This study aimed to explore the pathological change to hippocampal neurons and the expression of growth associated protein 43 in 21-day-old young rats following chronic intermittent hypoxia. Hematoxylin-eosin staining...This study aimed to explore the pathological change to hippocampal neurons and the expression of growth associated protein 43 in 21-day-old young rats following chronic intermittent hypoxia. Hematoxylin-eosin staining results showed varying degrees of degeneration and necrosis in hippocampal neurons depending on the modeling time. Immunohistochemistry revealed that growth associated protein 43 expression in young rats following chronic intermittent hypoxia decreased, but that levels were still higher than those of normal rats at each time point, especially 4 weeks after modeling. During 1 5 weeks after modeling, a slow growth in rat weight was observed. Experimental findings indicate that chronic intermittent hypoxia may induce growth dysfunction and necrosis of hippocampal neurons, as well as increase the expression of growth associated protein 43 in young rats.展开更多
BACKGROUND： Peripheral nerve injury may lead to neuropathic pain and cause a markedly increase expression of growth associated protein-43 （GAP-43） in the spinal cord and dorsal root ganglion, local anesthetics bloc...BACKGROUND： Peripheral nerve injury may lead to neuropathic pain and cause a markedly increase expression of growth associated protein-43 （GAP-43） in the spinal cord and dorsal root ganglion, local anesthetics blocking electrical impulse propagation of nerve fibers may also affect the expression of GAP-43 in the spinal cord and dorsal root ganglion. OBJECTIVE： To determine the effects of continuous peripheral nerve block by tetrodotoxin before and after nerve injury on GAP-43 expression in the dorsal root ganglion during the development of neuropathic pain. DESIGN： A randomized controlled animal experiment. SETTINGS： Department of Anesthesiology, the Second Hospital of Xiamen City; Department of Anesthesiology, the Second Affiliated Hospital of Shantou University Medical College. MATERIALS： Thirty-five Spragne Dawley （SD） rats, weighing 200 - 250 g, were randomly divided into four groups： control group （n =5）, simple sciatic nerve transection group （n =10）, peripheral nerve block before and after sciatic nerve transection groups （n =10）. All the sciatic nerve transection groups were divided into two subgroups according to the different postoperative survival periods： 3 and 7 days （n =5） respectively. Mouse anti-GAP-43 monoclonal antibody （Sigma Co., Ltd.）, supervision TM anti-mouse reagent （HRP, Changdao antibody diagnosis reagent Co., Ltd., Shanghai）, and HMIAS-100 image analysis system （Qianping Image Engineering Company, Tongji Medical University） were employed in this study. METHODS： This experiment was carried out in the Department of Surgery and Pathological Laboratory, the Second Affiliated Hospital of Shantou University Medical College from April 2005 to April 2006. ①The animals were anesthetized and the right sciatic nerve was exposed and transected at 1 cm distal to sciatic notch. ② Tetrodotoxin 10 μg/kg was injected percutaneously between the greater trochanter and the posterior superior iliac spine of fight hind limb to block the sciatic nerve proximally at 1 hour before or 4 hours after nerve injury respectively, the injection was repeated in all the rats every 12 hours.③ At 3 or 7 days after nerve injury, immunohistochemistry and image analysis were used to evaluate the expression of GAP-43 in the dorsal root ganglions of L5 to the transected sciatic nerve, and quantitative analysis was also performed. ④ Statistical analysis was performed using one way analysis of variance followed by t test. MAIN OUTCOME MEASURE： Expression of GAP-43 in the fight dorsal root ganglions of L5. RESULTS： All the 35 SD rats were involved in the final analysis of results. In normal rats, there were very low expressions of GAP-43 in the dorsal root ganglions. In simple sciatic nerve transection rats 3 and 7 days after sciatic nerve transection, the average absorbance value of GAP-43 immunopositive neurons were significantly different from that in normal rats （t =8.806, 6.771, P 〈 0.01）. Whereas 3 and 7 days after sciatic nerve transection in rats with peripheral nerve block before and after nerve injury, the average absorbance value of GAP-43 immunopositive neurons were not significantly different from that in normal rats （P 〉 0.05）. CONCLUSION： Local anesthetic continuous peripheral nerve block before or after nerve injury can suppress nerve injury induced high expression of GAP-43 during the development of neuropathic pain.展开更多
An enriched environment protects dopaminergic neurons from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP）-induced neuronal injury, but the underlying mechanism for this is not clear. Growth associated protein-43...An enriched environment protects dopaminergic neurons from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP）-induced neuronal injury, but the underlying mechanism for this is not clear. Growth associated protein-43（GAP-43） is closely associated with neurite outgrowth and axon regeneration during neural development. We speculate that an enriched environment can reduce damage to dopaminergic neurons by affecting the expression of GAP-43. This study is designed to test this hypothesis. Three-month-old female senescence-accelerated mouse prone 8（SAMP8） mice were housed for 3 months in an enriched environment or a standard environment. These mice were then subcutaneously injected in the abdomen with 14 mg/kg MPTP four times at 2-hour intervals. Morris water maze testing demonstrated that learning and memory abilities were better in the enriched environment group than in the standard environment group. Reverse-transcription polymerase chain reaction, immunohistochemistry and western blot assays showed that m RNA and protein levels of GAP-43 in the substantia nigra were higher after MPTP application in the enriched environment group compared with the standard environment group. These findings indicate that an enriched environment can increase GAP-43 expression in SAMP8 mice. The upregulation of GAP-43 may be a mechanism by which an enriched environment protects against MPTP-induced neuronal damage.展开更多
