Ashwagandha and Its Active Ingredient, Withanolide A, Increase Phosphorylation of TrkB in Cultured Hippocampal Neurons

Aims: To primary rat embryonic hippocampal neurons in culture, ashwagandha or one of its active ingredients, withanolide A were added in the presence or absence of nutrient supplementation and then assayed for activity of the BDNF receptor, TrkB. Study Design: Primary hippocampal neurons were cultured and grown in nutrient-rich or nutrient-poor medium. Ashwagandha or withanolide A were then be added to both types of media with or without an inhibitor of TrkB or either the PI-3K or MAPK pathway. Place and Duration of Study: Department of Biological Sciences, California State University, Los Angeles, CA, USA, between July 2021 and August 2022. Methodology: Rat embryos were removed by cesarean section from mother rats at 18 days’ gestation and the hippocampi of the former dissected, plated into culture dishes, and treated with the appropriate drug(s) (see Study Design above). After 4 days, neurons were harvested for Western blotting. Optical density of Western blot bands were quantified and statistically analyzed in a 2-way ANOVA, using a level of statistical significance at P < .05. Results: Under normal conditions (with N2 supplement), ashwagandha, but not withanolide A, increased phospho-TrkB immunoreactivity when compared to the effects of vehicle (controls, F(11, 24) = 22.48, P < .001), although withanolide A did not quite reach statistical significance (P = .069) when compared to that of the controlled condition. Likewise, under nutrient-deprived conditions, both ashwagandha and withanolide A also increased phosphorylation of TrkB when compared to that of vehicle-nutrient-deprived conditions (P < .0001). The same results were obtained in the presence of inhibitors of TrkB itself and the PI-3K (ashwagandha, P < .001; withanolide A, P < .001) and MAPK (ashwagandha, P = .027; withanolide A, P = .045) pathways. Conclusion: Ashwagandha or withanolide A activates TrkB, in nutrient-deprived hippocampal neurons, underscoring its role in neuronal survival signaling.

Antidepressant mechanism of Shenling Kaixin Granules based on BDNF/TrkB/CREB pathway / 中国中药杂志

To investigate the antidepressant mechanism of Shenling Kaixin Granules(SLKX) in treating chronic unpredictable mild stress(CUMS) model rats. Ninety male SD rats were randomly divided into control group, model group, Shugan Jieyu Capsules(110 mg·kg~(-1)) group and SLKX low-(90 mg·kg~(-1)), medium-(180 mg·kg~(-1)), and high-dose(360 mg·kg~(-1)) groups. Depression rat model was replicated by CUMS method. After treatment, the behavioral changes of rats were evaluated by sugar preference, open field, elevated cross maze and forced swimming experiments. The contents of interleukin 1 beta(IL-1β), tumor necrosis factor α(TNF-α), brain-derived neurotrophic factor(BDNF) and 5-hydroxytryptamine(5-HT) in serum were determined by enzyme linked immunosorbent assay(ELISA), and the activities of superoxide dismutase(SOD) and catalase(CAT) in hippocampal CA1 region were also detected. Pathological changes in hippocampal CA1 region were detected by hematoxylin-eosin(HE) staining, and Western blot was used to determine the expression of nerve growth factor(NGF), BDNF, phospho-tyrosine kinase receptor(p-TrkB)/TrkB, phospho-cAMP-response element binding protein(p-CREB)/CREB, nuclear factor E2 related factor 2(Nrf2), heme oxygenase 1(HO-1), B-cell lymphoma-2(Bcl-2)/Bcl-2 associated X protein(Bax) and caspase-3 in hippocampal CA1 region. RESULTS:: showed that compared with the control group, the model group had decreased sugar preference, reduced number of entries and time spent in the center of open field and shortened total distance of movement, reduced number of entries and proportion of time spent in open arm, and increased number and time of immobility in forced swimming experiment. Additionally, the serum contents of IL-1β and TNF-α and the expression of caspase-3 were higher, while the contents of BDNF and 5-HT, the activities of SOD and CAT in hippocampal CA1 region, the expressions of NGF, BDNF, p-TrkB/TrkB, p-CREB/CREB, HO-1 and Bcl-2/Bax, and the Nrf2 nuclear translocation were lower in model group than in control group. Compared with the conditions in model group, the sugar preference, the number of entries and time spent in the center of open, total distance of movement, and the number of entries and proportion of time spent in open arm in treatment groups were increased while the number and time of immobility in forced swimming experiment were decreased; the serum contents of IL-1β and TNF-α and the expression of caspase-3 were down regulated, while the contents of BDNF and 5-HT, the activities of SOD and CAT in hippocampal CA1 region, the expressions of NGF, BDNF, p-TrkB/TrkB, p-CREB/CREB, HO-1, Bcl-2/Bax, and Nrf2 nuclear translocation were enhanced. In conclusion, SLKX might regulate the Nrf2 nucleus translocation by activating BDNF/TrkB/CREB pathway, lower oxidative stress damage in hippocampus, inhibit caspase-3 activity, and reduce apoptosis of hippocampal nerve cells, thereby playing an antidepressant role.

