The role of medicinal products in the treatment of inflammatory bowel diseases (IBD) through inhibition of TLR4/NF-kappaB pathway

TLR4 inhibitors through inhibiting (MYD88-TRIF) pathway, protect against experimentally-induced intestinal (I/R) injury

Intestinal ischemia/reperfusion (I/R) injury is a serious condition that causes intestinal dysfunction and can be fatal. Previous research has shown that toll-like receptor 4 (TLR4) inhibitors have a protective effect against this injury. This study aimed to investigate the protective effects of TLR4 inhibitors, specifically cyclobenzaprine, ketotifen, amitriptyline, and naltrexone, in rats with intestinal (I/R) injury. Albino rats were divided into seven groups: vehicle control, sham-operated, I/R injury, I/R-cyclobenzaprine (10 mg/kg body weight), I/R-ketotifen (1 mg/kg body weight), I/R-amitriptyline (10 mg/kg body weight), and I/R-naltrexone (4 mg/kg body weight) groups. Anesthetized rats (urethane 1.8 g/kg) underwent 30 min of intestinal ischemia by occluding the superior mesenteric artery (SMA), followed by 2 h of reperfusion. Intestinal tissue samples were collected to measure various parameters, including malondialdehyde (MDA), nitric oxide synthase (NO), myeloperoxidase (MPO), superoxide dismutase (SOD), TLR4, intercellular adhesion molecule-1 (ICAM-1), nuclear factor kappa bp65 (NF-ĸBP65), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), macrophages CD68, myeloid differentiation factor 88 (MYD88), and toll interleukin receptor-domain-containing adaptor-inducing interferon β (TRIF). The use of TLR4 inhibitors significantly reduced MDA, MPO, and NO levels, while increasing SOD activity. Furthermore, it significantly decreased TLR4, ICAM-1, TNF-α, MCP-1, MYD88, and TRIF levels. These drugs also showed partial restoration of normal cellular structure with reduced inflammation. Additionally, there was a decrease in NF-ĸBP65 and macrophages CD68 staining compared to rats in the I/R groups. This study focuses on how TLR4 inhibitors enhance intestinal function and protect against intestinal (I/R) injury by influencing macrophages CD86 through (MYD88-TRIF) pathway, as well as their effects on oxidation and inflammation.

Uncovering the impact of alcohol on internal organs and reproductive health: Exploring TLR4/NF-kB and CYP2E1/ROS/Nrf2 pathways

This review delves into the detrimental impact of alcohol consumption on internal organs and reproductive health, elucidating the underlying mechanisms involving the Toll-like receptor 4 (TLR4)/Nuclear factor kappa light chain enhancer of activated B cells (NF-kB) pathway and the Cytochrome P450 2E1 (CYP2E1)/reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. The TLR4/NF-kB pathway, crucial for inflammatory and immune responses, triggers the production of pro-inflammatory agents and type-1 interferon, disrupting the balance between inflammatory and antioxidant responses when tissues are chronically exposed to alcohol. Alcohol-induced dysbiosis in gut microbes heightens gut wall permeability to pathogen-associated molecular patterns (PAMPs), leading to liver cell infection and subsequent inflammation. Concurrently, CYP2E1-mediated alcohol metabolism generates ROS, causing oxidative stress and damaging cells, lipids, proteins, and deoxyribonucleic acid (DNA). To counteract this inflammatory imbalance, Nrf2 regulates gene expression, inhibiting inflammatory progression and promoting antioxidant responses. Excessive alcohol intake results in elevated liver enzymes (ADH, CYP2E1, and catalase), ROS, NADH, acetaldehyde, and acetate, leading to damage in vital organs such as the heart, brain, and lungs. Moreover, alcohol negatively affects reproductive health by inhibiting the hypothalamic-pituitary-gonadal axis, causing infertility in both men and women. These findings underscore the profound health concerns associated with alcohol-induced damage, emphasizing the need for public awareness regarding the intricate interplay between immune responses and the multi-organ impacts of alcohol consumption.

Cinnamaldehyde, A Bioactive Compound from the Leaves of Cinnamomum osmophloeum Kaneh, Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Inhibiting the NLRP3 Inflammasome

Inflammatory bowel disease (IBD) comprises a group of idiopathic intestinal disorders, including ulcerative colitis and Crohn's disease, significantly impacting the quality of life for affected individuals. The effective management of these conditions remains a persistent challenge. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a complex molecular structure, regulates the production of pro-inflammatory cytokines such as interleukin-1β. Abnormal activation of the NLRP3 inflammasome plays a pivotal role in the development of IBD, making it a compelling target for therapeutic intervention. Our research revealed that cinnamaldehyde (CA), a major bioactive compound found in the leaves of Cinnamomum osmophloeum kaneh, demonstrated a remarkable ability to alleviate colitis induced by dextran sulfate sodium (DSS) in a mouse model. This effect was attributed to CA's ability to downregulate the activation of the NLRP3 inflammasome and reduce the expression of pro-inflammatory mediators in the colon. In the mechanism study, we observed that CA inhibited the NLRP3 inflammasome in macrophages, at least partially, by enhancing the autophagic response, without reducing mitochondrial damage. These findings collectively suggest that CA holds significant potential as a therapeutic agent for enhancing the management of IBD, offering a promising avenue for further research and development.

The protective effect of teprenone in TNBS-induced ulcerative colitis rats by modulating the gut microbiota and reducing inflammatory response

OBJECTIVE

Ulcerative colitis (UC), a chronic and refractory nonspecific inflammatory bowel disease, affects millions of patients worldwide and increases the risk of colorectal cancer. Teprenone is an acylic polyisoprenoid that exerts anti-inflammatory properties in rat models of peptic ulcer disease. This in vitro and in vivo study was designed to investigate the effects of teprenone on UC and to explore the underlying mechanisms.

METHODS

Human intestinal epithelial cells (Caco-2 cells) serve as the in vitro experimental model. Lipopolysaccharide (LPS, 1 μg/mL) was employed to stimulate the production of pro-inflammatory cytokines (interleukin [IL]-6, IL-1β, and tumor necrosis factor [TNF]-α), Toll-like receptor-4 (TLR4), MyD88 expression, and NF-κB activation. A trinitrobenzene sulfonic acid (TNBS)-induced chronic UC rat model was employed for the in vivo assay.

RESULTS

Pro-inflammatory cytokine stimulation by LPS in Caco-2 cells was inhibited by teprenone at 40 μg/mL through the TLR4/NF-κB signaling pathway. Teprenone attenuated TNBS-induced UC, decreased myeloperoxidase and malondialdehyde, induced TLR4 expression and NF-κB activation, and increased glutathione and zonula occludens-1 level in the rat colonic tissue. Moreover, Fusobacterium, Escherichia coli, Porphyromonas gingivalis elevation, and Mogibacterium timidum decline in UC rats were inhibited by teprenone.

CONCLUSION

Based on our results, the protective effects of teprenone for UC may be related to its ability to modulate the gut microbiota and reduce the inflammatory response.

An in vitro study elucidating the synergistic effects of aqueous cinnamon extract and an anti-TNF-α biotherapeutic: implications for a complementary and alternative therapy for non-responders

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is a critical pro-inflammatory cytokine, and its abnormal production is associated with several immune mediated inflammatory diseases (IMID). Biological anti-TNF-α therapy includes treatment with monoclonal antibodies such as infliximab which have proven successful and are well-tolerated in most patients. Unfortunately, some patients may not respond to therapy (primary non-responders) or may lose sensitivity to the biological agent over time (early and late secondary non-responders). Natural products can reduce inflammation and act synergistically with small molecules or biologics, although evidence remains limited. This study aimed to investigate whether complementary and alternative medicine (CAM) could play a role in infliximab non-responders. Reportedly, cinnamon can help manage chronic inflammatory conditions owing to its anti-inflammatory properties.

