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1.
J Med Imaging Radiat Sci ; 53(4S): S93-S99, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35850924

RESUMO

Healthcare worker burnout is a well-established phenomenon known to affect an individual's mental state, and has been shown to be diminished amongst individuals with higher levels of resilience. From a leadership perspective, practices that drive and inspire others to demonstrate resilience and surpass their own expectations fosters a resilient culture and allows employees to view adversity as an opportunity while knowing that support is omnipresent. In this paper, we describe and evaluate the outcomes of a virtual organizational intervention during the COVID-19 pandemic aimed to reduce healthcare staff burnout, and improve their levels of resilience, well-being, and self-compassion. Participants reported the workshops were relevant and provided strategies for wellness that were easy to incorporate into their daily routine. By nurturing one's own personal well-being through resiliency strategies learned in this educational series, staff can enact strategies to care for themselves, which in turn can contribute to organizational wide healthy work environments, improved health system outcomes, and enhanced patient care.


Assuntos
Esgotamento Profissional , COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Esgotamento Profissional/prevenção & controle , Pessoal de Saúde , Liderança
2.
Cell ; 178(5): 1159-1175.e17, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31442405

RESUMO

Expansion of CAG trinucleotide repeats in ATXN1 causes spinocerebellar ataxia type 1 (SCA1), a neurodegenerative disease that impairs coordination and cognition. While ATXN1 is associated with increased Alzheimer's disease (AD) risk, CAG repeat number in AD patients is not changed. Here, we investigated the consequences of ataxin-1 loss of function and discovered that knockout of Atxn1 reduced CIC-ETV4/5-mediated inhibition of Bace1 transcription, leading to increased BACE1 levels and enhanced amyloidogenic cleavage of APP, selectively in AD-vulnerable brain regions. Elevated BACE1 expression exacerbated Aß deposition and gliosis in AD mouse models and impaired hippocampal neurogenesis and olfactory axonal targeting. In SCA1 mice, polyglutamine-expanded mutant ataxin-1 led to the increase of BACE1 post-transcriptionally, both in cerebrum and cerebellum, and caused axonal-targeting deficit and neurodegeneration in the hippocampal CA2 region. These findings suggest that loss of ataxin-1 elevates BACE1 expression and Aß pathology, rendering it a potential contributor to AD risk and pathogenesis.


Assuntos
Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Ataxina-1/metabolismo , Encéfalo/metabolismo , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Ataxina-1/deficiência , Ataxina-1/genética , Encéfalo/patologia , Região CA2 Hipocampal/metabolismo , Região CA2 Hipocampal/patologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Feminino , Frequência do Gene , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Neurogênese , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Proto-Oncogênicas c-ets/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Repetições de Trinucleotídeos/genética , Regulação para Cima
3.
J Interprof Care ; 31(1): 122-124, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27918860

RESUMO

There is a growing interest in interprofessional care (IPC) as a way to provide better healthcare. However, it is difficult to evaluate this mode of healthcare delivery because identifying the appropriate measurement tool is a challenge, given the wide diversity in team composition and settings. Adding to this complexity is a key gap in the IPC evaluation research: the client/patient perspective. This perspective has generally not been included in the development of IPC healthcare team evaluations. The authors received a Canadian Institute for Health Research Planning Grant to host a one-day forum with 24 participants from across Canada representing health professions such as social work, medicine, occupational therapy, and physical therapy, in addition to researchers, client/patient advocates, and hospital administrators. The overarching goal of the forum was to create a demonstration project that supports the development of an IPC assessment tool for healthcare teams that includes clients/patients. Using a concept mapping methodology, participants discussed client/patient inclusion in IPC assessments, and through a consensus process, chose a demonstration project for further development.


