RESUMEN
Introduction. COVID-19 caused by SARS CoV-2 continues to be a major health concern globally. Methods for detection of the disease are necessary for public health efforts to monitor the spread of this disease as well as for detecting the emergence of new variants.Gap statement. Collection of Nasopharyngeal swab (NPS), the gold standard sample for the detection of COVID-19 infection by RT-qPCR is invasive and requires the expertise of a trained medical provider. This highlights the need for validating less invasive samples that can be self-collected without the need for trained medical provider.Aim. To validate saliva and tongue swab as potential samples for the diagnosis of COVID-19.Methodology. Adult and paediatric cases who had acute influenza like illness were enrolled in the study. The study involved comparison of Nucleic Acid Amplification Tests (NAAT) results for the detection of COVID-19 obtained by using saliva and tongue swab with that of NPS.Result and Conclusion. The sensitivity and specificity of saliva as sample for COVID-19 detection were found to be 71 and 88% respectively whereas those of tongue swab as sample were 78 and 90â%. Further validation was based on the positive and negative predictive values, the likelihood ratio, agreement percentage and the kappa statistic. The findings of the study point towards tongue swab and saliva as suitable alternative samples for the diagnosis of COVID-19 with a slightly higher accuracy and agreement for tongue swab than saliva. However considering the fatality of COVID-19, they are better suited for mass screening of people than for diagnosis.
Asunto(s)
COVID-19 , Adulto , Humanos , Niño , COVID-19/diagnóstico , Saliva , SARS-CoV-2 , Lengua , NasofaringeRESUMEN
OBJECTIVES: The purpose of the present study was to explore Muslim Arab American women's intersecting identities, the types of discrimination they experience, and the psychosocial effects of those experiences on identity and well-being. METHOD: Thirteen Muslim Arab American women were interviewed utilizing the consensual qualitative research (CQR) approach. RESULTS: Final domains that emerged from the data included conceptualization of racial, ethnic, and religious identity; experiences and effect of microaggressions; and coping strategies. CONCLUSIONS: The results document discrimination at the intersection of their multiple identities, a perceived shift in stereotypes from weak and oppressed to anti-American and violent, and within-group discrimination in the form of colorism and judgment. Reported psychological effects of discrimination include internalization of stereotypes, burden to represent all Muslims, rejection of the White racial label, and increased activism. The findings highlight resilience and coping through active self-acceptance and advocacy. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Asunto(s)
Árabes , Racismo , Humanos , Femenino , Árabes/psicología , Islamismo/psicología , Adaptación Psicológica , Agresión , BlancoRESUMEN
Alveolar epithelial type 2 cells (AEC2s) are the facultative progenitors responsible for maintaining lung alveoli throughout life but are difficult to isolate from patients. Here, we engineer AEC2s from human pluripotent stem cells (PSCs) in vitro and use time-series single-cell RNA sequencing with lentiviral barcoding to profile the kinetics of their differentiation in comparison to primary fetal and adult AEC2 benchmarks. We observe bifurcating cell-fate trajectories as primordial lung progenitors differentiate in vitro, with some progeny reaching their AEC2 fate target, while others diverge to alternative non-lung endodermal fates. We develop a Continuous State Hidden Markov model to identify the timing and type of signals, such as overexuberant Wnt responses, that induce some early multipotent NKX2-1+ progenitors to lose lung fate. Finally, we find that this initial developmental plasticity is regulatable and subsides over time, ultimately resulting in PSC-derived AEC2s that exhibit a stable phenotype and nearly limitless self-renewal capacity.
Asunto(s)
Pulmón , Células Madre Pluripotentes , Células Epiteliales Alveolares , Diferenciación Celular , Humanos , Alveolos PulmonaresRESUMEN
Efficient generation of human induced pluripotent stem cell (hiPSC)-derived human intestinal organoids (HIOs) would facilitate the development of in vitro models for a variety of diseases that affect the gastrointestinal tract, such as inflammatory bowel disease or Cystic Fibrosis. Here, we report a directed differentiation protocol for the generation of mesenchyme-free HIOs that can be primed towards more colonic or proximal intestinal lineages in serum-free defined conditions. Using a CDX2eGFP iPSC knock-in reporter line to track the emergence of hindgut progenitors, we follow the kinetics of CDX2 expression throughout directed differentiation, enabling the purification of intestinal progenitors and robust generation of mesenchyme-free organoids expressing characteristic markers of small intestinal or colonic epithelium. We employ HIOs generated in this way to measure CFTR function using cystic fibrosis patient-derived iPSC lines before and after correction of the CFTR mutation, demonstrating their future potential for disease modeling and therapeutic screening applications.