BACKGROUND： The main clinical treatments for optic nerve injury are optic canal decompression and systemic administration of hormones, but both treatments have disadvantages. OBJECTIVE： To observe the pathological c...BACKGROUND： The main clinical treatments for optic nerve injury are optic canal decompression and systemic administration of hormones, but both treatments have disadvantages. OBJECTIVE： To observe the pathological changes in the retina and growth associated protein-43 （GAP-43） expression, to compare the treatment of optic canal decompression, hormones, and their combination with the intracanalicular optic nerve injury.DESIGN, TIME AND SETTING： A randomized, controlled animal study was performed at the Department of Anatomy, Weifang Medical University, China, from September 2007 to November 2008.MATERIALS： Dexamethasone （Shandong Huaxin Pharmaceutical, China） and rabbit anti-GAP-43 polyclonal antibody （Boster, China） were used.METHODS： All 36 healthy adult rabbits were randomly assigned to control group （n = 4）, simple injury group （n = 20）, and treatment group （n = 12）. Intracanalicular optic nerve injury models were established using the metal cylinder free-fall impact method. The control group was left intact. The treatment group （four rabbits in each subgroup） was treated by optic nerve decompression, dexamethasone treatment （1 mg/kg daily via two intravenous infusions, 1/5 total dose reduction every 3 days, for 14 days）, and simultaneously giving surgery and hormone treatment.MAIN OUTCOME MEASURES： Pathological changes in the retina were determined using hematoxylin-eosin staining. GAP-43 expression was detected using immunohistochemistry in the retina.RESULTS： Retina injury induced obvious pathological changes in the retina. With prolonged time after optic nerve injury, the number of retinal ganglion cells was gradually decreased, and reached the minimum on day 14 （P〈0.01）. All three treatments increased the number of retinal ganglion cells （P〈0.01）, but surgery ＋ hormone treatment was most effective. No GAP-43 cells were present in the normal retinal, but they appeared 3 days after injury, peaked 7 days after injury, and then began to decline.CONCLUSION： Intracanalicular optic nerve injury induced obvious pathological changes in the retina, including increased GAP-43 expression. Optic canal decompression and hormones improved nerve repair after injury, and their combination produced better outcomes.展开更多
The present study was designed to investigate the role of quercetin on neurite growth in N1E-115 cells and the underlying mechanisms. Quercetin was evaluated for its effects on cell numbers of neurites, neurite length...The present study was designed to investigate the role of quercetin on neurite growth in N1E-115 cells and the underlying mechanisms. Quercetin was evaluated for its effects on cell numbers of neurites, neurite length, intracellular cAMP content, and Gap-43 expression in N1E-115 cells in vitro by use of microscopy, LANCE? cAMP 384 kit, and Western blot analysis, respectively. Our results showed that quercetin could increase the neurite length in a concentration-dependent manner, but had no effect on the numbers of cells. Quercetin significantly increased the expression of cellular cAMP in a time- and concentration-dependent manner. The Gap-43 expression was up-regulated in a time-dependent manner. In conclusion, quercetin could promote neurite growth through increasing the intracellular c AMP level and Gap-43 expression.展开更多
BACKGROUND： Transplantation of bone marrow-derived mesenchymal stem cells （BMSCs） improves motor functional recovery, but the mechanisms remain unclear. OBJECTIVE： To investigate expression of growth-associated pr...BACKGROUND： Transplantation of bone marrow-derived mesenchymal stem cells （BMSCs） improves motor functional recovery, but the mechanisms remain unclear. OBJECTIVE： To investigate expression of growth-associated protein 43 （GAP-43） and neural cell adhesion molecule following BMSC transplantation to the lateral ventricle in rats with acute focal cerebral ischemic brain damage. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment using immunohistochemistry was performed at the laboratories of Department of Neurology, Renmin Hospital of Wuhan University and Doctoral Scientific Research Work Station of C-BONS PHARMA, Hubei Province, China, from January 2007 to December 2008. MATERIALS： Monoclonal mouse anti-rat 5-bromo-2-deoxyuridine and neural cell adhesion molecule antibodies were purchased from Sigma, USA; monoclonal mouse anti-rat GAP-43 antibody was purchased from Wuhan Boster, China. METHODS： Rat models of right middle cerebral artery occlusion were established using the thread method. At 1 day after middle cerebral artery occlusion, 20μL culture solution, containing 5×10^5 BMSCs, was transplanted to the left lateral ventricle using micro-injection. MAIN OUTCOME MEASURES： Scores of neurological impairment were measured to assess neural function. Expression of GAP-43 and neural cell adhesion molecule at the lesion areas was examined by immunohistochemistry. RESULTS： GAP-43 and neural cell adhesion molecule expression was low in brain tissues of the sham-operated group, but expression increased at the ischemic boundary （P 〈 0.05）. Transplantation of BMSCs further enhanced expression of GAP-43 and neural cell adhesion molecule （P 〈 0.05） and remarkably improved neurological impairment of ischemic rats （P 〈 0.05）. CONCLUSION： BMSC transplantation promoted neurological recovery in rats by upregulating expression of GAP-43 and neural cell adhesion molecule.展开更多
