• International Journal of Oral Biology
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• v.43 no.1
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• pp.29-35
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• 2018

It is noted that chalcone derivatives have characteristic diverse pharmacological properties, and that precise evidence has been growing that they could regulate a tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) induced insulin resistance. The purpose of the present investigation is to elucidate the effects of the identified chalcone derivatives on adipogenesis, and to find the underlying mechanism of action in that case. Consequently, we first investigated whether the chalcone derivatives could affect the identified $PPAR{\gamma}$-induced transcriptional activity on the proliferator-activated receptor response elements (PPRE) at target promoters, and find that trans-chalcone most significantly increased the $PPAR{\gamma}$-induced transcriptional activity. Additionally, we confirmed that there were up-regulatory effects of trans-chalcone during the adipogenesis and lipid accumulation, and on the mRNA of adipogenic factors in 3T3-L1 cells. Next, we examined the effect of trans-chalcone on the inhibition induced by $TNF-{\alpha}$ on adipogenesis. To that end, we noted that the treatment with trans-chalcone attenuated the effect of $TNF-{\alpha}$ mediated secretion of various adipokines that are involved in insulin sensitivity. For this reason, we noted that this study clearly demonstrates that trans-chalcone enhanced adipogenesis, in part, by its potent effect on $PPAR{\gamma}$ activation and by its reverse effect on $TNF-{\alpha}$.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.6
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• pp.649-655
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• 2016

TonEBP belongs to the Rel family of transcription factors and plays important roles in inflammation as well as kidney homeostasis. Recent studies suggest that TonEBP expression is also involved in differentiation of several cell types such as myocytes, chondrocytes, and osteocytes. In this study, we investigated the roles of TonEBP during adipocyte differentiation in 3T3-L1 cells. TonEBP mRNA and protein expression was dramatically reduced during adipocyte differentiation. Sustained expression of TonEBP using an adenovirus suppressed the formation of lipid droplets as well as the expression of FABP4, a marker of differentiated adipocytes. TonEBP also inhibited the expression of $PPAR{\gamma}$, a known master regulator of adipocytes. RNAi-mediated knock down of TonEBP promoted adipocyte differentiation. However, overexpression of TonEBP did not affect adipogenesis after the initiation of differentiation. Furthermore, TonEBP expression suppressed mitotic clonal expansion and insulin signaling, which are required early for adipocyte differentiation of 3T3-L1 cells. These results suggest that TonEBP may be an important regulatory factor in the early phase of adipocyte differentiation.

• Nutrition Research and Practice
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• v.15 no.5
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• pp.568-578
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• 2021

BACKGROUND/OBJECTIVES: Psidium guajava L. (guava) leaves have been shown to exhibit hypoglycemic and antidiabetic effects in rodents. This study investigated the effects of guava leaf extract on adipogenesis, glucose uptake, and lipolysis of adipocytes to examine whether the antidiabetic properties are mediated through direct effects on adipocytes. MATERIALS/METHODS: 3T3-L1 cells were treated with 25, 50, 100 ㎍/mL of methanol extract from guava leaf extract (GLE) or 0.1% dimethyl sulfoxide as a control. Lipid accumulation was evaluated with Oil Red O Staining and AdipoRed assay. Immunoblotting was performed to measure the expression of adipogenic transcription factors, fatty acid synthase (FAS), and AMP-activated protein kinase (AMPK). Glucose uptake under basal or insulin-stimulated condition was measured using a glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose. Lipolysis from fully differentiated adipocytes was measured by free fatty acids release into the culture medium in the presence or absence of epinephrine. RESULTS: Oil Red O staining and AdipoRed assay have shown that GLE treatment reduced lipid accumulation during adipocyte differentiation. Mitotic clonal expansion, an early essential event for adipocyte differentiation, was inhibited by GLE treatment. GLE inhibited the expression of transcription factors involved in adipocyte differentiation, such as peroxisome proliferator-activated receptor 𝛄 (PPAR𝛄), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein-1c (SREBP-1c). FAS expression was also decreased while the phosphorylation of AMPK was increased by GLE treatment. In addition, GLE increased insulin-induced glucose uptake into adipocytes. In lipid-filled mature adipocytes, GLE enhanced epinephrine-induced lipolysis but reduced basal lipolysis dose-dependently. CONCLUSIONS: The results show that GLE inhibits adipogenesis and improves adipocyte function by reducing basal lipolysis and increasing insulin-stimulated glucose uptake in adipocytes, which can be partly associated with antidiabetic effects of guava leaves.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1688-1697
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• 2024

