mRNA Levels Of Occludin Research Articles

Pathological mechanism of intestinal mucosal barrier injury of large intestine dampness-heat syndrome rats and the protective effect of Yujin powder

Large intestine dampness-heat syndrome (LIDHS) is frequently-occurring in the inflammatory intestinal disease of animals and human. Yujin powder (YJP) is a classical prescription for treating LIDHS. To explore the pathological mechanism of intestinal mucosal barrier injury of LIDHS and the protection of YJP, the LIDHS rat model was established through imitating the inducing conditions of LIDHS and treated with YJP. The integrity of ileal and colonic mucosa was detected through histopathological examination. The serum DAO, D-LA and ET levels were detected by ELISA. The mRNA and protein expression levels of Occludin, ZO-1 and MUC2 in ileum and colon were detected using RT-PCR and immunohistochemistry methods, respectively. The results showed that the ileal and colonic epithelium of LIDHS rats were destroyed; the serum DAO, D-LA and ET levels were significantly increased; the mRNA and protein expression levels of Occludin, ZO-1 and MUC2 in ileum and colon were all abnormally expressed. After treatment with YJP, the mucosal integrity was restored; the levels of serum DAO, D-LA and ET, mRNA and protein levels of Occludin and ZO-1 in ileum and colon and MUC2 in ileum were back-regulated; however, MUC2 level in colon was further increased. The results demonstrated that the intestinal mucosal barrier was damaged in LIDHS rats and Occludin, ZO-1 and MUC2 were abnormally expressed, and YJP could repair the intestinal mucosal barrier through up-regulating the expression of Occludin and ZO-1 in ileum and colon as well as MUC2 in colon and down-regulating MUC2 in ileum.

Lactiplantibacillus plantarum YZX28 alleviated intestinal barrier dysfunction induced by enterotoxigenic Escherichia coli via inhibiting its virulence factor production

Probiotics are emerging as a promising approach to treating foodborne infections or gastrointestinal diseases. This study aimed to explore the protective effect of Lactiplantibacillus plantarum YZX28 (YZX28) on intestinal barrier dysfunction induced by enterotoxigenic Escherichia coli K80 (ETEC K80). Caco-2 cells were used for in vitro co-culture experiments of enterotoxin-producing ETEC K80 and YZX28. The barrier permeability (higher phenol red flux and decreased TEER) and levels of pro-inflammatory cytokines TNF-α and IL-8 increased by ETEC K 80 were attenuated by YZX28, and the mRNA levels of tight junctions, including ZO-1, occludin, claudin-1, and cingulin were significantly increased by YZX28 intervention. The redistribution of ZO-1, claudin-1, and actin fibers in Caco-2 cells induced by ETEC K 80 was restored. Furthermore, YZX28 could effectively reduce the adhesion level of ETEC to Caco-2 cells, alleviate the decrease of cell viability induced by ETEC, and inhibit the expression of ETEC virulence factors, including enterotoxin STa (est-A), STb (est-B), LT (elt) as well as fimbria adhesin FaeG and reduced the corresponding cAMP, cGMP, and CEACAM6 levels. This strain may be a potential therapeutic agent for treating intestinal-related problems caused by the intestinal pathogen ETEC.

Effects of alkaline mineral complex water supplementation on growth performance, inflammatory response, and intestinal barrier function in weaned piglets.

The purpose of the present study was to investigate the effects of drinking water alkaline mineral complex (AMC) supplementation on growth performance, intestinal morphology, inflammatory response, immunity, antioxidant defense system, and barrier functions in weaned piglets. In a 15-d trial, 240 weaned piglets (9.35 ± 0.86 kg) at 28 d of age (large white × landrace × Duroc) were randomly divided into two groups: the control (Con) group and the AMC group. Drinking water AMC supplementation improved (P < 0.01) final body weight (BW) and average daily gain (ADG) in weaned piglets compared to the Con group. Importantly, AMC reduced (P < 0.01) the feed-to-gain (F:G) ratio. AMC water improved the physical health conditions of piglets under weaning stress, as reflected by the decreased (P < 0.05) hair score and conjunctival score. Moreover, there was no significant (P > 0.05) difference in relatively small intestinal length, organ (liver, spleen, and kidney) indices, or gastrointestinal pH value in weaned piglets between the two groups. Of note, AMC significantly promoted the microvilli numbers in the small intestine and effectively ameliorated the gut morphology damage induced by weaning stress, as evidenced by the increased (P < 0.05) villous height (VH) and ratio of VH to crypt depth. Additionally, AMC lessened the levels of lipopolysaccharide (LPS, P < 0.01) and the contents of IL1β (P<0.05), and TNF-α (P<0.05) in the weaned piglet small intestine. Conversely, the gut immune barrier marker, secretory immunoglobulin A (sIgA) levels in serum and small intestine mucosa were elevated after AMC water treatment (P < 0.01). Furthermore, AMC elevated the antioxidant mRNA levels of (P < 0.05) SOD 1-2, (P < 0.01) CAT, and (P < 0.01) GPX 1-2 in the small intestine. Likewise, the mRNA levels of the small intestine tight junction factors Occludin (P < 0.01), ZO-1 (P < 0.05), Claudin 2 (P < 0.01), and Claudin 5 (P<0.01) in the AMC treatment group were notably higher than those in the Con group. In conclusion, drinking water AMC supplementation has an accelerative effect on growth performance by elevating gut health by improving intestinal morphology, the inflammatory response, the antioxidant defense system, and barrier function in weaned piglets.

