TAK-242 ameliorates DSS-induced colitis by regulating the gut microbiota and the JAK2/STAT3 signaling pathway

Tetrastigma hemsleyanum polysaccharide ameliorated ulcerative colitis by remodeling intestinal mucosal barrier function via regulating the SOCS1/JAK2/STAT3 pathway

Ulcerative colitis (UC) is characterized by a chronic and protracted course and often leads to a poor prognosis. Patients with this condition often experience postoperative complications, further complicating the management of their condition. Tetrastigma hemsleyanum polysaccharide (THP) has demonstrated considerable potential as a treatment for inflammatory bowel disease. However, its underlying mechanism in the treatment of UC remains unclear. This study systematically and comprehensively investigated the effects of THP on dextran sulfate-induced UC mice and illustrated its specific mechanism of action. The colon and spleen in UC mice were restored after THP treatment. The levels of key markers, such as secretory immunoglobulin A, β-defensin, and mucin-2 were increased, collagen deposition and epithelial cell apoptosis were decreased. Notably, THP administration led to increased levels of Ki67 and tight junction proteins in colon tissue and reduced colon tissue permeability. THP contributed to the restored balance of intestinal flora. Furthermore, THP downregulated the expressions of the proinflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-17 and promoted those of the regulatory factors forkhead box protein P3. It also exerted anti-inflammatory effects by promoting suppressor of cytokine signaling (SOCS1) expression and inhibiting the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Our results demonstrated that THP had an efficacy comparable to that of JAK inhibitor in treating UC. In addition, THP might play a role in UC therapy through modulation of the SOCS1/JAK2/STAT3 signaling pathway and remodeling of the intestinal mucosal barrier.

Embryo injected with Ochratoxin A induced jejunum injury in ducklings by activating the TLR4 signaling pathway: Involvement of intestinal microbiota

Ochratoxin A (OTA) is a common mycotoxin that causes intestinal injury in humans and various animal species. OTA may lead to intestinal injury in offspring due to the maternal effect. The aim of this study was to investigate the mechanism of embryo injected with OTA induced jejunum injury in ducklings. The results showed that OTA disrupted the jejunum tight junctions in hatching ducklings, and promoted the secretion of inflammatory cytokines. And this inflammatory response was caused by the activation of the TLR4 signaling pathway. Moreover, embryo injected with OTA could cause damage to the intestinal barrier in 21-day-old ducks, characterized by shortened villi, crypt hyperplasia, disrupted intestinal tight junctions, increased level of LPS in the jejunum, activation of the TLR4 signaling pathway, and increased levels of pro-inflammatory cytokines. Meanwhile, OTA induced oxidative stress in the jejunum. And dysbiosis of gut microbiota was mainly characterized by an increased the relative abundance of Bacteroides, Megamonas, Fournierella, and decreased the relative abundance of Alistipes and Weissella. Interestingly, embryo injected with OTA did not induce these changes in the jejunum of antibiotics-treated 21-day-old ducks. In conclusion, embryo injected with OTA induced jejunum injury in ducklings by activating the TLR4 signaling pathway, which involvement of intestinal microbiota.

The effect and mechanism of palmar ginseng in type 2 diabetic cognitive impairment

Objective

To investigate the therapeutic effect of palmar ginseng on cognitive impairment in rats with type 2 diabetes, evaluate its neuroprotective effects, and explore its underlying mechanism.

Methods

A rat model of diabetic cognitive impairment (DCI) was established by feeding with homemade high-fat, high-sugar chow combined with intraperitoneal injection of streptozotocin (STZ). Rats were continually fed high-fat, high-sugar chow for 60 days after successful induction of the model. Palmar ginseng was administered via gavage. The Morris test was performed after 30 days of treatment. At the end of the test, blood samples were collected, and the activities of IL-6, IL-10, TNF-α, and IL-1β in rat serum. Pathological changes in hippocampal tissues were observed by Haematoxylin-eosin (HE) staining of the brain, activation of microglia in hippocampal tissues was detected by immunofluorescence, and the expression of PI3K/Akt/mTOR and JAK2/STAT3 proteins in the hippocampal tissues by Western blot.

Results

During the administration of palmar Ginseng, the body weight and blood glucose levels of DCI rats were measured weekly, with results showing that Palmar Ginseng effectively reduced blood glucose levels and body weight of DCI rats. Behavioural tests in the water maze indicated that palmar ginseng effectively improved the learning and memory ability of DCI rats. HE and immunofluorescence staining showed that palmar ginseng improved DCI in rats, ameliorated hippocampal neuronal damage, and improved microglial activation. ELISA showed that palmar ginseng significantly reduced the expression of pro-inflammatory factors in the serum of DCI rats. Increased expression of anti-inflammatory factors was observed, and Western blot analysis showed that Palmar Ginseng regulated PI3K/Akt/mTOR and JAK2/STAT3 protein expression, promoted the phosphorylation of PI3K/Akt/mTOR, and inhibited JAK2/STAT3 protein phosphorylation in rat hippocampal tissues as well as in BV2 cells.

Conclusions

Palmar ginseng may improve the onset and development of DCI by upregulating the phosphorylation of proteins in the PI3K/Akt/mTOR pathway.

The protective role of phlorizin against lipopolysaccharide-induced acute orchitis in mice associated with changes in gut microbiota composition

Objective

Orchitis is a common reproductive disease of male animals, which has serious implications to human and animal reproduction. Additionally, phlorizin (PHN), a common polyphenol in apples and strawberries, has a variety of biological activities, including antioxidant, anti-inflammatory, anti-diabetic, and anti-aging activities. We aimed to determine the protective effects and potential mechanisms of PHN in lipopolysaccharide (LPS)-induced acute orchitis in mice.

Method

After 21 days of PHN pretreatment, mice were injected with LPS to induce testicular inflammation, and then the changes of testicular tissue structure, expression of inflammatory factors, testosterone level, expression of testosterone-related genes, adhesion gene and protein expression were detected, and the structural changes in the intestinal flora after PHN treatment were further detected by 16SRNA.

Result

Our results demonstrated that PHN treatment reduced LPS-induced testicular injury and body and testicular weight losses. The mRNA expression levels of pro-inflammatory cytokines-related genes and antioxidant enzyme activity were also decreased and elevated, respectively, by PHN administration; however, PHN treatment also reduced the LPS-induced decrease in testosterone levels in the testes. Additionally, further studies found that PHN increased the expression of marker proteins zonula occludens-1 (ZO-1) and occludin associated with the blood testosterone barrier compared with that in LPS treatment groups. To further examine the potential mechanisms of the protective effect of PHN on LPS-induced testicular injury, we compared the differences of gut microbiota compositions between the 100 mg/kg PHN treatment group and the control group using 16SRNA. Metagenomic analyses indicated that the abundances of Bacteroidetes, Muribaculaceae, Lactobacillaceae, uncultured bacterium f Muribaculaceae, and Lactobacillus in the PHN treatment group improved, while potential microbes that can induce intestinal diseases, including Verrucomicrobia, Epsilonbacteraeota, Akkermansiaceae, and Akkermansia decreased in the PHN treatment group.

Conclusion

Our results indicate that PHN pretreatment might alleviate orchitis by altering the composition of gut microflora, which may provide a reference for reducing the occurrence of acute orchitis in male animals.

