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Short‐, middle‐ and long‐term safety of superparamagnetic iron oxide‐labeled allogeneic bone marrow stromal cell transplantation in rat model of lacunar infarction
Author(s) -
Tan Chengbo,
Shichinohe Hideo,
Abumiya Takeo,
Nakayama Naoki,
Kazumata Ken,
Hokari Masaaki,
Hamauchi Shuji,
Houkin Kiyohiro
Publication year - 2015
Publication title -
neuropathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.701
H-Index - 61
eISSN - 1440-1789
pISSN - 0919-6544
DOI - 10.1111/neup.12180
Subject(s) - transplantation , medicine , pathology , bone marrow , stromal cell , microglia , cell therapy , stem cell , surgery , immunology , biology , microbiology and biotechnology , inflammation
Recently, both basic and clinical studies demonstrated that bone marrow stromal cell ( BMSC ) transplantation therapy can promote functional recovery of patients with CNS disorders. A non‐invasive method for cell tracking using MRI and superparamagnetic iron oxide ( SPIO )‐based labeling agents has been applied to elucidate the behavior of transplanted cells. However, the long‐term safety of SPIO ‐labeled BMSC s still remains unclear. The aim of this study was to investigate the short‐, middle‐ and long‐term safety of the SPIO ‐labeled allogeneic BMSC transplantation. For this purpose, BMSC s were isolated from transgenic rats expressing green fluorescent protein ( GFP ) and were labeled with SPIO . The N a/ K ATPase pump inhibitor ouabain or vehicle was stereotactically injected into the right striatum of wild‐type rats to induce a lacunar lesion ( n = 22). Seven days after the insult, either BMSC s or SPIO solution were stereotactically injected into the left striatum. A 7.0‐Tesla MRI was performed to serially monitor the behavior of BMSCs in the host brain. The animals were sacrificed after 7 days ( n = 7), 6 weeks ( n = 6) or 10 months ( n = 9) after the transplantation. MRI demonstrated that BMSCs migrated to the damage area through the corpus callosum. Histological analysis showed that activated microglia were present around the bolus of donor cells 7 days after the allogeneic cell transplantation, although an immunosuppressive drug was administered. The SPIO ‐labeled BMSCs resided and started to proliferate around the route of the cell transplantation. Within 6 weeks, large numbers of SPIO ‐labeled BMSCs reached the lacunar infarction area from the transplantation region through the corpus callosum. Some SPIO nanoparticles were phagocytized by microglia. After 10 months, the number of SPIO ‐positive cells was lower compared with the 7‐day and 6‐week groups. There was no tumorigenesis or severe injury observed in any of the animals. These findings suggest that BMSC s are safe after cell transplantation for the treatment of stroke.