Ann Thorac Surg 2007;83:1484-1490
© 2007 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Therapeutic Benefit of Intrathecal Injection of Marrow Stromal Cells on Ischemia-Injured Spinal Cord
Enyi Shi, MD, PhDa,b,*,
Teruhisa Kazui, MD, PhDb,
Xiaojing Jiang, MDc,
Naoki Washiyama, MD, PhDb,
Katsushi Yamashita, MD, PhDb,
Hitoshi Terada, MD, PhDb,
Abul Hasan Muhammad Bashar, MBBS, PhDb
a Department of Cardiac Surgery, First Affiliated Hospital, China Medical University, Shenyang, China
b First Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
c Department of Anesthesiology, Hamamatsu University School of Medicine, Hamamatsu, Japan
Accepted for publication November 16, 2006.
* Address correspondence to Dr Shi, Department of Cardiac Surgery, First Affiliated Hospital, China Medical University, 155 Nanjingbei St, Shenyang 110001, China (Email: shienyi2002{at}hotmail.com).
Presented at the Poster Session of the Forty-third Annual Meeting of The Society of Thoracic Surgeons, San Diego, CA, Jan 29–31, 2007.
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Abstract
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Background: Prophylactic transplantation of marrow stromal cells (MSCs) before spinal cord ischemia has been shown to attenuate neurologic injures. We sought to investigate the therapeutic effect of MSCs on ischemia-injured spinal cord.
Methods: Marrow stromal cells were expanded in vitro and prelabeled with bromodeoxyuridine. Spinal cord ischemia was induced in rabbits by infrarenal aortic occlusion for 30 minutes. Four groups were enrolled. About 1 x 108 MSCs were intrathecally injected 2 hours (group MSC-2h), 24 hours (group MSC-24h), or 48 hours (group MSC-48h) after spinal cord ischemia, respectively. The control group received intrathecal injection of medium alone. Hind-limb motor function was assessed during a 28-day recovery period with Tarlov criteria, and then histologic examination was performed.
Results: Marrow stromal cells still could be found in the spinal cord 4 weeks after transplantation. The capillary density in the ventral gray matter was significantly increased in the three MSC-treated groups (p < 0.01 versus control group, respectively). After a 28-day recovery, marked functional improvement was detected in group MSC-2h (from day 1 to 28, p < 0.05, versus control group, respectively) and group MSC-24h (from day 14 to 28, p < 0.05, versus control group, respectively), but not in group MSC-48h. The number of intact motor neurons was much greater in group MSC-2h (p < 0.05, versus control group).
Conclusions: Intrathecal injection of MSCs enhances angiogenesis in the host spinal cord and improves the motor functional recovery after spinal cord ischemia. The therapeutic time window is critical for the therapeutic effect of MSCs.
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Introduction
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Temporary or permanent interruption of the blood supply to the spinal cord may cause spinal cord injury manifested by paraplegia, which continues to be a major devastating and unpredictable complication after surgery repair of descending and thoracoabdominal aortic aneurysms. Although the neurologic deficits have significantly decreased in resent times with the progress of surgical adjuncts and pharmacologic interventions, the incidence of paraplegia is still high at 6.6% to 8.3% in patients with extent II thoracoabdominal aortic aneurysms [1, 2]. Once fully developed, the neurologic deficit associated with spinal cord ischemia is considered to be permanent and irreversible. Therefore, an effective postoperative therapy for the injured spinal cord requires further study.
Recent studies utilizing embryonic stem cells and neural stem cells appear to offer a promising treatment for neurodegeneration and neurologic injures, but their clinical use is restricted because of ethical and logistic problems. Bone marrow stromal cells (MSCs) can be readily harvested and expanded ex vivo, which have been believed to be a source for cell transplantation therapy and are given more and more consideration [3, 4]. Transplantation of MSCs has been reported to be therapeutic for cerebral ischemia in collective studies, as evidenced by reduction of infarct area and improvement of functional outcomes [5–8]. Transplantation of MSCs also provided therapeutic benefits to the spinal cord with contusion and hemisection injury [9–11]. In our previous study, MSCs survived and engrafted into the spinal cord after intrathecal injection. Furthermore, prophylactic transplantation of MSCs 2 days before the induction of a 30-minute spinal cord ischemia markedly increased the functional outcomes and the number of intact motor neurons [12]. Collectively, these data have led to the hypothesis that MSCs injected after ischemia can attenuate the neurologic deficits resulting from spinal cord ischemia. In the current study, we sought to investigate whether transplantation of MSCs after the induction of ischemia can improve the functional deficits associated with spinal cord ischemia and the therapeutic time window for the possible neuroprotective effects.
