ANA- 12 inhibits spinal inflammation and alleviates acute and chronic pain in rats by targeted blocking of BDNF/TrkB signaling / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effect of ANA-12 that blocks brain-derived neurotrophic factor (BDNF)/ tropomyosin receptor kinase B (TrkB) signaling on inflammatory pain in rats and explore the underlying mechanism.@*METHODS@#Forty-two adult SD rats were randomized into BDNF-induced acute pain group (n=24) and CFA-induced chronic pain group. The former group were randomly divided into 4 subgroups, including a control group, ANA-12 treatment group, BDNF treatment group, and BDNF+ANA-12 treatment group; the latter group were subgrouped into control group, CFA treatment group (CFA) and CFA + ANA-12 treatment group. The effects of ANA-12 treatment on pain behaviors of the rats with BDNF-induced acute pain and CFA-induced chronic inflammatory pain were observed. Western blotting was used to examine TrkB signaling and expressions of microglia marker protein Iba1 and TNF-α in the spinal cord of the rats.@*RESULTS@#BDNF injection into the subarachnoid space significantly increased the number of spontaneous paw withdrawal of the rats (P < 0.05), which was obviously reduced by ANA-12 treatment (P < 0.05). The rats with intraplantar injection of CFA, showed significantly increased ipsilateral mechanical stimulation sensitivity (P < 0.05), and ANA-12 treatment obviously increased the ipsilateral foot withdrawal threshold (P < 0.05). Treatment with either BDNF or CFA significantly increased the phosphorylation level of TrkB (Y705) in the spinal cord of the rats (P < 0.05), which was significantly lowered by ANA-12 treatment (P < 0.05). Treatment with BDNF and CFA both significantly up-regulated the expressions of Iba1 and TNF-α in the spinal cord (P < 0.05), but ANA-12 significantly reduced their expression levels (P < 0.05).@*CONCLUSION@#ANA-12 can reduce spinal cord inflammation and relieve acute and chronic pain in rats by targeted blocking of BDNF/TrkB signaling.

Wutoutang Modulation Hippocampal BDNF/TrkB Pathway to Relieve Pain-emotion Co-curation / 中国实验方剂学杂志

<b>Objective::To explore the mediating effect of Wutoutang (WTT) on brain-derived neurotrophic factor/tropomyosin receptor kinase B (BDNF/TrkB) pathway in hippocampus and to clarify the mechanism of therapeutic action of WTD on pain-emotion comorbidity by inhibiting neuropathic pain (NP) preliminarily. <b>Method::The mice were divided into sham group, spinal cord ligation (SNL) group, Wutoutang (WTT) group, Wutoutang-ANA12 antagonist (WTT-ANA12) group, pregabalin (PGB) group, Fluoxetine Hydrochloride (FLU) group randomly. Mice were fixed with the drug delivery cannula for hippocampal CA3.The L5 spinal cord of mice were tightly ligated but sham group (only exposed). During the 10-16^th day after surgery, WTT, WTT-ANA12 groups were gavaged with 126 mg·kg^-1 WTT, PGB and FLU groups were respectively given 25 mg·kg^-1 PGB and 3 mg·kg^-1 FLU, sham and SNL groups were given the physiological saline once a day. Then, 50 nmol·L^-1 ANA12 were given to the hippoicampal CA3 of the WTT-ANA12 mice by drug delivery cannula, and physiological saline were given to the others on the 10-16^th day after surgery. Mechanical pain were detected by Von Frey tests, anxiety and depression behaviors were separately detected by the open field and the tail tailing experiments, while the morphology of CA3 pyramidal neurons were qualified by the Golgi-staining. <b>Result::Compared with sham group, significant decreases of the mechanical pain thresholds, decreases of the duration time in the open field, as well as the increases of the no-struggling time during the tail-suspension were detected in the SNL mice(<italic>P</italic><0.01). In addition, as illustrated by the Golgi-staining, the atrophy of hippocampal pyramidal neurons were found in SNL mice as compared with sham(<italic>P</italic><0.05, <italic>P</italic><0.01). On the contrary, as compared to the SNL, significant increases of the mechanical pain thresholds, increases of the duration time in the open field, the decreases of the no-struggling time during the tail-suspension(<italic>P</italic><0.01), as well as the morphological improvements of the hippocampal CA3 pyramidal neurons were detected in the WTT mice. Furthermore, after 7 d hippocampal injections, There is no significant distinction of the mechanical pain thresholds, the duration time in the open field, the no-struggling time during the tail-suspension, as well as the atrophy of hippocampal neurons were detected in the WTT-ANA12 groups as compared with SNL. <b>Conclusion::The data suggested that the effective inhibition of WTT on SNL-induced vertebral neuron injury in hippocampus CA3 and pain-emotion disorder, which might attribute to it' s regulation of BDNF/TrkB pathway in hippocampus.

