CLDN1 Arg81His founder variant causes ichthyosis, leukocyte vacuoles, alopecia, and sclerosing cholangitis (ILVASC) syndrome in Moroccan Jews.

Neonatal ichthyosis and sclerosing cholangitis syndrome (NISCH), also known as ichthyosis, leukocyte vacuoles, alopecia, and sclerosing cholangitis (ILVASC), is an extremely rare disease of autosomal recessive inheritance, resulting from loss of function of the tight junction protein claudin-1. Its clinical presentation is highly variable, and is characterized by liver and ectodermal involvement. Although most ILVASC cases described to date were attributed to homozygous truncating variants in CLDN1, a single missense variant CLDN1 p.Arg81His, associated with isolated skin ichthyosis phenotype, has been recently reported in a family of Moroccan Jewish descent. We now describe seven patients with ILVASC, originating from four non consanguineous families of North African Jewish ancestry (including one previously reported family), harboring CLDN1 p.Arg81His variant, and broaden the phenotypic spectrum attributed to this variant to include teeth, hair, and liver/bile duct involvement, characteristic of ILVASC. Furthermore, we provide additional evidence for pathogenicity of the CLDN1 p.Arg81His variant by transmission electron microscopy of the affected skin, revealing distorted tight junction architecture, and show through haplotype analysis in the vicinity of the CLDN1 gene, that this variant represents a founder variant in Jews of Moroccan descent with an estimated carrier frequency of 1:220.

Melatonin Alleviates Intestinal Barrier Damaging Effects Induced by Polyethylene Microplastics in Albino Rats.

There have been concerns about the potential health risks posed by microplastics (MP). The detection of MP in a variety of food products revealed that humans are ingesting MP. Nevertheless, there is a paucity of data about their impacts, as well as their uptake, on intestinal barrier integrity. This study examined the toxic effects of oral administration of two doses of polyethylene microplastics (PE-MP) (3.75 or 15 mg/kg/day for 5 weeks; mean particle size: 4.0-6.0 µm) on the intestinal barrier integrity in rats. Moreover, the effect of melatonin treatment with MP exposure was also assessed. The PE-MP particle uptake, histopathological changes, Alcian blue staining, Muc2 mRNA, proinflammatory cytokines (IL-1ß and TNF-α), and cleaved caspase-3, as well as tight junction proteins (claudin-1, myosin light-chain kinase (MLCK), occludin, and zonula occludens-1 (ZO-1)) were assessed. Oral administration of PE-MP resulted in apparent jejunal histopathological alterations; significantly decreased mucin secretion, occludin, ZO-1, and claudin-1 expression; and significantly upregulated MLCK mRNA, IL-1ß concentration, and cleaved caspase-3 expression. Melatonin reversed these altered parameters and improved the PE-MP-induced histopathological and ultrastructure changes. This study highlighted the PE-MP's toxic effect on intestinal barrier integrity and revealed the protective effect of melatonin.

[Signaling molecules as biomarkers for predicting implant survival in people of different ages.]

Most patients over 50 years of age are diagnosed with diseases of the dentoalveolar apparatus, in particular, bone tissue disorders, which leads to a decrease in the survival rate of implants. Identification of the causes, as well as the development of a methodology for predicting survival by minimally invasive methods, is relevant. The aim of the study was to study the markers of tight junctions in the buccal epithelium (BE) in people of different ages. BE scrapings were taken before and after implantation in patients divided into 5 age groups, from young to centenarians. Immunocytochemical method was used to study markers for tight junction proteins - claudin-1, -7 and 10. It has been shown that with age there is a decrease in the intensity of expression of adhesion molecules, in particular claudin -1, -7 and -10 in the mucous membranes, the minimum values were recorded in the group of centenarians. The study found that after dental implantation, there was a decrease in the expression of claudin-1 and -10 and an increase in the expression of claudin-7. Changes in the expression of claudins may indicate the development of a pathological process in the body, including the success of implantation, especially in people of older age groups.

Food emulsifier polysorbate 80 promotes the intestinal absorption of mono-2-ethylhexyl phthalate by disturbing intestinal barrier.

