Resolution of Inflammation Increases hematopoietic Stem Cell Number and Erythropoiesis

To find new factors that control HSC formation, we screened for bioactive lipid mediators derived from n-3 polyunsaturated fatty acid (n-3 PUFA). n-3 PUFA-derived lipid mediators include compounds called specialized pro-resolving mediators (SPMs), which help resolve inflammation and fight infection. In this study, we investigated the pro-hematopoietic effects of n-3 PUFA-derived SPMs.

We exposed zebrafish embryos to various SPMs and found one SPM compound derived from n-3 docosapentaenoic acid, 7(S),17(s)-dihydroxy docosapentaenoic acid (7,17-diHDPAn-3) that increases the expression of HSC markers like cmyb, scl/tal-1, and runx1. 7,17-diHDPAn-3 exposure also increases the expression of gata1, an erythroid progenitor marker, leading to a significant rise in erythrocyte numbers. We confirmed these effects on both primitive and definitive erythropoiesis in zebrafish.