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BACKGROUND: Loss of smell and/or taste are cardinal symptoms of COVID-19. 'Long-COVID', persistence of symptoms, affects around one fifth of people. However, data regarding the clinical resolution of loss of smell and/or taste are lacking. In this study we assess smell and taste loss resolution at 4-6 week follow-up, aim to identify risk factors for persistent smell loss and describe smell loss as a feature of long-COVID in a community cohort in London with known SARS-CoV-2 IgG/IgM antibody status. We also compare subjective and objective smell assessments in a subset of participants. METHODS: Four hundred sixty-seven participants with acute loss of smell and/or taste who had undergone SARS-CoV-2 IgG/IgM antibody testing 4-6 weeks earlier completed a follow-up questionnaire about resolution of their symptoms. A subsample of 50 participants completed an objective olfactory test and results were compared to subjective smell evaluations. RESULTS: People with SARS-CoV-2 antibodies with an acute loss of sense of smell and taste were significantly less likely to recover their sense of smell/taste than people who were seronegative (smell recovery: 57.7% vs. 72.1%, p = 0.027. taste recovery 66.2% vs. 80.3%, p = 0.017). In SARS-CoV-2 positive participants, a higher percentage of male participants reported full resolution of smell loss (72.8% vs. 51.4%; p < 0.001) compared to female participants, who were almost 2.5-times more likely to have ongoing smell loss after 4-6 weeks (OR 2.46, 95%CI 1.47-4.13, p = 0.001). Female participants with SARS-CoV-2 antibodies and unresolved smell loss and unresolved taste loss were significantly older (> 40 years) than those who reported full resolution. Participants who experienced parosmia reported lower smell recovery rates and participants with distorted taste perception lower taste recovery rates. Parosmia had a significant association to unresolved smell loss (OR 2.47, 95%CI 1.54-4.00, p < 0.001). CONCLUSION: Although smell and/or taste loss are often transient manifestations of COVID-19, 42% of participants had ongoing loss of smell, 34% loss of taste and 36% loss of smell and taste at 4-6 weeks follow-up, which constitute symptoms of 'long-COVID'. Females (particularly > 40 years) and people with a distorted perception of their sense of smell/taste are likely to benefit from prioritised early therapeutic interventions. TRIALS REGISTRATION: ClinicalTrials.gov NCT04377815 Date of registration: 23/04/2020.
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Ageusia/etiología , Anticuerpos Antivirales/sangre , COVID-19/complicaciones , Trastornos del Olfato/etiología , Adulto , Estudios de Cohortes , Femenino , Humanos , Inmunoglobulina M/sangre , Londres , Masculino , Persona de Mediana Edad , Trastornos del Olfato/diagnóstico , SARS-CoV-2 , Factores Sexuales , Olfato , Encuestas y Cuestionarios , Resultado del TratamientoRESUMEN
BACKGROUND: Loss of smell and taste are commonly reported symptoms associated with coronavirus disease 2019 (COVID-19); however, the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in people with acute loss of smell and/or taste is unknown. The study aimed to determine the seroprevalence of SARS-CoV-2 antibodies in a community-based population with acute loss of smell and/or taste and to compare the frequency of COVID-19 associated symptoms in participants with and without SARS-CoV-2 antibodies. It also evaluated whether smell or taste loss are indicative of COVID-19 infection. METHODS AND FINDINGS: Text messages, sent via primary care centers in London, United Kingdom, invited people with loss of smell and/or taste in the preceding month, to participate. Recruitment took place between 23 April 2020 and 14 May 2020. A total of 590 participants enrolled via a web-based platform and responded to questions about loss of smell and taste and other COVID-19-related symptoms. Mean age was 39.4 years (SD ± 12.0) and 69.1% (n = 392) of participants were female. A total of 567 (96.1%) had a telemedicine consultation during which their COVID-19-related symptoms were verified and a lateral flow immunoassay test that detected SARS-CoV-2 immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies was undertaken under medical supervision. A total of 77.6% of 567 participants with acute smell and/or taste loss had SARS-CoV-2 antibodies; of these, 39.8% (n = 175) had neither cough nor fever. New loss of smell was more prevalent in participants with SARS-CoV-2 antibodies, compared with those without antibodies (93.4% versus 78.7%, p < 0.001), whereas taste loss was equally prevalent (90.2% versus 89.0%, p = 0.738). Seropositivity for SARS-CoV-2 was 3 times more likely in participants with smell loss (OR 2.86; 95% CI 1.27-6.36; p < 0.001) compared with those with taste loss. The limitations of this study are the lack of a general population control group, the self-reported nature of the smell and taste changes, and the fact our methodology does not take into account the possibility that a population subset may not seroconvert to develop SARS-CoV-2 antibodies post-COVID-19. CONCLUSIONS: Our findings suggest that recent loss of smell is a highly specific COVID-19 symptom and should be considered more generally in guiding case isolation, testing, and treatment of COVID-19. TRIALS REGISTRATION: ClinicalTrials.gov NCT04377815.
