RESUMEN
Mammalian voltage-activated L-type Ca2+ channels, such as Ca(v)1.2, control transmembrane Ca2+ fluxes in numerous excitable tissues. Here, we report that the pore-forming α1C subunit of Ca(v)1.2 is reversibly palmitoylated in rat, rabbit, and human ventricular myocytes. We map the palmitoylation sites to two regions of the channel: The N terminus and the linker between domains I and II. Whole-cell voltage clamping revealed a rightward shift of the Ca(v)1.2 current-voltage relationship when α1C was not palmitoylated. To examine function, we expressed dihydropyridine-resistant α1C in human induced pluripotent stem cell-derived cardiomyocytes and measured Ca2+ transients in the presence of nifedipine to block the endogenous channels. The transients generated by unpalmitoylatable channels displayed a similar activation time course but significantly reduced amplitude compared to those generated by wild-type channels. We thus conclude that palmitoylation controls the voltage sensitivity of Ca(v)1.2. Given that the identified Ca(v)1.2 palmitoylation sites are also conserved in most Ca(v)1 isoforms, we propose that palmitoylation of the pore-forming α1C subunit provides a means to regulate the voltage sensitivity of voltage-activated Ca2+ channels in excitable cells.
Asunto(s)
Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Ratas , Humanos , Conejos , Animales , Miocitos Cardíacos/metabolismo , Calcio/metabolismo , Lipoilación , Canales de Calcio Tipo L/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Calcio de la Dieta , Mamíferos/metabolismoRESUMEN
AIMS: To scope the key performance indicators (KPIs) used in nursing and midwifery across the United Kingdom and Republic of Ireland and explore how they influence practice in healthcare organizations. DESIGN: The study adopted a sequential, exploratory mixed-methods design. METHODS: Phase 1 incorporated a multiple-choice questionnaire completed by 77 Directors of Nursing recruited using voluntary response sampling. In phase 2, 35 nurses and midwives who were working at executive, senior manager and clinical levels, participated in semi-structured interviews. Data collection of both phases was conducted from January 2016 to October 2016. FINDINGS: Quantitative data revealed over 100 nursing and midwifery-specific KPIs. National requirements were a deciding factor in KPI selection, while clinical involvement was mainly through data collection. Respondents stated that they used patient experience KPIs, but only one was assessed as valid. Thematic analysis identified two themes: The leadership challenge (including 'voiceless in the national conversation', 'aligning KPIs in the practice context' and 'listening to those who matter'); and taking action (including 'establishing ownership and engaging staff', 'checks and balances' and 'closing the loop'). CONCLUSION: The large volume of KPI measurement taking place makes meaningful evaluation of performance and quality of care difficult, both in and across organizations. Nurses and midwives require enhanced knowledge of the nature and purpose of KPIs, as evidence gained from KPI data collection is insufficient to lead to improvements in practice. A practice context that encourages collective leadership, where multiple sources of evidence are gathered and everyone is included in KPI evaluation and subsequent decision-making, is key. IMPACT: This study adds to the body of evidence on KPI understanding. It informs the future effective management of indicators that will facilitate the delivery of meaningful care and reduce the cost, time and effort invested in the implementation of KPIs and data management.
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Partería , Femenino , Humanos , Irlanda , Liderazgo , Embarazo , Reino UnidoRESUMEN
BACKGROUND & AIMS: African Americans have the greatest colorectal cancer (CRC) burden in the United States; interethnic differences in protective effects of vitamin D might contribute to disparities. 1α,25(OH)2D3 vitamin D (the active form of vitamin D) induces transcription of the uridine phosphorylase gene (UPP1) in colon tissues of European Americans but to a lesser extent in colon tissues of African Americans. UPP1-knockout mice have increased intestinal concentrations of uridine and Deoxyuridine triphosphate (dUTP), have increased uridine-induced DNA damage, and develop colon tumors. We studied 1α,25(OH)2D3 regulation of UPP1 and uridine-induced DNA damage in the colon and differences in these processes between African and European Americans. METHODS: We quantified expression and activity of UPP1 in response to 1α,25(OH)2D3 in young adult mouse colonic cells, human CRC cells (LS174T), and organoids (derived from rectosigmoid biopsy samples of healthy individuals undergoing colonoscopies) using quantitative polymerase chain reaction, immunoblot, and immunocytochemistry assays. Binding of the vitamin D receptor to UPP1 was tested by chromatin immunoprecipitation. Uridine-induced DNA damage was measured by fragment-length analysis in repair enzyme assays. Allele-specific 1α,25(OH)2D3 responses were tested using luciferase assays. RESULTS: Vitamin D increased levels of UPP1 mRNA, protein, and enzymatic activity and increased vitamin D receptor binding to the UPP1 promoter in young adult mouse colonic cells, LS174T cells, and organoids. 1α,25(OH)2D3 significantly reduced levels of uridine and uridine-induced DNA damage in these cells, which required UPP1 expression. Organoids derived from colon tissues of African Americans expressed lower levels of UPP1 after exposure to 1α,25(OH)2D3 and had increased uridine-induced DNA damage compared with organoids derived from tissues of European Americans. Luciferase assays with the T allele of single nucleotide polymorphism rs28605337 near UPP1, which is found more frequently in African Americans than European Americans, expressed lower levels of UPP1 after exposure to 1α,25(OH)2D3 than assays without this variant. CONCLUSIONS: We found vitamin D to increase expression of UPP1, leading to reduce uridine-induced DNA damage, in colon cells and organoids. A polymorphism in UPP1 found more frequently in African Americans than European Americans reduced UPP1 expression upon cell exposure to 1α,25(OH)2D3. Differences in expression of UPP1 in response to vitamin D could contribute to the increased risk of CRC in African Americans.