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Material and Methods
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Animals
Japanese white rabbits weighing 1.6 to 2.3 kg were used in the current study. The animal protocol was approved by the Ethics Review Committee for Animal Experimentation of Hamamatsu University School of Medicine and was in accordance with the National Institutes of Health "Guide for the Use and Care of Laboratory Animals" (NIH publication 85-23, revised 1985).
Surgical Procedure
Spinal cord ischemia was induced by cross-clamping the abdominal aorta just distal to the renal arteries and just above the aortic bifurcation, according to the method described previously [12, 13].
Marrow Stromal Cell Culture
Bone marrow was harvested aseptically from tibias of rabbits approximately 2 months old. Nucleated cells were isolated by density gradient centrifugation using Percoll (1.073 g/mL) and were plated in growth medium consisting of DMEM/F12 (Dulbecco’s Modified Eagle’s Medium/Nutrient Mixture) supplemented with 20% fetal bovine serum and benzylpenicillin (1 x 105 u/mL) [12, 14]. The MSCs were isolated in the medium by their tendency to adhere to plastic [3, 4, 6]. After 3 days, the dishes were washed twice with phosphate-buffered saline (PBS) to remove nonadherent cells. The remaining cells were fed every third day. The MSC cultures were maintained at 50% confluence and passaged 3 to 5 times. Bromodeoxyuridine (3 µg/mL [BrdU; Sigma, St. Louis, Missouri]) was added into the medium 72 hours before transplantation [6, 12]. The MSCs were harvested by trypsinization and resuspended in DMEM for injection.
Intrathecal Injection
After anesthesia with pentobarbital, the intervertebral space between L5 and L6 was punctured with a 16G needle, and a polyethylene-10 tubing was inserted through it into the subarachnoid space. The desired position of the catheter was confirmed by cautious aspiration of cerebrospinal fluid (CSF). After intrathecal injection of either the MSCs or the vehicle, the catheter was removed. Then, the animals were placed head up for 60 minutes. Our previous study showed that intrathecal injection can be readily performed without neurologic injuries to the spinal cord [12].
Experimental Protocol
All rabbits underwewnt 30-minute spinal cord ischemia. For intrathecal injection of MSCs, approximately 1 x 108 MSCs were suspended in 0.2 mL DMEM. Four groups were enrolled, as shown in Figure 1. The control group (n = 6) received intrathecal injection of 0.2 mL vehicle 2 hours after the induction of ischemia. The MSCs were administered 2 hours (group MSC-2h, n = 8), 24 hours (group MSC-24h, n = 7), or 48 hours (group MSC-48h, n = 6) after ischemia.
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Fig 1. Experimental groups and protocol. (Group MSC-2h = marrow stromal cell [MSC] administration 2 hours after ischemia; group MSC-24h = MSC administration 24 hours after ischemia; group MSC-48h = MSC administration 48 hours after ischemia.)
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Neurologic Assessment
During a 28-day recovery period after spinal cord ischemia, hind-limb motor function was assessed by masked observers, using the modified Tarlov scale [15]: 0, no movement; 1, slight movement; 2, sit with assistance; 3, sit alone; 4, weak hop; 5, normal hop.
Histologic and Immunohistochemical Assessment
All animals of the four groups were sacrificed 28 days after the transient ischemia. Paraffin-embedded sections (4 µm) of lumbar spinal cords (L4 to L6) were stained with hematoxylin and eosin. In cases where the cytoplasm was diffusely eosinophilic, the large motor neuron cells were considered to be "necrotic or dead." When the cells demonstrated basophilic stippling (containing Nissl substance), the motor-neuron cells were considered to be "viable or alive" [16]. The intact motor neurons in the ventral gray matter were counted by a masked investigator in three sections for each rabbit, and the results were then averaged.
Immunohistochemical staining was used to identify cells derived from MSCs. Briefly, after deparaffinization, sections were incubated in 4N HCl for 30 minutes at room temperature followed by digestion with 0.1% trypsin for 10 minutes at 37°C. After blocking in normal serum, sections were treated with the monoclonal antibody against BrdU (Lab Vision, Fremont, California). Then the sections were incubated with biotinylated secondary antibody followed by high sensitivity streptavidin conjugated to horseradish peroxidase (R&D Systems, Minneapolis, Minnesota). Diaminobenzidine (DAB) was used as a chromogen for light microscopy. Counterstaining of sections by hematoxylin was then performed.
