• 한방비만학회지
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• 제19권2호
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• pp.89-96
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• 2019

Objectives: We investigated whether membrane free stem cell extract from adipose tissue (MFSCE) has anti-diabetic effect. Methods: To determine glucose uptake effect of MFSCE, we carried out glucose uptake assay in 3T3-L1 adipocytes. The regulatory mechanisms of MFSCE on glucose uptake were examined by Western blot analysis. Results: When MFSCE was treated to adipocytes at the concentration of 0.5, 1, 2.5, and 5 ㎍/mL, 2-deoxyglucose-6-phosphate uptake was elevated approximately 1.8-fold compared to cells not treated with MFSCE. It indicated that MFSCE enhances glucose uptake in 3T3-L1 adipocytes. In addition, MFSCE reduced phosphorylation of insulin receptor substrate-1 at serine 307 and induced Akt and glucose transporter 4 protein expressions that were related to insulin signaling. Furthermore, MFSCE regulated adenosine monophosphate-activated protein kinase (AMPK) pathway by increases of increase phosphorylation of AMPK and acetyl-CoA carboxylase that were related to AMPK pathway. Conclusions: These results indicated that MFSCE promotes glucose uptake via modulation of insulin signaling and AMPK pathway. Therefore, MFSCE could be a promising agent for treatment of diabetes mellitus.

• 한국자원식물학회지
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• 제28권5호
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• pp.582-590
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• 2015

본 연구는 HRL의 3T3-L1 지방전구세포의 분화과정 중에 HRL이 지방의 축적에 미치는 영향을 확인하였다. MTT assay를 이용하여 세포 독성을 측정한 결과 100 ㎍/㎖의 농도에서도 세포증식에 영향을 미치지 않는 것을 확인하였고, 이와 같은 결과를 토대로 Oil Red O 염색법을 이용하여 지방세포 분화 억제능을 측정하였다. 그 결과, HRL의 경우 100 ㎍/㎖의 농도에서 82.25% 지방 축적 억제능을 나타내었다. 지방생성에 영향을 미치는 유전자 발현량을 측정하기 위해 RT-PCR법과 western blot법을 시행하였다. HRL은 SREBP-1c, PPARγ와 C/EBPα의 mRNA 발현을 억제시켰고, 지방생성에 영향을 미치는 효소인 FAS의 생성을 조절하는 것으로 나타났다. 또한, HRL 처리로 AMPKα의 단백질 발현이 증가하였으며, PPARγ의 발현량이 감소하는 것을 확인하였다. 이상의 결과들로부터 HRL은 AMPKα의 활성화를 통한 지방 합성을 억제를 보유하고 있는 바, 향후 항비만 기능성 소재로 활용될 수 있을 것으로 생각한다.

• IMMUNE NETWORK
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• 제13권2호
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• pp.75-79
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• 2013

Evidence for immunoregulatory roles of prostaglandins (PGs) is accumulating. Since our observation of PG production by human follicular dendritic cells (FDCs), we investigated the regulatory mechanism of PG production in FDC and attempted to understand the functions of released PGs in the responses of adjacent lymphocytes. Here, using FDC-like cells, HK cells, we analyzed protein expression alterations in cyclooxygenase-2 (COX-2) in the presence of IL-4 or histone deacetylase (HDAC) inhibitors. Both IL-4 and HDAC inhibitors suppressed COX-2 expression in dose-dependent manners. Their effect was specific to COX-2 and did not reach to COX-1 expression. Interestingly, HDAC inhibitors gave rise to an opposing effect on COX-2 expression in peripheral blood monocytes. Our results suggest that IL-4 may regulate COX-2 expression in FDCs by affecting chromatin remodeling and provide insight into the role of cellular interactions between T cells and FDC during the GC reaction. Given the growing interests in wide-spectrum HDAC inhibitors, the differential results on COX-2 expression in HK cells and monocytes raise cautions on their clinical use.

• Journal of Ginseng Research
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• 제40권4호
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• pp.431-436
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• 2016

Background: Although numerous studies of the anticancer activities of Korean Red Ginseng (KRG) have been performed, the therapeutic effect of KRG on leukemia has not been fully elucidated. In this study, we investigated the antileukemia activities of KRG and its cellular and molecular mechanisms. Methods: An established leukemia tumor model induced by xenografted T cell lymphoma (RMA cells) was used to test the therapeutic activity of KRG water extract (KRG-WE). Direct cytotoxic activity of KRG-WE was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The immunomodulatory activities of KRG-WE were verified by immunohistochemistry, nitric oxide production assay. The inhibitory effect of KRG-WE on cell survival signaling was also examined. Results: Orally administered KRG-WE reduced the sizes of tumor masses. Levels of apoptosis regulatory enzymes and cleaved forms of caspases-3 and -8 were increased by this extract. In addition, expression of matrix metalloproteinase-9, a metastasis regulatory enzyme, was decreased by KRG-WE treatment. The proportion of CD11c+ cells was remarkably increased in the KRG-treated group compared to the control group. However, KRG-WE did not show significant direct cytotoxicity against RMA cells. Conclusion: Our results strongly suggest that the KRG might have antileukemia activity through CD11c+ cell-mediated antitumor immunity.