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Anticuerpos Antivirales/sangre , Infecciones por Coronavirus/complicaciones , Trastornos del Olfato/virología , Neumonía Viral/complicaciones , Trastornos del Gusto/virología , Adulto , Betacoronavirus , COVID-19 , Prueba de COVID-19 , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Londres , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/inmunología , Pruebas en el Punto de Atención , SARS-CoV-2 , Seroconversión , Estudios Seroepidemiológicos , Envío de Mensajes de TextoRESUMEN
Ageing is associated with the reduced performance of physiological processes and has been proposed as a major risk factor for disease. An age-related decline in stress response pathways has been widely documented in lower organisms. In particular, the heat shock response (HSR) becomes severely compromised with age in Caenorhabditis elegans. However, a comprehensive analysis of the consequences of ageing on the HSR in higher organisms has not been documented. We used both HS and inhibition of HSP90 to induce the HSR in wild-type mice at 3 and 22 months of age to investigate the extent to which different brain regions, and peripheral tissues can sustain HSF1 activity and HS protein (HSP) expression with age. Using chromatin immunoprecipitation, quantitative reverse transcription polymerase chain reaction, western blotting and enzyme linked immunosorbent assay (ELISA), we were unable to detect a difference in the level or kinetics of HSP expression between young and old mice in all brain regions. In contrast, we did observe an age-related reduction in chaperone levels and HSR-related proteins in the heart. This could result in a decrease in the protein folding capacity of old hearts with implications for age-related cardiac disorders.
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Envejecimiento/fisiología , Encéfalo/crecimiento & desarrollo , Corazón/crecimiento & desarrollo , Respuesta al Choque Térmico , Animales , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Factores de Transcripción del Choque Térmico , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Respuesta al Choque Térmico/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Miocardio/patología , Pliegue de Proteína , Piridonas/farmacología , Pirimidinas/farmacología , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
CONTEXT: There are limited comparative studies between one anastomosis gastric bypass (OAGB) versus Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on body composition and musculoskeletal health. OBJECTIVE: To compare changes in body composition, areal bone mineral density (aBMD), muscle strength, and physical function in the first year following OAGB, RYGB and SG within a UK-based healthcare setting. METHODS: This is a secondary analysis of the BARI-LIFESTYLE trial in 119 adults (77% women; mean±SD, age: 45.9±10.3 years; BMI: 43.6±5.5 kg/m2) who underwent OAGB (n=19), RYGB (n=39) and SG (n=61). Body composition and aBMD by dual energy x-ray absorptiometry, handgrip strength, sit-to-stand (STS) test and 6-minute walking test (6MWT) were assessed pre-surgery and at 12 months post-surgery. RESULTS: OAGB, RYGB, and SG exhibited similar reductions in body weight, body fat and lean mass (within-group comparisons, p<0.001). All surgery types were associated with reductions in aBMD at the total hip, femoral neck, and lumbar spine, which were more pronounced after OAGB and RYGB compared to SG (all p<0.03), though no difference between OAGB and RYGB. Despite reductions in absolute handgrip strength, relative handgrip strength, STS test and 6MWT improved post-surgery (all p<0.02), with no differences by surgical procedure. CONCLUSION: OAGB, RYGB, and SG resulted in comparable weight loss, changes in body composition and improvements in relative muscle strength and physical function. OAGB and RYGB, compared with SG, led to greater BMD reductions at clinically relevant sites. Future long-term studies should explore whether these BMD reductions translate into a greater fracture risk.