Resatorvid (TAK-242) Ameliorates Ulcerative Colitis by Modulating Macrophage Polarization and T Helper Cell Balance via TLR4/JAK2/STAT3 Signaling Pathway

Resatorvid (TAK-242), a specific inhibitor of Toll-like receptor-4 (TLR4), has attracted attention for its anti-inflammatory properties. Despite this, few studies have evaluated its effects on ulcerative colitis (UC). This study aimed to investigate the effects of TAK-242 on macrophage polarization and T helper cell balance and the mechanism by which it alleviates UC. Our findings indicated that TLR4 expression was elevated in patients with UC, a mouse model of UC, and HT29 cells undergoing an inflammatory response. TAK‑242 treatment reduced apoptosis in TNF-α and LPS-stimulated HT29 cells and alleviated symptoms of dextran sulfate sodium (DSS)‑induced colitis in vivo. TAK‑242 downregulated TLR4 expression and decreased the secretion of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β while enhancing IL-10 production. TAK-242 also reduced M1 macrophage polarization and diminished Th1 and Th17 cell infiltration while increasing Th2 cell infiltration and M2 macrophage polarization both in vitro and in vivo. Mechanistically, TAK-242 inhibited the JAK2/STAT3 signaling pathway, an important regulator of macrophage polarization and T helper cell balance. Furthermore, the in vivo and in vitro effects of TAK-242 were partially negated by the administration of the JAK2/STAT3 antagonist AG490, suggesting that TAK-242 inhibits the JAK2/STAT3 pathway to exert its biological activities. Taken together, this study underscores TAK-242 as a promising anti-UC agent, functioning by modulating macrophage polarization and T helper cell balance via the TLR4/JAK2/STAT3 signaling pathway.

HOXD10 regulates intestinal permeability and inhibits inflammation of dextran sulfate sodium-induced ulcerative colitis through the inactivation of the Rho/ROCK/MMPs axis

Ulcerative colitis (UC) has been identified as a severe inflammatory disease with significantly increased incidence across the world. The detailed role and mechanism of HOXD10 in UC remain unclear. In present study, we found that HOXD10 was lowly expressed in UC samples and was notably decreased by dextran sulfate sodium (DSS) administration. Overexpression of HOXD10 dramatically ameliorated DSS-induced UC symptoms, including the loss of weight, increased disease activity index values, and the shortened colon length. Additionally, terminal-deoxynucleoitidyl transferase mediated nick end labeling and immunohistochemistry staining assays showed that HOXD10 overexpression suppressed cell apoptosis and facilitated proliferation of colon tissues after DSS treatment. Moreover, HOXD10 overexpression obviously suppressed DSS-triggered inflammatory response by decreasing the expression level of TNF-α, IL-6, and IL-1β. Furthermore, overexpression of HOXD10 effectively restored the intestinal permeability, thereby alleviating DSS-induced intestinal barrier dysfunction. Mechanistic study demonstrated that HOXD10 significantly reduced the activities of Rho/ROCK/MMPs axis in colon tissues of mice with UC. In conclusion, this study revealed that HOXD10 might effectively improve DSS-induced UC symptoms by suppressing the activation of Rho/ROCK/MMPs pathway.

Gut microbiota-derived 5-hydroxyindoleacetic acid from pumpkin polysaccharides supplementation alleviates colitis via MAPKs-PPARγ/NF-κB inhibition

Polysaccharides from Pumpkin (Cucurbita moschata Duchesne) (PPs) have many pharmacological activities, including anti-oxidant, immune, and intestinal microbiota regulation. These activities have provided some reminders of its potential therapeutic effect on ulcerative colitis (UC), but this has not yet been confirmed. This study preliminarily confirmed its significant anti-UC activity superior to Salicylazosulfapyridine. The average molecular weight of PPs was 3.10 × 105 Da, and PPs mainly comprised Mannose, Rhamnose, Galacturonic acid, Galactosamine, Glucose, and Xylose with molar ratios of 1.58:3.51:34.54:1.00:3.25:3.02. PPs (50, 100 mg/kg) could significantly resist dextran sodium sulfate induced UC on C57BL/6 mice by improving gut microbiota dysbiosis, such as the changes of relative abundance of Bacteroides, Culturomica, Mucispirillum, Escherichia-Shigella, Alistipes and Helicobacter. PPs also reverse the abnormal inflammatory reaction, including abnormal level changes of TNF-α, IFN-γ, IL-1β, IL-4, IL-6, IL-10, and IL-18. Metabolomic profiling showed that PPs supplementation resulted in the participation of PPAR and MAPK pathways, as well as the increase of 5-hydroxyindole acetic acid (5-HIAA) level. 5-HIAA also exhibited individual and synergistic anti-UC activities in vivo. Furthermore, combination of PPs and 5-HIAA could also elevate the levels of PPARγ in nuclear and inhibit MAPK/NF-ĸB pathway in the colon. This study revealed that PPs and endogenous metabolite 5-HIAA might be developed to treat UC.

Peripheral inflammation triggering central anxiety through the hippocampal glutamate metabolized receptor 1

AIMS

This study aimed to investigate the relationship between ulcerative colitis (UC) and anxiety and explore its central mechanisms using colitis mice.

METHODS

Anxiety-like behavior was assessed in mice induced by 3% dextran sodium sulfate (DSS) using the elevated plus maze and open-field test. The spatial transcriptome of the hippocampus was analyzed to assess the distribution of excitatory and inhibitory synapses, and Toll-like receptor 4 (TLR4) inhibitor TAK-242 (10 mg/kg) and AAV virus interference were used to examine the role of peripheral inflammation and central molecules such as Glutamate Receptor Metabotropic 1 (GRM1) in mediating anxiety behavior in colitis mice.

RESULTS

DSS-induced colitis increased anxiety-like behaviors, which was reduced by TAK-242. Spatial transcriptome analysis of the hippocampus showed an excitatory-inhibitory imbalance mediated by glutamatergic synapses, and GRM1 in hippocampus was identified as a critical mediator of anxiety behavior in colitis mice via differential gene screening and AAV virus interference.

CONCLUSION

Our work suggests that the hippocampus plays an important role in brain anxiety caused by peripheral inflammation, and over-excitation of hippocampal glutamate synapses by GRM1 activation induces anxiety-like behavior in colitis mice. These findings provide new insights into the central mechanisms underlying anxiety in UC and may contribute to the development of novel therapeutic strategies for UC-associated anxiety.

The effect and mechanism of Huangqin-Baishao herb pair in the treatment of dextran sulfate sodium-induced ulcerative colitis

Background

The haungqing (Scutellariae Radix) and baishao (Paeoniae Radix Alba) herb pair (HBHP) is a common prescribed herbal formula or is added to other traditional Chinese medicine (TCM) prescriptions to treat ulcerative colitis (UC). However, the underlying mechanism is unclear.

Purpose

Elucidate the efficacy and potential mechanism of HBHP against UC.

Methods

First, The UC model of mice induced by dextran sulfate sodium (DSS) was established. The mice were randomly divided into Control group, DSS group, SASP group (390 mg/kg), and HPHP group (1.95 g/kg), with 8 mice per group. Drugs were administrated via oral gavage for 7 days. Then, Disease activity index (DAI), length of the colon, histopathology, and changes in inflammatory cytokines in colonic tissues were analyzed to assess the effect of HBHP on UC. Besides, Network pharmacology was applied to identify the active compounds, core targets of HBHP in the treatment of UC, and the corresponding signaling pathways to explore the underlying mechanisms. Finally, Western blot (WB), immunohistochemistry (IHC) and molecular docking were performed to validate the results.

Results

HBHP significantly reduced DAI score and decreased colon length shortening in DSS-induced UC mice. The administration of HBHP was able to effectively alleviated mucosal ulceration and epithelial destruction. In addition, HBHP treatment obviously - reduced the expressions of TNF-α, IL-6, and IL-1β in colon tissues (p < 0.05 or p < 0.01). 35 bioactive compounds and 290 HBHP targets related to UC were obtained. Among them 3 key active compounds (baicalein, panicolin, and norwogonin) with higher degree values in the drug-compound-target network and 21 hub genes (STAT3, JAK2, SRC, AKT1, PIK3CA, and VEGFA, etc.) were identified. KEGG enrichment analysis suggested that HBHP's mechanisms mainly involve the JAK-STAT pathway. Abnormal activation of JAK/STAT signaling is believed to be involved in the pathogeneses of UC. Notably, WB and IHC showed that HBHP significantly down-regulated the protein expression levels of p-JAK2 (p < 0.05) and p-STAT3 (p < 0.05 or p < 0.01). JAK2 and STAT3 might be core targets for the action of HBHP; this possibility was also supported by molecular docking.

