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2.
Circ Res ; 134(2): 143-161, 2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38156445

RESUMEN

BACKGROUND: Single-nucleotide polymorphisms linked with the rs1474868 T allele (MFN2 [mitofusin-2] T/T) in the human mitochondrial fusion protein MFN2 gene are associated with reduced platelet MFN2 RNA expression and platelet counts. This study investigates the impact of MFN2 on megakaryocyte and platelet biology. METHODS: Mice with megakaryocyte/platelet deletion of Mfn2 (Mfn2-/- [Mfn2 conditional knockout]) were generated using Pf4-Cre crossed with floxed Mfn2 mice. Human megakaryocytes were generated from cord blood and platelets isolated from healthy subjects genotyped for rs1474868. Ex vivo approaches assessed mitochondrial morphology, function, and platelet activation responses. In vivo measurements included endogenous/transfused platelet life span, tail bleed time, transient middle cerebral artery occlusion, and pulmonary vascular permeability/hemorrhage following lipopolysaccharide-induced acute lung injury. RESULTS: Mitochondria was more fragmented in megakaryocytes derived from Mfn2-/- mice and from human cord blood with MFN2 T/T genotype compared with control megakaryocytes. Human resting platelets of MFN2 T/T genotype had reduced MFN2 protein, diminished mitochondrial membrane potential, and an increased rate of phosphatidylserine exposure during ex vivo culture. Platelet counts and platelet life span were reduced in Mfn2-/- mice accompanied by an increased rate of phosphatidylserine exposure in resting platelets, especially aged platelets, during ex vivo culture. Mfn2-/- also decreased platelet mitochondrial membrane potential (basal) and activated mitochondrial oxygen consumption rate, reactive oxygen species generation, calcium flux, platelet-neutrophil aggregate formation, and phosphatidylserine exposure following dual agonist activation. Ultimately, Mfn2-/- mice showed prolonged tail bleed times, decreased ischemic stroke infarct size after cerebral ischemia-reperfusion, and exacerbated pulmonary inflammatory hemorrhage following lipopolysaccharide-induced acute lung injury. Analysis of MFN2 SNPs in the iSPAAR study (Identification of SNPs Predisposing to Altered ALI Risk) identified a significant association between MFN2 and 28-day mortality in patients with acute respiratory distress syndrome. CONCLUSIONS: Mfn2 preserves mitochondrial phenotypes in megakaryocytes and platelets and influences platelet life span, function, and outcomes of stroke and lung injury.


Asunto(s)
Lesión Pulmonar Aguda , Lipopolisacáridos , Anciano , Animales , Humanos , Ratones , Lesión Pulmonar Aguda/metabolismo , Plaquetas/metabolismo , Hemorragia/metabolismo , Mitocondrias/metabolismo , Fosfatidilserinas/metabolismo
3.
J Thromb Haemost ; 21(11): 3252-3267, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37558133

RESUMEN

BACKGROUND: The small noncoding RNAs (sncRNAs) in megakaryocytes (MKs) and platelets are not well characterized. Neither is the impact of SARS-CoV-2 infection on the sncRNAs of platelets. OBJECTIVES: To investigate the sorting of MK sncRNAs into platelets, and the differences in the platelet sncRNAomes of healthy donors (HDs) and COVID-19 patients. METHODS: We comprehensively profiled sncRNAs from MKs cultured from cord blood-derived CD34+ cells, platelets from HDs, and platelets from patients with moderate and severe SARS-CoV-2 infection. We also comprehensively profiled Argonaute (AGO)-bound sncRNAs from the cultured MKs. RESULTS: We characterized the sncRNAs in MKs and platelets and can account for ∼95% of all sequenced reads. We found that MKs primarily comprise microRNA isoforms (isomiRs), tRNA-derived fragments (tRFs), rRNA-derived fragments (rRFs), and Y RNA-derived fragments (yRFs) in comparable abundances. The platelets of HDs showed a skewed distribution by comparison: 56.7% of all sncRNAs are yRFs, 34.4% are isomiRs, and <2.0% are tRFs and rRFs. Most isomiRs in MKs and platelets are either noncanonical, nontemplated, or both. When comparing MKs and platelets from HDs, we found numerous isomiRs, tRFs, rRFs, and yRFs showing opposite enrichments or depletions, including molecules from the same parental miRNA arm, tRNA, rRNA, or Y RNA. The sncRNAome of platelets from patients with COVID-19 is skewed compared to that of HDs with only 19.8% of all sncRNAs now being yRFs, isomiRs increasing to 63.6%, and tRFs and rRFs more than tripling their presence to 6.1%. CONCLUSION: The sncRNAomes of MKs and platelets are very rich and more complex than it has been believed. The evidence suggests complex mechanisms that sort MK sncRNAs into platelets. SARS-CoV-2 infection acutely alters the contents of platelets by changing the relative proportions of their sncRNAs.


