Analysis of Therapeutic Effect after Human Mesenchymal Stem Cell Transplantation in Ischemic Stroke Rat

Background and PURPOSE: Mesenchymal stem cells (MSCs) have recently been investigated as an attractive therapeutic tool for ischemic stroke because of their plasticity and availability. For the understanding of therapeutic effect of MSCs after transplantation in ischemic rats, changes in free fatty acids (FFA) levels and proteins were detected in 4 days after MSC transplantation (Part 1, 2). I also evaluated the impact of the passage of MSCs on their effects in a rat stroke model (Part 3). Part I: Although ex vivo culture-expansion is necessary to use autologous MSCs in treating stroke patients and several researchers have utilized culture-expanded cells in their studies, the effects of culture-expansion on neurogenesis and trophic support are unknown. Thus, I evaluated the impact of the passage of MSCs on their effects in a rat stroke model. The intravenous application of ex vivo-cultured human MSCs, earlier (passage 2) or later passage (passage 6), was performed in a rat stroke model. Compared to rats that received later-passage human MSCs, behavioral recovery and neurogenesis as revealed by bromodeoxyuridine staining were more pronounced in rats that received earlier-passage human MSCs (P<0.01 in both cases). Double staining showed that most of the endogenous neuronal progenitor cells, but few human MSCs, expressed neuronal and glial phenotypes. Tissue levels of trophic factors, including glial cell-line-derived neurotrophic factor, nerve growth factor, vascular endothelial growth factor, and hepatocyte growth factor, were higher in earlier-passage MSC-treated brains than in control or later-passage MSC-treated brains (P<0.01 in all cases). This study indicated that ischemia-induced neurogenesis was enhanced by the intravenous administration of human MSCs. The effects were more pronounced with earlier-passage than with later-passage human MSCs, which may be related to the differential capacity in trophic support, depending on their passage. Part II: For the understanding of the complexity of biochemical and physiological changes of hMSC-treated MCAo rat, I performed proteomic analysis of sham (n=3), tMCAo-only group (n=3) and hMSC-treated tMCAo rat group (n=3). Using 2-dimensinal electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS), I was able to identify 14 proteins. Among the 14 identified proteins, 11 proteins were up-regulated or down-regulated in the hMSC-treated group compared to the tMCAo group, three proteins recovered to their normal condition after hMSC treatment. Differential protein expression was confirmed by western blotting. Up-regulated proteins such as Annexin A3 and GRP78 are involved in angiogenesis and neuroprotection. Recovered proteins such as synaptosomal-associated protein 25(SNAP-25) and transitional endoplasmic reticulum ATPase are involved in neuron loss and apoptosis. This study established differential proteomic profiles that characterize hMSC transplanted MCAo rat. The proteomic profiles helped to explain the MSC action mechanism of stroke therapy. Part III: Mesenchymal stem cells (MSCs) have the potential to promote brain repair and improve recovery following stroke. I investigated changes in FFAs following intravenous human MSC (hMSCs) transplantation into rats that had undergone transient middle cerebral artery occlusion (MCAo). Rats were subjected to 2-hours MCAo followed by intravenous transplantation of hMSC or phosphate-buffered saline (PBS) at one day after MCAo. All rats were sacrificed 5 days after MCAo. Metabolic profiling of free fatty acids (FFAs) levels was assessed in plasma and brain from control rats (n=8), PBS-treated MCAo rats (n=6), and hMSC-treated MCAo rats (MCAo + hMSC, n=6). The levels of some FFAs in plasma and brain samples of the MCAo and MCAo + hMSC groups were significantly different than those of the control group. The percentage composition of myristic acid in plasma, and of myristic acid, linoleic acid, and eicosenoic acid in brain tissues of the MCAo + hMSC group were significantly reduced compared to those in the untransplanted MCAo group. My metabolic approach has provided insights into understanding the events that occur in ischemic brain injury and the therapeutic effects of MSCs in stroke. This approach may be useful to monitor the therapeutic effects of hMSC transplantation in the rat cerebral ischemia model.

Author dc:creator

• 이, 문옥

Contributors dc:contributor

• 이, 광
• 대학원 의학과
• 200424193

• Ischemic stroke
• Mesenchymal stem cells
• Neurogenesis
• Passage
• 2-dimensinal electrophoresis
• Proteomics
• Fatty acids
• Gas chromatography-mass spectrometry
• 허혈성 뇌졸중
• 중간엽 줄기세포
• 신경재생
• 프로티오믹스
• 지방산

Language dc:language

en

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000006515
000000006515

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/1396