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1.
Nature ; 623(7988): 836-841, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37968395

RESUMO

Timely repair of chromosomal double-strand breaks is required for genome integrity and cellular viability. The polymerase theta-mediated end joining pathway has an important role in resolving these breaks and is essential in cancers defective in other DNA repair pathways, thus making it an emerging therapeutic target1. It requires annealing of 2-6 nucleotides of complementary sequence, microhomologies, that are adjacent to the broken ends, followed by initiation of end-bridging DNA synthesis by polymerase θ. However, the other pathway steps remain inadequately defined, and the enzymes required for them are unknown. Here we demonstrate requirements for exonucleolytic digestion of unpaired 3' tails before polymerase θ can initiate synthesis, then a switch to a more accurate, processive and strand-displacing polymerase to complete repair. We show the replicative polymerase, polymerase δ, is required for both steps; its 3' to 5' exonuclease activity for flap trimming, then its polymerase activity for extension and completion of repair. The enzymatic steps that are essential and specific to this pathway are mediated by two separate, sequential engagements of the two polymerases. The requisite coupling of these steps together is likely to be facilitated by physical association of the two polymerases. This pairing of polymerase δ with a polymerase capable of end-bridging synthesis, polymerase θ, may help to explain why the normally high-fidelity polymerase δ participates in genome destabilizing processes such as mitotic DNA synthesis2 and microhomology-mediated break-induced replication3.


Assuntos
Reparo do DNA por Junção de Extremidades , DNA Polimerase III , DNA Polimerase Dirigida por DNA , DNA/biossíntese , DNA/química , DNA/metabolismo , DNA Polimerase III/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Instabilidade Genômica , DNA Polimerase teta
2.
Nature ; 603(7899): 124-130, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35197626

RESUMO

A hallmark pathological feature of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is the depletion of RNA-binding protein TDP-43 from the nucleus of neurons in the brain and spinal cord1. A major function of TDP-43 is as a repressor of cryptic exon inclusion during RNA splicing2-4. Single nucleotide polymorphisms in UNC13A are among the strongest hits associated with FTD and ALS in human genome-wide association studies5,6, but how those variants increase risk for disease is unknown. Here we show that TDP-43 represses a cryptic exon-splicing event in UNC13A. Loss of TDP-43 from the nucleus in human brain, neuronal cell lines and motor neurons derived from induced pluripotent stem cells resulted in the inclusion of a cryptic exon in UNC13A mRNA and reduced UNC13A protein expression. The top variants associated with FTD or ALS risk in humans are located in the intron harbouring the cryptic exon, and we show that they increase UNC13A cryptic exon splicing in the face of TDP-43 dysfunction. Together, our data provide a direct functional link between one of the strongest genetic risk factors for FTD and ALS (UNC13A genetic variants), and loss of TDP-43 function.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Éxons/genética , Demência Frontotemporal/metabolismo , Estudo de Associação Genômica Ampla , Humanos , Neurônios Motores/patologia , Proteínas do Tecido Nervoso
3.
EMBO J ; 42(12): e111272, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37143403

RESUMO

Patients with chronic obstructive pulmonary disease (COPD) are still waiting for curative treatments. Considering its environmental cause, we hypothesized that COPD will be associated with altered epigenetic signaling in lung cells. We generated genome-wide DNA methylation maps at single CpG resolution of primary human lung fibroblasts (HLFs) across COPD stages. We show that the epigenetic landscape is changed early in COPD, with DNA methylation changes occurring predominantly in regulatory regions. RNA sequencing of matched fibroblasts demonstrated dysregulation of genes involved in proliferation, DNA repair, and extracellular matrix organization. Data integration identified 110 candidate regulators of disease phenotypes that were linked to fibroblast repair processes using phenotypic screens. Our study provides high-resolution multi-omic maps of HLFs across COPD stages. We reveal novel transcriptomic and epigenetic signatures associated with COPD onset and progression and identify new candidate regulators involved in the pathogenesis of chronic lung diseases. The presence of various epigenetic factors among the candidates demonstrates that epigenetic regulation in COPD is an exciting research field that holds promise for novel therapeutic avenues for patients.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Transcriptoma , Humanos , Epigênese Genética , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/patologia , Pulmão/patologia , Perfilação da Expressão Gênica , Metilação de DNA
4.
J Vasc Res ; 61(2): 68-76, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38219725

