Objective To investigate the mechanism underlying gasdermin E(GSDME)-mediated pyroptosis in radiation-induced intestinal injury and to find out whether gasdermin(GSDM)family members regulate pyroptosis through similar signaling pathways.Methods Human normal colon epithelial cells(NCM460)and human colon cancer cells(HT-29)were exposed to radiation of different doses and durations before pyroptosis indicators were evaluated by observing pyroptotic bubbles,cell survival,and the cleavage of pyroptosis execution proteins.HT-29 cells overexpressing GSDME were subjected to radiation,followed by enrichment analysis of pyroptosis-related differentially expressed genes using RNA-seq.Results Radiation induced substantial pyroptosis in NCM460 cells.Overexpression of GSDME in HT-29 cells resulted in substantial radiation-induced pyroptosis.The pyroptosis state of human intestinal cells was simulated in the HT-29 model cell line.Overexpressions of GSDME-N and GSDMD-N resulted in the expression of more than 50％ of the differentially expressed genes in the pyroptosis state.Sequencing analysis showed that the genes in the pyroptosis state were mainly overrepresented in immune response,inflammatory response,and Rapl signaling pathway.Conclusion GSDME activation can mediate radiation-induced pyroptosis by producing GSDME-N fragments.GSDM family members participate in pyroptosis in a similar mode of regulation.Furthermore,radiation-induced activation of GSDME/D may regulate pyroptosis through immune response,inflammatory response,and Rap1 signaling pathway.

Objective To investigate the protective effect and mechanism of glutathione peroxidase 3-(GPx3)modified mesenchymal stem cells(MSC)against radiation-induced lung injury(RILI).Methods GPx3-modified MSCs were injected into the tail vein of mice whose lungs were irradiated with 20 Gy.Lung tissues were collected and sections were stained to observe pathological changes.The expression levels of inflammation-related factors were detected by real time quantitative PCR(qPCR),while the levels of malondialdehyde(MDA),H2O2,and 8-hydroxyguanine(8-OHG)were detected via biochemical experiments.Additionally,RNA damage was assessed by reverse transcription blocking combining with double primer PCR.Results GPx3-modified MSCs significantly improved the pathological damage in post-radiation lung tissues and inhibited the fibrosis process and inflammatory response.GPx3-modified MSCs were able to scavenge reactive oxygen species(ROS)more effectively,resulting in a reduction of lipid peroxidation products such as MDA and oxidative damage to RNA formation of 8-OHG.Conclusion By decreasing ROS accumulation,GPx3-modified MSCs can potentially reduce oxidative damage and attenuate RILI.GPx3-modified MSCs can improve the therapeutic efficacy against RILI.

Objective : The CRISPR / dCas9-SAM system was used to explore genes related to the proliferation of gastric cancer cells AGS，and their role in the occurrence and development of gastric cancer was analyzed． Methods : sgRNA was designed for genes with differential expression between gastric cancer and normal gastric tissue， and a lentiviral library was obtained after packaging was constructed．The AGS cells at different time points after the library was infected with AGS cells were used as the screening pressure，and the AGS cells at three time points on days 0，7 and 14 were collected．High-throughput sequencing analyzed sgRNA enrichment in AGS cells at dif- ferent time points after infection to obtain differential genes related to AGS cell proliferation. Results : Bioinformat- ics showed that compared with the 0 d group，42 and 45 negative screening differential genes and 59 and 40 posi- tive screening differential genes were obtained in the 7 d group and 14 d group，respectively．Among them，the 7 d group and the 14 d group had 11 genes in the negative screening and the positive screening． Conclusion In this study，11 genes inhibiting the proliferation of AGS cells were screened，of which 5 were protein-coding genes and 6 were long non-coding RNA ( lncRNA ) genes． 11 candidate genes that promoted AGS cell proliferation were screened，of which 3 were protein-coding genes and 8 were lncRNA genes．It laid a foundation for further function- al verification and comprehensive analysis of the occurrence and development process of gastric cancer.