Neurotrophin 3 promotes osteogenic differentiation of human dental follicle cells / 华西口腔医学杂志

OBJECTIVE@#This study aims to investigate the effect of neurotrophin 3 (NT-3) on the osteogenic differentiation of human dental follicle cells (hDFCs).@*METHODS@#hDFCs were isolated and cultured in vitro. Immunocytochemical staining was used to identify the origin of hDFCs. The effects of different NT-3 concentrations on hDFCs proliferation were detected by using CCK-8 assay. The alkaline phosphatase (ALP) activities and mRNA expression levels of bone morphogenetic protein-2 (BMP-2) and osteocalcin (OCN) were determined to investigate the effects of NT-3 on hDFCs osteogenesis. The difference in the number of mineralized nodules was detected using alizarin red staining.@*RESULTS@#Vimentin and cytokeratin staining results showed that hDFCs originated from the mesenchymal cells. NT-3 exerted no evident effect on hDFCs proliferation. The ALP activity and the BMP-2 and OCN mRNA expression levels of hDFCs were significantly improved under treatment with different NT-3 concentrations (25, 50, and 100 ng·mL ⁻¹) compared with those in the control group. BMP-2 and OCN mRNA relative expression levels of hDFCs reached the highest when the NT-3 concentration was 100 ng·mL ⁻¹. The number of mineralized nodules reached the maximum when the hDFCs were treated with 50 and 100 ng·mL ⁻¹ NT-3.@*CONCLUSIONS@#Appropriate mass concentration of NT-3 can promote the osteogenic differentiation of hDFCs.

Serum levels of neurotrophic factors in active toxoplasmic retinochoroiditis

Abstract Toxoplasmic retinochoroiditis (TR) is the most common identifiable cause of posterior uveitis in Brazil. Response to treatment and clinical presentation may vary significantly. We assessed serum levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), neurotrophin (NT)-3, and NT-4/5 in patients with active TR, before and after TR treatment. Methods: Twenty patients with active lesion and 15 healthy controls were enrolled in the study. Serum concentration of neurotrophic factors was determined by enzyme-linked immunosorbent assay. Results: BDNF levels were significantly higher in patients before treatment when compared with controls (p = 0.0015). There was no significant difference in pro-BDNF, NGF, GDNF, NT-3, and NT-4/5 levels between TR patients and controls. Treatment did not affect the levels of these factors. Conclusion: BDNF may be released in the context of the active TR inflammatory response.

Papel del factor neurotrófico de origen cerebral y de la neurotropina-3 en la relación de Chlamydophila pneumoniae con la esquizofrenia / The relationship of Chlamydophila pneumoniae with schizophrenia: The role of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in this relationship

Several pathogens have been suspected of playing a role in the pathogenesis of schizophrenia. Chronic inflammation has been proposed to occur as a result of persistent infection caused by Chlamydophila pneumoniae cells that reside in brain endothelial cells for many years. It was recently hypothesized that brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) may play prominent roles in the development of schizophrenia. NT-3 and BDNF levels have been suggested to change in response to various manifestations of infection. Therefore, we aimed to elucidate the roles of BDNF and NT3 in the schizophrenia-C. pneumoniae infection relationship. RT-PCR, immunofluorescence and ELISA methods were used. Fifty patients suffering from schizophrenia and 35 healthy individuals were included as the patient group (PG) and the healthy control group (HCG), respectively. We detected persistent infection in 14 of the 50 individuals in the PG and in 1 of the 35 individuals in the HCG. A significant difference was found between the two groups (p < 0.05). Twenty-two individuals in the PG and 13 in the HCG showed seropositivity for past C. pneumoniae infection, and no difference was observed between the groups (p > 0.05). C. pneumoniae DNA was not detected in any group. A significant difference in NT-3 levels was observed between the groups, with very low levels in the PG (p < 0.001). A significant difference in BDNF levels was also found, with lower levels in the PG (p < 0.05). The mean serum NT-3 level was higher in the PG cases with C. pneumoniae seropositivity than in seronegative cases; however, this difference was not statistically significant (p > 0.05). In conclusion, we suggest that NT-3 levels during persistent C. pneumoniae infection may play a role in this relationship.