Conclusions

HBHP could alleviate DSS-induced UC, reduce tissue inflammation, and its mechanism might primarily be achieved by inhibiting JAK2/STAT3 signaling pathway. Meanwhile, our work revealed that network pharmacology combined with experimental verification is a cogent means of studying the mechanism of TCM.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

Adverse effect of oxidized cholesterol exposure on colitis is mediated by modulation of gut microbiota

Both cholesterol and oxidized cholesterol (OXC) are present in human diets. The incidence of inflammatory bowel diseases (IBDs) is increasing in the world. The present study was to investigate the mechanism by which OXC promotes colitis using C57BL/6 mice as a model. Results shown that more severe colitis was developed in OXC-treated mice with the administration of dextran sulfate sodium (DSS) in water. Direct effects of short-term OXC exposure on gut barrier or inflammation were not observed in healthy mice. However, OXC exposure could cause gut microbiota dysbiosis with a decrease in the relative abundance of short-train fatty acids (SCFAs)-producing bacteria (Lachnospiraceae_NK4A136_group and Blautia) and an increase in the abundance of some potential harmful bacteria (Bacteroides). OXC-induced symptoms of colitis were eliminated when mice were administered with antibiotic cocktails, indicating the promoting effect of OXC on DSS-induced colitis was mediated by its effect on gut microbiota. Moreover, bacteria-depleted mice colonized with gut microbiome from OXC-DSS-exposed mice exhibited a severe colitis, further proving the gut dysbiosis caused by OXC exposure was the culprit in exacerbating the colitis. It was concluded that dietary OXC exposure increased the susceptibility of colitis in mice by causing gut microbiota dysbiosis.

Daphnetin attenuates intestinal inflammation, oxidative stress, and apoptosis in ulcerative colitis via inhibiting REG3A-dependent JAK2/STAT3 signaling pathway

Daphnetin is a natural coumarin compound with anti-inflammatory, anti-oxidant, and anti-apoptotic effects, which has been previously demonstrated to ameliorate DSS-induced ulcerative colitis (UC). However, the molecular mechanism involved in the daphnetin-mediated pathological process of UC remains unclarified. The current study used DSS-induced mice and LPS-challenged Caco-2 cells as UC models. Bodyweight, disease activity index (DAI) score, and colon length were used to evaluate the severity of colitis. The histological changes in colon tissues were observed using H&E and PAS staining. Protein levels were detected by western blot. The malondialdehyde (MDA) and superoxide dismutase (SOD) activities were used to assess oxidative stress. Inflammatory responses were evaluated by detecting the levels of inflammatory cytokines (IFN-r, IL-1β, IL-6, and TNF-α) using flow cytometry. CCK-8 and TUNEL assay were employed to determine cell growth and cell death, respectively. The results showed that daphnetin could ameliorate the severity of colitis and attenuate the damage to intestinal structure in DSS-induced mice. Compared with the DSS group, the expression of ZO-1, occludin, and anti-apoptotic protein (BCL-2) was increased while the level of pro-apoptotic proteins (Bax and cleaved caspase 3) was decreased in DSS + daphnetin group. The activity of MDA and SOD, as well as the levels of inflammatory cytokines were substantially suppressed by daphnetin. In consistency, in vitro assays indicated that daphnetin protected Caco-2 cells from LPS-stimulated viability impairment, apoptosis, oxidative stress, and inflammation. Furthermore, daphnetin suppressed the activity of JAK2/STAT signaling in LPS-induced Caco-2 cells in a REG3A-dependent manner. REG3A overexpression abated the ameliorative effects of daphnetin while JAK2/STAT signaling inhibition functioned synergically with daphnetin in LPS-stimulated Caco-2 cells. Collectively, this study deepened the understanding of the therapeutic effects of daphnetin on UC and uncovered for the first time that daphnetin functioned through REG3A-activated JAK2/STAT3 signaling in UC, which may provide novel insights for the treatment of UC.

The alleviating effect and mechanism of GLP-1 on ulcerative colitis

Ulcerative Colitis (UC) is a major type of chronic inflammatory bowel disease of the colonic mucosa and exhibits progressive morbidity. The incidence and prevalence of UC is increasing worldwide. The global burden of UC, which can substantially reduce quality of life, is clearly increasing. These data highlight the need for research into prevention of UC and innovations in health-care systems to manage this complex and costly disease. Glucagon-like peptide-1 (GLP-1), a new antidiabetic drug, is used to treat Type 2 Diabetes Mellitus (T2DM). Accumulating evidence suggests that GLP-1 has additional roles other than glucose-lowering effects. Despite the abundance of GLP-1 research, studies in UC have been less consistent, especially body weight; for example, body weight, colon length, colon injury score, intestinal microbiota, remain to be studied further. To date, the molecular mechanism of the protective effect of GLP-1 on UC remains obscure. The effect of GLP-1 was studied by using a dextran sulfate sodium (DSS)-induced colitic mice and lipopolysaccharide (LPS) treated RAW264.7 cells (macrophage cell line) under in vivo and in vitro conditions, respectively. Our results indicate that GLP-1 significantly relieves ulcerative colitis as it represses the production of proinflammatory mediators. In addition, GLP-1 blocks the activation of the protein kinase B (AKT)/nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. GLP-1 also alleviates DSS-induced injury to the intestinal mucosa and dysbiosis of gut microbiota. Altogether, GLP-1 has protection effect on ulcerative colitis. Thus, GLP-1 can be considered as a potential therapeutic candidate for the treatment of UC.

LncRNA PVT1 promotes bladder cancer progression by forming a positive feedback loop with STAT5B

BACKGROUND

Plasmacytoma Variant Translocation 1 (LncRNA PVT1) and signal transducer and activator of transcription 5B (STAT5B) play important roles in various cancers, but their interaction in bladder cancer (BC) remains unclear.

PURPOSE

We aimed to explore the interaction between lncRNA PVT1 and STAT5B in BC tumorigenesis and find potential drugs for BC.

METHODS

The association of the expression of lncRNA PVT1 and STAT5B to the prognosis of BC patients was evaluated via bioinformatic analysis. Loss- and gain-of-function assays were performed to determine the biological functions of lncRNA PVT1 and STAT5B. Quantitative real time polymerase chain reaction, Western blot, immunohistochemistry, and immunofluorescence were used to detect lncRNA PVT1 and STAT5B expression. Fluorescence in situ hybridization, RNA pull-down and RNA immunoprecipitation assays were conducted to determine the regulatory effect of lncRNA PVT1 on STAT5B. The transcriptional effect of STAT5B on lncRNA PVT1 gene was determined using luciferase reporter assay, chromatin immunoprecipitation and DNA-affinity precipitation assays. Connectivity Map analysis was used to screen anticancer drugs.

RESULTS

LncRNA PVT1 and STAT5B enhance the expression of each other and promote the malignant phenotypes in BC, including cell viability and invasion. lncRNA PVT1 stabilizes STAT5B by decreasing ubiquitination, enhances STAT5B phosphorylation, and promotes the translocation to the nucleus of STAT5B to trigger further carcinogenesis activities. In the nucleus, STAT5B activates the transcription of lncRNA PVT1 by binding directly to its promoter region, leading to a positive feedback. Tanespimycin effectively abated the oncogenic effect.

CONCLUSIONS

We first identified the lncRNA PVT1/STAT5B positive feedback loop for bladder carcinogenesis, and found a potentially effective drug for BC.