Assuntos
Relações Interprofissionais , Equipe de Assistência ao Paciente/normas , Indicadores de Qualidade em Assistência à Saúde , Comportamento Cooperativo , Processos Grupais , Pessoal de Saúde/psicologia , Administradores Hospitalares/psicologia , Humanos , Pacientes/psicologia , Projetos de Pesquisa , Pesquisadores/psicologia , Assistentes Sociais/psicologia
4.
Neuron ; 80(2): 385-401, 2013 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-24055016

RESUMO

The generation of Aß, the main component of senile plaques in Alzheimer's disease (AD), is precluded by α-secretase cleavage within the Aß domain of the amyloid precursor protein (APP). We identified two rare mutations (Q170H and R181G) in the prodomain of the metalloprotease, ADAM10, that cosegregate with late-onset AD (LOAD). Here, we addressed the pathogenicity of these mutations in transgenic mice expressing human ADAM10 in brain. In Tg2576 AD mice, both mutations attenuated α-secretase activity of ADAM10 and shifted APP processing toward ß-secretase-mediated cleavage, while enhancing Aß plaque load and reactive gliosis. We also demonstrated ADAM10 expression potentiates adult hippocampal neurogenesis, which is reduced by the LOAD mutations. Mechanistically, both LOAD mutations impaired the molecular chaperone activity of ADAM10 prodomain. Collectively, these findings suggest that diminished α-secretase activity, owing to LOAD ADAM10 prodomain mutations, leads to AD-related pathology, strongly supporting ADAM10 as a promising therapeutic target for this devastating disease.


Assuntos
Proteínas ADAM/genética , Proteínas ADAM/fisiologia , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/fisiologia , Peptídeos beta-Amiloides/metabolismo , Predisposição Genética para Doença/genética , Proteínas de Membrana/genética , Proteínas de Membrana/fisiologia , Chaperonas Moleculares/metabolismo , Mutação de Sentido Incorreto/genética , Proteínas ADAM/metabolismo , Proteína ADAM10 , Doença de Alzheimer/enzimologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/genética , Animais , Encéfalo/enzimologia , Encéfalo/patologia , Encéfalo/fisiologia , Feminino , Gliose/patologia , Hipocampo/fisiologia , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Chaperonas Moleculares/genética , Neurogênese/genética , Placa Amiloide/metabolismo
5.
J Contin Educ Health Prof ; 31(1): 15-20, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21425355

RESUMO

BACKGROUND: Well before the H1N1 influenza, health care organizations worldwide prepared for a pandemic of unpredictable impact. Planners anticipated the possibility of a pandemic involving high mortality, high health care demands, rates of absenteeism rising up to 20-30% among health care workers, rationing of health care, and extraordinary psychological stress. METHOD: The intervention we describe emerged from the recognition that an expected influenza pandemic indicated a need to build resilience to maintain the health of individuals within the organization and to protect the capacity of the organization to respond to extraordinary demands. Training sessions were one component of a multifaceted approach to reducing stress through effective preparation and served as an evidence based platform for our hospital's response to the H1N1 pandemic. RESULTS: The training was delivered to more than 1250 hospital staff representing more than 22 departments within the hospital. The proportion of participants who felt better able to cope after the session (76%) was significantly higher than the proportion who felt prepared to deal confidently with the pandemic before the session (35%). Ten key themes emerged from our qualitative analysis of written comments, including family-work balance, antiviral prophylaxis, and mistrust or fear towards health care workers. CONCLUSIONS: Drawing on what we learned from the impact of SARS on our hospital, we had the opportunity to improve our organization's preparedness for the pandemic. Our results suggest that an evidence-based approach to interventions that target known mediators of distress and meet standards of continuing professional development is not only possible and relevant, but readily supportable by senior hospital administration.