In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we inv...In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we investigated the effects of enriched environment on cognitive abilities in prenatally stressed rat offspring, as well as the underlying mechanisms. Reverse transcription-PCR and western blot assay results revealed that growth-associated protein 43 mRNA and protein levels were upregulated on postnatal day 15 in the prenatal restraint stress group. Growth-associated protein 43 expression was significantly lower in the prenatal restraint stress group compared with the negative control and prenatal restraint stress plus enriched environment groups on postnatal days 30 and 50. Morris water maze test demonstrated that cognitive abilities were noticeably increased in rats from the prenatal restraint stress plus enriched environment group on postnatal day 50. These results indicate that enriched environment can improve the spatial learning and memory ability of prenatally stressed offspring by upregulating growth-associated protein 43 expression.展开更多
Studies have demonstrated that amyloid precursor protein （APP） expression increases in multiple sclerosis tissues during acutely and chronically active stages. To determine the relationship between axonal injury and...Studies have demonstrated that amyloid precursor protein （APP） expression increases in multiple sclerosis tissues during acutely and chronically active stages. To determine the relationship between axonal injury and regeneration in multiple sclerosis, an animal model of experimental autoimmune encephalomyelitis was induced using different doses of myelin basic protein peptide. APP and growth-associated protein 43 （GAP-43）, which is considered a specific marker of neural regeneration, were assessed by western blot analysis. Expression of APP and GAP-43, as well as the correlation between these two proteins, in brain white matter and spinal cord tissues of experimental autoimmune encephalomyelitis rats at different pathological stages was analyzed. Results showed that APP and GAP-43 expression increased during the acute stage and decreased during remission, with a positive correlation between APP and GAP-43 expression in brain white matter and spinal cord tissues. These results suggest that APP and GAP-43 could provide nutritional and protective effects on damaged neurons.展开更多
BACKGROUND： Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit spr...BACKGROUND： Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit sprouting and elongation of the axonal growth cone. OBJECTIVE： To verify regulatory effects of cyclovirobuxine D （CVB-D） extracted from Chinese box branchlet on human growth-associated protein 43 （GAP-43）, and neurocan expression in brain tissue of stroke-prone renovascular hypertensive （RHRSP） rats, at different time points after cerebral ischemia/reperfusion. DESIGN： Randomized grouping design and controlled animal study. SETTING： This study was performed at the Center of Guangdong Hospital of Traditional Chinese Medicine （a national key laboratory） from March 2003 to September 2006. MATERIALS： 100 healthy male Sprague-Dawley rats, aged 2 3 months and weighing 90-120 g, were selected for this study. CVB-D was provided by Nanjing Xiaoying Pharmaceutical Factory （Batch number： 307701）. METHODS： The initial tip of renal arteries was clamped bilaterally for 10 weeks to establish the RHRSP model. 100 RHRSP rats were randomly divided into 4 groups： naive group （n = 10）, sham surgery group （n = 10）, CVB-D group （n = 40）, and lesion group （n = 40）. Rats in the naive group did not undergo any treatment, and cervical vessels of rats in the sham surgery group were exposed, but not blocked. The right middle cerebral artery of rats in the CVB-D group and lesion group were occluded to establish cerebral ischemia. Rats in the CVB-D group were intraperitoneally injected with CVB-D （6.48 mg/kg） every day and with saline （1.5 mL/injection） twice a day. Rats in the lesion group were intraperitoneally injected with saline （2 mL/injection）. MAIN OUTCOME MEASURES： Immunohistochemistry was applied to detect GAP-43 and neurocan expression in the ischemic penumbra region of CVB-D and lesion brains at 2 hours post-cerebral ischemia and at 1, 7, 14, and 30 days post-perfusion （n = 10 at each time point）. Similarly, GAP-43 and neurocan expression was detected in the right hemisphere of naive and sham-operated animals. The results were expressed as positive cells. RESULTS： A total of 100 rats were included in the final analysis. The number of GAP-43 positive cells increased in the CVB-D group 1, 7, 14, and 30 days post-cerebral ischemia/perfusion compared to the lesion group, as indicated by a significant difference between the CVB-D and lesion group （P 〈 0.054）.01）. The number of neurocan-positive cells decreased in the CVB-D group on the first day compared to the model group; however, there was no significant difference between the two groups （P 〉 0.05）. On post-ischemia days 7, 14, and 30, the number of neurocan-positive cells in the CVB-D group was significantly less than in the lesion group （P 〈 0.05）. Both, GAP-43 and neurocan expression was not detectable in brains of naive and sham-operated animals. CONCLUSION： CVB-D treatment up-regulated GAP-43 expression and down-regulated neurocan expression in the ischemic region of RHRSP rats.展开更多
