Hyeonseon Park

Complete Spinal Cord Injury Treatment Using Autologous Bone Marrow Cell Transplantation and Bone Marrow Stimulation with Granulocyte Macrophage‐Colony Stimulating Factor: Phase I/II Clinical Trial

To assess the safety and therapeutic efficacy of autologous human bone marrow cell (BMC) transplantation and the administration of granulocyte macrophage‐colony stimulating factor (GM‐CSF), a phase I/II open‐label and nonrandomized study was conducted on 35 complete spinal cord injury patients. The BMCs were transplanted by injection into the surrounding area of the spinal cord injury site within 14 injury days (n = 17), between 14 days and 8 weeks (n = 6), and at more than 8 weeks (n = 12) after injury. In the control group, all patients (n = 13) were treated only with conventional decompression and fusion surgery without BMC transplantation. The patients underwent preoperative and follow‐up neurological assessment using the American Spinal Injury Association Impairment Scale (AIS), electrophysiological monitoring, and magnetic resonance imaging (MRI). The mean follow‐up period was 10.4 months after injury. At 4 months, the MRI analysis showed the enlargement of spinal cords and the small enhancement of the cell implantation sites, which were not any adverse lesions such as malignant transformation, hemorrhage, new cysts, or infections. Furthermore, the BMC transplantation and GM‐CSF administration were not associated with any serious adverse clinical events increasing morbidities. The AIS grade increased in 30.4% of the acute and subacute treated patients (AIS A to B or C), whereas no significant improvement was observed in the chronic treatment group. Increasing neuropathic pain during the treatment and tumor formation at the site of transplantation are still remaining to be investigated. Long‐term and large scale multicenter clinical study is required to determine its precise therapeutic effect.

GM-CSF inhibits apoptosis of neural cells via regulating the expression of apoptosis-related proteins

Recently, we reported that GM-CSF showed therapeutic effects on the spinal cord injury (SCI) in rat model possibly via its anti-apoptotic activity in the nervous system. This study investigated the molecular mechanism of its anti-apoptotic and neuroprotective effects in N2a neuroblastoma cells and in rat SCI model. GM-CSF inhibited staurosporine-induced cytotoxicity and apoptosis of N2a cells. Single administration of GM-CSF either intraperitoneally or locally using a gelfoam, clearly reduced the apoptotic events in the surrounding region of the injury site in rat SCI model. Immunohistochemical analysis showed that apoptosis of cells occurred mainly in the neurons, but not significantly in the astrocytes in the surrounding regions. In both N2a cells and in rat SCI model, GM-CSF actually reduced the expression of pro-apoptotic proteins (p53, p21(WAF1/CIP1) and Bax), while further induced that of an anti-apoptotic protein (Bcl-2). In the Basso-Beattie-Bresnahan (BBB) locomotor test, the single GM-CSF administration showed better behavioral recovery than the untreated control only at early times within 1 week after injury. Overall, GM-CSF was shown to exert its neuroprotective effect on the neural injury by regulating the expression of apoptosis related genes, providing the molecular basis on its anti-apoptotic activity. Longer administration of GM-CSF appeared to be necessary for the sustained functional recovery from SCI.

GM-CSF inhibits glial scar formation and shows long-term protective effect after spinal cord injury

