Emerging evidence highlights the oral–gut axis as an important contributor to the pathogenesis of inflammatory bowel disease (IBD); however, the specific role of the tongue coating microbiota remains poorly understood. To comprehensively delineate oral–gut microbial alterations in IBD, we analyzed tongue coating and fecal microbiota from 596 participants, including 278 patients with Crohn’s disease (CD), 91 with ulcerative colitis (UC), and 227 healthy controls (HCs), using 16S ribosomal RNA (rRNA) gene sequencing. Patients with IBD exhibited a distinct dysbiotic signature in tongue coating microbiota, characterized by increased abundances of Streptococcus, Prevotella, and Gemella in both CD and UC patients, alongside a CD-specific depletion of commensal taxa such as Neisseria and Fusobacterium compared with HCs. Notably, a similar oral microbial shift was observed in a spontaneous enteritis mouse model, which demonstrated enrichment of oral Streptococcus and concordant increases in Prevotella across both oral and intestinal niches. To establish causality, tongue coating microbiota from CD patients were transplanted into antibiotic-pretreated mice, resulting in significantly exacerbated colitis relative to recipients of HC-derived microbiota. Mechanistically, Streptococcus strains isolated from CD patients promoted Th1 cell polarization in vitro and aggravated colitis in vivo, implicating these orally derived pathobionts in the amplification of intestinal inflammation. Together, these findings identify the tongue coating microbiota as a previously underappreciated mediator of gut inflammation in IBD, support its potential utility as a non-invasive biomarker for CD, and provide mechanistic evidence that oral microbial dysbiosis can actively drive intestinal immune pathology.

Currently, there exists no definitive standardized therapy for radiation enteritis. This study unveils Metrnl as a pivotal regulator of intestinal radioprotection through multi-dimensional single-cell profiling and mechanistic dissection. We first demonstrate that radiation dynamically reprograms Metrnl expression in a time-dependent manner, revealing its role as a radiation-responsive mediator. Crucially, Metrnl confers potent protection against radiation-induced intestinal injury through double mechanisms; Metrnl safeguards label-retaining cells (LRCs) rather than conventional Lgr5+ intestinal stem cells, and activates a novel c-KIT-WNT signaling axis via ERK/GSK3β-mediated pathway crosstalk, both revitalizing intestinal epithelial regeneration. Therapeutically, recombinant Metrnl emerges as a potential biotherapeutic, effectively attenuating radiation enteritis. These findings establish Metrnl as a key mediator bridging radiation biology and regenerative medicine, offering a transformative potential for radiation injury management.

Peptidyl arginine deiminase 4 (PAD4) is previously known for its role in inflammatory bowel disease (IBD) through its facilitation of neutrophil extracellular traps (NETs) by citrullinating histones. However, the specific citrullinated substrates have not been fully elucidated, especially non-histones. By performing citrullination mapping, we unraveled the involvement of cathepsin H (CTSH), a novel substrate of PAD4, which undergoes citrullination at the R315 site. Then the citrullination of CTSH obviously altered its molecular conformation and subsequently reduced its enzymatic activity, which significantly boosted the formation of NETs. Consistently, CTSH knockout mice demonstrated exacerbated colonic inflammation and higher levels of NETs, which might be achieved by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K-Akt) signaling pathway. These findings underscore the critical role of CTSH in IBD pathogenesis and position it as a potential therapeutic target, highlighting the complex interplay among PAD4, CTSH, and IBD.