METHODS

We studied the synergistic effects of cinnamon and infliximab in vitro using a two-step approach. First, we investigated whether cinnamon and infliximab act synergistically. Second, we selected conditions that supported statistically significant synergy with infliximab and studied the mRNA expression of several genes involved in non-response to infliximab. We used aqueous cinnamon extract (aCE) from Cinnamomum cassia, Cinnamomum zeylanicum, and Cinnamomum loureiroi and bioactive trans-cinnamaldehyde (TCA), cinnamic acid (CA), and eugenol to study the synergy between infliximab and aCE/bioactive compounds using bioassays in fibroblast (L929) and monocytic (U937) cell lines, followed by qPCR for molecular-level insights. TCA, C. cassia aCE, and C. zeylanicum aCE demonstrated a dose-dependent synergistic effect with infliximab. Moreover, we saw differential gene expression for adhesion molecules, apoptotic factors, signaling molecules, and matrix remodelers in presence and absence of aCE/bioactives.

RESULTS

CAM supplementation was most effective with C. cassia aCE, where a synergistic effect was observed for all the tested genes specifically for MMP-1, BcL-xL, Bax and JAK2, followed by TCA, which affected most of the tested genes except TLR-2, MMP1, MMP3, TIMP-1, and BAX, and C. zeylanicum aCE, which did not affect ICAM-1, VCAM-1, TLR-2, TLR-4, MMP1, MMP3, TIMP-1, and STAT3.

CONCLUSION

In conclusion, cinnamon acted synergistically with infliximab to mitigate inflammation when used as an extract. Purified bioactive TCA also showed synergistic activity. Thus, aCE, or cinnamon bioactive may be used as a CAM to improve patients' quality of life.

Olive Mill Waste-Water Extract Enriched in Hydroxytyrosol and Tyrosol Modulates Host-Pathogen Interaction in IPEC-J2 Cells

The dietary supplementation of olive oil by-products, including olive mill waste-water (OMWW) in animal diets, is a novel application that allows for their re-utilization and recycling and could potentially decrease the use of antibiotics, antimicrobial resistance risk in livestock species, and the occurrence of intestinal diseases. Salmonella serovar typhimurium is one of the most widespread intestinal pathogens in the world, causing enterocolitis in pigs. The aim of this study was to investigate the effect of an OMWW extract enriched in polyphenols (hydroxytyrosol and tyrosol) in the immune response of an intestinal porcine epithelial cell line (IPEC-J2) following S. typhimurium infection. Cells were pre-treated with OMWW-extract polyphenols (OMWW-EP, 0.35 and 1.4 µg) for 24 h and then infected with S. typhimurium for 1 h. We evaluated bacterial invasiveness and assayed IPEC-J2 gene expression with RT-qPCR and cytokine release with an ELISA test. The obtained results showed that OMWW-EP (1.4 µg) significantly reduced S. typhimurium invasiveness; 0.35 µg decreased the IPEC-J2 gene expression of IL1B, MYD88, DEFB1 and DEFB4A, while 1.4 µg down-regulated IL1B and DEFB4A and increased TGFB1. The cytokine content was unchanged in infected cells. This is the first study demonstrating the in vitro immunomodulatory and antimicrobial activity of OMWW extracts enriched in polyphenols, suggesting a protective role of OMWW polyphenols on the pig intestine and their potential application as feed supplements in farm animals such as pigs.

The protective effect of Schisandra chinensis (Turcz.) Baill. polysaccharide on DSS-induced ulcerative colitis in mice via the modulation of gut microbiota and inhibition of NF-κB activation

BACKGROUND

Schisandra chinensis (Turcz.) Baill, a fruit utilized in traditional Chinese medicine (TCM), has a long history of medical application. It has been used to treat diseases of the gastrointestinal tract. Schisandra chinensis (Turcz.) Baill polysaccharide (SACP) is an important biologically active ingredient that has been shown to have a variety of beneficial effects including immune regulation and anti-oxidative properties. Ulcerative colitis (UC) is a complicated gastrointestinal inflammatory disease. We explore the protective effect of SACP against UC.

RESULTS

Schisandra chinensis (Turcz.) Baill polysaccharide significantly reduced the disease activity index (DAI) and levels of myeloperoxidase(MPO) and malondialdehyde (MDA) in colonic tissue. It also alleviated weight loss and histopathological damage of mice. The expression of MUC2 and occludin proteins was increased and the barrier function of the colonic mucosa was enhanced by SACP treatment. NF-κB pathway activation was also inhibited and the production of pro-inflammatory cytokines was decreased whereas anti-inflammatory cytokines were increased. 16SrDNA sequencing of fecal flora showed that SACP increased the abundance of Muribaculaceaeunclassified, LachnospiraceaeNK4A136group and reduced the abundance of Bacteroides and Erysipelatoclostridium.

CONCLUSION

Schisandra chinensis (Turcz.) Baill polysaccharide can protect against Dextran Sulfate Sodium Salt (DSS)-induced ulcerative colitis in mice. © 2023 Society of Chemical Industry.

Lactiplantibacillus plantarum HY7718 Improves Intestinal Integrity in a DSS-Induced Ulcerative Colitis Mouse Model by Suppressing Inflammation through Modulation of the Gut Microbiota

Inflammatory bowel disease (IBD), a chronic condition that causes persistent inflammation in the digestive system, is closely associated with the intestinal microbiome. Here, we evaluated the effects of Lactiplantibacillus plantarum HY7718 (HY7718) on IBD symptoms in mice with dextran sulfate sodium (DSS)-induced colitis. Oral administration of HY7718 led to significant improvement in the disease activity index score and the histological index, as well as preventing weight loss, in model mice. HY7718 upregulated the expression of intestinal tight junction (TJ)-related genes and downregulated the expression of genes encoding pro-inflammatory cytokines and genes involved in the TLR/MyD88/NF-κB signaling pathway. Additionally, HY7718 reduced the blood levels of pro-inflammatory cytokines, as well as reversing DSS-induced changes to the composition of the intestinal microbiome. HY7718 also increased the percentage of beneficial bacteria (Lactiplantibacillus and Bifidobacterium), which correlated positively with the expression of intestinal TJ-related genes. Finally, HY7718 decreased the population of pathogens such as Escherichia, which correlated with IBD symptoms. The data suggest that HY7718 improves intestinal integrity in colitis model mice by regulating the expression of TJ proteins and inflammatory cytokines, as well as the composition of the intestinal microflora. Thus, L. plantarum HY7718 may be suitable as a functional supplement that improves IBD symptoms and gut health.

Discovery of an effective anti-inflammatory agent for inhibiting the activation of NF-κB

In this study, based on the effect of compounds on the activation of NF-κB and NO release, compound 51 was discovered as the best one with NO release inhibition IC₅₀ value was 3.1 ± 1.1 μM and NF-κB activity inhibition IC₅₀ value was 172.2 ± 11.4 nM. Compound 51 could inhibit the activation of NF-κB through suppressing phosphorylation and nuclear translocation of NF-κB, and suppress LPS-induced inflammatory response in RAW264.7 cells, such as the over-expression of TNF-α and IL-6, which were target genes of NF-κB. This compound also showed preferable anti-inflammatory activity in vivo, including alleviating significantly gastric distention and splenomegaly caused by LPS stimulation, reducing the level of oxidative stress induced by LPS, and inhibiting the expression of IL-6 and TNF-α in serum. Thus, it's reasonable to consider that this compound is a promising small molecule with anti-inflammatory effect for inhibiting the NF-κB signalling pathway.

An overview of limonoid synthetic derivatives as promising bioactive molecules

Limonoids, a class of abundant natural tetracyclic triterpenoids, present diverse biological activity and provide a versatile platform amenable by chemical modifications for clinical use. Among all of the limonoids isolated from natural sources, obacunone, nomilin, and limonin are the primary hub of limonoid-based chemical modification research. To date, more than 800 limonoids analogs have been synthesized, some of which possess promising biological activities. This review not only discusses the synthesis of limonoid derivatives as promising therapeutic candidates and details the pharmacological studies of their underlying mechanisms from 2002 to 2022, but also proposes a preliminary limonoid synthetic structure-activity relationship (SAR) and provides future direction of limonoid derivatization research.

Investigation of the anti-inflammatory effects of native potential probiotics as supplementary therapeutic agents in an in-vitro model of inflammation

BACKGROUND

IBD is considered an inflammatory disease with abnormal and exaggerated immune responses. To control the symptoms, different theraputic agents could be used, however, utilizing the agents with the least side effects could be important. Probiotics as beneficial microorganisms are one of the complementory theraputic agents that could be used to modulate inflammatory signaling pathways. In the current study, we aimed to identify the precise molecular effects of potential probiotics on signaling pathways involved in the development of inflammation.

