30 results on '"Sun-Hun Kim"'
Search Results
2. SLPI in periodontal Ligament is not sleepy during biophysical force-induced tooth movement
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Min-Seok Kim, Ji-Yeon Jung, Dong-Wook Yang, Su-Young Lee, Ok-Su Kim, Hong-Il Yoo, Jung-Sun Moon, Sun-Hun Kim, Hyun-Ju Chung, and Jeong-Tae Koh
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biology ,Tooth Movement Techniques ,Activator (genetics) ,Chemistry ,Periodontal Ligament ,RANK Ligand ,030206 dentistry ,Cell biology ,Rats ,RUNX2 ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,RANKL ,In vivo ,biology.protein ,Periodontics ,Periodontal fiber ,Animals ,Secretory Leukocyte Peptidase Inhibitor ,030212 general & internal medicine ,Receptor ,Transcription factor ,Cells, Cultured ,SLPI - Abstract
Aim We aimed to identify a key molecule that maintains periodontal tissue homeostasis during biophysical force-induced tooth movement (BTM) by orchestrating alveolar bone (AB) remodelling. Materials and methods Differential display-PCR was performed to identify key molecules for BTM in rats. To investigate the localization and expression of the identified molecules, immunofluorescence, real-time RT-PCR and Western blotting were performed in rats and human periodontal ligament (PDL) cells. Functional test and micro-CT analysis were performed to examine the in vivo effects of the identified molecules on BTM. Results Secretory leucocyte peptidase inhibitor (SLPI) in the PDL was revealed as a key molecule for BTM-induced AB remodelling. SLPI was enhanced in the PDL under both compression and tension, and downregulated by an adenyl cyclases inhibitor. SLPI induced osteoblastogenic genes including runt-related transcription factor 2 (Runx2) and synergistically augmented tension-induced Runx2 expression. SLPI augmented mineralization in PDL cells. SLPI induced osteoclastogenic genes including receptor activator of nuclear factor kappa-Β ligand (RANKL) and synergistically augmented the compression-induced RANKL and macrophage colony-stimulating factor (MCSF) expression. Finally, the in vivo SLPI application into the AB significantly augmented BTM. Conclusions SLPI or its inhibitors might serve as a biological target molecule for therapeutic interventions to modulate BTM.
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- 2020
3. Dual role of phosphatidylserine and its receptors in osteoclastogenesis
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Geum-Dong Han, Su-Young Lee, Sun-Hun Kim, Jee-Hae Kang, Jeong-Tae Koh, Hyun-Mi Ko, Min-Seok Kim, and Jung-Sun Moon
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0301 basic medicine ,Cancer Research ,Cell biology ,Molecular biology ,Immunology ,Osteoclasts ,Apoptosis ,Bone Marrow Cells ,Receptors, Cell Surface ,Phosphatidylserines ,Giant Cells ,Article ,Exocytosis ,Cell Fusion ,Rats, Sprague-Dawley ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Multinucleate ,Adenosine Triphosphate ,Downregulation and upregulation ,Osteoclast ,Osteogenesis ,medicine ,Alveolar Process ,Animals ,lcsh:QH573-671 ,Receptor ,ATP Binding Cassette Transporter, Subfamily G, Member 1 ,Adenosine Triphosphatases ,030102 biochemistry & molecular biology ,biology ,lcsh:Cytology ,Tartrate-Resistant Acid Phosphatase ,CD47 ,Tooth Germ ,Phosphatidylserine ,Dendritic Cells ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Animals, Newborn ,RANKL ,biology.protein ,Multidrug Resistance-Associated Proteins - Abstract
Fusion and apoptosis share a breakdown of the membrane phospholipids asymmetry, modes of which are largely unknown in osteoclastogenesis. Here, we investigated the externalization of phosphatidylserine (PS) and its receptors, and their biological functions in osteoclastogenesis. Strong immunoreactivities in vivo for the PS receptors TIM4, BAI1, and STAB2 were observed in the TRAP-positive multinucleated cells in the alveolar bone that was being remodeled around the developing dental follicles in rats. These receptors were significantly upregulated during M-CSF/RANKL-induced in vitro osteoclastogenesis using mouse bone marrow-derived cells. PS externalization in preosteoclasts was increased by the M-CSF/RANKL treatment. Multinucleation of preosteoclasts was markedly inhibited by antibodies against PS and its receptors. Among the investigated lipid transporter proteins, floppases (Abcb4, Abcc5, and Abcg1) were upregulated, whereas flippases (Atp11c and Atp8a1) downregulated during osteoclastogenesis. Preosteoclast fusion was markedly blocked by the ATPase inhibitor Na3VO4 and siRNAs against Abcc5 and Abcg1, revealing the importance of these lipid transporters in PS externalization. Further, the levels of Cd47 and Cd31, don’t-eat-me signal inducers, were increased or sustained in the early phase of osteoclastogenesis, whereas those of AnnexinI and Mfg-e8, eat-me signals inducers, were increased in the late apoptotic phase. In addition, Z-VAD-FMK, a pan caspase inhibitor, had no effect on preosteoclast fusion in the early phase of osteoclastogenesis, whereas Abs against PS, TIM4, and BAI1 decreased osteoclast apoptosis during the late phase. These results suggest that PS externalization is essential for the whole process of osteoclastogenesis and share PS receptors and transporters in the early stage fusion and late stage apoptosis. Therefore, modulation of PS and its receptors could be a useful strategy to develop anti-bone resorptive agents.
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- 2020
4. Bone Generation Following Repeated Administration of Recombinant Bone Morphogenetic Protein 2
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Sin-Hye Oh, Jung-Woo Kim, Hye-Ju Son, Seung-Hee Kwon, Shee Eun Lee, Jeong-Tae Koh, Sun-Hun Kim, Mi Nam Lee, Soo-Chang Song, Yuri Kim, Hyuck Choi, and Byung-Chul Jeong
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medicine.medical_specialty ,Bone Regeneration ,0206 medical engineering ,Biomedical Engineering ,Medicine (miscellaneous) ,Bone Morphogenetic Protein 2 ,02 engineering and technology ,Bone morphogenetic protein ,Bone morphogenetic protein 2 ,Bone and Bones ,law.invention ,03 medical and health sciences ,Mice ,law ,In vivo ,Osteogenesis ,Internal medicine ,medicine ,Animals ,Bone regeneration ,030304 developmental biology ,0303 health sciences ,biology ,business.industry ,020601 biomedical engineering ,Recombinant Proteins ,Mice, Inbred C57BL ,Endocrinology ,Self-healing hydrogels ,biology.protein ,Recombinant DNA ,Original Article ,Antibody ,Stem cell ,business - Abstract
BACKGROUND: The delivery of recombinant human bone morphogenetic protein 2 (rhBMP2) by using various carriers has been used to successfully induce bone formation in many animal models. However, the effect of multiple administration of rhBMP2 on bone formation and BMP2 antibody production has not been determined. Our aim was to examine the bone formation activity of rhBMP2 and serum levels of anti-BMP2 antibodies following the repeated administration of rhBMP2 in mice. METHODS: Absorbable collagen sponges or polyphosphazene hydrogels containing rhBMP2 were subcutaneously implanted or injected into one side on the back of six-week-old C57BL/6 mice. Three or 4 weeks later, the same amount of rhBMP2 was administered again with the same carrier into the subcutaneous regions on the other side of the back or into calvarial defects. The effects of a single administration of rhBMP2 on the osteoinductive ability in the ectopic model were compared with those of repeated administrations. In vivo ectopic or orthotopic bone formation was evaluated using microradiography and histological analyses. Serum concentrations of anti-rhBMP2 antibodies were measured by ELISAs. RESULTS: Re-administration of the same amount of rhBMP2 into the subcutaneous area showed a comparable production of ectopic bone as after the first administration. The bone forming ability of repeated rhBMP2 administrations was equal to that of single rhBMP2 administration. The administration of rhBMP2 into calvarial defects, following the first subcutaneous administration of rhBMP2 on the back, completely recovered the defect area with newly regenerated bone within 3 weeks. Repeated administration of rhBMP2 at 4-week intervals did not significantly alter the serum levels of anti-BMP2 antibodies and did not induce any inflammatory response. The serum obtained from rhBMP2-exposed mice had no effect on the ability of rhBMP2 to induce osteogenic gene expressions in MC3T3-E1. CONCLUSION: We suggest that the osteoinductive ability of rhBMP2 is not compromised by repeated administrations. Thus, rhBMP2 can be repeatedly used for bone regeneration at various sites within a short duration. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13770-020-00290-4) contains supplementary material, which is available to authorized users.
