Objective : To investigate the effect of platelet particles on the extent of intestinal inflammation and in⁃ testinal mucosal permeability in mice with dextran sodium sulfate induced colitis. Methods : The experiment was divided into four groups : normal control group ( n = 10 , drinking sterile distilled water + intraperitoneal injection of 0. 9% sodium chloride solution) , PMPs group ( n = 10 , drinking sterile distilled water + intraperitoneal injection of PMPs) , DSS model group ( n = 10 , drinking DSS solution + intraperitoneal injection of 0. 9% sodium chloride solution) , and experimental group ( n = 15 , drinking DSS solution + intraperitoneal injection of PMPs) . Peripheral blood⁃derived PMPs suspension was collected from inflammatory bowel disease ( IBD) patients. A colitis model was constructed in mice by allowing them to freely drink a 5% DSS solution for 1 week , followed by continuous intraperitoneal injection of PMPs for 7 days. Disease activity index (DAI) scores was recorded daily and the severity of intestinal inflammation with histopathological scores (HI) was assessed by HE staining of colon samples at the end of the experiment. Myeloperoxidase (MPO) , neutrophil elastase (NE) , citrullinated histone H3 (citH3) , and free DNA levels were measured in colon homogenate , observe intestinal mucosal structure by transmission electron microscopy , and intestinal permeability was tested using fluorescein isothiocyanate⁃dextran (FITC⁃D) . Results: Compared with the normal control group , the colonic mucosa of mice in the PMPs group showed edema , severe destruction of epithelial structure , extensive aggregation of inflammatory cells , and increased overall HI score (P < 0. 01) ; the levels of inflammatory factors such as IL⁃1β and TNF⁃α in colonic tissue homogenates of mice in the PMPs group increased (P < 0. 05) , and the expression of NETs increased (P < 0. 05) ; the plasma FITC⁃D level of mice in the PMPs group significantly increased (P < 0. 05) , and the permeability of intestinal mucosa increased. Compared with the DSS group , the experimental group mice had higher plasma FITC⁃D levels ( P < 0. 05 ) and more electron microscopic colonic epithelial damage. Conclusion PMPs induces NETs formation in mice , promotes colonic inflammation in mice , increases intestinal mucosal permeability and aggravates intestinal inflammation in mice with DSS colitis.

Tuberculosis (TB) is one of the deadly diseases caused by Mycobacterium tuberculosis (Mtb), which presents a significant public health challenge. Treatment of TB relies on the combination of several anti-TB drugs to create shorter and safer regimens. Therefore, new anti-TB agents working by different mechanisms are urgently needed. FtsZ, a tubulin-like protein with GTPase activity, forms a dynamic Z-ring in cell division. Most of FtsZ inhibitors are designed to inhibit GTPase activity. In Mtb, the function of Z-ring is modulated by SepF, a FtsZ binding protein. The FtsZ/SepF interaction is essential for FtsZ bundling and localization at the site of division. Here, we established a yeast two-hybrid based screening system to identify inhibitors of FtsZ/SepF interaction in M. tuberculosis. Using this system, we found compound T0349 showing strong anti-Mtb activity but with low toxicity to other bacteria strains and mice. Moreover, we have demonstrated that T0349 binds specifically to SepF to block FtsZ/SepF interaction by GST pull-down, fluorescence polarization (FP), surface plasmon resonance (SPR) and CRISPRi knockdown assays. Furthermore, T0349 can inhibit bacterial cell division by inducing filamentation and abnormal septum. Our data demonstrated that FtsZ/SepF interaction is a promising anti-TB drug target for identifying agents with novel mechanisms.

[This corrects the article DOI: 10.1016/j.apsb.2023.01.022.].