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OBJECTIVE: The study's aim was to investigate the impact of a 12-month adjunctive lifestyle intervention on weight loss and health outcomes after bariatric surgery. METHODS: A total of 153 participants (78.4% females; mean [SD], age 44.2 [10.6] years; BMI 42.4 [5.7] kg/m2 ) were randomized to intervention (n = 79) and control (n = 74). The BARI-LIFESTYLE program combined 17 nutritional-behavioral tele-counseling sessions plus once-weekly supervised exercise for 12 weeks. The primary outcome was percentage weight loss at 6 months post surgery. Secondary outcomes included body composition, physical activity levels, physical function and strength, health-related quality of life, depressive symptomatology, and comorbidities. RESULTS: Longitudinal analysis of the entire cohort showed significant reductions in body weight, fat mass, fat-free mass, and bone mineral density at the total hip, femoral neck, and lumbar spine (all p < 0.001). The 6-minute walk test, sit-to-stand test, health-related quality of life, and depressive symptomatology improved significantly (all p < 0.001). The time spent in moderate-to-vigorous physical activity and sedentary behavior remained the same as before surgery (both p > 0.05). There was no significant difference in the primary outcome between the intervention versus control (20.4% vs. 21.2%; mean difference = -0.8%; 95% CI: -2.8 to 1.1; p > 0.05) and no between-group differences in secondary outcomes. CONCLUSIONS: An adjunctive lifestyle program implemented immediately after surgery had no favorable impact upon weight loss and health outcomes.
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Cirugía Bariátrica , Calidad de Vida , Femenino , Humanos , Adulto , Masculino , Estilo de Vida , Pérdida de Peso , Terapia por EjercicioRESUMEN
Importance: Metabolic surgery leads to weight loss and improved health, but these outcomes are highly variable. Poor weight loss is associated with lower circulating levels of glucagon-like peptide-1 (GLP-1). Objective: To assess the efficacy and safety of the GLP-1 receptor agonist, liraglutide, 3.0 mg, on percentage body weight reduction in patients with poor weight loss and suboptimal GLP-1 response after metabolic surgery. Design, Setting, and Participants: The Evaluation of Liraglutide 3.0 mg in Patients With Poor Weight Loss and a Suboptimal Glucagon-Like Peptide-1 Response (BARI-OPTIMISE) randomized placebo-controlled trial recruited adult patients at least 1 year after metabolic surgery who had experienced 20% or less body weight loss from the day of surgery and a suboptimal nutrient-stimulated GLP-1 response from 2 hospitals in London, United Kingdom, between October 2018 and November 2019. Key exclusion criteria were type 1 diabetes; severe concomitant psychiatric, gastrointestinal, cardiac, kidney or metabolic disease; and use of insulin, GLP-1 receptor analogues, and medication that can affect weight. The study period was 24 weeks followed by a 4-week follow-up period. Last participant follow-up was completed in June 2020. All participants and clinical study personnel were blinded to treatment allocation. Of 154 assessed for eligibility, 70 met trial criteria and were included in the study, and 57 completed follow-up. Interventions: Liraglutide, 3.0 mg, once daily or placebo as an adjunct to lifestyle intervention with a 500-kcal daily energy deficit for 24 weeks, on a 1:1 allocation by computer-generated randomization sequence, stratified by surgery type (Roux-en-Y gastric bypass [RYGB] or sleeve gastrectomy [SG]) and type 2 diabetes status. Main Outcome and Measures: The primary outcome was change in percentage body weight from baseline to the end of the 24-week study period based on an intention-to-treat analysis. Participant safety was assessed through monitoring of biochemical parameters, including kidney and liver function, physical examination, and assessment for adverse events. Results: A total of 70 participants (mean [SD] age, 47.6 [10.7] years; 52 [74%] female) with a poor weight loss response following RYGB or SG were randomized to receive 3.0-mg liraglutide (n = 35) or placebo (n = 35). All participants received at least 1 dose of the trial drug. Eight participants discontinued treatment (4 per group), and 2 in the 3.0-mg liraglutide group and 1 in the placebo group were lost to follow-up. Due to COVID-19 restrictions, 3 participants in the 3.0-mg liraglutide group and 7 in the placebo group were unable to attend their final in-person assessment. Estimated change in mean (SD) percentage body weight from baseline to week 24 was -8.82 (4.94) with liraglutide, 3.0 mg (n = 31), vs -0.54 (3.32) with placebo (n = 26). The mean difference in percentage body weight change for liraglutide, 3.0 mg, vs placebo was -8.03 (95% CI, -10.39 to -5.66; P < .001). Adverse events, predominantly gastrointestinal, were more frequent with liraglutide, 3.0 mg (28 events [80%]), than placebo (20 events [57%]). There were no serious adverse events and no treatment-related deaths. Conclusion and Relevance: These findings support the use of adjuvant liraglutide, 3.0 mg, for weight management in patients with poor weight loss and suboptimal GLP-1 response after metabolic surgery. Trial Registration: ClinicalTrials.gov Identifier: NCT03341429.
