Expression Of Zonula Occludens-1 Research Articles

Jagged1-Notch1 Signaling Pathway Induces M1 Microglia to Disrupt the Barrier Function of Retinal Microvascular Endothelial Cells

Purpose Microglia-related inflammation is closely linked to the pathogenesis of retinal diseases. The primary objective of this research was to investigate the impact and mechanism of M1 phenotype microglia on the barrier function of retina microvascular endothelial cells. Methods Quantitative polymerase chain reactions and western blot techniques were utilized to analysis the mRNA and protein expressions of M1 and M2 markers of human microglial clone 3 cell line (HMC3), as well as the levels of Notch ligands and receptors under the intervention of lipopolysaccharide (LPS) or interleukin (IL)-4. ELISA was utilized to detect the pro-inflammatory and anti-inflammatory cytokines from HMC3 cells. The cellular tight junction and apoptosis of human retinal microvascular endothelial cells (HRMECs) were assessed by western blot and fluorescein isothiocyanate-dextran permeability assay. The inhibitors of Notch1 and RNA interference (RNAi) targeting Jagged1 were used to assess their contribution to the barrier function of vascular endothelial cells. Results Inducible nitric oxide synthase (iNOS) and IL-1β were considerably elevated in LPS-treated HMC3, while CD206 and Arg-1 markedly elevated under IL-4 stimulation. The conditioned medium derived from LPS-treated HMC3 cells promoted permeability, diminished the expression of zonula occludens-1 and Occludin, and elevated the expression of Cleaved caspase-3 in HRMECs. RNAi targeting Jagged1 or Notch1 inhibitor could block M1 HMC3 polarization and maintain barrier function of HRMECs. Conclusion Our findings suggest that Jagged1-Notch1 signaling pathway induces M1 microglial cells to disrupt the barrier function of HRMECs, which may lead to retinal diseases.

Punicalagin ameliorates DSS-induced colitis in mice through strengthening gut barrier, decreasing oxidative stress and downregulating inflammation via AMPK–NF–κB-STAT3 pathway

Inflammatory bowel disease is characterized by compromised epithelium barrier function and hyperactive intestinal inflammation. This study aims to investigate the effects of punicalagin, a bioactive ellagitannin in pomegranate, on dextran-sodium sulfate (DSS) - induced colitis in mice and to examine the underlying mechanisms involved. Oral administration of punicalagin (100 mg/kg/day) effectively mitigated the severity of experimental colitis in mice, evidenced by increased colon length, improved intestinal permeability, and decreased histological scores. Punicalagin up-regulated the mRNA expression level of Muc2 in and the protein expression of zonula occludens-1 (ZO-1) and Occludin in colitic mice. Moreover, punicalagin effectively decreased reactive oxygen species (ROS) levels in the colon, and in Caco-2 cells exposed to H2O2in vitro. Mechanistically, punicalagin attenuated inflammation by inhibiting the secretion of interleukin-6 (IL-6) and the phosphorylation of the NF-κB/STAT3 pathway. In addition, punicalagin increased adenosine monophosphate activated protein kinase (AMPK) phosphorylation in the colon of DSS-treated mice and lipopolysaccharide (LPS) -induced RAW 264.7 macrophages. Knocking down AMPKα by siRNA diminished punicalagin's anti-inflammatory function in RAW 264.7 macrophages exposed to LPS. Furthermore, molecular docking analysis, cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) analysis supported the direct interaction between punicalagin and AMPK. In conclusion, punicalagin could mitigate DSS-induced colitis through enhancing intestinal epithelial barrier, alleviating oxidative stress, and attenuating inflammation partly through modulation of AMPK–NF–κB-STAT3 pathway.

Therapeutic effect of Yinhuapinggan granules mediated through the intestinal flora in mice infected with the H1N1 influenza virus.

In this study, we examined the therapeutic effects of Yinhuapinggan granules (YHPGs) in influenza-infected mice. We also examined how YHPGs affect the composition of the intestinal flora and associated metabolites. We used the nasal drip method to administer the influenza A virus (IAV) H1N1 to ICR mice. Following successful model construction, the mice were injected with 0.9% sterile saline and low (5.5 g/kg), medium (11 g/kg), and high (22 g/kg) doses of YHPGs. The pathological changes in the lungs and intestines were evaluated by gavage for 5 consecutive days. Detection of sIgA, IL-6, TNF-α, INF-γ, and TGF-β cytokine levels in serum by enzyme-linked immunosorbent assay. Real-time fluorescence quantitative polymerase chain reaction and Western blot were used to measure the mRNA and protein expression of the tight junction proteins claudin-1, occludin, and zonula occludens-1 (ZO-1) in the colon. To assess the influence of YHPGs on the intestinal microbiota, feces were obtained from the mice for 16s rRNA sequencing, and short-chain fatty acids (SCFAs) were measured in the feces. By reducing the production of pro-inflammatory cytokines and increasing the relative expression of claudin-1, occludin, and ZO-1 in colon tissues, YHPGs had a protective effect in tissues from the lungs and colon. When YHPGs were administered to mice with IAV infection, the relative abundance of Lactobacillus, Coprobacillus, Akkermansia, Prevotella, Oscillospira, and Ruminococcus increased, whereas the relative abundance of Desulfovibrio decreased. The therapeutic mechanism of YHPGs against IAV infection in mice may be underpinned by modulation of the structural composition of colonic bacteria and regulation of SCFA production.