Effects of lactic acid bacteria isolated from Tibetan chickens on the growth performance and gut microbiota of broiler

Lactic acid bacteria (LAB) are organic supplements that have several advantages for the health of the host. Tibetan chickens are an ancient breed, which evolve unique gut microbiota due to their adaptation to the hypoxic environment of high altitude. However, knowledge of LAB isolated from Tibetan chickens is very limited. Thus, the purpose of this study was to assess the probiotic properties of Lactobacillus Plantarum (LP1), Weissella criteria (WT1), and Pediococcus pentosaceus (PT2) isolated from Tibetan chickens and investigate their effects on growth performance, immunoregulation and intestinal microbiome in broiler chickens. Growth performance, serum biochemical analysis, real-time PCR, and 16S rRNA sequencing were performed to study the probiotic effects of LP1, WT1, and PT2 in broiler chickens. Results showed that LP1, WT1 and PT2 were excellent inhibitors against Escherichia coli (E. coli ATCC25922), meanwhile, LP1, WT1, and PT2 significantly increased weekly weight gain, villus height, antioxidant ability and gut microbiota diversity indexes in broilers. In addition, LP1 and PT2 increased the relative abundance of Lactobacillus and decreased Desulfovibrio in comparison with T1 (control group). Additionally, oral LAB can reduce cholesterol and regulate the expression of tight junction genes in broiler chickens, suggesting that LAB can improve the integrity of the cecal barrier and immune response. In conclusion, LAB improved the growth performance, gut barrier health, intestinal flora balance and immune protection of broiler chickens. Our findings revealed the uniqueness of LAB isolated from Tibetan chickens and its potential as a probiotic additive in poultry field.

Engineering fucoxanthin-loaded probiotics' membrane vesicles for the dietary intervention of colitis

Extracellular vesicles (EVs) are very attractive as carriers of active components due to their good immunological and their ability to penetrate the physiological barrier that synthetic delivery carriers cannot penetrate. However, the low secretion capacity of EVs limited its widespread adoption, let alone the lower yield of EVs loaded with active components. Here, we report a large-scale engineering preparation strategy of synthetic probiotic membrane vesicles for encapsulating fucoxanthin (FX-MVs), an intervention for colitis. Compared with the EVs naturally secreted by probiotics, the engineering membrane vesicles showed a 150-fold yield and richer protein. Moreover, FX-MVs improved the gastrointestinal stability of fucoxanthin and inhibited H₂O₂-induced oxidative damage by scavenging free radicals effectively (p < 0.05). The in vivo results showed that FX-MVs could promote the polarization of macrophages to M2 type, prevent the injury and shortening of colon tissue (p < 0.05), and improve the colonic inflammatory response. Consistently, proinflammatory cytokines were effectively suppressed after FX-MVs treatment (p < 0.05). Unexpectedly, such engineering FX-MVs could also reshape the gut microbiota communities and improve the abundance of short-chain fatty acids in the colon. This study lays a foundation for developing dietary interventions using natural foods to treat intestinal-related diseases.

Structural insight and analysis of TLR4 interactions with IAXO-102, TAK-242 and SN-38: an in silico approach

Introduction

Toll-like receptor 4 (TLR4) has attracted interest due to its role in chemotherapy-induced gastrointestinal inflammation. This structural study aimed to provide in silico rational of the recognition and potential binding of TLR4 ligands IAXO-102, TAK-242, and SN-38 (the toxic metabolite of the chemotherapeutic irinotecan hydrochloride), which could contribute to rationale development of therapeutic anti-inflammation drugs targeting TLR4 in the gastrointestinal tract.

Methods

In silico docking was performed between the human TLR4-MD-2 complex and ligands (IAXO-102, TAK-242, SN-38) using Autodock Vina, setting the docking grids to cover either the upper or the lower bound of TLR4. The conformation having the lowest binding energy value (kcal/mol) was processed for post-hoc analysis of the best-fit model. Hydrogen bonding was calculated by using ChimeraX.

Results

Binding energies of IAXO-102, TAK-242 and SN-38 at the upper bound of TLR4-MD-2 ranged between - 3.8 and - 3.1, - 6.9 and - 6.3, and - 9.0 and - 7.0, respectively. Binding energies of IAXO-102, TAK-242 and SN-38 at the lower bound ranged between - 3.9 and - 3.5, - 6.5 and - 5.8, and - 8.2 and - 6.8, respectively. Hydrogen bonding at the upper bound of TLR4/MD-2 with IAXO-102, TAK-242 and SN-38 was to aspartic acid 70, cysteine 133 and serine 120, respectively. Hydrogen bonding at the lower bound of TLR4-MD-2 with IAXO-102, TAK-242 and SN-38 was to serine 528, glycine 480 and glutamine 510, respectively.

Conclusion

The in silico rational presented here supports further investigation of the binding activity of IAXO-102 and TAK-242 for their potential application in the prevention of gastrointestinal inflammation caused by SN-38.

In vivo evidence of the prevents DSS-induced colitis of Lactiplantibacillus plantarum L15

Ulcerative colitis (UC) is challenging to treat and severely impacts patients and families. A previous study reported immunomodulatory and reduction of pro-inflammatory properties for the Lactiplantibacillus plantarum L15. This study aimed to analyze the preventive properties and mechanistic actions in an in vivo colitis model. The histopathological alteration, inflammation cytokines, and intestinal barrier function were analyzed. Subsequently, the cecal gut microbiota contents and products from different groups were detected. Finally, gene expressions related to the NF-κB signaling process were evaluated. L. plantarum L15 significantly decreased disease activity index (DAI), myeloperoxidase activity (MPO), pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) level, and increased weight change, colon length, and production of inflammation-suppressing cytokines. Furthermore, this strain supplementation substantially increased ZO-1, Occludin, and Claudin-1, and MUC2 mRNA expression levels with a corresponding decrease in serum lipopolysaccharide and D-lactic acid contents. In addition, L. plantarum L15 improved gut microbiota composition and increased short-chain fatty acid (SCFAs) in the colon content, which significantly reduced the transfer of NF-κB p65 to the nucleus. Our findings provide a theoretical basis for L. plantarum L15 as a preventive candidate for UC.

Toll-like receptor 4-mediated endoplasmic reticulum stress induces intestinal paneth cell damage in mice following CLP-induced sepsis

A marked elevation of TLR4 was observed in various organs of septic mice. The mechanism of TLR4 in intestinal epithelial cell damage in sepsis remains unclear. CLP mice models were used to assess the role of TLR4 in intestinal Paneth cell damage by histological, polymerase chain reaction, western-blot analyses. The ileal expression of TLR4 was increased by more than five-fold after CLP. CLP significantly increased 7-day mortality and was associated with a higher murine sepsis score (MSS), closely related with increased TLR4 expression. Histological staining revealed that a reduced number of Paneth cells, accompanied by reduced lysozyme and defensin alpha 5(DEF-5) expression as detected by PCR. Of note, the expression levels of ATF6, XBP1 and CHOP increased in the ileal of the sepsis group. Meanwhile, the uncleaved p90 ATF6 was markedly reduced and cleaved p50 ATF6 was increased in the sepsis group. Intriguingly, The TAK-242 had improved intestinal mucosal injury, reduced the expression of ATF6, XBP1 and CHOP and relieved the cleavage of ATF6. We found that increased the expression level of TLR4 in the ileal of CLP mice promoted the depletion of Paneth cell and reduced LYZ and DEF-5 expression. Furthermore, our findings suggested that TLR4-mediated the hyperactivation of ER stress, via activating the ATF6/CHOP pathway, might be one of the mechanisms associated with Paneth cells loss and dysfunction during intestinal barrier impairment of sepsis.

Bifidobacterium breve Alleviates DSS-Induced Colitis in Mice by Maintaining the Mucosal and Epithelial Barriers and Modulating Gut Microbes

This study was designed to explore the different intestinal barrier repair mechanisms of Bifidobacterium breve (B. breve) H4-2 and H9-3 with different exopolysaccharide (EPS) production in mice with colitis. The lipopolysaccharide (LPS)-induced IEC-6 cell inflammation model and dextran sulphate sodium (DSS)-induced mice colitis model were used. Histopathological changes, epithelial barrier integrity, short-chain fatty acid (SCFA) content, cytokine levels, NF-κB expression level, and intestinal flora were analyzed to evaluate the role of B. breve in alleviating colitis. Cell experiments indicated that both B. breve strains could regulate cytokine levels. In vivo experiments confirmed that oral administration of B. breve H4-2 and B. breve H9-3 significantly increased the expression of mucin, occludin, claudin-1, ZO-1, decreased the levels of IL-6, TNF-α, IL-1β and increased IL-10. Both strains of B. breve also inhibited the expression of the NF-κB signaling pathway. Moreover, B. breve H4-2 and H9-3 intervention significantly increased the levels of SCFAs, reduced the abundance of Proteobacteria and Bacteroidea, and increased the abundance of Muribaculaceae. These results demonstrate that EPS-producing B. breve strains H4-2 and H9-3 can regulate the physical, immune, and microbial barrier to repair the intestinal damage caused by DSS in mice. Of the two strains, H4-2 had a higher EPS output and was more effective at repair than H9-3. These results will provide insights useful for clinical applications and the development of probiotic products for the treatment of colitis.

