• BMB Reports
• /
• v.44 no.3
• /
• pp.182-186
• /
• 2011

Exogenous stimuli such as nerve growth factor (NGF) exert their effects on neurite outgrowth via Trk neurotrophin receptors. TrkA receptors are known to be ubiquitinated via proteasome inhibition in the presence of NGF. However, the effect of proteasome inhibition on neurite outgrowth has not been studied extensively. To clarify these issues, we investigated signaling events in PC12 cells treated with NGF and the proteasome inhibitor MG132. We found that MG132 facilitated NGF-induced neurite outgrowth and potentiated the phosphorylation of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) and phosphatidylinositol-3-kinase (PI3K)/AKT pathways and TrkA receptors. MG132 stimulated internalization of surface TrkA receptor and stabilized intracellular TrkA receptor, and the $Ub^{K63}$ chain was found to be essential for stability. These results indicate that the ubiquitin-proteasome system potentiated neurite formation by regulating the stability of TrkA receptors.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.89-90
• /
• 2001

Insulin-like growth factor-I(IGF-I)은 70개의 아미노산으로 이루어진 polypeptides로서 pronsulin과 구조적으로 유사하다(Froesch and Zapf, 1985). IGF-I은 척추동물에서 성장호르몬의 매개로 생성되어 동물의 성장 발달에 중요한 역할을 하고 있으며 세포의 성장, 분화, 대사에 다양한 효과를 보여주고 있다(Cohich and Clemmons, 1993; Baxter, 1993). 또한 체성장을 가속화시키고 in vivo에서는 단백질의 합성을 촉진시킨다(Rotwein et al., 1987). (중략)

• Fisheries and Aquatic Sciences
• /
• v.27 no.9
• /
• pp.588-599
• /
• 2024

Tank color is an important environmental factor influencing aquaculture performance, but it remains poorly understood for juvenile giant trevally (Caranx ignobilis) under laboratory conditions. This study evaluated the effects of five different tank colors (white, blue, red, yellow, and dark grey) on growth performance, survival, feed utilization efficiency, body coloration, and biochemical composition of juvenile giant trevally. In a 28-day experiment, juvenile giant trevally with an initial mean length of 1.91 ± 0.03 cm and an initial weight of 0.24 ± 0.04 g were reared in tanks with different colors at a density of 1 fish/L, and each treatment was replicated three times. Results showed that fish reared in yellow tanks had higher growth rate, higher survival, and lower feed conversion ratio compared to those reared in white and blue tanks (p < 0.05). Fish reared in yellow and red tanks had significantly darker yellow body coloration and accumulated more carotenoids than those reared in white and dark grey tanks. Additionally, fish reared in yellow and red tanks had higher body protein content, whereas fish reared in white tanks had higher body moisture content (p < 0.05). These findings indicate that tank color could be an important factor in improving the rearing performance and skin pigmentation of juvenile giant trevally. Yellow tank color is suggested as a potential strategy to optimize juvenile giant trevally seed production in aquaculture.

• Molecules and Cells
• /
• v.22 no.3
• /
• pp.291-299
• /
• 2006

Vitexin, a natural flavonoid compound identified as apigenin-8-C-${\beta}$-D-glucopyranoside, has been reported to exhibit antioxidative and anti-inflammatory properties. In this study, we investigated its effect on hypoxiainducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in rat pheochromacytoma (PC12), human osteosarcoma (HOS) and human hepatoma (HepG2) cells. Vitexin inhibited HIF-$1{\alpha}$ in PC12 cells, but not in HOS or HepG2 cells. In addition, it diminished the mRNA levels of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF), smad3, aldolase A, enolase 1, and collagen type III in the PC12 cells. We found that vitexin inhibited the migration of PC12 cells as well as their invasion rates, and it also inhibited tube formation by human umbilical vein endothelium cells (HUVECs). Interestingly, vitexin inhibited the hypoxia-induced activation of c-jun N-terminal kinase (JNK), but not of extracellular-signal regulated protein kinase (ERK), implying that it acts in part via the JNK pathway. Overall, these results suggest the potential use of vitexin as a treatment for diseases such as cancer.

