Characterization of human upper airway epithelial progenitors

RNAseq analysis of olfactory neuroepithelium cytological samples in individuals with Down syndrome compared to euploid controls: a pilot study

Down syndrome is a common genetic disorder caused by partial or complete triplication of chromosome 21. This syndrome shows an overall and progressive impairment of olfactory function, detected early in adulthood. The olfactory neuronal cells are located in the nasal olfactory mucosa and represent the first sensory neurons of the olfactory pathway. Herein, we applied the olfactory swabbing procedure to allow a gentle collection of olfactory epithelial cells in seven individuals with Down syndrome and in ten euploid controls. The aim of this research was to investigate the peripheral gene expression pattern in olfactory epithelial cells through RNAseq analysis. Validated tests (Sniffin' Sticks Extended test) were used to assess olfactory function. Olfactory scores were correlated with RNAseq results and cognitive scores (Vineland II and Leiter scales). All Down syndrome individuals showed both olfactory deficit and intellectual disability. Down syndrome individuals and euploid controls exhibited clear expression differences in genes located in and outside the chromosome 21. In addition, a significant correlation was found between olfactory test scores and gene expression, while a non-significant correlation emerged between olfactory and cognitive scores. This first preliminary step gives new insights into the Down syndrome olfactory system research, starting from the olfactory neuroepithelium, the first cellular step on the olfactory way.

Airway Epithelial Dynamics in Allergy and Related Chronic Inflammatory Airway Diseases

Allergic rhinitis, chronic rhinosinusitis, and asthma are highly prevalent, multifactorial chronic airway diseases. Several environmental and genetic factors affect airway epithelial dynamics leading to activation of inflammatory mechanisms in the airways. This review links environmental factors to host epithelial immunity in airway diseases. Understanding altered homeostasis of the airway epithelium might provide important targets for diagnostics and therapy of chronic airway diseases.

High-Efficiency, Selection-free Gene Repair in Airway Stem Cells from Cystic Fibrosis Patients Rescues CFTR Function in Differentiated Epithelia

Cystic fibrosis (CF) is a monogenic disorder caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Mortality in CF patients is mostly due to respiratory sequelae. Challenges with gene delivery have limited attempts to treat CF using in vivo gene therapy, and low correction levels have hindered ex vivo gene therapy efforts. We have used Cas9 and adeno-associated virus 6 to correct the ΔF508 mutation in readily accessible upper-airway basal stem cells (UABCs) obtained from CF patients. On average, we achieved 30%-50% allelic correction in UABCs and bronchial epithelial cells (HBECs) from 10 CF patients and observed 20%-50% CFTR function relative to non-CF controls in differentiated epithelia. Furthermore, we successfully embedded the corrected UABCs on an FDA-approved porcine small intestinal submucosal membrane (pSIS), and they retained differentiation capacity. This study supports further development of genetically corrected autologous airway stem cell transplant as a treatment for CF.

Porcine small intestine submucosal grafts improve remucosalization and progenitor cell recruitment to sites of upper airway tissue remodeling

BACKGROUND

To better understand upper airway tissue regeneration, the exposed cartilage and bone at donor sites of tissue flaps may serve as in vivo "Petri dishes" for active wound healing. The pedicled nasoseptal flap (NSF) for skull-base reconstruction creates an exposed donor site within the nasal airway. The objective of this study is to evaluate whether grafting the donor site with a sinonasal repair cover graft is effective in promoting wound healing.

METHODS

In this multicenter, prospective trial, subjects were randomized to intervention (graft) or control (no graft) intraoperatively after NSF elevation. Individuals were evaluated at 2, 6, and 12 weeks postintervention with endoscopic recordings. Videos were graded (Likert scale) by 3 otolaryngologists blinded to intervention on remucosalization, crusting, and edema. Scores were analyzed for interrater reliability and cohorts compared. Biopsy and immunohistochemistry at the leading edge of wound healing was performed in select cases.

RESULTS

Twenty-one patients were randomized to intervention and 26 to control. Subjects receiving the graft had significantly greater overall remucosalization (p = 0.01) than controls over 12 weeks. Although crusting was less in the small intestine submucosa (SIS) group, this was not statistically significant (p = 0.08). There was no overall effect on nasal edema (p = 0.2). Immunohistochemistry demonstrated abundant upper airway basal cell progenitors in 2 intervention samples, suggesting that covering grafts may facilitate tissue proliferation via progenitor cell expansion.

CONCLUSION

This prospective, randomized, controlled trial indicates that a porcine SIS graft placed on exposed cartilage and bone within the upper airway confers improved remucosalization compared to current practice standards.

An Official American Thoracic Society Workshop Report 2015. Stem Cells and Cell Therapies in Lung Biology and Diseases

The University of Vermont College of Medicine, in collaboration with the NHLBI, Alpha-1 Foundation, American Thoracic Society, Cystic Fibrosis Foundation, European Respiratory Society, International Society for Cellular Therapy, and the Pulmonary Fibrosis Foundation, convened a workshop, "Stem Cells and Cell Therapies in Lung Biology and Lung Diseases," held July 27 to 30, 2015, at the University of Vermont. The conference objectives were to review the current understanding of the role of stem and progenitor cells in lung repair after injury and to review the current status of cell therapy and ex vivo bioengineering approaches for lung diseases. These are all rapidly expanding areas of study that both provide further insight into and challenge traditional views of mechanisms of lung repair after injury and pathogenesis of several lung diseases. The goals of the conference were to summarize the current state of the field, discuss and debate current controversies, and identify future research directions and opportunities for both basic and translational research in cell-based therapies for lung diseases. This 10th anniversary conference was a follow up to five previous biennial conferences held at the University of Vermont in 2005, 2007, 2009, 2011, and 2013. Each of those conferences, also sponsored by the National Institutes of Health, American Thoracic Society, and respiratory disease foundations, has been important in helping guide research and funding priorities. The major conference recommendations are summarized at the end of the report and highlight both the significant progress and major challenges in these rapidly progressing fields.