The current study aimed to determine whether Strongylocentrotus intermedius (S. intermedius) extract (SIE) exerts anti-obesity potentials employing 3T3-L1 cells as in vitro model. Herein we reported that treatment of SIE for 6 days reduced lipid accretion and triglyceride content whereas it increased the release of free glycerol. The inhibited lipid accumulation and induced lipolysis were evidenced by the downregulation of lipogenesis proteins, such as fatty acid synthase and lipoprotein lipase, and the upregulation of hormone-sensitive lipase expression. Furthermore, the downregulation of adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein α, and sterol regulatory element-binding protein 1, highlights that reduced lipid accumulation is supported by lowering adipocyte differentiation. Additionally, treatment activates brown adipocyte phenotype in 3T3-L1 cells by inducing expression of brown adipose tissue-specific proteins, such as uncoupling protein 1 and peroxisome proliferator-activated receptor-γ coactivator 1α. Moreover, SIE induced the phosphorylation of AMP-activated protein kinase (AMPK). The pharmacological approach using AMPK inhibitor revealed that the restraining effect of SIE on adipogenesis and promotion of adipocyte browning were blocked. In GC-MS analysis, SIE was mainly composed of cholest-5-en-3-ol (36.71%) along with saturated and unsaturated fatty acids which have favorable anti-obesity potentials. These results reveal that SIE has the possibility as a lipid-lowering agent for the intervention of obesity.

• Toxicological Research
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• v.24 no.1
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• pp.37-44
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• 2008

The in vitro cell transformation assays (CTA) were performed using BALB/3T3 murine fibroblasts and HaCaT human keratinocytes in order to evaluate concordance between both in vitro CTAs and carcinogenicity with compounds differing in their genotoxic and carcinogenic potential. Six test articles were evaluated, two each from three classes of compounds: genotoxic carcinogens (2-amino-5-nitrophenol and 4-nitroquinoline-N-oxide), genotoxic noncarcinogens (8-hydroxyquinoline and benzyl alcohol), and nongenotoxic carcinogens (methyl carbamate and N-nitrosodiphenylamine). Any foci of size $\geq$2 mm regardless of invasiveness and piling was scored as positive in CTA with BALB/3T3. As expected, four carcinogens regardless of their genotoxicity had positive outcomes in two-stage CTA using BALB/3T3 cells. However, of the two genotoxic noncarcinogens, benzyl alcohol was positive CTA finding. We concluded that, of the 6 chemicals tested, the sensitivity for BALB/3T3 system was reasonably high, being 100%. The respective specificity for BALB/3T3 assay was 50%. We also investigated the correlation between results of BALB/3T3 assay and results from HaCaT assay in order to develop a reliable human cell transformation assay. However, evaluation of staining at later time points beyond the confluency stage did not yield further assessable data because most of HaCaT cells were detached after $2{\sim}3$ days of confluency. Thus, after test article treatment, HaCaT cells were split before massive cell death began. In this modified protocol for this HaCaT system, growing attached colonies were counted instead of transformed foci 3 weeks since last subculture. Compared to BALB/3T3 assay, HaCaT assay showed moderate low sensitivity and high specificity. Despite these differences in specificity and sensitivity, both cell systems did exhibit same good concordance between in vitro CTA and rodent carcinogenicity findings (overall 83% concordant results). At present the major weakness of these in vitro CTA is lack of validation for regulatory acceptance and use. Thus, more controlled studies will be needed in order to be better able to assess and quantitatively estimate in vitro CTA data.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.398-404
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• 2007

This study was performed to investigate the enhancement of anticancer activities and immuno modulatary activities from R. coreanus. by ultra high pressure extracts process. The cytotoxicity on human kidney cell (HEK293) was showed below 19.5% in adding 1.0 $mg/m{\ell}$ concentration. The anticancer activity was increased over 10% by high pressure processing in AGS and A549 cells. The immune cell growth using human immune B and T cells was improved by the high pressure extracts of Rubus coreanus in adding 1.0 $mg/m{\ell}$ concentration. The secretion of two kinds of cytokine, the IL-6 and $TNF-{\alpha}$ from human immune B and T cells were also enhanced in adding extracts by high pressure process of R. coreanus. The ultra high pressure extraction technique showed high efficiency in extracting of bioactive compound. The ultra high pressure technique could be used combined with other technique to improve the extracting rate and extracting efficiency.