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

• Journal of Periodontal and Implant Science
• /
• v.26 no.4
• /
• pp.799-821
• /
• 1996

The ultimate goal of periodontal treatment has been to facilitate regeneration of diseased periodontal tissues, destroyed by inflammatory periodontal disease. For regeneration of the periodontium to occur, all of component tissues must be restored to their original position and architecture. Growth factors which were known to promote the cellular processes, ie, proliferation, migration and matrix synthesis, have been in the spotlight of current periodontics. Platelet-derived growth factor(PDGF) stimulates collagen and non collagen protein synthesis, migration and proliferation of periodontal ligament cells. Insulin-like growth factor(IGF) has potentials to induce collagen and bone matrix synthesis so that it regulates normal bone remodeling. Application of the combination have been known to facilitate formation of bone and cementum, and to synergistically interact to promote coronal migration and proliferation of periodontal ligament cells. These two growth factors have been reported to exhibit positive effect in the periodontally diseased teeth or class m furcation defects. The aim of the present study was to test the hypothesis that PDGF-BB alone or the combination of PDGF-BB and IGF-I can predictably enhance regeneration of the periodontium in the dehiscence defect. Following the resection of premolars, roots were embedded. After 12 weeks of healing period, standardized experimental $4{\times}4mm$ dehiscence defects were created on the mid-facial of the premolar roots in each of 4 young adult dogs. In control group, only methylcellulose gel was inserted in the defects. In experimental group I and II, gel with $2{\mu}g$ of PDGF-BB or $2{\mu}g$ of PDGF-BB and $1{\mu}g$ of IGF-I was inserted in the defects, respectively. At 8 weeks postsurgery, the dogs were sacrificed. The results were observed histologically and analyzed histomorphometrically.The results of this study were as follws. 1. The new cementum formation was $1.26{\pm}0.69mm$ in the control group, $1.80{\pm}0.84mm$ in the experimental group I, $1.93{\pm}0.51mm$ in the experimental group II. The experimental group III, the experimental group I, the control group were in the order of cementum formation without statistically significant differences between control and all experimental groups. 2. The new bone formation was $1.00{\pm}0.53mm$ in the control group, $1.53{\pm}0.63mm$ in the experimental group I, $l.33{\pm}0.45mm$ in the experimental group II. The experimental group I, the experimental group II, the control group were in the order of bone formation without statistically significant differences between control and all experimental groups. 3. The root resorption was $1.12{\pm}0.64mm$ in the control group, $1.34{\pm}0.73mm$ in the experimental group I, $0.79{\pm}0.59mm$ in the experimental group II without statistically significant differences between control and all experimental groups. These results suggested that the use of PDGF-BB alone or PDGF-BB and IGF-I in the dehiscence defects might facilitate periodontal regeneration in some degree, but has not shown statistically significant results.

• Development and Reproduction
• /
• v.26 no.4
• /
• pp.165-174
• /
• 2022

Three proteins [myosin heavy chain (MHC), filamin-C fragment (FIL-C), and actin 2 (ACT2)] were identified in adductor muscle from diploid and triploid Pacific oysters (Crassostrea gigas) and the relationship between the condition index (CI) and mRNA expression of these genes was investigated, together with the mRNA expression of molluscan insulin-related peptide (MIP), C. gigas insulin receptor-related receptor (CIR), and insulin-like growth factor binding protein complex acid labile subunit (IGFBP-ALS). Monthly changes in the CI were similar to the changes in the tissue weight rate in both groups. ACT2 and MHC mRNA expression was statistically higher in the triploid than the diploid, while FIL-C mRNA expression was significantly higher in the diploid (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression of the diploid oysters were all significantly higher in July than in other months (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression in the triploid oysters was high in July, but there were no significant differences (p>0.05). Changes in the expression levels of the genes investigated in this study could be used as intrinsic indicators of the annual growth, maturity, and spawning period of cultured diploid and triploid C. gigas in Tongyeong, Korea.

