Transplantation of Human Brain-Derived Ischemia-Induced Multipotent Stem Cells Ameliorates Neurological Dysfunction in Mice After Stroke

Abstract

We recently demonstrated that injury/ischemia-induced multipotent stem cells (iSCs) develop within post-stroke human brains. Because iSCs are stem cells induced under pathological conditions, such as ischemic stroke, the use of human brain-derived iSCs (h-iSCs) may represent a novel therapy for stroke patients. We performed a preclinical study by transplanting h-iSCs transcranially into post-stroke mouse brains 6 weeks after middle cerebral artery occlusion (MCAO). Compared with PBS-treated controls, h-iSC transplantation significantly improved neurological function. To identify the underlying mechanism, green fluorescent protein (GFP)-labeled h-iSCs were transplanted into post-stroke mouse brains. Immunohistochemistry revealed that GFP+ h-iSCs survived around the ischemic areas and some differentiated into mature neuronal cells. To determine the effect on endogenous neural stem/progenitor cells (NSPCs) by h-iSC transplantation, mCherry-labeled h-iSCs were administered to Nestin-GFP transgenic mice which were subjected to MCAO. As a result, many GFP+ NSPCs were observed around the injured sites compared with controls, indicating that mCherry+ h-iSCs activate GFP+ endogenous NSPCs. In support of these findings, coculture studies revealed that the presence of h-iSCs promotes the proliferation of endogenous NSPCs and increases neurogenesis. In addition, coculture experiments indicated neuronal network formation between h-iSC- and NSPC-derived neurons. These results suggest that h-iSCs exert positive effects on neural regeneration through not only neural replacement by grafted cells but also neurogenesis by activated endogenous NSPCs. Thus, h-iSCs have the potential to be a novel source of cell therapy for stroke patients.

Administration of Human-Derived Mesenchymal Stem Cells Activates Locally Stimulated Endogenous Neural Progenitors and Reduces Neurological Dysfunction in Mice after Ischemic Stroke

“…We found that MSC transplantation activated endogenous iNSPCs around the grafted sites. Similar to these findings, we recently showed that h-iSC transplantation activated endogenous iNSPCs around the grafted sites but not NSPCs in the SVZ [21]. These findings suggest that although the precise traits of endogenous iNSPCs activated by MSC transplantation remain unclear, not only h-iSCs but also h-MSCs activate locally derived endogenous NSPCs, rather than SVZ-derived NSPCs, after cell transplantation.…”

Microglia Negatively Regulate the Proliferation and Neuronal Differentiation of Neural Stem/Progenitor Cells Isolated from Poststroke Mouse Brains

“…Nuclei were counterstained with DAPI (1:500), and fluorescence images were captured using a laser scanning microscope (LSM780). The number of nestin + iNSPCs (nestin + /mCherry − cells) or Sox2 + iNSPCs (Sox2 + /mCherry − cells) was compared between iNSPC monocultures (control) and iNSPCs cocultured with mCherry + MGs/MΦs using 12 data points (4 areas/sample, 3 samples/marker), as described [ 13 ]. Additionally, the ratio of Ki67 + iNSPCs (Ki67 + /mCherry − cells) to all iNSPCs (DAPI + /mCherry − ) cells was compared between iNSPC monocultures and iNSPCs cocultured with mCherry + MGs/MΦs using 12 data points (4 areas/sample, 3 samples/marker), as described [ 13 ].…”

“…Control GFP + iNSPC monocultures and GFP + iNSPCs cocultured with MGs/MΦs were collected by FACS. Next, total RNA isolated from cells with the RNeasy Micro Kit (Qiagen, Hilden, Germany) was used in microarray analysis, as described [ 2 , 6 , 13 ]. The microarray data were analyzed using the Affymetrix Transcriptome Analysis Console [ 2 , 6 , 13 ] and Metascape gene ontology (GO) tool [ 14 ], as described.…”

“…Next, total RNA isolated from cells with the RNeasy Micro Kit (Qiagen, Hilden, Germany) was used in microarray analysis, as described [ 2 , 6 , 13 ]. The microarray data were analyzed using the Affymetrix Transcriptome Analysis Console [ 2 , 6 , 13 ] and Metascape gene ontology (GO) tool [ 14 ], as described. Pathway analysis was performed using WikiPathways, as described [ 6 , 15 ].…”

Human iPSC-derived cell grafts promote functional recovery by molecular interaction with stroke-injured brain

“…To reduce the risk of tumor formation, the safety profile of iPSC-derived cell sources has been recently improved using genetic safety switch systems 22,23 . Previous studies showed that transplantation of iPSC-derived NPCs can release neurotrophic factors, form new connections within the damaged neural circuits 9,24 and repair functional deficits in stroke animals 25,26,10,8,7,27 .…”