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    11 July 2014, Volume 9 Issue 13 Previous Issue    Next Issue
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    Stem cell therapy for central nerve system injuries: glial cells hold the key
    Li Xiao, Chikako Saiki, Ryoji Ide
    2014, 9 (13):  1253-1260.  doi: 10.4103/1673-5374.137570
    Abstract ( 277 )   PDF (755KB) ( 729 )   Save

    Mammalian adult central nerve system (CNS) injuries are devastating because of the intrinsic difficulties for effective neuronal regeneration. The greatest problem to be overcome for CNS recovery is the poor regeneration of neurons and myelin-forming cells, oligodendrocytes. Endogenous neural progenitors and transplanted exogenous neuronal stem cells can be the source for neuronal regeneration. However, because of the harsh local microenvironment, they usually have very low efficacy for functional neural regeneration which cannot compensate for the loss of neurons and oligodendrocytes. Glial cells (including astrocytes, microglia, oligodendrocytes and NG2 glia) are the majority of cells in CNS that provide support and protection for neurons. Inside the local microenvironment, glial cells largely influence local and transplanted neural stem cells survival and fates. This review critically analyzes current finding of the roles of glial cells in CNS regeneration, and highlights strategies for regulating glial cells’ behavior to create a permissive microenvironment for neuronal stem cells.

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    Adult myelination: wrapping up neuronal plasticity
    Megan O’Rourke, Robert Gasperini, Kaylene M. Young
    2014, 9 (13):  1261-1264.  doi: 10.4103/1673-5374.137571
    Abstract ( 290 )   PDF (184KB) ( 729 )   Save

    The adult CNS is remarkably adaptable – it retains the ability to generate and integrate new cells, and remodel pre-existing circuits. Intense research over the last 25 years has provided critical insight into the cell generation and differentiation potential of endogenous neural stem and progenitor cells, and has described three core CNS plasticity mechanisms. While we are still a long way from fully understanding how neural plasticity is regulated from the level of the individual cell, through to the level of the neural network, there is growing evidence to support the idea that neurogenesis, synaptogenesis and myelin remodelling dynamically and co-operatively alter the structure and function of neural circuits in the adult CNS.
    Herein Dr. Kaylene M Young comes from University of Tasmania, Australia highlights the potential for interaction between key CNS plasticity mechanisms. While new genetic and imaging tools have led to major advances in our understanding of each plasticity mechanism separately, much work remains to be done to determine whether synaptic plasticity, neurogenesis and myelin plasticity operate in a coordinated and synergistic manner, as we have proposed, to regulate neural networks and support functions such as learning and memory, which span multiple CNS regions.

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    Beyond taxol: microtubule-based strategies for promoting nerve regeneration after injury
    Peter W. Baas
    2014, 9 (13):  1265-1266.  doi: 10.4103/1673-5374.137572
    Abstract ( 221 )   PDF (548KB) ( 643 )   Save

    After injury, damaged axons have the capacity to regenerate, but the regenerative capacity of the axon, particularly axons of the central nervous system, is quite limited. This is because the damaged axons tend to retract, because they encounter obstacles such as scar tissue and inhibitory molecules, and because their growth rates simply do not match those of a juvenile axon. Prof. Peter W. Baas from Drexel University, USA focus on microtubules as among the most important factors in encouraging injured adult axons to regenerate. Microtubules are hollow polymeric filaments composed of tubulin subunits that provide structural support for the axon. In addition to their structural role, microtubules are an important substrate for many of the molecular motor proteins responsible for intracellular transport. Microtubules are intrinsically polar structures, with their "plus" ends favored for assembly over their "minus" ends. Molecular motor proteins interact with cargo such as membranous organelles that are transported in conjunction with the motor. In the axon, the microtubules are aligned into a paraxial array with the plus ends of the microtubules directed away from the cell body, thus establishing the directionality with which different motors convey their cargo. Microtubules gather together and funnel into the hillock region of the axon and then splay apart again at sites of branch formation and within the growth cone at the tip of the elongating axon. Microtubules are relevant to axonal growth and regeneration for reasons related to all of these factors. Additionally, it appears that the dynamic properties of microtubules are critically important especially in the distal tip of the axon, for the capacity of the axon to form a viable growth cone, to turn properly in response to external cues, and to grow with the vitality typical of the developing nervous system.

