Expression Levels Of Brain-derived Neurotrophic Factor Research Articles

Sulfated Polysaccharide Isolated from the Nacre of Pearl Oyster Improves Scopolamine-Induced Memory Impairment.

Pearl and nacre have been used in traditional medicines for treating brain dysfunctions, such as epilepsy, myopia, palpitations and convulsions. We previously showed that a pearl oyster nacre extract improves scopolamine-induced memory impairments using the Y-maze, Banes maze and object recognition tests. In this study, we aimed to isolate the memory-improving substance using ion-exchange column chromatography and reverse-phase column chromatography and elucidate the molecular mechanism underlying its memory-improving activity. The isolated substance was found to be a sulfated polysaccharide with a molecular weight of approximately 750 kDa. Monosaccharide composition analysis showed that it was rich in galactose, glucose, mannose and uronic acid. Furthermore, the mRNA expression levels of oxidative stress, inflammatory response and neuroprotective factors in the cerebral cortex were investigated. Treatment with the polysaccharide increased the expression levels of the antioxidant enzymes Cu, Zn -superoxide dismutase (SOD) and catalase and attenuated the scopolamine-mediated upregulation of the inflammatory cytokines interleukin-1 and interleukin-6. In addition, the polysaccharide suppressed the decrease in the expression levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). These findings strongly suggest that the polysaccharide in the nacre extract mediated its antiamnesic effects by preventing oxidative stress and inflammation and increasing the expression levels of BDNF and NGF.

Caffeine improves bladder function in diabetic rats via a neuroprotective effect.

Diabetic cystopathy (DCP) is one of the most common complications of diabetes mellitus (DM). A previous study reported that caffeine may improve bladder dysfunction in rats with DM. The aim of the present study was to investigate the mechanisms behind the capacity for caffeine to improve bladder function in rats with DM. Sprague Dawley rats were divided into four groups: control, caffeine, DM and DM plus caffeine treatment (DM + caffeine). Bladder function was measured by urodynamic analyses. The levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and calcitonin gene-related peptide (CGRP) in the bladder tissue were detected by ELISA. Apoptosis in the dorsal root ganglion (DRG) was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, cleaved caspase-3, caspase-9 and cleaved caspase-9 proteins in the DRG were detected by western blotting. Following treatment with caffeine, the urination time and micturition interval of rats with DM were improved, the bladder wet weight was decreased, and the maximum voiding pressure was increased. Relative to that in the DM group, the expression levels of NGF, BDNF and CGRP in the bladder tissue of DM + caffeine rats increased; cellular apoptosis in the DRG of DM + caffeine rates decreased; and the expression levels of Bcl-2, Bax, cleaved caspase-3 and cleaved caspase-9 proteins in the DRG of DM + caffeine rats were restored to a certain extent. In conclusion, caffeine promotes bladder function in rats with DM through a protective effect on DRG.

Effects of combination treatment with transcranial magnetic stimulation and bone marrow mesenchymal stem cell transplantation or Raf inhibition on spinal cord injury in rats.

