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1.
Mol Genet Metab ; 143(1-2): 108575, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39243575

RESUMEN

Alström syndrome (AS) is an inherited rare ciliopathy characterised by multi-organ dysfunction and premature cardiovascular disease. This may manifest as an infantile-onset dilated cardiomyopathy with significant associated mortality. An adult-onset restrictive cardiomyopathy may also feature later in life. Loss of function pathogenic variants in ALMS1 have been identified in AS patients, leading to a lack of ALMS1 protein. The biological role of ALMS1 is unknown, particularly in a cardiovascular context. To understand the role of ALMS1 in infantile cardiomyopathy, the reduction of ALMS1 protein seen in AS patients was modelled using human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), in which ALMS1 was knocked out. MuscleMotion analysis and calcium optical mapping experiments suggest that ALMS1 knockout (KO) cells have increased contractility, with altered calcium extrusion and impaired calcium handling dynamics compared to wildtype (WT) counterparts. Seahorse metabolic assays showed ALMS1 knockout iPSC-CMs had increased glycolytic and mitochondrial respiration rates, with ALMS1 knockout cells portraying increased energetic demand and respiratory capacity than WT counterparts. Using senescence associated ß-galactosidase (SA-ß gal) staining assay, we identified increased senescence of ALMS1 knockout iPSC-CMs. Overall, this study provides insights into the molecular mechanisms in AS, particularly the role of ALMS1 in infantile cardiomyopathy in AS, using iPSC-CMs as a 'disease in a dish' model to provide insights into multiple aspects of this complex disease.

2.
Eur J Cardiothorac Surg ; 66(2)2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39029919

RESUMEN

OBJECTIVES: The use of ventricular assist devices (VADs) in children is increasing. However, absolute numbers in individual centres and countries remain small. Collaborative efforts such as the Paedi-European Registry for Patients with Mechanical Circulatory Support (EUROMACS) are therefore essential for combining international experience with paediatric VADs. Our goal was to present the results from the fourth Paedi-EUROMACS report. METHODS: All paediatric (<19 years) patients from the EUROMACS database supported by a VAD were included. Patients were stratified into a congenital heart disease (CHD) group and a group with a non-congenital aetiology. End points included mortality, a transplant and recovery. Cox proportional hazard models were used to explore associated factors for mortality, cerebrovascular accident and pump thrombosis. RESULTS: A total of 590 primary implants were included. The congenital group was significantly younger (2.5 vs 8.0 years, respectively, P < 0.001) and was more commonly supported by a pulsatile flow device (73.5% vs 59.9%, P < 0.001). Mortality was significantly higher in the congenital group (30.8% vs 20.4%, P = 0.009) than in the non-congenital group. However, in multivariable analyses, CHD was not significantly associated with mortality [hazard ratio (HR) 1.285; confidence interval (CI) 0.8111-2.036, P = 0.740]. Pump thrombosis was the most frequently reported adverse event (377 events in 132 patients; 0.925 events per patient-year) and was significantly associated with body surface area (HR 0.524, CI 0.333-0.823, P = 0.005), CHD (HR 1.641, CI 1.054-2.555, P = 0.028) and pulsatile flow support (HR 2.345, CI 1.406-3.910, P = 0.001) in multivariable analyses. CONCLUSIONS: This fourth Paedi-EUROMACS report highlights the increasing use of paediatric VADs. The patient populations with congenital and non-congenital aetiologies exhibit distinct characteristics and clinical outcomes.


Asunto(s)
Corazón Auxiliar , Sistema de Registros , Humanos , Sistema de Registros/estadística & datos numéricos , Corazón Auxiliar/estadística & datos numéricos , Corazón Auxiliar/efectos adversos , Niño , Preescolar , Masculino , Femenino , Lactante , Europa (Continente)/epidemiología , Adolescente , Cardiopatías Congénitas/cirugía , Cardiopatías Congénitas/mortalidad , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/cirugía , Recién Nacido
3.
Heart Lung Circ ; 33(8): 1193-1200, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38871532