Background:Cathelicidin (CAMP), plays important roles in pathogen defense, immune regulation, and epithelial barrier maintenance. While previous studies have highlighted its protective function, the post-translational modifications and downstream immune-metabolic effects of CAMP in the pathogenesis of inflammatory bowel disease remain unclear. Methods:A dextran sodium sulfate (DSS)-induced colitis mouse model was employed to assess the role of CAMP and its citrullination mediated by peptidyl arginine deiminase 4 (PAD4). Proteomic and metaproteomic analyses were performed to investigate microbiota composition and functional shifts. We generated gene-deficient mouse models, CAMP knockout (KO) and PAD4-KO mice, to dissect molecular mechanisms. Epithelial integrity, inflammatory markers, and immune responses have been evaluated at both the protein and mRNA levels. Bone marrow-derived dendritic cells and primary CD4⁺ T cells were co-cultured to examine the effects of CAMP-related metabolites on antigen presentation and Th17 differentiation. Furthermore, we evaluated the impact of CAMP peptide supplementation and the effects of CAMP-KO mice on DSS-induced colitis. Results:CAMP citrullination was significantly elevated in DSS-induced colitis mice but restored by PAD4 deletion. Citrullination was found to reduce CAMP protein levels without affecting its transcriptional expression. The absence of CAMP exacerbated intestinal inflammation in DSS-treated mice. Metaproteomic analysis identified 70 differentially expressed proteins and 15 altered microbiota families associated with CAMP deficiency. Elevated levels of arginase-1 and its metabolites, particularly polyamines, enhanced dendritic cell maturation and increased Th17 polarization in CAMP-KO mice. Conclusions:Our findings highlight that the protein level of CAMP decreased after PAD4-mediated citrullination, thus playing a vital role in regulating taxonomic community structure, restricting arginine metabolism, and regulating dendritic cell-Th17 immune responses in IBD.

Mitochondria are key regulators of inflammatory responses and mitochondrial dysfunction is closely linked to various inflammatory diseases. Increasing genetic and experimental evidence suggests that mitochondria play a critical role in inflammatory bowel disease (IBD). In the complex environment of the intestinal tract, intestinal epithelial cells (IECs) and their mitochondria possess unique phenotypic features, shaping each other and regulating intestinal homeostasis and inflammation through diverse mechanisms. Here, we focus on intestinal inflammation in IBD induced by mitochondrial damage-associated molecular patterns (mtDAMPs), which comprise mitochondrial components and metabolic products. The pathogenic mechanisms of mtDAMP signaling pathways mediated by two major mtDAMPs, mitochondrial DNA (mtDNA) and mitochondrial reactive oxygen species (mtROS), are discussed.

Mitochondrial dysfunction contributes to the pathogenesis of ulcerative colitis (UC). As a mitochondrial isozyme of creatine kinases, which control energy metabolism, CKMT1 is thought to be a critical molecule in biological processes. However, the specific role of CKMT1 in intestinal inflammation remains largely unknown. Here, we observed markedly decreased CKMT1 expression in the colon tissues of UC patients and dextran sodium sulfate (DSS)-induced colitis mice. We generated intestinal epithelial-specific CKMT1 knockout mice and demonstrated the key role of CKMT1 in mitochondrial homeostasis, intestinal epithelial barrier function, oxidative stress, and apoptosis. In the in vitro experiments, CKMT1 expression limited the activation of the intrinsic and extrinsic apoptotic pathways in IECs. Mechanistically, the loss of CKMT1 expression in IECs increased TNF-α-induced mitochondrial reactive oxygen species (ROS) generation via reverse electron transfer (RET). RET-ROS promoted mitochondrial permeability transition pore (mPTP) opening, ultimately resulting in cell apoptosis during intestinal inflammation. In conclusion, our data demonstrated that CKMT1 is important in maintaining intestinal homeostasis and mitochondrial function. This study provides a promising basis for future research and a potential therapeutic target for inflammatory bowel disease (IBD).

