Perturbation with Intrabodies Reveals That Calpain Cleavage Is Required for Degradation of Huntingtin Exon 1

Background: Proteolytic processing of mutant huntingtin (mHtt), the protein that causes Huntington's disease (HD), is critical for mHtt toxicity and disease progression. mHtt contains several caspase and calpain cleavage sites that generate N-terminal fragments that are more toxic than full-length mHtt. Further processing is then required for the degradation of these fragments, which in turn, reduces toxicity. This unknown, secondary degradative process represents a promising therapeutic target for HD. Methodology/Principal Findings: We have used intrabodies, intracellularly expressed antibody fragments, to gain insight into the mechanism of mutant huntingtin exon 1 (mHDx-1) clearance. Happ1, an intrabody recognizing the proline-rich region of mHDx-1, reduces the level of soluble mHDx-1 by increasing clearance. While proteasome and macroautophagy inhibitors reduce turnover of mHDx-1, Happ1 is still able to reduce mHDx-1 under these conditions, indicating Happ1-accelerated mHDx-1 clearance does not rely on these processes. In contrast, a calpain inhibitor or an inhibitor of lysosomal pH block Happ1-mediated acceleration of mHDx-1 clearance. These results suggest that mHDx-1 is cleaved by calpain, likely followed by lysosomal degradation and this process regulates the turnover rate of mHDx-1. Sequence analysis identifies amino acid (AA) 15 as a potential calpain cleavage site. Calpain cleavage of recombinant mHDx-1 in vitro yields fragments of sizes corresponding to this prediction. Moreover, when the site is blocked by binding of another intrabody, V_L12.3, turnover of soluble mHDx-1 in living cells is blocked. Conclusions/Significance: These results indicate that calpain-mediated removal of the 15 N-terminal AAs is required for the degradation of mHDx-1, a finding that may have therapeutic implications

Segurança do paciente em Unidades de Terapia Intensiva: desenvolvimento de um projeto de pesquisa

RESUMO Objetivo Relatar a experiência sobre os diferentes processos envolvidos no desenvolvimento de um Projeto de Pesquisa em Segurança do Paciente em Unidades de Terapia Intensiva. Método Estudo com delineamento misto: coorte histórica para a coleta dos dados dos pacientes e eventos adversos/incidentes e transversal para a coleta dos dados da equipe de enfermagem. A coleta de dados ocorreu durante 90 dias, em 2012, no Instituto Central do Hospital das Clínicas da Universidade de São Paulo e o Hospital Universitário da Universidade de São Paulo. Processos desenvolvidos A pesquisa envolveu diversas etapas para sua efetivação: implantação doNursing Activities Score (NAS) no Instituto Central do Hospital das Clínicas da Universidade de São Paulo, desenvolvimento de sistema de banco de dados, digitalização de prontuários, treinamento de monitores, extração e carga de dados dos pacientes e coleta de dados durante a passagem de plantão, prontuários. Considerações finais Treinamentos, comprometimento dos pesquisadores e parceria com profissionais da tecnologia da informação foram fundamentais para a qualidade dos resultados obtidos e da produção científica alcançada. Espera-se que esse relato de experiência possa orientar e encorajar os pesquisadores a realizar pesquisas complexas que contribuam para a construção do conhecimento na enfermagem e saúde

Estresse e Burnout entre residentes multiprofissionais

OBJECTIVE: To identify associations between high-stress and burnout syndrome in multidisciplinary residents from a federal university in Rio Grande do Sul, Brazil. METHOD: This is an analytical, cross-sectional and quantitative study. A socio-demographic questionnaire, the Work Stress Scale and the Maslach Burnout Inventory-Health Services Survey (MBI-HSS) were applied to 37 residents between April and June 2011. P-valuesOBJETIVO: Identificar la asociación entre alto estrés y Burnout en residentes Multiprofesionales de una universidad federal de Rio Grande do Sul. MÉTODO: se trata de un estudio analítico, transversal, cuantitativo. Se aplicaron un formulario de datos socio-demográficos, la Escala de Estrés en el Trabajo y el Maslach Burnout Inventory- Health Services en 37 residentes entre Abril y Junio de 2011. Valores de pOBJETIVO: identificar a associação entre alto estresse e Burnout em residentes multiprofissionais de uma universidade federal do Rio Grande do Sul. MÉTODO: trata-se de estudo analítico, transversal, quantitativo. Aplicaram-se um formulário de dados socio demográficos, a Escala de Estresse no Trabalho e o Maslach Burnout Inventory-Human Services Survey (MBI-HSS) em 37 residentes entre abril e junho de 2011. Valores de

