• The Korean Journal of Physiology and Pharmacology
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• v.13 no.5
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• pp.349-356
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• 2009

We previously reported that glial cell line-derived neurotropic factor (GDNF) receptor ${\alpha}$ 1 (GFR ${\alpha}$ 1) is a direct target of apurinic/apyrimidinic endonuclease 1 (Ape1/Ref-1). In the present study, we further analyzed the physiological roles of Ape1/Ref-1-induced GFR ${\alpha}$ 1 expression in Neuro2a mouse neuroblastoma cells. Ape1/Ref-1 expression caused the clustering of GFR ${\alpha}$ 1 immunoreactivity in lipid rafts in response to GDNF. We also found that Ret, a downstream target of GFR ${\alpha}$ 1, was functionally activated by GDNF in Ape1/Ref-1-expressing cells. Moreover, GDNF promoted the proliferation of Ape1/Ref-1-expressing Neuro2a cells. Furthermore, GFR ${\alpha}$ 1-specific RNA experiments demonstrated that the downregulation of GFR ${\alpha}$ 1 by siRNA in Ape1/Ref-1-expressing cells impaired the ability of GDNF to phosphorylate Akt and PLC ${\gamma}$-1 and to stimulate cellular proliferation. These results show an association between Ape1/Ref-1 and GDNF/GFR ${\alpha}$ signaling, and suggest a potential molecular mechanism for the involvement of Ape1/Ref-1 in neuronal proliferation.

• Journal of Life Science
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• v.23 no.10
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• pp.1183-1191
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• 2013

Human apurinic/apyrimidinic endonuclease (APEX-1) is a multifunctional protein that is capable of repairing abasic sites and single-strand breaks in damaged DNA. In addition, it serves as a redox-modifying factor for a number of transcription factors. Identifying the transcriptional targets of APEX-1 is essential for understanding how it affects various cellular outcomes. Expression array analysis was used to identify glial cell-derived neurotropic factor receptor ${\alpha}1$ ($GFR{\alpha}1$), which is an encoding receptor for the glial cell-derived neurotropic factor (GDNF) family, the expression of which is induced by APEX-1. A target of GDNF/$GFR{\alpha}$ signaling, c-Src (Tyr418) was strongly phosphorylated by GNDF in the APEX-1 expressing cells. Moreover, GDNF initiated cell proliferation, measured by counting the number of cells, in the APEX-1 expressing cells. Importantly, the down-regulation of APEX-1 by siRNA caused a marked reduction in the $GFR{\alpha}1$ expression level, and it reduced the ability of GDNF to phosphorylate c-Src (Tyr418) and stimulate cell proliferation. These results demonstrate an association between APEX-1 and GDNF/$GFR{\alpha}$ signaling and suggest a potential molecular mechanism for the involvement of APEX-1 in cell survival and proliferation.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.327-336
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• 2018

To date, there are no protocols optimized to the effective separation of spermatogonial stem cells (SSCs) from testicular cells derived from mouse testes, thus hindering studies based on mouse SSCs. In this study, we aimed to determine the most efficient purification method for the isolation of SSCs from mouse testes among previously described techniques. Isolation of SSCs from testicular cells derived from mouse testes was conducted using four different techniques: differential plating (DP), magnetic-activated cell sorting (MACS) post-DP, MACS, and positive and negative selection double MACS. DP was performed for 1, 2, 4, 8, or 16 h, and MACS was performed using EpCAM ($MACS^{EpCAM}$), Thy1 ($MACS^{Thy1}$), or GFR ${\alpha}1$ ($MACS^{GFR{\alpha}1}$) antibodies. The purification efficiency of each method was analyzed by measuring the percentage of cells that stained positively for alkaline phosphatase. DP for 8 h, $MACS^{Thy1}$ post-DP for 8 h, $MACS^{GFR{\alpha}1}$, positive selection double $MACS^{GFR{\alpha}1/EpCAM}$, and negative selection double $MACS^{GFR{\alpha}1/{\alpha}-SMA}$ were identified as the optimal protocols for isolation of SSCs from mouse testicular cells. Comparison of the purification efficiencies of the optimized isolation protocols showed that, numerically, the highest purification efficiency was obtained using $MACS^{GFR{\alpha}1}$. Overall, our results indicate that $MACS^{GFR{\alpha}1}$ is an appropriate purification technique for the isolation of SSCs from mouse testicular cells.