• IMMUNE NETWORK
• /
• v.3 no.1
• /
• pp.38-46
• /
• 2003

Background: Platelet-activating factor (PAF) induces nuclear factor $(NF)-{\kappa}B$ activation and angiogenesis and increases tumor growth and pulmonary tumor metastasis in vivo. The role of $NF-{\kappa}B$ activation in PAF-induced angiogenesis in a mouse model of Matrigel implantation, and in PAF-mediated pulmonary tumor metastasis were investigated. Methods: Angiogenesis using Matrigel and experimental pulmonary tumor metastasis were tested in a mouse model. Electrophoretic mobility shift assay was done for the assessment of $NF-{\kappa}B$ translocation to the nucleus. Expression of angiogenic factors, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\alpha}$, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were tested by RT-PCR and ELISA. Results: PAF induced a dose- and time-dependent angiogenic response. PAF-induced angiogenesis was significantly blocked by PAF antagonist, CV6209, and inhibitors of $NF-{\kappa}B$ expression or action, including antisense oligonucleotides to p65 subunit of $NF-{\kappa}B$ (p65 AS) and antioxidants such as ${\alpha}$-tocopherol and N-acetyl-L-cysteine. In vitro, PAF activated the transcription factor, $NF-{\kappa}B$ and induced mRNA expression of $TNF-{\alpha}$, $IL-1{\alpha}$, bFGF, VEGF, and its receptor, KDR. The PAF-induced expression of the above mentioned factors was inhibited by p65 AS or antioxidants. Also, protein synthesis of VEGF was increased by PAF and inhibited by p65 AS or antioxidants. The angiogenic effect of PAF was blocked when anti-VEGF antibodies was treated or antibodies against $TNF-{\alpha}$, $IL-1{\alpha}$, and bFGF was co-administrated, but not by antibodies against $TNF-{\alpha}$, $IL-1{\alpha}$, and bFGF each alone. PAF-augmented pulmonary tumor metastasis was inhibited by p65 AS or antioxidants. Conclusion: These data indicate that PAF increases angiogenesis and pulmonary tumor metastasis through $NF-{\kappa}B$ activation and expression of $NF-{\kappa}B$-dependent angiogenic factors.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.22
• /
• pp.9835-9839
• /
• 2014

Fisetin is an effective compound extracted from lacquer which has been used in the treatment of various diseases. Preliminary data indicate that it also exerts specific anti-cancer effects. However, the manner in which fisetin regulates cancer growth remains unknown. In this study, we elucidated interference of fisetin with targets of the nuclear factor ${\kappa}B$ signal transduction pathway activated by Epstein-Barr virus encoding latent membrane protein 1 (LMP1)in nasopharyngeal carcinoma (NPC) cells, Results showed that fisetin inhibited the survival rate of CNE-LMP1 cells and NF-${\kappa}B$ activation caused by LMP1. Fisetin also suppressed nuclear translocation of NF-${\kappa}B$ (p65) and $I{\kappa}B{\alpha}$ phosphorylation, while inhibiting CyclinD1, all key targets of the NF-${\kappa}B$ signal transduction pathway. It was suggested that interference effects of fisetin with signal transduction activated by LMP1 encoded by the Epstein-Barr virus may play an important role in its anticancer potential.

• Journal of Acupuncture Research
• /
• v.20 no.4
• /
• pp.85-92
• /
• 2003

목적 : 허혈시 발생되는 저산소중 상태에서는 세포독성을 유발한다고 알려져 있으나 정확한 기전은 아직 규명되지 않았다. 본 연구에서는 뇌허혈로 인한 세포독성의 기전을 유전자 발현을 통하여 살펴보고자 하였다. 방법 : 본 실험에서는 BV-2 microglia 세포주에 12시간 동안의 저산소 상태에서의 유전자 발현을 분석하기 위하여 마이크로에레이를 시행하였다. 결과 : 저산소 상태에서는 정상에 비하여 cathepsin F, growth factor independent 1, calcitonin/calcitonin-related poly, leucine-rich repeat LGI family membrane, dublecortin, cyclohydrolase 1, Ia-associated invariant chain, carbohydrate kinase-like과 erythrocyte protein band 4.1-like 3 등의 유전자 발현이 3배 이상 증가하였다. 한편 neuronal guanine nucleotide exchange factor, Bcl-2-related ovarian killer protein, chemokine (C-X-C motif) ligand 5, RNA binding motif protein 3, interleukin 2 receptor, alpha chain, crystallin zeta, cytochrome P450 subfamily IV B, asparagine synthetase과 moesin 등의 유전자 발현은 0.2배 이하로 감소하였다. 결론 : 이상의 결과는 저산소중에 관여하는 유전자 및 저산소중과 관련된 뇌경색 등의 질환의 기전을 밝히는데 기초적 자료로 이용될 수 있을 것이다.