The skin is known to be the largest organ in human organism creating interface with outer environment. The skin provides protective barrier against pathogens, physical and chemical insults, and against uncontrolled loss of water. The barrier function was primarily attributed to the stratum corneum (SC) but recent studies confirmed that epidermal tight junctions (TJs) also play important role in maintaining barrier properties of the skin. Independent observations indicate that barrier function and its recovery is impaired in aged skin. However, trans-epidermal water loss (TEWL) values remains rather unchanged in elderly population. UV radiation as major factor of photoageing impairs TJ proteins, but TJs have great self-regenerative potential. Since it may be possible that TJs can compensate TEWL in elderly due to its regenerative and compensatory capabilities, important question remains to be answered: how are TJs regulated during skin ageing? This review provides an insight into TJs functioning as epidermal barrier and summarizes current knowledge about the impact of ageing on the barrier function of the skin and epidermal TJs.

• Klíčová slova
• Barrier function, Epidermis, Skin ageing, TEWL, Tight junction, UV exposure,
• MeSH
• epidermis metabolismus   patologie   účinky záření   MeSH
• kožní absorpce MeSH
• lidé MeSH
• permeabilita MeSH
• perspiratio insensibilis MeSH
• stárnutí kůže * účinky záření   MeSH
• stárnutí metabolismus   patologie   MeSH
• těsný spoj metabolismus   patologie   účinky záření   MeSH
• ultrafialové záření škodlivé účinky   MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

PURPOSE: To document the expression of apical-basal polarity (ABP) determinants in the mouse corneal epithelium (CE) and elucidate the functions of Pard3 in establishment and maintenance of ABP, stratification, homeostasis, and barrier function in the CE. METHODS: Pard3Δ/ΔC mice (Pard3LoxP/LoxP; Aldh3A1-Cre/+) with cornea-specific Pard3 ablation were generated by breeding Aldh3A1-Cre/+ with Pard3LoxP/LoxP mice. The control (Aldh3A1-Cre/+ or Pard3LoxP/LoxP alone) and Pard3Δ/ΔC corneal histology, ocular surface properties, barrier function, and actin cytoskeleton were assessed by Haematoxylin and Eosin staining of paraformaldehyde-fixed, paraffin-embedded tissues, scanning electron microscopy, fluorescein staining, and phalloidin staining, respectively. The expression of specific markers of interest was evaluated by qRT-PCR, immunoblots and immunofluorescent staining. RESULTS: Dynamic changes were observed in the expression and localization of ABP determinants as the CE stratified and matured between post-natal day 5 (PN5) and PN52. Adult Pard3Δ/ΔC CE contained fewer cell layers with rounded basal cells, and loosely adherent superficial cells lacking microplicae. Adult Pard3Δ/ΔC CE also displayed impaired barrier function with decreased expression of tight junction, adherens junction, and desmosome components, disrupted actin cytoskeletal organization, increased proliferation, and upregulation of transcription factors that drive epithelial-mesenchymal transition (EMT). CONCLUSIONS: Disruption of ABP in Pard3Δ/ΔC CE, altered expression of cell junction complex components and disorganized actin cytoskeleton, increased cell proliferation, and upregulated EMT transcription factors suggest that the ABP-determinant Pard3 promotes CE features while suppressing mesenchymal cell fate. Collectively, these results elucidate that Pard3-mediated ABP is essential for CE stratification, homeostasis and barrier function.

• Klíčová slova
• Apical-basal polarity, Barrier function, Corneal epithelium, Par3, Par6, Pard3, Stratification, Tight junction,
• MeSH
• adaptorové proteiny signální transdukční * MeSH
• cytoskelet * metabolismus   MeSH
• homeostáza fyziologie   MeSH
• mikroskopie elektronová rastrovací MeSH
• myši MeSH
• polarita buněk * fyziologie   MeSH
• rohovkový epitel * metabolismus   ultrastruktura   MeSH
• těsný spoj * metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adaptorové proteiny signální transdukční * MeSH

