RESUMEN

Speciation leads to adaptive changes in organ cellular physiology and creates challenges for studying rare cell-type functions that diverge between humans and mice. Rare cystic fibrosis transmembrane conductance regulator (CFTR)-rich pulmonary ionocytes exist throughout the cartilaginous airways of humans1,2, but limited presence and divergent biology in the proximal trachea of mice has prevented the use of traditional transgenic models to elucidate ionocyte functions in the airway. Here we describe the creation and use of conditional genetic ferret models to dissect pulmonary ionocyte biology and function by enabling ionocyte lineage tracing (FOXI1-CreERT2::ROSA-TG), ionocyte ablation (FOXI1-KO) and ionocyte-specific deletion of CFTR (FOXI1-CreERT2::CFTRL/L). By comparing these models with cystic fibrosis ferrets3,4, we demonstrate that ionocytes control airway surface liquid absorption, secretion, pH and mucus viscosity-leading to reduced airway surface liquid volume and impaired mucociliary clearance in cystic fibrosis, FOXI1-KO and FOXI1-CreERT2::CFTRL/L ferrets. These processes are regulated by CFTR-dependent ionocyte transport of Cl- and HCO3-. Single-cell transcriptomics and in vivo lineage tracing revealed three subtypes of pulmonary ionocytes and a FOXI1-lineage common rare cell progenitor for ionocytes, tuft cells and neuroendocrine cells during airway development. Thus, rare pulmonary ionocytes perform critical CFTR-dependent functions in the proximal airway that are hallmark features of cystic fibrosis airway disease. These studies provide a road map for using conditional genetics in the first non-rodent mammal to address gene function, cell biology and disease processes that have greater evolutionary conservation between humans and ferrets.

Asunto(s)

Fibrosis Quística , Modelos Animales de Enfermedad , Hurones , Pulmón , Transgenes , Animales , Humanos , Animales Modificados Genéticamente , Linaje de la Célula , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Hurones/genética , Hurones/fisiología , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Pulmón/citología , Pulmón/metabolismo , Pulmón/patología , Tráquea/citología , Transgenes/genética

RESUMEN

BACKGROUND: Cystic fibrosis (CF) related diabetes is the most common comorbidity for CF patients and associated with islet dysfunction. Exocrine pancreas remodeling in CF alters the microenvironment in which islets reside. Since CFTR is mainly expressed in pancreatic ductal epithelium, we hypothesized altered CF ductal secretions could impact islet function through paracrine signals. METHOD: We evaluated the secretome and cellular proteome of polarized WT and CF ferret ductal epithelia using quantitative ratiometric mass spectrometry. Differentially secreted proteins (DSPs) or expressed cellular proteins were used to mine pathways, upstream regulators and the CFTR interactome to map candidate CF-associated alterations in ductal signaling and phenotype. Candidate DSPs were evaluated for their in vivo pancreatic expression patterns and their functional impact on islet hormone secretion. RESULTS: The secretome and cellular proteome of CF ductal epithelia was significantly altered relative to WT and implicated dysregulated TGFß, WNT, and BMP signaling pathways. Cognate receptors of DSPs from CF epithelia were equally distributed among endocrine, exocrine, and stromal pancreatic cell types. IGFBP7 was a downregulated DSP in CF ductal epithelia in vitro and exhibited reduced CF ductal expression in vivo. IGFBP7 also altered WT islet insulin secretion in response to glucose. Many CFTR-associated proteins, including SLC9A3R1, were differentially expressed in the CF cellular proteome. Upstream regulators of the differential CF ductal proteome included TGFß, PDX1, AKT/PTEN, and INSR signaling. Data is available via ProteomeXchange with identifier PXD025126. CONCLUSION: These findings provide a proteomic roadmap for elucidating disturbances in autocrine and paracrine signals from CF pancreatic ducts and how they may alter islet function and maintenance.