Spinal cord injury (SCI) remains a global challenge due to limited treatment strategies. Transcranial magnetic stimulation (TMS), bone marrow mesenchymal stem cell (BMSC) transplantation and downregulation of Raf/MEK/ERK signaling effectively improve SCI. The combination of BMSCs and TMS displays synergistic effects on vascular dementia. However, whether TMS displays a synergistic effect when combined with BMSC transplantation or Raf inhibitor (RafI) therapy for the treatment of SCI is not completely understood. The present study aimed to compare the therapeutic effect of monotherapy and combination therapy on SCI. In the present study, 8-week-old female Sprague Dawley rats were used to establish a model of SCI using the weight-drop method followed by treatment with monotherapy (TMS, BMSCs or RafI) or combination therapy (TMS+BMSCs or TMS+RafI). The effect of monotherapy and combination therapy on locomotor function, pathological alterations, neuronal apoptosis and expression of axonal regeneration-associated factors and Raf/MEK/ERK signaling-associated proteins in the spinal cord was analyzed by Basso, Beattie and Bresnahan (BBB) scoring, hematoxylin and eosin staining, TUNEL-neuronal nuclei (NeuN) staining and immunofluorescence or western blotting, respectively. The results demonstrated that compared with untreated SCI model rats, monotherapy significantly enhanced locomotor functional recovery, as evidenced by higher BBB scores, and slightly alleviated histopathological lesions of the spinal cord in SCI model rats. Furthermore, monotherapy markedly suppressed neuronal apoptosis and promoted axonal regeneration, as well as inhibiting astroglial activation in SCI model rats. The aforementioned results were demonstrated by significantly decreased numbers of apoptotic neurons, markedly decreased expression levels of glial fibrillary acidic protein (GFAP), significantly increased numbers of NeuN+ cells, markedly increased expression levels of growth-associated protein 43 (GAP-43) and significantly upregulated nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) expression levels in monotherapy groups (excluding the RafI monotherapy group) compared with untreated SCI model rats. In addition, monotherapy markedly suppressed activation of the Raf/MEK/ERK signaling pathway, as evidenced by significantly reduced p-Raf/Raf, p-MEK/MEK and p-ERK/ERK protein expression levels in monotherapy groups (excluding the BMSC monotherapy group) compared with untreated SCI model rats. Notably, combination therapy further alleviated SCI-induced spinal cord lesions and neuronal apoptosis, increased GAP-43, NGF and BDNF expression levels, downregulated GFAP expression levels and inhibited activation of the Raf/MEK/ERK signaling pathway in SCI model rats compared with the corresponding monotherapy groups. Therefore, it was hypothesized that compared with monotherapy, combination therapy displayed an improved therapeutic effect on SCI by further suppressing Raf/MEK/ERK signaling. The results of the present study provided an important basis for the clinical application of combination therapy.

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.

Preservation of spatial memory and neuroprotection by the fatty acid amide hydrolase inhibitor URB597 in a rat model of vascular dementia.

BackgroundChronic cerebral hypoperfusion (CCH) is a major risk factor for vascular dementia (VaD). There are currently no broadly effective prevention or treatment strategies for VaD, but recent studies have reported promising results following vascular bypass surgery and pharmacomodulation of the brain endocannabinoid system (ECS). In this study, early effects of encephalomyosynangiosis (EMS) bypass surgery and augmented endocannabinoid signaling on CCH-induced cognitive dysfunction and neuronal damage were investigated.MethodsAn animal model of VaD was established by bilateral common carotid artery occlusion (BCCAO). Cannabinoid signaling was upregulated by treatment with the fatty acid amide hydrolase inhibitor URB597 (URB). Spatial learning and memory, cerebral blood flow (CBF), revascularization, brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling, and apoptosis were compared among Sham, BCCAO, BCCAO + EMS, BCCAO + URB, and BCCAO + URB + EMS groups. Spatial learning and memory were evaluated using the Morris water maze (MWM). The CBF in cortex and hippocampus was evaluated by 3-dimensional arterial spin labeling. The neovascularization was visualized by CD34 immunofluorescence staining, and BDNF-TrkB signaling protein expression levels were assessed by Western blotting.ResultsTreatment with URB597 but not EMS alone reversed the spatial learning and memory deficits induced by BCCAO. Neovascularization was enhanced after EMS surgery but not by URB597. Alternatively, there were no significant differences in CBF among treatment groups. Expression levels of BDNF and TrkB were significantly reduced by CCH compared to Sham treatment, and downregulation of both proteins was reversed by URB597 treatment but not EMS. BCCAO enhanced neuronal apoptosis, which was also reversed by URB597.ConclusionsAugmentation of endogenous cannabinoid signaling but not EMS protects against CCH-induced neurodegeneration and preserves spatial learning and memory, possibly by activating BDNF-TrkB signaling.

The possible role of CREB-BDNF signaling pathway in neuroprotective effects of minocycline against alcohol-induced neurodegeneration: molecular and behavioral evidences.