• Journal of Applied Biological Chemistry
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• v.63 no.2
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• pp.169-174
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• 2020

The objective of this study was to investigate the effects of a hypodermic injectable solution comprised of an LPM LB meso solution containing Melissa officinalis L. leaf extract (LPM) on the lipogenesis in the 3T3-L1 cells line. The lipid accumulation measured by oil red o staining in the 3T3-L1 adipocytes treated with LPM, which was reduced in a dose dependent manner and showed 91.7 to 62.9% compared to control group. Its effectiveness with a 50% solution was significantly higher than the hydroxycitric acid (positive control) treatment without showing cell cytotoxicity. In a quantitative real-time PCR, it was demonstrated that the LPM treatment appeared to upregulate the mRNA expression of the adipogenesis-related genes, which included the peroxisome proliferator-activated receptor gamma (50% concentration) while down-regulating the CCAAT-enhancer binding protein alpha (50% concentration) and the sterol regulatory element-binding protein 1c (10, 25, and 50% concentrations). The results from the current study suggest that the LPM could be useful biomaterials that can inhibit obesity in the 3T3-L1 cells, which could possibly be by regulating the specific adipogenic gene transcription factors.

• Molecules and Cells
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• v.38 no.8
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• pp.697-704
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• 2015

Deleted in breast cancer-1 (DBC1) contributes to the regulation of cell survival and apoptosis. Recent studies demonstrated that DBC is phosphorylated at Thr454 by ATM/ATR kinases in response to DNA damage, which is a critical event for p53 activation and apoptosis. However, how DBC1 phosphorylation is regulated has not been studied. Here we show that protein phosphatase 4 (PP4) dephosphorylates DBC1, regulating its role in DNA damage response. PP4R2, a regulatory subunit of PP4, mediates the interaction between DBC1 and PP4C, a catalytic subunit. PP4C efficiently dephosphorylates pThr454 on DBC1 in vitro, and the depletion of PP4C/PP4R2 in cells alters the kinetics of DBC1 phosphorylation and p53 activation, and increases apoptosis in response to DNA damage, which are compatible with the expression of the phosphomimetic DBC-1 mutant (T454E). These suggest that the PP4-mediated dephosphorylation of DBC1 is necessary for efficient damage responses in cells.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.183-192
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• 2023

p38 MAPK has been implicated in the pathogenesis of asthma as well as pro-allergic Th2 cytokines, orosomucoid-like protein isoform 3 (ORMDL3), regulation of sphingolipid biosynthesis, and regulatory T cell-derived IL-35. To elucidate the role of p38 MAPK in the pathogenesis of asthma, we examined the effect of NJK14047, an inhibitor of p38 MAPK, against ovalbumin (OVA)-induced allergic asthma; we administrated NJK14047 before OVA sensitization or challenge in BALB/c mice. As ORMDL3 regulation of sphingolipid biosynthesis has been implicated in childhood asthma, ORMDL3 expression and sphingolipids contents were also analyzed. NJK14047 inhibited antigen-induced degranulation of RBL-2H3 mast cells. NJK14047 administration both before OVA sensitization and challenge strongly inhibited the increase in eosinophil and lymphocyte counts in the bronchoalveolar lavage fluid. In addition, NJK14047 administration inhibited the increase in the levels of Th2 cytokines. Moreover, NJK14047 reduced the inflammatory score and the number of periodic acid-Schiff-stained cells in the lungs. Further, OVA-induced increase in the levels of C16:0 and C24:1 ceramides was not altered by NJK14047. These results suggest that p38 MAPK plays crucial roles in activation of dendritic and mast cells during sensitization and challenge periods, but not in ORMDL3 and sphingolipid biosynthesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.822-828
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• 2014

Allium sacculiferum Max. (ASM) is a perennial plant of the Liliaceae family and grows over the entire regions of Korea. Obesity is a serious health problem worldwide and has currently become a prevalent chronic disease. Adipocytes produced by preadipocyte differentiation during adipogenesis and adipocytes combined with abnormal accumulation cause obesity. Recently, intracellular reactive oxygen species (ROS) were shown to accelerate lipid accumulation in 3T3-L1 cells. In this study, we investigated the effects of ASM methanol extracts on ROS production and lipid accumulation in 3T3-L1 adipocytes. Our results indicate that the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of ASM methanol extracts increased in a dose-dependent manner. ASM methanol extracts suppressed ROS production and lipid accumulation during adipogenesis. In addition, ASM methanol extracts inhibited the mRNA expression of both pro-oxidant enzymes such as glucose-6-phosphate dehydrogenase as well as the transcription factors, including sterol regulatory element-binding proteins 1c, peroxisome proliferator-activated receptor ${\gamma}$, and CCAAT/enhancer-binding protein ${\alpha}$. Our results suggest that ASM methanol extracts inhibit ROS production and lipid accumulation by controlling ROS regulatory genes and adipogenic transcription factors. Thus, ASM has potent natural antioxidant, anti-adipogenic properties and have potential in the development of a potent anti-obesity agent.