METHODS

A quantitative real-time polymerase chain reaction (qPCR) assay was used to analyze the expression of JAK /STAT (JAK1, JAK2, JAK3, TYK2, STAT1, STAT2, STAT3, STAT4, STAT5 and STAT6) and inflammatory genes (NEMO, TIRAP, IRAK, and RIP) after the HT -29 cell line treatment with the sonicated pathogens and potential probiotics. A cytokine assay was also used to evaluate IL -6 and IL -1β production after potential probiotic treatment.

RESULTS

The potential probiotic cocktail downregulated the JAK genes and TIRAP, IRAK4, NEMO, and RIP genes in the NF-kB pathway compared with cells that were treated with sonicated gram negative pathogens. The expression of STAT genes was different after potential probiotic treatment. The production of IL -6 and IL -1β decreased after potential probiotic treatment.

CONCLUSIONS

Considering the importance of controlling the symptoms of IBD to improve the life quality of the patients, using probiotic could be crucial. In the current study the studied native potential probiotic cocktails showed anti-inflammatory effects via modulation of JAK /STAT and NF-kB signaling pathways. This observation suggests that our native potential probiotics consumption could be useful in reducing intestinal inflammation.

Ameliorating inflammation in an in vitro model by screening the anti-inflammatory and immunomodulatory roles of putative probiotics in inflammatory bowel disease

IBD is considered a relapsing disease with relapsing phases. Probiotics are beneficial microorganisms that modulate inflammatory signaling pathways. Our aim was to identify the precise molecular effects of probiotics on inflammatory signaling pathways during the presence of inflammation. Evaluation of the expression of JAK/STAT and inflammatory genes after treatment of the HT -29 cell line with the sonicated pathogens and probiotics, simultaneously was performed by quantitative real-time polymerase chain reaction (qPCR) assay. The production of IL-6 and IL-1β after administration of probiotics was conducted by means of cytokine assay. The probiotic cocktail resulted in the downregulation of TIRAP, IRAK4, NEMO, and RIP genes in the NF-кB pathway compared with Sonicat-treated cells. The expression of JAK/STAT genes was various after probiotic treatment. The application of probiotics has been observed to result in a notable decrease in the production of IL-6 and IL-1β. The investigated probiotic cocktail, especially Bifidobacterium spp. showed anti-inflammatory effects on HT -29 cells via modulation of JAK/STAT and NF-кB signaling pathways. The use of probiotics with the least side effects could be considered a suitable treatment for patients with inflammatory bowel disease, even at the beginning of inflammation.

Mirabegron alleviates acetic acid-induced colitis in rats: role of adiponectin and GSTM1/GSH detoxification pathway

The prevalence of the debilitating chronic disease ulcerative colitis (UC) is increasing significantly. Mirabegron is a selective beta-3 adrenergic receptor (β-3 AR) agonist used to treat an overactive bladder. Previous reports have demonstrated the antidiarrheal effect of β-3AR agonists. Therefore, the current study aims to investigate the potential symptomatic effects of mirabegron on an experimental colitis model. The effects of oral administration of mirabegron (10mg/kg) for seven days on rats receiving intra-rectal acetic acid instillation on the sixth day were examined using adult male Wistar rats. Sulfasalazine was utilized as a reference medication. Gross, microscopic, and biochemical observations of the experimental colitis were performed. The quantity and mucin content of goblet cells were found to have significantly decreased in the colitis group. In the colons of rats administered mirabegron, the number of goblet cells and the optical density of its mucin content increased. Mirabegron's ability to increase adiponectin in serum and decrease glutathione, GSTM1, and catalase in the colon may account for its protective effects. In addition, mirabegron decreased the expression of the proteins caspase-3 and NF-κB p65. It also prevented the activation of their upstream signaling receptors TLR4 and p-AKT by acetic acid administration. In conclusion, mirabegron prevented acetic acid-induced colitis in rats, possibly due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

Prophylactic vs. Therapeutic Effect of Probiotics on the Inflammation Mediated by the NF-κB Pathway in Inflammatory Bowel Conditions

Probiotic supplements consumed adequately at the proper time can affect health by modulating inflammatory pathways in gastrointestinal epithelial cells and modifying the resultant inflammatory response. The current study applied in vitro models to investigate the effectiveness of probiotics in modulating inflammatory pathways and altering inflammatory gene expression in gastrointestinal epithelial cells, with the ultimate goal of promoting probiotic consumption as a therapeutic and preventive measure for chronic inflammatory bowel conditions. HT-29 cells were treated with Gram-negative bacteria to evaluate the changes in pathways related to inflammation activities before and after treatment with a Lactobacillus spp. cocktail (L. plantarum, L. rhamnosus, L. brevis, and L. ruteri) and a Bifidobacterium spp. cocktail (B. bifidum, B. langum, and B. breve) using the real-time PCR method and ELISA for IL-1β and IL-6 as pro-inflammatory cytokines. The results showed that the expression of NF-κB signaling pathway genes and IL-1β and IL-6 cytokines increased after exposure to Gram-negative components. In contrast, all probiotic combinations significantly decreased the expression of genes and the secretion of cytokines. However, this decrease was significantly smaller in cells that underwent probiotic treatment after inflammation induction. In addition, cocktails containing combined Lactobacillus and Bifidobacterium demonstrated robust anti-inflammatory activity relative to solo cocktails. Our observations confirm that probiotic consumption could positively impact inflammatory conditions and alleviate inflammatory symptoms; they can be particularly effective as a preventive measure. Our study provides preliminary evidence to support the lifetime consumption of probiotics.

Pathomorphological Manifestations and the Course of the Cervical Cancer Disease Determined by Variations in the TLR4 Gene

Cervical cancer (CC) is often associated with human papillomavirus (HPV). Chronic inflammation has been described as one of the triggers of cancer. The immune system fights diseases, including cancer. The genetic polymorphism of pathogen recognition receptors potentially influences the infectious process, development, and disease progression. Many candidate genes SNPs have been contradictory demonstrated to be associated with cervical cancer by association studies, GWAS. TLR4 gene activation can promote antitumor immunity. It can also result in immunosuppression and tumor growth. Our study aimed to investigate eight selected polymorphisms of the TLR4 gene (rs10759932, rs1927906, rs11536898, rs11536865, rs10983755, rs4986790, rs4986791, rs11536897) and to determine the impact of polymorphisms in genotypes and alleles on the pathomorphological characteristics and progression in a group of 172 cervical cancer subjects with stage I-IV. Genotyping was performed by RT-PCR assay. We detected that the CA genotype and A allele of rs11536898 were significantly more frequent in patients with metastases (p = 0.026; p = 0.008). The multivariate logistic regression analysis confirmed this link to be significant. The effect of rs10759932 and rs11536898 on progression-free survival (PFS) and overall survival (OS) has been identified as important. In univariate and multivariate Cox analyses, AA genotype of rs11536898 was a negative prognostic factor for PFS (p = 0.024; p = 0.057, respectively) and OS (p = 0.008; p = 0.042, respectively). Rs11536898 C allele predisposed for longer PFS (univariate and multivariate: p = 0.025; p = 0.048, respectively) and for better OS (univariate and multivariate: p = 0.010; p = 0.043). The worse prognostic factor of rs10759932 in a univariate and multivariate Cox analysis for survival was CC genotype: shorter PFS (p = 0.032) and increased risk of death (p = 0.048; p = 0.015, respectively). The T allele of rs10759932 increased longer PFS (univariate and multivariate: p = 0.048; p = 0.019, respectively) and longer OS (univariate and multivariate: p = 0.037; p = 0.009, respectively). Our study suggests that SNPs rs10759932 and rs11536898 may have the potential to be markers contributing to the assessment of the cervical cancer prognosis. Further studies, preferably with larger groups of different ethnic backgrounds, are needed to confirm the results of the current study.