Effects of electroacupuncture with "intestinal disease prescription" on NLRP3 inflammasome and intestinal mucosal barrier in rats with acute ulcerative colitis.

To observe the effects of electroacupuncture (EA) with "intestinal disease prescription" on the intestinal mucosal barrier and NLRP3 inflammasome in rats with dextran sulfate sodium (DSS)-induced acute ulcerative colitis (UC), and explore the underlying mechanism of EA with "intestinal disease prescription" for the treatment of UC. Thirty-two healthy male SPF-grade SD rats were randomly divided into a blank group, a model group, a medication group, and an EA group, with 8 rats in each group. Except for the blank group, the UC model was established by administering 5% DSS solution for 7 days. After modeling, the rats in the medication group were treated with mesalazine suspension (200 mg/kg) by gavage, while the rats in the EA group were treated with acupuncture at bilateral "Tianshu" (ST 25), "Shangjuxu" (ST 37) and "Zhongwan" (CV 12), with the ipsilateral "Tianshu" (ST 25) and "Shangjuxu" (ST 37) connected to the electrodes of the EA instrument, using disperse-dense wave, with a frequency of 10 Hz/50 Hz, and each intervention lasted for 20 minutes. Both interventions were performed once daily for 3 days. The general conditions of rats were observed daily. After intervention, the disease activity index (DAI) score was calculated; colon tissue morphology was observed using HE staining; serum levels of pro-inflammatory cytokines (interleukin [IL]-18, IL-1β) were measured by ELISA; protein expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and Caspase-1 in colon tissues was detected by Western blot; positive expression of zonula occludens-1 (ZO-1) and Occludin in colon tissues was examined by immunofluorescence. Compared with the blank group, the rats in the model group exhibited poor general conditions, slow body weight gain, shortened colon length (P<0.01), increased DAI score and spleen index (P<0.01), elevated serum IL-18 and IL-1β levels, and increased protein expression of NLRP3, ASC, and Caspase-1 in colon tissues (P<0.01), along with decreased positive expression of ZO-1 and Occludin in colon tissues (P<0.01). Compared with the model group, the rats in the medication group and the EA group exhibited improved general conditions, accelerated body weight gain, increased colon length (P<0.05), reduced DAI scores and spleen indexes (P<0.05), decreased serum IL-18 and IL-1β levels, and lower protein expression of NLRP3, ASC and Caspase-1 in colon tissues (P<0.05), as well as increased positive expression of ZO-1 and Occludin in colon tissues (P<0.05). There were no significant differences in the above indexes between the medication group and the EA group (P>0.05). Compared with the blank group, the rats in the model group exhibited disrupted colon mucosal morphology, disordered gland arrangement, and atrophy of crypts, along with significant inflammatory cell infiltration. Compared with the model group, the rats in both the medication group and the EA group showed relatively intact colon mucosal morphology, with restored and improved gland and crypt structures, and reduced inflammatory cell infiltration. EA with "intestinal disease prescription" has a significant therapeutic effect on DSS-induced UC, possibly by regulating the expression of NLRP3 inflammasome and proteins related to the intestinal mucosal barrier, thereby alleviating symptoms of ulcerative colitis.

Effects of moxibustion on intestinal barrier function and TLR4/NF-κB p65 signaling pathway in obese rats.