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Cirugía Bariátrica , Diabetes Mellitus Tipo 2 , Adulto , Humanos , Femenino , Persona de Mediana Edad , Masculino , Liraglutida/uso terapéutico , Liraglutida/efectos adversos , Hipoglucemiantes/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/complicaciones , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/uso terapéutico , Resultado del Tratamiento , Pérdida de Peso , Péptido 1 Similar al Glucagón/uso terapéutico , Método Doble CiegoRESUMEN
Huntington disease (HD) is a neurodegenerative disorder caused by an expansion of polyglutamines in the first exon of huntingtin (HTT), which confers aggregation-promoting properties to amino-terminal fragments of the protein (N-HTT). Mutant N-HTT aggregates are enriched for ubiquitin and contain ubiquitin E3 ligases, thus suggesting a role for ubiquitination in aggregate formation. Here, we report that tumor necrosis factor receptor-associated factor 6 (TRAF6) binds to WT and polyQ-expanded N-HTT in vitro as well as to endogenous full-length proteins in mouse and human brain in vivo. Endogenous TRAF6 is recruited to cellular inclusions formed by mutant N-HTT. Transient overexpression of TRAF6 promotes WT and mutant N-HTT atypical ubiquitination with Lys(6), Lys(27), and Lys(29) linkage formation. Both interaction and ubiquitination seem to be independent from polyQ length. In cultured cells, TRAF6 enhances mutant N-HTT aggregate formation, whereas it has no effect on WT N-HTT protein localization. Mutant N-HTT inclusions are enriched for ubiquitin staining only when TRAF6 and Lys(6), Lys(27), and Lys(29) ubiquitin mutants are expressed. Finally, we show that TRAF6 is up-regulated in post-mortem brains from HD patients where it is found in the insoluble fraction. These results suggest that TRAF6 atypical ubiquitination warrants investigation in HD pathogenesis.
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Encéfalo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/metabolismo , Péptidos/metabolismo , Factor 6 Asociado a Receptor de TNF/metabolismo , Ubiquitinación , Animales , Encéfalo/patología , Células HEK293 , Humanos , Proteína Huntingtina , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/patología , Cuerpos de Inclusión/genética , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/patología , Ratones , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Péptidos/genética , Unión Proteica , Transporte de Proteínas/genética , Factor 6 Asociado a Receptor de TNF/genéticaRESUMEN
The BARI-LIFESTYLE trial is a randomized controlled trial evaluating the efficacy of a post-surgery nutritional and behavioural tele-counselling, and supervised exercise programme to maximize the health benefits of bariatric surgery. Due to the coronavirus disease 2019 (COVID-19) pandemic, the in-person supervised exercise component had to be converted to remote tele-exercise. However, patients' acceptability of this method of exercise provision is unknown. Between 3 and 6 months following bariatric surgery, 13 adults participated in weekly, structured, 60-min supervised exercise classes delivered via Zoom by a trained exercise therapist. A total of 12 participants (n = 8 female), with a mean age of 46.3 (range 33-63) years, who had undergone either sleeve gastrectomy (n = 8) or Roux-en-Y gastric bypass (n = 4) surgery, participated in one-to-one semi-structured interviews following the tele-exercise classes. Interviews were audio-recorded, transcribed verbatim and analysed using thematic analysis. Participants described how the tele-exercise classes helped them to cope with the changes to their lives brought about by the COVID-19 pandemic. Participants found the tele-exercise schedule, content and intensity to be acceptable, and were satisfied with the privacy, security and safety of the technology and classes. Professional supervision and guidance from an exercise therapist were described as central to the tele-exercise provision. Importantly, participation in the tele-exercise provided physical, emotional and social benefits. Few participants reported barriers to participation. Overall, the tele-exercise classes were deemed acceptable and compared favourably to in-person exercise classes.
