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1.
Blood ; 142(16): 1348-1358, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37369099

RESUMO

Anti-CD19 immunotherapy tafasitamab is used in combination with lenalidomide in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) who are ineligible for autologous stem cell transplant. Open-label, phase 1b, First-MIND study assessed safety and preliminary efficacy of tafasitamab + R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) ± lenalidomide as first-line therapy in patients with DLBCL. From December 2019 to August 2020, 83 adults with untreated DLBCL (International Prognostic Index 2-5) were screened and 66 were randomly assigned (33 per arm) to R-CHOP-tafasitamab (arm T) or R-CHOP-tafasitamab-lenalidomide (arm T/L) for 6 cycles. Primary end point was safety; secondary end points included end-of-treatment (EoT) overall response rate (ORR) and complete response (CR) rate. All patients had ≥1 treatment-emergent adverse event, mostly grade 1 or 2. Grade ≥3 neutropenia and thrombocytopenia occurred, respectively, in 57.6% and 12.1% (arm T) and 84.8% and 36.4% (arm T/L) of patients. Nonhematologic toxicities occurred at similar rates among arms. R-CHOP mean relative dose intensity was ≥89% in both arms. EoT ORR was 75.8% (CR 72.7%) in arm T and 81.8% (CR 66.7%) in arm T/L; best ORR across visits was 90.0% and 93.9%. Eighteen-month duration of response and of CR rates were 72.7% and 74.5% (arm T) and 78.7% and 86.5% (arm T/L); 24-month progression-free and overall survival rates were 72.7% and 90.3% (arm T) and 76.8% and 93.8% (arm T/L). Manageable safety and promising signals of efficacy were observed in both arms. Potential benefit of adding tafasitamab + lenalidomide to R-CHOP is being investigated in phase 3 frontMIND (NCT04824092). This study is registered at www.clinicaltrials.gov as #NCT04134936.


Assuntos
Linfoma Difuso de Grandes Células B , Adulto , Humanos , Lenalidomida/uso terapêutico , Anticorpos Monoclonais Murinos/efeitos adversos , Rituximab/efeitos adversos , Linfoma Difuso de Grandes Células B/patologia , Vincristina/efeitos adversos , Ciclofosfamida/efeitos adversos , Prednisona/efeitos adversos , Doxorrubicina/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
2.
Cell ; 132(6): 1025-38, 2008 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-18358814

RESUMO

Insulin/IGF-1-like signaling (IIS) is central to growth and metabolism and has a conserved role in aging. In C. elegans, reductions in IIS increase stress resistance and longevity, effects that require the IIS-inhibited FOXO protein DAF-16. The C. elegans transcription factor SKN-1 also defends against oxidative stress by mobilizing the conserved phase 2 detoxification response. Here we show that IIS not only opposes DAF-16 but also directly inhibits SKN-1 in parallel. The IIS kinases AKT-1, -2, and SGK-1 phosphorylate SKN-1, and reduced IIS leads to constitutive SKN-1 nuclear accumulation in the intestine and SKN-1 target gene activation. SKN-1 contributes to the increased stress tolerance and longevity resulting from reduced IIS and delays aging when expressed transgenically. Furthermore, SKN-1 that is constitutively active increases life span independently of DAF-16. Our findings indicate that the transcription network regulated by SKN-1 promotes longevity and is an important direct target of IIS.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Proteínas de Ligação a DNA/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Animais , Redes Reguladoras de Genes , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Intestinos , Longevidade , Estresse Oxidativo , Fosforilação , Receptor de Insulina/metabolismo
3.
Cancer ; 127(22): 4190-4197, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343354

