Colon Tissue Research Articles

B3GNT7 regulates mucin O-glycosylation to alleviate colonic inflammation

BackgroundB3GNT7, a glycosyltransferase of significant importance that is highly expressed in intestinal epithelial cells, plays a pivotal role in intestinal physiological processes. This study elucidates novel insights into the potential role and underlying mechanisms of B3GNT7 in ulcerative colitis (UC).MethodsAn experimental colitis model was induced using DSS in mice to investigate B3GNT7 expression in the colon via transcriptomics and immunohistochemistry. Bioinformatics analysis was employed to delineate the biological functions of B3GNT7. Additionally, the correlation between the transcription levels of B3GNT7 in colonic tissues from patients with UC, sourced from the IBDMDB database, and the severity of colonic inflammation was analyzed to elucidate potential mechanisms.ResultsThe DSS-induced colitis model was successfully established, and transcriptomic analysis identified a marked downregulation of B3GNT7 expression in the colonic tissues compared to the controls. Functional enrichment analysis indicated B3GNT7’s predominant role in mucin O-glycosylation. Protein interaction analysis revealed that B3GNT7 predominantly interacts with members of the mucin MUC family, including MUC2, MUC3, and MUC6. In patients with UC, B3GNT7 transcription levels were significantly reduced, particularly in those with moderate to severe disease activity. The expression level of B3GNT7 exhibited a negative correlation with the endoscopic severity of UC. Gene set enrichment analysis (GSEA) further demonstrated significant enrichment of B3GNT7 in the mucin O-glycosylation synthesis pathway.ConclusionThe downregulation of B3GNT7 expression in the colonic tissues of UC patients may contribute to the compromised mucin barrier function and the exacerbation of colitis.

Matrine Ameliorates DSS-Induced Colitis by Suppressing Inflammation, Modulating Oxidative Stress and Remodeling the Gut Microbiota.

Matrine (MT) possesses anti-inflammatory, anti-allergic and antioxidative properties. However, the impact and underlying mechanisms of matrine on colitis are unclear. The purpose of this research was to examine the protective impact and regulatory mechanism of matrine on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. MT alleviated DSS-induced UC by inhibiting weight loss, relieving colon shortening and reducing the disease activity index (DAI). Moreover, DSS-induced intestinal injury and the number of goblet cells were reversed by MT, as were alterations in the expression of zonula occludens-1 (ZO-1) and occludin in colon. Simultaneously, matrine not only effectively restored DSS-induced oxidative stress in colonic tissues but also reduced the production of inflammatory cytokines. Furthermore, MT could treat colitis mice by regulating the regulatory T cell (Treg)/T helper 17 (Th17) cell imbalance. We observed further evidence that MT alleviated the decrease in intestinal flora diversity, reduced the proportion of Firmicutes and Bacteroidetes, decreased the proportion of Proteobacteria and increased the relative abundance of Lactobacillus and Akkermansia in colitis mice. In conclusion, these results suggest that MT may mitigate DSS-induced colitis by enhancing the colon barrier integrity, reducing the Treg/Th17 cell imbalance, inhibiting intestinal inflammation, modulating oxidative stress and regulating the gut microbiota. These findings provide strong evidence for the development and application of MT as a dietary treatment for UC.

Shaoyao Decoction reduced T lymphocyte activation by regulating of intestinal flora and 5-hydroxytryptamine metabolism in ulcerative colitis