BACKGROUND： Growth-associated protein-43 （GAP-43） expression in the nervous system has been demonstrated to promote neural regeneration, neuronal growth and development, as well as synaptic reconstruction. Neurofil...BACKGROUND： Growth-associated protein-43 （GAP-43） expression in the nervous system has been demonstrated to promote neural regeneration, neuronal growth and development, as well as synaptic reconstruction. Neurofilament 200 （NF200） expression could reflect degree of injury and repair in injured spinal axons. OBJECTIVE： To observe NF200 expression changes in a rat model of complete spinal cord injury following GAP-43 treatment and to explore the effects of GAP-43 following spinal cord injury. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Histology and Embryology of Kunming Medical University between March 2007 and October 2008. MATERIALS： GAP-43 and GAP-43 antibody were provided by Beijing Boao Biology, China; mouse anti-rat NF200 antibody was purchased from Chemicon, USA. METHODS： Female, 8-week-old, Sprague Dawley rats were randomly assigned into three groups following complete spinal cord injury, with 20 animals in each group： GAP-43 antibody, GAP-43, and model groups. In addition, each group was subdivided into four subgroups according to sampling time after modeling, Le., 3-, 5-, 9-, and 15-day groups, with 5 rats in each group. GAP-43 antibody or GAP-43 was injected into injury sites of the spinal cord, 5 μg/0.2 mL, respectively, twice daily for three consecutive days, followed by three additional days of injection, once daily. The model group did not receive any treatment following injury. MAIN OUTCOME MEASURES： NF200 expression in the damaged spinal area at different stages was detected by immunohistochemistry; lower limb motion function following injury was evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor rating scale. RESULTS： NF200 expression was significantly reduced in the GAP-43 antibody group, compared with GAP-43 and model groups, at 3 and 5 days after spinal cord injury （P 〈 0.05）. In addition, the model group expressed significantly less NF200 than the GAP-43 group （P 〈 0.05）. BBB scores from the GAP-43 antibody and model groups were remarkably less than the GAP-43 group （P 〈 0.05）. At 9 and 15 days of injury after drug withdrawal, NF200 expression was increased in the GAP-43 antibody group, and NF200 expression and BBB scores in the GAP-43 antibody and GAP-43 groups were significantly greater than in the model group （P 〈 0.05）. In particular, the GAP-43 group exhibited greater BBB scores than the GAP-43 antibody group at day 9 （P 〈 0.05）. CONCLUSION： GAP-43 promoted NF200 expression and recovery of lower limb function. Early administration of GAP-43 antibody produced reversible nerve inhibition, which was rapidly restored following withdrawal.展开更多
Following granulocyte colony-stimulating factor （G-CSF） treatment,the growth of processes in cul-tured rat retinal ganglion cells （RGCs） in vitro,expression of growth associated protein 43,and expression of microt...Following granulocyte colony-stimulating factor （G-CSF） treatment,the growth of processes in cul-tured rat retinal ganglion cells （RGCs） in vitro,expression of growth associated protein 43,and expression of microtubule-associated protein 2 mRNA expression were significantly increased.In contrast,RhoA/Rock protein content was significantly reduced by G-CSF treatment.These results indicate that G-CSF promotes the growth of processes in RGCs and increases the expression of growth-associated protein 43 and microtubule-associated protein 2 mRNA by inhibiting the RhoA/Rock pathway,thereby benefiting axonal repair in RGCs exposed to hypoxia.展开更多
Ginsenoside Rg1（Rg1） has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal ...Ginsenoside Rg1（Rg1） has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal survival and neurite outgrowth in vitro after exposure to amyloid-beta peptide fragment 25–35（Aβ_（25–35））, and to explore whether the extracellular signal-regulated kinase（ERK） and Akt signaling pathways are involved in these biological processes. We cultured hippocampal neurons from newborn rats for 24 hours, then added Rg1 to the medium for another 24 hours, with or without pharmacological inhibitors of the mitogen-activated protein kinase（MAPK） family or Akt signaling pathways for a further 24 hours. We then immunostained the neurons for growth associated protein-43, and measured neurite length. In a separate experiment, we exposed cultured hippocampal neurons to Aβ_（25–35） for 30 minutes, before adding Rg1 for 48 hours, with or without Akt or MAPK inhibitors, and assessed neuronal survival using Hoechst 33258 staining, and phosphorylation of ERK1/2 and Akt by western blot analysis. Rg1 induced neurite outgrowth, and this effect was blocked by API-2（Akt inhibitor） and PD98059（MAPK/ERK kinase inhibitor）, but not by SP600125 or SB203580（inhibitors of c-Jun N-terminal kinase and p38 MAPK, respectively）. Consistent with this effect, Rg1 upregulated the phosphorylation of Akt and ERK1/2; these effects were reversed by API-2 and PD98059, respectively. In addition, Rg1 significantly reversed Aβ_（25–35）-induced apoptosis; this effect was blocked by API-2 and PD98059, but not by SP600125 or SB203580. Finally, Rg1 significantly reversed the Aβ_（25–35）-induced decrease in Akt and ERK1/2 phosphorylation, but API-2 prevented this reversal. Our results indicate that Rg1 enhances neurite outgrowth and protects against Aβ_（25–35）-induced damage, and that its mechanism may involve the activation of Akt and ERK1/2 signaling.展开更多
基金supported by a grant from Luzhou Medical College,China
文摘This study aimed to explore the pathological change to hippocampal neurons and the expression of growth associated protein 43 in 21-day-old young rats following chronic intermittent hypoxia. Hematoxylin-eosin staining results showed varying degrees of degeneration and necrosis in hippocampal neurons depending on the modeling time. Immunohistochemistry revealed that growth associated protein 43 expression in young rats following chronic intermittent hypoxia decreased, but that levels were still higher than those of normal rats at each time point, especially 4 weeks after modeling. During 1 5 weeks after modeling, a slow growth in rat weight was observed. Experimental findings indicate that chronic intermittent hypoxia may induce growth dysfunction and necrosis of hippocampal neurons, as well as increase the expression of growth associated protein 43 in young rats.
