Inbo Han

Multimodal Actions of Neural Stem Cells in a Mouse Model of ALS: A Meta-Analysis

A meta-analysis reports the beneficial effects of transplanting mouse or human neural stem cells into the spinal cord of the SOD1G93A mouse, a model of ALS. Stem Cells to the Rescue Amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease is an untreatable fatal disorder characterized by rapid and unremitting degeneration of nerve cells in the spinal cord that enable movement and respiration. Multiple processes involving these neurons and other cell types have been implicated as the cause of this disease. Neural stem cells (NSCs) normally function in the nervous system to create structures during development and to restore function to damaged systems throughout life. When these cells are isolated from the nervous system, grown and expanded in a dish, and then transplanted back into a diseased or injured part of the nervous system, they are thought to be able to perform at least some of these same tasks by producing therapeutic factors, improving the milieu, rescuing dying neurons, protecting neural connections, and reducing inflammation. Transplanted NSCs might be able to ameliorate some of the pathological processes that occur in ALS. Teng et al. now test this hypothesis by performing a meta-analysis of 11 studies that have transplanted mouse or human NSCs into the spinal cord of the transgenic mutant SOD1 ALS mouse. The authors found that disease onset and progression were slowed, such that extensive, often motor symptom-reduced, survival was predictably achievable in a subset of animals. This was particularly noticeable in those mice where transplanted NSCs covered a large part of the spinal cord including regions mediating vital functions such as respiration. The benefits of transplanted NSCs seem to be derived from a number of different actions including production of trophic factors, preservation of neuromuscular function, and a reduction in astrogliosis and inflammation. Through multiple modulatory mechanisms, NSCs may have potential for treating ALS and other untreatable degenerative diseases. Amyotrophic lateral sclerosis (ALS) is a lethal disease characterized by the unremitting degeneration of motor neurons. Multiple processes involving motor neurons and other cell types have been implicated in its pathogenesis. Neural stem cells (NSCs) perform multiple actions within the nervous system to fulfill their functions of organogenesis and homeostasis. We test the hypothesis that transplanted, undifferentiated multipotent migratory NSCs may help to ameliorate an array of pathological mechanisms in the SOD1G93A transgenic mouse model of ALS. On the basis of a meta-analysis of 11 independent studies performed by a consortium of ALS investigators, we propose that transplanted NSCs (both mouse and human) can slow both the onset and the progression of clinical signs and prolong survival in ALS mice, particularly if regions sustaining vital functions such as respiration are rendered chimeric. The beneficial effects of transplanted NSCs seem to be mediated by a number of actions including their ability to produce trophic factors, preserve neuromuscular function, and reduce astrogliosis and inflammation. We conclude that the widespread, pleiotropic, modulatory actions exerted by transplanted NSCs may represent an accessible therapeutic application of stem cells for treating ALS and other untreatable degenerative diseases.

Alleviation of chronic pain following rat spinal cord compression injury with multimodal actions of huperzine A

Significance Neuropathic pain, one of the most debilitating sequelae of neurotrauma, is an unmet clinical need for at least 40% of patients with spinal cord injury (SCI). We demonstrate that [-]-huperzine A (HUP-A), a naturally occurring Lycopodium alkaloid isolated from the Chinese club moss, Huperzia serrata, with potent reversible inhibitory action on acetylcholinesterase and N-methyl-D-aspartate glutamate receptors, offers an exceptional prospect for multimodal treatment of SCI-induced neuropathic pain in rats. HUP-A restores homeostasis of central sensory neurocircuitry without invoking drug tolerance and dependence or respiratory suppression. We therefore conclude that multimodal actions provide a fresh translational approach to reduce chronic pain. Diverse mechanisms including activation of NMDA receptors, microglial activation, reactive astrogliosis, loss of descending inhibition, and spasticity are responsible for ∼40% of cases of intractable neuropathic pain after spinal cord injury (SCI). Because conventional treatments blocking individual mechanisms elicit only short-term effectiveness, a multimodal approach with simultaneous actions against major pain-related pathways may have value for clinical management of chronic pain. We hypothesize that [-]-huperzine A (HUP-A), an alkaloid isolated from the club moss Huperzia serrata, that is a potent reversible inhibitor of acetylcholinesterase and NMDA receptors, could mitigate pain without invoking drug tolerance or dependence by stimulating cholinergic interneurons to impede pain signaling, inhibiting inflammation via microglial cholinergic activation, and blocking NMDA-mediated central hypersensitization. We tested our hypothesis by administering HUP-A i.p. or intrathecally to female Sprague–Dawley rats (200–235 g body weight) after moderate static compression (35 g for 5 min) of T10 spinal cord. Compared with controls, HUP-A treatment demonstrates significant analgesic effects in both regimens. SCI rats manifested no drug tolerance following repeated bolus i.p. or chronic intrathecal HUP-A dosing. The pain-ameliorating effect of HUP-A is cholinergic dependent. Relative to vehicle treatment, HUP-A administration also reduced neural inflammation, retained higher numbers of calcium-impermeable GluR2-containing AMPA receptors, and prevented Homer1a up-regulation in dorsal horn sensory neurons. Therefore, HUP-A may provide safe and effective management for chronic postneurotrauma pain by reestablishing homeostasis of sensory circuits.

