Tight Junction Protein Gene Research Articles

Gastrointestinal structure and function of preweaning dairy calves fed a whole milk powder or a milk replacer high in fat

The composition of milk replacer (MR) for calves greatly differs from that of bovine whole milk, which may affect gastrointestinal development of young calves. In this light, the objective of the current study was to compare gastrointestinal tract structure and function in response to feeding liquid diets having a same macronutrient profile (e.g., fat, lactose, protein) in calves in the first month of life. Eighteen male Holstein calves (46.6 ± 5.12 kg; 1.4 ± 0.50 d of age at arrival; mean ± standard deviation) were housed individually. Upon arrival, calves were blocked based on age and arrival day, and, within a block, calves were randomly assigned to either a whole milk powder (WP; 26% fat, DM basis, n = 9) or a MR high in fat (25% fat, n = 9) fed 3.0 L 3 times daily (9 L total per day) at 135 g/L through teat buckets. On d 21, gut permeability was assessed with indigestible permeability markers [chromium (Cr)-EDTA, lactulose, and d-mannitol]. On d 32 after arrival, calves were slaughtered. The weight of the total forestomach without contents was greater in WP-fed calves. Furthermore, duodenum and ileum weights were similar between treatment groups, but jejunum and total small intestine weights were greater in WP-fed calves. The surface area of the duodenum and ileum did not differ between treatment groups, but the surface area of the proximal jejunum was greater in calves fed WP. Urinary lactulose and Cr-EDTA recoveries were greater in calves fed WP in the first 6 h post marker administration. Tight junction protein gene expression in the proximal jejunum or ileum did not differ between treatments. The free fatty acid and phospholipid fatty acid profiles in the proximal jejunum and ileum differed between treatments and generally reflected the fatty acid profile of each liquid diet. Feeding WP or MR altered gut permeability and fatty acid composition of the gastrointestinal tract and further investigation are needed to understand the biological relevance of the observed differences.

Toxic Effects of Copper Sulfate and Trichlorfon on the Intestines of Zebrafish (Danio rerio)

Copper sulfate and trichlorfon are commonly used in aquaculture. They are often used alone or in combination to kill pathogens and parasites. However, there are few studies evaluating the toxic effects of copper sulfate and trichlorfon on fish. The intestine is an important digestive and immune tissue for fish, which is essential for the growth and development. In this study, zebrafish were used as the research model to detect the toxic effects of copper sulfate (0.5 mg/L) and trichlorfon (0.5 mg/L) at common production concentrations on the fish intestine. The results showed that copper sulfate and trichlorfon significantly induced the activities of intestinal catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), and alkaline phosphatase (AKP), but had no significant effects on intestinal histology after short-term exposure for 7 days. Following 21 days of long-term exposure, copper sulfate and trichlorfon could significantly induce intestinal mucosal damage, and inhibit the activity of antioxidant enzymes, and the expression of tight junction protein genes tight junction protein 1 (ZO1), claudin 1 (Cldn1), and occludin (Oclna) in the zebrafish intestine. These results suggested that copper sulfate and trichlorfon probably induced intestinal oxidative stress injury by inhibiting the activity of antioxidant enzymes, or induced intestinal mucosal damage by inhibiting the expression of intestinal tight junction protein genes. Moreover, the combined exposure of copper sulfate and trichlorfon was more toxic than the single exposure, which suggest the toxicity of copper sulfate and trichlorfon had a synergistic effect. The present results suggest that copper sulfate and trichlorfon should be used with caution in aquaculture.

Sleeve gastrectomy decreases high-fat diet induced colonic pro-inflammatory status through the gut microbiota alterations.

High-fat diet (HFD) induced obesity is characterized with chronic low-grade inflammation in various tissues and organs among which colon is the first to display pro-inflammatory features associated with alterations of the gut microbiota. Sleeve gastrectomy (SG) is currently one of the most effective treatments for obesity. Although studies reveal that SG results in decreased levels of inflammation in multiple tissues such as liver and adipose tissues, the effects of surgery on obesity related pro-inflammatory status in the colon and its relation to the microbial changes remain unknown. To determine the effects of SG on the colonic pro-inflammatory condition and the gut microbiota, SG was performed on HFD-induced obese mice. To probe the causal relationship between alterations of the gut microbiota and improvements of pro-inflammatory status in the colon following SG, we applied broad-spectrum antibiotics cocktails on mice that received SG to disturb the gut microbial changes. The pro-inflammatory shifts in the colon were assessed based on morphology, macrophage infiltration and expressions of a variety of cytokine genes and tight junction protein genes. The gut microbiota alterations were analyzed using 16s rRNA sequencing. RNA sequencing of colon was conducted to further explore the role of the gut microbiota in amelioration of colonic pro-inflammation following SG at a transcriptional level. Although SG did not lead to pronounced changes of colonic morphology and macrophage infiltration in the colon, there were significant decreases in the expressions of several pro-inflammatory cytokines including interleukin-1β (IL-1β), IL-6, IL-18, and IL-23 as well as increased expressions of some tight junction proteins in the colon following SG, suggesting an improvement of pro-inflammatory status. This was accompanied by changing populations of the gut microbiota such as increased richness of Lactobacillus subspecies following SG. Importantly, oral administrations of broad-spectrum antibiotics to delete most intestinal bacteria abrogated surgical effects to relieve colonic pro-inflammation. This was further confirmed by transcriptional analysis of colon indicating that SG regulated inflammation related pathways in a manner that was gut microbiota relevant. These results support that SG decreases obesity related colonic pro-inflammatory status through the gut microbial alterations.