Existe la sospecha de que algunos patógenos pueden desempeñar un papel en la patogénesis de la esquizofrenia; en ese contexto, se ha propuesto que la infección persistente causada por células de Chlamydophila pneumoniae presentes en las células endoteliales cerebrales durante muchos años lleva a la inflamación crónica. Recientemente se ha planteado la hipótesis de que el factor neurotrófico de origen cerebral (BDNF, por sus siglas en inglés) y la neurotropina-3 (NT-3) podrían estar implicados en el desarrollo de la esquizofrenia, y se ha sugerido que sus niveles se modifican en respuesta a diversas manifestaciones de la infección. En esta investigación intentamos esclarecer el papel que desempeñan el BDNF y la NT3 en la relación entre la esquizofrenia y la infección por C. pneumoniae. Se utilizaron métodos de RT-PCR, inmunofluorescencia y ELISA. Se incluyeron 50 pacientes con esquizofrenia y 35 individuos sanos como grupo de pacientes (GP) y grupo de controles sanos (GCS), respectivamente. Detectamos una infección persistente en 14 sujetos del GP y en 1 de los del GCS, lo que constituyó una diferencia significativa (p < 0,05). Veinte participantes del GP y 13 del GCS fueron seropositivos para una infección pasada por C. pneumoniae, diferencia no significativa (p > 0,05). No se detectó ADN de C. pneumoniae en ninguno de los dos grupos. Se observó una diferencia significativa entre los grupos en los niveles de NT-3, que fueron muy bajos en el GP (p < 0,001), y de BDNF, inferiores en el GP (p < 0,05). La concentración sérica media de NT-3 fue mayor en los individuos seropositivos para C. pneumoniae en comparación con los seronegativos, pero esta diferencia no alcanzó significación estadística (p > 0,05). Sugerimos que los niveles de NT-3 durante una infección persistente por C. pneumoniae pueden estar implicados en la relación de Chlamydophila pneumoniae con la esquizofrenia.

Hippocampus-dependent Task Improves the Cognitive Function after Ovariectomy in Rats

OBJECTIVES: Estrogen is an important hormone for cell growth, development, and differentiation by transcriptional regulation and modulation of intracellular signaling via second messengers. The reduction in the estrogen level after ovariectomy may lead to cognitive impairments associated with morphological changes in areas of the brain mediate memory. The aim of the present study was to find out the effect of tasks on the cognitive function after ovariectomy in rats. METHODS: The animals used in the experiment were 50 Sprague-Dawley female rats. This study applied a hippocampus-independent task (wheel running) and a hippocampus-dependent task (Morris water maze) after ovariectomy in rats and measured the cognitive performance (object-recognition and object-location test) and growth-associated protein 43 (GAP-43) and neurotrophin 3 (NT-3) expression in the hippocampus, which is an important center for memory and learning. RESULTS: There were meaningful differences between the hippocampus-independent and hippocampus-dependent task groups for the object-location test and GAP-43 and NT-3 expression in the hippocampus, but not the object-recognition test. However, the hippocampus-independent task group showed a significant improvement in the object-recognition test, compared to the control group. CONCLUSION: These results suggest that hippocampus-dependent task training after ovariectomy enhances the hippocampus-related memory and cognitive function that are associated with morphological and functional changes in the cells of the hippocampus.

[Effect of a session resistance exercise on mRNA expression of NT-3 and TrkC proteins in soleus muscle of Wistar rats]

Background and Objective: Skeletal muscle expresses several neurotrophin and their receptors which providing the basis for neurotrophin signaling within the muscle compartments. This study was done to evaluate the effect of a session of resistance exercise on mRNA expression of NT-3 and TrkC proteins in soleus muscle of Wistar Rats

Methods: In this experimental study, 16 male Wistar rats were randomly allocated into exercise and control groups. The resistance training protocol consisted of climbing a 1-meter-long ladder, with a weight attached to a tail sleeve. Expressions of NT-4/5 and P75, quantitatively were measured using RT-PCR

