Dextran Sulfate Sodium-induced Colitis Research Articles

A Technique to Generate a Murine Model of Dextran Sulfate Sodium-Induced Colitis

A Technique to Generate a Murine Model of Dextran Sulfate Sodium-Induced Colitis

A Technique to Generate a Murine Model of Dextran Sulfate Sodium-Induced Colitis

A Technique to Generate a Murine Model of Dextran Sulfate Sodium-Induced Colitis

Interferon-gamma and tumor necrosis factor-alpha synergistically enhance the immunosuppressive capacity of human umbilical-cord-derived mesenchymal stem cells by increasing PD-L1 expression.

The immunosuppressive capacity of mesenchymal stem cells (MSCs) is dependent on the "license" of several proinflammatory factors to express immunosuppressive factors such as programmed cell death 1 ligand 1 (PD-L1), which determines the clinical therapeutic efficacy of MSCs for inflammatory or immune diseases. In MSCs, interferon-gamma (IFN-γ) is a key inducer of PD-L1 expression, which is synergistically enhanced by tumor necrosis factor-alpha (TNF-α); however, the underlying mechanism is unclear. To reveal the mechanism of pretreated MSCs express high PD-L1 and explore the application of pretreated MSCs in ulcerative colitis. We assessed PD-L1 expression in human umbilical-cord-derived MSCs (hUC-MSCs) induced by IFN-γ and TNF-α, alone or in combination. Additionally, we performed signal pathway inhibitor experiments as well as RNA interference experiments to elucidate the molecular mechanism by which IFN-γ alone or in combination with TNF-α induces PD-L1 expression. Moreover, we used luciferase reporter gene experiments to verify the binding sites of the transcription factors of each signal transduction pathway to the targeted gene promoters. Finally, we evaluated the immunosuppressive capacity of hUC-MSCs treated with IFN-γ and TNF-α in both an in vitro mixed lymphocyte culture assay, and in vivo in mice with dextran sulfate sodium-induced acute colitis. Our results suggest that IFN-γ induction alone upregulates PD-L1 expression in hUC-MSCs while TNF-α alone does not, and that the co-induction of IFN-γ and TNF-α promotes higher expression of PD-L1. IFN-γ induces hUC-MSCs to express PD-L1, in which IFN-γ activates the JAK/STAT1 signaling pathway, up-regulates the expression of the interferon regulatory factor 1 (IRF1) transcription factor, promotes the binding of IRF1 and the PD-L1 gene promoter, and finally promotes PD-L1 mRNA. Although TNF-α alone did not induce PD-L1 expression in hUC-MSCs, the addition of TNF-α significantly enhanced IFN-γ-induced JAK/STAT1/IRF1 activation. TNF-α up-regulated IFN-γ receptor expression through activation of the nuclear factor kappa-B signaling pathway, which significantly enhanced IFN-γ signaling. Finally, co-induced hUC-MSCs have a stronger inhibitory effect on lymphocyte proliferation, and significantly ameliorate weight loss, mucosal damage, inflammatory cell infiltration, and up-regulation of inflammatory factors in colitis mice. Overall, our results suggest that IFN-γ and TNF-α enhance both the immunosuppressive ability of hUC-MSCs and their efficacy in ulcerative colitis by synergistically inducing high expression of PD-L1.

N-acetylglucosamine-6-O-sulfation on intestinal mucins prevents obesity and intestinal inflammation by regulating gut microbiota.

