• 대한약리학회지
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• 제30권2호
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• pp.167-179
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• 1994

Recent evidence indicates that glial cells have a wide range of funtions which are critical for maintaining a balanced homeostatic environment in the central nervous system(CNS) peripheral nervous system(PNS). Morever, astrocytes are known to participate in the tissue repair and neuroimmunologic events within the CNS through many kinds of growth factors and cytokines. We investigated the effect of $TGF\;{\beta}_1$, on the growth and biochemical changes of rat glial cells in culture. The proliferative effect was determined by $^3H-thymidine$ uptake and the double immunostain with anti-cell-specific marker and anti-Bromodeoxyuridine(BrdU) antibody. To check the effect of biochemical changes we compared the amounts of glial fibrillar acidic protein(GFAP) and the activity of glutamine synthetase(GS) in astrocyte. And the amounts of myelin basic protein and the activity of 2',3'-cyclic nucleotide phosphohydrolase(CNPase) were measured in oligodendrocyte and the amounts of peripheral myelin in Schwann cell. When $TGF\;{\beta}_1$, was treated for 2 days with cultured glial cell, $TGF\;{\beta}_1$, decreased the $^3H-thymidine$ uptake and proliferation index of double immunostain of astrocytes, which indicates the inhibition of astroglial DNA synthesis, but stimulated the growth of Schwann cell. Also, $TGF\;{\beta}_1$, decrease the GS activity and increased the amounts of GFAP in astrocyte. In the case of Schwann cells the amounts of peripheral myelin was increased when treated with $TGF\;{\beta}_1$. However, $TGF\;{\beta}_1$, didn't show any effect on the proliferation and biochemical changes in oligodendrocyte. These results suggest that $TGF\;{\beta}_1$, might have a critical action in the regulation of proliferation and biochemical changes in glial cells, especially astrocyte.

• Journal of Radiation Protection and Research
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• 제34권1호
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• pp.15-24
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• 2009

The effect of low doses of ultraviolet (UV) irradiation on morphology changes of cell has been studied based on the observation of the cell length. It was shown that UV-irradiated cell has different behavior in comparison with non-irradiated cell. From the histogram of cell-length distribution, it was confirmed that cell cycle of non irradiated cell was 28 hours, and that cell cycle of irradiated cell with dose of $20\;Jm^{-2}$ was delayed (39 hours), while irradiated cell with $40\;Jm^{-2}$ and $60\;Jm^{-2}$ did not divide and kept growing continuously. It was supposed that in case of $20\;Jm^{-2}$ of irradiation dose, the cell cycle was delayed because the checkpoint worked in order to repair DNA damage induced by generation of pyrimidine dimer, reactive oxygen species and so on. It was also supposed that in case of $40\;Jm^{-2}$ and $60\;Jm^{-2}$ of irradiation dose, overgrowth was induced because the checkpoint was not worked well. The morphology of overgrown cell was similar to that of normally senescent cell. Therefore, it was considered that cell senescence was accelerated by UV irradiation with irradiation doses of $40\;Jm^{-2}$ and $60\;Jm^{-2}$.

• BMB Reports
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• 제44권8호
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• pp.529-534
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• 2011

Ribosomal protein S3 (rpS3) is a multifunctional protein involved in translation, DNA repair, and apoptosis. The relationship between rpS3 and cyclin-dependent kinases (Cdks) involved in cell cycle regulation is not yet known. Here, we show that rpS3 is phosphorylated by Cdk1 in G2/M phase. Co-immunoprecipitation and GST pull-down assays revealed that Cdk1 interacted with rpS3. An in vitro kinase assay showed that Cdk1 phosphorylated rpS3 protein. Phosphorylation of rpS3 increased in nocodazole-arrested mitotic cells; however, treatment with Cdk1 inhibitor or Cdk1 siRNA significantly attenuated this phosphorylation event. The phosphorylation of a mutant form of rpS3, T221A, was significantly reduced compared with wild-type rpS3. Decreased phosphorylation and nuclear accumulation of T221A was much more pronounced in G2/M phase. These results suggest that the phosphorylation of rpS3 by Cdk1 occurs at Thr221 during G2/M phase and, moreover, that this event is important for nuclear accumulation of rpS3.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.187-199
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• 1999