RESUMEN

AIM: Heart transplantation (HT) in patients with failing univentricular circulation is often challenging. This is compounded by the ever-increasing number of patients with prior Norwood-type reconstruction of the aorta, large aortic root, and often dense adhesions from multiple prior operations. We aimed to elucidate differences in outcomes of HT in patients with prior univentricular palliations, with and without prior Norwood-type aortic arch reconstruction (ArchRec). METHODS: All patients who underwent HT for failed univentricular palliation during the 1990-2022 period were included in the study. RESULTS: Of 45 patients, 18 had undergone ArchRec. Hospital mortality improved in the recent era (17.4% before 2006 vs 0% after 2006; p=0.11), despite a higher proportion of patients with ArchRec (17.4% before 2006 vs 60.8% after 2006, p=0.002). Patients with ArchRec had a higher number of prior cardiac surgeries (4.1±1.5 vs 3.2±1.3, p=0.04), longer cardiopulmonary bypass time (320±23 vs 242±21 min, p=0.02), more concomitant arch reconstruction (33.3% vs 0%, p=0.02), greater need for post-HT extracorporeal membrane oxygenation (33.3% vs 3.7%; p=0.01) and longer hospital stay (37.1±30.5 days vs 23.6±11.8 days, p=0.04). Freedom from death or retransplantation for all patients was 91%, 73%, 67%, and 53% at 1, 5, 10, and 15-years, respectively. Prior ArchRec, Fontan procedure, and earlier eras were not risk factors for death. CONCLUSIONS: The outcomes of HT after univentricular palliation have improved in recent times and low operative mortality can be achieved. Despite increased complexity, good similar outcomes can be achieved in patients with and without prior arch reconstruction regardless of the palliation stage.


Asunto(s)
Trasplante de Corazón , Humanos , Trasplante de Corazón/métodos , Masculino , Femenino , Mortalidad Hospitalaria/tendencias , Lactante , Estudios Retrospectivos , Cuidados Paliativos/métodos , Corazón Univentricular/cirugía , Procedimientos de Norwood/métodos , Tasa de Supervivencia/tendencias , Recién Nacido , Estudios de Seguimiento
4.
Ethical Theory Moral Pract ; 27(2): 167-183, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38725479

RESUMEN

Health institutions recommend that young infants be exclusively breastfed on demand, and it is widely held that parents who can breastfeed have an obligation to do so. This has been challenged in recent philosophical work, especially by Fiona Woollard. Woollard's work critically engages with two distinct views of parental obligation that might ground such an obligation-based on maximal benefit and avoidance of significant harm-to reject an obligation to breastfeed. While agreeing with Woollard's substantive conclusion, this paper (drawing on philosophical discussion of the 'right to rear') argues that there are several more moderate views of parental obligation which might also be thought to ground parental obligation. We first show that an obligation to breastfeed might result not from a general obligation to maximally benefit one's child, but from what we call 'choice-specific' obligations to maximise benefit within particular activities. We then develop this idea through two views of parental obligation-the Dual Interest view, and the Best Custodian view-to ground an obligation to exclusively breastfeed on demand, before showing how both these more moderate views fail. Finally, we argue that not only is there no general obligation to breastfeed children, but that it is often morally right not to do so. Since much advice from health institutions on this issue implies that exclusive breastfeeding on demand is the best option for all families, our argument drives the feeding debate forward by showing that this advice often misrepresents parents' moral obligations in potentially harmful ways.

5.
Monash Bioeth Rev ; 42(1): 1-15, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38421491

RESUMEN

Healthcare practitioners have access to a range of ethical guidance. However, the normative role of this guidance in ethical decision-making is underexplored. This paper considers two ways that healthcare practitioners could approach ethics guidance. We first outline the idea of deference to ethics guidance, showing how an attitude of deference raises three key problems: moral value; moral understanding; and moral error. Drawing on philosophical literature, we then advocate an alternative framing of ethics guidance as a form of moral testimony by colleagues and suggest that a more promising attitude to ethics guidance is to approach it in the spirit of 'critical engagement' rather than deference.


