Intestinal Immune Imbalance is an Alarm in the Development of IBD

Management of Atherosclerotic Cardiovascular Risk in Inflammatory Bowel Disease: Current Perspectives

Inflammatory bowel disease (IBD) is a complex condition characterized by inflammation of the gastrointestinal system, encompassing Crohn's disease and ulcerative colitis. Patients diagnosed with IBD have an increased risk of atherosclerotic cardiovascular disease. This heightened risk can be attributed to a combination of mechanisms, including traditional risk factors, chronic inflammation, intestinal dysbiosis, increased risk of thrombosis, and the use of certain medications such as corticosteroids. There are significant gaps in current knowledge, particularly regarding the management of risk factors and the use of medications for cardiovascular disease prevention. Similarly, the cardiovascular effects of specific IBD therapies, particularly the newer ones, are not yet fully understood. This review focuses on the epidemiological evidence linking IBD with cardiovascular risk factors and cardiovascular disease. It describes the potential pathophysiological mechanisms underlying this association and examines the challenges involved in accurately assessing cardiovascular risk in these patients, including the utility of complementary tools such as subclinical atherosclerosis detection. Additionally, we consider the potential therapeutic implications for managing these patients. Finally, this review also underscores the importance of multidisciplinary collaboration. Effective teamwork among gastroenterologists, cardiologists, and general practitioners is essential for providing comprehensive care to patients with IBD.

Glucose metabolism is controlled by non-coding RNAs in autoimmune diseases; a glimpse into immune system dysregulation

The immune system accidentally targets the body's tissues, causing inflammation and tissue damage, the root causes of autoimmune illnesses. In recent studies, non-coding RNAs have been shown to significantly control gene expression and metabolic pathways linked to autoimmune diseases. This review investigates the effects of non-coding RNA on glucose metabolism, a route frequently dysregulated in autoimmune illnesses such as multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, and diabetes. We review how non-coding RNA affects immune cell activity modulation, glucose absorption, glycolysis, and other metabolic processes critical to immune function. We also investigate the possibility of using non-coding RNA-mediated metabolic pathway targeting as a new therapeutic approach to treat autoimmune disorders. By clarifying the complex interplay of non-coding RNA, glucose metabolism, and immune dysregulation, this study endeavors to enhance comprehension of autoimmune etiology and facilitate the creation of focused therapies.

The potential of Sijunzi decoction in the fight against gastrointestinal disorders: a review

Sijunzi Decoction (SJZD) is a traditional Chinese medicine formula widely used in the treatment of gastrointestinal disorders. Clinical studies have substantiated the efficacy of SJZD in managing conditions such as functional dyspepsia, chronic gastritis, gastric cancer, irritable bowel syndrome, colorectal cancer, and ulcerative colitis. Despite its proven effectiveness, the precise mechanisms by which SJZD operates remain incompletely understood. In this study, we undertake a systematic review of both the clinical applications and the mechanistic underpinnings of SJZD in the context of gastrointestinal disease treatment. Research indicates that SJZD functions through a spectrum of mechanisms including the regulation of intestinal flora, alleviation of inflammation, modulation of immune responses, and facilitation of mucosal repair in the treatment of gastrointestinal ailments. This comprehensive analysis aims to provide a clearer understanding of how SJZD benefits patients with gastrointestinal disorders.

Lactobacillus fermentum 016 Alleviates Mice Colitis by Modulating Oxidative Stress, Gut Microbiota, and Microbial Metabolism

