Page 221 - 2014 Printable Abstract Book
P. 221
(PS3-56) Inhibiting glycogen synthase kinase-3 mitigates the hematopoietic acute radiation syndrome
1
3
2
1;3
2
in mice. Chang-Lung Lee ; William E. Lento ; Katherine D. Castle ; Nelson J. Chao ; and David G. Kirsch
1
Department of Radiation Oncology, Duke University Medical Center, Durham, NC ; Division of Cellular
2
Therapy, Department of Medicine, Duke University Medical Center, Durham, NC ; and Department of
3
Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC
Exposure to a nuclear accident or radiological attack may cause death from the acute radiation
syndrome (ARS), which results from radiation injury to vital organs such as the hematopoietic system.
However, the FDA has not approved any medical countermeasures for this specific purpose. With growing
concern over nuclear terrorism, there is an urgent need to develop small molecule deliverables that
mitigate mortality from the ARS. One emerging modulator of hematopoietic stem/progenitor cell activity
is glycogen synthase kinase-3 (GSK-3); the inhibition of GSK-3 has been shown to augment hematopoietic
repopulation in mouse models of bone marrow transplantation. Here we performed an in vitro screen
using irradiated bone marrow mononuclear cells (BM-MNCs) to test the effects of 4 GSK-3 inhibitors:
CHIR99021, 6-Bromoindirubin-3’-oxime (BIO), SB415286 and SB216763. This screen showed that
+
+
-
SB216763 significantly increased the frequency of ckit Lin Sca1 (KLS) cells and hematopoietic colony-
forming cells in irradiated BM-MNCs. Importantly, administration of a single dose of SB216763 to
C57BL/6J mice via subcutaneous injection 24 hours after total-body irradiation significantly improved
hematopoietic recovery and mitigated the hematopoietic ARS. Collectively, our results demonstrate that
the GSK-3 inhibitor SB216763 is an effective medical countermeasure against acute radiation injury of the
hematopoietic system.
(PS3-57) Radiation protection of hippocampal neurogenesis with Mn-containing porphyrins. Ting-Ting
1;3
1;2
4
4
1
Huang ; David Leu, MS ; Yani Zou, PhD ; Tin Weitner, PhD ; Artak Tovmasyan, PhD ; Ivan Spasojevic,
4
4
1
PhD ; and Ines Batinic-Haberle, PhD ; Stanford University, Palo Alto, CA ; VA Palo Alto Health Care System,
2
Palo Alto, CA ; PAIRE, Palo Alto, CA ; and Duke University, Durham, NC
4
3
Studies with transgenic mice overexpressing the antioxidant enzyme, extracellular superoxide
dismutase (EC-SOD), suggested that increased antioxidant capacity in the brain can achieve radiation
protection by preserving hippocampal neurogenesis, dendritic structures, and cognitive functions. The
results supported the premise that antioxidant supplementation may be effective in reducing the late
effects of cognitive impairments following radiation therapy. The class of Mn-containing porphyrin (MnP)
is designed to mimic the kinetics and thermodynamics of superoxide dismutases (SODs). Among them,
MnTnHex-2-PyP5+ (MnHex) and MnTnBuOE-2-PyP5+ (MnBuOE), have enhanced membrane permeability
and are able to cross the blood brain barrier. A 10-day treatment (ip injection at 1.5 mg/kg, twice daily)
of MnHex and MnBuOE in C57BL/6J mice showed an average of 60-90 nM in different brain regions.
Accumulation of MnBuOE in hippocampus was 40% better than that of MnHex. However, MnHex
appeared to accumulate to higher levels than MnBuOE in all other brain regions examined.