To observe the effects of moxibustion on intestinal barrier function and Toll-like receptor 4 (TLR4)/nuclear factor-κB p65 (NF-κB p65) signaling pathway in obese rats and explore the mechanism of moxibustion in the intervention of obesity. Fifty-five Wistar rats of SPF grade were randomly divided into a normal group (10 rats) and a modeling group (45 rats). In the modeling group, the obesity model was established by feeding high-fat diet. Thirty successfully-modeled rats were randomized into a model group, a moxibustion group, and a placebo-control group, with 10 rats in each one. In the moxibustion group, moxibustion was applied at the site 3 cm to 5 cm far from the surface of "Zhongwan" (CV 12), with the temperature maintained at (46±1 ) ℃. In the placebo-control group, moxibustion was applied at the site 8 cm to 10 cm far from "Zhongwan" (CV 12), with the temperature maintained at (38±1) ℃. The intervention was delivered once daily for 8 weeks in the above two groups. The body mass and food intake of the rats were observed before and after intervention in each group. Using ELISA methool, the levels of serum triacylglycerol (TG), total cholesterol (TC) and lipopolysaccharide (LPS) were detected and the insulin resistance index (HOMA-IR) was calculated. HE staining was used to observe the morphology of colon tissue. The mRNA expression of zonula occludens-1 (ZO-1), Occludin, Claudin-1, TLR4 and NF-κB p65 in the colon tissue was detected by quantitative real-time PCR; and the protein expression of ZO-1, Occludin, Claudin-1, TLR4 and NF-κB p65 was detected by Western blot in the rats of each group. Compared with the normal group, the body mass, food intake, the level of HOMA-IR, and the serum levels of TC, TG and LPS were increased in the rats of the model group (P<0.01); those indexes in the moxibustion group were all reduced when compared with the model group and the placebo-control group respectively (P<0.01, P<0.05). Compared with the normal group, a large number of epithelial cells in the mucosa of colon tissue was damaged, shed, and the inflammatory cells were infiltrated obviously in the interstitium in the rats of the model group. When compared with the model group, in the moxibustion group, the damage of the colon tissue was recovered to various degrees and there were few infiltrated inflammatory cells in the interstitium, while, the epithelial injury of the colon tissue was slightly recovered and the infiltrated inflammatory cells in the interstitium were still seen in the placebo-control group. The mRNA and protein expressions of ZO-1, Occludin and Caudin-1 were decreased in the model group compared with those in the normal group (P<0.01). When compared with the model group and the placebo-control group, the mRNA and protein expressions of these indexes were increased in the moxibustion group (P<0.01, P<0.05). In the model group, the mRNA and protein expressions of TLR4 and NF-κB p65 were increased when compared with those in the normal group (P<0.01), and the mRNA and protein expressions of these indexes were reduced in the moxibustion group when compared with those in the model group and the placebo-control group (P<0.01). Moxibustion can reduce the body mass and food intake, regulate the blood lipid and improve insulin resistance in the rats of obesity. It may be related to alleviating inflammatory response through improving intestinal barrier function and modulating the intestinal TLR4/NF-κB p65 signaling pathway.

Interactions between Age-Related Type 2 Diabetes and the Small Intestine.

The number of patients with type 2 diabetes is increasing worldwide. The mechanisms leading to type 2 diabetes and its complications is being researched; however, the pathological mechanisms of diabetes in the small intestine remain unclear. Therefore, we examined these pathological mechanisms in the small intestine using a mouse model of type 2 diabetes (KK-Ay/TaJcl) aged 10 and 50 weeks. The results showed that diabetes worsened with age in the mice with type 2 diabetes. In these mice, advanced glycation end products (AGEs) in the small intestine and mast cell expression increased, whereas diamine oxidase (DAO) decreased; increased tumor necrosis factor (TNF)-α and histamine levels in the plasma and small intestine were also detected. Additionally, the expression of zonula occludens (ZO)-1 and Claudin1 and cell adhesion molecules in the small intestine reduced. These results exacerbated with age. These findings indicate that type 2 diabetes causes AGE/mast cell/histamine and TNF-α signal transmission in the small intestine and decreases small intestinal wall cell adhesion molecules cause TNF-α and histamine to flow into the body, worsening the diabetic condition. In addition, this sequence of events is suggested to be strengthened in aged mice with type 2 diabetes, thus exacerbating the disease. These findings of this study may facilitate the elucidation of the pathological mechanisms of type 2 diabetes and its associated complications.

