1,8-Cineole potentiates IRF3-mediated antiviral response in human stem cells and in an ex vivo model of rhinosinusitis.

The common cold is one of the most frequent human inflammatory diseases caused by viruses and can facilitate bacterial superinfections, resulting in sinusitis or pneumonia. The active ingredient of the drug Soledum, 1,8-cineole, is commonly applied for treating inflammatory diseases of the respiratory tract. However, the potential for 1,8-cineole to treat primary viral infections of the respiratory tract remains unclear. In the present study, we demonstrate for the first time that 1,8-cineole potentiates poly(I:C)-induced activity of the antiviral transcription factor interferon regulatory factor 3 (IRF3), while simultaneously reducing proinflammatory nuclear factor (NF)-κB activity in human cell lines, inferior turbinate stem cells (ITSCs) and in ex vivo cultivated human nasal mucosa. Co-treatment of cell lines with poly(I:C) and 1,8-cineole resulted in significantly increased IRF3 reporter gene activity compared with poly(I:C) alone, whereas NF-κB activity was reduced. Accordingly, 1,8-cineole- and poly(I:C) treatment led to increased nuclear translocation of IRF3 in ITSCs and a human ex vivo model of rhinosinusitis compared with the poly(I:C) treatment approach. Nuclear translocation of IRF3 was significantly increased in ITSCs and slice cultures treated with lipopolysaccharide (LPS) and 1,8-cineole compared with the LPS-treated cells mimicking bacterial infection. Our findings strongly suggest that 1,8-cineole potentiates the antiviral activity of IRF3 in addition to its inhibitory effect on proinflammatory NF-κB signalling, and may thus broaden its field of application.

Identification of a Novel High Yielding Source of Multipotent Adult Human Neural Crest-Derived Stem Cells.

Due to their extraordinarily broad differentiation potential and persistence during adulthood, adult neural crest-derived stem cells (NCSCs) are highly promising candidates for clinical applications, particularly when facing the challenging treatment of neurodegenerative diseases or complex craniofacial injuries. Successful application of human NCSCs in regenerative medicine and pharmaceutical research mainly relies on the availability of sufficient amounts of tissue for cell isolation procedures. Facing this challenge, we here describe for the first time a novel population of NCSCs within the middle turbinate of the human nasal cavity. From a surgical point of view, high amounts of tissue are routinely and easily removed during nasal biopsies. Investigating the presence of putative stem cells in obtained middle turbinate tissue by immunohistochemistry, we observed Nestin+/p75NTR+/S100+/α smooth muscle actin (αSMA)- cells, which we successfully isolated and cultivated in vitro. Cultivated middle turbinate stem cells (MTSCs) kept their expression of neural crest and stemness markers Nestin, p75 NTR and S100 and showed the capability of sphere formation and clonal growth, indicating their stem cell character. Application of directed in vitro differentiation assays resulted in successful differentiation of MTSCs into osteogenic and neuronal cell types. Regarding the high amount of tissue obtained during surgery as well as their broad differentiation capability, MTSCs seem to be a highly promising novel neural crest stem cell population for applications in cell replacement therapy and pharmacological research.

Stem cells in middle ear cholesteatoma contribute to its pathogenesis.

Cholesteatoma is a potentially life-threatening middle ear lesion due to the formation of an inflamed ectopic mass of keratinizing squamous epithelium. Surgical removal remains the only treatment option, emphasizing the need to gain a better understanding of this severe disease. We show for the first time that stem cells residing in cholesteatoma tissue contribute to disease progression. Cells expressing the "stemness" markers Nestin and S100B were detected in middle ear cholesteatoma and auditory canal skin. Isolated Nestin + /S100B + -cells showed the capability for self-renewal, neurosphere formation and differentiation into mesodermal and ectodermal cell types. Compared to auditory canal skin stem cells middle ear cholesteatoma-derived stem cells displayed an enhanced susceptibility to inflammatory stimuli, and this suggested a possible contribution to the inflammatory environment in cholesteatoma tissue. Cholesteatoma derived stem cells were able to differentiate into keratinocyte-like cells using factors mimicking the microenvironment of cholesteatoma. Our findings demonstrate a new perspective on the pathogenesis of cholesteatoma and may lead to new treatment strategies for this severe middle ear lesion.

1,8-Cineol Reduces Mucus-Production in a Novel Human Ex Vivo Model of Late Rhinosinusitis.

Inflammatory diseases of the respiratory system such as rhinosinusitis, chronic obstructive pulmonary disease, or bronchial asthma are strongly associated with overproduction and hypersecretion of mucus lining the epithelial airway surface. 1,8-cineol, the active ingredient of the pharmaceutical drug Soledum, is commonly applied for treating such inflammatory airway diseases. However, its potential effects on mucus overproduction still remain unclear.In the present study, we successfully established ex vivo cultures of human nasal turbinate slices to investigate the effects of 1,8-cineol on mucus hypersecretion in experimentally induced rhinosinusitis. The presence of acetyl-α-tubulin-positive cilia confirmed the integrity of the ex vivo cultured epithelium. Mucin-filled goblet cells were also detectable in nasal slice cultures, as revealed by Alcian Blue and Periodic acid-Schiff stainings. Treatment of nasal slice cultures with lipopolysaccharides mimicking bacterial infection as observed during late rhinosinusitis led to a significantly increased number of mucin-filled goblet cells. Notably, the number of mucin-filled goblet cells was found to be significantly decreased after co-treatment with 1,8-cineol. On a molecular level, real time PCR-analysis further showed 1,8-cineol to significantly reduce the expression levels of the mucin genes MUC2 and MUC19 in close association with significantly attenuated NF-κB-activity. In conclusion, we demonstrate for the first time a 1,8-cineol-dependent reduction of mucin-filled goblet cells and MUC2-gene expression associated with an attenuated NF-κB-activity in human nasal slice cultures. Our findings suggest that these effects partially account for the clinical benefits of 1,8-cineol-based therapy during rhinosinusitis. Therefore, topical application of 1,8-cineol may offer a novel therapeutic approach to reduce bacteria-induced mucus hypersecretion.