Search

Background High-frequency transcutaneous neuromuscular electrical nerve stimulation (TENS) is currently used for the administration of electrical current in denervated muscle to alleviate muscle atrophy and enhance motor function; however, the time window (i.e. either immediate or delayed) for achieving benefit is still undetermined. In this study, we conducted an intervention of sciatic nerve crush injury using high-frequency TENS at different time points to assess the effect of motor and sensory functional recovery. Results Animals with left sciatic nerve crush injury received TENS treatment starting immediately after injury or 1 week later at a high frequency(100 Hz) or at a low frequency (2 Hz) as a control. In SFI gait analysis, either immediate or late admission of high-frequency electrical stimulation exerted significant improvement compared to either immediate or late administration of low-frequency electrical stimulation. In an assessment of allodynia, immediate high frequency electrical stimulation caused a significantly decreased pain threshold compared to late high-frequency or low-frequency stimulation at immediate or late time points. Immunohistochemistry staining and western blot analysis of S-100 and NF-200 demonstrated that both immediate and late high frequency electrical stimulation showed a similar effect; however the effect was superior to that achieved with low frequency stimulation. Immediate high frequency electrical stimulation resulted in significant expression of TNF-α and synaptophysin in the dorsal root ganglion, somatosensory cortex, and hippocampus compared to late electrical stimulation, and this trend paralleled the observed effect on somatosensory evoked potential. The CatWalk gait analysis also showed that immediate electrical stimulation led to a significantly high regularity index. In primary dorsal root ganglion cells culture, high-frequency electrical stimulation also exerted a significant increase in expression of TNF-α, synaptophysin, and NGF in accordance with the in vivo results. Conclusion Immediate or late transcutaneous high-frequency electrical stimulation exhibited the potential to stimulate the motor nerve regeneration. However, immediate electrical stimulation had a predilection to develop neuropathic pain. A delay in TENS initiation appears to be a reasonable approach for nerve repair and provides the appropriate time profile for its clinical application. Electronic supplementary material The online version of this article (10.1186/s12868-018-0437-9) contains supplementary material, which is available to authorized users.

Transferring exogenous mitochondria has therapeutic effects on damaged heart, liver, and lung tissues. Whether this protective effect requires the symbiosis of exogenous mitochondria in host cells remains unknown. Here xenogenic mitochondria derived from a hamster cell line were applied to ischemic rat brains and rat primary cortical neurons. Isolated hamster mitochondria, either through local intracerebral or systemic intra-arterial injection, significantly restored the motor performance of brain-ischemic rats. The brain infarct area and neuronal cell death were both attenuated by the exogenous mitochondria. Although internalized mitochondria could be observed in neurons and astrocytes, the low efficacy of mitochondrial internalization could not completely account for the high rate of rescue of the treated neural cells. We further illustrated that disrupting electron transport or ATPase synthase in mitochondria significantly attenuated the protective effect, suggesting that intact respiratory activity is essential for the mitochondrial potency on neural protection. These results emphasize that nonsymbiotic extracellular mitochondria can provide an effective cell defense against acute injurious ischemic stress in the central nervous system.

Dual leucine zipper kinase (DLK) is a member of mitogen-activated protein kinase kinase kinase (MAP3K) family mainly involved in neuronal degeneration. However, the role of DLK signaling in the neuropathic pain has not yet been fully determined. Chronic constrictive injury (CCI) was conducted by four 3-0 chromic gut ligatures loosely ligated around the sciatic nerve. Escalated DLK expression over the dorsal root ganglion was observed from one to four rings of CCI. Remarkable expression of DLK was observed in primary dorsal root ganglion cells culture subjected to electrical stimulation and attenuated by DLK short hairpin RNA (shRNA) treatment. Intrathecal injection of DLK shRNA attenuates the expression of DLK over the dorsal root ganglion and hippocampus neurons and increased the threshold of mechanical allodynia and decreased thermal hyperalgesia. In CatWalk gait analysis, significant decreases of print area, maximum contact maximum intensity, stand phase, single stance, and regular index by CCI were alleviated by the DLK shRNA administration. In conclusion, the expression of DLK was up-regulated in chronic constrictive injury and attenuated by the administration of DLK shRNA, which paralleled the improvement of neurobehavior of neuropathic pain. The modulation of DLK expression is a potential clinic treatment option for neuropathic pain.

Though the compromised blood-brain barrier (BBB) is a pathological hallmark of Japanese encephalitis-associated neurological sequelae, the underlying mechanisms and the specific cell types involved are not understood. BBB characteristics are induced and maintained by cross talk between brain microvascular endothelial cells and neighboring elements of the neurovascular unit. In this study, we show a potential mechanism of disruption of endothelial barrier integrity during the course of Japanese encephalitis virus (JEV) infection through the activation of neighboring pericytes. We found that cultured brain pericytes were susceptible to JEV infection but were without signs of remarkable cytotoxicity. JEV-infected pericytes were found to release biologically active molecules which activated ubiquitin proteasome, degraded zonula occludens-1 (ZO-1), and disrupted endothelial barrier integrity in cultured brain microvascular endothelial cells. Infection of pericytes with JEV was found to elicit elevated production of interleukin-6 (IL-6), which contributed to the aforementioned endothelial changes. We further demonstrated that ubiquitin-protein ligase E3 component n -recognin-1 (Ubr 1) was a key upstream regulator which caused proteasomal degradation of ZO-1 downstream of IL-6 signaling. During JEV central nervous system trafficking, endothelial cells rather than pericytes are directly exposed to cell-free viruses in the peripheral bloodstream. Therefore, the results of this study suggest that subsequent to primary infection of endothelial cells, JEV infection of pericytes might contribute to the initiation and/or augmentation of Japanese encephalitis-associated BBB breakdown in concerted action with other unidentified barrier disrupting factors.

Object Neuropathic pain is debilitating, and when chronic, it significantly affects the patient physically, psychologically, and socially. The neurobehavior of animals used as a model for chronic constriction injury seems analogous to the neurobehavior of humans with neuropathic pain. However, no data depicting the severity of histomorphological alterations of the nervous system associated with graded changes in neurobehavior are available. To determine the severity of histomorphological alteration related to neurobehavior, the authors created a model of chronic constrictive injury of varying intensity in rats and used the CatWalk XT system to evaluate neurobehavior. Methods A total of 60 Sprague-Dawley rats, weighing 250–300 g each, were randomly assigned to 1 of 5 groups that would receive sham surgery or 1, 2, 3, or 4 ligatures of 3-0 chromic gut loosely ligated around the left sciatic nerve. Neurobehavior was assessed by CatWalk XT, thermal hyperalgesia, and mechanic allodynia before injury and periodically after injury. The nerve tissue from skin to dorsal spinal cord was obtained for histomorphological analysis 1 week after injury, and brain evoked potentials were analyzed 4 weeks after injury. Results. Significant differences in expression of nerve growth factor existed in skin, and the differences were associated with the intensity of nerve injury. After injury, expression of cluster of differentiation 68 and tumor necrosis factor–α was increased, and expression of S100 protein in the middle of the injured nerve was decreased. Increased expression of synaptophysin in the dorsal root ganglion and dorsal spinal cord correlated with the intensity of injury. The amplitude of sensory evoked potential increased with greater severity of nerve damage. Mechanical allodynia and thermal hyperalgesia did not differ significantly among treatment groups at various time points. CatWalk XT gait analysis indicated significant differences for print areas, maximum contact maximum intensity, stand phase, swing phase, single stance, and regular index, with sham and/or intragroup comparisons. Conclusions. Histomorphological and electrophysiological alterations were associated with severity of nerve damage. Subtle neurobehavioral differences were detected by the CatWalk XT system but not by mechanical allodynia or thermal hyperalgesia. Thus, the CatWalk XT system should be a useful tool for monitoring changes in neuropathic pain, especially subtle alterations.