Neuroprotective effects of takinib on an experimental traumatic brain injury rat model via inhibition of transforming growth factor beta-activated kinase 1

Transforming growth factor β-activated kinase 1 (TAK1) plays a significant role in controlling several signaling pathways involved with regulating inflammation and apoptosis. As such, it represents an important potential target for developing treatments for traumatic brain injury (TBI). Takinib, a small molecule and selective TAK1 inhibitor, has potent anti-inflammatory activity and has shown promising activity in preclinical studies using rat models to evaluate the potential neuroprotective impact on TBI. The current study used a modified Feeney's weight-drop model to cause TBI in mature Sprague-Dawley male rats. At 30 min post-induction of TBI in the rats, they received an intracerebroventricular (ICV) injection of Takinib followed by assessment of their histopathology and behavior. The results of this study demonstrated how Takinib suppressed TBI progression in the rats by decreasing TAK1, p-TAK1, and nuclear p65 levels while upregulating IκB-α expression. Takinib was also shown to significantly inhibit the production of two pro-inflammatory factors, namely tumor necrosis factor-α and interleukin-1β. Furthermore, Takinib greatly upregulated the expression of tight junction proteins zonula occludens-1 and claudin-5, reducing cerebral edema. Additionally, Takinib effectively suppressed apoptosis via downregulation of cleaved caspase 3 and Bax and reduction of TUNEL-positive stained cell count. As a result, an enhancement of neuronal function and survival was observed post-TBI. These findings highlight the medicinal value of Takinib in the management of TBI and offer an experimental justification for further investigation of TAK1 as a potential pharmacological target.

Berberine alleviates concanavalin A-induced autoimmune hepatitis in mice by modulating the gut microbiota.

Autoimmune hepatitis (AIH) is an immune-mediated liver disease of unknown etiology accompanied by intestinal dysbiosis and a damaged intestinal barrier. Berberine (BBR) is a traditional antibacterial medicine that has a variety of pharmacological properties. It has been reported that BBR alleviates AIH, but relevant mechanisms remain to be fully explored. BBR was orally administered at doses of 100mg⋅kg-1⋅d-1 for 7 days to mice before concanavalin A-induced AIH model establishment. Histopathological, immunohistochemical, immunofluorescence, western blotting, ELISA, 16S rRNA analysis, flow cytometry, real-time quantitative PCR, and fecal microbiota transplantation studies were performed to ascertain BBR effects and mechanisms in AIH mice. We found that liver necrosis and apoptosis were decreased upon BBR administration; the levels of serum transaminase, serum lipopolysaccharide, liver proinflammatory factors TNF-α, interferon-γ, IL-1β, and IL-17A, and the proportion of Th17 cells in spleen cells were all reduced, while the anti-inflammatory factor IL-10 and regulatory T cell proportions were increased. Moreover, BBR treatment increased beneficial and reduced harmful bacteria in the gut. BBR also strengthened ileal barrier function by increasing the expression of the tight junction proteins zonula occludens-1 and occludin, thereby blocking lipopolysaccharide translocation, preventing lipopolysaccharide/toll-like receptor 4 (TLR4)/ NF-κB pathway activation, and inhibiting inflammatory factor production in the liver. Fecal microbiota transplantation from BBR to model mice also showed that BBR potentially alleviated AIH by altering the gut microbiota. BBR alleviated concanavalin A-induced AIH by modulating the gut microbiota and related immune regulation. These results shed more light on potential BBR therapeutic strategies for AIH.

Innovative probiotic Escherichia coli nissle 1917-derived outer membrane vesicles coupled microspheres demonstrate anti-inflammatory and barrier-enhancing properties in colitis

Occurrence of inflammatory bowel disease (IBD) is increasing worldwide and has become a global health threat. Nonetheless, the effective prevention and available treatment interventions of IBD are limited. Bacterial outer membrane vesicles (OMVs) derived from probiotic bacteria such as Escherichia coli Nissle 1917 (EcN) exhibit promising anti-inflammatory, anti-oxidant, immunomodulatory, and gut microbiota modulatory functions. However, the application of OMVs in vivo encounters potential challenges due to poor tolerance against gastric juice. A delivery system of probiotic-EcN-derived OMVs was established by aldehyde-coupling to silica microspheres (SAP@OMVs) in this study. These SAP@OMVs microspheres were nontoxic to murine macrophage RAW 264.7 and human intestinal epithelial cell lines Caco-2. In the dextran sulfate sodium (DSS)-induced acute colitis models, the application of SAP@OMVs significantly improved mouse survival and alleviated the harmful effects of DSS by maintaining colon length, reducing colon injury, decreasing expression of inflammatory factors such as TNF-α and IL-1β, and increasing expression of the tight junction proteins gene zonula occludens-1 (ZO-1). The SAP@OMVs restored gut microbiota with increasing abundance of the Lactobacillus. In conclusion, the novel vehicle of OMVs demonstrated anti-inflammatory effects, representing a crucial strategy for clinical translation of OMVs as a potential therapeutic intervention for IBD.