- Published
- 2020
5. 17β-Estradiol induces odontoblastic differentiation via activation of the c-Src/MAPK pathway in human dental pulp cells
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Won Jae Kim, Ji Yeon Jung, Kyung Joo Seong, Su Mi Woo, Hong Ju Park, Sun Hun Kim, and Sang-Jin Oh
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MAPK/ERK pathway ,medicine.medical_specialty ,Cell Survival ,MAP Kinase Signaling System ,Cellular differentiation ,Proto-Oncogene Proteins pp60(c-src) ,Biochemistry ,Estrogen Receptor Antagonists ,Calcification, Physiologic ,stomatognathic system ,Internal medicine ,medicine ,Humans ,Phosphorylation ,Protein Kinase Inhibitors ,Molecular Biology ,Dental Pulp ,Cell Line, Transformed ,Cell Proliferation ,Estradiol ,Odontoblasts ,biology ,Chemistry ,Cell growth ,Estrogen Receptor alpha ,Gene Expression Regulation, Developmental ,Cell Differentiation ,Estrogens ,Cell Biology ,Cell biology ,stomatognathic diseases ,Odontoblast ,Endocrinology ,Mitogen-activated protein kinase ,Dentin ,biology.protein ,Protein Processing, Post-Translational ,Estrogen receptor alpha ,Biomarkers ,Proto-oncogene tyrosine-protein kinase Src - Abstract
The present study is aimed at investigating the effects of the exogenous estrogen 17β-estradiol (E2) on odontoblastic differentiation in human dental pulp cells (HDPCs) immotalized with hTERT gene and their molecular mechanism. Proliferation was detected by BrdU assay, and odontoblast differentiation induction was evaluated by the expression of dentin sialophosphoprotein (DSPP), dentin sialoprotein (DSP) and dentin matrix protein1 (DMP1), and alkaline phosphatase (ALP) activity and mineralization. Estrogen receptor-α (ER-α), c-Src, and mitogen-activated protein kinases (MAPKs) were examined and their inhibitors were used to determine the roles on odontogenic induction. E2 significantly promoted the HDPC proliferation, which was mediated by extracellular signal-related kinase 1/2. E2 upregulated DSPP, DSP, and DMP1 as the odontogenic differentiation markers and enhanced ALP activity and mineralization. E2 increased phosphorylation of ER-α and fulvestrant, an ER downregulator, significantly downregulated DSPP, DMP1, and DSP induced by E2. Moreover, E2 treatment activated c-Src and MAPKs upon odontogenic induction, whereas chemical inhibition of c-Src and MAPKs decreased expression of DSPP, DMP1, and DSP and mineralization augmented by E2. Moreover, fulvestrant reduced E2-induced phosphorylation of c-Src and MAPK and inhibition of c-Src by PP2 attenuated activation of MAPKs during E2-induced odontoblastic differentiation. Taken together, these results indicated that E2 stimulates odontoblastic differentiation of HDPCs via coordinated regulation of ER-α, c-Src, and MAPK signaling pathways, which may play a key role in the regeneration of dentin.
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- 2015
6. Inhibitory effect of C-X-C motif chemokine ligand 14 on the osteogenic differentiation of human periodontal ligament cells through transforming growth factor-beta1
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Jung-Sun Moon, Sun-Hun Kim, Hyun-Mi Ko, Hae-Kyoung Shim, Jee-Hae Kang, Min-Seok Kim, Hyun-Ju Chung, and Su-Young Lee
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0301 basic medicine ,Chemokine ,Periodontal Ligament ,Chemokine CXCL1 ,medicine.medical_treatment ,Transforming Growth Factor beta1 ,03 medical and health sciences ,0302 clinical medicine ,Western blot ,Osteogenesis ,medicine ,Animals ,Humans ,Periodontal fiber ,CXCL14 ,General Dentistry ,Cells, Cultured ,medicine.diagnostic_test ,biology ,Chemistry ,Cell growth ,Growth factor ,Cell Differentiation ,030206 dentistry ,Cell Biology ,General Medicine ,In vitro ,Rats ,Cell biology ,030104 developmental biology ,Otorhinolaryngology ,Transforming Growth Factors ,biology.protein ,Transforming growth factor - Abstract
Objective This study aimed to determine the expression of chemokine (C-X-C motif) ligand 14 (CXCL14) in pulpal and periodontal cells in vivo and in vitro, and investigate function of CXCL14 and its underlying mechanism in the proliferation and osteogenic differentiation of human periodontal ligament (hPDL) cells. Methods To determine the expression level of CXCL14 in adult rat oral tissues and in hPDL cells after application of biophysical forces, RT-PCR, western blot, and histological analyses were performed. The role of CXCL14 in proliferation and osteogenic differentiation of PDL cells was evaluated by measuring dehydrogenase activity and Alizarin red S staining. Results Strong immunoreactivity against CXCL14 was observed in the PDL tissues and pulpal cells of rat molar, and attenuated apparently by orthodontic biophysical forces. As seen in rat molar, highly expressed CXCL14 was observed in human dental pulp and hPDL cells, and attenuated obviously by biophysical tensile force. CXCL14 expression in hPDL cells was increased in incubation time-dependent manner. Proliferation of hPDL cells was inhibited dramatically by small interfering (si) RNA against CXCL14. Furthermore, dexamethasone-induced osteogenic mineralization was inhibited by recombinant human (rh) CXCL14, and augmented by CXCL14 siRNA. rhCXCL14 increased transforming growth factor-beta1 (TGF- β1) in hPDL cells. Inhibition of the cell proliferation and osteogenic differentiation of hPDL cells by CXCL14 siRNA and rhCXCL14 were restored by rhTGF-β1 and SB431542, respectively. Conclusion These results suggest that CXCL14 may play roles as a growth factor and a negative regulator of osteogenic differentiation by increasing TGF-β1 expression in hPDL cells.
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- 2020
7. Inhibition of human mesenchymal stem cell proliferation via Wnt signaling activation
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Min-Seok Kim, Sun-Hun Kim, Jae-Hyung Kim, Hyun-Mi Ko, Ji-Il Park, and Jung-Sun Moon
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0301 basic medicine ,Cell ,Cyclin A ,Cell Cycle Proteins ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Humans ,Mesenchymal stem cell proliferation ,Propidium iodide ,Phosphorylation ,Molecular Biology ,Wnt Signaling Pathway ,Cells, Cultured ,beta Catenin ,Cell Proliferation ,biology ,Mesenchymal stem cell ,Wnt signaling pathway ,LRP5 ,Mesenchymal Stem Cells ,Cell Biology ,Cell cycle ,equipment and supplies ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,biology.protein ,Lithium Chloride - Abstract
Human mesenchymal stem cells (hMSCs), characterized by rapid in vitro expandability and multi-differentiation potential, have been widely used in the clinical field of tissue engineering. Recent studies have shown that various signaling networks are involved in the growth and differentiation of hMSCs. Although Wnts and their downstream signaling components have been implicated in the regulation of hMSCs, the role of Wnt signaling in hMSC self-renewal is still controversial. Here, it was observed that activation of endogenous canonical Wnt signaling with LiCl, which decreased β-catenin phosphorylation, leads to a decrease in hMSC proliferation. The fact that this growth arrest is not linked to apoptosis was verified by annexin V-FITC/propidium iodide assay. It was associated with sealing off of the cells in the G1 phase of the cell cycle accompanied by changes in expression of cell cycle-associated genes such as cyclin A and D. In addition, activation of Wnt signaling during hMSC proliferation seemed to reduce their clonogenic potential. On the contrary, Wnt signaling activation during hMSC proliferation had little effect on the osteogenic differentiation capability of cells. These findings show that canonical Wnt signaling is a critical regulator of hMSC proliferation and clonogenicity.
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- 2017
8. Nitric Oxide-Induced Apoptosis of Human Dental Pulp Cells Is Mediated by the Mitochondria-Dependent Pathway
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Yeon Jin Jeong, Min Young Park, Won Jae Kim, Sun Hun Kim, Hyun-Ju Chung, Mihwa Kim, Ji Yeon Jung, and Gi Chang Kang
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Pharmacology ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Physiology ,Cytochrome c ,Bcl-2 family ,Apoptosis ,Nitric oxide ,Caspase ,Cell biology ,Nitric oxide synthase ,chemistry.chemical_compound ,chemistry ,Annexin ,Immunology ,biology.protein ,Original Article ,Viability assay ,Human dental pulp cells - Abstract
Nitric oxide (NO) is recognized as a mediator and regulator of inflammatory responses. NO is produced by nitric oxide synthase (NOS), and NOS is abundantly expressed in the human dental pulp cells (HDPCs). NO produced by NOS can be cytotoxic at higher concentrations to HDPCs. However, the mechanism by which this cytotoxic pathway is activated in cells exposed to NO is not known. The purpose of this study was to elucidate the NO-induced cytotoxic mechanism in HDPCs. Sodium nitroprusside (SNP), a NO donor, reduced the viability of HDPCs in a dose- and time-dependent manner. We investigated the in vitro effects of nitric oxide on apoptosis of cultured HDPCs. Cells showed typical apoptotic morphology after exposure to SNP. Besides, the number of Annexin V positive cells was increased among the SNP-treated HDPCs. SNP enhanced the production of reactive oxygen species (ROS), and N-acetylcysteine (NAC) ameliorated the decrement of cell viability induced by SNP. However, a soluble guanylate cyclase inhibitor (ODQ) did not inhibited the decrement of cell viability induced by SNP. SNP increased cytochrome c release from the mitochondria to the cytosol and the ratio of Bax/Bcl-2 expression levels. Moreover, SNP-treated HDPCs elevated activities of caspase-3 and caspase-9. While pretreatment with inhibitors of caspase (z-VAD-fmk, z-DEVD-fmk) reversed the NO-induced apoptosis of HDPCs. From these results, it can be suggested that NO induces apoptosis of HDPCs through the mitochondria-dependent pathway mediated by ROS and Bcl-2 family, but not by the cyclic GMP pathway.