Intestinal mucins play an essential role in the defense against bacterial invasion and the maintenance of gut microbiota, which is instrumental in the regulation of host immune systems; hence, its dysregulation is a hallmark of metabolic disease and intestinal inflammation. However, the mechanism by which intestinal mucins control the gut microbiota as well as disease phenotypes remains nebulous. Herein, we report that N-acetylglucosamine (GlcNAc)-6-O-sulfation of O-glycans on intestinal mucins performs a protective role against obesity and intestinal inflammation. Chst4-/- mice, lacking GlcNAc-6-O-sulfation of the mucin O-glycans, showed significant weight gain and increased susceptibility to dextran sodium sulfate-induced colitis as well as colitis-associated cancer accompanied by significantly reduced immunoglobulin A (IgA) production caused by impaired T follicular helper cell-mediated IgA response. Interestingly, the protective effects of GlcNAc-6-O-sulfation against obesity and intestinal inflammation depend on the gut microbiota, evidenced by the modulation of the gut microbiota by co-housing or microbiota transplantation reversing disease phenotypes and IgA production. Collectively, our findings provide novel insight into the significance of host glycosylation, more specifically GlcNAc-6-O-sulfation on intestinal mucins, in protecting against obesity and intestinal inflammation via regulation of the gut microbiota.

Cantharidin analogue alleviates dextran sulfate sodium-induced colitis in mice by inhibiting the activation of NF-κB signaling

Ulcerative colitis is a chronic inflammatory disease with a remitting-relapsing clinical course, it has evolved into a global burden given its high incidence worldwide. Cantharidin (CTD) derivatives are a class of compounds whose structures characterized with a 7-oxabicyclo [2.2.1]heptane core. Though potent cytotoxicity CTD and its derivatives showed, their clinical usage as anti-cancer drugs was limited by the toxicity in organs. In order to find new CTD analogues with good activity and lower toxicity, 21 CTD analogues with or without alkynyl substitution at C5 position of 7-oxabicyclo [2.2.1]heptane core were synthesized, some compounds showed better in vitro anti-inflammatory activity compared to CTD and norcantharidin (NCTD). Based on the structure-activity relationship results of in vitro experiment, analogue 3i was chosen for further study. Results from the acute toxicity in mice showed that 3i was hypotoxic with the single-dose MTD (maximum tolerated dose) for oral administration is over 1852 mg/kg, at least 35-fold lower than that of NCTD. Mechanism study indicated that 3i could potently inhibit TNF-α induced activation of NF-κB signaling by down-regulation the expression levels of phosphor- IKK, IκBα, and NF-κB p65, and alleviated dextran sulfate sodium-induced colitis in mice. This study indicated that CTD analogues with alkynyl substitution at C5 position of 7-oxabicyclo [2.2.1]heptane core is a kind of new compounds with good anti-inflammatory activity and lower toxicity in vivo, and might be used as therapeutic agents for inflammatory diseases.

Exopolysaccharide from Bifidobacterium breve alleviate dextran sulfate sodium-induced colitis in mice via inhibiting oxidative stress and regulating intestinal flora

Exopolysaccharides are believed to alleviate colitis by maintaining intestinal homeostasis, but its specific action mechanism is worth exploring. Here, a type of exopolysaccharide (BBE) from Bifidobacterium breve composed with mannose, rhamnose, glucose, acetylglucosamine and galactose was isolated, along with sulfate groups and a steric helical structure. The protective effect and anti-inflammatory activity of BBE on intestine were evaluated in vitro and in vivo. Cell experiments indicated that BBE significantly increased the survival ability of intestinal epithelioid cell line 6 under action of hydrogen peroxide. Vivo experiments revealed that BBE restored the intestinal injury caused by dextran sulfate sodium (DSS) in mice by increasing the contents of mucin and the expression of occludin, claudin-1, ZO-1. BBE administration significantly inhibited the expression of oxidative protein and pyrin domain 3 inflammasome complex in colitis mice. The intervention of BBE also restored the production of abnormal inflammatory factors and the decrease of short-chain fatty acids (SCFAs) level caused by DSS. Besides, BBE also recovered the imbalanced intestinal flora by increasing the abundance of Muribaculaceae, and Lactobacillus as well as reducing the abundance of Escherichia-Shigella and Bacteroides. The aforementioned results confirmed that BBE could effectively repair intestinal damage, thereby laying a foundation for the application of BBE as a potential anti-inflammatory substance.