Bone remodeling is characterized by the continuing processes of osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Bone metabolism is tightly regulated at the local level by networks of hormones, cytokines, and other factors. In pathological conditions of bone remodeling, including osteoporosis and periodontal diseases, inflammatory cytokines and local mediators are responsible for enhancement of osteoclast resorption and inhibition of repair at the sites of bone resorption. TNF-${\alpha}$ is a pleiotropic hormone with actions on the differentiation, growth, and functional activities of normal and malignant cells from numerous tissues. TNF-${\alpha}$ has been proposed as a local mediator of the control of bone turnover in situations of chronic inflammation, and it has been assumed that the local source of TNF-${\alpha}$ is the monocyte in the adjacent bone marrow or the local circulation. TNF-${\alpha}$ is a potent inducer of bone resorption. TNF-${\alpha}$ is known to induce the activation of apoptotic signaling pathway, which leads to the apoptosis of bone cells. We demonstrated that treatment of murine osteoblastic MC3T3E1 cells with TNF-${\alpha}$ decreases proliferation as well as alkaline phosphatase (ALP) activity in a dose depenent manner. In addition, TNF-${\alpha}$ increases osteoclast-like cell formation in $1{\alpha}$, 25(OH)2D3 or PGE2-treated bone marrow cell culture. When cells were cultured in TNF-${\alpha}$ free ${\alpha}$-MEM, this inhibitory effect of ALP activity was reversible up to 10 ng/ml TNF-${\alpha}$, in contrast, at the 20 ng/ml TNF-${\alpha}$, irreversible. In this concentration, TNF-${\alpha}$ may induce apoptosis in MC3T3E1 cells. In this study, TNF-${\alpha}$ induces apoptosis resulting in chromosomal DNA fragmentation, preceded by JNK/SAPKs and caspase-3 activation. Our present results show that JNK/SAPKs and caspase-3 are activated by TNF-${\alpha}$, suggesting that the JNK/SAPKs and caspase-3 participate in the bone resorption, associated with apoptosis.

• 대한한의학회지
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• 제25권2호
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• pp.138-150
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• 2004

Objectives : Alzheimer's disease (AD) is a geriatric dementia that is widespread in old age. In the near future AD will be the biggest problem in public health service. Although a variety of oriental prescriptions, including Sesim-tang, have been traditionally utilized for the treatment of AD, their pharmacological effects and action mechanisms have not yet been fully elucidated. The present study investigated the effects of Sesim-tang on apoptotic cell death induced by CT105 (carboxy terminal 105 amino acid peptide fragment of APP) overexpression in SK-N-SH neuroblastoma cell lines. Methods: We studied the regenerative and inhibitory effects on Alzheimer's disease in CT105-induced SK-N-SH cell lines by Sesim-tang water extract. We examined for cell morphological pattern, DNA fragmentation, LDH activity assay, zymography assay, and immunohistochemistric analysis. Additionally, we investigated the association between the CT105 and neurite degeneration caused by CT105-induced apoptotic response in neurone cells. Results: Findings from our experiments have shown that Sesim-tang inhibits the synthesis or activities of CT105, which has neurotoxicities and apoptotic activities in the cell line. In addition, pretreatment with Sesim-tang ($>50\mu\textrm{g}/ml$ for 12 hours) partially prevented CT105-induced cytotoxicity in SK-N-SH cell lines. SK-N-SH cell lines overexpressed with CT105 exhibited remarkable apoptotic cell damage. Based on morphological observations by phase-contrast microscope and LDH activity measurements in the culture media, the CT105-induced cell death was significantly inhibited by Sesim-tang water extract. Sesim-tang was found to reduce the expression of APP and caspase-3 induced by CT105 in SK-N-SH cell lines and in rat hippocampus. Conclusions: As the result of this study, in the Sesim-tang group, apoptosis in the nervous system is inhibited, the repair against the degeneration of SK-N-SH cell lines by CT105 expression is promoted. Hence, Sesim-tang may be beneficial for the treatment of AD.

