Mouse Nerve Growth Factor Facilitates the Growth of Interspinal Schwannoma Cells by Activating NGF Receptors

OBJECTIVE: Nerve growth factor (NGF) is a member of the neurotrophic factor family and plays a vital role in the physiological processes of organisms, especially in the nervous system. Many recent studies have reported that NGF is also involved in the regulation of tumourigenesis by either promoting or suppressing tumor growth, which depends on the location and type of tumor. However, little is known regarding the effect of NGF on interspinal schwannoma (IS). In the present study, we aimed to explored whether mouse nerve growth factor (mNGF), which is widely used in the clinic, can influence the growth of interspinal schwannoma cells (ISCs) isolated from IS in vitro.METHODS: ISCs were isolated, cultured and identified by S-100 with immunofluorescence analysis. S-100-positive cells were divided into five groups, and separately cultured with various concentrations of mNGF (0 [phosphate buffered saline, PBS], 40, 80, 160, and 320 ng/mL) for 24 hours. Western blot and quantantive real time polymerase chain reaction (PCR) were applied to detect tyrosine kinase A (TrkA) receptor and p75 neurotrophin receptor (p75(NTR)) in each group. Crystal violet staining was selected to assess the effect of mNGF (160 ng/mL) on ISCs growth.RESULTS: ISCs growth was enhanced by mNGF in a dose-dependent manner. The result of crystal violet staining revealed that it was significantly strengthened the cells growth kinetics when cultured with 160 ng/mL mNGF compared to PBS group. Western blot and quantantive real time PCR discovered that TrkA receptor and mRNA expression were both up-regualated under the condition of mNGF, expecially in 160 ng/mL, while the exoression of p75(NTR) demonstrated no difference among groups.CONCLUSION: From these data, we conclude that exogenous mNGF can facilitate ISC growth by activating both TrkA receptor and p75(NTR). In addition, patients who are suffering from IS should not be administered mNGF in the clinic.

Mouse Nerve Growth Factor Facilitates the Growth of Interspinal Schwannoma Cells by Activating NGF Receptors

OBJECTIVE: Nerve growth factor (NGF) is a member of the neurotrophic factor family and plays a vital role in the physiological processes of organisms, especially in the nervous system. Many recent studies have reported that NGF is also involved in the regulation of tumourigenesis by either promoting or suppressing tumor growth, which depends on the location and type of tumor. However, little is known regarding the effect of NGF on interspinal schwannoma (IS). In the present study, we aimed to explored whether mouse nerve growth factor (mNGF), which is widely used in the clinic, can influence the growth of interspinal schwannoma cells (ISCs) isolated from IS in vitro. METHODS: ISCs were isolated, cultured and identified by S-100 with immunofluorescence analysis. S-100-positive cells were divided into five groups, and separately cultured with various concentrations of mNGF (0 [phosphate buffered saline, PBS], 40, 80, 160, and 320 ng/mL) for 24 hours. Western blot and quantantive real time polymerase chain reaction (PCR) were applied to detect tyrosine kinase A (TrkA) receptor and p75 neurotrophin receptor (p75(NTR)) in each group. Crystal violet staining was selected to assess the effect of mNGF (160 ng/mL) on ISCs growth. RESULTS: ISCs growth was enhanced by mNGF in a dose-dependent manner. The result of crystal violet staining revealed that it was significantly strengthened the cells growth kinetics when cultured with 160 ng/mL mNGF compared to PBS group. Western blot and quantantive real time PCR discovered that TrkA receptor and mRNA expression were both up-regualated under the condition of mNGF, expecially in 160 ng/mL, while the exoression of p75(NTR) demonstrated no difference among groups. CONCLUSION: From these data, we conclude that exogenous mNGF can facilitate ISC growth by activating both TrkA receptor and p75(NTR). In addition, patients who are suffering from IS should not be administered mNGF in the clinic.

