To get the mature peptide of human-derived neurotrophin-6 (NT-6), NT-6 gene encoding mature peptide was amplified by PCR, using the NT-6 cDNA that had been cloned as templet. The gene encoding mature peptide of NT-6 gene was cloned into pGEX1-lambdaT plasmid to construct the fusion expression vector. Expression of fusion protein in Escherichia coli was defected after induction by isopropyl beta-D-thiogalactoside(IPTG). The mature peptide of NT-6 was collected with GST fusion protein purifying kit. It was shown that a fragment of 460bp was gained by PCR. With the techniques of double-cleave and electrophoresis, the recombinant vector was identified as pGEX1-NT-6. The recombinant vector pGEX1-NT-6 transformed Escherichia coli expressed fusion protein of 41KD after induction by IPTG. Cleaved by thrombin, the mature peptide of NT-6 was obtained; its molecular weight was about 15KD. The cloning and expression of human-derived NT-6 gene encoding mature protein has provided a basis for further studies on the function and clinical application of NT-6.
Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Isopropyl Thiogalactoside ; pharmacology ; Nerve Growth Factors ; biosynthesis ; genetics ; Peptides ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification

OBJECTIVETo observe the position and quantity of nestin expression in SD rat eyes in different stages of postnatal development.

METHODSImmunocytochemical method was used to identify nestin expression in the eyes of SD rats of 1 to 30 days old.

RESULTSNestin expression was detected in the retina and extraocular muscles of SD rats. The expression varied with the time of postnatal development, distributing in the entire retina layers in earlier stages and confined in the nerve fiber layer in later stages. The quantities of nestin expression in the extraocular muscles decreased gradually with growth.

CONCLUSIONNestin expression in the retinas and extraocular muscles of SD rats decreases during the postnatal development.

Animals ; Animals, Newborn ; Eye ; growth & development ; metabolism ; Immunohistochemistry ; Intermediate Filament Proteins ; biosynthesis ; Nerve Tissue Proteins ; biosynthesis ; Nestin ; Oculomotor Muscles ; growth & development ; metabolism ; Rats ; Rats, Sprague-Dawley ; Retina ; growth & development ; metabolism ; Time Factors

OBJECTIVETo investigate the expression and pattern of vascular endothelial growth factor (VEGF) and its fetal liver kinase-1 (Flk-1) receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve in rats.

METHODSForty-five adult male Wistar rats were divided randomly into a control group (n=5) and an experimental group (n=40). The bilateral sciatic nerves of the rats in the experimental group underwent neurotomy and the L4-L6 spinal cord and the corresponding dorsal root ganglia were harvested respectively at 8 hours, and 1, 3, 5, 7, 10, 14 and 21 days (8 subgroups with 5 rats each) after operation. The rats in the control group only underwent an exposure of sciatic nerve without neurotomy. Immunohistochemistry and image analysis were used to study the expression of VEGF and its Flk-1 receptor.

RESULTSBoth VEGF and Flk-1 receptor expressed in the normal rat spinal cord and dorsal root ganglia. In response to neurotomy, their expression reached a higher level and persisted for a short time then declined to the normal level rapidly. Besides, positive staining of Flk-1 was observed in both glial cells and nerve fibers, which located in the white matter of the spinal cord.

CONCLUSIONSVEGF can promote the regeneration of peripheral nerves from the angle of central neurons, which establishes the experimental and theoretical foundation for VEGF treating peripheral nerve injuries.

Analysis of Variance ; Animals ; Ganglia, Spinal ; metabolism ; Immunoenzyme Techniques ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Sciatic Nerve ; metabolism ; surgery ; Vascular Endothelial Growth Factor Receptor-2 ; biosynthesis ; Vascular Endothelial Growth Factors ; biosynthesis

As a severe threat to human health, ischemic brain injury has a very complex pathological mechanism involving excitotoxic amino acids, oxygen free radical formation, nitric oxide (NO), Ca2+ overload and inflammation. Traditional Chinese medicine Qingkailing injection have shown good clinical efficacy in the treatment of cerebrovascular disease, and thus it is very significant to studies on its pharmacological mechanism. This essay summarizes relevant studies on pharmacological mechanism of a new compound traditional Chinese medicine Jingzhiqiangkailing (JZQKL) injection in treatment on cerebral ischemia, and explains the pharmacological mechanism of its single effective compounds and their compatibility in treatment of schemic brain injury in the aspects of regulating inflammatory response, neurotrophic factors, vascular protection, blood-brain barrier (BBB) protection and others, and thus providing information for further studies.
Animals ; Blood-Brain Barrier ; drug effects ; Brain Ischemia ; drug therapy ; Cell Adhesion Molecules ; physiology ; Cytokines ; biosynthesis ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Humans ; Injections ; Nerve Growth Factors ; physiology

OBJECTIVEIt has been known that glial line-cell derived neurotrophic factor (GDNF) has the nutritional and protective effect in motor neurons. In this experiment, we investigated the character of GDNF mRNA expression in a facial nerve-striking model; combined with other scholars' experimental results; and analyzed what role GDNF plays in the regeneration process of injured motor nerves.