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    Neuroprotective effect of the traditional Chinese herbal formula Tongxinluo: a PET imaging study in rats
    Xiao Cheng, Haoxuan Luo, Lihua Zhou, Lixin Wang, Jingbo Sun, Yan Huang, Enli Luo, Yefeng Cai
    2014, 9 (13):  1267-1274.  doi: 10.4103/1673-5374.137573
    Abstract ( 227 )   PDF (1141KB) ( 761 )   Save

    oprotection. However, there are few positron emission tomography (PET) studies on the neuroprotective effect of Tongxinluo on cerebral ischemia/reperfusion in small animals. In the present study, Tongxinluo superfine powder suspension or its vehicle was administered intragastrically to rats for 5 successive days before middle cerebral artery occlusion. 18F-fluorodeoxyglucose (FDG) small animal PET imaging showed that at 1 and 2 weeks after cerebral ischemia/reperfusion, glucose metabolism in the ischemic area was greater in rats that had received Tongxinluo than in those that had received the vehicle. Nissl staining showed that 2 weeks after cerebral ischemia/reperfusion, there was less neuronal loss in the prefrontal cortex in Tongxinluo-treated rats than in controls. In addition, Tongxinluo-treated animals showed better neurologic function and lower cerebral infarct volume than rats that received the vehicle. These findings suggest that Tongxinluo exhibits neuroprotective effects in cerebral ischemia/reperfusion injury and demonstrates that 18F-FDG small animal PET imaging is a useful tool with which to study the molecular pharmacology of traditional Chinese medicine.

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    Neuroprotective effects of Asiaticoside
    Feng-yan Qi, Le Yang, Zhen Tian, Ming-gao Zhao, Shui-bing Liu, Jia-ze An
    2014, 9 (13):  1275-1282.  doi: 10.4103/1673-5374.137574
    Abstract ( 316 )   PDF (566KB) ( 1062 )   Save

    In the central nervous system, Asiaticoside has been shown to attenuate in vitro neuronal damage caused by exposure to β-amyloid. In vivo studies demonstrated that Asiaticoside could attenuate neurobehavioral, neurochemical and histological changes in transient focal middle cerebral artery occlusion animals. In addition, Asiaticoside showed anxiolytic effects in acute and chronic stress animals. However, its potential neuroprotective properties in glutamate-induced excitotoxicity have not been fully studied. We investigated the neuroprotective effects of Asiaticoside in primary cultured mouse cortical neurons exposed to glutamate-induced excitotoxicity invoked by N-methyl-D-aspartate. Pretreatment with Asiaticoside decreased neuronal cell loss in a concentration-dependent manner and restored changes in expression of apoptotic-related proteins Bcl-2 and Bax. Asiaticoside pretreatment also attenuated the upregulation of NR2B expression, a subunit of N-methyl-D-aspartate receptors, but did not affect expression of NR2A subunits. Additionally, in cultured neurons, Asiaticoside significantly inhibited Ca2+ influx induced by N-methyl-D-aspartate. These experimental findings provide preliminary evidence that during excitotoxicity induced by N-methyl-D-aspartate exposure in cultured cortical neurons, the neuroprotective effects of Asiaticoside are mediated through inhibition of calcium influx. Aside from its anti-oxidant activity, down-regulation of NR2B-containing N-methyl-D-aspartate receptors may be one of the underlying mechanisms in Asiaticoside neuroprotection.

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    Treating Alzheimer’s disease with Yizhijiannao granules by regulating expression of multiple proteins in temporal lobe
    Hong Zhu, Liuyang Luo, Sihang Hu, Keli Dong, Guangcheng Li, Ting Zhang
    2014, 9 (13):  1283-1287.  doi: 10.4103/1673-5374.137575
    Abstract ( 247 )   PDF (446KB) ( 878 )   Save

    Yizhijiannao granules have been shown to improve cognitive function in Alzheimer’s disease patients. The present study sought to explore the mechanisms involved in the cognitive enhancing effects of Yizhijiannao granule. Senescence-accelerated mouse prone 8 mice with learning and memory disorders were intragastrically treated with Yizhijiannao granule for 8 weeks. Mice intragastrically treated with double distilled water for 8 weeks were considered as the control group. 2D gel electrophoresis was used to isolate total protein from the temporal lobe of senescence-accelerated mouse prone 8 mice, and differential protein spots were obtained by mass spectrometry. Thirty-seven differential protein spots were found in the temporal lobe area of both groups. Ten protein spots were identified: high mobility group box 1, dimethylarginine dimethylaminohydrolase-1, neuroglobin, hemoglobin beta adult major chain, peroxiredoxin-6, cofilin-1, flotillin 1, peptidylprolyl isomerase A, voltage-dependent anion channel-2 and chaperonin containing TCP1, and subunit 2. Among other functions, these proteins are separately involved in the regulation of amyloid beta production, oxidative stress, neuroinflammation, regulation of tau phosphorylation, and regulation of neuronal apoptosis. Our results revealed that Yizhijiannao granule can regulate the expression of various proteins in the temporal lobe of senescence-accelerated mouse prone 8 mice, and may be therapeutically beneficial for the treatment of Alzheimer’s disease.

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    Autophagy activation aggravates neuronal injury in the hippocampus of vascular dementia rats
    Bin Liu, Jing Tang, Jinxia Zhang, Shiying Li, Min Yuan, Ruimin Wang
    2014, 9 (13):  1288-1296.  doi: 10.4103/1673-5374.137576
    Abstract ( 200 )   PDF (9219KB) ( 1098 )   Save

    It remains unclear whether autophagy affects hippocampal neuronal injury in vascular dementia. In the present study, we investigated the effects of autophagy blockade on hippocampal neuronal injury in a rat model of vascular dementia. In model rats, hippocampal CA1 neurons were severely damaged, and expression of the autophagy-related proteins beclin-1, cathepsin B and microtubule-associated protein 1 light chain 3 was elevated compared with that in sham-operated animals. These responses were suppressed in animals that received a single intraperitoneal injection of wortmannin, an autophagy inhibitor, prior to model establishment. The present results confirm that autophagy and autophagy-related proteins are involved in the pathological changes of vascular dementia, and that inhibition of autophagy has neuroprotective effects.