Acute Spinal Subdural Hematoma Presenting with Spontaneously Resolving Hemiplegia

Although prompt diagnosis and emergent surgical intervention are important in acute spinal subdural hematoma (SSDH), some cases with spontaneous remission of symptom and hematoma without surgery have been reported. We present a case of acute nontraumatic SSDH presenting with transient left hemiplegia for 4 hours. A magnetic resonance imaging study of cervical spine confirmed SSDH with C3-6 cervical cord compression at the left side. The patient had conservative management without recurrence. Although hemiplegia is an unusual clinical manifestation of SSDH, it should be differentiated from that of cerebrovascular origin promptly. Conservative management may be an alternative therapeutic option for selective cases with transient neurological deficits.

Mass-producible nano-featured polystyrene surfaces for regulating the differentiation of human adipose-derived stem cells.

In this study, we report an efficient and cost-effective method of fabricating polystyrene (PS) nano-featured substrates containing nanopore (NPo) and nanopillar (NPi) arrays based on hot embossing using nickel nano-stamps. We investigate the behavior of adipose-derived stem cells (ASCs), including adhesion, morphology, proliferation and differentiation, on the replicated PS surfaces. Compared to a flat substrate, NPo- and NPi-featured substrates do not alter the morphology of stem cells. However, both NPo- and NPi-featured substrates induce different integrin expression and lower formation of focal adhesion complexes. In addition, ASCs on the NPo-featured substrate exhibit greater adipogenic differentiation, while the NPi-featured substrate induces higher osteogenic differentiation.

Targeted Nanotechnology in Glioblastoma Multiforme

Gliomas, and in particular glioblastoma multiforme, are aggressive brain tumors characterized by a poor prognosis and high rates of recurrence. Current treatment strategies are based on open surgery, chemotherapy (temozolomide) and radiotherapy. However, none of these treatments, alone or in combination, are considered effective in managing this devastating disease, resulting in a median survival time of less than 15 months. The efficiency of chemotherapy is mainly compromised by the blood-brain barrier (BBB) that selectively inhibits drugs from infiltrating into the tumor mass. Cancer stem cells (CSCs), with their unique biology and their resistance to both radio- and chemotherapy, compound tumor aggressiveness and increase the chances of treatment failure. Therefore, more effective targeted therapeutic regimens are urgently required. In this article, some well-recognized biological features and biomarkers of this specific subgroup of tumor cells are profiled and new strategies and technologies in nanomedicine that explicitly target CSCs, after circumventing the BBB, are detailed. Major achievements in the development of nanotherapies, such as organic poly(propylene glycol) and poly(ethylene glycol) or inorganic (iron and gold) nanoparticles that can be conjugated to metal ions, liposomes, dendrimers and polymeric micelles, form the main scope of this summary. Moreover, novel biological strategies focused on manipulating gene expression (small interfering RNA and clustered regularly interspaced short palindromic repeats [CRISPR]/CRISPR associated protein 9 [Cas 9] technologies) for cancer therapy are also analyzed. The aim of this review is to analyze the gap between CSC biology and the development of targeted therapies. A better understanding of CSC properties could result in the development of precise nanotherapies to fulfill unmet clinical needs.