Abuse of alcohol triggers neurodegeneration in human brain. Minocycline has characteristics conferring neuroprotection. Current study evaluates the role of the CREB-BDNF signaling pathway in mediating minocycline's neuroprotective effects against alcohol-induced neurodegeneration. Seventy adult male rats were randomly split into groups 1 and 2 that received saline and alcohol (2g/kg/day by gavage, once daily), respectively, and groups 3, 4, 5, and 6 were treated simultaneously with alcohol and minocycline (10, 20, 30 and 40mg/kg I.P, respectively) for 21days. Group 7 received minocycline alone (40mg/kg, i.p) for 21days. Morris water maze (MWM) has been used to assess cognitive activity. Hippocampal neurodegenerative and histological parameters as well as cyclic AMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) levels were assessed. Alcohol impaired cognition, and concurrent therapy with various minocycline doses attenuated alcohol-induced cognition disturbances. Additionally, alcohol administration boosted lipid peroxidation and levels of glutathione in oxidized form (GSSG), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and Bax protein, while decreased reducing type of glutathione (GSH), Bcl-2 protein, phosphorylated CREB, and BDNF levels in rat hippocampus. Alcohol also decreased the activity in the hippocampus of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR). In comparison, minocycline attenuated alcohol-induced neurodegeneration; elevating expression levels of P-CREB and BDNF and inhibited alcohol induced histopathological changes in both dentate gyrus (DG) and CA1 of hippocampus. Thus, minocycline is likely to provide neuroprotection against alcohol-induced neurodegeneration through mediation of the P-CREB/BDNF signaling pathway.

Neuroprotective effect and mechanism of butylphthalide after cerebral ischemia-reperfusion injury in rats.

To investigate the neuroprotective effect and mechanism of DL-3-n-butylphthalide (NBP) on the brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) and its downstream signalling pathway after cerebral ischemia/reperfusion injury (CIRI) in rats. The middle cerebral artery occlusion/reperfusion (MCAO/R) model was used. Reperfusion was performed 2 h after ischemia, and 20 mg/kg of NBP was intraperitoneally injected. Neurological defect score and pathological changes were performed. Apoptotic cells were detected using in situ end-labelling with TUNEL. The expression of BDNF and TrkB proteins was measured by Western blot and immunohistochemical staining. BDNF mRNA, TrkB mRNA, protein kinase B (AKT) mRNA and caspase-3 mRNA expression were measured using real-time polymerase chain reaction (qPCR). After 24 h of reperfusion, the neurological defect score and the percentage of apoptotic cells in the ischemia/reperfusion group (I/R group) were higher than those in the ischemia/reperfusion + drug group (I/R + d group). The positive expressions of BDNF and TrkB mRNA and protein in the I/R + d group were obviously higher than those in the I/R group (p < 0.05). After intervention with the TrkB receptor inhibitor (K252a), the expression levels of BDNF and TrkB and AKT mRNA were significantly decreased in the ischemia/reperfusion + drug + TrkB receptor inhibitor group (I/R + d + R group) compared with the I/R + d group, however the caspase-3 mRNA expression level showed the reverse trend. The expressions of BDNF, TrkB and p-Akt proteins in the I/R + d group were remarkably higher than those in the I/R group at each time point, and reached the peak at 24 hours after reperfusion, which were earlier than that in the I/R group. Butylphthalide represents aneuroprotective effect after CIRI in rats and used within 24h of early onset contributes to better prognosis. The underlying mechanism may be related to reducing the apoptosis of nerve cells through BDNF/TrkB signalling pathway.

Brain-derived neurotrophic factor and its related enzymes and receptors play important roles after hypoxic-ischemic brain damage.

Brain-derived neurotrophic factor (BDNF) regulates many neurological functions and plays a vital role during the recovery from central nervous system injuries. However, the changes in BDNF expression and associated factors following hypoxia-ischemia induced neonatal brain damage, and the significance of these changes are not fully understood. In the present study, a rat model of hypoxic-ischemic brain damage was established through the occlusion of the right common carotid artery, followed by 2 hours in a hypoxic-ischemic environment. Rats with hypoxic-ischemic brain damage presented deficits in both sensory and motor functions, and obvious pathological changes could be detected in brain tissues. The mRNA expression levels of BDNF and its processing enzymes and receptors (Furin, matrix metallopeptidase 9, tissue-type plasminogen activator, tyrosine Kinase receptor B, plasminogen activator inhibitor-1, and Sortilin) were upregulated in the ipsilateral hippocampus and cerebral cortex 6 hours after injury; however, the expression levels of these mRNAs were found to be downregulated in the contralateral hippocampus and cerebral cortex. These findings suggest that BDNF and its processing enzymes and receptors may play important roles in the pathogenesis and recovery from neonatal hypoxic-ischemic brain damage. This study was approved by the Animal Ethics Committee of the University of South Australia (approval No. U12-18) on July 30, 2018.

