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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<sup>-1</sup>） group， and low- （1.25 g·kg<sup>-1</sup>）， medium- （2.5 g·kg<sup>-1</sup>）， and high-dose （5 g·kg<sup>-1</sup>） 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.
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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.
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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.
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Objective:To investigate the effects of enriched environment on hippocampal neuronal apoptosis and brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway in neonatal rats with hypoxic-ischemic brain damage. Methods:Forty-eight newborn Wistar rats aged seven days were randomly divided into sham operation group, model group and enriched environment group, each group was divided in to 14 days group and 28 days group, with eight in each subgroup. The model was established with the Rice method. The sham operation group and the model group did not receive any intervention, and the enriched environment group received enriched environment stimulation 24 hours after modeling. Fourteen days and 28 days after modeling, the levels of neuronal apoptosis in hippocampus were detected by TUNEL and double immunofluorescence staining; BDNF and TrkB proteins in hippocampus were detected by immunohistochemical staining. Results:Fourteen days and 28 days after modeling, the numbers of TUNEL positive cells, double immunofluorescence positive cells, BDNF and TrkB positive cells were significantly more in the model group than in the sham operation group (t > 27.214, P < 0.001), while the numbers of TUNEL positive cells, double immunofluorescence positive cells were significantly less in the enriched environment group than in the model group (t > 12.687, P < 0.001); and the number of BDNF and TrkB positive cells were significantly more in the enriched environment group than in the model group 28 days after modeling (t > 137.998, P < 0.001). Conclusion:Enriched environmental stimulation could reduce the apoptosis of hippocampal neurons, and up-regulate the expression of BDNF and TrkB proteins in the neonatal rats with hypoxic-ischemic brain damage.
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OBJECTIVE: To study the effect of brain derived neurotrophic factor( BDNF)-tyrosine kinase receptor B( Trk B)pathway on the learning and memory impairment in rats induced by benzo[a]pyrene( B[a]P). METHODS: Seventy-two specific pathogen free healthy male SD rats were randomly divided into 3 groups with 24 rats in each group: the control group,the solvent group and the B[a]P group. The control group received no treatment. The solvent group was given intraperitoneal injection of olive oil( 1. 00 mg / kg body weight),and the B[a]P group was given intraperitoneal injection of B[a]P( 2. 50 mg / kg body weight,dissolved in olive oil) every other day. The rats were given corresponding treatment for30,60 and 90 days. The learning and memory ability of rats was evaluated using Morris water maze test. Western-blot analysis was used to detect the relative expression of BDNF and Trk B protein in hippocampus of rats. RESULTS: The escape latency of rats in the B[a]P group was longer than those in the control group and the solvent group( P < 0. 01). The duration of first passing through the platform in 3 time points in rats of B[a]P group was longer than those at the same time point in the control group and the solvent group( P < 0. 01). The target quadrant residence time and the times of passing through platform in rats of the B[a]P group were less than those in the control group and the solvent group( P < 0. 01). The duration of first passing through the platform in rats of B[a]P group increased with the increasing time of B[a]P exposure,showing a time-effect relationship( P < 0. 05). Compared with the control group and the solvent group,the relative expression of BDNF protein in hippocampus of rats in the B[a]P group was lower than those at the same time points( P < 0. 01). The relative expression of BDNF protein at time points of 60 and 90 days was lower than those at time point of 30 days in the same group( P <0. 01). The relative expression of Trk B protein in hippocampus of rats of the B[a]P group was lower than those in the control group and the solvent group( P < 0. 01). CONCLUSION: The impairment of learning and memory in rats caused by B[a]P has a time-effect relationship,which might be related to the decreased expression of BDNF and Trk B protein.