Di-2-ethylhexyl phosphate (DEHP) and its main toxic metabolite mono-2-ethylhexyl phthalate (MEHP) are the typical endocrine disrupting chemicals (EDCs) and widely affect human health. Our previous research reported that synthetic nonionic dietary emulsifier polysorbate 80 (P80, E433) had the promotional effect on the oral absorption of DEHP in rats. The aim of this study was to explore its mechanism of promoting oral absorption, focusing on the mucus barrier and mucosal barrier of the small intestine. A small molecule fluorescent probe 5-aminofluorescein-MEHP (MEHP-AF) was used as a tracker of MEHP in vivo and in vitro. First of all, we verified that P80 promoted the bioavailability of MEHP-AF in the long-term and low-dose exposure of MEHP-AF with P80 as a result of increasing the intestinal absorption of MEHP-AF. Afterwards, experimental results from Western blot, qPCR, immunohistochemistry, and immunofluorescence showed that P80 decreased the expression of proteins (mucus protein mucin-2, tight junction proteins claudin-1 and occludin) related to mucus barrier and mucosal barrier in the intestine, changed the integrity of intestinal epithelial cell, and increased the permeability of intestinal epithelial mucosa. These results indicated that P80 promoted the oral absorption of MEHP-AF by altering the intestinal mucus barrier and mucosal barrier. These findings are of great importance for assessing the safety risks of some food emulsifiers and clarifying the absorption mechanism of chemical pollutants in food, especially for EDCs.

Increased integrity of cell-cell junctions accompanied by increased expression of claudin 4 in keratinocytes stimulated with vitamin D3.

The stratified squamous epithelium has a multilayer structure formed by the differentiation of the keratinized epithelium, which covers the skin and oral mucosa. The epithelium plays a central role in regulating the interactions between the immune system and pathogens. The tight junction (TJ) barrier, which is composed of adhesion molecules called claudins (CLDN), is critical for the homeostasis of the skin and oral mucosa. Furthermore, the crucial roles of vitamin D3 (VD3) in the pathogeneses of skin and oral mucosal disease have been suggested. The aim of this in vitro study was to observe the correlations between the integrity of the keratinocyte population and the expression levels of CLDN1 and CLDN4 in gingival epithelial cells, stimulated with VD3. CLDN 1 and 4 expression levels were down and upregulated, respectively, in the cells stimulated with VD3. Additionally, transepithelial electrical resistance (TEER) levels were increased in the stimulated cells when compared to the controls. These findings indicate that CLDN 4 may play a more important role in the TJ barrier than CLDN 1. Hence, the therapeutic effect of VD3 in skin and oral diseases may be regulated by the increase in the expression of CLDN 4.

Influence of Porphyromonas gingivalis in gut microbiota of streptozotocin-induced diabetic mice.

OBJECTIVES: Increasing evidence suggests that periodontitis can exacerbate diabetes, and gut bacterial dysbiosis appears to be linked with the diabetic condition. The present study examined the effects of oral administration of the periodontopathic bacterium, Porphyromonas gingivalis, on the gut microbiota and systemic conditions in streptozotocin-induced diabetic mice. MATERIALS AND METHODS: Diabetes was induced by streptozotocin injection in C57BL/6J male mice (STZ). STZ and wild-type (WT) mice were orally administered P. gingivalis (STZPg, WTPg) or saline (STZco, WTco). Feces were collected, and the gut microbiome was examined by 16S rRNA gene sequencing. The expression of genes related to inflammation, epithelial tight junctions, and glucose/fatty acid metabolism in the ileum or liver were examined by quantitative PCR. RESULTS: The relative abundance of several genera, including Brevibacterium, Corynebacterium, and Facklamia, was significantly increased in STZco mice compared to WTco mice. The relative abundances of Staphylococcus and Turicibacter in the gut microbiome were altered by oral administration of P. gingivalis in STZ mice. STZPg mice showed higher concentrations of fasting blood glucose and inflammatory genes levels in the ileum, compared to STZco mice. CONCLUSIONS: Oral administration of P. gingivalis altered the gut microbiota and aggravated glycemic control in streptozotocin-induced diabetic mice.