Piwi-interacting RNAs (piRNAs) are critical regulators of stemness maintenance in germline cells and have emerging roles in tumorigenesis. Our previous study identified piR-19521 as up-regulated in colorectal cancer (CRC), with higher levels correlating with poorer differentiation, implicating a potential role in colorectal cancer stem cells (CR-CSCs). Here, we explored piR-19521's function in CR-CSC-like properties. In CRC tissues, piR-19521 expression positively correlated with CR-CSC markers and was enriched in CR-CSCs. Over-expression of piR-19521 enhanced CR-CSC markers expression, promoted clonogenicity, migration, invasion, oxaliplatin resistance in vitro, and increased tumorigenicity and liver metastasis in vivo. Conversely, piR-19521 inhibition suppressed CR-CSC markers expression and reduced tumor initiation and self-renewal. Mechanistically, piR-19521 up-regulated ALX4, which rescued the effects of piR-19521 inhibition. Notably, piR-19521 was transcribed from an active enhancer in HCT116 cells, and its inhibition reduced H3K27ac signals and disrupted the chromatin loop between the ALX4 promoter and the piR-19521-transcribing enhancer. piR-19521 over-expression enhanced enhancer activity and ALX4 transcription. Collectively, these findings demonstrate that piR-19521 reinforces CR-CSC-like properties by functioning as an enhancer RNA to promote ALX4 expression, highlighting its potential as a therapeutic target in CRC.

PURPOSE:Acute kidney injury (AKI), a common and severe complication of acute pancreatitis (AP), is significantly linked to patient prognosis. Albumin-corrected anion gap (ACAG) is a modified acid-base balance assessment metric with potential clinical significance in various critical illnesses. However, the role of ACAG in forecasting the risk of AKI in AP patients remains unclear. This study sheds light on the relationship between ACAG levels and AKI risk in the AP population. METHODS:This retrospective study utilized data from the MIMIC-IV database, including 1,552 adult patients diagnosed with AP during their stay in the intensive care unit (ICU). ACAG was calculated using a standard formula, and patients were grouped according to their ACAG levels. Cox proportional hazards and restricted cubic spline (RCS) models were employed to assess the correlation of ACAG levels with AKI risk in AP patients. The incidence of AKI was the primary outcome, and in-hospital mortality was the secondary outcome. Differences in primary and secondary outcomes between ACAG groups were evaluated through Kaplan-Meier (KM) survival analysis. Subgroup analyses were performed for examining the influence of confounding factors. RESULTS:Higher ACAG levels were significantly related to an elevated risk of AKI. The RCS model demonstrated a nonlinear correlation between higher ACAG levels and increased AKI risk in the AP cohort, and a linear association of ACAG with in-hospital death. KM survival analysis showed that patients exhibiting higher ACAG levels had poorer renal function outcomes and higher ICU mortality. Subgroup analyses further proved this correlation across varied patient characteristics. CONCLUSIONS:Elevated ACAG is an independent predictor of AKI risk in the AP cohort. ACAG may be useful for early AKI risk stratification and clinical decision-making in critically ill AP sufferers.

Peptidyl arginine deiminase 4 (PAD4) plays a pivotal role in infection and inflammatory diseases by facilitating the formation of neutrophil extracellular traps (NETs). However, the substrates of PAD4 and its exact role in inflammatory bowel disease (IBD) remain unclear. In this study, we employed single-cell RNA sequencing (scRNA-seq) and substrate citrullination mapping to decipher the role of PAD4 in intestinal inflammation associated with IBD. Our results demonstrated that PAD4 deficiency alleviated colonic inflammation and restored intestinal barrier function in a dextran sulfate sodium (DSS)-induced colitis mouse model. scRNA-seq analysis revealed significant alterations in intestinal cell populations, with reduced neutrophil numbers and changes in epithelial subsets upon PAD4 deletion. Gene expression analysis highlighted pathways related to inflammation and epithelial cell function. Furthermore, we found that neutrophil-derived extracellular vesicles (EVs) carrying PAD4 were secreted into intestinal epithelial cells (IECs). Within IECs, PAD4 citrullinates mitochondrial creatine kinase 1 (CKMT1) at the R242 site, leading to reduced CKMT1 protein stability via the autophagy pathway. This action compromises mitochondrial homeostasis, impairs intestinal barrier integrity, and induces IECs apoptosis. IEC-specific depletion of CKMT1 exacerbated intestinal inflammation and apoptosis in mice with colitis. Clinical analysis of IBD patients revealed elevated levels of PAD4, increased CKMT1 citrullination, and decreased CKMT1 expression. In summary, our findings highlight the crucial role of PAD4 in IBD, where it modulates IECs plasticity via CKMT1 citrullination, suggesting that PAD4 may be a potential therapeutic target for IBD.