BDNF expression in GISTs predicts poor prognosis when associated with PD-L1 positive tumor-infiltrating lymphocytes

ABSTRACT Substantial evidence indicates that brain-derived neurotrophic factor (BDNF) plays an important role in tumorigenesis, in addition to its primary role in neuronal activity. Gastrointestinal stromal tumors (GISTs), which are the most common mesenchymal neoplasms of the gastrointestinal tract, contain multiple types of tumor-infiltrating lymphocytes (TILs) that express relevant immune checkpoint proteins. However, no data have been reported on the role of BDNF in GISTs. This study aimed to investigate the expression pattern and prognostic value of BDNF in GIST patients with different degrees of risk, as well as the relationship between BDNF expression and immune checkpoints. Immunohistochemistry (IHC) demonstrated that higher BDNF expression was more likely to be present in high-risk patients and suggested a poor prognosis. A similar phenomenon was demonstrated in plasma. Even more interesting was that a positive correlation was present between BDNF and PD-L1+ expression on TILs. Moreover, high BDNF expression levels in combination with a high PD-L1+ TIL count predict extremely poor survival. The combination of BDNF expression and TIL PD-L1+ expression as a single biomarker was a powerful significant independent predictor of prognosis. Taken together, BDNF expression may serve as a significant prognostic factor, as the combination of BDNF expression and the PD-L1+ TIL subset led to superior prediction of GIST prognosis. Furthermore, our research coupled a neurotrophin with immunity, which provides novel evidence of neural and immune regulation in a clinical study of GIST.

Reduced Amygdala Microglial Expression of Brain-Derived Neurotrophic Factor and Tyrosine Kinase Receptor B (TrkB) in a Rat Model of Poststroke Depression.

BackgroundPrevious studies have implicated reduced brain-derived neurotrophic factor (BDNF) expression and BDNF-TrkB receptor signaling as well as microglial activation and neuroinflammation in poststroke depression (PSD). However, the contributions of microglial BDNF-TrkB signaling to PSD pathogenesis are unclear.Material/MethodsWe compared depression-like behaviors as well as neuronal and microglial BDNF and TrkB expression levels in the amygdala, a critical mood-relating limbic structure, in rat models of stroke, depression, and PSD. Depression-like behaviors were assessed using the sucrose preference test, open-field test, and weight measurements, while immunofluorescence double staining was employed to estimate BDNF and TrkB expression by CD11b-positive amygdala microglia and NeuN-positive amygdala neuron. Another group of PSD model rats were examined following daily intracerebroventricular injection of proBDNF, tissue plasminogen activator (t-PA), or normal saline (NS) for 7 days starting 4 weeks after chronic unpredictable mild stress (CUMS).ResultsThe numbers of BDNF/CD11b- and TrkB/CD11b-immunofluorescence-positive cells were lowest in the PSD group at 4 and 8 weeks after CUMS (P<0.05). PSD rats also showed reduced weight, sucrose preference, locomotion, and rearing compared with controls (P<0.05). The coexpression of BDNF/NeuN- and TrkB/NeuN-positive cells were not significantly different between groups at 4 and 8 weeks after CUMS (P>0.05). Injection of t-PA increased BDNF/CD11b- and TrkB/CD11b-positive cells in the amygdala of PSD rats and normalized behavior compared with NS or proBDNF injection (P<0.05). In contrast, proBDNF injection reduced BDNF and TrkB expression compared with NS (P<0.05).ConclusionsThese results suggest that decreased BDNF and TrkB expression by amygdala microglia may contribute to PSD pathogenesis and depression-like behaviors.

Norepinephrine in the dentate gyrus is involved in spatial learning and memory alteration induced by chronic restraint stress in aged rats.

