• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.14-40
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• 2002

15-Deoxy- Δ$\^$12,14/-prostaglandin J$_2$ (15-deoxy-PGJ$_2$), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$). Activation of PPAR-y has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-PGJ$_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-PGJ$_2$ (0.2 to 1.6 ${\mu}$M) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/$m\ell$). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-PGJ$_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-PGJ$_2$ (0.8 ${\mu}$M) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-PGJ$_2$ on the expression of p38 MAP kinase and activation of AP-1. The promoting ability of 15-deoxy-PGJ$_2$ did not occur through PPAR-${\gamma}$, as synthetic PPAR-${\gamma}$ agonist and antagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), PPAR-${\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and PGE$_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of 15-deoxy-PGJ$_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-PGJ$_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 signal pathway may be important in the promoting activity of 15-deoxy-PGJ$_2$ on the differentiation of PC12 cells.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.699-705
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• 1997

Although it is known that neuronal cell death during development occurs by apoptosis, the mechanisms underlying excitatory amino acid-induced neuronal cell death remain poorly understood. In this study we have examined the mechanism by which L-glutamate, an excitatory amino acid neurotransmitter, induces cell death in PC12 cell lines. To characterize cell death, we employed sandwich enzyme-linked immunosorbent assay(ELISA) method for cellular DNA fragmentation, DNA agarose gel electrophoresis and chromatin staining by acridine orange and ethidium bromide after treating the PC12 cells with L-glutamate. L-Glutamate caused dose-dependent cell death with a maximum at 24 hrs after the treatment. These cellular fragmentation was blocked by pretreatment of MK-801, a noncompetitive N-methyl-D-aspartic acid(NMDA) receptor antagonist, and nerve growth factor(NGF). Analysis of DNA integrity from L-glutamate-treated cells revealed cleavage of DNA into regular sized fragments, a biochemical hallmark of apoptosis. The PC12 cells that were induced to die by L-glutamate treatment exhibited classical chromatin condensation under the light microscopy after acridine orange and ethidium bromide staining. These results suggest that apoptosis is one of the key features that are involved in L-glutamate-induced excitotoxic cell death in PC12 cells, and these cell death are mediated by NMDA receptor and depend on NGF.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.245-263
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• 1993

신경성장인자 수용체(nerve growth factor receptor, HGFr)의 소재를 휜쥐 전뇌 기저부 핵들의 신경세포와 그 세포내 소기 관에서 연역세포화학적 방법으로 관찰하였다. NGFr에 면역반응을 보이는 신경세포들은 내측중격, 수직 및 수평대각선 브로카대, 거대세포 시삭전핵 그리고 Meynert 기저핵에는 다수 미상핵-피각과 복부담창구에는 소수 관찰 되었다 NGFr에 면역반응을 보이는 신경세포들은 형태학적으로 3가지 형 즉, 1) 난형(또는 원형). 2) 방추형, 3) 삼각형(또는 다각형)으로 구분되었다 내측중격은 주로 난형의 세포로 구성되었으며(91.2%), 수직 및 수평대각선 브로카대, 거대세포 시삭전핵 및 Meynert 기저 핵에는 난형의 세포가 높은 율로 구성되었으나, 방추형과 삼각형 세포들도 내측중격에서보다는 많았다 특히 복부담창구에는 다른 핵들에 비하여 방추형세포(25%)들이 높은 출현율을 보였다 일반적으로 이들 세포의 크기는 삼각형세포가 제일 컸으며, 방추형세포가 그 다음, 그리고 난형 세포가 제일 작았다 전자현미경적 관찰에서 0.05% triton X-100을 처리한 조직중 Meynert 기저핵을 관찰한 결과. Golgi체, multivesicular body 및 소포체들이 N6Fr에 면역반응을 보였으며. trion X-100을 처리하지 않은 조직에서는 단지 수평대각선 브로카대의 신경세포 원형질 막에서만 약한 면역반응을 보였다 위의 결과로 미루어 NGFr은 조연소포체에서 합성되어. Golgi체에서 농축되고, multivesicular body를 통하여 원형질막에 위치하게 되며, 원형질막에서 NGFr은 외래성의 NGF와 복합체를 형성한후, 궁극적으로는 Iysosome의 형태로 세포체 안으로 들어 가는 것으로 추정된다.

