GSDMD protects intestinal epithelial cells against bacterial infections through its N-terminal activity affecting intestinal immune homeostasis

The intestinal mucosal barrier serves as a vital guardian of the gut health,maintaining a delicate equilibrium between gut microbiota and host immune homeostasis.Gasdermin D(GSDMD),a key executioner of pyroptosis downstream of the inflammasome,has been found to play intricate roles in modulating colitis by influencing intestinal macrophages and regulating mucus secretion from goblet cells.However,the exact nature of the regulatory function of GSDMD in maintaining intestinal immune homeostasis and defending against pathogens remains to be elucidated.In the current study,by using the Citrobacter rodentium infection model,we found that GSDMD played a key role in the defense against intestinal Citrobacter rodentium infection,with high expression levels in intestinal epithelial and lamina propria myeloid cells.Our results showed that GSDMD acted specifically in intestinal epithelial cells to combat the infection,independently of its effects on antimicrobial peptides or mucin secretion.Instead,the resistance was mediated by the N-terminal fragment of GSDMD,highlighting its importance in intestinal immunity.However,the specific mechanism underlying the N-terminal activity of GSDMD in protecting against intestinal bacterial infections requires future investigation.

A metal-free carbon dots for wastewater treatment by visible light active photo-Fenton-like reaction in the broad pH range

Carbon dots(Cdots)has been proved to possess the catalytic decomposition of H_(2)O_(2) in the photocatalytic system.It is a potential photo-Fenton catalyst.Since multiple emissive Cdots have different light response range.There is rarely investigation on the performance of Cdots based photo-Fenton on the light wavelength.Herein,blue,green and red emissive carbon dots were synthesized from the different ratio of o-phenylenediamine and catechol by the solvothermal method.They exhibit different light adsorption range from UV to visible light.Furthermore,the photo-Fenton reactivity of Cdots was studied for catalyzing the decomposition of H_(2)O_(2) to generate free hydroxyl radicals and consequently applying for the removal of methyl blue.The results exhibit that Cdots with the broader light adsorption rang possess the stro nger catalytic activity for the photo-Fenton reaction.The H_(2)O_(2) decomposition rate of red emissive Cdots is 0.074 min^(-1),which is 2.64 and 1.46 times than the blue and green emissive Cdots,respectively.And the radical detection results confirm that the photo-Fenton happens in the reaction.In addition,the Cdots photo-Fenton can be carried out in the broad pH range from acidic to basic solution,which has a great potential to treat wastewater in the neutral system.