RESUMO

INTRODUCTION: While multiple factors influence coronary artery bypass graft (CABG) success rates, preserving saphenous vein endothelium during surgery may improve patency. Standard preparations include saphenous vein preparation in heparinized saline (saline) which can result in endothelial loss and damage. Here, we investigated the impact of preparing saphenous graft vessels in heparinized patient blood (blood) versus saline. METHODS: Saphenous vein tissues from a total of 23 patients undergoing CABG were split into 2 groups (1) saline and (2) heparinized patient blood. Excess tissue was fixed for analysis immediately following surgery. Level of endothelial coverage, oxidative stress marker 4-hydroxynonenal (4HNE), and oxidative stress protective marker nuclear factor erythroid 2-related factor 2 (NRF2) were evaluated. RESULTS: In saline patient veins, histological analysis revealed a limited luminal layer, suggesting a loss of endothelial cells (ECs). Immunofluorescent staining of EC markers vascular endothelial cadherin (VE-cadherin) and endothelial nitric oxide identified a significant improvement in EC coverage in the blood versus saline groups. Although both treatment groups expressed 4HNE to similar levels, EC blood samples expressed higher levels of NRF2. CONCLUSION: Our data indicate that use of heparinized patient blood helps preserve the endothelium and promotes vein graft health. This has the potential to improve long-term outcomes in patients.


Assuntos
Células Endoteliais , Veia Safena , Humanos , Veia Safena/patologia , Fator 2 Relacionado a NF-E2 , Endotélio Vascular/patologia , Ponte de Artéria Coronária/efeitos adversos
5.
Age Ageing ; 53(4)2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38619122

RESUMO

OBJECTIVE: To explore the practice of prescribing and implementing early mobilisation and weight-bearing as tolerated after hip fracture surgery in older adults and identify barriers and facilitators to their implementation. METHODS: Semi-structured interviews were conducted with 20 healthcare providers (10 orthopaedic surgeons and 10 physiotherapists) from Saudi Arabian government hospitals. Data were analysed using inductive thematic analysis. RESULTS: While early mobilisation and weight-bearing as tolerated were viewed as important by most participants, they highlighted barriers to the implementation of these practices. Most participants advocated for mobility within 48 h of surgery, aligning with international guidance; however, the implementation of weight-bearing as tolerated was varied. Some participants stressed the type of surgery undertaken as a key factor in weight-bearing prescription. For others, local protocols or clinician preference was seen as most important, the latter partially influenced by where they were trained. Interdisciplinary collaboration between orthopaedic surgeons and physiotherapists was seen as a crucial part of postoperative care and weight-bearing. Patient and family member buy-in was also noted as a key factor, as fear of further injury can impact a patient's adherence to weight-bearing prescriptions. Participants noted a lack of standardised postoperative protocols and the need for routine patient audits to better understand current practices and outcomes. CONCLUSION: This study contributes to national and global discussions on the prescription of early mobilisation and weight-bearing as tolerated. It highlights the necessity for a harmonised approach, incorporating standardised, evidence-based protocols with patient-specific care, robust healthcare governance and routine audits and monitoring for quality assurance and better patient outcomes.


Assuntos
Deambulação Precoce , Fraturas do Quadril , Humanos , Idoso , Arábia Saudita , Fraturas do Quadril/cirurgia , Pesquisa Qualitativa , Cuidados Pós-Operatórios
6.
Mol Cell ; 63(4): 662-673, 2016 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-27453047

RESUMO

DNA polymerase theta (Pol θ)-mediated end joining (TMEJ) has been implicated in the repair of chromosome breaks, but its cellular mechanism and role relative to canonical repair pathways are poorly understood. We show that it accounts for most repairs associated with microhomologies and is made efficient by coupling a microhomology search to removal of non-homologous tails and microhomology-primed synthesis across broken ends. In contrast to non-homologous end joining (NHEJ), TMEJ efficiently repairs end structures expected after aborted homology-directed repair (5' to 3' resected ends) or replication fork collapse. It typically does not compete with canonical repair pathways but, in NHEJ-deficient cells, is engaged more frequently and protects against translocation. Cell viability is also severely impaired upon combined deficiency in Pol θ and a factor that antagonizes end resection (Ku or 53BP1). TMEJ thus helps to sustain cell viability and genome stability by rescuing chromosome break repair when resection is misregulated or NHEJ is compromised.