Pathogenic role of endogenous TNF-α in the development of Sjögren's-like sialadenitis and secretory dysfunction in non-obese diabetic mice.

Patients with Sjögren's syndrome (SS), an autoimmune disease primarily affecting exocrine glands, exhibit enhanced TNF-α expression in the saliva and salivary glands. However, the precise in vivo role of TNF-α during the initiation and development of SS is not clearly defined. The present study is undertaken to determine the function of endogenously produced TNF-α in the pathogenesis of SS in non-obese diabetic (NOD) mice, a model of this human disease. Administration of a neutralizing anti-TNF-α antibody to female NOD mice during the stage prior to disease onset significantly improved salivary secretion, indicating a remission of clinical symptoms of SS. TNF-α blockade also decreased the number of leukocyte foci and reduced the number of T cells and B cells in the submandibular glands (SMG). Moreover, TNF-α blockade reduced T-bet protein levels in the SMG, suggesting a decrease in T helper 1 and T cytotoxic 1 cells. These cellular changes induced by TNF-α neutralization were associated with a reduction in T- and B-cell chemoattractants CXCL9 and CXC13. In addition, TNF-α blockade markedly increased the expression level of tight junction protein claudin-1 and water channel protein aquaporin-5, two key factors required for normal salivary secretion, in the SMG. Collectively, these findings indicate that endogenous TNF-α has a pathogenic role in the development of SS in the NOD model of this disease.

Therapeutic effects of different doses of polyethylene glycosylated porcine glucagon-like peptide-2 on ulcerative colitis in male rats.

BACKGROUND: Polyethylene glycosylated (PEGylated) porcine glucagon-like peptide-2 (pGLP-2) considerably increases half-life and stability compared with the native pGLP-2, but the effective dose for intestinal damage is still unclear. This study aims to evaluate the available dose of polyethylene glycosylated porcine glucagon-like peptide-2 (PEG-pGLP-2), a modified, long-acting form of pGLP-2 in an experimental rat model of ulcerative colitis. METHODS: Thirty-five male rats were randomly assigned into five groups: control, dextran sodium sulphate (DSS), DSS + PEG-pGLP-2(L), DSS + PEG-pGLP-2(M) and DSS + PEG-pGLP-2(H). Rats in control group received only water; other rats were fed with 5% (w/v) DSS and intraperitoneally administered with 12.5, 25 and 100 nmol/kg PEG-pGLP-2 daily for 6 days. RESULTS: Compared with the control treatment, DSS treatment significantly (p < 0.05) decreased body weight change, colonic length, duodenal villus height and expression of zonula occludens-1, whereas significantly (p < 0.05) increased colonic damage score and expression of claudin-1, interleukin (IL)-1, IL-7, IL-10, interferon-γ and tumour necrosis factor (TNF)-α in colon. However, the three doses of PEG-pGLP-2 all reduced these effects; these treatments significantly (p < 0.05) increased body weight change and duodenal villus height, whereas significantly (p < 0.05) decreased colonic damage score and expression of IL-1, IL-7 and TNF-α in colon. Specifically, low-dose (12.5 nmol/kg/d) PEG-pGLP-2 was effective. CONCLUSIONS: These results indicated that PEG-pGLP-2 is a novel and potentially effective therapy for intestinal healing in a relatively low dose.

Oral infection with Porphyromonas gingivalis augmented gingival epithelial barrier molecules alteration with aging.

