FAM3D is essential for colon homeostasis and host defense against inflammation associated carcinogenesis

FAM3D regulation of head and neck squamous cell carcinoma behaviour through the EMT pathway

OBJECTIVES

Head and neck squamous cell carcinoma present challenges in effective treatment, with 50%-60% of cases exhibiting recurrence or metastasis, often resistant to surgery alone. Immunotherapy, a promising approach, does not guarantee benefits for all patients. Thus, the imperative lies in identifying reliable biomarkers for predicting immunotherapy efficacy. FAM3D, a protein-coding gene known for its potent chemotactic activity in human peripheral blood monocytes and neutrophils, plays a crucial role in regulating tumour immune responses and holds promise as an immune biomarker.

MATERIALS AND METHODS

We employed comprehensive database analysis to scrutinise FAM3D, evaluating its gene expression, mutation profiles and prognostic implications in head and neck squamous cell carcinoma, along with its associations with clinical characteristics and immune cell infiltration. Complementary functional experiments were conducted to delve into the potential mechanisms governed by FAM3D.

RESULTS

Our findings establish a significant correlation between low FAM3D expression and the invasiveness and metastatic potential of head and neck squamous cell carcinoma. FAM3D likely exerts its influence through the regulation of epithelial-mesenchymal transition.

CONCLUSIONS

FAM3D emerges as a valuable biomarker for predicting the responsiveness of patients with head and neck squamous cell carcinoma to immunotherapy, holding substantial clinical diagnostic and therapeutic relevance.

Characterization of age-associated gene expression changes in mouse sweat glands

Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline are poorly understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice. We first identified SWG-enriched mRNAs by comparing the skin transcriptome of Eda mutant Tabby male mice, which lack SWGs, with that of wild-type control mice by RNA-sequencing analysis. This comparison revealed 171 mRNAs enriched in SWGs, including 47 mRNAs encoding 'core secretory' proteins such as transcription factors, ion channels, ion transporters, and trans-synaptic signaling proteins. Among these, 28 SWG-enriched mRNAs showed significantly altered abundance in the aged male footpad skin, and 11 of them, including Foxa1, Best2, Chrm3, and Foxc1 mRNAs, were found in the 'core secretory' category. Consistent with the changes in mRNA expression levels, immunohistology revealed that higher numbers of secretory cells from old SWGs express the transcription factor FOXC1, the protein product of Foxc1 mRNA. In sum, our study identified mRNAs enriched in SWGs, including those that encode core secretory proteins, and altered abundance of these mRNAs and proteins with aging in mouse SWGs.

Phosphatidylethanolamine Improves Postnatal Growth Retardation by Regulating Mucus Secretion of Intestinal Goblet Cells in Piglets

Phosphatidylethanolamine (PE), a multifunctional phospholipid, is necessary for neonate development. This study aimed to explore the impact of the regulation of exogenous PE on postnatal growth retardation (PGR) by improving intestinal barrier function. Thirty-two neonatal pigs were divided into four groups according to their body weight (BW 2.79 ± 0.50 kg or 1.88 ± 0.40 kg) at 7 days old, CON-NBW, PE-NBW, CON-PGR, and PE-PGR. PE was supplemented to NBW piglets and PGR piglets during lactation and post-weaning periods. Compared with the NBW piglets, the growth performance of PGR piglets was lower, while PE improved the poor growth performance. PGR piglets showed injured intestinal morphology, as evidenced by the reduced ratio of villus height to crypt depth (VH/CD) and goblet cell numbers in the jejunum and ileum. PE recovered the intestinal barrier injury by increasing VH/CD and goblet cell numbers. The decreased MUC2 mRNA and protein expressions were observed in the small intestine of PGR piglets, and PE remarkably increased the expression of MUC2. Mechanistically, PE increased the goblet cell differentiation promoting gene spdef mRNA levels and reduced the mRNA expressions involved in endoplasmic reticulum stress in the jejunal and ileal mucosa of PGR piglets. Overall, we found that PE alleviated growth retardation by regulating intestinal health and generalized its application in neonates.

Phenome-wide Mendelian randomisation analysis of 378,142 cases reveals risk factors for eight common cancers

For many cancers there are only a few well-established risk factors. Here, we use summary data from genome-wide association studies (GWAS) in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to identify potentially causal relationships for over 3,000 traits. Our outcome datasets comprise 378,142 cases across breast, prostate, colorectal, lung, endometrial, oesophageal, renal, and ovarian cancers, as well as 485,715 controls. We complement this analysis by systematically mining the literature space for supporting evidence. In addition to providing supporting evidence for well-established risk factors (smoking, alcohol, obesity, lack of physical activity), we also find sex steroid hormones, plasma lipids, and telomere length as determinants of cancer risk. A number of the molecular factors we identify may prove to be potential biomarkers. Our analysis, which highlights aetiological similarities and differences in common cancers, should aid public health prevention strategies to reduce cancer burden. We provide a R/Shiny app to visualise findings.

Fecal transplantation of young mouse donors effectively improves enterotoxicity in elderly recipients exposed to triphenyltin

Triphenyltin (TPT) is a widely used biocide known for its high toxicity to various organisms, including humans, and its potential contribution to environmental pollution. The aging process leads to progressive deterioration of physiological functions in the elderly, making them more susceptible to the toxic effects of environmental pollutants. This study aimed to investigate the mitigating effect of fecal transplantation in young mice on the toxicological impairment caused by TPT exposure. For the study, 18-month-old mice were divided into four groups with six replicates each. The control group was fed a basal diet, the TPT group was exposed to 3.75 mg/Kg TPT, the feces group received fecal transplantation from 8-week-old young mice, and the combined group was exposed to 3.75 mg/Kg TPT after receiving fecal transplantation. Compared with the elderly control group, TPT induced significant upregulation of mRNA expression of pro-inflammatory factors (IL-1β, IL-6, TNF-α), while the anti-inflammatory factor gene IL-10 was significantly suppressed. The mRNA expression of intestinal barrier proteins (Claudin, Occludin, Muc2) was also significantly downregulated. However, fecal transplantation in young mice alleviated TPT-induced changes in inflammatory factors, ameliorated oxidative stress, and increased the activities of antioxidant enzymes (including SOD, CAT, GSH-Px). Further analysis using 16 s RNA showed that exposure to TPT led to changes in the composition of the intestinal flora. Untargeted metabolomics observations of feces from older mice revealed that exposure to TPT resulted in altered fecal metabolites. Fecal transplantation in young mice altered the microbiota of TPT-exposed older mice, especially by enhancing the levels of core probiotics. Similar beneficial effects were observed through untargeted metabolomics. Overall, this study highlights the potential benefits of young fecal transplantation in protecting the elderly from the toxicity of TPT, offering a promising approach to improve healthy aging.