Results: There was not any significant alteration in NT-3 mRNA in soleus muscle after resistance exercise. However, one session of resistance exercise significantly increased mRNA expression of TrkC [1.7 Folds] in soleus muscle [P<0.05]

Conclusion: Resistance exercise increases TrkC expression in soleuse muscle of wistar rats

Charcot-Marie-Tooth type 1A disease from patient to laboratory

Charcot-Marie-Tooth [CMT] disease is a well-known neural or spinal type of muscular atrophy. It is the most familiar disease within a group of conditions called Hereditary Motor and Sensory Neuropathies [HMSN]. The disease was discovered by three scientists several years ago. Several genes are involved as the causative agents for the disease. Hundreds of causative mutations have been found and research work for the identification of a novel locus and for the treatment of CMT1A is going on. This review article was planned to gather information on CMT disease and updates on its treatment. National Center for Biotechnology Information [NCBI] and PubMed were searched for data retrieval. Molgen database, which is the exclusive site for CMT mutation, was the other source of articles. Different aspects of the CMT disease were compared. Advancements in the finding of the causative gene, discovery of the novel Loci are the current issues in this regard. CMT disease is incurable, but researchers are trying to get some benefits from different natural compounds and several therapeutic agents. Various groups are working on the treatment projects of CMT1A. Major step forward in CMT research was taken in 2004 when ascorbic acid was used for transgenic mice treatment. Gene therapy for constant neurotrophin-3 [NT-3] delivery by secretion by muscle cells for the CMT1A is also one of the possible treatments under trial

Neurotrophins up-express in peripheral blood of allergic rhinitis patients and related to Th2 hypothesis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To detect the expression of NGF, BDNF, NT-3 mRNA in the peripheral blood of patients with allergic rhinitis (AR). And to analyze the correlation between NGF, BDNF, NT-3 mRNA expression and the epidsode of rhinitis through Th-2 Hypothesis.@*METHOD@#This study was a group controlled trial. The expression of NGF, BDNF and NT-3 mRNA were tested by real-time quantitative RT-PCR and the concentrations of IL-4, IL-6, IL-10 and INF-alpha were tested by ELISA.@*RESULT@#The expression of NGF, BDNF and NT-3 mRNA in AR patients were 2.44, 4.46 and 1.78 times the amount of those in the healthy adults, respectively. The increased expression of NT-3 correlated positively with the scores of visual analog scale of AR. The concentrations of IL-4, IL-6 and IL-10, which were 2198 +/- 472 pg/mL, 9407 +/- 703 pg/mL and 3917 +/- 323 pg/mL respectively, were higher than those in the healthy adults. The concentration of INF-alpha was 2198 +/- 472 pg/mL and less than the healthy adults. The increased expressions of NGF, NT-3 were positively related to the increase of IL-4, IL-6 and IL-10.@*CONCLUSION@#The expressions of NGF, BDNF and NT-3 mRNA in AR patients are higher than those in the healthy adults. NGF, BDNF and NT-3 may contribute to the pathogenesis of AR. Moreover, NGF and NT-3 may induce the episode of rhinitis through Th-2 Hypothesis.

Increase expression of neurotrophins mRNA in peripheral blood of patients with allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To assess the expression of NGF, BDNF, NT-3 mRNA in the peripheral blood of patients with allergic rhinitis (AR). Meanwhile, to analysis whether the expression of NGF, BDNF, NT-3 mRNA correlate with the severity of rhinitis.@*METHOD@#This study is a group controlled trial, which takes the healthy adults as control group. The total RNA have been extracted from the peripheral blood of AR patients. The expression of NGF, BDNF and NT-3 mRNA have been tested by real-time quantitative RT-PCR.@*RESULT@#Comparing with the healthy adults, the expression of NGF, BDNF and NT-3 mRNA as 2(-deltadeltaCt) are 2.436 8, 4.4588 and 1.781 8 respectively. The increasing expression of NT-3 correlated positively with the scores of visual analog scale.@*CONCLUSION@#The expression of NGF, BDNF and NT-3 mRNA are as high as 2.4368, 4.4588 and 1.7818 times to healthy adults. We propose NGF, BDNF and NT-3 may contribute to the pathogenesis of AR. NT-3 could reflect the severity of rhinitis as a molecular biological index.