• Toxicological Research
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• 제22권2호
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• pp.95-102
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• 2006

Exposure to soluble nickel compound produces toxic effects on immune system, but the mechanism of action remains to be elucidated. Differential gene expression was studied to understand the potential molecular mechanism responsible for acute toxicity induced by nickel acetate in spleen cells. We exposed mouse spleen cells to nickel acetate with a nontoxic dose ($40{\mu}M$) and then extracted total RNA at 6 h and 12 h after exposure. The RNA was hybridized onto 10K mouse oligonucleotide microarrays, and data were analyzed using GeneSpring 7.1. Nickel had a modest effects on expression of many genes, in the range of 1.3-3 fold. The expression profile showed time-dependent changes in expression levels of differentially expressed genes, including some important genes related to cell cycle, apoptosis and DNA repair. In hierarchical cluster analysis of duplicate experiments, 111 genes were screened out. Out of these, 44 genes showing time- dependent up-regulation (>1.5 fold) and 38 genes showing down-regulation (>1.5 fold) at all time points were chosen for further analysis. The change in the expression of three genes (GPX1, GADD45B and FAIM) after nickel treatment was validated using RT-PCR. As a rule, a number of genes appear to be coordinately regulated between cell survival and cell death from nickel toxicity. In conclusion, changes in the gene profile in the spleen after nickel treatment are complex and genes with diverse functions are modulated. These findings will be contributed to the understanding of the complicated biological effects of nickel.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.187-195
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• 2020

To understand the molecular mechanism involved in the survivability of cold-tolerant lactic acid bacteria was of great significance in food processing, since these bacteria play a key role in a variety of low-temperature fermented foods. In this study, the cold-stress response of probiotic Lactobacillus plantarum K25 isolated from Tibetan kefir grains was analyzed by iTRAQ proteomic method. By comparing differentially expressed (DE) protein profiles of the strain incubated at 10℃ and 37℃, 506 DE proteins were identified. The DE proteins involved in carbohydrate, amino acid and fatty acid biosynthesis and metabolism were significantly down-regulated, leading to a specific energy conservation survival mode. The DE proteins related to DNA repair, transcription and translation were up-regulated, implicating change of gene expression and more protein biosynthesis needed in response to cold stress. In addition, two-component system, quorum sensing and ABC (ATP-binding cassette) transporters also participated in cell cold-adaptation process. These findings provide novel insight into the cold-resistance mechanism in L. plantarum with potential application in low temperature fermented or preserved foods.

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.327-335
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• 2009