Oral administration of ovalbumin ameliorates specific food allergy via inhibiting gasdermin C-mediated pyroptosis and regulating microbial homeostasis

Early intervention with food allergenic proteins is considered the most promising and effective approach in preventing the onset of food allergy (FA). However, the effects of oral administration of protein antigens from different food sources on specific FA outcomes and its regulatory mechanisms remain largely unclear. Here, the Balb/c mice were treated with 5 mg of egg ovalbumin (OVA) or cow's milk β-lactoglobulin (BLG) for 5 days prior to intraperitoneal sensitization with OVA/Alum and oral challenge with 20 mg OVA. The results indicated that oral administration of both OVA and BLG significantly increased the proportion of regulatory T cells. However, the introduction of OVA, but not the bystander antigen BLG, prevented the occurrence of allergic diarrhea (OT-OVA group: 0% vs OT-BLG group: 100%) and mitigated the decrease in body temperature (OT-OVA group: 0.11 °C vs OT-BLG group: 1.1 °C). Specifically, the levels of serum immunoglobulin-E and mast cell protease-1 were significantly reduced, and the expression of zonula occludens-1, occludin, and claudin-1 was increased in the OVA-treated mice but not BLG-treated mice. Subsequently, transcriptome sequencing and Western blot analysis revealed that oral administration of OVA reduced the expression and cleavage of gasdermin C, which further decreased interleukin-33 secretion. Additionally, the dysregulation of the gut microbiota and short-chain fatty acid metabolism in the intestinal microenvironment caused by FA was reversed in OVA-treated mice but not BLG. In summary, our results presented a unique approach to ameliorate FA through targeting gasdermin C-mediated pyroptosis and dysbiosis of the gut microbiota in the intestinal microenvironment with OVA.

Rosemary leaf powder improves egg quality, antioxidant status, gut barrier function, and cecal microbiota and metabolites of late-phase laying hens

This study sought to determine the effects of rosemary leaf powder (RP) on laying performance, egg quality, serum indices, gut barrier function, and cecal microbiota and metabolites of late-phase laying hens. A total of 84 “Jing Tint 6” laying hens at 65-week old were randomly divided into 2 groups and fed either a basal diet (CON) or a basal diet supplemented with 0.3% RP. Our study revealed that RP improved the Haugh unit and decreased yolk n-6/n-3 polyunsaturated fatty acid (PUFA) ratio of laying hens, increased serum superoxide dismutase (SOD), jejunal activities of SOD and catalase (CAT), and jejunal zonula occludens-1 (ZO-1) expression, as well as decreased serum tumor necrosis factor-α (TNF-α) level and jejunal TNF-α mRNA expression. Rosemary leaf powder markedly enhanced (P < 0.05) cecal abundances of Rikenellaceae, Rikenellaceae_RC9_gut_group, and Turicibacter, tended to promote (P = 0.076) butyrate concentration, and reduced (P < 0.05) cecal abundances of Erysipelatoclostridiaceae, Sutterellaceae, Fusobacteriaceae, Campylobacteraceae, Sutterella, Campylobacter, and Fusobacterium, which were closely linked with Haugh unit, yolk n-6/n-3 PUFA ratio, serum SOD and TNF-α. In addition, RP altered the metabolic functions of cecal microbiota and enhanced the abundances of butyrate-synthesizing enzymes, including lysine 2,3-aminomutase, β-lysine 5,6-aminomutase, and 3-oxoacid CoA-transferase. Together, 0.3% RP has the potential to enhance egg quality by partially modulating serum antioxidant status, jejunal barrier function, and cecal microbiota structure and metabolites, indicating that RP could be considered a promising feed additive to promote the production performance of late-phase laying hens.

Protective effect of Tao Hong Si Wu Decoction against inflammatory injury caused by intestinal flora disorders in an ischemic stroke mouse model

Background and aimsRecent studies have shown that intestinal flora are involved in the pathological process of ischemic stroke (IS). The potential protective effect of the traditional Chinese prescription, Tao Hong Si Wu Decoction (THSWD), against inflammatory injury after IS and its underlying mechanisms of action were investigated in the current study.MethodsFifty SPF(Specefic pathogen Free) male C57 mice were randomly assigned to sham operation, model, THSWD low-dose (6.5 g/kg), medium-dose (13 g/kg) and high-dose (26 g/kg) groups (10 mice per group). Mouse models of transient middle cerebral artery occlusion were prepared via thread embolism. Neurological function score, hematoxylin-eosin (HE) staining, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), 16S ribosomal DNA (rDNA) sequencing, quantitative reverse transcription PCR (qRT-PCR) and other methods were employed to elucidate the underlying molecular mechanisms.ResultsNotably, THSWD induced a reduction in the neurological function score (P < 0.01) and neuronal injury in brain tissue, increase in protein expression of Claudin-5 and zonula occludens-1 (ZO-1) in brain tissue(P < 0.01), and decrease in serum lipopolysaccharide (LPS)(P < 0.01), diamine oxidase (DAO)(P < 0.01) and D-lactic acid(P < 0.01, P < 0.05) levels to a significant extent. THSWD also inhibited the levels of tumor necrosis factor-α (TNF-α)(P < 0.01) and interleukin − 1β (IL-1β)(P < 0.01) in brain tissue, and increased alpha and beta diversity in ischemic stroke mice, along with a certain reversal effect on different microflora. Finally, THSWD inhibited the polarization of microglia cells(P < 0.01) and decreased the protein and gene expression of toll-like receptor-4 (TLR-4)(P < 0.01, P < 0.05) and nuclear factor kappa B (NF-κB)(P < 0.01) in brain tissue.ConclusionOur data indicate that THSWD may interfere with inflammatory response in ischemic stroke by regulating intestinal flora and promoting intestinal barrier repair.