OBJECT This study investigated the effects of granulocyte macrophage-colony stimulating factor (GM-CSF) on the scar formation and repair of spinal cord tissues in rat spinal cord injury (SCI) model. METHODS Sprague-Dawley male rats (8 weeks old) were randomly divided into the sham-operated group, spinal cord injury group, and injury with GM-CSF treated group. A spinal cord injury was induced at T9/10 levels of rat spinal cord using a vascular clip. GM-CSF was administrated via intraperitoneal (IP) injection or on the dural surface using Gelfoam at the time of SCI. The morphological changes, tissue integrity, and scar formation were evaluated until 4 weeks after SCI using histological and immunohistochemical analyses. RESULTS The administration of GM-CSF either via IP injection or local treatment significantly reduced the cavity size and glial scar formation at 3-4 weeks after SCI. GM-CSF also reduced the expression of core proteins of chondroitin sulfate proteoglycans (CSPGs) such as neurocan and NG2 but not phosphacan. In particular, an intensive expression of glial fibriallary acidic protein (GFAP) and neurocan found around the cavity at 4 weeks was obviously suppressed by GM-CSF. Immunostaining for neurofilament (NF) and Luxol fast blue (LFB) showed that GM-CSF preserved well the axonal arrangement and myelin structure after SCI. The expression of GAP-43, a marker of regenerating axons, also apparently increased in the rostral grey matter by GM-CSF. CONCLUSION These results suggest that GM-CSF could enhance long-term recovery from SCI by suppressing the glial scar formation and enhancing the integrity of axonal structure.

Hypoxia-inducible expression of vascular endothelial growth factor for the treatment of spinal cord injury in a rat model

OBJECT Vascular endothelial growth factor (VEGF) has been investigated as a therapy for many disorders and injuries involving ischemia. In this report, we constructed and evaluated a hypoxia-inducible VEGF expression system as a treatment for spinal cord injury (SCI). METHODS The hypoxia-inducible VEGF plasmid was constructed using the erythropoietin (Epo) enhancer with the Simian virus 40 (SV40) promoter (pEpo-SV-VEGF) or the RTP801 promoter (pRTP801-VEGF). The expression of VEGF in vitro was evaluated after transfection into N2A cells. The plasmids were then injected into rat spinal cords with contusion injuries. The expression of VEGF in vivo was measured using reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Locomotor recovery in the rats was evaluated using the Basso, Beattie and Bresnahan (BBB) scale for locomotor analysis. RESULTS In vitro transfection showed that pEpo-SV-VEGF or pRTP801-VEGF induced VEGF expression under hypoxic conditions, whereas pSV-VEGF did not. The VEGF level was higher in the pEpo-SV-VEGF and pRTP801-VEGF groups than in the control group. The VEGF expression was detected in neurons and astrocytes of the spinal cord. Locomotor recovery was improved in the pEpo-SV-VEGF and pRTP801-VEGF groups, and BBB scores were higher than in the control group. Staining using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling showed that the number of apoptotic cells decreased in the plasmid-injected groups compared with the control group, and significant differences were observed between the hypoxia-responsive groups and the pSV-VEGF group. CONCLUSIONS These results suggest that the hypoxia-inducible VEGF expression system may be useful for gene therapy of SCI.

Anterior cervical corpectomy and fusion using miniplate and screws in a 7-year-old child with eosinophilic granuloma of the cervical spine

STUDY DESIGN This is a case report of a 7-year-old child with eosinophilic granuloma in the cervical spine, which underwent anterior cervical corpectomy and fusion by using Miniplate and screws. OBJECTIVES To describe the use of Miniplate and screws for pediatric cervical anterior fusion. SUMMARY OF BACKGROUND DATA Eosinophilic granuloma is a rare disease causing destructive bony lesions of the cervical spine in children. A complete resection and fusion were considered to be the preferable treatment in our case. However, cervical spinal fusion and instrumentation in children may be technically difficult because of the size of the vertebral body and the iliac bone. In addition, a proper device for an internal fixation in pediatric patients is not yet available. METHODS A case of eosinophilic granuloma in pediatric spine was presented. RESULTS We confirmed successful bony fusion and the restoration of the normal cervical curvature without recurrence of the tumor 2 years after the procedure. CONCLUSIONS For proper internal fixation and prevention of dislodgement of the grafted bone, we used the Miniplate and screws as internal fixator after intralesional resection of the tumor mass.

Granulocyte-macrophage colony-stimulating factor promotes survival of dopaminergic neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced murine Parkinson's disease model.