RESUMO

BACKGROUND: B-precursor cell acute lymphoblastic leukemia (B-ALL) in adults is an aggressive and challenging condition, and patients with relapsed/refractory (R/R) disease after allogeneic stem cell transplantation (SCT), or noncandidates for SCT, have a particularly poor prognosis. The authors investigated the activity of the Fc-modified anti-CD19 antibody tafasitamab in adults with R/R B-ALL (NCT01685021). METHODS: Adults with R/R B-ALL received single-agent tafasitamab 12 mg/kg weekly for up to four 28-day cycles. Patients with complete remission (with or without neutrophil/platelet recovery; complete remission [CR] or complete remission with incomplete count recovery [CRi]) after cycles 2, 3, or 4 could continue tafasitamab every 2 weeks for up to 3 further months. The primary end point was overall response rate (ORR). RESULTS: Twenty-two patients were treated (median, 2 prior lines of therapy; range, 1-8). Six patients completed 2 cycles, and 2 of these patients responded for an ORR of 9%; 16 patients (73%) progressed before their first response assessment. Responses lasted 8 and 4 weeks in the 2 patients with CR and minimal residual disease (MRD)-negative CRi, respectively. Tafasitamab produced rapid B-cell/blast depletion in 21 of 22 patients within 1 to 2 weeks of first administration. Tafasitamab was well tolerated, with the most frequent adverse events being infusion-related reactions (59.1%) and fatigue (40.9%). Grade 3 to 4 febrile neutropenia (22.7%) was the most common hematologic adverse event. CONCLUSIONS: Tafasitamab monotherapy was associated with clinical activity in a subset of patients with R/R B-ALL, including short-lasting CR and MRD-negative CRi. Given its favorable tolerability profile, further development of tafasitamab in chemoimmunotherapy combinations and MRD settings should be explored.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adulto , Anticorpos Monoclonais Humanizados , Antígenos CD19 , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
5.
Haematologica ; 106(9): 2417-2426, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34196165

RESUMO

Tafasitamab (MOR208), an Fc-modified, humanized, anti-CD19 monoclonal antibody, combined with the immunomodulatory drug lenalidomide was clinically active with a good tolerability profile in the open-label, single-arm, phase II L-MIND study of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) ineligible for autologous stem-cell transplantation. To assess long-term outcomes, we report an updated analysis with ≥35 months' follow-up. Patients were aged >18 years, had received one to three prior systemic therapies (including ≥1 CD20-targeting regimen) and Eastern Cooperative Oncology Group performance status 0-2. Patients received 28-day cycles of tafasitamab (12 mg/kg intravenously), once weekly during cycles 1-3, then every 2 weeks during cycles 4-12. Lenalidomide (25 mg orally) was administered on days 1-21 of cycles 1-12. After cycle 12, progression-free patients received tafasitamab every 2 weeks until disease progression. The primary endpoint was best objective response rate. After ≥35 months' follow-up (data cut-off: October 30, 2020), the objective response rate was 57.5% (n=46/80), including a complete response in 40.0% of patients (n=32/80) and a partial response in 17.5% of patients (n=14/80). The median duration of response was 43.9 months (95% confidence interval [95% CI]: 26.1-not reached), the median overall survival was 33.5 months (95% CI: 18.3-not reached) and the median progression-free survival was 11.6 months (95% CI: 6.3-45.7). There were no unexpected toxicities. Subgroup analyses revealed consistent long-term efficacy results across most subgroups of patients. This extended follow-up of L-MIND confirms the long duration of response, meaningful overall survival, and well-defined safety profile of tafasitamab plus lenalidomide followed by tafasitamab monotherapy in patients with relapsed/refractory diffuse large B-cell lymphoma ineligible for autologous stem cell transplantation. ClinicalTrials.gov identifier: NCT02399085.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Linfoma Difuso de Grandes Células B , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Humanos , Lenalidomida/uso terapêutico , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Transplante Autólogo , Resultado do Tratamento
6.
Lancet Oncol ; 21(7): 978-988, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32511983