Resolvins protect against diabetes-induced colonic oxidative stress, barrier dysfunction, and associated diarrhea via the HO-1 pathway.

Diabetes is associated with increased oxidative stress, leading to altered tight junction formation and increased apoptosis in colonic epithelial cells. These changes may lead to intestinal barrier dysfunction and corresponding gastrointestinal symptoms in patients with diabetes, including diarrhea. The aim of this study was to characterize the effect and mechanism of Resolvin D1 (RvD1) on diabetes-induced oxidative stress and barrier disruption in the colon. Mice with streptozotocin-induced diabetes were treated with RvD1 for 2 weeks, then evaluated for stool frequency, stool water content, gut permeability, and colonic transepithelial electrical resistance as well as production of reactive oxygen species (ROS), apoptosis, and expression of tight junction proteins Zonula Occludens 1 (ZO-1) and occludin. The same parameters were assessed in human colonoid cultures subjected to elevated glucose. We found that RvD1 treatment did not affect blood glucose, but normalized stool water content and prevented intestinal barrier dysfunction, epithelial oxidative stress, and apoptosis. RvD1 also restored ZO-1 and occludin expression in diabetic mice. RvD1 treatment increased phosphorylation of Akt and was accompanied by a 3.5-fold increase in heme oxygenase-1 (HO-1) expression in the epithelial cells. The protective effects of RvD1 were blocked by ZnPP, a competitive inhibitor of HO-1. Similar findings were observed in RvD1-treated human colonoid cultures subjected to elevated glucose. In conclusion, Oxidative stress in diabetes results in mucosal barrier dysfunction, contributing to the development of diabetic diarrhea. Resolvins prevent ROS-mediated mucosal injury and protect gut barrier function by intracellular PI3K/Akt activation and subsequent HO-1 upregulation in intestinal epithelial cells. These actions result in normalizing stool frequency and stool water content in diabetic mice, suggesting that resolvins may be useful in the treatment of diabetic diarrhea.

Sporisorium reilianum polysaccharides improve DSS-induced ulcerative colitis by regulating intestinal barrier function and metabolites

This study investigated the regulatory effects of Sporisorium reilianum polysaccharides (SRPS) on metabolism and the intestinal barrier in mice with colitis induced by dextran sulfate sodium (DSS). SRPS were resistant to the digestion of saliva, gastric juices, and intestinal fluid. SRPS significantly reduced the disease activity index and inhibited DSS-induced colon shortening. The expression of proinflammatory cytokines in the colon was normal (P < 0.05). Acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid contents increased. Moreover, 64 biomarker metabolites were affected, including 42 abnormal decreases and 22 abnormal increases caused by DSS, which targeted amino acid biosynthesis; tryptophan metabolism; protein digestion and absorption; aminoacyl-tRNA biosynthesis; and glycine, serine, and threonine metabolism. In addition, SRPS reduced goblet cell loss and increased mucin secretion. The short-chain fatty acid receptor GPR41 was activated, and zonula occludens-1 and occludin expression levels were upregulated. Epithelial cell apoptosis was inhibited by increased Bcl-2 and decreased Bax expression NLRP3, ASC, and caspase-1 protein levels decreased. Intestinal barrier damage improved, and colon inflammation was reduced. Thus, our preliminary findings reveal that SRPS regulates metabolism and has the potential to protect the intestinal barrier in ulcerative colitis mice.

FOXO6 transcription inhibition of CTRP3 promotes OGD/R-triggered cardiac microvascular endothelial barrier disruption via SIRT1/Nrf2 signalling.