Tropomyosin receptor kinase B-mediated signaling in integration of neuropathic pain and obesity in diabetic polyneuropathy / Sinalização mediada pelo receptor de tropomiosina quinase tipo B na integração de dor neuropática e obesidade na polineuropatia diabética

ABSTRACT Objective: To assess the quantitative serum levels of tropomyosin receptor kinase receptor B, and to estimate its association with serum concentration of brain-derived neurotrophic factor and obesity in patients with painful and painless forms of diabetic polyneuropathy. Methods: We examined 70 patients with diabetic polyneuropathy with confirming peripheral nerve dysfunction by electroneuromyography and measuring of serum levels tropomyosin receptor kinase receptor B and brain-derived neurotrophic factor by enzyme immunoassay. Diabetic polyneuropathy was diagnosed using the modified Toronto Consensus (2011) criteria, while neuropathic pain was assessed using an 11-point Numerical Pain Rating Scale. The patients were divided into two groups according to presence or absence of neuropathic pain. Control Group consisted of 14 healthy persons. Results: The serum levels of tropomyosin receptor kinase receptor B and brain-derived neurotrophic factor in patients with diabetic polyneuropathy are significantly higher than healthy controls (p=0.000). Hyperexpression of brain-derived neurotrophic factor in serum was associated with painful form of diabetic polyneuropathy (R=0.392, p=0.012) and obesity (R=0.412, p=0.001). On the contrary high concentration of tropomyosin receptor kinase receptor B in serum associated with painless diabetic polyneuropathy by Pain DETECT (R=-0.354, p=0.015), low body weight (R=-0.354, p=0.015) and severe demyelization of nerve fibers (R=-0.574, p=0.001), indicated "non-working" receptor detected in serum. Conclusion: Tropomyosin receptor kinase receptor B signaling is involved in the modulation of neuropathic pain and obesity in diabetic polyneuropathy.

RESUMO Objetivo: Avaliar os níveis séricos quantitativos do receptor da tropomiosina quinase B, e estimar sua associação com os níveis séricos do fator neurotrófico derivado do cérebro e a obesidade, em pacientes com formas dolorosas e indolores de polineuropatia. Métodos: Examinamos 70 pacientes com polineuropatia diabética, com disfunção de nervo periférico confirmada por eletroneuromiografia e medida de níveis séricos do receptor da tropomiosina quinase B e do fator neurotrófico derivado do cérebro, por imunoensaio enzimático. Polineuropatia diabética foi diagnosticada através dos critérios modificados do Consenso de Toronto (2011), e a dor neuropática foi avaliada pela escala Numerical Pain Rating com 11 pontos. Os pacientes foram divididos em dois grupos, conforme presença ou ausência de dor neuropática. O Grupo Controle tinha 14 indivíduos saudáveis. Resultados: Os níveis séricos do receptor da tropomiosina quinase B e do fator neurotrófico derivado do cérebro em pacientes com polineuropatia diabética são significativamente mais elevados do que controles saudáveis (p=0,000). Hiperexpresssão do fator neurotrófico derivado do cérebro no soro foi associada à forma dolorosa da polineuropatia diabética (R=0,392, p=0,012) e obesidade (R=0,412, p=0,001). Por outro lado, alta concentração sérica de receptor da tropomiosina quinase B, associada à polineuropatia diabética indolor por PainDETECT (R=-0,354, p=0,015), baixo peso corporal (R=-0,354, p=0,015) e grave desmielização de fibras nervosas (R=-0,574, p=0,001), indicaram receptor "não funcionante" detectado no soro. Conclusão: A sinalização do receptor da tropomiosina quinase B está envolvida na modulação da dor neuropática e obesidade na polineuropatia diabética.

Effects of cerebroprotein hydrolysate for injection (II) on neuritogenesis and its underlying mechanisms / 中国药科大学学报

@#In most mammalian central nervous system diseases, axons are damaged.Due to the limited ability of damaged neurons to promote axonal regeneration, the formation of glial scar and the release of inhibitory nutrients, it is difficult to regenerate axons of damaged neurons. The purpose of this study was to investigate the effect of cerebroprotein hydrolysate for injection (II) (CBL) on neuritogenesis and its underlying mechanism. Immunofluorescence staining was used to detect the axon length of mouse neuroma cells (Neuro-2a) and mouse primary cortical neuronal cells. Western blotting was used to detect the expression of phosphorylated TrkB protein in Neuro-2a cells and mouse primary cortical neuronal cells. The results showed that CBL could increase the axon length of Neuro-2a cells or mouse primary cortical neuronal cells, and that the phosphorylation level of TrkB in neuronal cells was significantly increased when 5 μg/mL CBL was applied to neuronal cells for 1 h. In conclusion, CBL can promote neuritogenesis, and increase the expression of phosphorylated TrkB, which may be related to the activation of TrkB signaling pathway.

Effect and Mechanism of Chaihu Jia Longgu Muli Tang on Hippocampus of Rats with Chronic Stress Depression Based on BDNF/TrkB/CREB Pathway / 中国实验方剂学杂志

Objective:To explore the effect of Chaihu Jia Longgu Muli Tang on the hippocampus of rats with chronic stress depression based on the brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB)/cyclic adenosine phosphate response element-binding protein (CREB) pathway. Method:Sixty SD rats were divided into a blank group (<italic>n</italic>=10) and an experimental group (<italic>n</italic>=50) for the induction of the chronic stress depression model. The rats in the experimental group were further divided into the following five groups: a model group， a fluoxetine hydrochloride group (0.003 g·kg^-1), and low-(1.625 g·kg^-1), medium-(3.25 g·kg^-1), and high-dose (6.5 g·kg^-1) Chaihu Jia Longgu Muli Tang groups. The rats were administered correspondingly by gavage once a day for eight weeks. Behavioral tests were performed to evaluate the depression state of the rats before modeling， after modeling， and after drug administration. Hematoxylin-eosin (HE) staining was used to observe the morphological changes in the hippocampus of rats. The immunohistochemical (IHC) staining was used to quantitatively detect BDNF protein expression in the rat hippocampus. The mRNA and protein expression of BDNF， TrkB， and CREB in the rat hippocampus was detected by the real-time fluorescence-based quantitative PCR (Real-time PCR) and Western blot， respectively. Result:Compared with the blank group， the model group showed decreased sucrose preference rate (<italic>P</italic><0.05)， declining horizontal and vertical scores (<italic>P</italic><0.05)， and prolonged immobility time and floating time (<italic>P</italic><0.05). Additionally， HE staining results revealed that hippocampal neuron structure was damaged. IHC staining showed that the mRNA and protein expression of BDNF， TrkB， and CREB was significantly decreased (<italic>P</italic><0.05). Compared with the model group， the fluoxetine hydrochloride group and the Chaihu Jia Longgu Muli Tang groups displayed elevated sucrose preference rate (<italic>P</italic><0.05)， increased horizontal and vertical scores (<italic>P</italic><0.05)， and shortened immobility time and floating time (<italic>P</italic><0.05). Furthermore, the hippocampal neuron structure was significantly repaired. IHC staining showed that the mRNA and protein expression of BDNF， TrkB， and CREB was significantly increased (<italic>P</italic><0.05). Conclusion:Chaihu Jia Longgu Muli Tang can significantly improve the depression-like behaviors of rats after chronic stress stimulation and enhance the regeneration and repair of neurons in the hippocampus. The underlying mechanism may be related to the up-regulation of the BDNF/TrkB/CREB signaling pathway in the hippocampus of rats.