Alginate Oligosaccharides Ameliorate DSS-Induced Colitis through Modulation of AMPK/NF-κB Pathway and Intestinal Microbiota

Alginate oligosaccharides (AOS) are shown to have various biological activities of great value to medicine, food, and agriculture. However, little information is available about their beneficial effects and mechanisms on ulcerative colitis. In this study, AOS with a polymerization degree between 2 and 4 were found to possess anti-inflammatory effects in vitro and in vivo. AOS could decrease the levels of nitric oxide (NO), IL-1β, IL-6, and TNFα, and upregulate the levels of IL-10 in both RAW 264.7 and bone-marrow-derived macrophage (BMDM) cells under lipopolysaccharide (LPS) stimulation. Additionally, oral AOS administration could significantly prevent bodyweight loss, colonic shortening, and rectal bleeding in dextran sodium sulfate (DSS)-induced colitis mice. AOS pretreatment could also reduce disease activity index scores and histopathologic scores and downregulate proinflammatory cytokine levels. Importantly, AOS administration could reverse DSS-induced AMPK deactivation and NF-κB activation in colonic tissues, as evidenced by enhanced AMPK phosphorylation and p65 phosphorylation inhibition. AOS could also upregulate AMPK phosphorylation and inhibit NF-κB activation in vitro. Moreover, 16S rRNA gene sequencing of gut microbiota indicated that supplemental doses of AOS could affect overall gut microbiota structure to a varying extent and specifically change the abundance of some bacteria. Medium-dose AOS could be superior to low- or high-dose AOS in maintaining remission in DSS-induced colitis mice. In conclusion, AOS can play a protective role in colitis through modulation of gut microbiota and the AMPK/NF-kB pathway.

Heterophyllin B an Active Cyclopeptide Alleviates Dextran Sulfate Sodium-induced Colitis by Modulating Gut Microbiota and Repairing Intestinal Mucosal Barrier via AMPK Activation

SCOPE

Advances in pathology broaden our perception of the intimate interaction between gut microbiota dysbiosis and the pathogenesis of ulcerative colitis (UC), but the potential modulating roles remain to be elucidated.

METHODS AND RESULTS

DSS-induced colitis was used to investigate the effect of Heterophyllin B (HB), a typical active cyclopeptide extracted from Pseudostellaria heterophylla, on colitis and gut microbiota. Administration of HB substantially mitigated the symptoms of UC as evidenced by increasing body weight and colon length, as well as decreased macrophages infiltration in the colon. Meanwhile, HB significantly alleviated intestinal mucosal barrier dysfunction by reducing the production of inflammatory cytokines, while all the mentioned beneficial effects were significantly eliminated by co-treatment with compound C, a selective AMPK inhibitor. In addition, 16S rDNA gene analyses and fecal microbiota transplantation also revealed that HB dramatically prevented against UC by reshaping intestinal dysbiosis, especially elevated the relative abundance of Akkermansia muciniphila.

CONCLUSION

These findings illustrated that HB prominently improved intestinal epithelial homeostasis via activating AMPK and ameliorated the colonic inflammation in a gut microbiota-dependent manner, which provide evidence for microbial contribution to UC pathogenesis and suggesting a novel approach for colitis prevention. This article is protected by copyright. All rights reserved.

Comparative analysis of gut microbiota in healthy and diarrheic yaks

BACKGROUND

Yak (Bos grunniens) mainly inhabiting Tibet Plateau, displayed a high incidence of diarrhea due to harsh living environment and nutritional deficit. Gut microbial community has been reported to be closely related to many diseases including diabetes, obesity and inflammatory bowel disease, but information regarding diarrheic influence on gut microbiota in yaks remains scarce. Here, this study was performed to investigate the gut bacterial and fungal alternations of diarrheic yaks.

RESULTS

Results revealed that the gut bacterial and fungal communities of diarrheic yaks showed a distinct decline in alpha diversity, accompanied by significant shifts in taxonomic compositions. Specifically, diarrhea caused a distinct increase in the relative abundance of 1 phylum and 8 genera as well as a distinct decrease in 3 phyla and 30 genera. Fungal taxonomic analysis indicated that the relative richness of 1 phylum and 2 genera dramatically increased, whereas the relative richness of 2 phylum and 43 genera significantly decreased during diarrhea. Surprisingly, 2 bacterial genera and 5 fungal genera even cannot be detected in the gut microbiota of diarrheic yaks.

CONCLUSIONS

In summary, this study indicated that the gut bacterial and fungal compositions and diversities of yaks altered significantly during diarrhea. Moreover, these findings also contribute to understanding the gut microbial composition and diversity of yaks and developing strategies to alleviate and prevent diarrhea from gut microbial perspective.

Long-term hexavalent chromium exposure disturbs the gut microbial homeostasis of chickens

Industrial production, ore smelting and sewage disposal plant can discharge large amounts of heavy metals every year, which may contaminate soil, water and air, posing a great threat to ecological environment and animal production. Hexavalent chromium [Cr (VI)], a recognized metallic contaminant, has been shown to impair kidney, liver and gastrointestinal tract of many species, but little is known about the gut microbial characteristics of chickens exposed to Cr (VI). Herein, this study characterized the gut microbial alternations of chickens exposed to Cr (VI). Results indicated that the gut microbial alpha-diversity in chickens exposed to Cr (VI) decreased significantly, accompanied by a distinct shifts in taxonomic composition. Microbial taxonomic analysis demonstrated that the preponderant phyla (Firmicutes, Bacteroidetes, Proteobacteria and Epsilonbacteraeota) were the same in both groups, but different in types and relative abundances of dominant genera. Moreover, some bacterial taxa including 2 phyla and 47 genera significantly decreased, whereas 3 phyla and 17 genera significantly increased during Cr (VI) exposure. Among decreased taxa, 9 genera (Coprobacter, Ruminococcus_1, Faecalicoccus, Eubacterium_nodatum_group, Parasutterella, Slackia, Barnesiella, Family_XIII_UCG-001 and Collinsella) even cannot be detected. In conclusion, this study revealed that Cr (VI) exposure dramatically decrased the gut microbial diversity and altered microbial composition of chickens. Additionally, this study also provided a theoretical basis for relieving Cr (VI) poisoning from the perspective of gut microbiota.

Comparative Analysis of Gut Microbiota Between Healthy and Diarrheic Horses

Increasing evidence reveals the importance of gut microbiota in animals for regulating intestinal homeostasis, metabolism, and host health. The gut microbial community has been reported to be closely related to many diseases, but information regarding diarrheic influence on gut microbiota in horses remains scarce. This study investigated and compared gut microbial changes in horses during diarrhea. The results showed that the alpha diversity of gut microbiota in diarrheic horses decreased observably, accompanied by obvious shifts in taxonomic compositions. The dominant bacterial phyla (Firmicutes, Bacteroidetes, Spirochaetes, and Kiritimatiellaeota) and genera (uncultured_bacterium_f_Lachnospiraceae, uncultured_bacterium_f_p-251-o5, Lachnospiraceae_AC2044_group, and Treponema_2) in the healthy and diarrheic horses were same regardless of health status but different in abundances. Compared with the healthy horses, the relative abundances of Planctomycetes, Tenericutes, Firmicutes, Patescibacteria, and Proteobacteria in the diarrheic horses were observably decreased, whereas Bacteroidetes, Verrucomicrobia, and Fibrobacteres were dramatically increased. Moreover, diarrhea also resulted in a significant reduction in the proportions of 31 genera and a significant increase in the proportions of 14 genera. Taken together, this study demonstrated that the gut bacterial diversity and abundance of horses changed significantly during diarrhea. Additionally, these findings also demonstrated that the dysbiosis of gut microbiota may be an important driving factor of diarrhea in horses.