C1q/TNF-related protein 3 (CTRP3) has been clarified to display its protective roles in cardiac function. The current study is concentrated on exploring the impacts of CTRP3 on myocardial ischaemia. Oxygen and glucose hypoxia/reoxygenation (OGD/R) model was constructed in human cardiac microvascular endothelial cells (HCMECs). Reverse transcription-quantitative polymerase chain reaction and western blot analysis of CTRP3 expression were conducted. CCK-8 assay was to estimate cell activity and lactate dehydrogenase (LDH) assay kit was to test LDH release. TUNEL assay and western blot were to judge apoptosis. Endothelial barrier function was detected by in vitro vascular permeability assay kit. Zonula occludens-1 (ZO-1) expression was evaluated by immunofluorescence assay. The interaction between CTRP3 promoter and Forkhead Box O6 (FOXO6) was predicted by JASPAR database and verified by chromatin immunoprecipitation and luciferase reporter assays. After OGD/R-induced HCMECs were co-transfected with CTRP3 overexpression and FOXO6 overexpression plasmids, the above functional experiments above were conducted again. Lastly, the expression of sirtuin 1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signalling-related proteins was examined by western blot. CTRP3 was down-regulated in OGD/R-induced HCMECs. CTRP3 enhanced the viability and barrier integrity while reduced the apoptosis and permeability of OGD/R-insulted HCMECs. This process may be regulated by FOXO6 transcription. Also, FOXO6 inhibition-mediated CTRP3 up-regulation activated the SIRT1/Nrf2 signalling. FOXO6 transcription inhibition of CTRP3 promotes OGD/R-triggered cardiac microvascular endothelial barrier disruption via SIRT1/Nrf2 signalling.

Bacillus halotolerans SW207 alleviates enterotoxigenic Escherichia coli-induced inflammatory responses in weaned piglets by modulating the intestinal epithelial barrier, the TLR4/MyD88/NF-κB pathway, and intestinal microbiota.

Enterotoxigenic Escherichia coli (ETEC) is one of the major pathogens contributing to piglet diarrhea, with significant implications for both piglet health and the economic aspects of the livestock industry. SW207 is an isolate of Bacillus halotolerans isolated from the cold- and disease-resistant Leixiang pigs in Northeastern China. We have discovered that SW207 can survive in the pig's gastrointestinal fluid and under conditions of high bile salt concentration, displaying potent antagonistic activity against ETEC. In this study, we established a weaned piglet diarrhea model infected with ETEC to investigate the role of SW207 in preventing diarrhea and improving intestinal health. Results indicate that SW207 upregulates the expression of tight junction proteins, including claudin-1, occludin, and zonula occludens-1, at both the transcriptional and translational levels. Furthermore, SW207 reduces serum endotoxin, D-lactic acid, and various oxidative stress markers while enhancing piglet mechanical barrier function. In terms of immune barrier, SW207 suppressed the activation of the TLR4/MyD88/NF-κB pathway, reducing the expression of various inflammatory factors and upregulating the expression of small intestine mucosal sIgA. Concerning the biological barrier, SW207 significantly reduces the content of E. coli in the intestines and promotes the abundance of beneficial bacteria, thereby mitigating the microbiota imbalance caused by ETEC. In summary, SW207 has the potential to prevent weaned piglet diarrhea caused by ETEC, alleviate intestinal inflammation and epithelial damage, and facilitate potential beneficial changes in the intestinal microbiota. This contributes to elucidating the potential mechanisms of host-microbe interactions in preventing pathogen infections.IMPORTANCEEnterotoxigenic Escherichia coli (ETEC) has consistently been one of the significant pathogens causing mortality in weaned piglets in pig farming. The industry has traditionally relied on antibiotic administration to control ETEC-induced diarrhea. However, the overuse of antibiotics has led to the emergence of drug-resistant zoonotic bacterial pathogens, posing a threat to public health. Therefore, there is an urgent need to identify alternatives to control pathogens and reduce antibiotic usage. In this study, we assessed the protective effect of a novel probiotic in a weaned piglet model infected with ETEC and analyzed its mechanisms both in vivo and in vitro. The study results provide theoretical support and reference for implementing interventions in the gut microbiota to alleviate early weaned piglet diarrhea and improve intestinal health.

Geraniol attenuates oxygen-glucose deprivation/reoxygenation-induced ROS-dependent apoptosis and permeability of human brain microvascular endothelial cells by activating the Nrf-2/HO-1 pathway.