Role of proNGF-p75NTRin isoflurane-induced cognitive impairment in aging mice / 中国病理生理杂志

AIM:To investigate the role of specific binding of precursor form of nerve growth factor(proNGF) to p75NTR(proNGF-p75NTR)in isoflurane-induced cognitive impairment in aging mice.METHODS: Aging C57BL/6J male mice were randomly divided into 3 groups:control group,isoflurane(Iso)group and p75NTR specific inhibitor 2-ami-no-3-methyl-pentanoic acid amide(LM11A-31,LM)+isoflurane(LM+Iso)group.Aging C57BL/6J mice in Iso group and LM+Iso group were exposed to isoflurane,and the mice in control group were exposed to air.The mice in LM+Iso group were treated with LM,which dissolved in normal saline water and was administered daily by oral gavage at 50 mg· kg-1· d-1for 1 month.The mice in control group and Iso group received an equivalent volume of normal saline by the same route.Arterial blood gas analysis was conducted to detect the physiological state of the mice after isoflurane exposure. Morris water maze was performed to evaluate the cognitive function.The protein levels of proNGF,p75NTR,phosphorylated p38 MAPK and cleaved caspase-3 were determined by Western blot.RESULTS: Compared with the control group, the protein expression of proNGF and p75NTR in the hippocampus of Iso group was significantly elevated(P<0.05).The phos-phorylation level of p38 MAPK was higher in Iso group than that in control group(P<0.05),which was reduced in LM +Iso group significantly(P<0.05).A significant increase in the protein level of cleaved caspase-3 was observed in Iso group as compared with control group(P<0.05), while LM11A-31 treatment reversed this elevation significantly(P<0.05).The escape latency prolonged and the number of crossing the original platform location reduced in Iso group com -pared with control group(P<0.05), which were reversed by LM11A-31 in LM+Iso group(P<0.05).CONCLU-SION:ProNGF-p75NTR probably plays an vital role in the apoptotic pathway activation and the cognitive dysfunction in ag -ing mice exposure to isoflurane,which provides a potential target for clinical intervention.

Effect of Salidroside on Learning and Memory Abilities and Expression of p75NTR Signal Transducers and Aβ in Hippocampus of AD Rat / 医药导报

Objective To study the effect of salidroside (Sal) on learning and memory abilities and expression of p75NTR signal transducers and Aβ in AD rat hippocampus.Methods Totally,ninety-six male SD rats were randomly divided into sham-operation group,model control group,Sal low,medium and high dose group,Hup-A group (16 rats in each group).Except for sham-operation group,AD model in the other group was established by slowly injecting 1μL(10 μg)Aβ1-40 in tobilateral hippocampal CA1 area.Sham-operation group was given the same volume of 0.9％ sodium chloride solution.Sal low,medium and high dose group took orally as early as 24 h postoperatively with salidroside 25,50,100 mg· kg-1 for 21days,while Hup-A group took 50 mg kg-1 of Hup-A orally.The same volume of 0.9％ sodium chloride solution was administrated in shanmoperation group and model control group.After administration,the learning and memory function of rats were tested by Morris water maze.The contents of Aβ in serum and hippacampus were determined by ELISA,and protein expression of p75NTR and p-JNK in the hippocampus of the rats were measured by ELISA.Results Compared with model control group,the latent time in water maze training of Sal low,medium and high dose groups were significantly shortened (P ＜ 0.05 or P ＜ 0.01),the number of times of crossing platform of Sal low,medium and high dose group was significantly increased.The contents of Aβ in the hippocampus and the protein expression levels of p75NTR and p-JNK in the hippocampus of Sal low,medium and high dose group were decreased significantly (P ＜ 0.05,P ＜ 0.01).Conclusion Salidroside has protective effects on learning and memory consolidation of dysmnesia rats caused by Aβ.Its mechanism might be related to inhibition of p75NTR regulation pathways for Aβ,reducing the neurotoxic effect of Aβ,so as to reduce cell apoptosis of hippocampus neuron.

t-PA negatively regulating p75NRT for involving in atherosclerosis by changing reconstruction of vascular outer membrane autonomic nerve / 重庆医学

