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Table of Content

    25 August 2013, Volume 8 Issue 24 Previous Issue    Next Issue
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    Basic fibroblast growth factor attenuates the degeneration of injured spinal cord motor endplates
    Jianlong Wang, Jianfeng Sun, Yongxiang Tang, Gangwen Guo, Xiaozhe Zhou, Yanliang Chen, Minren Shen
    2013, 8 (24):  2213-2224.  doi: 10.3969/j.issn.1673-5374.2013.24.001
    Abstract ( 313 )   PDF (538KB) ( 1575 )   Save

    The distal end of the spinal cord and neuromuscular junction may develop secondary degeneration and damage following spinal cord injury because of the loss of neural connections. In this study, a rat model of spinal cord injury, established using a modified Allen’s method, was injected with basic fibroblast growth factor solution via subarachnoid catheter. After injection, rats with spinal cord injury displayed higher scores on the Basso, Beattie and Bresnahan locomotor scale. Motor function was also well recovered and hematoxylin-eosin staining showed that spinal glial scar hyperplasia was not apparent. Additionally, anterior tibial muscle fibers slowly, but progressively, atrophied. Immunohistochemical staining showed that the absorbance values of calcitonin gene related pep-tide and acetylcholinesterase in anterior tibial muscle and spinal cord were similar, and injection of basic fibroblast growth factor increased this absorbance. Results showed that after spinal cord injury, the distal motor neurons and motor endplate degenerated. Changes in calcitonin gene related pep-tide and acetylcholinesterase in the spinal cord anterior horn motor neurons and motor endplate then occurred that were consistent with this regeneration. Our findings indicate that basic fibroblast growth factor can protect the endplate through attenuating the decreased expression of calcitonin gene related peptide and acetylcholinesterase in anterior horn motor neurons of the injured spinal cord.

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    Stress protein expression in early phase spinal cord ischemia/reperfusion injury
    Shanyong Zhang, Dankai Wu, Jincheng Wang, Yongming Wang, Guoxiang Wang, Maoguang Yang, Xiaoyu Yang
    2013, 8 (24):  2225-2235.  doi: 10.3969/j.issn.1673-5374.2013.24.002
    Abstract ( 335 )   PDF (403KB) ( 1883 )   Save

    Spinal cord ischemia/reperfusion injury is a stress injury to the spinal cord. Our previous studies using differential proteomics identified 21 differentially expressed proteins (n > 2) in rabbits with spinal cord ischemia/reperfusion injury. Of these proteins, stress-related proteins included protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70. In this study, we established New Zealand rabbit models of spinal cord ischemia/reperfusion injury by abdominal aorta occlusion. Results demonstrated that hind limb function initially improved after spinal cord ischemia/reperfusion injury, but then deteriorated. The pathological morphology of the spinal cord became aggravated, but lessened 24 hours after reperfusion. However, the numbers of motor neurons and interneurons in the spinal cord gradually decreased. The expression of protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70 was induced by ischemia/reperfusion injury. The expression of these proteins increased within 12 hours after reperfusion, and then decreased, reached a minimum at 24 hours, but subsequently increased again to similar levels seen at 6–12 hours, showing a characterization of induction-inhibition-induc- tion. These three proteins were expressed only in cytoplasm but not in the nuclei. Moreover, the expression was higher in interneurons than in motor neurons, and the survival rate of interneurons was greater than that of motor neurons. It is assumed that the expression of stress-related proteins exhibited a protective effect on neurons.

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    Combined transplantation of GDAsBMP and hr-decorin in spinal cord contusion repair
    Liang Wu, Jianjun Li, Liang Chen, Hong Zhang, Li Yuan, Stephen JA Davies
    2013, 8 (24):  2236-2248.  doi: 10.3969/j.issn.1673-5374.2013.24.003
    Abstract ( 207 )   PDF (608KB) ( 2218 )   Save

    Following spinal cord injury, astrocyte proliferation and scar formation are the main factors inhibiting the regeneration and growth of spinal cord axons. Recombinant decorin suppresses inflammatory reactions, inhibits glial scar formation, and promotes axonal growth. Rat models of T8 spinal cord contusion were created with the NYU impactor and these models were subjected to combined transplantation of bone morphogenetic protein-4-induced glial-restricted precursor-derived astro-cytes and human recombinant decorin transplantation. At 28 days after spinal cord contusion, dou-ble-immunofluorescent histochemistry revealed that combined transplantation inhibited the early in-flammatory response in injured rats. Furthermore, brain-derived neurotrophic factor, which was se-creted by transplanted cells, protected injured axons. The combined transplantation promoted ax-onal regeneration and growth of injured motor and sensory neurons by inhibiting astrocyte prolifer-ation and glial scar formation, with astrocytes forming a linear arrangement in the contused spinal cord, thus providing axonal regeneration channels.

