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1.
N Engl J Med ; 382(1): 29-40, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31893514

RESUMO

BACKGROUND: Adeno-associated virus (AAV)-mediated gene therapy is under investigation as a therapeutic option for persons with hemophilia A. Efficacy and safety data include 3 years of follow-up after a single administration of AAV5-hFVIII-SQ. METHODS: We report durable efficacy, long-term safety, and clinical and biologic results in 15 adults with severe hemophilia A (factor VIII level, ≤1 IU per deciliter) who had received a single infusion of AAV5-hFVIII-SQ at various dose levels. We evaluated the factor VIII level, annualized rate of bleeding events, use of factor VIII, safety, expression kinetics, and biologic markers of AAV transduction for up to 3 years. RESULTS: Three years after infusion, two participants (one who had received 6×1012 vector genomes [vg] per kilogram of body weight and one who had received 2×1013 vg per kilogram) had factor VIII expression of less than 1 IU per deciliter, as assessed on chromogenic assay. Seven participants (who had received 6×1013 vg per kilogram) had a median factor VIII expression of 20 IU per deciliter; the median number of annualized treated bleeding events was 0, and the median use of exogenous factor VIII was reduced from 138.5 infusions to 0 infusions per year. Bleeding in all target joints (major joints with ≥3 bleeding events within 6 months) in this cohort resolved (≤2 bleeding events within 12 months). Two years after infusion, six participants (who had received 4×1013 vg per kilogram) had a median factor VIII expression of 13 IU per deciliter; the median annualized rate of bleeding events was 0, and the median use of factor VIII was reduced from 155.5 infusions to 0.5 infusions per year. Bleeding in target joints resolved in five of six participants. The factor VIII pharmacodynamic profiles reflected cellular turnover in the blood and molecular events leading to episomal DNA stabilization for persistent expression, findings that are consistent with previous observations in two model systems. Transgene-derived human factor VIII (hFVIII) protein activity mirrored native hFVIII in hemostatic ability. No inhibitor development, thromboses, deaths, or persistent changes in liver-function tests were observed. CONCLUSIONS: Gene therapy with AAV5-hFVIII-SQ vector in participants with hemophilia A resulted in sustained, clinically relevant benefit, as measured by a substantial reduction in annualized rates of bleeding events and complete cessation of prophylactic factor VIII use in all participants who had received 4×1013 vg per kilogram or 6×1013 vg per kilogram of the gene therapy. (Funded by BioMarin Pharmaceutical; ClinicalTrials.gov number, NCT02576795; EudraCT number, 2014-003880-38.).


Assuntos
Dependovirus , Fator VIII/genética , Terapia Genética , Vetores Genéticos , Hemofilia A/terapia , Adulto , Biomarcadores , Coagulantes/uso terapêutico , Fator VIII/uso terapêutico , Seguimentos , Terapia Genética/efeitos adversos , Hemofilia A/complicações , Hemorragia/etiologia , Hemorragia/prevenção & controle , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Transgenes , Adulto Jovem
2.
Gene Ther ; 29(1-2): 94-105, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34421119

RESUMO

Adeno-associated virus (AAV)-based gene therapy vectors are replication-incompetent and thus pose minimal risk for horizontal transmission or release into the environment. In studies with AAV5-FVIII-SQ (valoctocogene roxaparvovec), an investigational gene therapy for hemophilia A, residual vector DNA was detectable in blood, secreta, and excreta, but it remained unclear how long structurally intact AAV5 vector capsids were present. Since a comprehensive assessment of vector shedding is required by regulatory agencies, we developed a new method (termed iqPCR) that utilizes capsid-directed immunocapture followed by qPCR amplification of encapsidated DNA. The limit of detection for AAV5 vector capsids was 1.17E+04 and 2.33E+04 vg/mL in plasma and semen, respectively. Acceptable precision, accuracy, selectivity, and specificity were verified; up to 1.00E+09 vg/mL non-encapsidated vector DNA showed no interference. Anti-AAV5 antibody plasma concentrations above 141 ng/mL decreased AAV5 capsid quantification, suggesting that iqPCR mainly detects free capsids and not those complexed with antibodies. In a clinical study, AAV5-FVIII-SQ capsids were found in plasma and semen but became undetectable within nine weeks after dose administration. Hence, iqPCR monitors the presence and shedding kinetics of intact vector capsids following AAV gene therapy and informs the potential risk for horizontal transmission.


