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1.
Res Involv Engagem ; 7(1): 15, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33726817

RESUMO

BACKGROUND: Medical societies and funding agencies strongly recommend that patients be included as partners in research publications and grant applications. Although this "top-down" approach is certainly efficient at forcing this new and desirable type of collaboration, our past experience demonstrated that it often results in an ambiguous relationship as not yet well integrated into the cultures of either patients' or the researchers'. The question our group raised from this observation was: "How to generate a cultural shift toward a fruitful and long-lasting collaboration between patients and researchers? A "bottom-up" approach was key to our stakeholders. The overall objective was to build a trusting and bidirectional-ecosystem between patients and researchers. The specific objectives were to document: 1) the steps that led to the development of the first patient-partner strategic committee within a research center in the Province of Québec; 2) the committee's achievements after 3 years. METHODS: Eighteen volunteer members, 12 patient-partners and 6 clinician/institutional representatives, were invited to represent the six research themes of the Centre de recherche du CHU de Sherbrooke (CRCHUS) (Quebec, Canada). Information on the services offered by Committee was disseminated internally and to external partners. Committee members satisfaction was evaluated. RESULTS: From May 2017 to April 2020, members attended 29 scheduled and 6 ad hoc meetings and contributed to activities requiring over 1000 h of volunteer time in 2018-2019 and 1907 h in the 2019-2020 period. The Committee's implication spanned governance, expertise, and knowledge transfer in research. Participation in these activities increased annually at local, provincial, national and international levels. The Patient-Partner Committee collaborated with various local (n = 7), provincial (n = 6) and national (n = 4) partners. Member satisfaction with the Committee's mandate and format was 100%. CONCLUSIONS: The CRCHUS co-constructed a Patient-Partner Strategic Committee which resulted in meaningful bilateral, trusting and fruitful collaborations between patients, researchers and partners. The "bottom-up" approach - envisioned and implemented by the Committee, where the expertise and the needs of patients complemented those of researchers, foundations, networks and decision-makers - is key to the success of a cultural shift. The CRCHUS Committee created a hub to develop the relevant intrinsic potential aimed at changing the socio-cultural environment of science.

2.
Artigo em Inglês | MEDLINE | ID: mdl-27570627

RESUMO

BACKGROUND: Proximal humerus fractures can be treated surgically (eg: pinning, plate and screws) or conservatively by wearing a splint or a cast. Following both of these approaches, rehabilitation has proven effective to prevent functional limitations and to re-establish normal shoulder function. However, access to these rehabilitation services and compliance tends to be limited in elderly patients due to travelling difficulties caused by their precarious health status and, in some cases, social and marital status. Since the majority of patients with a proximal humerus fracture are elderly, it becomes relevant to find a new way to offer quick, simple and suitable rehabilitation service. Thus, the use of promising alternative approaches, as in-home telerehabilitation, can enhance access to rehabilitation services for such population. The main objective of the study is to compare the clinical effects of the innovative telerehabilitation approach (TELE group) compared to face-to-face visits to a clinic (CLINIC group) for patients treated for a proximal humerus fracture. METHODS/DESIGN: In this randomized controlled trial, individuals who have had a proximal humerus fracture treated conservatively at the Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie CHUS), and who are returning home will be included. Participants will be recruited during their visit to the emergency ward or outpatient clinic by the medical or research team and will then sign the informed consent form if they are interested to participate in the study. We expect to recruit 52 participants (26 per group). Randomization will be done by a random number generator with sealed envelopes. Each patient will be evaluated before the beginning of the rehabilitation (T1), and immediately after the 2-month intervention (T2). The following outcomes will be measured: 1) upper extremity function (Constant Shoulder Score and Disability of the Arm, Shoulder and Hand questionnaire [DASH]); 2) range of motion (conventional goniometer); 3) user satisfaction (Health Care Satisfaction questionnaire); and 4) cost of services to the public healthcare system. The difference between the two groups will be compared using a t-test or a chi-squared test, and through a cost-effectiveness economic analysis. DISCUSSION: We hypothesize that in-home telerehabilitation will provide a good alternative to conventional rehabilitation, in terms of its efficacy, simplicity, patient satisfaction, and low associated costs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02425267. April 22(nd), 2015.

