Maintaining a healthy intestinal barrier, the primary physical barrier between intestinal microbiota and the underlying lamina propria, is critical for optimal health. Epithelial integrity is essential for prevention of the entrance of luminal contents, such as bacteria and their products, through the large intestinal barrier. In this study, we investigated the protective functions of biosynthetic, specific sized, hyaluronan around 35 kDa (HA35) on intestinal epithelium in healthy mice, as well as mice infected Citrobacter rodentium, an established model that mimics infection with a serious human pathogen, enteropathogenic E. coli (EPEC). Our results reveal that treatment with HA35 protects mice from Citrobacter infection and enhances the epithelial barrier function. In particular, we have found that HA35 induces the expression of tight junction protein zonula occludens (ZO)-1 in both healthy and Citrobacter infected mice, as demonstrated by immunoflurorescence and Western blot analyses. Furthermore, we determined that HA35 treatment enhances ZO-1 expression and reduces intestinal permeability at the early stages of dextran sulfate sodium (DSS)-induced colitis in mice. Together, our data demonstrate that the expression and functionality of tight junctions, is increased by HA35 treatment, suggesting a novel mechanism for the protection from Citrobacter infection.

Tight junction proteins are critical in maintaining homeostatic intestinal permeability. Multiple intestinal inflammatory diseases are correlated with reduced expression of tight junction proteins. We have recently reported that oral treatment of mice with Hyaluronan 35kDa (HA35) increases colonic expression of tight junction protein zonula occludens-1 (ZO-1). Here, we investigate whether HA35 treatment enhances ZO-1 expression by direct interaction with intestinal epithelium in vitro and have identified the HA receptor responsible for HA35-mediated ZO-1 induction in colonic epithelium in vitro and in vivo. Our results reveal that HA35 treatment increases ZO-1 expression in mouse intestinal epithelial organoids, while large HA 2000kDa is not internalized into the cells. Our immunofluorescence data indicate that layilin, but neither toll-like receptor-4 (TLR-4) nor CD44, mediate the HA35-induced ZO-1 expression in colonic epithelium in vitro and in vivo. Additionally, using layilin null mice we have determined that layilin mediates HA35 induction of ZO-1 in healthy mice and during dextran sulfate sodium (DSS)-induced colitis. Furthermore, we find that while ZO-1 expression levels are reduced, layilin expression levels are equivalent in inflammatory bowel disease (IBD) patients and non-IBD controls. Together, our data suggest that layilin is an important HA receptor, that mediates the effect of oral HA35 treatment on intestinal epithelium. HA35 holds promise as a simple dietary supplement to strengthen gut barrier defense.

BACKGROUND & AIMS Defects in colonic epithelial barrier defenses are associated with ulcerative colitis (UC). The proteins that regulate bacterial clearance in the colonic epithelium have not been completely identified. The chromosome-associated protein D3 (dCAP-D3), regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing small hairpin RNAs against CAP-D3. We used immunoblot assays to measure levels of CAP-D3 in colonic epithelial cells from patients with UC and healthy individuals (controls). RNA sequencing identified genes activated by CAP-D3. We analyzed the roles of CAP-D3 target genes in bacterial clearance using gentamycin protection and immunofluorescence assays and studies with pharmacologic inhibitors. RESULTS CAP-D3 expression was reduced in colonic epithelial cells from patients with active UC. Reduced CAP-D3 expression decreased autophagy and impaired intracellular bacterial clearance by HT-29 and Caco-2 colonic epithelial cells. Lower levels of CAP-D3 increased transcription of genes encoding SLC7A5 and SLC3A2, whose products heterodimerize to form an amino acid transporter in HT-29 cells following bacterial infection; levels of SLC7A5–SLC3A2 were increased in tissues from patients with UC, compared with controls. Reduced CAP-D3 in HT-29 cells resulted in earlier recruitment of SLC7A5 to Salmonella-containing vacuoles, increased activity of mTORC1, and increased survival of bacteria. Inhibition of SLC7A5–SLC3A2 or mTORC1 activity rescued the bacterial clearance defects of CAP-D3– deficient cells. CONCLUSIONS CAP-D3 downregulates transcription of genes that encode amino acid transporters (SLC7A5 and SLC3A2) to promote bacterial autophagy by colon epithelial cells. Levels of CAP-D3 protein are reduced in patients with active UC; strategies to increase its levels might restore mucosal homeostasis to patients with active UC.

BackgroundIntravenous anesthesia has been reported to have a favorable effect on the prognosis of cancer patients. This study was performed to analyze data regarding the relation between anesthetics and the prognosis of cancer patients in our hospital.MethodsThe medical records of patients who underwent surgical resection for gastric, lung, liver, colon, and breast cancer between January 2006 and December 2009 were reviewed. Depending on the type of anesthetic, it was divided into total intravenous anesthesia (TIVA) or volatile inhaled anesthesia (VIA) group. The 5-year overall survival outcomes were analyzed by log-rank test. Cox proportional hazards modeling was used for sensitivity.ResultsThe number of patients finally included in the comparison after propensity matching came to 729 in each group. The number of surviving patients at 5 years came to 660 (90.5%) in the TIVA and 673 (92.3%) in the VIA. The type of anesthetic did not affect the 5-year survival rate according to the log-rank test (P = 0.21). Variables associated with a significant increase in the hazard of death after multivariable analysis were male sex and metastasis at surgery.ConclusionsThere were no differences in 5-year overall survival between two groups in the cancer surgery.Trial registrationTrial registration: CRIS KCT0004101. Retrospectively registered 28 June 2019.

Background: Although the loop electrosurgical excision procedure (LEEP) is a brief procedure, it can cause severe pain and discomfort to patients in the absence of adequate sedation. An admixture of ketamine with propofol (ketofol), may reduce patient movement due to insufficient sedation while providing hemodynamic and respiratory stability. This study evaluated the ability of two ratios of a propofol–ketamine combination, compared with propofol alone, to reduce patient movement during procedural sedation for LEEPs. Methods: One hundred and twenty women scheduled for a LEEP were randomly assigned to three groups. Anesthesia was induced with 1 mg/kg propofol (group P), 1 mg/kg propofol and 0.33 mg/kg ketamine (group K1), or 1 mg/kg propofol and 0.66 mg/kg ketamine (group K2). The primary outcome was the incidence of adduction motion in the lower extremities during the procedure. The requirements for respiratory interventions, changes in vital signs, sedation score, additional anesthetic usage, and surgeon and patient satisfaction were also evaluated. Results: The incidence of adduction motion was significantly lower in groups K1 and K2 than in group P (overall p-value <0.001) but did not differ significantly in groups K1 and K2. Group K2 needed more jaw thrust maneuvers than group K1. Additional propofol usage was lower and surgeon satisfaction scores higher in groups K1 and K2 than in group P. Conclusion: A propofol–ketamine combination is more effective than propofol alone in reducing procedural interference during LEEPs. However, increasing the dose of ketamine showed no additional benefit.