Assuntos
Fator VIII , Hemofilia A , Capsídeo , Proteínas do Capsídeo/genética , Dependovirus/genética , Fator VIII/genética , Fator VIII/uso terapêutico , Terapia Genética/métodos , Vetores Genéticos/genética , Hemofilia A/genética , Hemofilia A/terapia , Humanos
3.
Mol Ther ; 29(2): 597-610, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33309883

RESUMO

Evaluation of immune responses to adeno-associated virus (AAV)-mediated gene therapies prior to and following dose administration plays a key role in determining therapeutic safety and efficacy. This report describes up to 3 years of immunogenicity data following administration of valoctocogene roxaparvovec (BMN 270), an AAV5-mediated gene therapy encoding human B domain-deleted FVIII (hFVIII-SQ) in a phase 1/2 clinical study of adult males with severe hemophilia A. Patients with pre-existing humoral immunity to AAV5 or with a history of FVIII inhibitors were excluded from the trial. Blood plasma and peripheral blood mononuclear cell (PBMC) samples were collected at regular intervals following dose administration for assessment of humoral and cellular immune responses to both the AAV5 vector and transgene-expressed hFVIII-SQ. The predominant immune response elicited by BMN 270 administration was largely limited to the development of antibodies against the AAV5 capsid that were cross-reactive with other common AAV serotypes. No FVIII inhibitor responses were observed within 3 years following dose administration. In a context of prophylactic or on-demand corticosteroid immunosuppression given after vector infusion, AAV5 and hFVIII-SQ peptide-specific cellular immune responses were intermittently detected by an interferon (IFN)-γ and tumor necrosis factor (TNF)-α FluoroSpot assay, but they were not clearly associated with detrimental safety events or changes in efficacy measures.


Assuntos
Dependovirus/genética , Terapia Genética , Vetores Genéticos/genética , Hemofilia A/genética , Hemofilia A/terapia , Adulto , Reações Cruzadas/imunologia , Dependovirus/imunologia , Fator VIII/genética , Terapia Genética/efeitos adversos , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Vetores Genéticos/efeitos adversos , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Imunidade Humoral , Masculino , Transgenes , Resultado do Tratamento
4.
Haemophilia ; 27(6): 947-956, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34378280

RESUMO

INTRODUCTION: Valoctocogene roxaparvovec is an investigational AAV5-based factor VIII (FVIII) gene therapy that has demonstrated sustained clinical benefit in people with severe haemophilia A. AIM: To report safety, tolerability, efficacy, and quality of life (QOL) among participants who received valoctocogene roxaparvovec in a phase 1/2 clinical study (NCT02576795). METHODS: Men ≥18 years of age with severe haemophilia A (FVIII ≤1 IU/dl) without history of FVIII inhibitors or anti-AAV5 antibodies received a single infusion of valoctocogene roxaparvovec and were followed for 5 years (6 × 1013 vg/kg dose, n = 7) and 4 years (4 × 1013 vg/kg dose, n = 6). RESULTS: Over the past 2 years, few adverse events and no FVIII inhibitors were reported. Per chromogenic substrate (CSA) assay at years 5 and 4, four of seven and three of six participants in the 6 × 1013 and 4 × 1013 vg/kg cohorts, respectively, maintained median FVIII levels >5 IU/dl, corresponding to mild haemophilia. By regression analysis, rate of change in FVIII activity was -0.14 (95% confidence interval [CI]: -.32 to .03) IU/dl/wk in the 6 × 1013 vg/kg cohort in year 5 and -.06 (95% CI: -.14 to .01) IU/dl/wk in the 4 × 1013 vg/kg cohort in year 4. No participants resumed FVIII prophylaxis, and eight of 13 participants reported zero bleeds in the past 2 years. Improved QOL from baseline persisted in the 6 × 1013 vg/kg cohort; all six Haemo-QOL-A domain scores increased. For the 4 × 1013 vg/kg cohort, high baseline Haemo-QOL-A scores persisted. CONCLUSION: These results demonstrate transgene expression and haemostatic response for up to 5 years in individuals with haemophilia A.