Selenium Deficiency Leads to Inflammation, Autophagy, Endoplasmic Reticulum Stress, Apoptosis and Contraction Abnormalities via Affecting Intestinal Flora in Intestinal Smooth Muscle of Mice.

Selenium (Se) is a micronutrient that plays a predominant role in various physiological processes in humans and animals. Long-term lack of Se will lead to many metabolic diseases. Studies have found that chronic Se deficiency can cause chronic diarrhea. The gut flora is closely related to the health of the body. Changes in environmental factors can cause changes in the intestinal flora. Our study found that Se deficiency can disrupt intestinal flora. Through 16s high-throughput sequencing analysis of small intestinal contents of mice, we found that compared with CSe group, the abundance of Lactobacillus, Bifidobacterium, and Ileibacterium in the low selenium group was significantly increased, while Romboutsia abundance was significantly decreased. Histological analysis showed that compared with CSe group, the small intestine tissues of the LSe group had obvious pathological changes. We examined mRNA expression levels in the small intestine associated with inflammation, autophagy, endoplasmic reticulum stress, apoptosis, tight junctions, and smooth muscle contraction. The mRNA levels of NF-κB, IκB, p38, IL-1β, TNF-α, Beclin, ATG7, ATG5, LC3α, BaK, Pum, Caspase-3, RIP1, RIPK3, PERK, IRE1, elF2α, GRP78, CHOP2, ZO-1, ZO-2, Occludin, E-cadherin, CaM, MLC, MLCK, Rho, and RhoA in the LSe group were significantly increased. The mRNA levels of IL-10, p62 BcL-2 and BcL-w were significantly decreased in the LSe group compared with the CSe group. These results suggest that changes in the abundance of Lactobacillus, bifidobacterium, ileum, and Romboutsia may be associated with cellular inflammation, autophagy, endoplasmic reticulum stress, apoptosis, tight junction, and abnormal smooth muscle contraction. Intestinal flora may play an important role in chronic diarrhea caused by selenium deficiency.

Curcumin Improved Intestinal Epithelial Barrier Integrity by Up-Regulating ZO-1/Occludin/Claudin-1 in Septic Rats.

Objective To investigate the protective effect and mechanism of curcumin on intestinal barrier function in rats with enterogenic sepsis. Methods Rats were divided into Sham group (Sham), Model group (Model), low-dose curcumin group (100 mg/kg), and high-dose curcumin group (200 mg/kg), with 10 rats in each group. Sepsis model was established in model group, low-dose curcumin group, and high-dose curcumin group. After drug intervention, hematoxylin-eosin (HE) staining was used to observe the histopathological changes of small intestine in each group. The levels of TNF-α, IL-1β, and IL-6 in serum and intestinal tissues of rats were determined by ELISA. The expression of ZO-1, occludin, and claudin-1 in ileum was detected by QRT-PCR and Western blot. Western blotting was used to detect the expression of ERK/JNK signaling pathway, NF-κB p65, apoptosis-related proteins Caspase-3, and TNF-α in rat intestinal tissues. Results HE staining showed that curcumin treatment reduced epithelial cell shedding, interstitial edema, and apoptosis. Compared with model group, DAO activity, serum intestinal fatty acid binding protein (I-FABP), TNF-α, IL-6, and IL-1β expression in curcumin group were decreased in a dose-dependent manner. Curcumin can upregulate the mRNA and protein expression levels of ZO-1, occludin, and claudin-1 in ileum of CLP-induced rats. In addition, curcumin inhibits NF-κB p65 activation and apoptosis by regulating ERK/JNK signaling pathway. Conclusion Curcumin can reduce inflammatory response and upregulate the expression of intestinal tight junction proteins ZO-1, occludin, and claudin-1 in rats with enterogenic sepsis, and protect intestinal barrier function.

