Nitric Oxide-Induced Murine Hematopoietic Stem Cell Fate Involves Multiple Signaling Proteins, Gene Expression, and Redox Modulation

Abstract

There are a growing number of reports showing the influence of redox modulation in cellular signaling. Although the regulation of hematopoiesis by reactive oxygen species (ROS) and reactive nitrogen species (RNS) has been described, their direct participation in the differentiation of hematopoietic stem cells (HSCs) remains unclear. in this work, the direct role of nitric oxide (NO center dot), a RNS, in the modulation of hematopoiesis was investigated using two sources of NO center dot, one produced by endothelial cells stimulated with carbachol in vitro and another using the NO center dot-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP) in vivo. Two main NO center dot effects were observed: proliferation of HSCs-especially of the short-term HSCs- and its commitment and terminal differentiation to the myeloid lineage. NO center dot-induced proliferation was characterized by the increase in the number of cycling HSCs and hematopoietic progenitor cells positive to BrdU and Ki-67, upregulation of Notch-1, Cx43, PECAM-1, CaR, ERK1/2, Akt, p38, PKC, and c-Myc. NO center dot-induced HSCs differentiation was characterized by the increase in granulocytic-macrophage progenitors, granulocyte-macrophage colony forming units, mature myeloid cells, upregulation of PU.1, and C/EBP alpha genes concomitantly to the downregulation of GATA-3 and Ikz-3 genes, activation of Stat5 and downregulation of the other analyzed proteins mentioned above. Also, redox status modulation differed between proliferation and differentiation responses, which is likely associated with the transition of the proliferative to differentiation status. Our findings provide evidence of the role of NO center dot in inducing HSCs proliferation and myeloid differentiation involving multiple signaling.