METHODSWe established a striking model in rabbit facial nerves with a striking gun with the striking velocity of 10 m/s and the total striking energy of 7.5 J. Then we detected the GDNF mRNA expression in facial neurons and axons with in situ hybridization on days 3, 7, 14 and 21 after striking. We counted the expression numbers of facial neurons and, compared with normal facial neurons and peripheral facial nerves.

RESULTSWe detected GDNF mRNA expression in the facial neurons from day 3 to day 21 after the facial nerve injured by striking. The peak of GDNF mRNA expression appeared on the 7th day, and then the expression number of facial neurons decreased gradually. A high level expression was also detected on day 21. GDNF mRNA expression was not detected neither in Schwann cells nor in normal facial neurons from the 3rd day to the 21st day.

CONCLUSIONGDNF is a kind of neurotrophic growing factor (NGF) that could be activated by injury. The character of GDNF mRNA expression was accordant to the process of nerve regeneration. These results showed that GDNF plays a very important role in the regeneration of injured motor nerves.

Animals ; Facial Nerve ; metabolism ; Facial Nerve Injuries ; metabolism ; Glial Cell Line-Derived Neurotrophic Factor ; In Situ Hybridization ; Male ; Motor Cortex ; metabolism ; physiology ; Nerve Growth Factors ; biosynthesis ; genetics ; Nerve Regeneration ; Neuronal Plasticity ; physiology ; Neurons ; metabolism ; Pons ; cytology ; metabolism ; physiology ; RNA, Messenger ; biosynthesis ; genetics ; Rabbits

Pituitary adenylate cyclase activating polypeptide (PACAP) was first isolated from ovine hypothalamus and was known to stimulate the release of growth factor in various cells. Recently, we reported the cellular localization of PACAP and its type I (PAC1 ) receptor in rat placenta during pregnancy. Placenta is a critical organ that synthesizes several growth factors and angiogenic factors for the fetal development and its own growth. However, there is little information regarding the cellular localization of PACAP and its receptor in human placenta at various gestations. The aim of the present study was to define the expression and distribution of PACAP and PAC1 receptor mRNAs in the human placenta during the pregnancy period. PACAP and PAC1 receptor mRNAs were expressed in stroma cells of stem villi and terminal villi. At the early stage, on 7 and 14 weeks, PACAP and PAC1 receptor genes were moderately expressed in stroma cells surrounding the blood vessels within stem villi. These genes were strongly expressed in stroma cells of stem villi and terminal villi on 24 and 38 weeks. The expression of these genes was increased as gestation advanced, and localized in the same areas. Localization of PACAP and PAC1 receptor demonstrate the evidence that PACAP may play an important role, as an autoregulator or pararegulator via its PAC1 receptor. In conclusion, our findings strongly suggest that PACAP may have a critical role in physiological function of the placenta for gestational maintenance and fetal growth.
Chorionic Villi/metabolism ; Female ; Gene Expression ; Humans ; Nerve Growth Factors/*biosynthesis ; Neuropeptides/*biosynthesis ; Neurotransmitter Agents/*biosynthesis ; Pituitary Adenylate Cyclase-Activating Polypeptide ; Placenta/*metabolism ; Pregnancy ; Pregnancy Trimester, First ; Pregnancy Trimester, Second ; RNA, Messenger ; Receptors, Cell Surface/*biosynthesis ; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide ; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I

OBJECTIVETo explore whether the nerve growth factor has protective effects on PC12 cells from injury induced by 2, 5-hexanedione.

METHODSWith PC12 cells as the model of neurons, different concentrations of NGF were added into the culture of PC12 cells. Then cell viability was tested with MTT. The DNA fragment was observed with agarose gel electrophoresis. The apoptosis ratio was tested with flow cytometry (FACS). The p53 protein was detected with western blot. The differences among the groups were compared.

RESULTSCell viabilities were increased with the increase of the concentrations of NGF (P < 0.05). The DNA fragment, the apoptosis ratio and the expression of p53 were all decreased with the increase of the concentrations of NGF (P < 0.05).

CONCLUSIONThe NGF might have direct nutritional effects on PC12 cells, and protect them from injury induced by 2, 5 HD. Moreover, it might also have anti-apoptosis effect to some extent.

Animals ; Apoptosis ; drug effects ; DNA Fragmentation ; drug effects ; Dose-Response Relationship, Drug ; Electrophoresis, Agar Gel ; Flow Cytometry ; Hexanones ; toxicity ; Mice ; Nerve Growth Factors ; pharmacology ; PC12 Cells ; Rats ; Tumor Suppressor Protein p53 ; biosynthesis

