age compared to mock-treated animals. INTERPRETATION: Gene delivery using a lentiviral vector leads to efficient gene expression specifically in Schwann cells. Restoration of Cx32 expression ameliorates nerve pathology in a disease model and provides a promising approach for future treatments of CMT1X and other inherited neuropathies.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Conexinas/genética , RNA Mensageiro/metabolismo , Células de Schwann/metabolismo , Nervo Isquiático/metabolismo , Animais , Doença de Charcot-Marie-Tooth/metabolismo , Modelos Animais de Doenças , Terapia Genética , Vetores Genéticos , Lentivirus , Camundongos , Camundongos Knockout , Proteína beta-1 de Junções Comunicantes
16.
Mol Ther ; 22(10): 1730-40, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24985163

RESUMO

New treatment strategies for inflammatory bowel disease are needed and parasitic nematode infections or application of helminth components improve clinical and experimental gut inflammation. We genetically modified the probiotic bacterium Escherichia coli Nissle 1917 to secrete the powerful nematode immunomodulator cystatin in the gut. This treatment was tested in a murine colitis model and on post-weaning intestinal inflammation in pigs, an outbred model with a gastrointestinal system similar to humans. Application of the transgenic probiotic significantly decreased intestinal inflammation in murine acute colitis, associated with increased frequencies of Foxp3(+) Tregs, suppressed local interleukin (IL)-6 and IL-17A production, decreased macrophage inflammatory protein-1α/ß, monocyte chemoattractant protein -1/3, and regulated upon activation, normal T-cell expressed, and secreted expression and fewer inflammatory macrophages in the colon. High dosages of the transgenic probiotic were well tolerated by post-weaning piglets. Despite being recognized by T cells, secreted cystatin did not lead to changes in cytokine expression or macrophage activation in the colon. However, colon transepithelial resistance and barrier function were significantly improved in pigs receiving the transgenic probotic and post-weaning colon inflammation was reduced. Thus, the anti-inflammatory efficiency of a probiotic can be improved by a nematode-derived immunoregulatory transgene. This treatment regimen should be further investigated as a potential therapeutic option for inflammatory bowel disease.


Assuntos
Gastroenterite/terapia , Fatores Imunológicos/biossíntese , Fatores Imunológicos/genética , Probióticos/metabolismo , Probióticos/uso terapêutico , Animais , Quimiocinas/genética , Quimiocinas/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Colite/terapia , Cistatinas/biossíntese , Cistatinas/genética , Cistatinas/imunologia , Modelos Animais de Doenças , Escherichia coli/genética , Escherichia coli/metabolismo , Gastroenterite/imunologia , Gastroenterite/metabolismo , Gastroenterite/parasitologia , Expressão Gênica , Fatores Imunológicos/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Probióticos/administração & dosagem , Probióticos/efeitos adversos , Suínos
17.
Am J Med Genet B Neuropsychiatr Genet ; 168B(3): 211-22, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25740197

RESUMO

Accumulating evidence from mouse models points to the G protein-coupled receptor RGS2 (regulator of G-protein signaling 2) as a promising candidate gene for anxiety in humans. Recently, RGS2 polymorphisms were found to be associated with various anxiety disorders, e.g., rs4606 with panic disorder (PD), but other findings have been negative or inconsistent concerning the respective risk allele. To further examine the role of RGS2 polymorphisms in the pathogenesis of PD, we genotyped rs4606 and five additional RGS2 tag single nucleotide polymorphisms (SNPs; rs16834831, rs10801153, rs16829458, rs1342809, rs1890397) in two independent PD samples, comprising 531 matched case/control pairs. The functional SNP rs4606 was nominally associated with PD when both samples were combined. The upstream SNP rs10801153 displayed a Bonferroni-resistant significant association with PD in the second and the combined sample (P = 0.006 and P = 0.017). We furthermore investigated the effect of rs10801153 on dimensional anxiety traits, a behavioral avoidance test (BAT), and an index for emotional processing in the respective subsets of the total sample. In line with categorical results, homozygous risk (G) allele carriers displayed higher scores on the Agoraphobic Cognitions Questionnaire (ACQ; P = 0.015) and showed significantly more defensive behavior during fear provoking situations (P = 0.001). Furthermore, significant effects on brain activation in response to angry (P = 0.013), happy (P = 0.042) and neutral faces (P = 0.032) were detected. Taken together, these findings provide further evidence for the potential role of RGS2 as a candidate gene for PD.


Assuntos
Transtornos de Ansiedade/etiologia , Biomarcadores/análise , Predisposição Genética para Doença , Transtorno de Pânico/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas RGS/genética , Adulto , Transtornos de Ansiedade/psicologia , Mapeamento Encefálico , Estudos de Casos e Controles , Emoções/fisiologia , Feminino , Seguimentos , Genótipo , Haplótipos , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Transtorno de Pânico/complicações , Transtorno de Pânico/psicologia , Personalidade , Fenótipo , Projetos Piloto , Prognóstico , Testes Psicológicos
18.
J Gene Med ; 16(11-12): 364-73, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25394283

