Expression Of Tight Junction Proteins Research Articles

Selenoprotein M protects cardiac endothelial cell integrity against high-glucose stress via enhancing Parkin-mediated mitophagy

Selenoprotein M (SELENOM) has emerged as a crucial factor in maintaining cellular redox homeostasis and mitigating oxidative damage. This study aims to investigate its protective role in cardiac endothelial cells under hyperglycemic stress, a condition commonly associated with diabetes mellitus and its cardiovascular complications. Diabetic mice model and human umbilical vein endothelial cells (HUVECs) were applied for in vivo and in vitro studies. Results reveal that hyperglycemia significantly downregulates SELENOM expression in both diabetic mouse hearts and primary cultured cardiac endothelial cells. Overexpression of SELENOM in HUVECs mitigated high-glucose-induced FITC-Dextran diffusion and the loss of transendothelial electrical resistance. Additionally, SELENOM overexpression decreased reactive oxygen species (ROS) levels, preserved tight junction protein expression, and maintained cellular structural integrity under hyperglycemic conditions. Furthermore, SELENOM overexpression attenuated high-glucose-induced mitochondrial apoptosis. High-glucose conditions decreased Parkin and increased p62 and Beclin1 expressions. SELENOM overexpression restored Parkin levels and promoted co-localization of LAMP1 and TOMM20. Knockdown of Parkin significantly attenuated these protective effects, suggesting the importance of Parkin in Selenoprotein M-mediated mitophagy. Collectively, these findings suggest that Selenoprotein M enhances Parkin-mediated mitophagy to protect endothelial cells from hyperglycemic stress, offering potential therapeutic insights for diabetic cardiovascular complications.

Dietary Clostridium butyricum metabolites mitigated the disturbances in growth, immune response and gut health status of Ctenopharyngodon idella subjected to high cottonseed and rapeseed meal diet

Cottonseed meal and rapeseed meal exhibit a potential for fishmeal substitute in grass carp feed, while their excessive use contribute to growth decline and weakening immunity of aquatic animals. Clostridium butyricum metabolites (CBM) was recognized as a functional additive due to its antioxidant properties and maintenance of intestinal microbiota balance. CBM was added to a high of cottonseed and rapeseed meal diet to determine its effects on growth, immunity, and intestinal microbiota alterations of grass carp (Ctenopharyngodon idella) over 56 days. Eight hundred grass carp (mean weight, around 50 g) were randomized to five treatments and fed with the basic diet (CON), CBM0 diet (28 % cottonseed and 27 % rapeseed meal), and CBM diets (CBM0.5, CBM1, and CBM2, namely CBM0 diet supplemented with 500, 1000, and 2000 mg kg−1 CBM). The results indicated that compared to CBM0, The ingestion of 1000 mg kg−1 CBM diet by grass carp significantly promoted growth as measured by intestinal lipase activity, villus height, and muscle thickness. Moreover, accompanied by a decrease in intestine MDA content, and enhance antioxidant capacity by activating Keap1/Nrf2 signaling pathway to increase enzyme activities (SOD, CAT and T-AOC) and corresponding gene expression (mnsod, cat, gsto and gpx1) in the intestine of grass crap fed CBM1 diet. The dietary CBM1 diet increased serum levels of C3 and IgM, increased ACP activity and expression of the corresponding anti-inflammatory factors (tgf-β1 and il-15), and suppressed the expression of pro-inflammatory factors (tnf-α and il-12β), resulting in enhanced immunity. The dietary CBM1 diet up-regulates gene expression of tight junction proteins (zo-1, occludin, occludin7a and occludin-c), coupled with the decreases in DAO and D-lactate contents, implying that the decreased mucosal permeability could be observed in the gut. The dietary CBM1 diet largely altered the intestinal microbial community, especially reducing the relative abundance of intestinal pathogenic bacteria (Streptococcus and Actinomyces). And it significantly increased the content of short-chain fatty acids (acetic acid, butyric acid, isobutyric acid, propionic acid and isovaleric acid). Taken above, dietary CBM supplementation improved growth in grass carp and attenuated the intestinal oxidative stress, inflammation and microflora dysbacteriosis caused by high proportions of cottonseed and rapeseed meal diets.