Asunto(s)

Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Diabetes Mellitus/metabolismo , Insuficiencia Pancreática Exocrina/metabolismo , Hurones/metabolismo , Páncreas Exocrino/metabolismo , Animales , Humanos , Conductos Pancreáticos/metabolismo , Proteoma/metabolismo , Secretoma/metabolismo

RESUMEN

The mammalian airways are lined by a continuous epithelial layer that is maintained by diverse populations of resident multipotent stem cells. These stem cells are responsible for replenishing the epithelium both at homeostasis and following injury, making them promising targets for stem cell and genetic-based therapies for a variety of respiratory diseases. However, the mechanisms that regulate when and how these stem cells proliferate, migrate, and differentiate remains incompletely understood. Here, we find that the high mobility group (HMG) domain transcription factor Lef-1 regulates proliferation and differentiation of mouse tracheal basal cells. We demonstrate that conditional deletion of Lef-1 stalls basal cell proliferation at the G1/S transition of the cell cycle, and that Lef-1 knockout cells are unable to maintain luminal tracheal cell types in long-term air-liquid interface culture. RNA sequencing analysis revealed that Lef-1 knockout (Lef-1KO) results in downregulation of key DNA damage response and cell cycle progression genes, including the kinase Chek1. Furthermore, chemical inhibition of Chek1 is sufficient to stall basal cell self-renewal in a similar fashion as Lef-1 deletion. Notably, the cell cycle block imposed by Lef-1KO in vitro is transient and basal cells eventually compensate to proliferate normally in a Chek1-independent manner. Finally, Lef-1KO cells were unable to fully regenerate tracheal epithelium following injury in vivo. These findings reveal that Lef-1 is essential for proper basal cell function. Thus, modulating Lef-1 function in airway basal cells may have applications in regenerative medicine.

Asunto(s)

Células Madre , Factores de Transcripción , Animales , Ciclo Celular/genética , Diferenciación Celular , Proliferación Celular/genética , Células Epiteliales/metabolismo , Ratones , Células Madre/metabolismo , Factores de Transcripción/metabolismo

RESUMEN

CONTEXT: Although diabetes affects 40% to 50% of adults with cystic fibrosis, remarkably little is known regarding the underlying mechanisms leading to impaired pancreatic ß-cell insulin secretion. Efforts toward improving the functional ß-cell deficit in cystic fibrosis-related diabetes (CFRD) have been hampered by an incomplete understanding of whether ß-cell function is intrinsically regulated by cystic fibrosis transmembrane conductance regulator (CFTR). Definitively excluding meaningful CFTR expression in human ß-cells in situ would contribute significantly to the understanding of CFRD pathogenesis. OBJECTIVE: To determine CFTR messenger ribonucleic acid (mRNA) and protein expression within ß-cells in situ in the unmanipulated human pancreas of donors without any known pancreatic pathology. DESIGN: In situ hybridization for CFTR mRNA expression in parallel with insulin immunohistochemical staining and immunofluorescence co-localization of CFTR with insulin and the ductal marker, Keratin-7 (KRT7), were undertaken in pancreatic tissue blocks from 10 normal adult, nonobese deceased organ donors over a wide age range (23-71 years) with quantitative image analysis. RESULTS: CFTR mRNA was detectable in a mean 0.45% (range 0.17%-0.83%) of insulin-positive cells. CFTR protein expression was co-localized with KRT7. One hundred percent of insulin-positive cells were immunonegative for CFTR. CONCLUSIONS: For the first time, in situ CFTR mRNA expression in the unmanipulated pancreas has been shown to be present in only a very small minority (<1%) of normal adult ß-cells. These data signal a need to move away from studying endocrine-intrinsic mechanisms and focus on elucidation of exocrine-endocrine interactions in human cystic fibrosis.

Asunto(s)

Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Células Secretoras de Insulina/metabolismo , Páncreas/metabolismo , Adulto , Anciano , Animales , Animales Modificados Genéticamente , Animales Recién Nacidos , Autopsia , Recuento de Células , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Femenino , Hurones , Técnicas de Inactivación de Genes , Humanos , Células Secretoras de Insulina/patología , Masculino , Persona de Mediana Edad , Páncreas/patología , Adulto Joven

RESUMEN

Cystic fibrosis (CF) is a multiorgan disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). In patients with CF, abnormalities initiate in several organs before birth. However, the long-term impact of these in utero pathologies on disease pathophysiology is unclear. To address this issue, we generated ferrets harboring a VX-770 (ivacaftor)-responsive CFTR G551D mutation. In utero VX-770 administration provided partial protection from developmental pathologies in the pancreas, intestine, and male reproductive tract. Homozygous CFTR G551D/G551D animals showed the greatest VX-770-mediated protection from these pathologies. Sustained postnatal VX-770 administration led to improved pancreatic exocrine function, glucose tolerance, growth and survival, and to reduced mucus accumulation and bacterial infections in the lung. VX-770 withdrawal at any age reestablished disease, with the most rapid onset of morbidity occurring when withdrawal was initiated during the first 2 weeks after birth. The results suggest that CFTR is important for establishing organ function early in life. Moreover, this ferret model provides proof of concept for in utero pharmacologic correction of genetic disease and offers opportunities for understanding CF pathogenesis and improving treatment.