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    Role of Notch-1 signaling pathway in PC12 cell apoptosis induced by amyloid beta-peptide (25–35)
    Huimin Liang, Yaozhou Zhang, Xiaoyan Shi, Tianxiang Wei, Jiyu Lou
    2014, 9 (13):  1297-1302.  doi: 10.4103/1673-5374.137577
    Abstract ( 194 )   PDF (621KB) ( 987 )   Save

    Recent studies have demonstrated that Notch-1 expression is increased in the hippocampus of Alzheimer’s disease patients. We speculate that Notch-1 signaling may be involved in PC12 cell apoptosis induced by amyloid beta-peptide (25–35) (Aβ25–35). In the present study, PC12 cells were cultured with different doses (0, 0.1, 1.0, 10 and 100 nmol/L) of N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, a Notch-1 signaling pathway inhibitor, for 30 minutes. Then cultured cells were induced with Aβ25–35 for 48 hours. Pretreatment of PC12 cells with high doses of N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (> 10 nmol/L) prolonged the survival of PC12 cells after Aβ25–35 induction, decreased the expression of apoptosis-related proteins caspase-3, -8, -9, increased the activity of oxidative stress-related superoxide dismutase and catalase, inhibited the production of active oxygen, and reduced nuclear factor kappa B expression. This study indicates that the Notch-1 signaling pathway plays a pivotal role in Aβ25–35-induced PC12 apoptosis.

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    Morphological changes of gonadotropin-releasing hormone neurons in the rat preoptic area across puberty
    Haogang Xue, Xiaodong Gai, Weiqi Sun, Chun Li, Quan Liu
    2014, 9 (13):  1303-1312.  doi: 10.4103/1673-5374.137578
    Abstract ( 170 )   PDF (2148KB) ( 820 )   Save

    Gonadotropin-releasing hormone (GnRH) neurons in the preoptic area may undergo morphological changes during the pubertal period when their activities are upregulated. To clarify the regulatory mechanism of puberty onset, this study aimed to investigate the morphological changes of GnRH neurons in the preoptic area of GnRH-enhanced green fluorescent protein transgenic rats. Under confocal laser microscopy, pubertal GnRH neurons exhibited an inverted Y distribution pattern. Prepubertal GnRH neurons were generally unipolar and bipolar, and were distinguished as smooth type cells with few small processes or irregular type cells with many spine-like processes in the proximal dendrites. The number of GnRH neurons in the preoptic area and spine-like processes were increased during the course of reproductive maturation. There was no significant difference between male and female rats. Immunofluorescence staining revealed synaptophysin punctae close to the distal end of GnRH neurons, indicating that some presynaptic terminals may form a synaptic linkage with these neurons.

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    Targeted thrombolysis strategies for neuroprotective effect
    Junping Zhang, Guoxing Ma, Zhimin Lv, Yu Zhou, Chunguang Wen, Yaqing Wu, Ruian Xu
    2014, 9 (13):  1316-1322.  doi: 10.4103/1673-5374.137580
    Abstract ( 236 )   PDF (262KB) ( 1235 )   Save

    Stroke is usually treated by systemic thrombolytic therapy if the patient presents within an appropriate time window. There is also widespread interest in the development of thrombolytic agents that can be used in cases of delayed presentation. Current agents that can be used in cases of delayed presentation of nerve damage by thrombus. Current systemic thrombolytic therapy is associated with adverse effects such as fibrinogenolysis and bleeding. In an attempt to increase the efficacy, safety, and specificity of thrombolytic therapy, a number of targeted thrombolytic agents have been studied in recent years. This review focuses on the concepts underlying targeted thrombolytic therapy and describes recent drug developments in this field.

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    Changes in motor function in the unaffected hand of stroke patients should not be ignored
    Lingli Zhang, Peihong Li, Zhibang Mao, Xiang Qi, Jun Zou, Zhusheng Yu
    2014, 9 (13):  1323-1328.  doi: 10.4103/1673-5374.137581
    Abstract ( 174 )   PDF (602KB) ( 742 )   Save

    Motor function changes in the unaffected hand of stroke patients with hemiplegia. These changes are often ignored by clinicians owing to the extent of motor disability of the affected hand. Finger tapping frequency and Lind-mark hand function score showed that the motor function of unaffected hands in stroke patients was poorer than that of a healthy control hand. After 2 weeks of rehabilitation treatment, motor function of the unaffected hand of stroke patients was obviously improved. Therefore, attention should also be paid to motor function in the unaffected hand of stroke patients with hemiplegia during rehabilitation.

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