Network Analysis of Gut Microbial Communities Reveals Key Reason for Quercetin Protects against Colitis

As one of the most representative natural products among flavonoids, quercetin (QUE) has been reported to exhibit beneficial effects on gut health in recent years. In this study, we utilized a dextran sulfate sodium (DSS)-induced colitis mice model to explore the protective effects and underlying mechanisms of QUE on colitis. Our data demonstrated that QUE oral gavage administration significantly ameliorates the symptoms and histopathological changes associated with colitis. Additionally, the concentration of mucin-2, the number of goblet cells, and the expression of tight junction proteins (such as ZO-1, Occludin, and Claudin-1) were all found to be increased. Furthermore, QUE treatment regulated the levels of inflammatory cytokines and macrophage polarization, as well as the oxidative stress-related pathway (Nrf2/HO-1) and associated enzymes. Additionally, 16S rDNA sequencing revealed that QUE treatment rebalances the alterations in colon microbiota composition (inlcuding Bacteroidaceae, Bacteroides, and Odoribacter) in DSS-induced colitis mice. The analysis of network dynamics reveals a significant correlation between gut microbial communities and microenvironmental factors associated with inflammation and oxidative stress, in conjunction with the previously mentioned findings. Collectively, our results suggest that QUE has the potential to treat colitis by maintaining the mucosal barrier, modulating inflammation, and reducing oxidation stress, which may depend on the reversal of gut microbiota dysbiosis.

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery.

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI. Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay. The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups. Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

Selenium nanoparticles affect chicken offspring's intestinal health better than other selenium sources

This study aimed to assess the effects of maternal diets containing various selenium (Se) sources on the intestinal mucosal function in the jejunum of chicken offspring. A total of 630, 18-wk-old Hy-Line Grey hens and 70 18-wk-old Hy-Line Grey breeders were randomly allocated into 7 groups, with 5 replicates in each group (18 hens and tow roosters). After 4 wk of Se depletion, the birds were fed either a nonsupplemented basal diet (control) or the same basal diet supplemented with 0.15 mg/kg selenium nanoparticles (Nano-Se), 0.30 mg/kg Nano-Se, 0.30 mg/kg selenocysteine (Sec), 0.30 mg/kg sodium selenite (SS), 0.30 mg/kg selenomethionine (SeMet), or 0.15 mg/kg Nano-Se + 0.15 mg/kg Sec, for 8 wk. Frtilized eggs were collected and incubated during the final week of the experiment. Jejunal tissues from embryonic d 18 and the hatch day were collected for analysis, and the 7-d survival rate of the offspring was recorded. Compared to the control, the maternal diet of 0.30 mg/kg Nano-Se, 0.30 mg/kg Sec, and 0.30 mg/kg SeMet significantly increased the survival of 7-day-old offspring (P < 0.05). The maternal diet supplemented with 0.30 mg/kg Nano-Se significantly increased intestinal villus height and the villus height/crypt depth ratio in chicks at embryonic d 18 and in 1-day-old (P < 0.05). The maternal diet containing 0.30 mg/kg Nano-Se and Sec increased the mRNA expression levels of tight junction proteins in 1-day-old offspring (P < 0.05). Supplemental 0.30 mg/kg Nano-Se significantly increased the mRNA expression levels of marker genes in intestinal enteroendocrine, stem, and Paneth cells (P < 0.05). In 1-day-old chicks, the number of intestinal goblet cells, as well as the mRNA expression levels of intestinal mucin2 (Muc2) and goblet cell differentiation factors (Spdef and C-myc), were the highest in diets supplemented with 0.30 mg/kg Nano-Se. Moreover, the expression levels of intestinal Muc2 and Spdef in chicks at embryonic d 18 was the highest with 0.30 mg/kg Nano-Se supplementation (P < 0.05). Supplementing with 0.30 mg/kg Nano-Se significantly reduced reactive oxygen species levels and decreased the mRNA expression levels of apoptosis-related genes in 1-day-old chicks (P < 0.05). Additionally, 0.30 mg/kg Nano-Se supplementation significantly down-regulated NLRP3 pathway gene expression in 1-day-old chicks (P < 0.05). In conclusion, maternal dietary supplementation with Nano-Se improved jejunal microarchitecture, antioxidant levels, and the expression of tight-junction protein in chicken offspring along with supporting goblet cell development by inhibiting the NLRP3 signaling pathway.