Effect of Sinisan on BDNF/TrkB， 5-HT/5-HT1AR， and HPA axis in Depression Model Rats / 中国实验方剂学杂志

Objective:To observe the effect of Sinisan on the brain-derived neurotrophic factor （BDNF）/tyrosine kinase receptor B （TrKB）， 5-hydroxytryptamine （5-HT）/5-HT1A receptor （5-HT1AR）， and hypothalamus-pituitary-adrenal （HPA） axis in depressed rats， and explore the antidepressant mechanism of Sinisan based on BDNF/TrKB， 5-HT/5-HT1AR， and HPA axis. Method:A total of 120 male Wistar rats were randomly divided into a normal group， a model group， a fluoxetine （0.01 g·kg^-1） group， and low- （1.25 g·kg^-1）， medium- （2.5 g·kg^-1）， and high-dose （5 g·kg^-1） Sinisan groups， with 20 rats in each group. The depression model was induced by isolation combined with chronic unpredictable mild stimulation（CUMS） in rats except for those in the normal group for 21 days. Rats were then treated correspondingly once a day for 21 days by gavage. Those in the normal group and the model group received an equal volume of normal saline. During the intervention， the model rats were stimulated continuously. The depressive state of CUMS model rats was evaluated by sucrose preference test and open field test. Enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of corticotropin-releasing hormone （CRH）， adrenocorticotropic hormone （ACTH）， and corticosterone （CORT） in the plasma and BDNF and 5-HT levels in the hippocampal homogenate. The mRNA expression of hippocampal TrKB， 5-HT1AR， glucocorticoid receptor （GR）， and mineralocorticoid receptor （MR） was detected by real-time fluorescence-based quantitative polymerase chain reaction （Real-time PCR）. The protein expression of hippocampal TrKB， 5-HT1AR， GR， and MR was detected by Western blot. The histomorphological changes of the hippocampus were observed by hematoxylin-eosin （HE） staining. Result:Compared with the normal group， the model group showed decreased sucrose preference rate （<italic>P</italic><0.01）， reduced horizontal and vertical scores in the open field test （<italic>P</italic><0.01）， increased plasma content of CRH， ACTH， and CORT （<italic>P</italic><0.01）， declining content of BDNF and 5-HT in the hippocampus （<italic>P</italic><0.01）， dwindled mRNA and protein expression levels of TrKB， 5-HT1AR， and GR （<italic>P</italic><0.01）， elevated mRNA and protein expression of MR （<italic>P</italic><0.01）， and damaged hippocampal neurons revealed by HE staining. Compared with the model group， the groups with drug intervention showed increased sucrose preference rate （<italic>P</italic><0.01） and horizontal and vertical scores in the open field test （<italic>P</italic><0.05， <italic>P</italic><0.01）， decreased content of plasma CRH， ACTH， and CORT （<italic>P</italic><0.05， <italic>P</italic><0.01）， elevated content of hippocampal BDNF and 5-HT （<italic>P</italic><0.05， <italic>P</italic><0.01）， elevated mRNA and protein expression levels of hippocampal TrKB， 5-HT1AR， and GR （<italic>P</italic><0.05， <italic>P</italic><0.01）， reduced mRNA and protein expression levels of hippocampal MR （<italic>P</italic><0.05， <italic>P</italic><0.01）， and recovered hippocampal neurons as revealed by HE staining. Conclusion:Sinisan can exert a significant antidepressant effect by increasing hippocampal BDNF and 5-HT content， up-regulating TrKB， 5-HT1AR， and GR mRNA and protein expression， down-regulating MR mRNA and protein expression， inhibiting HPA axis hypertrophy， and enhancing the regeneration and repair of hippocampal neurons.

