A novel niche for skin derived precursors in non-follicular skin.

BACKGROUND: Skin derived precursors (SKP) comprise a subset of specialized dermal cells that can be distinguished from fibroblast by their capacity for spheroidal growth. Recent investigations have shown that hair follicles constitute a niche for this cell type, but their localization and their definite function in non-follicular skin remains largely unknown. OBJECTIVE: To identify the dermal niche of non-follicular SKPs and to analyze whether functional aspects correlate with this localization. METHODS: SKPs were isolated from separate anatomical regions of human abdominal skin. Fluorescence activated cell sorting then was used to obtain a pure population of non-follicular SKPs. Functional characterization of these cells was performed applying differentiation and proliferation assays. Information on specific in vivo functions was derived from histological evaluation of quantity and localization patterns. RESULTS: Sphere forming capacity and differentiation assays show that SKPs reside in the papillary part of the dermis. Further delineation revealed that the dermal capillaries represent a niche for these cells which subsequently could be isolated by FACS utilizing a perivascular marker. Whereas functional properties described for follicular SKPs could also be detected in the perivascular SKP population, histological analyses additionally point to a cross-talk with epidermal stem cells and a reduction during chronological aging. CONCLUSION: Our data show that SKPs isolated from non-follicular skin originate from a perivascular niche. Compared to their follicular counterparts, no functional differences could be observed upon cultivation, but ex vivo analyses also point to unique functions and a contribution to the phenotype of aged skin.

Anti-acids lead to immunological and morphological changes in the intestine of BALB/c mice similar to human food allergy.

We have shown that anti-acid medication for treating dyspeptic disorders can block protein digestion and induce a higher risk for food sensitization. This mechanism was confirmed in human and animal studies on the humoral as well as the cellular level. Here we aimed to investigate the outcome of the treatment with the anti-acid drug sucralfate on the intestine in our murine model, assuming that morphological and immunological changes will occur. BALB/c mice were fed codfish extract plus sucralfate. Antibodies were examined in ELISA, RBL assay and Western blot. Quantitative morphological analysis of the intestine was performed by design-based stereology, focussing on epithelium, lamina propria, smooth muscle, eosinophils and CD3(+) cells. Histological analyses were performed after H&E-, PAS- and Congo red-staining, while immune histochemistry was done for detection of CD3(+) cells. Codfish-specific IgE and its activity in RBL assay confirmed the Th2-response after treatment with sucralfate. The reactivity pattern of murine IgE in Western blot was similar to allergic patients' IgE. Histological examination showed more slender villi in the duodenum, and increased goblet cell mucus in the cecum after sucralfate treatment. Stereological analyses of the intestine revealed higher eosinophil/CD3(+) ratios, decreased mean thickness of the epithelium of duodenum and cecum, and thinner smooth muscle cell layer in the colon of food allergic mice. Anti-acid treatment with sucralfate induces changes in the structure of epithelium and villi, and an increase in eosinophils and mucus-producing cells in the intestine. Therefore, this medication leads to sensitization against food with changes typical for food allergy also in the intestine.