• Journal of Oriental Neuropsychiatry
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• v.22 no.2
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• pp.107-128
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• 2011

Objectives : This experiment was designed to investigate the efficacy of DDTCMT hot water extract & ultra-fine powder on Alzheimer's Disease Model. Methods : The effects of the DDTCMT hot water extract on expression of IL-$1{\beta}$, IL-6, TNF-${\alpha}$, COX-2, NOS-II, IL-10, IL-1 receptor antagonist mRNA and production of IL-$1{\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line treated by lipopolysacchaide(LPS) were investigated. Expression of NO, ROS in BV2 microglial cell line treated by LPS and AChE activity in PC-12 cell treated by NGF were investigated. anti-AChE was observed through Western blot analysis. The effects of the DDTCMT hot water extract & ultra-fine powder on the behavior of the memory deficit mice induced by scopolamine were investigated. Results : 1. The DDTCMT hot water extract significantly decreased the production of mIL-6, mNOS-II, mTNF-${\alpha}$, and increased the production of mIL-10, mIL-1 receptor antagonist. 2. The DDTCMT hot water extract significantly suppressed the production of IL-$1{\beta}$, IL-6, TNF-${\alpha}$ in BV2 microglial cell line treated by LPS. 3. The DDTCMT hot water extract significantly suppressed the NO and ROS production in BV2 microglial cell line treated by LPS. 4. The DDTCMT hot water extract groups showed inhibition of AChE activity in NGF treated PC-12 cell line. 5. The DDTCMT hot water extract suppressed anti-AChE expression in NGF treated PC-12 cell line was observed by Western blot analysis. 6. The DDTCMT hot water extract & ultra-fine powder groups showed significantly inhibitory effect on the scopolamine -induced impairment of memory in the experiment of Morris water maze. Conclusions : These results suggest that the DDTCMT hot water extract & ultra-fine powder may be effective for the prevention and treatment of Alzheimer's disease.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.110-110
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• 2002

15-Deoxy-$\Delta$12, 14-prostaglandin J2 (15-deoxy-PGJ2), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-$\gamma$(PPAR-$\gamma$). It was known to have promoting ability of nerve growth factor(NGF)-induced neurite extension. However, it is not clear yet as to what signaling pathway is involved in its promoting ability of neurite extension.(omitted)

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.317-322
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• 2003

TrkA is an essential component of the high affinity NGF receptor necessary to the mediate biological effects of the neurotrophins NGF. Here we report on the expression of TrkA in the olfactory bulb and basal nucleus of Mongolian gerbil brain during the postnatal development. The expressions of TrkA were identified in a immunohistochemical method. Higher levels of TrkA immunoreactivity were detected in septum than that in olfactory bulb and caudate putamen (CPu). But TrkA was not observed before postnatal days (PND6) in olfactory bulb and PND9 in CPu. No TrkA-positive cell was detectable in the olfactory fiber layer. Several regions, such as olfactory bulb and CPu, showed weak labeling. These data show that expression of TrkA is developmentally regulated during postnatal Mongolian gerbil brain development and suggest that high affinity neurotrophinreceptors mediate a transient response to neurotrophins in many regions during the brain ontogeny.

• Journal of Neurogastroenterology and Motility
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• v.26 no.1
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• pp.106-116
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• 2020

Background/Aims Emerging evidence shows that the mechanism of irritable bowel syndrome (IBS) is associated with neurotrophic factors and tight junction proteins (TJPs). It is known that there are sex differences in the pathophysiology of IBS. The aim of the present study is to determine expression levels of neurotrophic factors, TJPs, and cytokines according to IBS subtype and sex. Methods From 59 IBS (33 IBS-constipation, 21 IBS-diarrhea, and 5 IBS-mixed) and 36 control patients, colonic mucosa mRNA expression levels of transient receptor potential vanilloid-1 (TRPV1), nerve growth factor (NGF), glial cell-derived neurotrophic factor (GDNF), and various TJPs were assessed by real-time polymerase chain reaction. Western blot was performed to determine levels of zonular occludens-1 (ZO-1). Serum levels of cytokines were measured by enzyme-linked immunosorbent assay. Results TRPV1, GDNF, and NGF mRNA levels were significantly increased in those with IBS-constipation compared to those in controls (all P < 0.05). However, they showed no significant difference between those with IBS-diarrhea and controls. Expression level of TRPV1 correlated with that of GDNF (r = 0.741, P < 0.001) and NGF (r = 0.935, P < 0.001). ZO-1 RNA expression levels were lower (P = 0.021) in female IBS-diarrhea than those in controls, although they showed no significant differences between male IBS-diarrhea and controls. Serum IL-1β levels in female IBS were significantly higher than those of male IBS, especially in IBS-constipation (P < 0.001). Conclusion Our results suggest that neurotrophic factors and IL-1β are closely related to IBS-constipation and that decrease of ZO-1 is an important factor in female with IBS-diarrhea.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.107-114
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• 2014

