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The amniotic fluid is a clinically accessible source of mesenchymal stem cells (AF-MSC) during gestation, which enables autologous cellular therapy for perinatal disorders. The origin of AF-MSC remains elusive: renal and neuronal progenitors have been isolated from the AF-MSC pool, yet no cells with pulmonary characteristics. We analyzed gene expression of pulmonary and renal markers of 212 clonal lines of AF-MSC isolated from amniocentesis samples. AF-MSC were cultured on dishes coated with extracellular matrix (ECM) proteins from decellularized fetal rabbit lungs. In vivo differentiation potential of AF-MSC that expressed markers suggestive of lung fate was tested by renal subcapsular injections in immunodeficient mice. Of all the isolated AF-MSC lines, 26% were positive for lung endodermal markers FOXA2 and NKX2.1 and lacked expression of renal markers (KSP). This AF-MSC subpopulation expressed other lung-specific factors, including IRX1, P63, FOXP2, LGR6, SFTC, and PDPN. Pulmonary marker expression decreased over passages when AF-MSC were cultured under conventional conditions, yet remained more stable when culturing the cells on lung ECM-coated dishes. Renal subcapsular injection of AF-MSC expressing lung-specific markers resulted in engrafted cells that were SPTB positive. These data suggest that FOXA2+/NKX2.1+/KSP- AF-MSC lines have lung characteristics which are supported by culture on lung ECM-coated dishes., (© 2017 John Wiley & Sons, Ltd.)

Objective: Systemic juvenile idiopathic arthritis (JIA) is an immunoinflammatory disease characterized by arthritis and systemic manifestations. The role of natural killer (NK) cells in the pathogenesis of systemic JIA remains unclear. The purpose of this study was to perform a comprehensive analysis of NK cell phenotype and functionality in patients with systemic JIA., Methods: Transcriptional alterations specific to NK cells were investigated by RNA sequencing of highly purified NK cells from 6 patients with active systemic JIA and 6 age-matched healthy controls. Cytokines (NK cell-stimulating and others) were quantified in plasma samples (n = 18). NK cell phenotype and cytotoxic activity against tumor cells were determined (n = 10), together with their interferon-γ (IFNγ)-producing function (n = 8)., Results: NK cells from the systemic JIA patients showed an altered gene expression profile compared to cells from the healthy controls, with enrichment of immunoinflammatory pathways, increased expression of innate genes including TLR4 and S100A9, and decreased expression of immune-regulating genes such as IL10RA and GZMK. In the patients' plasma, interleukin-18 (IL-18) levels were increased, and a decreased ratio of IFNγ to IL-18 was observed. NK cells from the patients exhibited specific alterations in the balance of inhibitory and activating receptors, with decreased killer cell lectin-like receptor G1 and increased NKp44 expression. Although NK cells from the patients showed increased granzyme B expression, consistent with intact cytotoxicity and degranulation against a tumor cell line, decreased granzyme K expression in CD56 bright NK cells and defective IL-18-induced IFNγ production and signaling were demonstrated., Conclusion: NK cells are active players in the inflammatory environment typical of systemic JIA. Although their cytotoxic function is globally intact, subtle defects in NK-related pathways, such as granzyme K expression and IL-18-driven IFNγ production, may contribute to the immunoinflammatory dysregulation in this disease., (© 2016, American College of Rheumatology.)

Objective: This study aimed to evaluate the potential benefit of intra-tracheal injection of human amniotic fluid stem cells (hAFSC) on pulmonary development combined with TO in a rabbit model for CDH., Methods: In time-mated pregnant does a left diaphragmatic defect was created at d23 (term = 31). At d28, previously operated fetuses were assigned to either TO and injection with 70 μL of phosphate buffered saline (PBS) or 1.0 × 10(6) c-Kit positive hAFSC expressing LacZ or were left untouched (CDH). Harvesting was done at d31 to obtain their lung-to-body weight ratio (LBWR), airway and vascular lung morphometry, X-gal staining and immunohistochemistry for Ki67 and surfactant protein-B (SP-B)., Results: CDH-induced pulmonary hypoplasia is countered by TO + PBS, this reverses LBWR, mean terminal bronchiole density (MTBD) and medial thickness to normal. The additional injection of hAFSC decreases MTBD and results in a non-significant decrease in muscularization of intra-acinary vessels. There were no inflammatory changes and LacZ positive hAFSC were dispersed throughout the lung parenchyma 4 days after injection., Conclusion: HAFSC exert an additional effect on TO leading to a decrease in MTBD, a measure of alveolar number surrounding the terminal bronchioles, without signs of toxicity. © 2015 John Wiley & Sons, Ltd., (© 2015 John Wiley & Sons, Ltd.)