The aim of this study was to determine whether losartan, an angiotensin II (Ang II) type 1 ($AT_1$) receptor could influence the CA release from the isolated perfused model of the rat adrenal medulla. Losartan (5${\sim}$50 ${\mu}$M) perfused into an adrenal vein for 90 min produced dose- and time-dependent inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM, a direct membrane depolarizer), DMPP (100 ${\mu}$M) and McN-A-343 (100 ${\mu}$M). Losartan failed to affect basal CA output. Furthermore, in adrenal glands loaded with losartan (15 ${\mu}$M) for 90 min, the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}$M, an activator of L-type $Ca^{2+}$ channels), cyclopiazonic acid (10 ${\mu}$M, an inhibitor of cytoplasmic $Ca^{2+}$ -ATPase), veratridine (100 ${\mu}$M, an activator of $Na^+$ channels), and Ang II (100 nM) were markedly inhibited. However, at high concentrations (150${\sim}$300 ${\mu}$M), losartan rather enhanced the CA secretion evoked by ACh. Collectively, these experimental results suggest that losartan at low concentrations inhibits the CA secretion evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by membrane depolarization from the rat adrenal medulla, but at high concentration it rather inhibits ACh-evoked CA secretion. It seems that losartan has a dual action, acting as both agonist and antagonist to nicotinic receptors of the rat adrenal medulla, which might be dependent on the concentration. It is also thought that this inhibitory effect of losartan may be mediated by blocking the influx of both $Na^+$ and $Ca^{2+}$ into the rat adrenomedullary chromaffin cells as well as by inhibiting the $Ca^{2+}$ release from the cytoplasmic calcium store, which is thought to be relevant to the $AT_1$ receptor blockade, in addition to its enhancement of the CA release.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.581-590
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• 2016

Resistance to anoikis, a cell-detachment induced apoptosis, is one of the malignant phenotypes which support tumor metastasis. Molecular mechanisms underlying the establishment of this phenotype require further investigation. This study aimed at exploring protein expression profiles associated with anoikis resistance of a metastatic breast cancer cell. Cell survival of suspension cultures of non-metastatic MCF-7 and metastatic MDA-MB-231 cells were compared with their adherent cultures. Trypan blue exclusion assays demonstrated a significantly higher percentage of viable cells in MDA-MB-231 than MCF-7 cell cultures, consistent with analysis of annexin V-7-AAD stained cells indicating that MDA-MB-231 possess anti-apoptotic ability 1.7 fold higher than MCF-7 cells. GeLC-MS/MS analysis of protein lysates of MDA-MB-231 and MCF-7 cells grown under both culture conditions identified 925 proteins which are differentially expressed, 54 of which were expressed only in suspended and adherent MDA-MB-231 but not in MCF-7 cells. These proteins have been implicated in various cellular processes, including DNA replication and repair, transcription, translation, protein modification, cytoskeleton, transport and cell signaling. Analysis based on the STITCH database predicted the interaction of phospholipases, PLC and PLD, and 14-3-3 beta/alpha, YWHAB, with the intrinsic and extrinsic apoptotic signaling network, suggesting putative roles in controlling anti-anoikis ability. MDA-MB-231 cells grown in the presence of inhibitors of phospholipase C, U73122, and phospholipase D, FIPI, demonstrated reduced ability to survive in suspension culture, indicating functional roles of PLC and PLD in the process of anti-anoikis. Our study identified intracellular mediators potentially associated with establishment of anoikis resistance of metastatic cells. These proteins require further clarification as prognostic and therapeutic targets for advanced breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2705-2709
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• 2012

Objective: To evaluate the predictive value of glutathione S-transferase (GST) gene polymorphisms for the prognosis of osteosarcoma patients receiving chemotherapy. Methods: A total of 159 patients were included in our study between January 2005 and December 2007., with follow-up until January 2012. Genotyping was based upon the duplex polymerase-chain-reaction with the PCR-CTPP method. Results: At the time of diagnosis, 15.4% of the patients presented with metastasis, while 22.3% developed metastasis during follow-up. At the time of final analysis on January 2012, the median follow-up was 45.5 months. Patients with null GSTM1 and GSTT1 had a higher event free survival rate than non-null genotype, but no significant association was found between the two genotypes and prognosis of osteosarcoma. Individuals with GSTP1 Val/Val genotype tended to live shorter than with the IIe/IIe genotype, and we found a significantly higher risk of death from osteosarcoma (adjusted HR=2.35, 95% CI=1.13-4.85). Conclusion: The GSTP1 gene polymorphism may have an important role in the prognosis of osteosarcoma patients with chemotherapy. Further analyses with larger samples and more genes encoding metabolizing and DNA repair enzymes are warranted.