BackgroundShaoyao Decoction (SYD) is a widely recognized herbal formula utilized in traditional Chinese medicine for the treatment of diarrhea. Although it has demonstrated significant effectiveness in clinical practice for treating ulcerative colitis, the precise mechanisms by which it operates remain largely elusive.MethodsThe active ingredients of SYD were obtained by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), which were used to explore the potential pharmacological mechanism based on TCMSP (Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform) and PANTHER (Protein Analysis Through Evolutionary Relationships) classification system. In a mouse model of dextran sulfate sodium (DSS)-induced colitis, mRNA sequencing, 16S rDNA sequencing and targeted metabolomics techniques were used to elucidate the mechanisms of SYD, and immunohistochemistry, immunofluorescence, enzyme linked immunosorbent assay, real time quantitative polymerase chain reaction and western blot were used to test the key targets. In addition, QGP-1 and H9 cells were performed to validate the discoveries from the animal experiments.ResultsIn the mouse model of DSS-induced colitis, SYD effectively alleviated symptoms such as bloody stool, tissue damage, inflammation, intestinal flora dysbiosis and abnormal gene expression. Analyses of both differential expressed genes in colonic tissue and predicted 16S rDNA genes, as well as the analyses of targeted genes from TCMSP based on the active ingredients in UPLC-MS/MS of SYD, uncovered the enrichment of pathways involved in the biosynthesis and degredation of 5-hydroxytryptamine (5-HT). Interestingly, SYD suppressed the relative abundance of key genes in 5-HT synthesis, Tph1(Tryptophan hydroxylase 1) and Ddc (Dopa decarboxylase), in faeces from DSS-induced mice, leading to a reduction in the concentration of fecal 5-HT. Moreover, SYD augmented the production of butyric acid. Subsequently, increasing butyric acid influenced the metabolism of 5-HT in the organism through G protein-coupled receptor 43 by impeding its synthesis, facilitating its transport and degredation. These findings were additionally corroborated in a model utilizing enterochromaffin cell (QGP-1 cells). Furthermore, reduced levels of 5-HT hindered the activation of T lymphocytes (H9 cells) via the PKC (Protein kinase C) and NF-κB (Nuclear factor kappa-B) signaling pathways, by means of HTR1A (5-HT receptor 1A) and HTR3 (5-HT receptor 3). Additionally, diminished secretion of 5-HT resulted in reduced secretion of associated cytokines, thereby alleviating inflammation in the colon.ConclusionThrough modulation of T lymphocyte activation mediated by 5-HT metabolism in the local colon via the intestinal flora and its metabolite, SYD effectively mitigated colonic inflammation in DSS-induced mice.

CLK3 positively promoted colorectal cancer proliferation by activating IL-6/STAT3 signaling

Colorectal cancer (CRC) poses a significant challenge in oncology due to its increasing global incidence and treatment complexities. This study delved into the role of the dual-specificity protein kinase CLK3 in CRC progression and its potential as a therapeutic target. By analyzing clinical data and experimental models comprehensively, we found that CLK3 expression was markedly elevated in CRC tissues compared to normal colon tissue. High CLK3 levels were associated with advanced clinical stages and poor prognosis in CRC patients, suggesting its utility as a prognostic biomarker. Functional assays demonstrated that CLK3 overexpression boosted CRC cell proliferation and ATP production, whereas genetic CLK3 knockdown hindered cell proliferation in vitro and curbed tumor growth in vivo. Mechanistically, we uncovered that CLK3 positively influenced the IL-6/STAT3 signaling pathway by stabilizing JAK2 protein levels. These findings propose targeting CLK3 signaling as a promising therapeutic approach for CRC. Further investigation into CLK3's molecular mechanisms and clinical implications is necessary to fully harness its potential in managing CRC.

Identification and experimental validation of immune-related gene PPARG is involved in ulcerative colitis

BackgroundThe pathophysiology of ulcerative colitis (UC) is believed to be heavily influenced by immunology, which presents challenges for both diagnosis and treatment. The main aims of this study are to deepen our understanding of the immunological characteristics associated with the disease and to identify valuable biomarkers for diagnosis and treatment. MethodsThe UC datasets were sourced from the GEO database and were analyzed using unsupervised clustering to identify different subtypes of UC. Twelve machine learning algorithms and Deep learning model DNN were developed to identify potential UC biomarkers, with the LIME and SHAP methods used to explain the models' findings. PPI network is used to verify the identified key biomarkers, and then a network connecting super enhancers, transcription factors and genes is constructed. Single-cell sequencing technology was utilized to investigate the role of Peroxisome Proliferator Activated Receptor Gamma (PPARG) in UC and its correlation with macrophage infiltration. Furthermore, alterations in PPARG expression were validated through Western blot (WB) and immunohistochemistry (IHC) in both in vitro and in vivo experiments. ResultBy utilizing bioinformatics techniques, we were able to pinpoint PPARG as a key biomarker for UC. The expression of PPARG was significantly reduced in cell models, UC animal models, and colitis models induced by dextran sodium sulfate (DSS). Interestingly, overexpression of PPARG was able to restore intestinal barrier function in H2O2-induced IEC-6 cells. Additionally, immune-related differentially expressed genes (DEGs) allowed for efficient classification of UC samples into neutrophil and mitochondrial metabolic subtypes. A diagnostic model incorporating the three disease-specific genes PPARG, PLA2G2A, and IDO1 demonstrated high accuracy in distinguishing between the UC group and the control group. Furthermore, single-cell analysis revealed that decreased PPARG expression in colon tissue may contribute to the polarization of M1 macrophages through activation of inflammatory pathways. ConclusionIn conclusion, PPARG, a gene related to immunity, has been established as a reliable potential biomarker for the diagnosis and treatment of UC. The immune response it controls plays a key role in the progression and development of UC by enabling interaction between characteristic biomarkers and immune infiltrating cells.