Stimulation of Heme-Dependent Catalase Enhanced the Cytoprotective Effect of Lactobacillus plantarum against Oxidative Stress

Lactobacillus plantarum is a catalase-negative species and distributes in human intestinal tracts. However, the cytoprotective effects of the catalase-activated L. plantarum strain have yet to be exploited against reactive oxygen species (ROS). Here, a catalase-activated L. plantarum CGMCC 6888 (CatA+) was obtained using exogenous added heme. The scavenging free radical abilities of this strain were obviously increased. Moreover, the activated catalase A in L. plantarum CGMCC 6888 endowed the intestinal epithelium NCM460 with lower ROS content after degrading H2O2. In addition, the transcription levels of Nrf2 and Nrf2-related antioxidant enzyme genes (HO-1, GCLC, NQO-1 and TXNRD1) and tight junction protein genes (ZO-1, OCLN, and JAM-1) were upregulated significantly when co-incubated with CGMCC 6888/CatA+. This work confirmed that the catalase A conferred L. plantarum with the strong protection effects in the intestinal epithelial cells against ROS.

Intestinal permeability and gene expression after polyethylene and polyamide microplastic ingestion in Wistar rats

Microplastic particles are ubiquitous in the environment. However, little is known about their uptake and effects in humans or mammalian model organisms. Here, we studied the effects of pristine polyamide (15–20 µm) and polyethylene (40–48 µm) particles after oral ingestion in rats. The animals received feed containing microplastic particles (0.1% polyamide or polyethylene, or a mixture of both polymers) or a control diet without microplastic particles, for 5 weeks. The permeability of the duodenum was investigated in an Ussing chamber, whereas gene expression and concentration of tight junction proteins were measured in gut tissue and plasma. Microplastic particles were quantified by pyrolysis-gas chromatography/mass spectrometry in rats’ feces. Rats fed with microplastic particles had higher duodenal permeability. Expression of gene coding for the tight junction protein occludin (OCLN) was higher in PE treated animals compared to control or the PA group. No changes in the expression of the gene coding for zonula occludens protein 1 were detected. Occludin protein concentrations were below the limit of detection of the applied method in both gut and plasma. Zonula occludens protein 1 concentrations in the gut were significantly higher in groups exposed to PA and PE as compared to control, while zonula occludens protein 1 concentrations in plasma did not show significant changes. These results demonstrated that short-term exposure to a dose of 0.1% (w/w) microplastic particles in feed had limited effects on duodenal permeability, expression of pro-inflammatory protein genes and tight junction protein genes in the duodenum.

Effects of dietary chrysophyte (Poterioochromonas malhamensis) rich in beta-glucan on the growth performance, intestinal health, lipid metabolism, immune gene expression, and disease resistance against Aeromonas salmonicida in juvenile rainbow trout (Oncorhynchus mykiss)