Assuntos
Adaptação Psicológica , Educação Médica Continuada/organização & administração , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Pandemias , Recursos Humanos em Hospital/educação , Atitude do Pessoal de Saúde , Competência Clínica , Medicina Baseada em Evidências , Humanos , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Pandemias/estatística & dados numéricos , Recursos Humanos em Hospital/psicologia , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Pesquisa Qualitativa , Síndrome Respiratória Aguda Grave/psicologia , Estresse Psicológico/prevenção & controle
6.
Traffic ; 12(3): 330-48, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21143716

RESUMO

The Alzheimer's disease (AD)-associated ubiquilin-1 regulates proteasomal degradation of proteins, including presenilin (PS). PS-dependent γ-secretase generates ß-amyloid (Aß) peptides, which excessively accumulate in AD brain. Here, we have characterized the effects of naturally occurring ubiquilin-1 transcript variants (TVs) on the levels and subcellular localization of PS1 and other γ-secretase complex components and subsequent γ-secretase function in human embryonic kidney 293, human neuroblastoma SH-SY5Y and mouse primary cortical cells. Full-length ubiquilin-1 TV1 and TV3 that lacks the proteasome-interaction domain increased full-length PS1 levels as well as induced accumulation of high-molecular-weight PS1 and aggresome formation. Accumulated PS1 colocalized with TV1 or TV3 in the aggresomes. Electron microscopy indicated that aggresomes containing TV1 or TV3 were targeted to autophagosomes. TV1- and TV3-expressing cells did not accumulate other unrelated proteasome substrates, suggesting that the increase in PS1 levels was not because of a general impairment of the ubiquitin-proteasome system. Furthermore, PS1 accumulation and aggresome formation coincided with alterations in Aß levels, particularly in cells overexpressing TV3. These effects were not related to altered γ-secretase activity or PS1 binding to TV3. Collectively, our results indicate that specific ubiquilin-1 TVs can cause PS1 accumulation and aggresome formation, which may impact AD pathogenesis or susceptibility.


Assuntos
Doença de Alzheimer , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Presenilina-1/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Proteínas Relacionadas à Autofagia , Células Cultivadas , Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Fagossomos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica
7.
J Alzheimers Dis ; 22(2): 683-984, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20847415

RESUMO

Mounting evidence suggests that Alzheimer's disease (AD) is caused by the accumulation of the small peptide, amyloid-ß (Aß), a proteolytic cleavage product of amyloid-ß protein precursor (AßPP). Aß is generated through a serial cleavage of AßPP by ß- and γ-secretase. Aß40 and Aß42 are the two main components of amyloid plaques in AD brains, with Aß42 being more prone to aggregation. AßPP can also be processed by α-secretase, which cleaves AßPP within the Aß sequence, thereby preventing the generation of Aß. Little is currently known regarding the effects of cell density on AßPP processing and Aß generation. Here we assessed the effects of cell density on AßPP processing in neuronal and non-neuronal cell lines, as well as mouse primary cortical neurons. We found that decreased cell density significantly increases levels of Aß40, Aß42, total Aß, and the ratio of Aß42: Aß40. These results also indicate that cell density is a significant modulator of AßPP processing. Overall, these findings carry profound implications for both previous and forthcoming studies aiming to assess the effects of various conditions and genetic/chemical factors, e.g., novel drugs on AßPP processing and Aß generation in cell-based systems. Moreover, it is interesting to speculate whether cell density changes in vivo may also affect AßPP processing and Aß levels in the AD brain.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Contagem de Células , Fragmentos de Peptídeos/metabolismo , Processamento de Proteína Pós-Traducional , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/efeitos dos fármacos , Precursor de Proteína beta-Amiloide/genética , Animais , Contagem de Células/métodos , Células Cultivadas , Córtex Cerebral/citologia , Cricetinae , Cricetulus , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Camundongos , Peso Molecular , Neurônios/metabolismo , Estrutura Terciária de Proteína
8.
Early Interv Psychiatry ; 4(3): 243-50, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20712730