Dietary Saccharomyces cerevisiae improves intestinal flora structure and barrier function of Pekin ducks

This study aimed at investigating the effects of dietary Saccharomyces cerevisiae (SC) on the intestinal flora structure and barrier function of Pekin duck. A total of 180 1-day-old Pekin ducks were randomly divided into 3 groups with 6 replicates in each group and 10 birds per replicate. The birds in the control group (CON) were fed the basal diet, and those in the experimental group were fed the basal diets supplemented with 600 mg/kg SC (LSC) and 1,200 mg/kg (HSC), respectively. The trial lasted for 42 d. Results showed that LSC and HSC treatments tended to improve the feed conversion efficiency during the trial. The ileum length of birds in the LSC and HSC groups was elevated. Additionally, with 600mg/kg SC supplemented, the mRNA levels of villin, claudin3, and MUC 2 in d21 were up-regulated, as well as the mRNA levels of villin, claudin3, occludin, i-FABP, ZO-1, and MUC 2 in d42. In addition, dietary SC supplementation improved the α-diversity of the bacteria in cecal chyme and tended to increase the abundance (RA) of Bacteroidetes (P = 0.071). Besides, the RA of Ruminococcaceae_UCG-014 was raised in the LSC group. Beyond that, the RA of Proteobacteria was descended with two levels of SC added. In conclusion, dietary Saccharomyces cerevisiae, particularly at 600 mg/kg level, improved the intestinal flora structure and barrier function of Pekin duck.

Effects of dietary pantothenic acid on growth, antioxidant ability and innate immune response in juvenile black carp

An 8-week feeding study was conducted to examine how dietary pantothenic acid (PA) affects growth, antioxidant ability and innate immunity in juvenile black carp (Mylopharyngodon piceus). Juvenile fish (7.35 ± 0.06 g) were fed diets with PA at 0, 5, 10, 20, 40 and 80 mg/kg, respectively. The highest weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) were obtained with 10 mg/kg dietary PA (p < 0.05), as well as the lowest feed conversion ratio (FCR). Adequate dietary PA (10 and 20 mg/kg) markedly upregulated neuropeptide Y (NPY), orexin (ORX) and ghrelin (GRL) and downregulated cholecystokinin (CCK) in the brain of these animals (p < 0.05). Intestinal sodium-dependent multivitamin transporter (SMVT) expression and α amylase, trypsin, chymotrypsin and lipase activities were all improved after supplementation of PA at 10 or 20 mg/kg (p < 0.05). In addition, adequate dietary PA (10 and 20 mg/kg) significantly increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR), as well as the amounts of reduced glutathione (GSH) and total antioxidant capacity (T-AOC) in the liver of these animals (p < 0.05). Meanwhile, liver glutathione S-transferase (GST) activity and malondialdehyde (MDA) amounts levels were both markedly decreased with dietary PA at 10 or 20 mg/kg (p < 0.05). Furthermore, adequate dietary PA significantly elevated the mRNA amounts of NFE2-related nuclear factor 2 (Nrf2) and downregulated Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b (p < 0.05), and remarkably upregulated innate defense molecules, including lysozyme (LYZ), natural resistance-associated macrophage protein (NRAMP), liver-expressed antimicrobial peptide 2 (LEAP-2), hepcidin (HEPC), complement 3 (C3) and complement 9 (C9) in the liver (p < 0.05). Meanwhile, elevated dietary PA resulted in increased LYZ activity and C3 content and decreased aspartate aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum samples from juvenile black carp compared with the groups fed PA-deficient diets (p < 0.05). Moreover, 10, 20 and 40 mg/kg PA-containing diets starkly downregulated intestinal interleukin 8 (IL-8) and IL-11 at the mRNA level in comparison with the PA-deficient diet (0 mg/kg) (p < 0.05). However, PA supplementation at 10, 20 or 40 mg/kg resulted in increased intestinal zonula occludens-1 (ZO-1), ZO-2, ZO-3, claudin 3, claudin 4, claudin 8, claudin 15 and occludin mRNA levels in M. piceus in comparison with the 0 mg/kg PA group (p < 0.05). Jointly, the above findings suggested adequate dietary PA (10 and 20 mg/kg) enhances feed utilization and growth performance, as well as antioxidant capacities and non-specific immune reactions in juvenile M. piceus.

Apple polyphenols improve intestinal barrier function by enhancing antioxidant capacity and suppressing inflammation in weaning piglets.