OBJECTIVE: Disruption of the gingival epithelial barrier is often mediated by aging or the pathogen Porphyromonas gingivalis. This study examined the combined effects of aging and P. gingivalis exposure on gingival epithelial barrier molecules. METHODS: In vitro experiments involved treating young- and senescence-induced primary human gingival epithelial progenitor cells (HGEPp) with P. gingivalis lipopolysaccharide (LPS). Transepithelial electrical resistance (TER) and paracellular permeability were measured. In vivo, male C57BL/6J mice aged 10 (young) and 80 (old) weeks were divided into four groups: young, old, young with P. gingivalis (Pg-Young) inoculation, and old with P. gingivalis (Pg-Old) inoculation. P. gingivalis was inoculated orally thrice a week for 5 weeks. The mice were sacrificed 30 days after the last inoculation, and samples were collected for further procedures. The junctional molecules (Claudin-1, Claudin-2, E-cadherin, and Connexin) were analyzed for mRNA expression using qRT-PCR and protein production using western blotting and immunohistochemistry. The alveolar bone loss and inflammatory cytokine levels in gingival tissues were also assessed. RESULTS: LPS-treated senescent cells exhibited a pronounced reduction in TER, increased permeability to albumin protein, significant upregulation of Claudin-1 and Claudin-2, and significant downregulation of E-cadherin and Connexin. Furthermore, the Pg-Old group showed identical results with aging in addition to an increase in alveolar bone loss, significantly higher than that in the other groups. CONCLUSION: In conclusion, the host susceptibility to periodontal pathogens increases with age through changes in the gingival epithelial barrier molecules.

The impact of microplastics polystyrene on the microscopic structure of mouse intestine, tight junction genes and gut microbiota.

Microplastics, which are tiny plastic particles less than 5 mm in diameter, are widely present in the environment, have become a serious threat to aquatic life and human health, potentially causing ecosystem disorders and health problems. The present study aimed to investigate the effects of microplastics, specifically microplastics-polystyrene (MPs-PS), on the structural integrity, gene expression related to tight junctions, and gut microbiota in mice. A total of 24 Kunming mice aged 30 days were randomly assigned into four groups: control male (CM), control female (CF), PS-exposed male (PSM), and PS-exposed female (PSF)(n = 6). There were significant differences in villus height, width, intestinal surface area, and villus height to crypt depth ratio (V/C) between the PS group and the control group(C) (p <0.05). Gene expression analysis demonstrated the downregulation of Claudin-1, Claudin-2, Claudin-15, and Occludin, in both duodenum and jejunum of the PS group (p < 0.05). Analysis of microbial species using 16S rRNA sequencing indicated decreased diversity in the PSF group, as well as reduced diversity in the PSM group at various taxonomic levels. Beta diversity analysis showed a significant difference in gut microbiota distribution between the PS-exposed and C groups (R2 = 0.113, p<0.01), with this difference being more pronounced among females exposed to MPs-PS. KEGG analysis revealed enrichment of differential microbiota mainly involved in seven signaling pathways, such as nucleotide metabolism(p<0.05). The relative abundance ratio of transcriptional pathways was significantly increased for the PSF group (p<0.01), while excretory system pathways were for PSM group(p<0.05). Overall findings suggest that MPs-PS exhibit a notable sex-dependent impact on mouse gut microbiota, with a stronger effect observed among females; reduced expression of tight junction genes may be associated with dysbiosis, particularly elevated levels of Prevotellaceae.

Pegylated interferon-α2b and ribavirin decrease claudin-1 and E-cadherin expression in HepG2 and Huh-7.5 cells.

BACKGROUND: Hepatitis C virus (HCV) infection usually results in long-term viremia. Entry of HCV into the hepatocyte requires claudin-1, -6, -9 and occludin. The efficacy of Pegylated interferon-α (PEG-IFN) treatment against HCV infection increased when ribavirin (RBV) was added to the therapeutic scheme. Our aim was to investigate if PEG-IFN plus RBV regulate claudin expression. MATERIAL AND METHODS: HepG2, Huh-7 and Huh-7.5 cells were treated with PEG-IFN-α2a or α2b and/or RBV at different times before obtaining the cytosolic, membrane and cytoskeletal fractions. Claudin-1, 3, 4, 6, and 9, E-cadherin and occludin expression was evaluated by Western blot analysis. Transepithelial electrical resistance (TER) was also determined. RESULTS: Claudin-1, 3, 4, 6, E-cadherin and occludin are constitutively expressed mainly in HepG2 cell membrane. Claudin-1 and E-cadherin cell membrane expression diminished after exposure to PEGIFNα2b (50 ng) + RBV(50 µg); the maximal decrease was observed with 200 ng of PEG-IFNα2b + 200 µg of RBV. The effect was less intense with PEG-IFNα2a. The inhibition of claudin-1 and E-cadherin expression in Huh-7 and Huh-7.5 cells was only observed with 200 ng of PEG-IFNα2b + 200 µg of RBV. TER diminished marginally in the HCV containing hepatoma cells with 200 ng of PEG-IFNα2b + 200 µg of RBV. Claudin-1 mRNA expression level was not affected by the combined treatment. CONCLUSION: The increased therapeutic efficacy of the PEG-IFNα2b plus RBV treatment could be secondary to the inhibition of claudin-1 and E-cadherin cell membrane expression.

