• 한국임상수의학회지
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• 제18권4호
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• pp.418-423
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• 2001

각막상피의 창상치유에 중요한 역할을 하는 것으로 알려진 Nerve Growth Factor(NGF)의 내인성 변화와 국소적 투여효과를 알아보았다. 6마리의 Beagle 을 사용하여 비교군인 오른쪽 눈에만 6mm의 기계적인 각막 창상을 만들었고 왼쪽 눈은 대조군으로 사용하였다. 눈물은 수술후 1주일동안 매일, 각막 상피는 수술중 그리고 수술후 7일에 각각 채취하여 NGF 농도를 enzyme-linked immunosorbent assay (ELISA)를 사용하여 측정하였다. 2차 실험으로, 16마리의 Bealgle을 사용하여 오른쪽 눈에 위와 동일한 창상을 만든 후, 창상 부위가 회복될 때까지 recombinant human (rh) NGF (n=4), murine NGF (n=6) 그리고 anti-NGF blocking antibody (n=6)를 6시간마다 점안하였으며, 왼쪽 눈은 bovine serum albumin (BSA)를 점안하여 대조군으로 사용하였다. 창상 면적은 NIH image software를 이용하여 분석하였다. 대조군에 비하여, 비교군의 눈물내 NGF는 치유초기에 현저하게 증가하였으며, 각막 상피의 NGF도 유의적인 증가를 보였다. 그러나 rh NGF, murine NGF, anti-NGF blocking antibody처치군과 BSA처치군 간에는 각막창상 치유에 유의적인 차이가 인정되지 않았다. 각막창상후, rh NGF 혹은 murine NGF의 추가적인 국소점안은 정상개의 각막상피 치유에 효과가 없었으나, 창상후 초기 치유기동안 눈물과 손상받은 각막상피에서 내인성 NGF의 급격한 보상성 증가로 미루어 NGF는 각막 상피의 창상치유에 중요한 역할을 하는 것으로 사료된다.

• 폴리머
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• 제25권6호
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• pp.893-901
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• 2001

조직공학적 신경재생 및 파킨슨씨병 등의 시경퇴행성 질환에서의 치료에 이용 목적으로 신경성장인자(nerve growth factor, NGF)를 생분해성 고분자 담체에 NGF를 서방화시키고자 PLA 담체에 함유시켜 유화동결건조법으로 제조하였다. 제조된 NGF의 방출량은 생체외 pH 7.4, 37$^{\circ}C$의 PBS 조건하에서 4주 동안 방출실험 하였으며, 함유된 NGF의 활성을 확인하기 위하여 PC-l2 세포에 직접 배양하여 확인하였다. 제조되어진 PLA 담체는 열린 셀 구조를 가졌으며, 초기 NGF의 함량이 많을수록 방출량도 증가를 보였으며, 제조과정에서의 NGF의 환성을 확인하기 위하여 PC-12 세포를 배양한 결과 신경돌기가 성장하였다. 본 연구는 생분해성 고분자 특정인 확산과 분해에 의해서 생물학적 활성물질인 NGF의 방출을 조절할 수 있으며, 조직공학적으로 서방화되어 3차원적인 신경재생을 가능케 할 것으로 기대된다.

• Macromolecular Research
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• 제11권5호
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• pp.334-340
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• 2003

In order to fabricate new sustained delivery device of nerve growth factor (NGF), we developed NGF-loaded biodegradable poly(L-lactide-co-glycolide) (PLGA, the mole ratio of lactide to glycolide 75:25, molecular weight: 83,000 and 43,000 g/mole, respectively) film by novel and simple sandwich solvent casting method for the possibility of the application of neural tissue engineering. PLGA was copolymerized by direct condensation reaction and the molecular weight was controlled by reaction time. Released behavior of NGF from NGF-loaded films was characterized by enzyme linked immunosorbent assay (ELISA) and degradation characteristics were observed by scanning electron microscopy (SEM) and gel permeation chromatography (GPC). The bioactivity of released NGF was identified using a rat pheochromocytoma (PC-12) cell based bioassay. The release of NGF from the NGF-loaded PLGA films was prolonged over 35 days with zero-order rate of 0.5-0.8 ng NGF/day without initial burst and could be controlled by the variations of molecular weight and NGF loading amount. After 7 days NGF released in phosphate buffered saline and PC-12 cell cultured on the NGF-loaded PLGA film for 3 days. The released NGF stimulated neurite sprouting in cultured PC-12 cells, that is to say, the remained NGF in the NGF/PLGA film at 37 $^{\circ}C$ for 7 days was still bioactive. This study suggested that NGF-loaded PLGA sandwich film is released the desired period in delivery system and useful neuronal growth culture as nerve contact guidance tube for the application of neural tissue engineering.

