Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?

Brain-derived neurotrophic factor(BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters.

Increased expression of brain-derived neurotrophic factor is correlated with visceral hypersensitivity in patients with diarrheapredominant irritable bowel syndrome

BACKGROUND Visceral hypersensitivity is considered to play a vital role in the pathogenesis of irritable bowel syndrome(IBS). Neurotrophins have drawn much attention in IBS recently. Brain-derived neurotrophic factor(BDNF) was found to mediate visceral hypersensitivity via facilitating sensory nerve growth in pre-clinical studies. We hypothesized that BDNF might play a role in the pathogenesis of diarrhea-predominant IBS(IBS-D).AIM To investigate BDNF levels in IBS-D patients and its role in IBS-D pathophysiology.METHODS Thirty-one IBS-D patients meeting the Rome IV diagnostic criteria and 20 ageand sex-matched healthy controls were recruited. Clinical and psychological assessments were first conducted using standardized questionnaires. Visceral sensitivity to rectal distension was tested using a high-resolution manometry system. Colonoscopic examination was performed and four mucosal pinch biopsies were taken from the rectosigmoid junction. Mucosal BDNF expression and nerve fiber density were analyzed using immunohistochemistry. Mucosal BDNF mRNA levels were quantified by quantitative real-time polymerase chain reaction. Correlations between these parameters were examined.RESULTS The patients had a higher anxiety score [median(interquartile range), 6.0(2.0-10.0) vs 3.0(1.0-4.0), P = 0.003] and visceral sensitivity index score [54.0(44.0-61.0)vs 21.0(17.3-30.0), P < 0.001] than controls. The defecating sensation threshold[60.0(44.0-80.0) vs 80.0(61.0-100.0), P = 0.009], maximum tolerable threshold[103.0(90.0-128.0) vs 182.0(142.5-209.3), P < 0.001] and rectoanal inhibitory reflex threshold [30.0(20.0-30.0) vs 30.0(30.0-47.5), P = 0.032] were significantly lower in IBS-D patients. Intestinal mucosal BDNF protein [3.46 E-2(3.06 E-2-4.44 E-2) vs3.07 E-2(2.91 E-2-3.48 E-2), P = 0.031] and mRNA [1.57(1.31-2.61) vs 1.09(0.74-1.42), P = 0.001] expression and nerve fiber density [4.12 E-2(3.07 E-2-7.46 E-2) vs1.98 E-2(1.21 E-2-4.25 E-2), P = 0.002] were significantly elevated in the patients.Increased BDNF expression was positively correlated with abdominal pain and disease severity and negatively correlated with visceral sensitivity parameters.CONCLUSION Elevated mucosal BDNF may participate in the pathogenesis of IBS-D via facilitating mucosal nerve growth and increasing visceral sensitivity.

New insight in expression, transport, and secretion of brain-derived neurotrophic factor: Implications in brainrelated diseases

Brain-derived neurotrophic factor(BDNF) attracts increasing attention from both research and clinical fields because of its important functions in the central nervous system. An adequate amount of BDNF is critical to develop and maintain normal neuronal circuits in the brain. Given that loss of BDNF function has beenreported in the brains of patients with neurodegenerative or psychiatric diseases, understanding basic properties of BDNF and associated intracellular processes is imperative. In this review, we revisit the gene structure, transcription, translation, transport and secretion mechanisms of BDNF. We also introduce implications of BDNF in several brain-related diseases including Alzheimer's disease, Huntington's disease, depression and schizophrenia.

Role of brain-derived neurotrophic factor during the regenerative response after traumatic brain injury in adult zebrafish

Several mammalian animal models of traumatic brain injury have been used, mostly rodents. However, reparative mechanisms in mammalian brain are very limited, and newly formed neurons do not survive for long time. The brain of adult zebrafish, a teleost fish widely used as vertebrate model, possesses high regenerative properties after injury due to the presence of numerous stem cells niches. The ventricular lining of the zebrafish dorsal telencephalon is the most studied neuronal stem cell niche because its dorso-lateral zone is considered the equivalent to the hippocampus of mammals which contains one of the two constitutive neurogenic niches of mammals. To mimic TBI, stab wound in the dorso-lateral telencephalon of zebrafish was used in studies devoted to fish regenerative properties. Brain-derived neurotrophic factor, which is known to play key roles in the repair process after traumatic brain lesions, persists around the lesioned area of injured telencephalon of adult zebrafish. These results are extensively compared to reparative processes in rodent brain. Considering the complete repair of the damaged area in fish, it could be tempting to consider brain-derived neurotrophic factor as a factor contributing to create a permissive environment that enables the establishment of new neuronal population in damaged brain.

