Rat Brain-derived Neurotrophic Factor Research Articles

Influence of progestational stress on BDNF and NMDARs in the hippocampus of male offspring and amelioration by Chaihu Shugan San

BackgroundProgestational stress has been proven to be a risk for the neural development of offspring, especially in the hippocampus. However, whether Chaihu Shugan San (CSS) can ameliorate hippocampal neural development via the regulation of brain-derived neurotrophic factor (BDNF), and N-methyl-D-aspartate receptors (NMDAR) 2A (NR2A) and 2B (NR2B), and the mechanism of such action remains unclear. MethodsThirty-six female rats were randomly allocated into control, chronic immobilization stress (CIS) and CSS groups according to the random number table, respectively. The male offspring were fed for 21 days after birth then randomly divided into the same three groups (6 rats/group) as the female rats. Female rats, except for the control group, underwent 21-day CIS to established a progestational stress anxiety-like model which was evaluated by body weight, the elevated plus-maze (EPM) test and serum dopamine (DA) measured using an enzyme-linked immunosorbent assay (ELISA). The expression levels of estrogen receptors (ERα/ERβ) and progesterone receptor (PR) in female rat ovaries were quantified by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. The hippocampal tissue in the 21-day offspring was observed by hematoxylin-eosin (HE) staining. The concentration of BDNF, NR2A, and NR2B were measured by RT-qPCR and immunohistochemistry in the CA3 and dentate gyrus (DG) regions of offsprings’ hippocampus. ResultsCompared with the female control group, significant differences in body weight, EPM test and DA concentration were observed in the CIS group, meanwhile, the concentration of ERα (P < 0.05), PR (P < 0.05) and ERβ in the ovaries were decreased. In the offsprings’ hippocampus of the CIS group, the chromatin of the nucleus was edge set and with condensed and irregular morphology nucleus, and the cytoplasm was unevenly stained with spaces around the cells, moreover, the expression levels of BDNF, NR2A, and NR2B were also declined (P < 0.05). However, Chaihu Shugan San reversed these changes, especially the BDNF in the DG region (P < 0.05), and NR2A and NR2B in the CA3 and DG region (P < 0.05). ConclusionsCSS could ameliorate the neural development of the hippocampus in offspring damaged by anxiety-like progestational stress in female rats via regulating the expression levels of ERα, ERβ, and PR in female rat ovaries and BDNF, NR2A, and NR2B in the hippocampus of their offspring.

Adipose-derived stem cells modified by BDNF gene rescue erectile dysfunction after cavernous nerve injury

Cavernous nerve injury is the main cause of erectile dysfunction following radical prostatectomy. The recovery of erectile function following radical prostatectomy remains challenging. Our previous studies found that injecting adipose-derived stem cells (ADSCs) into the cavernosa could repair the damaged cavernous nerves, but the erectile function of the treated rats could not be restored to a normal level. We evaluated the efficacy of ADSCs infected with a lentiviral vector encoding rat brain-derived neurotrophic factor (lenti-rBDNF) in a rat model of cavernous nerve injury. The rats were equally and randomly divided into four groups. In the control group, bilateral cavernous nerves were isolated but not injured. In the bilateral cavernous nerve injury group, bilateral cavernous nerves were isolated and injured with a hemostat clamp for 2 minutes. In the ADSCGFP and ADSCrBDNF groups, after injury with a hemostat clamp for 2 minutes, rats were injected with ADSCs infected with lenti-GFP (1 × 106 in 20 μL) and lenti-rBDNF (1 × 106 in 20 μL), respectively. Erectile function was assessed 4 weeks after injury by measuring intracavernosal pressures. Then, penile tissues were collected for histological detection and western blot assay. Results demonstrated that compared with the bilateral cavernous nerve injury group, erectile function was significantly recovered in the ADSCGFP and ADSCrBDNF groups, and to a greater degree in the ADSCrBDNF group. Neuronal nitric oxide synthase content in the dorsal nerves and the ratio of smooth muscle/collagen were significantly higher in the ADSCrBDNF and ADSCGFP groups than in the bilateral cavernous nerve injury group. Neuronal nitric oxide synthase expression was obviously higher in the ADSCrBDNF group than in the ADSCGFP group. These findings confirm that intracavernous injection with ADSCs infected with lenti-rBDNF can effectively improve erectile dysfunction caused by cavernous nerve injury. This study was approved by the Medical Animal Care and Welfare Committee of Wuhan University, China (approval No. 2017-1638) on June 20, 2017.