• Development and Reproduction
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• v.15 no.1
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• pp.41-52
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• 2011

In the present study, embryoid bodies (EBs) obtained from induced pluripotent stem cells (iPSCs) were induced to differentiate into germ lineage cells by treatment with bone morphogenetic protein 4 (BMP4) and retinoic acid (RA). The results were compared to the results for embryonic stem cells (ESCs) and multipotent spermatogonial stem cells (mSSCs) and quantified using immunocytochemical analysis of germ cell-specific markers (integrin-${\alpha}6$, GFR-${\alpha}1$, CD90/Thy1), fluorescence activating cell sorting (FACS), and real time-RT-PCR. We show that the highest levels of germ cell marker-expressing cells were obtained from groups treated with 10 ng/$m{\ell}$ BMP4 or 0.01 ${\mu}M$ RA. In the BMP4-treated group, GFR-${\alpha}1$ and CD90/Thy-1 were highly expressed in the EBs of iPSCs and ESCs compared to EBs of mSSCs. The expression of Nanog was much lower in iPSCs compared to ESCs and mSSCs. In the RA treated group, the level of GFR-${\alpha}1$ and CD90/Thy-1 expression in the EBs of mSSCs Induced pluripotent stem cells, Mouse embryonic stem cells, Multipotent spermatogonial stem cells, Germ cell lineage, Differentiation potential. was much higher than the levels found in the EBs of iPSCs and similar to the levels found in the EBs of ESCs. FACS analysis using integrin-${\alpha}6$, GFR-${\alpha}1$, CD90/Thy1 and immunocytochemistry using GFR-${\alpha}1$ antibody showed similar gene expression results. Therefore our results show that iPSC has the potential to differentiate into germ cells and suggest that a protocol optimizing germ cell induction from iPSC should be developed because of their potential usefulness in clinical applications requiring patient-specific cells.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.170.1-170.1
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• 2006

• Journal of Pharmaceutical Investigation
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• v.13 no.4
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• pp.173-182
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• 1983

The influence of prazosin (0.1 mg/kg i.v.) on the excretion and diuretic action of furosemide (2mg/kg i.v.) in rabbits was studied to investigate an interaction between ${\alpha}-adrenergic$ blocking agent, prazosin and furosemide. The results were as follows; 1) With the combined administration of prazosin and furosemide, the plasma concentration of furosemide was increased, the urinary excretion rate and renal clearance of furosemide were reduced, and tile biological half-life of furosemide was increased. 2) The diuretic action of furosemide was significantly reduced with the combined administration of prazosin: maximal decrease in urine volume, urinary electrolytes, clearance of $Na^+$ and $Cl^-$, and GFR and RPF, as well as maximal increase in $Na^+$ reabsorption rate were noted 10 minutes after administration of furosemide (2mg/kg i.v.)

• Korean Journal of Exercise Nutrition
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• v.16 no.1
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• pp.27-33
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• 2012

This study was conducted to investigate the effect of a 24-week combined exercise training program in older women with hypertension. Women with hypertension who were 70 years and older were randomized into two groups: combined exercise group (CE; n = 15) and a control group (n = 15). The CE group performed a combined exercise training program four times per week for 24 weeks and the control group did not. Five factors, including body composition (percent body fat and skeletal muscle mass), health-related physical fitness, adipocytokines (interleukin-6 [IL-6] and tumor necrosis factor-alpha [TNF-α]), kidney risk factors (glomerular filtration rate [GFR] and cystatin C), and systolic and diastolic blood pressure were measured before and after the program. The findings showed that total muscle mass, health-related physical fitness factors, and GFR increased significantly in the CE group compared to those in the control. Additionally, systolic and diastolic blood pressure and IL-6, TNF-α, and cystatin C levels in the CE group decreased significantly after the intervention. In contrast, total muscle mass decreased significantly and blood pressure remained unchanged in the control group. These results suggest that CE training may positively impact circulating levels of adipocytokines and cystatin C and improve physical fitness levels in elderly women with hypertension. Therefore, CE training helps to prevent renal disease and improve health-related physical fitness, eventually leading to a better quality of life.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.107-107
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• 1993

