Human milk oligosaccharide disialyllacto-n-tetraose protects human intestinal epithelium integrity and permeability against mast cell chymase-induced disruption by stabilizing ZO-1/FAK/P38 pathway of intestinal epithelial cell.

CONTEXT: Inflammatory bowel disease (IBD) is a chronic gut disease with intestinal-epithelium disruption. Mast cell (MC) has been discussed in IBD studies, but its subset MCTC (chymase/tryptase) and MC-chymase have not been well-explored extensively. Human-milk-oligosaccharide-Disialyllacto-N-Tetraose (DSLNT) was reported as an effective strategy to protect infants against IBD with unclear mechanism. OBJECTIVE: This study was to examine the distribution of chymase-positive mast cells in the intestinal-epithelium-tissue of IBD infants, to explore the MC-chymase function on intestinal-epithelium, and to investigate the influences of DSLNT against MC-chymase-induced disruptions. MATERIALS AND METHODS: The intestinal-biopsies (surgical-waste) of the infants with IBD or with intestinal-atresia (non-IBD) were paraffin-embedded for immunohistochemistry. In-situ intestinal-tissue model and in-vitro human-intestinal-epithelial-cell (Caco-2) model were established with or without the treatments of MC-chymase (50mU/mL), DSLNT (600 µM) and DSLNT + MC-chymase respectively. The tissue morphology analysis, cell proliferation assay, cell-gap-closure assessment, fluorescence-immunocytochemistry, western blot, trans-epithelial-electrical-resistance, cell-cycle and statistical analysis were applied. RESULTS: There was an increased number of MCTC subset around the inflamed intestinal area in-vivo; MC-chymase caused intestinal-epithelial-barrier damage in-situ, decreased trans-epithelial-electrical-resistance of caco-2 cell monolayer in-vitro; while DSLNT protected epithelium against MC-chymase induced disruptions. MC-chymase reduced cell-viability, proliferation and migration, altered cell-cycle, down-regulated ZO-1, FAK, and P38 expressions, while DSLNT protected cells by impairing MC-chymase-induced interruptions. DSLNT can rescue ZO-1, FAK and P38 expressions and restore epithelial-cell integrity and cell cycle. CONCLUSIONS: Chymase-positive MCs are involved in IBD progress. MC-chymase disrupts intracellular ZO-1/FAK/P38 signal pathway and cell-cell/cell-matrix contacts, while DSLNT protects intestinal-epithelium against MC-chymase to maintain the intestinal epithelium integrity.

The Mechanism of Alisol B23 Acetate Inhibiting Lung Cancer: Targeted Regulation of CD11b/CD18 to Influence Macrophage Polarization.

Background: Tumor microenvironment has attracted more and more attention in oncology. Alisol B23 acetate (AB23A) inhibits the proliferation of tumor cells including non-small cell lung cancer (NSCLC) cells. However, whether AB23A plays a role in the tumor microenvironment of NSCLC still remains obscure. Methods: After THP-1 cells were polarized to M0 type by PMA, M0 macrophages were differentiated into M1 by LPS and IFNγ, and were differentiated into M2 by IL-4 and IL-13. The differentiation of THP-1 cells was detected by flow cytometry. After AB23A was given to macrophage RT-qPCR and ELISA detected the expressions of IL-6, IL-1ß, IL-10 and TGF-ß. Western blot and RT-qPCR detected the expressions of CD11b and CD18 at both mRNA and protein levels. Lung cancer cell A549 cells were induced by above related macrophage culture medium. Cell proliferation was detected by CCK-8. Tunel, wound healing and Transwell detected the apoptotic, migration and invasion capabilities. Next, M0 and M1-type macrophages were cultured in the cell culture medium of conventional A549 cells, to which AB23A was added. Subsequently, cell differentiation and inflammatory response were measured. Finally, the expression of CD18 in A549 cells was knocked down to construct NSCLC tumor-bearing mice and AB23A was applied for intragastric administration. Immunohistochemistry detected the polarization of macrophages in tumor tissues. Western blot detected the expressions of CD11b, CD18, invasion-, migration- and apoptosis-related proteins. Results: AB23A promoted the polarization of macrophages towards M1, thus promoting the apoptosis and inhibiting the invasion and migration of A549 cells. The tumor cell culture medium induced M0 macrophages to M2, while AB23A reversed this effect. AB23A targeted CD11b/CD18 and improved the polarization of macrophages, thereby affecting tumor invasion, migration and apoptosis. Conclusion: AB23A affected the polarization of tumor-associated macrophages through the targeted regulation of CD11b/CD18, thus inhibiting the development of lung cancer.