• Journal of Korean Neurosurgical Society
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• v.62 no.6
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• pp.626-634
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• 2019

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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.261-268
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• 1996

An experimental study was performed to evaluate the efficacy of nerve growth factor(NGF) on inferior alveolar nerve in a rabbit model. In 20 New Zealand white rabbits, 14mm of bilat eral alveolar nerve were resected and the defects were repaired with the 17mm silicone conduits. In group I, 5mm autologous nerve segment were located centrally in the left side after tubulization and NGF solution(Sigma chemical 0.1 mg/mL) was instilled into each conduit. In group II, nerve repair modality was the same but no NGF solution was instilled into the conduits. On 2 months and 6 months postoperatively, the results were evaluated by clinical and hist omorphometric assessment. The result was that autologous nerve segment group show the best nerve regeneration effect and NGF instilled group the worst.

• The Korean Journal of Pain
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• v.37 no.4
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• pp.288-298
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• 2024

Nerve growth factor (NGF) is a neurotrophic protein that has crucial roles in survival, growth and differentiation. It is expressed in neuronal and non-neuronal tissues. NGF exerts its effects via two types of receptors including the high affinity receptor, tropomyosin receptor kinase A and the low affinity receptor p75 neurotrophin receptor highlighting the complex signaling pathways that underlie the roles of NGF. In pain perception and transmission, multiple studies shed light on the effects of NGF on different types of pain including inflammatory, neuropathic, cancer and visceral pain. Also, the binding of NGF to its receptors increases the availability of many nociceptive receptors such as transient receptor potential vanilloid 1, transient receptor potential ankyrin 1, N-methyl-D-aspartic acid, and P2X purinoceptor 3 as well as nociceptive transmitters such as substance P and calcitonin gene-related peptide. The role of NGF in pain has been documented in pre-clinical and clinical studies. This review aims to shed light on the role of NGF and its signaling in different types of pain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.1
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• pp.3-10
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• 2014

Objectives: Although nerve growth factor (NGF) could promote the functional regeneration of an injured peripheral nerve, it is very difficult for NGF to sustain the therapeutic dose in the defect due to its short half-life. In this study, we loaded the NGF-bound heparin-conjugated fibrin (HCF) gel in the NGF-delivering implants and analyzed the time-dependent release of NGF and its bioactivity to evaluate the clinical effectiveness. Materials and Methods: NGF solution was made of 1.0 mg of NGF and 1.0 mL of phosphate buffered saline (PBS). Experimental group A consisted of three implants, in which $0.25{\mu}L$ of NGF solution, $0.75{\mu}L$ of HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin was injected via apex hole with micropipette and gelated, were put into the centrifuge tube. Three implants of experimental group B were prepared with the mixture of $0.5{\mu}L$ of NGF solution, $0.5{\mu}L$ HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin. These six centrifuge tubes were filled with 1.0 mL of PBS and stirred in the water-filled beaker at 50 rpm. At 1, 3, 5, 7, 10, and 14 days, 1.0 mL of solution in each tubes was collected and preserved at $-20^{\circ}C$ with adding same amount of fresh PBS. Enzyme-linked immunosorbent assay (ELISA) was done to determine in vitro release profile of NGF and its bioactivity was evaluated with neural differentiation of pheochromocytoma (PC12) cells. Results: The average concentration of released NGF in the group A and B increased for the first 5 days and then gradually decreased. Almost all of NGF was released during 10 days. Released NGF from two groups could promote neural differentiation and neurite outgrowth of PC12 cells and these bioactivity was maintained over 14 days. Conclusion: Controlled release system using NGF-HCF gel via NGF-delivering implant could be an another vehicle of delivering NGF to promote the nerve regeneration of dental implant related nerve damage.

• Polymer(Korea)
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• v.25 no.6
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• pp.893-901
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• 2001

We developed the nerve growth factor (NGF) loaded poly (L - lactide) (PLA) scaffolds by means of emulsion freeze drying method to the possibility for the application of the nerve regeneration of spinal cord disease and the degeneration in Alzheimer's disease. The release amount of NGF from NGF loaded PLA scaffold were analyzed over a 4 week period in vitro at phosphate buffered saline (PBS), pH 7.4, at $37^{\circ}C$. It can be observed the open cell pore structure of porous scaffolds and can be easily controlled the pore structure by the controlling of formulation factors resulting in the controlling of the release rate and the release period. The stability of NGF during the preparation of PLA scaffold was evaluated by comparing the released amounts of total NGF, assayed NGF enzyme - linked immunosorbent assay (ELISA). Released NGF has been found to enhance the neurite sprouting and outgrowth from pheochromocytoma (PC-12) cells. These results suggest that the released NGF from NGF loaded PLA scaffold such as conduit type can be very useful for the nerve regeneration in the neural tissue engineering area.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.411-415
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• 2005