RESUMO

BACKGROUND: Patients with relapsed or refractory diffuse large B-cell lymphoma who are ineligible for autologous stem-cell transplantation have poor outcomes and few treatment options. Tafasitamab (MOR208) is an Fc-enhanced, humanised, anti-CD19 monoclonal antibody that has shown preclinical and single-agent activity in patients with relapsed or refractory B-cell malignancies. Preclinical data suggested that tafasitamab might act synergistically with lenalidomide. We aimed to assess the antitumour activity and safety of tafasitamab plus lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma who were ineligible for autologous stem-cell transplantation. METHODS: In this multicentre, open-label, single-arm, phase 2 study (L-MIND), patients older than 18 years with histologically confirmed diffuse large B-cell lymphoma, who relapsed or had refractory disease after previous treatment with one to three systemic regimens (with at least one anti-CD20 therapy), were not candidates for high-dose chemotherapy and subsequent autologous stem-cell transplantation, had an Eastern Cooperative Oncology Group performance status of 0-2, and had measurable disease at baseline were recruited from 35 academic and community hospitals in ten countries. Patients received coadministered intravenous tafasitamab (12 mg/kg) and oral lenalidomide (25 mg/day) for up to 12 cycles (28 days each), followed by tafasitamab monotherapy (in patients with stable disease or better) until disease progression. The primary endpoint was the proportion of patients with an objective response (centrally assessed), defined as a complete or partial response according to the 2007 International Working Group response criteria for malignant lymphoma. Antitumour activity analyses are based on all patients who received at least one dose of both tafasitamab and lenalidomide; safety analyses are based on all patients who received at least one dose of either study medication. Recruitment is complete, and the trial is in follow-up. This trial is registered with ClinicalTrials.gov, NCT02399085. FINDINGS: Between Jan 18, 2016, and Nov 15, 2017, 156 patients were screened: 81 were enrolled and received at least one dose of either study medication, and 80 received at least one dose of both tafasitamab and lenalidomide. Median follow-up was 13·2 months (IQR 7·3-20·4) as of data cutoff on Nov 30, 2018. 48 (60%; 95% CI 48-71) of 80 patients who received tafasitamab plus lenalidomide had an objective response: 34 (43%; 32-54) had a complete response and 14 (18%; 10-28) had a partial response. The most common treatment-emergent adverse events of grade 3 or worse were neutropenia (39 [48%] of 81 patients), thrombocytopenia (14 [17%]), and febrile neutropenia (ten [12%]). Serious adverse events occurred in 41 (51%) of 81 patients. The most frequently reported serious adverse events (in two or more patients) were pneumonia (five [6%]), febrile neutropenia (five [6%]), pulmonary embolism (three [4%]), bronchitis (two [2%]), atrial fibrillation (two [2%]), and congestive cardiac failure (two [2%]). INTERPRETATION: Tafasitamab in combination with lenalidomide was well tolerated and resulted in a high proportion of patients with relapsed or refractory diffuse large B-cell lymphoma ineligible for autologous stem-cell transplantation having a complete response, and might represent a new therapeutic option in this setting. FUNDING: MorphoSys.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Terapia de Salvação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/administração & dosagem , Feminino , Seguimentos , Humanos , Lenalidomida/administração & dosagem , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estudos Prospectivos , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
7.
Leuk Lymphoma ; 62(14): 3440-3451, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34414843

RESUMO

Patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL) whose treatment failed with a Bruton's tyrosine kinase inhibitor have poor outcomes. We investigated tafasitamab plus idelalisib (cohort A) or venetoclax (cohort B) in this patient population in a phase II study (NCT02639910). In total, 24 patients were enrolled (cohort A: n = 11, median time on study, 7.4 months; cohort B: n = 13, median time on study, 15.6 months). The most common treatment-emergent adverse event (TEAE) in cohort A was anemia (63.6%) and in cohort B was infusion-related reaction (53.8%). The most common severe TEAE was neutropenia (cohort A: 45.5%; cohort B: 46.2%). The best overall response rate was 90.9% (cohort A) and 76.9% (cohort B). Undetectable minimal residual disease in peripheral blood was achieved in 2/8 patients (cohort A) and 6/7 patients (cohort B). Overall, these results suggest that anti-CD19 antibody-based combinations may be important in the treatment of patients with CLL.


