Office of Biological and Environmental Research

DOE Lowdose Radiation Program Workshop V

2005 Abstract

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Title: Proteomic and Biochemical Studies of Human Mesenchymal Stem Cells in Response to Low Dose Ionizing Radiation

Authors: Daojing Wang¹, Bjorn Rydberg¹ and Song Li²

Institutions: ¹ Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, djwang@lbl.gov ² Department of Bioengineering, University of California, Berkeley, CA 94720

In this newly funded DOE Low Dose Radiation Research project, we propose to elucidate molecular mechanisms and pathways involved in radiobiological responses of human bone marrow mesenchymal stem cells (hBM-MSCs) to low dose and low dose-rate ionizing radiation (LLIR). Stem cells provide a particularly important system to study the effects of LLIR and the underlying mechanisms, since these pluripotent cells are potential targets for carcinogenesis. hBM-MSCs can differentiate into many cell types, and participate in tissue regeneration and repair (e.g., in bone and cartilage). Differentiation of MSCs may amplify the effects of LLIR and provide a unique system to elucidate radiobiological responses. We will: (1) investigate the effects of LLIR on proliferation, apoptosis and differentiation (particularly along bone lineage) of MSCs; (2) study the DNA double-strand break (DSB) repair; and (3) profile proteomic changes including protein expression levels and post-translational modification due to LLIR. Protein markers discovered in this project will improve our understandings and help to define the health risks from exposures to LLIR. We will present some preliminary data to demonstrate the feasibility and relevance of the project.