Triclosan targeting of gut microbiome ameliorates hepatic steatosis in high fat diet-fed mice

Antibiotic use provides a promising strategy for the treatment of non-alcoholic fatty liver disease (NAFLD) by regulating the gut microbiota composition. Triclosan, a widely used antibiotic, may improve gut microbiome dysbiosis associated with NAFLD through the suppression of pathogenic gram-negative bacteria. However, the effects of triclosan on gut microbiota and hepatic steatosis and have not been explored in NAFLD mouse model. In this study, C57BL/6J mice were fed with high fat diet (HFD) for continuous 20 weeks and treated with triclosan at 400 mg/kg/d for 8 weeks from week 13. We explored the effects of triclosan on hepatic lipid accumulation and gut microbiome in HFD-fed mice by histological examination and 16 S ribosomal RNA sequencing, respectively. Analysis on the composition of gut microbiota indicated that triclosan suppressed pathogenic gram-negative bacteria, including Helicobacter, Erysipelatoclostridium and Citrobacter, and increased the ratio of Bacteroidetes/Firmicutes in HFD-fed mice. Meanwhile, triclosan increased the relative abundance of beneficial gut microbiomes including Lactobacillus, Bifidobacterium and Lachnospiraceae, which protected against metabolic abnormality. The results of alpha-diversity and beta-diversity also showed the improvement of triclosan on bacterial diversity and richness in HFD-fed mice. Pathway analysis further confirmed that triclosan can regulate nutrient and energy metabolism through the elimination of deleterious bacteria. As a result, triclosan intervention significantly reduced lipid accumulation and alleviated hepatic steatosis in HFD-fed mice. In conclusion, our results suggest that triclosan can alleviate liver steatosis in HFD-fed mice by targeting the gut microbiome.

Protective Effects of Aminooxyacetic Acid on Colitis Induced in Mice with Dextran Sulfate Sodium

As a known inhibitor of pyridoxal phosphate-dependent transaminase glutamic-oxaloacetic transaminase 1 (GOT1), aminooxyacetic acid (AOAA) has been pointed out to have potential pharmacological effects in antiepileptic, anticonvulsant, antibacterial, cancer cell proliferation inhibition, and acute myocardial infarction (MI) relief. However, its role in inflammatory bowel disease (IBD) has not been reported. Through the in vivo experiment of dextran sulfate sodium- (DSS-) induced colitis in mice, it was found that AOAA significantly attenuated the symptoms, signs, and pathological changes of colitis. In addition, AOAA treatment prevented gut barrier damages by enhancing the expression of zona occludens- (ZO-) 1, occludin, claudin-1, and E-cadherin and recovering the upregulation of the most abundant intermediate filament protein (vimentin). Moreover, the release of interleukin- (IL-) 1β, IL-6, and tumour necrosis factor- (TNF-) α was suppressed, yet the level of IL-10 was upregulated by AOAA treatment compared to the model group. Furthermore, it was shown that AOAA administration boosted M2-like phenotype and effectively reduced M1 macrophage phenotype in the lamina propria of mouse colonic epithelium. Similarly, the effect of AOAA was verified in vitro. AOAA effectively inhibited the classically activated M1 macrophage phenotype and proinflammatory cytokine (IL-1β, TNF-α, and IL-6) expression induced by lipopolysaccharide (LPS) and promoted M2-like phenotype. Collectively, this study reveals for the first time that short-term treatment of AOAA can significantly alleviate DSS-induced acute colitis by regulating intestinal barrier function and macrophage polarization, which provides a theoretical basis for the potential use of AOAA in the treatment of IBD.

The underlying mechanism of A-type procyanidins from peanut skin on DSS-induced ulcerative colitis mice by regulating gut microbiota and metabolism

Ulcerative colitis (UC) is a kind of inflammatory bowel disease. Procyanidins have been found to prevent UC. However, most research has been focused on the alleviation effect of B-type procyanidins on UC and ignored those of A-type procyanidins. Hence, this study aims to investigate the anti-UC effect and the potential mechanism of A-type procyanidins by combining gut microbiome and metabolic profile. UC was induced by dextran sulfate sodium (DSS) in Balb/c mice, and then the mice were administrated with peanut skin procyanidins (PSP; rich in A-type procyanidins) for 9 days. Administration of PSP can ameliorate DSS-induced UC by mediating the intestinal barrier, the expression of inflammatory cytokines (TNF-α, IL-β, IL-6, and IL-10) and oxidative stress (MDA, T-SOD, NO, and iNOS) in mice. We observed that PSP affects the gut microbiota and colon metabolomic patterns of mice. The 16S rDNA sequencing showed increase in abundance of Lachnospiraceae_NK4A136_group, Oscillibacter and Roseburia and decrease of Bacteroides, Helicobacter, Parabacteroides, Escherichia-Shigella, and Enterobacter after PSP treatment. The colon tissue metabolome was significantly altered, as reflected by regulating taste transduction, mTOR signaling pathway, PI3K-Akt signaling pathway, and FoxO signaling pathway to improve the protection against UC. PRACTICAL APPLICATIONS: We investigated the anti-ulcerative colitis (UC) effect and its potential mechanism of peanut skin procyanidins (PSP). This suggests that PSP with abundant A-type procyanidins may be an effective candidate for dietary supplementation to alleviate the symptoms of UC by regulating gut microbiota and metabolism.

The protective effect and potential mechanisms of eugenol against Salmonella in vivo and in vitro

Salmonella enterica serovar Typhimurium (S. Typhimurium) continues to be a serious concern to the poultry industry as a bacterial foodborne zoonosis, which generally results in intestinal inflammation and barrier dysfunction or even death. Eugenol is a phenolic compound with various pharmacological activities involved antioxidant, anti-inflammatory, and antibacterial effects, which is expected to be an effective nonantibiotic therapy. The purpose of this study was to explore the protective effects of eugenol in the cellular and broiler models of S. Typhimurium infection and the possible underlying mechanisms. The results of animal infection showed that eugenol treatments enhanced the relative weight gains and survival rates of broilers with a reduction of the organ bacterial load and intestinal ultrastructural injury. Moreover, eugenol significantly inhibited the mRNA levels of myeloid differentiation factor 88 (MyD88) and toll-like receptor-4 (TLR4), then declined the phosphorylation of p65 and IκBα of NF-κB pathway and the expressions of inflammatory factors (TNF-α, IL-1β, IL-2, and IL-18) in duodenum tissues, while maintained the expressions of intestinal tight junction proteins (ZO-1, claudin-1, occludin). Further experiments in vitro revealed that eugenol markedly inhibited the adhesion and invasion of S. Typhimurium to RAW264.7 or IEC-6 cells, then reduce bacterial multiplication in IEC-6 or DF-1 cells. In conclusion, eugenol could defend broilers from S. Typhimurium infection by stabilizing the intestinal mucosal barrier and relieving inflammatory response, as well as inhibiting bacterial adhesion and invasion to cells.

Alterations in the Gut Microbial Composition and Diversity of Tibetan Sheep Infected With Echinococcus granulosus

Hydatidosis/cystic echinococcosis (CE) caused by Echinococcus granulosus is a parasitic zoonotic disease worldwide, threatening animal health and production and public health safety. However, it is still unclear that whether E. granulosus infection can result in the alteration of gut microbiota in Tibetan sheep. Therefore, a study was designed to investigate the influences of E. granulosus infection on gut microbiota of Tibetan sheep. A total of 10 ovine small intestinal contents (five from healthy and five from infected) were obtained and subjected to high-throughput sequencing by MiSeq platform. A total of 2,395,641 sequences and 585 operational taxonomic units (OTUs) were identified. Firmicutes and Proteobacteria were the most dominant phyla in all samples. Moreover, the proportions of Armatimonadetes and Firmicutes in the infected Tibetan sheep were significantly decreased, whereas Actinobacteria, Chloroflexi, and Acidobacteria had significantly increased. At the genus level, the Christensenellaceae_R-7_group and Ruminococcaceae_NK4A214_group were the predominant bacterial genera in all the samples. Furthermore, the healthy Tibetan sheep exhibited higher abundances of Intestinimonas, Butyrivibrio, Pseudobutyrivibrio, Ruminococcaceae, Eubacterium_coprostanoligenes_group, Oxobacter, Prevotella_1, Ruminiclostridium_6, Coprococcus_1, Ruminococcus, Lachnospiraceae_UCG-002, Olsenella, and Acetitomaculum, whereas Kocuria, Clostridium_sensu_stricto_1, Slackia, Achromobacter, and Stenotrophomonas levels were lower. In conclusion, our results conveyed an information that E. granulosus infection may cause an increase in pathogenic bacteria and a decrease in beneficial bacteria. Additionally, a significant dynamical change in gut microbiota could be associated with E. granulosus infection.