基金the Natural Science Foundation of Guangdong Province, No.034628
文摘BACKGROUND： Peripheral nerve injury may lead to neuropathic pain and cause a markedly increase expression of growth associated protein-43 （GAP-43） in the spinal cord and dorsal root ganglion, local anesthetics blocking electrical impulse propagation of nerve fibers may also affect the expression of GAP-43 in the spinal cord and dorsal root ganglion. OBJECTIVE： To determine the effects of continuous peripheral nerve block by tetrodotoxin before and after nerve injury on GAP-43 expression in the dorsal root ganglion during the development of neuropathic pain. DESIGN： A randomized controlled animal experiment. SETTINGS： Department of Anesthesiology, the Second Hospital of Xiamen City; Department of Anesthesiology, the Second Affiliated Hospital of Shantou University Medical College. MATERIALS： Thirty-five Spragne Dawley （SD） rats, weighing 200 - 250 g, were randomly divided into four groups： control group （n =5）, simple sciatic nerve transection group （n =10）, peripheral nerve block before and after sciatic nerve transection groups （n =10）. All the sciatic nerve transection groups were divided into two subgroups according to the different postoperative survival periods： 3 and 7 days （n =5） respectively. Mouse anti-GAP-43 monoclonal antibody （Sigma Co., Ltd.）, supervision TM anti-mouse reagent （HRP, Changdao antibody diagnosis reagent Co., Ltd., Shanghai）, and HMIAS-100 image analysis system （Qianping Image Engineering Company, Tongji Medical University） were employed in this study. METHODS： This experiment was carried out in the Department of Surgery and Pathological Laboratory, the Second Affiliated Hospital of Shantou University Medical College from April 2005 to April 2006. ①The animals were anesthetized and the right sciatic nerve was exposed and transected at 1 cm distal to sciatic notch. ② Tetrodotoxin 10 μg/kg was injected percutaneously between the greater trochanter and the posterior superior iliac spine of fight hind limb to block the sciatic nerve proximally at 1 hour before or 4 hours after nerve injury respectively, the injection was repeated in all the rats every 12 hours.③ At 3 or 7 days after nerve injury, immunohistochemistry and image analysis were used to evaluate the expression of GAP-43 in the dorsal root ganglions of L5 to the transected sciatic nerve, and quantitative analysis was also performed. ④ Statistical analysis was performed using one way analysis of variance followed by t test. MAIN OUTCOME MEASURE： Expression of GAP-43 in the fight dorsal root ganglions of L5. RESULTS： All the 35 SD rats were involved in the final analysis of results. In normal rats, there were very low expressions of GAP-43 in the dorsal root ganglions. In simple sciatic nerve transection rats 3 and 7 days after sciatic nerve transection, the average absorbance value of GAP-43 immunopositive neurons were significantly different from that in normal rats （t =8.806, 6.771, P 〈 0.01）. Whereas 3 and 7 days after sciatic nerve transection in rats with peripheral nerve block before and after nerve injury, the average absorbance value of GAP-43 immunopositive neurons were not significantly different from that in normal rats （P 〉 0.05）. CONCLUSION： Local anesthetic continuous peripheral nerve block before or after nerve injury can suppress nerve injury induced high expression of GAP-43 during the development of neuropathic pain.
基金supported by a grant from the Health Department of Hebei Province of China,No.20120056,20140314the Funding Project for Introduced Abroad Study Personnel of Hebei Province of China,No.C2011003039
文摘An enriched environment protects dopaminergic neurons from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP）-induced neuronal injury, but the underlying mechanism for this is not clear. Growth associated protein-43（GAP-43） is closely associated with neurite outgrowth and axon regeneration during neural development. We speculate that an enriched environment can reduce damage to dopaminergic neurons by affecting the expression of GAP-43. This study is designed to test this hypothesis. Three-month-old female senescence-accelerated mouse prone 8（SAMP8） mice were housed for 3 months in an enriched environment or a standard environment. These mice were then subcutaneously injected in the abdomen with 14 mg/kg MPTP four times at 2-hour intervals. Morris water maze testing demonstrated that learning and memory abilities were better in the enriched environment group than in the standard environment group. Reverse-transcription polymerase chain reaction, immunohistochemistry and western blot assays showed that m RNA and protein levels of GAP-43 in the substantia nigra were higher after MPTP application in the enriched environment group compared with the standard environment group. These findings indicate that an enriched environment can increase GAP-43 expression in SAMP8 mice. The upregulation of GAP-43 may be a mechanism by which an enriched environment protects against MPTP-induced neuronal damage.