4.
Can J Surg ; 59(2): 123-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27007093

RESUMO

BACKGROUND: The Ankle Osteoarthritis Scale (AOS) is a self-administered score specific for ankle osteoarthritis (OA) with excellent reliability and strong construct and criterion validity. Many recent randomized multicentre trials have used the AOS, and the involvement of the French-speaking population is limited by the absence of a French version. Our goal was to develop a French version and validate the psychometric properties to assure equivalence to the original English version. METHODS: Translation was performed according to American Association of Orthopaedic Surgeons (AAOS) 2000 guidelines for cross-cultural adaptation. Similar to the validation process of the English AOS, we evaluated the psychometric properties of the French version (AOS-Fr): criterion validity (AOS-Fr v. Western Ontario and McMaster Universities Arthritis Index [WOMAC] and SF-36 scores), construct validity (AOS-Fr correlation to single heel-lift test), and reliability (AOS-Fr test-retest). Sixty healthy individuals tested a prefinal version of the AOS-Fr for comprehension, leading to modifications and a final version that was approved by C. Saltzman, author of the AOS. We then recruited patients with ankle OA for evaluation of the AOS-Fr psychometric properties. RESULTS: Twenty-eight patients with ankle OA participated in the evaluation. The AOS-Fr showed strong criterion validity (AOS:WOMAC r = 0.709 and AOS:SF-36 r = -0.654) and construct validity (r = 0.664) and proved to be reliable (test-retest intraclass correlation coefficient = 0.922). CONCLUSION: The AOS-Fr is a reliable and valid score equivalent to the English version in terms of psychometric properties, thus is available for use in multicentre trials.


CONTEXTE: L'Ankle Osteoarthritis Scale (AOS) est une échelle d'auto-évaluation de l'arthrose de la cheville très fiable, et dont la validité conceptuelle et critérielle est élevée. De nombreux essais multicentriques randomisés récents ont utilisé l'AOS, mais faute d'une version française, la participation de la population francophone est limitée. Notre objectif était donc de créer une version française et d'en valider les propriétés psychométriques pour veiller à ce qu'elle soit équivalente à la version anglaise originale. MÉTHODES: La traduction a été effectuée conformément aux lignes directrices de 2000 de l'American Association of Orthopaedic Surgeons (AAOS) en matière d'adaptation interculturelle. Comme ce fut le cas pour le processus de validation de l'échelle anglaise, nous avons évalué les propriétés psychométriques de la version française (AOS-Fr) : validité critérielle (AOS-Fr contre le Western Ontario and McMaster Universities Arthritis Index [WOMAC] et les scores du questionnaire SF-36), validité conceptuelle (corrélation de l'AOS-Fr au test d'élévation sur la pointe d'un seul pied) et fiabilité (test­ retest de l'AOS-Fr). Soixante personnes en santé ont fait l'essai d'une version préfinale de l'AOS-Fr pour en évaluer l'intelligibilité, ce qui a entraîné des modifications, et la version définitive a été approuvée par C. Saltzman, auteur de l'AOS. Nous avons ensuite recruté des patients atteints d'arthrose de la cheville pour évaluer les propriétés psychométriques de l'AOS-Fr. RÉSULTATS: Vingt-huit patients atteints d'arthrose à la cheville ont participé à l'évaluation. Une forte validité critérielle (AOS:WOMAC : r = 0,709 et AOS:SF-36 : r = ­0,654) et conceptuelle (r = 0,664) a été mise en évidence, et l'échelle s'est avérée fiable (coefficient de corrélation intraclasse = 0,922 pour le test­retest). CONCLUSION: L'AOS-Fr est une échelle fiable et valide équivalente à la version anglaise sur le plan des propriétés psychométriques; elle peut donc être utilisée pour les essais multicentriques.