[Study of the effect of surface-active agents on living cells, used as component parts in microemulsions, based on their chemical structures and critical micelle-formative concentration (CMC)]. / Mikroemulzió komponenseiként alkalmazott felületaktív anyagok élo sejtekre gyakorolt hatásának vizsgálata kémiai szerkezetük és micellaképzési tulajdonságuk alapján.

The aim of this study was to examine the cellular effects of two nonionic amphiphilic tenside groups and their mixtures on human Caco-2 cell monolayers as dependent upon their chemical structures and physicochemical properties. The first group of polyethylene glycol esters is represented by Polysorbates and Labrasol alone and in blends, while the members of the second group:Capryol 90, Capryol PGMC, Lauroglycol 90 and Lauroglycol FCC were used as propylene glycol esters. They are increasingly used in SMEDDS as recent tensides or co-tensides to increase the solubility of hydrophobic drug. Critical micelle concentration was measured by determination of surface tension. CMC refers to the ability of solubilization of surfactants. Cytotoxicity tests were performed on Caco-2 cell monolayers by MTT and LDH methods. Caco-2 cell monolayers are convenient and reliable in vitro models of the gastrointestinal tract. Paracellular permeability was examined with Lucifer yellow assays. The integrity of cell monolayers was observed by TransEpithelial Electrical Resistance (TEER) measurements. Tight junction alterations effected by the surfactants were also characterized as evidence for paracellular pathway. Changes in sub cellular localization of the tight junction proteins: ZO-1, Claudin-land beta-cathenin, were examined by confocal laser scanning microscopy.The results of cytotoxicity assays were in agreement and showed significant differences among the cytotoxic properties of surfactants in a concentration-dependent manner. Polysorbates 20, 60, 80 are the most toxic compounds. In the case of Labrasol, the degree of esterification and lack of sorbit component decreased cytotoxicity. If the hydrophyl head was changed from polyethylene glycol to propylene glycol, the main determined factor of cytotoxicity was the monoester content and the length of carbon chain. In our CMC experiments, we found that only Labrasol showed expressed cytotoxicity above the CMC. It refers to good ability of micelle solubilization of Labrasol. In our paracellular transport experiments each of polyethylene glycol surfactants (Polysorbates and Labrasol) altered TEER values but propylene glycol esters did not modify the monolayer integrity. Polyethylene glycol esters alone and in blends (0.05% Labrasol--0.001% Polysorbates 20, 60, 80) were able to increase Lucifer yellow permeability significantly below the IC50 concentration. On the other hand Labrasol and Polysorbates 20 have expressed effect on tight junctions of Caco-2 monolayer. It could be concluded that polyethylene glycol ester-type tensides were able to enhance the paracellular permeability by the redistribution of junctional proteins. Our results might ensure useful data for selection of suitable tensides, co-tensides and tenside mixtures for SMEDDS formulations.

Loss of claudin-1 in lipopolysaccharide-treated periodontal epithelium.