基金the Educational Commission of Shandong Province of China,No. J06L23
文摘BACKGROUND： The main clinical treatments for optic nerve injury are optic canal decompression and systemic administration of hormones, but both treatments have disadvantages. OBJECTIVE： To observe the pathological changes in the retina and growth associated protein-43 （GAP-43） expression, to compare the treatment of optic canal decompression, hormones, and their combination with the intracanalicular optic nerve injury.DESIGN, TIME AND SETTING： A randomized, controlled animal study was performed at the Department of Anatomy, Weifang Medical University, China, from September 2007 to November 2008.MATERIALS： Dexamethasone （Shandong Huaxin Pharmaceutical, China） and rabbit anti-GAP-43 polyclonal antibody （Boster, China） were used.METHODS： All 36 healthy adult rabbits were randomly assigned to control group （n = 4）, simple injury group （n = 20）, and treatment group （n = 12）. Intracanalicular optic nerve injury models were established using the metal cylinder free-fall impact method. The control group was left intact. The treatment group （four rabbits in each subgroup） was treated by optic nerve decompression, dexamethasone treatment （1 mg/kg daily via two intravenous infusions, 1/5 total dose reduction every 3 days, for 14 days）, and simultaneously giving surgery and hormone treatment.MAIN OUTCOME MEASURES： Pathological changes in the retina were determined using hematoxylin-eosin staining. GAP-43 expression was detected using immunohistochemistry in the retina.RESULTS： Retina injury induced obvious pathological changes in the retina. With prolonged time after optic nerve injury, the number of retinal ganglion cells was gradually decreased, and reached the minimum on day 14 （P〈0.01）. All three treatments increased the number of retinal ganglion cells （P〈0.01）, but surgery ＋ hormone treatment was most effective. No GAP-43 cells were present in the normal retinal, but they appeared 3 days after injury, peaked 7 days after injury, and then began to decline.CONCLUSION： Intracanalicular optic nerve injury induced obvious pathological changes in the retina, including increased GAP-43 expression. Optic canal decompression and hormones improved nerve repair after injury, and their combination produced better outcomes.
基金supported by the National Natural Science Foundation of China(No.81271338)Specialized Research Fund for Doctoral Program of Higher Education of China(No.20130096 110011)
文摘The present study was designed to investigate the role of quercetin on neurite growth in N1E-115 cells and the underlying mechanisms. Quercetin was evaluated for its effects on cell numbers of neurites, neurite length, intracellular cAMP content, and Gap-43 expression in N1E-115 cells in vitro by use of microscopy, LANCE? cAMP 384 kit, and Western blot analysis, respectively. Our results showed that quercetin could increase the neurite length in a concentration-dependent manner, but had no effect on the numbers of cells. Quercetin significantly increased the expression of cellular cAMP in a time- and concentration-dependent manner. The Gap-43 expression was up-regulated in a time-dependent manner. In conclusion, quercetin could promote neurite growth through increasing the intracellular c AMP level and Gap-43 expression.
文摘BACKGROUND： Transplantation of bone marrow-derived mesenchymal stem cells （BMSCs） improves motor functional recovery, but the mechanisms remain unclear. OBJECTIVE： To investigate expression of growth-associated protein 43 （GAP-43） and neural cell adhesion molecule following BMSC transplantation to the lateral ventricle in rats with acute focal cerebral ischemic brain damage. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment using immunohistochemistry was performed at the laboratories of Department of Neurology, Renmin Hospital of Wuhan University and Doctoral Scientific Research Work Station of C-BONS PHARMA, Hubei Province, China, from January 2007 to December 2008. MATERIALS： Monoclonal mouse anti-rat 5-bromo-2-deoxyuridine and neural cell adhesion molecule antibodies were purchased from Sigma, USA; monoclonal mouse anti-rat GAP-43 antibody was purchased from Wuhan Boster, China. METHODS： Rat models of right middle cerebral artery occlusion were established using the thread method. At 1 day after middle cerebral artery occlusion, 20μL culture solution, containing 5×10^5 BMSCs, was transplanted to the left lateral ventricle using micro-injection. MAIN OUTCOME MEASURES： Scores of neurological impairment were measured to assess neural function. Expression of GAP-43 and neural cell adhesion molecule at the lesion areas was examined by immunohistochemistry. RESULTS： GAP-43 and neural cell adhesion molecule expression was low in brain tissues of the sham-operated group, but expression increased at the ischemic boundary （P 〈 0.05）. Transplantation of BMSCs further enhanced expression of GAP-43 and neural cell adhesion molecule （P 〈 0.05） and remarkably improved neurological impairment of ischemic rats （P 〈 0.05）. CONCLUSION： BMSC transplantation promoted neurological recovery in rats by upregulating expression of GAP-43 and neural cell adhesion molecule.