Neuroprotective Effect by Wutoutang in Spinal Nerve Ligation Mice via BDNF/TrkB Signaling Pathway / 中国实验方剂学杂志

Objective::To investigate the neuroprotective effect and mechanism by Wutoutang (WTT) in the spinal nerve ligation (SNL) mice by neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling BDNF/tyrosine kinase receptor B (TrkB). Method::The 40 mice were randomly divided into Sham group, SNL group, WTT group(126 mg·kg-1), ANA-12+ WTT group.The L5 spinal nerve ligation model mice were established in mice, After that, WTT was administrated from the first day to the 10th day, then the consecutive 7-day hippocampal injection of ANA-12(0.05 nmol·L-1)were lasted for 7 days.The levels of brain-derived BDNF, cAMP-response element binding protein(CREB), and protein kinase B(Akt)and the change of hippocampal glutamatergic and GABAergic neurons in mice were detected by tissue immunofluorescence.E14 pregnant ICR mice were sacrificed and the hippocampus were dissected which were divided into control group, glycine group, tumo necrosis factor(TNF)-α(5 mg·L-1)+ glycine group, TNF-α+ WTT(5 mg·L-1)+ glycine group, TNF-α+ WTT+ glycine+ BDNF-siRNA group, TNF-α+ WTT+ glycine+ Akt-siRNA group, TNF-α+ WTT+ glycine+ CREB-siRNA group, the primary and secondary dendrrictes, in which the arrowheads indicate the expression od postsynapti desity protein 95(PSD95) in the shafts and arrows were tested by cellular immunofluorescence.The neurons were divided into control group, glycine group, ANA-12 group(0.5 mmol·L-1), ANA-12+ glycine group, ANA-12+ WTT group, ANA-12+ WTT+ glycine group, the morphology of hippocampal neurons were tested by cellular immunofluorescence. Result::Compared with Sham group, BDNF, Akt and CREB positive cell of SNL group decreased significantly(P<0.01), the hippocampal glutamatergic and GABAergic neurons out of balance(P<0.01). Compared with SNL group, the BDNF, Akt and CREB positive cell of WTT group increased significantly(P<0.01), Glutamine-aminobutyric acid neurons regein balance(P<0.01). Compared with WTT group, BDNF and CREB positive cell of ANA-12+ WTT group decreased significantly(P<0.05), Glutamine-aminobutyric acid neurons was disorderedd(P<0.05). Comparaed with control group, the level of PSD95 of glycine group were increase significantly(P<0.01). The number of dendritic spine density apically and basally of glycine group were increase significantly(P<0.01), but the primary and secondary dendrites of ANA-12 group, ANA-12+ glycine group, ANA-12+ WTT group, ANA-12+ WTT+ glycine group were not change.Comparaed with glycine group, the level of PSD95 of TNF-α+ glycine group were decreased significantly(P<0.01). Comparaed with TNF-α+ glycine group, the level of PSD95 of TNF-α+ WTT+ glycine group were increase significantly(P<0.01). Comparaed with TNF-α+ WTT+ glycine group, the level of PSD95 of TNF-α+ WTT+ glycine+ BDNF-siRNA group, TNF-α+ WTT+ glycine+ Akt-siRNA group, TNF-α+ WTT+ glycine+ CREB-siRNA group were decreased significantly(P<0.01). Conclusion::In vivo and in vitro studies have shown that the WTT mediated remission of the primary hippocampal glutamatergic neurons were dependent on the BDNF/TrkB pathway.

Anti-depressant Mechanism of Qing' ewan in CUMS Rats Based on Estrogen Receptor Pathway / 中国实验方剂学杂志

Objective::To study the anti-depressive effect of Qing' ewan in treating chronic unpredictable mild stress (CUMS) in rats, and the regulatory effect on estrogen receptor and estrogen receptor-related signaling pathways, in order to explore its anti-depressive mechanism. Method::The CUMS model was established. The experiment was divided into normal control group, model group, escitalopram oxalate group (positive control) and Qing' ewan groups (1.71, 5.13, 15.39 g·kg-1). After 4 weeks of modeling, rats were treated with corresponding drugs for 2 weeks. Behavioral evaluation [sucrose preference test (SPT), forced swimming test (FST), open field test (OFT)] was conducted to assess if the CUMS model was successful. Western blot was used to analyze the protein expression levels of estrogen receptor α (ERα), estrogen receptor β (ERβ), brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB). Result::Compared with the normal group, the sucrose consumption rate and the score of OFT in the model group decreased(P<0.05, P<0.01), the immobility time of FST prolonged significantly(P<0.01), and the protein expression levels of ERα, ERβ, BDNF and TrkB decreased(P<0.05, P<0.01). Compared with the model group, the behavioral performance of the treated group was improved, the sucrose consumption rate and the score of OFT increased(P<0.05, P<0.01), and the immobility time decreased(P<0.05). The protein expressions of ERα, ERβ, BDNF and TrkB in the treated group were significantly up-regulated(P<0.05, P<0.01), especially the middle-dose Qing' ewan group (5.13 g·kg-1). Conclusion::Qing' ewan can improve depression-like behavior in CUMS rats. Its mechanism may be related to the neuroprotective effect by up-regulating the expressions of ERα and ERβ and activating estrogen receptor-mediated ERβ/BDNF/TrkB pathways.

Dabuyuan Jian Improves Hippocampal Synaptic Plasticity of APP/PS1 Double Transgenic Mice by Regulating BDNF/TrkB/CREB Signal Pathway / 中国实验方剂学杂志