Brain-derived neurotrophic factor mediates macrophage migration inhibitory factor to protect neurons against oxygen-glucose deprivation

Macrophage migration inhibitory factor(MIF)is a chemokine that plays an essential role in immune system function.Previous studies suggested that MIF protects neurons in ischemic conditions.However,few studies are reported on the role of MIF in neurological recovery after ischemic stroke.The purpose of this study is to identify the molecular mechanism of neuroprotection mediated by MIF.Human neuroblastoma cells were incubated in Dulbecco’s modified Eagle’s medium under oxygen-glucose deprivation(OGD)for 4 hours and then returned to normal aerobic environment for reperfusion(OGD/R).30 ng/mL MIF recombinant(30 ng/mL)or ISO-1(MIF antagonist;50μM)was administered to human neuroblastoma cells.Then cell cultures were assigned to one of four groups:control,OGD/R,OGD/R with MIF,OGD/R with ISO-1.Cell viability was analyzed using WST-1 assay.Expression levels of brain-derived neurotrophic factor(BDNF),microtubule-associated protein 2(MAP2),Caspase-3,Bcl2,and Bax were detected by western blot assay and immunocytochemistry in each group to measure apoptotic activity.WST-1 assay results revealed that compared to the OGD/R group,cell survival rate was significantly higher in the OGD/R with MIF group and lower in the OGD/R with ISO-1 group.Western blot assay and immunocytochemistry results revealed that expression levels of BDNF,Bcl2,and MAP2 were significantly higher,and expression levels of Caspase-3 and Bax were significantly lower in the MIF group than in the OGD/R group.Expression levels of BDNF,Bcl2,and MAP2 were significantly lower,and expression levels of Caspase-3 and Bax were significantly higher in the ISO-1 group than in the OGD/R group.MIF administration promoted neuronal cell survival and induced high expression levels of BDNF,MAP2,and Bcl2(anti-apoptosis)and low expression levels of Caspase-3 and Bax(pro-apoptosis)in an OGD/R model.These results suggest that MIF administration is effective for inducing expression of BDNF and leads to neuroprotection of neuronal cells against hypoxic injury.

Three important components in the regeneration of the cavernous nerve： brain-derived neurotrophic factor, vascular endothelial growth factor and the JAK/STAT signaling pathway

Retroperitoneal operations, such as radical prostatectomy, often damage the cavernous nerve, resulting in a high incidence of erectile dysfunction. Although improved nerve-sparing techniques have reduced the incidence of nerve injury, and the administration of phosphodiesterase type 5 inhibitors has revolutionized the treatment of erectile dysfunction, this problem remains a considerable challenge. In recent years, scientists have focused on brain-derived neurotrophic factor and vascular endothelial growth factor in the treatment of cavernous nerve injury in rat models. Results showed that both compounds were capable of enhancing the regeneration of the cavernous nerve and that activation of the Janus kinase （JAK）/signal transducer and activator of transcription （STAT） pathway played a major role in the process.

Effect of Transcranial Magnetic Stimulation on the Expression of c-Fos and Brain-derived Neurotrophic Factor of the Cerebral Cortex in Rats with Cerebral Infarct