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- 2014
9. Twist1 Suppresses Cementoblast Differentiation
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Min-Seok Kim, Young-Jun Kim, Sun-Hun Kim, Seong-Duk Kim, Jung-Sun Moon, and Hyun-Mi Ko
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0301 basic medicine ,Bone sialoprotein ,animal structures ,Cementoblast ,cementoblast differentiation ,Article ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,Dentin sialophosphoprotein ,Osteopontin ,General Dentistry ,Transcription factor ,biology ,Chemistry ,OCCM-30 ,Mesenchymal stem cell ,030206 dentistry ,DMP1 ,Cell biology ,Cementogenesis ,lcsh:RK1-715 ,030104 developmental biology ,lcsh:Dentistry ,biology.protein ,Twist1 - Abstract
The transcription factor Twist1 is known to be closely associated with the formation of bone by mesenchymal stem cells and osteoblasts, however, the role of Twist1 in cementogenesis has not yet been determined. This study was undertaken to elucidate the roles of Twist1 in cementoblast differentiation by means of the gain- or loss-of-function method. We used alkaline phosphatase (ALP) and alizarin red S staining and quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) to determine whether the forced transient expression or knock-down of Twist1 in a mouse cementoblast cell line, OCCM-30, could affect cementogenic differentiation. Silencing Twist1 with small interference RNA (siRNA) enhanced the formation of mineralized tissue. The expression of several cementogenesis markers, such as bone sialoprotein (BSP), osteopontin (OPN), dentin matrix protein1 (DMP1), and dentin sialophosphoprotein (DSPP) mRNA, were upregulated. Transient Twist1 overexpression in OCCM-30 consistently suppressed mineralization capacity and downregulated the differentiation markers. These results suggest that the Twist1 transcription factor may play a role in regulating cementoblast differentiation.
- Published
- 2018
10. Effects of CoCl2 on Osteogenic Differentiation of Human Mesenchymal Stem Cells
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Jung Wan Son, Yeon Hee Moon, Min-Seok Kim, Sun Hun Kim, Jee Hae Kang, and Jung Sun Moon
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Bone sialoprotein ,biology ,Chemistry ,Growth factor ,medicine.medical_treatment ,Mesenchymal stem cell ,ALIZARIN RED ,equipment and supplies ,Cell biology ,Immunology ,Gene expression ,medicine ,biology.protein ,Viability assay ,Osteopontin ,Stem cell - Abstract
Objective. To investigate the effects of the hypoxia inducible factor-1 (HIF-1) activation–mimicking agent cobalt chloride (CoCl2) on the osteogenic differentiation of human mesenchy-mal stem cells (hMSCs) and elucidate the underlying mole-cular mechanisms. Study design. The dose and exposure periods for CoCl2 in hMSCs were optimized by cell viability assays. After confirmation of CoCl2-induced HIF-1α and vas-cular endothelial growth factor expression in these cells by RT-PCR, the effects of temporary preconditioning with CoCl2 on hMSC osteogenic differentiation were evaluated by RT- PCR analysis of osteogenic gene expression, an alkaline phos-phatase (ALP) activity assay and by alizarin red S staining. Results. Variable CoCl2 dosages (up to 500 µM) and exposure times (up to 7 days) on hMSC had little effect on hMSC survival. After CoCl2 treatment of hMSCs at 100 µM for 24 or 48 hours, followed by culture in osteogenic differentiating media, several osteogenic markers such as Runx-2, osteocal-cin and osteopontin, bone sialoprotein mRNA expression level were found to be up-regulated. Moreover, ALP acti-vity was increased in these treated cells in which an accele-rated osteogenic capacity was also verified by alizarin red S staining. Conclusions. The osteogenic differentiation poten-tial of hMSCs could be preserved and even enhanced by CoCl2 treatment.
- Published
- 2013
11. Focal adhesion linker proteins expression of fibroblast related to adhesion in response to different transmucosal abutment surfaces
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Mi-Kyeong Yoon, Yeon-Hee Moon, Min-Seok Kim, Jung-Sun Moon, Sun-Hun Kim, Hong-Seo Yang, and Jee-Hae Kang
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Biocompatibility ,medicine.diagnostic_test ,biology ,Chemistry ,Nanotechnology ,Adhesion ,Vinculin ,Focal adhesion linker proteins ,Transmucosal abutment ,Focal adhesion ,medicine.anatomical_structure ,Western blot ,medicine ,biology.protein ,Biophysics ,Dentistry (miscellaneous) ,Original Article ,Viability assay ,Oral Surgery ,Gingival fibroblast ,Fibroblast ,Paxillin - Abstract
PURPOSE. To evaluate adherence of human gingival fibroblasts (HGFs) to transmucosal abutment of dental implant with different surface conditions with time and to investigate the roles of focal adhesion linker proteins (FALPs) involved in HGFs adhesion to abutment surfaces. MATERIALS AND METHODS. Morphologies of cultured HGFs on titanium and ceramic discs with different surface were observed by scanning electron microscopy. Biocompatibility and focal adhesion were evaluated by ultrasonic wave application and cell viability assay. FALPs expression levels were assessed by RT-PCR and western blot. RESULTS. There seemed to be little difference in biocompatibility and adhesion strength of HGFs depending on the surface conditions and materials. In all experimental groups, the number of cells remaining on the disc surface after ultrasonic wave application increased more than 2 times at 3 days after seeding compared to 1-day cultured cells and this continued until 7 days of culture. FALPs expression levels, especially of vinculin and paxillin, also increased in 5-day cultured cells compared to 1-day cultured fibroblasts on the disc surface. CONCLUSION. These results might suggest that the strength of adhesion of fibroblasts to transmucosal abutment surfaces increases with time and it seemed to be related to expressions of FALPs. [J Adv Prosthodont 2013;5:341-50]
- Published
- 2013
12. Effect of Nifedipine on the Differentiation of Human Dental Pulp Cells Cultured with Mineral Trioxide Aggregate
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Sun-Hun Kim, Su-Mi Woo, Hoi-Soon Lim, Seon-Mi Kim, Ji-Yeon Jung, Nam-Ki Choi, Won-Jae Kim, and Yun-Chan Hwang
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Adult ,Mineral trioxide aggregate ,MAPK/ERK pathway ,Materials science ,Nifedipine ,Pyridines ,Sialoglycoproteins ,p38 mitogen-activated protein kinases ,Cell Culture Techniques ,chemistry.chemical_element ,Calcium ,p38 Mitogen-Activated Protein Kinases ,Root Canal Filling Materials ,stomatognathic system ,Nitriles ,Butadienes ,Humans ,Aluminum Compounds ,Extracellular Signal-Regulated MAP Kinases ,Protein kinase A ,General Dentistry ,Cells, Cultured ,Dental Pulp ,Cell Proliferation ,Anthracenes ,Extracellular Matrix Proteins ,Odontoblasts ,biology ,Kinase ,Silicates ,Imidazoles ,JNK Mitogen-Activated Protein Kinases ,Cell Differentiation ,Oxides ,Anatomy ,Calcium Compounds ,Calcium Channel Blockers ,Phosphoproteins ,Culture Media ,Cell biology ,Drug Combinations ,chemistry ,Cell culture ,Mitogen-activated protein kinase ,biology.protein ,Mitogen-Activated Protein Kinases ,Tooth Calcification - Abstract
Introduction Mineral trioxide aggregate (MTA) can induce differentiation of the dental pulp cells into odontoblast-like cells and generate a dentin-like mineral structure. The mechanisms underlying MTA-induced odontoblastic differentiation in human dental pulp cells (HDPCs) are not completely understood. The purpose of this study was to evaluate the effect of nifedipine as calcium channel blocker on MTA-induced odontoblastic differentiation in HDPCs. Methods HDPCs extracted from maxillary supernumerary incisors and third molars were directly cultured on MTA with or without nifedipine in the culture medium. Cell growth and expression of odontoblastic differentiation markers were determined by using methyl-thiazol-diphenyl-tetrazolium assay and reverse transcription–polymerase chain reaction analysis, respectively. Phosphorylation of mitogen-activated protein kinase was measured by Western blotting, and calcium deposition was assessed by using alizarin red S staining. Results MTA at a concentration of 1 mg/mL significantly up-regulated the expression of dentin sialophosphoprotein and dentin matrix protein-1 and enhanced mineralized nodule formation. However, nifedipine attenuated the MTA-induced odontoblastic differentiation in HDPCs. In addition, MTA-induced mineralization was blocked by inhibition of extracellular signal-regulated kinase (ERK), p38, and Jun N-terminal kinase (JNK) by using U0126, SB203580, and SP600125, respectively. Furthermore, phosphorylation of ERK and JNK in response to MTA was inhibited when the medium was supplemented with nifedipine. Conclusions This study showed that calcium ions released from MTA play an important role in odontoblastic differentiation of HDPCs via modulation of ERK and JNK activation.