Peer Support Workers in Health:A Qualitative Metasynthesis of Their Experiences

Peer support models, where an individual has a specific illness or lifestyle experience and supports others experiencing similar challenges, have frequently been used in different fields of healthcare to successfully engage hard-to-reach groups. Despite recognition of their value, the impact of these roles on the peer has not been systematically assessed. By synthesising the qualitative literature we sought to review such an impact, providing a foundation for designing future clinical peer models.Systematic review and qualitative metasynthesis of studies found in Medline, CINAHL or Scopus documenting peer worker experiences.1,528 papers were found, with 34 meeting the criteria of this study. Findings were synthesised to reveal core constructs of reframing identity through reciprocal relations and the therapeutic use of self, enhancing responsibility.The ability of the Peer Support Worker to actively engage with other marginalised or excluded individuals based on their unique insight into their own experience supports a therapeutic model of care based on appropriately sharing their story. Our findings have key implications for maximising the effectiveness of Peer Support Workers and in contributing their perspective to the development of a therapeutic model of care

Revisiting Lynam's notion of the "fledgling psychopath": are HIA-CP children truly psychopathic-like?

<p>Abstract</p> <p>Background</p> <p>In his developmental model of emerging psychopathy, Lynam proposed that the "fledgling psychopath" is most likely to be located within a subgroup of children elevated in both hyperactivity/inattention/impulsivity (HIA) and conduct problems (CP). This approach has garnered some empirical support. However, the extent to which Lynam's model captures children who resemble psychopathy with regard to the core affective and interpersonal features remains unclear.</p> <p>Methods</p> <p>In the present study, we investigated this issue within a large community sample of youth (<it>N </it>= 617). Four groups (non-HIA-CP, HIA-only, CP-only, and HIA-CP), defined on the basis of teacher reports of the Strengths and Difficulties Questionnaire (SDQ), were compared with respect to parent-reported psychopathic-like traits and subjective emotional reactivity in response to unpleasant, emotionally-laden pictures from the International Affective Pictures System (IAPS).</p> <p>Results</p> <p>Results did not support Lynam's model. HIA-CP children did not appear most psychopathic-like on dimensions of callous-unemotional and narcissistic personality, nor did they report reduced emotional reactivity to the IAPS relative to the other children. Post-hoc regression analyses revealed a significant moderation such that elevated HIA weakened the association between CP and emotional underarousal.</p> <p>Conclusions</p> <p>Implications of these findings with regard to the development of psychopathy are discussed.</p

D-β-Hydroxybutyrate Is Protective in Mouse Models of Huntington's Disease

Abnormalities in mitochondrial function and epigenetic regulation are thought to be instrumental in Huntington's disease (HD), a fatal genetic disorder caused by an expanded polyglutamine track in the protein huntingtin. Given the lack of effective therapies for HD, we sought to assess the neuroprotective properties of the mitochondrial energizing ketone body, D-β-hydroxybutyrate (DβHB), in the 3-nitropropionic acid (3-NP) toxic and the R6/2 genetic model of HD. In mice treated with 3-NP, a complex II inhibitor, infusion of DβHB attenuates motor deficits, striatal lesions, and microgliosis in this model of toxin induced-striatal neurodegeneration. In transgenic R6/2 mice, infusion of DβHB extends life span, attenuates motor deficits, and prevents striatal histone deacetylation. In PC12 cells with inducible expression of mutant huntingtin protein, we further demonstrate that DβHB prevents histone deacetylation via a mechanism independent of its mitochondrial effects and independent of histone deacetylase inhibition. These pre-clinical findings suggest that by simultaneously targeting the mitochondrial and the epigenetic abnormalities associated with mutant huntingtin, DβHB may be a valuable therapeutic agent for HD

Targeting Huntington’s disease through histone deacetylases

Huntington’s disease (HD) is a debilitating neurodegenerative condition with significant burdens on both patient and healthcare costs. Despite extensive research, treatment options for patients with this condition remain limited. Aberrant post-translational modification (PTM) of proteins is emerging as an important element in the pathogenesis of HD. These PTMs include acetylation, phosphorylation, methylation, sumoylation and ubiquitination. Several families of proteins are involved with the regulation of these PTMs. In this review, I discuss the current evidence linking aberrant PTMs and/or aberrant regulation of the cellular machinery regulating these PTMs to HD pathogenesis. Finally, I discuss the evidence suggesting that pharmacologically targeting one of these protein families the histone deacetylases may be of potential therapeutic benefit in the treatment of HD