Asunto(s)
COVID-19 , MicroARNs , ARN Pequeño no Traducido , Humanos , Megacariocitos , SARS-CoV-2/genética , Plaquetas , MicroARNs/genética , ARN de Transferencia/genética
4.
J Clin Invest ; 133(18)2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37471144

RESUMEN

Protease-activated receptor 4 (PAR4) (gene F2RL3) harbors a functional dimorphism, rs773902 A/G (encoding Thr120/Ala120, respectively) and is associated with greater platelet aggregation. The A allele frequency is more common in Black individuals, and Black individuals have a higher incidence of ischemic stroke than White individuals. However, it is not known whether the A allele is responsible for worse stroke outcomes. To directly test the in vivo effect of this variant on stroke, we generated mice in which F2rl3 was replaced by F2RL3, thereby expressing human PAR4 (hPAR4) with either Thr120 or Ala120. Compared with hPAR4 Ala120 mice, hPAR4 Thr120 mice had worse stroke outcomes, mediated in part by enhanced platelet activation and platelet-neutrophil interactions. Analyses of 7,620 Black subjects with 487 incident ischemic strokes demonstrated the AA genotype was a risk for incident ischemic stroke and worse functional outcomes. In humanized mice, ticagrelor with or without aspirin improved stroke outcomes in hPAR4 Ala120 mice, but not in hPAR4 Thr120 mice. P selectin blockade improved stroke outcomes and reduced platelet-neutrophil interactions in hPAR4 Thr120 mice. Our results may explain some of the racial disparity in stroke and support the need for studies of nonstandard antiplatelet therapies for patients expressing PAR4 Thr120.


Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Animales , Ratones , Receptores de Trombina/genética , Agregación Plaquetaria/genética , Plaquetas/fisiología , Inhibidores de Agregación Plaquetaria/farmacología , Accidente Cerebrovascular/genética , Receptor PAR-1
5.
Blood ; 140(23): 2477-2489, 2022 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-35930749

RESUMEN

The MAPK-interacting kinase (Mnk) family includes Mnk1 and Mnk2, which are phosphorylated and activated in response to extracellular stimuli. Mnk1 contributes to cellular responses by regulating messenger RNA (mRNA) translation, and mRNA translation influences platelet production and function. However, the role of Mnk1 in megakaryocytes and platelets has not previously been studied. The present study investigated Mnk1 in megakaryocytes and platelets using both pharmacological and genetic approaches. We demonstrate that Mnk1, but not Mnk2, is expressed and active in human and murine megakaryocytes and platelets. Stimulating human and murine megakaryocytes and platelets induced Mnk1 activation and phosphorylation of eIF4E, a downstream target of activated Mnk1 that triggers mRNA translation. Mnk1 inhibition or deletion significantly diminished protein synthesis in megakaryocytes as measured by polysome profiling and [35S]-methionine incorporation assays. Depletion of Mnk1 also reduced megakaryocyte ploidy and proplatelet forming megakaryocytes in vitro and resulted in thrombocytopenia. However, Mnk1 deletion did not affect the half-life of circulating platelets. Platelets from Mnk1 knockout mice exhibited reduced platelet aggregation, α granule secretion, and integrin αIIbß3 activation. Ribosomal footprint sequencing indicated that Mnk1 regulates the translation of Pla2g4a mRNA (which encodes cPLA2) in megakaryocytes. Consistent with this, Mnk1 ablation reduced cPLA2 activity and thromboxane generation in platelets and megakaryocytes. In vivo, Mnk1 ablation protected against platelet-dependent thromboembolism. These results provide previously unrecognized evidence that Mnk1 regulates mRNA translation and cellular activation in platelets and megakaryocytes, endomitosis and thrombopoiesis, and thrombosis.