The role of norepinephrine of the hippocampal dentate gyrus in spatial learning and memory alteration induced by chronic restraint stress (CRS, 3 h/day, 6 weeks) was investigated in aged rats. Spatial learning and memory were assessed by the Morris water maze (MWM), and the extracellular concentration of norepinephrine and amplitude of field excitatory postsynaptic potential (fEPSP) were measured in the dentate gyrus during MWM test in freely-moving rats. Next, the involvement of β-adrenoceptors in spatial learning and memory of CRS rats was examined by microinjection of its antagonist (propranolol) into the dentate gyrus. In addition, we observed the expression of brain-derived neurotrophic factor (BDNF) protein and activation of cAMP-response element binding protein (CREB) in the dentate gyrus. Compared with the control group, the basal level of norepinephrine, BDNF expression and CREB activation in the dentate gyrus were increased, and the spatial learning and memory abilities were enhanced in CRS rats. In the control group, the norepinephrine concentration and fEPSP amplitude in the dentate gyrus were increased on the second to fourth days of MWM test, and these responses were significantly enhanced in CRS rats. Furthermore, in CRS rats, propranolol significantly decreased the spatial learning and memory abilities, and attenuated the fEPSP response during MWM test, and the BDNF expression and CREB activation in the dentate gyrus. Our results suggest that norepinephrine activation of β-adrenoceptors in the hippocampal dentate gyrus is involved in spatial learning and memory enhancement induced by CRS in aged rats, in part via modulations of synaptic efficiency and CREB-BDNF signaling pathway.

LncRNA KCNQ1OT1 Sponges miR-206 to Ameliorate Neural Injury Induced by Anesthesia via Up-Regulating BDNF.

ObjectiveWidely used in anesthesia, ketamine is reported to induce neurotoxicity in patients. This study aimed to investigate the molecular regulatory mechanism of long non-coding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in ameliorating ketamine-induced neural injury.Materials and MethodsSprague–Dawley rats were intraperitoneally injected with ketamine to induce neuronal injury. PC-12 cells treated with ketamine were used as the cell model. Ketamine-induced aberrant expression of KCNQ1OT1, miR-206 and brain-derived neurotrophic factor (BDNF) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of KCNQ1OT1 and miR-206 on ketamine-induced neural injury in PC-12 cells were then examined by MTT and LDH assay. The regulatory relationships between KCNQ1OT1 and miR-206, and miR-206 and BDNF were detected by dual-luciferase reporter assay.ResultsKetamine induced the apoptosis of neurons of the hippocampus in rats, and the apoptosis of PC-12 cells, accompanied by down-regulation of KCNQ1OT1 and BDNF expressions, and up-regulation of miR-206 expression. Overexpression of KCNQ1OT1 enhanced the resistance to apoptosis of PC-12 cells and significantly ameliorated ketamine-induced nerve injury, while transfection of miR-206 had opposite effects. Mechanistically, KCNQ1OT1 could target miR-206 and reduce its expression level, in turn indirectly increase the expression level of BDNF, and play a protective role in neural injury.ConclusionKCNQ1OT1/miR-206/BDNF axis is demonstrated to be an important regulatory mechanism in regulating ketamine-induced neural injury. Our study helps to clarify the mechanism by which ketamine exerts its toxicological effects and provides clues for the neuroprotection during anesthesia.

Mood disorders are associated with the reduction of brain derived neurotrophic factor in the hypocampus in rats submitted to the hipercaloric diet

Adipose tissue accumulation, resulting from the consumption of hypercaloric foods, can cause a dysfunction of the endocrine system. Such endocrine changes can influence the expression of various neurochemicals including brain-derived neurotrophic factor (BDNF) - associated with cognitive and emotional problems. Here, we investigated the effects of a hypercaloric diet on depression- and anxiety-like behaviors in young rats along with concomitant changes in BDNF expression levels in the hippocampus. Eight week-old Wistar rats (n = 20) were divided in: control diet (CD) group which received industrial food (n = 8) and hypercaloric diet (HD) group which received animal fat and soybean oil (n = 12). After 45days on the diet, the animals were evaluated: body weight and blood biochemical analisys. Changes in mood disposition were evaluated using forced swim test and the elevated plus-maze, whereas hippocampal BDNF expression levels were quantified by ELISA. After 45weeks, the CD group showed a significant increase in body weight relative to the HD group. However, the HD rats had a body fat percentage and exhibited increased level of the biochemical markers. Furthermore, the animals in the HD group presented increased immobility time in the forced swimming test, as well as reduced response to plus-maze test suggesting a depression- and anxiety-like emotional state. In addition, the HD group also showed lower BDNF expression levels in the hippocampus. This study demonstrates that a hypercaloric diet induced increase in adipose tissue concentration in young rats was associated with reduced hippocampal BDNF expression and resulted in an increase in depression- and anxiety-like behaviors. Graphical abstract.