Enhanced neuroprotective efficacy of bone marrow mesenchymal stem cells co-overexpressing BDNF and VEGF in a rat model of cardiac arrest-induced global cerebral ischemia

Cardiac arrest-induced global cerebral ischemia injury (CA-GCII) usually leads to a poor neurological outcome without an effective treatment. Bone marrow-derived mesenchymal stem cells (BMMSCs) may provide a potential cell-based therapy against neurologic disorders through induction of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF). To optimize the neuroprotective efficacy of BMMSCs further, in this study we have derived BMMSCs, which co-overexpress both BDNF and VEGF, and tested them for the treatment of CA-GCII in a rat model. Lentiviruses that express rat BDNF exon IV or VEGF-A were created using the bicistronic shuttle vectors of pLVX-IRES-ZsGreen1 and pLVX-IRES-tdTomato, respectively. BMMSCs that were co-transduced with the engineered lentiviruses with co-overexpression of both BDNF and VEGF along with corresponding fluorescent protein reporters were injected via jugular vein of rats that just recovered from a cardiac arrest. Animals were then scored for neurofunctional deficits and examined for brain pathology and gene expression relevant to the engraftment seven days after the treatments. We demonstrate that anchorage of lentiviral vector-transduced BMMSCs, which co-overexpressed both BDNF and VEGF in the hippocampus and temporal cortex along with significantly ameliorated brain pathology and improved neurofunctional performance in CA-GCII rats after transplantation. These findings provide a proof of concept for the further validation of engineered BMMSCs for the treatment of CA-GCII patients in clinical practice in the future.

S-adenosylmethionine Administration Attenuates Low Brain-Derived Neurotrophic Factor Expression Induced by Chronic Cerebrovascular Hypoperfusion or Beta Amyloid Treatment.

Chronic cerebrovascular hypoperfusion is a high-risk factor for Alzheimer's disease (AD) as it is conducive to beta amyloid (Aβ) over-production. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family widely expressed in the central nervous system. The structure of the rat BDNF gene is complex, consisting of eight non-coding exons (I-VIII) and one coding exon (IX). The BDNF gene is transcribed from multiple promoters located upstream of different 5' non-coding exons to produce a heterogeneous population of BDNF mRNAs. S-adenosylmethionine (SAM) produced in the methionine cycle is the primary methyl donor and the precursor of glutathione. In this study, a cerebrovascular hypoperfusion rat model and an Aβ intrahippocampal injection rat model were used to explore the expression profiles of all BDNF transcripts in the hippocampus with chronic cerebrovascular hypoperfusion or Aβ injection as well as with SAM treatment. We found that the BDNF mRNAs and protein were down-regulated in the hippocampus undergoing chronic cerebrovascular hypoperfusion as well as Aβ treatment, and BDNF exons IV and VI played key roles. SAM improved the low BDNF expression following these insults mainly through exons IV and VI. These results suggest that SAM plays a neuroprotective role by increasing the expression of endogenous BDNF and could be a potential target for AD therapy.

Dendritic targeting of short and long 3' UTR BDNF mRNA is regulated by BDNF or NT-3 and distinct sets of RNA-binding proteins.

Sorting of mRNAs in neuronal dendrites relies upon inducible transport mechanisms whose molecular bases are poorly understood. We investigated here the mechanism of inducible dendritic targeting of rat brain-derived neurotrophic factor (BDNF) mRNAs as a paradigmatic example. BDNF encodes multiple mRNAs with either short or long 3′ UTR, both hypothesized to harbor inducible dendritic targeting signals. However, the mechanisms of sorting of the two 3′ UTR isoforms are controversial. We found that dendritic localization of BDNF mRNAs with short 3′ UTR was induced by depolarization and NT3 in vitro or by seizures in vivo and required CPEB-1, -2 and ELAV-2, -4. Dendritic targeting of long 3′ UTR was induced by activity or BDNF and required CPEB-1 and the relief of soma-retention signals mediated by ELAV-1, -3, -4, and FXR proteins. Thus, long and short 3′ UTRs, by using different sets of RNA-binding proteins provide a mechanism of selective targeting in response to different stimuli which may underlay distinct roles of BDNF variants in neuronal development and plasticity.

