• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.278-285
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• 2008

An efficient transformation method for soybean [Glycine max (L.) Merr.] using meristematic tissues of germinating seeds has been established. The embryonic axes were excised from germinating seeds of Korean soybean cultivar, Iksannamulkong and 0.5-2 cm long segment containing meristematic tissues were prepared by cutting hypocotyl region. The explants were inoculated with Agrobacterium tumefaciens strain LBA4404 harboring a binary vector with the bar gene as a selectable marker gene and a ${\beta}-glucuronidase$ (GUSINT) reporter gene, and then co-cultured for 7 days on co-cultivation medium (CCM). The meristematic tissues were cultured on shoot induction medium (SIMP6) supplemented with 0.4 mg/l $N_6-benzylaminopurine$ (BAP) and 0.1 mg/l indolebutyric acid (IBA) in the presence of 6 mg/l L-phosphinotricin (PPT) for 2 weeks and the surviving explants were transferred to shoot elongation medium (SEMP6). Transformation was confirmed by Southern blot analysis and the transformation efficiencies ranged from 1.48 to 2.07%. The new modified transformation method was successfully implemented for obtaining several transgenic lines with SMV-CP gene. It is expected that this method could efficiently be used for the transformation of recalcitrant soybean cultivars.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.527-538
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• 2019

Background: Ginsenoside Rg1 was shown to exert ligand-independent activation of estrogen receptor (ER) via mitogen-activated protein kinase-mediated pathway. Our study aimed to delineate the mechanisms by which Rg1 activates the rapid ER signaling pathways. Methods: ER-positive human breast cancer MCF-7 cells and ER-negative human embryonic kidney HEK293 cells were treated with Rg1 ($10^{-12}M$, $10^{-8}M$), $17{\beta}$-estradiol ($10^{-8}M$), or vehicle. Immunoprecipitation was conducted to investigate the interactions between signaling protein and ER in MCF-7 cells. To determine the roles of these signaling proteins in the actions of Rg1, small interfering RNA or their inhibitors were applied. Results: Rg1 rapidly induced $ER{\alpha}$ translocation to plasma membrane via caveolin-1 and the formation of signaling complex involving linker protein (Shc), insulin-like growth factor-I receptor, modulator of nongenomic activity of ER (MNAR), $ER{\alpha}$, and cellular nonreceptor tyrosine kinase (c-Src) in MCF-7 cells. The induction of extracellular signal-regulated protein kinase and mitogen-activated protein kinase kinase (MEK) phosphorylation in MCF-7 cells by Rg1 was suppressed by cotreatment with small interfering RNA against these signaling proteins. The stimulatory effects of Rg1 on MEK phosphorylation in these cells were suppressed by both PP2 (Src kinase inhibitor) and AG1478 [epidermal growth factor receptor (EGFR) inhibitor]. In addition, Rg1-induced estrogenic activities, EGFR and MEK phosphorylation in MCF-7 cells were abolished by cotreatment with G15 (G protein-coupled estrogen receptor-1 antagonist). The increase in intracellular cyclic AMP accumulation, but not Ca mobilization, in MCF-7 cells by Rg1 could be abolished by G15. Conclusion: Ginsenoside Rg1 exerted estrogenic actions by rapidly inducing the formation of ER containing signalosome in MCF-7 cells. Additionally, Rg1 could activate EGFR and c-Src ER-independently and exert estrogenic effects via rapid activation of membrane-associated ER and G protein-coupled estrogen receptor.

• Journal of Life Science
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• v.32 no.4
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• pp.318-324
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• 2022

PPARγ and C/EBPα are master adipogenic transcription factors (TFs) required for adipose tissue development. They control the induction of many adipocyte genes and the early phase of adipogenesis in the embryonic development of adipose tissue. Adipose tissue continues to expand after birth, which, as a late phase of adipogenesis, requires the lipogenesis of adipocytes. In particular, the liver and adipose tissues are major sites for de novo lipogenesis (DNL), where carbohydrates are primarily converted to fatty acids. Furthermore, fatty acids are esterified with glycerol-3-phosphate to produce triglyceride, a major source of lipid droplets in adipocytes. Hepatic DNL has been actively studied, but the DNL of adipocytes in vivo remains not fully understood. Thus, an understanding of lipogenesis and adipose expansion may provide therapeutic opportunities for obesity, type 2 diabetes, and metabolic diseases. In adipocytes, DNL gene expression is transcriptionally regulated by lipogenesis coactivators, as well as by lipogenic TFs such as ChREBP and SREBP1a. Recent in vivo studies have revealed new insights into the lipogenesis gene expression and adipose expansion. Future detailed molecular mechanism studies will determine how nutrients and metabolism regulate DNL and adipose expansion. This review will summarize recent updates of DNL in adipocytes and adipose expansion in terms of transcriptional regulation.