Cellular inflammatory response plays an important role in ischemic brain injury and anti-inflammatory treatments in stroke are beneficial. Dietary supplementation with docosahexaenoic acid (DHA) shows anti-inflammatory and neuroprotective effects against ischemic stroke. However, its effectiveness and its precise modes of neuroprotective action remain incompletely understood. This study provides evidence of an alternative target for DHA and sheds light on the mechanism of its physiological benefits. We report a global inhibitory effect of 3 consecutive days of DHA preadministration on circulating and intracerebral cellular inflammatory responses in a rat model of permanent cerebral ischemia. DHA exhibited a neuroprotective effect against ischemic deficits by reduction of behavioral disturbance, brain infarction, edema and blood-brain barrier disruption. The results of enzymatic assay, Western blot, real-time reverse transcriptase polymerase chain reaction and flow cytometric analysis revealed that DHA reduced central macrophages/microglia activation, leukocyte infiltration and pro-inflammatory cytokine expression and peripheral leukocyte activation after cerebral ischemia. In parallel with these immunosuppressive phenomena, DHA attenuated post-stroke oxidative stress, c-Jun N-terminal kinase (JNK) phosphorylation, c-Jun phosphorylation and activating protein-1 (AP-1) activation but further elevated ischemia-induced NF-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) expression. DHA treatment also had an immunosuppressive effect in lipopolysaccharide/interferon-γ-stimulated glial cultures by attenuating JNK phosphorylation, c-Jun phosphorylation and AP-1 activation and augmenting Nrf2 and HO-1 expression. In summary, we have shown that DHA exhibited neuroprotective and anti-inflammatory effects against ischemic brain injury and these effects were accompanied by decreased oxidative stress and JNK/AP-1 signaling as well as enhanced Nrf2/HO-1 expression.

In response to aggravation by activated microglia, IL-13 can significantly enhance ER stress induction, apoptosis, and death via reciprocal signaling through CCAAT/enhancer-binding protein alpha (C/EBP-α) and C/EBP-beta (C/EBP-β). This reciprocal signaling promotes neuronal survival. Since the induction of cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptor gamma/heme oxygenase 1 (PPAR-γ/HO-1) by IL-13 plays a crucial role in the promotion of and protection from activated microglia, respectively; here, we investigated the role of IL-13 in regulating C/EBPs in activated microglia and determined its correlation with neuronal function. The results revealed that IL-13 significantly enhanced C/EBP-α/COX-2 expression and PGE2 production in LPS-treated microglial cells. Paradoxically, IL-13 abolished C/EBP-β/PPAR-γ/HO-1 expression. IL-13 also enhanced ER stress-evoked calpain activation by promoting the association of C/EBP-β and PPAR-γ. SiRNA-C/EBP-α effectively reversed the combined LPS-activated caspase-12 activation and IL-13-induced apoptosis. In contrast, siRNA-C/EBP-β partially increased microglial cell apoptosis. By NeuN immunochemistry and CD11b staining, there was improvement in the loss of CA3 neuronal cells after intrahippocampal injection of IL-13. This suggests that IL-13-enhanced PLA2 activity regulates COX-2/PGE2 expression through C/EBP-α activation. In parallel, ER stress-related calpain downregulates the PPAR-γ/HO-1 pathway via C/EBP-β and leads to aggravated death of activated microglia via IL-13, thereby preventing cerebral inflammation and neuronal injury.

Energy failure and oxidative stress have been implicated in the pathogenesis of ischemia. Here, we report a potential link between cytosolic phospholipase A₂ (cPLA₂) activation and energy failure/oxidative stress-induced astrocyte damage involving reactive oxygen species (ROS), protein kinase C-α (PKC-α), Src, Raf, and extracellular signal-regulated kinase (ERK) signaling and concurrent elevation of endogenous chelatable zinc. Energy failure and oxidative stress were produced by treating astrocytes with glycolytic inhibitor iodoacetate and glutathione chelator diethylmaleate, respectively. Diethylmaleate and iodoacetate in combination caused augmented damage to astrocytes in a time- and concentration-dependent manner. The cell death caused by diethylmaleate/iodoacetate was accompanied by increased ROS generation, PKC-α membrane translocation, Src, Raf, ERK, and cPLA₂ phosphorylation. Pharmacological studies revealed that these activations all contributed to diethylmaleate/iodoacetate-induced astrocyte death. Intriguingly, the mobilization of endogenous chelatable zinc was observed in diethylmaleate/iodoacetate-treated astrocytes. Zinc appears to act as a downstream mediator in response to diethylmaleate/iodoacetate treatment because of the attenuating effects of its chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine. These observations indicate that ROS/PKC-α, Src/Raf/ERK signaling and cPLA₂ are active participants in diethylmaleate/iodoacetate-induced astrocyte death and contribute to a vicious cycle between the depletion of ATP/glutathione and the mobilization of chelatable zinc as critical upstream effectors in initiating cytotoxic cascades.

N(e)-carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes-induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML-related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)-mediated SH2 domain-containing tyrosine phosphatase-1 (SHP-1) activation by CML inhibits the VEGF receptor-2 (VEGFR-2, KDR/Flk-1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR-2 activation in parallel with the increased SHP-1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP-1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP-1 with VEGFR-2. Consistently, SHP-1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [(3)H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML-increased SHP-1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP-1 and CML was increased, but phospho-VEGFR-2 staining was decreased in the aortic endothelium of streptozotocin-induced and high-fat diet-induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP-1-regulated VEGFR-2 dephosphorylation through NADPH oxidase-derived ROS is involved in the CML-triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications.