MP89-20 BDNF OVEREXPRESSION ALTERS THE PHENOTYPE OF CHOLINERGIC NEURONS IN RAT BLADDER

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Non-Neurogenic Voiding Dysfunction1 Apr 2015MP89-20 BDNF OVEREXPRESSION ALTERS THE PHENOTYPE OF CHOLINERGIC NEURONS IN RAT BLADDER Mahendra Kashyap, Subrata Pore, Willam C. Degroat, Christopher J. Chermansky, Naoki Yoshimura, and Pradeep Tyagi Mahendra KashyapMahendra Kashyap More articles by this author , Subrata PoreSubrata Pore More articles by this author , Willam C. DegroatWillam C. Degroat More articles by this author , Christopher J. ChermanskyChristopher J. Chermansky More articles by this author , Naoki YoshimuraNaoki Yoshimura More articles by this author , and Pradeep TyagiPradeep Tyagi More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1819AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Evidence for Brain-derived neurotrophic factor (BDNF) overexpression in OAB is indicated by urine analysis of OAB patients and from animal studies involving detrusor overactivity induced by chemicals or by spinal cord injury. Studies in cardiac field indicate that BDNF signaling enhances parasympathetic tone, but the effect of BDNF overexpression on the phenotype of cholinergic neurons in bladder remain to be investigated. Since spinal cord injury and chemicals induces several other chemicals besides BDNF, we investigated its effect on cholinergic neurons in rat bladder transfected with exogenous BDNF plasmid. METHODS Under isoflurane anesthesia, the bladder wall of adult female Sprague-Dawley rats were non-virally transfected with either 10μg of plasmid DNA encoding the rat BDNF transgene or luciferase plasmid. A week later, bladder tissue was harvested to analyze the expression by immunoreactivity, qPCR and Western blot for BDNF and the proteins involved in neuroexocytosis of acetylcholine. RESULTS 10 fold higher expression of cholinergic neuron specific proteins such as choline acetyltransferase (ChAT) red stain merged with green immunoreactivity for BDNF expression in rat injected with BDNF transgene, compared to rat group injected with luciferase (LUCI). Lumen is indicated by arrow and blue DAPI stains the nucleus in image. Significant upregulation (P<0.05) in high-affinity and low affinity receptor for BDNF namely, TrkB and P75NTR by 4.2 fold and 3.6 fold, respectively was observed. There was 14 fold increase in expression of □1 receptors along with modest rise in Vesicular ACh transporter (VAChT) for facilitating ACh release. Expression of molecules involved in downstream signaling pathways namely, phospholipase C-γ (PLCγ2) and PLCγ1 was increased 51 and 5.5 fold, respectively. CONCLUSIONS Our findings reveal a previously unknown role for BDNF in enhancing the Ach release in bladder through altered phenotype of cholinergic neurons innervating bladder. BDNF induced alterations in the expressions of proteins involved in neuroexocytosis of ACh, especially ChAT, VAChT and α1 adrenergic receptors in bladder establish a mechanistic link between detrusor overactivity and BDNF overexpression induced by chemical or by genetic means. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e1108 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mahendra Kashyap More articles by this author Subrata Pore More articles by this author Willam C. Degroat More articles by this author Christopher J. Chermansky More articles by this author Naoki Yoshimura More articles by this author Pradeep Tyagi More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

BAC-based cellular model for screening regulators of BDNF gene transcription.

BackgroundBrain derived neurotrophic factor (BDNF) belongs to a family of structurally related proteins called neurotrophins that have been shown to regulate survival and growth of neurons in the developing central and peripheral nervous system and also to take part in synaptic plasticity related processes in adulthood. Since BDNF is associated with several nervous system disorders it would be beneficial to have cellular reporter system for studying its expression regulation.MethodsUsing modified bacterial artificial chromosome (BAC), we generated several transgenic cell lines expressing humanised Renilla luciferase (hRluc)-EGFP fusion reporter gene under the control of rat BDNF gene regulatory sequences (rBDNF-hRluc-EGFP) in HeLa background. To see if the hRluc-EGFP reporter was regulated in response to known regulators of BDNF expression we treated cell lines with substances known to regulate BDNF and also overexpressed transcription factors known to regulate BDNF gene in established cell lines.ResultsrBDNF-hRluc-EGFP cell lines had high transgene copy numbers when assayed with qPCR and FISH analysis showed that transgene was maintained episomally in all cell lines. Luciferase activity in transgenic cell lines was induced in response to ionomycin-mediated rise of intracellular calcium levels, treatment with HDAC inhibitors and by over-expression of transcription factors known to increase BDNF expression, indicating that transcription of the transgenic reporter is regulated similarly to the endogenous BDNF gene.ConclusionsGenerated rBDNF-hRluc-EGFP BAC cell lines respond to known modulators of BDNF expression and could be used for screening of compounds/small molecules or transcription factors altering BDNF expression.