Asunto(s)
ARN Mensajero , Humanos , Animales , Ratones
6.
Br J Haematol ; 198(5): 802, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35802037

Asunto(s)
Hematología , Humanos
8.
Blood Adv ; 6(7): 2303-2308, 2022 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-34883511

RESUMEN

Platelet-neutrophil interactions regulate ischemic vascular injury. Platelets are activated by serine proteases that cleave protease-activated receptor (PAR) amino termini, resulting in an activating tethered ligand. Neutrophils release cathepsin G (CatG) at sites of injury and inflammation, which activates PAR4 but not PAR1, although the molecular mechanism of CatG-induced PAR4 activation is unknown. We show that blockade of the canonical PAR4 thrombin cleavage site did not alter CatG-induced platelet aggregation, suggesting CatG cleaves a different site than thrombin. Mass spectrometry analysis using PAR4 N-terminus peptides revealed CatG cleavage at Ser67-Arg68. A synthetic peptide, RALLLGWVPTR, representing the tethered ligand resulting from CatG proteolyzed PAR4, induced PAR4-dependent calcium flux and greater platelet aggregation than the thrombin-generated GYPGQV peptide. Mutating PAR4 Ser67or Arg68 reduced CatG-induced calcium flux without affecting thrombin-induced calcium flux. Dog platelets, which contain a conserved CatG PAR4 Ser-Arg cleavage site, aggregated in response to human CatG and RALLLGWVPTR, while mouse (Ser-Gln) and rat (Ser-Glu) platelets were unresponsive. Thus, CatG amputates the PAR4 thrombin cleavage site by cleavage at Ser67-Arg68 and activates PAR4 by generating a new functional tethered ligand. These findings support PAR4 as an important CatG signaling receptor and suggest a novel therapeutic approach for blocking platelet-neutrophil-mediated pathophysiologies.


Asunto(s)
Neutrófilos , Receptores de Trombina , Animales , Catepsina G , Perros , Ligandos , Ratones , Neutrófilos/metabolismo , Proteolisis , Ratas , Receptores de Trombina/metabolismo
9.
Blood Cells Mol Dis ; 92: 102624, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34775219

RESUMEN

The purpose of this research was to assess the effects of a microRNA (miRNA) cluster on platelet production. Human chromosome 19q13.41 harbors an evolutionarily conserved cluster of three miRNA genes (MIR99B, MIRLET7E, MIR125A) within 727 base-pairs. We now report that levels of miR-99b-5p, miR-let7e-5p and miR-125a-5p are strongly correlated in human platelets, and all are positively associated with platelet count, but not white blood count or hemoglobin level. Although the cluster regulates hematopoietic stem cell proliferation, the function of this genomic locus in megakaryocyte (MK) differentiation and platelet production is unknown. Furthermore, studies of individual miRNAs do not represent broader effects in the context of a cluster. To address this possibility, MK/platelet lineage-specific Mir-99b/let7e/125a knockout mice were generated. Compared to wild type littermates, cluster knockout mice had significantly lower platelet counts and reduced MK proplatelet formation, but no differences in MK numbers, ploidy, maturation or ultra-structural morphology, and no differences in platelet function. Compared to wild type littermates, knockout mice showed similar survival after pulmonary embolism. The major conclusions are that the effect of the Mir-99b/let7e/125a cluster is confined to a late stage of thrombopoiesis, and this effect on platelet number is uncoupled from platelet function.


