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Objective To investigate the effect of recombinant botulinum neurotoxin serotype A heavy chain (BoNT/A heavy chain)on local proteins which are related to nerve growth after spinal cord injury in rats,and to get some experimental evidence to explain the mechanism of BoNT/A heavy chain in stimulating neuritogenesis. Methods Recombinant botulinum neurotoxin serotype A heavy chain was applied locally or intrathecally to rats with ipsilateral semi-dissociated lumbar spinal injury. Local spinal tissue was extracted for general protein expression by two dimension electrophoresis plus nitrate silver staining after different time period of injury. Based on the results of 2-D gel electrophoresis,growth-associated protein 43(GAP-43)and of superior cervical ganglion 10(SCG 10)were selected to examine the changes of their expression and distribution features under BoNT/A heavy chain administration using SDS-PAGE,western blot and immunofluorescence. Results (1)The model of spinal cord injury(SCI)in this study was an ipsilateral semi-dissociated lumbar SCI in rat. The rats showed obvious motor and sensory dysfunction in the ipsilateral hind limb.(2)The results from 2-D gel electrophoresis plus nitrate silver staining showed that the administration of BoNT/A heavy chain based on SCI altered the local protein expression pattern. The decrease or increase in the expression of some protein dots /dots group was clearly seen after single SCI. However, these changes were transformed by BoNT/A heavy chain treatment,which appeared as a reversed pattern turning toward that in control group or further increased expression upon SCI,such as the dots located respectively at 35-45 kDa and 18-25 kDa level,pI between 5-7. In addition,the expression of the two dots located at the level as above increased after SCI only, and showed further increase in their expression with BoNT/A heavy chain intervention.(3)The changes of selective GAP-43 and SCG 10 expression and distribution by western blot and immunofluorescence indicated that the administration of BONT/A heavy chain based on SCI amplified the expression of GAP-43 and SCG 10(P < 0.05). Meanwhile,the positive immuonfluorescent staining for both GAP-43 and SCG 10 mainly distributed nearby the proximal area of injury, both cytoplasm and neuronal processes were positively stained. Conclusions Intrathecal delivery of BoNT/A heavy chain increases the expression of growth-associated proteins GAP 43 and SCG 10 after SCI in rats.
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OBJECTIVES: The ginsenoside Rg1 and Rb1, the major components of ginseng saponin, have neurotrophic and neuroprotective effects including promotion of neuronal survival and proliferation, facilitation of learning and memory, and protection from ischemic injury and apoptosis. In this study, to investigate the molecular basis of the effects of ginsenoside on neuron, we analyzed gene expression profiling of SH-SY5Y human neuroblastoma cells treated with ginsenoside Rg1 or Rb1. METHODS: SH-SY5Y cells were cultured and treated in triplicate with ginsenoside Rg1 or Rb1(80micrometer, 40micrometer, 20micrometer). The proliferation rates of SH-SY5Y cells were determined by MTT assay and microscopic examination. We used a high density cDNA microarray chip that contained 8K human genes to analyze the gene expression profiles in SH-SY5Y cells. We analyzed using the Significance Analysis of Microarray(SAM) method for identifying genes on a microarray with statistically significant changes in expression. RESULTS: Treatment of SH-SY5Y cells with 80microliter ginsenoside Rg1 or Rb1 for 36h showed maximal proliferation compared with other concentrations or control. The results of the microarray experiment yielded 96 genes were upregulated(> or =3 fold) in Rg1 treated cells and 40 genes were up-regulated(> or =2 fold) in Rb1 treated cells. Treatment with ginsenoside Rg1 for 36h induced the expression of some genes associated with protein biosynthesis, regulation of transcription or translation, cell proliferation and growth, neurogenesis and differentiation, regulation of cell cycle, energy transport and others. Genes associated with neurogenesis and neuronal differentiation such as SCG10 and MLP increased in ginsenoside Rg1 treated cells, but such changes did not occur in Rb1- group. CONCLUSION: Our data provide novel insights into the gene mechanisms involved in possible role for ginsenoside Rg1 or Rb1 in mediating neuronal proliferation or cell viability, which can elicit distinct patterns of gene expression in neuronal cell line. Ginsenoside Rg1 have more broad and strong effects than ginsenoside Rb1 in gene expression and related cellular physiology. In addition, we suggest that SCG10 gene, which is known to be expressed in neuronal differentiation during development and neuronal regeneration during adulthood, may have a role in enhancement of activity dependent synaptic plasticity or cytoskeletal regulation following treatment of ginsenoside Rg1. Further, ginsenoside Rg1 may have a possible role in regeneration of injured neuron, promotion of memory, and prevention from aging or neuronal degeneration.