Restoration of Cdk5, TrkB and Soluble N-ethylmaleimide-Sensitive Factor Attachment Protein Receptor Proteins after Chronic Methylphenidate Treatment in Spontaneous Hypertensive Rats, a Model for Attention-Deficit Hyperactivity Disorder

OBJECTIVE: Synaptic vesicle mobilization and neurite outgrowth regulation molecules were examined in modulation of effects of methylphenidate (MPH) in Spontaneous Hypertensive Rats (SHRs), a model for attention-deficit hyperactivity disorder (ADHD). METHODS: We compared the changes in the protein expression level of Cyclin dependent kinase 5 (Cdk5) and molecular substrates of Cdk5; tropomyosin receptor kinase B (TrkB), syntaxin 1A (STX1A) and synaptosomal-associated protein 25 (SNAP25). Comparisons were made in prefrontal cortex of vehicle (distilled water i.p. for 7 days)-treated SHRs, vehicle-treated Wistar Kyoto Rats (WKYs) and MPH (2 mg/kg i.p. for 7 days) treated SHRs. RESULTS: The Cdk5 level of vehicle-treated SHRs was significantly decreased compared to the Cdk5 level of vehicle-treated WKY rats, but was restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. The ratio of p25/p35 was significantly decreased in MPH-treated SHR compared to vehicle-treated SHR. Moreover, TrkB, STX1A and SNAP25 of vehicle-treated SHRs were significantly decreased compared to vehicle-treated WKY rats, but were restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. CONCLUSION: The results show that Cdk5, TrkB, STX1A, and SNAP25 were involved in the modulation of MPH effects in prefrontal cortex of SHRs and play important role in treatment of ADHD.

Effect of Aerobic Exercise on Behavioral Function in Rats with Cerebral Small Vessel Disease / 中国康复理论与实践

Objective:To explore the effect of aerobic exercise on behavioral function in rats with cerebral small vessel disease and its mechanism. Methods:Eight-week-old male Sprague-Dawley rats were randomly divided into sham group (n = 16), model group (n = 16) and swimming group (n = 16). The model was developed with bilateral common carotid artery ligation. They were assessed with burrowing test after four weeks of swimming exercise. The levels of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) protein in hippocampus were detected with Western blotting. The development of dendrites and synaptic spines in hippocampal neurons was observed with Golgi staining. The expression of Ki67, doublecortin (DCX) and Neun in hippocampal dentate gyrus was detected with immunofluorescence. Results:Compared with the model group, the burrowing ability improved in the swimming group (P < 0.05), with increase of levels of BDNF and TrkB in hippocampus (P < 0.05), Ki67/DCX and Neun positive cells in hippocampal dentate gyrus (P < 0.05), and extension of dendrites and length of synaptic spine in hippocampal neurons (P < 0.05). Conclusion:Aerobic exercise may promote the proliferation and differentiation of hippocampal neurons through BDNF/TrkB signaling pathway, expression of Ki67/DCX and Neun and development of hippocampal neurons, to improve behavioral function in rats with cerebral small vessel disease.

Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

The expression of brain-derived neurotrophic factor and tropomyosin receptor kinase B protein in the prefrontal cortex of the post-stroke depression in the rat model / 中华行为医学与脑科学杂志

Objective To explore the expression of brain-derived neurotrophic factor(BDNF) and highaffinity receptors tropomyosin receptor kinase B(TrkB) protien in the prefrontal cortex of the post stroke depression in the rats.Methods Focal cerebral ischemic rat models were made with thread embolization method.Post stroke depression 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 compared with PSD group.6 rats were used in each group.Immunohistochemistry for detecting the expression of BDNF and TrkB in the prefrontal was used at 29th day since the CUMS.Results The number of BNDF immunopositive cells in PSD group was the least ((21.00 ± 12.41) per microscope field of vision) than other groups.Whereas there was no statistical difference among groups(P＞ 0.05).The number of TrkB immunopositive cells in the prefrontal cortex in PSD group was the least (20.78 ± 7.20) among three groups,and depreesion group was secondary (21.00 ±5.61).Stroke group has the most number of immunopositive cells(31.67 ± 7.38) in the prefrontal cortex among four groups.One way ANOVA statistical analysis showed the number of TrkB immunopositive cells decreased significantly in the PSD group and depression group compared with stroke group (P＜0.05).Conclusion The downregulation of TrkB immunopositive cells in the prefrontal cortex may be responsible for the pathogenesis of PSD.