Raffinose Ameliorates DSS-Induced Colitis in Mice by Modulating Gut Microbiota and Targeting the Inflammatory TLR4-MyD88-NF-κB Signaling Pathway.

This study aimed to explore the protective effects of raffinose (Raf) against inflammatory bowel disease in mice with colitis. Mice were administered 100, 200, or 400 mg/kg Raf for 21 d, followed by drinking-water containing 3% dextran sulfate sodium salt (DSS) for 3 d. Thereafter, the phenotype, pathological lesions in the colon, cytokines levels, and gut microbiota were evaluated. Treatment with Raf reduced the severity of the pathological changes in the colon, mitigating the reduction in colon length. Following Raf intervention, serum levels of inflammatory cytokines (IL-2, IL-6, IL-1β, and TNF-α) tended to return to normal. These results suggest that the anti-inflammatory effects of Raf are associated with a reduction in TLR4-MyD88-NF-κB pathway expression in mouse colonic tissues. Analysis of gut microbiota abundance and its correlation with colitis parameters revealed that DSS-induced dysbiosis was partially mitigated by Raf. In conclusion, Raf exerts a protective effect in colitis by modulating the gut microbiota and TLR4-MyD88-NF-κB pathway.

Effects of acupuncture on fecal short-chain fatty acids and TLR4/MyD88/NF-κB signaling pathway in spontaneously hypertensive rats

To observe the effects of acupuncture on blood pressure, fecal short-chain fatty acids (SCFAs) and toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway in spontaneously hypertensive rats (SHR), and to explore the mechanism of acupuncture for anti-hypertension. Twenty-four male SHR of SPF grade were randomly divided into a model group, a western medication group, an acupuncture group and a sham acupuncture group, with 6 rats in each group, and 6 male Wistar-Kyoto rats were selected as the blank group additionally. Hydrochlorothiazide solution was given by gavage in the western medication group; acupuncture was applied at bilateral "Renying" (ST 9) and "Zusanli" (ST 36) in the acupuncture group, 20 min a time; acupuncture was applied at the non-meridian and non-acupoint points close to bilateral "Renying" (ST 9) and "Zusanli" (ST 36) in the sham acupuncture group, 20 min a time. The intervention was adopted once a day for 4 weeks continuously in each group. The systolic blood pressure (SBP) of the caudal artery was measured before intervention and after 1, 2, 3 and 4 weeks of intervention. After intervention, the morphology of colonic tissue was observed by HE staining; the fecal level of SCFAs was detected by gas chromatography; the serum levels of interleukin (IL)-6, IL-1βand tumor necrosis factor-α (TNF-α) were detected by ELISA; the protein expression of TLR4, MyD88 and NF-κB p65 in the mesenteric artery was detected by Western blot. Compared with the blank group, in the model group, the SBP was increased (P<0.05), significant pathological changes could be found in the colonic tissue, the fecal SCFAs level was decreased (P<0.05), the serum levels of IL-6, IL-1β and TNF-α were increased (P<0.05), the protein expression of TLR4, MyD88 and NF-κB p65 in the mesenteric artery was increased (P<0.05). Compared with the model group, the SBP after 2, 3 and 4 weeks of intervention was decreased (P<0.05), the serum levels of IL-6, IL-1β and TNF-α were decreased (P<0.05) in the acupuncture group and the western medication group; the mucosal epithelium of colonic tissue was intact, the number of intestinal glands was abundant, the fecal SCFAs level was increased (P<0.05), and the protein expression of TLR4, MyD88 and NF-κB p65 in the mesenteric artery was decreased (P<0.05) in the acupuncture group. Compared with the sham acupuncture group, the SBP after 2, 3 and 4 weeks of intervention was decreased (P<0.05), the fecal SCFAs level was increased (P<0.05), the serum levels of IL-6, IL-1β and TNF-α were decreased (P<0.05), the protein expression of TLR4, MyD88 and NF-κB p65 in the mesenteric artery was decreased (P<0.05) in the acupuncture group. Acupuncture at bilateral "Renying" (ST 9) and "Zusanli" (ST 36) can effectively play an anti-hypertensive role in SHR. Its mechanism may be related to regulating fecal SCFAs level and inhibiting the TLR4/MyD88/NF-κB signaling pathway.