Asunto(s)
Ética Clínica , Humanos , Principios Morales , Personal de Salud/ética , Actitud del Personal de Salud , Toma de Decisiones/ética
6.
Nat Neurosci ; 27(4): 643-655, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38424324

RESUMEN

Dipeptide repeat proteins are a major pathogenic feature of C9orf72 amyotrophic lateral sclerosis (C9ALS)/frontotemporal dementia (FTD) pathology, but their physiological impact has yet to be fully determined. Here we generated C9orf72 dipeptide repeat knock-in mouse models characterized by expression of 400 codon-optimized polyGR or polyPR repeats, and heterozygous C9orf72 reduction. (GR)400 and (PR)400 knock-in mice recapitulate key features of C9ALS/FTD, including cortical neuronal hyperexcitability, age-dependent spinal motor neuron loss and progressive motor dysfunction. Quantitative proteomics revealed an increase in extracellular matrix (ECM) proteins in (GR)400 and (PR)400 spinal cord, with the collagen COL6A1 the most increased protein. TGF-ß1 was one of the top predicted regulators of this ECM signature and polyGR expression in human induced pluripotent stem cell neurons was sufficient to induce TGF-ß1 followed by COL6A1. Knockdown of TGF-ß1 or COL6A1 orthologues in polyGR model Drosophila exacerbated neurodegeneration, while expression of TGF-ß1 or COL6A1 in induced pluripotent stem cell-derived motor neurons of patients with C9ALS/FTD protected against glutamate-induced cell death. Altogether, our findings reveal a neuroprotective and conserved ECM signature in C9ALS/FTD.


Asunto(s)
Esclerosis Amiotrófica Lateral , Demencia Frontotemporal , Células Madre Pluripotentes Inducidas , Animales , Humanos , Ratones , Demencia Frontotemporal/patología , Esclerosis Amiotrófica Lateral/metabolismo , Factor de Crecimiento Transformador beta1 , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Neuronas Motoras/metabolismo , Drosophila , Matriz Extracelular/metabolismo , Dipéptidos/metabolismo , Expansión de las Repeticiones de ADN/genética
8.
J Thorac Cardiovasc Surg ; 167(1): 289-302.e11, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37169063

RESUMEN

OBJECTIVE: This study evaluates the long-term results of tetralogy of Fallot repair and assesses the risk factors for adverse outcomes. METHODS: This retrospective study included 960 patients who underwent transatrial transpulmonary tetralogy of Fallot repair between 1990 and 2020. RESULTS: A transannular patch was placed in 722 patients, and pulmonary valve preservation was achieved in 233 patients. The median age at tetralogy of Fallot repair was 9.4 (interquartile range, 6.2-14.2) months. The median follow-up duration was 10.6 (interquartile range, 5.4-16.3) years. There were 8 early deaths (0.8%) and 20 late deaths (2.1%). Genetic syndrome and pulmonary valve annulus Z score less than -3 were risk factors for mortality. The survival was 97.7% (95% confidence interval, 96.4-98.5) and 94.5% (95% confidence interval, 90.9-96.7) at 10 and 30 years, respectively. Freedom from any reoperation was 86.4% (95% confidence interval, 83.6-88.7) and 65.4% (95% confidence interval, 59.8-70.4) at 10 and 20 years, respectively. Postoperative right ventricular outflow tract peak gradient of 25 mm Hg or greater correlated with reoperation. Propensity score-matched analysis demonstrated that freedom from pulmonary valve replacement at 15 years was higher in the pulmonary valve preservation group compared with the transannular patch group (98.2% vs 78.4%, P = .004). Freedom from reoperation for right ventricular outflow tract obstruction at 15 years was lower in the pulmonary valve preservation group compared with the transannular patch group (P = .006). CONCLUSIONS: The long-term outcomes of tetralogy of Fallot repair are excellent. A postoperative right ventricular outflow tract peak gradient less than 25 mm Hg appears to be optimal to prevent reoperation. If the pulmonary valve size is suitable, pulmonary valve preservation reduces the risk of pulmonary valve replacement, yet increases the reoperation rate for right ventricular outflow tract obstruction.


Asunto(s)
Válvula Pulmonar , Tetralogía de Fallot , Obstrucción del Flujo de Salida Ventricular Derecho , Humanos , Lactante , Estudios Retrospectivos , Resultado del Tratamiento , Válvula Pulmonar/cirugía , Reoperación , Estudios de Seguimiento
10.
J Cardiovasc Dev Dis ; 10(8)2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37623364

