Differential Cathelicidin Expression in Duodenal and Gastric Biopsies from Tanzanian and German Patients

Epithelial surfaces such as the gastrointestinal mucosa depend on expression of antimicrobial peptides like cathelicidin for immune defence against pathogens. The mechanisms behind mucosal cathelicidin regulation are incompletely understood. Cathelicidin expression was analysed in duodenal, antral and corpus/fundic mucosal biopsies from African and German patients. Additionally, cathelicidin expression was correlated with Helicobacter pylori (HP) infection and the inflammatory status of the mucosa. High cathelicidin transcript abundance was detected in duodenal biopsies from African subjects. On the contrary, cathelicidin mRNA expression was either undetectable or very low in tissue specimens from German patients. Also, in the antrum and corpus/fundus regions of the stomach significantly higher cathelicidin transcript levels were measured in Tanzanian compared to German patients. In gastric biopsies from African patients cathelicidin expression was increased in HP positive compared to HP negative subjects. Additionally, the inflammatory status measured by IL-8 expression correlated well with the HP infection status. A higher duodenal and gastric cathelicidin expression in African (compared with European) individuals may be due to upregulation by antigenic stimulation and may confer a higher resistance against enteric infections

Influence of apple polyphenols on the intestinal barrier in a colonic cell model

Apples (Malus spp., Rosaceae) and apple-derived foods contain polyphenols that are associated with various desirable health attributes. Amongst other effects, in vivo studies with rodent models have shown that these substances can help to prevent and aid the treatment of intestinal inflammation and other lesions linked to reductions in intestinal barrier function (and thus adverse effects on the status of tight junctions, TJs). In the study presented here we investigated effects of apple polyphenols and their intestinal degradation products on the TJ status (as indicated by the transepithelial resistance, TER), and the mRNA levels of TJ-associated genes (using quantitative real-time PCR) in T84 colon carcinoma cell line monolayers. T84 monolayers were preincubated with sodium caprate (C10) to obtain a model system with decreased barrier function. Polyphenols and their intestinal degradation products significantly increased the TER during 4 h incubations both with and without C10 treatment in comparison to controls. The transcription analyses revealed that polyphenols influenced the transcript levels of all of the tested genes encoding TJ-associated genes. Using physiological concentrations up to 5.7-fold increasing mRNA levels were achieved. Further, apple-specific dihydrochalcones strongly affected both the TER and the expression of tight junction-relevant genes. Generally, apple polyphenols and their intestinal metabolites appeared to enhance the epithelial barrier functions in the T84 colonic cell monolayer model, indicating that consumption of apples and apple-derived foods may have positive effects on the intestinal barrier in healthy humans and may play an important role in the prevention of inflammatory bowel diseases (IBDs)

Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin-Atacamite Composite and its Application

The design of new composite materials using extreme biomimetics is of crucial importance for bioinspired materials science. Further progress in research and application of these new materials is impossible without understanding the mechanisms of formation, as well as structural features at the molecular and nano-level. It presents a challenge to obtain a holistic understanding of the mechanisms underlying the interaction of organic and inorganic phases under conditions of harsh chemical reactions for biopolymers. Yet, an understanding of these mechanisms can lead to the development of unusual-but functional-hybrid materials. In this work, a key way of designing centimeter-scale macroporous 3D composites, using renewable marine biopolymer spongin and a model industrial solution that simulates the highly toxic copper-containing waste generated in the production of printed circuit boards worldwide, is proposed. A new spongin-atacamite composite material is developed and its structure is confirmed using neutron diffraction, X-ray diffraction, high-resolution transmission electron microscopy/selected-area electron diffraction, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. The formation mechanism for this material is also proposed. This study provides experimental evidence suggesting multifunctional applicability of the designed composite in the development of 3D constructed sensors, catalysts, and antibacterial filter systems