An eight-week growth trial was conducted to investigate the effects of different dietary levels (0%, 2%, 4%, and 8%) of chrysophyte (Poterioochromonas malhamensis) rich in water-soluble beta-glucan on the growth performance, intestinal health, lipid metabolism, immune responses, and disease resistance of juvenile rainbow trout (Oncorhynchus mykiss). At the end of the feeding trial, no significant difference in weight gain was observed between the non-supplemented control and moderate doses (2% and 4%), but decreased weight gain was found at the highest dose (8%) of P. malhamensis compared with the control group. The survival rate in each group was above 97%, with no significant differences between groups. P. malhamensis supplementation in diets changed bacterial diversity and altered the composition of intestinal microbes. In particular, the abundance of the beneficial bacteria Lactobacillus was increased with moderate doses, and the abundance of the pathogenic bacteria Acinetobacter was enhanced with the highest dose (8%) of P. malhamensis. The mRNA expression levels of tight junction protein genes (e.g., claudin-1, occludin, and tricellulin) were also increased after P. malhamensis supplementation. Meanwhile, P. malhamensis supplementation altered lipid metabolism, including reduced crude lipid content in whole fish and decreased CHO, TG, HDL, and LDL in the serum of the highest dose group. Several free fatty acids, including C14:0, C16:1, and C18:3n3, were also reduced in the liver in the highest dose group. In contrast, P. malhamensis induced mRNA expression of the immune-related genes c3, c4, and c5 and the upregulation of mRNA expression in pro-inflammatory cytokines (IL1β and IL8) in the highest dose group. After the 8-week feeding trial, fish were intraperitoneally injected with a bacterial pathogen, Aeromonas salmonicida. The survival rate increased by 14% in the moderate dose groups and decreased by 11% in the highest dose group compared with the control. In addition, the mRNA expression levels of cytokines and complement system genes were differentially influenced by the challenge test, with an increase of c7 in the moderate dose groups, a decrease of c3 in the highest dose group, a reduction of IL1β in the moderate dose groups, and an upregulation of the anti-inflammatory cytokine IL10 in the moderate dose groups. In conclusion, the dietary inclusion of P. malhamensis at optimum levels (2–4%) efficiently regulated lipid metabolism, improved intestinal health, heightened immune responses, and increased resistance to A. salmonicida in juvenile rainbow trout. P. malhamensis could be a good source of beta-glucan for fish.

Low-density cell culture enhances hepatic function through tight junction formation in HepG2 cells.

An in vitro evaluation system using cultured hepatocytes is the most useful method in preclinical research, such as drug metabolism and toxicity test. Human hepatocytes should be used in an in vitro evaluation system because the expression of drug-metabolizing enzymes varies among animal species. HepG2 cells, a liver cancer-derived cell line, are widely used as a human hepatocyte model; however, their hepatic functions are generally weak. In this study, we showed that low-density HepG2 cell culture induces hepatic function. The morphology of HepG2 cells was altered depending on the cell density at the time of seeding. Low-density cultured HepG2 cells proliferated as tightly packed colonies. The HepG2 cell colonies in low-density culture demonstrated enhanced tight junction formation. Tight junction protein gene expression levels, such as those of zonula occludens-1 (ZO-1), junctional adhesion molecule 1 (JAM), claudin, occludin, and tricellulin, increased in low-density cultured HepG2 cells. Phases I and II metabolic enzymes, phase III transporter gene expression, and CYP3A4 activity also increased in low-density cultured HepG2 cells. Occludin and tricellulin knockdown inhibited the increased hepatic function in low-density cultures. Tricellulin knockdown reduced the expression of hepatocyte nuclear factor 6 (HNF6), CCAAT/enhancer-binding protein alpha (CEBPA), and aryl hydrocarbon receptor (AHR). In addition, the expression of nuclear receptor subfamily 1 group h member 2 (NR1H2) increased in low-density cultures, canceled by occludin and tricellulin knockdown. Our results suggest that low-density HepG2 cell cultures enhance hepatic function by promoting tight junction formation and demonstrate the importance of cell density in drug evaluation using hepatocyte cell lines.

Condensed tannins protect against aflatoxin B1-induced toxicity in Lateolabrax maculatus by restoring intestinal integrity and regulating bacterial microbiota

Condensed tannins (CT) have been shown to enhance the exogenous stress resistance of fish, whereas the protective effects of CT against damage induced by dietary aflatoxin B1 (AFB1) on the growth and health of fish have not been evaluated. A 56-day feeding trial was carried out to assess the effects of CT on alleviating dietary AFB1-induced damages in growth, antioxidant and immune response, intestinal integrity and bacterial microbiota of the Chinese sea bass (Lateolabrax maculatus). Three diets were formulated to contain 0 mg/kg of AFB1 and 0 g/kg of CT (G1), 1 mg/kg of AFB1 and 0 g/kg of CT (G2), and 1 mg/kg of AFB1 and 1 g/kg of CT (G3), respectively. Each diet was randomly assigned to three tanks with 40 fish in each tank. Fish were fed to apparent satiation twice daily. Results indicated that fish fed G2 had lower (P < 0.05) final body weight, weight gain rate, specific growth rate, feed intake, viscerosomatic index, total antioxidant capacity, superoxide dismutase, catalase, alkaline phosphatase and lysozyme, but higher (P < 0.05) malondialdehyde, diamine oxidase and lipopolysaccharide compared to those of fish fed G1 and G3. Fish fed G3 had higher (P < 0.05) villus length and intestinal tight junction protein gene expression (ZO-1, Claudin-3 and Occludin), but lower (P < 0.05) villus width than G2. Fish had similar growth performance, serum parameters and intestinal morphology between G1 and G3. In the top 10 dominant genera of intestinal microbiota, the relative abundance of Pseudomonas was higher in G2 but lower in G3 than in G1 (P < 0.05). Compared with G1, G2 and G3 had higher relative abundances of Aeromonas and Klebsiella, but lower relative abundance of Plesiomonas (P < 0.05). Dietary treatments did not alter the alpha and beta diversity of bacterial communities. In conclusion, dietary inclusion of 1 mg/kg of AFB1 reduced feed intake and decreased growth of L. maculatus. AFB1 reduced serum antioxidant capacity and immunity, increased intestinal permeability, induced intestinal damage and altered bacterial microbiota of fish. Supplementation of 1 g/kg of grape seed CT effectively protected against AFB1 toxicity by alleviating the negative impacts of dietary AFB1 exerted on fish. This study provides a rational for the application of CT in aquaculture to prevent fish from AFB1-induced damage.