This study aimed to examine the effects of apple polyphenols (APPs) on antioxidant capacity, immune and inflammatory response, and barrier function in weaning piglets. Results showed that APPs improved jejunal barrier function by increasing the villus height, villus height/crypt depth, the mRNA levels of occludin, mucin-1, and mucin-4 and up-regulating the protein expression of occluding (P < 0.05). As for antioxidant capacity, APPs increased the activities of total superoxide dismutase and glutathione peroxidase and total antioxidant capacity level in jejunum (P < 0.05). Besides, APPs up-regulated the protein expressions of NAD(P)H quinone dehydrogenase 1 (NQO1), heme oxygenase-1 (HO-1), and nuclear-related factor 2 (NRF2) and down-regulated the protein expression of kelch-like ECH-associated protein 1 (Keap1). As regard to immune and inflammatory response, APPs increased the immunoglobulin A content in serum and decreased the mRNA levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), and IL-8 in jejunum (P < 0.05). Overall, dietary APPs supplementation improves the jejunal barrier function by enhancing antioxidant capacity and suppressing the mRNA expression related to inflammation, which may be related to the NRF2 signal and TLR4/NF-κB signal.

Impact of Citrus Pulp or Inulin on Intestinal Microbiota and Metabolites, Barrier, and Immune Function of Weaned Piglets.

We investigated the use of citrus pulp (CP) as a novel prebiotic capable of exerting microbiota and immunomodulating capacities to alleviate weaning stress. Inulin (IN), a well-known prebiotic, was used for comparison. Hundred and 28 male weaned piglets of 21 days old were assigned to 32 pens of 4 piglets each. Piglets were assigned to one of the four treatments, i.e., control, IN supplemented at 0.2% (IN0.2%), and CP supplemented either at 0.2% (CP0.2%) or at 2% (CP2%). On d10–11 and d31–32 post-weaning, one pig per pen was euthanized for intestinal sampling to evaluate the growth performance, chyme characteristics, small intestinal morphology, colonic inflammatory response and barrier integrity, metabolite profiles [gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS)], and microbial populations. The IN treatment and the two CP treatments induced higher small intestinal villus height to crypt depth ratios in comparison with the control diet at both sampling times. All treatments decreased acidic goblet cell absolute counts in the crypts in comparison to the control diet of the duodenum on d10–11 and d31–32. The gene expression of β-defensin 2 was downregulated in colonic tissues following the IN and CP2% inclusion on d31–32. On d31–32, piglets fed with IN and CP0.2% showed lower mRNA levels of occludin and claudin-3, respectively. Not surprisingly, flavonoids were observed in the colon in the CP treatments. Increased colonic acetate proportions on d10–11, at the expense of branched-chain fatty acid (BCFA) levels, were observed following the CP2% supplementation compared to the control diet, inferring a reduction of proteolytic fermentation in the hindgut. The beneficial microbial community Faecalibacterium spp. was promoted in the colon of piglets fed with CP2% on d10–11 (p = 0.04; false discovery rate (FDR) non-significant) and on d31–32 (p = 0.03; FDR non-significant) in comparison with the control diet. Additionally, on d31–32, CP2% increased the relative abundance of Megasphaera spp. compared to control values (p = 0.03; FDR non-significant). In conclusion, CP2% promoted the growth of beneficial bacterial communities in both post-weaning time points, modulating colonic fermentation patterns in the colon. The effects of CP supplementation were similar to those of IN and showed the potential as a beneficial feed supplement to alleviate weaning stress.

Evaluation of immune efficacy of Omp2 protein against Lawsonia intracellularis in mice

Porcine proliferative enteropathy (PPE) is caused by the obligate intracellular bacterium Lawsonia intracellularis. Infection results in an enteric disease characterised by decreased growth performance of pigs, and presents a major economic burden for swine industries worldwide. Since vaccination is an effective technique for controlling PPE, novel effective vaccine platforms are need to be developed. In this study, five proteins of L. intracellularis were screened through animal experiments and the highly immunoprotective Omp2 protein was identified. Then, the immune efficacy of Omp2 was further evaluated based on humoral and cell mediated immune (CMI) responses, faecal bacterial shedding, histopathological lesions, immune barrier function of intestinal mucosa as well as digestive and absorptive capacity following challenge of mice with L. intracellularis. Mice immunised with Omp2 had reduced faecal shedding, fewer histopathological lesions and reduced bacteria colonisation of the ileum. Additionally, Omp2 immunised mice showed stronger serum IgG and IFN-γ levels, up-regulated Occludin and zonula occludens-1 (ZO-1) mRNA levels, as well as increased numbers of intestinal intraepithelial lymphocytes (IELs) and levels of sIgA. On the contrary, the activities of LPS, α-AMS and AKP were significantly increased.Our investigation indicated that immunization with Omp2 reduced the severity of clinical signs and provided efficacious immunoprotection for target animals against L. intracellularis infection in mouse model.