Isoflurane Exposure did not Adversely Affect Recognition Memory or Decrease Hippocampal Brain Derived Neurotrophic Factor Expression in the 17 Day Old Rat Pup

A previous study showed that hippocampal BDNF mRNA decreased in 17 day old (D17) rats, relative to agematched naive rats, at day 1, 3, 7 and 14 after sham surgery in a traumatic brain injury model. The anesthetic isoflurane activates GABA and inhibits NMDA receptor currents, both of which are known to decrease Brain-Derived Neurotrophic Factor (BDNF) mRNA in rat hippocampi. Hippocampal BDNF is necessary for normal cognitive function. Effects of isoflurane alone on hippocampal BDNF are not known. We hypothesized that, in D17 rat pups, isoflurane would decrease hippocampal mRNA/protein levels of BDNF and Synapsin I (a downstream target of BDNF important for cognitive function) and impair performance on the Novel Object Recognition Test (NOR). ISOF BDNF and Synapsin I mRNA decreased relative to Naive at day 1 and 8 after exposure, but not at day 14. Isoflurane exposure did not decrease hippocampal protein levels of BDNF or Synapsin I and did not impair NOR performance. In contrast to the neonatal rat pup, anesthetic exposure did not impair cognitive function. We speculate that adverse effects of anesthetics on rat pup cognitive function and BDNF expression are highly dependent on age at exposure.

Stem cell-based delivery of brain-derived neurotrophic factor gene in the rat retina

As an alternative to a viral vector, the application of stem cells to transfer specific genes is under investigation in various organs. Using this strategy may provide more effective method to supply neurotrophic factor to the neurodegenerative diseases caused by neurotrophic factor deprivation. This study investigated the possibility and efficacy of stem cell-based delivery of the brain-derived neurotrophic factor (BDNF) gene to rat retina. Rat BDNF cDNA was transduced into rat bone marrow mesenchymal stem cells (rMSCs) using a retroviral vector. Its incorporation into the experimental rat retina and the expression of BDNF after intravitreal injection or subretinal injection were detected by real-time PCR, western blot analysis, and immunohistochemical staining. For the incorporated rMSCs, retinal-specific marker staining was performed to investigate the changes in morphology and the characteristics of the stem cells. Transduction of the rMSCs by retrovirus was effective, and the transduced rMSCs expressed high levels of the BDNF gene and protein. The subretinal injection of rMSCs produced rMSC migration and incorporation into the rat retina (about 15.7% incorporation rate), and retinal BDNF mRNA and protein expression was increased at 4 weeks after transplantation. When subretinal injection of rMSCs was applied to axotomized rat retina, it significantly increased the expression of BDNF until 4 weeks after transplantation. Some of the transplanted rMSCs exhibited morphological changes, but the retinal-specific marker stain was not sufficient to indicate whether neuronal differentiation had occurred. Using mesenchymal stem cells to deliver the BDNF gene to the retina may provide new treatment for glaucoma.

Sciatic Nerve Regeneration by Microporous Nerve Conduits Seeded With Glial Cell Line‐Derived Neurotrophic Factor or Brain‐Derived Neurotrophic Factor Gene Transfected Neural Stem Cells

Neurotrophic factors such as the glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) promote nerve cell survival and regeneration, but their efficacy in repairing a longer gap defect of rat sciatic nerve (15 mm) has not been established. In this study, two recombinant mammalian vectors containing either rat GDNF gene or BDNF gene were constructed and each was transfected into neural stem cells (NSCs). It was found that the transfection of GDNF or BDNF gene into NSCs led to significantly enhanced expression of GDNF or BDNF mRNA. The amount of GDNF or BDNF protein secreted from the transfected NSCs showed a 3.3-fold or 2.5-fold increase than that from nontransfected NSCs, respectively. The regeneration capacity of rat sciatic nerve in a poly(D,L-lactide) conduit seeded with GDNF or BDNF-transfected NSCs was evaluated by the histology, functional gait, and electrophysiology after 8 weeks of implantation. It was observed that the degree of myelination and the size of regenerated tissue in the conduits seeded with GDNF- and BDNF-transfected NSCs were higher than those seeded with the nontransfected NSCs. Conduits seeded with GDNF-transfected NSCs had the greatest number of blood vessels. The functional recovery assessed by the functional gait and electrophysiology was significantly improved for conduits seeded with GDNF or BDNF-transfected NSCs. It was concluded that the genetically modified NSCs may have potential applications in promoting nerve regeneration and functional recovery.