• 한국수산과학회지
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• 제50권3호
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• pp.302-310
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• 2017

Interferon regulatory factor 8 (IRF8) is essential for the development of B and T cells, as well as for the activity of dendritic cells and macrophages. We performed molecular characterization of IRF8 from rock fish, Sebastes schlegelii (Ss), and investigated the spatial and temporal profile of mRNA expression after challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), or Streptococcus iniae. The full-length cDNA sequence of SsIRF8 was 1,657 bp, containing an ORF of 1,266 bp. The gene had a predicted molecular mass of 47.7 kDa and an isoelectric point of 5.99. The amino acid sequence coded by this gene showed the highest degree of identity (90.8%) and similarity (96.2%) with IRF8 from Oplegnathus fasciatus. The SsIRF8 mRNA was expressed ubiquitously, at varying levels, with the highest level of expression observed in the spleen. To confirm the role of SsIRF8 in mediating the immune response, we measured SsIRF8 mRNA expression in the splenic tissue at different time points after injection with LPS, poly I:C, or S. iniae. The qRT-PCR results showed that SsIRF8 mRNA expression in the poly I:C-injected group was highly upregulated 6 hr after exposure (P<0.05). Expression of SsIRF8 mRNA in the S. iniae-injected group peaked at 24 hr. These results suggest that SsIRF8 might be important in regulating the strength of the rockfish immune response to immunostimulatory agents.

• BMB Reports
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• 제54권1호
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• pp.2-11
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• 2021

Antibody-based therapeutics targeting the inhibitory receptors PD-1, PD-L1, or CTLA-4 have shown remarkable clinical progress on several cancers. However, most patients do not benefit from these therapies. Thus, many efforts are being made to identify new immune checkpoint receptor-ligand pathways that are alternative targets for cancer immunotherapies. Nectin and nectin-like molecules are widely expressed on several types of tumor cells and play regulatory roles in T- and NK-cell functions. TIGIT, CD226, CD96 and CD112R on lymphoid cells are a group of immunoglobulin superfamily receptors that interact with Nectin and nectin-like molecules with different affinities. These receptors transmit activating or inhibitory signals upon binding their cognate ligands to the immune cells. The integrated signals formed by their complex interactions contribute to regulating immune-cell functions. Several clinical trials are currently evaluating the efficacy of anti-TIGIT and anti-CD112R blockades for treating patients with solid tumors. However, many questions still need to be answered in order to fully understand the dynamics and functions of these receptor networks. This review addresses the rationale behind targeting TIGIT, CD226, CD96, and CD112R to regulate T- and NK-cell functions and discusses their potential application in cancer immunotherapy.

• Asian-Australasian Journal of Animal Sciences
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• 제33권6호
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• pp.1012-1022
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• 2020

Objective: Caseins and fatty acids of milk are synthesized and secreted by the epithelial cells of the mammary gland. All-trans retinoic acid (ATRA), an active metabolite of vitamin A, has been shown to promote mammary development. This study was conducted to determine the effect of ATRA on casein synthesis and fatty acid composition in MAC-T cells. Methods: MAC-T cells were allowed to differentiate for 4 d, treated with ATRA (0, 1.0, 1.5, and 2.0 μM), and incubated for 3 d. We analyzed the fatty acid composition, the mRNA expression of casein and fatty acid synthesis-related genes, and the phosphorylation of casein synthesis-related proteins of MAC-T cells by gas chromatography, quantitative polymerase chain reaction, and western blotting, respectively. Results: In MAC-T cells, ATRA increased the mRNA levels of α_S1-casein and β-casein, janus kinase 2 (JAK2) and E74-like factor 5 of the signal transducer and activator of transcription 5 β (STAT5-β) pathway, ribosomal protein S6 kinase beta-1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 of the mammalian target of rapamycin (mTOR) pathway, inhibited the mRNA expression of phosphoinositide 3-kinase and eukaryotic initiation factor 4E of the mTOR pathway, and promoted the phosphorylation of STAT5-β and S6K1 proteins. Additionally, ATRA increased the de novo synthesis of fatty acids, reduced the content of long-chain fatty acids, the ratio of monounsaturated fatty acids to saturated fatty acids (SFA), the ratio of polyunsaturated fatty acids (PUFA) to SFA, and the ratio of ω-6 to ω-3 PUFA. The mRNA levels of acetyl-CoA carboxylase 1, fatty acid synthase, lipoprotein lipase, stearoyl-CoA desaturase, peroxisome proliferator-activated receptor gamma, and sterol regulatory element-binding protein 1 (SREBP1) were enhanced by ATRA. Conclusion: ATRA promotes the synthesis of casein by regulating JAK2/STAT5 pathway and downstream mTOR signaling pathway, and it improves the fatty acid composition of MAC-T cells by regulating SREBP1-related genes.