基金supported by a grant from Guangzhou Medical University in China,No. 2010-2012
文摘In our previous study, we reported that prenatal restraint stress could induce cognitive deficits, which correlated with a change in expression of growth-associated protein 43 in the hippocampus. In this study, we investigated the effects of enriched environment on cognitive abilities in prenatally stressed rat offspring, as well as the underlying mechanisms. Reverse transcription-PCR and western blot assay results revealed that growth-associated protein 43 mRNA and protein levels were upregulated on postnatal day 15 in the prenatal restraint stress group. Growth-associated protein 43 expression was significantly lower in the prenatal restraint stress group compared with the negative control and prenatal restraint stress plus enriched environment groups on postnatal days 30 and 50. Morris water maze test demonstrated that cognitive abilities were noticeably increased in rats from the prenatal restraint stress plus enriched environment group on postnatal day 50. These results indicate that enriched environment can improve the spatial learning and memory ability of prenatally stressed offspring by upregulating growth-associated protein 43 expression.
基金the National Natural Science Foundation of China,No. 30873230Beijing Natural Science Foundation,No. 7092014+1 种基金Scientific Research Common Program of Beijing Municipal Education Commission,No. KM2007100025015Fund-ing Project for Academic Human Resources Devel-opment in Institutions of Higher Learning Under the Jurisdiction of Beijing Mu-nicipality,No. PHR201008401
文摘Studies have demonstrated that amyloid precursor protein （APP） expression increases in multiple sclerosis tissues during acutely and chronically active stages. To determine the relationship between axonal injury and regeneration in multiple sclerosis, an animal model of experimental autoimmune encephalomyelitis was induced using different doses of myelin basic protein peptide. APP and growth-associated protein 43 （GAP-43）, which is considered a specific marker of neural regeneration, were assessed by western blot analysis. Expression of APP and GAP-43, as well as the correlation between these two proteins, in brain white matter and spinal cord tissues of experimental autoimmune encephalomyelitis rats at different pathological stages was analyzed. Results showed that APP and GAP-43 expression increased during the acute stage and decreased during remission, with a positive correlation between APP and GAP-43 expression in brain white matter and spinal cord tissues. These results suggest that APP and GAP-43 could provide nutritional and protective effects on damaged neurons.
基金the grants from Guangdong Province Administration of Traditional Chinese Medicine, No.103142
文摘BACKGROUND： Experimental data indicate that human growth-associated protein 43 mRNA expression coincides with axonal growth during nerve ganglion development; while neurocan, secreted from astrocytes, can inhibit sprouting and elongation of the axonal growth cone. OBJECTIVE： To verify regulatory effects of cyclovirobuxine D （CVB-D） extracted from Chinese box branchlet on human growth-associated protein 43 （GAP-43）, and neurocan expression in brain tissue of stroke-prone renovascular hypertensive （RHRSP） rats, at different time points after cerebral ischemia/reperfusion. DESIGN： Randomized grouping design and controlled animal study. SETTING： This study was performed at the Center of Guangdong Hospital of Traditional Chinese Medicine （a national key laboratory） from March 2003 to September 2006. MATERIALS： 100 healthy male Sprague-Dawley rats, aged 2 3 months and weighing 90-120 g, were selected for this study. CVB-D was provided by Nanjing Xiaoying Pharmaceutical Factory （Batch number： 307701）. METHODS： The initial tip of renal arteries was clamped bilaterally for 10 weeks to establish the RHRSP model. 100 RHRSP rats were randomly divided into 4 groups： naive group （n = 10）, sham surgery group （n = 10）, CVB-D group （n = 40）, and lesion group （n = 40）. Rats in the naive group did not undergo any treatment, and cervical vessels of rats in the sham surgery group were exposed, but not blocked. The right middle cerebral artery of rats in the CVB-D group and lesion group were occluded to establish cerebral ischemia. Rats in the CVB-D group were intraperitoneally injected with CVB-D （6.48 mg/kg） every day and with saline （1.5 mL/injection） twice a day. Rats in the lesion group were intraperitoneally injected with saline （2 mL/injection）. MAIN OUTCOME MEASURES： Immunohistochemistry was applied to detect GAP-43 and neurocan expression in the ischemic penumbra region of CVB-D and lesion brains at 2 hours post-cerebral ischemia and at 1, 7, 14, and 30 days post-perfusion （n = 10 at each time point）. Similarly, GAP-43 and neurocan expression was detected in the right hemisphere of naive and sham-operated animals. The results were expressed as positive cells. RESULTS： A total of 100 rats were included in the final analysis. The number of GAP-43 positive cells increased in the CVB-D group 1, 7, 14, and 30 days post-cerebral ischemia/perfusion compared to the lesion group, as indicated by a significant difference between the CVB-D and lesion group （P 〈 0.054）.01）. The number of neurocan-positive cells decreased in the CVB-D group on the first day compared to the model group; however, there was no significant difference between the two groups （P 〉 0.05）. On post-ischemia days 7, 14, and 30, the number of neurocan-positive cells in the CVB-D group was significantly less than in the lesion group （P 〈 0.05）. Both, GAP-43 and neurocan expression was not detectable in brains of naive and sham-operated animals. CONCLUSION： CVB-D treatment up-regulated GAP-43 expression and down-regulated neurocan expression in the ischemic region of RHRSP rats.