Granulocyte–macrophage colony‐stimulating factor (GM‐CSF) is a hematopoietic cytokine that has the potential for clinical application. The biological effects of GM‐CSF have been well characterized, and include stimulation of bone marrow hematopoietic stem cell proliferation and inhibition of apoptosis of hematopoietic cells. In contrast, the therapeutic effects of GM‐CSF on the central nervous system in acute injury such as stroke and spinal cord injury have been reported only recently. To better understand the protective effect of GM‐CSF on dopaminergic neurons in Parkinson’s disease (PD), we investigated the effect of GM‐CSF on the survival of dopamine neurons and changes in locomotor behavior in a murine PD model. We investigated the neuroprotective effects of GM‐CSF in 1‐methyl‐4‐phenylpyridinium (MPP+)‐treated PC12 cells as well as in embryonic mouse primary mesencephalic neurons (PMNs) in vitro. To investigate the role of GM‐CSF in vivo, we prepared a mouse 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) PD model, and examined the effects of GM‐CSF on dopaminergic neuron survival in the substantia nigra and on locomotor behavior. Treatment with GM‐CSF significantly reduced MPP+‐induced dopaminergic cell death in PC12 cells and PMNs in vitro. GM‐CSF modulated the expression of apoptosis‐related proteins, Bcl‐2 and Bax, in vitro. Furthermore, administration of GM‐CSF (50 μg/kg body weight/day) in vivo for 7 days protected dopaminergic neurons in the substantia nigra and improved locomotor behavior in a mouse MPTP model of PD.

Adjacent Segment Disease After Interbody Fusion and Pedicle Screw Fixations for Isolated L4-L5 Spondylolisthesis : A Minimum Five-Year Follow-up

Study Design. A retrospective study. Objective. The purpose of this study are (1) to analyze prevalence of clinical and radiologic adjacent segment diseases (ASD), (2) to find precipitating factor of clinical ASD in each isthmic and degenerative spondylolisthesis groups, and (3) to compare clinical and radiologic change in isthmic and degenerative spondylolisthesis. Summary of Background Data. There is no clinical report regarding the use of magnetic resonance imaging (MRI) for evaluating ASD in patient who underwent 360° fusion with single-level spondylolisthesis with healthy adjacent segment. Methods. A total of 69 patients who underwent instrumented single-level interbody fusion at the L4–L5 level and showed no definitive degenerated disc in adjacent segments on preoperative MRI and plain radiographs were evaluated at more than 5 years after surgery. The patients were divided into 2 groups: group I was isthmic spondylolisthesis patients and group II was degenerative spondylolisthesis patients. The radiologic ASD was diagnosed by plain radiographs and MRI. Clinical ASD is defined as symptomatic spinal stenosis, intractable back pain, and subsequent sagittal or coronal imbalance with accompanying radiographic changes. Symptomatic spinal stenosis was defined as stenosis diagnosed by MRI and combined with neurologic claudication. Results. The prevalence of radiologic ASD on group I and group II was 72.7% and 84.0%, respectively. About 7 (15.9%) patients showed clinical ASD in group I and 6 (24.0%) patients showed clinical ASD in group II. MRI showed significant reliability for diagnosis of clinical ASD. Compared with patients with asymptomatic ASD, patients with clinical ASD showed significantly less postoperative lordotic angle at the L4–L5 level (i.e., less than 20°) in both groups. Conclusion. Maintaining postoperative L4–L5 segmental lordotic angle at about 20° or more is important for prevention of clinical ASD in single-level 360° fusion operation. MRI is reliable method for diagnosing clinical ASD.