Antimicrobials added to the feed of weaned piglets at two ages improves the molecular expression of intestinal barrier proteins

Context Weaning is the most critical period during a pig’s life, because it is a challenge with the change of environment, and the digestive system is not adapted to a solid diet at the time of weaning, favouring the appearance of intestinal disorders, infections and diarrhoea. Aims To quantify the gene abundance of intestinal barrier tight junction proteins in pigs fed diets added with antimicrobials and weaned at two ages. Methods A total of 150 pigs weaned at two ages (21 and 28 days) were distributed into groups: Control Diet 1 (D1-Ctrl) without antimicrobial; Diet 2 (D2-Ant): Ctrl with an antibiotic (bacitracin zinc); Diet 3 (D3-Prob): Ctrl with Bacillus subtilis PB6 (PTA-6737); Diet 4 (D4-OEO): Ctrl with oregano essential oil (OEO; Lippia origanoides); Diet 5 (D5-OA): Ctrl with a mixture of organic acids. On post-weaning Days 1, 15 and 30, pigs were euthanised, and a portion of the jejunum was removed to assess the gene abundance of the intestinal tight junction proteins (occludin-OCLN, zonula occludens-ZO-1 and claudins-CLAU) that were measured by qPCR. Key results The pigs fed the diet with the addition of D3-Prob and D4-OEO showed a higher abundance (P &lt; 0.05) of intestinal barrier tight junction protein genes (CLAU-1, CLAU-4, OCLN, ZO-1) compared with the other diets. This abundance was observed in both piglets weaned early, at 21 days, and later at 28 days of age, where, in addition, a statistically significant difference between weaning ages (P &lt; 0.05) was evidenced in favour of later weaning. Conclusions The addition of probiotics in the growth phase, together with weaning at 28 days of age, have a favourable impact on the intestinal digestive function of pigs, being able to influence morphometric and productive parameters, and serve as a basis for the analysis of molecular research related to intestinal health. Implications This research provides a basis for the use of natural nutritional alternatives, such as probiotic bacteria, as alternatives to growth-promoting antibiotics in the feed of growing pigs; in addition to encouraging a better adaptation of the piglet to the post-weaning phase, through late weaning.

Supplementation of reduced protein diets with

Context The impact of necrotic enteritis (NE) on acute-phase proteins, interleukins, blood mineral profiles, and gene expression have not been well documented. Aims This study aimed to determine the effects of l-arginine (Arg) or l-citrulline (Cit) supplementation on serum immunological parameters, serum mineral composition and gene expression in broilers fed reduced-protein diets (RP) during subclinical NE challenge. Methods Ross 308 cockerels (n = 720) were randomly assigned to six experimental treatments, with eight replicates of 15 birds per pen. The treatments were standard protein without and with NE challenge (SP−, SP+); reduced protein (2% points lower crude protein) without and with NE challenge (RP−, RP+), RP plus added Arg (103% of Ross 308 requirement) with NE challenge (RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. A 2 × 2 factorial arrangement was employed for the first four treatments. Additionally, treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results The NE × protein interactions indicated that serum calcium concentration decreased in birds fed the RP diets only when challenged with NE (P &lt; 0.05). The NE × protein interactions showed that the NE challenge downregulated the mRNA expression of jejunal y+ L amino acid transporter-2, and mucin 2 only in birds fed the RP diets (P &lt; 0.05). Feeding the RP decreased expression of catenin alpha 1, but increased expression of claudin 5 and tight junction protein genes compared with the SP (P &lt; 0.05). Birds in the RPC+ treatment had increased gene expression of tight junction protein and claudin 5 compared with the SP+ treatment (P &lt; 0.05). Conclusions Dietary protein level and infection with NE both have an impact on immune response and expression of genes involved in immunity and nutrient digestibility. In part replacement of Arg with Cit in the RPC diet may have beneficial effects on gene expression in NE-challenged birds. Implications Feeding RP diets may alleviate a decline in growth during subclinical NE by increasing gene expression of tight junction proteins compared with the SP diets.