Objective:To observe the effect of Dabuyuan Jian on the synaptic plasticity of hippocampus and the brain derived neurotrophic factor （BDNF）/tyrosine kinase receptor （TrkB）/cyclic adenosine phosphate reactive element binding protein （CREB） signaling pathway in amyloid precursor protein/presenilil （APP/PS1） mice， and to explore its possible mechanism for improving synaptic plasticity. Method:Totally 36 APP/PS1 mice were divided into model group， donepezil group（6.5×10-4 g·kg-1·d-1） and Dabuyuan Jian group （13.2 g·kg-1·d-1）， and another wild mice were set as control group. The mice in control group and model group received an equal volume of saline， and the mice in each group received drugs by gavage for 30 days. The learning ability and memory of mice in each group were detected by Morris water maze. The pathological changes of neurons and synapses in the hippocampus of each group were observed by Nissl staining and Golgi staining. The expression levels of postsynaptic density protein 95 （PSD95） and synaptophysin （SYN） in hippocampus of each group were detected by immunofluorescence （IF）. The protein expression levels of BDNF， TrkB， CREB and phosphorylated CREB （p-CREB） in hippocampus were detected by Western blot. Result:As compared with the control group， the platform latency and total swimming distance of the model group were increased in the model group （P<0.01）， with decreased times of crossing the platform and staying time in the target quadrant （P<0.01）， the intracellular Nissl bodies of neurons in hippocampal CA3 area decreased or disappeared in model group， with decreased number of neurons and dendritic branches and decreased density of dendritic spine in hippocampal CA3 area of the mice （P<0.01）， and the protein expression levels of SYN， PSD95， BDNF， TrkB and p-CREB in hippocampus of mice were also decreased in model group （P<0.05， P<0.01）. As compared with the model group， the platform latency and total swimming distance were decreased in the donepezil group and Dabuyuan Jian group （P<0.05， P<0.01）， with increased times of crossing platform and staying time in target quadrant （P<0.05， P<0.01）， the number of Nissl bodies of neurons in hippocampal CA3 area was increased in the donepezil group and Dabuyuan Jian group， with increased number of neurons and dendritic branches and increased density of dendritic spine in hippocampal CA3 area of the mice， and the protein expression levels of SYN， PSD95， BDNF， TrkB and p-CREB in hippocampus of mice were increased in the donepezil group and Dabuyuan Jian group （P<0.05， P<0.01）. Conclusion:Dabuyuan Jian can improve the synaptic plasticity of APP/PS1 double transgenic mice， and its mechanism may be related to its up-regulation of BDNF/TrkB/CREB signal pathway in mouse hippocampus.

Effect of Wendantang-containing Serum on CREB Gene Silencing Hippocampal Neuron Apoptosis and BDNF/TrkB/CREB Signaling Pathway / 中国实验方剂学杂志

Objective:To investigate the effect of Wendantang on cyclic adenosine monophosphate （cAMP）-response element binding protein（CREB） gene silencing hippocampal cell activity， apoptosis and signal pathway of brain-derived neurotrophic factor/protomyosin related receptor kinase B/adenosine cyclophosphate effector binding protein （BDNF/TrkB/CREB）. Method:Wendantang-containing serum was prepared. Animal grouping： SD male rats were randomly divided into high， medium， low-dose groups， clozapine group and normal saline group， with 10 rats in each group， while 15 rats for the normal group. Dosage： 20 mL·kg-1 normal saline was given to normal group N， clozapine 0.02 g·kg-1 was given to dozapine group X， while high， medium and low-dose Wendantang groups were respectively given the same amount of Wendantang concentrated crude drug， with concentrations of 2， 1 and 0.5 g·mL-1 respectively once a day for 8 days continuously， and then blood was taken from femoral artery， and centrifuged for 15 min at 5 000 r·min-1. Supernatant was taken， inactivated， stored at -80 ℃ for standby. The CREB gene silenced hippocampal neuron cell line was constructed through transfection of liposomes into hippocampal cells， and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to verify the effect of small interfering RNA （siRNA） transcription. The mRNA expressions of BDNF， TrkB， CREB and CaMKⅡ in normal hippocampal cells and CREB gene silenced hippocampal cells were measured. Result:Compared with normal group， the apoptosis of the normal gene silencing group was significantly increased （P<0.01）， compared with the normal gene silencing group， the apoptosis of each group was significantly reduced （P<0.01）. As for the mRNA expressions of BDNF， TrkB， CREB and CaMKⅡ， compared with the normal group， the mRNA expression of CREB， BDNF in the normal gene silencing group was significantly decreased （P<0.01）. Compared with the normal gene silencing group， the mRNA expression of BDNF in each administration group was highly increased （P<0.01）， but with no statistically significant difference between TrkB and CaMKⅡ groups. Conclusion:The Wendantang-containing serum could improve the mRNA expression of BDNF， protect hippocampal neurons and prevent cognitive impairment of schizophrenia by regulating BDNF/TrkB/CREB signal pathway.

Expressão de neurotrofinas e de seus receptores no osteossarcoma primário / Expression of neurotrophins and their receptors in primary osteosarcoma

RESUMO Objetivo: determinar a expressão de neurotrofinas e seus receptores tirosina quinases em pacientes com osteossarcoma (OS) e sua correlação com desfechos clínicos. Métodos: biópsias de tumores primários de pacientes com OS tratados em uma única instituição, consecutivamente, entre 2002 e 2015, foram analisados através de imuno-histoquímica para expressão de receptores de tirosina quinase A e B (TrKA e TrKB), fator de crescimento neural (NGF) e fator neurotrófico derivado do cérebro (BDNF). De forma independente, dois patologistas classificaram os marcadores de imuno-histoquímica como negativos (negativos e focais fracos) ou positivos (moderado focal/difuso ou forte focal/difuso). Resultados: foram analisados dados de 19 pacientes (10 do sexo feminino e 9 do masculino) com mediana de idade de 12 anos (5 a 17,3 anos). Dos tumores, 83,3% estavam localizados em membros inferiores e 63,2% dos pacientes eram metastáticos ao diagnóstico. A sobrevida global em cinco anos foi de 55,3%. BDNF foi positivo em 16 pacientes (84%) e NGF em 14 pacientes (73%). TrKA e TrKB apresentaram coloração positiva em quatro (21,1%) e oito (42,1%) pacientes, respectivamente. A análise de sobrevida não demonstrou diferença significativa entre receptores TrK e neurotrofinas. Conclusão: amostras de OS primário expressam neurotrofinas e receptores TrK através de imuno-histoquímica. Estudos futuros podem auxiliar na identificação do papel das mesmas na patogênese do OS e determinar se há possível correlação prognóstica.