Reduction in programmed cell death and improvement in functional outcome of transient focal cerebral ischemia after administration of granulocyte-macrophage colony-stimulating factor in rats: Laboratory investigation

OBJECT Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent hematopoietic growth factor that both enhances the survival and drives the differentiation and proliferation of myeloid lineage cells. Recent studies have suggested that GM-CSF has a neuroprotective effect against CNS injury. In this paper, the authors investigated the neuroprotective effect of GM-CSF on neuron survival and locomotor behavior in a rat model of focal cerebral ischemic injury. MATERIALS To understand its neuroprotective effect in vitro, GM-CSF was administered to a glutamate-induced excitotoxicity neuronal injury cell culture model that mimics the pathophysiology of focal hypoxic cerebral injury. In the animal study, the authors prepared a rat focal cerebral ischemia model by occluding the unilateral middle cerebral artery. They then examined the effects of GM-CSF administration on changes in infarct volume, apoptosis-related gene expression, and improvement in locomotor behavior. RESULTS Treatment with GM-CSF significantly increased cell viability in a cell culture model of glutamate-induced neuronal injury. Furthermore, in vivo administration of GM-CSF at 60 microg/kg body weight daily for 5 consecutive days beginning immediately after injury decreased infarction volume, altered the expression of several apoptosis-related genes (Bcl-2, Bax, caspase 3, and p53), and improved locomotor behavior in the focal cerebral ischemia model. CONCLUSIONS The GM-CSF had neuroprotective effects in in vitro and in vivo experiments and resulted in decreased infarction volume and improved locomotor behavior. Although the specific mechanism involved in stroke recovery was not fully elucidated as it was not the primary focus of this study, administration of GM-CSF appeared to decrease the extent of neuronal apoptosis by modulating the expression of several apoptosis-related genes such as Bcl-2, Bax, caspase 3, and p53. Further investigations are necessary to better understand the role of GM-CSF on neural regeneration during the recovery phase of a stroke, as well as the intracellular signal transduction pathways that mediate neuroprotection.

Spinal clear cell meningioma presented with progressive paraparesis in infancy

Abstract Clear cell meningioma, about 20 cases of which have been reported in the literature, is a morphological variant of meningioma. The authors report a case of spinal clear cell meningioma that occurred in a child. A 14-month-old girl showed gradually progressive paraparesis 1 month after she started to walk. Magnetic resonance image showed an intradural extramedullary mass compressing the conus medullaris and cauda equina. Complete excision of the tumor was done, and the patient gradually recovered from motor weakness and neurogenic bladder. Histological examinations along with immunohistochemical and ultrastructural investigations allowed a diagnosis of clear cell meningioma. During the follow-up period, a recurrent mass lesion was detected on the 8-month follow-up MR image in the same region. Because clear cell meningioma might be biologically aggressive, postoperative adjuvant therapy and close follow-up investigation should be considered.

Signal transduction pathways of GM-CSF in neural cell lines.

GM-CSF is recently being suggested to play important role(s) in the nervous system. Present study was intended to understand signal transduction pathways of GM-CSF in human neuroblastoma (SK-N-(BE)2) and glioblastoma (A172) cell lines. The expression of GM-CSF receptors on the surface of these cells was confirmed by immunocytochemistry, Western blot analysis and RT-PCR. When treated for 10min, GM-CSF activated the signal transducer and activator of transcription 5 (STAT5) and extracellular signal regulated kinase (ERK) in both cell lines. However, Janus kinase 2 (JAK2) was activated only in A172 cells but not in SK-N-(BE)2 cells by GM-CSF. The GM-CSF-activated cellular signal pathways were specifically inhibited by the pretreatment of GM-CSF receptor alpha antibody, suggesting the specificity of the signal activation. The experiment using specific inhibitors (AG490) to the JAK/STAT pathway showed that JAK2/STAT5 cascade was well preserved and activated by GM-CSF in A172 cells, while STAT5 was activated by GM-CSF without JAK2 activation in SK-N-(EB)2 cells. The ERK pathway was activated by GM-CSF independently of JAK2 in both cell lines. Finally, GM-CSF showed cytoprotective effect on these cell lines by inhibiting cytotoxicity of saturosporine. The results revealed the signal transduction pathways activated by GM-CSF in neural cells and suggested that GM-CSF might affect the neural functions via these signal pathways.