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Cirugía Bariátrica , COVID-19 , Adulto , COVID-19/epidemiología , Femenino , Humanos , Estilo de Vida , Persona de Mediana Edad , Pandemias , SARS-CoV-2RESUMEN
The induction of Rrs1 expression is one of the earliest events detected in a presymptomatic knock-in mouse model of Huntington disease (HD). Rrs1 up-regulation fulfills the HD criteria of dominance, striatal specificity, and polyglutamine dependence. Here we show that mammalian Rrs1 is localized both in the nucleolus as well as in the endoplasmic reticulum (ER) of neurons. This dual localization is shared with its newly identified molecular partner 3D3/lyric. We then show that both genes are induced by ER stress in neurons. Interestingly, we demonstrate that ER stress is an early event in a presymptomatic HD mouse model that persists throughout the life span of the rodent. We further show that ER stress also occurs in postmortem brains of HD patients.
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Retículo Endoplásmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/patología , Neuronas/metabolismo , Estrés Fisiológico/fisiología , Animales , Nucléolo Celular/metabolismo , Células Cultivadas , Cuerpo Estriado/citología , Citoplasma/metabolismo , Modelos Animales de Enfermedad , Técnicas de Sustitución del Gen , Proteínas de Choque Térmico/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Neuronas/citología , ARN Mensajero/metabolismo , Proteínas de Unión al ARN , Técnicas del Sistema de Dos HíbridosRESUMEN
INTRODUCTION: Roux-en-Y gastric bypass and sleeve gastrectomy are the two most common bariatric surgery performed in the UK that result in comparable weight loss and remission of obesity-associated comorbidities. However, there is a paucity of studies examining the impact of these procedures on body composition, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life and costs. METHODS AND ANALYSIS: The BARI-LIFESTYLE observational study is a 1-year prospective, longitudinal cohort study within a real-world routine clinical care setting aiming to recruit 100 patients with severe obesity undergoing either primary Roux-en-Y gastric bypass or sleeve gastrectomy from two bariatric centres in London, UK. Participants will be followed up four times during the study period; presurgery baseline (T0) and at 3 (T1), 6 (T2) and 12 months (T3) postsurgery. In addition to the standard follow-up investigations, assessments including dual-energy X-ray absorptiometry scan, bioelectric impedance analysis, 6 min walk test, sit-to-stand test and handgrip test will be undertaken together with completion of questionnaires. Physical activity levels and sedentary behaviour will be assessed using accelerometer, and dietary intake will be recorded using a 3-day food diary. Outcome measures will include body weight, body fat mass, lean muscle mass, bone mineral density, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life, remission of comorbidities, healthcare resource utilisation and costs. ETHICS AND DISSEMINATION: This study has been reviewed and given a favourable ethical opinion by London-Dulwich Research Ethics Committee (17/LO/0950). The results will be presented to stakeholder groups locally, nationally and internationally and published in peer-reviewed medical journals. The lay-person summary of the findings will be published on the Centre for Obesity Research, University College London website (http://www.ucl.ac.uk/obesity).