Aging alters the expression of trophic factors and tight junction proteins in the mouse choroid plexus

BackgroundThe choroid plexus (CP) is an understudied tissue in the central nervous system and is primarily implicated in cerebrospinal fluid (CSF) production. CP also produces numerous neurotrophic factors (NTF) which circulate to different brain regions. Regulation of NTFs in the CP during natural aging is largely unknown. Here, we investigated the age and gender-specific transcription of NTFs along with the changes in the tight junctional proteins (TJPs) and the water channel protein Aquaporin (AQP1).MethodsMale and female mice were used for our study. Age-related transcriptional changes were analyzed using quantitative PCR at three different time points: mature adult, middle-aged, and aged. Transcriptional changes during aging were further confirmed with digital droplet PCR. Additionally, we used immunohistochemical analysis (IHC) for the evaluation of in vivo protein expression. We further investigated the cellular phenotype of these NTFS, TJP, and water channel proteins in the mouse CP by co-labeling them with the classical vascular marker, Isolectin B4, and epithelial cell marker, Plectin.ResultsAging significantly altered NTF gene expression in the CP. Brain-derived neurotrophic factor (BDNF), Midkine (MDK), VGF, Insulin-like growth factor (IGF1), IGF2, Klotho (KL), Erythropoietin (EPO), and its receptor (EPOR) were reduced in the aged CP of males and females. Vascular endothelial growth factor (VEGF) transcription was gender-specific; in males, gene expression was unchanged in the aged CP, while females showed an age-dependent reduction. Age-dependent changes in VEGF localization were evident, from vasculature to epithelial cells. IGF2 and klotho localized in the basolateral membrane of the CP and showed an age-dependent reduction in epithelial cells. Water channel protein AQP1 localized in the tip of epithelial cells and showed an age-related reduction in mRNA and protein levels. TJP’s JAM, CLAUDIN1, CLAUDIN2 and CLAUDIN5 were reduced in aged mice.ConclusionsOur study highlights transcriptional level changes in the CP during aging. The age-related transcriptional changes exhibit similarities as well as gene-specific differences in the CP of males and females. Altered transcription of the water channel protein AQP1 and TJPs could be involved in reduced CSF production during aging. Importantly, reduction in the neurotrophic factors and longevity factor Klotho can play a role in regulating brain aging.Graphical

Naringenin alleviates intestinal ischemia/reperfusion injury by inhibiting ferroptosis via targeting YAP/STAT3 signaling axis

BackgroundIntestinal ischemia/reperfusion injury (IRI) is a significant clinical emergency, and investigating novel therapeutic approaches and understanding their underlying mechanisms is essential for improving patient outcomes. Naringenin (Nar), a flavanone present in tomatoes and citrus fruits, is frequently consumed in the human diet and recognized for having immunomodulatory, anti-inflammatory, and antioxidant properties. Despite Nar being able to alleviate intestinal IRI, the exact molecular mechanisms remain elusive. PurposeTo investigate Nar's protective properties on intestinal IRI and elucidate the mechanisms, a comprehensive approach that combines network pharmacology analysis with experimental verification in vitro and in vivo was adopted. MethodsThe oxygen-glucose deprivation/reoxygenation (OGD/R) model in IEC-6 cells and a murine model of intestinal IRI were used. Nar's effects on intestinal IRI were assessed through histological analysis using H&E staining and tight junction (TJ) protein expression. Ferroptosis-related parameters, including iron levels, superoxide dismutase (SOD), glutathione (GSH), reactive oxygen species (ROS), malondialdehyde (MDA), and mitochondrial morphology, were analyzed. Network pharmacology was utilized to predict the pathways through which Nar exerts its anti-ferroptosis effects. Further mechanistic insights were obtained through si-RNA transfection, YAP inhibitor (verteporfin, VP) treatment, ferroptosis inhibitor (Ferrostatin-1) and ferroptosis inducer (Erastin) application, co-immunoprecipitation (Co-IP) and Western blotting. ResultsOur results revealed that pretreatment with Nar significantly mitigated intestinal tissue damage and improved gut barrier function, as evidenced by increased TJ proteins (ZO-1 and Occludin). Nar reduced iron, MDA, and ROS, while it increased GSH and SOD levels. Additionally, Nar alleviated mitochondrial damage in mice. Nar treatment increased GPX4 and SLC7A11, while decreasing ACSL4 levels both in vivo and in vitro. Network pharmacology analysis suggested that Nar may target the Hippo signaling pathway. Notably, YAP, a key transcriptional co-activator within the Hippo pathway, was downregulated in intestinal IRI mice and OGD/R-induced IEC-6 cells. Nar pretreatment activated YAP, thereby augmenting anti-ferroptosis effects. The inhibition of YAP activation by VP or YAP knockdown increased p-STAT3 expression, thereby diminishing Nar's efficacy. Co-IP and immunofluorescence studies confirmed the interaction between YAP and STAT3. ConclusionThis study shows that Nar can inhibit ferroptosis in intestinal IRI via activating YAP, which in turn suppresses STAT3 phosphorylation, thereby unveiling a novel mechanism and supporting Nar's potential to be a promising therapeutic agent for intestinal IRI.