Apoptosis, the cell's intrinsic death program, plays a crucial role in the regulation of tissue homeostasis, and abnormal inhibition of apoptosis is an indicator of cancer and autoimmune diseases, whereas excessive cell death is implicated in neurodegenerative disorders such as Alzheimer's disease (AD). Using cDNA subtraction analysis, we compared p60TRP (p60 transcription regulator protein) expressing cells with control cells during the process of apoptosis and we identified the new zinc-finger protein p48ZnF that is predominantly located in the cytoplasm of the cell. Additionally, we demonstrate here that p48ZnF is up-regulated in rat neuronal PC12 cells upon stimulation with the neurotrophic factor NGF (50 ng/ml). These findings point to a possible pivotal role of p48ZnF in the control of neuronal survival.
Alzheimer Disease/genetics/metabolism ; Animals ; Apoptosis ; Autoimmune Diseases/genetics/metabolism ; Base Sequence ; Biological Markers ; CHO Cells ; Cell Survival/drug effects ; Cloning, Molecular ; Cytoplasm/*metabolism ; DNA-Binding Proteins/*biosynthesis ; Gene Expression Profiling ; Gene Expression Regulation/drug effects ; Hamsters ; Molecular Sequence Data ; Neoplasms/metabolism ; Nerve Growth Factor/*pharmacology ; Nerve Tissue Proteins/*biosynthesis ; PC12 Cells ; RNA, Messenger/*biosynthesis ; Rats ; Research Support, Non-U.S. Gov't ; Transcription Factors/*biosynthesis/*genetics ; Transfection ; Zinc Fingers/*genetics

OBJECTIVE: To explore the effect of Th1/Th2 cytokines on the expression of nerve growth factor(NGF)in splenic lymphocytes in asthmatic model. METHODS: Four SD rats were sensitized and challenged with ovalbumin to establish an asthmatic model, and the rat splenic lymphocytes were isolated and cultured with ConA. The expressions of NGF mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), and were observed after the lymphocytes were exogenously added with interferon-gamma(IFN-gamma) or interleukin-4 (IL-4). RESULTS: The lymphocytes of the asthmatic model stimulated by ConA in vitro expressed NGF mRNA in a time-dependent manner. After the lymphocytes had been cultured with IL-4 for 12 h, 24 h, 36 h, and 48 h, 50 microg/L IL-4 upregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were significantly higher than the basal values at the same time(all Ps<0.01). After 0, 10, 50, and 100 microg/L IL-4 had been added for 24 h, IL-4 upregulated the expressions of NGF mRNA in a dose-dependent manner and the NGF mRNA expressions were all significantly higher than the values of the lower dose IL-4(all Ps<0.05). After the lymphocytes had been cultured with 10 mug/L IFN-gamma for 0 h, 12 h, 24 h, 36 h, and 48 h, IFN-gamma downregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were significantly lower than the basal values at the same time(all Ps<0.01). After 0, 1, 10, and 50 microg/L IFN-gamma have been added for 24 h, IFN-gamma downregulated the expressions of NGF mRNA in a dose-dependent manner and all the NGF mRNA expressions were significantly lower than the values of the lower IFN-gamma dose(all Ps<0.05). CONCLUSION In the splenic lymphocytes of asthmatic rats, IL-4, one of the Th2 cytokines, can upregulate the expressions of NGF; IFN-gamma, one of the Th1 cytokines, can downregulate the expressions of NGF both in a time-dependent manner and in a dose-dependent manner. Th1/Th2 cytokine immune imbalance may indirectly induce the airway neurogenic inflammation by regulating the NGF mRNA expression.
Animals ; Asthma ; chemically induced ; immunology ; Cells, Cultured ; Cytokines ; pharmacology ; Gene Expression ; drug effects ; Interferon-gamma ; pharmacology ; Interleukin-4 ; pharmacology ; Lymphocytes ; cytology ; drug effects ; metabolism ; Male ; Nerve Growth Factors ; genetics ; Ovalbumin ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Spleen ; cytology ; immunology ; Th1 Cells ; metabolism ; Th2 Cells ; metabolism

Down syndrome cell adhesion molecule (DSCAM) acts as a netrin-1 receptor and mediates attractive response of axons to netrin-1 in neural development. However, the signaling mechanisms of netrin-DSCAM remain unclear. Here we report that AMP-activated protein kinase (AMPK) interacts with DSCAM through its γ subunit, but does not interact with DCC (deleted in colorectal cancer), another major receptor for netrin-1. Netrin-treatment of cultured cortical neurons leads to increased phosphorylation of AMPK. Both AMPK mutant with dominant-negative effect and AMPK inhibitor can significantly suppress netrin-1 induced neurite outgrowth. Together, these findings demonstrate that AMPK interacts with DSCAM and plays an important role in netrin-1 induced neurite outgrowth. Our study uncovers a previously unknown component, AMPK, in netrin-DSCAM signaling pathway.
AMP-Activated Protein Kinases ; antagonists & inhibitors ; genetics ; metabolism ; Animals ; Cell Adhesion Molecules ; genetics ; metabolism ; Cells, Cultured ; HEK293 Cells ; Humans ; Mice ; Nerve Growth Factors ; pharmacology ; Netrin-1 ; Neurites ; physiology ; Neurons ; cytology ; drug effects ; metabolism ; Phosphorylation ; Protein Binding ; Protein Kinase Inhibitors ; pharmacology ; RNA Interference ; RNA, Small Interfering ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Signal Transduction ; drug effects ; Transfection ; Tumor Suppressor Proteins ; pharmacology