SCFAs improve disease resistance via modulate gut microbiota, enhance immune response and increase antioxidative capacity in the host

To evaluate the effects of dietary short chain fatty acids (SCFAs) on the intestinal health and innate immunity in crucian carp, a six-week feeding trial was carried out with following treatments: basal diet (BD), basal diet supplementation with 1% sodium acetate (BDSA), basal diet supplementation with 1% sodium propionate (BDSP) and basal diet supplementation with 1% sodium butyrate (BDSB). The results showed dietary BDSA, BDSP and BDSB could protect the host against oxidative stress by improving the activity of certain antioxidative enzymes (T-SOD, GSH-Px and CAT). Additionally, dietary SCFAs could enhance mucosal and humoral immune responses by improving certain innate immune parameters in serum and skin mucus productions (IgM, ACH50 and T-SOD). Furthermore, dietary BDSA and BDSP could up-regulate the expression of immune related genes (TNF-α, TGF-β and IL-8) and tight junction protein genes (occludin and ZO-1). Dietary BDSB could also elevate the expression of IL-8, TGF-β, ZO-1 and Occludin in the midgut. Although dietary differences of SCFAs didn't alter the α-diversity of the intestinal flora, they altered the core microbiota. Finally, the challenge trial showed that dietary basal diet supplementation with SCFAs could protect zebrafish against Aeromonas hydrophila. These results suggest that dietary SCFAs could improve innate immunity, modulate gut microbiota and increase disease resistance in the host, which indicated the potential of SCFAs as immunostimulants in aquaculture.

Capparis spinosa Alleviates DSS-Induced Ulcerative Colitis via Regulation of the Gut Microbiota and Oxidative Stress.

Ulcerative colitis (UC) is a chronic inflammatory disease. Here, the potential effects of Capparis spinosa water extract (CSWE) on colonic histopathology, inflammation, and gut microbiota composition in dextran sulfate sodium (DSS) induced UC mice were evaluated. Our results showed that CSWE treatment improved the colonic histopathology of UC mice, increased the levels of tight junction protein gene ZO-1 and Occludin in intestinal epithelial cells, and inhibited the expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α). Furthermore, CSWE administration alleviated oxidative stress in the colon of UC mice. The effects of CSWE on the compositions and metabolomic profiles of the gut microbiota in UC mice were investigated. It was found that CSWE could enhance the diversity of gut microbes and the abundance of probiotics and metabonomics had the strongest association with Firmicutes. Our results indicated that CSWE might be an ideal candidate as a potential therapeutic natural product for the treatment of UC.

Microbiota transplantation from younger to older mice could restore lost immunity to effectively clear salmonella infection in Th2-biased BALB/c mice

AimsThe composition, overtly abundance, and diversity of gut microbiota, play a significant role in maintaining physiological homeostasis with age. Reports revealed that the gut microbial profile might be correlated with immunity and metabolism. It is, therefore, tantamount to know if an older individual can achieve the immunity and metabolic profile of a younger individual by receiving the gut microbiome of a younger individual. In the current report, we have studied the effects of cecal microbiota transplantation (CMT) from younger to older mice. Materials and methodsIn this study, older BALB/c mice (23 weeks) received CMT from younger BALB/c mice (3 weeks). Key findingsCMT recipient mice showed altered expressions of immune and tight junction protein genes in the colon of mice, while the non-CMT recipient mice did not. Older mice were treated with AVNM to make them compatible with CMT. Further data from metabolite studies revealed that AVNM treatment mainly affected the aromatic amino acid biosynthesis pathway while CMT mostly affected the metabolism of different carbohydrates. We repeated the analysis in C57BL/6 mice without any significant effects of CMT. SignificanceResults revealed that mice who received CMT showed more efficient restoration of gut microbiota than non-CMT recipient mice. CMT caused the alleviation of Salmonella infection and efficient recovery of the cecal index in the mice following antibiotics treatment.