Objective To study the effect of tissue plasminogen activator (t-PA) on p57NTR ,inflammatory reaction ,immune regulation and oxidative stress and its effect on intimal hyperplasia .Methods The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of ace-tylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxi-dative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the athero-sclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neu-ron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Results The vascular injury treatment was performed in the diabetic rabbit model with carotid arterial adventitia stripping ,meanwhile t-PA controlled release microspheres were given ,the nerve distribution in the local blood vessels was observed by immunohistochemical staining .The change of nerve remodeling in the control group and treatment group was observed ,meanwhile the effect of giving t-PA controlled release microspheres on the release of acetylcholine and norepinephrine was detected .RT-PCR was used to detect local vascular tissue inflammation ,immune effects and oxidative stress .The sympathetic neurons and smooth muscle cell co-culture was adopted ,then giving glyoxal treatment as the ath-erosclerosis cell model .With the t-PA treatment group as the intervention group ,the effect of t-PA on the number of cholinergic neuron ,and synaptic connections between the smooth muscle cells and acetylcholine secretion was observed .The change of t-PA-MMP-p75NTR and NF-kappa B signaling pathway were detected by RT-PCR .Conclusion t-PA activates MMPs and feedback in-hibits p75NTR-NF-kappa B signaling pathway to increase vascular adventitia autonomic nerve reconstruction and delay the occur-rence and development of atherosclerosis disease .

Expression of neurotrophins receptor p75NTR in human breast cancer resistant cell line and its correlation with multidrug resistance / 实用医学杂志

Objective To investigate the expression of neurotrophins receptor 75NTR in human breast cancer resistant cell line and its correlation with multidrug resistance. Methods Western blot was used to detect the expression level of p75NTR protein in various breast cancer cell lines and multidrug resistant cell lines. The over-expression vector and siRNA vector of p75NTR were constructed by gene recombination method. Western blot was used to detect the expression levels of p75NTR protein in transfected p75NTR and p75NTR - siRNA breast cancer resistant cell line MDA-MB-231/ADR;the sensitivity of MDA-MB-231 and MDA-MB-231/ADR to different chemotherapeutic anticancer drug (PTX ,ADM ,GEM ,DDP ,OXA) and the multi-drug resistance effects in over-expression and knock-down p75NTR MDA-MB-231/ADR were detected by CCK-8 assay. Results Western blot result showed that the expressions of p75NTR protein in the multidrug-resistant breast cancer cell lines MDA-MB-231/ADR and MCF-7/5-FU were higher than that of other breast cancer cell lines. Over-expression of p75NTRcan up-regulate the expression of p75NTR protein in MDA-MB-231/ADR;the CCK-8 assay indicated that over-expression of p75NTR can effectively enhance the resistance of MDA-MB-231/ADR cells to ADM,GEM and OXA. Conclusion The expression of p75NTR in breast cancer resistant cell line is higher than that of its parental cell line;over-expression of p75NTR can reduce the sensitivity to chemotherapeutic drugs and promote its multidrug resistance.

Promoting effect of p75NTR receptor overexpression on oxidative stress injury in human retinal pigment epithelium cells / 中华实验眼科杂志

Background Choroidal neovascularization (CNV) is the primary pathogenic cause of many fundus diseases.Oxidative stress injury of retinal pigment epithelial (RPE) cells plays important role in angiogenesis of choroid new blood vessels.Oxidative stress injury can active p75NTR receptor, a member of tumor necrosis factors family,resulting in the proliferation of vascular endothelial cells.However, the mechanisms of vascular endothelial cell proliferation remain unclear.Objective This study was conducted to investigate the effect of p75NTR overexpression on CNV and the relative mechanism.Methods The ARPE-19 cell line was used in this study.RPE cells were transfected with p75NTR receptor overexpressed plasmid, and untransfected cells served as the control group.The transfected results were verified by reverse transcription-PCR and Western blot assay.Viability of the cells over time was determined in the p75NTR receptor plasmid transfected group by using BrdU assay.The percentage of apoptotic cells was detected by flow cytometry using Annexin V-FITC/PI fluorescence staining.The percentage of reactive oxygen species (ROS) expression in the cells was detected by using H2 DCFDA fluorescence and flow cytometry.Mitochondrial membrane potential and cytochrome C expression were examined under the confocal microscope.The protein expressions of cleaved caspase-3, Fas and VEGF were determined by Western blot assay.Results The relative expression level of p75 NTR receptor mRNA was (6.11 ±0.77) times higher than that of the control group, and relative expression level of p75NTR receptor protein in the cells in the p75NTR receptor plasmid transfected group was (7.42±0.48) times higher than that in the control group (t=11.49 and 23.17 ,both at P＜0.01).The absorbency values of the p75NTR receptor plasmid transfected group were (93.12±0.56) ％ , (86.30±0.66) ％ , (72.53-±0.86) ％ and (60.77 ±2.81) ％ in 12,24,36 and 48 hours after plasmid transfection, which were significantly lower than 100％ in the control group, and the apoptotic percentages were evidently higher than that in the control group (all at P＜0.05).The relative fluorescence intensity of ROS fluorescence in the p75NTR receptor plasmid transfected group was 2.4 times higher than that in the control group,showing significant difference (t=16.45, P＜0.01).The positive expressing rate of mitomarker (mitochondrial membrane potentials) was 100％ in the control group and (37.30± 2.06)％ in the p75NTR receptor plasmid transfected group, with significant difference between them (t =57.71,P＜0.01).The fluorescence intensity of cytochrome C expression was elevated in the p75NTR receptor plasmid transfected group compared with the control group.Compared with the control group,the expressing levels of cleaved caspase-3 ,Fas and VEGF165 proteins in the cells were significantly raised in the p75NTR receptor plasmid transfected group (all at P＜0.01).Conclusions Overexpression of p75NTR receptors in RPE cells leads to mitochondrial damage and cellular apoptosis and the secretion of VEGF protein, which sequentially promote CNV.P75NTR receptor may be another important regulation pathway in RPE oxygen damage.