Protective effects of pretreatment with neurotrophin-3 on intrathecal ropivacaine in rats / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of pretreatment with neurotrophin-3 (NT-3) on intrathecal ropivacaine in rats.@*METHODS@#A total of 144 male Sprague Dawley rats weighing 280-320 g were successfully implanted with microspinal cather following the improved methods of Yaksh. The rats were randomly divided into 4 groups and given saline (Group NS, n=36), 0.5% ropivacaine (Group M, n=36), 1% ropivacaine (Group R, n=36), and ropivacaine+NT-3 (Group T, n=36). The rats received 0.12 mL/ kg body weight of ropivacaine at 0.5% or 1%, or normal saline only, via an implanted intrathecal catheter at 90-min interval for 12 h in Group NS, M, R and T. In the meantime the rats also received NT-3 0.1 mg/kg in group T. On days 1, 3, 5, 7, 14 and 28, we assessed the paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL), behavioural change and histopathological damage score changed for possible neuronal injury within the spinal cord.@*RESULTS@#Compared with Group NS and Group M, the PWMT and PWTL were significantly higher on 1, 3, 5 d and the histopathological damage score was significantly higher on 1, 3, 5, 7, 14 d in Group R (P<0.05). Compared with Group T, the PWMT and PWTL in Group R were significantly higher on 1, 3, 5 d and histopathological damage score was significantly higher on 5, 7, 14 d (P<0.05).@*CONCLUSION@#NT-3 pretreatment in mice has obvious protective effect against repeated intrathecal injection of 1% ropivacaine in the spinal nerve.

Effect of Macrophage Migration Inhibitory Factor on Corneal Sensitivity after Laser In Situ Keratomileusis in Rabbit

PURPOSE: To investigate the effect of macrophage migration inhibitory factor (MIF) on corneal sensitivity after laser in situ keratomileusis (LASIK) surgery. METHODS: New Zealand white rabbits were used in this study. A hinged corneal flap (160-microm thick) was created with a microkeratome, and -3.0 diopter excimer laser ablation was performed. Expressions of MIF mRNA in the corneal epithelial cells and surrounding inflammatory cells were analyzed using reverse transcription polymerase chain reaction at 48 hours after LASIK. After LASIK surgery, the rabbits were topically given either 1) a balanced salt solution (BSS), 2) MIF (100 ng/mL) alone, or 3) a combination of nerve growth factor (NGF, 100 ug/mL), neurotrophine-3 (NT-3, 100 ng/mL), interleukin-6 (IL-6, 5 ng/mL), and leukemia inhibitory factor (LIF, 5 ng/mL) four times a day for three days. Preoperative and postoperative corneal sensitivity at two weeks and at 10 weeks were assessed using the Cochet-Bonnet esthesiometer. RESULTS: Expression of MIF mRNA was 2.5-fold upregulated in the corneal epithelium and 1.5-fold upregulated in the surrounding inflammatory cells as compared with the control eyes. Preoperative baseline corneal sensitivity was 40.56 +/- 2.36 mm. At two weeks after LASIK, corneal sensitivity was 9.17 +/- 5.57 mm in the BSS treated group, 21.92 +/- 2.44 mm in the MIF treated group, and 22.42 +/- 1.59 mm in the neuronal growth factors-treated group (MIF vs. BSS, p < 0.0001; neuronal growth factors vs. BSS, p < 0.0001; MIF vs. neuronal growth factors, p = 0.815). At 10 weeks after LASIK, corneal sensitivity was 15.00 +/- 9.65, 35.00 +/- 5.48, and 29.58 +/- 4.31 mm respectively (MIF vs. BSS, p = 0.0001; neuronal growth factors vs. BSS, p = 0.002; MIF vs. neuronal growth factors, p = 0.192). Treatment with MIF alone could achieve as much of an effect on recovery of corneal sensation as treatment with combination of NGF, NT-3, IL-6, and LIF. CONCLUSIONS: Topically administered MIF plays a significant role in the early recovery of corneal sensitivity after LASIK in the experimental animal model.