文摘BACKGROUND： Growth-associated protein-43 （GAP-43） expression in the nervous system has been demonstrated to promote neural regeneration, neuronal growth and development, as well as synaptic reconstruction. Neurofilament 200 （NF200） expression could reflect degree of injury and repair in injured spinal axons. OBJECTIVE： To observe NF200 expression changes in a rat model of complete spinal cord injury following GAP-43 treatment and to explore the effects of GAP-43 following spinal cord injury. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Histology and Embryology of Kunming Medical University between March 2007 and October 2008. MATERIALS： GAP-43 and GAP-43 antibody were provided by Beijing Boao Biology, China; mouse anti-rat NF200 antibody was purchased from Chemicon, USA. METHODS： Female, 8-week-old, Sprague Dawley rats were randomly assigned into three groups following complete spinal cord injury, with 20 animals in each group： GAP-43 antibody, GAP-43, and model groups. In addition, each group was subdivided into four subgroups according to sampling time after modeling, Le., 3-, 5-, 9-, and 15-day groups, with 5 rats in each group. GAP-43 antibody or GAP-43 was injected into injury sites of the spinal cord, 5 μg/0.2 mL, respectively, twice daily for three consecutive days, followed by three additional days of injection, once daily. The model group did not receive any treatment following injury. MAIN OUTCOME MEASURES： NF200 expression in the damaged spinal area at different stages was detected by immunohistochemistry; lower limb motion function following injury was evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor rating scale. RESULTS： NF200 expression was significantly reduced in the GAP-43 antibody group, compared with GAP-43 and model groups, at 3 and 5 days after spinal cord injury （P 〈 0.05）. In addition, the model group expressed significantly less NF200 than the GAP-43 group （P 〈 0.05）. BBB scores from the GAP-43 antibody and model groups were remarkably less than the GAP-43 group （P 〈 0.05）. At 9 and 15 days of injury after drug withdrawal, NF200 expression was increased in the GAP-43 antibody group, and NF200 expression and BBB scores in the GAP-43 antibody and GAP-43 groups were significantly greater than in the model group （P 〈 0.05）. In particular, the GAP-43 group exhibited greater BBB scores than the GAP-43 antibody group at day 9 （P 〈 0.05）. CONCLUSION： GAP-43 promoted NF200 expression and recovery of lower limb function. Early administration of GAP-43 antibody produced reversible nerve inhibition, which was rapidly restored following withdrawal.
文摘Following granulocyte colony-stimulating factor （G-CSF） treatment,the growth of processes in cul-tured rat retinal ganglion cells （RGCs） in vitro,expression of growth associated protein 43,and expression of microtubule-associated protein 2 mRNA expression were significantly increased.In contrast,RhoA/Rock protein content was significantly reduced by G-CSF treatment.These results indicate that G-CSF promotes the growth of processes in RGCs and increases the expression of growth-associated protein 43 and microtubule-associated protein 2 mRNA by inhibiting the RhoA/Rock pathway,thereby benefiting axonal repair in RGCs exposed to hypoxia.
基金financially supported by the National Program on Key Basic Research Project of China(973 Program),No.2010CB945600,2011CB965100the National Natural Science Foundation of China,No.81070987,30971531,81371213a grant from the International Science & Technology Collaboration Program,No.2011DF30010
文摘Ginsenoside Rg1（Rg1） has anti-aging and anti-neurodegenerative effects. However, the mechanisms underlying these actions remain unclear. The aim of the present study was to determine whether Rg1 affects hippocampal survival and neurite outgrowth in vitro after exposure to amyloid-beta peptide fragment 25–35（Aβ_（25–35））, and to explore whether the extracellular signal-regulated kinase（ERK） and Akt signaling pathways are involved in these biological processes. We cultured hippocampal neurons from newborn rats for 24 hours, then added Rg1 to the medium for another 24 hours, with or without pharmacological inhibitors of the mitogen-activated protein kinase（MAPK） family or Akt signaling pathways for a further 24 hours. We then immunostained the neurons for growth associated protein-43, and measured neurite length. In a separate experiment, we exposed cultured hippocampal neurons to Aβ_（25–35） for 30 minutes, before adding Rg1 for 48 hours, with or without Akt or MAPK inhibitors, and assessed neuronal survival using Hoechst 33258 staining, and phosphorylation of ERK1/2 and Akt by western blot analysis. Rg1 induced neurite outgrowth, and this effect was blocked by API-2（Akt inhibitor） and PD98059（MAPK/ERK kinase inhibitor）, but not by SP600125 or SB203580（inhibitors of c-Jun N-terminal kinase and p38 MAPK, respectively）. Consistent with this effect, Rg1 upregulated the phosphorylation of Akt and ERK1/2; these effects were reversed by API-2 and PD98059, respectively. In addition, Rg1 significantly reversed Aβ_（25–35）-induced apoptosis; this effect was blocked by API-2 and PD98059, but not by SP600125 or SB203580. Finally, Rg1 significantly reversed the Aβ_（25–35）-induced decrease in Akt and ERK1/2 phosphorylation, but API-2 prevented this reversal. Our results indicate that Rg1 enhances neurite outgrowth and protects against Aβ_（25–35）-induced damage, and that its mechanism may involve the activation of Akt and ERK1/2 signaling.