Bacillus coagulans SCC-19 maintains intestinal health in cadmium-exposed common carp (Cyprinus carpio L.) by strengthening the gut barriers, relieving oxidative stress and modulating the intestinal microflora

Heavy metal cadmium (Cd) pollution is a serious problem affecting the sustainable development of aquaculture and the safety of aquatic foods. Research about the use of probiotics to attenuate toxic damage caused by Cd2+ in aquatic animals has received widespread attention. Bacillus coagulans (B. coagulans), a kind of probiotics commonly used in aquaculture, has been shown to adsorb Cd2+ both in vivo and vitro. Here, we aimed to determine the effects of B. coagulans on Cd2+ bioaccumulation, gut barrier function, oxidative stress and gut microbiota in common carp following Cd2+ exposure. The fish were exposure to Cd2+ at 0 and 0.5 mg/L and/or fed a B. coagulans-containing diet at 107, 108 and 109 CFU/g for 8 weeks. The results indicated that B. coagulans can maintain gut barrier function in Cd2+-exposed fish by reducing Cd2+ bioaccumulation, increasing the mRNA levels of tight junction protein genes (occludin, claudin-2 and zonula occludens-1), and decreasing the levels of diamine oxidase and D-lactic acid. In addition, B. coagulans could relieve oxidative stress in Cd2+-exposed fish by restoring the activities of glutathione peroxidase, catalase and superoxide dismutase. Moreover, Cd2+ exposure decreased the intestinal microbiota diversity and changed the intestinal microbiota compositions in common carp. However, supplementation with B. coagulans could reverse the altered intestinal microbiota diversity and composition after Cd2+ exposure, decrease the abundance of some pathogens (Shewanella and Vibrio), and increase the abundance of probiotics (Bacillus and Lactobacillus). These results indicate that B. coagulans may serve as a potential antidote for alleviating Cd2+ toxicity.

Dietary resveratrol alleviated lipopolysaccharide-induced ileitis through Nrf2 and NF-κB signalling pathways in ducks (Anas platyrhynchos).

Gram-negative bacteria contamination of feed can occur at all the stage of feed production, storage, transportation and utilization. Lipopolysaccharide (LPS) is a major toxic metabolite of Gram-negative bacteria. The aim of this study was to explore the effect of dietary resveratrol on the duck ileitis caused by LPS and its optimum addition level in diet. The results showed that LPS-induced duck ileitis with the destruction of intestinal structure, oxidative stress, mitochondrial dysfunction, inflammatory response and permeability alteration. Dietary resveratrol alleviated LPS-induced intestinal dysfunction and the increase of intestinal permeability by linearly increasing mRNA levels of tight junction protein genes (Claudin-1, Occludin-1, ZO-1) (p<0.05) and protein expression of Claudin-1 (p<0.01). In addition, dietary resveratrol improved the antioxidant capacity of duck ileum by reducing the production of MDA and increasing the activity of T-SOD (p<0.01) and CAT. Lipopolysaccharide increased Keap1 at mRNA and protein level (p<0.01) and decreased the protein level of Nrf2 (p<0.05). Dietary resveratrol significantly downregulated expression of Keap1 and upregulated expression of Nrf2 in duck (p<0.05). Dietary resveratrol suppressed the TLR4/NF-κB signalling pathway and the expression of its downstream genes including IKK, TXNIP, NLRP3, Caspase-1, IL-6 and IL-18. Meanwhile, the levels of inflammatory cytokines (IL-6, IL-18 and TNF-α) showed a linearly decrease (p<0.01) with increasing dietary resveratrol level. These results demonstrated that resveratrol alleviated the LPS-induced acute ileitis of duck through Nrf2 and NF-κB signalling pathways, and the dietary resveratrol of 500mg/kg is more efficiently.

Thiamine modulates intestinal morphological structure and microbiota under subacute ruminal acidosis induced by a high-concentrate diet in Saanen goats

Ruminant animals are generally fed with starch-rich grain as the main energy source, and the incidence of metabolic diseases such as subacute ruminal acidosis (SARA) is high due to the intensive farming. Thiamin has been reported to alleviate SARA caused by high-concentrate diets, but the exact mechanism is not well understood. The goal of this study was to examine the role of thiamine in intestinal inflammation and microbiota caused by high-concentrate diets. The SARA model was induced by low neutral detergent fibre/starch ration to study the effects of thiamine on intestinal tissue structure and microbiota. 18 mid-lactation (148 ± 3 d in milk; milk yield = 0.71 ± 0.0300 kg/d) Saanen goats (BW = 36.5 ± 1.99 kg; body condition score = 2.73 ± 0.16, where 1 = emaciated and 6 = obese) in parities 1 or 2 were selected. The goats were randomly divided into three groups with six replicates: (1) control diet (C; concentrate:forage 30:70), (2) high-concentrate diet (H; concentrate:forage 70:30), and (3) high-concentrate diet with 200 mg of thiamine/kg of DM intake (H + T;concentrate:forage 70:30). The experimental period was lasted for 56 d. The small and large intestine, expression of inflammatory factor genes, tight junction protein genes, total antioxidant capacity, and intestinal microbiota were measured. The results showed that SARA was observed in treatment H, whereas rumen fluid pH was improved in treatment H + T. Treatment H + T also significantly repaired the intestinal tissue structure damaged by SARA, improved the total antioxidant capacity of the small intestinal mucosa, reduced mRNA expression of inflammatory factors in the small intestine tissue, and increased the mRNA expression of tight junction genes in small intestine tissue. The high-concentrate diet reduced the diversity of intestinal microbiota. When thiamine is added to the high-concentrate diet, the relative abundance of intestinal Firmicutes and beneficial bacteria represented by Lactobacilli were upregulated, and the relative abundance of Proteus, a marker of intestinal dysbacteriosis, returned to normal. In conclusion, thiamine supplementation could alleviate the damage to the intestinal tissue structure and microbial environment caused by SARA condition in dairy goats fed a high-concentrate diet.