BACKGROUND AND OBJECTIVE: The epithelial barrier is a critical component of innate immunity and provides protection against microbial invasion. Claudin-1, a tight junction protein, is known to contribute to the epithelial cell barrier. An experimentally induced rat periodontal disease model was used to study the effects of lipopolysaccharide (LPS) on the expression of tight junction-associated molecule genes in the junctional epithelium. MATERIAL AND METHODS: LPS was applied for 8 wk in the gingival sulcus, and junctional epithelium was collected by laser-capture microdissection and subjected to microarray analysis. RESULTS: Microarray analysis identified that expression of the claudin-1 gene was decreased in the epithelium by chronic LPS challenge. Immunohistochemical analysis confirmed the expression of claudin-1 protein in junctional epithelium and that 8 wk of chronic LPS topical application significantly reduced claudin-1 expression. The effect of LPS on claudin-1 protein expression was validated using a porcine junctional epithelial cell culture Transwell model. The epithelial barrier, as measured using transmembrane resistance, was significantly reduced after 3 wk of LPS challenge and this was associated with a decreased level of expression of claudin-1 protein. CONCLUSION: These results confirm that the initiation of experimental periodontal disease is associated with reduction in the expression of claudin-1 gene and protein. This decreased level of a critical tight junction protein may result in the disruption of barrier function and may play an important role in the initiation of periodontal disease.

Irsogladine maleate regulates epithelial barrier function in tumor necrosis factor-α-stimulated human gingival epithelial cells.

BACKGROUND AND OBJECTIVE: As epithelial cells function as a mechanical barrier, the permeability of the gingival epithelial cell layer indicates a defensive capability against invasion by periodontal pathogens. We have reported the expression of claudin-1 and E-cadherin, key regulators of permeability, in the gingival junctional epithelium. Irsogladine maleate (IM) is a medication for gastric ulcers and also regulates Aggregatibacter actinomycetemcomitans-stimuated chemokine secretion and E-cadherin expression in gingival epithelium. In this study, we have further investigated the effects of IM on the barrier functions of gingival epithelial cells under inflammatory conditions. MATERIAL AND METHODS: We examined the permeability, and the expression of claudin-1 and E-cadherin, in human gingival epithelial cells (HGECs) stimulated with tumor necrosis factor (TNF)-α, with or without IM. RESULTS: TNF-α increased the permeability of HGECs, and IM abolished the increase. TNF-α reduced the expression of E-cadherin in HGECs, and IM reversed the reduction. In addition, immunofluorescence staining showed that TNF-α disrupted claudin-1 expression in HGECs, and IM reversed this effect. CONCLUSION: The results suggest that IM reverses the TNF-α-induced disruption of the gingival epithelial barrier by regulating E-cadherin and claudin-1.

Tooth Formation as Experimental Model to Study Chemotherapy on Tissue Development: Effect of a Specific Dose of Temozolomide/Veliparib.

BACKGROUND: Chemotherapy treatment of cancer in children can influence formation of normal tissues, leading to irreversible changes in their structure and function. Tooth formation is susceptible to several types of chemotherapy that induce irreversible changes in the structure of enamel, dentin and dental root morphology. These changes can make the teeth more prone to fracture or to caries when they have erupted. Recent studies report successful treatment of brain tumors with the alkylating drug temozolomide (TMZ) in combination with veliparib (VLP) in a glioblastoma in vivo mouse model. Whether these drugs also affect tooth formation is unknown. AIM: In this study the effect of TMZ/VLP on incisor formation was investigated in tissue sections of jaws from mice and compared with mice not treated with these drugs. MATERIALS AND METHOD: The following aspects were studied using immunohistochemistry of specific protein markers including: (1) proliferation (by protein expression of proliferation marker Ki67) (2) a protein involved in paracellular ion transport (expression of tight junction (TJ) protein claudin-1) and (3) in transcellular passage of ions across the dental epithelium (expression of Na+, K+ 2Cl- cotransporter/NKCC1). RESULTS: Chemotherapy with TMZ/VLP strongly reduced immunostaining for claudin-1 in distal parts of maturation ameloblasts. No gross changes were found in the treated mice, either in cell proliferation in the dental epithelium at the cervical loop or in the immunostaining pattern for NKCC1 in (non-ameloblastic) dental epithelium. The salivary glands in the treated mice contained strongly reduced immunostaining for NKCC1 in the basolateral membranes of acinar cells. DISCUSSION/CONCLUSIONS: Based on the reduction of claudin-1 immunostaining in ameloblasts, TMZ/VLP may potentially influence forming enamel by changes in the structure of TJs structures in maturation ameloblasts, structures that are crucial for the selective passage of ions through the intercellular space between neighboring ameloblasts. The strongly reduced basolateral NKCC1 staining seen in fully-grown salivary glands of TMZ/VLP-treated mice suggests that TMZ/VLF could also influence ion transport in adult saliva by the salivary gland epithelium. This may cause treated children to be more susceptible to caries.