RESUMEN

Purpose: The withdrawal of HVAD in 2021 created a concern for the pediatric population. The alternative implantable centrifugal blood pump HeartMate 3 has since been used more frequently in children. This paper analyses the outcome of children on LVAD support provided with an HVAD or HM3. Methods: A retrospective analysis of the EUROMACS database on children supported with VAD < 19 years of age from 1 January 2009 to 1 December 2021 was conducted. All patients with an LVAD and either an HVAD or HM3 were included. Patients with missing data on VAD status and/or missing baseline and/or follow up information were excluded. Kaplan-Meier survival analysis was performed to evaluate survival differences. Analyses were performed using Fisher's exact test. Results: The study included 150 implantations in 142 patients with 128 implants using an HVAD compared to 28 implants using an HM3. Nine patients (6%) needed temporary right ventricular mechanical support, which was significantly higher in the HM3 group, with 25% (p: 0.01). Patients in the HVAD group were significantly younger (12.7 vs. 14.5 years, p: 0.01), weighed less (45.7 vs. 60 kg, p: <0.000) and had lower BSA values (1.3 vs. 1.6 m2, p: <0.000). Median support time was 204 days. Overall, 98 patients (69%) were discharged and sent home, while 87% were discharged in group HM3 (p: ns). A total of 123 children (86%) survived to transplantation, recovery or are ongoing, without differences between groups. In the HVAD group, 10 patients (8%) died while on support, whereas in 12% of HM3 patients died (p: 0.7). Conclusions: Survival in children implanted with an HM3 was excellent. Almost 90% were discharged and sent home on the device.

11.
Clin Ethics ; 18(3): 287-291, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37621986

RESUMEN

I introduce a distinction between health need and medical need, and raise several questions about their interaction. Health needs are needs that relate directly to our health condition. Medical needs are needs which bear some relation to medical institutions or processes. I suggest that the question of whether medical insurance or public care should cover medical needs, health needs, or only needs which fit both categories is a political question that cannot be resolved definitionally. I also argue against an overly strict definition of medical need on the grounds that this presupposes, wrongly, that medical intervention should always be a last resort.

12.
Euro Surveill ; 28(19)2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37166761

RESUMEN

BackgroundIn 2020, Wales experienced some of the highest rates of confirmed COVID-19 cases in Europe. We set up a serosurveillance scheme using residual samples from blood donations to inform the pandemic response in Wales.AimTo identify changes in SARS-CoV-2 antibody seroprevalence in Wales by time, demography and location.MethodsResidual samples from blood donations made in Wales between 29 June 2020 and 20 November 2022 were tested for antibodies to the nucleocapsid antigen (anti-N) of SARS-CoV-2, resulting from natural infection. Donations made between 12 April 2021 and 20 November 2022 were also tested for antibodies to the spike antigen (anti-S) occurring as a result of natural infection and vaccination.ResultsAge-standardised seroprevalence of anti-N antibodies in donors remained stable (4.4-5.5%) until November 2020 before increasing to 16.7% by February 2021. Trends remained steady until November 2021 before increasing, peaking in November 2022 (80.2%). For anti-S, seroprevalence increased from 67.1% to 98.6% between May and September 2021, then remained above 99%. Anti-N seroprevalence was highest in younger donors and in donors living in urban South Wales. In contrast, seroprevalence of anti-S was highest in older donors and was similar across regions. No significant difference was observed by sex. Seroprevalence of anti-N antibodies was higher in Black, Asian and other minority ethnicities (self-reported) compared with White donors, with the converse observed for anti-S antibodies.ConclusionWe successfully set up long-term serological surveillance of SARS-CoV-2 using residual samples from blood donations, demonstrating variation based on age, ethnicity and location.


Asunto(s)
Donantes de Sangre , COVID-19 , Anciano , Humanos , Anticuerpos Antivirales , COVID-19/epidemiología , Etnicidad , SARS-CoV-2 , Estudios Seroepidemiológicos , Gales/epidemiología
13.
Am J Bioeth ; : 1-14, 2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37104661

RESUMEN

Throughout the COVID-19 pandemic, shortages of scarce healthcare resources consistently presented significant moral and practical challenges. While the importance of vaccines as a key pharmaceutical intervention to stem pandemic scarcity was widely publicized, a sizable proportion of the population chose not to vaccinate. In response, some have defended the use of vaccination status as a criterion for the allocation of scarce medical resources. In this paper, we critically interpret this burgeoning literature, and describe a framework for thinking about vaccine-sensitive resource allocation using the values of responsibility, reciprocity, and justice. Although our aim here is not to defend a single view of vaccine-sensitive resource allocation, we believe that attending critically with the diversity of arguments in favor (and against) vaccine-sensitivity reveals a number of questions that a vaccine-sensitive approach to allocation should answer in future pandemics.