The effects of p75NTR gene on the apoptosis of tongue squamous cell carcinoma Tca8113 cells / 实用口腔医学杂志

Objective:To study the effect of p75NTR gene on the apoptosis of tongue squamous cell carcinoma Tca8113 cells. Methods:p75NTR +Tca8113 cells were isolated from Tca 8113 cell line and transfected by p75NTR siRNA using lipofectamine. p75NTR mRNA and protein expression was examined by real time RT-PCR and western blot respectively.Cell proliferation was stud-ied by MTT assay,cell apoptosis was examined by flow cytometry.Results:Proliferation of p75NTR + cells was faster than that of p75NTR - cells.Transfection of p75NTR siRNA inhibited p75NTR mRNA and protein expression in p75NTR + Tca8113 cells,inhibi-ted the proliferation and increased the apoptosis of the cells.Conclusion:p75NTR gene plays a role in the apoptosis of Tca8113 cells.

EGCG ameliorating learning and memory impairment in APP/PS1 mice by inhibiting p75 NTR pathway / 中国药理学通报

Aim To investigate whether EGCG treat-ment ameliorates cognitive deficits in APP/PS1 trans-genic mice and, whether it has the ameliorating effect of p75 NTR signaling to neuronal apoptosis in the hippo-campus of APP/PS1 mice. Methods Morris water maze test and locomotivity test were used to predict be-havioral changes; further TUNEL staining and Fluoro-Jade B staining were applied to confirm the neuronal apoptosis and neuronal degeneration;Western blot was employed to detect protein expression levels of p75 NTR signaling in the hippocampus of APP/PS1 mice. Re-sults EGCG treatment dramatically ameliorated the cognitive impairments, and inhibited the neuronal ap-optosis in the APP/PS1 mice. Moreover, EGCG treat-ment dramatically inhibited the p75 NTR signaling by de-creasing the p75ICD expression, JNK2 phosphorylation, and cleaved-caspase 3 expression. Conclusion EGCG treatment dramatically ameliorates the cognitive impairments, and inhibits the neuronal apoptosis by in-hibiting the p75NTR signaling.

Expression of tumor stem cell markers in the tumor sphere from esophageal squamous cells carcinoma Eca109 / 解剖学报

Objective To observe the expression of tumor stem cell markers P 75NTR,Oct-4,Sox-2,Lin28 and Nanog in the tumor sphere from esophageal squamous cells carcinoma Eca 109 and identify the esophageal squamous cell cancer stem cell marker .Methods The serum-free culture method was used for generating tumor spheres: proliferation was observed in enrichment culture tumor spheres .Small tumor spheres were obtained after 5 days culture and big and round tumor spheres appeared after 14 days culture which were collected for experiments and passaged .The expression and location of P75NTR,Oct-4,Sox-2,Lin28, and Nanog were detected by immunofluorescence cytochemistry .Results The expressions of P75NTR,Oct-4 and Lin28 were positive in the center of tumor spheres and some on cytoplasm and other in nuclei of Eca109 monolayer cells.However, Oct-4 fluorescence intensity was weaker than P75NTR.The expressions of Sox-2 and Nanog were positive in cytoplasm of tumor spheres and Eca 109 monolayer cells .Conclusion The cells expressing P75NTR, Oct-4, and Lin28 in the center of the tumor sphere may be esophageal cancer stem cells .