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Objective To investigate the influence of the eye acupuncture therapy in the expressions of brain derived neurophic factor(BDNF)and tyrosine kinase receptor B(TrkB)in penumbra brain tissue of ischemic area in the rats with acute cerebral ischemia reperfusion inj ury,and to explore the related mechanism of protective effect on brain of eye acupunture.Methods 62 SD rats were randomly divided into blank control group (n=11),sham operation group (n=11)and model copy group (n=40).The rats in copy model group were used to establish models with suture method,and the successful model rats (n=32)were randomly divided into model group(n=16)and eye acupuncture group(n=16).The rats in eye acupuncture group were treated with eye acupuncture intervention;the acupoints were chosen according to human acupoint selection method, the liver, the upper-jiao, the down-jiao district,and renal were selected for acupuncture intervention. After reperfusion for 2 h,the acupuncture was performed once every 8 h,lasted for 10 times;30 min after the last intervention,the rats were sacrificed;the regional ischemia penumbra around the parts of the brain tissue was obtained and the expressions of BDNF and TrkB mRNA and protein in brain tissue of the rats were detected with RT-PCR and Western blotting method. Results Compared with blank control group,the expression levels of BDNF and TrkB mRNA and protein in brain tissue of the rats in sham operation group had no statistical significance(P>0.05);compared with sham operation group,the expression levels of BDNF and TrkB mRNA and protein in brain tissue of the rats in model group were significantly up-regulated(P<0.01);compared with model group,the expression levels of BDNF and TrkB mRNA and protein in brain tissue of the rats in eye acupuncture group were significantly up-regulated(P<0.05 or P<0.01).Conclusion The expressions of BDNF and TrkB are increased after cerebral ischemia and reperfusion injury.Eye acupuncture can protect the brain of MCAO/R rats,which may be related to the up-regulation of the expressions of BDNF and TrkB in the corresponding penumbra.
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Objective To explore the expression of brain-derived neurotrophic factor(BDNF) mRNA and high-affinity receptor TrkB mRNA in the prefrontal cortex of the post stroke depression in the rats.Methods Focal cerebral ischemic rat models were made with thread embolism method.Post stroke depression(PSD) rat models were established with comprehensive separately breeding and chronic unpredicted mild stress (CUMS) on this basis.Normal control group,depression group and stroke group were used to compare with PSD group.8 rats were used in each group.RT-PCR was employed to detect gene expression of BDNF and TrkB.GADPH was used as control at 29th day after the CUMS.Results The results showed that the gene level of BNDF in the prefrontal cortex of rat subjected PSD was lowest among all groups(0.75 ± 0.21).And the expression of BNDF mRNA in the normal control rats was (0.83 ± 0.16) and was highest among all groups.While it was (0.77 ± 0.22) in the depression group and (0.80 ± 0.20) in the stroke group.The one-way analysis of variance showed the expression of BDNF mRNA in the prefrontal cortex decreased significantly in the PSD group compared with normal control rats (P ＜ 0.05).Whereas,the expression of TrkB mRNA had no statistical difference among groups (P ＞ 0.05).Conclusion The downregulation of BDNF mRNA in the prefrontal cortex may be responsible for the pathogenesis of PSD.
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Brain-derived neurotrophic factor(BDNF) is a key signaling molecule during the development of nervous system.When BDNF is binded tyrosine kinase receptor B ( Trk B ),it can lead to a variety of physiological effects.Although the mechanisms of their action remain unclear,studies have proved that they may be related to effects of nerve cell survival,growth,differentiation,repair after injury and apoptosis,etc.This review describes the affecting factors in the expression of BDNF and TrkB,the effects of BDNF and TrkB in the development of behavioral disorders and the relationship with early environment.
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Objective To study the effect of neurotrophic tyrosine kinase receptor B(TrKB) on in vitro invasiveness of malignant transformed hFOB1.19 cells and the role of TrKB in invasion and metastasis of osteosarcoma.Methods Expression of TrKB in malignant transformed hFOB1.19 cells and SaOS-2 osteosarcoma cells was detected by RT-PCR and immunofluorescence.Function of TrKB of malignant transformed hFOB1.19 cells was further studied.Malignant transformed hFOB1.19 cells were treated with specific tyrosine kinase inhibitor K252a for 24 h as a treatment group,and untreated malignant transformed hFOB1.19 cells into which DMSO was added served as a control group.Morphology of cells was observed under an inverted phase contrast microscope.Cell invasiveness was detected by Transwell assays.Microfilaments of cells were detected by actin immunofluorescence.Results The expression of TrKB was significantly higher in malignant transformed hFOB1.19 cells than in SaOS-2 osteosarcoma cells(P
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Objective To explore the expression and its significance of growth-associated protein(GAP-43 ) and brain-derived neurotrophic factor (BDNK) receptor TrkB gene in rat hippocampus after epilepsy induced by pilocarpine (PILO). Methods In situ hybrid histochemical method was used to observe the changes of the expression of GAP-43 and TrkB mRNA in hippocampus after status epilepticus( SE) induced by PIOL. Results At 3 - 6h following the onset of status epilepticus(SE), TrkB mRNA expression was dramatically high than control groups in the dentate gyrus granule cell and CA3,CA1 pyramidal cell layers(P