The effect of transcranial magnetic stimulation （TMS） on the neurological functional recovery and expression of c-Fos and brain-derived neurotrophic factor （BDNF） of the cerebral cortex in rats with cerebral infarction was investigated. Cerebral infarction models were established by using left middle cerebral artery occlusion （MCAO） and were randomly divided into a model group （n=40） and a TMS group （n=40）. TMS treatment （2 times per day, 30 pulses per time） with a frequency of 0.5 Hz and magnetic field intensity of 1.33 Tesla was carried out in TMS group after MCAO. Modified neurological severity score （NSS） were recorded before and 1, 7, 14, 21, and 28 day（s） after MCAO. The expression of c-Fos and BDNF was immunohistochemically detected 1, 7, 14, 21, and 28 day（s） after infarction respectively. Our results showed that a significant recovery of NSS （P〈0.05） was found in animals treated by TMS on day 7, 14, 21, and 28 as compared with the animals in the model group. The positive expression of c-Fos and BDNF was detected in the cortex surrounding the infarction areas, while the expression of c-Fos and BDNF increased significantly in TMS treatment group in comparison with those in model group 7, 14, 21, and 28 days （P〈0.05） and 7 14, 21 days （P〈0.01） after infarction, respectively. It is concluded that TMS has therapeutic effect on cerebral infarction and this may have something to do with TMS＇s ability to promote the expression of c-Fos and BDNF of the cerebral cortex in rats with cerebral infarction.

Role of brain-derived neurotrophic factor and neuronal nitric oxide synthase in stress-induced depression

BACKGROUND： Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor （BDNF） participates in hippocampal dendrite growth. OBJECTIVE： To discuss the role of BDNF and neuronal nitric oxide synthase （nNOS） in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING： Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS： Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine （Xi＇an, China）. BDNF antibody and nNOS antibody were provided by Santa Cruz （USA）. K252a （BDNF inhibitor） and 7-NI （nNOS inhibitor） were provided by Sigma （USA）. METHODS： Animals were randomly divided into five groups： Control group, chronic unpredicted mild stress （CUMS） group, K252a group, K252a＋7-NI group and 7-NI＋CUMS group. While the Control, K252a and K252a＋7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a＋7-NI group, and 1 μL of 7-NI in the 7-NI＋CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES： ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS： Compared with the Control group, the behavior of the CUMS rats was significantly depressed, the expression of BDNF decreased （P 〈 0.01） but the expression of nNOS increased （P 〈 0.01）. The behavior of rats given intra-hippocampal injection of BDNF inhibitor was significantly depressed and the expression of nNOS was significantly increased （P 〈 0.01）. Intra-hippocampal injections of an nNOS inhibitor reversed the depression-like behavioral changes induced by CUMS or intra-hippocampal injection of BDNF inhibitor. CONCLUSION： CUMS induced a decrease in expression of BDNF and an increase in expression of NO in the hippocampus, which may lead to depression.

Effects of lateral ventricular transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene on cognition in a rat model of Alzheimer's disease

In the present study, transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene into the lateral ventricle of a rat model of Alzheimer＇s disease, resulted in significant attenuation of nerve cell damage in the hippocampal CA1 region. Furthermore, brain-derived neurotrophic factor and tyrosine kinase B mRNA and protein levels were significantly increased, and learning and memory were significantly improved. Results indicate that transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene can significantly improve cognitive function in a rat model of Alzheimer＇s disease, possibly by increasing the levels of brain-derived neurotrophic factor and tyrosine kinase B in the hippocampus.

Post-traumatic stress disorder risk and brain-derived neurotrophic factor Val66Met

Brain-derived neurotrophic factor(BDNF), which regulates neuronal survival, growth differentiation, and synapse formation, is known to be associated with depression and post-traumatic stress disorder(PTSD). However, the molecular mechanism for those mental disorders remains unknown. Studies have shown that BDNF is associated with PTSD risk and exaggerated startle reaction(a major arousal manifestation of PTSD) in United States military service members who were deployed during the wars in Iraq and Afghanistan. The frequency of the Met/Met in BDNF gene was greater among those with PTSD than those without PTSD. Among individuals who experienced fewer lifetime stressful events, the Met carriers have significantly higher total and startle scores on the PTSD Checklist than the Val/Val carriers. In addition, subjects with PTSD showed higher levels of BDNF in their peripheral blood plasma than the non-probable-PTSD controls. Increased BDNF levels and startle response were observed in both blood plasma and brain hippocampus by inescapable tail shock in rats. In this paper, we reviewed these data to discuss BDNF as a potential biomarker for PTSD risk and its possible roles in the onset of PTSD.