Effect of chitosan on blood profile, inflammatory cytokines by activating TLR4/NF-\u03baB signaling pathway in intestine of heat stressed mice

Heat stress can significantly affect the immune function of the animal body. Heat stress stimulates oxidative stress in intestinal tissue and suppresses the immune responses of mice. The protecting effects of chitosan on heat stress induced colitis have not been reported. Therefore, the aim of this study was to investigate the protective effects of chitosan on immune function in heat stressed mice. Mice were exposed to heat stress (40 °C per day for 4 h) for 14 consecutive days. The mice (C57BL/6J), were randomly divided into three groups including: control group, heat stress, Chitosan group (LD: group 300 mg/kg/day, MD: 600 mg/kg/day, HD: 1000 mg/kg/day). The results showed that tissue histology was improved in chitosan groups than heat stress group. The current study showed that the mice with oral administration of chitosan groups had improved body performance as compared with the heat stress group. The results also showed that in chitosan treated groups the production of HSP70, TLR4, p65, TNF-α, and IL-10 was suppressed on day 1, 7, and 14 as compared to the heat stress group. In addition Claudin-2, and Occludin mRNA levels were upregulated in mice receiving chitosan on day 1, 7, and 14 of heat stress. Furthermore, the IL-6, IL-10, and TNF-α plasma levels were down-regulated on day 1, 7, and 14 of heat stress in mice receiving the oral administration of chitosan. In conclusion, the results showed that chitosan has an anti-inflammatory ability to tolerate hot environmental conditions.

Effects of Low- and High-Level Gossypol and Sodium Butyrate Supplementation Under High-Level Gossypol Condition on Growth Performance and Intestinal Health of Hybrid Grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)

The supplementation of gossypol in excess is noted to cause detrimental effects such as the reduction of antioxidant enzymes and disruption of lipid metabolism in animals. Studies regarding the effects of different levels of gossypol are very rare; thus, this study was conducted to evaluate the effects of low and high dietary levels of gossypol and of supplementation with 0.13 % sodium butyrate (NaB) under high gossypol conditions on the growth performance and intestinal health of hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂). Four treatments were used: Feed containing 40% fish meal was used as the control group [fishmeal (FM)], the FM diet plus 0.03% gossypol acetic acid (abbreviated as gossypol) as the low-level gossypol group (gL), FM + 0.15% gossypol was used as the high-level gossypol group (gH), and FM+0.15 % gossypol with 0.13 % NaB as the repair group (gHNaB). All diets were isonitrogenous and isolipidic. The results showed that the gL treatment significantly increased specific growth rate (SGR) and feed utilization; upregulated mRNA levels of distal intestinal transforming growth factor-β1 (tgfβ1), jam, occludin, claudin3, and zo1; and downregulated mRNA levels of il8, ifnγ, and akt. The gH treatment significantly reduced SGR and feed utilization; increased distal intestinal total nitric oxide synthase (NOS) activity and nitric oxide (NO) content; upregulated mRNA levels of distal intestinal tnfα, il1β, il6, ifnγ, caspase2, caspase9, and akt; and downregulated mRNA levels of tgfβ1, jam, and zo1. NaB supplementation significantly increased distal intestinal total NOS activity and NO content; downregulated distal intestinal tnfα, il1β, ifnγ, pi3k p85, and akt mRNA levels; and increased distal intestinal tgfβ1, jam, occludin, and zo1 mRNA levels. Above all, low- and high-level gossypol exhibited positive and negative effects on growth performance, distal intestinal anti-inflammatory capacity, and tight junctions, respectively, in hybrid groupers. NaB supplementation improved distal intestinal anti-inflammatory capacity and tight junctions in hybrid groupers to a certain extent.

Dietary supplementation of \u03b2-conglycinin, with or without sodium butyrate on the growth, immune response and intestinal health of hybrid grouper

We investigated the effects of low and high doses of β-conglycinin and the ameliorative effects of sodium butyrate (based on high-dose β-conglycinin) on the growth performance, serum immunity, distal intestinal histopathology, and gene, protein expression related to intestinal health in hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂). The results revealed that the instantaneous growth rate (IGR) of grouper significantly increased, decreased, and increased in the low-dose β-conglycinin (bL), high-level β-conglycinin (bH) and high-level β-conglycinin plus sodium butyrate (bH-NaB), respectively. The feed coefficient ratio (FCR) was significantly increased in the bH and bH-NaB, serum levels of IFN-γ, IL-1β, and TNF-α were upregulated in the bH. The intestinal diameter/fold height ratio was significantly increased in the bH. Furthermore, there were increases in nitric oxide (NO), total nitric oxide synthase (total NOS), and peroxynitrite anion (ONOO−) in the bH, and decreases in total NOS and ONOO− in the bH-NaB. In the distal intestine, IL-1β and TGF-β1 mRNA levels were downregulated and upregulated, respective in the bL. The mRNA levels of TNF-α and IL-6 were upregulated in the bH, and downregulated in the bH-NaB, respectively. Occludin, claudin3 and ZO-3 mRNA levels were upregulated in the bL, downregulated in the bH and then upregulated in the bH-NaB. No significant differences were observed in the mRNA levels of IFN-γ and jam4. And the p-PI3K p85Tyr458/total PI3K p85 value was significantly increased in the bH and then decreased in the bH-NaB, and the total Akt value was significantly increased in the bH. These indicate β-conglycinin has a regulatory effect on serum immunity and affect distal intestinal development by modulating distal intestinal injury-related parameters. Within the distal intestinal tract, low- and high-dose β-conglycinin differentially affect immune responses and tight junctions in the distal intestine, which eventually manifests as a reduction in growth performance. Supplementing feed with sodium butyrate might represent an effective approach for enhancing serum immunity, and protects the intestines from damage caused by high-dose β-conglycinin.