Object Mobilization of hematopoietic progenitor cells (HPCs) from bone marrow involved in the process of peripheral nerve regeneration occurs mostly through deposits of CD34+ cells. Treadmill exercise, with either differing intensity or duration, has been shown to increase axon regeneration and sprouting, but the effect of mobilization of HPCs on peripheral nerve regeneration due to treadmill exercise has not yet been elucidated. Methods Peripheral nerve injury was induced in Sprague-Dawley rats by crushing the left sciatic nerve using a vessel clamp. The animals were categorized into 2 groups: those with and without treadmill exercise (20 m/min for 60 minutes per day for 7 days). Cytospin and flow cytometry were used to determine bone marrow progenitor cell density and distribution. Neurobehavioral analysis, electrophysiological study, and regeneration marker expression were investigated at 1 and 3 weeks after exercise. The accumulation of HPCs, immune cells, and angiogenesis factors in injured nerves was determined. A separate chimeric mice study was conducted to assess CD34+ cell distribution according to treadmill exercise group. Results Treadmill exercise significantly promoted nerve regeneration. Increased Schwann cell proliferation, increased neurofilament expression, and decreased Schwann cell apoptosis were observed 7 days after treadmill exercise. Elevated expression of S100 and Luxol fast blue, as well as decreased numbers of vacuoles, were identified in the crushed nerve 3 weeks after treadmill exercise. Significantly increased numbers of mononuclear cells, particularly CD34+ cells, were induced in bone marrow after treadmill exercise. The deposition of CD34+ cells was abolished by bone marrow irradiation. In addition, deposits of CD34+ cells in crushed nerves paralleled the elevated expressions of von Willebrand factor, isolectin B4, and vascular endothelial growth factor. Conclusions Bone marrow HPCs, especially CD34+ cells, were able to be mobilized by low-intensity treadmill exercise, and this effect paralleled the significant expression of angiogenesis factors. Treadmill exercise stimulation of HPC mobilization during peripheral nerve regeneration could be used as a therapy in human beings.

Bile duct obstruction and subsequent cholestasis are associated with hepatocellular injury, cholangiocyte proliferation, stellate cell activation, Kupffer cell activation, oxidative stress, inflammation and fibrosis. Docosahexaenoic acid (DHA) is an essential polyunsaturated fatty acid that has been shown to possess health beneficial effects, including hepatoprotection. However, the molecular mechanism of DHA-mediated hepatoprotection is not fully understood. In the present study, we report the protective effect of DHA on cholestatic liver injury. Cholestasis was produced by bile duct ligation (BDL) in male Sprague–Dawley rats for 3 weeks. Daily administration of DHA was started 2 weeks before injury and lasted for 5 weeks. In comparison with the control group, the BDL group showed hepatic damage as evidenced by histological changes and elevation in serum biochemicals, ductular reaction, fibrosis, inflammation and oxidative stress. These pathophysiological changes were attenuated by chronic DHA supplementation. DHA alleviated BDL-induced transforming growth factor beta-1 (TGF-β1), intereukin-1beta, connective tissue growth factor and collagen expression. The anti-fibrotic effect of DHA was accompanied by reductions in α-smooth muscle actin-positive matrix-producing cells and Smad 2/3 activity critical to the fibrogenic potential of TGF-β1. DHA also attenuated BDL-induced leukocyte accumulation and nuclear factor-κB (NF-κB) activation. Further studies demonstrated an inhibitory effect of DHA on redox-sensitive intracellular signaling molecule extracellular signal-regulated kinase (ERK). Taken together, the hepatoprotective, anti-inflammatory and anti-fibrotic effects of DHA seem to be multifactorial. The beneficial effects of chronic DHA supplementation are associated with anti-oxidative and anti-inflammatory potential as well as down-regulation of NF-κB and transforming growth factor beta/Smad signaling probably via interference with ERK activation.

Object Increased integration of CD34+ cells in injured nerve significantly promotes nerve regeneration, but this effect can be counteracted by limited migration and short survival of CD34+ cells. SDF-1α and its receptor mediate the recruitment of CD34+ cells involved in the repair mechanism of several neurological diseases. In this study, the authors investigate the potentiation of CD34+ cell recruitment triggered by SDF-1α and the involvement of CD34+ cells in peripheral nerve regeneration. Methods Peripheral nerve injury was induced in 147 Sprague-Dawley rats by crushing the left sciatic nerve with a vessel clamp. The animals were allocated to 3 groups: Group 1, crush injury (controls); Group 2, crush injury and local application of SDF-1α recombinant proteins; and Group 3, crush injury and local application of SDF-1α antibody. Electrophysiological studies and assessment of regeneration markers were conducted at 4 weeks after injury; neurobehavioral studies were conducted at 1, 2, 3, and 4 weeks after injury. The expression of SDF-1α, accumulation of CD34+ cells, immune cells, and angiogenesis factors in injured nerves were evaluated at 1, 3, 7, 10, 14, 21, and 28 days after injury. Results Application of SDF-1α increased the migration of CD34+ cells in vitro, and this effect was dose dependent. Crush injury induced the expression of SDF-1α, with a peak of 10–14 days postinjury, and this increased expression of SDF-1α paralleled the deposition of CD34+ cells, expression of VEGF, and expression of neurofilament. These effects were further enhanced by the administration of SDF-1α recombinant protein and abolished by administration of SDF-1α antibody. Furthermore, these effects were consistent with improvement in measures of neurological function such as sciatic function index, electrophysiological parameters, muscle weight, and myelination of regenerative nerve. Conclusions Expression of SDF-1α facilitates recruitment of CD34+ cells in peripheral nerve injury. The increased deposition of CD34+ cells paralleled significant expression of angiogenesis factors and was consistent with improvement of neurological function. Utilization of SDF-1α for enhancing the recruitment of CD34+ cells involved in peripheral nerve regeneration may be considered as an alternative treatment strategy in peripheral nerve disorders.

Zinc overload is known to cause the death of neural cells. Although the activation of extracellular signal-regulated kinase (ERK) and cytosolic phospholipase A(2) (cPLA(2)) have been implicated in zinc-induced astrocyte death, the detailed mechanisms of their activation and upstream regulatory cascades are incompletely understood. Here, we report that protein kinase C (PKC)- and Src-related Ras/Raf/ERK cascades and ERK-associated cPLA(2) participate in astrocyte death caused by ZnCl(2). Sustained exposure to ZnCl(2) caused damage to astrocytes in a time- and concentration-dependent manner. The cell death caused by ZnCl(2) was accompanied by increased reactive oxygen species (ROS) generation, PKC-α membrane association, Src phosphorylation, Ras membrane association, Raf phosphorylation, ERK phosphorylation, and cPLA(2) activation, and decreased protein phosphatase activity. Pharmacological studies revealed that these activations/inactivations all contributed to ZnCl(2)-induced astrocyte death. ROS, such as superoxide, appear to be a key trigger in response to ZnCl(2) treatment in astrocytes because of the attenuations in protein phosphatase inhibition, signaling activation, and cell death by antioxidant treatments. Mechanistic studies had suggested that ROS/PKC-α/Ras/Raf/ERK and ROS/Src/Ras/Raf/ERK were potential signals linking zinc and cPLA(2). These observations indicated that ROS/PKC-α/Ras/Raf/ERK and ROS/Src/Ras/Raf/ERK signaling and cPLA(2) were actively involved in zinc-induced astrocyte damage.

