AIM:This study aims to explore the impact of Escherichia coli(E.coli)high-pathogenicity island(HPI)on pyroptosis and intestinal inflammation.METHODS:Kunming mice and IPEC-J2 cells(porcine small intesti-nal epithelial cells)were treated with HPI-containing E.coli strain(HPI+),HPI-deleting E.coli strain(ΔHPI),or lipo-polysaccharide(LPS).The intestinal lactate dehydrogenase(LDH)activity,superoxide dismutase(SOD)activity,IgA expression and secretory IgA(SIgA)content were assessed in mice.The expression of key regulatory factors in the nucleo-tide-binding oligomerization domain-like receptor protein 3(NLRP3)/caspase-1 signaling pathway-related proteins in mouse intestinal tract and IPEC-J2 cells was analyzed by RT-qPCR,immunohistochemical staining and Western blot.The levels of interleukin-1β(IL-1β)and IL-18 in mouse serum and IPEC-J2 cell culture supernatants were measured by ELISA.The pivotal role of NLRP3 in HPI+infection was confirmed by silencing NLRP3 in IPEC-J2 cells using siRNA.RE-SULTS:The HPI+infection markedly decreased SOD activity,increased IgA+B cell count,and induced the LDH release and SIgA secretion in the mouse intestine compared with ΔHPI infection.The results of ELISA,HE staining and TUNEL staining indicated that E.coli HPI triggered DNA damage,tissue injury and inflammation in mouse intestinal epithelial cells.Western blot revealed an increase in intestinal gasdermin D N-terminal fragment(GSDMD-N)protein level with HPI+infection compared with ΔHPI infection.E.coli HPI significantly up-regulated mRNA and protein expression of NLRP3,apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),caspase-1,GSDMD,IL-1β and IL-18 in mouse intestinal tissues and IPEC-J2 cells,accompanied by the elevated secretion of IL-1β and IL-18.The confo-cal microscopy demonstrated an enhanced assembly of the NLRP3 inflammasome with HPI+infection compared with ΔHPI infection,leading to colocalization of NLRP3 and caspase-1.Furthermore,NLRP3 silencing in IPEC-J2 cells attenuated E.coli HPI-induced cell inflammation,damage,and NLRP3/caspase-1 signaling pathway activation.CONCLUSION:The presence of HPI enhances the virulence of E.coli and exacerbates intestinal inflammation.Moreover,pyroptosis,regu-lated by the NLRP3/caspase-1 signaling pathway,plays a pivotal role in the intestinal injury induced by E.coli HPI.

Objective:To summarize experience of managing adult Langerhans cell histiocytosis(LCH) in hypothalamic-pituitary region(HPR) from Shanghai Huashan Hospital.Methods:Adult HPR-LCH patients diagnosed at oar endocrinology department from January 2013 to February 2022 were included. Clinical characteristics and treatment response were retrospectively analyzed.Results:A total of 27 adult HPR-LCH patients were included, with 14 cases involving the hypothalamus(H group) and 13 cases without(group NH). The common radiological findings included thickening of the pituitary stalk(25/27, 92.6%). At the time of diagnosis, 14 cases(51.9%) presented with panhypopituitarism, and 19 cases(70.4%) exhibited metabolic abnormalities. The group H had higher proportions of adrenal insufficiency, central hypothyroidism, panhypopituitarism, and diabetes compared to group NH(78.6% vs 23.1%; 78.6% vs 23.1%; 92.9% vs 30.8%, 35.7% vs 0%, respectively, all P<0.05). Hypothalamus syndrome was identified in 71.4%(10/14) of group H. The inital diagnosis rate was 79.2%(19/24), with 48.1% and 51.9% through biopsy of sellar and extrasellar lesions, respectively. Repeated biopsies confirmed the diagnosis in 25.9%(7/27) of cases. The peripheral lesions included bone, thyroid, lung, lymph node, thymus and liver. Out of 20 cases treated with chemotherapy, the objective response rate was 85% at 12 weeks. Four cases received local therapy, one case received traditional Chinese medicine treatment, one case abandoned treatment, and one case was lost to follow-up. The median follow-up time was 28(range 15 to 54) months. During this period, there were 3 deaths in group H and 1 death in group NH. Conclusion:Adult HPR-LCH patients presented with diabetes insipidus and high prevalences of hypopituitarism, hypothalamus syndrome and metabolic abnormalities. Typical imaging features were pituitary stalk thickening. A solitary mass in the HPR was usually very small, posing a great challenge for early diagnosis. Systemic evaluation would help to clarify the diagnosis. Patients with hypothalamus involvement had a higher mortality rate, suggesting the hypothalamus as a risk organ with poor prognosis.