Assuntos
Leucemia Linfocítica Crônica de Células B , Linfoma de Células B , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Humanos , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversos , Purinas , Quinazolinonas , Sulfonamidas
8.
Dev Cell ; 6(4): 577-88, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15068796

RESUMO

The DAF-2 insulin receptor-like signaling pathway controls metabolism, development, longevity, and stress response in C. elegans. Here we show that SGK-1, the C. elegans homolog of the serum- and glucocorticoid-inducible kinase SGK, acts in parallel to the AKT kinases to mediate DAF-2 signaling. Loss of sgk-1 results in defective egg-laying, extended generation time, increased stress resistance, and an extension of life span. SGK-1 forms a protein complex with the AKT kinases, and is activated by and strictly depends on PDK-1. All three kinases of this complex are able to directly phosphorylate DAF-16/FKHRL1, yet have different functions in DAF-2 signaling. Whereas AKT-1 and AKT-2 are more important for regulating dauer formation, SGK-1 is the crucial factor for the control of development, stress response, and longevity. Our data also suggest the existence of a second pathway from DAF-2 to DAF-16 that does not depend on AKT-1, AKT-2, and SGK-1.


Assuntos
Caenorhabditis elegans/metabolismo , Longevidade/genética , Proteínas Nucleares , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptor de Insulina/metabolismo , Estresse Fisiológico/metabolismo , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas Imediatamente Precoces , Insulina/metabolismo , Substâncias Macromoleculares , Mutação/genética , Fenótipo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-akt , Receptor de Insulina/genética , Transdução de Sinais/genética , Estresse Fisiológico/genética
9.
J Endocrinol ; 190(2): 191-202, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16899554

RESUMO

Modulation of insulin/IGF signaling in the nematode Caenorhabditis elegans is the central determinant of the endocrine control of stress response, diapause, and aging. Mutations in many genes that interfere with, or are controlled by, insulin signaling have been identified in the last decade by genetic analyses in the worm. Most of these genes have orthologs in vertebrate genomes, and their functional characterization has provided multiple hints about conserved mechanisms for the genetic influence on aging. The emerging picture is that insulin-like molecules, through the activity of the DAF-2/insulin/ IGF-I-like receptor, and the DAF-16/FKHRL1/FOXO transcription factor, control the ability of the organism to deal with oxidative stress, and interfere with metabolic programs that help to determine lifespan.


Assuntos
Caenorhabditis elegans/metabolismo , Insulina/metabolismo , Longevidade , Transdução de Sinais/fisiologia , Somatomedinas/metabolismo , Estresse Fisiológico/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Fosforilação
10.
Exp Gerontol ; 41(6): 557-63, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16584861

RESUMO

Evidence gathered over the past 15 years shows that the nematode Caenorhabditis elegans is excellently suited as a model to study aging processes in the entire organism. Genetic approaches have been used to identify and elucidate multiple mechanisms and their corresponding genes that limit the life span of C. elegans. These highly conserved pathways include the well-studied insulin/IGF-1 receptor-like signaling pathway, which is thought to be a central determinant of life span, since several other mechanisms depend or converge on the insulin/IGF-1 pathway transcription factor DAF-16/FoxO. In this review we focus on new insights into the molecular mechanisms of aging in C. elegans, including new genes acting in the insulin/IGF-1 pathway and germline signaling. In addition, stress response pathways and mitochondrial mechanisms, dietary restriction, SIR2 deacetylase activity, TOR and TUBBY signaling, as well as telomere length contribution are discussed in relation to recent developments in C. elegans aging research.


