• Journal of Life Science
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• v.27 no.10
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• pp.1104-1110
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• 2017

SET1A is a histone H3K4 methyltransferase that catalyzes di- and trimethylation of histone H3 at lysine 4 (H3K4). Mono-, di-, and trimethylations on H3K4 (H3K4me1, H3K4me2, and H3K4me3, respectively) are generally correlated with gene activation. Although H3K4 methylation is associated with the stimulation of adipogenesis of 3T3-L1 preadipocytes, it remains unknown whether SET1A plays a role in the regulation of adipogenesis of 3T3-L1 preadipocytes. Here, we investigated whether SET1A regulates 3T3-L1 preadipocytes' adipogenesis and characterized the mechanism involved in this regulation. SET1A expression increased during 3T3-L1 preadipocytes' adipogenesis. Consistent with the increased SET1A expression, the global H3K4me3 level had also increased on day 2 after the induction of adipogenesis in 3T3-L1 adipocytes. SET1A knockdown using siRNA in 3T3-L1 preadipocytes inhibited 3T3-L1 preadipocytes' adipogenesis, as assessed by Oil Red O staining and the expression of adipogenic genes, indicating that SET1A stimulates the adipogenesis of 3T3-L1 preadipocytes. SET1A knockdown inhibited the cell proliferation of 3T3-L1 cells during mitotic clonal expansion (MCE) via down-regulation of the cell cycle gene cyclin E1, as well as the DNA synthesis gene, dihydrofolate reductase. Furthermore, SET1A knockdown repressed peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) expression during the late stage of adipogenesis. These results indicate that SET1A stimulates MCE and $PPAR{\gamma}$ expression, which leads to the promotion of 3T3-L1 preadipocytes' adipogenesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.651-663
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• 2016

Corn silk, Job's tears, Lentinus edodes, and apple peel 70% ethanol extracts (CS, JT, LE, and AP) were studied for their antioxidant activities. CS among all extracts showed the highest antioxidant activities based on total polyphenol and flavonoid contents, 2,2-diphenyl-${\beta}$-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity, and reducing power. Adipocyte differentiation was investigated by Oil Red O staining assay using CS, JT, LE, AP, and extract of developed bread containing corn silk, Job's tears, Lentinus edodes, and apple peel (DB) treated to 3T3-L1 adipocytes. DB1 and DB2 showed anti-adipogenic and antioxidant effects. Triglyceride (TG) accumulation in 3T3-L1 cells was measured, and among the samples tested (CS, JT, LE, and AP), CS was found to have the highest inhibitory activity against TG accumulation of differentiated 3T3-L1 adipocytes and regulated factors associated with adipogenesis. CS suppressed lipid droplet formation and adipocyte differentiation in 3T3-L1 cells in a dose-dependent manner. We examined the effects of CS on the levels of CCAAT-enhancer-binding protein ${\beta}(C/EBP{\beta})$, peroxisome proliferator activated receptor ${\gamma}(PPAR{\gamma})$, and adipocyte-specific lipid binding protein (aP2) mRNA as well as protein levels in 3T3-L1 cells treated with CS at various concentrations (0, 10, 50, and $100{\mu}g/mL$) during adipocyte differentiation and treatment with CS in 3T3-L1 adipocytes down-regulated expression of $PPAR{\gamma}$ and aP2 mRNA. CS also significantly inhibited up-regulation of $C/EBP{\beta}$, $PPAR{\gamma}$, and aP2 proteins during adipocyte differentiation. These data indicate that DBs have anti-adipogenic activity induced by CS in 3T3-L1 preadipocytes, and CS exerts anti-adipogenic activity by inhibiting expression of $C/EBP{\beta}$, $PPAR{\gamma}$, and aP2 signaling pathway in 3T3-L1 adipocytes. JT, LE, and AP had no inhibitory effects on differentiation of 3T3-L1 preadipocytes but displayed strong antioxidant effects. These results suggest that the developed bread may be a health beneficial food that can prevent or treat obesity and diseases induced by oxidative stress.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.19-23
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• 2013

