单核细胞对食管和胃中巨噬细胞的更新

Objective·To reveal the renewal kinetics of esophageal and gastric macrophages by circulating monocytes. Methods· The monocytes of the Ms4a3^Cre-Rosa^TdT fate mapping model mice carry an irreversible tdTomato red fluorescent marker. The macrophages derived from these monocytes will also carry red fluorescence, distinguishing them from the embryonic-derived macrophages. The contribution of monocytes to esophageal and gastric macrophages was determined by detecting the number and the proportion of red fluorescence labeling in the ionized calcium-binding adapter molecule 1 (IBA1) positive macrophages in the esophagus and stomach from Ms4a3^Cre-Rosa^TdT mice of different ages (2 weeks, 8 weeks and 15 months of age) by immunofluorescence imaging. Results·In the esophagus and stomach of 2-week-old Ms4a3^Cre-Rosa^TdT mice, most macrophages were tdTomato negative, indicating that the esophageal macrophages and gastric macrophages of young mice were mainly embryonic derived. In 8-week-old adult mice, many tdTomato positive monocyte-derived macrophages could be detected in the stomach. In 15-month-old mice, most of the esophageal and gastric macrophages were tdTomato positive, indicating that the esophagus and stomach macrophages of the old mice were mainly produced by monocytes. Conclusion·In juvenile mice, esophageal and gastric macrophages are mainly embryonic-derived macrophages, while with age, monocyte-derived macrophages gradually replace tissue-resident macrophages in the esophagus and stomach. Esophageal and gastric macrophages in aged mice are mainly derived from circulating monocytes. Thus, the macrophage pool in the esophagus and stomach of mice consists of embryonic- and mononuclear-derived cells with their proportions changing with age.