Effects of extract of ginkgo biloba on learning and memory ability and NGF and NT-3 expression in diabetic rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of extract of Ginkgo Biloba(EGB) on nerve growth factor(NGF) and Neurotrophin-3(NT-3) expression of hippocampus neurons in streptozotocin-induced type I diabetic rats.</p><p><b>METHODS</b>Thirty male SD rats were divided into three groups (n = 10): the control group, diabetic group and EGB-treated group. Strepozotocin were injected intraperitoneally in the later two groups to induce diabetes. EGB-treated group was injected intraperitoneally with EGB, and the same volume of normal saline was injected to the other groups. Concentration of blood glucose and body weight and behaviour were dynamicly monitored. At the end of the 12th week, morphological changes of the hippocampus neurons were observed under microscopy by HE stain. The expression of NGF and NT-3 were assayed by Western blot and RT-PCR respectively.</p><p><b>RESULTS</b>Compared with diabetic group, the behaviour and body weight (P < 0.05) and the concentration of blood glucose (P < 0.05) were significantly improved and the escape latency of Morris water maze test (P < 0.05) was significantly shortened, while the platform searching score was significantly increased (P < 0.01) in EGB treated group; The pathological changes of hippocampus neurons were significantly attenuate by EGB treated; The expression of NGF and NT-3 in hippocampus neurons were significantly increased which assayed by Western blotting and RT-PCR respectively (P < 0.05) in EGB treated group.</p><p><b>CONCLUSION</b>EGB may improve the learning and memory ability of diabetic rats the mechanism may be attributed to its improvement of the expression of NGF and NT-3 and reducing apoptosis in hippocampus neurons.</p>

Chronic Stress Induces Neurotrophin-3 in Rat Submandibular Gland

PURPOSE: Plasma neurotrophin-3 (NT-3) levels are associated with several neural disorders. We previously reported that neurotrophins were released from salivary glands following acute immobilization stress. While the salivary glands were the source of plasma neurotrophins in that situation, the association between the expression of neurotrophins and the salivary gland under chronic stress conditions is not well understood. In the present study, we investigated whether NT-3 levels in the salivary gland and plasma were influenced by chronic stress. MATERIALS AND METHODS: Expressions of NT-3 mRNA and protein were characterized, using real-time polymerase chain reactions, enzyme-linked immunosorbent assay, and immunohistochemistry, in the submandibular glands of male rats exposed to chronic stress (12 h daily for 22 days). RESULTS: Plasma NT-3 levels were significantly increased by chronic stress (p<0.05), and remained elevated in bilaterally sialoadenectomized rats under the same condition. Since chronic stress increases plasma NT-3 levels in the sialoadenectomized rat model, plasma NT-3 levels were not exclusively dependent on salivary glands. CONCLUSION: While the salivary gland was identified in our previous study as the source of plasma neurotrophins during acute stress, the exposure to long-term stress likely affects a variety of organs capable of releasing NT-3 into the bloodstream. In addition, the elevation of plasma NT-3 levels may play important roles in homeostasis under stress conditions.