High-fat diet led to testicular inflammation and ferroptosis via dysbiosis of gut microbes

The disorder of gut microbiota has negative impact on male reproductive, and testicular damage is associated with obesity. However, the detailed mechanism of gut microbiota on the obesity-induced testis injury are still unknown. Therefore, we constructed a mouse model to investigate the effects of obesity on testis injury. In this study, we found that HFD-induced obesity could disorder gut microbiota homeostasis, which increased the abundance of Brevundimonas, Desulfovibrionaceae_unclassified and Ralstonia, ultimately leading to the overproduction of lipopolysaccharides (LPS). Meanwhile, HFD-feeding promoted intestinal permeability via inhibiting expression of tight junction proteins (ZO-1, Occludin and Claudin) and reducing excretion of mucus, leading to translocation of LPS. The over-accumulation of LPS in the bloodstream triggered an inflammatory response by activating TLR4/NF-κB pathway in testis. On the other hand, the gut microbiota produced-LPS also could induce ferroptosis in testis, as reflected by enhancing iron content and lipid peroxidation (MDA), as well as decreasing ferroptosis-related proteins, including GPX4, FTH1 and SLC1A11. Moreover, inhibition of LPS ligand (TLR4) with Resatorvid (TAK-242) alleviated obesity-induced testis injury through suppression of inflammation and ferroptosis. In conclusion, this study provides novel insights into the underlying mechanisms of obesity–related testis injury induced by gut microbiota disorder via the gut–testis axis, thus offering potential targets to counteract obesity-induced male reproductive disorder.

Esculetin Combats Multidrug-Resistant Salmonella Infection and Ameliorates Intestinal Dysfunction via the Nrf2 Pathway.

The increasing incidence of multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Tm), known for causing invasive enteric infections, presents a significant public health challenge. Given the diminishing efficacy of existing antibiotics, it is imperative to explore novel alternatives for the treatment of MDR S. Tm infections. Here, we identified esculetin (EST), a natural coumarin abundant in dietary foods and herbs, as a compound exhibiting broad-spectrum antibacterial properties against a range of MDR bacteria. Our findings demonstrate that EST effectively inhibited the proliferation and expansion of MDR S. Tm in both in vitro experiments and animal models. Specifically, EST significantly downregulated the type 3 secretion system-1 (T3SS-1) virulence expression of MDR S. Tm, thereby preventing its invasion into intestinal epithelial cells. In S. Tm-infected mice, we observed cecal injury characterized by the upregulation of inflammatory cytokines, a reduction in goblet cell numbers, a decreased expression of tight junction proteins, and microbial dysbiosis. Conversely, EST treatment ameliorated these pathological changes induced by S. Tm infection and reduced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, thereby improving intestinal barrier function. These results suggest that dietary coumarins or a targeted plant-based diet may offer a promising strategy to counteract MDR bacteria-induced enteric diseases.