Asunto(s)
Plaquetas/metabolismo , Megacariocitos/metabolismo , MicroARNs/genética , Animales , Plaquetas/citología , Eliminación de Gen , Humanos , Megacariocitos/citología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Familia de Multigenes , Recuento de Plaquetas , Pruebas de Función Plaquetaria , Trombocitopenia/genética , Trombopoyesis
10.
Blood Adv ; 5(9): 2362-2374, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33944898

RESUMEN

Human anucleate platelets cannot be directly modified using traditional genetic approaches. Instead, studies of platelet gene function depend on alternative models. Megakaryocytes (the nucleated precursor to platelets) are the nearest cell to platelets in origin, structure, and function. However, achieving consistent genetic modifications in primary megakaryocytes has been challenging, and the functional effects of induced gene deletions on human megakaryocytes for even well-characterized platelet genes (eg, ITGA2B) are unknown. Here we present a rapid and systematic approach to screen genes for platelet functions in CD34+ cell-derived megakaryocytes called CRIMSON (CRISPR-edited megakaryocytes for rapid screening of platelet gene functions). By using CRISPR/Cas9, we achieved efficient nonviral gene editing of a panel of platelet genes in megakaryocytes without compromising megakaryopoiesis. Gene editing induced loss of protein in up to 95% of cells for platelet function genes GP6, RASGRP2, and ITGA2B; for the immune receptor component B2M; and for COMMD7, which was previously associated with cardiovascular disease and platelet function. Gene deletions affected several select responses to platelet agonists in megakaryocytes in a manner largely consistent with those expected for platelets. Deletion of B2M did not significantly affect platelet-like responses, whereas deletion of ITGA2B abolished agonist-induced integrin activation and spreading on fibrinogen without affecting the translocation of P-selectin. Deletion of GP6 abrogated responses to collagen receptor agonists but not thrombin. Deletion of RASGRP2 impaired functional responses to adenosine 5'-diphosphate (ADP), thrombin, and collagen receptor agonists. Deletion of COMMD7 significantly impaired multiple responses to platelet agonists. Together, our data recommend CRIMSON for rapid evaluation of platelet gene phenotype associations.


Asunto(s)
Plaquetas , Megacariocitos , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Factores de Intercambio de Guanina Nucleótido , Humanos , Fenotipo , Trombopoyesis
11.
Res Pract Thromb Haemost ; 5(2): 356-365, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33733035

RESUMEN

BACKGROUND: Acquired von Willebrand syndrome (AVWS) has been associated with monoclonal gammopathy of undetermined significance (MGUS), with limited data on its management. METHODS: We conducted a systematic literature search in Medline (Ovid), Embase, and Scopus up to September 11, 2019, for studies reporting on the management of AVWS associated with MGUS (AVWS-MGUS). Data on patient characteristics, laboratory parameters at presentation, and clinical and laboratory outcomes were extracted. OBJECTIVES: To describe the clinical presentation and outcomes of different therapeutic approaches. RESULTS: Seventy-five studies were included in the final review, for a total of 137 patients. Most patients had von Willebrand factor ristocetin cofactor activity <30 IU/dL (86.6%) and factor VIII levels <50 IU/dL (91.8%). Bleeding severity ranged from no bleeding (16.1%) to minor bleeding (46.4%) and major bleeding (37.5%). The overall clinical success rates for 1-deamino-8-D-arginine vasopressin (DDAVP), factor replacement therapy, and intravenous immunoglobulin (IVIG) were 43.8%, 33.3%, and 85.4%, respectively. The laboratory response rates for DDAVP, factor replacement therapy, and IVIG were 39.0%, 62.9%, and 88.6%, respectively. Several other treatments were also reported in small numbers, out of which myeloma-directed therapies, plasma exchange, recombinant factor VIIa, and antifibrinolytics appeared most successful, while immunosuppressive agents were largely ineffective. CONCLUSION: IVIG appears to be an effective treatment for AVWS-MGUS bleeding, conferring a high clinical success rate with measurable laboratory outcomes; albeit temporary. DDAVP and factor replacement therapy may be partially successful in controlling minor bleeds, but not major bleeds. Other less commonly used agents may be effective in certain cases, although data are limited.