RESUMO

AIM: Although advances in the treatment of schizophrenia have been made, little is known about the process of recovery from first episode of schizophrenia (FES). To date, the study of recovery in the field of mental health has focused on long-term mental illness. This qualitative study addresses ways in which individuals with FES describe their process of recovery and how identified individuals (e.g. family members) describe their perceptions of and roles in the participant's process of recovery. METHODS: Charmaz's constructivist grounded theory methodology was used to interview 10 young adults twice who self-identified as recovering from FES. In addition, 10 individuals were identified who had influenced their recovery and were interviewed once, for a total of 30 interviews. Data collection sources included in-depth semi-structured interviews. Data analysis methods were consistent with Charmaz's methodology and included coding, and constant comparison of data. RESULTS: The results provide a substantive theory of the process of recovery from FES that is comprised of the following phases: 'Who they were prior to the illness', 'Lives interrupted: Encountering the illness', 'Engaging in services and supports', 'Re-engaging in life', 'Envisioning the future'; and the core category, 'Re-shaping an enduring sense of self', that occurred throughout all phases. A prominent feature of this model is that participants' enduring sense of self were reshaped rather than reconstructed throughout their recovery. CONCLUSIONS: This model of recovery from FES is unique, and as such, provides implications for clinical care, research and policy development for these young adults and their families.


Assuntos
Remissão Espontânea , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Autoimagem , Adulto , Família , Feminino , Humanos , Masculino , Modelos Psicológicos , Teoria Psicológica , Pesquisa Qualitativa
9.
Hum Mol Genet ; 18(20): 3987-96, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19608551

RESUMO

ADAM10, a member of a disintegrin and metalloprotease family, is an alpha-secretase capable of anti-amyloidogenic proteolysis of the amyloid precursor protein. Here, we present evidence for genetic association of ADAM10 with Alzheimer's disease (AD) as well as two rare potentially disease-associated non-synonymous mutations, Q170H and R181G, in the ADAM10 prodomain. These mutations were found in 11 of 16 affected individuals (average onset age 69.5 years) from seven late-onset AD families. Each mutation was also found in one unaffected subject implying incomplete penetrance. Functionally, both mutations significantly attenuated alpha-secretase activity of ADAM10 (>70% decrease), and elevated Abeta levels (1.5-3.5-fold) in cell-based studies. In summary, we provide the first evidence of ADAM10 as a candidate AD susceptibility gene, and report two potentially pathogenic mutations with incomplete penetrance for late-onset familial AD.


Assuntos
Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Doença de Alzheimer/enzimologia , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação , Proteína ADAM10 , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Animais , Células CHO , Cricetinae , Cricetulus , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Nucleotídeo Único
10.
J Mol Neurosci ; 38(1): 19-30, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18953672

RESUMO

Previous studies have implicated the unfolded protein response (UPR) in the pathogenesis of Alzheimer's disease (AD). We previously reported that DNA variants in the ubiquilin 1 (UBQLN1) gene increase the risk for AD. Since UBQLN1 has been shown to play a role in the UPR, we assessed the effects of overexpression and downregulation of UBQLN1 splice variants during tunicamycin-induced ER stress. In addition to previously described transcript variants, TV1 and TV2, we identified two novel transcript variants of UBQLN1 in brain: TV3 (lacking exons 2-4) and TV4 (lacking exon 4). Overexpression of TV1-3, but not TV4 significantly decreased the mRNA induction of UPR-inducible genes, C/EBP homologous protein (CHOP), BiP/GRP78, and protein disulfide isomerase (PDI) during the UPR. Stable overexpression of TV1-3, but not TV4, also significantly decreased the induction of CHOP protein and increased cell viability during the UPR. In contrast, downregulation of UBQLN1 did not affect CHOP mRNA induction, but instead increased PDI mRNA levels. These findings suggest that overexpression UBQLN1 transcript variants TV1-3, but not TV4, exert a protective effect during the UPR by attenuating CHOP induction and potentially increasing cell viability.