14.
Artif Organs ; 47(8): 1319-1325, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36855905

RESUMEN

BACKGROUND: Data on the use and outcome of children on ventricular assist device (VAD) support provided with an implantable cardioverter-defibrillator (ICD) remains poor. METHODS: A retrospective analysis of the EUROMACS database on children supported with VAD < 19 years of age from January 1, 2009 to April 1, 2020. Patients with missing data on status of ICD, missing baseline and/or follow up information were excluded. The primary independent variable of interest was the concomitant presence or absence of an ICD at the time of VAD placement. Kaplan-Meier survival analysis was performed to evaluate survival differences between children on VAD with and without an ICD. RESULTS: Out of 303 patients provided with a VAD, 7% (7♀, 15♂) had an ICD implanted and formed the study group. Median age was 14 years, median weight was 43.5 kg, and median BSA was 1.39. Median Intermacs stage was 2 (range: 1-7). Seventeen patients (77%) were transplanted, 4 (18%) died while on support, and 1 (5%) was weaned from device after myocardial recovery. Median time on support was 68 days compared to 361 days in the control group (p: 0.01). Three patients underwent device exchange due to thrombus formation in the pump. There was no difference in survival between groups (p = 0.342). CONCLUSION: The presence of ICD in pediatric patients supported with a VAD is low (7%). Children on VAD support provided with an ICD do not have a survival benefit compared to children without an ICD.


Asunto(s)
Desfibriladores Implantables , Insuficiencia Cardíaca , Corazón Auxiliar , Humanos , Niño , Adolescente , Insuficiencia Cardíaca/cirugía , Estudios Retrospectivos , Sistema de Registros , Resultado del Tratamiento
15.
Analysis ; 83(4): 673-682, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38298497

RESUMEN

Subjectivists think that our well-being is grounded in our subjective attitudes. Many such views are vulnerable to variations on the 'paradox of desire', where theories cannot make determinate judgements about the well-being of agents who take a positive valuing attitude towards their life going badly. However, this paradox does not affect all subjectivist theories; theories grounded on agents' prudential values can avoid it. This paper suggests a new paradox for subjectivist theories which has a wider scope, and includes such prudential judgement theories. I outline the new paradox and show how two plausible idealisztions (coherence and consideration) will not help. Subjectivists about well-being must either add an additional idealization that can solve the paradox of judgement or explain why such paradoxes do not constitute serious objections to a theory of well-being.

16.
Ethics Policy Environ ; : 1-18, 2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-38652828

RESUMEN

Sufficientarians face a problem of arbitrariness: why place a sufficiency threshold at any particular point? One response is to seek universal goods to justify a threshold. However, this faces difficulties (despite sincere efforts) by either being too low, or failing to accommodate individuals with significant cognitive disabilities. Some sufficientarians have appealed to individuals' subjective evaluations of their lives. I build on this idea, considering another individualized threshold: 'tolerability'. I respond to some traditional challenges to individualistic approaches to justice: 'expensive' tastes, and adaptive preferences. Finally, I end by offering some suggestions about how this relates to policymaking.

17.
Camb Q Healthc Ethics ; : 1-12, 2022 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-36352770

RESUMEN

Some philosophers and segments of the public think age is relevant to healthcare priority-setting. One argument for this is based in equity: "Old" patients have had either more of a relevant good than "young" patients or enough of that good and so have weaker claims to treatment. This article first notes that some discussions of age-based priority that focus in this way on old and young patients exhibit an ambiguity between two claims: that patients classified as old should have a low priority, and that patients classified as young should have high priority. The author next argues, drawing on a problem raised by Christine Overall, that equity cannot justify giving "old" patients low priority, since there is wide variety in the total lifetime experiences of older people, partly influenced by gender, race, class, and disability injustice. Finally, the author suggests that there might be a limited role for age-based prioritization in the context of infant and childhood death, since those who die in childhood are always and uncontroversially among the worst-off.