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Negro o Afroamericano/genética , Calcitriol/farmacología , Colon/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Uridina Fosforilasa/metabolismo , Uridina/toxicidad , Población Blanca/genética , Animales , Sitios de Unión , Línea Celular , Colon/enzimología , Colon/patología , Citoprotección , Células Epiteliales/enzimología , Células Epiteliales/patología , Regulación Enzimológica de la Expresión Génica , Humanos , Ratones , Organoides/efectos de los fármacos , Organoides/enzimología , Organoides/patología , Polimorfismo Genético , Regiones Promotoras Genéticas , Receptores de Calcitriol/agonistas , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Factores de Tiempo , Técnicas de Cultivo de Tejidos , Uridina/metabolismo , Uridina Fosforilasa/genéticaRESUMEN
Following the introduction of a regional nurse mentor preparation programme, research was undertaken within a health and social care trust to explore both the trainee mentors' and their supervisors' perception of this new programme. A qualitative study involving focus groups was undertaken. The focus groups comprised a total of twelve participants including five trainee mentors and seven supervisors (experienced mentors) who had recently completed a mentor preparation programme. Data were analysed using Braun and Clarke's thematic analysis. Three themes were identified from the data: personal investment (including the emotional impact of mentoring) contextual perceptions (environmental factors such as time) and intellectual facets (related to personal and professional growth). Comprehensive preparation for mentors appears to be effective in developing mentors with the ability to support nursing students in practice. However, further study is required to explore how to support mentors to balance the demands of the mentoring role with the delivery of patient care.
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Educación en Enfermería/organización & administración , Mentores/psicología , Competencia Profesional , Estudiantes de Enfermería/psicología , Adulto , Femenino , Grupos Focales , Humanos , Masculino , Evaluación de Programas y Proyectos de Salud , Investigación Cualitativa , Reino UnidoRESUMEN
Madagascar's lemurs, now deemed the most endangered group of mammals, represent the highest primate conservation priority in the world. Due to anthropogenic disturbances, an estimated 10% of Malagasy forest cover remains. The endangered Lemur catta is endemic to the southern regions of Madagascar and now occupies primarily fragmented forest habitats. We examined the influence of habitat fragmentation and isolation on the genetic diversity of L. catta across 3 different forest fragments in south-central Madagascar. Our analysis revealed moderate levels of genetic diversity. Genetic differentiation among the sites ranged from 0.05 to 0.11. These data suggest that the L. catta populations within south-central Madagascar have not yet lost significant genetic variation. However, due to ongoing anthropogenic threats faced by ring-tailed lemurs, continued conservation and research initiatives are imperative for long-term viability of the species.
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Ecosistema , Variación Genética , Lemur/genética , Animales , Bosques , Madagascar , Repeticiones de MicrosatéliteRESUMEN
Vascular homeostasis and pathophysiology are tightly regulated by mechanical forces generated by hemodynamics. Vascular disorders such as atherosclerotic diseases largely occur at curvatures and bifurcations where disturbed blood flow activates endothelial cells while unidirectional flow at the straight part of vessels promotes endothelial health. Integrated analysis of the endothelial transcriptome, the 3D epigenome, and human genetics systematically identified the SNP-enriched cistrome in vascular endothelium subjected to well-defined atherosclerosis-prone disturbed flow or atherosclerosis-protective unidirectional flow. Our results characterized the endothelial typical- and super-enhancers and underscored the critical regulatory role of flow-sensitive endothelial super-enhancers. CRISPR interference and activation validated the function of a previously unrecognized unidirectional flow-induced super-enhancer that upregulates antioxidant genes NQO1, CYB5B, and WWP2, and a disturbed flow-induced super-enhancer in endothelium which drives prothrombotic genes EDN1 and HIVEP in vascular endothelium. Our results employing multiomics identify the cis-regulatory architecture of the flow-sensitive endothelial epigenome related to atherosclerosis and highlight the regulatory role of super-enhancers in mechanotransduction mechanisms.