Quantification of Capillary Density
Alkaline phosphatase staining was used as a specific marker of endothelial cells in paraffin-embedded sections (10 µm) [17]. The number of microvessels in the ventral gray matter was counted by a masked investigator. Three individual sections from the low thoracic spinal cord (T11 to T12) were analyzed.
Statistical Analysis
Values were expressed as mean ± SD. Kruskal-Wallis test for nonparametric values and analysis of variance with subsequent Duncan’s test for parametric values were used. Statistical significance was defined as a p value less than 0.05.
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Results
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Migration of Transplanted MSCs
In vitro, more than 90% of the cultured cells showed BrdU reactivity. Within the spinal cord, transplanted MSCs were identified by BrdU immunoreactivity and characterized by round-to-oval dark brown nuclei. Immunohistochemical staining at 28 days after transient ischemia revealed that some MSC transplants still survived, integrated into the host gray matter or located around the lesion cavity at the injury site (Fig 2).
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Fig 2. Micrographs of lumbar spinal cords 28 days after 30 minutes of ischemia show morphologic characteristics of marrow stromal cell (MSC) transplants (original magnification, x200). With immunoperoxidase staining with diaminobenzidine and counterstaining with hematoxylin, bromodeoxyuridine (BrdU) reactivity is present in the nuclei of donor cells (arrows). Few BrdU-positive cells are located in the gray matter of the ischemic lesion.
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Neurologic Evaluation
The averaged neurologic scores of the four groups before ischemia and 1 day, 2, 7, 14, 21, and 28 days after ischemia are shown in Figure 3. A 30-minute period of infrarenal aortic occlusion resulted in severe lower extremity neurologic deficits in the control rabbits, and no functional recovery was found 28 days later. Compared with the controls, significantly better motor function was detected in rabbits treated with MSCs 2 hours after ischemia throughout the observation period (at each observation time point from day 1 to 28, p < 0.05, respectively). For rabbits receiving MSCs 24 hours after ischemia, a treatment-by-time interaction was detected, and the Tarlov scores were much higher than those of the control group from day 14 to 28 (at each observation time point from days 14 to 28, p < 0.05, respectively). However, no marked functional recovery was found when the transplantation of MSCs was delayed to 48 hours (from days 2 to 28, p > 0.05, respectively).
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Fig 3. Neurologic function before and 1 day, 2, 7, 14, 21, and 28 days after 30 minutes of spinal cord ischemia as evaluated using the Tarlov scale. Data are reported as means ± SD. (Boxes = marrow stromal cell [MSC] administration 2 hours after ischemia; triangles = MSC administration 24 hours after ischemia; diamonds = MSC administration 48 hours after ischemia; X = control.)
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Angiogenesis Induced by Transplantation of MSCs
As the architecture of the gray matter of lumbar spinal cord was seriously destroyed in the control rabbits, low thoracic spinal cords (nonischemic level) were used for assessment of angiogenesis. The microvessels in the spinal cord of rabbits transplanted with MSCs showed a more complex pattern than those of the control rabbits 28 days after ischemia (Fig 4A). Consistently, the capillary density in the ventral gray matter was significantly increased after MSCs transplantation (group MSC-2h, MSC-24h, and MSC-48h versus control group, p < 0.01, respectively; Fig 4B). No significant difference of capillary density was found among the three MSC-treated groups (p > 0.05).
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Fig 4. Angiogenic effects of marrow stromal cell (MSC) transpantation on the spinal cord 28 days after 30 minutes of ischemia. (A) Representative cross sections of low thoracic spinal cord (original magnification, x100). (B) Number of vessels in the ventral gray matter of the spinal cord. Values are expressed as means ± SD. (Group MSC-2h = MSC administration 2 hours after ischemia; group MSC-24h = MSC administration 24 hours after ischemia; group MSC-48h = MSC administration 48 hours after ischemia.)
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Histologic Assessment
Four rabbits that underwent a sham operation were also enrolled in the histologic study. Representative photographs of sections stained with hematoxylin and eosin are shown in Figure 5A, and the results of counting viable motor neurons are summarized in Figure 5B. Thirty minutes of ischemia induced severe neuronal damage in the control animals 28 days after reperfusion, as evidenced by vacuolization and frank necrosis, and almost 80% of the motor neurons were lost. However, only slighter changes were found in group MSC-2h, and many more motor neurons remained intact (p < 0.05 versus the control group). Although many motor neurons were also preserved in group MSC-24h, compared with the control group, the difference did not reach statistical significance (p > 0.05). Apparent neuronal damage was observed in group MSC-48h, and there was no significant difference in the motor neuron count between group MSC-48h and the control group (p > 0.05).