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    Degenerative alterations in noradrenergic neurons of the locus coeruleus in Alzheimer’s disease
    Lihua Liu, Saiping Luo, Leping Zeng, Weihong Wang, Liming Yuan, Xiaohong Jian
    2013, 8 (24):  2249-2255.  doi: 10.3969/j.issn.1673-5374.2013.24.004
    Abstract ( 523 )   PDF (284KB) ( 1929 )   Save

    Mice carrying mutant amyloid-β precursor protein and presenilin-1 genes (APP/PS1 double trans-genic mice) have frequently been used in studies of Alzheimer’s disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer’s disease is known to correlate with the amount of amyloid-β protein deposition and the number of dead neurons in the locus coeruleus. In the present study, we assigned APP/PS1 double transgenic mice to two groups according to age: young mice (5–6 months old) and aged mice (16–17 months old). Age-matched wild-type mice were used as controls. Immunohistochemistry for tyrosine hydroxylase (a marker of catecholaminergic neurons in the locus coeruleus) revealed that APP/PS1 mice had 23% fewer cells in the locus coeruleus compared with aged wild-type mice. APP/PS1 mice also had increased numbers of cell bodies of neurons positive for tyrosine hydroxylase, but fewer tyrosine hydroxylase-positive fibers, which were also short, thick and broken. Quantitative analysis using unbiased stereology showed a significant age-related increase in the mean volume of tyrosine hy-droxylase-positive neurons in aged APP/PS1 mice compared with young APP/PS1 mice. Moreover, the mean volume of tyrosine hydroxylase-positive neurons was positively correlated with the total volume of the locus coeruleus. These findings indicate that noradrenergic neurons and fibers in the locus coeruleus are predisposed to degenerative alterations in APP/PS1 double transgenic mice.

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    The mechanism of astragaloside IV promoting sciatic nerve regeneration
    Xiaohong Zhang, Jiajun Chen
    2013, 8 (24):  2256-2265.  doi: 10.3969/j.issn.1673-5374.2013.24.005
    Abstract ( 265 )   PDF (338KB) ( 1450 )   Save

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    Nanofibrous nerve conduits for repair of 30-mm-long sciatic nerve defects
    Esmaeil Biazar, Saeed Heidari Keshel, Majid Pouya, Hadi Rad, Melody Omrani Nava, Mohammad Azarbakhsh, Shirin Hooshmand
    2013, 8 (24):  2266-2274.  doi: 10.3969/j.issn.1673-5374.2013.24.006
    Abstract ( 286 )   PDF (501KB) ( 1196 )   Save

    It has been confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit can promote peripheral nerve regeneration in rats. However, its efficiency in repair of over 30-mm-long sciatic nerve defects needs to be assessed. In this study, we used a nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve conduit implantation, regenerated nerves were macroscopi-cally observed and histologically assessed. In the nanofibrous graft, the rat sciatic nerve trunk had been reconstructed by restoration of nerve continuity and formation of myelinated nerve fiber. There were Schwann cells and glial cells in the regenerated nerves. Masson’s trichrome staining showed that there were no pathological changes in the size and structure of gastrocnemius muscle cells on the operated side of rats. These findings suggest that nanofibrous poly(3-hydroxybutyrate-co-3- hydroxyvalerate) nerve conduit is suitable for repair of long-segment sciatic nerve defects.

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    Autophagy and neurodegenerative disorders
    Evangelia Kesidou, Roza Lagoudaki, Olga Touloumi, Kyriaki-Nefeli Poulatsidou, Constantina Simeonidou
    2013, 8 (24):  2275-2283.  doi: 10.3969/j.issn.1673-5374.2013.24.007
    Abstract ( 439 )   PDF (209KB) ( 2604 )   Save

    Accumulation of aberrant proteins and inclusion bodies are hallmarks in most neurodegenerative diseases. Consequently, these aggregates within neurons lead to toxic effects, overproduction of reactive oxygen species and oxidative stress. Autophagy is a significant intracellular mechanism that removes damaged organelles and misfolded proteins in order to maintain cell homeostasis. Excessive or insufficient autophagic activity in neurons leads to altered homeostasis and influences their survival rate, causing neurodegeneration. The review article provides an update of the role of autophagic process in representative chronic and acute neurodegenerative disorders.

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    Inner ear hair cell regeneration A look from the past to the future
    Francisco Santaolalla, Carlos Salvador, Agustín Martínez, Jose María Sánchez, Ana Sánchez del Rey
    2013, 8 (24):  2284-2289.  doi: 10.3969/j.issn.1673-5374.2013.24.008
    Abstract ( 238 )   PDF (118KB) ( 2894 )   Save

    Most recent studies on regeneration of inner ear hair cells focus on use of stem cells, gene therapy and neurotrophic factors. Cochlear gene therapy has been successfully used in the treatment of neu-rosensory hearing loss. This suggests that cochlear hair cell regeneration is possible. The objective of this paper is to review research and clinical application of inner near hair cell regeneration.

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    Insights into the structural biology of G-protein coupled receptors impacts drug design for central nervous system neurodegenerative processes
    Farfán-García Eunice Dalet, Trujillo-Ferrara José Guadalupe, Castillo-Hernández María del Carmen, Guerra-Araiza Christian Humberto, Soriano-Ursúa Marvin Antonio
    2013, 8 (24):  2290-2302.  doi: 10.3969/j.issn.1673-5374.2013.24.009
    Abstract ( 428 )   PDF (409KB) ( 1197 )   Save

    In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec-tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifically, new possibilities are explored in relation to allosteric and orthosteric binding sites on dopamine receptors for the treatment of Parkinson’s disease, and on muscarinic receptors for Alzheimer’s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa-mine receptor holds promise as a relevant therapeutic strategy for Parkinson’s disease. Regarding the treatment of Alzheimer’s disease, the design of dualsteric ligands for mono-oligomeric musca-rinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.

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