Assuntos
Envelhecimento/fisiologia , Caenorhabditis elegans/fisiologia , Transdução de Sinais/fisiologia , Envelhecimento/genética , Animais , Caenorhabditis elegans/genética , Insulina/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Longevidade/fisiologia , Modelos Biológicos , Transdução de Sinais/genética
11.
Sci Aging Knowledge Environ ; 2006(9): pe14, 2006 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-16723639

RESUMO

The aging-related research field has focused on the detection of genetic factors that affect the aging process, but more recently scientists have started to shift their attention to novel and more integrative ways of studying cellular and organismal function. Such approaches allow them to uncover and explore unexpected patterns and themes, resulting in a more comprehensive knowledge of the complex regulatory pathways and networks involved in aging and age-related diseases. Eventually, this knowledge will lead to a systems-level understanding of aging. The third "Functional Genomics of Aging" conference held in Palermo, Italy, in March/April 2006 highlighted some of the more exciting work in this area.


Assuntos
Envelhecimento/fisiologia , Apoptose , Senescência Celular , Neoplasias/fisiopatologia , Células-Tronco/fisiologia , Envelhecimento/genética , Epigênese Genética , Humanos , Longevidade , Neoplasias/genética , Regeneração
12.
Mech Ageing Dev ; 126(1): 139-45, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15610772

RESUMO

The nematode Caenorhabditis elegans is excellently suited as a model for studying the genetic and molecular genetic basis of aging, and to test chemical compounds that interfere with the aging process. Mutants of factors in both the insulin and target of rapamycin (TOR) signalling pathways have been shown to extend life span of the worm. Phenotypic similarities among those mutants suggested that, exploiting the corresponding phenotypes in a semiautomated way, may increase the speed of investigating life span and aging in C. elegans. Here, we discuss several methodological approaches to automate longevity assays in the nematode.


Assuntos
Envelhecimento/genética , Regulação da Expressão Gênica/genética , Genes de Helmintos , Modelos Genéticos , Transdução de Sinais/genética , Envelhecimento/fisiologia , Animais , Automação/métodos , Caenorhabditis elegans , Transdução de Sinais/fisiologia
13.
Sci Aging Knowledge Environ ; 2005(41): pe31, 2005 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-16222001

RESUMO

The worm Caenorhabditis elegans has become a popular model organism for the study of mechanisms involved in aging. The C. elegans life span is controlled by several pathways that have been extensively characterized at the molecular level. These include pathways that regulate metabolism and development (namely, the insulin/IGF-1 pathway), nutrition, mitochondrial activity, and reproduction. Presentations at a recent C. elegans conference add to the growing body of knowledge about the genetic networks that control the complex process of aging and suggest new avenues for further investigations.


Assuntos
Envelhecimento/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Animais , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Mitocôndrias/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Reprodução/fisiologia , Transdução de Sinais
14.
Neurol Neuroimmunol Neuroinflamm ; 2(4): e117, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26185773

RESUMO

OBJECTIVES: To determine the safety, pharmacokinetics (PK), and immunogenicity of the recombinant human monoclonal antibody MOR103 to granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with multiple sclerosis (MS) with clinical or MRI activity. METHODS: In this 20-week, randomized, double-blind, placebo-controlled phase 1b dose-escalation trial (registration number NCT01517282), adults with relapsing-remitting MS (RRMS) or secondary progressive MS (SPMS) received an IV infusion of placebo (n = 6) or MOR103 0.5 (n = 8), 1.0 (n = 8), or 2.0 (n = 9) mg/kg every 2 weeks for 10 weeks. Patients had to have ≤10 gadolinium (Gd)-enhancing brain lesions on T1-weighted MRI at baseline. The primary objective was safety. RESULTS: Most treatment-emergent adverse events (TEAEs) were mild to moderate in severity. The most frequent was nasopharyngitis. Between-group differences in TEAE numbers were small. There were no TEAE-related trial discontinuations, infusion-related reactions, or deaths. Nine patients experienced MS exacerbations: 3, 5, 1, and 0 patient(s) in the placebo, 0.5, 1.0, and 2.0 mg/kg groups, respectively. A few T1 Gd-enhancing lesions and/or new or enlarging T2 lesions indicative of inflammation were observed in all treatment groups. No clinically significant changes were observed in other clinical assessments or laboratory safety assessments. No anti-MOR103 antibodies were detected. PK evaluations indicated dose linearity with low/no drug accumulation over time. CONCLUSIONS: MOR103 was generally well-tolerated in patients with RRMS or SPMS. No evidence of immunogenicity was found. CLASSIFICATION OF EVIDENCE: This phase 1b study provides Class I evidence that MOR103 has acceptable tolerability in patients with MS.