Effect of various surgical modalities in recurrent or persistent trigeminal neuralgia

Background/Aims: In recurrent or persistent idiopathic trigeminal neuralgia (TN) after initial operation, additional surgical procedures may be required. There are numerous articles reporting the outcomes of additional surgical treatment and it is unclear how best to treat patients with recurrent or persistent TN. We evaluated the subsequent therapeutic options for recurrent or persistent TN. Methods: The study was a retrospective study. The authors reviewed 29 patients (15 female/14 male) who underwent retreatments for recurrent or persistent symptoms after an initial operation. Results: The mean follow-up duration was 56.4 months (range 12–78.7) from final treatment. Patients underwent a mean of 2.3 retreatments with a mean period of 26 months (range 1–72) between treatments. Final treatments were as follows: microvascular decompression (MVD) in 12 patients, percutaneous rhizotomy in 10, and radiosurgery in 7. Of the 29 patients, after final treatments, 9 patients (31%) achieved excellent results and 15 (52%) good results. Failure results were seen in 17% of patients with recurrent TN. Conclusion: In this study the authors demonstrate that percutaneous rhizotomy is recommended for most patients with recurrent pain after MVD, and MVD can be effective in patients with a history of failed percutaneous procedures. Radiosurgery can be utilized to treat those that have not responded to other surgical modalities.

An efficient device to experimentally model compression injury of mammalian spinal cord

We report an efficient and effective device to reproducibly model clinically relevant spinal cord injury (SCI) via controlled mechanical compression. In the present study, following skin incision, dorsal laminectomy was performed to expose T10 spinal cord of adult female Sprague-Dawley rats (230-250 g). The vertebral column was suspended and stabilized by Allis clamps at T8 and 12 spinous processes. A metal impounder was then gently loaded onto T10 dura (20, 35 or 50 g × 5 min; n=7/group), resulting in acute mild, moderate, or severe standing weight compression, respectively. Neurobehavioral outcomes were evaluated using the BBB locomotor scale and inclined plane test for coordinated hindlimb function, and a battery of spinal reflex tests for sensorimotor functions, at 1 day following SCI and weekly thereafter for 7 weeks. Quantitative histopathology was used to assess injury-triggered loss of white matter, gray matter and ventral horn motor neurons. Immunocytochemical levels of glial fibrillary acidic protein (GFAP) and β-amyloid precursor protein (APP) at the cervical and lumbar regions were measured to determine the distal segment impact of T10 compression. The data demonstrates that the standardized protocol generates weight-dependent hindlimb motosensory deficits and neurodegeneration primarily at and near the lesion epicenter. Importantly, there are significantly increased GFAP and APP expressions in spinal cord segments involved in eliciting post-SCI allodynia. Therefore, the described system reliably produces compression trauma in manners partially emulating clinical quasi-static insults to the spinal cord, providing a pragmatic model to investigate pathophysiological events and potential therapeutics for compression SCI.

Intraoperative facial electromyography and brainstem auditory evoked potential findings in microvascular decompression for hemifacial spasm: correlation with postoperative delayed facial palsy.

Background: Delayed facial palsy (DFP) after microvascular decompression (MVD) in patients with hemifacial spasm (HFS) is not uncommon, but the cause remains unknown. Objectives: To assess whether intraoperative electromyography (EMG) and brainstem auditory evoked potential (BAEP) can predict DFP after MVD. Methods: Between September 2009 and February 2011 we examined 86 patients, 9 of whom (10.4%) developed DFP after MVD on the same side. All patients underwent MVD and were followed-up for a median period of 13 months (range 6–22). We retrospectively examined intraoperative facial EMG and BAEP findings using our MVD patients’ registry. We excluded secondary HFS and immediate postoperative facial palsy after MVD in this study. We assessed the prevalence and clinical characteristics of DFP and compared EMG and BAEP findings between DFP and non-DFP groups. Results: All patients recovered completely, with a mean time to recovery of 37.8 days (range 22–57). There were no significant differences between DFP and non-DFP patients in terms of the amplitude and latency of intraoperative EMG and BAEP. Conclusion: The usefulness of intraoperative facial EMG and BAEP is limited and cannot predict DFP after MVD for HFS. We speculate that DFP after MVD is not associated with permanent nerve damage according to the EMG findings.