Environmental hexavalent chromium exposure induces gut microbial dysbiosis in chickens

Hexavalent chromium [Cr (VI)] is a hazardous heavy metal that pollutes soil, water and crops. Moreover, its prolonged exposure can harm the gastrointestinal system, liver and respiratory tract in different species, but knowledge regarding Cr (VI) influence on gut microbiota in chickens remains scarce. Therefore, this study was performed to investigate the impact of Cr (VI) on gut microbiota in chickens. Results revealed that the gut microbiota in Cr (VI)-induced chickens exhibited a distinct reduction in alpha diversity, accompanied by significant shifts in microbial composition. Specifically, Firmicutes and Bacteroidetes were the most dominant phyla in the control chickens, whereas Firmicutes and Actinobacteria were observed to be predominant in the Cr (VI)-induced populations. Moreover, the types and relative abundances of predominant bacterial genus in control and Cr (VI)-induced chickens were also different. Bacterial taxonomic analysis revealed that the relative abundances of 3 phyla and 7 genera obviously increased, whereas 8 phyla and 30 genera dramatically decreased during Cr (VI) induction. Among them, 1 phylum (Deferribacteres) and 5 genera (Butyricicoccus, Butyricimonas, Intestinimonas, Lachnospiraceae_FCS020_group and Ruminococcaceae_V9D2013_group) even could not be found in the gut microbial community of Cr (VI)-induced chickens. Taken together, our study indicated that the long-term exposure to Cr (VI) dramatically alter the gut microbial diversity and composition in chickens. Notably, it represents a breakthrough in understanding the impact of Cr (VI) on the intestinal microbiota of chickens.

Toll-Like Receptors as Drug Targets in the Intestinal Epithelium

Toll-like receptors (TLRs) receptors are responsible for initiation of inflammatory responses by their recognition of molecular patterns present in invading microorganisms (such as bacteria, viruses or fungi) or in molecules released following tissue damage in disease states. Expressed in the intestinal epithelium, they initiate an intracellular signalling cascade in response to molecular patterns resulting in the activation of transcription factors and the release of cytokines, chemokines and vasoactive molecules. Intestinal epithelial cells are exposed to microorganisms on a daily basis and form part of the primary defence against pathogens by using TLRs. TLRs and their accessory molecules are subject to tight regulation in these cells so as to not overreact or react in unnecessary circumstances. TLRs have more recently been associated with chronic inflammatory diseases as a result of inappropriate regulation, this can be damaging and lead to chronic inflammatory diseases such as inflammatory bowel disease (IBD). Targeting Toll-like receptors offers a potential therapeutic approach for IBD. In this review, the current knowledge on the TLRs is reviewed along with their association with intestinal diseases. Finally, compounds that target TLRs in animal models of IBD, clinic trials and their future merit as targets are discussed.

Alleviative Effects of Exopolysaccharide Produced by Lactobacillus helveticus KLDS1.8701 on Dextran Sulfate Sodium-Induced Colitis in Mice

Ulcerative colitis (UC) is a non-specific chronic inflammatory disease with lesions located in the colon and rectum. The aim of this study was to evaluate the anti-inflammatory effects of exopolysaccharide-1 (EPS-1) isolated by L. helveticus KLDS1.8701 on UC. The anti-inflammatory effects of EPS-1 were studied using dextran sulphate sodium (DSS)-induced UC model. In vivo results showed that EPS-1 administration significantly ameliorated weight loss, colon shortening, disease activity index (DAI) score, myeloperoxidase (MPO) activity, and colon tissue damage. In addition, EPS-1 administration significantly decreased the levels of pro-inflammatory cytokines and increased levels of anti-inflammatory cytokines. Meanwhile, EPS-1 administration significantly up-regulated the expression of tight junction proteins and mucin. Furthermore, EPS-1 administration modulated gut microbiota composition caused by DSS and increased the short-chain fatty acids (SCFAs) levels. Collectively, our study showed the alleviative effects of EPS- isolated by L. helveticus KLDS1.8701 on DSS-induced UC via alleviating intestinal inflammation, improving mucosal barrier function, and modulating gut microbiota composition.

Integrated Bacterial and Fungal Diversity Analysis Reveals the Gut Microbial Alterations in Diarrheic Giraffes

Gut microbiota has been demonstrated to be associated with multiple gastrointestinal diseases, but information regarding the gut microbial alternations in diarrheic giraffe remains scarce. Here, 16S rDNA and ITS gene amplicon sequencing were conducted to investigate the gut microbial composition and variability in diarrheic giraffes. Results demonstrated that Firmicutes and Proteobacteria were the most dominant phyla in the gut bacterial community, whereas Ascomycota and Basidiomycota were observed to be predominant in the gut fungal community regardless of health status. However, the species and relative abundance of preponderant bacterial and fungal genera in healthy and diarrheic giraffes were different. In contrast to the relatively stabilized gut fungal community, gut bacterial community displayed a significant decrease in the alpha diversity, accompanied by distinct changes in taxonomic compositions. Bacterial taxonomic analysis revealed that the relative abundances of eight phyla and 12 genera obviously increased, whereas the relative abundances of two phyla and eight genera dramatically decreased during diarrhea. Moreover, the relative richness of five fungal genera significantly increased, whereas the relative richness of seven fungal genera significantly declined in diarrheic giraffes. Taken together, this study demonstrated that diarrhea could cause significant alternations in the gut microbial composition of giraffes, and the changes in the gut bacterial community were more significant than those in the gut fungal community. Additionally, investigating the gut microbial characteristics of giraffes in different health states is beneficial to provide a theoretical basis for establishing a prevention and treatment system for diarrhea from the gut microbial perspective.

Puerarin Ameliorates 5-Fluorouracil-Induced Intestinal Mucositis in Mice by Inhibiting JAKs

Intestinal mucositis resulting from 5-fluorouracil (5-FU)-based chemotherapy subjects patients to great pain and hampers cancer treatment progress. Puerarin, the major active ingredient in Pueraria lobata, exerts anti-inflammatory and antioxidative effects. However, whether puerarin has an effect on 5-FU-induced intestinal mucositis remains unknown. We established a mice model of intestinal mucositis through the intraperitoneal injection of 5-FU and then injected puerarin (50 and 100 mg/kg) intraperitoneally for 7 consecutive days. Routine parameters, such as body weight, food intake, and diarrheal incidence, were examined to evaluate the effects of puerarin on intestinal mucositis in mice. The intestinal barrier's functions were also evaluated by measuring the serum recovery of fluorescein isothiocyanate-4kD dextran in this study. The expression levels of inflammatory cytokines, inflammatory mediators, oxidative reactions, as well as apoptotic marker proteins were determined to elucidate the underlying mechanisms of puerarin on intestinal mucositis. The model mice presented symptoms and histopathological changes typical of 5-FU-induced intestinal mucositis. In addition to vigorous inflammatory reactions, oxidative reactions, and cell apoptosis, Janus kinase (JAK) was markedly activated. Puerarin decreased the expression levels of those of inflammatory mediators, oxidative reactions, and apoptosis-related proteins in 5-FU-induced mucositis by blocking the activation of JAK. Puerarin decreased inflammation, oxidative reactions, and apoptosis and protected intestinal barrier functions to ameliorate 5-FU-induced intestinal mucositis by inhibiting the activation of JAK. This study provides novel insights into the pathologic mechanisms of (and treatment alternatives for) 5-FU-induced intestinal mucositis. SIGNIFICANCE STATEMENT: This study reveals the mechanism responsible for the protective effects of puerarin in 5-fluorouracil-induced intestinal mucositis. Puerarin inhibits the activation of JAK, thereby suppressing inflammation, oxidative reactions, cell apoptosis, and protected intestinal barrier functions to ameliorate 5-FU-induced intestinal mucositis. Overall, our results suggest that puerarin can serve as a potential natural JAK inhibitor in the treatment of 5-FU-induced intestinal mucositis.