Exosomal secreted SCIMP regulates communication between macrophages and neutrophils in pneumonia

In pneumonia, the deficient or delayed pathogen clearance can lead to pathogen proliferation and subsequent overactive immune responses, inducing acute lung injury (ALI). While screening human genome coding genes using our peripheral blood cell chemotactic platform, we unexpectedly find SLP adaptor and CSK interacting membrane protein (SCIMP), a protein with neutrophil chemotactic activity secreted during ALI. However, the specific role of SCIMP in ALI remains unclear. In this study, we investigate the secretion of SCIMP in exosomes (SCIMPexo) by macrophages after bacterial stimulation, both in vitro and in vivo. We observe a significant increase in the levels of SCIMPexo in bronchoalveolar lavage fluid and serum of pneumonia patients. We also find that bronchial perfusion with SCIMPexo or SCIMP N-terminal peptides increases the survival rate of the ALI model. This occurs due to the chemoattraction and activation of peripheral neutrophils dependent on formyl peptide receptor 1/2 (FPR1/2). Conversely, exosome suppressors and FPR1/2 antagonists decrease the survival rate in the lethal ALI model. Scimp-deficient and Fpr1/2-deficient mice also have lower survival rates and shorter survival times than wild-type mice. However, bronchial perfusion of SCIMP rescues Scimp-deficient mice but not Fpr1/2-deficient mice. Collectively, our findings suggest that the macrophage-SCIMP-FPRs-neutrophil axis plays a vital role in the innate immune process underlying ALI.

Bacterial indole-3-lactic acid affects epithelium-macrophage crosstalk to regulate intestinal homeostasis

Tryptophan and its derivatives perform a variety of biological functions; however, the role and specific mechanism of many tryptophan derivatives in intestinal inflammation remain largely unclear. Here, we identified that an Escherichia coli strain (Ec-TMU) isolated from the feces of tinidazole-treated individuals, and indole-3-lactic acid (ILA) in its supernatant, decreased the susceptibility of mice to dextran sulfate sodium-induced colitis. Ec-TMU and ILA contribute to the relief of colitis by inhibiting the production of epithelial CCL2/7, thereby reducing the accumulation of inflammatory macrophages in vitro and in vivo. Mechanistically, ILA downregulates glycolysis, NF-κB, and HIF signaling pathways via the aryl hydrocarbon receptor, resulting in decreased CCL2/7 production in epithelial cells. Clinical evidence suggests that the fecal ILA level is negatively correlated with the progression indicator of inflammatory bowel diseases. These results demonstrate that ILA has the potential to regulate intestinal homeostasis by modulating epithelium-macrophage interactions.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Acute chlorothalonil exposure had the potential to influence the intestinal barrier function and micro-environment in mice

The intestinal barrier maintains intestinal homeostasis and metabolism and protects against harmful pollutants. Some environmental pollutants seriously affect intestinal barrier function. However, it remains unclear whether or how chlorothalonil (CTL) impacts the intestinal barrier function in animals. Herein, 6-week-old male mice were acutely exposed to different CTL concentrations (100 and 300 mg/kg BW) via intragastric administration once a day for 7 days. Histopathological examination revealed obvious inflammation in the mice' colon and ileum. Most notably, CTL exposure increased the intestinal permeability, particularly in the CTL-300 group. CTL exposure reduced the secretion of colonic epithelial mucus and changed the transcription levels of genes bound up with ion transport and ileal antimicrobial peptide (AMP) secretion, indicating intestinal chemical barrier damage. The results of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay and Ki67 staining revealed abnormal apoptosis and increased intestinal epithelial cell proliferation, suggesting that CTL exposure led to cytotoxicity and inflammation. The results of 16S rRNA sequencing revealed that CTL exposure altered the intestinal microbiota composition and reduced its diversity and richness in the colon contents. Thus, acute CTL exposure affected the different intestinal barrier- and gut microenvironment-related endpoints in mice.

Oat β-glucan supplementation pre- and during pregnancy alleviates fetal intestinal immunity development damaged by gestational diabetes in rats

Oat β-glucan (OG) has been shown to improve intestinal microecology in gestational diabetes mellitus (GDM), but the effect on fetal intestine health is unknown. Herein, we aimed to investigate the effects of OG supplementation during gestation in GDM dams on fetal intestinal immune development. OG was supplemented one week before mating until the end of the experiment. GDM rats were made with a high-fat diet (HFD) with a minimal streptozotocin (STZ) dose. The fetal intestines were sampled at gestation day (GD) 19.5, and the intestinal morphology, chemical barrier molecules, intraepithelial immune cell makers, and levels of inflammatory cytokines were investigated. The results showed that OG supplementation alleviated the decrease of the depth of fetal intestinal villi and crypts, the number of goblet cells (GCs), protein expression of mucin-1 (Muc1) and Muc2, the mRNA levels of Gpr41, Gpr43, and T cell markers, and increased the number of paneth cells (PCs), the mRNA levels of defensin-6 (defa6), and macrophage (Mø) marker and the expression of cytokines induced by GDM. In addition, OG supplementation alleviated the function of immune cell self-proliferation, chemotaxis and assembly capabilities, protein, fat, folic acid, and zinc absorption damaged by GDM. As indicated by these findings, OG supplementation before and during pregnancy improved the fetal intestinal chemical barriers, immune cells, cytokines, and the metabolism of nutrients to protect the fetal intestinal immunity.

FAM3 family genes are associated with prognostic value of human cancer: a pan-cancer analysis