- Published
- 2013
13. p38 MAP kinase and ERK play an important role in nitric oxide-induced apoptosis of the mouse embryonic stem cells
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Ji-Yeon Jung, Sang-Won Lee, Won-Jae Kim, Seong-Ho Choi, Sun-Hun Kim, and Jin-Ha Lee
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Nitroprusside ,MAPK/ERK pathway ,animal structures ,Cell Survival ,Pyridines ,p38 mitogen-activated protein kinases ,Apoptosis ,Biology ,Mitogen-activated protein kinase kinase ,Nitric Oxide ,Toxicology ,Mice ,Animals ,Nitric Oxide Donors ,ASK1 ,Protein Kinase Inhibitors ,Embryonic Stem Cells ,bcl-2-Associated X Protein ,MAP kinase kinase kinase ,Kinase ,Imidazoles ,General Medicine ,Molecular biology ,Cell biology ,Caspases ,Mitogen-activated protein kinase ,biology.protein ,Mitogen-Activated Protein Kinases ,Reactive Oxygen Species - Abstract
Previous study showed that nitric oxide (NO) induces apoptosis in mouse embryonic stem (mES) cells, but the precise mechanism governing NO-induced apoptosis in mES remains unclear. This study investigated the mechanism of NO-induced apoptosis of mES cells via MAP kinase signaling pathway. Sodium nitroprusside (SNP), a NO donor, induced apoptosis in mES cells with enhanced production of reactive oxygen species (ROS). In addition, treatment with SNP induced the activation of caspase-3, -8 and -9 as well as mitogen-activated protein (MAP) kinases (JNK, p38 MAP kinase and ERK). However, pretreatment with the p38 MAP kinase inhibitor SB203580 and ERK inhibitor U0126 attenuated NO-induced cell toxicity, ROS production, and caspase-3 activation. Moreover, SB203580 inhibited the translocation of Bax from the cytosol to the mitochondria. Taken together, these results suggest that NO-induced apoptosis in mES cells was mediated through p38 MAP kinase/ERK signaling pathway by triggering caspases activation and Bax translocation from the cytosol to the mitochondria.
- Published
- 2013
14. Epigallocatechin gallate protects against nitric oxide-induced apoptosis via scavenging ROS and modulating the Bcl-2 family in human dental pulp cells
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Won Jae Kim, Ji Yeon Jung, Sun Hun Kim, Yeon Jin Jeong, and Sam Young Park
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Nitroprusside ,Cell Survival ,Apoptosis ,Pharmacology ,Epigallocatechin gallate ,Nitric Oxide ,Toxicology ,Catechin ,Nitric oxide ,chemistry.chemical_compound ,Humans ,Nitric Oxide Donors ,Viability assay ,Cells, Cultured ,Dental Pulp ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Chemistry ,Cytochrome c ,Bcl-2 family ,food and beverages ,Free Radical Scavengers ,Proto-Oncogene Proteins c-bcl-2 ,Multigene Family ,biology.protein ,Reactive Oxygen Species ,Intracellular - Abstract
Nitric oxide (NO) is produced by three different isoforms of the enzyme NO synthase (NOS). NOS isoforms are expressed in many cell types, including human dental pulp cells (HDPC). NO acts as an intracellular messenger at physiological levels although it can be cytotoxic at higher concentrations. Epigallocatechin gallate (EGCG), a major green tea polyphenol, has diverse pharmacological activities in cell growth and death. This study is aimed to investigate the apoptotic mechanism by NO and effects of EGCG on NO-induced apoptosis in HDPC. Sodium nitroprusside (SNP), an NO donor, decreased the cell viability of HDPC in a dose- and time-dependent manner. EGCG was administered for 1 hr before the SNP treatment, resulting in increased cell viability and reactive oxygen species (ROS) production inhibition. Expression of Bax, a pro-apoptotic Bcl-2 family, was upregulated, whereas expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated in SNP-treated HDPC. SNP augmented the release of cytochrome c from mitochondria into cytosol and enhanced caspase-9, and -3 activities, a marker of the apoptotic executing stage. EGCG ameliorated caspase-9 and -3 activities and cytochrome c release increased by SNP. These results suggest that EGCG has a protective effect against NO-induced apoptosis in HDPC by scavenging ROS and modulating the Bcl-2 family.
- Published
- 2013
15. Orphan Nuclear Receptor Chicken Ovalbumin Upstream Promoter-Transcription Factor II (COUP-TFII) Protein Negatively Regulates Bone Morphogenetic Protein 2-induced Osteoblast Differentiation through Suppressing Runt-related Gene 2 (Runx2) Activity
- Author
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Kkot Nim Lee, Sun Hun Kim, Hye Ju Son, Jeong Tae Koh, Eun Jung Kim, Won Gu Jang, Renny T. Franceschi, Sin Hye Oh, Xiao-kun Zhang, and Shee Eun Lee
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Pluripotent Stem Cells ,musculoskeletal diseases ,Cellular differentiation ,Chicken ovalbumin upstream promoter-transcription factor ,Core Binding Factor Alpha 1 Subunit ,Biochemistry ,Bone morphogenetic protein 2 ,Cell Line ,COUP Transcription Factor II ,Mice ,medicine ,Animals ,Humans ,Molecular Biology ,COUP-TFII ,Osteoblasts ,biology ,Cell Differentiation ,Mesenchymal Stem Cells ,Osteoblast ,Cell Biology ,Molecular biology ,RUNX2 ,Bone morphogenetic protein 7 ,medicine.anatomical_structure ,Gene Expression Regulation ,embryonic structures ,Osteocalcin ,biology.protein ,Matrix Metalloproteinase 2 ,Protein Binding - Abstract
Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) is an orphan nuclear receptor of the steroid-thyroid hormone receptor superfamily. COUP-TFII is widely expressed in multiple tissues and organs throughout embryonic development and has been shown to regulate cellular growth, differentiation, and organ development. However, the role of COUP-TFII in osteoblast differentiation has not been systematically evaluated. In the present study, COUP-TFII was strongly expressed in multipotential mesenchymal cells, and the endogenous expression level decreased during osteoblast differentiation. Overexpression of COUP-TFII inhibited bone morphogenetic protein 2 (BMP2)-induced osteoblastic gene expression. The results of alkaline phosphatase, Alizarin Red staining, and osteocalcin production assay showed that COUP-TFII overexpression blocks BMP2-induced osteoblast differentiation. In contrast, the down-regulation of COUP-TFII synergistically induced the expression of BMP2-induced osteoblastic genes and osteoblast differentiation. Furthermore, the immunoprecipitation assay showed that COUP-TFII and Runx2 physically interacted and COUP-TFII significantly impaired the Runx2-dependent activation of the osteocalcin promoter. From the ChIP assay, we found that COUP-TFII repressed DNA binding of Runx2 to the osteocalcin gene, whereas Runx2 inhibited COUP-TFII expression via direct binding to the COUP-TFII promoter. Taken together, these findings demonstrate that COUP-TFII negatively regulates osteoblast differentiation via interaction with Runx2, and during the differentiation state, BMP2-induced Runx2 represses COUP-TFII expression and promotes osteoblast differentiation.