12.
Blood Adv ; 5(2): 414-431, 2021 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-33496739

RESUMEN

Accurate and consistent sequence variant interpretation is critical to the correct diagnosis and appropriate clinical management and counseling of patients with inherited genetic disorders. To minimize discrepancies in variant curation and classification among different clinical laboratories, the American College of Medical Genetics and Genomics (ACMG), along with the Association for Molecular Pathology (AMP), published standards and guidelines for the interpretation of sequence variants in 2015. Because the rules are not universally applicable to different genes or disorders, the Clinical Genome Resource (ClinGen) Platelet Disorder Expert Panel (PD-EP) has been tasked to make ACMG/AMP rule specifications for inherited platelet disorders. ITGA2B and ITGB3, the genes underlying autosomal recessive Glanzmann thrombasthenia (GT), were selected as the pilot genes for specification. Eight types of evidence covering clinical phenotype, functional data, and computational/population data were evaluated in the context of GT by the ClinGen PD-EP. The preliminary specifications were validated with 70 pilot ITGA2B/ITGB3 variants and further refined. In the final adapted criteria, gene- or disease-based specifications were made to 16 rules, including 7 with adjustable strength; no modification was made to 5 rules; and 7 rules were deemed not applicable to GT. Employing the GT-specific ACMG/AMP criteria to the pilot variants resulted in a reduction of variants classified with unknown significance from 29% to 20%. The overall concordance with the initial expert assertions was 71%. These adapted criteria will serve as guidelines for GT-related variant interpretation to increase specificity and consistency across laboratories and allow for better clinical integration of genetic knowledge into patient care.


Asunto(s)
Pruebas Genéticas , Genoma Humano , Variación Genética , Genómica , Humanos , Integrina alfa2/genética , Integrina beta3/genética , Fenotipo , Estados Unidos
13.
Bioinformatics ; 37(13): 1828-1838, 2021 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-33471076

RESUMEN

MOTIVATION: MicroRNA (miRNA) precursor arms give rise to multiple isoforms simultaneously called 'isomiRs.' IsomiRs from the same arm typically differ by a few nucleotides at either their 5' or 3' termini or both. In humans, the identities and abundances of isomiRs depend on a person's sex and genetic ancestry as well as on tissue type, tissue state and disease type/subtype. Moreover, nearly half of the time the most abundant isomiR differs from the miRNA sequence found in public databases. Accurate mining of isomiRs from deep sequencing data is thus important. RESULTS: We developed isoMiRmap, a fast, standalone, user-friendly mining tool that identifies and quantifies all isomiRs by directly processing short RNA-seq datasets. IsoMiRmap is a portable 'plug-and-play' tool, requires minimal setup, has modest computing and storage requirements, and can process an RNA-seq dataset with 50 million reads in just a few minutes on an average laptop. IsoMiRmap deterministically and exhaustively reports all isomiRs in a given deep sequencing dataset and quantifies them accurately (no double-counting). IsoMiRmap comprehensively reports all miRNA precursor locations from which an isomiR may be transcribed, tags as 'ambiguous' isomiRs whose sequences exist both inside and outside of the space of known miRNA sequences and reports the public identifiers of common single-nucleotide polymorphisms and documented somatic mutations that may be present in an isomiR. IsoMiRmap also identifies isomiRs with 3' non-templated post-transcriptional additions. Compared to similar tools, isoMiRmap is the fastest, reports more bona fide isomiRs, and provides the most comprehensive information related to an isomiR's transcriptional origin. AVAILABILITY AND IMPLEMENTATION: The codes for isoMiRmap are freely available at https://cm.jefferson.edu/isoMiRmap/ and https://github.com/TJU-CMC-Org/isoMiRmap/. IsomiR profiles for the datasets of the 1000 Genomes Project, spanning five population groups, and The Cancer Genome Atlas (TCGA), spanning 33 cancer studies, are also available at https://cm.jefferson.edu/isoMiRmap/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