Expressions of nerve growth factor and its high-affinity receptor, tyrosine kinase A, as well as low-affinity common receptor, p75 neurotrophin receptor, in the lesions of lichen planus and their clinical significance / 中华皮肤科杂志

Objective To detect the expressions of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) as well as p75 neurotrophin receptor (p75NTR) in the lesions of lichen planus.Methods Biopsy specimens were collected from the lesions of 32 patients with lichen planus and normal skin of 12 healthy human controls and subjected to paraffin embedding.Immunohistochemical avidin-biotin complex (ABC) method was used to detect the expressions of NGF,TrkA and p75NTR.Results NGF and TrkA,which were located in the cytoplasm of keratinocytes,were strongly or moderately expressed in the lesional skin specimens,but absent or weakly expressed in the normal skin specimens (both P ＜ 0.01).No significant differences were observed in the expression of p75NTR between the lesional and normal skin specimens,or in the expressions of NGF,TrkA or p75NTR among specimens from patients in different age groups,patients of different gender or lesions at different sites (all P ＞ 0.05).There was a positive correlation between the expression of NGF and TrkA in the lesions of lichen planus (R2 =0.535,P ＜ 0.01).Conclusion NGF may play a certain role in the development of lichen planus via its highaffinity receptor TrkA.

Supraorganized collagen enhances Schwann cell reactivity and organization in vitro

We investigated the reactivity and expression of basal lamina collagen by Schwann cells (SCs) cultivated on a supraorganized bovine-derived collagen substrate. SC cultures were obtained from sciatic nerves of neonatal Sprague-Dawley rats and seeded on 24-well culture plates containing collagen substrate. The homogeneity of the cultures was evaluated with an SC marker antibody (anti-S-100). After 1 week, the cultures were fixed and processed for immunocytochemistry by using antibodies against type IV collagen, S-100 and p75NTR (pan neurotrophin receptor) and for scanning electron microscopy (SEM). Positive labeling with antibodies to the cited molecules was observed, indicating that the collagen substrate stimulates SC alignment and adhesion (collagen IV labeling - organized collagen substrate: 706.33 ± 370.86, non-organized collagen substrate: 744.00 ± 262.09; S-100 labeling - organized collagen: 3809.00 ± 120.28, non-organized collagen: 3026.00 ± 144.63, P < 0.05) and reactivity (p75NTR labeling - organized collagen: 2156.33 ± 561.78, non-organized collagen: 1424.00 ± 405.90, P < 0.05; means ± standard error of the mean in absorbance units). Cell alignment and adhesion to the substrate were confirmed by SEM analysis. The present results indicate that the collagen substrate with an aligned suprastructure, as seen by polarized light microscopy, provides an adequate scaffold for SCs, which in turn may increase the efficiency of the nerve regenerative process after in vivo repair.

p75NTR in isolation and identification of cancer stem cells from human esophageal carcinoma / 第二军医大学学报

Objective: To isolate and identify cancer stem cells from esophageal cancer cells (ECCs) using cell surface marker p75NTR. Methods: ECCs were cultured from surgically resected ECC specimens; ECC cell lines TE-1 and Ecal09 were also cultured. The expression of p75NTR in human ECCs was examined by flow cytometry. p75NTR positive cells were isolated from ECCs using magnetic activated cell sorting (MACS) method. The proliferation, differentiation, and the ability of colony-forming in soft agar of the p75 NTR positive cells were observed. The p75NTR positive cells were injected into BALB/c nude mice subcutaneously to observe their tumorigenesis ability. The survival rates of p75NTR positive and negative cells were assessed after treated with chemotherapy drugs to evaluate the resistance of p75NTR positive cells. Results: Six out of the eight cell lines, including SHEC-4, SHEC-6, SHEC-7, SHEC-8, EcalO9, and TE-1, were positive of p75NTR, with the positive rates being 2.71%, 0.32%, 3.35%, 1.13%, 2.15%, and 0.45%. respectively. It was showed that p75 NTR positive cells possessed higher proliferation ability compared with p75NTR negative cells (P<0.01). The p75NTR positive cells had higher colony-forming ability in soft agar compared with p75NTR negative cells (P<0.01). The p75NTR positive cells demonstrated stronger tumorigenesis ability in nude mice. As few as 2 000 SHEC-7 cells could give rise to new tumors in xenotransplantation, with a tumorigenesis ability 50 times as high as that of the p75NTR negative cells. When treated with chemotherapy drugs for 48 h, p75NTR positive cells had significantly higher survival rate than p75NTR negative cells (P<0.05). Conclusion: The p75NTR positive ECCs possess self-renewal, differentiation, and proliferation abilities; they are strongly resistant to chemotherapy drugs, which gives them strong tumorigenesis ability and the characters of tumor stem cells.

