Hematopoietic failure is the major cause of death in Acute Radiation Sickness. Unfortunately, few therapies exist that are effective at mitigating radiation-induced damage to the hematopoietic system. We hypothesized that cells within the bone marrow microenvironment, specifically endothelial cells (ECs), regulate hematopoietic regeneration following radiation injury. Our recent studies validated this hypothesis, demonstrating that human ECs produce soluble proteins that induce the expansion of human hematopoietic stem cells (HSCs) in vitro and transplantation of ECs alone rescued animals from lethal radiation exposure and accelerated hematopoietic reconstitution in vivo. A genetic screen revealed pleiotrophin (PTN), a heparin binding growth factor with no known function in hematopoiesis, as 25-fold overexpressed in ECs with HSC-supportive activity. Our preliminary studies demonstrate that treatment with PTN induces a 10-fold expansion of murine HSCs in culture and systemic administration of PTN to irradiated mice demonstrates that PTN treatment markedly accelerates reconstitution of BM HSCs and progenitor cells compared GCSF- or saline-treated controls. We hypothesize that PTN regulates the selfrenewal and regeneration of BM HSCs in vitro and in vivo and that PTN is an excellent candidate mitigator of radiation-induced hematopoietic failure. In order to test our hypothesis, we propose the following Specific Aims: 1) Determine the function of PTN in regulating HSC self renewal and homeostasis. 2) Determine if PTN can mitigate radiation-induced myelosuppression in vivo, and 3) Test the efficacy of PTN in mitigating human hematopoietic cell toxicity from radiation injury. Our broad objective in this proposal is to deliver a translatable and potent mitigator of radiation-induced hematopoietic injury. Our preliminary results demonstrate that PTN is a soluble growth factor for murine and human HSCs and systemic administration of PTN for 1 week induces the accelerated regeneration of BM HSCs and progenitor cells in vivo compared to GCSF-treated mice. PTN has therapeutic potential as a mitigator of the radiation-induced hematopoietic syndrome.

Public Health Relevance

In a radiation mass casualty event, the majority of deaths from radiation sickness will be caused by bone marrow failure. Unfortunately, few treatments exist to ameliorate radiation-induced toxicity to the bone marrow. We have discovered a novel protein which stimulates the self renewal of bone marrow stem cells in vitro and the regeneration of the blood system in vivo after radiation injury. This protein is a candidate therapeutic for the treatment of victims of acute radiation sickness.

National Institute of Health (NIH)
Research Program--Cooperative Agreements (U19)
Project #
Application #
Study Section
Special Emphasis Panel (ZAI1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Duke University
United States
Zip Code
Batinic-Haberle, Ines; Tovmasyan, Artak; Roberts, Emily R H et al. (2014) SOD therapeutics: latest insights into their structure-activity relationships and impact on the cellular redox-based signaling pathways. Antioxid Redox Signal 20:2372-415
Spitz, Douglas R; Hauer-Jensen, Martin (2014) Ionizing radiation-induced responses: where free radical chemistry meets redox biology and medicine. Antioxid Redox Signal 20:1407-9
Himburg, Heather A; Yan, Xiao; Doan, Phuong L et al. (2014) Pleiotrophin mediates hematopoietic regeneration via activation of RAS. J Clin Invest 124:4753-8
Johnson, Jason N; Hornik, Christoph P; Li, Jennifer S et al. (2014) Cumulative radiation exposure and cancer risk estimation in children with heart disease. Circulation 130:161-7
Cheema, Amrita K; Pathak, Rupak; Zandkarimi, Fereshteh et al. (2014) Liver metabolomics reveals increased oxidative stress and fibrogenic potential in gfrp transgenic mice in response to ionizing radiation. J Proteome Res 13:3065-74
Lee, Chang-Lung; Lento, William E; Castle, Katherine D et al. (2014) Inhibiting glycogen synthase kinase-3 mitigates the hematopoietic acute radiation syndrome in mice. Radiat Res 181:445-51
Hauer-Jensen, Martin (2014) Toward development of interleukin-11 as a medical countermeasure for use in radiological/nuclear emergencies. Dig Dis Sci 59:1349-51
Tovmasyan, Artak; Carballal, Sebastian; Ghazaryan, Robert et al. (2014) Rational design of superoxide dismutase (SOD) mimics: the evaluation of the therapeutic potential of new cationic Mn porphyrins with linear and cyclic substituents. Inorg Chem 53:11467-83
Gauter-Fleckenstein, Benjamin; Reboucas, Julio S; Fleckenstein, Katharina et al. (2014) Robust rat pulmonary radioprotection by a lipophilic Mn N-alkylpyridylporphyrin, MnTnHex-2-PyP(5+). Redox Biol 2:400-10
Stanton, Ian N; Belley, Matthew D; Nguyen, Giao et al. (2014) Europium- and lithium-doped yttrium oxide nanocrystals that provide a linear emissive response with X-ray radiation exposure. Nanoscale 6:5284-8

Showing the most recent 10 out of 131 publications