Many respiratory pathogens compromise epithelial barrier function during lung infection by disrupting intercellular junctions, such as adherens junctions and tight junctions, that maintain intercellular integrity. This includes Streptococcus pneumoniae, a leading cause of pneumonia, which can successfully breach the epithelial barrier and cause severe infections such as septicemia and meningitis. Fluorescence microscopy analysis on intercellular junction protein manipulation by respiratory pathogens has yielded major advances in our understanding of their pathogenesis. Unfortunately, a lack of automated image analysis tools that can tolerate variability in sample-sample staining has limited the accuracy in evaluating intercellular junction organization quantitatively. We have created an open source, automated Python computer script called "Intercellular Junction Organization Quantification" or IJOQ that can handle a high degree of sample-sample staining variability and robustly measure intercellular junction integrity. In silico validation of IJOQ was successful in analyzing computer generated images containing varying degrees of simulated intercellular junction disruption. Accurate IJOQ analysis was further confirmed using images generated from in vitro and in vivo bacterial infection models. When compared in parallel to a previously published, semi-automated script used to measure intercellular junction organization, IJOQ demonstrated superior analysis for all in vitro and in vivo experiments described herein. These data indicate that IJOQ is an unbiased, easy-to-use tool for fluorescence microscopy analysis and will serve as a valuable, automated resource to rapidly quantify intercellular junction disruption under diverse experimental conditions.

• Klíčová slova
• adherens junctions, brightness normalization, image analysis, pneumonia, tight junctions,
• MeSH
• adhezní spoje MeSH
• mezibuněčné spoje metabolismus   MeSH
• respirační sliznice MeSH
• Streptococcus pneumoniae * MeSH
• těsný spoj * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Tumor cells interact with blood constituents and these interactions promote metastasis. Selectins are vascular receptors facilitating interactions of tumor cells with platelets, leukocytes, and endothelium, but the role of endothelial E-selectin remains unclear. Here we show that E-selectin is a major receptor for monocyte recruitment to tumor cell-activated endothelium. Experimental and spontaneous lung metastasis using murine tumor cells, without E-selectin ligands, were attenuated in E-selectin-deficient mice. Tumor cell-derived CCL2 promoted endothelial activation, resulting in enhanced endothelial E-selectin expression. The recruitment of inflammatory monocytes to metastasizing tumor cells was dependent on the local endothelial activation and the presence of E-selectin. Monocytes promoted transendothelial migration of tumor cells through the induction of E-selectin-dependent endothelial retractions and a subsequent modulation of tight junctions through dephosphorylation of VE-cadherin. Thus, endothelial E-selectin shapes the tumor microenvironment through the recruitment, adhesion, and activation of monocytes that facilitate tumor cell extravasation and thereby metastasis. These findings provide evidence that endothelial E-selectin is a novel factor contributing to endothelial retraction required for efficient lung metastasis. Cancer Res; 76(18); 5302-12. ©2016 AACR.

• MeSH
• CD antigeny metabolismus   MeSH
• cévní endotel metabolismus   MeSH
• E-selektin metabolismus   MeSH
• endoteliální buňky metabolismus   MeSH
• imunoblotting MeSH
• imunoprecipitace MeSH
• invazivní růst nádoru patologie   MeSH
• kadheriny metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• monocyty metabolismus   MeSH
• mutantní kmeny myší MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• polymerázová řetězová reakce MeSH
• průtoková cytometrie MeSH
• těsný spoj metabolismus   patologie   MeSH
• transendoteliální a transepiteliální migrace fyziologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• cadherin 5 MeSH Prohlížeč
• CD antigeny MeSH
• E-selektin MeSH
• kadheriny MeSH

Puwainaphycins (PUW) and minutissamides (MIN) are cyanobacterial lipopeptides found in various cyanobacterial species. The first possible target of human exposure to them is intestinal epithelium but effect of PUW/MIN on enterocytes is not known at all. Using differentiated Caco-2 cells, PUW F was found to be cytotoxic from 5 µM concentration based on lactate dehydrogenase release assay and total protein concentration. However, it is also able to induce production of interleukin 8 in non-cytotoxic concentrations 1 and 2.5 µM detected by ELISA. Effects of MIN A and C were similar but less pronounced compared to PUW F. On the other hand, MIN D was the least toxic compound with no significant pro-inflammatory effects. Surprisingly, pro-inflammatory activation of the cells by PUW F and MIN C resulted in an increase in tight junction (TJ) protein claudin 4 expression determined by western blot analysis and confirmed by confocal microscopy. Furthermore, decrease in expression of zonula occludens 3, another TJ protein, was observed after the exposure to PUW F. Taken together, these cytotoxic lipopeptides, especially PUW F, are to be studied more deeply due to their capability to activate and/or deregulate human enterocytes in low concentrations.

