• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.233-241
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• 1996

Previous studies have shown that glucocorticoid suppresses microsomal epoxide hydrolase(EH) gene expression and that EH expression is altered during pregnancy. The effects of progesterone on the expression of rat EH and certain glutathione S-transferase(GST) genes were examined in this study. Northern RNA blot analysis revealed that progesterone was effective in increasing hepatic EH mRNA levels at 12 h to 48 h after treatment with a maximal 9-fold increase being noted at 12 h time point. Nonetheless, multiple daily treatment with progesterone rather caused minimal relative increases in EH mRNA levels. GST Ya and Yb1/2 mRNA levels were also transiently elevated at 12 h after progesterone treatment, followed by gradual decreases from the maximal Increases at day 1, 2 and 5 post-treatment. These changes in EH and GST mRNA levels were noted only at a relatively high dose of progesterone. Furthermore, immunoblot analyses showed that rats treated with progesterone for 5 days failed to show EH or GST induction, indicating that progesterone-induced alterations in EH and GST mRNA levels do not reflect bona fide induction of the detoxifying enzymes. Concomitant progesterone treatment of rats with the known EH inducers including ketoconazole and clotrimazole failed to additively nor antagonistically alter EH mRNA levels. In contrast, dexamethasone substantially reduced ketoconazole- or clotrimazole-inducible EH expression. These results showed that progesterone stimulates the EH, GST Ya and Yb1/2 gene expression at early times followed by marked reduction in the RNA levels from the maximum after multiple treatment and that the changes in mRNA do not necessarily reflect induction of the proteins.

• Journal of Environmental Science International
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• v.29 no.6
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• pp.633-641
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• 2020

Water temperature is one of the most important factors of fish survival, affecting the habitat, migration route, development, and reproduction. This experiment studied the induction level of heat shock protein (HSP70) mRNA and protein in a walleye pollock (Gadus chalcogrammus) primary hepatocyte culture based on different temperatures. Hepatocytes were attached at 7.5℃ for 24 hours. Hsp70 induction levels were then measured for 48 hours at 5, 8, 11, 14, and 17℃. The induction level was lowest at 5℃ and generally increased with temperature until 14℃. The induction level was reduced at 17℃, indicating that 14℃ is the highest tolerable temperature for hepatocytes. These data indicate that primary hepatocyte cell culture is under no stress at 5 and 8℃. Temperatures greater than 11℃ induce stress, showing similar induction patterns in both mRNA and protein in hepatocytes. The results suggest that 14℃ is the maximum internal defense temperature of walleye pollock survival.

• Toxicological Research
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• v.17 no.3
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• pp.181-186
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• 2001

The estrogenic potency of bisphenol A using reverse trancriptase-PCR response of liver vitellogenin mRNA in male carp was studied. For this, six combination of primers which were synthesized on the basis of cDNA consensus region of various species, were evaluated and one pair of primers was selected as the best to show 286 bp size-transcript. By using the selected primers, vitellogenin mRNA induction in carp treated with bisphenol A was measured and the chemical showed dose-and time-dependent Induction response. From this result, it was concluded that RT-PCR technique wing the selected primers in this study can be wed to monitor the estrogenic effects exerted In carp living in Korean freshwater.

• Environmental Analysis Health and Toxicology
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• v.16 no.1
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• pp.29-34
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• 2001

The estrogenic potency of di -2-ethylhexyl phthalate (DEHP) using reverse transcriptase-PCR respouse of liver vitellogenin mRNA in male African clawed frog (Xenopus laevis) was studied. Male frogs were injected with DEHP at dose of 300$\mu\textrm{g}$/kg and 300 mg/kg body weight through the dorsal lymph sac. After 4 days, using suitable pair of RT-PCR primers, vitellogenin mRNA induction in the liver was measured and DEHP showed vitellogenin mRNA induction in only the group treated with 300 mg/kg. Any significant histological abnormalities by the exposure of DEHP was not shown in both testis and liver.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.159-164
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• 2003

Effects of Al on vitellogenin (VTG) and VTG mRNA induction by estradiol-17 $\beta$($E_2$) were examined in primary hepatocyte culture of rainbow trout. Hepatocytes were precultured for 2 days and then E2 ($2{\times}10^{-6}$M) and Al ($10^{-6}-10^{-4}$M) were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days. Media and hepatocytes were then analyzed by SDS-PAGE and Northern blotting for VTG and VTG mRNA, respectively. These metal had no appreciable effect on the viability of hepatocytes in culture. However, Al interfered with VTG production and VTG mRNA expression. Al reduced VTG production in a concentration-dependent way and a significant reduction accurred at Al concentrations greater than $5{\times}10^{-5}$M. VTG mRNA expression also decreased with a negative correlation with Al concentration (r＝-0.98). These results suggest that Al inhibit VTG production at the transcriptional level to reduce VTG mRNA expression.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.446-457
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• 2018