Family with sequence similarity three member (FAM3) plays a crucial role in the malignant development of various cancers of human. However, there remains doubtful what specific role of FAM3 family genes in pan-cancer. Our study aimed to investigate the role of FAM3 family genes in prognosis, immune subtype, tumor immune microenvironment, stemness score, and anticancer drug sensitivity of pan-cancer. We obtained data from UCSC Xena GDC and CellMiner databases, and used them to study the correlation of the expression, survival, immune subtype, tumor microenvironment, stemness score, and anticancer drug sensitivity between FAM3 family genes with pan-cancer. Furthermore, we investigated the tumor cellular functions and clinical prognostic value FAMC3 in pancreatic cancer (PAAD) using cellular experiments and tissue microarray. Cell Counting Kit-8 (CCK-8), transwell invasion, wound-healing and apoptosis assays were performed to study the effect of FAM3C on SW1990 cells' proliferation, migration, invasion and apoptosis. Immunohistochemical staining was used to study the relationship between FAM3C expression and clinical characteristics of pancreatic cancer patients. The results revealed that FAM3 family genes are significantly differential expression in tumor and adjacent normal tissues in 7 cancers (CHOL, HNSC, KICH, LUAD, LUSC, READ, and STAD). The expression of FAM3 family genes were negatively related with the RNAss, and robust correlated with immune type, tumor immune microenvironment and drug sensitivity. The expression of FAM3 family genes in pan-cancers were significantly different in immune type C1 (wound healing), C2 (IFN-gamma dominant), C3 (inflammatory), C4 (lymphocyte depleted), C5 (immunologically quiet), and C6 (TGF-beta dominant). Meanwhile, overexpression FAM3C promoted SW1990 cells proliferation, migration, invasion and suppressed SW1990 cells apoptosis. While knockdown of FAM3C triggered opposite results. High FAM3C expression was associated with duodenal invasion, differentiation and liver metastasis. In summary, this study provided a new perspective on the potential therapeutic role of FAM3 family genes in pan-cancer. In particular, FAM3C may play an important role in the occurrence and progression of PAAD.

Modified Prebiotic-Based "Shield" Armed Probiotics with Enhanced Resistance of Gastrointestinal Stresses and Prolonged Intestinal Retention for Synergistic Alleviation of Colitis

Oral administration of probiotics is a promising method to alleviate inflammatory bowel diseases (IBDs). However, gastrointestinal environmental sensitivity and inferior intestinal colonization of probiotics hinder the alleviation effect. Here, we developed a simple yet effective modified prebiotic-based "shield" (Fe-TA@mGN) composed of an Fe3+-tannic acid cross-linking network and carboxymethylated β-glucan for arming Escherichia coli Nissle 1917 (EcN@Fe-TA@mGN). The Fe-TA@mGN "shield" not only acted as a dynamic barrier to enhance the gastrointestinal stress resistance ability of EcN but also aided the intestinal colonization of EcN as well as synergized with EcN for the alleviation of dextran sulfate sodium (DSS) induced colitis. More specifically, with the protection of the Fe-TA@mGN "shield", the survival rate of armed EcN could be up to ∼1720 times higher than that of bare EcN after exposure to simulated gastric fluid. Excitingly, the intestinal retention rate of EcN@Fe-TA@mGN was as high as 47.54 ± 6.06% at 16 h post-administration, while almost all bare EcNs were excreted out at 8 h post-administration. With all of the aforementioned attributes, EcN@Fe-TA@mGN efficiently alleviated colitis, verified by the repair of the intestinal barrier and the attenuation of inflammation. Moreover, for EcN@Fe-TA@mGN, mGN synergized with EcN to positively modulate gut microbiota and promote the production of short-chain fatty acids (SCFAs, especially for butyric acid, a primary source for maintaining intestinal health), both of which would further advance the alleviation of colitis. We envision that the strategy developed here will inspire the exploitation of various prebiotics to arm probiotics for the effective alleviation of IBD.

Hepatocyte-secreted FAM3D ameliorates hepatic steatosis by activating FPR1-hnRNP U-GR-SCAD pathway to enhance lipid oxidation

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide; however, the underlying mechanisms remain poorly understood. FAM3D is a member of the FAM3 family; however, its role in hepatic glycolipid metabolism remains unknown. Serum FAM3D levels are positively correlated with fasting blood glucose levels in patients with diabetes. Hepatocytes express and secrete FAM3D, and its expression is increased in steatotic human and mouse livers. Hepatic FAM3D overexpression ameliorated hyperglycemia and steatosis in obese mice, whereas FAM3D-deficient mice exhibited exaggerated hyperglycemia and steatosis after high-fat diet (HFD)-feeding. In cultured hepatocytes, FAM3D overexpression or recombinant FAM3D protein (rFAM3D) treatment reduced gluconeogenesis and lipid deposition, which were blocked by anti-FAM3D antibodies or inhibition of its receptor, formyl peptide receptor 1 (FPR1). FPR1 overexpression suppressed gluconeogenesis and reduced lipid deposition in wild hepatocytes but not in FAM3D-deficient hepatocytes. The addition of rFAM3D restored FPR1's inhibitory effects on gluconeogenesis and lipid deposition in FAM3D-deficient hepatocytes. Hepatic FPR1 overexpression ameliorated hyperglycemia and steatosis in obese mice. RNA sequencing and DNA pull-down revealed that the FAM3D-FPR1 axis upregulated the expression of heterogeneous nuclear ribonucleoprotein U (hnRNP U), which recruits the glucocorticoid receptor (GR) to the promoter region of the short-chain acyl-CoA dehydrogenase (SCAD) gene, promoting its transcription to enhance lipid oxidation. Moreover, FAM3D-FPR1 axis also activates calmodulin-Akt pathway to suppress gluconeogenesis in hepatocytes. In conclusion, hepatocyte-secreted FAM3D activated the FPR1-hnRNP U-GR-SCAD pathway to enhance lipid oxidation in hepatocytes. Under obesity conditions, increased hepatic FAM3D expression is a compensatory mechanism against dysregulated glucose and lipid metabolism.

Study of the cross-talk between Fasciola hepatica juveniles and the intestinal epithelial cells of the host by transcriptomics in an in vitro model

Fasciolosis is a globally widespread trematodiasis with a major economic and veterinary impact. Therefore, this disease is responsible for millions of dollars in losses to the livestock industry, and also constitutes an emerging human health problem in endemic areas. The ubiquitous nature of Fasciola hepatica, the main causative agent, is one of the key factors for the success of fasciolosis. Accordingly, this parasite is able to subsist in a wide variety of ecosystems and hosts, thanks to the development of a plethora of strategies for adaption and immune evasion. Fasciolosis comprises a growing concern due to its high prevalence rates, together with the emergence of strains of the parasite resistant to the treatment of choice (triclabendazole). These facts highlight the importance of developing novel control measures which allow for an effective protection against the disease before F. hepatica settles in a niche inaccessible to the immune system. However, knowledge about the initial phases of the infection, including the migration mechanisms of the parasite and the early innate host response, is still scarce. Recently, our group developed an in vitro host-parasite interaction model that allowed the early events to be unveiled after the first contact between the both actors. This occurs shortly upon ingestion of F. hepatica metacercariae and the emergence of the newly excysted juveniles (FhNEJ) in the host duodenum. Here, we present a transcriptomic analysis of such model using an approach based on RNA sequencing (RNA-Seq), which reveals changes in gene expression related to proteolysis and uptake of metabolites in FhNEJ. Additionally, contact with the parasite triggered changes in host intestinal cells related to pseudogenes expression and host defence mechanisms, including immune response, among others. In sum, these results provide a better understanding of the early stages of fasciolosis at molecular level, and a pool of targets that could be used in future therapeutic strategies against the disease.