Assuntos
Articulação do Tornozelo , Idioma , Osteoartrite/diagnóstico , Índice de Gravidade de Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Canadá , Comparação Transcultural , Características Culturais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicações , Psicometria , Reprodutibilidade dos Testes , Autorrelato
5.
Gerontology ; 62(5): 477-90, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26812523

RESUMO

BACKGROUND: Healthy elderly individuals are particularly prone to catastrophic events at any moment of their lives. One stressful event for individuals aged 65 and older is a fall that results in a fracture of the hip (HF). HF causes a state of inflammation that may affect immune responses. In this connection, we have reported that HF induced alterations in neutrophil functions. OBJECTIVE: To assess the impact of HF on classical (cM), intermediate (iM) and non-classical (ncM) monocyte subsets. METHODS: Distribution, functions (chemotaxis, phagocytosis, superoxide production and cytokine production), phenotype and activation (NF-x03BA;B and PI3K) were evaluated in monocyte subsets before surgery and 6 weeks and 6 months after the event. RESULTS: The distribution of cM and ncM was unchanged, but iM transiently increased before surgery. Sustained increases (iM response to CCL2 and CX3CL1) and decreases (cM and ncM response to CCL2) in chemotaxis were observed. Phagocytosis and superoxide production were impaired in cM but not in iM or ncM. Sustained expression of HLA-DR occurred in cM but not in iM and ncM. Sustained decreased expression of CD11b occurred only in ncM. Sustained decreases (cM and ncM) and increases (iM) in CCR2 expression were observed. An elevated expression of CX3CR1 was found only in iM. cM produced elevated quantities of TNFα. There was a transient oxidative burst of production before surgery in iM and a sustained decrease in ncM. IL-10 production was severely impaired in cM and decreased in iM prior to surgery. Sustained activation (cM), inhibition (ncM) and transient activation (iM) of NF-x03BA;B were observed. Activation of PI3K was severely impaired in cM and ncM but was sustained in iM. CONCLUSION: HF had more impact on cM and ncM functions than on iM. HF triggered a switch in cM functions from phagocytic to inflammatory elevated TNFα-producing cells. These changes may impact clinical outcomes of HF with respect to inflammation, opportunistic infections and physical recovery.


Assuntos
Envelhecimento/fisiologia , Fraturas do Quadril , Monócitos , Fator de Necrose Tumoral alfa/análise , Idoso , Quimiotaxia/fisiologia , Citocinas/metabolismo , Feminino , Fraturas do Quadril/metabolismo , Fraturas do Quadril/patologia , Humanos , Estudos Longitudinais , Masculino , Monócitos/patologia , Monócitos/fisiologia , Período Perioperatório , Fagocitose/fisiologia , Fosfatidilinositol 3-Quinases/análise , Superóxidos/metabolismo
6.
Exp Gerontol ; 65: 58-68, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25797136

RESUMO

BACKGROUND: Fracture of the hip (HF) is a significant cause of morbidity and mortality in elderly individuals. HF is an acute stress that triggers a state of inflammation which may affect immune responses and physical recovery. METHODS: Longitudinal study of the impact of HF on the functions of polymorphonuclear neutrophils (PMNs) in elderly subjects. Data were recorded prior to surgery, 6weeks and 6months later. RESULTS: PMN functions were severely impaired shortly after HF (chemotaxis, phagocytosis, superoxide production) but there was a time-related recovery of some PMN functions (chemotaxis, phagocytosis) over time, except in the case of superoxide production. Whereas FcγRII (CD32) expression remained unchanged, FcγRIII (CD16) increased from low values before surgery to levels of controls 6months post-surgery. This was also the case for the C5a complement receptor and CD11b. TLR2 and TLR4 expressions were unchanged. Cytokine and chemokine secretions by stimulated PMN were altered. TNFα and IL-10 secretions were increased following HF but IL-8 secretion was decreased. Impaired PMN functions prior to surgery were related to alterations in PI3K and NF-κB signaling pathways. Recovery of these functions paralleled increased PI3K activity, although superoxide production remained low. Sustained activation of the NF-κB pathway by TNFα has been reported to involve upregulation of IKKß kinase activity. Activated IKKß kinase inhibits ERK1/2 and results in concomitant downstream inhibition of NADPH oxidase complex which can account for sustained impaired production of ROS in HF patients. CONCLUSION: Our data showed that the stress caused by HF negatively affects initial PMN responses shortly after the event and that may negatively influence clinical outcomes such as resolving long-term inflammation and recovery, as well as explaining susceptibility to opportunistic infections.