Asunto(s)
Células Madre Pluripotentes Inducidas/metabolismo , Intestinos/fisiología , Mesodermo/metabolismo , Organoides/metabolismo , Factor de Transcripción CDX2/metabolismo , Diferenciación Celular , Fibrosis Quística , Células Epiteliales , Técnicas de Sustitución del Gen , Vectores Genéticos , Humanos , Intestino Delgado , Organoides/citología , Factor Nuclear Tiroideo 1/genéticaRESUMEN
Alveolar epithelial type II cells (AEC2s) are the facultative progenitors of lung alveoli and serve as the surfactant-producing cells of air-breathing organisms. Although primary human AEC2s are difficult to maintain stably in cell cultures, recent advances have facilitated the derivation of AEC2-like cells from human pluripotent stem cells (hPSCs) in vitro. Here, we provide a detailed protocol for the directed differentiation of hPSCs into self-renewing AEC2-like cells that can be maintained for up to 1 year in culture as epithelial-only spheres without the need for supporting mesenchymal feeder cells. The month-long protocol requires recapitulation of the sequence of milestones associated with in vivo development of the distal lung, beginning with differentiation of cells into anterior foregut endoderm, which is followed by their lineage specification into NKX2-1+ lung progenitors and then distal/alveolar differentiation to produce progeny that express transcripts and possess functional properties associated with AEC2s.
Asunto(s)
Células Epiteliales Alveolares/citología , Técnicas de Cultivo de Célula/métodos , Células Madre Pluripotentes/citología , Células Epiteliales Alveolares/fisiología , Animales , Diferenciación Celular , Línea Celular , Linaje de la Célula , Proliferación Celular , Autorrenovación de las Células/genética , Autorrenovación de las Células/fisiología , Células Epiteliales/citología , Células Nutrientes , Humanos , Pulmón/citología , Células Madre Pluripotentes/fisiologíaRESUMEN
Lung epithelial lineages have been difficult to maintain in pure form in vitro, and lineage-specific reporters have proven invaluable for monitoring their emergence from cultured pluripotent stem cells (PSCs). However, reporter constructs for tracking proximal airway lineages generated from PSCs have not been previously available, limiting the characterization of these cells. Here, we engineer mouse and human PSC lines carrying airway secretory lineage reporters that facilitate the tracking, purification, and profiling of this lung subtype. Through bulk and single-cell-based global transcriptomic profiling, we find PSC-derived airway secretory cells are susceptible to phenotypic plasticity exemplified by the tendency to co-express both a proximal airway secretory program as well as an alveolar type 2 cell program, which can be minimized by inhibiting endogenous Wnt signaling. Our results provide global profiles of engineered lung cell fates, a guide for improving their directed differentiation, and a human model of the developing airway.
Asunto(s)
Epitelio/metabolismo , Perfilación de la Expresión Génica , Células Madre Pluripotentes Inducidas/metabolismo , Pulmón/citología , Análisis de la Célula Individual , Animales , Diferenciación Celular/genética , Línea Celular , Linaje de la Célula , Plasticidad de la Célula , Epitelio/ultraestructura , Genes Reporteros , Humanos , Células Madre Pluripotentes Inducidas/citología , Cinética , Ratones , Secretoglobinas/metabolismo , Análisis de Secuencia de ARN , Solubilidad , Esferoides Celulares/citología , Esferoides Celulares/metabolismo , Factores de Tiempo , Transcriptoma/genética , Vía de Señalización WntRESUMEN
Lung alveoli, which are unique to air-breathing organisms, have been challenging to generate from pluripotent stem cells (PSCs) in part because there are limited model systems available to provide the necessary developmental roadmaps for in vitro differentiation. Here we report the generation of alveolar epithelial type 2 cells (AEC2s), the facultative progenitors of lung alveoli, from human PSCs. Using multicolored fluorescent reporter lines, we track and purify human SFTPC+ alveolar progenitors as they emerge from endodermal precursors in response to stimulation of Wnt and FGF signaling. Purified PSC-derived SFTPC+ cells form monolayered epithelial "alveolospheres" in 3D cultures without the need for mesenchymal support, exhibit self-renewal capacity, and display additional AEC2 functional capacities. Footprint-free CRISPR-based gene correction of PSCs derived from patients carrying a homozygous surfactant mutation (SFTPB121ins2) restores surfactant processing in AEC2s. Thus, PSC-derived AEC2s provide a platform for disease modeling and future functional regeneration of the distal lung.