• Clinical and Experimental Pediatrics
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• 제48권4호
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• pp.411-415
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• 2005

목 적 : 방광의 발달과정은 척수배뇨반사에서 척수연수척수반사로의 전환을 특징으로 한다고 알려져 왔다. 향신경인자가 이러한 방광의 발달과정에 관여한다는 동물연구에도 불구하고 인간의 방광 발달과정에도 향신경인자가 역할을 하는지에 관한 연구는 없는 실정이다. 본 연구는 인간의 방광 발달과정에 향신경인자가 관여할 것이라는 가정 하에 방광 발달과정에서 소변의 nerve growth factor(NGF) 변화를 관찰하였다. 방 법 : 배뇨생식기의 선천적 이상을 동반하지 않고 배뇨이상, 요로감염의 증거가 없는 지원자 60명을 대상으로 하였다. 지원자는 출생 후 한달 미만의 신생아, 1년 미만의 유아, 1세, 2세, 3세, 4세의 소아로 분류하였고 각각 10명씩 소변을 채취하였다. 소변의 NGF의 정량은 ELISA 방법을 이용하였고 소아의 연령, 요자제 유무에 따른 NGF의 변화를 NGF/Cr, NGF/total protein 값으로 비교하였다. 결 과 : 연령별로 NGF/Cr은 신생아에서 증가하였다가 유아에 감소하고 1세, 2세에 증가하였다가 3세 때부터 감소하였다. 신생아에서 다른 군과 비교하였을 때 의미있는 증가가 관찰이 되었고(P<0.05) 다른 군에서는 의미있는 차이를 보이지는 않았다. NGF/total protein도 NGF/Cr과 비슷한 양상으로 관찰이 되었다. 자발적 배뇨조절이 가능한 소아는 1세에 2명, 2세에 8명, 3세와 4세에는 10명씩이었다. 1세 이상에서 요자제 유무에 따른 NGF/Cr을 비교하였을 때 요자제가 있는 소아에서 의미있게 감소하였다(P<0.05). 결 론 : 단절배뇨와 높은 방광압력을 특징으로 하는 요자제 이전에 NGF가 증가하였다가 요자제 이후에는 감소하는 것을 확인하였다. 이는 배뇨근-괄약근 협동장애로 인해 증가된 방광조직의 NGF가 역행성 축삭수송을 통해 중추신경계에서 척수반사를 척수연수척수반사로 성숙시키고 이것이 다시 배뇨근-괄약근 성숙을 통해 요자제를 형성하였다고 추정할 수 있다. 이는 인간의 방광 발달과정에도 향신경인자가 방광신경 성장과 배뇨반사의 재구성에 관여함을 시사한다고 생각한다.

• The Korean Journal of Physiology and Pharmacology
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• 제6권5호
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• pp.275-279
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• 2002

Nerve growth factor (NGF) is an important autocrine growth factor and also a survival factor for keratinocytes. NGF may act in the hyperproliferative condition, psoriasis. Clinically, the combination of psoralen and UVA (PUVA) has been used in the treatment of a wide variety of cutaneous disorders, such as psoriasis and vitiligo. However, the precise therapeutic mechanism of PUVA on the dermatologic diseases remains unclear. The purpose of this study was to examine whether the expression of NGF in cultured keratinocytes is influenced by PUVA. Thus, normal human keratinocytes were isolated from neonatal foreskin, and the third to fifth-passaged cells were used in this study. The cells were exposed to various doses of UVA (30, 60, 120 $mJ/cm^2)$ after adding 8-methoxypsoralen (8-MOP) to examine the expression of NGF mRNA. The RNA and protein of the cells were extracted at various time points (1, 8, 24 hours) after UVA irradiation to examine the expression of NGF mRNA and production of NGF protein. In keratinocytes, there were no differences in the expression of NGF mRNA between the different doses of UVA irradiation, however, the expression of NGF mRNA in UVA and PUVA groups tended to increase as the time increased. The expression of NGF mRNA was the highest in PUVA group, followed by UVA group and the lowest in 8-MOP group. The expressions of NGF protein at 1 and 8 hours after UVA irradiation were lower in the PUVA group than in the other groups. This study showed that the expression level of NGF protein in keratinocytes was relatively lower in the PUVA groups than in the other groups, suggesting that the therapeutic mechanism of PUVA in psoriasis is related to the decrease of NGF protein.

• BMB Reports
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• 제29권3호
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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 Korean Neurosurgical Society
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• 제62권6호
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권1호
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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.

• 한국식품영양학회지
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• 제21권4호
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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.

• Journal of Korean Neurosurgical Society
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• 제61권4호
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• pp.441-449
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• 2018

Objective : Notch receptors are heterodimeric transmembrane proteins that regulate cell fate, such as differentiation, proliferation, and apoptosis. Dysregulated Notch pathway signaling has been observed in glioblastomas, as well as in other human malignancies. Nerve growth factor (NGF) is essential for cell growth and differentiation in the nervous system. Recent reports suggest that NGF stimulates glioblastoma proliferation. However, the relationship between NGF and Notch1 in glioblastomas remains unknown. Therefore, we investigated expression of Notch1 in a glioblastoma cell line (U87-MG), and examined the relationship between NGF and Notch1 signaling. Methods : We evaluated expression of Notch1 in human glioblastomas and normal brain tissues by immunohistochemical staining. The effect of NGF on glioblastoma cell line (U87-MG) was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. To evaluate the relationship between NGF and Notch1 signaling, Notch1 and Hes1 expression were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. To confirm the effects of NGF on Notch1 signaling, Notch1 and Hes1 small interfering RNAs (siRNAs) were used. Results : In immunohistochemistry, Notch1 expression was higher in glioblastoma than in normal brain tissue. MTT assay showed that NGF stimulates U87-MG cells in a dose-dependent manner. RT-PCR and Western blot analysis demonstrated that Notch1 and Hes1 expression were increased by NGF in a dose-dependent manner. After transfection with Notch1 and Hes1 siRNAs, there was no significant difference between controls and 100 nM $NGF-{\beta}$, which means that U87-MG cell proliferation was suppressed by Notch1 and Hes1 siRNAs. Conclusion : These results indicate that NGF stimulates glioblastoma cell proliferation via Notch1 signaling through Hes 1.