• YAKHAK HOEJI
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• v.41 no.2
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• pp.260-267
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• 1997

To establish prediabetes in vitro model concerning the etiology of IDDM(Insulin Dependent Diabetes Mellitus) in cellular level we have designed prediabetes in vitro models in pa ncreatic beta cells. HIT-T15, RINm5F and isolated rat islets were chosen as pancreatic beta cells, and streptozotocin (STZ) used as diabetogenic agent. Degree of beta cell destruction to establish prediabetic in vitro model was determined by cell proliferation and insulin release using thymidine uptake and radio immuno assay. When HIT-T15 and RINm5F cells were treated with STZ, the degree of cell deterioration was dependent upon the origin and passage number of beta cells, and in the case of isolated islets STZ showed the more sensitivity than above two beta cell lines. The concentration and exposure time of STZ treatment to establish prediabetes in vitro model in beta cell lines and isolated rat islets were 2 ~ 10mM, 30 min. and 1 ~ 5mM, 30 min., respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.43-51
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• 2006

This experiment was designed to investigate the effect of Amomum villosum(AMV) on the Alzheimer's disease. The effects of AMV extract on amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell line treated by amyloid $\beta$ protein($A{\beta}$) : IL-$1{\beta}$, IL-6, TNF-$\alpha$ mRNA of THP-1 cell line treated by lipopolysaccharide(LPS) : AChE activity of PC-12 cell lysate treated by $A{\beta}$ : serum glucose, uric acid, AChE activity of memory deficit rats induced by scopolamine : behavior of memory deficit mice induced by scopolamine were investigated, respectively. AMV extract suppressed APP, AChE, GFAP mRNA in PC-12 cell treated by $A{\beta}$ : IL-$1{\beta}$, IL-6, TNF-$\alpha$ mRNA in THP-1 cell treated by LPS , AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$. AMV extract increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit rats induced by scopolamine. AMV extract group showed significantly inhibitory effect on the memory deficit of mice induced by scopolamine in the experiment of Morris water maze. According to the above results, it is suggested that AMV extract might be usefully applied for prevention and treatment of Alzheimer's disease.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.130-138
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• 2005

This experiment was designed to investigate the effect of Phellodendron amurense(PLDA) on the Alzheimer's disease. The effects of PLDA extract on $IL-1{\beta}$, IL-6, amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$ and AChE activity of PC-12 cell lysate treated by $A{\beta}$ plus $rIL-1{\beta}$ and behavior of memory deficit mice induced by scopolamine and mice glucose, uric acid, AChE activity of memory deficit rats induced by scopolamine were investigated, respectively. PLDA extract suppressed $IL-1{\beta}$, IL-6, APP, AChE, GFAP mRNA in PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$ ; AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$ plus $rIL-1{\beta}$. PLDA extract increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit rats induced by scopolamine. PLDA extract group showed significantly inhibitory effect on the memory deficit of mice induced by scopolamine in the experiment of Morris water maze. According to the above results, it is suggested that PLDA extract might be usefully applied for prevention and treatment of Alzheimer's disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.314-319
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• 2001

In the present study, effects of $\beta$-alanine, a known taurine antagonist for its structural similarity, on the adaptive regulation and kinetic behavior of the taurine transporter were investigated in the HT-29, human colon carcinoma cell line. Pretreatment of the cell with $\beta$-alanine(10mM) for varying periods from 3 to 30 hrs significantly reduced the taurine uptake compared to the value for control cells. This decrease in the taurine transporter activity was dependent on the incubation time with $\beta$-alanine, and the maximal down-regulation of the transporter activity was observed in cells pretreated with $\beta$-alanine for 24 hrs (25% of the control value, p<0.01). The taurine transporter appears to bind exclusively with $\beta$-alanine in the HT-29 cells since the same concentration of $\alpha$-alanine added in the culture medium for 24 hrs did not influence the taurine uptake. Kinetic analyses of the taurine transporter activity was performed in the HT-29 cell line with varying taurine concentration (5~60$\mu$M) in the uptake medium. Active taurine uptake was significantly lower in $\beta$-alanine pretreated cells compared to the value for control cells in the range of taurine concentration used in the experiment (p<0.001). The cells pretreated with $\beta$-alanine showed a 50% lower maximal velocity (Vmax, 1.7$\pm$2.0 nmole.mg $protein^{-1}$.$30min^{-1}$), and a 99% higher Michaelis constant (Km, 40.3$\pm$7.6$\mu$M) than the control values (3.3$\pm$1.9 nmole.mg $protein^{-1}$.$30min^{-1}$, and 20.3$\pm$2.1$\mu$M, respectively). These results on kinetic data suggest that $\beta$-alanine induced down-regulation of the taurine transporter activity was associated with decreases in both maximal velocity and affinity of the transporter.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.37-43
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• 2007