Effects of olanzapine on brain-derived neurotrophic factor gene promoter activity in SH-SY5Y neuroblastoma cells

Purpose Atypical antipsychotics have neuroprotective effects, which may be one of the mechanisms for their success in the treatment of schizophrenia. Growing evidence suggest that brain-derived neurotrophic factor (BDNF) is abnormally regulated in patients with schizophrenia, and its expression can be up-regulated by atypical antipsychotics. Atypical antipsychotic drugs may positively regulate transcription of the BDNF gene, but the molecular mechanism of atypical antipsychotic drug action on BDNF gene activity has not been investigated. The aim of the present study was to explore the possible involvement of some intracellular signaling pathways in olanzapine action on BDNF promoter activity. Methods We examined the effects of olanzapine on BDNF gene promoter activity in SH-SY5Y cells transfected with a rat BDNF promoter fragment (− 108 to + 340) linked to the luciferase reporter gene. The changes in glycogen synthase kinase-3β (GSK-3β) and cAMP response element (CRE) binding protein (CREB) phosphorylation were measured by Western blot analysis. Results Olanzapine treatment (10–100 µM) increased basal BDNF gene promoter activity in a dose-dependent manner and increased protein levels at high dose, and inhibitors of protein kinase A (PKA), H-89 (10 µM), phosphatidylinositol 3-kinase (PI3K), wortmannin (0.01 µM), PKC (protein kinase C), GF109203 (10 µM), calcium/calmodulin kinase II (CaMKII), and KN-93 (20 µM) partially attenuated the stimulatory effect of olanzapine on BDNF promoter activity. In line with these results, a Western blot study showed that olanzapine (100 µM) increased phosphorylated levels of GSK-3β and CREB, which are notable downstream effectors of the PKA, PI3K, PKC, and CaMKII signaling pathways. Conclusions These results demonstrate that the up-regulation of olanzapine on BDNF gene transcription is linked with enhancement of CREB-mediated transcription via PKA, PI3K, PKC, and CaMKII signaling pathways, and olanzapine may exert neuroprotective effects through these signaling pathways in neuronal cells.

Excitation-Transcription Coupling via Calcium/Calmodulin-dependent Protein Kinase/ERK1/2 Signaling Mediates the Coordinate Induction of VGLUT2 and Narp Triggered by a Prolonged Increase in Glutamatergic Synaptic Activity

Homeostatic scaling of glutamatergic and GABAergic transmission is triggered by prolonged alterations in synaptic neuronal activity. We have previously described a presynaptic mechanism for synaptic homeostasis and plasticity that involves scaling the level of vesicular glutamate (VGLUT1) and gamma-aminobutyric acid (GABA) (VGAT) transporter biosynthesis. These molecular determinants of vesicle filling and quantal size are regulated by neuronal activity in an opposite manner and bi-directionally. Here, we report that a striking induction of VGLUT2 mRNA and synaptic protein is triggered by a prolonged increase in glutamatergic synaptic activity in mature neocortical neuronal networks in vitro together with two determinants of inhibitory synaptic strength, the neuronal activity-regulated pentraxin (Narp), and glutamate decarboxylase (GAD65). Activity-dependent induction of VGLUT2 and Narp exhibits a similar intermediate-early gene response that is blocked by actinomycin D and tetrodotoxin, by inhibitors of ionotropic glutamate receptors and L-type voltage-gated calcium channels, and is dependent on downstream signaling via calmodulin, calcium/calmodulin-dependent protein kinase (CaMK) and extracellular signal-regulated kinase 1/2 (ERK1/2). The co-induction of VGLUT2 and Narp triggered by prolonged gamma-aminobutyric acid type A receptor blockade is independent of brain-derived nerve growth factor and TrkB receptor signaling. VGLUT2 protein induction occurs on a subset of cortically derived synaptic vesicles in excitatory synapses on somata and dendritic processes of multipolar GABAergic interneurons, recognized sites for the clustering of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate glutamate receptors by Narp. We propose that VGLUT2 and Narp induction by excitation-transcription coupling leads to increased glutamatergic transmission at synapses on GABAergic inhibitory feedback neurons as part of a coordinated program of Ca(2+)-signal transcription involved in mechanisms of homeostatic plasticity after prolonged hyperactivity.