Pretreatment with human urine-derived stem cells protects neurological function in rats following cardiopulmonary resuscitation after cardiac arrest.

Cardiopulmonary resuscitation (CPR) after cardiac arrest (CA) often leads to neurological deficits in the absence of effective treatment. The aim of the present basic research study was to investigate the effects of human urine-derived stem cells (hUSCs) on the recovery of neurological function in rats after CA/CPR. hUSCs were isolated in vitro and identified using flow cytometry. A rat model of CA was established, and CPR was performed. Animals were scored for neurofunctional deficits following hUSC transplantation. The expression levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in the hippocampus and temporal cortex were detected via immunofluorescence. Moreover, brain water content and serum S100 calcium binding protein B (S100B) levels were measured 7 days following hUSC transplantation. The results demonstrated that hUSCs had upregulated expression levels of CD29, CD90, CD44, CD105, CD73, CD224 and CD146, and expressed low levels of CD34 and human leukocyte antigen-DR isotype. In addition, hUSCs were able to differentiate into neuronal cells in vitro. The SPSS 19.0 statistical package was used for statistical analysis, and it was found that the neurological function of the rats after CA/CPR was significantly improved following hUSC transplantation. Furthermore, hUSCs aggregated in the hippocampus and temporal cortex, and secreted large amounts of BDNF and VEGF. hUSC transplantation also effectively inhibited brain edema and serum S100B levels after CPR. Therefore, the results suggested that hUSC transplantation significantly improved the neurological function of rats after CA/CPR, possibly by promoting the expression levels of BDNF and VEGF, as well as inhibiting brain edema.

Vitamin D3/vitamin D receptor signaling mitigates symptoms of post-stroke depression in mice by upregulating hippocampal BDNF expression

Elucidation of the pathogenic mechanisms underlying post-stroke depression (PSD) could aid in the development of effective treatments. The present study explored whether Vitamin D3 (VitD3) can function as an antidepressant in PSD model mice and whether the effect is mediated by upregulation of brain-derived neurotrophic factor (BDNF). Mice were subjected to middle cerebral artery occlusion (MCAO) combined with chronic unpredicted mild stress (CUMS) to established the PSD model. For the mice in each group, Longa and Berderson behavioral tests were performed to evaluate motor function, sucrose preference and forced swimming tests were conducted to assess the cardinal depression-like behaviors anhedonia and helplessness, and western blot and immunohistochemistry were conducted to measure the levels of vitamin D receptor (VDR) and BDNF expression levels in mouse hippocampus. Compared to MCAO alone, subsequent CUMS aggravated motor dysfunction and depression-like behaviors, whereas injection of calcitriol (VitD3) enhanced expression levels of VDR and BDNF in the hippocampus as well as ameliorated both motor dysfunction and depression-like behaviors of PSD model mice, with optimal efficacy at 25 μg/kg. Injection of a BDNF-binding protein (TrkB-IgG) almost completely reversed the antidepressant and neuroprotective effects of VitD3, strongly suggesting that VitD3 improved motor dysfunction and depression-like behaviors in PSD model mice by promoting hippocampal BDNF signaling. Modulation of hippocampal BDNF by VitD3 treatment could be an effective strategy for prevention and treatment of PSD.

In Vitro Study of Adipose-Derived Mesenchymal Stem Cells Transduced with Lentiviral Vector Carrying the Brain-Derived Neurotrophic Factor Gene.

Brain-derived neurotrophic factor (BDNF) exerts its survival-promoting effects on photoreceptors and retinal ganglion cells, however, delivery systems with little-to-no side effect are needed to sustain its controlled release and long-term efficacy. Our previous studies demonstrated that adipose-derived stem cells (ADSCs) are ideal delivery systems for gene therapy; moreover, ADSCs present unique properties like migration to damaged tissue sites, immunomodulation and anti-inflammation. Herein, we propose to employ ADSCs as the BDNF gene delivery vehicle. Different Analyses like flow cytometry, differentiation and cell proliferation assays etc demonstrated that BDNF were successfully transduced into ADSCs and the stemness of ADSCs was maintained even with the transduction. Real Time PCR and Western blot were used to measure mRNA and protein expressions of the BDNF-transduced ADSCs. The results demonstrated that the BDNF expression level of the lentiviral-BDNF transduced ADSCs is significantly increased and, moreover, enhanced the expression of other neurotrophic and downstream signaling factors. The data suggest that ADSCs are a reliable delivery vehicle for BDNF and could be used for the treatment of various diseases.