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Fig 5. Histologic assessment of the spinal cord 28 days after 30 minutes of ischemia. (A) Representative sections of lumbar spinal cords stained with hematoxylin and eosin (original magnification, x100) (MSC = marrow stromal cells). (B) Number of large motor neurons in the ventral gray matter. Data are reported as means ± SD. (Group MSC-2h = MSC administration 2 hours after ischemia; group MSC-24h = MSC administration 24 hours after ischemia; group MSC-48h = MSC administration 48 hours after ischemia.)
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Comment
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Spinal cord ischemia initiates a cascade of events that produce neuronal death and lead to neurologic deficits. Our previous study demonstrated that prophylactic intrathecal injection of MSCs attenuated neurologic injuries resulting from spinal cord ischemia. Here, we focused on the therapeutic benefits of MSCs for functional recovery after spinal cord ischemia. The current results demonstrated that MSCs provided robust functional recovery when they were injected 2 or 24 hours after spinal cord ischemia, but not 48 hours later. And transplantation of MSCs enhanced angiogenesis in the host spinal cord, which may contribute to the observed therapeutic effects.
When bone marrow is extracted and the cells are placed in a plastic dish, the populations of cells that float are hemopoietic cells, and those that adhere are referred to as MSCs, including mesenchymal stem or progenitor cells [18, 19]. The MSCs selectively targeted injured tissues and reduced functional deficits and lesion size associated with cerebral ischemia [5–8, 20]. Therapeutic benefit still could be achieved even when the administration of MSCs was delayed to 7 days [7, 21] or 1 month after stroke [22]. In the current study, however, the time window of MSCs therapy for ischemic spinal cord was critical and was no longer than 24 hours after ischemia. Collective evidences indicate that tissue replacement as the mechanism by which MSCs promote their beneficial effects is very unlikely, although some transplanted MSCs express proteins typical of neural cells. A far more reasonable explanation for the benefit is that MSCs induce cerebral tissue to activate endogenous restorative effects of the brain. The MSCs may turn on reactions and interact with brain to activate restorative and possible regenerative mechanisms [23]. The therapeutic benefit may be induced by a set of events associated with brain plasticity. This process includes but is not limited to angiogenesis, neurogenesis, synaptogenesis, and reduction of apoptosis within the strategically important tissue in the boundary zone of the ischemic lesion [23]. In the current model, however, occlusion of abdominal aorta caused ischemia for the whole spinal cord of low lumbar level and there was almost no such ischemic boundary zone, which indicated that once the infarction was fully developed, the restoration of spinal cord would be more difficult than that of the brain. After spinal cord ischemia, the number of necrotic neurons peaked 2 days after reperfusion [24]. A 30-minute ischemia induced almost a total loss of motor neurons 2 days after reperfusion [25], whereas only about 50% motor neurons were lost 1 day after reperfusion [26]. Transplanted MSCs lead to the production of several growth factors and cytokines, which may have potential for neuron survival [23]. Therefore, a possible explanation is that MSCs injected within 24 hours after ischemia protected some still intact neurons, avoiding death, and that induced the observed improvement of motor function.
Our data also demonstrated that transplantation of MSCs enhanced the angiogenesis in the host spinal cord, which was consistent with the findings in the ischemic brain [8]. Marrow stromal cells have been shown to produce many angiogenic agents such as hepatocyte growth factor, vascular endothelial growth factor, and fibroblast growth factor, which contribute to MSC-induced angiogenesis [8]. Newly formed vessels improved tissue perfusion around the ischemic boundary zone and promoted functional recovery in rats after stroke [8, 27]. The induction of angiogenesis functioned by enhancement of plasticity of the remaining tissue, particularly tissue in the boundary zone of the ischemic lesion [8]. In the current study, induction of angiogenesis may also contribute to the functional restoration of rabbits receiving MSCs 2 hours and 24 hours after spinal cord ischemia. For rabbits receiving MSCs 48 hours later, although angiogenesis was induced to a similar extent as that in the rabbits treated with MSCs earlier, no significant functional recovery was observed, indicating that the induction of angiogenesis could not directly translate into promotion of function. Almost a total loss of motor neurons 48 hours after ischemia determined the poor restoration of the ischemic spinal cord even under the induction of angiogenesis. However, benefits of angiogenesis rather than functional recovery, such as reduction of the cavity formation, could not be ruled out [10].