Incarcereted Epigastric Hernia with Liver Content: a Case Report

The epigastric hernia sac usually contains preperitoneal fat tissue, omentum, and intestines, but the presence of liver tissue is extremely rare. Epigastric hernia is a type of hernia in the midline of the abdominal wall between the umbilicus and the xiphoid process. It may be asymptomatic in some patients and cause complaints such as pain and nausea in most patients, but serious complications such as incarceration and strangulation are rare. In the present case, a 74-year-old woman was examined and found to have an irreduced omentum, transverse colon and liver tissue inside the hernia sac. She underwent an open procedure with onlay mesh-assisted hernia repair. Rare but serious complications, such as liver tissue incarceration, should be considered in epigastric hernia patients.

A novel variant in the SLCO2A1 gene in a Chinese patient with chronic gastroenteropathy and primary hypertrophic osteoarthropathy

BackgroundChronic enteropathy associated with SLCO2A1 gene (CEAS) results from loss-of-function variants in SLCO2A1, which encodes the prostaglandin transporter (PGT). CEAS follows an autosomal recessive inheritance pattern. To date, approximate 30 pathogenic variants have been reported in CEAS.MethodsWe performed whole exome sequencing (WES) to screen for potential pathogenic variants in a patient suspected of having CEAS, and confirmed a variant in SLCO2A1 using Sanger sequencing. We established an in vitro minigene model to compare splicing between wild type (WT) and mutant transcripts. Quantitative polymerase chain reaction (qPCR) was used to evaluate SLCO2A1 transcription in the stomach and colon tissues from the patient and a healthy control (HC). The transcripts were further cloned and sequenced.ResultsThe patient had a novel, homozygous, recessive c.929A > G variant in exon 7 of SLCO2A1, which has not been previously reported in CEAS or PHO. This variant altered splicing, resulting in an exon 7‐truncated transcript lacking 16 bases. No normal transcript was detected in the patient’s stomach or colon tissue. qPCR also showed significantly decreased SLCO2A1 transcription compared to HC.ConclusionA previously unreported variant caused defective SLCO2A1 splicing and reduced mRNA levels in a patient with CEAS and PHO. This research enhances understanding of CEAS and PHO pathophysiology and aids genetic counseling and diagnosis.

Sishen Pill inhibits intestinal inflammation in diarrhea mice via regulating kidney-intestinal bacteria-metabolic pathway.

Sishen Pill (SSP) has good efficacy in diarrhea with deficiency kidney-yang syndrome (DKYS), but the mechanism of efficacy involving intestinal microecology has not been elucidated. This study investigated the mechanism of SSP in regulating intestinal microecology in diarrhea with DKYS. Adenine combined with Folium sennae was used to construct a mouse model of diarrhea with DKYS and administered with SSP. The behavioral changes and characteristics of gut content microbiota and short-chain fatty acids (SCFAs) of mice were analyzed to explore the potential association between the characteristic bacteria, SCFAs, intestinal inflammatory and kidney function-related indicators. After SSP intervention, the body weight and anal temperature of diarrhea with DKYS gradually recovered and approached the normal level. Lactobacillus johnsonii was significantly enriched, and propionic, butyric, isobutyric and isovaleric acids were elevated. Serum creatinine (Cr), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) levels of the mice were reduced, while serum blood urea nitrogen (BUN) and secretory immunoglobulin A (sIgA) in the colonic tissues were increased. Moreover, there were correlations between L. johnsonii, SCFAs, intestinal inflammatory, and kidney function. SSP might suppress the intestinal inflammation by regulating the "L. johnsonii-propionic acid" pathway, thus achieving the effect of treating diarrhea with DKYS.