- Published
- 2012
16. EGCG induces apoptosis in human laryngeal epidermoid carcinoma Hep2 cells via mitochondria with the release of apoptosis-inducing factor and endonuclease G
- Author
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Yeon-Jin Jeong, Sang-Won Lee, Doman Kim, Sun-Hun Kim, Sang-Jin Oh, Ji-Yeon Jung, Won-Jae Kim, Jin-Ha Lee, Hoi-Soon Lim, and Hee-Kyun Oh
- Subjects
Cancer Research ,Programmed cell death ,Blotting, Western ,ENDOG ,Biology ,Mitochondrion ,complex mixtures ,Catechin ,Cell Line, Tumor ,In Situ Nick-End Labeling ,Anticarcinogenic Agents ,Humans ,heterocyclic compounds ,Laryngeal Neoplasms ,Membrane Potential, Mitochondrial ,Endodeoxyribonucleases ,Cytochrome c ,Cell Cycle ,Apoptosis Inducing Factor ,food and beverages ,Cell cycle ,Immunohistochemistry ,Mitochondria ,Cell biology ,Protein Transport ,Proto-Oncogene Proteins c-bcl-2 ,Oncology ,Apoptosis ,Carcinoma, Squamous Cell ,biology.protein ,Apoptosis-inducing factor ,sense organs ,Tumor Suppressor Protein p53 ,Reactive Oxygen Species ,Intracellular - Abstract
(-)-Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol, was tested for in vitro cytotoxicity against human laryngeal epidermoid carcinoma of the larynx Hep2 cells. EGCG-induced apoptotic cell death accompanied by a change in the cell cycle. However, EGCG did not result in caspase activation, nor did a caspase inhibitor block cell death. Furthermore, EGCG caused no change in the intracellular levels of reactive oxygen species (ROS). The levels of p53 were increased in the EGCG-treated cells, with a corresponding decrease in Bcl-2 and Bid protein levels as well as an increase in the Bax level. In addition, EGCG induced the cytoplasmic release of cytochrome c from the mitochondria accompanied by a decreased mitochondrial membrane potential, and subsequently upregulated translocation of apoptosis-inducing factor (AIF) and endonuclease G (EndoG) into the nucleus during the apoptotic process. Taken together, these findings indicate that the p53-mediated mitochondrial pathway and the nuclear translocation of AIF and EndoG play a crucial role in EGCG-induced apoptosis of human laryngeal epidermoid carcinoma Hep2 cells, which proceeds through a caspase-independent pathway.
- Published
- 2010
17. COMP-Ang1, a chimeric form of Angiopoietin 1, enhances BMP2-induced osteoblast differentiation and bone formation
- Author
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Hyun Joo Kim, Gou Young Koh, Kyung-Keun Kim, Kkot-Nim Lee, Byung-Chul Jeong, Sun-Hun Kim, Shee-Eun Lee, In-Ho Bae, Won-Mann Oh, In-Chol Kang, Jeong-Tae Koh, and Kwang Youl Lee
- Subjects
Male ,Transcriptional Activation ,musculoskeletal diseases ,medicine.medical_specialty ,animal structures ,Histology ,Transcription, Genetic ,Physiology ,Recombinant Fusion Proteins ,Endocrinology, Diabetes and Metabolism ,Bone Morphogenetic Protein 2 ,Bone morphogenetic protein ,Bone morphogenetic protein 2 ,Cell Line ,Mice ,Calcification, Physiologic ,Osteogenesis ,Internal medicine ,Angiopoietin-1 ,medicine ,Animals ,Humans ,Phosphorylation ,Protein kinase B ,Endochondral ossification ,PI3K/AKT/mTOR pathway ,Osteoblasts ,biology ,Cell Differentiation ,Osteoblast ,Receptor, TIE-2 ,Angiopoietin receptor ,Extracellular Matrix ,Cell biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Endocrinology ,Gene Expression Regulation ,Osteocalcin ,biology.protein ,Signal Transduction - Abstract
Introduction Angiogenesis is closely associated with bone formation, especially endochondral ossification. Angiopoietin 1 (Ang1) is a specific growth factor functioning to generate a stable and matured vasculature through the Tie2 receptor/PI3K/AKT pathway. Recently cartilage oligomeric matrix protein (COMP)-Ang1, an Ang1 variant which is more potent than native Ang1 in phosphorylating Tie2 receptor and AKT, was developed. This study was designed to examine the effects of angiogenic COMP-Ang1 on BMP2-induced osteoblast differentiation and bone formation. Methods Expression of endogenous Ang-1 and its binding receptor Tie 2 mRNA was examined in osteoblast-like cells and primary mouse calvarial cells by RT-PCR analysis, and was also monitored during osteoblast differentiation induced by BMP-2 and/or ascorbic acid and β-glycerophosphate. Effects of COMP-Ang-1 on osteoblast differentiation and mineralization were evaluated by alkaline phosphatase (ALP) activity and osteocalcin (OC) production, and Alizarin red stain. For a molecular mechanism, Western blot and OG2 and 6xOSE promoter assays were done. For in vivo evaluation, adenoviral (Ad) vectors containing COMP-Ang-1 or BMP-2 gene were administered into thigh muscle of mice, and after 2 weeks bone formation was analyzed by micro-computed tomography and histology. Angiogenic event of COMP-Ang1 was confirmed by immunofluorescence analysis with anti-CD31 antibody. Results Expression of Tie2 receptor was significantly increased in the course of osteoblast differentiation. Treatment or overexpression of COMP-Ang1 enhanced BMP2-induced ALP activity, OC production, and mineral deposition in a dose-dependent manner. In addition, COMP-Ang1 synergistically increased OG2 and 6xOSE promoter activities of BMP2, and sustained p38, Smad and AKT phosphorylation of BMP2. Notably, in vivo intramuscular injection of COMP-Ang1 dose-dependently enhanced BMP2-induced ectopic bone formation with increases in CD31 reactivity. Conclusions These results suggest that COMP-Ang1 synergistically enhanced osteoblast differentiation and bone formation through potentiating BMP2 signaling pathways and angiogenesis. Combination of BMP2 and COMP-Ang1 should be clinically useful for therapeutic application to fracture and destructive bone diseases.
- Published
- 2010
18. The Orphan Nuclear Receptor Estrogen Receptor-related Receptor γ Negatively Regulates BMP2-induced Osteoblast Differentiation and Bone Formation
- Author
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Yong-Soo Lee, Sun Hun Kim, Seung Hoi Koo, Hueng Sik Choi, Byung Chul Jeong, Renny T. Franceschi, Yun Yong Park, Hong Ran Choi, Don Kyu Kim, Jeong Tae Koh, and In-Ho Bae
- Subjects
Transcriptional Activation ,musculoskeletal diseases ,Bone sialoprotein ,medicine.medical_specialty ,Cellular differentiation ,Bone Morphogenetic Protein 2 ,Down-Regulation ,Core Binding Factor Alpha 1 Subunit ,Biology ,Biochemistry ,Bone morphogenetic protein 2 ,Cell Line ,Mice ,Calcification, Physiologic ,Osteogenesis ,Internal medicine ,medicine ,Animals ,Humans ,Transcription, Chromatin, and Epigenetics ,Molecular Biology ,Osteoblasts ,Gene Expression Profiling ,Stem Cells ,Cell Differentiation ,Osteoblast ,Cell Biology ,Cell biology ,RUNX2 ,medicine.anatomical_structure ,Endocrinology ,Receptors, Estrogen ,Nuclear receptor ,Organ Specificity ,embryonic structures ,Osteocalcin ,biology.protein ,Estrogen-related receptor gamma ,E1A-Associated p300 Protein ,Protein Binding - Abstract
Estrogen receptor-related receptor gamma (ERRgamma/ERR3/NR3B3) is a member of the orphan nuclear receptor with important functions in development and homeostasis. Recently it has been reported that ERRalpha is involved in osteoblast differentiation and bone formation. In the present study we examined the role of ERRgamma in osteoblast differentiation. Here, we showed that ERRgamma is expressed in osteoblast progenitors and primary osteoblasts, and its expression is increased temporarily by BMP2. Overexpression of ERRgamma reduced BMP2-induced alkaline phosphatase activity and osteocalcin production as well as calcified nodule formation, whereas inhibition of ERRgamma expression significantly enhanced BMP2-induced osteogenic differentiation and mineralization, suggesting that endogenous ERRgamma plays an important role in osteoblast differentiation. In addition, ERRgamma significantly repressed Runx2 transactivity on osteocalcin and bone sialoprotein promoters. We also observed that ERRgamma physically interacts with Runx2 in vitro and in vivo and competes with p300 to repress Runx2 transactivity. Notably, intramuscular injection of ERRgamma strongly inhibited BMP2-induced ectopic bone formation in a dose-dependent manner. Taken together, these results suggest that ERRgamma is a novel negative regulator of osteoblast differentiation and bone formation via its regulation of Runx2 transactivity.