Recombinant filaggrin-2 improves skin barrier function and attenuates ultraviolet B (UVB) irradiation-induced epidermal barrier disruption

The integrity of the skin barrier is essential for maintaining skin health, with the stratum corneum and filaggrin 2 (FLG-2) playing a key role. FLG-2 deficiency or mutation has been linked to diseases such as atopic dermatitis, while external stressors such as ultraviolet B (UVB) radiation further damage the epidermal barrier. This study investigated the effects of recombinant filaggrin (rFLG) on skin barrier function and UVB induced epidermal destruction. Cell experiments showed that 10 μg/mL of rFLG could increase the mobility of HaCaT cells from 20 % to 42 %, increase the epithelial resistance (TEER) value by about 2 times, and up-regulate the tight junction associated protein by about 2 times. In mouse models of UVB-induced epidermal barrier destruction, rFLG at concentrations of 0.5, 1, and 2 mg/mL showed effective cell uptake and skin penetration, alleviating erythema, and reducing skin thickness in mice by 1.5–3 times. Among them, 2 mg/mL of rFLG treatment restored the expression of tight junction proteins (LOR, ZO-1, and caspase-14), reduced collagen degradation, and reduced oxidative stress by normalizing serum hydroxyproline and superoxide dismutase levels. In addition, 2 mg/mL of rFLG inhibited UVB-induced upregulation of matrix metalloproteinases (MMP-3 and MMP-9) and reduced pro-inflammatory factors (IL-10, IL-1α, IL-6, and TNF-α) and apoptotic markers (P38, Bax, and Bcl-2) to normal levels. These findings suggested that rFLG effectively enhanced skin barrier integrity and mitigated UVB-induced epidermal barrier destruction, highlighting its potential as a therapeutic agent for diseases associated with skin barrier dysfunction.

A New Combination of Bifidobacterium bifidum and Lactococcus lactis Strains with Synergistic Effects Alleviates Colitis-Associated Colorectal Cancer.

Chronic inflammation is a factor in the development of cancer, and probiotics play a role in preventing or treating inflammation as an adjuvant therapy. To investigate potential probiotics for the prevention of colitis-associated colorectal cancer (CAC), Bifidobacterium bifidum H3-R2 and Lactococcus lactis KLDS4.0325 were used to examine the effects on colon cancer cells and in an inflammation-related cancer animal model. The results revealed that B. bifidum H3-R2 in combination with L. lactis KLDS4.0325 caused apoptosis in colon cancer cells by increasing caspase-3 and caspase-9 protein levels, enhancing Bax expression, and lowering Bcl-2 expression. In addition, the combination of the two strains relieved the tissue damage; reduced proinflammatory cytokines, myeloperoxidase (MPO) activity, and hypoxia-inducible factor 1-alpha (HIF-1α) level; upregulated anti-inflammatory cytokines; increased colonic tight junction protein expression; regulated intestinal homeostasis by inhibiting NLRP3 inflammasome signaling pathway; and improved the imbalance of gut microbiota in animal models. Moreover, the combination of the two strains had a greater preventive impact than each strain alone. These findings are supportive of clinical studies and product development of multi-strain probiotic preparations for diseases associated with colitis.

Sinisan Alleviates Stress-Induced Intestinal Dysfunction and Depressive-like Behaviors in Mice with Irritable Bowel Syndrome by Enhancing the Intestinal Barrier and Modulating Central 5-Hydroxytryptamine

Irritable bowel syndrome (IBS) is a common chronic functional bowel disorder and is strongly associated with an increased risk of depression and anxiety. The brain–gut axis plays an important role in the pathophysiologic changes in IBS, yet effective treatments for IBS are still lacking. Sinisan, originating from the Treatise on Typhoid Fever by the medical sage Zhang Zhongjing, is a classic formula in the Eight Methods of Traditional Chinese Medicine (TCM) that focuses on dispersing the liver and regulating the spleen, relieving depression and transmitting evils, and has been widely used in the treatment of liver-depression and spleen-deficiency, diarrhea, and related liver and stomach disorders. However, the therapeutic effect of sinisan in IBS has not been clarified. The aim of this study was to investigate the effects of sinisan on stress-induced intestinal dysfunction and depressive behavior in IBS mice. We established a diarrhea-predominant irritable bowel syndrome (IBS-D) mouse model using a 4% acetic acid enema combined with restraint stress, and analyzed the results using behavioral tests, relevant test kits, hematoxylin-eosin (HE) staining, immunofluorescence (IF), Western blot (WB), and quantitative fluorescence polymerase chain reaction (qRT-PCR). The results showed that sinisan administration significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice, improved mild colonic inflammation and intestinal mucosal permeability, up-regulated the expression of tight junction proteins ZO-1 and occludin. Sinisan significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice by decreasing the expression of TNF-α, promoting the expression of tight junction proteins (occludin, ZO-1) expression, and inhibiting the Tlr4/Myd88 signaling pathway, thereby attenuating the inflammatory response, protecting the intestinal barrier, and alleviating symptoms in the IBS-D mouse model. Taken together, sinisan may ameliorate intestinal inflammation and the intestinal barrier by regulating 5-HT expression and the Tlr4/Myd88 pathway, thereby alleviating stress-induced intestinal dysfunction and depressive behaviors in IBS-D mice.