Ameliorative Effects of Peptides Derived from Oyster (Crassostrea gigas) on Immunomodulatory Function and Gut Microbiota Structure in Cyclophosphamide-Treated Mice.

The intestinal flora is recognized as a significant contributor to the immune system. In this research, the protective effects of oyster peptides on immune regulation and intestinal microbiota were investigated in mice treated with cyclophosphamide. The results showed that oyster peptides restored the indexes of thymus, spleen and liver, stimulated cytokines secretion and promoted the relative mRNA levels of Th1/Th2 cytokines (IL-2, IFN-γ, IL-4 and IL-10). The mRNA levels of Occludin, Claudin-1, ZO-1, and Mucin-2 were up-regulated, and the NF-κB signaling pathway was also activated after oyster peptides administration. Furthermore, oyster peptides treatment reduced the proportion of Firmicutes/Bacteroidetes, increased the relative abundance of Alistipes, Lactobacillus, Rikenell and the content of short-chain fatty acids, and reversed the composition of intestinal microflora similar to that of normal mice. In conclusion, oyster peptides effectively ameliorated cyclophosphamide-induced intestinal damage and modified gut microbiota structure in mice, and might be utilized as a beneficial ingredient in functional foods for immune regulation.

Terpinen4-ol inhibits heat stress induced inflammation in colonic tissue by Activating Occludin, Claudin-2 and TLR4/NF-κB signaling pathway

Heat stress has severe implications on the health of mice involving intestinal mucosal barrier damage and dysregulated mucosal immune response. This study was designed with long-term heat stress to detect the protective effect of terpinen4-ol on body weight, colon length, organ index, morphological structure, inflammatory cytokines expression, Claudin-2, Occludin, and TLR4 signaling pathway of colonic tissue in mice under heat stress. A study found that oral administration of terpinen4-ol helped against mortality and intestinal inflammation in a mouse model of acute colitis induced by heat stress (40 °C per day for 4 h) exposed for 14 consecutive days. The mice were divided into five groups including control, heat stress, terpinen4-ol low dose (TER LD: 5 mg/kg), medium dose (TER MD: 10 mg/kg), and high dose (TER HD: 20 mg/kg) group. Our study showed that the heat-stress terpinen4-ol group had improved body weight, colon length, and organ index, the number of white blood cells, lymphocytes, and neutrophils in the blood as compared to the heat stress group. In addition, results showed that heat stress upregulated the expression of TLR4, p65, TNF-α, and IL-10. While, in mice receiving the oral administration of terpinen4-ol, the production of TNF-α, IL-10, TLR4, and p65 was suppressed on day 1, 7, and 14 of heat stress. In addition Claudin-2, Occludin mRNA levels were upregulated in mice receiving terpinen4-ol on day 1, 7, and 14 of heat stress. Furthermore, the IL-6, IL-10, TNF-α serum levels were also upregulated in mice under heat stress, but in mice receiving the oral administration of terpinen4-ol, the IL-6, IL-10, TNF-α level was down-regulated on day 1, 7, and 14 of heat stress. Histomorphological examination found that as compared to the control group, the muscle layer thickness and villi height of mice in the heat stress group were significantly reduced, while the changes of the above indicators in the terpinene4-ol groups were improved than those in the heat stress group. In conclusion, the terpinen4-ol has a protective effect on colonic tissue damage induced by heat stress.

Effects of Dietary Supplementation of Algae-Derived Polysaccharides on Morphology, Tight Junctions, Antioxidant Capacity and Immune Response of Duodenum in Broilers under Heat Stress.