Numerous studies have demonstrated that the disease pathogenesis of Japanese encephalitis involves cytokine-mediated bystander damage. The mechanisms involved in the regulation of Japanese encephalitis virus (JEV)-induced cytokine expression are not well defined but rely mainly on the tight regulation of transcription factor NF-κB. The Src-family tyrosine kinases participate in diversity of cellular signaling and have been demonstrated in JEV-infected cells. A direct link leading from Src activation to NF-κB activation in JEV-induced cytokine expression is incompletely understood. Here, we report that Src-related Ras/Raf/extracellular signal-regulated kinase (ERK) cascades participate in NF-κB activation and consequent tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) expression in JEV-infected microglia. Central microglia were capable of producing TNF-α and IL-1β after JEV infection. However, JEV infection had a negligible effect on triggering TNF-α and IL-1β production by neurons and astrocytes. The expression of TNF-α and IL-1β caused by JEV was accompanied by increased Src phosphorylation, Ras membrane association, Raf serine-338 as well as tyrosine-340 phosphorylation, ERK phosphorylation, NF-κB DNA binding activity, and decreased Raf serine-259 phosphorylation. Pharmacological studies revealed that the integrity of lipid raft and the activation of Src, Ras, Raf, ERK, and NF-κB all contributed to JEV-induced TNF-α and IL-1β expression. Pharmacological and biochemical studies further suggested that Src, upon activation, might transmit signals to the Raf/ERK cascades via Ras-dependent and -independent mechanisms that in turn might lead to NF-κB activation. Overall, our results show that the lipid raft might play a role in mediating JEV-initiated Src/Ras/Raf/ERK/NF-κB signaling and TNF-α/IL-1β expression in microglia.

Infection with Japanese encephalitis virus (JEV) causes neuroinfection and neuroinflammation characterized by profound neuronal destruction/dysfunction, concomitant microgliosis/astrogliosis, and production of various molecules that initiate the recruitment of immune cells to the sites of infection. Previously, we reported that glial cells expressed RANTES (regulated upon activation, normal T cell expressed and secreted) with chemotactic activity in response to JEV infection. In this study, we further demonstrated that JEV-infected microglia had an additional activity in regulating RANTES production. Both astrocytes and microglia responded to JEV infection by releasing RANTES through a process likely related to viral replication. Independent of infectious virus, supernatants of JEV-infected microglia, but not JEV-infected astrocytes, caused additional RANTES production from astrocytes. Antibody neutralization studies suggested the potential involvement of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in mediating additional RANTES production. Treatment of astrocyte cultures with TNF-α and IL-1β caused activation of several signaling molecules and transcription factors crucial to RANTES gene expression, including reactive oxygen species, extracellular signal-regulated kinase, NF-κB, and NF-IL6, increased RANTES gene promoter activity, and provoked RANTES production. As with RANTES, neutralization of bioactive TNF-α and IL-1β caused an attenuation of chemotactic activity from supernatants of mixed glia containing astrocytes and microglia during the course of JEV infection. In conclusion, TNF-α and IL-1β produced by JEV-infected microglia might trigger another mechanism which induces a secondary wave of RANTES gene expression by activating astrocytes. The released RANTES from glial cells might play a role in the recruitment of immune cells during JEV infection.

Traumatic brain injury (TBI) results in neurological dysfunction and death through primary or secondary mechanisms. Here, we evaluated the effect of osmotic pump delivery of granulocyte colony-stimulating factor (G-CSF) on the histopathology and motor function recovery of rats after experimental TBI.Sprague-Dawley rats were used as experimental model by fluid percussion device to cause brain injury on the motor cortex area. The rats were simultaneously subjected to TBI and were implanted of min-osmotic pump containing recombinant human G-CSF (300 μg/700 μl) via intraperitoneal injection. Motor function was assessed by rotarod test. 5-bromo-2'-deoxyuridine (BrdU) was used to label the proliferating cells and their differentiation was evaluated by histology and immunohistochemistry.The G-CSF group showed significantly better motor function recovery than the control group, and the effect lasted up to 14 days after TBI. Moreover, the G-CSF group exhibited a greater increase in the number of BrdU-positive cells compared with the control group. The G-CSF group also had a significantly higher number of DCX-positive cells in the ipsilateral subventricular zone (SVZ) than the control group.These data suggest that the beneficial effect of delivering G-CSF via an osmotic pump may improve the motor function and enhance neurogenesis in the SVZ of the injured brain.

Zinc and cytosolic phospholipase A(2) (cPLA(2)) have been implicated in the death of neural cells and the pathogenesis of ischemia, and hyperglycemia is a potential augmenting factor. However, their potential crosstalk and/or interaction in mediating cell damage have not yet been fully elucidated. Here, we report that a potential link between cPLA(2) activation and zinc-induced astrocyte damage involving reactive oxygen species (ROS)/protein kinase C-α (PKC-α)/extracellular signal-regulated kinase (ERK) signaling and glucose is able to increase zinc uptake and potentiate zinc-induced alterations and astrocyte damage. The cell death caused by ZnCl(2) was accompanied by increased ROS generation, PKC-α membrane translocation, ERK phosphorylation, and cPLA(2) phosphorylation and activity. Pharmacological studies revealed that these activations contributed to ZnCl(2)-induced astrocyte death. Mechanistic studies had suggested that ROS/PKC-α/ERK was a potential signal linking zinc and cPLA(2). Glucose increased zinc uptake and potentiated ZnCl(2)-induced alterations and astrocyte death. These observations indicated that ROS/PKC-α/ERK signaling and cPLA(2) were actively involved in zinc-induced astrocyte damage, and suggested zinc was a potential downstream effector in hyperglycemia-aggravated astrocyte injury.

Interleukin 13 (IL-13) has been shown to induce the death of activated microglia. We observed that IL-13, but not IL-4 or IL-10, significantly enhanced endoplasmic reticulum (ER) stress induction, apoptosis and death in microglia activated by lipopolysaccharide (LPS). IL-13 enhanced ER stress-regulated calpain activation and calpain-II expression in LPS-activated microglia. Calpain-II siRNA effectively reversed the IL-13 + LPS-activated caspase-12 activation. Expression of heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) was also increased in activated microglia, and this was effectively blocked by IL-13 and recombinant calpain. Both HO-1 inhibitor and PPAR-gamma antagonist augmented, but calpain inhibitor and PPAR-gamma agonists reversed, apoptosis induction in activated microglia. Transfection of PPAR-gamma siRNA effectively inhibited HO-1 protein expression in activated microglia. LPS stimulated transcriptional activation of HO-1 via an increase in PPAR-gamma DNA binding activity, which was reversed by IL-13. These results indicate that an ER stress-related calpain-down-regulated PPAR-gamma/HO-1 pathway is involved in the IL-13-enhanced activated death of microglia.

Granulocyte colony-stimulating factor (G-CSF) demonstrates neuroprotective effects through different mechanisms, including mobilization of bone marrow cells. However, the influence of G-CSF-mediated mobilization of bone marrow-derived cells on injured sciatic nerves remains to be elucidated. The administration of G-CSF promoted a short-term functional recovery 7 days after crush injury in sciatic nerves. A double-immunofluorescence study using green fluorescent protein-chimeric mice revealed that bone marrow-derived CD34+ cells were predominantly mobilized and migrated into injured nerves after G-CSF treatment. G-CSF-mediated beneficial effects against sciatic nerve injury were associated with increased CD34+ cell deposition, vascular endothelial growth factor (VEGF) expression, and vascularization/angiogenesis as well as decreased CD68+ cell accumulation. However, cell differentiation and VEGF expression were not demonstrated in deposited cells. The results suggest that the promotion of short-term functional recovery in sciatic nerve crush injury by G-CSF involves a paracrine modulatory effect and a bone marrow-derived CD34+ cell mobilizing effect.