BAC transgenic mice reveal distal cis‐regulatory elements governing BDNF gene expression

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of neurotrophic factors, has important functions in the peripheral and central nervous system of vertebrates. We have generated bacterial artificial chromosome (BAC) transgenic mice harboring 207 kb of the rat BDNF (rBDNF) locus containing the gene, 13 kb of genomic sequences upstream of BDNF exon I, and 144 kb downstream of protein encoding exon IX, in which protein coding region was replaced with the lacZ reporter gene. This BDNF-BAC drove transgene expression in the brain, heart, and lung, recapitulating endogenous BDNF expression to a larger extent than shorter rat BDNF transgenes employed previously. Moreover, kainic acid induced the expression of the transgenic BDNF mRNA in the cerebral cortex and hippocampus through preferential activation of promoters I and IV, thus recapitulating neuronal activity-dependent transcription of the endogenous BDNF gene. genesis 48:214–219, 2010. © 2010 Wiley-Liss, Inc.

Brain-Derived Neurotrophic Factor Stimulates Production of Prostacyclin in Cerebral Arteries

The role of brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin receptor kinase B, in control of cerebral circulation is poorly understood. The present study was designed to investigate the cerebral vascular effects of BDNF in vivo. Replication incompetent adenovirus encoding either rat BDNF (AdBDNF) or green fluorescent protein was injected intracisternally into rabbits. Forty-eight hours later, animals were euthanized. Plasma and cerebrospinal fluid levels of BDNF were measured by enzyme-linked immunosorbent assay, vasomotor function of isolated basilar arteries was studied in organ chambers, protein expression in the basilar arteries was studied by Western blotting, prostanoid levels were measured by enzyme-linked immunosorbent assay, and cyclic adenosine 3',5'-monophosphate levels were measured by radioimmunoassay. The levels of BDNF in the cerebrospinal fluid were significantly elevated in AdBDNF-treated rabbits as compared with adenovirus encoding green fluorescent protein-treated rabbits (37+/-5 ng/mL versus 0.006+/-0.003 ng/mL, respectively; P<0.05; n=14). Western blotting studies revealed that in basilar arteries, AdBDNF increased protein expression of prostacyclin synthase, whereas expression of endothelial nitric oxide synthase and phosphorylated (Ser 1177) endothelial nitric oxide synthase remained unchanged. During incubation with arachidonic acid (1 micromol/L), PGI(2) production and levels of cyclic adenosine 3',5'-monophosphate were significantly elevated only in AdBDNF-treated rabbit basilar arteries (P<0.05, n=6). Relaxations to acetylcholine (10(-9) to 10(-5) mol/L) and arachidonic acid (10(-9) to 10(-5) mol/L) were significantly potentiated in basilar arteries from rabbits injected with AdBDNF. Potentiation of relaxations to acetylcholine in AdBDNF-treated basilar arteries was inhibited by the nonselective cyclooxygenase inhibitor, indomethacin (10(-5) mol/L, P<0.05, n=6) and constitutive phospholipase A(2) inhibitor, AACOCF3 (2x10(-5) mol/L, P<0.05, n=5). Our results demonstrate that in cerebral arteries, BDNF-induced activation of tropomyosin receptor kinase B receptor signaling in vivo promotes prostacyclin biosynthesis. These findings provide novel mechanistic insight into the vascular protective effect of BDNF in cerebral circulation.

Differential effects of aripiprazole and haloperidol on BDNF-mediated signal changes in SH-SY5Y cells