Porphyromonas gingivalis secretion leads to dysplasia of normal esophageal epithelial cells via the Sonic hedgehog pathway.

Objectives: To investigate the pathogenic effect of Porphyromonas gingivalis cultured media on the esophagus and the mechanism underlying the effect. Background: Periodontitis is strongly associated with esophageal squamous cell carcinoma (ESCC). The cultured media of P. gingivalis may act on healthy esophagus to trigger a malignant transformation; however, this has not been confirmed. Methods: Cell migration assays and cell cycle measurements were performed on normal human esophageal epithelial cells in the presence or absence of P. gingivalis cultured media. The esophagi of healthy adult C57BL/6J mice were isolated and cultured in-vitro. Hematoxylin-eosin and immunohistochemical staining using antibodies against proliferating cell nuclear antigen (PCNA), Claudin 1 and Claudin 4 were performed to detect dysplasia in specific tissues. Total mRNA was extracted to determine transcriptional dysregulation. A specific inhibitor of Sonic hedgehog signaling, cyclopamine, was used to confirm the underlying molecular mechanism. Results: In the presence of P. gingivalis cultured media, proliferation and migration of normal human esophageal epithelial cells were up-regulated, and aneuploid cells appeared. Compared with control cells, the arrangement of mouse esophageal epithelial cells became disordered, the percentage of PCNA-positive cells increased, and the positive staining of Claudin 1 and Claudin 4 became weak. In addition, the expression of cancer-related pathway genes was up-regulated but tight junction-related gene expression was down-regulated. The Sonic hedgehog pathway was abnormally activated, and its inhibition reduced the pathogenic effect of P. gingivalis cultured media. Conclusions: We revealed that the cultured media of the key periodontal pathogen, P. gingivalis, can induce the malignant transformation of normal esophageal epithelium through the Sonic hedgehog pathway.

Mo3Se4 nanoparticle with ROS scavenging and multi-enzyme activity for the treatment of DSS-induced colitis in mice.

Ulcerative colitis (UC), as a most common inflammatory bowel disease (IBD), has become a global public health concern. Exploring novel method of treating UC is urgent and necessary. Recently, nanozyme with excellent antioxidant properties may be one useful therapeutic strategy. In this study, a two-dimensional transition metal chalcogenide (TMCs) nano flake and polyethylene glycol (PEG) modified Mo3Se4 nano flakes (PMNFs) was synthesized, which had multi-enzyme activity, including peroxidase, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). The inhibition effect of PMNFs on sodium dextran sulfate (DSS)-induced colitis was explored. UC was effectively inhibited by PMNFs in this work. PMNFs significantly reduced disease activity index (DAI) score, including weight loss, colon shorten and histopathological abnormalities. The possible mechanism of PMNFs-attenuated colitis was investigated. The results showed that PMNFs reversed DSS-induced oxidative damage, and the antioxidant pathway Nrf2-keap1 signal was activated by PMNFs. Moreover, PMNFs suppressed the expression of pro-inflammatory factors including IL-1ß, TNF-α, IFN-ß and IL-6 via the inactivation of TLR4/NF-κB pathway in DSS-induced colitis and LPS-treated macrophage. Furthermore, PMNFs treatment prevented the reduction of tight junction proteins (ZO-1, occludin, and claudin-1) and mucin-2 (MUC-2) as well as the up-regulation of epithelial apoptosis caused by DSS. These findings demonstrate that the PMNFs against DSS-induced colitis due to its prevention on oxidative damage, inflammation, and intestine barrier breakdown. Thus, PMNFs have a potential application in the treatment of various oxidative stress or inflammation-related diseases.

Polystyrene nanoplastics deteriorate LPS-modulated duodenal permeability and inflammation in mice via ROS drived-NF-κB/NLRP3 pathway.

