• BMB Reports
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• v.33 no.6
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• pp.525-530
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• 2000

The nerve growth factor (NGF) induces neuronal differentiation and neurite outgrowth of PC12 cells, whereas epidermal growth factors (EGF) stimulate growth and proliferation of the cells. In spite of this difference, NGF-or EGF-treated PC12 cells share various properties in cellular-signaling pathways. These include the activation of the phosphoinositide (PI)-3 kinase, 70 kDa S6 kinase, and in the mitogen-activated protein (MAP) kinase pathway, following the binding of these growth factors to intrinsic receptor tyrosine kinases (RTKs). Therefore, many studies have been attempted to access the critical signaling events in determining the differentiation and proliferation of PC12 cells. In this study, we investigated the cytosolic phospholipase $A_2$ ($cPLA_2$) in neurite behavior in order to identify the differences of signaling pathways between the NGF-induced differentiation and the EGF-induced proliferation of PC12 cells. We have showed here that the $cPLA_2$ was translocated from cytosol to membrane only in NGF-treated cells. We also demonstrated that this translocation is associated with NGF-induced activation of phospholipase $C-{\gamma}(PLC-{\gamma})$, which elevates intracellular $Ca^{2+}$ concentration. These results reveal that the translocation of $cPLA_2$ may be a requisite event in the neuronal differentiation of PC12 cells. Various phospholipase inhibitors were used to confirm the importance of these enzymes in the differentiation of PC12 cells. Neomycin B, a PLC inhibitor, dramatically inhibited the neurite outgrowth, and two distinct $PLA_2$ inhibitors, 4-bromophenacyl bromide (BPB) and arachidonyltrifluoro-methyl ketone ($AACOCF_3$) also suppressed the neurite outgrowth of the cells, as well Taken together, these data indicated that $cPLA_2$ is involved in NGF-induced neuronal differentiation and neurite outgrowth of PC12 cells.

• Molecules and Cells
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• v.21 no.2
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• pp.237-243
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• 2006

Brain-derived neurotrophic factor (BDNF) is a neuromodulator of nociceptive responses in the dorsal root ganglia (DRG) and spinal cord. BDNF synthesis increases in response to nerve growth factor (NGF) in trkA-expressing small and medium-sized DRG neurons after inflammation. Previously we demonstrated differential activation of multiple BDNF promoters in the DRG following peripheral nerve injury and inflammation. Using reporter constructs containing individual promoter regions, we investigated the effect of NGF on the multiple BDNF promoters, and the signaling pathway by which NGF activates these promoters in PC12 cells. Although all the promoters were activated 2.4-7.1-fold by NGF treatment, promoter IV gave the greatest induction. The p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294003, protein kinase A (PKA) inhibitor, H89, and protein kinase C (PKC) inhibitor, chelerythrine, had no effect on activation of promoter IV by NGF. However, activation was completely abolished by the MAPK kinase (MEK) inhibitors, U0126 and PD98059. In addition, these inhibitors blocked NGF-induced phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2. Taken together, these results suggest that the ERK1/2 pathway activates BDNF promoter IV in response to NGF independently of NGF-activated signaling pathways involving PKA and PKC.

• Korean Journal of Biological Psychiatry
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• v.13 no.2
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• pp.95-102
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• 2006

Object : Nerve growth factor(NGF) is a protein involved in neuronal survival and plasticity in the central nervous system, which might play an important role in stress, depression and suicide. This study was performed to determine whether there is an alteration in plasma NGF concentrations in depressed patients with suicidal attempt. Methods : The subjects were 32 depressed patients who attempted suicide and admitted in emergency room. Forty-four hospitalized non-suicidal depressive patients and the 30 normal controls were closely matched with the suicidal group in terms of age and sex. Individuals in all 3 groups were evaluated independently by a semi-structured interview for the purpose of establishing a DSM-IV criteria diagnosis. The severity of depressive symptoms was evaluated using Hamilton depression rating scale(HDRS). The severity of the suicidal behavior was evaluated by Weisman and Worden's risk-rescue rating(RRR) system and the Lethality Suicide Attempt Rating Scale(LSARS). Plasma NGF level was measured by the enzyme linked immunosorbent assay(ELISA) method. Results : There were no statistically significant differences of the plasma NGF levels among groups. LSARS and RRR did not reveal any significant correlation with ${\beta}$-NGF level in suicidal depressive patients. Conclusion : This study do not support an association between ${\beta}$-NGF and suicidal depression. However it is necessary to investigate this association through other route such as postmortem brain.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.2
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• pp.143-158
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• 2011