18.
Bioethics ; 36(9): 970-977, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35912506

RESUMEN

This article is about the potential justification for deploying some form of affirmative action (AA) in the context of healthcare, and in particular in relation to the pandemic. We call this Affirmative Action in healthcare Resource Allocation (AARA). Specifically, we aim to investigate whether the rationale and justifications for using prioritization policies based on race in education and employment apply in a healthcare setting, and in particular to the COVID-19 pandemic. We concentrate in this article on vaccines and ventilators because these are both highly scarce resources in the pandemic, and there has been a need to develop policies for allocating them. However, as will become clear, the ethical considerations relating to them may diverge. We first set out two rationales for AAs and what they might entail in a healthcare setting. We then consider some disanalogies between AA and AARA, as well as the different implications of AARA for allocating ventilators as opposed to vaccines. Finally, we consider some of the practical ways in which AARA could be implemented, and conclude by responding to some key objections.


Asunto(s)
COVID-19 , Vacunas , Humanos , Pandemias , COVID-19/prevención & control , Ventiladores Mecánicos , Política Pública , Atención a la Salud , Asignación de Recursos
19.
Ratio (Oxf) ; 35(2): 112-122, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35966618

RESUMEN

A considerable literature has emerged around the idea of using 'personal responsibility' as an allocation criterion in healthcare distribution, where a person's being suitably responsible for their health needs may justify additional conditions on receiving healthcare, and perhaps even limiting access entirely, sometimes known as 'responsibilisation'. This discussion focuses most prominently, but not exclusively, on 'luck egalitarianism', the view that deviations from equality are justified only by suitably free choices. A superficially separate issue in distributive justice concerns the two-way relationship between health and other social goods: deficits in health typically undermine one's abilities to secure advantage in other areas, which in turn often have further negative effects on health. This paper outlines the degree to which this latter relationship between health and other social goods exacerbates an existing problem for proponents of responsibilisation (the 'harshness objection') in ways that standard responses to this objection cannot address. Placing significant conditions on healthcare access because of a person's prior responsibility risks trapping them in, or worsening, negative cycles where poor health and associated lack of opportunity reinforce one another, making further poor yet ultimately responsible choices more likely. It ends by considering three possible solutions to this problem.

20.
Front Immunol ; 13: 918636, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35874787

RESUMEN

Current genetic tools designed to target macrophages in vivo often target cells from all myeloid lineages. Therefore, we sought to generate a novel transgenic mouse which has a tamoxifen inducible Cre-recombinase under the control of the human CD68 promoter (hCD68-CreERT2). To test the efficiency and specificity of the of Cre-recombinase activity we crossed the hCD68-CreERT2 mice with a loxP-flanked STOP cassette red fluorescent protein variant (tdTomato) mouse. We established that orally dosing mice with 2 mg of tamoxifen for 5 consecutive days followed by a 5-day induction period resulted in robust expression of tdTomato in CD11b+ F4/80+ tissue resident macrophages. Using this induction protocol, we demonstrated tdTomato expression within peritoneal, liver and spleen macrophages and blood Ly6Clow monocytes. Importantly there was limited or no inducible tdTomato expression within other myeloid cells (neutrophils, monocytes, dendritic cells and eosinophils), T cells (CD4+ and CD8+) and B cells (CD19+). We also demonstrated that the level of tdTomato expression can be used as a marker to identify different populations of peritoneal and liver macrophages. We next assessed the longevity of tdTomato expression in peritoneal macrophages, liver and splenic macrophages and demonstrated high levels of tdTomato expression as long as 6 weeks after the last tamoxifen dose. Importantly, hCD68-CreERT2 expression is more restricted than that of LysM-Cre which has significant expression in major myeloid cell types (monocytes and neutrophils). To demonstrate the utility of this novel macrophage-specific Cre driver line we demonstrated tdTomato expression in recruited CD11b+CD64+F4/80+ monocyte-derived macrophages within the atherosclerotic lesions of AAV8-mPCSK9 treated mice, with limited expression in recruited neutrophils. In developing this new hCD68-CreERT2 mouse we have a tool that allows us to target tissue resident macrophages, with the advantage of not targeting other myeloid cells namely neutrophils and inflammatory monocytes.


Asunto(s)
Integrasas , Tamoxifeno , Animales , Humanos , Integrasas/genética , Macrófagos/metabolismo , Ratones , Ratones Transgénicos , Tamoxifeno/farmacología
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