The beneficial effects of commensal E. coli for colon epithelial cell recovery are related with Formyl peptide receptor 2 (Fpr2) in epithelial cells

BACKGROUND

Formyl peptide receptor 2 (Fpr2) plays a crucial role in colon homeostasis and microbiota balance. Commensal E. coli is known to promote the regeneration of damaged colon epithelial cells. The aim of the study was to investigate the connection between E. coli and Fpr2 in the recovery of colon epithelial cells.

RESULTS

The deficiency of Fpr2 was associated with impaired integrity of the colon mucosa and an imbalance of microbiota, characterized by the enrichment of Proteobacteria in the colon. Two serotypes of E. coli, O22:H8 and O91:H21, were identified in the mouse colon through complete genome sequencing. E. coli O22:H8 was found to be prevalent in the gut of mice and exhibited lower virulence compared to O91:H21. Germ-free (GF) mice that were pre-orally inoculated with E. coli O22:H8 showed reduced susceptibility to chemically induced colitis, increased proliferation of epithelial cells, and improved mouse survival. Following infection with E. coli O22:H8, the expression of Fpr2 in colon epithelial cells was upregulated, and the products derived from E. coli O22:H8 induced migration and proliferation of colon epithelial cells through Fpr2. Fpr2 deficiency increased susceptibility to chemically induced colitis, delayed the repair of damaged colon epithelial cells, and heightened inflammatory responses. Additionally, the population of E. coli was observed to increase in the colons of Fpr2-/- mice with colitis.

CONCLUSION

Commensal E. coli O22:H8 stimulated the upregulation of Fpr2 expression in colon epithelial cells, and the products from E. coli induced migration and proliferation of colon epithelial cells through Fpr2. Fpr2 deficiency led to an increased E. coli population in the colon and delayed recovery of damaged colon epithelial cells in mice with colitis. Therefore, Fpr2 is essential for the effects of commensal E. coli on colon epithelial cell recovery.

FAM3D: A gut secreted protein and its potential in the regulation of glucose metabolism

The number of diabetic patients is rising globally and concomitantly so do the diabetes associated complications. The gut secretes a variety of proteins to control blood glucose levels and/or food intake. As the drug class of GLP-1 agonists is based on a gut secreted peptide and the positive metabolic effects of bariatric surgery are at least partially mediated by gut peptides, we were interested in other gut secreted proteins which have yet to be explored. In this respect we identified the gut secreted protein FAM3D by analyzing sequencing data from L- and epithelial cells of VSG and sham operated as well as chow and HFD fed mice. FAM3D was overexpressed in diet induced obese mice via an adeno-associated virus (AAV), which resulted in a significant improvement of fasting blood glucose levels, glucose tolerance and insulin sensitivity. The liver lipid deposition was reduced, and the steatosis morphology was improved. Hyperinsulinemic clamps indicated that FAM3D is a global insulin sensitizer and increases glucose uptake into various tissues. In conclusion, the current study demonstrated that FAM3D controls blood glucose levels by acting as an insulin sensitizing protein and improves hepatic lipid deposition.

Targeting cytokine-like protein FAM3D lowers blood pressure in hypertension

Current antihypertensive options still incompletely control blood pressure, suggesting the existence of uncovered pathogenic mechanisms. Here, whether cytokine-like protein family with sequence similarity 3, member D (FAM3D) is involved in hypertension etiology is evaluated. A case-control study exhibits that FAM3D is elevated in patients with hypertension, with a positive association with odds of hypertension. FAM3D deficiency significantly ameliorates angiotensin II (AngII)-induced hypertension in mice. Mechanistically, FAM3D directly causes endothelial nitric oxide synthase (eNOS) uncoupling and impairs endothelium-dependent vasorelaxation, whereas 2,4-diamino-6-hydroxypyrimidine to induce eNOS uncoupling abolishes the protective effect of FAM3D deficiency against AngII-induced hypertension. Furthermore, antagonism of formyl peptide receptor 1 (FPR1) and FPR2 or the suppression of oxidative stress blunts FAM3D-induced eNOS uncoupling. Translationally, targeting endothelial FAM3D by adeno-associated virus or intraperitoneal injection of FAM3D-neutralizing antibodies markedly ameliorates AngII- or deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Conclusively, FAM3D causes eNOS uncoupling through FPR1- and FPR2-mediated oxidative stress, thereby exacerbating the development of hypertension. FAM3D may be a potential therapeutic target for hypertension.

Developmental and homeostatic signaling transmitted by the G-protein coupled receptor FPR2

Formyl peptide receptor 2 (FPR2) and its mouse counterpart Fpr2 are the members of the G protein-coupled receptor (GPCR) family. FPR2 is the only member of the FPRs that interacts with ligands from different sources. FPR2 is expressed in myeloid cells as well as epithelial cells, endothelial cells, neurons, and hepatocytes. During the past years, some unusual properties of FPR2 have attracted intense attention because FPR2 appears to possess dual functions by activating or inhibiting intracellular signal pathways based on the nature, concentration of the ligands, and the temporal and spatial settings of the microenvironment in vivo, the cell types it interacts with. Therefore, FPR2 controls an abundant array of developmental and homeostatic signaling cascades, in addition to its "classical" capacity to mediate the migration of hematopoietic and non-hematopoietic cells including malignant cells. In this review, we summarize recent development in FPR2 research, particularly in its role in diseases, therefore helping to establish FPR2 as a potential target for therapeutic intervention.

Risk factors for eight common cancers revealed from a phenome-wide Mendelian randomisation analysis of 378,142 cases and 485,715 controls

For many cancers there are few well-established risk factors. Summary data from genome-wide association studies (GWAS) can be used in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to identify causal relationships. We performed a MR-PheWAS of breast, prostate, colorectal, lung, endometrial, oesophageal, renal, and ovarian cancers, comprising 378,142 cases and 485,715 controls. To derive a more comprehensive insight into disease aetiology we systematically mined the literature space for supporting evidence. We evaluated causal relationships for over 3,000 potential risk factors. In addition to identifying well-established risk factors (smoking, alcohol, obesity, lack of physical activity), we provide evidence for specific factors, including dietary intake, sex steroid hormones, plasma lipids and telomere length as determinants of cancer risk. We also implicate molecular factors including plasma levels of IL-18, LAG-3, IGF-1, CT-1, and PRDX1 as risk factors. Our analyses highlight the importance of risk factors that are common to many cancer types but also reveal aetiological differences. A number of the molecular factors we identify have the potential to be biomarkers. Our findings should aid public health prevention strategies to reduce cancer burden. We provide a R/Shiny app (https://mrcancer.shinyapps.io/mrcan/) to visualise findings.