Asunto(s)
Diferenciación Celular , Células Epiteliales/citología , Células Madre Pluripotentes/citología , Alveolos Pulmonares/citología , Secuencia de Bases , Línea Celular , Proliferación Celular , Autorrenovación de las Células , Separación Celular , Células Epiteliales/ultraestructura , Perfilación de la Expresión Génica , Genes Reporteros , Humanos , Enfermedades Pulmonares/patología , Modelos Biológicos , Alveolos Pulmonares/ultraestructura , Surfactantes Pulmonares/metabolismo , Factor Nuclear Tiroideo 1/metabolismo , Factores de Tiempo , Proteínas Wnt/metabolismo , Vía de Señalización WntRESUMEN
The in vitro-directed differentiation of pluripotent stem cells (PSCs) through stimulation of developmental signaling pathways can generate mature somatic cell types for basic laboratory studies or regenerative therapies. However, there has been significant uncertainty regarding a method to separately derive lung versus thyroid epithelial lineages, as these two cell types each originate from Nkx2-1+ foregut progenitors and the minimal pathways claimed to regulate their distinct lineage specification in vivo or in vitro have varied in previous reports. Here, we employ PSCs to identify the key minimal signaling pathways (Wnt+BMP versus BMP+FGF) that regulate distinct lung- versus thyroid-lineage specification, respectively, from foregut endoderm. In contrast to most previous reports, these minimal pathways appear to be evolutionarily conserved between mice and humans, and FGF signaling, although required for thyroid specification, unexpectedly appears to be dispensable for lung specification. Once specified, distinct Nkx2-1+ lung or thyroid progenitor pools can now be independently derived for functional 3D culture maturation, basic developmental studies or future regenerative therapies.
Asunto(s)
Tipificación del Cuerpo , Diferenciación Celular , Pulmón/citología , Pulmón/embriología , Células Madre Pluripotentes/citología , Transducción de Señal , Glándula Tiroides/citología , Animales , Biomarcadores/metabolismo , Tipificación del Cuerpo/genética , Proteínas Morfogenéticas Óseas/metabolismo , Linaje de la Célula , Embrión de Mamíferos/citología , Desarrollo Embrionario , Endodermo/citología , Endodermo/metabolismo , Células Epiteliales/citología , Factores de Crecimiento de Fibroblastos/metabolismo , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Proteínas Fluorescentes Verdes/metabolismo , Proteínas de Homeodominio/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Ratones , Células Madre Embrionarias de Ratones/citología , Células Madre Embrionarias de Ratones/metabolismo , Reproducibilidad de los Resultados , Esferoides Celulares/citología , Esferoides Celulares/metabolismo , Glándula Tiroides/embriología , Transcriptoma/genética , Proteínas Wnt/metabolismoRESUMEN
It has been postulated that during human fetal development, all cells of the lung epithelium derive from embryonic, endodermal, NK2 homeobox 1-expressing (NKX2-1+) precursor cells. However, this hypothesis has not been formally tested owing to an inability to purify or track these progenitors for detailed characterization. Here we have engineered and developmentally differentiated NKX2-1GFP reporter pluripotent stem cells (PSCs) in vitro to generate and isolate human primordial lung progenitors that express NKX2-1 but are initially devoid of differentiated lung lineage markers. After sorting to purity, these primordial lung progenitors exhibited lung epithelial maturation. In the absence of mesenchymal coculture support, this NKX2-1+ population was able to generate epithelial-only spheroids in defined 3D cultures. Alternatively, when recombined with fetal mouse lung mesenchyme, the cells recapitulated epithelial-mesenchymal developing lung interactions. We imaged these progenitors in real time and performed time-series global transcriptomic profiling and single-cell RNA sequencing as they moved through the earliest moments of lung lineage specification. The profiles indicated that evolutionarily conserved, stage-dependent gene signatures of early lung development are expressed in primordial human lung progenitors and revealed a CD47hiCD26lo cell surface phenotype that allows their prospective isolation from untargeted, patient-specific PSCs for further in vitro differentiation and future applications in regenerative medicine.
Asunto(s)
Células Madre Pluripotentes Inducidas/fisiología , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Animales , Diferenciación Celular , Separación Celular , Células Cultivadas , Citometría de Flujo , Regulación Enzimológica de la Expresión Génica , Humanos , Ratones , Factor Nuclear Tiroideo 1 , TranscriptomaRESUMEN
Effective derivation of functional airway organoids from induced pluripotent stem cells (iPSCs) would provide valuable models of lung disease and facilitate precision therapies for airway disorders such as cystic fibrosis. However, limited understanding of human airway patterning has made this goal challenging. Here, we show that cyclical modulation of the canonical Wnt signaling pathway enables rapid directed differentiation of human iPSCs via an NKX2-1+ progenitor intermediate into functional proximal airway organoids. We find that human NKX2-1+ progenitors have high levels of Wnt activation but respond intrinsically to decreases in Wnt signaling by rapidly patterning into proximal airway lineages at the expense of distal fates. Using this directed approach, we were able to generate cystic fibrosis patient-specific iPSC-derived airway organoids with a defect in forskolin-induced swelling that is rescued by gene editing to correct the disease mutation. Our approach has many potential applications in modeling and drug screening for airway diseases.