Objective To investigate the effect of glycosylation of MUC2 on the invasions and metabolic functions of Escherichia and its involvement in the pathogenesis of ulcerative colitis.

Methods A total of 75 patients with ulcerative colitis (UC) were included in the study group, and 75 healthy subjects were included in control group. Immunohistochemistry was used to detect MUC2 protein levels in normal mucosal tissues and UC tissues. C-reactive protease (CRP) and fecal calprotectin (FC) were detected by enzyme-linked immunosorbent assay (ELISA), and procalcitonin (PCT) was detected by automatic biochemical analyzer. HT29 cells were treated with Escherichia, and then divided into group A (cell+MUC2 polysaccharide), group B (cell+monosaccharide) and group C (cell+phosphate buffer). Escherichia biofilm was observed, and the adhesion and invasion ability of Escherichia were detected by AGAR plate. LasR, pvdA, pcrV and GUS levels were detected by polymerase chain reaction (PCR).

Results The expression level of MUC2 protein in normal mucosa tissues and UC tissues was statistically significant (t=13.770, P < 0.001). The MUC2 protein level was (0.63±0.10) in patients with mild UC, (0.55±0.09) in patients with moderate UC, and (0.50±0.05) in patients with severe UC, and the difference was statistically significant (F=14.880, P < 0.001). Compared with the control group, the levels of CRP, FC and PCT in the study group were statistically increased (P < 0.05). Compared with mild patients, the levels of CRP, FC and PCT in moderate patients were significantly increased, while those in severe patients were significantly increased (P < 0.05); in UC disease, MUC2 was negatively correlated with CRP, FC, and PCT levels. The adhesion rates of Escherichia in group A, group B and group C were (15.30±2.55)%, (63.25±8.08)% and (48.61±6.67)%, respectively (F=93.480, P < 0.001). The invasion rates of Escherichia in groups A, B, and C were (24.80±5.11)%, (70.21±10.60)% and (53.34±8.06)%, respectively, and the differences were statistically significant (F=46.620, P < 0.001). Compared with group A, the levels of LasR, pvdA, pcrV and GUS genes in group B were significantly increased, and the levels of LasR, pvdA, pcrV and GUS genes in group C were significantly decreased compared with group B (P < 0.05).

Conclusion The expression of MUC2 in UC is decreased and decreased with the severity of the disease, which is negatively correlated with the expression of CRP, FC and PCT. The monosaccharide culture of Escherichia and MUC2 can increase its invasion and adhesion ability, and enhance its toxicity.