Acute Myelogenous Leukemia-Induced Sympathetic Neuropathy Promotes Malignancy in an Altered Hematopoietic Stem Cell Niche

Perivascular mesenchymal stem and progenitor cells (MSPCs) are critical for forming a healthy hematopoietic stem cell (HSC) niche. However, the interactions and influence of acute myelogenous leukemia (AML) stem cells with the microenvironment remain largely unexplored. We have unexpectedly found that neuropathy of the sympathetic nervous system (SNS) promotes leukemic bone marrow infiltration in an MLL-AF9 AML model. Development of AML disrupts SNS nerves and the quiescence of Nestin+ niche cells, leading to an expansion of phenotypic MSPCs primed for osteoblastic differentiation at the expense of HSC-maintaining NG2+ periarteriolar niche cells. Adrenergic signaling promoting leukemogenesis is transduced by the β2, but not β3, adrenergic receptor expressed on stromal cells of leukemic bone marrow. These results indicate that sympathetic neuropathy may represent a mechanism for the malignancy in order to co-opt the microenvironment and suggest separate mesenchymal niche activities for malignant and healthy hematopoietic stem cells in the bone marrow. [Display omitted] •AML leads to sympathetic neuropathy and expansion of an altered bone marrow niche•MSC differentiation is enhanced toward osteoprogenitors with maturation arrest•AML reduces NG2+ cell numbers and HSC niche regulating activity•Sympathetic neuropathy promotes AML through stromal Adrβ2 Development of acute myelogenous leukemia (AML) disrupts sympathetic nerves and the quiescence of Nestin+ niche cells, enhancing expansion of phenotypic mesenchymal stem/progenitor cells primed for osteoblastic differentiation at the expense of HSC-maintaining NG2+ periarteriolar niche cells.