NF-κB pathway activation by Octopus peptide hydrolysate ameliorates gut dysbiosis and enhances immune response in cyclophosphamide-induced mice

Cyclophosphamide (CTX) is an anticancer medication that suppresses host immunity as well as adversely affects mucosal inflammation and gut microflora dysbiosis. The gut microflora is recognized as a substantial factor in host metabolism and immunological homeostasis. To improve immunity and inhibit cytotoxic and homeostatic imbalances triggered by CTX, it is essential to monitor immunoregulators. In this research, we assessed the impact of Octopus peptide hydrolysate (OPH) on immune modulation, intestinal integrity, and gut microbial composition in CTX-induced immune-deficient mice. The results revealed that OPH increased body weight, and immunological organ indices, and improved the histological changes in the colon, thymus, and spleen. The OPH stimulated the secretion of cytokines (IL-1β, IL-6, and TNF-α) and antibodies (IgM and IgA) while reducing the ratio of lipopolysaccharide (LPS) and diamine oxidase (DAO) in the serum. OPH further enhanced goblet cell and mucus production, upregulated the expression of gut tight-junction proteins (Occludin, Zonula Occludin-1, Mucin-2, and Claudin-1), and activated the TLR4/NF-κB cascade (p-IκBα, P65/p-p65). In addition, OPH treatment declined the Bacteroidetes/Firmicutes ratio, enhanced the relative ratio of Alistipes/Lachnospiraceae, and reversed the ecological equilibrium of the gut microflora. The findings revealed that OPH serves as a prebiotic to prevent CTX-mediated disruption in the intestinal barrier and boosts gut mucosal immunity by attenuating gut microflora imbalance, implying that OPH could be used as an immunological ingredient in nutritious foods to regulate the immune system and protect the gut from inflammatory diseases.

Branched Short-Chain Fatty Acid-Rich Fermented Protein Food Improves the Growth and Intestinal Health by Regulating Gut Microbiota and Metabolites in Young Pigs.

The diet in early life is essential for the growth and intestinal health later in life. However, beneficial effects of a diet enriched in branched short-chain fatty acids (BSCFAs) for infants are ambiguous. This study aimed to develop a novel fermented protein food, enriched with BSCFAs and assess the effects of dry and wet ferment products on young pig development, nutrient absorption, intestinal barrier function, and gut microbiota and metabolites. A total of 18 young pigs were randomly assigned to three groups. The dry corn gluten-wheat bran mixture (DFCGW) and wet corn gluten-wheat bran mixture (WFCGW) were utilized as replacements for 10% soybean meal in the basal diet. Our results exhibited that the WFCGW diet significantly increased the growth performance of young pigs, enhanced the expression of tight junction proteins, and regulated associated cytokines expression in the colonic mucosa. Simultaneously, the WFCGW diet led to elevated levels of colonic isobutyric and isovaleric acid, as well as the activation of GPR41 and GPR109A. Furthermore, more potential probiotics including Lactobacillus, Megasphaera, and Lachnospiraceae_ND3007_group were enriched in the WFCGW group and positively associated with the beneficial metabolites such as 5-hydroxyindole-3-acetic acid. Differential metabolite KEGG pathway analysis suggested that WFCGW might exert gut health benefits by modulating tryptophan metabolism. In addition, the WFCGW diet significantly increased ghrelin concentrations in serum and hypothalamus and promoted the appetite of young pigs by activating hypothalamic NPY/AGRP neurons. This study extends the knowledge of BSCFAs and provides a reference for the fermented food application in the infant diet.

Meta-analysis of the make-up and properties of in vitro models of the healthy and diseased blood-brain barrier.