14.
J Asthma ; 58(4): 554-563, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-31868043

RESUMEN

OBJECTIVE: To describe the evaluation of implementation effectiveness of an asthma shared decision making (SDM) intervention at the 10 individual facilitator-led primary care practices in the ADAPT-NC Study using the Consolidated Framework for Implementation Research (CFIR). METHODS: Practices were scored across 40 CFIR constructs within 5 domains using a previously published scoring system of -2 to +2. Based on overall construct scores, practices were then classified as high, medium, or low adopters. To evaluate clinical outcomes, changes in asthma exacerbations were assessed for emergency department (ED) visits, hospitalizations, and oral steroid prescription orders. Using regression analysis, the absolute change in percent for each outcome relative to the CFIR score for each practice was analyzed. (Trial registration #NCT02047929). RESULTS: Implementation effectiveness was reflected in CFIR score differences with 7 high, 1 medium, and 2 low adopter practices. High adopters mostly scored well across all domains. Weaknesses were consistent amongst the 2 low adopters with lower scores in the Inner Setting, Characteristics of Individuals, and Process domains. While no significant correlations were seen between the practices' CFIR scores and the absolute change in ED visits, hospitalizations, or oral steroid prescription orders, practices with higher percentages of children had greater improvements in clinical outcomes. CONCLUSIONS: The CFIR was used to evaluate the asthma SDM intervention implementation at 10 facilitator-led practices. While there was no significant correlation between higher implementation effectiveness and greater improvement in clinical outcomes, practices with a higher proportion of pediatric patients did experience a significant reduction in overall exacerbations post-implementation.


Asunto(s)
Corticoesteroides/uso terapéutico , Asma/tratamiento farmacológico , Toma de Decisiones Conjunta , Servicio de Urgencia en Hospital/organización & administración , Atención Primaria de Salud/organización & administración , Corticoesteroides/administración & dosificación , Niño , Femenino , Humanos , Capacitación en Servicio , Masculino , Participación del Paciente , Factores Socioeconómicos
15.
Blood Coagul Fibrinolysis ; 31(8): 522-529, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32941196

RESUMEN

: The objectives of this study were firstly to determine the prevalence of overweight/obesity in adult persons with hemophilia in Utah, and to explore the association between age, disease severity and race with body mass index (BMI), and secondly to provide recent data on the prevalence of overweight/obesity in the hemophilia population via a review of the literature. We conducted a retrospective cross section study of adult persons with hemophilia who were seen at a Utah hemophilia treatment center from 1 January 2017 to 31 December 2019. The electronic database PubMed was searched for studies with observation periods from 1 January 2012 to 31 December 2019. The age-adjusted prevalence for overweight/obesity in the adult Utah hemophilia population was higher than the overall Utah population and the general US population. After adjusting for race and age, mild hemophilia was associated with a 7.7% higher BMI (95% confidence interval, 0.023-15.98%, P < 0.05). Review of the literature demonstrated high levels of overweight/obesity in hemophilia communities globally with considerable heterogeneity between studies. Despite increasing awareness, prevalence of overweight/obesity in the hemophilia population remains high in comparison with the general population. There is a critical need to address this issue acutely at hemophilia treatment centers due to the considerable burden of obesity.


Asunto(s)
Hemofilia A/complicaciones , Hemofilia B/complicaciones , Obesidad/complicaciones , Sobrepeso/complicaciones , Adulto , Factores de Edad , Índice de Masa Corporal , Femenino , Hemofilia A/epidemiología , Hemofilia B/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Sobrepeso/epidemiología , Prevalencia , Utah/epidemiología , Adulto Joven
16.
Blood ; 136(15): 1760-1772, 2020 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-32844999

RESUMEN

There is heritability to interindividual variation in platelet count, and better understanding of the regulating genetic factors may provide insights for thrombopoiesis. MicroRNAs (miRs) regulate gene expression in health and disease, and megakaryocytes (MKs) deficient in miRs have lower platelet counts, but information about the role of miRs in normal human MK and platelet production is limited. Using genome-wide miR profiling, we observed strong correlations among human bone marrow MKs, platelets, and differentiating cord blood-derived MK cultures, and identified MK miR-125a-5p as associated with human platelet number but not leukocyte or hemoglobin levels. Overexpression and knockdown studies showed that miR-125a-5p positively regulated human MK proplatelet (PP) formation in vitro. Inhibition of miR-125a-5p in vivo lowered murine platelet counts. Analyses of MK and platelet transcriptomes identified LCP1 as a miR-125a-5p target. LCP1 encodes the actin-bundling protein, L-plastin, not previously studied in MKs. We show that miR-125a-5p directly targets and reduces expression of MK L-plastin. Overexpression and knockdown studies show that L-plastin promotes MK progenitor migration, but negatively correlates with human platelet count and inhibits MK PP formation (PPF). This work provides the first evidence for the actin-bundling protein, L-plastin, as a regulator of human MK PPF via inhibition of the late-stage MK invagination system, podosome and PPF, and PP branching. We also provide resources of primary and differentiating MK transcriptomes and miRs associated with platelet counts. miR-125a-5p and L-plastin may be relevant targets for increasing in vitro platelet manufacturing and for managing quantitative platelet disorders.


