title: Dose-dependent short- and long-term effects of ionizing irradiation on neural stem cells in murine hippocampal tissue cultures: neuroprotective potential of resveratrol.
abstract: Radiation therapy plays an essential role in the treatment of brain tumors, but neurocognitive deficits remain a significant risk, especially in pediatric patients. In recent trials, hippocampal sparing techniques are applied to reduce these adverse effects. Here, we investigate dose-dependent effects of ionizing radiation (IR) on juvenile hippocampal neurogenesis. Additionally, we evaluate the radioprotective potential of resveratrol, a plant polyphenol recognized for its bifunctional tumor-preventive and anticancer effects.
  
  
  
  Organotypic entorhinal-hippocampal slice cultures from transgenic nestin-CFPnuc C57BL/J6 mice, postnatal days 3-6, were irradiated on a X-ray machine (4.5, 8, 12, and 16 Gy, single doses) after about 2 weeks. Nestin-positive neural stem cells were counted at a confocal live imaging microscope 0, 2, 4, 14, 25, and 42 days after IR. Resveratrol (15 μmol/L) was added 2 hr before and 24 hr after IR. Proliferation and cell death were assessed by BrdU pulse label, 48 hr after and by propidium iodide staining 96 hr after IR. GFAP- and NeuN-positive cells were counted 42 days after IR in cryosectioned immunofluorescence-stained slices.
  
  
  
  The observed age-related changes of nestin-positive stem cells in the organotypic slice culture model resembled the reduction of neural stem cells in vivo. IR (4.5-16 Gy) led to a dose-dependent damage of the neural stem cell pool in the dentate gyrus. No recovery was seen within 42 days after doses from 4.5 Gy onward. The decline of nestin-positive cells was paralleled by increased cell death and decreased proliferation. The number of GFAP-positive cells was significantly enhanced. No significant change was detected in the overall NeuN-positive cell population, whereas the number of newborn, NeuN/BrdU double-positive neurons was reduced. Resveratrol treatment reversed the irradiation-induced decline of neural stem cells.
  
  
  
  The neuroprotective action of resveratrol on irradiated hippocampal tissue warrants further investigation as a possible supplement to hippocampal sparing procedures.
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Isabell
authors: I
authors: Prager
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Ina
authors: I
authors: Patties
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Katrin
authors: K
authors: Himmelbach
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Eva
authors: E
authors: Kendzia
authors: Institute of Anatomy University of Leipzig Leipzig Germany.
authors: Felicitas
authors: F
authors: Merz
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Klaus
authors: K
authors: Müller
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Rolf-Dieter
authors: RD
authors: Kortmann
authors: Department of Radiation Therapy University of Leipzig Leipzig Germany.
authors: Annegret
authors: A
authors: Glasow
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004353:Drug Evaluation, Preclinical; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D064231:Nestin / Q000235:genetics / Q000378:metabolism; D058953:Neural Stem Cells / Q000187:drug effects* / Q000473:pathology / Q000502:physiology / Q000528:radiation effects*; D009457:Neuroglia / Q000187:drug effects / Q000473:pathology / Q000502:physiology / Q000528:radiation effects; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000502:physiology / Q000528:radiation effects; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011833:Radiation Injuries, Experimental / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D011839:Radiation, Ionizing; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D013997:Time Factors; D046509:Tissue Culture Techniques; D014965:X-Rays
chemical_list: C577485:Nes protein, mouse; D064231:Nestin; D018696:Neuroprotective Agents; D011837:Radiation-Protective Agents; D013267:Stilbenes; D000077185:Resveratrol
keywords: hippocampus; ionizing radiation; nestin; organotypic slices; resveratrol