- Published
- 2009
19. Estradiol protects PC12 cells against CoCl2-induced apoptosis
- Author
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Sun Hun Kim, Min-Seok Kim, Won Jae Kim, Won Mann Oh, Yeon Jin Jeong, Kwang Hoon Roh, Hee Kyun Oh, Ji Yeon Jung, and Eun Ju Lee
- Subjects
Programmed cell death ,Fas Ligand Protein ,Blotting, Western ,Apoptosis ,DNA Fragmentation ,PC12 Cells ,Animals ,fas Receptor ,Protein kinase B ,Caspase ,PI3K/AKT/mTOR pathway ,bcl-2-Associated X Protein ,Electrophoresis, Agar Gel ,Caspase 8 ,Estradiol ,biology ,Caspase 3 ,Reverse Transcriptase Polymerase Chain Reaction ,General Neuroscience ,Cytochrome c ,Bcl-2 family ,Cytochromes c ,Estrogens ,Cobalt ,Molecular biology ,Caspase 9 ,Mitochondria ,Rats ,Enzyme Activation ,Proto-Oncogene Proteins c-bcl-2 ,biology.protein ,Signal transduction ,Reactive Oxygen Species ,Proto-Oncogene Proteins c-akt - Abstract
In hypoxic/ischemic conditions, neuronal apoptotic events are occurred, resulting in neuronal diseases. Estradiol is a female sex hormone with steroid structure known to provide neuroprotection through multiple mechanisms in the central nervous system. This study was aimed to investigate the signal transduction pathway leading to the inhibitory effects of estradiol against cobalt chloride (CoCl 2 )-mediated hypoxic death in PC12 cells. Estradiol inhibits CoCl 2 -induced cell death with genomic DNA fragmentation and morphologic changes such as cell shrinkage and condensed nuclei. Pre-incubation of estradiol prior to CoCl 2 treatment attenuated CoCl 2 -mediated the reactive oxygen species (ROS) production and limited the activities of the caspase cascades, such as caspase-8, -9 and -3. Furthermore, estradiol downregulated the Bax:Bcl-2 ratio and decreased the release of cytochrome c from the mitochondria into the cytosol in CoCl 2 -treated cells, indicating that estradiol affect on mitochondrial pathway. Estradiol attenuated also CoCl 2 -induced upregulation of Fas-ligand (Fas-L) and truncated of Bid in sequence of death receptor-mediated pathway. In addition, estradiol increased the phosphorylation of Akt in CoCl 2 -treated cells, demonstrating that estradiol has no affect on upstream signaling through the PI3K/Akt in inhibition of CoCl 2 -induced apoptosis in PC12 cells. Taken together, estradiol was found to have a neuroprotective effect against CoCl 2 -induced apoptosis of PC12 cells by the attenuating ROS production and the modulating apoptotic signal pathway through Bcl-2 family, cytochrome c , Fas/Fas-L as well as PI3K/Akt pathway.
- Published
- 2008
20. Involvement of both mitochondrial- and death receptor-dependent apoptotic pathways regulated by Bcl-2 family in sodium fluoride-induced apoptosis of the human gingival fibroblasts
- Author
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Yeon-Jin Jeong, Nam-Ki Choi, Jin-Ha Lee, Jae-Hong Park, Won-Jae Kim, Kyu-Ho Yang, Ji-Yeon Jung, and Sun-Hun Kim
- Subjects
inorganic chemicals ,Programmed cell death ,Fas Ligand Protein ,Time Factors ,Voltage-dependent anion channel ,Cell Survival ,Poly ADP ribose polymerase ,Blotting, Western ,Gingiva ,Poly (ADP-Ribose) Polymerase-1 ,Apoptosis ,DNA Fragmentation ,Toxicology ,chemistry.chemical_compound ,Sodium fluoride ,Humans ,Viability assay ,Cells, Cultured ,bcl-2-Associated X Protein ,Dose-Response Relationship, Drug ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Cytochrome c ,Bcl-2 family ,technology, industry, and agriculture ,Cytochromes c ,Receptors, Death Domain ,Fibroblasts ,Molecular biology ,Chromatin ,Mitochondria ,body regions ,Proto-Oncogene Proteins c-bcl-2 ,chemistry ,Caspases ,biology.protein ,Sodium Fluoride ,bcl-Associated Death Protein ,Poly(ADP-ribose) Polymerases ,Reactive Oxygen Species - Abstract
Sodium fluoride (NaF) has been shown to be cytotoxic and produces inflammatory responses in humans. However, the cellular mechanisms underlying the NaF-induced cytotoxicity in periodontal tissues are unclear. This study examined whether or not NaF induces apoptosis in human gingival fibroblasts (HGF), and its underlying mechanisms by monitoring various apoptosis-associated processes. NaF reduced the cell viability of HGF in a dose- and time-dependent manner. NaF increased TUNEL-positive cell and induced apoptosis with concomitant chromatin condensation and DNA fragmentation in HGF. In addition, NaF increased the level of cytochrome c released from the mitochondria into the cytosol, enhanced the caspase-9, -8 and -3 activities, the cleavage of poly (ADP-ribose) polymerase (PARP), and up-regulated the voltage-dependent anion channel (VDAC) 1. However, NaF did not affect the production of reactive oxygen species (ROS) which is a strong apoptotic inducer. Furthermore, NaF up-regulated the Fas-ligand (Fas-L), a ligand of death receptor. Bcl-2, a member of the anti-apoptotic Bcl-2 family, was down-regulated, whereas the expression of Bax, a member of the pro-apoptotic Bcl-2 family, was unaffected in the NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both the mitochondria-mediated pathways regulated by the Bcl-2 family and death receptor-mediated pathway.
- Published
- 2008
21. Inhibition by epigallocatechin gallate of CoCl2-induced apoptosis in rat PC12 cells
- Author
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Nam-Ki Choi, Hyun-Jin Kim, Sun-Hun Kim, Yeon-Jin Jeong, Kyu-Ho Yang, Ji-Yeon Jung, Hyeon-Gyeong Yoo, Jin-Ha Lee, Hee-Kyun Oh, Won-Mann Oh, Won-Jae Kim, and Hyun-Chul Mo
- Subjects
Programmed cell death ,Blotting, Western ,Tetrazolium Salts ,Apoptosis ,DNA Fragmentation ,Epigallocatechin gallate ,Mitochondrion ,PC12 Cells ,complex mixtures ,Catechin ,General Biochemistry, Genetics and Molecular Biology ,Membrane Potentials ,chemistry.chemical_compound ,Animals ,General Pharmacology, Toxicology and Pharmaceutics ,Electrophoresis, Agar Gel ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Caspase 3 ,Cytochrome c ,Bcl-2 family ,food and beverages ,Cell Differentiation ,Cobalt ,General Medicine ,Flow Cytometry ,Molecular biology ,Caspase 9 ,Genes, bcl-2 ,Rats ,Thiazoles ,Neuroprotective Agents ,chemistry ,Hypoxia-Ischemia, Brain ,Mitochondrial Membranes ,biology.protein ,DNA fragmentation ,Reactive Oxygen Species - Abstract
Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea polyphenols. This study was aimed to investigate the possible mechanisms of EGCG-mediated inhibition against apoptosis in rat pheochromocytoma PC12 cells by exposure to CoCl(2). Exposure to CoCl(2) caused the generation of ROS and induced cell death with appearance of apoptotic morphology and DNA fragmentation. However, EGCG rescued the loss of viability in the cells exposed to CoCl(2) and led the reduction of DNA fragmentation and sub-G(1) fraction of cell cycle. Also, EGCG attenuated the CoCl(2)-induced disruption of mitochondrial membrane potential (DeltaPsim), release of cytochrome c from the mitochondria to cytosol and abolished the CoCl(2)-stimulated activities of the caspase cascades, caspase-9 and caspase-3. In addition, EGCG ameliorated the increase in the Bax to Bcl-2 ratio, a marker of apoptosis proceeding, induced by CoCl(2) treatment. Taken together, the present results suggest that EGCG inhibit the CoCl(2)-induced apoptosis of PC12 cells through the mitochondria-mediated apoptosis pathway involved in modulating the Bcl-2 family.