Assuntos
Hemofilia A , Hemostáticos , Pré-Escolar , Fator VIII/genética , Terapia Genética , Hemofilia A/tratamento farmacológico , Hemofilia A/genética , Hemorragia/prevenção & controle , Humanos , Masculino , Qualidade de Vida
5.
Ann Rheum Dis ; 75(6): 1081-91, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26511996

RESUMO

OBJECTIVES: The efficacy of tocilizumab (TCZ), an anti-interleukin-6 receptor antibody, has not previously been evaluated in a population consisting exclusively of patients with early rheumatoid arthritis (RA). METHODS: In a double-blind randomised controlled trial (FUNCTION), 1162 methotrexate (MTX)-naive patients with early progressive RA were randomly assigned (1:1:1:1) to one of four treatment groups: 4 mg/kg TCZ+MTX, 8 mg/kg TCZ+MTX, 8 mg/kg TCZ+placebo and placebo+MTX (comparator group). The primary outcome was remission according to Disease Activity Score using 28 joints (DAS28-erythrocyte sedimentation rate (ESR) <2.6) at week 24. Radiographic and physical function outcomes were also evaluated. We report results through week 52. RESULTS: The intent-to-treat population included 1157 patients. Significantly more patients receiving 8 mg/kg TCZ+MTX and 8 mg/kg TCZ+placebo than receiving placebo+MTX achieved DAS28-ESR remission at week 24 (45% and 39% vs 15%; p<0.0001). The 8 mg/kg TCZ+MTX group also achieved significantly greater improvement in radiographic disease progression and physical function at week 52 than did patients treated with placebo+MTX (mean change from baseline in van der Heijde-modified total Sharp score, 0.08 vs 1.14 (p=0.0001); mean reduction in Health Assessment Disability Index, -0.81 vs -0.64 (p=0.0024)). In addition, the 8 mg/kg TCZ+placebo and 4 mg/kg TCZ+MTX groups demonstrated clinical efficacy that was at least as effective as MTX for these key secondary endpoints. Serious adverse events were similar among treatment groups. Adverse events resulting in premature withdrawal occurred in 20% of patients in the 8 mg/kg TCZ+MTX group. CONCLUSIONS: TCZ is effective in combination with MTX and as monotherapy for the treatment of patients with early RA. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, number NCT01007435.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antirreumáticos/administração & dosagem , Artrite Reumatoide/tratamento farmacológico , Metotrexato/administração & dosagem , Adulto , Progressão da Doença , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Índice de Gravidade de Doença , Resultado do Tratamento
6.
Nat Med ; 28(4): 789-797, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35411075

RESUMO

Factor VIII gene transfer with a single intravenous infusion of valoctocogene roxaparvovec (AAV5-hFVIII-SQ) has demonstrated clinical benefits lasting 5 years to date in people with severe hemophilia A. Molecular mechanisms underlying sustained AAV5-hFVIII-SQ-derived FVIII expression have not been studied in humans. In a substudy of the phase 1/2 clinical trial ( NCT02576795 ), liver biopsy samples were collected 2.6-4.1 years after gene transfer from five participants. Primary objectives were to examine effects on liver histopathology, determine the transduction pattern and percentage of hepatocytes transduced with AAV5-hFVIII-SQ genomes, characterize and quantify episomal forms of vector DNA and quantify transgene expression (hFVIII-SQ RNA and hFVIII-SQ protein). Histopathology revealed no dysplasia, architectural distortion, fibrosis or chronic inflammation, and no endoplasmic reticulum stress was detected in hepatocytes expressing hFVIII-SQ protein. Hepatocytes stained positive for vector genomes, showing a trend for more cells transduced with higher doses. Molecular analysis demonstrated the presence of full-length, inverted terminal repeat-fused, circular episomal genomes, which are associated with long-term expression. Interindividual differences in transgene expression were noted despite similar successful transduction, possibly influenced by host-mediated post-transduction mechanisms of vector transcription, hFVIII-SQ protein translation and secretion. Overall, these results demonstrate persistent episomal vector structures following AAV5-hFVIII-SQ administration and begin to elucidate potential mechanisms mediating interindividual variability.