Granulocyte colony-stimulating factor (G-CSF) inhibits programmed cell death and stimulates neuronal progenitor differentiation. Neuronal stem cells transplanted into injured spinal cord can survive, differentiating into astroglia and oligodendroglia, and supporting axon growth and myelination. Herein, we evaluate the combined effects of G-CSF and neuronal stem cells on spinal cord injury. For 40 Sprague-Dawley rats (n=10 in each group) transverse spinal cord resections at the T8-9 level were carried out, leaving an approximately 2-mm gap between the distal and proximal ends of the cord. Neuronal stem cells embedded in fibrin glue treated with or without G-CSF (50 microg/kg x 5 days) (groups III and IV) or fibrin glue with or without G-CSF (50 microg/kg x 5 days) (groups I and II) were transplanted into the gap in the injured spinal cord. Spinal cord regeneration was assessed using a clinical locomotor rating scale scores and electrophysiological, histological and immunohistochemical analysis 3 months after injury. Regeneration was more advanced in group IV than in groups III or II according to the clinical motor score, motor evoked potential, and conduction latency. Most advanced cord regeneration across the gap was observed in group IV rats. Higher densities of bromodeoxyuridine in the injured area and higher expression levels of Neu-N and MAP-2 over the distal end of the injured spinal cord were observed in group IV compared with groups II or III, but there was no significant difference in expression of glial fibrillary acid protein. This synergy between G-CSF and neuronal stem cells may be due to increased proliferation of progenitor cells in the injured area and increased expression of neuronal stem cell markers extrinsically or intrinsically in the distal end of injured cord.

Autogenous iliac crest bone is the gold standard for graft material in cervical spinal fusion, but a high incidence of donor site morbidity has been reported. Therefore, to achieve a better fusion rate and decrease the rate of donor site morbidity, we used a novel method whereby hollow bone cement filled with impacted cancellous bone is used as a substitute for bone graft in cervical interbody fusion. From 2003 to 2004, 21 patients with cervical spinal disorders who were treated using this method were included in this study. Fourteen patients underwent single-level grafts and seven underwent two-level grafts. Evaluation included a monthly clinical and X-ray examination for the first 3 months, and then follow-up every 3 months thereafter. Multiple-slice computed tomography (CT) scan with reconstruction to evaluate the viability of the bone graft was performed when evidence of bone fusion was found on X-ray. The mean age of the patients was 59 years (range 27-79). The mean follow-up period was 19 months (13-24 months). Evidence of impacted cancellous bone bridging the adjacent vertebral body was observed in all patients at the 6-month follow-up based on X-rays and reconstructive CT scans. No severe donor site morbidity occurred. One patient experienced hardware failure due to screw fracture, but a reconstructive CT scan revealed well-bridged cancellous bone between the vertebral bodies. Hollow bone cement filled with impacted cancellous bone could be an alternative material for cervical spine interbody fusion. Using this method, we found not only satisfactory growth of cancellous bone in the holes of the bone cement, but also low morbidity in the donor site. However, for this method, the long-term stability, potential complications, and the necessity of instrumentation all require further investigation.

Background Axon degeneration leads to cytoskeletal disassembly, metabolism imbalance, and mitochondrial dysfunction during neurodegeneration or nerve injury. Objective In this study, we assess the possibility of mitigating axon degeneration by local injection of mitochondria in a crushed sciatic nerve. Methods Sciatic nerve explants cocultured with mitochondria were assessed for the optimal dosage in local injection and nerve regeneration potential. The left sciatic nerve was crushed in Sprague-Dawley rats and then local injection of mitochondria into the distal end of the injured nerve was conducted for further assessment. Results Mitochondrial coculture attenuated cytoskeletal loss and oxidative stress in isolated nerve explants. In Vivo analyses also showed that mitochondrial transplantation improved animal neurobehaviors, electrophysiology of nerve conduction, and muscle activities. Mitochondria injection significantly attenuated the oxidative stress and increased the expression of neurotrophic factors both in injured nerves and denervated muscles, as well as restored muscular integrity, and increased the pool of muscular progenitor cells and total muscle weight. Conclusion Mitochondria injection can protect injured nerves from axonal degeneration both in Vitro and in Vivo. This improvement was accompanied with the expression of neurotrophic factors as well as the reduction of oxidative stress, which may account for the functional recovery of both injured nerves and denervated muscles.

Object.This retrospective review was conducted to determine the surgical treatment principle for rheumatoid arthritis (RA) patients with atlantoaxial instability (AAI).Methods.Thirteen patients with AAI, including 5 RA patients, received preoperative computed tomography- (CT-) based image-guided navigation system (IGS) in C1 lateral mass-C2 pedicle screw-rod system fixation (LC1-PC2 fixation). These 13 patients were analyzed for 52 screws inserted into C1 and C2. We defined these patients as non-RA group (8 patients, 32 screws) and RA group (5 patients, 20 screws). The neurological status for RA group was evaluated using the Ranawat classification. The causes of AAI, surgical indications, complications, surgical method revolution, and CT-based navigation application are discussed.Results.None of the 13 patients expressed neurological function deterioration. The non-RA group screw accuracy was 100%. In the RA group, 1 RA patient developed left C2 screw loosening at 1+months after operation due to screw malposition. The screw accuracy for this group was 95%.Conclusions.Higher intraoperative surgical complication rate was described in RA patients. Preoperative CT-based IGS in LC1-PC2 fixation can provide good neurological function and screw accuracy results. However, for higher screw accuracy in RA patients, intraoperative CT-based IGS application may be considered.

Purpose The skeletal muscle develops various degrees of atrophy and metabolic dysfunction following nerve injury. Neurotrophic factors are essential for muscle regeneration. Human amniotic fluid derived stem cells (AFS) have the potential to secrete various neurotrophic factors necessary for nerve regeneration. In the present study, we assess the outcome of neurological function by intramuscular injection of AFS in a muscle denervation and nerve anastomosis model. Materials and Methods Seventy two Sprague-Dawley rats weighing 200–250 gm were enrolled in this study. Muscle denervation model was conducted by transverse resection of a sciatic nerve with the proximal end sutured into the gluteal muscle. The nerve anastomosis model was performed by transverse resection of the sciatic nerve followed by four stitches reconnection. These animals were allocated to three groups: control, electrical muscle stimulation, and AFS groups. Results NT-3 (Neurotrophin 3), BDNF (Brain derived neurotrophic factor), CNTF (Ciliary neurotrophic factor), and GDNF (Glia cell line derived neurotrophic factor) were highly expressed in AFS cells and supernatant of culture medium. Intra-muscular injection of AFS exerted significant expression of several neurotrophic factors over the distal end of nerve and denervated muscle. AFS caused high expression of Bcl-2 in denervated muscle with a reciprocal decrease of Bad and Bax. AFS preserved the muscle morphology with high expression of desmin and acetylcholine receptors. Up to two months, AFS produced significant improvement in electrophysiological study and neurological functions such as SFI (sciatic nerve function index) and Catwalk gait analysis. There was also significant preservation of the number of anterior horn cells and increased nerve myelination as well as muscle morphology. Conclusion Intramuscular injection of AFS can protect muscle apoptosis and likely does so through the secretion of various neurotrophic factors. This protection furthermore improves the nerve regeneration in a long term nerve anastomosis model.