Objectives : Peripheral nerve injuries are commonly encountered clinical problem and often result in severe functional deficits. The aim of this study is to evaluate the effects of aqueous extract of Achyranthes japonica(AJ) on functional recovery in sciatic nerve after crushed sciatic nerve injury. Methods : In the present study, the animals in the AJ-treated groups received the aqueous extract of AJ at the respective doses orally for 13 consecutive days. In order to assess the effects of the aqueous extract of AJ on function recovery in crushed sciatic nerve injury, sciatic functional index(SFI) was performed. c-Fos expression in the paraventricular nucleus(PVN) and ventrolateral periaqueductal gray(vIPAG), and neurofilament, and the expressions of brain-derived neurotrophic factor(BDNF), nerve growth factor(NGF) following crushed sciatic nerve injury in rats were investigated. For this, immunohistochemistry and western blot were performed. Results : In the present study, crushed sciatic nerve injury showed characteristic gait changes showing decrease of SFI value and treatment with the aqueous extract of AJ significantly enhanced the SFI value. Neurofilament expression in the sciatic nerve was decreased by crushed sciatic nerve injury and treatment with the AJ increased neurofilament expression. The expressions of BDNF and NGF in the sciatic nerve were increased following crushed sciatic nerve injury and treatment with the AJ significantly controlled the sciatic nerve injury-induced increment of BDNF and NGF expressions. c-Fos expressions in the PVN and vIPAG were increased following crushed sciatic nerve injury and treatment with the AJ significantly suppressed the sciatic nerve injury-induced increment of c-Fos expressions. Conclusions : These results suggest that AJ treatment after crushed sciatic nerve injury is effective in the functional recovery by enhancing axonal regeneration and suppressing of pain.

• The Korean Journal of Pain
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• v.36 no.1
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• pp.60-71
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• 2023

Background: The purpose of this research was to assess the role of heparanase (HPSE)/syndecan1 (SDC1)/nerve growth factor (NGF) on cancer pain from melanoma. Methods: The influence of HPSE on the biological function of melanoma cells and cancer pain in a mouse model was evaluated. Immunohistochemical staining was used to analyze HPSE and SDC1. HPSE, NGF, and SDC1 were detected using western blot. Inflammatory factors were detected using ELISA assay. Results: HPSE promoted melanoma cell viability, proliferation, migration, invasion, and tumor growth, as well as cancer pain, while SST0001 treatment reversed the promoting effect of HPSE. HPSE up-regulated NGF, and NGF feedback promoted HPSE. High expression of NGF reversed the inhibitory effect of HPSE down-regulation on melanoma cell phenotype deterioration, including cell viability, proliferation, migration, and invasion. SST0001 down-regulated SDC1 expression. SDC1 reversed the inhibitory effect of SST0001 on cancer pain. Conclusions: The results showed that HPSE promoted melanoma development and cancer pain by interacting with NGF/SDC1. It provides new insights to better understand the role of HPSE in melanoma and also provides a new direction for cancer pain treatment.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.445-452
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• 2014

The purpose of this study was to investigate the therapeutic effects of DA-9801, an optimized extract of Dioscorea species, on diabetic peripheral neuropathy in a type 2 diabetic animal model. In this study, db/db mice were treated with DA-9801 (30 and 100 mg/kg, daily, p.o.) for 12 weeks. DA-9801 reduced the blood glucose levels and increased the withdrawal latencies in hot plate tests. Moreover, it prevented nerve damage based on increased nerve conduction velocity and ultrastructural changes. Decrease of nerve growth factor (NGF) may have a detrimental effect on diabetic neuropathy. We previously reported NGF regulatory properties of the Dioscorea genus. In this study, DA-9801 induced NGF production in rat primary astrocytes. In addition, it increased NGF levels in the sciatic nerve and the plasma of type 2 diabetic animals. DA-9801 also increased neurite outgrowth and mRNA expression of Tieg1/Klf10, an NGF target gene, in PC12 cells. These results demonstrated the attenuation of diabetic peripheral neuropathy by oral treatment with DA-9801 via NGF regulation. DA-9801 is currently being evaluated in a phase II clinical study.

• Journal of Korean Neurosurgical Society
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• v.44 no.6
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• pp.375-381
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• 2008