MiR-200a attenuated oxidative stress, inflammation, and apoptosis in dextran sulfate sodium-induced colitis through activation of Nrf2.

Oxidative stress and inflammatory responses are critical factors in ulcerative colitis disease pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) modulates oxidative stress and suppresses inflammatory responses, and the protective benefits of Nrf2 activation have been associated with the therapy of ulcerative colitis. MicroRNA-200a (miR-200a) could target Kelch-like ECH-associated protein 1 (Keap1) and activate the Nrf2-regulated antioxidant pathway. Nevertheless, whether miR-200a modulates the Keap1/Nrf2 pathway in dextran sulfate sodium (DSS)-induced colonic damage is unknown. Here, our research intends to examine the impact of miR-200a in the model of DSS-induced colitis. Prior to DSS intervention, we overexpressed miR-200a in mice for four weeks using an adeno-associated viral (AAV) vector to address this problem. ELISA detected the concentration of inflammation-related cytokines. The genes involved in inflammatory reactions and oxidative stress were identified using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and immunofluorescence. Moreover, we applied siRNAs to weakened Nrf2 expression to confirm the hypothesis that miR-200a provided protection via Nrf2. The present study discovered miR-200a down-regulation, excessive inflammatory activation, enterocyte apoptosis, colonic dysfunction, and Keap1/Nrf2 antioxidant pathway inactivation in mouse colitis and NCM460 cells under DSS induction. However, our data demonstrated that miR-200a overexpression represses Keap1 and activates the Nrf2 antioxidant pathway, thereby alleviating these adverse alterations in animal and cellular models. Significantly, following Nrf2 deficiency, we failed to observe the protective benefits of miR-200a against colonic damage. Taken together, through activating the Keap1/Nrf2 signaling pathway, miR-200a protected against DSS-induced colonic damage. These studies offer an innovative therapeutic approach for ulcerative colitis.

Capsulated Cellular Nanosponges for the Treatment of Experimental Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal tract disorder characterized by uncontrolled inflammatory responses to the disrupted intestinal epithelial barrier and gut microbiome dysbiosis. Currently available small-molecule immunosuppressive agents and anticytokine biologics show limited potency, mainly due to the complexity of the inflammatory network involved in IBD. Here, we develop an oral formulation of macrophage membrane-coated nanoparticles capsulated in enteric polymer-coated gelatin capsules (denoted "cp-MΦ-NPs") for IBD treatment. The capsules protect the nanoparticles from gastric degradation and allow for targeted delivery to the colon. At the inflamed colon, cp-MΦ-NPs act as macrophage decoys that bind and neutralize pro-inflammatory cytokines. The in vivo treatment efficacy of cp-MΦ-NPs is tested in a mouse model of dextran sulfate sodium-induced colitis. In both prophylactic and delayed treatment regimens, the oral delivery of cp-MΦ-NPs significantly alleviates IBD severity, reflected by reduced intestinal inflammation and intestinal barrier restoration. Overall, cp-MΦ-NPs provide a biomimetic nanomedicine strategy for the treatment of IBD.

Tamarind Seed Polysaccharide Hydrolysate Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis via Regulating the Gut Microbiota.