Development and validation of ferroptosis-related lncRNA signature and immune-related gene signature for predicting the prognosis of cutaneous melanoma patients

Ferroptosis, a form of cell death caused by iron-dependent peroxidation of lipids, plays an important role in cancer. Recent studies have shown that long noncoding RNAs (lncRNAs) are involved in the regulation of ferroptosis in tumor cells and are also closely related to tumor immunity. Immune cell infiltration in the tumor microenvironment affects the prognosis and clinical outcome of immunotherapy in melanoma patients, and immune cell classification may be able to accurately predict the prognosis of melanoma patients. However, the prognostic value of ferroptosis-related lncRNAs (FRLs) in melanoma has not been thoroughly explored, and it is difficult to define the immune characteristics of melanoma. We used The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression (GTEx) database, and the FerrDb database to identify FRLs. FRLs with prognostic value were evaluated in an experimental cohort utilizing univariate, LASSO (least absolute shrinkage and selection operator) and multivariate Cox regression, followed by in vitro assays evaluating the expression levels and the biological functions of three candidate FRLs. Kaplan-Meier (K-M) and receiver operating characteristic (ROC) curve analyses were used to assess the validity of the risk model, and the drug sensitivity of FRLs was examined by drug sensitivity analysis. The differentially expressed genes between the high- and low-risk groups in the risk model were enriched in the immune pathway, and we further found immune gene signatures (IRGs) that could predict the prognosis of melanoma patients through a series of methods including single-sample Gene Set Enrichment Analysis (ssGSEA). Finally, two GEO cohorts were used to validate the predictive accuracy and reliability of these two signature models. Our findings suggest that FRLs and IRGs have the potential to predict the prognosis of patients with cutaneous melanoma.

Risk factors for eight common cancers revealed from a phenome-wide Mendelian randomisation analysis of 378,142 cases and 485,715 controls

For many cancers there are few well-established risk factors. Summary data from genome-wide association studies (GWAS) can be used in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to identify causal relationships. We performed a MR-PheWAS of breast, prostate, colorectal, lung, endometrial, oesophageal, renal, and ovarian cancers, comprising 378,142 cases and 485,715 controls. To derive a more comprehensive insight into disease aetiology we systematically mined the literature space for supporting evidence. We evaluated causal relationships for over 3,000 potential risk factors. In addition to identifying well-established risk factors (smoking, alcohol, obesity, lack of physical activity), we provide evidence for specific factors, including dietary intake, sex steroid hormones, plasma lipids and telomere length as determinants of cancer risk. We also implicate molecular factors including plasma levels of IL-18, LAG-3, IGF-1, CT-1, and PRDX1 as risk factors. Our analyses highlight the importance of risk factors that are common to many cancer types but also reveal aetiological differences. A number of the molecular factors we identify have the potential to be biomarkers. Our findings should aid public health prevention strategies to reduce cancer burden. We provide a R/Shiny app (https://mrcancer.shinyapps.io/mrcan/) to visualise findings.

Clonal cell states link Barrett's esophagus and esophageal adenocarcinoma

Barrett's esophagus is a common type of metaplasia and a precursor of esophageal adenocarcinoma. However, the cell states and lineage connections underlying the origin, maintenance, and progression of Barrett's esophagus have not been resolved in humans. To address this, we performed single-cell lineage tracing and transcriptional profiling of patient cells isolated from metaplastic and healthy tissue. Our analysis revealed discrete lineages in Barrett's esophagus, normal esophagus, and gastric cardia. Transitional basal progenitor cells of the gastroesophageal junction were unexpectedly related to both esophagus and gastric cardia cells. Barrett's esophagus was polyclonal, with lineages that contained all progenitor and differentiated cell types. In contrast, precancerous dysplastic foci were initiated by the expansion of a single molecularly aberrant Barrett's esophagus clone. Together, these findings provide a comprehensive view of the cell dynamics of Barrett's esophagus, linking cell states along the full disease trajectory, from its origin to cancer.

Single-cell profiling reveals differences between human classical adenocarcinoma and mucinous adenocarcinoma

Colorectal cancer is a highly heterogeneous disease. Most colorectal cancers are classical adenocarcinoma, and mucinous adenocarcinoma is a unique histological subtype that is known to respond poorly to chemoradiotherapy. The difference in prognosis between mucinous adenocarcinoma and classical adenocarcinoma is controversial. Here, to gain insight into the differences between classical adenocarcinoma and mucinous adenocarcinoma, we analyse 7 surgical tumour samples from 4 classical adenocarcinoma and 3 mucinous adenocarcinoma patients by single-cell RNA sequencing. Our results indicate that mucinous adenocarcinoma cancer cells have goblet cell-like properties, and express high levels of goblet cell markers (REG4, SPINK4, FCGBP and MUC2) compared to classical adenocarcinoma cancer cells. TFF3 is essential for the transcriptional regulation of these molecules, and may cooperate with RPS4X to eventually lead to the mucinous adenocarcinoma mucus phenotype. The observed molecular characteristics may be critical in the specific biological behavior of mucinous adenocarcinoma.

Formyl peptide receptor 2 as a potential therapeutic target for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a global health burden whose existing treatment is largely dependent on anti-inflammatory agents. Despite showing some therapeutic actions, their clinical efficacy and adverse events are unacceptable. Resolution as an active and orchestrated phase of inflammation involves improper inflammatory response with three key triggers, specialized pro-resolving mediators (SPMs), neutrophils and phagocyte efferocytosis. The formyl peptide receptor 2 (FPR2/ALX) is a human G protein-coupled receptor capable of binding SPMs and participates in the resolution process. This receptor has been implicated in several inflammatory diseases and its association with mouse model of IBD was established in some resolution-related studies. Here, we give an overview of three reported FPR2/ALX agonists highlighting their respective roles in pro-resolving strategies.