New Insights into the Mechanism of Ulva pertusa on Colitis in Mice: Modulation of the Pain and Immune System

Inflammatory bowel diseases (IBDs) involving Crohn's disease (CD) and ulcerative colitis (UC) are gastrointestinal (GI) disorders in which abdominal pain, discomfort, and diarrhea are the major symptoms. The immune system plays an important role in the pathogenesis of IBD and, as indicated by several clinical studies, both innate and adaptative immune response has the faculty to induce gut inflammation in UC patients. An inappropriate mucosal immune response to normal intestinal constituents is a main feature of UC, thus leading to an imbalance in local pro- and anti-inflammatory species. Ulva pertusa, a marine green alga, is known for its important biological properties, which could represent a source of beneficial effects in various human pathologies. We have already demonstrated the anti-inflammatory, antioxidant, and antiapoptotic effects of an Ulva pertusa extract in a murine model of colitis. In this study, we aimed to examine thoroughly Ulva pertusa immunomodulatory and pain-relieving properties. Colitis was induced by using the DNBS model (4 mg in 100 μL of 50% ethanol), whereas Ulva pertusa was administered daily at the dosage of 50 and 100 mg/kg by oral gavage. Ulva pertusa treatments have been shown to relieve abdominal pain while modulating innate and adaptative immune-inflammatory responses. This powerful immunomodulatory activity was specifically linked with TLR4 and NLRP3 inflammasome modulation. In conclusion, our data suggest Ulva pertusa as a valid approach to counteract immune dysregulation and abdominal discomfort in IBD.

Azelaic Acid Regulates the Renin-Angiotensin System and Improves Colitis Based on Network Pharmacology and Experimentation

Inflammatory bowel disease (IBD), which encompasses Crohn's disease and ulcerative colitis, has a complicated etiology that might be brought on by metabolic dysbiosis. Previous metabonomic studies have found a correlation between decreased azelaic acid (AzA) and IBD. Herein, data from the Metabolomics Workbench showed that the content of AzA decreased in IBD patients (PR000639) and dextran sulfate sodium (DSS)-induced mice (PR000837). The effects of AzA on IBD were then examined using a DSS-induced mouse model, and the results demonstrated that AzA alleviated clinical activity, decreased pro-inflammatory cytokine production, and reduced CD4⁺CD25⁺Foxp3⁺Treg percentages in mesenteric lymph nodes. Through network pharmacology analysis, we discovered 99 candidate IBD-associated genes that are potentially regulated by AzA. After the enrichment analysis of the candidate genes, the renin-angiotensin system (RAS) pathway was one of the most substantially enriched pathways. Additionally, AzA reversed the increased expression of important RAS components (ACE, ACE2, and MAS1L) following DSS induction, suggesting that AzA exerts therapeutic effects possibly via the RAS pathway. This study suggests that AzA may be a promising drug for treating IBD.

Frontier Review of the Molecular Mechanisms and Current Approaches of Stem Cell-Derived Exosomes

Exosomes are effective therapeutic vehicles that may transport their substances across cells. They are shown to possess the capacity to affect cell proliferation, migration, anti-apoptosis, anti-scarring, and angiogenesis, via the action of transporting molecular components. Possessing immense potential in regenerative medicine, exosomes, especially stem cell-derived exosomes, have the advantages of low immunogenicity, minimal invasiveness, and broad clinical applicability. Exosome biodistribution and pharmacokinetics may be altered, in response to recent advancements in technology, for the purpose of treating particular illnesses. Yet, prior to clinical application, it is crucial to ascertain the ideal dose and any potential negative consequences of an exosome. This review focuses on the therapeutic potential of stem cell-derived exosomes and further illustrates the molecular mechanisms that underpin their potential in musculoskeletal regeneration, wound healing, female infertility, cardiac recovery, immunomodulation, neurological disease, and metabolic regulation. In addition, we provide a summary of the currently effective techniques for isolating exosomes, and describe the innovations in biomaterials that improve the efficacy of exosome-based treatments. Overall, this paper provides an updated overview of the biological factors found in stem cell-derived exosomes, as well as potential targets for future cell-free therapeutic applications.

Intestinal Absorption and Anti-Inflammatory Effects of Siphonein, a Siphonaxanthin Fatty Acid Ester from Green Algae

Siphonein is a C19 acylated siphonaxanthin found in some edible green algae (e.g., Codium fragile and Caulerpa lentillifera). Although the content of siphonein in these green algae is similar to or higher than that of siphonaxanthin, studies of health-related biological activity of siphonein are much less than those of siphonaxanthin. Given the difference in the position of the acyl chain, one cannot infer intestinal absorption of siphonein from other general carotenoid fatty acid esters. In this study, we first investigated the intestinal absorption of siphonein using mouse and cell culture models. A small amount of siphonein was detected in the plasma of treated mice, and its concentration was higher than that of siphonaxanthin (i.e., the hydrolyzed product of ingested siphonein) from 1 to 6 h after administration. Pharmacological inhibition tests with differentiated Caco-2 cells showed that Nieman-Pick C1-like 1-mediated facilitated diffusion was involved in the cellular uptake of siphonein. These results indicate that, unlike general carotenoid fatty acid esters, siphonein can be absorbed without hydrolysis. We also evaluated the anti-inflammatory effect of siphonein in differentiated Caco-2 cells. Siphonein pretreatment modulated lipopolysaccharide-induced cellular lipidome alterations and suppressed mRNA expression of proinflammatory chemokines, CXCL8 protein release, and activation of NF-κB. This study provides new insights into the absorption processes of carotenoids and shows the anti-inflammatory effect of siphonein for the first time.

Protective Effect of Lactiplantibacillus plantarum subsp. plantarum SC-5 on Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) is a specific immune-associated intestinal disease. At present, the conventional treatment for patients is not ideal. Probiotics are widely used in the treatment of IBD patients due to their ability to restore the function of the intestinal mucosal barrier effectively and safely. Lactiplantibacillus plantarum subsp. plantarum is a kind of probiotic that exists in the intestines of hosts and is considered to have good probiotic properties. In this study, we evaluated the therapeutic effect of Lactiplantibacillus plantarum subsp. plantarum SC-5 (SC-5) on dextran sulfate sodium (DSS)-induced colitis in C57BL/6J mice. We estimated the effect of SC-5 on the clinical symptoms of mice through a body weight change, colon length, and DAI score. The inhibitory effects of SC-5 on the levels of cytokine IL-1β, IL-6, and TNF-α were determined by ELISA. The protein expression levels of NF-κB, MAPK signaling pathway, and the tight junction proteins occludin, claudin-3, and ZO-1 were verified using Western Blot and immunofluorescence. 16S rRNA was used to verify the modulatory effect of SC-5 on the structure of intestinal microbiota in DSS-induced colitis mice. The results showed that SC-5 could alleviate the clinical symptoms of DSS-induced colitis mice, and significantly reduce the expression of pro-inflammatory cytokines in the colon tissue. It also attenuated the inflammatory response by inhibiting the protein expression of NF-κB and MAPK signaling pathways. SC-5 improved the integrity of the intestinal mucosal barrier by strengthening tight junction proteins. In addition, 16S rRNA sequencing demonstrated that SC-5 was effective in restoring intestinal flora balance, as well as in increasing the relative abundance and diversity of beneficial microbiota. These results indicated that SC-5 has the potential to be developed as a new probiotic candidate that prevents or alleviates IBD.

Therapeutic Potential of Bioactive Components from Scutellaria baicalensis Georgi in Inflammatory Bowel Disease and Colorectal Cancer: A Review

Scutellaria baicalensis Georgi (SBG), an herbal medicine with various biological activities, including anti-inflammatory, anticancer, antiviral, antibacterial, and antioxidant activities, is effective in treatment of colitis, hepatitis, pneumonia, respiratory infections, and allergic diseases. This herbal medicine consists of major active substances, such as baicalin, baicalein, wogonoside, and wogonin. Inflammatory bowel disease (IBD) comprises a group of inflammatory conditions of the colon and small intestine, with Crohn's disease and ulcerative colitis being the main types. IBD can lead to serious complications, such as increased risk of colorectal cancer (CRC), one of the most common cancers worldwide. Currently, there is no cure for IBD, and its incidence has been increasing over the past few decades. This review comprehensively summarizes the efficacy of SBG in IBD and CRC and may serve as a reference for future research and development of drugs for IBD and cancer treatment.

Sanhuang xiexin decoction ameliorates secondary liver injury in DSS-induced colitis involve regulating inflammation and bile acid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

SanHuang XieXin decoction (SXD) is a widely applicated traditional Chinese medicine (TCM) with a significant gut-liver axis regulation effect.