Cell Adhesion Molecules and Stem Cell-Niche-Interactions in the Limbal Stem Cell Niche

Interactions between stem cells and their microenvironment are critical for regulation and maintenance of stem cell function. To elucidate the molecular interactions within the human limbal epithelial stem/progenitor cell (LEPC) niche, which is essential for maintaining corneal transparency and vision, we performed a comprehensive expression analysis of cell adhesion molecules (CAMs) using custom-made quantitative real-time polymerase chain reaction (qRT-PCR) arrays and laser capture-microdissected LEPC clusters, comprising LEPCs, melanocytes, mesenchymal cells, and transmigrating immune cells. We show that LEPCs are anchored to their supporting basement membrane by the laminin receptors α3β1 and α6β4 integrin and the dystroglycan complex, while intercellular contacts between LEPCs and melanocytes are mediated by N-, P-, and E-cadherin together with L1-CAM, a member of the immunoglobulin superfamily (Ig)CAMs. In addition to the LEPC-associated heparan sulfate proteoglycans syndecan-2, glypican-3, and glypican-4, the IgCAM members ICAM-1 and VCAM-1 were found to be variably expressed on LEPCs and associated niche cells and to be dynamically regulated in response to chemokines such as interferon-γ to enhance interactions with immune cells. Moreover, junctional adhesion molecule JAM-C accumulating in the subepithelial limbal matrix, appeared to be involved in recruitment of immune cells, while mesenchymal stromal cells appeared to use the nephronectin receptor integrin α8 for approaching the limbal basement membrane. In summary, we identified a novel combination of cell surface receptors that may regulate both stable and dynamic cell-matrix and cell-cell interactions within the limbal niche. The findings provide a solid foundation for further functional studies and for advancement of our current therapeutic strategies for ocular surface reconstruction.

Diversity of epithelial stem cell types in adult lung

Lung is a complex organ lined with epithelial cells. In order to maintain its homeostasis and normal functions following injuries caused by varied extraneous and intraneous insults, such as inhaled environmental pollutants and overwhelming inflammatory responses, the respiratory epithelium normally undergoes regenerations by the proliferation and differentiation of region-specific epithelial stem/progenitor cells that resided in distinct niches along the airway tree. The importance of local epithelial stem cell niches in the specification of lung stem/progenitor cells has been recently identified. Studies using cell differentiating and lineage tracing assays, in vitro and/or ex vivo models, and genetically engineered mice have suggested that these local epithelial stem/progenitor cells within spatially distinct regions along the pulmonary tree contribute to the injury repair of epithelium adjacent to their respective niches. This paper reviews recent findings in the identification and isolation of region-specific epithelial stem/progenitor cells and local niches along the airway tree and the potential link of epithelial stem cells for the development of lung cancer.

Nasal symptoms after radioiodine therapy: a rarely described side effect with similar frequency to lacrimal dysfunction

BACKGROUND

Salivary and lacrimal side effects of radioiodine therapy have been carefully described. However, nasal side effects are rarely described. The objective of this study was to document the frequency of nasal side effects in comparison to the already well-documented lacrimal side effects and to determine contributing risk factors.

METHODS

A retrospective review of the medical records of 807 patients with differentiated thyroid cancer who received care at an academic medical center was conducted. Four hundred eleven patients who received treatment with radioactive iodine (RAI) were identified and included in the analysis. The frequency of both nasal and lacrimal side effects was ascertained. Factors that may have contributed to patients sustaining nasal damage after RAI therapy were also documented. These factors included radioactive iodine dose, method of preparation for receiving RAI therapy, and patient characteristics.

RESULTS

The mean dose of RAI administered was 109 mCi. Forty-three patients (10.5%) and 40 patients (9.7%) developed nasal and lacrimal side effects, respectively, following RAI treatment. The mean time of onset of nasal symptoms was 11 days, compared with 10 months for lacrimal symptoms. Radioiodine dose and body mass index were significantly positively and negatively correlated, respectively, with sustaining nasal side effects (p values of 0.04 and 0.01, respectively). Similarly, both RAI dose and body mass index were significantly correlated, positively and negatively, respectively, with sustaining lacrimal side effects (p values of 0.02 and 0.01). Preparation for treatment using a withdrawal protocol was associated with increased risk of both nasal and lacrimal side effects, compared with a recombinant human thyrotropin (rhTSH) protocol (p values of <0.01 and 0.01). The odds ratios (95% confidence interval [CI]) for nasal and lacrimal side effects with recombinant rhTSH preparation were 0.22 [0.11-0.44] and 0.37 [0.18-0.76], respectively. Instructions to maintain adequate hydration and development of lacrimal symptoms were only associated with nasal symptoms in unadjusted analyses.

CONCLUSIONS

Both nasal and lacrimal dysfunction occurred at an approximately 10% frequency. Although it cannot be determined whether acute nasal side effects are followed by long-term ramifications, these consequences of RAI could potentially add to the reasons to carefully evaluate the benefits and risks of RAI therapy on an individual basis.