(1) Background: Ulcerative colitis (UC) is a disease caused by noninfectious chronic inflammation characterized by varying degrees of inflammation affecting the colon or its entire mucosal surface. Current therapeutic strategies rely on the suppression of the immune response, which is effective, but can have detrimental effects. Recently, different plant polysaccharides and their degradation products have received increasing attention due to their prominent biological activities. The aim of this research was to evaluate the mitigation of inflammation exhibited by tamarind seed polysaccharide hydrolysate (TSPH) ingestion in colitis mice. (2) Methods: TSPH was obtained from the hydrolysis of tamarind seed polysaccharide (TSP) by trifluoroacetic acid (TFA). The structure and physical properties of TSPH were characterized by ultraviolet spectroscopy (UV), thin-layer chromatography (TLC), fourier transform infrared spectroscopy (FT-IR), and High-Performance Liquid Chromatography and Electrospray Ionization Mass Spectrometry (HPLC-ESI/MS) analysis. Then, the alleviative effects of the action of TSPH on 2.5% dextran sodium sulfate (DSS)-induced colitis mice were investigated. (3) Results: TSPH restored pathological lesions in the colon and inhibited the over-secretion of pro-inflammatory cytokines in UC mice. The relative expression level of mRNA for colonic tight junction proteins was increased. These findings suggested that TSPH could reduce inflammation in the colon. Additionally, the structure of the gut microbiota was also altered, with beneficial bacteria, including Prevotella and Blautia, significantly enriched by TSPH. Moreover, the richness of Blautia was positively correlated with acetic acid. (4) Conclusions: In conclusion, TSPH suppressed colonic inflammation, alleviated imbalances in the intestinal flora and regulated bacterial metabolites. Thus, this also implies that TSPH has the potential to be a functional food against colitis.

A gut-restricted glutamate carboxypeptidase II inhibitor reduces monocytic inflammation and improves preclinical colitis.

There is an urgent need to develop therapeutics for inflammatory bowel disease (IBD) because up to 40% of patients with moderate-to-severe IBD are not adequately controlled with existing drugs. Glutamate carboxypeptidase II (GCPII) has emerged as a promising therapeutic target. This enzyme is minimally expressed in normal ileum and colon, but it is markedly up-regulated in biopsies from patients with IBD and preclinical colitis models. Here, we generated a class of GCPII inhibitors designed to be gut-restricted for oral administration, and we interrogated efficacy and mechanism using in vitro and in vivo models. The lead inhibitor, (S)-IBD3540, was potent (half maximal inhibitory concentration = 4 nanomolar), selective, gut-restricted (AUCcolon/plasma > 50 in mice with colitis), and efficacious in acute and chronic rodent colitis models. In dextran sulfate sodium-induced colitis, oral (S)-IBD3540 inhibited >75% of colon GCPII activity, dose-dependently improved gross and histologic disease, and markedly attenuated monocytic inflammation. In spontaneous colitis in interleukin-10 (IL-10) knockout mice, once-daily oral (S)-IBD3540 initiated after disease onset improved disease, normalized colon histology, and attenuated inflammation as evidenced by reduced fecal lipocalin 2 and colon pro-inflammatory cytokines/chemokines, including tumor necrosis factor-α and IL-17. Using primary human colon epithelial air-liquid interface monolayers to interrogate the mechanism, we further found that (S)-IBD3540 protected against submersion-induced oxidative stress injury by decreasing barrier permeability, normalizing tight junction protein expression, and reducing procaspase-3 activation. Together, this work demonstrated that local inhibition of dysregulated gastrointestinal GCPII using the gut-restricted, orally active, small-molecule (S)-IBD3540 is a promising approach for IBD treatment.

Sustained ameliorative effect of Lactobacillus acidophilus LA85 on dextran sulfate sodium-induced colitis in mice.