Ulcerative colitis (UC) is a chronic and progressive inflammatory gastrointestinal disease closely associated with gut microbiota dysbiosis and metabolic homeostasis disruption. Although targeted microbial therapies are an emerging intervention strategy for inflammatory bowel disease (IBD), the mechanisms by which specific probiotics, such as Lactobacillus fermentum 016 (LF), alleviate UC remain unclear. The current study evaluated the effects of LF supplementation on gut health in a basal model using C57BL/6 mice. Subsequently, the preventive effects and mechanisms of LF supplementation on DSS-induced UC were systematically investigated. According to our findings, LF supplementation revealed immunoregulatory capabilities with significantly altered gut the composition of microbiota and metabolic activities, particularly enhancing tryptophan metabolism. In the UC model, LF supplementation effectively mitigated weight loss, increased the disease activity index (DAI), and alleviated diarrhea, rectal bleeding, and colon shortening. Moreover, it reduced colonic pathological damage and histological injury scores. LF intervention improved antioxidant markers and intestinal mucosal barrier function with the activation of the Nrf2-Keap1 signaling pathway and regulation of systemic inflammatory markers, i.e., IL-1β, IL-6, TNF-α, IFN-γ, IL-4, and IL-10. Importantly, LF supplementation reversed metabolic disturbances by significantly increasing the abundance of beneficial genera (e.g., g_Dubosiella, g_Faecalibaculum, g_Odoribacter, g_Candidatus_saccharimonas, g_Roseburia, and g_Eubacterium_xylanophilum_group) and elevating tryptophan metabolites (e.g., melatonin, kynurenic acid, 3-indoleacetic acid, 5-methoxytryptophan, and 5-hydroxyindoleacetic acid). In conclusion, Lactobacillus fermentum 016 exhibits potential for regulating gut microbiota homeostasis, enhancing tryptophan metabolism, and alleviating UC, providing critical insights for developing probiotic-based precision therapeutic strategies for IBD.

Neutrophil-macrophage hybrid membrane-coated prussian blue nanozyme for ulcerative colitis treatment and mechanistic insights

BACKGROUND

Ulcerative colitis (UC) is a chronic and recurrent digestive tract disease that can lead to significant morbidity and mortality. The pathogenesis of UC is intricately associated with the presence of reactive oxygen species (ROS). Prussian blue (PB), an inorganic nanozyme with potent antioxidant properties, has been extensively applied in the treatment of various inflammatory conditions and tumors. However, despite the explicit antioxidant properties, the underlying molecular mechanism of PB nanozyme in the treatment of UC remains poorly understood. Furthermore, there is a deficiency in antioxidants that possess specific targeting capabilities towards UC lesions. The present study pioneered the fabrication of neutrophil (N)-macrophage (M) hybrid membrane-coated PB (NM-PB) nanozyme for the treatment of UC and investigated its underlying molecular mechanism.

RESULTS

We have successfully constructed PB, N-PB, M-PB, and NM-PB nanozymes. In both the colitis cell model and UC mouse model, compared with PB, N-PB, and M-PB nanozymes, NM-PB nanozymes exhibited remarkable targeting capabilities, significantly enhancing the localization and uptake of PB nanozymes at the lesion site. NM-PB nanozymes significantly reduced levels of ROS (•OH, •OOH, and H2O2) and decreased the production of proinflammatory cytokines (TNF-α, IL-6, IL-1β). Meanwhile, these nanozymes regulated the expression of intestinal mucosal barrier-related proteins (ZO-1, E-cadherin, and Occludin) and apoptosis-related proteins (Bcl2, Bax). Furthermore, NM-PB nanozymes facilitated the polarization of proinflammatory M1-phenotype macrophage towards an anti-inflammatory M2-phenotype. The mechanistic studies demonstrated that NM-PB nanozymes mitigated the progression of UC by inhibiting the pathway of cytokine-cytokine receptor interaction.

CONCLUSION

The NM-PB nanozymes provide a promising and innovative alternative for the treatment of UC, offering enhanced targeting and efficacy through their unique design and mechanism of action.

DAMP-ing IBD: Extinguish the Fire and Prevent Smoldering

In inflammatory bowel diseases (IBD), the most promising therapies targeting cytokines or immune cell trafficking demonstrate around 40% efficacy. As IBD is a multifactorial inflammation of the intestinal tract, a single-target approach is unlikely to solve this problem, necessitating an alternative strategy that addresses its variability. One approach often overlooked by the pharmaceutically driven therapeutic options is to address the impact of environmental factors. This is somewhat surprising considering that IBD is increasingly viewed as a condition heavily influenced by such factors, including diet, stress, and environmental pollution-often referred to as the "Western lifestyle". In IBD, intestinal responses result from a complex interplay among the genetic background of the patient, molecules, cells, and the local inflammatory microenvironment where danger- and microbe-associated molecular patterns (D/MAMPs) provide an adjuvant-rich environment. Through activating DAMP receptors, this array of pro-inflammatory factors can stimulate, for example, the NLRP3 inflammasome-a major amplifier of the inflammatory response in IBD, and various immune cells via non-specific bystander activation of myeloid cells (e.g., macrophages) and lymphocytes (e.g., tissue-resident memory T cells). Current single-target biological treatment approaches can dampen the immune response, but without reducing exposure to environmental factors of IBD, e.g., by changing diet (reducing ultra-processed foods), the adjuvant-rich landscape is never resolved and continues to drive intestinal mucosal dysregulation. Thus, such treatment approaches are not enough to put out the inflammatory fire. The resultant smoldering, low-grade inflammation diminishes physiological resilience of the intestinal (micro)environment, perpetuating the state of chronic disease. Therefore, our hypothesis posits that successful interventions for IBD must address the complexity of the disease by simultaneously targeting all modifiable aspects: innate immunity cytokines and microbiota, adaptive immunity cells and cytokines, and factors that relate to the (micro)environment. Thus the disease can be comprehensively treated across the nano-, meso-, and microscales, rather than with a focus on single targets. A broader perspective on IBD treatment that also includes options to adapt the DAMPing (micro)environment is warranted.