Asunto(s)
Plaquetas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Megacariocitos/citología , Megacariocitos/metabolismo , Glicoproteínas de Membrana/genética , MicroARNs/genética , Proteínas de Microfilamentos/genética , Trombopoyesis/genética , Actinas/metabolismo , Biomarcadores , Técnicas de Silenciamiento del Gen , Humanos , Glicoproteínas de Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Interferencia de ARN
17.
BMC Nurs ; 19: 40, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32477003

RESUMEN

BACKGROUND: Practice facilitation is a method of introducing and sustaining organizational change. It involves the use of skilled healthcare professionals called practice facilitators (PFs) to help address the challenges associated with implementing evidence-based guidelines and complex interventions into practice. PFs provide a framework for translating research into practice by building relationships, improving communication, fostering change, and sharing resources. Nurses are well positioned to serve as PFs for the implementation of complex interventions, however, there is little evidence currently available to describe nurses in this role. Additionally, the best strategies to implement complex interventions into practices are still not fully understood. Combining practice facilitation with the train-the-trainer model has the potential to spread knowledge and skills. Shared decision making (SDM), which involves patients and providers jointly engaging in decisions around treatment options, has been shown to improve outcomes for patients with asthma. The goal of this manuscript is to describe and evaluate the practice facilitation process from the ADAPT-NC Study which successfully utilized research nurses to implement a complex asthma SDM toolkit intervention into primary care practices. METHODS: As part of a larger study, 10 primary care practices were recruited for a facilitator-led dissemination intervention involving a 12-week rollout of an asthma SDM toolkit (trial registration: 1.28.2014, #NCT02047929). An experienced lead PF trained research nurses as PFs from each of the 4 participating practice-based research networks (PBRNs) in a train-the-trainer model utilizing a one-day training event and subsequent remote meetings. Evaluation of PF engagement was measured through process improvement surveys. RESULTS: Overall, the asthma SDM intervention was successfully implemented within the 4 PBRNs. All 10 facilitator-led practices remained engaged with their PFs, with 8 out of the 10 practices able to incorporate and sustain SDM visits or clinics. Responses from the surveys for process improvement yielded improved PF communication and team dynamics over time. CONCLUSIONS: This study demonstrated effective use of research nurses as practice facilitators during the dissemination of an asthma SDM intervention into primary care practices, adding to the knowledge of best practices by describing a model of large-scale implementation of a complex intervention through practice facilitation with nurses. TRIAL REGISTRATION: "Comparing Traditional and Participatory Dissemination of a Shared Decision Making Intervention" was retrospectively registered at https://clinicaltrials.gov/ on January 28th, 2014 (NCT02047929).