Adiponectin, a hormone predominantly originated from adipose tissue, has exhibited potent anti-inflammatory properties. Accumulating evidence suggests that autophagy induction plays a crucial role in anti-inflammatory responses by adiponectin. However, underlying molecular mechanisms are still largely unknown. Association of Bcl-2 with Beclin-1, an autophagy activating protein, prevents autophagy induction. We have previously shown that adiponectin-induced autophagy activation is mediated through inhibition of interaction between Bcl-2 and Beclin-1. In the present study, we examined the molecular mechanisms by which adiponectin modulates association of Bcl-2 and Beclin-1 in macrophages. Herein, we demonstrated that globular adiponectin (gAcrp) induced increase in the expression of AUF1 and ZFP36L1, which act as mRNA destabilizing proteins, both in RAW 264.7 macrophages and primary peritoneal macrophages. In addition, gene silencing of AUF1 and ZFP36L1 caused restoration of decrease in Bcl-2 expression and Bcl-2 mRNA half-life by gAcrp, indicating crucial roles of AUF1 and ZFP36L1 induction in Bcl-2 mRNA destabilization by gAcrp. Moreover, knock-down of AUF1 and ZFP36L1 enhanced interaction of Bcl-2 with Beclin-1, and subsequently prevented gAcrp-induced autophagy activation, suggesting that AUF1 and ZFP36L1 induction mediates gAcrp-induced autophagy activation via Bcl-2 mRNA destabilization. Furthermore, suppressive effects of gAcrp on LPS-stimulated inflammatory mediators expression were prevented by gene silencing of AUF1 and ZFP36L1 in macrophages. Taken together, these results suggest that AUF1 and ZFP36L1 induction critically contributes to autophagy induction by gAcrp and are promising targets for anti-inflammatory responses by gAcrp.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.15-19
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• 2003

Metallothionein gene expression activity of cadmium was investigated in a human lung epithelial cell line. Cells, grown to near confluence, were exposed to 0∼10 ${\mu}$M Cd metal for 6 hours. Cadmium did not cause morphological alteration in lung epithelial cells that are characteristic of cell damages such as cell shrinkage, detachment of the cell from its neighbors, cytoplasmic and chromatic condensation. However, metallothionein genes of MT-1 and MT-2 were rapidly induced in the treated cell measured by RT-PCR. Regarding the induction pattern of motallothionein mRNA, MT-1 mRNA was induced in a dependent manner. MT-2 mRNA induction, which was measured using oligo primers based on cDNA of human reticulocytes, seemed to be slightly increased in low doses but decreased at high concentration used in the experiment.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.186-191
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• 2001

Vitellogenin (VTG) and VTG mRNA induction by $estradiol-17\beta\;(E_2)$ were examined in the primary cultures of hepatocyte in the rainbow trout. Hepatocytes were precultured for 2 days, then $E_2$ was added and cultured for another 5 days. Media and hepatocytes were then analyzed by electrophoresis and Northern blotting for VTG and VTG mRNA, respectively. The hepatocytes were formed a few aggregates within 5 days without further spreading to a monolayer. Cell viability and high DNA content were maintained during the incubation. The hepatocyte culture with E2 induced a weak VTG band at a molecular weight of 175kDa on Day 2 after $E_2$ addition. The relative amount of VTG was expressed in percentage of total protein concentrations. VTG was gradually increased as $1.9\%$ on Day 2, $6.3\%$ on Day 4 and $7.3\%$ on Day 5. VTG mRNA band was detected at about 6.6 kb in the culture with $E_2$ at day 1 of culture. The level of VTG mRNA expression linearly increased with time until Day 5 (r=0.97).

• Biomedical Science Letters
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• v.10 no.4
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• pp.479-483
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• 2004

The aim of this study was carried to the induction of follistatin-like 1 (FSTL1) in rat myometrium tissue by exogenous estrogen. PCR was performed by using estrogen treatment after ovariectomy of myometrium mRNA and only ovariectomy of myometrium mRNA and on ovariectomy of myometrium mRNA in rat normal uterus tissue. The PCR products were visualized on agarose gel (1.2％) electrophoresis. FSTL1 mRNA expression level was significantly higher (**P<0.001 or *P<0.05) in estrogen treatment after ovariectomy than in only ovariectomy, and was significantly higher (**P<0.001) in no ovariectomy than in estrogen with treatment after ovariectomy. In conclusion, Although the mechanisms of FSTL1 gene were uncertain, It also might be inducted by exogenous estrogen. And also it is thought to be related to the estorgen mechanism.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.241-248
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• 2017

BACKGROUND: RNA interference (RNAi) eliminates or decreases gene expression by disrupting the target mRNA or by interfering with translation. Recently, RNAi technique was applied to generate new crop traits which provide protection against pests. To establish the environmental risk assessment protocol of RNAi LMO in lab scale, we developed dsRNA expression system using E. coli and tested acute oral toxicity assay to honey. METHOD AND RESULTS: The dsRNA expression vector, L4440, was chosen and cloned 240 bp of Snf7 and GFP gene fragment. To develop the maximum dsRNA induction condition in E. coli, we tested induction time, temperature and IPTG concentration in media. To estimate the risk assessment of dsRNA to honey bee, it has been selected and cultured with dsRNA supplement for 48 hours according to OECD guideline. As a result, the optimum condition of dsRNA induction was $37^{\circ}C$, 4 hours and 0.4 mM IPTG concentration and the difference between Snf7 and GFP dsRNA molecules from E. coli was not significant in survival and behavior to honey bee. Furthermore, blast search results indicated that effective match of predicted dsRNA fragments were not existed in honey bee genome. CONCLUSION: In this study, we developed and tested the acute oral toxicity of dsRNA using E. coli expression system to honey bee.