The widespread occurrence of nanoplastics (NPs), has markedly affected the ecosystem and has become a global threat to animals and human health. There is growing evidence showing that polystyrene nanoparticles (PSNPs) exposure induced enteritis and the intestinal barrier disorder. Lipopolysaccharide (LPS) can trigger the inflammation burden of various tissues. Whether PSNPs deteriorate LPS-induced intestinal damage via ROS drived-NF-κB/NLRP3 pathway is remains unknown. In this study, PSNPs exposure/PSNPs and LPS co-exposure mice model were duplicated by intraperitoneal injection. The results showed that exposure to PSNPs/LPS caused duodenal inflammation and increased permeability. We evaluated the change of duodenum structure, oxidative stress parameters, inflammatory factors, and tight junction protein in the duodenum. We found that PSNPs/LPS could aggravate the production of ROS and oxidative stress in cells, activate NF-κB/NLRP3 pathway, decrease the expression tight junction proteins (ZO-1, Claudin 1, and Occludin) levels, promote inflammatory factors (TNF-α, IL-6, and IFN-γ) expressions. Duodenal oxidative stress and inflammation in PS + LPS group were more serious than those in single exposure group, which could be alleviated by NF-kB inhibitor QNZ. Collectively, the results verified that PSNPs deteriorated LPS-induced inflammation and increasing permeability in mice duodenum via ROS drived-NF-κB/NLRP3 pathway. The current study indicated the relationship and molecular mechanism between PSNPs and intestinal injury, providing novel insights into the adverse effects of PSNPs exposure on mammals and humans.

The expressions of claudin-1 and E-cadherin in junctional epithelium.

BACKGROUND AND OBJECTIVE: The epithelium provides an important barrier against microbial invasion. Tight junction structural proteins called claudins are known to contribute to the epithelial cell barrier. Junctional epithelium is located at a strategically important interface between gingival sulcus and is interconnected by desmosomes and gap junctions, but not by tight junctions. Although claudins are tight junction-associated proteins, they are also expressed in the epithelium despite its lack of tight junctions in invertebrates. Therefore, claudins may play an important role in junctional epithelium without tight junctions. E-cadherin is a key molecule in the formation of adherence junctions and desmosomes. In the present study, we aimed to investigate the expressions of claudin-1,claudin-3, claudin-7 and E-cadherin in the junctional epithelium of Fischer 344 rats. MATERIAL AND METHODS: Gingival tissues from Fischer 344 rats were analyzed by immunohistochemical staining for claudin-1, claudin-3, claudin-7, and E-cadherin. RESULTS: Intense staining for claudin-1 and E-cadherin were observed in the junctional epithelium. In contrast to claudin-1, claudin-3 was mainly expressed in oral gingival epithelium and claudin-7 could not be detected on immunohistochemical analysis of the rat gingiva. CONCLUSION: These data suggest that claudin-1 and E-cadherin exist in the junctional epithelium and may play an important role in epithelial barrier function.

Effects of Porphyromonas gingivalis infection on human gingival epithelial barrier function in vitro.

The gingival epithelium plays an important role in the protection of oral tissues from microbial challenge. Oral keratinocytes form various cellular contacts, including tight junctions, and thus are able to create an epithelial barrier. A measurable indicator of barrier function in vitro is the transepithelial electrical resistance (TER). Porphyromonas gingivalis is recognized as a major aetiologic agent of periodontal disease and exhibits a variety of virulence factors. The aim of the study was to investigate the effect, in vitro, of infection with P. gingivalis on gingival barriers composed of primary and immortalized human keratinocytes. Primary and immortalized human gingival keratinocytes were infected with different strains of P. gingivalis. The impact of the bacterial challenge on the barrier was analysed by measuring the TER. The destructive effects of gingipains were blocked by specific enzyme inhibitors. After an initial increase of about 20-30% in infected wells, the TER decreased to zero. Gingipain inhibitors delayed the destruction of the barrier by 12 ± 4 h. In all cases, the loss of TER was accelerated if the system was infected from the basolateral side. A distinct effect of P. gingivalis on the epithelial barrier function of three-dimensional cultured epithelial cell models was demonstrated, which can partly be attributed to the activity of gingipains.