결과 및 고찰: 이 약의 흰쥐에서의 체내동태는 혈중농도로 볼 때 2-exponential pharmacokinetics에 따르고, HPLC법으로 정량한 경우의 $T_1$/$_2$$\alpha$, $T_1$/$_2$$\beta$, AUC, C $L_{T}$, C $L_{R}$, V $D_{SS}$ 는 각각 1.90min, 21.89min, 1899.36$\mu\textrm{g}$ㆍmin/ml, 10.66ml/min/kg, 7.48ml/min/kg, 0.28l/kg으로 bioassay법과는 약간의 차이를 보였다. 분포특성은 간장과 신장에 많이 이행하였으며, 폐로의 이행도 적지만 관찰되었다. 이 약의 단백결합률은 그 농도가 31.3$\mu$M일 때 42.3%였고 water/n-octanol계에서의 유상으로의 분배는 거의 일어나지 않았다. 이 약의 분포용적이 작은 것은 단백결합 때문이라기보다는 높은 극성때문으로 추정되었다. 이 약의 C $L_{R}$은 GFR의 문헌치보다 컸으며 C $L_{T}$의 약 2/3을 차지하므로 약물소실에 있어서 신장의 기여도가 크고 신배설 과정에 신분비가 관여하고 있음을 알 수 있었다. 이런 사실은 CAZ나 CTX등의 기존 세파계 항생제들과 유사했으며, 추후 다회투여시와 용량의존적 체내동태에 관해 더 많은 연구가 필요하리라 생각되었다.되었다.

• Journal of Nutrition and Health
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• v.30 no.1
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• pp.3-11
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• 1997

This study was conducted to investigate the effects of protein levels and casein/whey ratios on organ growth and protein metabolism in early weaned rats. Premature rats weaned by the 17th day were fed six semipurified synthetic, isocaloric and gel diets that contained three levels (low, medium and high) and two different combinations(casein/whey ; 80 : 20 or 20 : 80) of milk protein for 8 days. On the 25th day postpartum, frest weigth and DNA, RNA and milk protein contents in brain, liver, kidney and muscle were determined to ascertain organ and cellular growth. Futher, with a view to ascertain protein metabolism and renal functions, serum total protein, $\alpha$-amino N, urea N, and creatinine and creatinine and urinary urea N, creatinine and hydroxproline were determined. Total DNA contents of brain, liver and kidney, which may represent as an index of cell numbers in those organs were significantly decreased in the rats fed diets containing low level protein regardless of casein/whey ratio. However, as fat as the rats fed high protein diets were concerned, their fresh weight, protein contents and GFR of kidney were significantly increased. Furthermore, nitrogen components, $\alpha$-amino N, urea N and creatinie in serum and urine were also increassed. Another observation was that high casein/whey ratio significantly facilitated accumulation of porteins in muscle and kidney and urinary hydorxyproline excretion, not affecting the DNA content of those organs. This study showed that low(8%) or high(32%) contents of protein had less desirable effects either on protein metabolism or on organ cellular growth in prematurely weaned rats, whereas there were no effects on general growth and bone strength.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.67-75
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• 2011

The faulty regulation of imprinting gene lead to the abnormal development of reconstructed embryo after nuclear transfer. However, the correlation between the imprinting status of donor cell and preimplantation stage of embryo development is not yet clear. In this study, to determine this correlation, we used the porcine spermatogonial stem cell (pSSC) and fetal fibroblast (pFF) as donor cells. As the results, the isolated cells with laminin matrix selection strongly expressed the GFR ${\alpha}$-1 and PLZF genes of SSCs specific markers. The pSSCs were maintained to 12 passages and positive for the pluripotent marker including OCT4, SSEA1 and NANOG. The methylation analysis of H19 DMR of pSSCs revealed that the zinc finger protein binding sites CTCF3 of H19 DMRs displayed an androgenic imprinting pattern (92.7%). Also, to investigate the reprogramming potential of pSSCs as donor cell, we compared the development rate and methylation status of H19 gene between the reconstructed embryos from pFF and pSSC. This result showed no significant differences of the development rate between the pFFs ($11.2{\pm}0.8%$) and SSCs ($13.3{\pm}1.1%$). However, interestingly, while the CTCF3 methylation status of pFF-NT blastocyst was decreased (36.3%), and the CTCF3 methylation status of pSSC-NT blastocyst was maintained. Therefore, this result suggested that the genomic imprinting status of pSSCs is more effective than that of normal somatic cells for the normal development because the maintenance of imprinting pattern is very important in early embryo stage.