손상된 흰쥐 척수에 사람중간엽세포 이식이 미치는 영향

Abstract

Two sources of adult stem cells that have occured great interest are human bone marrow-derived mesenchymal stem cells (hMSCs) and human umbilical cord blood cells. The hMSCs have been reported to maintain their differentiation capacity into the neuronal-lineages cells in central nervous system. Therefore, thransplantation of hMSCs represented an attractive new form of cellular therapy for clinical application in the spinal cord injury(SCI). The aim of this study is to investigate that the transplanted hMSCs by the venous circulation moved into target zone on compression injury of spinal cord and ameliorated the behavioral impairments associated with SCI. The SCI of the rats was induced by compressing the spinal cord for 30 second with an aneurysm clip. Cholera toxin subunit B conjugated to fluorescein isothiocyanate (CTX-FITC) prelabeled hMSCs were injected intravenously through the tail vein or directly on SCI site using a 27-gauge needle. Suspensions of hMSCs collected from the human adult were delivered at concentrations in 1 or 5 day after SCI(1× 106/200㎕ for I.V. injection). After transplantation of hMSCs, the area of SCI displayed some endogenous background fluorescence, but CTX-FITC prelabeled hMSCs were clearly identifiable. The prelabeled hMSCs observed in injured areas, but not in noninjured areas and the observed hMSCs were usually round or slightly elongated with a prominent nucleus. The number of hMSCs found in the spinal cord in each case was not plentiful, but the number of cells in the SCI1 + hMSCs group were found more than in the SCI5 + hMSCs. Also, this study demonstrated that transplanted hMSCs were reaffirmed using antisera recognizing human specific nuclei or mitochondia. The result of double immunofluorescence analysis showed some neuronal and glial marker expression in the lesion of SCI. Behavioral test scores of spinal cord injured rats treated with hMSCs at 1 days were significantly improved as compared to scores of rats similarly injured but treated at 5 day as well as the otherwise untreated injured group. These results suggest that hMSCs are beneficial in reversing the behavioral effects of SCI, even when infused 1 day after injury. Thus, hMSCs may be a viable source of stem cells for treatment of neurological disorders.