Poly-β-hydroxybutyrate alleviated diarrhea and colitis via Lactobacillus johnsonii biofilm-mediated maturation of sulfomucin

Maintainance of sulfomucin is a key end point in the treatment of diarrhea and inflammatory bowel disease (IBD). However, the mechanisms underlying the microbial sense to sulfomucin are poorly understood, and to date, there are no therapies targeting the secretion and maturation of sulfomucin in IBD. Herein, we biosynthesized poly-β-hydroxybutyrate (PHB) and found that PHB could alleviate inflammation caused by diarrhea and colitis by enhancing the differentiation of sulfomucin. Microbiota transplantation and clearance together demonstrate that PHB promoting sulfomucin is mediated by Lactobacillus johnsonii (L. johnsonii). Further studies revealed that PHB provides a favorable niche for L. johnsonii biofilm formation to resist disturbance and support its growth. L. johnsonii-biofilm alleviates colitis by regulating fucose residues to promote goblet cell differentiation and subsequent sulfomucin maturation. Importantly, PHB alleviates colitis by enhancing sulfomucin secretion and maturation in a L. johnsonii-dependent manner. PHB represents a class of guardians, acting as a safe probiotic-biofilm delivery system that significantly promotes probiotic proliferation. Altogether, this study adds weight to the possible role of probiotics and functional materials in the treatment of intestinal inflammation. The application of PHB and biofilm self-coating L. johnsonii carries high translational potential and may be of clinical relevance.

Exploiting lactic acid bacteria for colorectal cancer: a recent update

Colorectal cancer (CRC) is the third most common cancer in the world. Currently, chemotherapy and radiotherapy used to treat CRC exhibit many side effects, hence, it is an urgent need to design effective therapies to prevent and treat CRC. Lactic acid bacteria (LAB) can regulate gut microbiota, intestinal immunity, and intestinal mechanical barrier, which is becoming a hot product for the prevention and treatment of CRC, whereas comprehensive reviews of their anti-CRC mechanisms are limited. This review systematically reveals the latest incidence, mortality, risk factors, and molecular mechanisms of CRC, then summarizes the roles of probiotics in alleviating CRC in animal and clinical studies and critically reviews the possible mechanisms by which these interventions exert their activities. It then shows the limitations in mechanisms and clinical studies, and the suggestions for future research are also put forward, which will play an important role in guiding and promoting the basic and clinical research of remising CRC by LAB and the development of LAB products.

FAM3D as a Prognostic Indicator of Head and Neck Squamous Cell Carcinoma Is Associated with Immune Infiltration

Background

Globally, head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor with high morbidity and mortality. Hence, it is important to find effective biomarkers for the diagnosis and prediction of the prognosis of patients with HNSCC. FAM3D had been proven to be vital in other cancers. However, its predictive and therapeutic value in HNSCC is unclear. Therefore, it is valuable to explore the association between the expression level of FAM3D and its impacts on the prognosis and tumor microenvironment in HNSCC.

Methods

The Cancer Genome Atlas (TCGA) dataset, Genotype-Tissue Expression (GTEx) dataset, the Clinical Proteomic Tumor Analysis Consortium (CPTAC) dataset, and The Human Protein Atlas (THPA) website were used to assess HNSCC expressions in tumor and nontumor tissues. Then, we further conducted immunohistochemistry experiment as internal cohort to validate the same results. The Cox regression analysis, Kaplan-Meier analysis, and nomograms were performed to find the predictive prognostic value of FAM3D in HNSCC patients and its relationship with the clinicopathological features in HNSCC. The Gene Expression Omnibus (GEO) dataset was utilized to externally verify the prognosis value of FAM3D in HNSCC. Gene Set Enrichment Analysis (GESA) was applied to search the molecular and biological functions of FAM3D. The association between FAM3D and immune cell infiltration was investigated with the Tumor Immune Estimating Resource, version 2 (TIMER2). The relationships between FAM3D expression and tumor microenvironment (TME) scores, immune checkpoints, and antitumor compound half-maximal inhibitory concentration predictions were also explored.

Results

In different datasets, FAM3D mRNA and protein levels were all significantly lower in HNSCC tissues than in normal tissues, and they were strongly inversely associated with tumor grade, stage, lymph node metastasis, and T stage. Patients with high-FAM3D-expression displayed better prognosis than those with low-FAM3D-expression. FAM3D was also determined to be a suitable biomarker for predicting the prognosis of patients with HNSCC. This was externally validated in the GEO dataset. As for gene and protein level, the functional and pathway research results of FAM3D indicated that it was enriched in alteration of immune-related pathways in HNSCC. The low-expression group had higher stromal and ESTIMATE scores by convention than the high-expression group. FAM3D expression were found to be positively correlated with immune infiltrating cells, such as cancer-associated fibroblasts, myeloid-derived suppressor cells, macrophage cells, T cell CD8+ cells, regulatory T cells, and T cell follicular helper cells. FAM3D's relationships with immune checkpoints and sensitivity to antitumor drugs were also investigated.

Conclusion

Our study explored the impact of FAM3D as a favorable prognostic marker for HNSCC on the tumor immune microenvironment from multiple perspectives. The results may provide new insights into HNSCC-targeted immunotherapy.

TDAG51 deficiency attenuates dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a group of chronic inflammatory diseases of the gastrointestinal tract. Although the multifactorial etiology of IBD pathogenesis is relatively well documented, the regulatory factors that confer a risk of IBD pathogenesis remain less explored. In this study, we report that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the development of dextran sulfate sodium (DSS)-induced colitis in mice. TDAG51 expression was elevated in the colon tissues of DSS-induced experimental colitis mice. TDAG51 deficiency protected mice against acute DSS-induced lethality and body weight changes and disease severity. DSS-induced structural damage and mucus secretion in colon tissues were significantly reduced in TDAG51-deficient mice compared with wild-type mice. We observed similar results in a DSS-induced chronic colitis mouse model. Finally, we showed that the production of inflammatory mediators, including proinflammatory enzymes, molecules and cytokines, was decreased in DSS-treated TDAG51-deficient mice compared with DSS-treated wild-type mice. Thus, we demonstrated that TDAG51 deficiency plays a protective role against DSS-induced colitis by decreasing the production of inflammatory mediators in mice. These findings suggest that TDAG51 is a novel regulator of the development of DSS-induced colitis and is a potential therapeutic target for IBD.

Group 3 innate lymphoid cells require BATF to regulate gut homeostasis in mice

Group 3 innate lymphoid cells (ILC3s) are crucial for the maintenance of host-microbiota homeostasis in gastrointestinal mucosal tissues. The mechanisms that maintain lineage identity of intestinal ILC3s and ILC3-mediated orchestration of microbiota and mucosal T cell immunity are elusive. Here, we identified BATF as a gatekeeper of ILC3 homeostasis in the gut. Depletion of BATF in ILC3s resulted in excessive interferon-γ production, dysbiosis, aberrant T cell immune responses, and spontaneous inflammatory bowel disease (IBD), which was considerably ameliorated by the removal of adaptive immunity, interferon-γ blockade, or antibiotic treatment. Mechanistically, BATF directly binds to the cis-regulatory elements of type 1 effector genes, restrains their chromatin accessibility, and inhibits their expression. Conversely, BATF promotes chromatin accessibility of genes involved in MHCII antigen processing and presentation pathways, which in turn directly promotes the transition of precursor ILC3s to MHCII+ ILC3s. Collectively, our findings reveal that BATF is a key transcription factor for maintaining ILC3 stability and coordinating ILC3-mediated control of intestinal homeostasis.

