The purpose of this investigation was to re-evaluate the neurotrophic effect of GPI-1046 on neurite outgrowth in vitro. GPI-1046 was synthesized and identified with mass spectrometry, nuclear magnetic resonance and elemental analysis. Chicken dorsal root ganglions (DRGs) were removed and divided into three groups: (1) The DRGs were cultured in DMEM containing different concentrations of GPI-1046; (2) The DRGs were cultured in DMEM containing nerve growth factor (NGF) alone at 0.8 and 8 ng/mL, respectively; (3) The DRGs were cultured in DMEM containing both different concentrations of GPI-1046 and NGF at 0.8 ng/mL. The results showed that GPI-1046 alone could not stimulate chicken DRG neurite outgrowth; however, GPI-1046 stimulated DRG neurite outgrowth only in the presence of NGF at low concentration in the culture medium.
Animals ; Cells, Cultured ; Chickens ; Ganglia, Spinal ; drug effects ; growth & development ; Nerve Growth Factor ; pharmacology ; Neurites ; drug effects ; Pyrrolidines ; pharmacology

OBJECTIVETo observe the early bone integration of oral implants after injection of exogenous nerve growth factor (NGF) and investigate the effects of NGF on peri-implant osseointegration.

METHODSTwelve New Zealand white rabbits were used in this study to establish bi-mandible implant model. Then local injection of 1 µg NGF was given on the right side of the mandible as experimental group and normal saline only was injected on the left side as control group once a day for seven days. The rabbits were respectively sacrificed at 2, 4 and 8 weeks after surgery. The implant-bone grinding samples were prepared and stained by toluidine blue for general observation, X-ray, histology and bone histomorphometry analysis.

RESULTSThe density of the new bone around implants at 2 and 4 weeks was lower than normal bone. Compared with the control group, the quantity of new bone and bone-implant contact ratio significantly increased in the experimental group. At 8 weeks, the new bone density in both groups was similar to the normal bone. In the experimental group, the haversian system was observed. Bone contact ratio was significantly different between experimental and control group at 2 and 4 weeks, but similar at 8 weeks.[control group at 2 weeks (26.67 ± 3.88)%, 4 weeks (52.59 ± 5.07)% and 8 weeks (97.33 ± 6.75)%, experimental group at 2 weeks (42.24 ± 6.67)%, 4 weeks (72.25 ± 6.30)% and 8 weeks (99.15 ± 4.68)%].

CONCLUSIONSApplying exogenous NGF in the early phase could accelerate the formation and maturation of trabecular bone around the implants and shorten the period of osseointegration. Nerve growth factor could promote osseointegration in the early stage of oral implantation.

Animals ; Bone Density ; Bone and Bones ; Dental Implants ; Mandible ; Nerve Growth Factor ; pharmacology ; Osseointegration ; Prostheses and Implants ; Rabbits

OBJECTIVETo assess the effects of both TrkA and p75(NTR) on nerve growth factor (NGF)-induced differentiation of neuroblastoma cells.

METHODSRetroviral vectors were constructed to express the high affinity NGF receptor (TrkA) and low affinity NGF receptor (p75(NTR)). Neuroblastoma cell line IMR-32 was transfected by the vectors expressing either TrkA or p75(NTR) or both by using lipofectmine trade mark reagent separately or cotransfected at the same time. Southern blot, Northern blot, RT-PCR and flow cytometry were used to determine the success of the transfection. MTT technique was to monitor the cell proliferation. Colony formation in soft agar and tumor forming assay in nude mice were used to test the biological characteristics of the tumor cells. Terminal-deoxynucleotidytransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay was used to test the apoptosis of the tumor cells.

RESULTSStable transformant cell lines expressing TrkA, p75(NTR) or both genes were established. Studies on these transformant cell lines have shown different NGF responses. The p75(NTR) transfection only resulted in the mild differentiation response, and transfection of TrkA gene caused remarkable neurite extension, up-regulation of neurofilament and decreased expression of N-myc oncogene after NGF treatment. The cotransfection of the two genes into this cell line resulted in the more rapid and more apparent morphological changes than single TrkA transfected cells after NGF treatment. The cotransfected cells underwent apoptosis after withdrawal of NGF.

CONCLUSIONSThe results indicate that coexpression of both low- and high-affinity NGF receptors are not only more efficient in restoration of NGF-induced differentiation pathway, but also be able to activate the pro-apoptotic activity of low-affinity NGF receptor and make the tumor cells become NGF-dependent and irreversibly differentiated.