In rat models of spinal cord contusion, long-term assessment showed that functional restoration could be achieved by MSC therapy 7 days [28] or even 3 months [29, 30] after injury, which indicated that the therapeutic time windows were much longer than what was observed in the current study. In those models, the contusive injuries were induced on spinal cord of thoracic level, suggesting that the motor functional deficits were mainly caused by the disrupture of nerve fibers in the white matter; and it was plausible to attribute the functional recovery mainly to the regeneration of axons promoted by MSCs transplantation [28, 31]. However, the paraplegia in the present study resulted mainly from the loss of motor neurons. The different mechanisms for spinal cord injury may be a possible explanation for the discrepancy of therapeutic time window of MSC transplantation between the contusive and ischemic spinal cord injury. The ability of neurogenesis may also be different between rats and rabbits. Of cause, the therapeutic benefits of MSC transplantation still need to be assessed during a longer term in another study.
In summary, our study demonstrates that intrathecal injection of MSCs improves motor functional recovery after spinal cord ischemia and that the therapeutic time window is crucial to the therapeutic efficiency. The observations provide compelling evidence that intrathecal injection of MSCs could be a novel postoperative therapeutic strategy to treat the neurologic injury after thoracic aneurysm surgeries.
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Acknowledgments
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Enyi Shi is supported by the Japan Society for the Promotion of Science.
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References
|
|---|
- Coselli JS, LeMaire SA, Miller III CC, et al. Mortality and paraplegia after thoracoabdominal aortic aneurysm repair: a risk factor analysis Ann Thorac Surg 2000;69:409-414.[Abstract/Free Full Text]
- Safi HJ, Miller III CC, Huynh TT, et al. Distal aortic perfusion and cerebrospinal fluid drainage for thoracoabdominal and descending thoracic aortic repair: ten years of organ protection Ann Surg 2003;238:372-380.[Medline]
- Azizi SA, Stokes D, Augelli BJ, DiGirolamo C, Prockop DJ. Engraftment and migration of human bone marrow stromal cells implanted in the brains of albino rats—similarities to astrocyte grafts Proc Natl Acad Sci USA 1998;95:3908-3913.[Abstract/Free Full Text]
- Colter DC, Class R, DiGirolamo CM, Prockop DJ. Rapid expansion of recycling stem cells in cultures of plastic-adherent cells from human bone marrow Proc Natl Acad Sci USA 2000;97:3213-3218.[Abstract/Free Full Text]
- Honma T, Honmou O, Iihoshi S, et al. Intravenous infusion of immortalized human mesenchymal stem cells protects against injury in a cerebral ischemia model in adult rat Exp Neurol 2005;199:56-66.[Medline]
- Chen J, Li Y, Wang L, Lu M, Zhang X, Chopp M. Therapeutic benefit of intracerebral transplantation of bone marrow stromal cells after cerebral ischemia in rats J Neurol Sci 2001;189:49-57.[Medline]
- Chen J, Li Y, Wang L, et al. Therapeutic benefit of intravenous administration of bone marrow stromal cells after cerebral ischemia in rats Stroke 2001;32:1005-1011.[Abstract/Free Full Text]
- Chen J, Zhang ZG, Li Y, et al. Intravenous administration of human bone marrow stromal cells induces angiogenesis in the ischemic boundary zone after stroke in rats Circ Res 2003;92:692-699.[Abstract/Free Full Text]
- Hofstetter CP, Schwarz EJ, Hess D, et al. Marrow stromal cells form guiding strands in the injured spinal cord and promote recovery Proc Natl Acad Sci USA 2002;99:2199-2204.[Abstract/Free Full Text]
- Ohta M, Suzuki Y, Noda T, et al. Bone marrow stromal cells infused into the cerebrospinal fluid promote functional recovery of the injured rat spinal cord with reduced cavity formation Exp Neurol 2004;187:266-278.[Medline]
- Neuhuber B, Timothy Himes B, Shumsky JS, Gallo G, Fischer I. Anon growth and recovery of function supported by human bone marrow stromal cells in the injured spinal cord exhibit donor variations Brain Res 2005;1035:73-85.[Medline]