Intestinal epithelial glycocalyx and intestinal disease

With the continuous research on glycobiology, more and more diseases are found to be associated with the glycocalyx. Glycocalyx can be categorized as endothelial glycocalyx and epithelial glycocalyx. Past studies mostly target endothelial glycocalyx, and this review focuses on the structure and function of intestinal epithelial glycocalyx, its degradation mechanism and biological relevance to different diseases of the intestinal tract, as well as the targeted delivery of drugs to organs by nanoparticle libraries mimicking the glycocalyx, in order to provide a theoretical basis for the study of potential diagnostic markers and therapeutic targets of intestinal epithelial glycocalyx in intestinal diseases.

NPSR1 promotes chronic colitis through regulating CD4+ T cell effector function in inflammatory bowel disease

BACKGROUND

Neuropeptide S receptor 1 (NPSR1) has been implicated in the the onset of inflammatory bowel disease (IBD), though its exact mechanism remains unclear. This study investigates the role of NPSR1 in regulating CD4+ T cell effector function in IBD.

METHODS

Peripheral blood and colonic mucosal biopsies from IBD patients, as well as dextran sodium sulfate (DSS)-induced mouse colitis models, were analyzed to assess the effects of NPSR1 on colitis and CD4+ T cell-mediated immune responses. NPSR1 knockdown was conducted both in vitro and in vivo to elucidate underlying mechanisms. Expression of NPSR1 and CD4+ T cell-related factors was measured using quantitative real-time PCR, immunoblotting, cytometric bead array, immunofluorescence, and immunohistochemistry. CD4 + T cell effector functions were evaluated through flow cytometry, EdU incorporation assay, Annexin V-FITC/PI staining, and transwell assay.

RESULTS

NPSR1 expression was elevated in the intestinal tissues from IBD patients. Its downregulation provided protection in DSS-induced mouse colitis models. NPSR1 correlated positively with CD4 + T cell-mediated inflammation, and its knockdown reduced CD4+ T cell-mediated immune responses and inhibited CD4+ T cell differentiation. Additionally, NPSR1 knockdown decreased CD4+ T cell proliferation, increased apoptosis, and enhanced CCL2-induced migration in vitro, while significantly reducing Th1 cell chemotaxis in vivo.

CONCLUSIONS

This study demonstrates that NPSR1 promotes chronic colitis by regulating CD4 + T cell effector functions in IBD, offering potential new therapeutic strategies for IBD treatment.