Antidepressant functions of Jie Yu Chu Fan capsule in promoting hippocampal nerve cell neurogenesis in a mouse model of chronic unpredictable mild stress.

BackgroundDepression is a major public health challenge that imposes a great societal burden. Depression has been attributed to the decreased level of neurotransmitters and brain-derived neurotrophic factor (BDNF) levels. Chinese herbal medicine Jie Yu Chu Fan (JYCF) capsule has been shown to be effective in the management of depression. However, the mechanism has yet to be determined. This study aimed to explore the activity of JYCF against depression by establishing a mouse model of chronic unpredictable mild stress (CUMS) with fluoxetine as the positive control drug.MethodsThe open field test, sucrose preference test, forced swim test, and tail suspension test were carried out to observe the behavioral changes of animals. The levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine, as well as their respective metabolic products 5-hydroxyindoleacetic acid, homovanillic acid (HVA), and 3,4-dihydroxyphenylacetic acid in the mouse hippocampi were quantified by high-performance liquid chromatography (HPLC). Cell proliferation and apoptosis, and early and mature nerve cells in the hippocampi were observed by immunofluorescence. Reverse transcription polymerase chain reaction was used to identify BDNF expression in the hippocampi.ResultsAfter 5 weeks of unpredictable stimulation, a CUMS mouse model was successfully obtained, as indicated by sharply decreased sucrose preference and locomotor activity, as well as an increased immobility time in the forced swim test. Our results demonstrated that treatment with JYCF (1 and 5 g/kg) and fluoxetine (20 mg/kg) dramatically reversed the behavioral abnormalities in CUMS mice. At 1 g/kg, JYCF significantly increased NE, DA, and HVA levels in the hippocampi of CUMS mice. JYCF up-regulated the mRNA expression of BDNF and promoted cell proliferation in hippocampi of CUMS mice.ConclusionsOur study demonstrated that JYCF exhibits antidepressant activity comparable to that of fluoxetine in CUMS mice. Moreover, the antidepressant-like activity of JYCF was shown to be mediated by enhancing hippocampal nerve cell neurogenesis through increasing the levels of monoamine neurotransmitters and BDNF expression.

Effects of physical activity and melatonin on brain-derived neurotrophic factor and cytokine expression in the cerebellum of high-fat diet-fed rats.

AimsObesity suppresses brain‐derived neurotrophic factor (BDNF) expression and increases the expression of pro‐inflammatory cytokines. Herein, we assessed whether exercise training (ET), melatonin administration (MT), or their combination can affect the expressions of BDNF and cytokines in the cerebellum of high‐fat diet (HFD)‐fed rats.MethodsWistar rats (4 weeks old) were divided into five groups: normal diet (ND)‐fed control (ND‐SED), HFD‐fed control (HFD‐SED), HFD‐fed ET (HFD‐ET), HFD‐fed MT (HFD‐MT), and HFD‐fed MT plus ET (HFD‐ETMT) group. The rats were fed ND or HFD for 17 weeks. Rats were subjected to ET (running on a treadmill) and/or MT (melatonin 5 mg/kg body weight, i.p.) for 9 weeks, 8 weeks after beginning the diet intervention. Changes in BDNF and cytokine expression levels were determined using immunoblotting and cytokine arrays, respectively, 36 hours following the last bout of ET.ResultsNeither HFD‐ET nor HFD‐MT rats exhibited enhanced BDNF expression in the cerebellum, but HFD‐ETMT rats had higher level of BDNF expression compared with the others. The expression of TrkB, a BDNF receptor, was higher in HFD‐ETMT rats than in HFD‐ET and HFD‐MT rats. HFD enhanced the expression of interleukin (IL)‐1, IL‐2, and interferon‐γ but reduced the expression of IL‐4, IL‐6, and IL13. ET and ET plus MT counteracted these HFD‐induced changes in cytokine expressions.ConclusionExercise in combination with melatonin confers the potential benefits of increasing BDNF and improving HFD‐induced dysregulations of cytokines in the cerebellum.