Brain-derived neurotrophic factor plasma levels and premature cognitive impairment/dementia in type 2 diabetes

AIM To assess the relationship of brain-derived neurotrophic factor(BDNF) with cognitive impairment in patients with type 2 diabetes. METHODS The study included 40 patients with diabetes mellitus type 2(DM2), 37 patients with chronic kidney disease in hem dialysis hemodialysis therapy(HD) and 40 healthy subjects. BDNF in serum was quantified by ELISA. The Folstein Mini-Mental State Examination was used to evaluate cognitive impairment.RESULTS The patients with DM2 and the patients in HD were categorized into two groups, with cognitive impairment and without cognitive impairment. The levels of BDNF showed significant differences between patients with DM2(43.78 ± 9.05 vs 31.55 ± 10.24, P = 0.005). There were no differences between patients in HD(11.39 ± 8.87 vs 11.11 ± 10.64 P = 0.77); interestingly, ferritin levels were higher in patients with cognitive impairment(1564 ± 1335 vs 664 ± 484 P = 0.001). The comparison of BDNF values, using a Kruskal Wallis test, between patients with DM2, in HD and healthy controls showed statistical differences(P < 0.001).CONCLUSION Low levels of BDNF are associated with cognitive impairment in patients with DM2. The decrease of BDNF occurs early and progressively in patients in HD.

Brain-derived neurotrophic factors increase the proliferation and differentiation of endogenous neural stem cells in mouse models of cerebral infarction

BACKGROUND： It has been confirmed that brain-derived neurotrophic factor （BDNF） can promote the proliferation of neural stem cells （NSCs） and protect neuron-like cells in vitro. However, its effect on endogenous NSCs in vivo is still unclear. OBJECTIVE： To evaluate whether BDNF can induce the endogenous NSCs to proliferate and differentiate into the neurons in the mice model of cerebral infarction. DESIGN： A synchronal controlled observation. SETTINGS： Department of Neurology, Microbiology Division of the Department of Laboratory, Tianjin First Central Hospital; Howard Florey Institute, Medical College, the University of Melbourne. MATERIALS： Twenty-four pure breed C57BL/6J mice at the age of 10 weeks old （12 males and 12 females） were divided into saline control group and BDNF-treated group, 6 males and 6 females in each group. METHODS： The experiments were performed at the University of Melbourne from July 2004 to February 2005. ① The left middle cerebral artery （MCA） was ligated in both groups to establish models of cerebral infarction and the Matsushita measuring method was used to monitor the blood flow of the lesioned region supplied by MCA. 75% reduction of blood flow should be reached in the lesioned region. ② At 24 hours after infarction, mice in the BDNF-treated group were administrated with BDNF, which was slowly delivered using an ALZET osmium pump design. BDNF was dissolved in saline at the dosage of 500 mg/kg and injected into the pump, which could release the solution consistently in the following 28 days. The mice in the saline control group accepted the same volume of saline at 24 hours after infarction. ③ The Rotarod function test began at 1 week preoperatively, the time stayed on Rotarod was recorded. The mice were tested once a day till the end of the experiment. At 4 weeks post cerebral infarction, double labeling of Nestin and GFAP, BIH tubulin and CNPase immunostaining was performed to observe the differentiation directions of the re-expressed endogenous NSCs, and the percentages of the cells differentiated into astrocytes, neurons and oligodendrocytes were calculated. MAIN OUTCOME MEASURES： ① The differentiation directions of the re-expressed endogenous NSCs, and the percentage of the cells differentiated into astrocytes, neurons and oligodendrocytes.② Comparison of motor function between the two groups. RESULTS： All the 24 pure C57BL/6J mice were involved in the analysis of results. ①Positively expressed endogenous NSCs appeared in the mice of both groups, and they mainly distributed around the focus of lesion, as well as the contralateral side. The expressed cells in the BDNF-treated group were obviously more than those in the saline control group. ②Activations of endogenous NSCs： At 4 weeks after infarction, re-expressions of endogenous NSCs appeared in both groups. The number of the re-expressed cells in the BDNF-treated group was about 4.2 times higher than that in the saline control group. The percentage of the cells differentiated into neurons in the BDNF-treated group was significantly higher than that in the saline control group （36%, 15%）, the percentage of the cells differentiated into astrocytes was lower than that in the saline control group （54%, 77%）, whereas the percentage of the cells differentiated into oligodendrocytes was similar to that in the saline control group （10%, 8%）. ③ Results of motor functional test： Compared with before cerebral infarction, the mice in both groups manifested as obvious decrease in motor function at 1 week after infarction, whereas the recovery of motor function in the BDNF-treated group was significantly superior to that in the saline control group at 2, 3 and 4 weeks （P 〈 0.01）. CONCLUSION： BDNF can promote the proliferation of endogenous NSCs in the brain of mice with cerebral infarction, it can decrease the differentiation rate of astrocytes, and increase the differentiation rate of neurons. BDNF has small influence on the differentiation of endogenous NSCs into oligodendrocytes, which was not benefit for the recovery of neural axon. Endogenous NSCs may improve the motor function of mice through the above pathways.