Background Acute myeloid leukemia (AML) is a highly heterogeneous hematologic malignancy and the most frequently acute leukemia of stem cell precursors and the myeloid derivatives in adult. Longitudinal studies have indicated the therapeutic landscape and drug resistance for patients with AML are still intractable, which largely attribute to the deficiency of detailed information upon the pathogenesis. Methods In this study, we compared the cellular phenotype of resident NK cells (rAML-NKs, rHD-NKs) and expanded NK cells (eAML-NKs, eHD-NKs) from bone marrow of AML patients (AML) and healthy donors (HD). Then, we took advantage of the co-culture strategy for the evaluation of the in vitro cytotoxicity of NK cells upon diverse tumor cell lines (e.g., K562, Nalm6, U937). With the aid of RNA-sequencing (RNA-SEQ) and bioinformatics analyses (e.g., GOBP analysis, KEGG analysis, GSEA, volcano plot), we verified the similarities and differences of the omics features between eAML-NKs and eHD-NKs. Results Herein, we verified the sharp decline in the content of total resident NK cells (CD3 − CD56 + ) in rAML-NKs compared to rHD-NKs. Differ from the expanded eHD-NKs, eAML-NKs revealed decline in diverse NK cell subsets (NKG2D + , CD25 + , NKp44 + , NKp46 + ) and alterations in cellular vitality but conservations in cytotoxicity. According to transcriptomic analysis, AML-NKs and HD-NKs showed multifaceted distinctions in gene expression profiling and genetic variations. Conclusions Collectively, our data revealed the variations in the cytobiological and transcriptomic features between AML-NKs and HD-NKs in bone marrow environment. Our findings would benefit the further development of novel biomarkers for AML diagnosis and NK cell-based cytotherapy in future.

Increasing evidence suggests that body composition is associated with the development of acute pancreatitis (AP). This study aimed to investigate the applicability of body composition in predicting AP severity. Data of 213 patients with AP from Affiliated Hospital of Putian University (AHOPTU) were included in this study, whilst data of 173 patients with AP from Fujian Medical University Union Hospital (FMUUH) were used for external validation. Patients were classified into the non-severe and severe groups according to AP severity. After seven days of treatment, in patients from AHOPTU, the difference in skeletal muscle index before and after treatment (ΔSMI) was significantly higher (P = 0.002), while the skeletal muscle radiodensity before treatment (PreSMR) was significantly lower (P = 0.042) in the non-severe group than in the severe group. The multivariate logistic regression model also revealed that the ΔSMI and PreSMR were independent risk factors for AP severity. The optimal cut-off values of ΔSMI and PreSMR were 1.0 and 43.7, respectively. The following metabolic score (SMS) was established to predict AP severity: 0: ΔSMI < 1.0 and PreSMR < 43.7; 1: ΔSMI ≥ 1.0 and PreSMR < 43.7 or ΔSMI < 1.0 and PreSMR ≥ 43.7; 3: ΔSMI ≥ 1.0 and PreSMR ≥ 43.7. In patients from AHOPTU and FMUUH, the areas under the curves (AUC) for this model were 0.764 and 0.741, respectively. ΔSMI and PreSMR can accurately predict AP severity. It is recommended to routinely evaluate the statuses of patients with AP using the predictive model presented in this study for individualized treatment.