A Traditional Chinese Medicine, Zhenqi Granule, Potentially Alleviates Dextran Sulfate Sodium-Induced Mouse Colitis Symptoms.

Ulcerative colitis (UC) is an inflammatory bowel disease that causes chronic inflammation in the large intestine. The etiology of UC is complex and incompletely understood, with potential contributing factors including genetic susceptibility, environmental influences, immune dysregulation, and gut barrier dysfunction. Despite available therapeutic drugs, the suboptimal cure rate for UC emphasizes the necessity of developing novel therapeutics. Traditional Chinese Medicine (TCM) has attracted great interest in the treatment of such chronic inflammatory diseases due to its advantages, such as multi-targets and low side effects. In this study, a mouse model of Dextran Sulfate Sodium (DSS)-induced acute colitis was established and the efficacy of Zhenqi Granule, a TCM preparation composed of the extractives from Astragali Radix and Fructus Ligustri Lucidi, was evaluated. The results showed that treatment with Zhenqi Granule prior to or post-DSS induction could alleviate the symptoms of colitis, including weight loss, diarrhea, hematochezia, colon length shortening, and pathological damage of colon tissues of the DSS-treated mice. Further, network pharmacology analysis showed that there were 98 common targets between the active components of Zhenqi Granule and the targets of UC, and the common targets were involved in the regulation of inflammatory signaling pathways. Our results showed that Zhenqi Granule had preventive and therapeutic effects on acute colitis in mice, and the mechanism may be that the active components of Zhenqi Granule participated in the regulation of inflammatory response. This study provided data reference for further exploring the mechanism of Zhenqi Granule and also provided potential treatment strategies for UC.

Histopathological evaluation of ulcerative colitis induced by white vinegar in albino rats

The ulcerative colitis (UC) is an inflammatory bowel illness which causes persistent inflammation of the colon's innermost layers. A prominent characteristic of ulcerative colitis (UC) is the stool's blood and mucous contents. This study determined to investigate the effects of white vinegar (WV) on colon tissues in rats. Two groups of twenty rats were created; the primary group was a control, healthy group, and the WV was administered to the second group at a dose of [1 ml/kg (5%)] via orally gavage for two weeks. Findings revealed the emergence of histopathological alterations like mucosal erosions, ulceration, loss of normal architecture, mucosal atrophy, and hemorrhage; numerous crypts have inflammatory cells that entered them, blood vessels are dilated and oedema, the serosa is destroyed, which demonstrates the devastation of the mucosal lining destruction with goblet cell hyperplasia, focal necrosis of epithelium with demolished connective tissues, accumulation of inflammatory cells in the mucosa, lamina propria, and muscularis mucosa, as well as submucosal oedema when compared with the control rats. The PAS-reaction histochemical analysis showed that the treated rats had lower levels of carbohydrates than the control animals. The findings of the study demonstrated that white vinegar was a dangerous substance linked to histological alterations that resulted in acute ulcerative colitis when used daily for two weeks.

Characterization of a novel sulfated-rhamnoglucuronan isolated from Korean seaweed Ulva pertusa and its efficacy for treatment of inflammatory bowel disease in mice

This study aimed to isolate Ulva pertusa polysaccharide (UPP), which elicits anti-inflammatory bowel disease (IBD) effects, from the Korea seaweed U. pertusa and identify its structure. Firstly, UPP was isolated from U. pertusa using hydrothermal extraction and ethanol precipitation. UPP is a novel polysaccharide that exhibits unique structural features such as 3-sulfated rhamnose, glucuronic acid, iduronic acid, and 3-sulfated xylose, which are repeated in 1,4-glycosidic bonds. Prophylactic oral administration of UPP in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) suppressed the levels of inflammatory cytokines and MAPK- and NF-κB-related factors in the serum and colon tissue. Tight junction (TJ)-related factors such as occludin, claudin-1, and mucin were effectively augmented by UPP in the colon tissue. In addition, UPP administration prevented the DSS treatment-led cecal short chain fatty acid imbalance, and this effect was most evident for propionic acid. In conclusion, UPP isolated from the Korean U. pertusa demonstrates potent anti-IBD activity. Characterization of this ulvan revealed its unique structure. Moreover, its efficacy may be associated with its anti-inflammatory effects and regulation of gut microbiota and TJ proteins. Thus, this study provides new insights into the biological effects of UPP in IBD.