Objectives: Stem cells (SCs) can be isolated from amniotic fluid (AF) for a variety of perinatal applications. In view of this, we compared different cryopreservation protocols for these AFSCs., Methods: We screened seven freezing and thawing protocols using two well-established human AFSC lines: freezing protocol 1 (FP1), 10% dimethyl sulfoxide (DMSO); FP2, 2.5% DMSO, caspase inhibitor, and catalase; FP3, 5% glycerol, caspase inhibitor, and catalase; FP4, sperm freezing medium; FP5, slow-freezing solution; FP6, ethylene glycol, sucrose, and Ficoll 70; and FP7, vitrification solution. Outcome measures were post-thawing cell viability, recovery, doubling time and mesenchymal SC markers. The three best performing protocols were subsequently tested on cells isolated from clinical consecutive freshly harvested AF samples from two fetal medicine units., Results: Protocols 1, 5, and 6 performed significantly better on well-characterized cell lines. They performed equally well on cell pellets from freshly harvested AF (n = 28)., Conclusions: We identified three suitable cryopreservation protocols because of high cell recovery and unchanged SC characteristics. Given one of these, the slow-freezing solution, is compatible with current good manufacturing practice legislation, it may be ultimately clinically used., (© 2015 John Wiley & Sons, Ltd.)

Introduction: With this pictorial essay, we aimed to provide gestational age specific reference ranges of relevant fetal structures using micro-ultrasound, as well as its correlation with postmortem MRI and whole body sections., Material and Methods: Time-mated pregnant rabbits (n = 24) were assessed once at various gestational ages in the second half of pregnancy (15, 17, 21 to 23, 25 to 28, and 30 to 31 days; term = 31 days). We obtained biometric data, together with Doppler flow patterns in the ductus venosus, umbilical artery and umbilical vein. After euthanasia, micro-ultrasound images were compared with images obtained by 9.4 Tesla MRI and whole body paraffin sections at 15, 23, 26, and 28 days., Results: We constructed biometric normative curves, which showed a significant correlation with gestational age. The pulsatility index (PI) in the umbilical artery decreased with gestation (PI = 5.746-0.2969(GA) + 0.004931(GA)(2) ; R(2)  = 0.30), whereas pulsatility index for veins (PIV) in the ductus venosus remained constant (median PIV = 0.82 (0.60-1.12)). In this report, we provide an anatomical atlas of fetal thoracic development using both micro-ultrasound and MRI., Conclusion: We describe anatomical fetal leporine development as can be visualized by micro-ultrasound and MR imaging. The reported reference ranges may be useful for researchers using the fetal rabbit model., (© 2013 John Wiley & Sons, Ltd.)

Introduction: Stem cells (SCs) isolated from amniotic fluid (AF) are a promising source for autologous perinatal cell therapy. The aim of this study was to develop a routine isolation, selection, and expansion protocol of clonal SC lines from redundant clinical amniocentesis samples., Materials and Methods: Amniotic fluids were collected between 15 and 22 weeks of gestation, and SCs were isolated by CD117-based and mechanical selection protocols. SCs were characterized by mesenchymal SC marker expression and differentiation protocols. Cells were manipulated with a lentiviral vector system expressing the β-galactosidase reporter gene and were injected into immunodeficient newborn mouse pups. Qualitative assessment was performed to detect the infused cells after 1 week., Results: A total of 78 clonal AF SC populations were successfully isolated by mechanical selection from 21 consecutive amniocentesis samples. They were positive for mesenchymal SC cluster of differentiation markers and could be differentiated into the different lineages. SCs were stably labeled using β-galactosidase and were detected in the lungs and hearts of the neonatal mice., Conclusion: We demonstrate that mesenchymal SCs can be routinely isolated and clonally expanded from mid-gestation human AF using mechanical isolation. They can easily be transduced and be tested for perinatal treatment in animal models., (© 2013 John Wiley & Sons, Ltd.)