| 1. |
- Cusulin, Carlo, et al.
(författare)
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Embryonic Stem Cell-Derived Neural Stem Cells Fuse with Microglia and Mature Neurons.
- 2012
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099.
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Tidskriftsartikel (refereegranskat)abstract
- Transplantation of neural stem cells (NSCs) is a novel strategy to restore function in the diseased brain, acting through multiple mechanisms, e.g., neuronal replacement, neuroprotection and modulation of inflammation. Whether transplanted NSCs can operate by fusing with microglial cells or mature neurons is largely unknown. Here we have studied the interaction of a mouse embryonic stem cell-derived neural stem (NS) cell line with rat and mouse microglia and neurons in vitro and in vivo. We show that NS cells spontaneously fuse with co-cultured cortical neurons, and that this process requires the presence of microglia. Our in vitro data indicate that the NS cells can first fuse with microglia, and then with neurons. The fused NS/microglial cells express markers and retain genetic and functional characteristics of both parental cell types, being able to respond to microglia-specific stimuli (LPS and IL-4/IL-13) and to differentiate to neurons and astrocytes. The NS cells fuse with microglia, at least partly, through interaction between phosphatidylserine (PS) exposed on the surface of NS cells and CD36 receptor on microglia. Transplantation of NS cells into rodent cortex results in fusion with mature pyramidal neurons, which often carry two nuclei, a process probably mediated by microglia. The fusogenic role of microglia could be even more important after NSC transplantation into brains affected by neurodegenerative diseases associated with microglia activation. It remains to be elucidated how the occurrence of the fused cells will influence the functional outcome after NSC transplantation in the diseased brain.
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| 2. |
- Fritze, Jonas, et al.
(författare)
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Loss of Cxcr5 alters neuroblast proliferation and migration in the aged brain
- 2020
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 38:9, s. 1175-1187
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Tidskriftsartikel (refereegranskat)abstract
- Neurogenesis, the production of new neurons from neural stem cells, dramatically decreases during aging concomitantly with increased inflammation both systemically and in the brain. However, the precise role of inflammation and whether local or systemic factors drive the neurogenic decline during aging is poorly understood. Here, we identify CXCR5/5/CXCL13 signaling as a novel regulator of neurogenesis in the aged brain. The chemokine Cxcl13 was found to be upregulated in the brain during aging. Loss of its receptor, Cxcr5, led to increased proliferation and decreased numbers of neuroblasts in the aged subventricular zone (SVZ), together with accumulation of neuroblasts in the rostral migratory stream and olfactory bulb (OB), without increasing the amount of new mature neurons in the OB. The effect on proliferation and migration was specific to neuroblasts and likely mediated through increased levels of systemic IL-6 and local Cxcl12 expression in the SVZ. Our study raises the possibility of a new mechanism by which interplay between systemic and local alterations in inflammation regulates neurogenesis during aging.
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| 3. |
- Oki, Koichi, et al.
(författare)
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Human Induced Pluripotent Stem Cells form Functional Neurons and Improve Recovery After Grafting in Stroke-Damaged Brain.
- 2012
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 30:6, s. 1120-1133
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Tidskriftsartikel (refereegranskat)abstract
- Reprogramming of adult human somatic cells to induced pluripotent stem cells (iPSCs) is a novel approach to produce patient-specific cells for autologous transplantation. Whether such cells survive long-term, differentiate to functional neurons, and induce recovery in the stroke-injured brain is unclear. We have transplanted long-term self-renewing neuroepithelial-like stem (lt-NES) cells, generated from adult human fibroblast-derived iPSCs, into the stroke-damaged mouse and rat striatum or cortex. Recovery of forepaw movements was observed already at 1 week after transplantation. Improvement was most likely not due to neuronal replacement but was associated with increased vascular endothelial growth factor levels, probably enhancing endogenous plasticity. Transplanted cells stopped proliferating, could survive without forming tumors for at least 4 months, and differentiated to morphologically mature neurons of different subtypes. Neurons in intrastriatal grafts sent axonal projections to the globus pallidus. Grafted cells exhibited electrophysiological properties of mature neurons and received synaptic input from host neurons. Our study provides the first evidence that transplantation of human iPSC-derived cells is a safe and efficient approach to promote recovery after stroke and can be used to supply the injured brain with new neurons for replacement.
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