Ulcerative colitis (UC) is a type of inflammatory bowel disease associated with immune system dysfunction caused by gut dysbiosis. This study aimed to investigate the alleviating effect of Lactobacillus acidophilus LA85 on colitis and its underlying mechanism using mouse models of dextran sulfate sodium (DSS)-induced UC. The UC mouse models were established by treating C57BL/6J male mice with 2.5% (w/v) DSS in drinking water for 7 days. These mice received supplementation with either L. acidophilus LA85 (1 × 109 colony-forming units/day) or 200 µL of sterile water once daily (LA85-treated and UC model mice, respectively). The disease activity index (DAI), colon length, and histological changes in the colons of mice were then analyzed at Day 21, and the effects of L. acidophilus LA85 on the gut microbiota and serum inflammatory cytokines were also investigated. Compared with the UC model mice, L. acidophilus LA85-treated UC mice showed significant reductions in a variety of colitis symptoms, including weight loss, the DAI score, colon shortening, and colon tissue damage. Lactobacillus acidophilus LA85 supplementation also significantly decreased the serum concentrations of tumor necrosis factor α and interleukin-6 while increasing the serum concentration of IL-10. Furthermore, LA85 supplementation improved the diversity and composition of the gut microbiota, both of which had been decreased by DSS. In particular, L. acidophilus LA85-treated UC mice showed higher relative abundances of Akkermansia and Romboutsia than the UC model mice. These results demonstrate that L. acidophilus LA85 can alleviate inflammatory diseases of the intestine, such as inflammatory bowel disease, by regulating immune responses and restoring the gut microbiota. PRACTICAL APPLICATION: Ulcerative colitis is a type of inflammatory bowel disease caused by imbalance of gut microbiota. This study showed that L. acidophilus LA85 can alleviate DSS-induced colitis in mice through regulation of inflammatory cytokines, protection of intestinal barrier, and regulation of specific gut microbiota. L. acidophilus LA85 is a promising probiotic candidate for the treatment of UC.

Lactobacillus johnsonii N5 from heat stress-resistant pigs improves gut mucosal immunity and barrier in dextran sodium sulfate-induced colitis

Developing effective strategies to prevent diarrhea and associated-gut disorders in mammals has gained great significance. Owing to the many health benefits provided by the commensal microbiota of the intestinal tract, such as against environmental perturbation, we explored the host phenotype-associated microbes and their probiotic potential. Based on the observations that the chronic heat stress-exposed weaned piglets present as heat stress-susceptible (HS-SUS) or heat stress-resistant (HS-RES) individuals, we confirmed the phenotypic difference between the two on growth performance (P < 0.05), diarrhea index (P < 0.001), intestinal heat shock protein 70 (HSP70) regulation (P < 0.01), and inflammatory responses (P < 0.01). By comparing the gut microbiome using 16S rRNA gene sequencing and KEGG functional analysis, we found that Lactobacillus johnsonii exhibited significantly higher relative abundance in the HS-RES piglets than in the HS-SUS ones (P < 0.05). Further experiments using a mouse model for chemical-induced inflammation and intestinal injury demonstrated that oral administration of a representative L. johnsonii N5 (isolated from the HS-RES piglets) ameliorated the clinical and histological signs of colitis while suppressing intestinal pro-inflammatory cytokines TNF-α and IL-6 production (P < 0.05). We found that N5 treatment enhanced tight junction proteins ZO-1 and occludin and cytoprotective HSP70 levels under physiological condition and restored their mucosal expressions in colitis (P < 0.05). In support of the high production of the anti-inflammatory cytokine IL-10, N5 promoted the intestinal Peyer's patches MHCII+ and CD103+ dendritic cell populations (P < 0.05), increased the regulatory T (Treg) cell numbers (P < 0.05), and decreased the Th17 population and its IL-17a production under physiological condition and during colitis (P < 0.01). Our results shed light on understanding the interaction between commensal Lactobacillus and the host health, and provide L. johnsonii N5 as an alternative to antibiotics for preventing diarrhea and intestinal diseases.

Matrine Protects Intestinal Barrier Function via MicroRNA-155 Through ROCK1-Signaling Pathway.