Recent studies have suggested that first and second generation antipsychotics (FGAs and SGAs) have different neuroprotective effects. However, the molecular mechanisms of SGAs are not fully understood, and investigations into changes in intracellular signaling related to their neuroprotective effects remain scarce. In the present study, we compared the SGA aripiprazole with the FGA haloperidol in SH-SY5Y human neuroblastoma cells via brain-derived neurotrophic factor (BDNF)-mediated signaling, notably BDNF, glycogen synthase kinase-3β (GSK-3β), and B cell lymphoma protein-2 (Bcl-2). We examined the effects of aripiprazole (five and 10 μM) and haloperidol (one and 10 μM) on BDNF gene promoter activity in SH-SY5Y cells transfected with a rat BDNF promoter fragment (− 108 to + 340) linked to the luciferase reporter gene. The changes in BDNF, p-GSK-3β, and Bcl-2 levels were measured by Western blot analysis. The haloperidol was not associated with a significant difference in BDNF promoter activity. In contrast, aripiprazole was associated with increased BDNF promoter activity only with a dose of 10 μM (93%, p < 0.01). Treatment with aripiprazole at 10 μM increased the levels of BDNF by 85%, compared with control levels ( p < 0.01), whereas haloperidol had no effect. Moreover, cells treated with aripirazole effectively increased the levels of GSK-3β phosphorylation and Bcl-2 at doses of five and 10 μM (30% and 58% and 31% and 80%, respectively, p < 0.05 or p < 0.01). However, haloperidol had no effects on p-GSK-3 β and Bcl-2 expression. This study showed that aripiprazole, but not haloperidol, appeared to offer neuroprotective effects on human neuronal cells. The actions of signaling systems associated with BDNF may represent key targets for both aripiprazole and haloperidol, but the latter may be associated with distinct effects. These differences might be related to the different therapeutic effects of FGAs and SGAs in patients with schizophrenia.

An Analysis of Time-Dependent Changes of Neurotrophic Factors (BDNF, CNTF) in Traumatic Facial Nerve Injury of a Nerve-Cut and Nerve-Crush Model in Rats

To investigate neurotrophic changes in the injured facial nerve in rats. Time-dependent follow-up of brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) concentrations in a standardized nerve-cut and nerve-crush trauma model could present valuable information about estimation of the extent of the injury. Ninety Wistar rats were grouped into permanent (transection: nerve-cut) and transient (compression: nerve-crush) nerve injury and analyzed for neurotrophic changes at Week 1 and after 1, 3, and 6 months. Ten undissected rats served as controls. Permanent injury was accomplished with a 5-mm transection. To model transient injury, the facial nerve was pressed by vascular clamps for 40 minutes. Rat BDNF and CNTF enzyme-linked immunosorbent assay kits were used to perform histochemical analysis of blood samples. Measurements were compared with variance analysis and Student's t tests. BDNF levels in nerve-injured preparations from both groups at consecutive intervals were not significant from those of controls, except for transient increases in the first week. When BDNF levels in nerve-cut and nerve-crush groups were compared at each interval separately, differences were insignificant (p > 0.05). CNTF levels at consecutive intervals were significant from that of control rats in both groups. When CN0054F levels in nerve-cut and nerve-crush groups were compared at each interval separately, differences were significant (p = 0.023, p = 0.001, p = 0.043, and p = 0.023). Elevated levels of BDNF in the first week after nerve injury do not differentiate the severity of the facial nerve injury. However, diminished CNTF levels in the nerve-crush group were significant when compared with that of nerve-cut group. This finding suggests the possibility that CNTF levels can distinguish whether the facial nerve is interrupted after trauma. Further experimental studies should investigate the indicative role of CNTF levels as a marker of nerve disruption in the clinical setting.

Expression changes of multiple brain-derived neurotrophic factor transcripts in selective spinal nerve ligation model and complete Freund's adjuvant model

Brain-derived neurotrophic factor (BDNF) expression changes in the dorsal root ganglion (DRG) and spinal cord in some pain models. Recently, rat BDNF transcripts containing novel 5′ untranslated exons were identified and characterized, and a new numbering system for rat BDNF exons was introduced. We examined the expression profiles of these novel BDNF transcripts in bilateral L4/5 DRGs in an L5-selective spinal nerve ligation (SSNL) model and bilateral L5 DRGs in a complete Freund's adjuvant (CFA) model of rats. L5SSNL increased significantly ( P < 0.05) the expression of total BDNF mRNA and exon I, IIA, IIB, IIC, III, IV, VI, and IXA transcripts in ipsilateral L4 DRG. Although expression of total BDNF mRNA remained unchanged in ipsilateral L5 DRG in the L5SSNL model, expression of exon I transcript increased significantly ( P < 0.05) and that of exon IV transcript decreased significantly ( P < 0.05). The expression profiles of the variant exons in ipsilateral L4 DRG of the L5SSNL model were quite similar to those in ipsilateral DRG of the CFA model, and exon I transcript was the most common BDNF mRNA in these DRGs. Although L5SSNL increased significantly ( P < 0.05) the expression of total BDNF mRNA and exon IIC and IXA transcripts in the contralateral L4/5 DRGs, CFA treatment did not alter the expression of total BDNF mRNA or specific transcripts in the contralateral DRGs. These findings suggest that exon I plays an important role in the increase in BDNF expression in ipsilateral DRGs regardless of condition.