Alleviation of fluoride-induced colitis by tea polysaccharides: Insights into the role of Limosilactobacillus vaginalis and butyric acid

Endemic fluorosis has gained increasing attention as a public health concern, and the escalating risk of colitis resulting from excessive fluoride intake calls for effective mitigation strategies. This study aimed to investigate the potential mechanisms underlying the alleviation of fluoride-induced colitis by Tea polysaccharides (TPS). Under conditions of excessive fluoride intake, significant changes were observed in the gut microbiota of rats, leading to aggravated colitis. However, the intervention of TPS exerted a notable alleviating effect on colitis symptoms. Antibiotic intervention and fecal microbiota transplantation (FMT) experiments provided evidence that TPS-mediated relief of fluoride-induced colitis is mediated through its effects on the gut microbiota. Furthermore, TPS supplementation was found to modulate the structure of gut microbiota, enhance the relative abundance of Limosilactobacillus vaginalis in the gut microbiota, and promote the expression of short-chain fatty acid (SCFAs) receptors in colonic tissue. Notably, L. vaginalis played a significant role in alleviating fluoride-induced colitis and facilitating the absorption of butyric acid in the rat colon. Subsequent butyric acid intervention experiments confirmed its remarkable alleviating effect on fluoride-induced colitis. Overall, these findings provide a potential preventive strategy for fluoride-induced colitis by TPS intervention, which is mediated by L. vaginalis and butyric acid.

Bletilla striata polysaccharide-coated andrographolide nanomicelles for targeted drug delivery to enhance anti-colon cancer efficacy.

Vitamin E, which is also known as tocopherol, is a compound with a polyphenol structure. Its esterified derivative, Vitamin E succinate (VES), exhibits unique anticancer and healthcare functions as well as immunomodulatory effects. Natural polysaccharides are proved to be a promising material for nano-drug delivery systems, which show excellent biodegradability and biocompatibility. In this study, we employed a novel bletilla striata polysaccharide-vitamin E succinate polymer (BSP-VES) micelles to enhance the tumor targeting and anti-colon cancer effect of andrographolide (AG). BSP-VES polymer was synthesized through esterification and its structure was confirmed using 1H NMR. AG@BSP-VES was prepared via the dialysis method and the drug loading, entrapment efficiency, stability, and safety were assessed. Furthermore, the tumor targeting ability of AG@BSP-VES was evaluated through targeted cell uptake and in vivo imaging. The antitumor activity of AG@BSP-VES was measured in vitro using MTT assay, Live&Dead cell staining, and cell scratch test. In this study, we successfully loaded AG into BSP-VES micelles (AG@BSP-VES), which exhibited good stability, biosafety and sustained release effect. In addition, AG@BSP-VES also showed excellent internalization capability into CT26 cells compared with NCM460 cells in vitro. Meanwhile, the specific delivery of AG@BSP-VES micelles into subcutaneous and in-situ colon tumors was observed compared with normal colon tissues in vivo during the whole experiment process (1-24 h). What's more, AG@BSP-VES micelles exhibited significant antitumor activities than BSP-VES micelles and free AG. The study provides a meaningful new idea and method for application in drug delivery system and targeted treatment of colon cancer based on natural polysaccharides.

Bacteria colonization and gene expression related to immune function in colon mucosa is associated with growth in neonatal calves regardless of live yeast supplementation