Colonic Epithelial PHLPP2 Deficiency Promotes Colonic Epithelial Pyroptosis by Activating the NF-κB Signaling Pathway

Background

Ulcerative colitis (UC) is a chronic inflammatory disease with increasing prevalence worldwide. Barrier defect in intestinal epithelial cells (IECs) is one of the main pathogeneses in UC. Pyroptosis is a programmed lytic cell death and is triggered by inflammatory caspases, while little is known about its role in UC.

Methods

Differentially expressed genes (DEGs) were identified by comparing UC patients with healthy controls from the GEO datasets. The candidate genes involved in pyroptosis were obtained, and the underlying molecular mechanism in the progression of UC was explored in vivo and in vitro.

Results

Pleckstrin homology domain leucine-rich repeat protein phosphatase 2 (PHLPP2), a protein phosphatase, was downregulated and involved in regulating inflammation-induced IEC pyroptosis by modulating the NF-κB signaling in UC through bioinformatics analysis. Moreover, we demonstrated that PHLPP2 was downregulated in UC patients and UC mice. Besides, we found that PHLPP2 depletion activated the NF-κB signaling and increased the expressions of caspase-1 P20, Gasdermin N, IL-18, and IL-1β contributing to IEC pyroptosis and inflammation in UC mice. Furthermore, we found that PHLPP2^−/− mice developed hypersensitivity to dextran sulfate sodium (DSS) treatment toward colitis showing activated NF-κB signaling and dramatically induced expressions of caspase-1 P20, Gasdermin N, IL-18, and IL-1β. Mechanically, this inflammation-induced downregulation of PHLPP2 was alleviated by an NF-κB signaling inhibitor in intestinal organoids of PHLPP2^−/− mice and fetal colonic cells.

Conclusions

PHLPP2 downexpression activated the NF-κB signaling and promoted the IEC pyroptosis, leading to UC progression. Therefore, PHLPP2 might be an attractive candidate therapeutic target for UC.

Saffron Pre-Treatment Promotes Reduction in Tissue Inflammatory Profiles and Alters Microbiome Composition in Experimental Colitis Mice

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with an incompletely understood pathogenesis. Long-standing colitis is associated with increased risk of colon cancer. Despite the availability of various anti-inflammatory and immunomodulatory drugs, many patients fail to respond to pharmacologic therapy and some experience drug-induced adverse events. Dietary supplements, particularly saffron (Crocus sativus), have recently gained an appreciable attention in alleviating some symptoms of digestive diseases. In our study, we investigated whether saffron may have a prophylactic effect in a murine colitis model. Saffron pre-treatment improved the gross and histopathological characteristics of the colonic mucosa in murine experimental colitis. Treatment with saffron showed a significant amelioration of colitis when compared to the vehicle-treated mice group. Saffron treatment significantly decreased secretion of serotonin and pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6, in the colon tissues by suppressing the nuclear translocation of NF-κB. The gut microbiome analysis revealed distinct clusters in the saffron-treated and untreated mice in dextran sulfate sodium (DSS)-induced colitis by visualization of the Bray-Curtis diversity by principal coordinates analysis (PCoA). Furthermore, we observed that, at the operational taxonomic unit (OTU) level, Cyanobacteria were depleted, while short-chain fatty acids (SCFAs), such as isobutyric acid, acetic acid, and propionic acid, were increased in saffron-treated mice. Our data suggest that pre-treatment with saffron inhibits DSS-induced pro-inflammatory cytokine secretion, modulates gut microbiota composition, prevents the depletion of SCFAs, and reduces the susceptibility to colitis.

Inhibition of TLR4 Signaling Impedes Tumor Growth in Colitis-Associated Colon Cancer

Patients suffering from ulcerative colitis are at increased risk of developing colorectal cancer. Although the exact underlying mechanisms of inflammation-associated carcinogenesis remain unknown, the intestinal microbiota as well as pathogenic bacteria are discussed as contributors to inflammation and colitis-associated colon cancer (CAC). In the present study, we analyzed the impact of TLR4, the receptor for Gram-negative bacteria derived lipopolysaccharides, on intestinal inflammation and tumorigenesis in a murine model of CAC. During the inflammatory phases of CAC development, we observed a strong upregulation of Tlr4 expression in colonic tissues. Blocking of TLR4 signaling by a small-molecule-specific inhibitor during the inflammatory phases of CAC strongly diminished the development and progression of colonic tumors, which was accompanied by decreased numbers of infiltrating macrophages and reduced colonic pro-inflammatory cytokine levels compared to CAC control mice. Interestingly, inhibiting bacterial signaling by antibiotic treatment during the inflammatory phases of CAC also protected mice from severe intestinal inflammation and almost completely prevented tumor growth. Nevertheless, application of antibiotics involved rapid and severe body weight loss and might have unwanted side effects. Our results indicate that bacterial activation of TLR4 on innate immune cells in the colon triggers inflammation and promotes tumor growth. Thus, the inhibition of the TLR4 signaling during intestinal inflammation might be a novel approach to impede CAC development.

Long-term efficacy and safety of monotherapy with a single fresh fecal microbiota transplant for recurrent active ulcerative colitis: a prospective randomized pilot study

BACKGROUND

To assess the long-term safety and efficacy of monotherapy with a single fresh fecal microbiota transplant (FMT) for recurrent ulcerative colitis (UC).

RESULTS

Twenty-six eligible patients were enrolled, and 6 patients were excluded. Ultimately, 20 patients were randomized to the FMT group (n = 10) and the control group (n = 10); 80% were females (F/M = 16/4), the mean age was 48 ± 14 years, and the mean duration was 6.4 ± 8.2 years. The mean length of post-FMT follow-up was 19.1 ± 10.1 months (6-38). No statistically significant differences in baseline demographic or clinical characteristics were found between the groups. Ninety percent of patients in the FMT group and 50% of patients in the control group met the primary endpoint at week 8. The Mayo score was significantly decreased compared with that of the control group (n = 10) when reassessed at week 4 (P = 0.001) and week 8 (P = 0.019) after FMT; there was no significant difference 6 months after treatment. The median remission time was 24 months (95% CI 68.26-131.7%) in both the FMT (range 6-38 months) and control groups (range 7-35 months), with no significant difference (P = 0.895). Participants tolerated FMT treatment, and no adverse events occurred during long-term follow-up, with one treatment-related significant adverse event (EBV infection) occurring within 2 weeks after FMT. Stool microbiota composition analysis indicated improved gut microbiota diversity after FMT, with expansion of stool-donor taxa. Bacteroidetes, Firmicutes and Proteobacteria were the dominant bacterial phyla of the gut microbiota in active UC patients. The relative abundance of Bacteroidetes decreased and that of Proteobacteria increased significantly in active UC patients compared with donors, while Firmicutes showed no significant changes. A single fresh FMT could effectively reconstruct the gut microbiota composition in patients with active UC and maintain stability, with increased Bacteroidetes and decreased Proteobacteria abundance. FMT significantly reduced the relative abundance of Escherichia and increased the relative abundance of Prevotella at the genus level. Pyruvate metabolism, glyoxylate and dicarboxylate metabolism, and pantothenate and CoA biosynthesis showed significant differences after transplantation.

CONCLUSIONS

Monotherapy with a single fresh FMT is an effective and safe strategy to induce long-term remission without drugs in patients with active UC and may be an alternative induction therapy for recurrent UC or even primary UC.