Brain-derived neurotrophic factor induces neuron-like cellular differentiation of mesenchymal stem cells derived from human umbilical cord blood cells in vitro

Human umbilical cord blood was collected from full-term deliveries scheduled for cesarean section. Mononuclear cells were isolated, amplified and induced as mesenchymal stem cells. Isolated mesenchymal stem cells tested positive for the marker CD29, CD44 and CD105 and negative for typical hematopoietic and endothelial markers. Following treatment with neural induction medium containing brain-derived neurotrophic factor for 7 days, the adherent cells exhibited neuron-like cellular morphology. Immunohistochemical staining and reverse transcription-PCR revealed that the induced mesenchymal stem cells expressed the markers for neuron-specific enolase and neurofilament. The results demonstrated that human umbilical cord blood-derived mesenchymal stem cells can differentiate into neuron-like cells induced by brain-derived neurotrophic factor in vitro.

Effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats

AIMTo observe effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats.

Neural stem cells over-expressing brain-derived neurotrophic factor promote neuronal survival and cytoskeletal protein expression in traumatic brain injury sites

Cytoskeletal proteins are involved in neuronal survival.Brain-derived neurotrophic factor can increase expression of cytoskeletal proteins during regeneration after axonal injury.However,the effect of neural stem cells genetically modified by brain-derived neurotrophic factor transplantation on neuronal survival in the injury site still remains unclear.To examine this,we established a rat model of traumatic brain injury by controlled cortical impact.At 72 hours after injury,2 × 10~7 cells/m L neural stem cells overexpressing brain-derived neurotrophic factor or naive neural stem cells（3 m L） were injected into the injured cortex.At 1–3 weeks after transplantation,expression of neurofilament 200,microtubule-associated protein 2,actin,calmodulin,and beta-catenin were remarkably increased in the injury sites.These findings confirm that brain-derived neurotrophic factor-transfected neural stem cells contribute to neuronal survival,growth,and differentiation in the injury sites.The underlying mechanisms may be associated with increased expression of cytoskeletal proteins and the Wnt/β-catenin signaling pathway.

Overexpression of brain-derived neurotrophic factor in the hippocampus protects against post-stroke depression

Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor （BDNF）. In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. A BDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo- campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open field test in these rats as well. These findings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.

Tropomyosin-related kinase B/brain derived-neurotrophicfactor signaling pathway as a potential therapeutic targetfor colorectal cancer

Colorectal cancer(CRC) is the second most common cause of cancer-related death in western countries. Approximately one-quarter of newly diagnosed patients for CRC have metastases, and a further 40%-50% experience disease recurrence or develop metastases after all standard therapies. Therefore, understanding the molecular mechanisms involved in the progression of CRC and subsequently developing novel therapeutic targets is crucial to improve management of CRC and patients' long-term survival. Several tyrosine kinase receptors have been implicated in CRC development, progression and metastasis, including epidermal growth factor receptor(EGFR) and vascular EGFR. Recently, tropomyosin-related kinase B(Trk B), a tyrosine kinase receptor, has been reported in CRC and found to clearly exert several biological and clinical features, such as tumor cell growth and survival in vitro and in vivo, metastasis formation and poor prognosis. Here we review the significance of Trk B and its ligand brain derived-neurotrophic factor in CRC. We focus on their expression in CRC tumor samples, and their functional roles in CRC cell lines and in in vivo models. Finally we discuss therapeutic approaches that can lead to the development of novel therapeutic agents for treating Trk B-expressing CRC tumors.