Expression of the p75NTR Neurotrophin Receptor in the Thymic Medullary Epithelial Cells and Interdigitating Dendritic Cells during Rat Thymus Regeneration Following Acute Thymic Involution / 대한해부학회지

The existence of a functional link between the nervous and immune systems has been well established. The present study was to characterize the expression of p75NTR during thymus regeneration from acute involution induced by cyclophosphamide in the rat. Immunohistochemical and double immunofluorescence analyses demonstrated that expression of the p75NTR was decreased in the thymic medullary epithelial cells and interdigitating dendritic cells during thymus regeneration. The presence of p75NTR protein in extracts from the control and regenerating rat thymus was confirmed by western blot. Furthermore, RT-PCR analysis supported these results by demonstrating that thymic extracts contain p75NTR mRNA at lower levels during thymus regeneration. Thus, our results suggest that the p75NTR located on the thymic medullary epithelial cells and interdigitating dendritic cells could play a role in the development of new T cells to replace the thymocytes damaged during thymus regeneration

Expression of nerve growth factors and its receptors in granulosa cells and human ovarian follicle development in polycystic ovarian syndrome / 中国综合临床

Objective To investigate the possible role of nerve growth factors (NGF) and its receptors in ovarian follicle development,and detect the difference between polycystic ovarian symdrome (PCOS) and normal control.Methods Immunohistochemisty was applied to detect the expression of NGF,p75NTR,TrkA in ovarian follicle granulosa cells.Results In 54 cases (including 9 cases of IVM-PCOS,16 cases of IVF-PCOS and 29 cases of IVF-Normal),49 cases showed NGF protein positive in granulose cells with significance difference between groups (P＜0.05),and especially NGF was the strongest expressed factor in IVF-PCOS group but there was no remarkable difference between the other two groups in the expression of NGF.41 were TrkA protein positive,almost all IVF cases were TrkA protein positive while only 2 in IVM and there was no remarkable difference in expression of TrkA between IVF PCOS and IVF Normal(P＞0.05).The cases with stronger expression of NGF or TrkA had higher estradiol level than that of lower expression group (P＜0.05).51 cases had positive expression of p75 NTR protein but there was no significant difference between groups (P＞0.05).Conclusions TrkA is expressed in mature ovarian follicle,and the interaction of NGF-TrkA may be involved in ovarian follicle development,and overexpression of NGF may be associated with PCOS development.

p75NTR expression in cultured hippocampal neurons during glutamate-induced excitotoxicity / 重庆医科大学学报

Objective:To observe the change in expression level ofp75NTR(p75 neurotrophin receptor)in cultured hippocampal neurons during glutamate-induced excitotoxicity.Methods:Excitotoxicity was induced by glutamate in rat cultured hippocampal neurons; RT-PCR and western blot were used to detect the change in expression level of p75NTR.Results:After glutamate exposure,p75NTR mRNA(P

Change in the Expression of p75 Neurotrophin Receptor and TRPV1 in the Spinal Cord and Dorsal Root Ganglion after an Injury to the Spinal Nerves in Rats / 대한정형외과학회잡지

PURPOSE: To determine the relationship between change in the expression of the p75 neurotrophin receptor (NTR) and transient receptor potential vanilloid 1 (TRPV1) after a spinal nerve injury with time. MATERIALS AND METHODS: The L5 and L6 spinal nerve of the rats were cut unilaterally. The spinal cord and dorsal root ganglion (DRG) were subjected to immunohistochemistry for p75 NTR and TRPV1. RESULTS: The immunoreaction (IR) for p75 NTR in the neuronal cytoplasm was persistently lower on the ipsilateral L5 and L6 DRG but higher in the satellite cells and fibers. The colocalization between p75 NTR and TRPV1 was increased temporarily in the L4 DRG in both sides. In the spinal cord, p75 NTR-IR decreased temporalily in the ipsilateral dorsal horn of the L4-L6 level and had recovered at 28 days after injury. CONCLUSION: These results show that a differential change in the expression of p75 NTR and TRPV1 is related to the different functional recovery of the sensory and motor system, and that increased colocalizations between p75 NTR and TRPV1 in a non-injured DRG might be related to the development of neuropathic pain after a peripheral nerve injury.