Assuntos
Doença de Alzheimer/metabolismo , Proteínas de Transporte/biossíntese , Proteínas de Ciclo Celular/biossíntese , Dobramento de Proteína , Proteínas Adaptadoras de Transdução de Sinal , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Relacionadas à Autofagia , Proteínas de Transporte/química , Proteínas de Transporte/genética , Caspase 3/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/fisiologia , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/genética , Humanos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Isomerases de Dissulfetos de Proteínas/biossíntese , Isomerases de Dissulfetos de Proteínas/química , Isomerases de Dissulfetos de Proteínas/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , Fator de Transcrição CHOP/biossíntese , Fator de Transcrição CHOP/química , Fator de Transcrição CHOP/genética , Tunicamicina/farmacologia
11.
Can J Public Health ; 99(6): 486-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19149392

RESUMO

We describe an evidence-based approach to enhancing the resilience of healthcare workers in preparation for an influenza pandemic, based on evidence about the stress associated with working in healthcare during the SARS outbreak. SARS was associated with significant long-term stress in healthcare workers, but not with increased mental illness. Reducing pandemic-related stress may best be accomplished through interventions designed to enhance resilience in psychologically healthy people. Applicable models to improve adaptation in individuals include Folkman and Greer's framework for stress appraisal and coping along with psychological first aid. Resilience is supported at an organizational level by effective training and support, development of material and relational reserves, effective leadership, the effects of the characteristics of "magnet hospitals," and a culture of organizational justice. Evidence supports the goal of developing and maintaining an organizational culture of resilience in order to reduce the expected stress of an influenza pandemic on healthcare workers. This recommendation goes well beyond the provision of adequate training and counseling. Although the severity of a pandemic is unpredictable, this effort is not likely to be wasted because it will also support the health of both patients and staff in normal times.


Assuntos
Planejamento em Desastres/organização & administração , Surtos de Doenças , Influenza Humana/epidemiologia , Saúde Ocupacional , Administração de Recursos Humanos em Hospitais/métodos , Recursos Humanos em Hospital/psicologia , Resiliência Psicológica , Síndrome Respiratória Aguda Grave/epidemiologia , Estresse Psicológico/prevenção & controle , Medicina Baseada em Evidências , Humanos , Influenza Humana/terapia , Ontário/epidemiologia , Cultura Organizacional , Síndrome Respiratória Aguda Grave/terapia , Justiça Social , Estresse Psicológico/etiologia
12.
J Biol Chem ; 281(43): 32240-53, 2006 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-16945923

RESUMO

Ubiquilin 1 (UBQLN1) is a ubiquitin-like protein, which has been shown to play a central role in regulating the proteasomal degradation of various proteins, including the presenilins. We recently reported that DNA variants in UBQLN1 increase the risk for Alzheimer disease, by influencing expression of this gene in brain. Here we present the first assessment of the effects of UBQLN1 on the metabolism of the amyloid precursor protein (APP). For this purpose, we employed RNA interference to down-regulate UBQLN1 in a variety of neuronal and non-neuronal cell lines. We demonstrate that down-regulation of UBQLN1 accelerates the maturation and intracellular trafficking of APP, while not interfering with alpha-, beta-, or gamma-secretase levels or activity. UBQLN1 knockdown increased the ratio of APP mature/immature, increased levels of full-length APP on the cell surface, and enhanced the secretion of sAPP (alpha- and beta-forms). Moreover, UBQLN1 knockdown increased levels of secreted Abeta40 and Abeta42. Finally, employing a fluorescence resonance energy transfer-based assay, we show that UBQLN1 and APP come into close proximity in intact cells, independently of the presence of the presenilins. Collectively, our findings suggest that UBQLN1 may normally serve as a cytoplasmic "gatekeeper" that may control APP trafficking from intracellular compartments to the cell surface. These findings suggest that changes in UBQLN1 steady-state levels affect APP trafficking and processing, thereby influencing the generation of Abeta.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Regulação para Baixo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas Relacionadas à Autofagia , Biotinilação , Proteínas de Transporte/química , Proteínas de Ciclo Celular/química , Linhagem Celular Tumoral , Células Cultivadas , Éxons , Fibroblastos/citologia , Fibroblastos/metabolismo , Transferência Ressonante de Energia de Fluorescência , Glioma/metabolismo , Glioma/patologia , Humanos , Imuno-Histoquímica , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Estrutura Terciária de Proteína , Transporte Proteico , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transfecção
13.
Amyloid ; 13(2): 86-92, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16911962