Novel immune cross-talk between inflammatory bowel disease and IgA nephropathy

The mechanisms underlying the complex correlation between immunoglobulin A nephropathy (IgAN) and inflammatory bowel disease (IBD) remain unclear. This study aimed to identify the optimal cross-talk genes, potential pathways, and mutual immune-infiltrating microenvironments between IBD and IgAN to elucidate the linkage between patients with IBD and IgAN. The IgAN and IBD datasets were obtained from the Gene Expression Omnibus (GEO). Three algorithms, CIBERSORTx, ssGSEA, and xCell, were used to evaluate the similarities in the infiltrating microenvironment between the two diseases. Weighted gene co-expression network analysis (WGCNA) was implemented in the IBD dataset to identify the major immune infiltration modules, and the Boruta algorithm, RFE algorithm, and LASSO regression were applied to filter the cross-talk genes. Next, multiple machine learning models were applied to confirm the optimal cross-talk genes. Finally, the relevant findings were validated using histology and immunohistochemistry analysis of IBD mice. Immune infiltration analysis showed no significant differences between IBD and IgAN samples in most immune cells. The three algorithms identified 10 diagnostic genes, MAPK3, NFKB1, FDX1, EPHX2, SYNPO, KDF1, METTL7A, RIDA, HSDL2, and RIPK2; FDX1 and NFKB1 were enhanced in the kidney of IBD mice. Kyoto Encyclopedia of Genes and Genomes analysis showed 15 mutual pathways between the two diseases, with lipid metabolism playing a vital role in the cross-talk. Our findings offer insights into the shared immune mechanisms of IgAN and IBD. These common pathways, diagnostic cross-talk genes, and cell-mediated abnormal immunity may inform further experimental studies.

The landscape of miRNA-mRNA regulatory network and cellular sources in inflammatory bowel diseases: insights from text mining and single cell RNA sequencing analysis

Background

Inflammatory Bowel Diseases (IBDs), encompassing Ulcerative Colitis (UC) and Crohn's Disease (CD), are chronic, recurrent inflammatory conditions of the gastrointestinal tract. The microRNA (miRNA) -mRNA regulatory network is pivotal in the initiation and progression of IBDs. Although individual studies provide valuable insights into miRNA mechanisms in IBDs, they often have limited scope due to constraints in population diversity, sample size, sequencing platform variability, batch effects, and potential researcher bias. Our study aimed to construct comprehensive miRNA-mRNA regulatory networks and determine the cellular sources and functions of key miRNAs in IBD pathogenesis.

Methods

To minimize potential bias from individual studies, we utilized a text mining-based approach on published scientific literature from PubMed and PMC databases to identify miRNAs and mRNAs associated with IBDs and their subtypes. We constructed miRNA-mRNA regulatory networks by integrating both predicted and experimentally validated results from DIANA, Targetscan, PicTar, Miranda, miRDB, and miRTarBase (all of which are databases for miRNA target annotation). The functions of miRNAs were determined through gene enrichment analysis of their target mRNAs. Additionally, we used two large-scale single-cell RNA sequencing datasets to identify the cellular sources of miRNAs and the association of their expression levels with clinical status, molecular and functional alternation in CD and UC.

Results

Our analysis systematically summarized IBD-related genes using text-mining methodologies. We constructed three comprehensive miRNA-mRNA regulatory networks specific to IBD, CD, and UC. Through cross-analysis with two large-scale scRNA-seq datasets, we determined the cellular sources of the identified miRNAs. Despite originating from different cell types, hsa-miR-142, hsa-miR-145, and hsa-miR-146a were common to both CD and UC. Notably, hsa-miR-145 was identified as myofibroblast-specific in both CD and UC. Furthermore, we found that higher tissue repair and enhanced glucose and lipid metabolism were associated with hsa-miR-145 in myofibroblasts in both CD and UC contexts.

Conclusion

This comprehensive approach revealed common and distinct miRNA-mRNA regulatory networks in CD and UC, identified cell-specific miRNA expressions (notably hsa-miR-145 in myofibroblasts), and linked miRNA expression to functional alterations in IBD. These findings not only enhance our understanding of IBD pathogenesis but also offer promising diagnostic biomarkers and therapeutic targets for clinical practice in managing IBDs.

T Cell-Derived Apoptotic Extracellular Vesicles Hydrolyze cGAMP to Alleviate Radiation Enteritis via Surface Enzyme ENPP1

Radiation enteritis is the most common complication of pelvic radiotherapy, but there is no effective prevention or treatment drug. Apoptotic T cells and their products play an important role in regulating inflammation and maintaining physiological immune homeostasis. Here it is shown that systemically infused T cell-derived apoptotic extracellular vesicles (ApoEVs) can target mice irradiated intestines and alleviate radiation enteritis. Mechanistically, radiation elevates the synthesis of intestinal 2'3' cyclic GMP-AMP (cGAMP) and activates cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) proinflammatory pathway. After systemic infusion of ApoEVs, the ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) enriches on the surface of ApoEVs hydrolyze extracellular cGAMP, resulting in inhibition of the cGAS-STING pathway activated by irradiation. Furthermore, after ApoEVs are phagocytosed by phagocytes, ENPP1 on ApoEVs hydrolyzed intracellular cGAMP, which serves as an intracellular cGAMP hydrolyzation mode, thereby alleviating radiation enteritis. The findings shed light on the intracellular and extracellular hydrolysis capacity of ApoEVs and their role in inflammation regulation.

