Multimodal imaging of subventricular zone neural stem/progenitor cells in the cuprizone mouse model reveals increased neurogenic potential for the olfactory bulb pathway, but no contribution to remyelination of the corpus callosum.

Multiple sclerosis is a devastating demyelinating disease of the central nervous system (CNS) in which endogenous remyelination, and thus recovery, often fails. Although the cuprizone mouse model allowed elucidation of many molecular factors governing remyelination, currently very little is known about the spatial origin of the oligodendrocyte progenitor cells that initiate remyelination in this model. Therefore, we here investigated in this model whether subventricular zone (SVZ) neural stem/progenitor cells (NSPCs) contribute to remyelination of the splenium following cuprizone-induced demyelination. Experimentally, from the day of in situ NSPC labeling, C57BL/6J mice were fed a 0.2% cuprizone diet during a 4-week period and then left to recover on a normal diet for 8weeks. Two in situ labeling strategies were employed: (i) NSPCs were labeled by intraventricular injection of micron-sized iron oxide particles and then followed up longitudinally by means of magnetic resonance imaging (MRI), and (ii) SVZ NSPCs were transduced with a lentiviral vector encoding the eGFP and Luciferase reporter proteins for longitudinal monitoring by means of in vivo bioluminescence imaging (BLI). In contrast to preceding suggestions, no migration of SVZ NSPC towards the demyelinated splenium was observed using both MRI and BLI, and further validated by histological analysis, thereby demonstrating that SVZ NSPCs are unable to contribute directly to remyelination of the splenium in the cuprizone model. Interestingly, using longitudinal BLI analysis and confirmed by histological analysis, an increased migration of SVZ NSPC-derived neuroblasts towards the olfactory bulb was observed following cuprizone treatment, indicative for a potential link between CNS inflammation and increased neurogenesis.

Guglielmetti C ，Praet J ，Rangarajan JR ，Vreys R ，De Vocht N ，Maes F ，Verhoye M ，Ponsaerts P ，Van der Linden A ... -  《-》

Neural Stem Cells of the Subventricular Zone Contribute to Neuroprotection of the Corpus Callosum after Cuprizone-Induced Demyelination.

Myelin loss occurring in demyelinating diseases, including multiple sclerosis, is the leading cause of long-lasting neurological disability in adults. While endogenous remyelination, driven by resident oligodendrocyte precursor cells (OPCs), might partially compensate myelin loss in the early phases of demyelinating disorders, this spontaneous reparative potential fails at later stages. To investigate the cellular mechanisms sustaining endogenous remyelination in demyelinating disorders, we focused our attention on endogenous neural precursor cells (eNPCs) located within the subventricular zone (SVZ) since this latter area is considered one of the primary sources of new OPCs in the adult forebrain. First, we fate mapped SVZ-eNPCs in cuprizone-induced demyelination and found that SVZ endogenous neural stem/precursor cells are recruited during the remyelination phase to the corpus callosum (CC) and are capable of forming new oligodendrocytes. When we ablated SVZ-derived eNPCs during cuprizone-induced demyelination in female mice, the animals displayed reduced numbers of oligodendrocytes within the lesioned CC. Although this reduction in oligodendrocytes did not impact the ensuing remyelination, eNPC-ablated mice experienced increased axonal loss. Our results indicate that, in toxic models of demyelination, SVZ-derived eNPCs contribute to support axonal survival.SIGNIFICANCE STATEMENT One of the significant challenges in MS research is to understand the detrimental mechanisms leading to the failure of CNS tissue regeneration during disease progression. One possible explanation is the inability of recruited oligodendrocyte precursor cells (OPCs) to complete remyelination and to sustain axonal survival. The contribution of endogenous neural precursor cells (eNPCs) located in the subventricular zone (SVZ) to generate new OPCs in the lesion site has been debated. Using transgenic mice to fate map and to selectively kill SVZ-derived eNPCs in the cuprizone demyelination model, we observed migration of SVZ-eNPCs after injury and their contribution to oligodendrogenesis and axonal survival. We found that eNPCs are dispensable for remyelination but protect partially from increased axonal loss.

