title: Cranial grafting of stem cell-derived microvesicles improves cognition and reduces neuropathology in the irradiated brain.
abstract: Cancer survivors face a variety of challenges as they cope with disease recurrence and a myriad of normal tissue complications brought on by radio- and chemotherapeutic treatment regimens. For patients subjected to cranial irradiation for the control of CNS malignancy, progressive and debilitating cognitive dysfunction remains a pressing unmet medical need. Although this problem has been recognized for decades, few if any satisfactory long-term solutions exist to resolve this serious unintended side effect of radiotherapy. Past work from our laboratory has demonstrated the neurocognitive benefits of human neural stem cell (hNSC) grafting in the irradiated brain, where intrahippocampal transplantation of hNSC ameliorated radiation-induced cognitive deficits. Using a similar strategy, we now provide, to our knowledge, the first evidence that cranial grafting of microvesicles secreted from hNSC affords similar neuroprotective phenotypes after head-only irradiation. Cortical- and hippocampal-based deficits found 1 mo after irradiation were completely resolved in animals cranially grafted with microvesicles. Microvesicle treatment was found to attenuate neuroinflammation and preserve host neuronal morphology in distinct regions of the brain. These data suggest that the neuroprotective properties of microvesicles act through a trophic support mechanism that reduces inflammation and preserves the structural integrity of the irradiated microenvironment.
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Baulch
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Munjal M
authors.initials: MM
authors.lastname: Acharya
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Barrett D
authors.initials: BD
authors.lastname: Allen
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Ning
authors.initials: N
authors.lastname: Ru
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Nicole N
authors.initials: NN
authors.lastname: Chmielewski
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Vahan
authors.initials: V
authors.lastname: Martirosian
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Erich
authors.initials: E
authors.lastname: Giedzinski
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Amber
authors.initials: A
authors.lastname: Syage
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Audrey L
authors.initials: AL
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Benke
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695.
authors.forename: Vipan K
authors.initials: VK
authors.lastname: Parihar
authors.affiliation: Department of Radiation Oncology, University of California, Irvine, CA 92697-2695 climoli@uci.edu.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Limoli
mesh_terms: D000679:Amygdala / Q000648:ultrastructure; D000818:Animals; D001925:Brain Damage, Chronic / Q000209:etiology / Q000628:therapy*; D055252:Cell-Derived Microparticles / Q000637:transplantation*; D002478:Cells, Cultured; D003072:Cognition Disorders / Q000209:etiology / Q000628:therapy*; D016371:Cranial Irradiation / Q000009:adverse effects*; D017930:Genes, Reporter; D006185:Habituation, Psychophysiologic / Q000502:physiology; D064593:Heterografts; D006624:Hippocampus / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D017628:Microglia / Q000502:physiology; D019579:Neocortex / Q000648:ultrastructure; D058953:Neural Stem Cells / Q000648:ultrastructure*; D011833:Radiation Injuries, Experimental / Q000628:therapy*; D051381:Rats; D011923:Rats, Nude
keywords: dendritic complexity; human neural stem cells; microvesicles; neuroinflammation; radiation-induced cognitive dysfunction