Animals ; Apoptosis ; Cell Differentiation ; Genes, myc ; Humans ; Mice ; Mice, Nude ; Nerve Growth Factor ; pharmacology ; Neuroblastoma ; pathology ; Receptor, Nerve Growth Factor ; Receptor, trkA ; physiology ; Receptors, Nerve Growth Factor ; physiology ; Transfection ; Tumor Cells, Cultured

OBJECTIVETo observe the effects of NGF, estrogens and minoxidil on the growth of human hair follicle in vitro.

METHODSIn a model of human hair follicle in vitro, the follicle was separately treated with the NGF, estrogens and minoxidil. The growth of the hair follicle was measured in length with an eyepiece micrometer. The effects of the NGF, estrogens and minoxidil were evaluated by measuring the rates of incorporation of 3H-TdR of DNA synthesis.

RESULTSThe growth of the human hair follicle was showing significantly faster in the 100 ng/ml NGF and 125 micrograms/ml minoxidil groups, compared with the control (P < 0.05), but the growth was significantly inhibited in the 0.5 microgram/ml 17 beta-E2 group (P < 0.05). There was no difference shown for the growth of the hair follicle in the group mixed with 100 ng/ml NGF and 0.5 microgram/ml 17 beta-E2 (P > 0.05). The rates of incorporation of 3H-TdR in the groups were shown that the results just correlated with the results of the above-mentioned method.

CONCLUSIONSThe 100 ng/ml NGF and 125 micrograms/ml minoxidil could increase the growth of human hair follicle while the 0.5 microgram/ml 17 beta-E2 could inhibit it. The 100 ng/ml NGF could neutralized the effect of the 0.5 microgram/ml 17 beta-E2.

Adolescent ; Adult ; Estrogens ; pharmacology ; Hair Follicle ; cytology ; drug effects ; growth & development ; Humans ; In Vitro Techniques ; Middle Aged ; Minoxidil ; pharmacology ; Nerve Growth Factor ; pharmacology ; Vasodilator Agents ; pharmacology

OBJECTIVETo investigate the effects of nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) to promoting the sensitive and motor fibres regeneration.

METHODSThirty two Sprague-Dawley rats with 10 mm gap of sciatic nerve were operated and bridged with the new double channel nerve conduit in rhomboid shape. They were randomly divided into two groups, with each in twelve animals. In the first group, 200 micro1 of chitin for medical use was injected into the conduit, and in the second group the two branches of the conduit contained 100 microl of the chitin and 5 microl NGF or CNTF. At twelve and sixteen weeks after the operation, we evaluated the sensitive and motor fibres of regenerative nerve with Holmes, Acetylcholinesterase and Carbonic anhydrase staining.

RESULTSAfter the twelve and sixteen weeks of the operation, there were not significant differences of the regenerative nerve fibres between two channels in the first groups. But in the second group, the number of the motor fibres of the regenerative nerve of CNTF branch channel was much more and distributed better than the others, while the number and density of sensitive fibres was inferior to NGF. The latency of compound muscle active potential and cortical somatosensory evoked potential of the nerve in the CNTF branch was shorter than the one in the NGF branch, but its amplitude was higher.

CONCLUSIONSThe CNTF could significantly promote the regeneration of motor fibres and the NGF could promote better for the regeneration of sensitive fibres.

Animals ; Ciliary Neurotrophic Factor ; pharmacology ; Female ; Male ; Motor Neurons ; Nerve Growth Factor ; pharmacology ; Nerve Regeneration ; drug effects ; Neurons, Afferent ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of nerve growth factor (NGF) on lipopolysaccharide (LPS) injury and activation of nuclear factor-kappa B in PC12 cells.

METHODSIn order to set injury models, the PC12 cells were incubated in different concentration of LPS. Cells were cultured in the culture and were reduced by LPS, and then cells were treated by NGF of various concentrations. The cell viability was determined by methyl thiazolyl tetrazolium (MTT) assay, cellular morphology was observed under inverted microscope and fluorescence microscope, and the content of NF-kappaB was assessed by RT-PCR.

RESULTS(1) The viability of PC12 cell was decreased with concentration of LPS increasing. (2) The cellular morphology change showed that NGF had an ability to reduce LPS injury. (3) The result of RT-PCR showed that the content of NF-kappaB in LPS injury was more than the normal and treated cell, and the treated one was close to the normal one.

CONCLUSIONThe reports about NGF in brain cells repair after inflammatory are very small. And our study is about that NGF can protect the PC12 cell from LPS injury, and this mechanism possible bears on the activation of NF-kappaB.