Differences in brain-derived neurotrophic factor gene polymorphisms between acute ischemic stroke patients and healthy controls in the Han population of southwest China

Single-nucleotide polymorphisms in the brain-derived neurotrophic factor gene may affect the secretion and function of brain-derived neurotrophic factor, thereby affecting the occurrence, severity and prognosis of ischemic stroke. This case-control study included 778 patients (475 males and 303 females, mean age of 64.0 ± 12.6 years) in the acute phase of ischemic stroke and 865 control subjects (438 males and 427 females, mean age of 51.7 ± 14.7 years) from the Department of Neurology, Wes: China Hospital, Sichuan University, China between September 2011 and December 2014. The patients' severities of neurological defici:s in the acute phase were assessed using the National Institutes of Health Stroke Scale immediately after admission to hospital. The ischemic stroke patients were divided into different subtypes according to the Trial of Org 10172 in Acute Stroke Treatment classification. Early prognosis was evaluated using the Modified Rankin Scale when the patients were discharged. Genomic DNA was extracted from peripheral blood of participants. Genotyping of rs7124442 and rs6265 was performed using Kompetitive Allele Specific polymerase chain reaction genotyping technology. Our results demonstrated that patients who carried the C allele of the rs7124442 locus had a lower risk of poor prognosis than the T allele carriers (odds ratio [OR]= 0.67;95% confidence interval [CI]: 0.45-1.00;P = 0.048). The patients with the CC or TC genotype also exhibited lower risk than TT carriers (OR = 0.65;95% CI: 0.42-1.00;P = 0.049). The AA genotype at the rs6265 locus was associated with the occurrence of ischemic stroke in patients with large-artery atherosclerosis (OR = 0.5& 95% CI: 0.37-0.90;P = 0.015). We found that the C allele (CC and TC genotypes) at the rs7124442 locus may be protective for the prognosis of ischemic stroke. The AA genotype at the rs6265 locus is likely a protective factor against the occurrence of ischemic stroke in patients with large-artery atherosclerosis. The study protocol was approved by the Ethics Committee of West China Hospital of Sichuan University, China (approval ID number 2008,4]) on July 25, 2008.

Gastrodin promotes the secretion of brain-derived neurotrophic factor in the injured spinal cord

Gastrodin, an active component of tall gastrodia tuber, is widely used in the treatment of dizziness, paralysis, epilepsy, stroke and dementia, and exhibits a neuroprotective effect. A rat model of spinal cord injury was established using Allen＇s method, and gastrodin was administered via the subarachnoid cavity and by intraperitoneal injection for 7 days. Results show that gastrodin promoted the secretion of brain-derived neurotrophic factor in rats with spinal cord injury. After gastrodin treatment, the maximum angle of the inclined plane test, and the Basso, Beattie and Bresnahan scores increased. Moreover, gastrodin improved neural tissue recovery in the injured spinal cord. These results demonstrate that gastrodin promotes the secretion of brain-derived neurotrophic factor, contributes to the recovery of neurological function, and protects neural cells against injury.

Neural stem cell transplantation in the hippocampus of rats with cerebral ischemia/reperfusion injury Activation of the phosphatidylinositol-3 kinase/Akt pathway and increased brain-derived neurotrophic factor expression

The phosphatidylinositol-3 kinase （PI3K）/Akt pathway and brain-derived neurotrophic factor （BDNF） are involved in neurological functional recovery following cerebral ischemia. Therefore, we hypothesized that mechanisms of neuroprotection by transplantation of neural stem cells （NSCs） on cerebral ischemia contributed to activation of the PI3K/Akt pathway and enhanced BDNF expression. In the present study, Wortmannin （a specific, covalent inhibitor of PI3K） was administered adjacent to ischemic hippocampus by stereotactic transplantation to further confirm the neuroprotective mechanisms of NSC transplantation following cerebral ischemia. Results showed that focal infarct volume was significantly smaller in the NSCs group, but the neurological behavior score in the NSC group was significantly greater than the middle cerebral artery occlusion model group, Wortmannin treatment group, and NSCs ＋ Wortmannin treatment group. Protein expression of BDNF was significantly greater in the NSC group compared with the Wortmannin treatment group and NSCs ＋ Wortmannin treatment group. These results suggest that the neuroprotective role of NSC transplantation in the cerebral ischemia activated the PI3K/Akt pathway and upregulated BDNF expression in lesioned brains.