Asunto(s)

Aminofenoles/administración & dosificación , Agonistas de los Canales de Cloruro/administración & dosificación , Fibrosis Quística/tratamiento farmacológico , Quinolonas/administración & dosificación , Animales , Animales Modificados Genéticamente , Animales Recién Nacidos , Glucemia/metabolismo , Fibrosis Quística/genética , Fibrosis Quística/fisiopatología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Hurones , Técnicas de Sustitución del Gen , Genitales Masculinos/anomalías , Genitales Masculinos/efectos de los fármacos , Edad Gestacional , Humanos , Masculino , Mutación , Páncreas Exocrino/efectos de los fármacos , Páncreas Exocrino/patología , Páncreas Exocrino/fisiopatología , Embarazo , Infecciones del Sistema Respiratorio/etiología , Infecciones del Sistema Respiratorio/prevención & control , Investigación Biomédica Traslacional

RESUMEN

The domestic ferret (Mustela putorius furo) has proven to be a useful species for modeling human genetic and infectious diseases of the lung and brain. However, biomedical research in ferrets has been hindered by the lack of rapid and cost-effective methods for genome engineering. Here, we utilized CRISPR/Cas9-mediated, homology-independent insertion at the ROSA26 "safe harbor" locus in ferret zygotes and created transgenic animals expressing a dual-fluorescent Cre-reporter system flanked by PhiC31 and Bxb1 integrase attP sites. Out of 151 zygotes injected with circular transgene-containing plasmid and Cas9 protein loaded with the ROSA26 intron-1 sgRNA, there were 23 births of which 5 had targeted integration events (22% efficiency). The encoded tdTomato transgene was highly expressed in all tissues evaluated. Targeted integration was verified by PCR analyses, Southern blot, and germ-line transmission. Function of the ROSA26-CAG-LoxPtdTomatoStopLoxPEGFP (ROSA-TG) Cre-reporter was confirmed in primary cells following Cre expression. The Phi31 and Bxb1 integrase attP sites flanking the transgene will also enable rapid directional insertion of any transgene without a size limitation at the ROSA26 locus. These methods and the model generated will greatly enhance biomedical research involving lineage tracing, the evaluation of stem cell therapy, and transgenesis in ferret models of human disease.

Asunto(s)

Animales Modificados Genéticamente/genética , Sistemas CRISPR-Cas/genética , Técnicas de Sustitución del Gen/métodos , Técnicas de Transferencia de Gen , Ingeniería Genética/métodos , Animales , ADN (Citosina-5-)-Metiltransferasas/genética , Hurones , Genes Reporteros/genética , ARN Guía de Kinetoplastida/genética , Proteínas Represoras/genética , Proteínas Virales/genética

RESUMEN

Toolsets available for in-depth analysis of scRNA-seq datasets by biologists with little informatics experience is limited. Here, we describe an informatics tool (PyMINEr) that fully automates cell type identification, cell type-specific pathway analyses, graph theory-based analysis of gene regulation, and detection of autocrine-paracrine signaling networks in silico. We applied PyMINEr to interrogate human pancreatic islet scRNA-seq datasets and discovered several features of co-expression graphs, including concordance of scRNA-seq-graph structure with both protein-protein interactions and 3D genomic architecture, association of high-connectivity and low-expression genes with cell type enrichment, and potential for the graph structure to clarify potential etiologies of enigmatic disease-associated variants. We further created a consensus co-expression network and autocrine-paracrine signaling networks within and across islet cell types from seven datasets. PyMINEr correctly identified changes in BMP-WNT signaling associated with cystic fibrosis pancreatic acinar cell loss. This proof-of-principle study demonstrates that the PyMINEr framework will be a valuable resource for scRNA-seq analyses.

Asunto(s)

ARN Citoplasmático Pequeño/genética , Análisis de Secuencia de ARN/métodos , Comunicación Autocrina , Humanos , Comunicación Paracrina

RESUMEN

The mouse trachea is thought to contain two distinct stem cell compartments that contribute to airway repair-basal cells in the surface airway epithelium (SAE) and an unknown submucosal gland (SMG) cell type. Whether a lineage relationship exists between these two stem cell compartments remains unclear. Using lineage tracing of glandular myoepithelial cells (MECs), we demonstrate that MECs can give rise to seven cell types of the SAE and SMGs following severe airway injury. MECs progressively adopted a basal cell phenotype on the SAE and established lasting progenitors capable of further regeneration following reinjury. MECs activate Wnt-regulated transcription factors (Lef-1/TCF7) following injury and Lef-1 induction in cultured MECs promoted transition to a basal cell phenotype. Surprisingly, dose-dependent MEC conditional activation of Lef-1 in vivo promoted self-limited airway regeneration in the absence of injury. Thus, modulating the Lef-1 transcriptional program in MEC-derived progenitors may have regenerative medicine applications for lung diseases.