Background and Aim: Although studies have shown that the quality of bowel preparation with low-residue diet (LRD) is as effective as that of clear fluid diet (CLD), there is currently no consensus on how long an LRD should last. The aim of this study was to compare a 1-day versus 3-day LRD on bowel preparation before colonoscopy.Methods: A systematic review search was conducted in MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane database from inception to April 2023. We identified randomized controlled trials (RCTs) that compared 1-day with 3-day LRD bowel cleansing regiments for patients undergoing colonoscopy. The rate of adequate bowel preparation, polyp detection rate, adenoma detection rate, tolerability, willingness to repeat preparation, and adverse events were estimated using odds ratios (OR) and 95% confidence interval (CI). We also performed meta-analysis to identify risk factors and predictors of inadequate preparation. Results: Four studies published between 2019 and 2023 with 1927 participants were included. The present meta-analysis suggested that 1-day LRD was comparable with 3-day LRD for adequate bowel preparation (OR 0.89; 95% CI, 0.65-1.21; P = 0.45; I-2 = 0%; P = 0.52). The polyp detection rate (OR 0.94; 95% CI, 0.77-1.14; P = 0.52; I-2 = 23%; P = 0.27) and adenoma detection rate (OR 0.87; 95% CI, 0.71-1.08; P = 0.21; I-2 = 0%; P = 0.52) were similar between the groups. There were significantly higher odds of tolerability in patients consuming 1-day LRD compared with 3-day LRD (OR 1.64; 95% CI, 1.13-2.39; P < 0.01; I-2 = 47%; P = 0.15). In addition, constipation was identified as the independent predictor of inadequate preparation (OR 1.98; 95% CI, 1.27-3.11; P < 0.01; I-2 = 0%; P = 0.46).Conclusion: The present study demonstrated that a 1-day LRD was as effective as a 3-day CLD in the quality of bowel preparation before colonoscopy and significantly improved tolerability of patients. In addition, constipation is an independent risk factor of poor bowel preparation, and the duration of LRD in patients with constipation still needs further clinical trials.

Excessive induction of inflammatory and immune responses is widely considered as one of vital factors contributing to the pathogenesis and progression of central nervous system (CNS) diseases. Neutrophils are well-studied members of inflammatory and immune cell family, contributing to the innate and adaptive immunity. Neutrophil-released neutrophil extracellular traps (NETs) play an important role in the regulation of various kinds of diseases, including CNS diseases. In this review, current knowledge on the biological features of NETs will be introduced. In addition, the role of NETs in several popular and well-studied CNS diseases including cerebral stroke, Alzheimer’s disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS), and neurological cancers will be described and discussed through the reviewing of previous related studies.

Concentrations of the secondary bile acid, deoxycholic acid (DCA), are aberrantly elevated in colorectal cancer (CRC) patients, but the consequences remain poorly understood. Here, we screened a library of gut microbiota -derived metabolites and identified DCA as a negative regulator for CD8 + T cell effector function. Mechanistically, DCA suppressed CD8 + T cell responses by targeting plasma membrane Ca 2+ ATPase (PMCA) to inhibit Ca 2+ -nuclear factor of activated T cells (NFAT)2 signaling. In CRC patients, CD8 + T cell effector function negatively correlated with both DCA concentration and expression of a bacterial DCA biosynthetic gene. Bacteria harboring DCA biosynthetic genes suppressed CD8 + T cells effector function and promoted tumor growth in mice. This effect was abolished by disrupting bile acid metabolism via bile acid chelation, genetic ablation of bacterial DCA biosynthetic pathway, or specific bacteriophage. Our study demonstrated causation between microbial DCA metabolism and anti -tumor CD8 + T cell response in CRC, suggesting potential directions for anti -tumor therapy.

Longitudinal studies have highlighted allogeneic natural killer (NK) cell-based cytotherapy for cancer immunosurveillance and immunotherapy, yet the deficiency of systematic and detailed comparison of NK cells from candidate sources including umbilical cord blood (UC) and bone marrow (BM) largely hinders the large-scale application. Herein, we isolated resident NK cells (rUC-NK, rBM-NK) from mononuclear cells (MNC), and analyzed the corresponding expanded NK cell counterparts (eUC-NK, eBM-NK). Then, the eUC-NK and eBM-NK were turned to multifaceted bioinformatics from the aspects of gene expression profiling and genetic variations. The percentages of total or activated NK cells in rBM-NK group were approximate 2-fold higher over those in the rUC-NK group, respectively. Instead, the proportion of total NK cells in eUC-NK was higher than that in the eBM-NK group, and in particular, the CD25+ memory-like NK cell subset. Furthermore, eUC-NK and eBM-NK manifested multidimensional similarities and diversities in gene expression pattern and genetic spectrum, whereas both eUC-NK and eBM-NK exhibited effective tumor killing capacity. Collectively, we dissected the cellular and transcriptomic signatures of NK cells generated from UC-MNC and BM-MNC, which supplied new literature for further exploring the characteristics of the indicated NK cells and would benefit the clinical application for cancer immunotherapy in future.