In vitro models of the human blood-brain barrier (BBB) are increasingly used to develop therapeutics that can cross the BBB for treating diseases of the central nervous system. Here we report a meta-analysis of the make-up and properties of transwell and microfluidic models of the healthy BBB and of BBBs in glioblastoma, Alzheimer's disease, Parkinson's disease and inflammatory diseases. We found that the type of model, the culture method (static or dynamic), the cell types and cell ratios, and the biomaterials employed as extracellular matrix are all crucial to recapitulate the low permeability and high expression of tight-junction proteins of the BBB, and to obtain high trans-endothelial electrical resistance. Specifically, for models of the healthy BBB, the inclusion of endothelial cells and pericytes as well as physiological shear stresses (~10-20 dyne cm-2) are necessary, and when astrocytes are added, astrocytes or pericytes should outnumber endothelial cells. We expect this meta-analysis to facilitate the design of increasingly physiological models of the BBB.

New insights into evodiamine attenuates IPEC-J2 cells pyroptosis induced by T-2 toxin - Activating Keap1-Nrf2/NF-κB signaling pathway through binding with Keap1

T-2 toxin (T-2) is a highly toxic mycotoxin with a molecular weight of 466.52 g/mol. Evodiamine (EV), an alkaloid component of Evodia, has anti-inflammation and antioxidant properties. As a receptor of oxidative stress, Keap1 with a molecular weight of 70 kDa, is a molecular switch that controls the Nrf2 signaling pathway. In this paper, the effect of EV on Keap1-Nrf2/NF-κB pathway was investigated. Based on our research outcomes, it was observed that T-2 exposure substantially increased IPEC-J2 cells intracellular ROS levels and MDA accumulation, decreased SOD and CAT activities, disrupted intestinal tight junction (ZO-1, occludin, and claudin-1), and up-regulated pyroptosis-related protein (ASC, NLRP3, caspase-1, GSDMD, IL-1β, and IL-18). Additionally, EV could bind well with Keap1, the separating it from Nrf2, promoting Nrf2 into the nucleus, enhanced antioxidant enzyme activities, reduced the production of ROS, down-regulated NF-κB expression, alleviated T-2-induced pyroptosis, and restored tight junction protein expression. However, after treatment with the Nrf2 inhibitor ML385, ML385 reversed the protective effect of EV on IPEC-J2 cells. Collectively, EV can activate the Keap1-Nrf2/NF-κB signaling pathway via binding to Keap1, exert anti-inflammatory and antioxidant effects, inhibit the pyroptosis of IPEC-J2 cells triggered by T-2, and retore intestinal barrier function.

GAS6 as a potential target to alleviate neuroinflammation during Japanese encephalitis in mouse models

Viral encephalitis is characterized by inflammation of the brain parenchyma caused by a variety of viruses, among which the Japanese encephalitis (JE) virus (JEV) is a typical representative arbovirus. Neuronal death, neuroinflammation, and breakdown of the blood brain barrier (BBB) constitute vicious circles of JE progression. Currently, there is no effective therapy to prevent this damage. Growth arrest specific gene 6 (GAS6) is a secreted growth factor that binds to the TYRO3, AXL, and MERTK (TAM) family of receptor tyrosine kinases and has been demonstrated to participate in neuroprotection and suppression of inflammation in many central nervous system (CNS) diseases which has great potential for JE intervention. In this study, we found that GAS6 expression in the brain was decreased and was reversely correlated with viral load and neuronal loss. Mice with GAS6/TAM signalling deficiency showed higher mortality and accelerated neuroinflammation during peripheral JEV infection, accompanied by BBB breakdown. GAS6 directly promoted the expression of tight junction proteins in bEnd.3 cells and strengthened BBB integrity, partly via AXL. Mice administered GAS6 were more resistant to JEV infection due to increased BBB integrity, as well as decreased viral load and neuroinflammation. Thus, targeted GAS6 delivery may represent a strategy for the prevention and treatment of JE especially in patients with impaired BBB.