Assuntos
Dependovirus , Hemofilia A , Dependovirus/genética , Dependovirus/metabolismo , Fator VIII/genética , Fator VIII/uso terapêutico , Terapia Genética/métodos , Vetores Genéticos/genética , Hemofilia A/genética , Hemofilia A/terapia , Humanos , RNA Mensageiro , Transgenes/genética
7.
Lancet Rheumatol ; 2(11): e666-e676, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38279363

RESUMO

BACKGROUND: Otilimab is a human monoclonal antibody that inhibits granulocyte-macrophage colony-stimulating factor (GM-CSF), a driver in many immune-mediated inflammatory conditions. We evaluated the effect of otilimab on the GM-CSF-chemokine (C-C motif) ligand 17 (CCL17) axis and synovitis in patients with rheumatoid arthritis. METHODS: This phase 2a, randomised, double-blind, multicentre, placebo-controlled, parallel-group study was done at nine sites across the USA, Poland, and Germany. Patients aged 18 years or older with rheumatoid arthritis per American College of Rheumatology-European League Against Rheumatism 2010 criteria and receiving stable methotrexate were randomly assigned (3:1) by an interactive response technology system to either subcutaneous otilimab 180 mg or placebo once weekly for 5 weeks, then every other week until week 10 (within a 12-week treatment period), followed by a 10-week safety follow-up. Randomisation was stratified by early rheumatoid arthritis (≤2 years since diagnosis) and established rheumatoid arthritis (>2 years since diagnosis). Patients and study personnel (except for an unblinded coordinator or nurse who prepared and administered the study drug) were blinded to treatment assignment; the syringe was shielded during administration. Patients were enrolled by study investigators and allocated to a treatment by central randomisation on the basis of a schedule generated by the sponsor. The primary endpoint was change over time (assessed at baseline and weeks 1, 2, 4, 6, 8, 12, and 22 of follow-up) in 112 biomarkers, including target engagement biomarkers and those that may be indicative of rheumatoid arthritis disease activity and response to otilimab. Secondary endpoints were change from baseline in synovitis, osteitis and erosion assessed by rheumatoid arthritis MRI scoring system (RAMRIS) and rheumatoid arthritis MRI quantitative score (RAMRIQ), and safety evaluation. The primary, secondary, and safety endpoints were assessed in the intention-to-treat population. Biomarker and MRI endpoints were analysed for differences between treatment groups using a repeated measures model. This study is registered with ClinicalTrials.gov, NCT02799472. FINDINGS: Between Aug 9, 2016, and Oct 30, 2017, 39 patients were randomly assigned and included in the analysis (otilimab n=28; placebo n=11). In the otilimab group, mean serum concentrations of GM-CSF-otilimab complex peaked at week 4 (138·4 ng/L, 95% CI 90·0-212·9) but decreased from week 6-12. CCL17 concentrations decreased from baseline to week 1, remained stable to week 8, and returned to baseline at week 12; least-squares mean ratio to baseline was 0·65 (95% CI 0·49-0·86; coefficient of variation 13·60) at week 2, 0·68 (0·53-0·88; 12·51) at week 4, 0·78 (0·60-1·00; 12·48) at week 6, and 0·68 (0·54-0·85; 11·21) at week 8. No meaningful change in CCL17 concentrations was observed with placebo. In the otilimab group, the least-squares mean ratio to baseline in MMP-degraded type I collagen was 0·86-0·91 over weeks 1-8, returning to baseline at week 12; concentrations remained above baseline at all timepoints in the placebo group. There were no observable differences between otilimab and placebo for all other biomarkers. At week 12, least-squares mean change in RAMRIS synovitis score from baseline was -1·3 (standard error [SE] 0·6) in the otilimab group and 0·8 (1·2) with placebo; RAMRIQ synovitis score showed a least-squares mean change from baseline of -1417·0 µl (671·5) in the otilimab group and -912·3 µl (1405·8) with placebo. Compared with placebo, otilimab did not show significant reductions from baseline to week 12 in RAMRIS synovitis, osteitis and bone erosion, or in RAMRIQ synovitis and erosion damage. Adverse events were reported in 11 (39%) of 28 otilimab-treated and four (36%) of 11 placebo-treated patients, most commonly cough in the otilimab group (2 [7%] of 28; not reported in placebo group), and pain in extremity (four [36%] of 11) and rheumatoid arthritis (two [18%] of 11) in the placebo group (not reported in otilimab group). There were no serious adverse events or deaths. INTERPRETATION: Serum concentrations of GM-CSF-otilimab complex indicated that target engagement was achieved with initial weekly dosing, but not sustained with every other week dosing. CCL17 might be a pharmacodynamic biomarker for otilimab activity in future studies. Otilimab was well tolerated and, despite suboptimal exposure, showed some evidence for improved synovitis over 12 weeks in patients with active rheumatoid arthritis. FUNDING: GlaxoSmithKline.