Simple SummaryHeat stress (HS) has become a great challenge for poultry production in tropical and subtropical regions. HS results in the intestinal dysfunction of broilers, which seriously affects their productivity. Our previous study suggested that dietary supplementation of algae-derived polysaccharides (ADP) could promote the intestinal barrier function in broilers, but the effect of dietary ADP supplementation on the intestinal health of broilers under HS remains unclear. The present study showed that dietary ADP supplementation improved the duodenal tight junction expression of broilers under HS, and found that dietary ADP mitigated HS-induced oxidative stress and inflammation response by regulating Nrf2 and NF-κB signaling pathways. These findings reveal the potential application of ADP as an HS-alleviating agent to maintain gut health in broilers.To evaluate the ameliorative effect of algae-derived polysaccharide (ADP) supplementation on duodenal injury caused by heat stress (HS) in broilers, a total of 144 male yellow-feathered broilers (56-day-old) were randomly allocated into three groups: The TN group (thermoneutral zone, broilers were raised at 23.6 ± 1.8 °C); HS group (heat stress, broilers were exposed to 33.2 ± 1.5 °C 10 h/day, 8:00 a.m.–18:00 p.m., the temperature in the remaining period was consistent with the TN group); HSA group (heat-stressed broilers were fed with ADP supplemented diet at 1000 mg/kg). There were six replications in each treatment, and eight broilers in each replication. The feeding trial lasted four weeks. The results showed that dietary ADP supplementation tended to increase the villus height (p = 0.077) and villus width (p = 0.062), and decrease the apoptosis rate (p = 0.081) in the duodenum of broilers under HS. Furthermore, dietary ADP increased the relative mRNA and protein (based on immunofluorescence) expression levels of occludin and zonula occludens-1 (ZO-1) in the duodenum of broilers under HS (p < 0.05). In addition, dietary ADP enhanced the total antioxidation capacity (T-AOC) and activity of glutathione-S transferase (GST), while reducing the malondialdehyde (MDA) concentration of the duodenum in broilers under HS (p < 0.05). Moreover, dietary ADP supplementation upregulated the duodenal nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), glutathione peroxidase 1 (GPx1) and glutathione S-transferase theta 1 (GSTT1) mRNA expression levels in heat-stressed broilers (p < 0.05). Furthermore, compared with the HS group, broilers fed with an ADP supplemented diet had a higher relative mRNA expression of inhibitor kappa B alpha (IκBα) (p < 0.05) and a lower relative mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the duodenum (p < 0.05). In summary, dietary ADP supplementation had an ameliorative effect on HS-induced impairment of tight junctions, antioxidant capacity and the immune response of the duodenum in broilers. These beneficial effects might be related to the modulation of Nrf2 and NF-κB signaling pathways.

MD2 blockage prevents the migration and invasion of hepatocellular carcinoma cells via inhibition of the EGFR signaling pathway.

The toll-like receptor (TLR) is an emerging signaling pathway in tumor invasion and metastasis. The activation of TLRs requires specific accessory proteins, such as the small secreted glycoprotein myeloid differentiation protein 2 (MD2), which contributes to ligand responsiveness. However, the role of MD2 in tumorigenesis and metastasis has rarely been reported. This study aimed to investigate the effects and underlying mechanisms of MD2 on the proliferation, migration, and invasion of hepatocellular carcinoma (HCC). Cell counting kit 8 (CCK8), cell colony formation, wound healing, and transwell assays were conducted to determine cell viability, proliferation, migration, and invasion, respectively. Quantitative real-time PCR (qRT-PCR) was performed to assess the expression of MD2 in HCC cell lines and human normal liver cell lines as well as the silencing efficiency of MD2 blockage. Western blot and qRT-PCR assays were performed to detect the protein and mRNA expression levels of epithelial mesenchymal transformation (EMT) markers and epidermal growth factor receptor (EGFR) signaling molecules. MD2 was highly expressed in HCC tissues and cell lines. High expression of MD2 was associated with poor prognosis of HCC patients. In addition, MD2 silencing slightly inhibited the proliferation of HepG2 and HCCLM3, and significantly suppressed cell migration and invasion. Furthermore, MD2 blockage could distinctly prevent the EMT process by increasing the protein and mRNA levels of E-cadherin and Occludin, and decreasing the levels of Vimentin, N-cadherin, and Snail. Finally, the phosphorylation level of EGFR as well as its downstream molecular Src, Akt, I-κBα, and p65 were downregulated in HCC cells with MD2 silencing. Our findings suggest that high expression of MD2 may affect the EMT, migration, and invasion via modulation of the EGFR pathway in HCC cells.

