Type III interferons induce pyroptosis in gut epithelial cells and impair tissue repair upon intestinal injury.. Type III interferons induce pyroptosis in gut epithelial cells and impair tissue repair upon intestinal injury.

Tissue damage and repair are hallmarks of inflammation. Despite a wealth of information on the mechanisms that govern tissue damage, mechanistic insight on how inflammation affects repair is lacking. Here, we investigated how interferons influence tissue repair after damage to the intestinal mucosa. We found that type III, not type I or II, interferons delay epithelial cell regeneration by inducing the upregulation of Z-DNA-binding protein 1 (ZBP1). Z-nucleic acids formed following intestinal damage are sensed by ZBP1, leading to Caspase-8 activation, and cleavage of Gasdermin C (GSDMC). Cleaved GSDMC drives epithelial cell death by pyroptosis and delays repair of the large or small intestine after colitis or irradiation, respectively. The type III interferon/ZBP1/Caspase-8/GSDMC axis is also active in patients with inflammatory bowel disease (IBD). Our findings highlight the capacity of type III interferons to delay gut repair, which has important implications for IBD patients or individuals exposed to radiation therapies. Overall design: Age-matched (8–12-weeks old) cohorts of male and female mice were given 2.5% DSS drinking water for 7 days, followed by 3 days of recovery. On day 10, three mice per condition and genotype were sacrificed and colons were harvested. Single-cell RNA-sequencing was performed using 10x Genomics 3' v3.1 transcriptomics kit with mouse replicates (per tissue region) combined together and labeled with biotinylated antibodies, followed by oligo-conjugated streptavidin to differentiate between samples (using Biolegend TotalSeqB reagents).

组织损伤与修复是炎症的标志性特征。尽管目前已有大量关于调控组织损伤的机制的研究成果，但对于炎症如何影响组织修复的机制性认知仍存在空白。本研究探讨了干扰素如何影响肠黏膜损伤后的组织修复过程。
我们发现，Ⅲ型而非Ⅰ型或Ⅱ型干扰素可通过诱导Z-DNA结合蛋白1（Z-DNA-binding protein 1, ZBP1）的表达上调，延缓上皮细胞再生。肠黏膜损伤后形成的Z型核酸可被ZBP1识别，进而激活半胱天冬酶-8（Caspase-8）并切割Gasdermin C（GSDMC）。经切割活化的GSDMC可通过细胞焦亡介导上皮细胞死亡，分别在结肠炎或辐射损伤后延缓大肠或小肠的组织修复。
Ⅲ型干扰素/ZBP1/Caspase-8/GSDMC信号轴在炎症性肠病（IBD）患者体内同样具有活性。本研究结果揭示了Ⅲ型干扰素延缓肠道组织修复的能力，这一发现对于IBD患者或接受放射治疗的人群具有重要的临床参考价值。
实验整体设计：选取年龄匹配（8~12周龄）的雌雄小鼠队列，给予2.5%葡聚糖硫酸钠（DSS）饮用水持续7天，随后恢复3天。于第10天，对每种处理条件和基因型的3只小鼠实施安乐死并采集结肠组织。采用10x Genomics 3' v3.1转录组试剂盒进行单细胞RNA测序，将（每个组织区域的）小鼠重复样本合并，使用生物素标记抗体进行标记，随后采用寡核苷酸偶联链霉亲和素（使用Biolegend TotalSeqB试剂）区分不同样本。