• Klíčová slova
• Cytotoxicity, Inflammation, Intestinal epithelium, Minutissamides, Puwainaphycins, Tight junction,
• MeSH
• Caco-2 buňky MeSH
• lidé MeSH
• lipopeptidy * MeSH
• sinice * MeSH
• střevní sliznice MeSH
• těsný spoj MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• lipopeptidy * MeSH

Non-melanoma skin cancer (NMSC) is the most frequent human cancer with continuously rising incidences worldwide. Herein, we investigated the molecular basis for the impaired skin barrier function of organotypic NMSC models. We unraveled disturbed epidermal differentiation by reflectance confocal microscopy and histopathological evaluation. While the presence of claudin-4 and occludin were distinctly reduced, zonula occludens protein-1 was more wide-spread, and claudin-1 was heterogeneously distributed within the NMSC models compared with normal reconstructed human skin. Moreover, the cancer altered stratum corneum lipid packing and profile with decreased cholesterol content, increased phospholipid amount, and altered ceramide subclasses. These alterations contributed to increased surface pH and to 1.5 to 2.6-fold enhanced caffeine permeability of the NMSC models. Three topical applications of ingenol mebutate gel (0.015%) caused abundant epidermal cell necrosis, decreased Ki-67 indices, and increased lactate dehydrogenase activity. Taken together, our study provides new biological insights into the microenvironment of organotypic NMSC models, improves the understanding of the disease model by revealing causes for impaired skin barrier function in NMSC models at the molecular level, and fosters human cell-based approaches in preclinical drug evaluation.

• Klíčová slova
• Ceramides, Ingenol mebutate, Non-melanoma skin cancer, Reflectance confocal microscopy, Skin absorption, Tight junctions,
• MeSH
• diterpeny farmakologie   MeSH
• esterasy metabolismus   MeSH
• fibroblasty metabolismus   MeSH
• keratinocyty metabolismus   MeSH
• kofein farmakologie   MeSH
• kokultivační techniky MeSH
• kůže účinky léků   metabolismus   MeSH
• lidé MeSH
• metabolismus lipidů MeSH
• nádorové buněčné linie MeSH
• nádory kůže metabolismus   MeSH
• proteiny těsného spoje metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 3-ingenyl angelate MeSH Prohlížeč
• diterpeny MeSH
• esterasy MeSH
• kofein MeSH
• proteiny těsného spoje MeSH

Helicenes are inherently chiral polyaromatic molecules composed of all-ortho fused benzene rings possessing a spring-like structure. Here, using a combination of density functional theory and tight-binding calculations, it is demonstrated that controlling the length of the helicene molecule by mechanically stretching or compressing the molecular junction can dramatically change the electronic properties of the helicene, leading to a tunable switching behavior of the conductance and thermopower of the junction with on/off ratios of several orders of magnitude. Furthermore, control over the helicene length and number of rings is shown to lead to more than an order of magnitude increase in the thermopower and thermoelectric figure-of-merit over typical molecular junctions, presenting new possibilities of making efficient thermoelectric molecular devices. The physical origin of the strong dependence of the transport properties of the junction is investigated, and found to be related to a shift in the position of the molecular orbitals.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Enterococcus cecorum (EC) is one of the most relevant bacterial pathogens in modern broiler chicken production from an economic and animal welfare perspective. Although EC pathogenesis is generally well described, predisposing factors are still unknown. This study aimed to understand the effect of heat stress on the caecal microbiota, intestinal integrity, and EC pathogenesis. A total of 373 1-day-old commercial broiler chicks were randomly assigned to four groups: (1) noninoculated, thermoneutral conditions (TN); (2) noninoculated, heat stress conditions (HS); (3) EC-inoculated, thermoneutral conditions (TN + EC); and (4) EC-inoculated, heat stress conditions (HS + EC). Birds were monitored daily for clinical signs. Necropsy of 20 broilers per group was performed at 7, 14, 21, and 42 days post-hatch (dph). A trend towards enhanced and more pronounced clinical disease was observed in the EC-inoculated, heat-stressed group. EC detection rates in extraintestinal tissues via culture were higher in the HS + EC group (~19%) than in the TN + EC group (~11%). Significantly more birds were colonized by EC at 7 dph in the HS + EC group (100%) than in the TN + EC group (65%, p < 0.05). The caecal microbiota in the two EC-inoculated groups was significantly more diverse than that in the TN group (p < 0.05) at 14 dph, which may indicate an effect of EC infection. An influence of heat stress on mRNA expression of tight junction proteins in the caecum was detected at 7 dph, where all six investigated tight junction proteins were expressed at significantly lower levels in the heat stressed groups compared to the thermoneutral groups. These observations suggest that heat stress may predispose broilers to EC-associated disease and increase the severity thereof. Furthermore, heat stress may impair intestinal integrity and promote EC translocation.