Effects of novel microecologics combined with traditional Chinese medicine and probiotics on growth performance and health of broilers

In this study, we prepared a kind of novel microecologics, namely Chinese medicine–probiotic compound microecological preparation (CPCMP), which is composed of 5 traditional Chinese medicine herbs (Galla Chinensis, Andrographis paniculata, Arctii Fructus, Glycyrrhizae Radix, and Schizonepeta tenuifolia) fermented by Aspergillus niger and a kind of compound probiotics (Lactobacillus plantarum A37 and L. plantarum MIII). The effects of the CPCMP in broilers on growth performance, serum parameters, immune function, and intestinal health were investigated. A total of 450 one-day-old male Arbor Acres broilers were randomly divided into 6 treatment groups with 5 replicates, 15 birds per replicate. Treatments consisted of: blank control, CPCMP, positive control, commercial CPCMP, traditional Chinese medicine, and probiotics groups, which were birds fed with basal diet supplemented with no extra additives, 0.2% CPCMP, 0.0035% chlortetracycline, 0.2% commercially available CPCMP, 0.2% fermented traditional Chinese medicines, and 0.2% compound probiotics, respectively. CPCMP obviously increased the average body weight and average daily gain (P < 0.05, compared with any other group) and decreased the feed:gain ratio of broilers (P < 0.05, compared with the blank control, commercial CPCMP, traditional Chinese medicine, or probiotics group). Moreover, it significantly increased glutathione peroxidase and secretory immunoglobulin A levels and spleen/bursa indices (P < 0.05 for all, compared with the blank control, commercial CPCMP, traditional Chinese medicine, or probiotics group). Villus heights in duodenum, jejunum, and ileum were also elevated by CPCMP treatment (P < 0.05, compared with any other group). Furthermore, CPCMP substantially increased jejunal mRNA levels of occludin and zonula occludens-1 (P < 0.05, compared with the blank control, positive control, or probiotics group) and facilitated the growth and colonization of beneficial cecal bacteria, such as Olsenella, Barnesiella, and Lactobacillus. Overall results show that the CPCMP prepared in our work contributes to improving growth performance, serum parameters, immune function, and intestinal health of broilers and exerts synergistic effects of traditional Chinese medicines and probiotics to some extent. Our findings suggest that CPCMP is a promising antibiotic substitute in the livestock and poultry industry in the future.

Gastrointestinal Digestion of a Grape Pomace Extract: Impact on Intestinal Barrier Permeability and Interaction with Gut Microbiome

Grape pomace (GP) is a winemaking by-product rich in polyphenols and fibre. Supplementation with GP extracts has shown potential benefits against oxidative stress- and inflammation-related pathologies. As a new nutritional target, this paper explores the impact of the ingestion of a grape pomace extract on intestinal barrier functionality. A GP extract was sequentially subjected to gastrointestinal and colonic digestion using the dynamic gastrointestinal simulator (simgi®). This generated two simulated fluids: intestinal-digested extract (IDE) and colonic-digested extract (CDE). The effects of these two fluids on paracellular permeability and the expression of tight junction (TJ) proteins (i.e., zonula occludens-1 (ZO-1) and occludin) were assessed in Caco-2-cell monolayers grown in Transwell® inserts. The IDE fluid significantly (p < 0.001) reduced the paracellular transport of FITC-dextran with respect to the control, whereas no significant differences (p > 0.05) were found for CDE, which could be due, at least partially, to the pro-leaky effect of the colonic digestion medium. Accordant slight increases in the mRNA levels of both ZO-1 and occludin were observed for IDE, but without statistical significance. Additionally, the colonic fermentation of the GP extract promoted the production of short-chain fatty acids (SCFA) and phenolic metabolites and led to changes in the relative abundance of some bacteria that might affect paracellular permeability. Overall, this paper reports first trends about the effects of grape pomace extracts on intestinal permeability that would require further confirmation in future experiments.

Effect of replacing fish meal by yeast hydrolysate on growth and intestinal function of| juvenile Jian carp (Cyprinus carpio var. jian)

This experiment was performed to investigate the effects of replacing fish meal in the diet of Cyprinus carpio var. jian (average weight 19.44±0.06 g) by yeast hydrolysate (YH), on growth, intestinal histology and function. Six hundred fish were assigned into five groups and fed with five isonitrogenous and isocaloric diets replacing fishmeal by 0% (G1), 1% (G2), 3% (G3), 5% (G4) and 7% (G5) YH. YH supplementation at 3% level significantly increased average body weight, daily growth index, feed intake, condition factor, specific growth rate, intestinal villi length and digestive and brush-border enzymes activity compared to the control group (p&lt;0.05). Moreover, YH supplementation significantly increased (p&lt;0.05) intestinal lipase, γ-GT, Na+/K+-ATPase and AKP expression levels. Intestinal Claudin-7 and Occludin mRNA levels in fish of dietary group G5 were significantly higher (p&lt;0.05) than that in the control group. Replacing fish meal with 3% YH increased growth performance, intestinal digestion and absorption, as well as improved intestinal villi length without triggering any negative effects on intestinal tight junction structure. Keywords: Enzyme activities, Growth, Intestinal histology, Jian carp, Tight junction structure, Yeast hydrolysate