BackgroundAs Holstein calves are susceptible to gastrointestinal disorders during the first week of life, understanding how intestinal immune function develops in neonatal calves is important to promote better intestinal health. Feeding probiotics in early life may contribute to host intestinal health by facilitating beneficial bacteria colonization and developing intestinal immune function. The objective of this study was to characterize the impact of early life yeast supplementation and growth on colon mucosa-attached bacteria and host immune function.ResultsTwenty Holstein bull calves received no supplementation (CON) or Saccharomyces cerevisiae boulardii (SCB) from birth to 5 d of life. Colon tissue biopsies were taken within 2 h of life (D0) before the first colostrum feeding and 3 h after the morning feeding at d 5 of age (D5) to analyze mucosa-attached bacteria and colon transcriptome. Metagenome sequencing showed that there was no difference in α and β diversity of mucosa-attached bacteria between day and treatment, but bacteria related to diarrhea were more abundant in the colon mucosa on D0 compared to D5. In addition, qPCR indicated that the absolute abundance of Escherichia coli (E. coli) decreased in the colon mucosa on D5 compared to D0; however, that of Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii, which could competitively exclude E. coli, increased in the colon mucosa on D5 compared to D0. RNA-sequencing showed that there were no differentially expressed genes between CON and SCB, but suggested that pathways related to viral infection such as “Interferon Signaling” were activated in the colon mucosa of D5 compared to D0.ConclusionsGrowth affected mucosa-attached bacteria and host immune function in the colon mucosa during the first 5 d of life in dairy calves independently of SCB supplementation. During early life, opportunistic pathogens may decrease due to intestinal environmental changes by beneficial bacteria and/or host immune function. Predicted activation of immune function-related pathways may be the result of host immune function development or suggest other antigens in the intestine during early life. Further studies focusing on the other antigens and host immune function in the colon mucosa are required to better understand intestinal immune function development.

Circadian rhythm disruption-mediated downregulation of Bmal1 exacerbates DSS-induced colitis by impairing intestinal barrier.

Circadian rhythm disruption (CRD) is thought to increase the risk of inflammatory bowel disease. The deletion of Bmal1, a core transcription factor, leads to a complete loss of the circadian rhythm and exacerbates the severity of dextran sodium sulfate (DSS)-induced colitis in mice. However, the underlying mechanisms by which CRD and Bmal1 mediate IBD are still unclear. We used a CRD mouse model, a mouse colitis model, and an in vitro model of colonic epithelial cell monolayers. We also knocked down and overexpressed Bmal1 in Caco-2 cells by transfecting lentivirus in vitro. The collected colon tissue and treated cells were assessed and analyzed using immunohistochemistry, immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction, western blot, flow cytometry, transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling staining. We found that CRD mice with downregulated Bmal1 expression were more sensitive to DSS-induced colitis and had more severely impaired intestinal barrier function than wild-type mice. Bmal1-/- mice exhibited more severe colitis, accompanied by decreased tight junction protein levels and increased apoptosis of intestinal epithelial cells compared with wild-type mice, which were alleviated by using the autophagy agonist rapamycin. Bmal1 overexpression attenuated Lipopolysaccharide-induced apoptosis of intestinal epithelial cells and impaired intestinal epithelial cells barrier function in vitro, while inhibition of autophagy reversed this protective effect. This study suggests that CRD leads to the downregulation of Bmal1 expression in the colon, which may exacerbate DSS-induced colitis in mice, and that Bmal1 may serve as a novel target for treating inflammatory bowel disease.

Correlations Between the Expression of MicroRNA-155 and Suppressor of Cytokine Signaling 1 in Colonic Mucosal Tissue and Disease Severity in Patients With Ulcerative Colitis

Objective To explore the relationship between the expression levels of microRNA-155 (miR-155) and suppressor of cytokine signaling 1 (SOCS1) in the colonic mucosal tissue of patients with ulcerative colitis (UC) and the severity of the disease.Methods A total of 130 UC patients admitted to the Second Affiliated Hospital of Hebei North University from September 2021 to June 2023 were selected.According to the modified Mayo score system,the patients were assigned into an active stage group (n=85) and a remission stage group (n=45).According to the modified Truelove and Witts classification criteria,the UC patients at the active stage were assigned into a mild group (n=35),a moderate group (n=30),and a severe group (n=20).A total of 90 healthy individuals who underwent colonoscopy for physical examination or those who had normal colonoscopy results after single polypectomy and excluded other diseases were selected as the control group.The colonic mucosal tissues of UC patients with obvious lesions and the colonic mucosal tissue 20 cm away from the anus of the control group were collected.The levels of miR-155 and SOCS1 mRNA in tissues were determined by fluorescence quantitative PCR,and the expression of SOCS1 protein in tissues was determined by immunohistochemistry.The correlations of the levels of miR-155 and SOCS1 mRNA in the colonic mucosal tissue with the modified Mayo score of UC patients were analyzed.The values of the levels of miR-155 and SOCS1 mRNA in predicting the occurrence of severe illness in the UC patients at the active stage were evaluated.Results Compared with the control group and the remission stage group,the active stage group showed up-regulated expression level of miR-155,down-regulated level of SOCS1 mRNA,and decreased positive rate of SOCS1 protein in the colonic mucosal tissue (all P<0.001).The expression level of miR-155 and modified Mayo score in colonic mucosal tissues of UC patients at the active stage increased,while the mRNA level of SOCS1 was down-regulated as the disease evolved from being mild to severe (all P<0.001).The modified Mayo score was positively correlated with the miR-155 level and negative correlated with the mRNA level of SOCS1 in colonic mucosal tissues of UC patients (all P<0.001).The high miR-155 level (OR=2.762,95%CI=1.284-5.944,P=0.009),low mRNA level of SOCS1 (OR=2.617,95%CI=1.302-5.258,P=0.007),and modified Mayo score≥12 points (OR=3.232,95%CI=1.450-7.204,P=0.004) were all risk factors for severe disease in the UC patients at the active stage.The area under curve of miR-155 combined with SOCS1 mRNA in predicting severe illness in the UC patients at the active stage was 0.920.Conclusions The expression levels of miR-155 and SOCS1 mRNA were correlated with the disease severity in the UC patients at the active stage.The combination of the two indicators demonstrates good performance in predicting the occurrence of severe illness in UC patients at the active stage.