Assuntos
Quimiotaxia/imunologia , Fraturas do Quadril , Neutrófilos , Procedimentos Ortopédicos/reabilitação , Fagocitose/imunologia , Complicações Pós-Operatórias , Idoso , Idoso de 80 Anos ou mais , Canadá , Estudos de Casos e Controles , Feminino , Fraturas do Quadril/metabolismo , Fraturas do Quadril/patologia , Fraturas do Quadril/reabilitação , Fraturas do Quadril/cirurgia , Humanos , Inflamação/metabolismo , Interleucina-10/metabolismo , Interleucina-8/metabolismo , Masculino , Neutrófilos/metabolismo , Neutrófilos/patologia , Procedimentos Ortopédicos/métodos , Período Perioperatório , Complicações Pós-Operatórias/metabolismo , Complicações Pós-Operatórias/patologia , Estudos Prospectivos , Receptores de IgG/metabolismo , Recuperação de Função Fisiológica/imunologia , Superóxidos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
7.
J Pediatr Orthop ; 34(8): 774-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24787301

RESUMO

STUDY DESIGN: This was a prospective blinded validity and reliability analysis. OBJECTIVE: The aim of this study was validation and reliability evaluation of the Scoligauge iPhone app. BACKGROUND: The scoliometer is used to clinically measure the rib hump in scoliosis as a means to evaluate the axial trunk rotation. The increasing availability of smartphone with built-in accelerometer led to the development of a vast number of applications to measure angles. Of these, the Scoligauge mimics a scoliometer. The aim of this study was to compare the validity of the Scoligauge iPhone application without an associated adapter with the traditional scoliometer and to test the reliability of the application in a clinical setting. METHODS: Two observers measured the rib hump deformity on 34 consecutive patients with idiopathic scoliosis with an average Cobb angle of 24.2 ± 13.5 degrees (range, 4 to 65 degrees). Measurements were made with an iPhone without the adapter and with a scoliometer. The validity as well as the interobserver and intraobserver reliability were calculated using the intraclass coefficient (ICC) and the Bland-Altman test. RESULTS: The mean difference between the scoliometer and the Scoligauge application was 0.4 degrees [95% confidence interval (CI) of ± 3.1 degrees] with an ICC of 0.947 (P < 0.001). The intraobserver and interobserver ICC were 0.961 (P < 0.001) and 0.901 (P < 0.001), respectively. The mean intraobserver difference was 0.0 degrees (95% CI of ± 2.7 degrees) and the mean interobserver difference was 0.1 degrees (95% CI of ± 4.4 degrees). CONCLUSIONS: The intraobserver and interobserver reliability of the Scoligauge iPhone app, as well as its validity compared with the scoliometer, are excellent. The mean differences between measurements are small and clinically not significant. Thus, the Scoligauge application is valid for clinical evaluation even without special adapter. LEVEL OF EVIDENCE: Level I (Diagnostic Study).


Assuntos
Aplicativos Móveis , Costelas/patologia , Escoliose/patologia , Adolescente , Telefone Celular , Criança , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
8.
EMBO J ; 30(19): 3947-61, 2011 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-21841772

RESUMO

Chromatin represents a repressive barrier to the process of ligand-dependent transcriptional activity of nuclear receptors. Here, we show that H3K27 methylation imposes ligand-dependent regulation of the oestrogen receptor α (ERα)-dependent apoptotic response via Bcl-2 in breast cancer cells. The activation of BCL2 transcription is dependent on the simultaneous inactivation of the H3K27 methyltransferase, EZH2, and the demethylation of H3K27 at a poised enhancer by the ERα-dependent recruitment of JMJD3 in hormone-dependent breast cancer cells. We also provide evidence that this pathway is modified in cells resistant to anti-oestrogen (AE), which constitutively express BCL2. We show that the lack of H3K27 methylation at BCL2 regulatory elements due to the inactivation of EZH2 by the HER2 pathway leads to this constitutive activation of BCL2 in these AE-resistant cells. Our results describe a mechanism in which the epigenetic state of chromatin affects ligand dependency during ERα-regulated gene expression.