AIM OF THE STUDY

To evaluate the therapeutic effect and elucidate the possible underlying molecular mechanisms of SXD on liver damage secondary to ulcerative colitis (UC) in mice.

MATERIALS AND METHODS

A model of liver damage secondary to UC was induced by drinking 5% dextran sodium sulfate (DSS) in mice. These mice were treated with one of three doses of SXD or sulfasalazine (SASP), then liver samples were collected and tested.

RESULTS

The results reveal that SXD treatment reduced liver cells swelling, and inhibited the accumulation of the hepatic-pro-inflammatory cytokines IL-1β and tumor necrosis factor-α (TNF-α) in mice with colitis. In addition, SXD reduced the production of nitric oxide (NO) and malondialdehyde (MDA), and increased the activities of superoxide dismutase (SOD). In inflammation regulating, SXD significantly down regulated the protein expression of MyD88 and p-Iκα, but upregulated Iκα. In bile acid metabolism regulating, SXD significantly down regulated the protein expression of FXR, MRP₂, BESP and SHP. Therefore, SXD treatment can regulate the TLR4-NF-κB and bile acid metabolism pathways to alleviate liver inflammation and cholestasis.

CONCLUSIONS

These results demonstrate that SXD is a potential alternative therapeutic medicine for the treatment of liver damage secondary to colitis.

The protective effects of nesfatin-1 in neurological dysfunction after spinal cord injury by inhibiting neuroinflammation

AIMS

Spinal cord injury (SCI) is one of the most severe neurological diseases. However, there is still no effective treatment for it. Nesfatin, a precursor neuropeptide derived from nucleobindin 2 (NUCB2), has displayed a wide range of protective effects in different types of cells and tissue. However, the effects of nesfatin-1 in SCI have not been reported before.

MATERIALS AND METHODS

A SCI model was established. The behavior of mice was assessed using the Basso, Beattie, and Bresnahan (BBB) assessment.

RESULTS

Here, we report that the administration of nesfatin-1 improved neurological recovery in SCI mice by increasing BBB scores, reducing lesion area volume and spinal cord water content. Also, nesfatin-1 ameliorated oxidative stress by reducing reactive oxygen species (ROS) levels and increasing superoxide dismutase (SOD) activity. We also found that nesfatin-1 prevented neuronal apoptosis in SCI mice by reducing caspase 3 activity and the expression of Bax, as well as increasing B-cell lymphoma-2 (Bcl-2). Additionally, nesfatin-1 reduced the levels of interleukin 6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). Nesfatin-1 also promoted microglia towards M2 polarization by increasing the marker CD206 but reducing CD16. Importantly, nesfatin-1 enhanced the phosphorylation of signal transducer and activator of transcription 1 (STAT1) but reduced the expression levels of toll-like receptor 4 (TLR4) and phosphorylated nuclear factor kappa-B p65 (p-NF-κB p65).

CONCLUSION

Our findings imply that nesfatin-1 exerts neuroprotective actions in SCI by promoting the activation of M2 microglia, and its underlying mechanisms might be related to the activation of STAT1 and inhibition of the TLR4/NF-κB signaling pathway.

Effect of Ginger on Inflammatory Diseases

Ulcerative colitis, Crohn's disease, rheumatoid arthritis, psoriasis, and lupus erythematosus are some of common inflammatory diseases. These affections are highly disabling and share signals such as inflammatory sequences and immune dysregulation. The use of foods with anti-inflammatory properties such as ginger (Zingiber officinale Roscoe) could improve the quality of life of these patients. Ginger is a plant widely used and known by its bioactive compounds. There is enough evidence to prove that ginger possesses multiple biological activities, especially antioxidant and anti-inflammatory capacities. In this review, we summarize the current knowledge about the bioactive compounds of ginger and their role in the inflammatory process and its signaling pathways. We can conclude that the compounds 6-shoagol, zingerone, and 8-shoagol display promising results in human and animal models, reducing some of the main symptoms of some inflammatory diseases such as arthritis. For lupus, 6-gingerol demonstrated a protective attenuating neutrophil extracellular trap release in response to phosphodiesterase inhibition. Ginger decreases NF-kβ in psoriasis, and its short-term administration may be an alternative coadjuvant treatment. Ginger may exert a function of supplementation and protection against cancer. Furthermore, when receiving chemotherapy, ginger may reduce some symptoms of treatment (e.g., nausea).

In vitro evaluation of immunomodulatory activities of goat milk Extracellular Vesicles (mEVs) in a model of gut inflammation

Gut represents a major immunological defense barrier with mucosal immune system and intestinal epithelial cells (IECs). In all intestinal diseases, in particular inflammatory bowel disease (IBD), both the absorption and the local immune system are compromised and alternative effective therapies are sought after. Extracellular Vesicles (EVs) have the capability to regulate immune cells within the inflammatory microenvironment, by dampening inflammation and restoring intestinal barrier integrity. Recently, the immune-modulatory role of EVs has also been confirmed for milk EVs (mEVs), notable for their easy production, high sample volumes, cost-effective scalable production and non-toxic and non-immunogenic behavior. In this context, the aim of this study was to evaluate goat mEV anti-inflammatory and immuno-modulating effects on an in vitro model (IPEC-J2) of intestinal inflammation through gene expression evaluation with RT-qPCR and cytokine release dosage with ELISA test. After the establishment of a pro-inflammatory environment due to LPS stimuli, IL6, CXCL8, IL12p35, IL12p40, IFNB, IL18, TLR7 and NOS2 resulted significantly up-regulated in stimulated IPEC-J2 cells compared to those of the basal culture. After 48 h of mEV treatment in inflamed IPEC-J2 a partial restoration of initial conditions was detected, with the IL18 and IL12p40 significant down-regulation, and IL12p35, EBI3, TLR7, BD1 and BD3 up-regulation. IL-18 reduced protein production was also detected in supernatants. Moreover, a decrease of MMP9 and NOS2 together with a strong up-regulation of MUC2 indicated a recovery of cellular homeostasis and, therefore, potential beneficial effects on the intestinal mucosa. Nevertheless, 48 h post-treatment, an increased gene expression and protein release of IL-8 was observed. This paper is one of the firsts to assess the effect of goat mEVs and the first one, in particular, of doing this on an in vitro model of gut inflammation. The obtained results show a potential capability of goat mEVs to modulate inflammation and to play beneficial effects on the intestinal mucosa.

Research trends in ulcerative colitis: A bibliometric and visualized study from 2011 to 2021

Background: Ulcerative colitis (UC) is an idiopathic inflammatory bowel disease with repeated relapses and remissions. Despite decades of effort, numerous aspects, including the initiating event and pathogenesis of UC, still remain ambiguous, which requires ongoing investigation. Given the mass of publications on UC, there are multidimensional challenges to evaluating the scientific impact of relevant work and identifying the current foci of the multifaceted disease. Accordingly, herein, we aim to assess the global growth of UC research production, analyze patterns of research areas, and evaluate trends in this area.

Methods: The Web of Science Core Collection of Clarivate Analytics was searched for articles related to UC published from 2011 to 2021. Microsoft Office Excel 2019 was used to visualize the number of publications over time. Knowledge maps were generated using CiteSpace and VOSviewer to analyze collaborations among countries, institutions, and authors and to present the journey of UC research as well as to reveal the current foci of UC research.

Results: A total of 5,088 publications were evaluated in the present study. China had the most publications (1,099, 22.5%). Univ Calif San Diego was the most productive institution (126, 2.48%). William J Sandborn published the greatest number of articles (100, 1.97%). Toshifumi Hibi was the most influential author in the field with a betweenness centrality of 0.53. Inflammatory bowel diseases was identified as the most prolific journal (379, 7.45%). Gastroenterology was the most co-cited journal (3,730, 4.02%). “Vedolizumab,” “tofacitinib,” “Faecalibacterium prausnitzii,” “fecal microbiota transplantation (FMT),” “toll-like receptor 4,” and “nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome” were considered the hot topics.

Conclusion: In UC research, manuscripts that had high impacts on the scientific community provided an evidence base. UC therapy has entered the era of personalized and precision therapy. As research on FMT, anti-integrin antibodies, Janus kinase inhibitors, and anti-tumor necrosis factor drugs continues to grow, their use in the clinical setting may also expand.