Effects of bone marrow mesenchymal stem cell transplantation on retinal cell apoptosis in premature rats with retinopathy / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the effects of marrow mesenchymal stem cell (BMSC) transplantation on retinal cells apoptosis and changes to neurotrophin-3 (NT-3 and ciliary neurotrophic factor (CNTF) in rats with retinopathy of prematurity (ROP).</p><p><b>METHODS</b>Seven-day-old Sprague-Dawley rats were randomly divided into normal control (CON), ROP, BMSC transplantation (BMSCs were transplanted 5 days after oxygen conditioning) and phosphate buffered saline (PBS) groups. The ROP model was prepared according to the classic hyperoxygen method. Seven days after transplantation, TUNEL/DAPI, NT-3/API and CNTF/DAPI double-labeled immunofluorescence were used to examine the effects of BMSC transplantation on both the apoptosis of retinal cells and the expression of NT-3 and CNTF protein in the retinal cells of the ROP rats.</p><p><b>RESULTS</b>Seven days after BMSC transplantation, there were few TUNEL+ DAPI+ cells observed in the CON group. There were fewer TUNEL+DAPI+ cells observed in the BMSC group than in the ROP group (P<0.01), but there was no significant difference between the ROP and PBS groups (P>0.05). There were few NT-3+DAPI+ cells and CNTF+DAPI+ cells in the CON group. There were more NT-3+DAPI+ and CNTF+DAPI+ cells in the ROP group than in the CON group, but there was no significant difference between the ROP and CON groups (P>0.05). More NT-3+DAPI+ and CNTF+DAPI+ cells were observed in the BMSC group compared with the ROP group (P<0.01), and there was no significant difference in either NT-3+DAPI+ or CNTF+DAPI+ cells between the ROP and PBS groups (P>0.05).</p><p><b>CONCLUSIONS</b>BMSC transplantation therapy could alleviate the apoptosis of retinal cells in ROP rats, and its mechanisms might be associated with promoting the expression of NT-3 and CNTF protein in retinal cells.</p>

Decreased neurotrophin-3 expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness / 生理学报

The present study aimed to study the changes of neurotrophin-3 (NT-3) expression of intrafusal muscle fibers in rat soleus muscles under simulated weightlessness. The tail-suspension (SUS) rat model was used to simulate weightlessness. Forty mature female Sprague-Dawley rats were randomly assigned to ambulatory control (CON), 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups. Immunohistochemistry ABC staining method and enzyme linked immunosorbent assay (ELISA) were used to detect the NT-3 expression of intrafusal muscle fibers in rat soleus muscles. The results from the immunohistochemistry staining technique showed that the extrafusal muscle fibers did not exhibit the NT-3-like immunoreactivity, and NT-3-like immunoreactivity was mainly expressed in nuclear bag 1 and nuclear bag 2 fibers of the muscle spindles. The ELISA results showed that the expression quantity of NT-3 in rat soleus muscles in control, 3-day SUS, 7-day SUS, 14-day SUS and 21-day SUS groups were (14.23±1.65), (14.11±1.53), (13.09±1.47), (12.45±1.51) and (9.85±1.52) pg/mg of tissue respectively. Compared to the control group, the expression quantity of NT-3 was significantly decreased after 14 days of SUS (P<0.05). After 21 days of SUS, the NT-3 expression was further reduced (P<0.01). These results suggest that simulated weightlessness induces an obvious decrease in the NT-3 expression level of intrafusal fibers in rat soleus muscles. Accompanying the simulated weightlessness extension, NT-3 expression in rat soleus muscle spindles is progressively decreased. These changes may contribute to the proprioceptive adaptations to microgravity.

Changes in facial nerve function, morphology and neurotrophic factor III expression following three types of facial nerve injury / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To study the changes in facial nerve function, morphology and neurotrophic factor III (NT-3) expression following three types of facial nerve injury.@*METHOD@#Changes in facial nerve function (in terms of blink reflex (BF), vibrissae movement (VM) and position of nasal tip) were assessed in 45 rats in response to three types of facial nerve injury: partial section of the extratemporal segment (group one), partial section of the facial canal segment (group two) and complete transection of the facial canal segment lesion (group three). All facial nerves specimen were then cut into two parts at the site of the lesion after being taken from the lesion site on 1st, 7th, 21st post-surgery-days (PSD). Changes of morphology and NT-3 expression were evaluated using the improved trichrome stain and immunohistochemistry techniques ,respectively.@*RESULT@#Changes in facial nerve function: In group 1, all animals had no blink reflex (BF) and weak vibrissae movement (VM) at the 1st PSD; The blink reflex in 80% of the rats recovered partly and the vibrissae movement in 40% of the rats returned to normal at the 7th PSD; The facial nerve function in 600 of the rats was almost normal at the 21st PSD. In group 2, all left facial nerve paralyzed at the 1st PSD; The blink reflex partly recovered in 40% of the rats and the vibrissae movement was weak in 80% of the rats at the 7th PSD; 8000 of the rats'BF were almost normal and 40% of the rats' VM completely recovered at the 21st PSD. In group 3, The recovery couldn't happen at anytime. Changes in morphology: In group 1, the size of nerve fiber differed in facial canal segment and some of myelin sheath and axons degenerated at the 7th PSD; The fibres' degeneration turned into regeneration at the 21st PSD; In group 2, the morphologic changes in this group were familiar with the group 1 while the degenerated fibers were more and dispersed in transection at the 7th PSD; Regeneration of nerve fibers happened at the 21st PSD. In group 3, most of the fibers crumbled at the 7th PSD and no regeneration was seen at the 21st PSD. Changes in NT-3: Positive staining of NT-3 was largely observed in axons at the 7th PSD, although little NT-3 was seen in the normal fibers.@*CONCLUSION@#Facial palsy of the rats in group 2 was more extensive than that in group 1 and their function partly recovers at the 21st PSD. The fibres' degeneration occurs not only dispersed throughout the injury site but also occurred throught the length of the nerve. NT-3 immunoreactivity increased in activated fibers after partial transection.