Tetramethylpyrazine (TMP) has been used to treat ischemic stroke. However, scientific evidence related to its effectiveness or precise modes of neuroprotective action is largely unclear. This study provides evidence of an alternative target for TMP and sheds light on the mechanism of its physiological benefits. We report a global inhibitory effect of TMP on intracerebral cellular inflammatory response in a rat model of permanent cerebral ischemia. TMP exhibited a neuroprotective effect against ischemic deficits by reduction of behavioral disturbance, brain infarction, and edema. The results of immunohistochemistry, enzymatic assay, Western blot, real-time reverse transcriptase-polymerase chain reaction (RT-PCR), and flow cytometric analysis revealed that TMP reduced the percentages of activated macrophages/microglia and infiltrative lymphocytes, neutrophils, and macrophages and pro-inflammatory cytokine expression after cerebral ischemia. In parallel with these immunosuppressive phenomena, TMP also attenuated the activities of ischemia-induced inflammation-associated signaling molecules and transcription factors. Another finding in this study was that the anti-inflammatory and neuroprotective effects of TMP were accompanied by a further elevated expression of NF-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in ipsilateral neurons and macrophages/microglia after cerebral ischemia. Taken together, our results suggest that both the promotion of endogenous defense capacity and the attenuation of the extent and composition percentage of the major cellular inflammatory responses via targeting of macrophages/microglia by elevating Nrf2/HO-1 expression might actively contribute to TMP-mediated neuroprotection against cerebral ischemia.

The organized neural cells form neural ­networks for receiving, transducing and integrating neural information. In developing embryo, asymmetrical distribution of specific molecules in neural progenitors contributes to neural polarization and initiates the formation of axons and dendrites on cell cycle exit. Axon is responsible for propagating action potential and triggering an electric or chemical output to the contacted cells. This chapter describes the recent findings about the cellular mechanisms of axon initiation and axon elongation in vitro by using isolated hippocampal neurons and embryonic stem cells-derived motoneurons. In addition, the in vivo studies related to the axon specification are emphasized. Environmental cues for stimulating the axon formation and axon guidance are also introduced.

Background A new version of the CatWalk XT system was evaluated as a tool for detecting very subtle alteration in gait based on higher speed sample rate; the system could also demonstrate minor changes in neurological function. In this study, we evaluated the neurological outcome of sciatic nerve injury intervened by local injection of hyaluronic acid. Using the CatWalk XT system, we looked for differences between treated and untreated groups and differences within the same group as a function of time so as to assess the power of the Catwalk XT system for detecting subtle neurological change. Methods Peripheral nerve injury was induced in 36 Sprague–Dawley rats by crushing the left sciatic nerve using a vessel clamp. The animals were randomized into one of two groups: Group I: crush injury as the control; Group II: crush injury and local application with hyaluronic acid. These animals were subjected to neurobehavior assessment, histomorphology evaluation, and electrophysiology study periodically. These data were retrieved for statistical analysis. Results The density of neurofilament and S-100 over the distal end of crushed nerve showed significant differences either in inter-group comparison at various time points or intra-group comparison from 7 to 28 days. Neuronal structure architecture, axon counts, intensity of myelination, electrophysiology, and collagen deposition demonstrate significant differences between the two groups. There was significant difference of SFI and angle of ankle in inter- group analysis from 7 to 28 days, but there were no significant differences in SFI and angle of ankle at time points of 7 and 14 days. In the Cat Walk XT analysis, the intensity, print area, stance duration, and swing duration all showed detectable differences at 7, 14, 21, and 28 days, whereas there were no significant difference at 7 and 14 days with CatWalk 7 testing. In addition, there were no significant differences of step sequence or regularity index between the two versions. Conclusion Hyaluronic acid augmented nerve regeneration as early as 7 days after crush injury. This subtle neurological alteration could be detected through the CatWalk XT gait analysis but not the SFI, angle of ankle, or CatWalk 7 methods.

Currently, the underlying mechanisms and the specific cell types associated with Japanese encephalitis-associated leukocyte trafficking are not understood. Brain microvascular endothelial cells represent a functional barrier and could play key roles in leukocyte central nervous system trafficking. We found that cultured brain microvascular endothelial cells were susceptible to Japanese encephalitis virus (JEV) infection with limited amplification. This type of JEV infection had negligible effects on cell viability and barrier integrity. Instead, JEV-infected endothelial cells attracted more leukocytes adhesion onto surfaces and the supernatants promoted chemotaxis of leukocytes. Infection with JEV was found to elicit the elevated production of intercellular adhesion molecule-1, cytokine-induced neutrophil chemoattractant-1, and regulated-upon-activation normal T-cell expressed and secreted, contributing to the aforementioned leukocyte adhesion and chemotaxis. We further demonstrated that extracellular signal-regulated kinase was a key upstream regulator which stimulated extensive endothelial gene induction by up-regulating cytosolic phospholipase A₂, NF-κB, and cAMP response element-binding protein via signals involving phosphorylation. These data suggest that JEV infection could activate brain microvascular endothelial cells and modify their characteristics without compromising the barrier integrity, making them favorable for the recruitment and adhesion of circulating leukocytes, thereby together with other unidentified barrier-disrupting mechanisms contributing to Japanese encephalitis and associated neuroinflammation.

The substantial activation of microglia in Japanese encephalitis virus (JEV)-induced Japanese encephalitis found in numerous studies demonstrates that the disease pathogenesis involves bystander damage caused by microglia-released mediators. Previously, we reported that microglia synthesized and secreted bioactive mediators with neurotoxic potential into the cultured supernatants in response to JEV infection. In this study, we found that the supernatants of JEV-infected microglia caused MK801-inhibitable neuronal damage in cultured neurons, indicating a potential excitotoxic mechanism. Infection with JEV was found to elicit the extracellular glutamate accumulation from microglia but not from neuron and astrocyte cultures. The glutaminase inhibitor 6-diazo-5-oxo-L-norleucine, cystine/glutamate antiporter inhibitor α-aminoadipic acid, and the gap junction inhibitor carbenoxolone reduced JEV infection-induced microglial glutamate release and neurotoxicity. We further demonstrated that tumor necrosis factor-alpha (TNF-α) was a key cytokine which stimulated extensive microglial glutamate release by up-regulating glutaminase expression via signals involving protein kinase C, cAMP responsive element-binding protein, and CAAT-enhancer-binding protein-beta. Although the elevated expression of excitatory amino acid transporter 1 and 2 was observed in JEV-infected cells, the glutamate uptake activity was significantly inhibited by TNF-α. The JEV infection-induced alterations, such as the extracellular glutamate release and glutamate-mediated excitoneurotoxicity, also occurred in neuron/glia cultures. Our findings support a potential link between neuroinflammation and the development of excitotoxic neuronal injury in Japanese encephalitis. The link between neuroinflammation and excitotoxic death may involve a mechanism in which TNF-α released by microglia plays a facilitory role in glutamate excitoneurotoxicity via up-regulation of glutamate synthesis and down-regulation of glutamate uptake. © 2011 Wiley Periodicals, Inc.