Taste is an important sense in survival and growth of animals. The growth and maintenance of taste buds, the receptor organs of taste sense, are under the regulation of various neurotrophic factors. But the distribution aspect of neurotrophic factors and their receptors in distinct taste cell types are not clearly known. The present research was designed to characterize mRNA expression pattern of neurotrophic factors and their receptors in distinct type of taste cells. In male 45-60 day-old Sprague-Dawley rats, epithelial tissues with and without circumvallate and folliate papillaes were dissected and homogenized, and mRNA expressions for neurotrophic factors and their receptors were determined by RT-PCR. The mRNA expressions of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT3), receptor tyrosine kinase B (TrkB), exclusion of nerve growth factor (NGF), neurotrophin-4/5 (NT4/5), receptor tyrosine kinase A (TrkA), receptor tyrosine kinase C (TrkC), and p75NGFR were observed in some population of taste cell. In support of this result and to characterize which types of taste cells express NT3, BDNF, or TrkB, we examined mRNA expressions of NT3, BDNF, or TrkB in the $PLC{\beta}2$ (a marker of Type II cell)-and/or SNAP25 (a marker of Type III cell)-positive taste cells by a single taste cell RT-PCR and found that the ratio of positively stained cell numbers were 17.4, 6.5, 84.1, 70.3, and 1.4 % for $PLC{\beta}2$, SNAP25, NT3, BDNF, and TrkB, respectively. In addition, all of $PLC{\beta}2$-and SNAP25-positive taste cells expressed NT3 mRNA, except for one taste bud cell. The ratios of NT3 mRNA expressions were 100% and 91.7% in the SNAP25-and $PLC{\beta}2$-positive taste cells, respectively. However, two TrkB-positive taste cells co-expressed neither $PLC{\beta}2$ nor SNAP 25. The results suggest that the most of type II or type III cells express BDNF and NT3 mRNA, but the expression is shown to be less in type I taste cells.

• The Korean Journal of Zoology
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• v.37 no.3
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• pp.385-408
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• 1994

출생후 0일. 7일. 14일 및 21일 그리고 성체의 흰쥐 전뇌 기저부의 내측중격핵, 수직 및 수평 대각 Broca대 거대세포 시삭전핵 그리고 복부담창구에서 신경성장인자수용체 (nerv-growth 배ctor receptor, NGFr)에 면역반응을 보이는 신경조직과 세포의 분화를 면역조직화학적 및 전자현미경적 방법을 이용하여 조사하였다. 출생후 초기와 성체에서 신경세포 원형질막 뿐만 아니라 세포질에서 NGFr 면역반응이 확인되었다. 그러나 성체에서 신경세포 원형질 막에서의 면역반응은 관찰되지 않았다. 특히 NGFr 면역반응은 골지 부위에서 보였고, 점상의 면역반응물들이 세포체의 세포질과 수상돌기에 소수 분산 분포하였다. 뇌 기저부의 NGFr 면역반응 신경세포들은 뇌 크기의 증대와 뇌 조직의 분화에 따라 점차 수적 증가를 보였다. 이 NGFr 면역반응 신경세포들은 세포의 모양과 세포체의 장 .단축의 비에 따라 6가지 형. 즉 1) 원형. 2) 타원형. 3) 세장형, 4) 방추형, 5) 삼각형, 6) 다각형으로 분류되었다. 전뇌 기저 핵에서 원형과 난형신경세포들의 출현율은 출생후 0일에서 높았으나 성체로 되면서 감소된 반면, 세장형. 방추형, 삼각형 그리고 다각형신경세포들의 출현율은 출생후 0일에서는 낮았으나 성체로 되면서 증가하였다. 모든 핵들에서 NGFr 면역반응 신경세포체의 부피는 출생후 0일에 759-1,640 Um3로 제일 작았으며, 수직 대각 Broca대와 복부담창구에서는 출생후 14일에 각각 5 107 7.385 Um3 그리고 내측중격핵, 수평 대각 Broca대, 거대세포 시삭전핵에서는 출생후 21일에 각각 4,705, 6,061, 6,412 Um3로 최대치를 보였다. 그후 성체로 되면서 모든 핵에서 1,893-3,464 $\mu$m3로 다시 감소하였다. 전자현미경적 관찰에서 출생후 21일된 흰쥐 수평 대각 Broca대에서 NGFr 면역반응은 세포체와 수상돌기의 원형질막 그리고 세포체내에서는 골지체, 다소포성소체 및 조면소포체에서 관찰되었다. 이 결과들로 미루어 NGFr은 출생후 발생단계와 성체의 횐쥐 전뇌 기저부에서 신경세포의 분화와 분포에 관계되는 것으로 생각된다.