15.
Exp Gerontol ; 38(3): 345-6, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12581802

RESUMO

The 1 mm long nematode Caenorhabditis elegans is one of the prime animal models to study the genetics of aging. Wild type animals under laboratory conditions live only for an average of 18 days, whereas mutations in about 50 genes have been identified that extend longevity up to sixfold. High-throughput analyses have been devised that allow large-scale analysis to identify additional genes, as well as compounds that affect life-span.


Assuntos
Envelhecimento/genética , Caenorhabditis elegans/genética , Longevidade/genética , Animais , Genes de Helmintos/genética , Mutação/genética
16.
Sci Aging Knowledge Environ ; 2004(40): pe37, 2004 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-15470191

RESUMO

Whole-genome sequences are now available, and methods have evolved for targeting, in parallel, each gene in a genome, offering for the first time the opportunity to study the entire dynamic network of genes involved in aging. At a recent conference in Hersonissos, Crete, around 200 internationally renowned experts gathered to discuss techniques and emerging results as the science of aging undergoes a shift toward systems biology.


Assuntos
Biologia Computacional/métodos , Biologia Computacional/tendências , Genes/fisiologia , Longevidade/fisiologia , Envelhecimento/genética , Envelhecimento/patologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/fisiologia , Drosophila/genética , Proteínas de Drosophila/fisiologia , Fatores de Transcrição Forkhead , Humanos , Proteínas Imediatamente Precoces , Insulina/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Camundongos , Proteínas Nucleares/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Receptor de Insulina/fisiologia , Transdução de Sinais/fisiologia , Fatores de Transcrição/fisiologia
17.
Genes Dev ; 22(19): 2721-35, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18832074

RESUMO

Correlative evidence links stress, accumulation of oxidative cellular damage, and aging in several species. Genetic studies in species ranging from yeast to mammals revealed several pathways regulating stress response and life span, including caloric intake, mitochondrial respiration, insulin/IGF-1 (IIS), and JNK (c-Jun N-terminal kinase) signaling. How IIS and JNK signaling cross-talk to defend against diverse stressors contributing to aging is of critical importance but, so far, only poorly understood. In this study, we demonstrate that the adaptor protein SHC-1, the Caenorhabditis elegans homolog of human p52Shc, coordinates mechanisms of stress response and aging. Using genetic and biochemical approaches, we discover that SHC-1 not only opposes IIS but also activates JNK signaling. Loss of shc-1 function results in accelerated aging and enhanced sensitivity to heat, oxidative stress, and heavy metals, whereas expression of human p52Shc rescues the shc-1 mutant phenotype. SHC-1 acts upstream of the insulin/IGF receptor DAF-2 and the PI3 kinase AGE-1 and directly interacts with DAF-2. Moreover, SHC-1 activates JNK signaling by binding to MEK-1 kinase. Both aspects converge on controlling the nuclear translocation and activation of the FOXO transcription factor DAF-16. Our findings establish C. elegans SHC-1 as a critical scaffold that directly cross-connects the two parallel JNK and IIS pathways and help to explain how these signaling cascades cooperate to ascertain normal stress response and life span in C. elegans.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/fisiologia , Longevidade/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Envelhecimento/genética , Envelhecimento/fisiologia , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição Forkhead , Genes de Helmintos , Humanos , Insulina/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Longevidade/genética , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Mutação , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Homologia de Sequência de Aminoácidos , Proteínas Adaptadoras da Sinalização Shc , Transdução de Sinais , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
18.
J Biol Chem ; 283(21): 14257-68, 2008 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-18353773