New insights into natural products that target the gut microbiota: Effects on the prevention and treatment of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant carcinomas. CRC is characterized by asymptomatic onset, and most patients are already in the middle and advanced stages of disease when they are diagnosed. Inflammatory bowel disease (IBD) and the inflammatory-cancer transformation of advanced colorectal adenoma are the main causes of CRC. There is an urgent need for effective prevention and intervention strategies for CRC. In recent years, rapid research progress has increased our understanding of gut microbiota. Meanwhile, with the deepening of research on the pathogenesis of colorectal cancer, gut microbiota has been confirmed to play a direct role in the occurrence and treatment of colorectal cancer. Strategies to regulate the gut microbiota have potential value for application in the prevention and treatment of CRC. Regulation of gut microbiota is one of the important ways for natural products to exert pharmacological effects, especially in the treatment of metabolic diseases and tumours. This review summarizes the role of gut microbiota in colorectal tumorigenesis and the mechanism by which natural products reduce tumorigenesis and improve therapeutic response. We point out that the regulation of gut microbiota by natural products may serve as a potential means of treatment and prevention of CRC.

Wumei Pill Ameliorates AOM/DSS-Induced Colitis-Associated Colon Cancer through Inhibition of Inflammation and Oxidative Stress by Regulating S-Adenosylhomocysteine Hydrolase- (AHCY-) Mediated Hedgehog Signaling in Mice

Wumei Pill (WMP) is a traditional Chinese herbal formulation and widely used to treat digestive system diseases in clinical. S-Adenosylhomocysteine hydrolase (AHCY) can catalyze the hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine in living organisms, and its abnormal expression is linked to the pathogenesis of many diseases including colorectal cancer (CRC). A previous study reported that WMP could prevent CRC in mice; however, the underlying mechanisms especially the roles of AHCY in WMP-induced anti-CRC remain largely unknown. Here, we investigated the regulatory roles and potential mechanisms of AHCY in WMP-induced anti-CRC. WMP notably alleviated the azoxymethane/dextran sulfate sodium- (AOM/DSS-) induced colitis-associated colon cancer (CAC) in mice. Besides, WMP inhibited the inflammation and oxidative stress in AOM/DSS-induced CAC mice. AHCY was high expression in clinical samples of colon cancer compared to the adjacent tissues. WMP inhibited the AHCY expression in AOM/DSS-induced CAC mice. An in vitro study found that AHCY overexpression induced cell proliferation, colony formation, invasion, and tumor angiogenesis, whereas its knockdown impaired its oncogenic function. AHCY overexpression enhanced, while its knockdown weakened the inflammation and oxidative stress in colon cancer cells. Interestingly, WMP potently suppressed the hedgehog (Hh) signaling in AOM/DSS-induced CAC mice. A further study showed that AHCY overexpression activated the Hh signaling while AHCY knockdown inactivated the Hh signaling. Moreover, activation of the Hh signaling reversed the effect of AHCY silencing on inflammation and oxidative stress in vitro. In conclusion, WMP alleviated the AOM/DSS-induced CAC through inhibition of inflammation and oxidative stress by regulating AHCY-mediated hedgehog signaling in mice. These findings uncovered a potential molecular mechanism underlying the anti-CAC effect of WMP and suggested WMP as a promising therapeutic candidate for CRC.

Effects of Milk-Derived Extracellular Vesicles on the Colonic Transcriptome and Proteome in Murine Model

Evidence shows that effective nutritional intervention can prevent or mitigate the risk and morbidity of inflammatory bowel disease (IBD). Bovine milk extracellular vesicles (mEVs), a major bioactive constituent of milk, play an important role in maintaining intestinal health. The aims of this study were to assess the effects of mEV pre-supplementation on the colonic transcriptome and proteome in dextran sulphate sodium (DSS)-induced acute colitis, in order to understand the underlying molecular mechanisms of mEV protection against acute colitis. Our results revealed that dietary mEV supplementation alleviated the severity of acute colitis, as evidenced by the reduced disease activity index scores, histological damage, and infiltration of inflammatory cells. In addition, transcriptome profiling analysis found that oral mEVs significantly reduced the expression of pro-inflammatory cytokines (IL-1β, IL-6, IL-17A and IL-33), chemokine ligands (CXCL1, CXCL2, CXCL3, CXCL5, CCL3 and CCL11) and chemokine receptors (CXCR2 and CCR3). Moreover, oral mEVs up-regulated 109 proteins and down-regulated 150 proteins in the DSS-induced murine model, which were involved in modulating amino acid metabolism and lipid metabolism. Collectively, this study might provide new insights for identifying potential targets for the therapeutic effects of mEVs on colitis.

Genome-wide screening identifies DNA methylation sites that regulate the blood proteome

Background: Identifying DNA methylation sites that regulate the blood proteome is important for biomedical purposes. Materials & methods: Here the authors performed a genome-wide search to find DNA methylation sites that impact proteins. Results: The authors identified 165 methylation sites associated with 138 proteins. The authors noted hotspot genomic regions that control the levels of several proteins. For example, methylation of the ABO locus impacted 37 proteins and contributed to cardiometabolic comorbidities, including the severity of SARS-CoV-2 infection. The authors made these findings publicly available as a Unix software that identifies methylation sites that cause disease and reveals the underlying proteins. The authors underlined the software application by showing that components of innate immunity contribute to systolic blood pressure. Conclusion: This study provides a catalog of DNA methylation sites that regulate the proteome, and the results are available as freeware for biological insight.

Immunomodulation by Gut Microbiome on Gastrointestinal Cancers: Focusing on Colorectal Cancer

Simple Summary

A symbiotic relationship with the host gut microbiome influences the immune system’s development, functions, and activities. In the mucosa, the gut microbiome mediates several immune activities such as the induction of naïve T-cells differentiation, production of cytokines, and myeloid cells activation. The gut-immune interaction and GI cancer development were investigated more recently. Understanding the interaction’s underlying mechanism provides insight to use them as potential anti-cancer targets. Even though multiple reports support the role of gut-immune interactions in targeting cancer-related pathways such as inflammation, apoptosis, and cellular proliferation, efforts are required to assess their interaction and impact on current treatment options.