Blood-brain barrier breakdown and ROS overproduction are important events during the progression of ischemic stroke aggravating brain damage. Geraniol, a natural monoterpenoid, possesses anti-apoptotic, cytoprotective, anti-oxidant, and anti-inflammatory activities. Our study aimed to investigate the effect and underlying mechanisms of geraniol in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced human brain microvascular endothelial cells (HBMECs). Apoptosis, caspase-3 activity, and cytotoxicity of HBMECs were evaluated using TUNEL, caspase-3 activity, and CCK-8 assays, respectively. The permeability of HBMECs was examined using FITC-dextran assay. Reactive oxygen species (ROS) production was measured using the fluorescent probe DCFH-DA. The protein levels of zonula occludens-1 (ZO-1), occludin, claudin-5, β-catenin, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were determined by western blotting. Geraniol showed no cytotoxicity in HBMECs. Geraniol and ROS scavenger N-acetylcysteine (NAC) both attenuated OGD/R-induced apoptosis and increase of caspase-3 activity and the permeability to FITC-dextran in HBMECs. Geraniol relieved OGD/R-induced ROS accumulation and decrease of expression of ZO-1, occludin, claudin-5, and β-catenin in HBMECs. Furthermore, we found that geraniol activated Nrf2/HO-1 pathway to inhibit ROS in HBMECs. In conclusion, geraniol attenuated OGD/R-induced ROS-dependent apoptosis and permeability in HBMECs through activating the Nrf2/HO-1 pathway.

Oral mucosal changes in tight junction proteins in patients with oral lichen planus.

This study aimed to investigate the expression of tight junction, its distribution pattern in oral lichen planus samples and its potential association with the severity of oral lichen planus. Cross-sectional study designs were conducted. Transcriptome sequencing was conducted using oral mucosal tissues from 22 patients with oral lichen planus and 11 healthy controls. Immunohistochemistry and quantitative reverse transcription PCR were performed to verify the expression of claudin-1, claudin-4, occludin and zonula occludens-1 in oral mucosal tissues from another 30 patients with oral lichen planus and 26 healthy controls. The relationship between tight junction protein expression and oral lichen planus severity was explored using correlation analysis. 5603 and 2475 differentially expressed genes were upregulated and downregulated respectively, in oral lichen planus tissues. KEGG analysis showed that tight junctions including CLDN1, CLDN4, OCLN and TJP1 were downregulated in oral lichen planus. Claudin-1, claudin-4, occludin and zonula occludens-1 expression was verified to be significantly lower in oral lichen planus. Furthermore, correlation analyses showed that decreased occludin expression was positively related to oral lichen planus severity. Decreased expression of TJ barrier proteins may be associated with the development of oral lichen planus.

Short-term exposure to cigarette smoke upregulates cathepsin S and alters expression of tight junction ZO-1

A long-term exposure to cigarette smoke (CS) alters the integrity of airway epithelial barrier, contributes to lung dysfunction, and elicits the expression and activity of lung cathepsin S (CatS), a cysteine protease that participates in the remodeling of connective tissue and cell junctions. Here, we observed that a short-term (4 days) exposure of mice to CS increased the expression and activity of CatS, while the expression level of zonula occludens 1 (ZO-1), an epithelial tight junction protein that stabilizes barrier assembly, was reduced in lung tissue lysates. Present data support that proteolytically active CatS may contribute to the defect of ZO-1 in CS-exposed mice.

Changes in Tight Junction Protein Expression Levels but Not Distribution in Commercial White and Brown Laying Hens Supplemented with Chondrus crispus or Ascophyllum nodosum Seaweed.

It is proposed that prebiotic diet supplements improve intestinal function, in part by improving the barrier function of the intestinal epithelium with an associated increase in the expression of tight junction proteins, including occludin and zonula occludens-1 (ZO-1). We examined the expression of these proteins in two strains of laying hens (Lohman LSL-lite (White) and Lohman Brown-lite (Brown)) who were supplemented or not with 3% Chondrus crispus or 0.5% Ascophyllum nodosum seaweeds from 31 to 72 weeks of age. Occludin was localized to the lateral surfaces and across the intestinal epithelium in all animals. Reactivity for ZO-1 was concentrated at the apicolateral epithelial cell membrane border. Mood's median test indicated that White hens may express more occludin in villus epithelium (median intensity 3.5 vs. 2.5 in Brown hens, p = 0.06) but less ZO-1 in the deep cryptal epithelium (median intensity 1.5 vs. 2.5 in Brown hens, p = 0.06). Western blotting also showed higher levels of occludin in White than Brown hens (p < 0.05). A decrease in ZO-1 Western blot expression was associated with Chondrus crispus supplementation in comparison to controls (p < 0.05), but not with Ascophyllum nodosum supplementation (p > 0.05). In conclusion, genetic strain and dietary seaweed supplements affect tight junction regulatory protein expression levels but do not impact the anatomical distribution, as seen in cryosections.