Loss of Huntingtin Function Complemented by Small Molecules Acting as Repressor Element 1/Neuron Restrictive Silencer Element Silencer Modulators

Increased levels of the repressor element 1/neuron restrictive silencer element (RE1/NRSE) silencing activity promoter, and a consequent reduction in the transcription of many RE1/NRSE-bearing neuronal genes, including brain-derived neurotrophic factor (BDNF), have been demonstrated in Huntington disease (HD) and represent one possible effector of its selective neuronal vulnerability. Restoring the expression levels of neuronal genes in diseased neurons therefore seems to be an attractive therapeutic approach. To this end, we have developed a cell-based reporter assay for monitoring RE1/NRSE silencing activity and validated it by genetically inactivating the RE1/NRSE or pharmacologically stimulating global transcription. In a pilot compound screen, we identified three closely related structural analogues that up-regulate reporter expression at low nanomolar concentrations, and follow-up studies have shown that they efficaciously increase endogenous BDNF levels in HD cells. Moreover, one of the compounds increases the viability of HD cells. Our findings suggest a new avenue for the development of drugs for HD and other neurodegenerative disorders based on the pharmacological up-regulation of the production of the neuronal survival factor BDNF and of other RE1/NRSE-regulated neuronal genes.

Central κ-opioid receptor-mediated antidepressant-like effects of nor-Binaltorphimine: Behavioral and BDNF mRNA expression studies

κ-opioid receptor antagonists such as nor-Binaltorphimine (nor-BNI) have been shown to produce antidepressant-like behavioral effects in animal models of depression. The aim of this study was to investigate further the duration of centrally administered nor-BNI-induced antidepressant-like actions measured by both behavior and brain-derived neurotrophic factor (BDNF) gene expression. In addition, antagonist studies were conducted to determine the role of opioid receptor subtypes and the time course of nor-BNI's pharmacological actions. Antidepressant-like behavioral effects were measured by decreased immobility in the rat forced swim test and BDNF mRNA expression was determined by in situ hybridization. Centrally administered nor-BNI (20 μg, i.c.v.) decreased immobility and increased BDNF mRNA expression in the hippocampus on day 1, not on days 3–14, post-administration. Systemic administration of selective μ-, δ- and κ-opioid receptor antagonists did not block nor-BNI-induced antidepressant-like effects. In contrast, i.c.v. administration of nor-BNI 7 or 14 days earlier significantly blocked subsequent nor-BNI-induced decreased immobility and upregulation of BDNF mRNA expression. Although the duration of nor-BNI's antidepressant-like effects did not synchronize with that of its κ-opioid receptor antagonist effects, this study is the first to show that centrally administered nor-BNI, like most clinically used antidepressants, can upregulate BDNF mRNA expression in the rat hippocampus. These findings further demonstrate that central κ-opioid receptor mediates antidepressant-like effects of nor-BNI measured by both behavior and BDNF gene expression.

Mouse and rat BDNF gene structure and expression revisited

Brain-derived neurotrophic factor (BDNF) has important functions in the development of the nervous system and in brain plasticity-related processes such as memory, learning, and drug addiction. Despite the fact that the function and regulation of rodent BDNF gene expression have received close attention during the last decade, knowledge of the structural organization of mouse and rat BDNF gene has remained incomplete. We have identified and characterized several mouse and rat BDNF transcripts containing novel 5′ untranslated exons and introduced a new numbering system for mouse and rat BDNF exons. According to our results both mouse and rat BDNF gene consist of eight 5′ untranslated exons and one protein coding 3′ exon. Transcription of the gene results in BDNF transcripts containing one of the eight 5′ exons spliced to the protein coding exon and in a transcript containing only 5′ extended protein coding exon. We also report the distinct tissue-specific expression profiles of each of the mouse and rat 5′ exon-specific transcripts in different brain regions and nonneural tissues. In addition, we show that kainic acid-induced seizures that lead to changes in cellular Ca2+ levels as well as inhibition of DNA methylation and histone deacetylation contribute to the differential regulation of the expression of BDNF transcripts. Finally, we confirm that mouse and rat BDNF gene loci do not encode antisense mRNA transcripts, suggesting that mechanisms of regulation for rodent and human BDNF genes differ substantially. © 2006 Wiley-Liss, Inc.