RESUMO

The study of amyloidogenic beta-amyloid precursor protein (AbetaPP) metabolism and amyloid beta protein (Abeta) production has been a major focus of Alzheimer's disease (AD) neuropathogenesis research. Cell transfection is a commonly employed method for assessing the effects of various genes on AbetaPP processing and Abeta production. Certain cell transfection reagents utilize lipid-based formulations that could potentially affect AbetaPP processing and Abeta production. Thus, we set out to assess the effects of cell transfection reagents with lipid formulations (TKO, FuGene6, RNAifect) on AbetaPP processing and Abeta level in H4 human neuroglioma cells overexpressing human AbetaPP. We found both TKO and RNAifect increase the protein levels of AbetaPP-C-terminal fragments (CTFs) and Abeta levels, while FuGene6 increases the protein levels of AbetaPP-CTFs without altering Abeta level. In contrast, electroporation-based cell transfection does not affect AbetaPP processing and Abeta production in our studies. These results suggest for the first time that lipid-based cell transfection reagents may artefactually affect AbetaPP processing and Abeta production, thereby confounding studies aimed at assessing the effects of transfected genes on AbetaPP metabolism.


Assuntos
Precursor de Proteína beta-Amiloide/biossíntese , Lipídeos/farmacologia , Proteínas Recombinantes/biossíntese , Transfecção , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/genética , Linhagem Celular Tumoral , Humanos , Lipídeos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Transfecção/métodos
14.
J Mol Neurosci ; 25(1): 67-77, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15781968

RESUMO

The gamma-secretase complex consists of PS1/PS2, nicastrin, APH-1a, and PEN-2. PS1 undergoes endoproteolytic processing to yield two fragments: PS1-NTF and PS1-CTF. Changes in PEN-2 levels have been shown previously to affect the endoproteolytic processing of wild-type (wt)-PS1. However, the effects of PEN-2 on the proteolytic processing of familial Alzheimer's disease (FAD) mutant forms of PS1 have not yet been reported. To determine whether PEN-2 affects the proteolytic processing of mutant PS1 in the same manner as that of wt-PS1, we established RNA interference (RNAi) for PEN-2 in H4 human neuroglioma cells stably transfected to express wt or FAD mutant forms of PS1 including L286V, A246E, and that lacking exon 9 (Delta9). As expected, in H4 cells expressing wt-PS1, RNAi for PEN-2 increased levels of PS1-FL and attenuated PS1 endoproteolysis. Likewise, in cells expressing PS1 with the FAD missense mutations, L286V and A246E, RNAi for PEN-2 increased PS1-FL and reduced PS1 endoproteolysis. However, in H4 cells stably transfected to express the FAD-linked Delta9 mutation (PS1 lacking exon 9), RNAi for PEN-2 did not increase but, instead, decreased PS1-FL. In contrast, RNAi for nicastrin and APH-1a decreased PS1-FL in H4 cells expressing either wt-PS1 or Delta9-PS1. In summary, the metabolism of wt-PS1 and FAD-linked Delta9-PS1 is specifically and differentially affected by loss of function of PEN-2.