Assuntos
Apoptose , Receptor alfa de Estrogênio/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/metabolismo , Metilação de DNA , Elementos Facilitadores Genéticos , Feminino , Regulação Neoplásica da Expressão Gênica , Glutationa Transferase/metabolismo , Humanos , Ligantes , Modelos Biológicos
9.
Cell Cycle ; 9(2): 364-70, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20023423

RESUMO

We recently showed that histone H2A.Z, as well as members of the ATP-dependent p400 chromatin remodeling complex (p400.com), are essential components of estrogen receptor alpha (ERalpha) signaling. More specifically, we showed that H2A.Z and p400.com are incorporated into the promoter regions of ERalpha target genes only upon gene induction, and also in a cyclic fashion. RNAi-mediated cellular depletion of H2A.Z and p400.com strongly impedes estrogen-dependent growth of breast cancer cells as well as strongly affect ERalpha-target gene expression. Two mechanisms emerged from our studies of how H2A.Z incorporation within ERalpha-target regulatory regions can actually regulate estrogen-mediated signaling: (1) by stabilizing nucleosomes within the translational DNA axis, a process that allows general transcription factors to be efficiently recruited to promoter regions; (2) by allowing estrogen-responsive enhancer function. In the current study, we now show that in MCF7 cells, ectopic overexpression of H2A.Z increases proliferation, and such in conditions where estrogen levels are low. Also, immunohistochemical studies of breast cancer biopsies show that the presence of H2A.Z correlates highly with that of ERalpha, but is associated with high-grade ER-negative cancers. Finally we show that ERalpha directly associates to the H2A.Z promoter, and consequently modulates its expression. Our study provides a possible link between H2A.Z and endocrine resistance by showing that H2A.Z overexpression leads to increased growth, particularly when estrogen levels are very low.


Assuntos
Neoplasias da Mama/metabolismo , Histonas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Feminino , Fase G1 , Histonas/genética , Humanos , Regiões Promotoras Genéticas , Fase S
10.
Genes Dev ; 23(13): 1522-33, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19515975

RESUMO

Incorporation of H2A.Z into the chromatin of inactive promoters has been shown to poise genes for their expression. Here we provide strong evidence that H2A.Z is incorporated into the promoter regions of estrogen receptor (ERalpha) target genes only upon gene induction, and that, in a cyclic pattern. Moreover, members of the human H2A.Z-depositing complex, p400, also follow the same gene recruitment kinetics as H2A.Z. Importantly, cellular depletion of H2A.Z or p400 leads to a severe defect in estrogen signaling, including loss of estrogen-specific cell proliferation. We find that incorporation of H2A.Z within TFF1 promoter chromatin allows nucleosomes to adopt preferential positions along the DNA translational axis. Finally, we provide evidence that H2A.Z is essential to allow estrogen-responsive enhancer function. Taken together, our results provide strong mechanistic insight into how H2A.Z regulates ERalpha-mediated gene expression and provide a novel link between H2A.Z-p400 and ERalpha-dependent gene regulation and enhancer function.


Assuntos
Adenosina Trifosfatases/metabolismo , Histonas/metabolismo , Regiões Promotoras Genéticas/genética , Receptores de Estrogênio/fisiologia , Transdução de Sinais , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/metabolismo , Estrogênios/fisiologia , Regulação da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Histonas/genética , Humanos , Ligantes , Nucleossomos/genética , Receptores de Estrogênio/genética , Fator Trefoil-1 , Proteínas Supressoras de Tumor/genética
11.
Methods Mol Biol ; 543: 243-51, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19378170

RESUMO

The ensemble of the genes in the mammalian genome is organized into a structure of DNA and proteins known as chromatin. The control of gene expression by the proteins that bind to chromatin regulates many cell processes, such as differentiation and proliferation. Transcription of protein-encoding genes in mammalian cells is performed by the concerted action of the RNA polymerase II holoenzyme, transcription factors, co-activator complexes that bind to the promoter areas of genes. In addition, different proteins can interact with these complexes and chromatin to create a repressive state. In order to fundamentally understand transcriptional control, it is important to define the areas that these proteins will bind. Classical laboratory techniques unable to provide distinct locations of these factors have now been replaced by the chromatin immunoprecipitation (ChIP) assay. The ChIP technique allows us to isolate chromatin along with its associated proteins from cells and analyse the binding sites of specific proteins and complexes at high resolution.