Fast-Responsive HClO-Activated Near-Infrared Fluorescent Probe for In Vivo Diagnosis of Inflammatory Bowel Disease and Ex Vivo Optical Fecal Analysis

Inflammatory bowel disease (IBD) is an idiopathic intestinal inflammatory disease, whose etiology is intimately related to the overproduction of hypochlorous acid (HClO). Optical monitoring of HClO in the living body favors real-time diagnosis of inflammatory diseases. However, HClO-activated near-infrared (NIR) fluorescent probes with rapid response and high inflammatory cell uptake are still lacking. Herein, we report an activatable acceptor-π-acceptor (A-π-A)-type NIR fluorescent probe (Cy-DM) bearing two d-mannosamine groups for the sensitive detection of HClO in early IBD and stool testing. Once reacted with HClO, nonfluorescent Cy-DM could be turned on within 2 s by generating a donor-π-acceptor (D-π-A) structure due to the enhanced intramolecular charge transfer mechanism, showing intense NIR fluorescence emission at 700 nm and a large Stokes shift of 115 nm. Moreover, it was able to sensitively and selectively image exogenous and endogenous HClO in the lysosomes of living cells with a detection limit of 0.84 μM. More importantly, because of the d-mannosamine modification, Cy-DM was efficiently taken up by inflammatory cells in the intestine after intravenous administration, allowing noninvasive visualization of endogenous HClO in a lipopolysaccharide-induced IBD mouse model with a high fluorescence contrast of 6.8/1. In addition, water-soluble Cy-DM has also been successfully applied in ex vivo optical fecal analysis, exhibiting a 3.4-fold higher fluorescence intensity in the feces excreted by IBD mice. We believe that Cy-DM is promising as an invaluable tool for rapid diagnosis of HClO-related diseases as well as stool testing.

Ca2+-Dependent Processes of Innate Immunity in IBD

IBD is an uncontrolled inflammatory condition of the gastrointestinal tract, which mainly manifests in two forms: ulcerative colitis (UC) and Crohn's disease (CD). The pathogenesis of IBD appears to be associated with an abnormal response of innate and adaptive immune cells. Innate immunity cells, such as macrophages, mast cells, and granulocytes, can produce proinflammatory (e.g., TNF-α) and oxidative stress (ROS) mediators promoting intestinal damage, and their abnormal responses can induce an imbalance in adaptive immunity, leading to the production of inflammatory cytokines that increase innate immune damage, abate intestinal barrier functions, and aggravate inflammation. Considering that Ca2+ signalling plays a key role in a plethora of cellular functions, this review has the purpose of deepening the potential Ca2+ involvement in IBD pathogenesis.

Immune Diseases Associated with Aging: Molecular Mechanisms and Treatment Strategies

Aging is associated with a decline in immune function, thereby causing an increased susceptibility to various diseases. Herein, we review immune diseases associated with aging, focusing on tumors, atherosclerosis, and immunodeficiency disorders. The molecular mechanisms underlying these conditions are discussed, highlighting telomere shortening, tissue inflammation, and altered signaling pathways, e.g., the mammalian target of the rapamycin (mTOR) pathway, as key contributors to immune dysfunction. The role of the senescence-associated secretory phenotype in driving chronic tissue inflammation and disruption has been examined. Our review underscores the significance of targeting tissue inflammation and immunomodulation for treating immune disorders. In addition, anti-inflammatory medications, including corticosteroids and nonsteroidal anti-inflammatory drugs, and novel approaches, e.g., probiotics and polyphenols, are discussed. Immunotherapy, particularly immune checkpoint inhibitor therapy and adoptive T-cell therapy, has been explored for its potential to enhance immune responses in older populations. A comprehensive analysis of immune disorders associated with aging and underlying molecular mechanisms provides insights into potential treatment strategies to alleviate the burden of these conditions in the aging population. The interplay among immune dysfunction, chronic tissue inflammation, and innovative therapeutic approaches highlights the importance of elucidating these complex processes to develop effective interventions to improve the quality of life in older adults.