Adenosine has been reported to provide cytoprotection in the central nervous systems as well as myocardium by activating cell surface adenosine receptors. However, the exact target and mechanism of its action still remain controversial. The present study was performed to examine whether adenosine has a protective effect against $A{\beta}$-induced injury in neuroglial cells. The astrocyte-derived human neuroglioma cell line, A172 cells, and $A{\beta}_{25{\sim}35}$ were employed to produce an experimental $A{\beta}$-induced glial cell injury model. Adenosine significantly prevented $A{\beta}$-induced apoptotic cell death. Studies using various nucleotide receptor agonists and antagonists suggested that the protection was mediated by $A_1$ receptors. Adenosine attenuated $A{\beta}$-induced impairment in mitochondrial functional integrity as estimated by cellular ATP level and MTT reduction ability. In addition, adenosine prevented $A{\beta}$-induced mitochondrial permeability transition, release of cytochrome c into cytosol and subsequent activation of caspase-9. The protective effect of adenosine disappeared when cells were pretreated with 5-hydroxydecanoate, a selective blocker of the mitochondrial ATP-sensitive $K^+$ channel. In conclusion, therefore we suggest that adenosine exerts protective effect against $A{\beta}$-induced cell death of A172 cells, and that the underlying mechanism of the protection may be attributed to preservation of mitochonarial functional integrity through opening of the mitochondrial ATP-sensitive $K^+$ channels.

• BMB Reports
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• v.45 no.3
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• pp.159-164
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• 2012

CD99 is known to be involved in the regulation of cell-cell adhesion. However, it remains unclear whether CD99 controls cell-extracellular matrix adhesion. In this study, the effects of CD99 activation on cell-extracellular matrix adhesion were investigated. It was found that engagement of CD99 with the stimulating antibody YG32 downregulated the adhesion of MCF-7 cells to fibronectin, laminin and collagen IV in a dose-dependent manner. The CD99 effect on cell-ECM adhesion was inhibited by overexpression of the dominant negative form of CD99 or CD99 siRNA transfection. Treatment of cells with $Mn^{2+}$ or by ${\beta}_1$ integrin-stimulating antibody restored the inhibitory effect of CD99 on cell-ECM adhesion. Cross-linking CD99 inactivated ${\beta}_1$ integrin through conformational change. CD99 activation caused dephosphorylation at Tyr-397 in FAK, which was restored by the ${\beta}_1$ stimulating antibody. Taken together, these results provide the first evidence that CD99 inhibits cell-extracellular matrix adhesion by suppressing ${\beta}_1$ integrin affinity.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.161-169
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• 2018

We previously demonstrated that epidermal growth factor (EGF) enhances cell migration and invasion of breast cancer cells in a SMAD ubiquitination regulatory factor 1 (SMURF1)-dependent manner and that SMURF1 induces degradation of ${\beta}-catenin$ in C2C12 cells. However, the relationship between EGF-induced SMURF1 and ${\beta}-catenin$ expression in breast cancer cells remains unclear. So, we investigated if EGF and SMURF1 regulate ${\beta}-catenin$ expression in MDAMB231 human breast cancer cells. When MDAMB231 cells were incubated with EGF for 24, 48, and 72 hours, EGF significantly increased expression levels of SMURF1 mRNA and protein while suppressing expression levels of ${\beta}-catenin$ mRNA and protein. Overexpression of SMURF1 downregulated ${\beta}-catenin$ mRNA and protein, whereas knockdown of SMURF1 increased ${\beta}-catenin$ expression and blocked EGF-induced ${\beta}-catenin$ downregulation. Knockdown of ${\beta}-catenin$ enhanced cell migration and invasion of MDAMB231 cells, while ${\beta}-catenin$ overexpression suppressed EGF-induced cell migration and invasion. Furthermore, knockdown of ${\beta}-catenin$ enhanced vimentin expression and decreased cytokeratin expression, whereas ${\beta}-catenin$ overexpression decreased vimentin expression and increased cytokeratin expression. These results suggest that EGF downregulates ${\beta}-catenin$ in a SMURF1-dependent manner and that ${\beta}-catenin$ downregulation contributes to EGF-induced cell migration and invasion in MDAMB breast cancer cells.