Asunto(s)

Células Epiteliales/citología , Glándulas Exocrinas/citología , Mucosa Respiratoria/citología , Células Madre/citología , Tráquea/citología , Animales , Células Cultivadas , Femenino , Masculino , Ratones , Ratones Endogámicos , Ratones Transgénicos

RESUMEN

Pancreatic ductular epithelial cells comprise the majority of duct cells in pancreas, control cystic fibrosis transmembrane conductance regulator (CFTR)-dependent bicarbonate ([Formula: see text]) secretion, but are difficult to grow as a polarized monolayer. Using NIH-3T3-J2 fibroblast feeder cells and a Rho-associated kinase inhibitor, we produced well-differentiated and polarized porcine pancreatic ductular epithelial cells. Cells grown on semipermeable filters at the air-liquid interface developed typical epithelial cell morphology and stable transepithelial resistance and expressed epithelial cell markers (zona occludens-1 and ß-catenin), duct cell markers (SOX-9 and CFTR), but no acinar (amylase) or islet cell (chromogranin) markers. Polarized cells were studied in Ussing chambers bathed in Krebs-Ringer [Formula: see text] solution at 37°C gassed with 5% CO2 to measure short-circuit currents ( Isc). Ratiometric measurement of extracellular pH was performed with fluorescent SNARF-conjugated dextran at 5% CO2. Cells demonstrated a baseline Isc (12.2 ± 3.2 µA/cm2) that increased significantly in response to apical forskolin-IBMX (∆ Isc: 35.4 ± 3.8 µA/cm2, P < 0.001) or basolateral secretin (∆ Isc: 31.4 ± 2.5 µA/cm2, P < 0.001), both of which increase cellular levels of cAMP. Subsequent addition of apical GlyH-101, a CFTR inhibitor, decreased the current (∆ Isc: 20.4 ± 3.8 µA/cm2, P < 0.01). Extracellular pH and [Formula: see text] concentration increased significantly after forskolin-IBMX (pH: 7.18 ± 0.23 vs. 7.53 ± 0.19; [Formula: see text] concentration, 14.5 ± 5.9 vs. 31.8 ± 13.4 mM; P < 0.05 for both). We demonstrate the development of a polarized pancreatic ductular epithelial cell epithelium with CFTR-dependent [Formula: see text] secretion in response to secretin and cAMP. This model is highly relevant, as porcine pancreas physiology is very similar to humans and pancreatic damage in the cystic fibrosis pig model recapitulates that of humans. NEW & NOTEWORTHY Pancreas ductular epithelial cells control cystic fibrosis transmembrane conductance regulator (CFTR)-dependent bicarbonate secretion. Their function is critical because when CFTR is deficient in cystic fibrosis bicarbonate secretion is lost and the pancreas is damaged. Mechanisms that control pancreatic bicarbonate secretion are incompletely understood. We generated well-differentiated and polarized porcine pancreatic ductular epithelial cells and demonstrated feasibility of bicarbonate secretion. This novel method will advance our understanding of pancreas physiology and mechanisms of bicarbonate secretion.

Asunto(s)

Epitelio/fisiología , Conductos Pancreáticos/fisiología , Animales , Bicarbonatos/metabolismo , Línea Celular , Colforsina/metabolismo , Fibrosis Quística/metabolismo , Fibrosis Quística/fisiopatología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/fisiología , Epitelio/metabolismo , Humanos , Ratones , Células 3T3 NIH , Conductos Pancreáticos/metabolismo , Jugo Pancreático/metabolismo , Jugo Pancreático/fisiología , Transducción de Señal/fisiología , Porcinos