- Published
- 2007
22. Epigallocatechin gallate inhibits nitric oxide-induced apoptosis in rat PC12 cells
- Author
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Hoi Soon Lim, Chang Ryoung Han, Hyun-Jin Kim, Won Mann Oh, Won Jae Kim, Ki-Heon Lee, Yeon Jin Jeong, Ha Ok Park, Ji Yeon Jung, and Sun Hun Kim
- Subjects
Nitroprusside ,Programmed cell death ,Time Factors ,Voltage-dependent anion channel ,Blotting, Western ,Tetrazolium Salts ,Apoptosis ,Epigallocatechin gallate ,Nitric Oxide ,PC12 Cells ,complex mixtures ,Antioxidants ,Catechin ,chemistry.chemical_compound ,Animals ,Voltage-Dependent Anion Channels ,Drug Interactions ,Nitric Oxide Donors ,heterocyclic compounds ,Viability assay ,bcl-2-Associated X Protein ,chemistry.chemical_classification ,Reactive oxygen species ,Dose-Response Relationship, Drug ,biology ,General Neuroscience ,Cytochrome c ,Bcl-2 family ,Cytochromes c ,food and beverages ,Rats ,Cell biology ,Thiazoles ,Gene Expression Regulation ,Proto-Oncogene Proteins c-bcl-2 ,chemistry ,Biochemistry ,Caspases ,biology.protein ,sense organs ,Reactive Oxygen Species - Abstract
Nitric oxide (NO) is associated with many pathophysiology of the central nervous system including brain ischemia, neurodegeneration and inflammation. Epigallocatechin gallate (EGCG) is a major compound of green tea polyphenol that has shown the protective activity against neuronal diseases. This study examined the effect of EGCG on NO-induced cell death in PC12 cells. The administration of sodium nitroprusside (SNP), a NO donor, decreased the cell viability and induced apoptosis showing characterization such as cell shrinkage and chromatin condensation as well as subG1 fraction of cell cycles. EGCG inhibited the cytotoxicity and apoptotic morphogenic changes induced by SNP. EGCG attenuated the production of reactive oxygen species (ROS) by SNP, and ameliorated the SNP-induced Bax to Bcl-2 expression ratio leading to apoptosis. In addition, EGCG prevented the release of cytochrome c from the mitochondria into the cytosol as well as the upregulation of the voltage-dependent anion channel (VDAC), a cytochrome c releasing channel, in the mitochondria of SNP-treated cells. EGCG abrogated the activation of caspase-9, caspase-8 and caspase-3 induced by SNP. These results demonstrate that EGCG has a protective effect against SNP-induced apoptosis in PC12 cells by scavenging ROS and modulating the signal molecules associated with cytochrome c, caspases, VDAC and the Bcl-2 family. These findings suggest that EGCG might be a natural neuroprotective substance.
- Published
- 2007
23. Effects of Acupuncture on c-Fos Expression in Brain After Noxious Tooth Stimulation of the Rat
- Author
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Sang-Won Park, Won-Mann Oh, Won-Jae Kim, Yeon-Jin Jeong, Hye-Ryung Yang, Sun-Hun Kim, Ji-Yeon Jung, Mong-Sook Vang, Daehwan Youn, and Chang-Su Na
- Subjects
Male ,medicine.medical_specialty ,Narcotic Antagonists ,Acupuncture Therapy ,Blood Pressure ,Stimulation ,Zusanli ,c-Fos ,Supraoptic nucleus ,Potassium Chloride ,Rats, Sprague-Dawley ,Heart Rate ,Physical Stimulation ,Internal medicine ,medicine ,Acupuncture ,Animals ,Dental Pulp ,Neurons ,biology ,Naloxone ,business.industry ,Phenylethanolamine N-Methyltransferase ,Brain ,Nociceptors ,Toothache ,General Medicine ,Rostral ventrolateral medulla ,Stimulation, Chemical ,Rats ,Endocrinology ,Nociception ,nervous system ,Complementary and alternative medicine ,Needles ,Hypothalamus ,Anesthesia ,biology.protein ,business ,Acupuncture Points ,Proto-Oncogene Proteins c-fos - Abstract
Clinically, acupuncture therapy is useful for the control of acute or chronic pain. This study was designed to elucidate the antinociceptive mechanism of acupuncture and the mechanisms underlying cardiovascular reflex elicited by toothache. Expression of c-Fos, a neuronal activation marker, and the phenylethanalamine-N-methyltransferase (PNMT) were examined 1.5 hours after noxious intrapulpal tooth stimulation. Manual acupuncture was performed 20 min before noxious intrapulpal stimulation by 2 M KCl injection into upper or lower anterior tooth pulp. The acupuncture points were Li4 (Hegu) between the 1st and 2nd metacarpal bones or St36 (Zusanli) between the anterior crest of the tibial tuberosity and the fibula head below the patella. After noxious intrapulpal tooth stimulation, Fos-immunoreactive (IR) neurons were identified in the trigeminal subnucleus caudalis (Vc) and the transitional region between the subnucleus caudalis and the subnucleus interpolaris (Vi), in the inferior olivory nucleus (IO) connecting the cerebellum and other brain regions, and also the thalamic ventral posteromedial (VPM) nucleus and centrolateral (CL) nucleus, respectively. In addition, Fos-IR neurons were found in the central cardiovasuclar regulation centers, such as the hypothalamus supraoptic nucleus (SON) and paraventricular nucleus (PVN), and nucleus tractus solitarius (NTS) and rostral ventromedulla (RVLM). All acupuncture at St36 or Li4 significantly suppressed Fos-IR neurons in all Fos-expressed brain areas except the IO nucleus and attenuated the increases in arterial blood pressure (BP) and heart rate (HR) after noxious intrapulpal stimulation. Its Fos-suppressive effects were mostly blocked by naloxone, an opioid antagonist. In addition, acupuncture at St36 or Li4 significantly decreased Fos-containing PNMT, and this effect was also reversed by naloxone. These results suggest that: 1) tooth pulpal noxious signals transmit to the Vc and Vc/Vi transitional region and the 2nd afferent neuron synapse in the thalamic VPM and CL, 2) tooth pulpal pain elicits cardiovascular reflex mediated by NTS, VLM, hypothalamic SON and PVN, and 3) acupuncture reduces cardiovascular reflex elicited by toothache, is associated with the adrenergic system.
- Published
- 2006
24. NAMPT enzyme activity regulates catabolic gene expression in gingival fibroblasts during periodontitis
- Author
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Min-Suk Kook, Sun Hun Kim, Gyuseok Lee, Yunkyung Hong, Je-Hwang Ryu, Jeong Tae Koh, Duck Kyu Kim, Yun Hyun Huh, Jang-Soo Chun, Su Hyeon Lee, Shee Eun Lee, and Ka Hyon Park
- Subjects
0301 basic medicine ,MMP3 ,Interleukin-1beta ,Clinical Biochemistry ,Alveolar Bone Loss ,Gingiva ,Nicotinamide phosphoribosyltransferase ,Gene Expression ,Biochemistry ,Piperazines ,Mice ,chemistry.chemical_compound ,Sirtuin 2 ,0302 clinical medicine ,Nicotinamide Phosphoribosyltransferase ,Regulation of gene expression ,biology ,Sirtuin ,Cytokines ,Molecular Medicine ,Original Article ,Female ,Matrix Metalloproteinase 3 ,Matrix Metalloproteinase 1 ,medicine.symptom ,Adult ,Niacinamide ,medicine.medical_specialty ,Morpholines ,Primary Cell Culture ,Inflammation ,SIRT2 ,Proinflammatory cytokine ,03 medical and health sciences ,Adipokines ,Internal medicine ,medicine ,Animals ,Humans ,Periodontitis ,Molecular Biology ,030206 dentistry ,Fibroblasts ,medicine.disease ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Endocrinology ,Gene Expression Regulation ,chemistry ,Cyclooxygenase 2 ,biology.protein - Abstract
Periodontal disease is one of the most prevalent chronic disorders worldwide. It is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss. Here, we focused on the role of adipokines, which are locally expressed by periodontal tissues, in the regulation of catabolic gene expression leading to periodontal inflammation. The expression of the nicotinamide phosphoribosyltransferase (NAMPT) adipokine was dramatically increased in inflamed human and mouse gingival tissues. NAMPT expression was also increased in lipopolysaccharide- and proinflammatory cytokine-stimulated primary cultured human gingival fibroblasts (GF). Adenovirus-mediated NAMPT (Ad-Nampt) overexpression upregulated the expression and activity of COX-2, MMP1 and MMP3 in human GF. The upregulation of IL-1β- or Ad-Nampt-induced catabolic factors was significantly abrogated by the intracellular NAMPT (iNAMPT) inhibitor, FK866 or by the sirtuin (SIRT) inhibitor, nicotinamide (NIC). Recombinant NAMPT protein or extracellular NAMPT (eNAMPT) inhibition using a blocking antibody did not alter NAMPT target gene expression levels. Moreover, intragingival Ad-Nampt injection mediated periodontitis-like phenotypes including alveolar bone loss in mice. SIRT2, a part of the SIRT family, was positively associated with NAMPT actions in human GF. Furthermore, in vivo inhibition of the NAMPT-NAD+-SIRT axis by NIC injection in mice ameliorated the periodontal inflammation and alveolar bone erosion caused by intragingival injection of Ad-Nampt. Our findings indicate that NAMPT is highly upregulated in human GF, while its enzymatic activity acts as a crucial mediator of periodontal inflammation and alveolar bone destruction via regulation of COX-2, MMP1, and MMP3 levels.