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Gastrectomía/métodos , Derivación Gástrica/métodos , Estilo de Vida , Obesidad Mórbida/cirugía , Absorciometría de Fotón , Adulto , Anciano , Composición Corporal , Peso Corporal , Ejercicio Físico , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Conducta Sedentaria , Adulto JovenRESUMEN
TBPL2 is the most recently discovered and less characterized member of the TATA box binding protein (TBP) family that also comprises TBP, TATA box binding protein-like 1 (TBPL1), and Drosophila melanogaster TBP related factor (TRF). In this paper we report our in silico and in vitro data on (i) the genomics of the TBPL2 gene in Homo sapiens, Pan troglodytes, Mus musculus, Rattus norvegicus, Gallus gallus, Xenopus tropicalis, and Takifugu rubripes; (ii) its evolution and phylogenetic relationship with TBP, TBPL1, and TRF; (iii) the structure of the TBPL2 proteins that belong to the recently identified group of the intrinsically unstructured proteins (IUPs); and (iv) TBPL2 expression in different organs and cell types of Homo sapiens and Rattus norvegicus. Similar to TBP, both the TBPL2 gene and protein are bimodular. The 3' region of the gene encoding the DNA binding domain (DBD) was well conserved during evolution. Its high homology to vertebrate TBP suggests that TBPL2 also should bind to the TATA box and interact with the proteins binding to TBP carboxy-terminal domain, such as the TBP associated factors (TAFs). As already demonstrated for TBP, TBPL2 amino-terminal segment is intrinsically unstructured and, even though variable among vertebrates, comprises a highly conserved motif not found in any other known protein. Absence of TBPL2 from the genome of invertebrates and plants demonstrates its specific origin within the subphylum of vertebrates. Our RT-PCR analysis of human and rat RNA shows that, similar to TBP, TBPL2 is ubiquitously synthesized even though at variable levels that are at least two orders of magnitude lower. Higher expression of TBPL2 in the gonads than in other organs suggests that it could perform important functions in gametogenesis. Our genomic and expression data should contribute to clarify why TBP has a general master role within the transcription apparatus (TA), whereas both TBPL1 and TBPL2 perform tissue-specific functions.
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Evolución Molecular , Proteínas Similares a la Proteína de Unión a TATA-Box/genética , Proteína de Unión a TATA-Box/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cartilla de ADN/genética , Expresión Génica , Genómica , Humanos , Técnicas In Vitro , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Filogenia , Regiones Promotoras Genéticas , Mapeo de Interacción de Proteínas , Ratas , Homología de Secuencia de Aminoácido , Proteínas Similares a la Proteína de Unión a TATA-Box/química , Proteína de Unión a TATA-Box/química , Vertebrados/genéticaRESUMEN
Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder characterized by a polyglutamine expansion within the N-terminal region of huntingtin protein (HTT). Cellular mechanisms promoting mutant huntingtin (mHTT) clearance are of great interest in HD pathology as they can lower the level of the mutant protein and its toxic aggregated species, thus affecting disease onset and progression. We have previously shown that the prolyl-isomerase PIN1 represents a promising negative regulator of mHTT aggregate accumulation using a genetically precise HD mouse model, namely HdhQ111 mice. Therefore, the current study aims at underpinning the mechanism by which PIN1 affects huntingtin's aggregates. We found that PIN1 overexpression led to a reduction of mHTT aggregates in HEK293 cells, and that this could be linked to a negative regulation of mHTT half-life by PIN1. Furthermore, we show that PIN1 has the ability to stimulate the proteasome presenting evidence of a mechanism regulating this phenomenon. Our findings provide a rationale for future investigation into PIN1 with the potential for the development of novel therapeutic strategies.
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Huntington's disease (HD) is a neurodegenerative disorder for which there are no disease-modifying treatments. SIRT1 is a NAD+-dependent protein deacetylase that is implicated in maintaining neuronal health during development, differentiation and ageing. Previous studies suggested that the modulation of SIRT1 activity is neuroprotective in HD mouse models, however, the mechanisms controlling SIRT1 activity are unknown. We have identified a striatum-specific phosphorylation-dependent regulatory mechanism of SIRT1 induction under normal physiological conditions, which is impaired in HD. We demonstrate that SIRT1 activity is down-regulated in the brains of two complementary HD mouse models, which correlated with altered SIRT1 phosphorylation levels. This SIRT1 impairment could not be rescued by the ablation of DBC1, a negative regulator of SIRT1, but was linked to changes in the sub-cellular distribution of AMPK-α1, a positive regulator of SIRT1 function. This work provides insights into the regulation of SIRT1 activity with the potential for the development of novel therapeutic strategies.