Protective effect of brain-derived neurotrophic factor on high dose glutamate-injured rat cortical neurons and its mechanism / 第三军医大学学报

Objective To explore the protective effect of brain-derived neurotrophic factor (BDNF) on cultured rat cortical neurons against glutamate (Glu)-induced injury and its mechanism. Methods Cortical neurons were primarily cultured from 1-day-old newborn Sprague-Dawley rats and then cultured for 7 d. The cortical neurons were divided randomly into 3 groups: control group,Glu group and BDNF group after identified with neuron-specific enolase (NSE) immunostaining. The cells of BDNF were treated with 50 ng/ml BDNF on day 6 for 24 h followed by cultured with 50 ?mol/L Glu for 0.5 h. While,the cells of Glu group were cultured with 50 ?mol/L Glu for 0.5 h on day 7. The control cells received no such treatments. On day 8,cell viability were determined by the colorimetric MTT assay. The morphological features of the neuron cells were observed under AO/EB fluorescence microscopy. Expressions of p75NTR,JNK and ERK were observed using Western blot analysis. Results On day 8,the primary cortical neurons grew well. BDNF protected cortical neural cells from Glu injury. Cell viability of BDNF group was (1.14?0.06),significantly higher than that of Glu group (0.72?0.10,P

The expressions of neurotrophic factor recepor protein in laser-induced retinal injury / 解放军医学杂志

Objective To investigate the effects of high-affinity tyrosine kinase receptors TrkA, TrkC and the low-affinity neurotrophin receptor p75 (p75~ NTR) protein in laser-induced retinal injury. Methods The Wistar rats were anesthetized and exposed to frequency doubling Neodymium:Yttrium,aluminum garnet(ND:YAG,?=532nm) laser for 100 plus per eye, which were sacrificed on 12 hours,1,3,7,14 and 28 days after laser exposure and eyeball was taken out. We investigated retinal histology by hematoxylin and eosin staining, and the expression of TrkA, TrkC and p75~ NTR protein was studied by means of immunohistochemistry. Results Immunohistochemistry results showed a differential distribution for these three neurotrophin receptors in the laser injuried retina. TrkA was enhanced in nerve fiber layer (NFL), ganglion cell layer(GCL) and inner nuclear layer(INL) ,which is the most nuclei of the ganglion cells, proximal M?ller cell end feet and a little cells in the innermost part of the INL, its peak of up-regulation was after day 1-3, after day 28 there was sustained. Whereas TrkC and p75~ NTR expression was enhanced in the outer nuclear layer(ONL), which is distal M?ller cell processes, TrkC up-regulated after 12 hours, its peak was on day 1-3, after day 28 there was sustained, p75~ NTR up-regulated after 24 hours, its peak was on day 3, on day 14-28 there was sustained in the GCL, which is proximal M?ller cell processes. Conclusion The expression of TrkA, TrkC and p75~ NTR participated in the course of laser injuried retinal pathology.

Effects of astragalosides on the expression of BDNF,TrkB and p75NTR mRNA against focal cerebral ischemia-reperfusion injury / 中国药理学通报

Aim To observe the neurological protective effects of astragalosides(AST) on focal cerebral ischemia-reperfusion(I/R) injury in rats and to explore its possible mechanism.Methods Male SD rats received right middle cerebral artery occlusion for 120 min,and were decapitated 1,3,7,and 14 days after reperfusion.AST(40 mg?kg-1) was orally administered after I/R.Neurological deficit score was daily determined,the expressions of BDNF and p75NTR mRNA were detected by RT-PCR,and the expression of TrkB mRNA was detected by real-time PCR.Results AST reduced the neurological deficit score on days 3,increased the expression of BDNF mRNA on days 3,7 and 14,decreased p75NTR mRNA and increased TrkB mRNA on days 3 and 7.Conclusions AST improves the neurological deficits after I/R in rats.The mechanism may be related with increasing BDNF,and TrkB mRNA,and decreasing p75NTR mRNA.