Animals ; Lipopolysaccharides ; toxicity ; NF-kappa B ; metabolism ; Nerve Growth Factor ; pharmacology ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Rats

OBJECTIVE: To explore the effects of exogenous transforming growth factor-beta 1 (TGFbeta1) on peripheral nerve regeneration after the peripheral nerve injury and if TGFbeta1 regulates the expression of basic fibroblast growth factor (bFGF) in the anterior horn motoneurons of spinal cord during regeneration. METHODS: Forty-eight rats were crushed on the right sciatic nerve and then randomly divided into 2 groups: TGFbeta1 group and NS group. In TGFbeta1 group, TGFbeta1 50 microL (0.1 microg/mL) was injected into the proximal nerve near to the crushed nerve and after the operation the injured leg was injected with equal TGFbeta1 whereas the NS was replaced in the NS group. The rats of each group survived for 3, 7, 14 and 21 days after the lesion. The bFGF expression in the anterior horn motoneurons of spinal cord was detected by immunohistochemistry (IHC). Semi-thin section and Fast Blue retrograde tracing were also performed with the rats surviving for 21 days to observe the regeneration of distal end in the injured right sciatic nerve. RESULTS: The number of bFGF immunoreactive positive motoneurons in TGFbeta1 group was obviously higher than that of the NS group (P < 0.05). In the distal sciatic nerve of the rats treated with TGFbeta1, the number and diameter of regenerating myelinated axons and the thickness of myelinated sheath were more than those of the NS group (P < 0.05). The number of motoneurons in spinal cord and neurons in dorsol root ganglia (DRG) labelled with Fast Blue in the NS group was obviously lower than in the TGFbeta1 group (P < 0.01). CONCLUSION Exogenous TGFbeta1 plays an important role in promoting the peripheral nerve regeneration; TGFbeta1 up-regulates the bFGF expression in the anterior horn motoneurons of spinal cord during the peripheral nerve regeneration.
Animals ; Female ; Fibroblast Growth Factor 2 ; biosynthesis ; genetics ; Male ; Motor Neurons ; metabolism ; Nerve Regeneration ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; metabolism ; physiology ; Spinal Cord ; metabolism ; Transforming Growth Factor beta ; pharmacology ; Transforming Growth Factor beta1

OBJECTIVETo investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury.

METHODSThe sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD-4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.

RESULTSThe latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P<0.05). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP-positive cells in the Group A than in the Group B in one and four weeks respectively.

CONCLUSIONSNGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.

Animals ; Evoked Potentials ; Female ; Immunohistochemistry ; Myelin Basic Protein ; metabolism ; Nerve Growth Factor ; pharmacology ; Peripheral Nerve Injuries ; Peripheral Nerves ; metabolism ; Rats ; Rats, Wistar ; Sciatic Nerve ; injuries ; metabolism

AIM AND METHODSThe properties and sensitivity to acetylcholine of PC12 cells differentiated with nerve growth factor (NGF) have been investigated by using whole-cell clamp technique.

RESULTSWhen cultured in the presence of NGF, PC12 cells not only differentiated to resemble sympathetic neurons morphologically, but also developed electrical excitability. NGF-treated PC12 cells were highly sensitive to ACh than untreated cells. The I(Ach) proved to be generated by nAChR by pharmacological identification. Nicotinic receptor was characterized by desensitization. The macroscopic I(ACh) was inward rectified and concentration dependent.

CONCLUSIONPC12 cells are easily cultured and provides a homogenous population of cells. When culture in NGF, they differentiate to sympathetic-like neurons that contain on their surface neuronal nAChR, it can be used as good model system for studying regulation of a sympathetic neuronal nAChR.

Acetylcholine ; pharmacology ; Animals ; Cell Differentiation ; Nerve Growth Factor ; metabolism ; Neurons ; metabolism ; PC12 Cells ; Patch-Clamp Techniques ; Rats ; Receptors, Nicotinic ; metabolism

In order to investigate the effect of nerve growth factor (NGF) on the proliferation of rabbit corneal endothelial cells and epithelial cells, the in vitro cultured rabbit corneal endothelial cells and epithelial cells were treated with different concentrations of NGF. MTT assay was used to examine the clonal growth and proliferation of the cells by determining the absorbency values at 570 nm. The results showed that NGF with three concentrations ranging from 5 U/mL to 500 U/mL enhanced the proliferation of rabbit corneal endothelial cells in a concentration-dependent manner. 50 U/mL and 500 U/mL NGF got more increase of proliferation than that of 5 U/mL NGF did. Meanwhile, 50 U/mL and 500 U/mL NGF could promote the proliferation of the rabbit corneal epithelial cells significantly in a concentration-dependent manner. However, 5 U/mL NGF did not enhance the proliferation of epithelial cells. It was suggested that exogenous NGF can stimulate the proliferation of both rabbit corneal endothelial and epithelial cells, but the extent of modulation is different.
Cell Proliferation/*drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Endothelium, Corneal/*cytology ; Epithelium, Corneal/*cytology ; Nerve Growth Factor/*pharmacology