Purpose : This study was performed to determine the developmental expression pattern of nerve growth factor(NGF) in the urine of healthy children. It was hypothesized that NGF may contribute to the development of the spinobulbospinal micturition reflex that represents the adult micturition pattern. Methods : Voided urine was collected in 60 healthy children during the first 5 years of life(0-1 month, n=10; 1 month-1 year, n=10; 2 years, n=10; 3 years, n=10; 4 years, n=10). The urinary NGF was analyzed by using an enzyme linked immunosorbent assay. Results were normalized based on creatinine or total protein in urine. Results : NGF was significantly greater among neonates compared to other age groups(P<0.05). NGF levels declined during 1 month to 1 year and increased by age 2 years. NGF levels at age 3 years were less than in neonates examined. When comparing the NGF levels according to continence in children over 1 year old, NGF levels were significantly lower in children with continence than in children with incontinence(P<0.05). Conclusion : These data suggest that NGF is involved in the achievement of continence and in mechanisms of bladder nerve growth and in the reorganization of bladder reflex pathway.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.75-79
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• 2008

Nerve growth factor (NGF) is a protein plays a major role in the development and maintenance of central and peripheral nervous system. Recent data suggest that reduced availability of NGF may play a significant role in the pathogenesis of diabetic $polyneuropathy.^{1)}$ In our previous study, steroidal saponin from Liriope platyphylla showed neurotrophic effect by stimulation of NGF synthesis and activation of tyrosine kinase $signaling.^{2)}$ In this study, we examined the neurotrophic effect of Liriope platyphylla (LP); which was from Mylyang(MYL) and Cheongyang(CHE), and Ophiopogon japonicus (CHI) on in vitro and in vivo model for the comparison of their NGF induction. We quantitatively analyzed spicatoside A in the LP and CHI by HPLC. And we investigated the correlation between the contents of spicatoside A and NGF induction efficacy on PC 12 cells and mouse serum. These results suggest that spicatoside A may enhance NGF induction in animal model.

• BMB Reports
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• v.29 no.3
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• pp.200-204
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• 1996

Nerve growth factor (NGF) is literally known to promote neural differentiation and survival in several peripheral and central neurons. Thus, it is Widely believed that NGF may serve as a therapeutic agent for many types of neuronal diseases. One of the mechanisms suggested to explain the protective role of NGF is that the trophic factor can prevent the increase of intracellular calcium ions which might be responsible for neural death. To examine whether or not the calcium hypothesis works even under pathological conditions, we applied NGF to cultures deprived of glucose. Surprisingly, what was observed here is that NGF rather promoted cell death under a glucose-deprived condition. What we call the NGF paradox phenomenon occurred in a calcium concentration-dependent manner, indirectly suggesting that NGF might increase intracellular calcium ions in cells deprived of glucose. This suggestion is further supported by the fact that nifedipine, a well-known L-type calcium channel blocker, could block the cell death potentiated by NGF. Here it is still premature to propose the complete mechanism underlying the NGF paradox phenomenon. However, this study certainly indicates that NGF as a therapeutic agent for neuronal diseases should be carefully considered before use.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.418-423
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• 2001

To investigate the modulation of nerve growth factor (NGF) during corneal epithelial wound healing and the effect of topical NGF on corneal epithelial wound healing in dogs. An axial epithelial defect was created in the right eye using 6mm axial corneal mechanical debridement while the left served as an unwounded control. The tears were collected from both eyes during 1 week and the corneal epithelium was processed for the measurement of NGF at day 0 and 7. The NGF content of tears and corneal epithelium was determined by enzyme-linked immunosorbent assay. In another experiment, the animals were divided into 3 groups. The right eyes in each group were treated every six hours with 200 ug/ml of recombinant human (rh) NGF, murine NGF, or 600 ug/ml of anti-NGF blocking antibody. The left eye of each animal was treated with bovine serum albumin (BSA) to serve as controls. Wound healing was analyzed using NIH image software. Tear NGF was markedly increased in the wounded eyes, relative to tears from control eyes during the early healing period. The NGF content of the corneal epithelium was elevated in the wounded eye (p=0.024). Time to wound closure and rate of epithelial migration were not significantly different between the NGF treated or the NGF antibody treated, and the control BSA treated eyes. Corneal epithelial wounding increased NGF content only on the wounded side during the early healing period. Neither topical recombinant human or murine NGF affected corneal epithelial wound healing in the normal dog.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.430-435
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• 2008

The main cause of diabetic neuropathy, one of the most debilitating complications, is the chronic hyperglycemia, the increase sorbitol or the decrease of nerve growth factor(NGF). NGF, a protein, plays a major role in the development and maintenance of peripheral nervous system. Systemic administration of NGF prevents manifestations of neuropathy in rodent models of diabetic neuropathy. In the previous investigation, we report the hypoglycemia effect of Dioscorea rhizoma extract(DRE) in diabetic mice. The present study shows protective effect of DRE on diabetic neuropathy by induction of NGF protein. We investigated the NGF level in salivary gland and sciatic nerve of normal mouse and the effect of DRE on sciatic nerve conductivity and thermal hyperalgesia test in Type 2 db/db mouse. DRE increased endogenous NGF level in salivary gland and sciatic nerve of mouse. And sensory nerve conductivity velocity(SNCV), motor nerve conductivity velocity(MNCV) and thermal hyperalgesia increased in DRE treatment mice compared with control group. On the basis of our results, we conclude that DRE increase induction of endogenous NGF level and have protective effect on diabetic neuropathy by induction of NGF. Therefore, we propose that long-term use of DRE might help prevention of diabetes-associated complication; diabetic neuropathy.