Objective : The effects on neural proliferation and differentiation of neural stem cells (NSC) of basic fibroblast growth factor-2 (bFGF). insulin growth factor-I (IGF-I). brain-derived neurotrophic factor (BDNF). and nerve growth factor (NGF) were assessed. Also, following combinations of various factors were investigated : bFGF+IGF-I, bFGF+BDNF, bFGF+NGF, IGF-I+BDNF, IGF-I+NGF, and BDNF+NGF. Methods : Isolated NSC of Fisher 344 rats were cultured with individual growth factors, combinations of factors, and no growth factor (control) for 14 days. A proportion of neurons was analyzed using $\beta$-tubulin III and NeuN as neural markers. Results : Neural differentiations in the presence of individual growth factors for $\beta$-tubulin III-positive cells were : BDNF, 35.3%; IGF-I, 30.9%; bFGF, 18.1%; and NGF, 15.1%, and for NeuN-positive cells was : BDNF, 34.3%; bFGF, 32.2%; IGF-I, 26.6%; and NGF, 24.9%. However, neural differentiations in the absence of growth factor was only 2.6% for $\beta$-tubulin III and 3.1% for NeuN. For $\beta$-tubulin III-positive cells, neural differentiations were evident for the growth factor combinations as follows : bFGF+IGF-I, 73.1 %; bFGF+NGF, 65.4%; bFGF+BDNF, 58.7%; BDNF+IGF-I, 52.2%; NGF+IGF-I, 40.6%; and BDNF+NGF, 40.0%. For NeuN-positive cells : bFGF+IGF-I, 81.9%; bFGF+NGF, 63.5%; bFGF+BDNF, 62.8%; NGF+IGF-I, 62.3%; BDNF+NGF, 56.3%; and BDNF+IGF-I, 46.0%. Significant differences in neural differentiation were evident for single growth factor and combination of growth factors respectively (p<0.05). Conclusion : Combinations of growth factors have an additive effect on neural differentiation. The most prominent neural differentiation results from growth factor combinations involving bFGF and IGF-I. These findings suggest that the combination of a mitogenic action of bFGF and post-mitotic differentiation action of IGF-I synergistically affects neural proliferation and NSC differentiation.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.4
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• pp.35-46
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• 2010

Purpose: This study was designed to investigate the effects of Cyperi Rhizoma (CR) on changes in weights morphological and histopathological observations in Polycystic Ovary(PCO) rats. Methods: PCO was induced by single intramuscular injection with EV(2mg) in female rats. Normal group(n=8) were injected with sesame oil and orally administrated distilled water for five weeks. PCO control group(n=8) were injected with EV and orally administrated distilled water for five weeks. CR treated group(n=8) were injected with EV and orally administrated CR for five weeks. Then we measured weight of body, ovaries. The histopathology changes of ovaries, and the expression of nerve growth factor(NGF) were also evaluated. Results: Single injection of EV induced suppression of weight gain, formation of cysts, increase of NGF expression. Oral administration of CR prevent suppression of weight gain shown in control group. In addition CR group showed upward tendency of ovarian size. Formation of cystic follicles induced by EV injection is suppressed by CR treatment. In additon, CR treatment lowered expression levels of nerve growth factor(NGF), which were elevated by induction of PCOS. Conclusion: These results suggest that CR can be used for patients with PCOS to prevent formation of cystic follicles and malfunction of ovary. And also suggest that the related mechanisms are involved in suppression of NGF expression.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.403-407
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• 2011

A form of polycystic ovary (PCO) resembling some aspects of the human PCO syndrome (PCOS) can be induced in rats by a single injection of estradiol valerate (EV). An increase in sympathetic outflow to the ovary precedes, by several weeks, the appearance of cysts, suggesting the involvement of a neurogenic component in the pathology of this ovarian dysfunction. To test the hypotheses that the change in sympathetic tone is related to an augmented production of hippocampal and/or ovarian nerve growth factor (NGF), and that this abnormally elevated production of NGF contributes to the induction of PCOS induced by EV. The animals were sacrificed after PCOS induction and the ovaries and hippocampus were sectioned and compared to the normal control. The expression of NGF was measured by immunohistochemical staining and Western blot analysis in the ovaries and hippocampus. EV-induced PCOS showed significant increase of ovarian NGF expression. Immunohistochemical expression of NGF was confined to the follicular cells and interstitial cells. Hippocampal NGF expression was not significantly changed. In conclusion EV-induced PCOS was related to the ovarian sympathetic activation which was mediated by NGF.

• BMB Reports
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• v.28 no.4
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• pp.316-322
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• 1995

The GTPase activating protein (GAP) can function both as a negative regulator and an effector of $p21^{ras}$. Overexpression of GAP in NIH-3T3 cells has been shown to inhibit transformation by ms or src. To investigate the function of GAP in a differentiative system, we overexpressed this protein in the nerve growth factor (NGF)-responsive PC12 cell line. Two-fold overexpression of GAP caused a delay of several days in the onset of NGF- but not FGF-induced neuronal differentiation of PC12 cells. However, the NGF-induced activation or tyrosine phosphorylation of upstream (Trk, PLC-${\gamma}1$, SHC) and downstream (B-Raf and $p44^{mapk/erk1}$) components of $p21^{ras}$, signalling cascade was not altered by GAP overexpression. Therefore, the change of phenotype induced by GAP was probably not due to GAP functioning as a negative regulator of $p21^{ras}$. Rather, we found that NGF-induced tyrosine phosphorylation of SNT, a specific target of neurotrophin-induced tyrosine kinase activity, was inhibited by GAP overexpression. SNT is thought to function upstream or independent of $p21^{ras}$. Thus in PC12 cells, overexpressed GAP may control the rate of neuronal differentiation through a pathway involving SNT rather than the $p21^{ras}$ signalling pathway.