Assuntos
Inativação Gênica , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Mutação , Interferência de RNA , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide , Linhagem Celular Tumoral , Endopeptidases , Humanos , Glicoproteínas de Membrana/genética , Proteínas de Membrana/genética , Peptídeo Hidrolases , Presenilina-1 , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
15.
J Biol Chem ; 280(15): 15413-21, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15699037

RESUMO

Processing of the beta-amyloid precursor protein (APP) plays a key role in Alzheimer disease neuropathogenesis. APP is cleaved by beta- and alpha-secretase to produce APP-C99 and APP-C83, which are further cleaved by gamma-secretase to produce amyloid beta-protein (Abeta) and p3, respectively. APP adaptor proteins with phosphotyrosine-binding domains, including X11alpha (MINT1, encoded by gene APBA1) and X11beta (MINT2, encoded by gene APBA2), can bind to the conserved YENPTY motif in the APP C terminus. Overexpression of X11alpha and X11beta alters APP processing and Abeta production. Here, for the first time, we have described the effects of RNA interference (RNAi) silencing of X11alpha and X11beta expression on APP processing and Abeta production. RNAi silencing of APBA1 in H4 human neuroglioma cells stably transfected to express either full-length APP or APP-C99 increased APP C-terminal fragment levels and lowered Abeta levels in both cell lines by inhibiting gamma-secretase cleavage of APP. RNAi silencing of APBA2 also lowered Abeta levels, but apparently not via attenuation of gamma-secretase cleavage of APP. The notion of attenuating gamma-secretase cleavage of APP via the APP adaptor protein X11alpha is particularly attractive with regard to therapeutic potential given that side effects of gamma-secretase inhibition due to impaired proteolysis of other gamma-secretase substrates, e.g. Notch, might be avoided.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Peptídeos beta-Amiloides/química , Precursor de Proteína beta-Amiloide/química , Proteínas de Transporte/genética , Inativação Gênica , Proteínas do Tecido Nervoso/genética , Interferência de RNA , Motivos de Aminoácidos , Peptídeos beta-Amiloides/biossíntese , Western Blotting , Caderinas , Linhagem Celular Tumoral , Eletroporação , Ensaio de Imunoadsorção Enzimática , Humanos , Ligação Proteica , RNA Interferente Pequeno/metabolismo , Fatores de Tempo , Transfecção
16.
J Biol Chem ; 279(33): 34130-7, 2004 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-15184387

RESUMO

Familial Alzheimer's disease mutations in the presenilin 1 gene (PSEN1) have been previously shown to potentiate caspase activation and apoptosis in transfected cells and transgenic mice. However, the mechanism underlying this effect is not known. We set out to determine whether cellular sensitivity to caspase activation could be affected by modulating presenilin 1 (PS1) processing. PS1 processing was altered using RNA interference (RNAi) aimed at silencing the expression of the genes encoding the four components of the gamma-secretase complex, PSEN1, APH-1, PEN-2, and nicastrin. RNAi for these genes was carried out in naive H4 human neuroglioma cells, as well as H4 cell lines overexpressing either wild-type PSEN1 or the Familial Alzheimer's disease mutant PSEN1-Delta9 (PS1-mutant), that were induced to undergo apoptosis. In wild-type PSEN1 cells, RNAi for PEN-2, as expected, increased levels of full-length PS1 (PS1-FL) and decreased PS1 endoproteolysis. This was accompanied by potentiated caspase-3 activation in response to an apoptotic stimulus. In contrast, nicastrin RNAi, which only decreased levels of PS1-amino-terminal fragment and did not affect PS1-FL levels, had no effect on caspase-3 activation during apoptosis. Surprisingly, in the PS1-mutant cells, RNAi for PEN-2 (and APH-1) did not increase but instead reduced the levels of PS1-FL deleted for exon 9. In turn, this was accompanied by attenuated caspase-3 activation in response to an apoptotic stimulus. Finally, in naive H4 cells, PSEN1 RNAi also attenuated caspase-3 activation in response to an apoptotic stimulus. Collectively, these findings indicate that cellular sensitivity to caspase activation correlates with overall PS1 protein levels, particularly with levels of FL-PS1.