Propitious Therapeutic Modulators to Prevent Blood-Spinal Cord Barrier Disruption in Spinal Cord Injury.

The blood-spinal cord barrier (BSCB) is a specialized protective barrier that regulates the movement of molecules between blood vessels and the spinal cord parenchyma. Analogous to the blood-brain barrier (BBB), the BSCB plays a crucial role in maintaining the homeostasis and internal environmental stability of the central nervous system (CNS). After spinal cord injury (SCI), BSCB disruption leads to inflammatory cell invasion such as neutrophils and macrophages, contributing to permanent neurological disability. In this review, we focus on the major proteins mediating the BSCB disruption or BSCB repair after SCI. This review is composed of three parts. Section 1. SCI and the BSCB of the review describes critical events involved in the pathophysiology of SCI and their correlation with BSCB integrity/disruption. Section 2. Major proteins involved in BSCB disruption in SCI focuses on the actions of matrix metalloproteinases (MMPs), tumor necrosis factor alpha (TNF-α), heme oxygenase-1 (HO-1), angiopoietins (Angs), bradykinin, nitric oxide (NO), and endothelins (ETs) in BSCB disruption and repair. Section 3. Therapeutic approaches discusses the major therapeutic compounds utilized to date for the prevention of BSCB disruption in animal model of SCI through modulation of several proteins.

Targeted Treatment of Experimental Spinal Cord Glioma With Dual Gene-Engineered Human Neural Stem Cells.

BACKGROUND There are currently no satisfactory treatments or experimental models showing autonomic dysfunction for intramedullary spinal cord gliomas (ISCG). OBJECTIVE To develop a rat model of ISCG and investigate whether genetically engineered human neural stem cells (F3.hNSCs) could be developed into effective therapies for ISCG. METHODS Immunodeficient/Rowett Nude rats received C6 implantation of G55 human glioblastoma cells (10K/each). F3.hNSCs engineered to express either cytosine deaminase gene only (i.e., F3.CD) or dual genes of CD and thymidine kinase (i.e., F3.CD-TK) converted benign 5-fluorocytosine and ganciclovir into oncolytic 5-fluorouracil and ganciclovir-triphosphate, respectively. ISCG rats received injection of F3.CD-TK, F3.CD, or F3.CD-TK debris near the tumor epicenter 7 days after G55 seeding, followed with 5-FC (500 mg/kg/5 mL) and ganciclovir administrations (25 mg/kg/1 mL/day × 5/each repeat, intraperitoneal injection). Per humane standards for animals, loss of weight-bearing stepping in the hindlimb was used to determine post-tumor survival. Also evaluated were autonomic functions and tumor growth rate in vivo. RESULTS ISCG rats with F3.CD-TK treatment survived significantly longer (37.5 ± 4.78 days) than those receiving F3.CD (21.5 ± 1.75 days) or F3.CD-TK debris (19.3 ± 0.85 days; n = 4/group; P < .05, median rank test), with significantly improved autonomic function and reduced tumor growth rate. F3.DC-TK cells migrated diffusively into ISCG clusters to mediate oncolytic effect. CONCLUSION Dual gene-engineered human neural stem cell regimen markedly prolonged survival in a rat model that emulates somatomotor and autonomic dysfunctions of human cervical ISCG. F3.CD-TK may provide a novel approach to treating clinical ISCG. ABBREVIATIONS 5FC, 5-fluorocytosineBBB, Basso, Beattie, and BresnahanCD, cytosine deaminaseDP, diastolic blood pressureGCV, ganciclovir; hNSCs, human neural stem cellsISCG, intramedullary spinal cord gliomasMAP, mean arterial blood pressureNSCs, neural stem cellsSP, systolic blood pressureTK, thymidine kinase.