Assuntos
Quebra Cromossômica , Reparo do DNA por Junção de Extremidades , DNA Polimerase Dirigida por DNA/metabolismo , Instabilidade Genômica , Animais , Sistemas CRISPR-Cas , Linhagem Celular Transformada , DNA Polimerase Dirigida por DNA/deficiência , DNA Polimerase Dirigida por DNA/genética , Genótipo , Autoantígeno Ku/genética , Autoantígeno Ku/metabolismo , Camundongos Knockout , Fenótipo , Fatores de Tempo , DNA Polimerase teta
7.
Am J Respir Cell Mol Biol ; 67(1): 36-49, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35377835

RESUMO

Idiopathic pulmonary fibrosis is a progressive lung disease with limited therapeutic options that is characterized by pathological fibroblast activation and aberrant lung remodeling with scar formation. YAP (Yes-associated protein) is a transcriptional coactivator that mediates mechanical and biochemical signals controlling fibroblast activation. We previously identified HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors (statins) as YAP inhibitors based on a high-throughput small-molecule screen in primary human lung fibroblasts. Here we report that several Aurora kinase inhibitors were also identified from the top hits of this screen. MK-5108, a highly selective inhibitor for AURKA (Aurora kinase A), induced YAP phosphorylation and cytoplasmic retention and significantly reduced profibrotic gene expression in human lung fibroblasts. The inhibitory effect on YAP nuclear translocation and profibrotic gene expression is specific to inhibition of AURKA, but not Aurora kinase B or C, and is independent of the Hippo pathway kinases LATS1 and LATS2 (Large Tumor Suppressor 1 and 2). Further characterization of the effects of MK-5108 demonstrate that it inhibits YAP nuclear localization indirectly via effects on actin polymerization and TGFß (Transforming Growth Factor ß) signaling. In addition, MK-5108 treatment reduced lung collagen deposition in the bleomycin mouse model of pulmonary fibrosis. Our results reveal a novel role for AURKA in YAP-mediated profibrotic activity in fibroblasts and highlight the potential of small-molecule screens for YAP inhibitors for identification of novel agents with antifibrotic activity.


Assuntos
Aurora Quinase A , Fibrose Pulmonar Idiopática , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Aurora Quinase A/metabolismo , Proteínas de Ciclo Celular/metabolismo , Fibroblastos/metabolismo , Humanos , Fibrose Pulmonar Idiopática/patologia , Camundongos , Fator de Crescimento Transformador beta/metabolismo , Proteínas de Sinalização YAP
8.
Health Res Policy Syst ; 20(1): 68, 2022 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-35717233

RESUMO

BACKGROUND: COVID-19 has tested healthcare and research systems around the world, forcing the large-scale reorganization of hospitals, research infrastructure and resources. The United Kingdom has been singled out for the speed and scale of its research response. The efficiency of the United Kingdom's research mobilization was in large part predicated on the pre-existing embeddedness of the clinical research system within the National Health Service (NHS), a public, free-at-point-of-delivery healthcare system. In this paper we discuss the redeployment of the clinical research workforce to support the pandemic clinical services, detailing the process of organizing this redeployment, as well as the impacts redeployment has had on both staff and research delivery at one research-intensive acute NHS trust in London. METHODS: A social science case study of one large research-active NHS trust drawing on data from an online questionnaire; participant observation of key research planning meetings; semi-structured interviews with staff involved in research; and document analysis of emails and official national and trust communications. RESULTS: We found that at our case-study hospital trust, the research workforce was a resource that was effectively redeployed as part of the pandemic response. Research delivery workers were redeployed to clinical roles, to COVID-related research and to work maintaining the research system during the redeployment itself. Redeployed research workers faced some difficulties with technology and communication, but many had a positive experience and saw the redeployment as a significant and valuable moment in their career. CONCLUSIONS: This study explicates the role of the research delivery workforce for the United Kingdom's COVID response. Redeployed research workers facilitated the emergency response by delivering significant amounts of patient care. The public also benefited from having a well-developed research infrastructure in place that was able to flexibly respond to a novel virus. Many research workers feel that the NHS should provide more support for this distinctive workforce.


Assuntos
COVID-19 , Hospitais , Humanos , Pandemias , Medicina Estatal , Recursos Humanos
9.
J Card Surg ; 37(11): 3485-3491, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36116062

RESUMO

BACKGROUND AND AIM OF THE STUDY: Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery which can result in increased mortality and increased healthcare costs. During Hurricane Maria (2017), a nationwide shortage of mannitol occurred, and our institution switched to the utilization of albumin as a priming fluid solution. We observed decreased rates of POAF during that time and began alternating albumin and mannitol priming fluid solutions. We hypothesized this observation may be from altered perinexal conduction from albumin utilization. METHODS: A retrospective chart review of all patients from January 2020 through December 2020 who underwent cardiac surgery was performed, to determine if albumin was associated with reduced POAF rates. Two hundred and thirteen patients were identified and 4 were excluded. Two hundred and nine patients (110 albumin priming fluid and 99 mannitol priming fluid) were included in our final analysis. RESULTS: Analysis was performed for all patients with POAF and in patients with new-onset AF (without a history of prior AF) after surgery. POAF rates showed no statistically significant difference between cohorts. For all patients, POAF occurred in 43% of the albumin subgroup and 47% of the mannitol subgroup (p = .53) and for patients with new-onset AF, POAF occurred in 35% of the albumin subgroup versus 42% of the mannitol subgroup (p = .36). Logistic regression revealed that age, ejection fraction and cardiopulmonary bypass time was associated with POAF, in our cohort. CONCLUSIONS: The use of albumin compared to mannitol as priming fluid solutions was not associated with statistically significant reductions in POAF rate, in our population.


Assuntos
Fibrilação Atrial , Albuminas , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/etiologia , Fibrilação Atrial/prevenção & controle , Humanos , Manitol , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Fatores de Risco
10.
Am J Respir Cell Mol Biol ; 62(4): 479-492, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31944822

RESUMO

Idiopathic pulmonary fibrosis is a lung disease with limited therapeutic options that is characterized by pathological fibroblast activation and aberrant lung remodeling with scar formation. YAP (Yes-associated protein) is a transcriptional coactivator that mediates mechanical and biochemical signals controlling fibroblast activation. In this study, we developed a high-throughput small-molecule screen for YAP inhibitors in primary human lung fibroblasts. Multiple HMG-CoA (hydroxymethylglutaryl-coenzyme A) reductase inhibitors (statins) were found to inhibit YAP nuclear localization via induction of YAP phosphorylation, cytoplasmic retention, and degradation. We further show that the mevalonate pathway regulates YAP activation, and that simvastatin treatment reduces fibrosis markers in activated human lung fibroblasts and in the bleomycin mouse model of pulmonary fibrosis. Finally, we show that simvastatin modulates YAP in vivo in mouse lung fibroblasts. Our results highlight the potential of small-molecule screens for YAP inhibitors and provide a mechanism for the antifibrotic activity of statins in idiopathic pulmonary fibrosis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Fibrose Pulmonar/tratamento farmacológico , Acil Coenzima A/metabolismo , Animais , Biomarcadores/metabolismo , Bleomicina/farmacologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Ácido Mevalônico/metabolismo , Camundongos , Fosfoproteínas/metabolismo , Fibrose Pulmonar/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sinvastatina/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Proteínas de Sinalização YAP
11.
Sociol Health Illn ; 42(6): 1312-1327, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32449794

RESUMO

The UK National Health Service (NHS) is changing. Consecutive UK industrial strategies have supported the shift from an NHS that provides free-at-point-of-delivery healthcare to one that also facilitates research. Said to promote healthcare's triple aim of 'better health, better healthcare, and lower cost' (Wachter, 2016, 3), the digitisation of patient records is a core part in opening routine aspects of the health system to potential research. In this paper, we thematically analyse 11 policy documents and ask, how does the NHS discuss its decision to digitise patient records and what are the implications of such practices on the citizen? We document how (1) digitisation is presented as a collective endeavour for patients and NHS professionals, offering new possibilities for patients to participate in their own health and that of the population through research and, (2) digitisation contributes to the building of an efficient health system. Through this analysis we reflect on how discussions of digitisation present uncritically the potential of Electronic Health Records and big data analytics to improve care and generate wealth through research, and reconfigure patienthood, by placing research participation as a routine part of accessing NHS healthcare.


Assuntos
Registros Eletrônicos de Saúde , Medicina Estatal , Atenção à Saúde , Humanos , Reino Unido
12.
Eur J Immunol ; 48(11): 1904-1914, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30169894

RESUMO

Steroid refractory inflammation is an unmet medical need in the management of inflammatory diseases. Thus, mechanisms, improving steroid sensitivity and simultaneously decreasing inflammation have potential therapeutic utility. The FK506-binding protein 51 (FKBP51) is reported to influence steroid sensitivity in mental disorders. Moreover, biochemical data highlight a connection between FKBP51 and the IKK complex. The aim of this study was to elucidate whether FKBP51 inhibition had utility in modulating steroid resistant inflammation by increasing the sensitivity of the glucocorticoid receptor (GR) signalling and simultaneously inhibiting NFκB-driven inflammation. We have demonstrated that FKBP51 silencing in a bronchial epithelial cell line resulted in a 10-fold increased potency for dexamethasone towards IL1beta-induced IL6 and IL8, whilst FKBP51 over-expression of FKBP51 reduced significantly the prednisolone sensitivity in a murine HDM-driven pulmonary inflammation model. Immunoprecipitation experiments with anti-FKBP51 antibodies, confirmed the presence of FKBP51 in a complex comprising Hsp90, GR and members of the IKK family. FKBP51 silencing reduced NFκB (p50/p65) nucleus translocation, resulting in reduced ICAM expression, cytokine and chemokine secretion. In conclusion, we demonstrate that FKBP51 has the potential to control inflammation in steroid insensitive patients in a steroid-dependent and independent manner and thus may be worthy of further study as a drug target.


Assuntos
NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Esteroides/farmacologia , Proteínas de Ligação a Tacrolimo/metabolismo , Células A549 , Animais , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Dexametasona/farmacologia , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Imunoprecipitação/métodos , Camundongos , Camundongos Endogâmicos BALB C , Pneumonia/tratamento farmacológico , Pneumonia/metabolismo , Prednisolona/farmacologia , Receptores de Glucocorticoides/metabolismo
13.
Epilepsia ; 59(11): 2153-2161, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30357823

RESUMO

OBJECTIVE: Clobazam oral soluble film (COSF) is a novel dosage form under development for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. The present study was undertaken to assess the pharmacokinetics of clobazam administered as single doses of COSF 20 and 10 mg compared with clobazam tablets (CTAB) 20 and 10 mg in healthy adults. A secondary objective was to assess the safety and tolerability of single doses of COSF 20 and 10 mg. METHODS: A total of 51 adult volunteers were enrolled in a single-dose, open-label, randomized four-sequence, four-period, crossover study with treatments (A) COSF 20 mg, (B) CTAB 20 mg, (C) COSF 10 mg, and (D) CTAB 10 mg. Pharmacokinetic sampling for clobazam and N-desmethylclobazam was carried out until 21 days postdose with a 28-day washout. Subjects were monitored for adverse events (AEs) throughout the study. Visual inspections of the administration site were performed before and after COSF administration to monitor for mucosal irritation. RESULTS: COSF at single doses of 10 and 20 mg was bioequivalent to CTAB at equivalent doses for both clobazam and its active metabolite N-desmethylclobazam. The pharmacokinetics of both formulations was dose-proportional at doses of 10 and 20 mg. The number of AEs and the number of subjects experiencing AEs were dose-related across the treatment groups, with somnolence the most common event. None of these events was severe or serious, and most were mild. There was no evidence for local irritation at the administration site following COSF. SIGNIFICANCE: COSF is a novel clobazam dosage form that is bioequivalent to CTAB. Because of its ease of administration, COSF may be expected to improve adherence, reduce likelihood of dosing error, and provide more accurate dosing than formulations of clobazam that are currently available.


Assuntos
Anticonvulsivantes/farmacocinética , Clobazam/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Administração Oral , Adolescente , Adulto , Área Sob a Curva , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Equivalência Terapêutica , Adulto Jovem
14.
PLoS Genet ; 10(10): e1004654, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25275444

RESUMO

Although a defect in the DNA polymerase POLQ leads to ionizing radiation sensitivity in mammalian cells, the relevant enzymatic pathway has not been identified. Here we define the specific mechanism by which POLQ restricts harmful DNA instability. Our experiments show that Polq-null murine cells are selectively hypersensitive to DNA strand breaking agents, and that damage resistance requires the DNA polymerase activity of POLQ. Using a DNA break end joining assay in cells, we monitored repair of DNA ends with long 3' single-stranded overhangs. End joining events retaining much of the overhang were dependent on POLQ, and independent of Ku70. To analyze the repair function in more detail, we examined immunoglobulin class switch joining between DNA segments in antibody genes. POLQ participates in end joining of a DNA break during immunoglobulin class-switching, producing insertions of base pairs at the joins with homology to IgH switch-region sequences. Biochemical experiments with purified human POLQ protein revealed the mechanism generating the insertions during DNA end joining, relying on the unique ability of POLQ to extend DNA from minimally paired primers. DNA breaks at the IgH locus can sometimes join with breaks in Myc, creating a chromosome translocation. We found a marked increase in Myc/IgH translocations in Polq-defective mice, showing that POLQ suppresses genomic instability and genome rearrangements originating at DNA double-strand breaks. This work clearly defines a role and mechanism for mammalian POLQ in an alternative end joining pathway that suppresses the formation of chromosomal translocations. Our findings depart from the prevailing view that alternative end joining processes are generically translocation-prone.


Assuntos
Instabilidade Cromossômica , DNA Polimerase Dirigida por DNA/metabolismo , Animais , Linfócitos B/fisiologia , Bleomicina/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/fisiologia , Células da Medula Óssea/efeitos da radiação , Células Cultivadas , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades/genética , DNA Polimerase Dirigida por DNA/genética , Feminino , Células HEK293 , Humanos , Switching de Imunoglobulina , Redes e Vias Metabólicas , Camundongos Endogâmicos C57BL , Camundongos Mutantes , DNA Polimerase teta
15.
Cancer Chemother Pharmacol ; 93(4): 307-317, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37955741

RESUMO

Fedratinib is an oral Janus kinase 2-selective inhibitor for the treatment of adult patients with intermediate-2 or high-risk myelofibrosis; however, some patients have difficulty with oral dosing. This randomized, phase 1, open-label, 2-part crossover study evaluated the relative bioavailability, safety, tolerability, taste, and palatability of fedratinib resulting from various alternative oral administration methods in healthy adults. Participants could receive fedratinib 400 mg orally as intact capsules along with a nutritional supplement; as contents of capsules dispersed in a nutritional supplement, delivered via nasogastric tube; or as a divided dose of 200 mg orally twice daily as intact capsules with a nutritional supplement. Fifty-eight participants received treatment. Total exposure to fedratinib was similar after oral administration of intact capsules or when dispersed in a nutritional supplement (area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration geometric mean ratio [AUC0-t GMR] [90% CI], 1.007 [0.929-1.092]). Total exposure to fedratinib was slightly reduced following nasogastric administration (AUC0-t GMR 0.850 [0.802-0.901]) and as a divided dose (AUC0-t GMR 0.836 [0.789-0.886]). No new safety signals were identified for fedratinib, and most participants found the taste and palatability acceptable when dispersed in a nutritional supplement. Overall, results suggest no clinically meaningful differences in total exposure to fedratinib between the tested oral administration methods. These findings may facilitate administration of fedratinib to patients who are intolerant of swallowing the capsule dosage form. (ClinicalTrials.gov: NCT05051553).


Assuntos
Disponibilidade Biológica , Adulto , Humanos , Estudos Cross-Over , Administração Oral , Área Sob a Curva
16.
NPJ Parkinsons Dis ; 9(1): 91, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37322068

RESUMO

Prion-like transmission of pathology in α-synucleinopathies like Parkinson's disease or multiple system atrophy is increasingly recognized as one potential mechanism to address disease progression. Active and passive immunotherapies targeting insoluble, aggregated α-synuclein are already being actively explored in the clinic with mixed outcomes so far. Here, we report the identification of 306C7B3, a highly selective, aggregate-specific α-synuclein antibody with picomolar affinity devoid of binding to the monomeric, physiologic protein. 306C7B3 binding is Ser129-phosphorylation independent and shows high affinity to several different aggregated α-synuclein polymorphs, increasing the likelihood that it can also bind to the pathological seeds assumed to drive disease progression in patients. In support of this, highly selective binding to pathological aggregates in postmortem brains of MSA patients was demonstrated, with no staining in samples from other human neurodegenerative diseases. To achieve CNS exposure of 306C7B3, an adeno-associated virus (AAV) based approach driving expression of the secreted antibody within the brain of (Thy-1)-[A30P]-hα-synuclein mice was used. Widespread central transduction after intrastriatal inoculation was ensured by using the AAV2HBKO serotype, with transduction being spread to areas far away from the inoculation site. Treatment of (Thy-1)-[A30P]-hα-synuclein mice at the age of 12 months demonstrated significantly increased survival, with 306C7B3 concentration reaching 3.9 nM in the cerebrospinal fluid. These results suggest that AAV-mediated expression of 306C7B3, targeting extracellular, presumably disease-propagating aggregates of α-synuclein, has great potential as a disease-modifying therapy for α-synucleinopathies as it ensures CNS exposure of the antibody, thereby mitigating the selective permeability of the blood-brain barrier.

17.
Biomedicines ; 10(11)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36359226

RESUMO

This review examines the effects of particle properties on drug-carrier interactions in the preparation of a dry powder inhaler (DPI) formulation, including appropriate mixing technology. The interactive effects of carrier properties on DPI formulation performance make it difficult to establish a direct cause-and-effect relationship between any one carrier property and its effect on the performance of a DPI formulation. Alpha lactose monohydrate remains the most widely used carrier for DPI formulations. The physicochemical properties of α-lactose monohydrate particles, such as particle size, shape and solid form, are profoundly influenced by the method of production. Therefore, wide variations in these properties are inevitable. In this review, the role of surface energetics in the optimisation of dry powder inhaler formulations is considered in lactose carrier selection. Several useful lactose particle modification methods are discussed as well as the use of fine lactose and force control agents in formulation development. It is concluded that where these have been investigated, the empirical nature of the studies does not permit early formulation prediction of product performance, rather they only allow the evaluation of final formulation quality. The potential to leverage particle interaction dynamics through the use of an experimental design utilising quantifiable lactose particle properties and critical quality attributes, e.g., surface energetics, is explored, particularly with respect to when a Quality-by-Design approach has been used in optimisation.

18.
Disabil Rehabil ; 44(6): 940-947, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-32609547

RESUMO

PURPOSE: To explore older adult's perceptions of early rehabilitation and recovery after hip fracture, as a complement to the UK standards for acute physiotherapy after hip fracture. METHODS: In-depth semi-structured interviews with 15 adults aged 60 years or more in hospital after hip fracture surgery. A thematic analysis approach with interpretation informed by Bury's biographical disruption theoretical framework. RESULTS: Participants voiced the importance of self-determination, professional support, meaningful feedback, and social capital after hip fracture. Collaborative working with staff was required for meeting the UK standards. Participants voiced anxieties about their hip fracture when considered in conjunction with their age and co-existing conditions, anticipating a disruption to their previous physical and social activities. This new, more dependent, life situation was not acceptable to participants. CONCLUSIONS: This study suggests hip fracture alone, was not perceived as a biographical disruption by older adults although it is presented as a potential tipping point in the loss of independence, contributing to the wider disruption of advancing age and co-existing conditions. For successful implementation of the UK standards, goal setting should consider patients in the wider context of their advancing age and co-existing conditions to empower them to define a fresh narrative of self.Implications for rehabilitationHip fracture was perceived as a potential tipping point in the loss of independence, contributing to the wider disruption of advancing age and co-existing conditions.Participants expressed uncertainty over their ability to recover their previous identity in the absence of professional support and/or social capital.Healthcare professionals need to educate and empower older adults to take charge of their own recovery.For successful implementation of the UK standards for acute physiotherapy, there is a need to contextualize goal setting to empower patients to define a fresh narrative of self.


Assuntos
Fraturas do Quadril , Idoso , Fraturas do Quadril/reabilitação , Fraturas do Quadril/cirurgia , Humanos , Modalidades de Fisioterapia , Pesquisa Qualitativa , Reino Unido
19.
Disabil Rehabil ; 44(21): 6194-6209, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34428389

RESUMO

PURPOSE: The purpose of the current review is to synthesize the evidence of patients' perspectives of recovery after hip fracture across the care continuum. METHODS: A systematic search was conducted, focusing on qualitative data from hip fracture patients. Screening, quality appraisal, and a subset of articles for extraction were completed in duplicate. Themes were generated using a thematic synthesis of data from original studies. RESULTS: Fourteen high-quality qualitative studies were included. Four review themes were identified: recovery as participation, feelings of vulnerability, driving recovery, and reliance on support. Patients considered recovery as a return to pre-fracture activities or "normal" enabling independence. Feelings of vulnerability were observed irrespective of the time since hip fracture and only diminished when recovery of function and activities enabled participation in valued activities, e.g., outdoor mobility. Participants expressed a desire to engage in recovery with realistic expectations and the benefits of meaningful feedback reported. While reliance on healthcare professionals decreased towards a later stage of recovery, reliance on social support persisted until recovery was perceived to have been achieved. CONCLUSION: Patient perspectives highlighted hip fracture as a major life event requiring health professional and social support to overcome feelings of vulnerability and enable active engagement in recovery.IMPLICATIONS FOR REHABILITATIONRehabilitation professionals should ensure expectations and goals are set early in the recovery process.Rehabilitation professionals should ensure goals set with patients are tailored to the individual's pre-fracture activities or "normal" promoting independence.Rehabilitation professionals should monitor goals ensuring they are providing support, motivation, and managing expectations across the care continuum.Rehabilitation professionals should address patients' feelings of vulnerability, particularly in the absence of social support, and ensure appropriate ongoing input to maximize recovery.


Assuntos
Fraturas do Quadril , Humanos , Fraturas do Quadril/reabilitação , Pesquisa Qualitativa , Cuidados Paliativos , Apoio Social , Pessoal de Saúde
20.
Health Soc Care Community ; 30(6): e5186-e5195, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35869786

RESUMO

Care home residents with stroke have higher levels of disability and poorer access to health services than those living in their own homes. We undertook observations and semi-structured interviews (n = 28 participants) with managers, staff, residents who had experienced a stroke and their relatives in four homes in London, England, in 2018/2019. Thematic analysis revealed that residents' needs regarding valued activity and stroke-specific care and rehabilitation were not always being met. This resulted from an interplay of factors: staff's lack of recognition of stroke and its effects; gaps in skills; time pressures; and the prioritisation of residents' safety. To improve residential care provision and residents' quality of life, care commissioners, regulators and providers may need to re-examine how care homes balance safety and limits on staff time against residents' valued activity, alongside improving access to specialist healthcare treatment and support.


Assuntos
Instituição de Longa Permanência para Idosos , Acidente Vascular Cerebral , Humanos , Idoso , Casas de Saúde , Qualidade de Vida , Assistência Centrada no Paciente , Acidente Vascular Cerebral/terapia
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