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Aterosclerosis , Células Endoteliales , Mecanotransducción Celular , Humanos , Aterosclerosis/genética , Endotelio VascularRESUMEN
In Tibetans, noncoding alleles in EPAS1-whose protein product hypoxia-inducible factor 2α (HIF-2α) drives the response to hypoxia-carry strong signatures of positive selection; however, their functional mechanism has not been systematically examined. Here, we report that high-altitude alleles disrupt the activity of four EPAS1 enhancers in one or more cell types. We further characterize one enhancer (ENH5) whose activity is both allele specific and hypoxia dependent. Deletion of ENH5 results in down-regulation of EPAS1 and HIF-2α targets in acute hypoxia and in a blunting of the transcriptional response to sustained hypoxia. Deletion of ENH5 in mice results in dysregulation of gene expression across multiple tissues. We propose that pleiotropic adaptive effects of the Tibetan alleles in EPAS1 underlie the strong selective signal at this gene.
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BACKGROUND: Artemisia annua L.is a well-established medicinal herb used for millennia to treat parasites and fever-related ailments caused by various microbes. Although effective against many infectious agents, the plant is not a miracle cure and there are infections where it has proved ineffective or limited. It is important to report those failures. METHODS: Here artemisinin, artesunate and dried leaf slurries of A. annua were used daily for 6 days in vivo against Babesia microti in mice 2 days post infection at 100 µg artemisinin/kg body weight. Parasitemia was measure before and 15 days days post treatment. Artemisinin and extracts of A. annua also were tested in vitro against six Candida sp. at artemisinin concentrations up to 180 µM and growth measured after cultures were fed drugs once at different stages of growth and also after repeated dosing. RESULTS: A. annua, artesunate, and artemisinin were ineffective in reducing or eliminating parasitemia in B. microti-infected mice treated at 100 µg artemisinin/kg body weight. Although the growth of exponential cultures of many of the tested Candida sp. was inhibited, the response was not sustained and both artemisinin and Artemisia were essentially ineffective at concentrations of artemisinin at up to 180 µM of artemisinin. CONCLUSIONS: Together these results show that artemisinin, its derivatives, and A. annua are ineffective against B. microti and at least six species of Candida.
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Evidence indicates that bodily perception is negatively related to Parkinson's disease (PD); in particular, people with Parkinson's (PwP) feel dissatisfaction in their physical abilities and appearance. While established treatments exist to ameliorate motor symptoms in PD, research has yet to explore the effects of well-being-focused interventions in relation to the subjective experience of bodily concerns of PwP. This mixed methods exploratory study investigated the constructs of body appreciation in relation to well-being in PwP and the impact of participation in a dance class on body appreciation and well-being, comparing PwP with age-matched controls. Participants (n = 27 PwP, n = 14 controls) completed the Warwick Edinburgh Mental Well-Being Scale and the Body Appreciation Scale before and after taking part in a dance class. Well-being was positively associated with body appreciation in PwP (r s = 0.64, p < 0.001) but not in controls. Following participation in a dance class, all participants' well-being scores increased; a greater increase in well-being scores was observed for controls. A pilot qualitative study explored bodily awareness with PwP who attended dance classes (n = 4) and other movement-based activities (n = 4). Analysis of the interview data indicated that PwP who danced showed heightened bodily awareness, including bodily limitations, in comparison with PwP who did not dance. These preliminary findings provide initial insight explaining the lack of improvements in body appreciation in PwP following a dance class. The current study highlights the need for dance interventions for PwP to consider incorporating elements that encourage a body positive attitude alongside fostering perceived well-being.
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The phospholipid l-α-lysophosphatidylinositol (LPI), an endogenous ligand for GPR55, is elevated in patients with acute coronary syndrome, and a GPR55 antagonist cannabidiol (CBD) reduces experimental ischemia/reperfusion (I/R) injury. While LPI activates multiple signaling pathways, little is known about which ones are important in cardiomyocytes. In this study we explored whether activation of the Rho kinase/ROCK/p38 MAPK pathway is responsible for LPI-induced extension of I/R injury. Using a high-throughput screening method (dynamic mass redistribution; DMR), mouse- and human-induced pluripotent stem cell (iPSC) cardiomyocytes exposed to LPI were shown to exhibit a rapid, sustained, and concentration-dependent (1 nmol L-1-30 µmol L-1) cellular response. Y-27632 (ROCK inhibitor; 10 & 50 µmol L-1) and CBD (1 µmol L-1) both abolished the DMR response to LPI (10 µmol L-1). In murine iPSC cardiomyocytes, LPI-induced ROCK and p38 MAPK phosphorylation, both of which were prevented by Y-27632 and CBD, but did not induce JNK activation or cleavage of caspase-3. In hearts isolated from wild type (WT) mice subjected to 30 minutes global I/R, LPI (10 µmol L-1) administered via the coronary circulation increased infarct size when applied prior to ischemia onset, but not when given at the time of reperfusion. The exacerbation of tissue injury by LPI was not seen in hearts from GPR55-/- mice or in the presence of Y-27632, confirming that injury is mediated via the GPR55/ROCK/p38 MAPK pathway. These findings suggest that raised levels of LPI in the vicinity of a developing infarct may worsen the outcome of AMI.