3D Human Bone Marrow Microphysiological System Used to Investigate HSPC Mobilization via Inflammation-Derived ExtracellularVesicles

University Of California At Davis, Davis CA

Investigators

Abstract

ABSTRACT The ultimate goal of this F31 Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship to Promote Diversity in Health-Related Research is to request support to address the mechanisms of HSPC and neutrophil mobilization from the bone marrow. The bone marrow microenvironment (BMM) is an intricate system composed of different cell types including osteoblasts, osteoclasts, mesenchymal stem cells, endothelial cells, fibroblasts, macrophages, and many others. This system plays a significant role in pathogenesis by regulating the production of blood cells to maintain homeostasis and responding to stress signals that contribute to cell production. In infections and cancer, there are changes in the BMM associated with HSPC and neutrophil proliferation. However, in both cases, the mechanisms driving the release of HSPC and neutrophil are only partially understood. Some studies suggest that the CXCR4/SDF-1 interaction between stromal cells, neutrophils and HSPCs retains these immune cells in the bone marrow and interaction with G-CSF mobilizes these cells. The primary goal of the project is to use our bone marrow microphysiological system (BM MPS), which I have proven produces neutrophils and HSPCs (preliminary data), to study the mobilization of HSPCs from the bone marrow microenvironment (BMM) in response to inflammation at distant sites. I will test the hypothesis that hematopoietic stem/progenitor cells (HSPCs) can be mobilized from the bone marrow in response to extracellular vesicles (EVs) derived from inflamed cells (derived from cancer and skin infections) . Understanding the mechanism that leads to HSPC mobilization is important as it is believed to play a significant role in tumor progression and hematopoiesis dysfunction in cancer and is thought to be a key mediator of innate immune response in skin and viral infections. The research milestones include: 1) Quantify number of HSPCs in BM MPS when dosed with G-CSF; 2) Isolate and characterize EVs derived from keratinocytes, dermal fibroblasts, and the MCF10A cell line series and confirm expression of G-CSF within these particles; and 3) Examine HSPC mobilization mechanism in the BM MPS by introducing inflammation derived EVs in the presence and absence of CSL324, a G-CSF antagonist. In addition to the research milestones, the proposal will seek to accomplish a series of milestones associated with my career development including: 1) prepare for my qualifying exam by attending seminars and lectures in biomedical research 2) continue to mentor undergraduate researchers; 3) present my work at the MPS World Summit, and the SACNAS conference; and 4) publish my work in a peer-reviewed archived journal(s); Accomplishing these milestones will equip me with the writing and project development skills necessary for a career as an independent investigator.