The potential role of Bifidobacterium spp. as a preventive and therapeutic agent in controlling inflammation via affecting inflammatory signalling pathways

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with relapses and periods of remission. Forasmuch as, dysregulation of the immune system is one of the triggers of IBD, taking probiotics as one of the immunomodulators in the gut, could help to control inflammation and IBD via influencing signalling pathways. Here, we aimed to investigate the efficacy of five selected Bifidobacterium strains in modulating JAK/STAT and NF-kB inflammatory signalling pathways via using the in vitro assay. A quantitative real-time polymerase chain reaction assay was used to analyse the expression of JAK/STAT and inflammatory genes followed by potential probiotic treatments before, after and simultaneously with the inflammation induction (sonicated pathogen). The production of IL-6 and IL-1β after probiotic treatment was evaluated. Probiotic treatment resulted in the downregulation of TIRAP, IRAK4, NEMO and RIP genes in the NF-kB pathway, as well as JAK genes compared to sonicate-treated cells. The expression of STAT genes was different after our selected Bifidobacterium strains treatment. The production of IL-6 and IL-1β decreased after probiotic treatment. These strains of Bifidobacterium spp. showed anti-inflammatory effects on HT-29 cells via modulation of JAK/STAT and NF-kB signalling pathways. The use of Bifidobacterium spp. could be considered as a suitable preventive and complementary treatment for patients with inflammatory bowel disease.

Dexmedetomidine reduces IL-4 and IgE expression through downregulation of theTLR4/NF-κB signaling pathway to alleviate airway hyperresponsiveness in OVA mice

BACKGROUND

Airway hyperresponsiveness (AHR) is a clinical manifestation of airflow limitation due to abnormal tracheal and bronchial sensitivity and is the main basis for the diagnosis of asthma. Patients with AHR are at high risk of perioperative tracheal and bronchospasm, which can lead to hypoxaemia and haemodynamic instability and, in severe cases, to a life-threatening 'silent lung'. It is therefore important to reduce the incidence or intensity of AHR episodes in the perioperative period. The inflammatory response is key to the development and progression of AHR.

HYPOTHESIS/PURPOSE

Based on the modulatory role of dexmedetomidine (DEX) in the inflammatory response, we hypothesised that dexmedetomidine (DEX) attenuates inflammatory properties by inhibiting the toll-like receptor 4 (TLR4)/nuclear factor (NF-κB) signalling pathway and can reduce the respiratory parameters of mechanical ventilation in ovalbumin-induced allergic airway hyperresponsiveness.

STUDY DESIGN

BABL/C mice were divided into control and OVA groups (ovalbumin-induced allergy. Ten mice in all OVA models were randomly selected for in vivo invasive lung function monitoring to analyse airway resistance parameters and demonstrate successful model establishment. The remaining OVA mice were treated with dexmedetomidine 25 μg/kg for 5 days (OVA + DEX group) or dexmedetomidine 25 μg/kg + yohimbine 1 mg/kg for 5 days (OVA + DEX + yohimbine). After treatment, bronchoalveolar lavage fluid (BAL) and peripheral blood (ELISA) and lung tissue (H&E and PAS) were collected for analysis of inflammatory factors, and lung tissue was verified by PCR for genes and proteins that do correlate with inflammatory mediators.

RESULTS

All airway resistance parameters were increased in OVA mice by invasive lung function monitoring. Proximal airway resistance (parameter Rn) and total respiratory resistance (parameter Rrs) were attenuated after dexmedetomidine intervention treatment. Dexmedetomidine reduced total inflammatory cell count and inflammatory infiltration of lung tissue in BALF and down-regulated IL-4 and IgE levels in BALF and peripheral blood, as shown by Giemsa, H&E, PAS staining and ELISA; this mechanism of action was found to be related to the TLR4/NFκB pathway, but not to TLR4/NFκB, as measured by PCR.

CONCLUSION

Dexmedetomidine reduces hyperresponsiveness and airway inflammatory responses. This mechanism of action may be related to the TLR4/NFκB signalling pathway. Overall conclusions are presented in.

Molecular Mechanism of Equine Endometrosis: The NF-κB-Dependent Pathway Underlies the Ovarian Steroid Receptors’ Dysfunction

Endometrosis is a frequently occurring disease decreasing mares’ fertility. Thus, it is an important disease of the endometrium associated with epithelial and stromal cell alterations, endometrium gland degeneration and periglandular fibrosis. Multiple degenerative changes are found in uterine mucosa, the endometrium. However, their pathogenesis is not well known. It is thought that nuclear factor-κB (NF-κB), a cell metabolism regulator, and its activation pathways take part in it. The transcription of the profibrotic pathway genes of the NF-κB in fibrotic endometria differed between the follicular (FLP) and mid-luteal (MLP) phases of the estrous cycle, as well as with fibrosis progression. This study aimed to investigate the transcription of genes of estrogen (ESR1, ESR2) and progesterone receptors (PGR) in equine endometria to find relationships between the endocrine environment, NF-κB-pathway, and fibrosis. Endometrial samples (n = 100), collected in FLP or MLP, were classified histologically, and examined using quantitative PCR. The phase of the cycle was determined through the evaluation of ovarian structures and hormone levels (estradiol, progesterone) in serum. The transcription of ESR1, ESR2, and PGR decreased with the severity of endometrial fibrosis and degeneration of the endometrium. Moreover, differences in the transcription of ESR1, ESR2, and PGR were noted between FLP and MLP in the specific categories and histopathological type of equine endometrosis. In FLP and MLP, specific moderate and strong correlations between ESR1, ESR2, PGR and genes of the NF-κB pathway were evidenced. The transcription of endometrial steroid receptors can be subjected to dysregulation with the degree of equine endometrosis, especially in both destructive types of endometrosis, and mediated by the canonical NF-κB pathway depending on the estrous cycle phase.

Phytochemicals targeting Toll-like receptors 4 (TLR4) in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a collective term for inflammatory diseases including Crohn's disease and ulcerative colitis. Toll-like receptor 4 (TLR4) is thought to play a key role in the pathogenesis of IBD. Inhibition of TLR4 has been recognized as an effective target for the treatment of IBD. Many phytochemicals have been shown to have potential as new drugs for the treatment of IBD. This review surveyed the available literature and reports which focused on the in vivo effects of phytochemicals targeting TLR4 in different models of IBD, and clarified the significance of TLR4 as a current therapeutic target for IBD. Based on our review, we have concluded that phytochemicals targeting TLR4 are potentially effective candidates for developing new therapeutic drugs against IBD.

Dual roles of the caspase-11 non-canonical inflammasome in inflammatory bowel disease

Inflammation is a two-step process comprising the first priming step that prepares inflammatory responses and the second triggering step that activates inflammatory responses. The key feature of the triggering step is the activation of inflammasomes and intracellular inflammatory protein complexes that provide molecular platforms to activate inflammatory signal transduction cascades. Although canonical inflammasomes have been well demonstrated to be actively involved in numerous human diseases, the roles of the recently identified non-canonical inflammasomes are largely unknown. However, recent studies have demonstrated the emerging roles of the caspase-11 non-canonical inflammasome in various human inflammatory diseases, ultimately providing strong evidence that the caspase-11 non-canonical inflammasome is a key player in the pathogenesis of various human diseases. Here, we comprehensively reviewed the regulatory roles of the caspase-11 non-canonical inflammasome in the pathogenesis of inflammatory bowel disease (IBD) and its underlying mechanisms. Overall, this review highlights the current understanding of the regulatory roles of the caspase-11 non-canonical inflammasome in IBD and may provide insight into new strategies for preventing and treating IBD and caspase-11 non-canonical inflammasome-driven diseases.

Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation

Chronic inflammatory diseases and transplant rejection represent major challenges for modern health care. Thus, identification of immune checkpoints that contribute to resolution of inflammation is key to developing novel therapeutic agents for those conditions. In recent years, the CD83 (cluster of differentiation 83) protein has emerged as an interesting potential candidate for such a "pro-resolution" therapy. This molecule occurs in a membrane-bound and a soluble isoform (mCD83 and sCD83, respectively), both of which are involved in resolution of inflammation. Originally described as a maturation marker on dendritic cells (DCs), mCD83 is also expressed by activated B and T cells as well as regulatory T cells (Tregs) and controls turnover of MHC II molecules in the thymus, and thereby positive selection of CD4+ T cells. Additionally, it serves to confine overshooting (auto-)immune responses. Consequently, animals with a conditional deletion of CD83 in DCs or regulatory T cells suffer from impaired resolution of inflammation. Pro-resolving effects of sCD83 became evident in pre-clinical autoimmune and transplantation models, where application of sCD83 reduced disease symptoms and enhanced allograft survival, respectively. Here, we summarize recent advances regarding CD83-mediated resolution of inflammatory responses, its binding partners as well as induced signaling pathways, and emphasize its therapeutic potential for future clinical trials.

Ginger and its constituents: Role in treatment of inflammatory bowel disease

Inflammatory bowel diseases (IBD), with obscure etiology, are rising and are of worldwide concern. Of the various components of IBD pathogenesis and progression, irritation appears to play a major part. Investigations on the molecular and cellular pathways that activate the IBD provide the focus for the development of useful therapies. Ginger (the rhizome of Zingiber officinale) has a broad spectrum of clinical applications due to its anti-inflammatory and anti-oxidative functions. Inflammation and oxidative stress are the key pathogenic factors in many diseases, including IBD. The most established components of ginger are phenolic compounds called gingerols. A wide range of pharmacological activities of the potential therapeutic benefit of Z. officinale have been detailed. In this regard, the anti-inflammatory activity of ginger has been documented by many researchers. It was shown that ginger is a potent inhibitor of the nuclear factor kappa B (NF-κB), signal transducer of activators of transcription (STATs), Nod-like receptor family proteins (NLRPs), toll-like receptors (TLRs), mitogen-activated protein kinase (MAPKs), and mTOR (mTOR) pathways, as well as inhibiting various pro-inflammatory cytokines. In the present report, the potential application of ginger in the management of IBD is reviewed in detail, with an emphasis on the relevant properties of ginger and its bioactive components. The significance of the functions, side effects, and delivery of ginger to the digestive system for particular application in IBD are also considered.

NF-κB signaling in inflammation and cancer

Since nuclear factor of κ-light chain of enhancer-activated B cells (NF-κB) was discovered in 1986, extraordinary efforts have been made to understand the function and regulating mechanism of NF-κB for 35 years, which lead to significant progress. Meanwhile, the molecular mechanisms regulating NF-κB activation have also been illuminated, the cascades of signaling events leading to NF-κB activity and key components of the NF-κB pathway are also identified. It has been suggested NF-κB plays an important role in human diseases, especially inflammation-related diseases. These studies make the NF-κB an attractive target for disease treatment. This review aims to summarize the knowledge of the family members of NF-κB, as well as the basic mechanisms of NF-κB signaling pathway activation. We will also review the effects of dysregulated NF-κB on inflammation, tumorigenesis, and tumor microenvironment. The progression of the translational study and drug development targeting NF-κB for inflammatory diseases and cancer treatment and the potential obstacles will be discussed. Further investigations on the precise functions of NF-κB in the physiological and pathological settings and underlying mechanisms are in the urgent need to develop drugs targeting NF-κB for inflammatory diseases and cancer treatment, with minimal side effects.

Equine Endometrosis Pathological Features: Are They Dependent on NF-κB Signaling Pathway?

Simple Summary

Endometrosis is a serious problem mainly affecting older mares’ fertility. Despite the importance of this disease, its etiology and pathogenesis are not fully known. Thus, no effective treatment exists to cease or restore degenerative processes and fibrogenesis in the mares’ endometria. The nuclear factor kappaB (NF-κB) is an important factor regulating cell metabolism. Nevertheless, it is also known to promote inflammation and fibrosis in various tissues and species, as well as in the mares’ endometria. The main goal was to bring new knowledge regarding endometrosis pathogenesis, which could allow for therapy development. Endometrial samples, collected postmortem from cyclic mares in estrus or diestrus, were classified histologically and used for gene expression assessment. Gene transcription of NF-κB subunits (subunit RelA—RelA; subunit 1—NF-κB1; subunit 2—NF-κB2), pro-inflammatory molecules (monocyte chemoattractant protein-1—MCP-1; interleukin-6—IL-6), and hyaluronan synthases (hyaluronan synthase 1—HAS 1; hyaluronan synthase 2—HAS 2; hyaluronan synthase 3—HAS 3) were compared among endometrosis types (active, non-active, destructive, non-destructive), according to the classification of Hoffmann and co-authors. These results suggest that activation of the NF-κB canonical pathway is involved especially in destructive endometrosis, the type when endometrial glands are damaged. These data give substantial information for further evaluations and treatment development.

Abstract

Endometrosis is an important mares’ disease which considerably decreases their fertility. As classic endometrial classification methods might be insufficient for tissue pathological evaluation, further categorization into active/inactive and destructive/non-destructive types was developed by Hoffmann and others. This study aimed to compare NF-κB pathway genes transcription among histopathological types of endometrosis, following Hoffmann and co-authors’ classification. Endometrial samples, collected postmortem from cyclic mares (n = 100) in estrus or diestrus, were classified histologically and used for gene transcription assessment. Gene transcription of NF-κB subunits (RelA, NF-κB1, NF-κB2), pro-inflammatory molecules (MCP-1, IL-6), and hyaluronan synthases (HAS 1, HAS 2, HAS 3) was compared among endometrosis types (active, non-active, destructive, non-destructive). Most individual mRNA samples showed high expression of RelA, NF-κB1, and MCP-1 gene transcripts and the destructive type of endometrosis, simultaneously. The expression of RelA and NF-κB1 genes was higher in active destructive group than in the other groups only in the follicular phase, as well as being higher in the inactive destructive group than in the others, only in the mid-luteal phase. The increase in gene transcription of the NF-κB canonical activation pathway in destructive endometrosis may suggest the highest changes in extracellular matrix deposition. Moreover, the estrous cycle phase might influence fibrosis pathogenesis.

Amitriptyline blocks innate immune responses mediated by TLR4 & IL1R: preclinical and clinical evidence in OA and gout

Background and Purpose

Osteoarthritis, a major cause of disability in developed countries does not have effective treatment. Activation of TLR4 and innate immune response factors contribute to osteoarthritis progressive cartilage degradation. There are no clinically available TLR4 inhibitors. Interestingly, the antidepressant amitriptyline could block this receptor. Thus, we evaluated amitriptyline anti‐TLR4 effects on human osteoarthritis chondrocytes in order to repurpose it as an inhibitor of innate immune response in joint inflammatory pathologies.

Experimental Approach

Using in silico docking analysis, RT‐PCR, siRNA, elisa, proteomics and clinical data mining of drug consumption, we explored the clinical relevance of amitriptyline blockade of TLR4‐mediated innate immune responses in human osteoarthritis chondrocytes.

Key Results

Amitriptyline bound TLR4 but not IL‐1 receptor. Interestingly, amitriptyline binding to TLR4 inhibited TLR4‐ and IL‐1 receptor‐mediated innate immune responses in human osteoarthritis chondrocytes, synoviocytes and osteoblasts cells. Amitriptyline reduced basal innate immune responses and promoted anabolic effects in human osteoarthritis chondrocytes. Supporting its anti‐innate immune response effects, amitriptyline down‐regulated basal and induced expression of NLRP3, an inflammasome member from IL‐1 receptor signalling linked to osteoarthritis and gout pathologies. Accordingly, mining of dissociated and aggregated drug consumption data from 107,172 elderly patients (>65 years) revealed that amitriptyline consumption was significantly associated with lower colchicine consumption associated with inflammatory gout flare treatment.

Conclusion and Implications

Amitriptyline blocks TLR4‐, IL‐1 receptor and NLRP3‐dependent innate immune responses. This together with clinical data amitriptyline could be repurposed for systemic or local innate immune response management in diverse joint inflammatory pathologies.