8.
Lancet Rheumatol ; 2(11): e677-e688, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38279364

RESUMO

BACKGROUND: The human monoclonal antibody otilimab inhibits granulocyte-macrophage colony-stimulating factor (GM-CSF), a key driver in immune-mediated inflammatory conditions. We aimed to evaluate the efficacy, safety, and key patient-reported outcomes related to pain in patients with active rheumatoid arthritis receiving otilimab. METHODS: This phase 2b, dose-ranging, multicentre, placebo-controlled study was done at 64 sites across 14 countries. Patients aged 18 years or older with rheumatoid arthritis who were receiving stable methotrexate were randomly assigned (1:1:1:1:1:1) to subcutaneous placebo or otilimab 22·5 mg, 45 mg, 90 mg, 135 mg, or 180 mg, plus methotrexate, once weekly for 5 weeks, then every other week until week 50. The randomisation schedule was generated by the sponsor, and patients were assigned to treatment by interactive response technology. Randomisation was blocked (block size of six) but was not stratified. Investigators, patients, and the sponsor were blinded to treatment. An unblinded administrator prepared and administered the study drug. The primary endpoint was the proportion of patients who achieved disease activity score for 28 joints with C-reactive protein (DAS28-CRP) <2·6 at week 24. Patients who were not in the otilimab 180 mg group, without a good or moderate European League Against Rheumatism response (week 12) or with DAS28-CRP >3·2 (week 24) escaped to otilimab 180 mg. Patients who escaped were treated as non-responders in their original assigned group. Safety endpoints were incidence of adverse events and serious adverse events, infections, and pulmonary events. Efficacy and safety outcomes were assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02504671. FINDINGS: Between July 23, 2015, and Dec 29, 2017, 222 patients were randomly assigned (37 to each group). 86 (49%) of 175 escaped to otilimab 180 mg at week 12 and 57 (69%) of 83 at week 24. At week 24, the proportion of patients with DAS28-CRP <2·6 was two (5%) of 37 in the otilimab 22·5 mg group, six (16%) of 37 in the 45 mg group, seven (19%) of 37 in the 90 mg group, five (14%) of 37 in the 135 mg group, five (14%) of 37 in the 180 mg, and one (3%) of 37 in the placebo group. The largest difference was achieved with otilimab 90 mg (16·2%; odds ratio [OR] 8·39, 95% CI 0·98-72·14; p=0·053). Adverse events were reported pre-escape in 19-24 (51-65%) patients and post escape in 10-17 (40-61%) patients across otilimab dose groups and in 18 (49%) of 37 and 22 (67%) of 33 in the placebo group. The most common adverse event was nasopharyngitis: 3-9 (8-24%) in otilimab groups and one (3%) in the placebo group pre-escape and 1-3 (4-10%) in otilimab groups and seven (21%) in the placebo group post escape. Pre-escape serious adverse events were foot fracture (otilimab 45 mg); arthralgia, myocardial infarction, dizziness (otilimab 90 mg); oesophageal spasm, acute pyelonephritis (otilimab 22·5 mg), and uterine leiomyoma (otilimab 135 mg). Post-escape serious adverse events were ankle fracture (placebo) and rheumatoid arthritis (otilimab 135 mg). There were no deaths or pulmonary events of clinical concern, and rates of serious infection were low. INTERPRETATION: Otilimab plus methotrexate was well tolerated and, despite not achieving the primary endpoint of DAS28-CRP remission, there were improvements compared with placebo in disease activity scores. Of note, patients reported significant improvement in pain and physical function, supporting further clinical development of otilimab in rheumatoid arthritis. FUNDING: GlaxoSmithKline.