RESUMEN

RATIONALE: Classical interpretation of cystic fibrosis (CF) lung disease pathogenesis suggests that infection initiates disease progression, leading to an exuberant inflammatory response, excessive mucus, and ultimately bronchiectasis. Although symptomatic antibiotic treatment controls lung infections early in disease, lifelong bacterial residence typically ensues. Processes that control the establishment of persistent bacteria in the CF lung, and the contribution of noninfectious components to disease pathogenesis, are poorly understood. OBJECTIVES: To evaluate whether continuous antibiotic therapy protects the CF lung from disease using a ferret model that rapidly acquires lethal bacterial lung infections in the absence of antibiotics. METHODS: CFTR (cystic fibrosis transmembrane conductance regulator)-knockout ferrets were treated with three antibiotics from birth to several years of age and lung disease was followed by quantitative computed tomography, BAL, and histopathology. Lung disease was compared with CFTR-knockout ferrets treated symptomatically with antibiotics. MEASUREMENTS AND MAIN RESULTS: Bronchiectasis was quantified from computed tomography images. BAL was evaluated for cellular differential and features of inflammatory cellular activation, bacteria, fungi, and quantitative proteomics. Semiquantitative histopathology was compared across experimental groups. We demonstrate that lifelong antibiotics can protect the CF ferret lung from infections for several years. Surprisingly, CF animals still developed hallmarks of structural bronchiectasis, neutrophil-mediated inflammation, and mucus accumulation, despite the lack of infection. Quantitative proteomics of BAL from CF and non-CF pairs demonstrated a mucoinflammatory signature in the CF lung dominated by Muc5B and neutrophil chemoattractants and products. CONCLUSIONS: These findings implicate mucoinflammatory processes in the CF lung as pathogenic in the absence of clinically apparent bacterial and fungal infections.

Asunto(s)

Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Infecciones/microbiología , Inflamación/microbiología , Enfermedades Pulmonares/microbiología , Pulmón/microbiología , Pulmón/fisiopatología , Infecciones del Sistema Respiratorio/microbiología , Animales , Modelos Animales de Enfermedad , Hurones/microbiología , Infecciones/fisiopatología , Inflamación/fisiopatología , Enfermedades Pulmonares/fisiopatología , Infecciones del Sistema Respiratorio/fisiopatología

RESUMEN

In cystic fibrosis (CF), there is early destruction of the exocrine pancreas, and this results in a unique form of diabetes that affects approximately half of adult CF individuals. An animal model of cystic fibrosis-related diabetes has been developed in the ferret, which progresses through phases of glycemic abnormalities because of islet remodeling during and after exocrine destruction. Herein, we quantified the pancreatic histopathological changes that occur during these phases. There was an increase in percentage ductal, fat, and islet area in CF ferrets over time compared with age-matched wild-type controls. We also quantified islet size, shape, islet cell composition, cell proliferation (Ki-67), and expression of remodeling markers (matrix metalloprotease-7, desmin, and α-smooth muscle actin). Pancreatic ducts were dilated with scattered proliferating cells and were surrounded by activated stellate cells, indicative of tissue remodeling. The timing of islet and duct proliferation, stellate cell activation, and matrix remodeling coincided with the previously published stages of glycemic crisis and inflammation. This mapping of remodeling events in the CF ferret pancreas provides insights into early changes that control glycemic intolerance and subsequent recovery during the evolution of CF pancreatic disease.

Asunto(s)

Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Hurones/metabolismo , Técnicas de Inactivación de Genes , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Tejido Adiposo/patología , Envejecimiento/patología , Animales , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Humanos , Hiperplasia , Antígeno Ki-67/metabolismo , Metaloproteinasa 7 de la Matriz/metabolismo , Modelos Biológicos , Células Estrelladas Pancreáticas/metabolismo , Células Estrelladas Pancreáticas/patología , Regulación hacia Arriba/genética

RESUMEN

This paper presents an approach to the real-time, label-free, specific, and sensitive monitoring of insulin using a graphene aptameric nanosensor. The nanosensor is configured as a field-effect transistor, whose graphene-based conducting channel is functionalized with a guanine-rich IGA3 aptamer. The negatively charged aptamer folds into a compact and stable antiparallel or parallel G-quadruplex conformation upon binding with insulin, resulting in a change in the carrier density, and hence the electrical conductance, of the graphene. The change in the electrical conductance is then measured to enable the real-time monitoring of insulin levels. Testing has shown that the nanosensor offers an estimated limit of detection down to 35 pM and is functional in Krebs-Ringer bicarbonate buffer, a standard pancreatic islet perfusion medium. These results demonstrate the potential utility of this approach in label-free monitoring of insulin and in timely prediction of accurate insulin dosage in clinical diagnostics.

Asunto(s)

Insulina/química , Técnicas Biosensibles , G-Cuádruplex , Grafito , Islotes Pancreáticos