Sevoflurane leads to learning and memory dysfunction via breaking the balance of tPA/PAI-1

Exposure to general anesthesia in early childhood may lead to adverse effects on adolescent neurocognition. This study investigated the effects of multiple inhalations of sevoflurane on long-term learning and memory in developing rats, and explored the mechanistic role of the tissue plasminogen activator (tPA)/plasminogen activator inhibitor-1 (PAI-1) fibrinolysis system and its regulatory relationship with the brain derived neurotrophic factor (BDNF) by activation of tropomysin related kinase B (TrkB). After rats were inhaled with sevoflurane for 2 h/d for three days, the expression levels of tPA, PAI-1, BDNF, its precursor(proBDNF), TrkB and phosphorylation of TrkB (p-TrkB) were detected at different time points. After 28 d, Morris water maze was used to examine learning and memory function; Golgi staining was used to investigate synaptic plasticity and synaptic-related proteins, such as Synapsin I(SYN1), growth associated protein 43(GAP-43), and postsynaptic density protein 95(PSD-95). Rats were given exogenous tPA and an inhibitor of PAI-1, TM5275. The results showed multiple inhalation of sevoflurane led to learning and memory dysfunction, downregulated the expression of the synaptic-related proteins, decreased dendritic spine density in the hippocampus, increased the expression level of proBDNF and PAI-1, and reduced expression of BDNF, tPA, and p-TrkB. Interestingly, tPA or TM5275 partially reversed the learning and memory dysfunction and the reduction of synaptic plasticity induced by sevoflurane exposure. Furthermore, they blocked the upregulation of proBDNF and PAI-1 protein expression and increased the expression of BDNF, tPA, and p-TrkB. The protective effect of tPA or TM5275 on rats following multiple sevoflurane inhalation was blocked by a TrkB inhibitor. Multiple inhalation of sevoflurane in rats inhibited the cleavage of proBDNF by disrupting the balance of the tPA/PAI-1 fibrinolysis system. This blocked the activation of the downstream TrkB signaling pathway and reduced hippocampal synaptic plasticity, leading to long-term learning and memory dysfunction. Therefore, Sevoflurane exposure could lead to learning and memory dysfunction by inhibiting BDNF cleavage via breaking the balance of tPA/PAI-1.

Retracted: Allopregnanolone restores the tyrosine hydroxylase‐positive neurons and motor performance in a 6‐OHDA‐injected mouse model

AimsIt has been reported that allopregnanolone (APα) promotes the neurogenesis of the neural progenitor cells (NPCs) in the subventricular zone (SVZ) and prevents the decrease of dopaminergic neurons in 6‐hydroxydopamine (6‐OHDA)‐treated mice by binding to γ‐aminobutyric acid A receptor (GABAAR) and then opening voltage‐gated L‐type Ca2+ channel, but the underlying mechanisms remain elusive. The aim of this study was to explore the possible involvement of GABAAR and calcium/calmodulin‐dependent protein kinase II delta 3 (CaMKIIδ3) in this process.Methods6‐OHDA‐treated mice and primary cultured midbrain cells were administrated with APα and GABAAR antagonist bicuculline (Bic), and the proliferation and differentiation of NPCs, the tyrosine hydroxylase (TH)‐positive neurons and their fibers, the expression levels of CaMKIIδ3 and brain‐derived neurotrophic factor (BDNF), and motor functions were measured using ELISA, immunohistochemical staining, real‐time RT‐PCR, Western blot, and behavioral test.ResultsAllopregnanolone significantly promoted the phosphorylation of cytoplasmic CaMKIIδ3 and its nuclear translocation by binding to GABAAR, which, in turn, increased the expression levels of BDNF. This may account for the findings that the exogenous APα enhanced the proliferation and differentiation of NPCs, and ameliorated the nigrostriatal system and behavioral performance in 6‐OHDA‐treated mice.ConclusionsAllopregnanolone may directly activate GABAAR, which, in turn, enhance the proliferation and differentiation of NPCs via upregulating the expression levels of CaMKIIδ3, and finally contribute to the restoration of dopaminergic neurons in 6‐OHDA‐treated mice.