The bone marrow is the major site of hematopoiesis where all blood cells emerge from the regulated differentiation of hematopoietic stem cells (HSCs). Studies from the applicant?s laboratory have uncovered key functions for innervation of the sympathetic nervous system (SNS) in the egress of HSCs from marrow. SNS nerves are required to entrain the circadian release of HSCs and also the circadian recruitment of mature leukocytes to the periphery. In addition, the bone marrow is also innervated by peptidergic sensory fibers whose functions in hematopoiesis remain unclear. In this application, we propose a 3-year experimental plan that will advance our knowledge on the neuroanatomy and neurophysiology of the bone marrow.
In Specific Aim 1, we will characterize the functions of sensory nerves in the marrow. We will define the functional neural circuits using immunofluorescence imaging and transneuronal viral tract tracing, and evaluate the interplay of signals between sensory and SNS fibers using pharmacological and genetic model systems.
In Specific Aim 2, we will identify the intercellular transduction pathways that relay SNS nerve signals in bone marrow. We will identify the stromal cell types that receive adrenergic signals mediating ROS oscillations which may represent an important link for the propagation of neural signals.
Specific Aim 3 will harness endogenous neural circuits to improve hematopoietic regeneration. We will establish selective bone marrow DREADDs using adenoviral transduction that will lead to organ-specific neural activation to enhance regeneration following genotoxic insults such as ionizing irradiation or chemotherapy. Manipulation of endogenous neural circuits may indeed provide a useful future strategy to accelerate hematopoietic regeneration. !
! The bone marrow, a broadly distributed organ in which blood is generated, is highly innervated by nerves from sympathetic nervous system and sensory nerve fibers. This project seeks to map nerves in the bone marrow and evaluate their functional neural circuitry toward the development of model systems that will locally manipulate neural input for accelerating hematopoietic regeneration.
|Xu, Chunliang; Gao, Xin; Wei, Qiaozhi et al. (2018) Stem cell factor is selectively secreted by arterial endothelial cells in bone marrow. Nat Commun 9:2449|
|Maryanovich, Maria; Zahalka, Ali H; Pierce, Halley et al. (2018) Adrenergic nerve degeneration in bone marrow drives aging of the hematopoietic stem cell niche. Nat Med 24:782-791|
|Wei, Qiaozhi; Frenette, Paul S (2018) Niches for Hematopoietic Stem Cells and Their Progeny. Immunity 48:632-648|
|Boulais, Philip E; Mizoguchi, Toshihide; Zimmerman, Samuel et al. (2018) The Majority of CD45- Ter119- CD31- Bone Marrow Cell Fraction Is of Hematopoietic Origin and Contains Erythroid and Lymphoid Progenitors. Immunity 49:627-639.e6|