Inosine Monophosphate Preferentially Regulates Myeloid Progenitor Differentiation toward Neutrophil Production in Diabetes

Previous studies described hyperglycemia-induced myelopoiesis and atherosclerotic progression in mice with type I diabetes. By targeted metabolomics, we reported the increase of inosine monophosphate (IMP) in granulocyte/monocyte progenitors (GMP) in db/db mice. Moreover, IMP treatment stimulated GMP proliferation, resulting in skewed myelopoiesis and enhanced acute pancreatitis progression. However, how IMP modulates granulocyte production is not known. To investigate that, equal amount of FACS-sorted GMP of wild-type mice were cultivated with PBS or 15 mM IMP for 5 days in vitro. FACS analysis revealed that the absolute number of neutrophils was 1.7-fold higher but the number of CD11b+ monocytes was 3.2-fold lower in IMP group compared to control (p<0.05 for both). Thereafter, FACS-sorted GMP treated with or without IMP for 3 days were harvested for single cell RNA sequencing. When classified by marker gene expression, 19 clusters representing 7 cell types were identified including neutrophils, monocytes, GMP, intermediate GMP/neutrophils, basophils, Megakaryocyte erythroid progenitors/megakaryocytes (MEP/Mgk), and platelets. The proportions of neutrophils and MEP/Mgk increased 1.3-, and 1.6-fold in IMP-treated GMP cells compared with controls (p=0.059 for neutrophils; p=0.032 for MEP/Mgk). Nevertheless, the percentage of other cell populations were comparable between two groups (p≥0.08 for all). Furthermore, cycling neutrophils in cluster 3 was 1.4-fold increase in IMP-treated GMP cells compared with controls (p=0.04). Accordingly, GO analysis and Gene set enrichment analysis illustrated that genes involved in cell cycles was enriched in cycling neutrophil clusters. In conclusion, our data demonstrated that IMP preferentially regulated GMP proliferation and differentiation toward neutrophil production, which provides new insights on the crosstalk between skewed metabolites and inflammation in diabetes. Disclosure Y.Dong: None. C.Yan: None. Y.Zhang: None. X.Yang: None. Y.Feng: None. Funding National Natural Science Foundation of China (81670765, 82070841)