- Shi E, Kazui T, Jiang X, et al. Intrathecal injection of bone marrow stromal cells attenuates neurologic injury after spinal cord ischemia Ann Thorac Surg 2006;81:2227-2233.[Abstract/Free Full Text]
- Shi E, Kazui T, Jiang X, et al. NS-7, a novel Na+/Ca2+ channel blocker, prevents neurologic injury after spinal cord ischemia in rabbits J Thorac Cardiovasc Surg 2005;129:364-371.[Abstract/Free Full Text]
- Thompson RB, Emani SM, Davis BH, et al. Comparison of intracardiac cell transplantation: autologous skeletal myoblasts versus bone marrow cells Circulation 2003;108:II264-II271.[Medline]
- Tarlov IM. Acute spinal cord compression paralysis J Neurosurg 1972;36:10-20.[Medline]
- Mutch WA, Graham MR, Halliday WC, Thiessen DB, Girling LG. Use of neuroanesthesia adjuncts (hyperventilation and mannitol administration) improves neurological outcome after thoracic aortic cross-clamping in dogs Stroke 1993;24:1204-1210.[Abstract/Free Full Text]
- Yoshimura S, Morishita R, Hayashi K, et al. Gene transfer of hepatocyte growth factor to subarachnoid space in cerebral hypoperfusion model Hypertension 2002;39:1028-1034.[Abstract/Free Full Text]
- Javazon EH, Colter DC, Schwarz EJ, Prockop DJ. Rat marrow stromal cells are more sensitive to plating density and expand more rapidly from single-cell-derived colonies than human marrow stromal cells Stem Cells 2001;19:219-225.[Medline]
- Lennon DP, Haynesworth SE, Young RG, Dennis JE, Caplan AI. A chemically defined medium supports in vitro proliferation and maintains the osteochondral potential of rat marrow-derived mesenchymal stem cells Exp Cell Res 1995;219:211-222.[Medline]
- Ikeda N, Nonoguchi N, Zhao MZ, et al. Bone marrow stromal cells that enhanced fibroblast growth factor-2 secretion by herpes simplex virus vector improve neurological outcome after transient focal cerebral ischemia in rats Stroke 2005;36:2725-2730.[Abstract/Free Full Text]
- Li Y, Chen J, Zhang CL, et al. Gliosis and brain remodeling after treatment of stroke in rats with marrow stromal cells Glia 2005;49:407-417.[Medline]
- Shen LH, Li Y, Chen J, et al. Therapeutic benefit of bone marrow stromal cells administered 1 month after stroke J Cereb Blood Flow Metab 2007;27:6-13.[Medline]
- Chopp M, Li Y. Treatment of neural injury with marrow stromal cells Lancet Neurol 2002;1:92-100.[Medline]
- Sakamoto T, Kawaguchi M, Kurita N, et al. Long-term assessment of hind limb motor function and neuronal injury following spinal cord ischemia in rats J Neurosurg Anesthesiol 2003;15:104-109.[Medline]
- Suzuki K, Kazui T, Terada H, et al. Experimental study on the protective effects of edaravone against ischemic spinal cord injury J Thorac Cardiovasc Surg 2005;130:1586-1592.[Abstract/Free Full Text]
- Kaplan S, Bisleri G, Morgan JA, Cheema FH, Oz MC. Resveratrol, a natural red wine polyphenol, reduces ischemia-reperfusion-induced spinal cord injury Ann Thorac Surg 2005;802242–1.
- Zhang ZG, Zhang L, Jiang Q, et al. VEGF enhances angiogenesis and promote blood-brain barrier leakage in the ischemic brain J Clin Invest 2000;106:829-838.[Medline]
- Himes BT, Neuhuber B, Coleman C, et al. Recovery of function following grafting of human bone marrow-derived stromal cells into the injured spinal cord Neurorehabil Neural Repair 2006;20:278-296.[Abstract/Free Full Text]
- Zurita M, Vaquero J. Bone marrow stromal cells can achieve cure of chronic paraplegic rats: functional and morphological outcome one year after transplantation Neurosci Lett 2006;402:51-56.[Medline]
- Vaquero J, Zurita M, Oya S, Santos M. Cell therapy using bone marrow stromal cells in chronic paraplegic rats: systemic or local administration? Neurosci Lett 2006;398:129-134.[Medline]
- Ankeny DP, McTigue DM, Jakeman LB. Bone marrow transplants provide tissue protection and directional guidance for axons after contusive spinal cord injury in rats Exp Neurol 2004;190:17-31.[Medline]
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Abstract
Introduction