Seasonal variation of melatonin secretion across various segments of the gastrointestinal tract in rats

ObjectiveTo investigate whether melatonin (MT) secretion in different parts of the gastrointestinal tract (GIT) exhibits seasonal variations and its correlation with immune regulation. MethodsSixty Sprague-Dawley rats were divided into control and model groups, and the pineal gland was removed in the model group. Stomach, jejunum, ileum, and colon tissues were obtained during the spring equinox, summer solstice, beginning of autumn, autumn equinox, and winter solstice. The levels of MT, MT receptors (MR), arylalkylamine N-acetyltransferase (AANAT), hydroxyindole-O-methyltransferase (HIOMT), interleukin-2 (IL-2), and interleukin-10 (IL-10) in the GIT were measured using enzyme-linked immunosorbent assay. ResultsExcept for the stomach, the jejunum, ileum, and the colon showed seasonal tendencies in MT secretion. In the control group, MT secretion in the jejunum and ileum was the highest in the long summer, and colonic MT secretion was the highest in winter. In the model group, MT levels in the colon were highest in the summer. The seasonal rhythms of the MR, AANAT, HIOMT, IL-2, and IL-10 in the colon were roughly similar to those of MT, and changed accordingly after pinealectomy. ConclusionsGastrointestinal MT secretion is related to seasonal changes, and MT secretion in each intestinal segment is influenced by different seasons. The biological effects of MT in the gut are inextricably linked to the mediation of MR, and a hormone-receptor linkage exists between MT and MR. The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.

Transcriptomic profiling of gastrointestinal tracts in dairy cattle during lactation reveals molecular adaptations for milk synthesis

During lactation, dairy cattle’s digestive tract requires significant adaptations to meet the increased nutrient demands for milk production. As we attempt to improve milk-related traits through selective pressure, it is crucial to understand the biological functions of the epithelia of the rumen, small intestine, and colonic tissues in response to changes in physiological state driven by changes in nutrient demands for milk synthesis. In this study, we obtained a total of 108 transcriptome profiles from three tissues (epithelia of the colon, duodenum, and rumen) of five Holstein cows, spanning eight time points from the early, mid, late lactation periods to the dry period. On average 97.06% of reads were successfully mapped to the reference genome assembly ARS-UCD1.2. We analyzed 27,607 gene expression patterns at multiple periods, enabling direct comparisons within and among tissues during different lactation stages, including early and peak lactation. We identified 1645, 813, and 2187 stage-specific genes in the colon, duodenum, and rumen, respectively, which were enriched for common or specific biological functions among different tissues. Time series analysis categorized the expressed genes within each tissue into four clusters. Furthermore, when the three tissues were analyzed collectively, 36 clusters of similarly expressed genes were identified. By integrating other comprehensive approaches such as gene co-expression analyses, functional enrichment, and cell type deconvolution, we gained profound insights into cattle lactation, revealing tissue-specific characteristics of the gastrointestinal tract and shedding light on the intricate molecular adaptations involved in nutrient absorption, immune regulation, and cellular processes for milk synthesis during lactation.