ABSTRACT Objective: to determine the expression of neurotrophins and their tyrosine-kinase receptors in patients with osteosarcoma (OS) and their correlation with clinical outcomes. Methods: we applied immunohistochemistry to biopsy specimens of patients consecutively treated for primary OS at a single institution between 2002 and 2015, analyzing them for expression receptors of tyrosine kinase A and B (TrKA and TrKB), neural growth factor (NGF) and brain derived neurotrophic factor (BDNF). Independently, two pathologists classified the immunohistochemical markers as negative (negative or weak focal) or positive (moderate focal/diffuse or strong focal/diffuse). Results: we analyzed data from 19 patients (10 females and 9 males), with median age of 12 years (5 to 17.3). Tumors' location were 83.3% in the lower limbs, and 63.2% of patients had metastases at diagnosis. Five-year overall survival was 55.3%. BDNF was positive in 16 patients (84%) and NGF in 14 (73%). TrKA and TrKB presented positive staining in four (21,1%) and eight (42,1%) patients, respectively. Survival analysis showed no significant difference between TrK receptors and neurotrophins. Conclusion: primary OS samples express neurotrophins and TrK receptors by immunohistochemistry. Future studies should explore their role in OS pathogenesis and determine their prognostic significance in larger cohorts.

The expression changes of BDNF in trigeminal ganglia of rats with trigeminal neuralgia / 中国药理学通报

Aim: To observe the expression changes of brain-derived neurotropic factor (BDNF) and receptor TrkB in trigeminal ganglion (TG) of trigeminal neuralgia (TN) rats. Methods: Animal model of TN was established using the infraorbital nerve chronic injury compression model (ION-CCI). The sham operation group (sham group) and the TN model group were composed of randomly divided 180 - 220 g SD male rats. The mechanical threshold of the injury side of the two groups was determined. Quantitative real-time PCR (qPCR), immunohistochemistry and immunfluorescence methods were used to detect the expression of BDNF, TrkB, pro-inflammatory TNF-α and IL-1B in the injured TGs. Results: After two weeks of modeling, the mechanical pain threshold was significantly down-regulated in TN group compared to sham group (P<0. 05). The expression of BDNF and TrkB in TGs of TN group was significantly higher than that in sham operation group. Besides, the levels of pro-inflammatory factors TNF-a and IL-1β also significantly increased in TGs of TN group compared with sham group (P < 0. 05). Conclusions: The expression of BDNF and TrkB in TG of ION-CCI rats increases in trigeminal neuralgia group, which may be involved in the pathogenesis of trigeminal neuralgia and promote the pain transmission of trigeminal neuralgia.

Effects of moxibustion on learning and memory ability and the hippocampal BDNF/TrkB expressions in the rats of vascular dementia / 中国针灸

OBJECTIVE@#To explore the effects of (resolving stasis, promoting collateral circulation) moxibustion on learning and memory ability and the expressions of brain derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) in the rats of vascular dementia (VD) in the microenvironment of neurovascular niche.@*METHODS@#Using 2-vessel occlusion (2-VO), the VD rat models were duplicated. The neural stem cells (NSCs) labeled with lentiviral vector-mediated enhanced green fluorescent protein (EGFP) were co-cultured with endothelial progenitor cells (EPCs) to structure the NSCs + EPCs implant. The implant was transplanted into the lateral ventricle of VD rats and the VD rat models with neurovascular niche were established. In No.1 experiment, the successful-modeled rats were divided into 3 groups, i.e. a NSCs + EPCs moxibustion group, a NSCs + EPCs blank group and a model group, 12 rats in each one. No any treatment was provided in the model group and the NSCs + EPCs blank group. The moxibustion therapy was adopted in the NSCs + EPCs moxibustion group, in which, the suspending moxibustion technique was applied to "Baihui" (GV 20), "Dazhui" (GV 14) and "Shenting" (GV 24), 20 min at each acupoint. The treatment was given once every day and a 14-day treatment was as one course. Totally, 3 courses of treatment were required. At the end of treatment, Morris water maze experiment was adopted to determine the learning and memory ability of the rats in each group. In the No.2 experiment, the model rats were divided into 3 groups, a NSCs + EPCs moxibustion group, a NSCs + EPCs blank group and a model group, 18 rats in each one. In each group, according to the durations of treatment, 3 subgroups were divided and 6 rats in each one. The intervention method was same as the No.1 experiment. Additionally, after corresponding treatment course, using perfusion, the brains were collected in each subgroup and the slices were frozen. BDNF/TrkB expressions were observed in the immunofluorescence test.@*RESULTS@#After treatment, in the NSCs + EPCs moxibustion group, the escape incubation was reduced, the time of the first running-cross platform was shortened and the frequency of running-cross platform increased as compared with the model group and the NSCs + EPCs blank group (<0.01, <0.05). The protein expressions were increased in tendency among the 3 courses of treatment in the NSCs + EPCs moxibustion group, indicating the significant differences (all <0.05), in which, the increase of the protein expressions in the NSCs + EPCs moxibustion group was better than the NSCs + EPCs blank group (<0.05, <0.01).@*CONCLUSION@#The moxibustion therapy is the effective approach to VD in clinical treatment. This therapy up-regulates the BDNF/TrkB protein expressions in the microenvironment of neurovascular niche, co-modulates NSCs-EPCs coupling mechanism, promotes nerve neogenesis and repairs the injured nerve.