Abstract

Gastrointestinal cancer (GI) is a global health disease with a huge burden on a patient’s physical and psychological aspects of life and on health care providers. It is associated with multiple disease related challenges which can alter the patient’s quality of life and well-being. GI cancer development is influenced by multiple factors such as diet, infection, environment, and genetics. Although activating immune pathways and components during cancer is critical for the host’s survival, cancerous cells can target those pathways to escape and survive. As the gut microbiome influences the development and function of the immune system, research is conducted to investigate the gut microbiome–immune interactions, the underlying mechanisms, and how they reduce the risk of GI cancer. This review addresses and summarizes the current knowledge on the major immune cells and gut microbiome interactions. Additionally, it highlights the underlying mechanisms of immune dysregulation caused by gut microbiota on four major cancerous pathways, inflammation, cellular proliferation, apoptosis, and metastasis. Overall, gut-immune interactions might be a key to understanding GI cancer development, but further research is needed for more detailed clarification.

Sodium Humate Alleviates Enterotoxigenic Escherichia coli-Induced Intestinal Dysfunction via Alteration of Intestinal Microbiota and Metabolites in Mice

Enterotoxigenic Escherichia coli (ETEC) can damage intestinal epithelial barrier function and lead to serious intestinal diarrhea in newborns and young animals. Sodium humate (HNa) is natural organic bioactive compound possessing antibacterial, anti-inflammatory, and anti-diarrheal properties. This study investigated the alleviative potential of HNa on the impaired intestinal barrier and intestinal inflammation, and regulatory effects on gut microbiota and metabolites in ETEC K88 infected mice. A total of 30 female mice were randomly assigned into three groups. The mice in the control and ETEC groups were gavaged with 0.2 mL of sterile saline, while the mice in the ETEC + HNa group were gavaged with 0.2 mL of 5% HNa, daily. On day 8, the mice in ETEC and ETEC + HNa group were challenged with ETEC K88. The trial lasted for 12 days. HNa administration elevated ETEC K88-induced body weight loss and ameliorated jejunum and colon pathological injury. HNa also reduced the levels of pro-inflammatory cytokines in the serum, jejunum, and colon. Additionally, HNa reduced intestinal barrier damage by up-regulating the expression of tight junction proteins (TJPs) and mucosal repair factors. 16s rDNA gene sequencing results showed that HNa increased the abundance of beneficial bacteria Lactobacillus, Prevotella_9, and Odoribacter but decreased the abundance of pathogenic bacteria Escherichia and Gastranaerophilales in the feces of mice. Moreover, metabolomic analysis revealed that the concentrations of 15 metabolites, the pathways of protein digestion and absorption, and propanoic acid metabolism were changed by HNa administration. In conclusion, HNa could alleviate ETEC K88-induced intestinal dysfunction through restoring intestinal barrier integrity, modulating gut microbiota, and metabolites.

Depletion of transmembrane mucin 4 (Muc4) alters intestinal homeostasis in a genetically engineered mouse model of colorectal cancer

Mucins are components of the mucus layer overlying the intestinal epithelial cells, which maintains physiological homeostasis. Altered mucin expression is associated with disease progression. Expression of MUC4 decreases in colorectal cancer (CRC); however, its functional role and implications in the intestinal pathology in CRC are not studied well. Therefore, we generated a genetically engineered Muc4 knockout (Muc4^-/-) CRC mouse model by crossing with Muc4^-/- and Apc^flox/flox mice in the presence of colon-specific inducible Cre. We observed that deficiency of Muc4 results in an increased number of macroscopic tumors in the colon and rectal region and leads to poor survival. Further, the absence of Muc4 was associated with goblet cell dysfunction where the expression of intestinal homeostasis molecules (Muc2 and Fam3D) was downregulated. Next, we also observed that loss of Muc4 showed reduced thickness of mucus layer, leading to infiltration of bacteria, reduction in anti-microbial peptides, and upregulation of pro-inflammatory cytokines. Further, Apc gene mutation results in activation of the Wnt/β-catenin signaling pathway that corroborated with an increased nuclear accumulation of β-catenin and activation of its target genes: cyclin D1 and c-Myc in Muc4^-/- mice was observed. We conclude that the presence of Muc4 is essential for intestinal homeostasis, reduces tumor burden, and improves overall survival.

An in vitro chronic damage model impairs inflammatory and regenerative responses in human colonoid monolayers

Acute damage to the intestinal epithelium can be repaired via de-differentiation of mature intestinal epithelial cells (IECs) to a stem-like state, but there is a lack of knowledge on how intestinal stem cells function after chronic injury, such as in inflammatory bowel disease (IBD). We developed a chronic-injury model in human colonoid monolayers by repeated rounds of air-liquid interface and submerged culture. We use this model to understand how chronic intestinal damage affects the ability of IECs to (1) respond to microbial stimulation, using the Toll-like receptor 5 (TLR5) agonist FliC and (2) regenerate and protect the epithelium from further damage. Repeated rounds of damage impair the ability of IECs to regrow and respond to TLR stimulation. We also identify mRNA expression and DNA methylation changes in genes associated with IBD and colon cancer. This methodology results in a human model of recurrent IEC injury like that which occurs in IBD.

The Anti-Inflammatory Effect and Mucosal Barrier Protection of Clostridium butyricum RH2 in Ceftriaxone-Induced Intestinal Dysbacteriosis

This study aimed at determining the beneficial effect of Clostridium butyricum (CB) RH2 on ceftriaxone-induced dysbacteriosis. To this purpose, BALB/c mice were exposed to ceftriaxone (400 mg/ml) or not (control) for 7 days, and administered a daily oral gavage of low-, and high-dose CB RH2 (10⁸ and 10¹⁰ CFU/ml, respectively) for 2 weeks. CB RH2 altered the diversity of gut microbiota, changed the composition of gut microbiota in phylum and genus level, decreased the F/B ratio, and decreased the pro-inflammatory bacteria (Deferribacteres, Oscillibacter, Desulfovibrio, Mucispirillum and Parabacteroides) in ceftriaxone-treated mice. Additionally, CB RH2 improved colonic architecture and intestinal integrity by improving the mucous layer and the tight junction barrier. Furthermore, CB RH2 also mitigated intestinal inflammation through decreasing proinflammatory factors (TNF-α and COX-2) and increasing anti-inflammatory factors (IL-10). CB RH2 had direct effects on the expansion of CD4⁺ T cells in Peyer’s patches (PPs) in vitro, which in turn affected their immune response upon challenge with ceftriaxone. All these data suggested that CB RH2 possessed the ability to modulate the intestinal mucosal and systemic immune system in limiting intestinal alterations to relieve ceftriaxone-induced dysbacteriosis.