RESUMO

Ectodomain shedding of the amyloid precursor protein (APP) by the two proteases alpha- and beta-secretase is a key regulatory event in the generation of the Alzheimer disease amyloid beta peptide (Abeta). beta-Secretase catalyzes the first step in Abeta generation, whereas alpha-secretase cleaves within the Abeta domain, prevents Abeta generation, and generates a secreted form of APP with neuroprotective properties. At present, little is known about the cellular mechanisms that control APP alpha-secretase cleavage and Abeta generation. To explore the contributory pathways, we carried out an expression cloning screen. We identified a novel member of the sorting nexin (SNX) family of endosomal trafficking proteins, called SNX33, as a new activator of APP alpha-secretase cleavage. SNX33 is a homolog of SNX9 and was found to be a ubiquitously expressed phosphoprotein. Exogenous expression of SNX33 in cultured cells increased APP alpha-secretase cleavage 4-fold but surprisingly had little effect on beta-secretase cleavage. This effect was similar to the expression of the dominant negative dynamin-1 mutant K44A. SNX33 bound the endocytic GTPase dynamin and reduced the rate of APP endocytosis in a dynamin-dependent manner. This led to an increase of APP at the plasma membrane, where alpha-secretase cleavage mostly occurs. In summary, our study identifies SNX33 as a new endocytic protein, which modulates APP endocytosis and APP alpha-secretase cleavage, and demonstrates that the rate of APP endocytosis is a major control factor for APP alpha-secretase cleavage.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas de Transporte/metabolismo , Endocitose , Proteínas de Transporte Vesicular/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Proteínas de Transporte/química , Linhagem Celular , Chlorocebus aethiops , Clonagem Molecular , Dinaminas/metabolismo , Regulação Enzimológica da Expressão Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Transporte Proteico , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Nexinas de Classificação , Transferrina/metabolismo , Proteínas de Transporte Vesicular/química
19.
Eur J Biochem ; 269(1): 175-83, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11784311

RESUMO

A number of antibiotics have been reported to disturb the decoding process in prokaryotic translation and to inhibit the function of various natural ribozymes. We investigated the effect of several antibiotics on in vitro splicing of a eukaryotic nuclear pre-mRNA (beta-globin). Of the eight antibiotics studied, erythromycin, Cl-tetracycline and streptomycin were identified as splicing inhibitors in nuclear HeLa cell extract. The K(i) values were 160, 180 and 230 microm, respectively. Cl-tetracycline-mediated and streptomycin-mediated splicing inhibition were in the molar inhibition range for hammerhead and human hepatitis delta virus ribozyme self-cleavage (tetracycline), of group-I intron self-splicing (streptomycin) and inhibition of RNase P cleavage by some aminoglycosides. Cl-tetracycline and the aminocyclitol glycoside streptomycin were found to have an indirect effect on splicing by unspecific binding to the pre-mRNA, suggesting that the inhibition is the result of disturbance of the correct folding of the pre-mRNA into the splicing-compatible tertiary structure by the charged groups of these antibiotics. The macrolide, erythromycin, the strongest inhibitor, had only a slight effect on formation of the presplicing complexes A and B, but almost completely inhibited formation of the splicing-active C complex by binding to nuclear extract component(s). This results in direct inhibition of the second step of pre-mRNA splicing. To our knowledge, this is the first report on specific inhibition of nuclear splicing by an antibiotic. The functional groups involved in the interaction of erythromycin with snRNAs and/or splicing factors require further investigation.


Assuntos
Antibacterianos/farmacologia , Núcleo Celular/metabolismo , Precursores de RNA/genética , Splicing de RNA/efeitos dos fármacos , Catálise , Clortetraciclina/farmacologia , Eritromicina/farmacologia , Estreptomicina/farmacologia
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