Assuntos
Caspases/metabolismo , Endopeptidases/metabolismo , Inativação Gênica , Proteínas de Membrana/metabolismo , Interferência de RNA , Secretases da Proteína Precursora do Amiloide , Animais , Apoptose , Ácido Aspártico Endopeptidases , Western Blotting , Caspase 3 , Linhagem Celular Tumoral , Ativação Enzimática , Éxons , Deleção de Genes , Humanos , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Mutação , Peptídeo Hidrolases , Presenilina-1 , Estrutura Terciária de Proteína , RNA Interferente Pequeno/metabolismo
17.
Perspect Psychiatr Care ; 40(1): 20-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15147049

RESUMO

TOPIC: The use of Heinz Kohut's self-psychology perspective in understanding and providing care for patients with narcissistic personality disorder (NPD). PURPOSE: To describe how nurses can apply the self-psychology perspective as a way to understand the development of self for individuals with NPD and to enhance the therapeutic relationship between the nurse and patient with NPD. SOURCES: Theoretical literature; the author's clinical experience. CONCLUSIONS: Self-psychology provides nurses with a theoretical perspective that can enhance the interpersonal relationship between the nurse and patient with NPD.


Assuntos
Papel do Profissional de Enfermagem , Transtornos da Personalidade , Enfermagem Psiquiátrica/métodos , Psicologia do Self , Adulto , Criança , Contratransferência , Transtorno Depressivo/etiologia , Transtorno Depressivo/enfermagem , Transtorno Depressivo/psicologia , Empatia , Humanos , Masculino , Relações Enfermeiro-Paciente , Apego ao Objeto , Participação do Paciente , Transtornos da Personalidade/complicações , Transtornos da Personalidade/enfermagem , Transtornos da Personalidade/psicologia , Filosofia em Enfermagem , Psicologia da Criança , Autoimagem , Transferência Psicológica
18.
Neurodegener Dis ; 1(1): 29-37, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16908971

RESUMO

BACKGROUND: At least half of all cases of early onset (<60) familial Alzheimer's disease (FAD) are caused by any of over 150 mutations in three genes: the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2). Mutant forms of PS1 have been shown to sensitize cells to apoptotic cell death. OBJECTIVE: We investigated the effects of hypocapnia, a risk factor for both cognitive and neurodevelopment deficits, on caspase-3 activation, apoptosis, and amyloid beta-protein (Abeta) production, and assessed the influence of the PS1Delta9 FAD mutation on these effects. METHOD: For this purpose, we exposed stably transfected H4 human neuroglioma cells to conditions consistent with hypocapnia (PCO2<40 mm Hg) and hypocapnia plus hypoxia (PO2<21%). RESULTS: Hypocapnia (20 mm Hg CO2 for 6 h) induced caspase-3 activation and apoptosis; the PS1Delta9 FAD mutation significantly potentiated these effects. Moreover, the combination of hypocapnia (20 mm Hg CO2) and hypoxia (5%O2) induced caspase-3 activation and apoptosis in a synergistic manner. Hypocapnia (5 and 20 mm Hg CO2 for 6 h) also led to an increased Abeta production. CONCLUSION: The findings suggest that hypocapnia (e.g. during general anesthesia) could exacerbate AD neuropathogenesis.


Assuntos
Peptídeos beta-Amiloides/biossíntese , Apoptose/fisiologia , Caspases/metabolismo , Hipocapnia/fisiopatologia , Doença de Alzheimer/fisiopatologia , Western Blotting , Caspase 3 , Hipóxia Celular/fisiologia , Linhagem Celular Tumoral , Ativação Enzimática/fisiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Concentração de Íons de Hidrogênio , Proteínas de Membrana/genética , Mutação , Presenilina-1 , Transfecção
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