To determine if MnBuOE administration can achieve the desired radiation protection of hippocampal
neurogenesis, mice were injected with saline or BuOE (1.5 mg/kg, twice daily) for two weeks, starting at
one week prior to and ending at one week after a single dose of 5 Gy irradiation, and the production of
new neurons, including the number of immature neurons (Dcx+) and mature neurons (BrdU+/NeuN+), in
the subgranular zone (SGZ) of hippocampal dentate gyrus was determined. Compared to saline-treated
group, MnBuOE-treated mice had 30% more Dcx+ neurons in the SGZ at 4 weeks after irradiation, and the
219 | P a g e
1
3
2
1;3
2
in mice. Chang-Lung Lee ; William E. Lento ; Katherine D. Castle ; Nelson J. Chao ; and David G. Kirsch
1
Department of Radiation Oncology, Duke University Medical Center, Durham, NC ; Division of Cellular
2
Therapy, Department of Medicine, Duke University Medical Center, Durham, NC ; and Department of
3
Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC
Exposure to a nuclear accident or radiological attack may cause death from the acute radiation
syndrome (ARS), which results from radiation injury to vital organs such as the hematopoietic system.
However, the FDA has not approved any medical countermeasures for this specific purpose. With growing
concern over nuclear terrorism, there is an urgent need to develop small molecule deliverables that
mitigate mortality from the ARS. One emerging modulator of hematopoietic stem/progenitor cell activity
is glycogen synthase kinase-3 (GSK-3); the inhibition of GSK-3 has been shown to augment hematopoietic
repopulation in mouse models of bone marrow transplantation. Here we performed an in vitro screen
using irradiated bone marrow mononuclear cells (BM-MNCs) to test the effects of 4 GSK-3 inhibitors:
CHIR99021, 6-Bromoindirubin-3’-oxime (BIO), SB415286 and SB216763. This screen showed that
+
+
-
SB216763 significantly increased the frequency of ckit Lin Sca1 (KLS) cells and hematopoietic colony-
forming cells in irradiated BM-MNCs. Importantly, administration of a single dose of SB216763 to
C57BL/6J mice via subcutaneous injection 24 hours after total-body irradiation significantly improved
hematopoietic recovery and mitigated the hematopoietic ARS. Collectively, our results demonstrate that
the GSK-3 inhibitor SB216763 is an effective medical countermeasure against acute radiation injury of the
hematopoietic system.
(PS3-57) Radiation protection of hippocampal neurogenesis with Mn-containing porphyrins. Ting-Ting
1;3
1;2
4
4
1
Huang ; David Leu, MS ; Yani Zou, PhD ; Tin Weitner, PhD ; Artak Tovmasyan, PhD ; Ivan Spasojevic,
4
4
1
PhD ; and Ines Batinic-Haberle, PhD ; Stanford University, Palo Alto, CA ; VA Palo Alto Health Care System,
2
Palo Alto, CA ; PAIRE, Palo Alto, CA ; and Duke University, Durham, NC
4
3
Studies with transgenic mice overexpressing the antioxidant enzyme, extracellular superoxide
dismutase (EC-SOD), suggested that increased antioxidant capacity in the brain can achieve radiation
protection by preserving hippocampal neurogenesis, dendritic structures, and cognitive functions. The
results supported the premise that antioxidant supplementation may be effective in reducing the late
effects of cognitive impairments following radiation therapy. The class of Mn-containing porphyrin (MnP)
is designed to mimic the kinetics and thermodynamics of superoxide dismutases (SODs). Among them,
MnTnHex-2-PyP5+ (MnHex) and MnTnBuOE-2-PyP5+ (MnBuOE), have enhanced membrane permeability
and are able to cross the blood brain barrier. A 10-day treatment (ip injection at 1.5 mg/kg, twice daily)
of MnHex and MnBuOE in C57BL/6J mice showed an average of 60-90 nM in different brain regions.
Accumulation of MnBuOE in hippocampus was 40% better than that of MnHex. However, MnHex
appeared to accumulate to higher levels than MnBuOE in all other brain regions examined.
To determine if MnBuOE administration can achieve the desired radiation protection of hippocampal
neurogenesis, mice were injected with saline or BuOE (1.5 mg/kg, twice daily) for two weeks, starting at
one week prior to and ending at one week after a single dose of 5 Gy irradiation, and the production of
new neurons, including the number of immature neurons (Dcx+) and mature neurons (BrdU+/NeuN+), in
the subgranular zone (SGZ) of hippocampal dentate gyrus was determined. Compared to saline-treated
group, MnBuOE-treated mice had 30% more Dcx+ neurons in the SGZ at 4 weeks after irradiation, and the
219 | P a g e