Magnesium (Mg) supplements have been shown to significantly improve functional recovery in various neurological disorders. The essential benefits of Mg supplementation in peripheral nerve disorders have not been elucidated yet. The effect and mechanism of Mg supplementation on a sciatic nerve crush injury model was investigated. Sciatic nerve injury was induced in mice by crushing the left sciatic nerve. Mice were randomly divided into three groups with low-, basal- or high-Mg diets (corresponding to 10, 100 or 200% Mg of the basal diet). Neurobehavioral, electrophysiological and regeneration marker studies were conducted to explore nerve regeneration. First, a high Mg diet significantly increased plasma and nerve tissue Mg concentrations. In addition, Mg supplementation improved neurobehavioral, electrophysiological functions, enhanced regeneration marker, and reduced deposits of inflammatory cells as well as expression of inflammatory cytokines. Furthermore, reduced Schwann cell apoptosis was in line with the significant expression of bcl-2, bcl-X(L) and down-regulated expression of active caspase-3 and cytochrome C. In summary, improved neurological function recovery and enhanced nerve regeneration were found in mice with a sciatic nerve injury that were fed a high- Mg diet, and Schwann cells may have been rescued from apoptosis by the suppression of inflammatory responses.

The developing neural cell must form a highly organized architecture to properly receive and transmit nerve signals. Neural formation from embryonic stem (ES) cells provides a novel system for studying axonogenesis, which are orchestrated by polarity-regulating molecules. Here the ES-derived motoneurons, identified by HB9 promoter-driven green fluorescent protein (GFP) expression, showed characteristics of motoneuron-specific gene expression. In the majority of motoneurons, one of the bilateral neurites developed into an axon that featured with axonal markers, including Tau 1, vesicle acetylcholine transporter, and synaptophysin. Interestingly, one third of the motoneurons developed bi-axonal processes but no multiple axonal GFP cell was found. The neuronal polarity-regulating proteins, including the phosphorylated AKT and ERK, were compartmentalized into both of the bilateral axonal tips. Importantly, this aberrant axon morphology was still present after the engraftment of GFP+ neurons into the spinal cord, suggesting that even a mature neural environment fails to provide a proper niche to guide normal axon formation. These findings underscore the necessity for evaluating the morphogenesis and functionality of neurons before the clinical trials using ES or somatic stem cells.

Clearance of fibrin and associated inflammatory cytokines by tissue-type plasminogen activator (t-PA) is related to improved regeneration in neurological disorder. The biological activity of fermented soybean (natto) is very similar to that of t-PA. We investigated the effect of the dietary supplement of natto on peripheral nerve regeneration. The peripheral nerve injury was produced by crushing the left sciatic nerve with a vessel clamp in Sprague-Dawley rats. The injured animals were fed orally either with saline or natto (16 mg/day) for seven consecutive days after injury. Increased functional outcome such as sciatic nerve functional index, angle of ankle, compound muscle action potential and conduction latency were observed in natto-treated group. Histological examination demonstrated that natto treatment improved injury-induced vacuole formation, S-100 and vessel immunoreactivities and axon loss. Oral intake of natto prolonged prothrombin time and reduced fibrinogen but did not change activated partial thromboplastin time and bleeding time. Furthermore, natto decreased injury-induced fibrin deposition, indicating a tolerant fibrinolytic activity. The treatment of natto significantly improved injury-induced disruption of blood-nerve barrier and loss of matrix component such as laminin and fibronectin. Sciatic nerve crush injury induced elevation of tumor necrosis factor alpha (TNF-alpha) production and caused apoptosis. The increased production of TNF-alpha and apoptosis were attenuated by natto treatment. These findings indicate that oral intake of natto has the potential to augment regeneration in peripheral nerve injury, possibly mediated by the clearance of fibrin and decreased production of TNF-alpha.

Background Anastomosis of the nerve especially at narrow surgical field and presence of surgical tension is not easily accessible. DuraSeal demonstrates strong adhesive power without producing neurotoxicity. Herein, we evaluate the possibility of DuraSeal as a substitute in the repair of sciatic nerve gap injury. Materials and Methods The nerve gap model was constructed by excising the sciatic nerve (5 mm in length) in Sprague Dawley rats leaving a 5 mm nerve defect between nerve stumps. Animals were categorized into four groups: Group I: no treatment; Group II: 4 stitches suture; Group III: nerve approximation fixed by tissue glue; Group IV: nerve approximation fixed by DuraSeal. The motor function assessment included the CatWalk and SFI as well as electrophysiological studies. Nerve continuity and regeneration was examined at 1 and 8 wk after injury. The inflammatory cells, Schwann cell apoptosis, and Schwann cell proliferation were also investigated 1 wk after injury. Results The achievement of nerve continuity and myelination by DuraSeal approached that of suture demonstrated by crystal violet and Luxol Fast Blue staining at 1 and 8 wk, respectively. Motor function and electrophysiological parameters were restored in DuraSeal and suture group. Early expression of neurofilament and bromodeoxyuridine (BrdU) was also observed in these two groups. There was no statistically significant difference in deposits of macrophages and neutrophil cells or cell apoptosis among these four groups. Conclusions DuraSeal achieved the same nerve regeneration compared with that of suture and produced better regeneration than that of the tissue glue or without any treatment. The accomplishment of nerve regeneration and continuity without causing neurotoxicity justifies using DuraSeal as a ligature in the anastomosis of nerve gap injury.

Evidence suggests that inactivation of cell-damaging mechanisms and/or activation of cell-survival mechanisms may provide effective preventive or therapeutic interventions to reduce cerebral ischemia/reperfusion (I/R) injuries. Docosahexaenoic acid (DHA) is an essential polyunsaturated fatty acid in the central nervous system that has been shown to possess neuroprotective effects. We examined whether different preadministrative protocols of DHA have effects on brain injury after focal cerebral I/R and investigated the potential neuroactive mechanisms involved. Sprague–Dawley rats were intraperitoneally pretreated with DHA once 1 h or 3 days being subjected to focal cerebral I/R or daily for 6 weeks before being subjected to focal cerebral I/R. Reduction of brain infarction was found in all three DHA-pretreated groups. The beneficial effect of DHA on the treatment groups was accompanied by decreases in blood–brain barrier disruption, brain edema, malondialdehyde (MDA) production, inflammatory cell infiltration, interleukin-6 (IL-6) expression and caspase-3 activity. Elevation of antioxidative capacity, as evidenced by decreased MDA level and increased superoxide dismutase activity and glutathione level, was detected only in the chronic daily-administration group. The two single-administration groups showed increased phosphorylation of extracellular-signal-regulated kinase (ERK). Elevation of Bcl-2 expression was detected in the chronic daily-administration and 3-day-administration groups. In vitro study demonstrated that DHA attenuated IL-6 production from stimulated glial cells involving nuclear factor κB inactivation. Therefore, the data suggest that the neuroprotective mechanisms of DHA pretreatment are, in part, mediated by attenuating damaging mechanisms through reduction of cytotoxic factor production and by strengthening survival mechanisms through ERK-mediated and/or Bcl-2-mediated prosurvival cascade.