A novel murine model of multi-day moderate ethanol exposure reveals increased intestinal dysfunction and liver inflammation with age

BackgroundThere are currently > 600 million people over the age of 65 globally and this number is expected to double by the year 2050. Alcohol use among this population is on the rise, which is concerning as aging is associated with increased risk for a number of chronic illnesses. As most studies investigating the effects of alcohol have focused on young/middle-aged populations, there is a dearth of information regarding the consequences of alcohol use in older consumers. In addition, most murine ethanol models have concentrated on exposure to very high levels of ethanol, while the vast majority of elderly drinkers do not consume alcohol in excess; instead, they drink on average 2 alcoholic beverages a day, 3–4 days a week.MethodsWe designed a murine model of aging and moderate ethanol consumption to determine if the deleterious effects of alcohol on the gut-liver axis are exacerbated in aged, relative to younger, animals. Aged and young mice were exposed to a multi-day moderate exposure ethanol regimen for 4 weeks and changes in gut permeability along with intestinal tight junction protein and antimicrobial peptide gene expression were measured. In addition, hepatic inflammation was assessed by histological analysis, inflammatory gene expression and flow cytometric analysis of inflammatory infiltrate.ResultsOur results reveal that in aged, but not young mice, moderate ethanol exposure yielded significantly worsened intestinal permeability, including increased bacterial translocation from the gut, elevated serum iFABP and leakage of FITC-dextran from the gut. Interestingly, moderate ethanol exposure in young animals led to gut protective transcriptional changes in the ileum while this protective response was blunted in aged mice. Finally, moderate ethanol exposure in aged mice also resulted in marked inflammatory changes in the liver.ConclusionsThese results demonstrate that aged mice are more susceptible to ethanol-induced gut barrier dysfunction and liver inflammation, even at moderate doses of ethanol. This increased vulnerability to ethanol’s gastrointestinal effects has important implications for alcohol use in the aging population. Future studies will explore whether improving intestinal barrier function can reverse these age-related changes.

Effects of high level of fermented soybean meal substitution for fish meal on the growth, enzyme activity, intestinal structure protein and immune‐related gene expression and intestinal flora in juvenile pearl gentian grouper

The present study preliminarily investigated the effects of high level of fermented soybean meal (FSBM) protein substituted for fish meal (FM) protein on the growth and intestinal homeostasis of pearl gentian grouper. Seven hundred and twenty juvenile groupers were randomly divided into three groups, including the FM control group, 20% FSBM protein substituted for FM protein group (FSBM20) and FSBM40 group (n = 4). Three iso-nitrogenous and iso-lipidic diets were prepared and fed to fish for 10 weeks. Each barrel of cultural water is 1 m3, using natural light and temperature. Results showed that weight gain, specific growth rate, intestine plica length/width and microvilli length in FSBM groups decreased significantly (p < .05), and the lamina propria width in FSBM groups increased significantly (p < .05). The enzyme activities of glutathione reductase, glutathione peroxidase and total superoxide dismutase in distal intestinal tissues and alanine aminotransferase and aspartate transaminase in liver tissues increased significantly with dietary FSBM addition (p < .05). The pro-inflammatory and immune-related gene expressions of IL1β, IL12, IL32 and TNF-α increased significantly in FSBM40 group (p < .05), while the anti-inflammatory and immune-related gene expressions of IL5, IL10, IgM, CD4 and lysozyme decreased significantly in FSBM40 group (p < .05). The aquaporin protein gene expressions of aqu1, aqu4 and aqu12, and the tight junction protein gene expressions of jam, claudin3, claudin12, claudin15 and ZO-3 decreased significantly (p < .05), while the gene expressions of aqu8, aqu9, aqu10 and ZO-1 increased significantly (p < .05), and the ion transport carrier gene expressions of nkcc and clc decreased significantly (p < .05). 16S high-throughput sequencing showed that at the phylum level, the abundance of Proteobacteria decreased significantly in FSBM40 group (p < .05), while that of Bacteroidetes, Firmicutes, Acidobacteria and Actinobacteria increased significantly in FSBM40 group (p < .05). At the genus level, the top 10 species were Photobacterium, Stenotrophlomonas, Vibrio, Phyllobacterium, Chromohalobacter, etc. The abundance of Photobacterium in FSBM40 group decreased significantly (p < .05), while that of other species increased significantly (p < .05). High level of FSBM substituted for FM resulted in a significant decrease in the functional abundance of aerobic_chemoheterotrophy and chemoheterotrophy in FSBM40 group (p < .05), while animal_parasites_or_symbiont abundance increased significantly in FSBM40 group (p < .05). Present study showed that experimental level of FSBM had a significantly negative effect on the growth performance, intestinal mucosa structure and intestinal flora composition in pearl gentian grouper.