18.
BMJ Open ; 10(3): e030883, 2020 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-32152153

RESUMEN

OBJECTIVE: To qualitatively analyse different types of dissemination of information during monthly group calls between researchers, providers and clinical staff used to establish best practices for implementing an asthma shared decision-making (SDM) intervention. Evaluating dissemination of information can provide a better understanding of how best practices are shared, informing implementation approaches to improve the uptake of new evidence and overcome barriers. SETTING: 10 primary care practices in North Carolina. PARTICIPANTS: Providers and clinical staff participated in monthly group phone calls with researchers to share best practices during implementation of a SDM intervention for asthma patients. DESIGN: The research team transcribed and coded statements using content analysis into three different knowledge types: Knowledge Position, Knowledge Form and Knowledge Object. Knowledge Objects were further classified using directed content analysis where the research team interpreted the content objects through a classification process of identifying themes or patterns to describe three different types of dissemination of information: (A) Confirmation of Existing Knowledge, (B) Generation of New Knowledge and (C) Spreading of New Knowledge. RESULTS: Across the 8 transcripts, 4 Knowledge Positions, 7 Knowledge Forms and 18 types of Knowledge Objects were identified. From the Knowledge Objects, Confirmation of Existing Knowledge occurred during the training of participating practices. The review also identified Generation of New Knowledge by providers and clinical staff raised in these calls. This Generation of New Knowledge was later documented being used by other practices with the identification of Spreading of New Knowledge. CONCLUSION: The research team described the types of dissemination of information that occurred between researchers, providers and clinical staff during implementation of an asthma SDM intervention. Both Confirmation of Existing Knowledge and Generation of New Knowledge in response to barriers occurred. These exploratory dissemination of information results provide additional mechanisms for evaluating implementation science. TRIAL REGISTRATION NUMBER: NCT02047929; Post-results.


Asunto(s)
Asma/terapia , Toma de Decisiones Conjunta , Personal de Salud , Difusión de la Información , Relaciones Interprofesionales , Atención Primaria de Salud/organización & administración , Investigadores , Humanos , Ciencia de la Implementación , North Carolina , Investigación Cualitativa
19.
Haematologica ; 105(4): 888-894, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32139434

RESUMEN

Glanzmann thrombasthenia (GT) is an autosomal recessive disorder of platelet aggregation caused by quantitative or qualitative defects in integrins αIIb and ß3. These integrins are encoded by the ITGA2B and ITGB3 genes and form platelet glycoprotein (GP)IIb/IIIa, which acts as the principal platelet receptor for fibrinogen. Although there is variability in the clinical phenotype, most patients present with severe mucocutaneous bleeding at an early age. A classic pattern of abnormal platelet aggregation, platelet glycoprotein expression and molecular studies confirm the diagnosis. Management of bleeding is based on a combination of hemostatic agents including recombinant activated factor VII with or without platelet transfusions and antifibrinolytic agents. Refractory bleeding and platelet alloimmunization are common complications. In addition, pregnant patients pose unique management challenges. This review highlights clinical and molecular aspects in the approach to patients with GT, with particular emphasis on the significance of multidisciplinary care.


Asunto(s)
Trombastenia , Plaquetas , Humanos , Integrina beta3/genética , Agregación Plaquetaria , Pruebas de Función Plaquetaria , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria , Trombastenia/diagnóstico , Trombastenia/genética , Trombastenia/terapia
20.
J Public Health Manag Pract ; 26(1): 67-70, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-30807462

RESUMEN

Diabetes is a significant public health problem in eastern North Carolina, and completion of formal diabetes self-management education (DSME) is low. To seek methods to increase DSME completion, patients with diabetes in an eastern North Carolina regional health care system who had not completed DSME (n = 58) were surveyed during wellness visits to examine attitudes toward the use of vouchers (eg, coupons that purchase healthy food, exercise classes, gym memberships). There was an extremely low awareness (19%) of and referral (5%) to DSME. Most respondents (77%) said they would or might be more likely to complete DSME if they received a voucher at the end. Vouchers for healthy food venues such as farmers' markets were most preferred, and 6 months or less was found to be an acceptable time frame to use the voucher. This study offers some evidence for DSME providers to explore vouchers as one approach to increase program completion.


Asunto(s)
Diabetes Mellitus Tipo 2/psicología , Aceptación de la Atención de Salud/psicología , Educación del Paciente como Asunto/normas , Automanejo/educación , Adulto , Diabetes Mellitus Tipo 2/terapia , Escolaridad , Femenino , Conductas Relacionadas con la Salud , Humanos , Masculino , Persona de Mediana Edad , North Carolina , Aceptación de la Atención de Salud/estadística & datos numéricos , Educación del Paciente como Asunto/métodos , Educación del Paciente como Asunto/estadística & datos numéricos , Automanejo/métodos , Automanejo/estadística & datos numéricos , Encuestas y Cuestionarios
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