Effect of electrical stimulation at auricular points combined with sound masking on the expression of CREB, BDNF and TrkB in the auditory cortex of tinnitus rats / 中国针灸

OBJECTIVE@#To explore the effect of electrical stimulation at auricular points (EAS) combined with sound masking on the expression of cAMP-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB) in the auditory cortex of tinnitus rats.@*METHODS@#A total of 27 adult male SD rats were randomly divided into a control group, a model group and an EAS group. The rats in the model group and the EAS group were intervened with intraperitoneal injection of sodium salicylate to induce tinnitus model, while the rats in the control group were intervened with injection of 0.9% NaCl solution. After the model was successfully established, the rats in the EAS group were treated with electrical stimulation at "Shenmen" (TF) and "Yidan" (CO), combined with sound masking; the treatment was given once a day for 15 days. The gap prepulse inhibition of acoustic startle (GPIAS) and prepulse inhibition (PPI) testing were performed using the acoustic startle reflex starter package for rats. The expression of BDNF, TrkB, CREB and p-CREB in the auditory cortex of each group were measured with Western Blot analysis.@*RESULTS@#① Compared with the control group, the GPIAS values in 12 kHz, 16 kHz, 20 kHz and 28 kHz were significantly decreased in the model group (all 0.05).@*CONCLUSION@#EAS could improve the GPIAS values of high-frequency background sound in tinnitus rats, which may be related with the upregulation of the BDNF/TrkB/CREB signaling pathway in the auditory cortex, leading to the reversion of the maladaptive plasticity.

Early-Life Stress in D2 Heterozygous Mice Promotes Autistic-like Behaviors through the Downregulation of the BDNF-TrkB Pathway in the Dorsal Striatum

A number of specific genetic variants including gene mutations and single nucleotide variations have been identified in genomewide association studies of autism spectrum disorder (ASD). ASD phenotypes in individuals carrying specific genetic variations are manifest mostly in a heterozygous state. Furthermore, individuals with most genetic variants show incomplete penetrance and phenotypic variability, suggesting that non-genetic factors are also involved in developing ASD. However, the mechanisms of how genetic and environmental factors interactively promote ASD are not clearly understood. In the present study, we investigated whether early-life stress (ELS) in D2 dopamine receptor heterozygous knockout (D2(+/−)) mice induces ASD-like symptoms. To address that, we exposed D2 heterozygous pups to maternal separation stress for 3 h daily for 13 days beginning on postnatal day 2. D2(+/−) adult mice that had experienced ELS exhibited impaired sociability in the three-chamber test and home-cage social interaction test and increased grooming behavior, whereas wildtype littermates exposed to ELS did not show those phenotypes. ELS-exposed D2(+/−) mice had decreased levels of BDNF, TrkB, phospho-ERK1/2 and phospho-CREB in the dorsal striatum. Administration of the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) to ELS-exposed D2(+/−) mice rescued the sociability deficits and repetitive behavior. In contrast, behavioral rescue by 7,8-DHF in ELS-exposed D2(+/−) mice was blocked when TrkB expression in the dorsal striatum was locally inhibited by the injection of TrkB-siRNA. Together, our results suggest that the interaction between ELS and defective D2 gene function promotes autistic-like behaviors by downregulating the BDNF-TrkB pathway in the dorsal striatum.

Investigating Trk Protein Expression between Oropharyngeal and Non-oropharyngeal Squamous Cell Carcinoma: Clinical Implications and Possible Roles of Human Papillomavirus Infection / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The relationship between head and neck squamous cell carcinoma (HNSCC) and subtypes of tropomyosin-related kinase (Trk) has not been studied in-depth. In this study, we evaluated the expression patterns of TrkA, TrkB, and panTrk and their clinicopathological significance as well as association with p16 expression and human papilloma virus (HPV) status. MATERIALS AND METHODS: Total of 396 radically resected oropharyngeal (n=121) and non-oropharyngeal (n=275) HNSCCs were included. Immunohistochemistry for TrkA, TrkB, and panTrk was performed. In addition, p16 immunohistochemistry was performed to assess the HPV status. Using HPV-negative HNSCC cell lines, FaDu and CAL27, HPV type 16 E6/E7 gene was transfected, and then changes of TrkA and TrkB expression were analyzed. RESULTS: In the clinical samples of HNSCC, high expression of TrkA and panTrk were more associated with oropharyngeal and p16 positive squamous cell carcinoma (SCC). In patients with completely resected (R0-resected) oropharyngeal SCC, high TrkA expression was related to superior overall survival and recurrence-free survival (RFS). In patients with R0-resected oral cavity SCC, high panTrk was related to poor RFS. In HPV type E6/E7 gene-transfected FaDu and CAL27 cell lines, increase of TrkA expression was observed. CONCLUSION: It seems that expression pattern of panTrk and TrkA differed according to anatomical sites of HNSCC and was closely related to p16 expression and patient prognosis. Trk expression should be considered in the context of anatomical site, p16 expression or HPV status and Trk subtypes.

Efficacy of sevoflurane in preventing depression-like behavior in mice: the relationship with BDNF/TrkB signaling pathway / 中华麻醉学杂志

Objective To evaluate the efficacy of sevoflurane in preventing depression-like behavior in mice and the relationship with brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) signaling pathway.Methods Forty-four clean-grade male C57BL/6 mice,weighing 18-22 g,aged 8-10 weeks,were divided into 2 groups (n =22 each) using a random number table method:control group (group C) and sevoflurane group (group S).Mice in group C inhaled oxygen for 30 min,and mice in group S inhaled 2.5％ sevoflurane for 30 min.The forced swimming test and novelty-suppressed feeding test were performed after the mice were fully awake.The brains were immediately removed under anesthesia at the end of inhalation of oxygen or sevoflurane,and the prefrontal cortex and hippocampus were isolated for detection of the expression of BDNF,TrkB and phosphorylated TrkB (p-TrkB) by Western blot.Results Compared to group C,the immobility time and feeding latency were significantly shortened,the expression of p-TrkB in the prefrontal cortex and hippocampus was up-regulated (P＜0.05),and no significant change was found in the feeding consumption or expression of BDNF and TrkB in the prefrontal cortex and hippocampus in group S (P＞0.05).Conclusion Sevoflurane produces a preventive effect on depression-like behavior in mice,and the mechanism is related to increased phosphorylation of TrkB in BDNF/TrkB signaling pathway.