The aim of this study was to investigate the protective effects on intestinal barrier function and tight junction by matrine via a small, non-coding RNA microRNA-155-signaling pathway. Tight junction protein and target gene expressions were determined through microRNA-155 inhibition or overexpression of Caco-2 cell line with or without the treatment of matrine. In order to further verify the role of matrine, dextran sulfate sodium-induced mice colitis was treated by matrine. MicroRNA-155 and ROCK1 expressions were detected in clinical specimens of acute obstruction patients. Matrine could enhance the expression level of occludin, which might be inhibited by the overexpression of microRNA-155. After the transfection of the precursor of microRNA-155 into Caco-2 cells, ROCK1 expression was increased at both mRNA and protein levels. MicroRNA-155 inhibitor could decrease the ROCK1 expression after transfection. Furthermore, matrine could increase the permeability and decrease tight junction-associated proteins induced by dextran sulfate sodium-induced mice colitis. Clinical sample detection also found high levels of microRNA-155 in stercoral obstruction patients. Matrine could maintain the tight junction and protect the intestinal barrier from dysfunction. The molecular mechanism may be that matrine might inhibit microRNA-155 and increase the expression level of tight junction proteins.

α-Terpineol Mitigates Dextran Sulfate Sodium-Induced Colitis in Rats by Attenuating Inflammation and Apoptosis.

Ulcerative colitis (UC) is one of the major inflammatory disorders of the gastrointestinal tract. α-Terpineol (αTL) is naturally present in several plants, and it belongs to the monoterpenes category. αTL possesses various pharmacological properties such as antioxidant, antibacterial, antifungal, anticancer, and antiulcer activities. Importantly, αTL has been reported to possess potent anti-inflammatory effects also. In this study, we hypothesize that αTL may have protective effects against dextran sodium sulfate (DSS)-induced colitis in Wistar rats. Animals were randomly allocated to 3 groups of 6 rats each. In group III, αTL was administered at a dose of 50 mg/kg b. wt. orally from days 1 to 14, while in groups II and III, 4% DSS in drinking water was given to rats ad libitum from the 7th to 14th days. After 24 h of the last dose of αTL, all animals were euthanized. αTL administration reduced the DSS-induced colonic disease activity index, tissue damage, and goblet cell disintegration. αTL suppressed the orchestration of mast cells in the inflamed colon, enhanced the immunostaining of NF-kB-p65, COX-2, iNOS, p53, caspase-9, and cleaved caspase-3, and suppressed the immunostaining of connexin-43, survivin, and Bcl-2. The activities of caspases-9 and -3 were reduced significantly by αTL pretreatment, as also confirmed by calorimetric assays. Moreover, αTL significantly attenuated the nitric oxide level and myeloperoxidase activity. Histological results further support the fact that αTL reduced DSS-induced colonic damage and reduced inflammatory cell infiltration. Overall, our findings suggest that αTL has strong protective effects against DSS-induced colitis by mitigating inflammatory and apoptotic responses.

Triclocarban exposure aggravates dextran sulfate sodium-induced colitis by deteriorating the gut barrier function and microbial community in mice.

Triclocarban (TCC) is an antibacterial component widely used in personal care products with potential toxicity possessing public health issues. Unfortunately, enterotoxicity mechanisms of TCC exposure remain largely unknown. Using a combination of 16S rRNA gene sequencing, metabolomics, histopathological and biological examinations, this study systematically explored the deteriorating effects of TCC exposure on a dextran sulfate sodium (DSS)-induced colitis mouse model. We found that TCC exposure at different doses significantly aggravated colitis phenotypes including shortened colon length and altered colonic histopathology. Mechanically, TCC exposure further disrupted intestinal barrier function, manifested by significant downregulation of the number of goblet cells, mucus layer thickness and expression of junction proteins (MUC-2, ZO-1, E-cadherin and Occludin). The gut microbiota composition and its metabolites such as short-chain fatty acids (SCFAs) and tryptophan metabolites were also markedly altered in DSS-induced colitis mice. Consequently, TCC exposure markedly exacerbated colonic inflammatory status of DSS-treated mice by activating NF-κB pathway. These findings provided new evidence that TCC could be an environmental hazards for development of IBD or even colon cancer.

Gastrointestinal Microenvironment Responsive Nanoencapsulation of Probiotics and Drugs for Synergistic Therapy of Intestinal Diseases.