- Published
- 2017
25. Ginsenosides Have a Suppressive Effect on c-Fos Expression in Brain and Reduce Cardiovascular Responses Increased by Noxious Stimulation to the Rat Tooth
- Author
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In-Ohk Moon, Sun-Hun Kim, Kyung-Joo Seong, Won-Jae Kim, Jin-Hyoung Cho, and Ji-Yeon Jung
- Subjects
medicine.medical_specialty ,Ginsenosides ,Physiology ,Stimulation ,Cardiovascular ,c-Fos ,Supraoptic nucleus ,Antinociception ,stomatognathic system ,Internal medicine ,Noxious stimulus ,Medicine ,Pharmacology ,biology ,business.industry ,Toothache ,Rostral ventrolateral medulla ,Anatomy ,Ventral posteromedial nucleus ,stomatognathic diseases ,Nociception ,medicine.anatomical_structure ,Endocrinology ,nervous system ,biology.protein ,Original Article ,business ,Nucleus - Abstract
The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth.
- Published
- 2012
26. Metformin induces osteoblast differentiation via orphan nuclear receptor SHP-mediated transactivation of Runx2
- Author
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Chul-Ho Lee, Hueng Sik Choi, Kkot Nim Lee, Yong Deuk Kim, In-Ho Bae, Renny T. Franceschi, Don Kyu Kim, Jeong Tae Koh, Eun Jung Kim, Won Gu Jang, and Sun Hun Kim
- Subjects
musculoskeletal diseases ,Transcriptional Activation ,Chromatin Immunoprecipitation ,animal structures ,Histology ,endocrine system diseases ,Physiology ,Endocrinology, Diabetes and Metabolism ,Cellular differentiation ,Core Binding Factor Alpha 1 Subunit ,Biology ,Polymerase Chain Reaction ,Transactivation ,Mice ,medicine ,Animals ,Hypoglycemic Agents ,Mice, Knockout ,Osteoblasts ,Reverse Transcriptase Polymerase Chain Reaction ,nutritional and metabolic diseases ,AMPK ,Osteoblast ,Cell Differentiation ,Molecular biology ,Metformin ,RUNX2 ,medicine.anatomical_structure ,embryonic structures ,Osteocalcin ,biology.protein ,Small heterodimer partner ,medicine.drug - Abstract
Metformin is an oral anti-diabetic drug of the biguanide class that is commonly used to treat type 2 diabetes mellitus. This study examined the molecular mechanism for the action of metformin on osteoblast differentiation. Metformin-induced mRNA expression of the osteogenic genes and small heterodimer partner (SHP) in MC3T3E1 cells were determined by RT-PCR and real-time PCR. Metformin increased significantly the expression of the key osteogenic genes, such as alkaline phosphatase (ALP), osteocalcin (OC) and bone sialoprotein (BSP) as well as SHP. Transient transfection assays were performed in MC3T3E1 cells to confirm the effects of metformin on SHP, OC and Runx2 promoter activities. Metformin increased the transcription of the SHP and OC genes, and the metformin effect was inhibited by dominant negative form of AMPK (DN-AMPK) or compound C (an inhibitor of AMPK). The adenoviral overexpression of SHP increased significantly the level of ALP staining and OC production. However, metformin did not have any significant effect on osteogenic gene expression, ALP staining and activity, and OC production in SHP null (SHP-/-) primary calvarial cells. Moreover, upstream stimulatory factor-1 (USF-1) specifically mediated metformin-induced SHP gene expression. In addition, metformin-induced AMPK activation increased the level of Runx2 mRNA and protein. However, USF-1 and SHP were not involved in metformin-induced Runx2 expression. Transient transfection and chromatin immunoprecipitation assays confirmed that metformin-induced SHP interacts physically and forms a complex with Runx2 on the osteocalcin gene promoter in MC3T3E1 cells. These results suggest that metformin may stimulate osteoblast differentiation through the transactivation of Runx2 via AMPK/USF-1/SHP regulatory cascade in mouse calvaria-derived cells.
- Published
- 2010
27. Myelin basic protein is temporospatially expressed in developing rat molars
- Author
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Sun-Hun Kim, Nam-Ki Choi, Young-Ju Kim, Won-Man Oh, Hyun-Jin Kim, In-Nam Hwang, Won-Jae Kim, Eun Ju Lee, Jee-Hae Kang, Yun-Chan Hwang, Ji-Yeon Jung, and Min-Seok Kim
- Subjects
Molar ,Fluorescent Antibody Technique ,Rats, Sprague-Dawley ,Nerve Fibers ,stomatognathic system ,Ameloblasts ,Animals ,Dental papilla ,General Dentistry ,Messenger RNA ,Enamel paint ,biology ,Odontoblasts ,Reverse Transcriptase Polymerase Chain Reaction ,Gene Expression Regulation, Developmental ,Tooth Germ ,Myelin Basic Protein ,Molecular biology ,Myelin basic protein ,Rats ,Blot ,Molecular Weight ,stomatognathic diseases ,Odontoblast ,visual_art ,Immunology ,visual_art.visual_art_medium ,biology.protein ,Odontogenesis ,Ameloblast - Abstract
Tooth development occurs through a complex and intricate set of gene-expression cascades. Although its early events have been examined extensively, there are fewer reports on the late events, such as dental hard-tissue formation. This study searched for genes involved in the late stages of tooth development. Differential display-polymerase chain reaction revealed myelin basic protein (MBP) mRNA to be expressed differentially in the second molar root stage germs compared with the third molar cap/early bell stage germs. The MBP expressed during hard tissue formation was confirmed to be a 21.5 kDa molecule by Western blotting. Immunoreactivity of MBP in the third molar (cap/early bell stage) germs was barely detectable in the dental papilla and inner enamel epithelia, whereas strong reactivity was noted in the differentiating and differentiated ameloblasts and odontoblasts in a temporospatial pattern. However, after complete formation of the full-thickness enamel, no reactivity was observed in the maturation-stage and protection stage ameloblasts. Myelin basic protein immunoreactive nerve fibers were also observed near the developing molar germs. This is the first report showing the presence of MBP in dental hard tissue cells, and its functional implications should be studied further.
- Published
- 2008
28. Bcl-2 Family and Caspases are Involved in CoCl2-Induced Apoptosis of PC12 Cells
- Author
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Hee Ju Park, Won Jae Kim, Ji Yeon Jung, and Sun Hun Kim
- Subjects
biology ,Apoptosis ,Intrinsic apoptosis ,Bcl-2 family ,biology.protein ,DNA fragmentation ,Apoptotic signaling pathway ,DNA laddering ,Fragmentation (cell biology) ,Molecular biology ,Caspase ,Cell biology - Abstract
Hypoxic/ischemic condition induces the neuronal apoptotic events, consequently resulting in neuronal damages. Cobalt chloride (CoCl₂) could mimic the hypoxic condition including the production of reactive oxygen species (ROS). This study aimed to investigate the roles of Bcl-2 family and caspases as central regulators of apoptosis, in CoCl₂-induced apoptosis of PC12 cells. Cell viability was determined by MTT assay and DNA fragmentation was detected by DNA laddering. The expression levels of Bcl-2, Bax, Bid, cytochrome c and Fas/APO-1 were determined by RT-PCR or Western blotting analysis in CoCl₂-treated PC12 cells. Caspase-9 and caspase-3 activities were assessed using spectrophotometry and caspase-8 activity was measured with fluorospectrocytometry. Administration of CoCl₂ decreased viability of cells in a dose- and time-dependent manner. Furthermore, fragmentation of the genomic DNA and apoptotic bodies were induced in CoCl₂-treated PC12 cells. Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas Bax, pro-apoptotic molecule, was upregulated in CoCl₂-treated cells. Treatment of CoCl₂ augumented the release of cytochrome c into the cytoplasm and increase of caspase-8, -9, and -3 activities. In addition, CoCl₂ upregulated Fas and downregulated pro-Bid, which are known to be correlated with death receptor-mediated apoptotic signaling pathway. Therefore, these results suggest that Bcl-2 family and caspase play crucial roles in CoCl₂-induced apoptosis through mitochondria- and death receptor-dependent pathways in PC12 cells.
- Published
- 2006
29. Expression of RANKL and OPG in the Developing Teeth of the Postnatal Rat
- Author
-
Hyun Jin Kim, Min Seok Kim, Sun Hun Kim, and Il Sup Kim
- Subjects
Andrology ,biology ,business.industry ,RANKL ,biology.protein ,Dentistry ,Medicine ,business ,Developing Teeth - Published
- 2005
30. Inhibition of Amyloid beta Peptide-induced Neuronal Cytotoxicity by EGCG
- Author
-
Eun Cheol Kim, Won Jae Kim, Hyun-Jin Kim, Sun Hun Kim, Min-Seok Kim, Ji Yeon Jung, and Eun Ju Lee
- Subjects
chemistry.chemical_classification ,chemistry ,biology ,Amyloid beta ,P3 peptide ,biology.protein ,Peptide ,Cytotoxicity ,Molecular biology ,Amyloid β peptide - Published
- 2005
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