Melatonin Augments the Effects of Fluoxetine on Depression-Like Behavior and Hippocampal BDNF-TrkB Signaling / 神经科学通报·英文版

Depression is a debilitating psychiatric disorder with a huge socioeconomic burden, and its treatment relies on antidepressants including selective serotonin reuptake inhibitors (SSRIs). Recently, the melatonergic system that is closely associated with the serotonergic system has been implicated in the pathophysiology and treatment of depression. However, it remains unknown whether combined treatment with SSRI and melatonin has synergistic antidepressant effects. In this study, we applied a sub-chronic restraint stress paradigm, and evaluated the potential antidepressant effects of combined fluoxetine and melatonin in adult male mice. Sub-chronic restraint stress (6 h/day for 10 days) induced depression-like behavior as shown by deteriorated fur state, increased latency to groom in the splash test, and increased immobility time in the forced-swim test. Repeated administration of either fluoxetine or melatonin at 10 mg/kg during stress exposure failed to prevent depression-like phenotypes. However, combined treatment with fluoxetine and melatonin at the selected dose attenuated stress-induced behavioral abnormalities. Moreover, we found that the antidepressant effects of combined treatment were associated with the normalization of brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling in the hippocampus, but not in the prefrontal cortex. Our findings suggest that combined fluoxetine and melatonin treatment exerts synergistic antidepressant effects possibly by restoring hippocampal BDNF-TrkB signaling.

Protective effects of spirulina on hippocampal injury in exercise-fatigue mice and its mechanism / 中国应用生理学杂志

OBJECTIVE@#To investigate the roles of BDNF/TrkB neurotrophic signaling in hippocampal injury for fatigue rats induced by incremental load exercise and the protective effects and mechanism of spirulina supplement.@*METHODS@#Sixty SD rats were randomly divided into normal control group (NC), normal plus spirulina group(NS), exercise model group (EM), exercise plus spirulina group (ES), and positive control group (PC), 12 rats in each group.Group EM, Group ES and Group PC were applied by treadmill running with high-intensity increasing for three weeks, and Group NC had not any intervention measures.Group ES and Group NS were treated with spirulina at a dose of 300 mg/kg.bw.by intragastric administration.Group PC was gavaged at the same volume of ginseng extract of 1.92 g/kg for three weeks.The expressions of brain-derived neurotrophic factor (BDNF), tyrosine kinase recptor (TrkB), phospho-tyrosine kinase recptor (p-TrkB) were tested by Western blot and immunohistochemical method, and micromorphology changes of hippocampal CA1 were observed by light microscope at the end of the experiment.The general situations of rats such as body weights were recorded during the experiment.@*RESULTS@#Compared with Group NC, Group EM showed significantly decrease in body weight and hippocampal CA1 neurons of the group loosely arrayed and disarrayed and some neurons were shrinked, and even some neurons disappeared.The expressions of BDNF, TrkB and p-TrkB in group EM were increased significantly(<0.01).Compared with Group EM, body weight of Group ES was increased significantly, and the above mentioned injuries of neurons were improved significantly:the number of neurons and nissl bodies were significantly increased and the neurons arrayed regularly and its morphology was more complete.The expressions of BDNF, TrkB and p-TrkB in the group were increased significantly(<0.05 or <0.01).And there was no difference between Group ES and Group PC.@*CONCLUSIONS@#BDNF/TrkB neurotrophic signal pathway could be involved in the repair process of hippocampal nervous damage caused by incremental load exercise for fatigue rats.Spirulina supplement had a protective effect on the damaged nervous through increasing the expressions of BDNF, TrkB and p-TrkB.

Effects of long-term microwave irradiation on NMDAR, BDNF and related molecular expression in their signal pathways in rat hippocampus / 军事医学

Objective To evaluate the effect of long-term microwave radiation on the expression of N-methyl-D-aspartate receptor(NMDAR),brain derived neurotrophic factor(BDNF) and related molecules in signal pathways in the hippocampus of rats.Methods Fifty male Wistar rats were exposed to microwave radiation at an average power density of 0,5,10,20 and 30 mW/cm2for 6 min/time,3 times/week,and for 6 weeks,which were sacrificed and the hippocampus was quickly removed at 14 d and 28 d after exposure.The changes in NMDAR (NR1,NR2A,NR2B),postsynaptic density protein(PSD)-95,cortactin,BDNF and tyrosine kinase receptor B (TrkB) in hippocampal neurons of each group were detected by Western blotting and image analysis techniques.Results Compared with the control group,the expressions of related proteins did not change significantly after microwave irradiation of 5 mW/cm2 at each time point.After 20 mW/cm2 microwave radiation,the expression of NR1 was increased at 14 and 28 d (P ＜0.05),the expression of NR2A was increased at 28 d (P ＜ 0.05),but the expression of NR2B was decreased at 14 and 28 d (P ＜ 0.05).At a average power density of 30 mW/cm2,the expressions of NR1,NR2A and PSD-95 and the expression of NR2B were decreased at 14 and 28 d(P ＜0.05),and cortactin,BDNF and TrkB were increased at 14 d after irradiation (P ＜ 0.05).Conclusion The effect of different dosages of long-term microwave radiation on the proteins of NMDAR and its signal pathway related molecules is different.Microwave radiation may affect the NMDAR of postsynaptic information transmission through the BDNF-TrkB signaling pathways,which might play an important role in the impediment of learning and memory function caused by microwave radiation.