The current study was carried out to determine the effects of Kohlrabi (Brassica oleracea var. gongylodes) on proliferation and differentiation of pig preadipocytes and $_3T_3-L_1$ cells. Pig preadipocytes were isolated from the backfat of the new-born pigs. Twenty-four hours after seeding, the cells were washed with DMEM/F-12 (designated day 0). To measure the cell proliferation, the cells were treated with 25 ng/ml and 100 ng/ml ethanol extracts of Kohlrabi (peel and flesh) for two days (day 0 ~ 2). To measure differentiation, the cells were treated with Kohlrabi for two days (day 0 ~ 2) and cell differentiation was measured on day 6. Twenty-five ng/ml and 100 ng/ml of Kohlrabi peel decreased proliferation of pig preadipocytes by 4.59% and 17.7%, respectively, compared with the control and Kohlrabi flesh by 11.4% and 19.2%, respectively. However, Kohlrabi did not inhibit cell differentiation. To measure the effects of Kohlrabi on proliferation and differentiation of $_3T_3-L_1$ cells, the cells were treated with Kohlrabi for two days in culture, like pig preadipocytes. Kohlrabi (both peel and flesh) did not show any effects on cell proliferation and differentiation. In summary, the results of the current study showed that Kohlrabi decreased proliferation of pig preadipocytes, but no inhibitory effects on differentiation of the cells. Kohlrabi had no effects on proliferation and differentiation of $_3T_3-L_1$ cells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.541-545
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• 2000

This study examines the effects of alginic acid, a source of dietary fiber, in a glucose-derived media. In particular, we examined how the presence or absence of alginic acid affected the differentiation and triglyceride densities of 3T3-L1 cells. We established that the addition of insulin-like growth factor-I (IGE-I) to 3T3-L1 cells results in acceleration of differentiation. We sought to determine the role of alginic acid in the production of fat by adding alginic acid to 3T3-L1 cells and examining its ability to limit or potentiate this stimulatory effects of IGE-I and IGF binding proteins. We have determined that alginic acid restricts 3T3-L1 cell differentiation and the creation of triglycerides, effectively attenuating 3T3-L1 cell metablolism and growth.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.47-52
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• 2002

In order to search for insulin-like substances from the constituted herbs of Sogal prescriptions, we selected 19 traditional herbs, based on a review of the Donguibogam. The effects of the hot-water extract from the selected herbs on the proliferation and the differentiation of 3T3-L1 fibroblasts were tested. The various water-extracts from Pinellia ternata, Magnolia obovata, Rheum palmatum, Acanthopanax sessiliflorun, Atractylodes japonica and Strychnos ignatii inhibited the proliferation of 3T3-L1 fibroblasts, did not influence entirely in differentiation of 3T3-L1 fibroblasts. Treatment of 3T3-L1 fibroblasts with the extract from Ephedra sinica, Trichosanthes kirilowii, Scrophularia buergeriana and Sophora flavescens significantly increased the differentiation of the cells. In conclusion, these may contain such compounds that play a role of insulin-like action.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.383-388
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• 2020

Elephant garlic (Allium ampeloprasum L.) has been reported to have several pharmacological effects. However, its anti-adipogenic effect and the possible molecular mechanisms have not yet been reported. In this study, we demonstrate that elephant garlic extracts suppress adipogenesis in 3T3-L1 adipocytes. Raw and steamed elephant garlic extracts (REG and SEG, respectively) suppressed the differentiation of adipocytes and cellular lipid accumulation. Of note, the anti-differentiation effect of REG treatment on 3T3-L1 cells resulted in cytotoxicity, whereas SEG-treated cells displayed no such cytotoxicity. Additionally, SEG treatment significantly reduced the adipogenesis-related gene expression of PPAR γ, C/EBPα, adiponectin, Ap2, and LPL. To our knowledge, these results are the first evidence of the anti-adipogenic effects of elephant garlic extracts on 3T3-L1 adipocytes.

• Journal of Life Science
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• v.33 no.11
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• pp.859-867
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• 2023