• Journal of Life Science
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• v.33 no.6
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• pp.455-462
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• 2023

During pregnancy, maternal immune activation (MIA) from infection increases the risk of neurodevelopmental diseases, including schizophrenia and autism spectrum disorders. MIA induced by polyinosinic-polycytidylic acid (poly (I:C)) and lipopolysaccharide (LPS) in animal experiments has led to offspring with abnormal behaviors and brain development. In addition, it has recently been reported that microglia, which reside in the brain and function as immune cells, play an important role in behavioral abnormalities and brain development in MIA-induced offspring. However, the underlying mechanism remains unclear. In this study, we investigated whether microglia-specific inhibition of GPR56, a member of the G protein-coupled receptor (GPCR) family, causes behavioral abnormalities in brain development. First, MIA induction did not affect the microglia population, but when examining the expression of microglial GRP56 in MIA-induced fetuses, GPR56 expression was inhibited between embryonic days 14.5 (E14.5) and E18.5 regardless of sex. Furthermore, microglial GPR56-suppressed mice showed abnormal behaviors in the MIA-induced offspring, including sociability deficits, repetitive behavioral patterns, and increased anxiety levels. Although abnormal cortical development such as that in the MIA-induced offspring were not observed in the microglial GPR56-suppressed mice, their brain activity was observed through c-fos staining. These results suggest that microglia-specific GPR56 deficiency may cause abnormal behaviors and could be used as a biomarker for the diagnosis and/or as a therapeutic target of behavioral deficits in MIA offspring.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.161-167
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• 2007

In this study, we constructed and tested retrovirus vectors designed to express the human thrombopoietin gene under the control of the tetracycline-inducible promoters. To increase the hTPO gene expression at him-on state, WPRE sequence was also introduced into retrovirus vector at downstream region of either the hTPO gene or the sequence encoding reverse tetracycline-controlled transactivator (rtTA). Primary culture cells (PFF, porcine fetal fibroblast; CEF, chicken embryonic fibroblast) infected with the recombinant retrovirus were cultured in the medium supplemented with or without doxycycline for 48hr, and induction efficiency was measured by comparing the hTPO gene expression level using RT-PCR, western blot and ELISA. Higher hPTO expression and tighter expression control were observed from the vector in which the WPRE sequence was placed at downstream of the hTPO (in CEF) or rtTA(in PFF) gene. This resulting tetracycline inducible vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals.

• Clinical and Experimental Pediatrics
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• v.51 no.8
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• pp.874-878
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• 2008

Purpose : This study was undertaken to develop an animal model of periventricular leukomalacia (PVL) induced by in utero clamping of pregnant rat aorta in fetal rats. Methods : A timed pregnanct Sprague-Dawley rat on embryonic day 21 just prior to delivery was sedated and anesthetized, and a Harvard ventilator for small animals was applied. Following laparotomy, the maternal aorta was clamped reversibly for 40 minutes using a surgical clip. The fetal rats were then delivered by Cesarean section, resuscitated if necessary, and reared by a surrogate mother rat until postnatal day 21 to obtain the brain specimen. After systemic perfusion and fixation, $10{\mu}m$ thick serial brain sections were obtained and stained for pathologic examination and assessment of ventriculomegaly. Ventriculomegaly was assessed by the measured ventricle to total brain volume ratio. Results : Eight out of eleven fetal rats (73%) survived in the ischemia group after induction of in utero ischemia by clamping maternal rat aorta, and all ten survived in the control group. Body and brain weights measured at postnatal day 21 were significantly lower in the ischemia group compared to the control group. In pathologic findings, significant ventriculomagaly ($3.67{\pm}1.21%$ vs. $0.23{\pm}0.06%$) was observed in the ischemia group compared to the control group; although cystic lesion was not observed, mild (n=6) and moderate (n=2) rerefaction of the brain tissue was observed. Conclusion : A fetal rat model of PVL induced by in utero clamping of pregnant rat aorta was developed.

• Journal of Life Science
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• v.30 no.12
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• pp.1092-1100
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• 2020

The six-transmembrane epithelial antigen of prostate 4 (Steap4) is a metalloreductase that plays a role in intracellular iron and cupper homeostasis, inflammatory response, and glucose and lipid metabolism. Previously, Steap4 has been reported to stimulate adipocyte differentiation; however, the underlying mechanisms of this action remain unexplored. In the present study, we investigated the molecular mechanisms involved in Steap4-induced adipocyte differentiation using 3T3-L1 cells, immortalized brown adipocyte (iBA) cells, and mouse embryonic fibroblast C3H10T1/2 cells. The knockdown of Steap4 using adenovirus-containing shRNA attenuated mitotic clonal expansion (MCE), as evidenced by the impaired proliferation of 3T3-L1 cells, iBA cells, and C3H10T1/2 cells within 48 hr after adding the differentiation medium. Steap4 knockdown downregulated G1/S phase transition-related cell cycle regulators (including cyclin A and cyclin D) and upregulated cell cycle inhibitors (including p21 and p27). Furthermore, Steap4 knockdown inhibited the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and Akt. Moreover, Steap4 knockdown repressed the expression of early adipogenic activators, such as CCAAT-enhancer-binding protein β (C/EBPβ) and Kruppel-like factor family factor 4 (KLF4). On the other hand, Steap4 knockdown stimulated the expression of adipogenic inhibitors, including KLF2, KLF3, and GATA2. The overexpression of Steap4 using an adenovirus removed the repressive histone marks H3K9me2 and H3K9me3 on the promoter of C/EBPβ. These results indicate that Stepa4 stimulates adipocyte differentiation through the induction of MCE and the modulation of early adipogenic transcription factors, including C/EBPβ, during the early phase of adipocyte differentiation.