RESUMO

BACKGROUND: Most leukodystrophies result from mutations in genes expressed in oligodendrocytes that may cause autonomous loss of function of cell structural proteins. Therefore, effective gene delivery to oligodendrocytes is necessary to develop future treatments. MATERIALS: To achieve this, we cloned a lentiviral vector in which the enhanced green fluorescent protein (EGFP) expression was driven by the oligodendrocyte specific 2,3-cyclic nucleotide 3-phosphodiesterase promoter. The vector was inserted into C57BL/6 neonatal mouse brain by combined intraventricular and parenchymal injections. RESULTS: Assessment of EGFP expression revealed a widespread distribution, specifically in cells of the oligodendrocyte linage, starting from postnatal day 6 (P6) in the subventricular zone and spreading through migrating oligodendrocyte precursors. By P30, it was detectable throughout the brain and persisted for at least 3 months, showing an increase both in the number of expressing cells and in intensity over time. EGFP expression was restricted to oligodendrocyte linage cells. On average, 20.3 ± 2.56% of all oligodendrocytes in different central nervous system areas were EGFP-positive, with regional variations. CONCLUSIONS: Lentiviral gene delivery using an oligodendrocyte-specific promoter may achieve widespread and long-lasting expression selectively in oligodendrocytes, offering a possibility for gene therapy in certain leukodystrophies, although the relatively low rates of oligodendrocyte transduction are a limitation that remains to be overcome.


Assuntos
Terapia Genética , Lentivirus/genética , Oligodendroglia/metabolismo , Animais , Encéfalo/metabolismo , Técnicas de Cocultura , Feminino , Expressão Gênica , Vetores Genéticos , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Masculino , Camundongos Endogâmicos C57BL , Células PC12 , Ratos , Nervo Isquiático/metabolismo
19.
J Virol ; 87(22): 12249-59, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24006446

RESUMO

The aim of this study was to gain insights into the tempo and mode of the evolutionary processes that sustain genetic diversity in coxsackievirus B5 (CVB5) and into the interplay with virus transmission. We estimated phylodynamic patterns with a large sample of virus strains collected in Europe by Bayesian statistical methods, reconstructed the ancestral states of genealogical nodes, and tested for selection. The genealogies estimated with the structural one-dimensional gene encoding the VP1 protein and nonstructural 3CD locus allowed the precise description of lineages over time and cocirculating virus populations within the two CVB5 clades, genogroups A and B. Strong negative selection shaped the evolution of both loci, but compelling phylogenetic data suggested that immune selection pressure resulted in the emergence of the two genogroups with opposed evolutionary pathways. The genogroups also differed in the temporal occurrence of the amino acid changes. The virus strains of genogroup A were characterized by sequential acquisition of nonsynonymous changes in residues exposed at the virus 5-fold axis. The genogroup B viruses were marked by selection of three changes in a different domain (VP1 C terminus) during its early emergence. These external changes resulted in a selective sweep, which was followed by an evolutionary stasis that is still ongoing after 50 years. The inferred population history of CVB5 showed an alternation of the prevailing genogroup during meningitis epidemics across Europe and is interpreted to be a consequence of partial cross-immunity.


Assuntos
Adaptação Biológica , Enterovirus Humano B/classificação , Infecções por Enterovirus/virologia , Evolução Molecular , Variação Genética/genética , Filogenia , Replicação Viral , Sequência de Aminoácidos , Teorema de Bayes , Proteínas do Capsídeo/genética , DNA Viral/genética , Enterovirus Humano B/genética , Infecções por Enterovirus/genética , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Dinâmica Populacional , Seleção Genética , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
20.
Br J Nutr ; 111(6): 1040-9, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24229735

RESUMO

Protein fermentation end products may damage the colonic mucosa, which could be counteracted by dietary inclusion of fermentable carbohydrates (fCHO). Although fermentable crude protein (fCP) and fCHO are known to affect microbial ecology, their interactive effects on epithelial barrier function are unknown. In the present study, in a 2 × 2 factorial experiment, thirty-two weaned piglets were fed low-fCP/low-fCHO (14·5 % crude protein (CP)/14·5 % total dietary fibre (TDF)), low-fCP/high-fCHO (14·8 % CP/16·6 % TDF), high-fCP/low-fCHO (19·8 % CP/14·5 % TDF) and high-fCP/high-fCHO (20·1 % CP/18·0 % TDF) diets. After 21-23 d, samples of proximal and distal colonic mucosae were investigated in Ussing chambers with respect to the paracellular and transcytotic passages of macromolecules and epithelial ion transport. The high-fCHO diets were found to reduce the permeability of the distal colon to the transcytotic marker horseradish peroxidase (HRP, 44 kDa; P <0·05) and also reduce the paracellular permeation of N-hydroxysuccinimide-biotin into the submucosa (443 Da; P <0·05), whereas that of HRP was decreased by the high-fCP diets (P <0·01). Short-circuit current (active ion transport), transepithelial resistance (barrier function) and charge selectivity were largely unaffected in both the segments. However, the high-fCP diets were found to suppress the aldosterone-induced epithelial Na channel activity (P <0·01) irrespective of fCHO inclusion. The high-fCP diets generally reduced the expression of colonic claudin-1, claudin-2 and claudin-3 (P <0·01), while that of claudin-4 was increased by the high-fCHO diets (P <0·01). The high-fCHO diets also altered the ratio between occludin forms (P <0·05) and increased the expression of tricellulin in the proximal colon, which was not observed with high-fCP diets. In conclusion, dietary fCHO and fCP exerted few and largely independent effects on functional measurements, but altered tight junction protein composition in a compensatory way, so that colonic transport and barrier properties were only marginally affected.


Assuntos
Colo/fisiologia , Fibras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Fermentação , Sus scrofa/fisiologia , Proteínas de Junções Íntimas/análise , Animais , Colo/química , Dieta/veterinária , Feminino , Absorção Intestinal , Mucosa Intestinal/fisiologia , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA