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PURPOSE OF REVIEW: This review focuses on the molecular taxonomy of osteoarthritis from the perspective of molecular biomarkers. We discuss how wet biochemical markers may be used to understand disease pathogenesis and progression and define molecular endotypes of osteoarthritis and how these correspond to clinical phenotypes. RECENT FINDINGS: Emerging evidence suggests that osteoarthritis is a heterogeneous and multifaceted disease with multiple causes, molecular endotypes and corresponding clinical phenotypes. Biomarkers may be employed as tools for patient stratification in clinical trials, enhanced disease management in the primary care centres of the future and for directing more rational and targeted osteoarthritis drug development. Proximal molecular biomarkers (e.g synovial fluid) are more likely to distinguish between molecular endotypes because there is less interference from systemic sources of biomarker noise, including comorbidities. SUMMARY: In this review, we have focused on the molecular biomarkers of four distinct osteoarthritis subtypes including inflammatory, subchondral bone remodelling, metabolic syndrome and senescent age-related endotypes, which have corresponding phenotypes. Progress in the field of osteoarthritis endotype and phenotype research requires a better understanding of molecular biomarkers that may be used in conjunction with imaging, pain and functional assessments for the design of more effective, stratified and individualized osteoarthritis treatments.
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Osteoartrite/diagnóstico , Fenótipo , Biomarcadores/metabolismo , Remodelação Óssea , Gerenciamento Clínico , Progressão da Doença , Humanos , Osteoartrite/metabolismoRESUMO
BACKGROUND: Rigorous antimicrobial stewardship programmes (ASPs) are an essential strategy against antimicrobial resistance. OBJECTIVES: To evaluate and score ASPs in acute English NHS hospitals and determine association of ASP scores with antimicrobial prescribing. METHODS: ASP structure and process were evaluated through an online survey in 148/152 acute hospitals in 2017. Scores were assigned to quality indicators based on resource- and labour-intensiveness, and their association with total and modified WHO-categorized 'Access', 'Watch' and 'Reserve' (AwaRe) prescribing was analysed. RESULTS: The survey response rate was 97% with 78% of trusts submitting antimicrobial prescribing data. Over 80% of ASPs contained stewardship teams, policies and access to outpatient parenteral antimicrobial therapy, whilst less than 50% scored well for leadership or funding. High process performance was observed for antimicrobial pre-authorization, prescribing review and feedback, restricted susceptibility reporting, antimicrobial consumption monitoring, adherence to guidelines and junior doctor training. Low process attainment included education of senior prescribers and lack of resistance surveillance data distribution. Between 2016 and 2017, there was no difference in total trust prescribing (Pâ=â0.117) although carbapenem prescribing fell (incidence rate ratioâ=â0.93, 95% CI 0.88-0.98) in non-teaching hospitals; 'Watch' prescribing also increased for specialist hospitals (ORâ=â1.10, 95% CI 1.01-1.20), as did 'Reserve' category prescribing in teaching (ORâ=â1.58, 95% CI 1.23-3.02) and specialist hospitals (ORâ=â3.09, 95% CI 2.02-4.74). A high process score was associated with lower 'Reserve' prescribing (ORâ=â0.82, 95% CI 0.67-1.01). CONCLUSIONS: All responding trusts had established ASPs. The association of a scoring system with total and 'AWaRe' prescribing to assess effectiveness of ASPs merits further study.
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Anti-Infecciosos , Gestão de Antimicrobianos , Revisão de Uso de Medicamentos , Uso de Medicamentos , Hospitais , Medicina Estatal , Inglaterra/epidemiologia , Hospitais/estatística & dados numéricos , Humanos , Vigilância em Saúde Pública , Indicadores de Qualidade em Assistência à Saúde , Qualidade da Assistência à Saúde , Medicina Estatal/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: Appropriate use of and access to antimicrobials are key priorities of global strategies to combat antimicrobial resistance (AMR). The WHO recently classified key antibiotics into three categories (AWaRe) to improve access (Access), monitor important antibiotics (Watch) and preserve effectiveness of 'last resort' antibiotics (Reserve). This classification was assessed for antibiotic stewardship and quality improvement in English hospitals. METHODS: Using an expert elicitation exercise, antibiotics used in England but not included in the WHO AWaRe index were added to an appropriate category following a workshop consensus exercise with national experts. The methodology was tested using national antibiotic prescribing data and presented by primary and secondary care. RESULTS: In 2016, 46/108 antibiotics included within the WHO AWaRe index were routinely used in England and an additional 25 antibiotics also commonly used in England were not included in the WHO AWaRe index. WHO AWaRe-excluded and -included antibiotics were reviewed and reclassified according to the England-adapted AWaRE index with the justification by experts for each addition or alteration. Applying the England-adapted AWaRe index, Access antibiotics accounted for the majority (60.9%) of prescribing, followed by Watch (37.9%) and Reserve (0.8%); 0.4% of antibiotics remained unclassified. There was unexplained 2-fold variation in prescribing between hospitals within each AWaRe category, highlighting the potential for quality improvement. CONCLUSIONS: We have adapted the WHO AWaRe index to create a specific index for England. The AWaRe index provides high-level understanding of antibiotic prescribing. Subsequent to this process the England AWaRe index is now embedded into national antibiotic stewardship policy and incentivized quality improvement schemes.
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Gestão de Antimicrobianos/legislação & jurisprudência , Gestão de Antimicrobianos/métodos , Prescrições de Medicamentos/estatística & dados numéricos , Hospitais/estatística & dados numéricos , Organização Mundial da Saúde , Antibacterianos/uso terapêutico , Gestão de Antimicrobianos/organização & administração , Inglaterra , Humanos , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricosRESUMO
Osteoarthritis (OA) is an age related joint disease associated with degeneration and loss of articular cartilage. Consequently, OA patients suffer from chronic joint pain and disability. Weight bearing joints and joints that undergo repetitive stress and excessive 'wear and tear' are particularly prone to developing OA. Cartilage has a poor regenerative capacity and current pharmacological agents only provide symptomatic pain relief. OA patients that respond poorly to conventional therapies are ultimately treated with surgical procedures to promote cartilage repair by implantation of artificial joint structures (arthroplasty) or total joint replacement (TJR). In the last two decades, stem cells derived from various tissues with varying differentiation and tissue regeneration potential have been used for the treatment of OA either alone or in combination with natural or synthetic scaffolds to aid cartilage repair. Although stem cells can be differentiated into chondrocytes in vitro or aid cartilage regeneration in vivo, their potential for OA management remains limited as cartilage regenerated by stem cells fails to fully recapitulate the structural and biomechanical properties of the native tissue. Efficient tissue regeneration remains elusive despite the simple design of cartilage, which unlike most other tissues is avascular and aneural, consisting of a single cell type. In this article, we have comprehensively reviewed the types of stem cells that have been proposed or tested for the management of OA, their potential efficacy as well as their limitations. We also touch on the role of biomaterials in cartilage tissue engineering and examine the prospects for their use in cell-based therapies.
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Cartilagem Articular , Osteoartrite/terapia , Regeneração , Medicina Regenerativa/tendências , Células-Tronco/citologia , Condrócitos/citologia , HumanosRESUMO
Biomaterials are key components in tissue engineering and regenerative medicine applications, with the intended purpose of reducing the burden of disease and enhancing the quality of life of a large number of patients. The success of many regenerative medicine strategies, such as cell-based therapies, artificial organs, and engineered living tissues, is highly dependent on the ability to design or produce suitable biomaterials that can support and guide cells during tissue healing and remodelling processes. This chapter presents an overview about basic research concerning the use of different biomaterials for tissue engineering and regenerative medicine applications. Starting from a historical perspective, the chapter introduces the basic principles of designing biomaterials for tissue regeneration approaches. The main focus is set on describing the main classes of biomaterials that have been applied in regenerative medicine, including natural and synthetic polymers, bioactive ceramics, and composites. For each class of biomaterials, some of the most important physicochemical and biological properties are presented. Finally, some challenges and concerns that remain in this field are presented and discussed.
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Medicina Regenerativa , Materiais Biocompatíveis , Cerâmica , Humanos , Qualidade de Vida , Engenharia TecidualRESUMO
The provision of better access to and use of surveillance data is a key component of the UK 5 Year Antimicrobial Resistance (AMR) Strategy. Since April 2016, PHE has made data on practice (infection prevention and control; antimicrobial stewardship) and outcome (prevalence of AMR, antibiotic use and healthcare-associated infections) available through Fingertips, a publicly accessible web tool (https://fingertips.phe.org.uk/profile/amr-local-indicators). Fingertips provides access to a wide range of public health data presented as thematic profiles, with the above data being available through the 'AMR local indicators' profile. Local data on a range of indicators can be viewed at the level of National Health Service acute trusts, Clinical Commissioning Groups or general practitioner practices, all of which can be compared with the corresponding aggregate values for England to allow benchmarking. The data can be viewed in a range of formats including an overview showing counts and rates, interactive maps, spine charts and graphs that show temporal trends over a range of time scales or allow correlations between pairs of indicators. The aim of the AMR local indicators profile on Fingertips is to support the development of local action plans to optimize antibiotic prescribing and reduce AMR and healthcare-associated infections. Provision of access to relevant information in an easy to use format will help local stakeholders, including healthcare staff, commissioners, Directors of Public Health, academics and the public, to benchmark relevant local AMR data and to monitor the impact of local initiatives to tackle AMR over time.
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Antibacterianos/uso terapêutico , Resistência Microbiana a Medicamentos , Uso de Medicamentos/normas , Política de Saúde , Disseminação de Informação/métodos , Inglaterra , Monitoramento Epidemiológico , Retroalimentação , Administração de Serviços de SaúdeRESUMO
Background: Public Health England developed and led a new UK-wide pledge campaign aiming to improve behaviours around the prudent use and prescription of antibiotics. This paper presents a process evaluation for the first season of the campaign to determine the impact of the campaign and inform future campaigns. Methods: Data were collected from AntibioticGuardian.com and Google analytics between August 2014 and January 2015. The primary outcome was the decision to pledge and was assessed according to target audience, location, source and route of referral to the website. Results: There were 47 158 unique visits to the website and 12 509 visitors made a pledge (26.5%) to become Antibiotic Guardians (AGs); 69% were healthcare professionals. Social media directed the most traffic to the website (24% of the public that signed up cited social media as how they discovered the campaign), other acquisition routes such as self-directed, email or website referral, were more effective at encouraging visitors to pledge. Conclusions: The campaign completed its goal of 10 000 AGs in the first year. Further work is required to improve engagement with target audiences and determine whether this campaign has an impact on antibiotic consumption and prescribing behaviour among the public and healthcare professionals.
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Antibacterianos/administração & dosagem , Infecções Bacterianas/prevenção & controle , Farmacorresistência Bacteriana , Promoção da Saúde/métodos , Promoção da Saúde/estatística & dados numéricos , Prescrição Inadequada/prevenção & controle , Prescrição Inadequada/estatística & dados numéricos , Humanos , Inquéritos e Questionários , Reino UnidoRESUMO
The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.
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Antifúngicos , COVID-19 , Candida auris , Candidíase , Controle de Infecções , Humanos , Candidíase/prevenção & controle , Candidíase/epidemiologia , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Controle de Infecções/métodos , Candida auris/efeitos dos fármacos , COVID-19/prevenção & controle , COVID-19/epidemiologia , Antifúngicos/uso terapêutico , Antifúngicos/farmacologia , Inglaterra/epidemiologia , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , SARS-CoV-2 , Farmacorresistência Fúngica , Candida/efeitos dos fármacos , Candida/classificação , Candida/isolamento & purificação , Surtos de Doenças/prevenção & controleRESUMO
Healthcare-associated (HA) meticillin-resistant Staphylococcus aureus (MRSA) clone CC22 SCCmecIV (EMRSA-15) has recently overtaken CC30/ST36 SCCmecII (EMRSA-16) as the dominant clone in UK hospitals. CC22 SCCmecIV shows greater fitness than CC30 SCCmecII, although both are successful global pathogens. The aim of this study was to test whether mobile genetic elements (MGEs), specifically SCCmec and large plasmids encoding resistance genes, are a burden and contribute to this fitness difference. Thirty-nine clinical isolates of MRSA and meticillin-sensitive S. aureus from lineages CC30 and CC22 with a variety of antibiotic resistance genes were grown in the absence of antibiotics. A range of relative fitness measures were used to compare clinical isolates with and without SCCmecII and SCCmecIV. The same fitness measures were used to compare eight isolates with and without naturally occurring large antibiotic resistance plasmids carrying gentamicin resistance (determined by microarray) and an isolate with an introduced plasmid. Growth rate, competitive ability during co-culture and survival after desiccation were then compared. Carriage of SCCmecII contributed to the reduced fitness of CC30 MRSA. However, we found no evidence of a fitness cost due to carriage of SCCmecIV in CC22, or large antibiotic resistance plasmids in CC30 or multiple resistances in both lineages. In conclusion, many large MGEs are not a fitness burden. Surprisingly, lineage background was the most important determinant of fitness. Our results suggest CC22 SCCmecIV will remain a successful healthcare-associated clone, and resistance to meticillin and gentamicin is likely to be maintained even in the absence of antibiotic pressure.
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Farmacorresistência Bacteriana Múltipla , Sequências Repetitivas Dispersas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Dessecação , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/fisiologia , Viabilidade Microbiana , Plasmídeos , Reino UnidoRESUMO
OBJECTIVES: The majority of HA-MRSA infections are caused by endogenous infection and by only a small number of clones. The reasons for the success of some clones over others are unknown. METHODS: We investigated the evolution of an MRSA population from a large, acute-care teaching hospital in London, UK over a 10 year period. MRSA incidence and antibiotic prescribing were correlated with changes in resistance genes and prevalence of clonal groups. RESULTS: Three clones caused the majority of infections, CC30 SCCmecII (EMRSA-16), CC22 SCCmecIV (EMRSA-15) and ST239 SCCmecIII. Clones that were multidrug resistant were selected for, and CC22 became dominant once it acquired a wide range of extra resistance genes. CC22 MRSA was also the fittest clone in an independent growth assay and a competition assay, and had a greater ability to survive desiccation. No individual isolate was fully drug resistant, and there was evidence of substantial horizontal gene transfer (HGT) as well as resistance gene loss within the clonal groups. The exception was fluoroquinolone resistance, which was rarely lost by any of the dominant hospital clones, suggesting that this resistance contributes to selection and survival of HA-MRSA. In support of this, a decrease in hospital-wide ciprofloxacin (a fluoroquinolone) prescribing was strongly associated with an overall decrease in MRSA infection. CONCLUSION: Our data suggest successful HA-MRSA clones such as CC22 SCCmecIV are resistant to fluoroquinolones as well as fitter and able to acquire, but not necessarily accumulate, resistance to a wide range of additional antibiotics.
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Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina/classificação , Tipagem Molecular , Infecções Estafilocócicas/epidemiologia , Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Prescrições de Medicamentos/estatística & dados numéricos , Farmacorresistência Bacteriana Múltipla , Fluoroquinolonas/farmacologia , Hospitais de Ensino , Humanos , Incidência , Londres/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções Estafilocócicas/microbiologia , Fatores de TempoRESUMO
Using a parallel synthesis approach to target a non-conserved region of the PI3K catalytic domain a pan-PI3K inhibitor 1 was elaborated to provide alpha, delta and gamma isoform selective Class I PI3K inhibitors 21, 24, 26 and 27. The compounds had good cellular activity and were selective against protein kinases and other members of the PI3K superfamily including mTOR and DNA-PK.
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Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Tiazóis/química , Tiazóis/farmacologia , Animais , Domínio Catalítico , Feminino , Humanos , Camundongos , Modelos Moleculares , Fosfatidilinositol 3-Quinases/química , Fosfatidilinositol 3-Quinases/metabolismo , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Ratos , Transdução de Sinais/efeitos dos fármacos , Tiazóis/farmacocinéticaRESUMO
Changes in antibacterial prescribing during the COVID-19 pandemic were anticipated given that the clinical features of severe respiratory infection syndrome caused by SARS-CoV-2 mirror bacterial respiratory tract infections. Antibacterial consumption was measured in items/1000 population for primary care and in Defined Daily Doses (DDDs)/1000 admissions for secondary care in England from 2015 to October 2020. Interrupted time-series analyses were conducted to evaluate the effects of the pandemic on antibacterial consumption. In the community, the rate of antibacterial items prescribed decreased further in 2020 (by an extra 1.4% per month, 95% CI: -2.3 to -0.5) compared to before COVID-19. In hospitals, the volume of antibacterial use decreased during COVID-19 overall (-12.1% compared to pre-COVID, 95% CI: -19.1 to -4.4), although the rate of usage in hospitals increased steeply in April 2020. Use of antibacterials prescribed for respiratory infections and broad-spectrum antibacterials (predominately 'Watch' antibacterials in hospitals) increased in both settings. Overall volumes of antibacterial use at the beginning of the COVID-19 pandemic decreased in both primary and secondary settings, although there were increases in the rate of usage in hospitals in April 2020 and in specific antibacterials. This highlights the importance of antimicrobial stewardship during pandemics to ensure appropriate prescribing and avoid negative consequences on patient outcomes and antimicrobial resistance.
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Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel are established as the primary causative factor in the devastating lung disease cystic fibrosis (CF). More recently, cigarette smoke exposure has been shown to be associated with dysfunctional airway epithelial ion transport, suggesting a role for CFTR in the pathogenesis of chronic obstructive pulmonary disease (COPD). Here, the identification and characterization of a high throughput screening hit 6 as a potentiator of mutant human F508del and wild-type CFTR channels is reported. The design, synthesis, and biological evaluation of compounds 7-33 to establish structure-activity relationships of the scaffold are described, leading to the identification of clinical development compound icenticaftor (QBW251) 33, which has subsequently progressed to deliver two positive clinical proofs of concept in patients with CF and COPD and is now being further developed as a novel therapeutic approach for COPD patients.
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Aminopiridinas/química , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Administração Oral , Aminopiridinas/metabolismo , Aminopiridinas/uso terapêutico , Animais , Fibrose Cística/tratamento farmacológico , Regulador de Condutância Transmembrana em Fibrose Cística/antagonistas & inibidores , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Deleção de Genes , Meia-Vida , Humanos , Ligação Proteica , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Solubilidade , Relação Estrutura-AtividadeRESUMO
Chondrocytes are the main cells in the extracellular matrix (ECM) of articular cartilage and possess a highly differentiated phenotype that is the hallmark of the unique physiological functions of this specialised load-bearing connective tissue. The plasma membrane of articular chondrocytes contains a rich and diverse complement of membrane proteins, known as the membranome, which defines the cell surface phenotype of the cells. The membranome is a key target of pharmacological agents and is important for chondrocyte function. It includes channels, transporters, enzymes, receptors, and anchors for intracellular, cytoskeletal and ECM proteins and other macromolecular complexes. The chondrocyte channelome is a sub-compartment of the membranome and includes a complete set of ion channels and porins expressed in these cells. Many of these are multi-functional proteins with "moonlighting" roles, serving as channels, receptors and signalling components of larger molecular assemblies. The aim of this review is to summarise our current knowledge of the fundamental aspects of the chondrocyte channelome, discuss its relevance to cartilage biology and highlight its possible role in the pathogenesis of osteoarthritis (OA). Excessive and inappropriate mechanical loads, an inflammatory micro-environment, alternative splicing of channel components or accumulation of basic calcium phosphate crystals can result in an altered chondrocyte channelome impairing its function. Alterations in Ca2+ signalling may lead to defective synthesis of ECM macromolecules and aggravated catabolic responses in chondrocytes, which is an important and relatively unexplored aspect of the complex and poorly understood mechanism of OA development.
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Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Canais Iônicos/biossíntese , Osteoartrite/fisiopatologia , Matriz Extracelular/metabolismo , Humanos , Osteoartrite/metabolismo , Porinas/biossínteseRESUMO
INTRODUCTION: Osteoarthritis (OA), a chronic, debilitating and degenerative disease of the joints, is the most common form of arthritis. The seriousness of this prevalent and chronic disease is often overlooked. Disease modifying OA drug development is hindered by the lack of soluble biomarkers to detect OA early. The objective of OA biomarker research is to identify early OA prior to the appearance of radiographic signs and the development of pain. Areas covered: This review has focused on extracellular genomic material that could serve as biomarkers of OA. Recent studies have examined the expression of extracellular genomic material such as miRNA, lncRNA, snoRNA, mRNA and cell-free DNA, which are aberrantly expressed in the body fluids of OA patients. Changes in genomic content of peripheral blood mononuclear cells in OA could also function as biomarkers of OA. Expert commentary: There is an unmet need for soluble biomarkers for detecting and then monitoring OA disease progression. Extracellular genomic material research may also reveal more about the underlying pathophysiology of OA. Minimally-invasive liquid biopsies such as synovial fluid and blood sampling of genomic material may be more sensitive over radiography in the detection, diagnosis and monitoring of OA in the future.
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Biomarcadores , Genômica , Osteoartrite/diagnóstico , Osteoartrite/genética , Animais , Progressão da Doença , Espaço Extracelular/genética , Genômica/métodos , Humanos , Biópsia Líquida , Sensibilidade e Especificidade , Líquido SinovialRESUMO
PURPOSE OF REVIEW: Degenerative skeletal disorders including osteoarthritis (OA) and osteoporosis (OP) are the result of attenuation of tissue regeneration and lead to painful conditions with limited treatment options. Preventative measures to limit the onset of OA and OP remain a significant unmet clinical need. MicroRNAs (miRNAs) are known to be involved in the differentiation of stem cells, and in combination with stem cell therapy could induce skeletal regeneration and potentially prevent OA and OP onset. RECENT FINDINGS: The combination of stem cells and miRNA has been successful at regenerating the bone and cartilage in vivo. MiRNAs, including miR-146b known to be involved in chondrogenic differentiation, could provide innovative targets for stem cell-based therapy, for the repair of articular cartilage defects forestalling the onset of OA or in the generation of a stem cell-based therapy for OP. SUMMARY: This review discusses the combination of skeletal stem cells (SSCs) and candidate miRNAs for application in a cell-based therapy approach for skeletal regenerative medicine.
RESUMO
Articular cartilage injury can result in chondrocyte loss and diminishment of specialised extracellular matrix, which can progress to an osteoarthritic (OA) phenotype. Stem cells have emerged as a favourable approach for articular cartilage regeneration. Identification of miRNAs which influence stem cell fate offers new approaches for application of miRNAs to regenerate articular cartilage. Skeletal stem cells (SSCs) isolated from human bone marrow were cultured as high density micromass' using TGF-ß3 to induce chondrogenesis. qPCR and TaqMan qPCR were used to assess chondrogenic gene and miRNA expression. Target prediction algorithms identified potential targets of miR-146b. Transient transfection with miR-146b mimic and western blotting was used to analyse SOX5. Human OA articular chondrocytes were examined for miR-146b expression. Chondrogenic differentiation of human bone marrow derived SSCs resulted in significant down-regulation of miR-146b. Gain of miR-146b function resulted in down-regulation of SOX5. MiR-146b expression was up-regulated in OA chondrocytes. These findings demonstrate the functional role of miR-146b in the chondrogenic differentiation of human bone marrow derived SSCs. MiR-146b may play a role in the pathophysiology of OA. Application of miR-146b combined with stem cell therapy could enhance regeneration of cartilaginous tissue and serve as a potential therapeutic target in the treatment of OA.
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Células da Medula Óssea/metabolismo , Diferenciação Celular/genética , Condrócitos/metabolismo , Condrogênese/genética , MicroRNAs/genética , Osteoartrite/genética , Células-Tronco/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Condrogênese/efeitos dos fármacos , Regulação para Baixo , Regulação da Expressão Gênica , Humanos , Osteoartrite/metabolismo , Osteoartrite/patologia , Fatores de Transcrição SOXD/genética , Fatores de Transcrição SOXD/metabolismo , Fator de Crescimento Transformador beta3/farmacologia , Regulação para CimaRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) CC22 SCCmecIV is a successful hospital-associated (HA-) MRSA, widespread throughout the world, and now the dominant clone in UK hospitals. We have recently shown that MRSA CC22 is a particularly fit clone, and it rose to dominance in a UK hospital at the same time as it began acquiring an increased range of antibiotic resistances. These resistances were not accumulated by individual CC22 isolates, but appear to shuffle frequently between isolates of the MRSA CC22 population. Resistances are often encoded on mobile genetic elements (MGEs) that include plasmids, transposons, bacteriophage and S. aureus pathogenicity islands (SaPIs). Using multi-strain whole genome microarrays, we show that there is enormous diversity of MGE carried within a MRSA CC22 SCCmecIV population, even among isolates from the same hospital and time period. MGE profiles were so variable that they could be used to track the spread of variant isolates within the hospital. We exploited this to show that the majority of patients colonised with MRSA at hospital admission that subsequently became infected were infected with their own colonising isolate. Our studies reveal MGE spread, stability, selection and clonal adaptation to the healthcare setting may be key to the success of HA-MRSA clones, presumably by allowing rapid adaptation to antibiotic exposure and new hosts.