Assuntos
Imunoprecipitação da Cromatina/métodos , Animais , Extratos Celulares , Linhagem Celular , Cromatina/metabolismo , Reagentes de Ligações Cruzadas/química , DNA/metabolismo , Eletroforese em Gel de Ágar , Formaldeído/química , Proteínas/metabolismo , Sonicação
12.
Methods Mol Biol ; 543: 281-91, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19378173

RESUMO

The basic repeating unit of chromatin, the nucleosome, is known to play a critical role in regulating the process of gene transcription. The positioning of nucleosomes on a promoter is a significant determinant in its responsiveness to gene-inducing signals. For example, positioning and subsequent mobilization of nucleosomes can regulate the access of various DNA factors to underlying DNA templates. Several mechanisms have been proposed to direct the process of nucleosome displacement such as chemical histone modifications, ATP-dependent remodelling, and the incorporation of histone variants. Thus, rather than being an inert molecular structure, chromatin is highly dynamic in response to the transcription process. In this section, we describe two methodologies that allow the determination of exact nucleosome positioning within specific gene regions.


Assuntos
Biologia Molecular/métodos , Nucleossomos/metabolismo , Animais , DNA/isolamento & purificação , Nuclease do Micrococo/metabolismo , Reação em Cadeia da Polimerase , Saccharomyces cerevisiae/citologia
13.
Biochem Cell Biol ; 87(1): 179-88, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19234533

RESUMO

The mammalian genome is organized into a structure of DNA and proteins known as chromatin. In general, chromatin presents a barrier to gene expression that is regulated by several pathways, namely by the incorporation of histone variants into the nucleosome. In yeast, H2A.Z is an H2A histone variant that is incorporated into nucleosomes as an H2A.Z/H2B dimer by the Swr1 complex and by the SRCAP and p400/Tip60 complexes in mammalian cells. H2A.Z has been associated with the poising of genes for transcriptional activation in the yeast model system, and is essential for development in higher eukaryotes. Recent studies in our laboratory have demonstrated a p400-dependent deposition of H2A.Z at the promoter of p21WAF1/CIP1, a consequence that prevents the activation of the gene by p53, thereby inhibiting p53-dependent replicative senescence, a form of cell-cycle arrest crucial in the prevention of carcinogenic transformation of cells. Moreover, H2A.Z is overexpressed in several different types of cancers, and its overexpression has been associated functionally with the proliferation state of cells. Therefore, we suggest that H2A.Z is an important regulator of gene expression, and its deregulation may lead to the increased proliferation of mammalian cells.


Assuntos
Regulação da Expressão Gênica , Histonas/metabolismo , Animais , Proliferação de Células , Senescência Celular , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Transporte Proteico
14.
Biochem Biophys Res Commun ; 328(2): 461-70, 2005 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-15694370

RESUMO

We have previously shown that the transcription factor C/EBP delta is involved in the intestinal inflammatory response. C/EBP delta regulates several inflammatory response genes, such as haptoglobin, in the rat intestinal epithelial cell line IEC-6 in response to IL-1. However, the different C/EBP delta domains involved in IL-1 beta-mediated transcriptional activation and the kinases implicated have not been properly defined. To address this, we determined the role of the p38 MAP kinase in the regulation of C/EBP delta transcriptional activity. The IL-1-dependent induction of the acute phase protein gene haptoglobin in IEC-6 cells was decreased in response to the p38 MAP kinase inhibitor SB203580, as determined by Northern blot. Transcriptional activity of C/EBP delta was repressed by the specific inhibitor of the p38 MAP kinase, as assessed by transient transfection assays. Mutagenesis studies and transient transfection assays revealed an important domain for transcriptional activation between amino acids 70 and 108. This domain overlapped with a docking site for the p38 MAP kinase, between amino acids 75 and 85, necessary to insure C/EBP delta phosphorylation. Deletion of this domain led to a decrease in basal transcriptional activity of C/EBP delta and in p300-dependent transactivation, as assessed by transient transfection assays, and in IL-1-dependent haptoglobin induction. This unusual arrangement of a kinase docking site within a transactivation domain may functionally be important for the regulation of C/EBP delta transcriptional activity.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/química , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Interleucina-1/farmacologia , Mucosa Intestinal/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Sítios de Ligação , Proteínas Estimuladoras de Ligação a CCAAT/genética , Linhagem Celular , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Mutagênese Sítio-Dirigida , Ligação Proteica , Ratos , Relação Estrutura-Atividade , Fator de Transcrição CHOP , Fatores de Transcrição/genética , Ativação Transcricional/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/química
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