Lupeol is a type of pentacyclic triterpene that has been reported to have therapeutic effects for treating many diseases; however, its effect on insulin resistance is unclear clear. This study examined the inhibitory effect of lupeol on the serine phosphorylation of insulin receptor substrate-1 in insulin resistance-induced 3T3-L1 adipocytes. 3T3-L1 cells were cultured and treated with tumor necrosis factor-α (TNF-α) for 24 hours to induce insulin resistance. Cells treated with different concentrations of lupeol (15 μM or 30 μM) or 100 nM of rosiglitazone were incubated. Then, lysed cells underwent western blotting. Lupeol exhibited a positive effect on the negative regulator of insulin signaling and inflammation-activated protein kinase caused by TNF-α in adipocytes. Lupeol inhibited the activation of protein tyrosine phosphatase-1B (PTP-1B)-a negative regulator of insulin signaling-and c-Jun N-terminal kinase (JNK); it was also an inhibitor of nuclear factor kappa-B kinase (IKK) and inflammation-activated protein kinases. In addition, Lupeol downregulated serine phosphorylation and upregulated tyrosine phosphorylation in insulin receptor substrate-1. Then, the downregulated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway was activated, the translocation of glucose transporter type 4 was stimulated to the cell membrane, and intracellular glucose uptake increased in the insulin resistance-induced 3T3-L1 adipocytes. Lupeol may improve TNF-α-induced insulin resistance by downregulating the serine phosphorylation of insulin receptor substrate 1 by inhibiting negative regulators of insulin signaling and inflammation-activated protein kinases in 3T3-L1 adipocytes.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.103-109
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• 2012

Present study was performed to investigate the effect of single and co-culture of adipocyte and muscle cell lines on cell differentiation. 3T3-L1 (adipocyte) and L6 (muscle) cell lines were single-cultured on the condition of 10% fetal bovine serum (FBS)/Dulbeco's modified eagle's medium (DMEM) for 48 h followed by culture within 5% FBS/DMEM as a growth media. Then, the growth media was replaced by differentiation media composed of 2% FBS/DMEM without additives in single- or co-culture of the 3T3-L1 and the L6 cells to induce differentiation of both cell types. In co-culture system, the 3T3-L1 and the L6 cells were grown in separated places by being seeded on a $0.4{\mu}m$ insert membrane and on the bottom of 6 well plate, respectively. Cell differentiation was measured using morphological investigation and cytosolic analysis of glycerol-3-phosphate dehydrogenase (GPDH; for 3T3-L1) and creatine kinase (CK; for L6). Based on the GPDH results, the presence of L6 cells did not stimulate 3T3-L1 differentiation showing more differentiation of 3T3-L1 cells in the single-culture compared to the co-culture condition. In contrast, 3T3-L1 cells in the co-culture promoted differentiation of L6 cells. Enzymatic analysis supported this result showing that 3T3-L1 cells showed statistically (P<0.05) higher GPDH activity in the single-culture than the co-culture, whereas CK results of L6 cells were vice versa (P<0.05). Overall, present results may indicate that co-culture system is more reliable and precise technique compared to single-culture. Further studies on several co-culture trials including different media conditions, supplementation of differentiating substances, molecular biological analysis, etc. should be required to obtain practical and fundamental mass data.

• Journal of Life Science
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• v.21 no.6
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• pp.783-787
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• 2011

The effects of thaumatin isolated from katemfe fruit of Thaumatococcus daiellii Benth on 3T3-L1 preadipocyte differentiation was investigated in vitro. 3T3-L1 adipocytes were treated with various concentrations of thaumatin ranging in 0-5 ${\mu}M$. Thaumatin reduced fat accumulation in differentiated 3T3-L1 adipocytes in a dose-dependent manner. 3T3-L1 cell proliferation was 97.0 and 88.3% at 1 and 3 ${\mu}M$ after 8 days of thaumatin treatment, respectively. Thaumatin showed a potent inhibitory effect on stained lipid droplets at a concentration of 3 ${\mu}M$. Thaumatin reduced triglyceride accumulation in differentiated 3T3-L1 cells in a dose-dependent manner, compared with positive control cells. This study provides basic information on the anti-obesity activity of thaumatin.

• Journal of Life Science
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• v.18 no.11
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• pp.1600-1605
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• 2008

This study was performed to verify the gene expression of 3T3-L1 using the siRNA of the aromatase gene, which is the estrogen synthesis enzymes. First of all three pairs of siRNA were designed from the CYP19A1 (aromatase) and analyzed the formation of fat cell mechanism by transferring gene to 3T3-L1 and differentiating it. As a result, the expression of leptin gene, which is the main gene causing the obesity, was controlled and the cause of the obesity is related with the insulin specifically. The overexpression of adiponectin and adipsin was observed. This result showed that the formation of the fat was controlled a little without any side effect by obstructing a specific material out of all the signal systems in the fat formation. This study will be an important clue to make it clear that the lack or overexpression of estrogen might be the cause of fat formation mechanism.