• Molecules and Cells
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• v.41 no.9
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• pp.853-867
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• 2018

As the most common type of endocrine malignancy, papillary thyroid cancer (PTC) accounts for 85-90% of all thyroid cancers. In this study, we presented the hypothesis that SDC4 gene silencing could effectively attenuate epithelial mesenchymal transition (EMT), and promote cell apoptosis via the $Wnt/{\beta}-catenin$ signaling pathway in human PTC cells. Bioinformatics methods were employed to screen the determined differential expression levels of SDC4 in PTC and adjacent normal samples. PTC tissues and adjacent normal tissues were prepared and their respective levels of SDC4 protein positive expression, in addition to the mRNA and protein levels of SDC4, $Wnt/{\beta}-catenin$ signaling pathway, EMT and apoptosis related genes were all detected accordingly. Flow cytometry was applied in order to detect cell cycle entry and apoptosis. Finally, analyses of PTC migration and invasion abilities were assessed by using a Transwell assay and scratch test. In PTC tissues, activated $Wnt/{\beta}-catenin$ signaling pathway, increased EMT and repressed cell apoptosis were determined. Moreover, the PTC K1 and TPC-1 cell lines exhibiting the highest SDC4 expression were selected for further experiments. In vitro experiments revealed that SDC4 gene silencing could suppress cell migration, invasion and EMT, while acting to promote the apoptosis of PTC cells by inhibiting the activation of the $Wnt/{\beta}-catenin$ signaling pathway. Besides, $si-{\beta}-catenin$ was observed to inhibit the promotion of PTC cell migration and invasion caused by SDC4 overexpression. Our study revealed that SDC4 gene silencing represses EMT, and enhances cell apoptosis by suppressing the activation of the $Wnt/{\beta}-catenin$ signaling pathway in human PTC.

• Experimental and Molecular Medicine
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• v.50 no.12
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• pp.8.1-8.12
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• 2018

FAM46B is a member of the family with sequence similarity 46. Little is known about the expression and functional role (s) of FAM46B in prostate cancer (PC). In this study, the expression of FAM46B expression in The Cancer Genome Atlas, GSE55945, and an independent hospital database was measured by bioinformatics and real-time PCR analysis. After PC cells were transfected with siRNA or a recombinant vector in the absence or presence of a ${\beta}$-catenin signaling inhibitor (XAV-939), the expression levels of FAM46B, C-myc, Cyclin D1, and ${\beta}$-catenin were measured by western blot and realtime PCR. Cell cycle progression and cell proliferation were measured by flow cytometry and the CCK-8 assay. The effects of FAM46B on tumor growth and protein expression in nude mice with PC tumor xenografts were also measured. Our results showed that FAM46B was downregulated but that ${\beta}$-catenin was upregulated in patients with PC. FAM46B silencing promoted cell proliferation and cell cycle progression in PC, which were abrogated by XAV-939. Moreover, FAM46B overexpression inhibited PC cell cycle progression and cell proliferation in vitro and tumor growth in vivo. FAM46B silencing promoted ${\beta}$-catenin protein expression through the inhibition of ${\beta}$-catenin ubiquitination. Our data clearly show that FAM46B inhibits cell proliferation and cell cycle progression in PC through ubiquitination of ${\beta}$-catenin.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.261-265
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• 1991

In a microbial cell-free extract system, side chain cleavage on various sterols and steroids was tested. The cell-free extracts of Mycobacterium sp. NRRL B-3805 showed the side chain cleavage activity on lithocholic acid to form 5$\beta$-androstan-3.17-dione. The properties of the activity were examined.