• Molecules and Cells
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• 제40권6호
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• pp.393-400
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• 2017

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by lack of insulin and high glucose levels. T2DM can cause bone loss and fracture, thus leading to diabetic osteoporosis. Promoting osteogenic differentiation of osteoblasts may effectively treat diabetic osteoporosis. We previously reported that Sirtuin 1 (Sirt1), a $NAD^+$-dependent deacetylase, promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor (PPAR) ${\gamma}$. We also found that miR-132 regulates osteogenic differentiation by downregulating Sirt1 in a $PPAR{\beta}/{\delta}$-dependent manner. The ligand-activated transcription factor, $PPAR{\alpha}$, is another isotype of the peroxisome proliferator-activated receptor family that helps maintain bone homeostasis and promot bone formation. Whether the regulatory role of $PPAR{\alpha}$ in osteogenic differentiation is mediated via Sirt1 remains unclear. In the present study, we aimed to determine this role and the underlying mechanism by using high glucose (HG) and free fatty acids (FFA) to mimic T2DM in MC3T3-E1 cells. The results showed that HG-FFA significantly inhibited expression of $PPAR{\alpha}$, Sirt1 and osteogenic differentiation, but these effects were markedly reversed by $PPAR{\alpha}$ overexpression. Moreover, siSirt1 attenuated the positive effects of $PPAR{\alpha}$ on osteogenic differentiation, suggesting that $PPAR{\alpha}$ promotes osteogenic differentiation in a Sirt1-dependent manner. Luciferase activity assay confirmed interactions between $PPAR{\alpha}$ and Sirt1. These findings indicate that $PPAR{\alpha}$ promotes osteogenic differentiation via the Sirt1-dependent signaling pathway.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.83-92
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• 2019

Based on the reactive oxygen species (ROS) regulatory properties of diphenyleneiodonium (DPI), we investigated the effects of DPI on host-infected T. gondii proliferation and determined specific concentration that inhibit the intracellular parasite growth but without severe toxic effect on human retinal pigment epithelial (ARPE-19) cells. As a result, it is observed that host superoxide, mitochondria superoxide and $H_2O_2$ levels can be increased by DPI, significantly, followed by suppression of T. gondii infection and proliferation. The involvement of ROS in anti-parasitic effect of DPI was confirmed by finding that DPI effect on T. gondii can be reversed by ROS scavengers, N-acetyl-L-cysteine and ascorbic acid. These results suggest that, in ARPE-19 cell, DPI can enhance host ROS generation to prevent T. gondii growth. Our study showed DPI is capable of suppressing T. gondii growth in host cells while minimizing the un-favorite side-effect to host cell. These results imply that DPI as a promising candidate material for novel drug development that can ameliorate toxoplasmosis based on ROS regulation.

• Nutrition Research and Practice
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• 제17권6호
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• pp.1043-1055
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• 2023

BACKGROUND/OBJECTIVES: The fruit of Cydonia oblonga Miller (COM) is used traditionally in Mediterranean region medicine to prevent or treat obesity, but its mechanism of action is still unclear. Beyond a demonstrated anti-obesity effect, the fruit was tested for the mechanism of adipogenesis in 3T3-L1 preadipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were cultured for 8 days with COM fruit extract (COME) at different concentrations (0-600 ㎍/mL) with adipocyte differentiation medium. The cell viability was measured using an MTT assay; triglyceride (TG) was stained with Oil Red O. The expression levels of the adipogenesis-related genes and protein expression were analyzed by reverse transcription polymerase chain reaction and Western blotting, respectively. RESULTS: COME inhibited intracellular TG accumulation during adipogenesis. A COME treatment in 3T3-L1 cells induced upregulation of the adenosine monophosphate-activated protein kinase (AMPK)α phosphorylation and downregulation of the adipogenic transcription factors, such as sterol regulatory element-binding protein 1c, peroxisome proliferator-activated receptor γ, and CCAAT/enhancer binding protein α. The COME treatment reduced the mRNA expression of fatty acyl synthetase, adenosine triphosphate-citrate lyase, adipocyte protein 2, and lipoprotein lipase. It increased the mRNA expression of hormone-sensitive lipase and carnitine palmitoyltransferase I in 3T3-L1 cells. CONCLUSIONS: COME inhibits adipogenesis via the AMPK signaling pathways. COME may be used to prevent and treat obesity.