Effect of willed movement therapy on the expression of neurotrophin 3 and growth-associated protein 43 in rats with cerebral ischemia reperfusion / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of willed movement therapy on the expression of neurotrophin 3 (NT-3) and growth associated protein 43 (GAP-43) in rats with cerebral ischemia-reperfusion (IR) and investigate the neuroprotective mechanism of willed movement therapy in nerve regeneration and repair.</p><p><b>METHODS</b>Cerebral IR model was established by middle cerebral artery occlusion (MCAO) in SD rats. The rats were randomly divided into MCAO group, environment modification group (EM group) and willed movement therapy group (WM group). The rats were evaluated for neurological deficits and decapitated on days 3, 7 and 15 after the reperfusion to examine the expressions of NT-3 and GAP-43 in the ischemic brain tissues by immunohistochemistry.</p><p><b>RESULTS</b>Compared with MCAO and EM groups, the rats in WM group showed significantly lowered grade of neurological deficits (P<0.05) at 15 days and significantly increased the expressions of NT-3 and GAP-43 (P<0.05) at 7 and 15 days after the reperfusion. No significant difference was found in the expression of NT-3 and GAP-43 between MCAO and EM groups (P>0.05). The expression of NT-3 was positively correlated to that of GAP-43 in the ischemic tissues.</p><p><b>CONCLUSIONS</b>Willed movement therapy increases the expression of NT-3 and GAP-43 in the ischemic brain area in rats with cerebral ischemia-reperfusion, which is probably related to nerve regeneration and repair.</p>

Effects of neurotrophin 3 on interdigestive migrating motor complex in rats with acute liver injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of neurotrophin 3(NT-3)on interdigestive migrating motor complex (MMC) in rats with D-galactosamine induced acute liver injury.</p><p><b>METHODS</b>Twenty-four specific pathogen-free purebred rats were equally randomized into control and acute liver injury groups. The control group was injected with equal volume of normal saline via tail vein. Acute liver injury model of the rats was induced by D-galactosamine injection via the tail vein in the acute liver injury group. And the indexes of interdigestive MMC before and after NT-3 injection were recorded by a polygraph and analyzed in model group. The serum NT-3 concentration was assayed in the two groups.</p><p><b>RESULTS</b>There were no significant changes of gastrointestinal MMC cycle and jejunal phase I MMC after NT-3 injection. Compared with the acute liver injury rats before NT-3 injection , the antral phases I, III and IV MMC were significantly prolonged [(577.44 ± 248.60)s vs (343.58 ± 227.30) s, (80.94 ± 21.15) s vs (24.76 ± 7.41) s, (405.69 ± 131.34) s vs (191.67 ± 128.15) s, P < 0.05] and the phase II MMC was shortened [ (883.94 ± 488.50) s vs (1519.00 ± 831.14) s, P < 0.05] in the acute liver injury group. The duodenal phases I, III and IV MMC were significantly prolonged [ (557.63 ± 335.14) s vs (309.46 ± 220.22) s,(75.91 ± 15.75) s vs (31.15 ± 13.67) s, (423.38 ± 135.22) s vs (209.77 ± 123.83) s, P < 0.05] and MMC II phase was shortened [ (748.81 ± 579.69) s vs (1535.86 ± 930.50) s, P < 0.05] in the acute liver injury rats. In addition, the jejunal MMC III and MMC IV phase was significantly prolonged [ (86.58 ± 23.40) s vs (31.41 ± 16.09) s,(385.18 ± 110.02) s vs (220.59 ± 159.30) s, P < 0.05] and phase II MMC was shortened [ (876.89 ± 652.01) s vs (1870.89 ± 1010.35) s, P < 0.05 ] in the acute liver injury rats. The serum NT-3 level was significantly higher in model group than in control group.</p><p><b>CONCLUSION</b>NT-3 could enhance the gastrointestinal motility in acute liver injury rats.</p>