• Klíčová slova
• Enterococcus cecorum, broiler, caecal microbiota, heat stress, intestinal integrity,
• MeSH
• cékum mikrobiologie   MeSH
• Enterococcus MeSH
• kur domácí * mikrobiologie   MeSH
• mikrobiota * MeSH
• proteiny těsného spoje MeSH
• reakce na tepelný šok MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie veterinární MeSH
• Názvy látek
• proteiny těsného spoje MeSH

Mammalian corneal development is a multistep process, including formation of the corneal epithelium (CE), endothelium and stroma during embryogenesis, followed by postnatal stratification of the epithelial layers and continuous renewal of the epithelium to replace the outermost corneal cells. Here, we employed the Cre-loxP system to conditionally deplete Pax6 proteins in two domains of ocular cells, i.e., the ocular surface epithelium (cornea, limbus and conjunctiva) (OSE) or postnatal CE via K14-cre or Aldh3-cre, respectively. Earlier and broader inactivation of Pax6 in the OSE resulted in thickened OSE with CE and limbal cells adopting the conjunctival keratin expression pattern. More restricted depletion of Pax6 in postnatal CE resulted in an abnormal cornea marked by reduced epithelial thickness despite increased epithelial cell proliferation. Immunofluorescence studies revealed loss of intermediate filament Cytokeratin 12 and diffused expression of adherens junction components, together with reduced tight junction protein, Zonula occludens-1. Furthermore, the expression of Cytokeratin 14, a basal cell marker in apical layers, indicates impaired differentiation of CE cells. Collectively, our data demonstrate that Pax6 is essential for maintaining proper differentiation and strong intercellular adhesion in postnatal CE cells, whereas limbal Pax6 is required to prevent the outgrowth of conjunctival cells to the cornea.

• Klíčová slova
• Conditional knockout, Cornea, Development, E-cadherin, Eye, Keratins, Pax6,
• MeSH
• keratin-12 metabolismus   MeSH
• keratin-14 metabolismus   MeSH
• keratiny metabolismus   MeSH
• proteiny těsného spoje metabolismus   MeSH
• rohovka * metabolismus   MeSH
• rohovkový epitel * metabolismus   MeSH
• savci metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• keratin-12 MeSH
• keratin-14 MeSH
• keratiny MeSH
• proteiny těsného spoje MeSH

Intestinal milieu disorders are strongly related to the occurrence of inflammatory bowel diseases (IBDs), which results from mucosa destruction, epithelium disruption, and tight junction (TJ) proteins loss. Excess of H2 S in the intestinal milieu produced by the sulfate-reducing bacteria metabolism contributes to development of IBDs via epithelial barrier breakdown. Conventional interventions, such as surgery and anti-inflammatory medications, are considered not completely effective because of frequent recurrence and other complications. Herein, a novel oral delivery system, a hydroxypropyl methylcellulose acetate succinate (HPMCAS)-based polymer-coated Zr-based metal-organic framework (UiO-66) with a Cux -rhodamine B (CR) probe (hereinafter referred to as HUR), is produced via a co-flow microfluidic approach with the ability to reduce H2 S levels, thus restoring the intestinal lumen milieu. HPMCAS serves as an enteric coating that exposes UiO-66@CR at the pH of the intestine but not the acidic pH of the stomach. The synthesized HUR exhibits notable therapeutic efficacy, including mucosa recovery, epithelium integrity restoration, and TJ proteins upregulation via H2 S scavenging to protect against intestinal barrier damage and microbiome dysbiosis. Thus, HUR is verified to be a promising theranostic platform able to decrease the H2 S content for intestinal milieu disorder treatment. The presented study therefore opens the door for further exploitation for IBDs therapy.

• Klíčová slova
• Zr metal-organic frameworks, hydrogen sulfide scavenging, inflammatory bowel disease, intestinal milieu restoration, microfluidic technology,
• MeSH
• mikrofluidika MeSH
• porézní koordinační polymery * metabolismus   MeSH
• střeva MeSH
• střevní sliznice metabolismus   MeSH
• sulfan chemie   MeSH
• těsný spoj MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• porézní koordinační polymery * MeSH
• sulfan MeSH
• UiO-66 MeSH Prohlížeč