The gut microbiota are prominent in preserving intestinal environmental homeostasis and managing human health, and their dysbiosis has been directly related to many kinds of intestinal diseases. Probiotics-based therapy appears as a promising approach for the treatment of gut microbiota dysbiosis, while it always suffers from limited bioavailability and therapeutic effect after oral administration. Herein, we presented a facile and safe strategy to treat colitis by nanoencapsulation of probiotics and an anti-inflammatory agent, 5-aminosalicylic acid (5-ASA), within the gastrointestinal microenvironment responsive alginate polysaccharide. Because of acid resistance, the alginate-based coating protected probiotics from the harsh gastric condition. The coating could be disintegrated to release probiotics and 5-ASA upon arriving in the intestinal tract, where the pH is normally higher than 5. In the dextran sulfate sodium-induced colitis mouse model, probiotics recovered their bioactivities and acted together with anti-inflammatory 5-ASA to alleviate colitis by upregulating microbiota richness and diversity, reducing expression of proinflammatory cytokines, and restoring intestinal barriers. This work demonstrated the synergistic therapy of intestinal diseases based on alginate-encapsulated probiotics and a clinical drug, which provided an extensive method to improve the therapeutic effect of oral microecologics.

Mucosal transcriptomics highlight lncRNAs implicated in ulcerative colitis, Crohn's disease, and celiac disease.

Ulcerative colitis (UC), Crohn's disease (CD), and celiac disease are prevalent intestinal inflammatory disorders with nonsatisfactory therapeutic interventions. Analyzing patient data-driven cohorts can highlight disease pathways and new targets for interventions. Long noncoding RNAs (lncRNAs) are attractive candidates, since they are readily targetable by RNA therapeutics, show relative cell-specific expression, and play key cellular functions. Uniformly analyzing gut mucosal transcriptomics from 696 subjects, we have highlighted lncRNA expression along the gastrointestinal (GI) tract, demonstrating that, in control samples, lncRNAs have a more location-specific expression in comparison with protein-coding genes. We defined dysregulation of lncRNAs in treatment-naive UC, CD, and celiac diseases using independent test and validation cohorts. Using the Predicting Response to Standardized Pediatric Colitis Therapy (PROTECT) inception UC cohort, we defined and prioritized lncRNA linked with UC severity and prospective outcomes, and we highlighted lncRNAs linked with gut microbes previously implicated in mucosal homeostasis. HNF1A-AS1 lncRNA was reduced in all 3 conditions and was further reduced in more severe UC form. Similarly, the reduction of HNF1A-AS1 ortholog in mice gut epithelia showed higher sensitivity to dextran sodium sulfate-induced colitis, which was coupled with alteration in the gut microbial community. These analyses highlight prioritized dysregulated lncRNAs that can guide future preclinical studies for testing them as potential targets.

Colon-Targeted Release of Turmeric Nonextractable Polyphenols and Their Anticolitis Potential via Gut Microbiota-Dependent Alleviation on Intestinal Barrier Dysfunction in Mice.

Solid evidence has emerged supporting the role of nonextractable polyphenols (NEPs) and dietary fibers (DFs) as gut microbiota modulators. This study aims to elucidate gut microbiota-dependent release of turmeric NEPs and examine the possible anti-inflammatory mechanism in the dextran sulfate sodium-induced ulcerative colitis (UC) model. 1.5% DSS drinking water-induced C57BL/6J mice were fed a standard rodent chow supplemented with or without 8% extractable polyphenols (EPs), NEPs, or DFs for 37 days. The bound curcumin, demethoxycurcumin, and bisdemethoxycurcumin in NEPs were released up to 181.5 ± 10.6, 65.2 ± 6.0, and 69.5 ± 7.6 μg/mL by in vitro gut microbiota-simulated fermentation and released into the colon of NEP-supplemented mice by 5.7-, 11.0-, and 7.8-fold higher than pseudo germ-free mice, respectively (p < 0.05). NEPs also enhanced the colonic microbiota-dependent production of short-chain fatty acids in vitro and in vivo (p < 0.05). Interestingly, NEP feeding significantly improved the DSS-caused gut microbiota disorder, epithelial barrier damage, and inflammation of UC mice better than EPs or DFs (p < 0.05). Meanwhile, the pseudo germ-free mice supplemented with NEPs failed to ameliorate UC symptoms. These findings manifest that turmeric NEPs as macromolecular carriers exert the target delivery of polyphenols into the colon for regulating gut microbiota to restore the impaired gut barrier function for alleviation of inflammation.