Butti E ，Bacigaluppi M ，Chaabane L ，Ruffini F ，Brambilla E ，Berera G ，Montonati C ，Quattrini A ，Martino G ... -  《-》

Cuprizone demyelination induces a unique inflammatory response in the subventricular zone.

Hillis JM ，Davies J ，Mundim MV ，Al-Dalahmah O ，Szele FG ... -  《Journal of Neuroinflammation》

Mobilization of progenitors in the subventricular zone to undergo oligodendrogenesis in the Theiler's virus model of multiple sclerosis: implications for remyelination at lesions sites.

Remyelination involves the generation of new myelin sheaths around axons, as occurs spontaneously in many multiple sclerosis (MS) lesions and other demyelinating diseases. When considering repairing a diseased brain, the adult mouse subventricular zone (SVZ) is of particular interest since the stem cells in this area can migrate and differentiate into the three major cell types in the central nervous system (CNS). In Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), we assessed the relative contribution of the SVZ to the remyelination in the corpus callosum at preclinical stages in this MS model. CNPase, MBP and Luxol Fast Blue staining revealed prominent demyelination 35days post-infection (dpi), concomitant with a strong staining in GFAP(+) type B astrocytes in the SVZ and the increased proliferation in this area. The migration of oligodendrocyte progenitors from the SVZ contributed to the remyelination observed at 60 dpi, evident through the number of APC(+)/BrdU(+) mature oligodendrocytes in the corpus callosum of infected animals. These data suggest that the inflammation induced by the Theiler's virus not only provokes strong preclinical demyelination but also, it is correlated with oligodendrocyte generation in the adult SVZ, cells that along with resident progenitor cells contribute to the prompt remyelination observed in the corpus callosum.

Mecha M ，Feliú A ，Carrillo-Salinas FJ ，Mestre L ，Guaza C ... -  《-》

17β-Estradiol enhances the efficacy of adipose-derived mesenchymal stem cells on remyelination in mouse model of multiple sclerosis.

Previous studies have demonstrated the potential of monotherapy with either mesenchymal stem cells (MSCs) or estrogen in autoimmune and cuprizone models of multiple sclerosis (MS). The aim of this study was to examine the effects of co-administration of 17β-estradiol (E2) and adipose-derived mesenchymal stem cells (ADSCs) on remyelination of corpus callosum axons in a cuprizone model of MS. Forty eight male C57BL/6 mice were fed cuprizone (0.2%) for 6 weeks. At day 0 after cuprizone removal, animals were randomly divided into four groups. The E2 monotherapy, ADSCs monotherapy, E2/ADSCs combined therapy and vehicle control. Some mice of the same age were fed with their normal diet to serve as healthy control group. E2 pellets, designed to release 5.0 mg E2 over 10 days, were implanted subcutaneously. 10(6) PKH26 labeled ADSCs were transplanted into lateral tail. The extent of demyelination, remyelination, and cell type's composition of host brain were examined at 10 days post-transplantation in the body of the corpus callosum. Transplanted cells migrated to the corpus callosum injury. Histological examination revealed efficacy of intravenous ADSCs transplantation in remyelination of mouse cuprizone model of MS can be significantly enhanced by E2 administration. Flow cytometry showed that the mean percentages of expression of Iba-1, Olig2 and O4 were significantly increased in E2/ADSCs combined therapy in comparison with ADSCs monotherapy. In conclusion, the findings of this study revealed that E2 administration enhanced efficacy of intravenous ADSCs transplantation in remyelination of corpus callosum axons in mouse cuprizone model of MS.

Ragerdi Kashani I ，Hedayatpour A ，Pasbakhsh P ，Kafami L ，Atlasi N ，Pirhajati Mahabadi V ，Mamoudi R ，Baazm M ... -  《-》