Arctium lappaL. polysaccharides alleviate oxidative stress and inflammation in the liver and kidney of aging mice by regulating intestinal homeostasis

Arctium lappa L. polysaccharide (ALP) is a prominent bioactive compound renowned for its multifaceted functional properties, including anti-inflammatory, antioxidant, antifibrotic, immunomodulatory, and pro-apoptotic effects. This study evaluated the aging-delaying effect of ALP and its mechanisms using a D-galactose (D-gal)-induced aging model. After an 8-week treatment, ALP significantly ameliorated D-gal-induced inflammation and oxidative stress in the liver, kidneys, and intestines. Notably, ALP administration led to a marked reduction of the pathogenic bacterium Desulfovibrio and a substantial increase in the beneficial bacterium Muribaculum. These microbial shifts were associated with upregulated expression of intestinal tight junction proteins and intestinal mucins, leading to enhanced intestinal barrier integrity. Consequently, the leakage of enterotoxins and inflammatory mediators was effectively reduced. The findings indicate that ALP alleviates tissue inflammation and oxidative stress, while also delaying aging in mice. This effect is achieved through the regulation of intestinal ecological homeostasis and the repair of the intestinal immune barrier.

Rifaximin ameliorates influenza A virus infection-induced lung barrier damage by regulating gut microbiota

Prior research has indicated that the gut-lung-axis can be influenced by the intestinal microbiota, thereby impacting lung immunity. Rifaximin is a broad-spectrum antibacterial drug that can maintain the homeostasis of intestinal microflora. In this study, we established an influenza A virus (IAV)-infected mice model with or without rifaximin supplementation to investigate whether rifaximin could ameliorate lung injury induced by IAV and explore the molecular mechanism involved. Our results showed that IAV caused significant weight loss and disrupted the structure of the lung and intestine. The analysis results of 16S rRNA and metabolomics indicated a notable reduction in the levels of probiotics Lachnoclostridium, Ruminococcaceae_UCG-013, and tryptophan metabolites in the fecal samples of mice infected with IAV. In contrast, supplementation with 50 mg/kg rifaximin reversed these changes, including promoting the repair of the lung barrier and increasing the abundance of Muribaculum, Papillibacter and tryptophan-related metabolites content in the feces. Additionally, rifaximin treatment increased ILC3 cell numbers, IL-22 level, and the expression of RORγ and STAT-3 protein in the lung. Furthermore, our findings demonstrated that the administration of rifaximin can mitigate damage to the intestinal barrier while enhancing the expression of AHR, IDO-1, and tight junction proteins in the small intestine. Overall, our results provided that rifaximin alleviated the imbalance in gut microbiota homeostasis induced by IAV infection and promoted the production of tryptophan-related metabolites. Tryptophan functions as a signal to facilitate the activation and movement of ILC3 cells from the intestine to the lung through the AHR/STAT3/IL-22 pathway, thereby aiding in the restoration of the barrier.Key points• Rifaximin ameliorated IAV infection-caused lung barrier injury and induced ILC3 cell activation.• Rifaximin alleviated IAV-induced gut dysbiosis and recovered tryptophan metabolism.• Tryptophan mediates rifaximin-induced ILC3 cell activation via the AHR/STAT3/IL-22 pathway.

Serum exosomal miRNA promote glioma progression by targeting SOS1 via abscopal effect of radiation

IntroductionLocal exposure to ionizing radiation (IR) can induce changes in biological processes in distant tissues and organs. Exosomes are nanoscale vesicles that transport biomolecules, mediate communication between cells and tissues, and can affect the abscopal effects of radiotherapy. MethodsMice were treated with 8.0 Gy doses of chest and abdomen IR, after which serum samples were taken 24 h after exposure. Their serum exosomes were then isolated via ultracentrifugation and the small RNA portions were extracted for sequencing and bioinformatic analysis. Exosomes were injected intravenously into the mice to assess their ability to cross the blood-brain barrier (BBB). Glioma cells and glioma stem cells (GSCs) were examined for malignant biological behaviors, stemness, and tumorigenic capacity after co-culturing with different groups of exosomes. ResultsWe found that serum exosomes crossed the BBB in mice after local IR exposure-which induced decreases in the expression of BBB tight-junction proteins and increased brain endothelial cell apoptosis. Exosomes from the exposed groups promoted malignant biological behaviors, stemness, and tumorigenic capacity in glioma cells and GSCs by upregulating the expression of SOS1. Phospho-MEK1/2 and Phospho-ERK1/2, of the MAPK signaling pathway, were found to be up-regulated in cells that were co-cultured with the exposing groups of the exosomes. Further analyses demonstrated that differentially expressed levels of miR-93–5p in mouse serum exosomes regulated the cellular expression of SOS1. ConclusionFollowing local IR exposure, serum exosomes cross the BBB to promote the progression of distant gliomas. Exosomal microRNAs play an important role in this process.