Suppression of PTRF Alleviates Post-Infectious Irritable Bowel Syndrome via Downregulation of the TLR4 Pathway in Rats

Background: Accumulating evidence suggests that the polymerase I and transcript release factor (PTRF), a key component of the caveolae structure on the plasma membrane, plays a pivotal role in suppressing the progression of colorectal cancers. However, the role of PTRF in the development of functional gastrointestinal (GI) disorders remains unclear. Post-infectious irritable bowel syndrome (PI-IBS) is a common functional GI disorder that occurs after an acute GI infection. Here, we focused on the role of PTRF in the occurrence of PI-IBS and investigated the underlying mechanisms. Methods: Lipopolysaccharide (LPS) (5 μg/ml) was used to induce inflammatory injury in human primary colonic epithelial cells (HCoEpiCs). Furthermore, a rat model of PI-IBS was used to study the role of PTRF. Intestinal sensitivity was assessed based on the fecal water content. A two-bottle sucrose intake test was used to evaluate behavioral changes. Furthermore, shRNA-mediated knockdown of PTRF was performed both in vitro and in vivo. We detected the expression of PTRF in colonic mucosal tissues through immunohistochemistry (IHC), western blotting (WB), and immunofluorescence (IF) analysis. Luciferase activity was quantified using a luciferase assay. Co-localization of PTRF and Toll-like receptor 4 (TLR4) was detected using IF analysis. The activation of the signaling pathways downstream of TLR4, including the iNOs, p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) pathways, was detected via WB. The levels of NO, IL-1β, IL-6, and TNF-α were measured using enzyme-linked immunosorbent assays. Results: LPS significantly induced PTRF expression and signaling downstream of TLR4, including p38, ERK, and JNK pathways, in HCoEpiCs. Moreover, shRNA-mediated knockdown of PTRF in HCoEpiCs significantly decreased the phosphorylation of JNK, ERK, and p38 and iNOS expression. In PI-IBS rats, the lack of PTRF not only reduced fecal water content and suppressed depressive behavior but also increased the body weight. Furthermore, we found a strong co-localization pattern for PTRF and TLR4. Consistently, the lack of PTRF impaired TLR4 signaling, as shown by the decreased levels of p-JNK, p-ERK, and p-p38, which are upstream factors involved in iNOS expression. Conclusion: PTRF promoted PI-IBS and stimulated TLR4 signaling both in vitro and in vivo. The results of this study not only enlighten the pathogenesis of PI-IBS but also help us understand the biological activity of PTRF and provide an important basis for the clinical treatment of PI-IBS by targeting PTRF.

TLR4 signaling in the development of colitis-associated cancer and its possible interplay with microRNA-155

Ulcerative colitis (UC) has closely been associated with an increased risk of colorectal cancer. However, the exact mechanisms underlying colitis-associated cancer (CAC) development remain unclear. As a classic pattern-recognition receptor, Toll like receptor (TLR)4 is a canonical receptor for lipopolysaccharide of Gram-negative bacteria (including two CAC-associated pathogens Fusobacterium nucleatum and Salmonella), and functions as a key bridge molecule linking oncogenic infection to colonic inflammatory and malignant processes. Accumulating studies verified the overexpression of TLR4 in colitis and CAC, and the over-expressed TLR4 might promote colitis-associated tumorigenesis via facilitating cell proliferation, protecting malignant cells against apoptosis, accelerating invasion and metastasis, as well as contributing to the creation of tumor-favouring cellular microenvironment. In recent years, considerable attention has been focused on the regulation of TLR4 signaling in the context of colitis-associated tumorigenesis. MicroRNA (miR)-155 and TLR4 exhibited a similar dynamic expression change during CAC development and shared similar CAC-promoting properties. The available data demonstrated an interplay between TLR4 and miR-155 in the context of different disorders or cell lines. miR-155 could augment TLR4 signaling through targeting negative regulators SOCS1 and SHIP1; and TLR4 activation would induce miR-155 expression via transcriptional and post-transcriptional mechanisms. This possible TLR4-miR-155 positive feedback loop might result in the synergistic accelerating effect of TLR4 and miR-155 on CAC development.

A Gut-Ex-Vivo System to Study Gut Inflammation Associated to Inflammatory Bowel Disease (IBD)

Simple Summary

Inflammatory Bowel Disease (IBD) is a complex and multifactorial systemic disease of the gastrointestinal tract, characterized by chronic inflammation, thus resulting in tissue damage and, occasionally, in cancer development. Although the precise origin is still elusive, it is widely considered a disease of modern society, caused by a complex interaction between environment, genetic, immune system, and gut microflora (microbiota). Potentially affected by all the above-mentioned variables, which interplay are highly heterogeneous, the disease appears to be patient-specific. The latter phenomenon, together with the uncertain origin, also contributes to the lack of optimal clinical treatment of these patients. Therefore, the development of appropriate models is crucial to push the research forward and to define new valuable therapeutic approaches. Although tissue biopsies and/or animal models represent the best models to study IBD onset, progression, and clinical interventions, they are both affected by limitations such as invasiveness, cost- and time-consuming, and ethical issues such as animal suffering. Here we propose a novel approach based on the cultivation of mouse tissues (colon) in an ex vivo microfluidic device (Gut-Ex-Vivo System, GEVS) to study IBD. We demonstrate that explanted mouse tissues cultivated in our GEVS can be appropriately stimulated to recapitulate the onset of the disease, in a time- and cost- effective manner.

Abstract

Inflammatory bowel disease (IBD) is a complex, chronic, and dysregulated inflammatory condition which etiology is still largely unknown. Its prognosis and disease progression are highly variable and unpredictable. IBD comprises several heterogeneous inflammatory conditions ranging from Ulcerative Colitis (UC) to Crohn’s Disease (CD). Importantly, a definite, well-established, and effective clinical treatment for these pathologies is still lacking. The urgent need for treatment is further supported by the notion that patients affected by UC or CD are also at risk of developing cancer. Therefore, a deeper understanding of the molecular mechanisms at the basis of IBD development and progression is strictly required to design new and efficient therapeutic regimens. Although the development of animal models has undoubtedly facilitated the study of IBD, such in vivo approaches are often expensive and time-consuming. Here we propose an organ ex vivo culture (Gut-Ex-Vivo system, GEVS) based on colon from Balb/c mice cultivated in a dynamic condition, able to model the biochemical and morphological features of the mouse models exposed to DNBS (5–12 days), in 5 h. Indeed, upon DNBS exposure, we observed a dose-dependent: (i) up-regulation of the stress-related protein transglutaminase 2 (TG2); (ii) increased intestinal permeability associated with deregulated tight junction protein expression; (iii) increased expression of pro-inflammatory cytokines, such as TNFα, IFNγ, IL1β, IL6, IL17A, and IL15; (iv) down-regulation of the anti-inflammatory IL10; and (v) induction of Endoplasmic Reticulum stress (ER stress), all markers of IBD. Altogether, these data indicate that the proposed model can be efficiently used to study the pathogenesis of IBD, in a time- and cost-effective manner.

Chrysin Derivative CM1 and Exhibited Anti-Inflammatory Action by Upregulating Toll-Interacting Protein Expression in Lipopolysaccharide-Stimulated RAW264.7 Macrophage Cells

Although our previous study revealed that gamma-irradiated chrysin enhanced anti-inflammatory activity compared to intact chrysin, it remains unclear whether the chrysin derivative, CM1, produced by gamma irradiation, negatively regulates toll-like receptor (TLR) signaling. In this study, we investigated the molecular basis for the downregulation of TLR4 signal transduction by CM1 in macrophages. We initially determined the appropriate concentration of CM1 and found no cellular toxicity below 2 μg/mL. Upon stimulation with lipopolysaccharide (LPS), CM1 modulated LPS-stimulated inflammatory action by suppressing the release of proinflammatory mediators (cytokines TNF-α and IL-6) and nitric oxide (NO) and downregulated the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways. Furthermore, CM1 markedly elevated the expression of the TLR negative regulator toll-interacting protein (Tollip) in dose- and time-dependent manners. LPS-induced expression of cell surface molecules (CD80, CD86, and MHC class I/II), proinflammatory cytokines (TNF-α and IL-6), COX-2, and iNOS-mediated NO were inhibited by CM1; these effects were prevented by the knockdown of Tollip expression. Additionally, CM1 did not affect the downregulation of LPS-induced expression of MAPKs and NF-κB signaling in Tollip-downregulated cells. These findings provide insight into effective therapeutic intervention of inflammatory disease by increasing the understanding of the negative regulation of TLR signaling induced by CM1.