PF Reduces IGF-1/PKA to Promote Lineage-Balanced Hematopoietic Regeneration
(Figure 7) PF Reduces IGF-1/PKA to Promote Lineage-Balanced Hematopoietic Regeneration
(A) A simplified model for a partially conserved nutrient signaling PKA pathway in yeast and mammalian cells. Arrows show activating actions, and horizontal bars indicate inhibitory actions. GH, growth hormone; AC, adenylate cyclase; PKA, protein kinase A; CREB, cAMP response element binding protein; Foxo1, Forkhead box protein O1; G9a, H3 Lys-9 methyltransferase.
(B) A simplified model for PF-induced effects on WBC and HSCs. Fasting causes a major reduction in WBCs followed by their replenishment after refeeding, based on effects on HSCs self-renewal resulting in increased progenitor and immune cells. These effects of PF can result in reversal of chemotherapy-based immunosuppression but
also in the rejuvenation of the immune cell profile in old mice.