Vitronectin Destroyed Intestinal Epithelial Cell Differentiation through Activation of PDE4-Mediated Ferroptosis in Inflammatory Bowel Disease.

Vitronectin (VTN) has been reported to trigger cell pyroptosis to aggravate inflammation in our previous study. However, the function of VTN in inflammatory bowel disease (IBD) remains to be addressed. Real-time PCR and western blotting were performed to analyze VTN-regulated intestinal epithelial cell (IEC) differentiation through ferroptosis, and immunofluorescence (IF), luciferase, and chromatin immunoprecipitation were used to identify whether VTN-modulated ferroptosis is dependent on phosphodiesterase 4 (PDE4)/protein kinase A (PKA)/cyclic adenosine monophosphate-response element-binding protein (CREB) cascade pathway. In vivo experiment in mice and a pilot study in patients with IBD were used to confirm inhibition of PDE4-alleviated IECs ferroptosis, leading to cell differentiation during mucosal healing. Herein, we found that caudal-related homeobox transcription factor 2-mediated IECs differentiation was impaired in response to VTN, which was attributed to enhanced ferroptosis characterized by decreased glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 expression. Inhibition of ferroptosis in IECs rescued the inhibitory effect of VTN on cell differentiation. Further analysis showed that VTN triggered phosphorylation of PDE4, leading to inhibit PKA/CREB activation and CREB nuclear translocation, which further reduced GPX4 transactivation. Endogenous PKA interacted with CREB, and this interaction was destroyed in response to VTN stimulation. What is more, overexpression of CREB in CaCO2 cells overcame the promotion of VTN on ferroptosis. Most importantly, inhibition of PDE4 by roflumilast or dipyridamole could alleviate dextran sulfate sodium-induced colitis in mice and in a pilot clinical study confirmed by IF. These findings demonstrated that highly expressed VTN disrupted IECs differentiation through PDE4-mediated ferroptosis in IBD, suggesting targeting PDE4 could be a promising therapeutic strategy for patients with IBD.

Epithelial TIPE1 Protein Guards against Colitis by Inhibiting TNF-α-Mediated Inflammation.

Intestinal epithelial cells (IECs) at the internal/external interface orchestrate the mucosal immune response, and IEC dysfunction has been linked to multiple inflammatory diseases, including inflammatory bowel disease. In this study, we found that a member of the TNF-α-induced protein 8 (TNFAIP8 or TIPE) family called TIPE1 is indispensable for maintaining epithelial cell barrier integrity and homeostasis under inflammatory conditions. TIPE1-deficient mice, or chimeric mice that were deficient in TIPE1 in their nonhematopoietic cells, were more sensitive to dextran sulfate sodium-induced experimental colitis; however, TIPE1 deficiency had no impact on the development of inflammation-associated and sporadic colorectal cancers. Mechanistically, TIPE1 prevented experimental colitis through modulation of TNF-α-dependent inflammatory response in IECs. Importantly, genetic deletion of both TIPE1 and its related protein TNFAIP8 in mice led to the development of spontaneous chronic colitis, indicating that both of these two TIPE family members play crucial roles in maintaining intestinal homeostasis. Collectively, our findings highlight an important mechanism by which TIPE family proteins maintain intestinal homeostasis and prevent inflammatory disorders in the gut.