9.
Nurs Stand ; 31(29): 36, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28294010

RESUMO

Ageism was not something I thought about during my training, but I became aware of it on a clinical placement working with older people, some of whom had dementia.

10.
Glia ; 55(10): 1011-22, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17508424

RESUMO

D-type cyclins are direct targets of extracellular signals and critical regulators of G(1) progression. Our previous data demonstrated that IGF-I and FGF-2 synergize to enhance cyclin D1 expression, cyclin E/cdk2 complex activation, and S-phase entry in OP cells. Here, we provide a mechanistic explanation for how two growth factor signaling pathways converge on a major cell cycle regulator. IGF-I and FGF-2 differentially activate signaling pathways to coordinately promote cyclin D1 expression. We show that the p44/p42 MAPK signaling pathway is essential for FGF-2 induction of cyclin D1 mRNA. In contrast, blocking the PI3-Kinase pathway results in loss of IGF-I/FGF-2 synergistic induction of cyclin D1 protein levels. Moreover, the presence of IGF-I significantly enhances nuclear localization of cyclin D1, which also requires PI3K signaling. GSK-3beta, a downstream target of the PI3K/Akt pathway, is phosphorylated in the presence of IGF-I in OPs. Consistent with a known role for GSK-3beta in cyclin D1 degradation, we show that proteasome inhibition in OPs exposed to FGF-2 increased cyclin D1 levels, equivalent to levels seen in IGF-I/FGF-2 treated cells. Thus, we provide a model for cyclin D1 coordinate regulation where FGF-2 stimulation of the MAPK pathway promotes cyclin D1 mRNA expression while IGF-I activation of the PI3K pathway inhibits proteasome degradation of cyclin D1 and enhances nuclear localization of cyclin D1.


Assuntos
Ciclinas/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Oligodendroglia/metabolismo , Transdução de Sinais/fisiologia , Células-Tronco/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Animais Recém-Nascidos , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Ciclina D , Ciclinas/efeitos dos fármacos , Sinergismo Farmacológico , Fator 2 de Crescimento de Fibroblastos/farmacologia , Quinase 3 da Glicogênio Sintase/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Fator de Crescimento Insulin-Like I/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Modelos Biológicos , Oligodendroglia/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
11.
Dev Neurosci ; 24(5): 437-45, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12666655

RESUMO

A previous study from our laboratory demonstrated differences in the ability of insulin-like growth factor-I (IGF-I) and neurotrophin-3 (NT-3) to promote survival of pro-oligodendroblasts (pro-OLs) against glutamate-mediated apoptosis. In the current study, we tested whether submaximal concentrations of NT-3 would maintain receptor tyrosine kinase TrkC activation and Akt phosphorylation and thus promote long-term survival of the pro-OL against glutamate. Our results demonstrate that NT-3 at any concentration sufficient to activate the TrkC receptor results in a transient phosphorylation of the receptor and of Akt due, in part, to downregulation of the Trk receptor. In contrast, even submaximal IGF-I concentrations maintain long-term Akt activation and prevent glutamate-mediated apoptosis in pro-OLs. In addition, we also present data showing that IGF-I and NT-3 differentially activate their receptors and Akt depending on the maturational stage of the oligodendrocyte.


Assuntos
Encéfalo/crescimento & desenvolvimento , Fator de Crescimento Insulin-Like I/farmacologia , Neurotrofina 3/farmacologia , Oligodendroglia/efeitos dos fármacos , Proteínas Serina-Treonina Quinases , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Western Blotting , Encéfalo/metabolismo , Células Cultivadas , Ácido Glutâmico/toxicidade , Fármacos Neuroprotetores/farmacologia , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Fosforilação , Proteínas Proto-Oncogênicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Receptores Proteína Tirosina Quinases/efeitos dos fármacos , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/fisiologia
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