结直肠癌是全球较常见的恶性肿瘤之一，是现阶段我国消化系统发病率排名第一的恶性肿瘤，也是影响国民健康的重要公共卫生问题。早筛、早诊和早治能够有效改善结直肠肿瘤的预后。结肠镜是结直肠疾病最为准确的诊断、筛查和随访手段，但结肠镜检查的效果取决于其质控。本文主要从结直肠癌发病率、癌变途径、危险因素、诊断筛查方式和结肠镜检查质控标准等方面对该领域相关成果进行综述。

Background & Aim: Exosomes are effective mediators of cell-to-cell interactions and carry many regulatory molecules, including miRNAs, that can play crucial roles in diverse fundamental biological processes. However, to date, no study has reported macrophage exosomal involvement in the development of inflammatory bowel disease (IBD). This study investigated the specific miRNAs in macrophage-derived exosomes in IBD and the potential molecular mechanism.Methods: Dextran sulfate sodium (DSS) was used to generate IBD mice. The supernatants of murine bone marrow-derived macrophages (BMDMs) with or without lipopolysaccharide (LPS) were collected for exome isolation and miRNA sequencing. Lentiviruses were used to modify miRNA expression and further investigate the role of macrophage-derived exosomal miRNAs. In vitro, both mouse and human organoids were applied to a Transwell system in coculture with BMDMs as a cellular IBD-related challenge.Results: Here, we show that LPS-induced macrophages can release exosomes containing various miRNAs, aggravating IBD. We analyzed miRNA sequencing of macrophage-derived exosomes, and miR-223 was selected for further study. In vivo, exosomes with high miR-223 expression contributed to the exacerbation of intestinal barrier dysfunction, which was further verified in both mouse and human colon organoids. Furthermore, time-dependent analysis of the mRNAs of DSS-induced colitis mouse tissue combined with miR-223 target gene prediction was performed to select the candidate gene, and the barrier-related factor TMIGD1 was identified.Conclusion: Collectively, these data indicated that macrophage-derived exosomal miR-223 played a novel role in intestinal barrier dysfunction by inhibiting TMIGD1 in the progression of DSS-induced colitis.

BACKGROUND & AIM:Exosomes are effective mediators of cell-to-cell interactions and transport several regulatory molecules, including microRNAs (miRNAs), involved in diverse fundamental biological processes. The role of macrophage-derived exosomes in the development of inflammatory bowel disease (IBD) has not been previously reported. This study investigated specific miRNAs in macrophage-derived exosomes in IBD and their molecular mechanism.METHODS:A dextran sulfate sodium (DSS)-induced IBD mouse model was established. The culture supernatant of murine bone marrow-derived macrophages (BMDMs) cultured with or without lipopolysaccharide (LPS) was used for isolating exosomes, which were subjected to miRNA sequencing. Lentiviruses were used to alter miRNA expression and investigate the role of macrophage-derived exosomal miRNAs. Both mouse and human organoids were co-cultured with macrophages in a Transwell system to model cellular IBD in vitro.RESULTS:LPS-induced macrophages released exosomes containing various miRNAs and exacerbated IBD. Based on miRNA sequencing of macrophage-derived exosomes, miR-223 was selected for further analysis. Exosomes with upregulated miR-223 expression contributed to the exacerbation of intestinal barrier dysfunction in vivo, which was further verified using both mouse and human colon organoids. Furthermore, time-dependent analysis of the mRNAs in DSS-induced colitis mouse tissue and miR-223 target gene prediction were performed to select the candidate gene, resulting in the identification of the barrier-related factor Tmigd1.CONCLUSION:Macrophage-derived exosomal miR-223 has a novel role in the progression of DSS-induced colitis by inducing intestinal barrier dysfunction through the inhibition of TMIGD1.