Neuronal differentiation of PC12 cells induced by sciatic nerve and optic nerve conditioned medium / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous work has shown that optic nerve and sciatic nerve conditional medium had neurotrophic activity on neurons. In order to find if the optic nerve conditioned media (CM) had a similar activity to make PC12 cells differentiate as sciatic nerve CM did, we explored the neurotrophic activity in optic nerve CM in the same in vitro system and compared the neurotrophin expression levels in optic and sciatic nerves under both conditions.</p><p><b>METHODS</b>PC12 cells were used to examine the effects of neurotrophins secreted by the sciatic nerve and optic nerve. RT-PCR and real-time QPCR showed that the sciatic nerve and optic nerve produced a range of neurotrophins including nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3).</p><p><b>RESULTS</b>The effects of sciatic nerve and optic nerve CM on neurite outgrowth were tested against a range of neurotrophins, and they had different neuritogenic activities. Only NGF and sciatic nerve CM had obvious neuritogenic activities, although the concentration of NGF in the sciatic nerve CM was very low.</p><p><b>CONCLUSIONS</b>Our experiment showed that sciatic nerve CM had a higher neurotrophic activity on PC12 cells than optic nerve CM. These results suggested that peripheral nervous system (PNS) and central nervous system (CNS) had different expression levels of neurotrophin, which may in part explain the lack of ability to regenerate the CNS.</p>

Dok6 promote neurite outgrowth of tropomyosin-related kinase C overexpressed PC12 cells in stimulation of neurotrophin-3 / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role of adaptor protein Dok6 in neurite outgrowth in PC12 cells.</p><p><b>METHODS</b>Series of fusion clones were constructed by fusing different domains of Dok6 into mutant TrkC/Y516F. These constructs were transiently transfected into PC12 cells separately and the expression levels of fusion proteins were detected by Western blot. Neurite outgrowth in these PC12 cells was tested after stimulation of NT-3.</p><p><b>RESULTS</b>Each fusion clone was stably expressed in PC12 cells. The fusion clones that fused both TrkC/Y516F-Dok6 (PTB+C) and TrkC/Y516F-Dok6C rescued the loss of neurite outgrowth in PC12 cells resulting from the mutation in tyrosine 516, while fusion clones that fused with single TrkC/Y516F-Dok6PTB did not show such effect.</p><p><b>CONCLUSION</b>Dok6 can promote neurite outgrowth induced by NT-3 stimulation through its C-terminal in TrkC-positive PC12 cells.</p>

Neurotrophins: are they meaningful in chronic spontaneous urticaria?

Plasma neurotrophin levels are elevated in patients with allergic and autoimmune diseases. The present study was designed to investigate the serum neurotrophin levels in 42 patients displaying chronic spontaneous urticaria, as well as 22 healthy control subjects. Blood samples were obtained from subjects during their first visit to the clinic, and then again after one month of desloratadine therapy. No significant difference was found between patient and control groups in terms of basal serum neurotrophin levels. However, basal nerve growth factor levels in patients whose symptoms persisted despite treatment were significantly lower than those of the drug-responsive patients and the control group. In treatment-responsive patients, nerve growth factor increased after suppression of the symptoms. Our study suggests that chronic spontaneous urticaria is linked with changes serum nerve growth factor levels, and that the deregulation of neurotrophins may contribute to urticaria pathophysiology.