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Encéfalo/metabolismo , Enfermedad de Huntington/patología , Sirtuina 1/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Proteínas de Ciclo Celular , Cerebelo/metabolismo , Cuerpo Estriado/metabolismo , Modelos Animales de Enfermedad , Femenino , Enfermedad de Huntington/metabolismo , Inmunohistoquímica , Inmunoprecipitación , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Noqueados , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Fenotipo , Fosforilación , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Sirtuina 1/deficiencia , Sirtuina 1/genéticaRESUMEN
[This corrects the article DOI: 10.1371/journal.pone.0145425.].
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Huntington's disease (HD) is a fatal, dominantly inherited, neurodegenerative disorder due to a pathological expansion of the CAG repeat in the coding region of the HTT gene. In the quest for understanding the molecular basis of neurodegeneration, we have previously demonstrated that the prolyl isomerase Pin1 plays a crucial role in mediating p53-dependent apoptosis triggered by mutant huntingtin (mHtt) in vitro. To assess the effects of the lack of Pin1 in vivo, we have bred Pin1 knock-out mice with Hdh(Q111) knock-in mice, a genetically precise model of HD. We show that Pin1 genetic ablation modifies a portion of Hdh(Q111) phenotypes in a time-dependent fashion. As an early event, Pin1 activity reduces the DNA damage response (DDR). In midlife mice, by taking advantage of next-generation sequencing technology, we show that Pin1 activity modulates a portion of the alterations triggered by mHtt, extending the role of Pin1 to two additional Hdh(Q111) phenotypes: the unbalance in the "synthesis/concentration of hormones", as well as the alteration of "Wnt/ß-catenin signaling". In aging animals, Pin1 significantly increases the number of mHtt-positive nuclear inclusions while it reduces gliosis. In summary, this work provides further support for a role of Pin1 in HD pathogenesis.
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The heat shock response (HSR) is the main pathway used by cells to counteract proteotoxicity. The inability of differentiated neurons to induce an HSR has been documented in primary neuronal cultures and has been proposed to play a critical role in ageing and neurodegeneration. However, this accepted dogma has not been demonstrated in vivo. We used BAC transgenic mice generated by the Gene Expression Nervous System Atlas project to investigate the capacity of striatal medium sized spiny neurons to induce an HSR as compared to that of astrocytes and oligodendrocytes. We found that all cell populations were competent to induce an HSR upon HSP90 inhibition. We also show the presence and relative abundance of heat shock-related genes and proteins in these striatal cell populations. The identification of a competent HSR in adult neurons supports the development of therapeutics that target the HSR pathway as treatments for neurodegenerative disorders.
Asunto(s)
Respuesta al Choque Térmico/fisiología , Enfermedades Neurodegenerativas/metabolismo , Neuronas/patología , Administración Oral , Animales , Astrocitos/citología , Encéfalo/metabolismo , Cromosomas Artificiales Bacterianos , Cuerpo Estriado/metabolismo , Femenino , Citometría de Flujo , Regulación de la Expresión Génica , Proteínas HSP90 de Choque Térmico/metabolismo , Hipocampo/patología , Masculino , Ratones , Ratones Transgénicos , Enfermedades Neurodegenerativas/patología , Neuronas/citología , Neuronas/metabolismo , Oligodendroglía/citología , Piridonas/química , Pirimidinas/química , ARN Mensajero/metabolismoRESUMEN
For the past decade protein acetylation has been shown to be a crucial post-transcriptional modification involved in the regulation of protein functions. Histone acetyltransferases (HATs) mediate acetylation of histones which results in the nucleosomal relaxation associated with gene expression. The reverse reaction, histone deacetylation, is mediated by histone deacetylases (HDACs) leading to chromatin condensation followed by transcriptional repression. HDACs are divided into distinct classes: I, IIa, IIb, III, and IV, on the basis of size and sequence homology, as well as formation of distinct repressor complexes. Implications of HDACs in many diseases, such as cancer, heart failure, and neurodegeneration, have identified these molecules as unique and attractive therapeutic targets. The emergence of HDAC4 among the members of class IIa family as a major player in synaptic plasticity raises important questions about its functions in the brain. The characterization of HDAC4 specific substrates and molecular partners in the brain will not only provide a better understanding of HDAC4 biological functions but also might help to develop new therapeutic strategies to target numerous malignancies. In this review we highlight and summarize recent achievements in understanding the biological role of HDAC4 in neurodegenerative processes.