The time window in the treatment of ischemic stroke with tissue plasminogen activator (tPA) is narrow, arbitrarily within 3 hours after the onset of symptom. Hemorrhagic transformation resulting from cerebral ischemia may be related to damage of the microvascular basal lamina of the brain, which may in turn cause microvascular fibrin deposition and aggravate cerebral ischemia. Here, we investigated the effect of tPA on the microvascular tissue changes during cerebral ischemia/reperfusion. Sprague-Dawley rats were subjected to focal cerebral ischemia by ligation of the right middle cerebral artery and bilateral common carotid arteries for 90 minutes. Sixty minutes after the onset of ischemia, escalated dosages of tPA from 2.5 to 10 mg/kg or saline were intravenously infused for 60 minutes. Twenty-four hours after reperfusion, the animals were allowed to be killed for examination. Low dosage of tPA (2.5-7.5 mg/kg) reduced post-ischemic brain infarction, suppressed metalloproteinase 2 (MMP-2) activity and restored blood-brain barrier (BBB) integrity. In contrast, high dose of tPA (10 mg/kg) aggravated brain infarction, increased MMP-2 activity and exacerbated BBB disruption. Cerebral ischemia/reperfusion decreased the immunoreactivity of both collagen type IV- and laminin-positive microvessels, whereas the low dosage of tPA (2.5-7.5 mg/kg) attenuated the reduction. When these molecules in whole cortical tissues were analysed, tPA dosage-dependently decreased the total content of collagen type IV, laminin and fibronectin. Although the detailed mechanisms regarding the action of tPA are yet to be investigated, our findings demonstrate that the detrimental effect of tPA was mediated, at least in part, through the destruction of the basal lamina in the cerebral microvessels by activating MMP-2.

We report a 21-year-old woman with a penetrating abdominal wound. Injuries of the abdominal aorta and alimentary tract were found during emergency surgery. The patient had a follow-up computed tomography (CT) scan 3 months after surgery. Arterial-phase 16-row multidetector computed tomography (MDCT) showed a suspicious dilated vessel adjacent to the repaired aorta on 5-mm transverse images. A fistula between a lumbar artery and the inferior vena cava was clearly demonstrated on images reformatted with two- (2D) and three-dimensional (3D) techniques. The patient suffered from symptoms of high-output heart failure 8 months after surgery.

The occurrence of dural arteriovenous fistulae in children is quite rare. Endovascular embolization is typically the first line treatment. In general, Gamma Knife radiosurgery is used as adjuvant treatment and seldom performed as the first line treatment in children. We report a case of a 27-month-old girl who presented with an initial dural arteriovenous fistula (AVF) located at anterior base of the left middle cranial fossa. She subsequently developed another dural AVF over the left transverse-sigmoid sinus region 2 years later. Both fistulae were successfully obliterated with Gamma Knife radiosurgery.

Objective Amniotic fluid mesenchymal stem cells (MSCs) have the potential to differentiate into neuronal stem cells in vitro. We evaluated using amniotic fluid MSCs to support or enhance the ability of the injured sciatic nerve to cross a nerve gap. Materials and methods We created a 5 mm nerve defect in Sprague Dawley rats. One group received therapy with MSCs embedded into woven oxidised regenerated cellulose gauze (Surgical; Ethicon, Somerville, NJ) and fibrin glue, while a control group received woven Surgicel and fibrin glue only. Evaluation methods included behavioural, electrophysiological and immunohistochemical studies. Results In gait analysis, the angle of the ankles in the treatment and control group were 46.4° (standard deviation [SD] = 15°) and 36° (SD = 8.2°), respectively, which was statistically significant ( p = 0.045). Five of 10 treated rats (50%) demonstrated partial foot movement, while none of the control group had any movement. The percentage amplitude of muscle compound action potential in the experimental group was 43% (SD = 12.5%) compared to 29% (SD = 8.8%) in the control group ( p = 0.038). The conduction latencies in the control and experimental groups was 2.5 ms (SD = 0.45) and 1.7 ms (SD = 0.47), respectively ( p = 0.005). Histological examination demonstrated that 70% of the treatment group achieved a maximum axon diameter percentage across the nerve gap of greater than 50%, compared with 0% in the control group. There were no differences in direction of fibre growth and fibrotic reaction between the two groups. Conclusion Amniotic fluid MSC can augment growth of injured nerve across a nerve gap. This effect may be due to neurotrophic or induction effects of the MSC interacting with Schwann cells. Further study is required to determine the underlying mechanism of this effect.

We report a case brachial plexus neuromuscular hamartoma (choristoma) in a 28-year-old man who complained of numbness of the left hand and forearm for several years. MRI revealed a circumscribed, rounded mass in the left brachial plexus. The patient is well 2 years after surgery, with no neurological deficit.

Attenuation of inflammatory cell deposits and associated cytokines prevented the apoptosis of transplanted stem cells in a sciatic nerve crush injury model. Suppression of inflammatory cytokines by fermented soybean extracts (Natto) was also beneficial to nerve regeneration. In this study, the effect of Natto on transplanted human amniotic fluid mesenchymal stem cells (AFS) was evaluated. Peripheral nerve injury was induced in SD rats by crushing a sciatic nerve using a vessel clamp. Animals were categorized into four groups: Group I: no treatment; Group II: fed with Natto (16 mg/day for 7 consecutive days); Group III: AFS embedded in fibrin glue; Group IV: Combination of group II and III therapy. Transplanted AFS and Schwann cell apoptosis, inflammatory cell deposits and associated cytokines, motor function, and nerve regeneration were evaluated 7 or 28 days after injury. The deterioration of neurological function was attenuated by AFS, Natto, or the combined therapy. The combined therapy caused the most significantly beneficial effects. Administration of Natto suppressed the inflammatory responses and correlated with decreased AFS and Schwann cell apoptosis. The decreased AFS apoptosis was in line with neurological improvement such as expression of early regeneration marker of neurofilament and late markers of S-100 and decreased vacuole formation. Administration of either AFS, or Natto, or combined therapy augmented the nerve regeneration. In conclusion, administration of Natto may rescue the AFS and Schwann cells from apoptosis by suppressing the macrophage deposits, associated inflammatory cytokines, and fibrin deposits.