The Gut Microbiota Regulates the Metabolic Benefits Mediated by Red Raspberry Polyphenols

ObjectivesRed raspberry (RR) polyphenols, including ellagic acid and their gut-derived metabolites, the urolithins, reduce inflammation and improve insulin sensitivity. However, it is unknown whether the gut microbiota is responsible for these health benefits and why certain individuals do not transform ellagic acid into urolithins. Here, we determined the causative role for the microbiome in mediating the health benefits from RR polyphenols using germ-free and conventionalized mouse models of diet-induced obesity. We also tested whether Gordonibacter urolithinfaciens (G. uro), a gut microbe previously shown to metabolize ellagic acid into urolithins, could enhance metabolic benefits when administered as a synbiotic with RR polyphenols. MethodsRR polyphenols were extracted using a macroporous ion-exchange resin column to remove sugars and fibers. C3H/HeN mice with (CVZ) or without a microbiota (GF) were fed either a low fat (LF), high fat (HF), or HF diet with RR polyphenols (HF + RR) for 12 weeks. For synbiotic studies, GF C57BL/6 mice were given a G. uro deficient-microbiome and then fed either a HF or HF + RR diet plus 20% fructose water with or without G. uro for 7 weeks. ResultsFeeding a HF diet increased body weight and fat mass for both GF and CVZ mice compared to feeding a LF diet (P < 0.05). Feeding a HF diet with RR polyphenols significantly decreased visceral adipose tissue and liver triglycerides (P < 0.05) compared to a HF control diet in CVZ but not GF mice. G. uro administration to mice receiving a HF diet and fructose water significantly reduced body weight, body fat percentage, fasting blood glucose, and subcutaneous adipose tissue mass as well as increased ileal tight junction protein gene expression (P < 0.05) compared to controls. Notably, mice supplemented with both G. uro and RR polyphenols experienced no metabolic improvements compared to controls (P < 0.05). ConclusionsOur results demonstrate that the microbiome is required for mediating RR polyphenol metabolic benefits. Supplementation of G. uro improved metabolic health; however, those beneficial effects were abrogated in the presence of RR polyphenols. Together, these results highlight the importance of considering specific diet-microbiota interactions when developing foods for preventing and treating obesity-related diseases. Funding SourcesUSDA NIFA.

CdSe/ZnS Core-Shell-Type Quantum Dot Nanoparticles Disrupt the Cellular Homeostasis in Cellular Blood–Brain Barrier Models

Two immortalized brain microvascular endothelial cell lines (hCMEC/D3 and RBE4, of human and rat origin, respectively) were applied as an in vitro model of cellular elements of the blood–brain barrier in a nanotoxicological study. We evaluated the impact of CdSe/ZnS core-shell-type quantum dot nanoparticles on cellular homeostasis, using gold nanoparticles as a largely bioorthogonal control. While the investigated nanoparticles had surprisingly negligible acute cytotoxicity in the evaluated models, a multi-faceted study of barrier-related phenotypes and cell condition revealed a complex pattern of homeostasis disruption. Interestingly, some features of the paracellular barrier phenotype (transendothelial electrical resistance, tight junction protein gene expression) were improved by exposure to nanoparticles in a potential hormetic mechanism. However, mitochondrial potential and antioxidant defences largely collapsed under these conditions, paralleled by a strong pro-apoptotic shift in a significant proportion of cells (evidenced by apoptotic protein gene expression, chromosomal DNA fragmentation, and membrane phosphatidylserine exposure). Taken together, our results suggest a reactive oxygen species-mediated cellular mechanism of blood–brain barrier damage by quantum dots, which may be toxicologically significant in the face of increasing human exposure to this type of nanoparticles, both intended (in medical applications) and more often unintended (from consumer goods-derived environmental pollution).