• Molecules and Cells
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• 제45권5호
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• pp.343-352
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• 2022

The advent of the assay for transposase-accessible chromatin using sequencing (ATAC-seq) has shown great potential as a leading method for analyzing the genome-wide profiling of chromatin accessibility. A comprehensive reference to the ATAC-seq dataset for disease progression is important for understanding the regulatory specificity caused by genetic or epigenetic changes. In this study, we present a genome-wide chromatin accessibility profile of 44 liver samples spanning the full histological spectrum of nonalcoholic fatty liver disease (NAFLD). We analyzed the ATAC-seq signal enrichment, fragment size distribution, and correlation coefficients according to the histological severity of NAFLD (healthy control vs steatosis vs fibrotic nonalcoholic steatohepatitis), demonstrating the high quality of the dataset. Consequently, 112,303 merged regions (genomic regions containing one or multiple overlapping peak regions) were identified. Additionally, we found differentially accessible regions (DARs) and performed transcription factor binding motif enrichment analysis and de novo motif analysis to determine new biomarker candidates. These data revealed the gene-regulatory interactions and noncoding factors that can affect NAFLD progression. In summary, our study provides a valuable resource for the human epigenome by applying an advanced approach to facilitate diagnosis and treatment by understanding the non-coding genome of NAFLD.

• 비만대사연구학술지
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• 제3권1호
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• pp.35-42
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• 2024

Serotonin, a biogenic amine widely found in many organisms, functions as both a neurotransmitter and hormone. Although serotonin is involved in various physiological processes, this study aimed to review its role in energy metabolism. Given that serotonin cannot cross the blood-brain barrier and is synthesized by two different isoforms of tryptophan hydroxylase in the central nervous system (CNS) and peripheral tissues, it is reasonable to assume that serotonin in the CNS and peripheral tissues functions independently. Recent studies have demonstrated how serotonin influences energy metabolism in metabolic target organs such as the intestines, liver, pancreas, and adipose tissue. In summary, serotonin in the CNS induces satiety and appetite suppression, stimulates thermogenesis, and reduces body weight. Conversely, serotonin in the periphery increases intestinal motility, stimulates gluconeogenesis in the liver, suppresses glucose uptake by hepatocytes, promotes fat uptake by liver cells, stimulates insulin secretion while suppressing glucagon secretion in the pancreatic islets, promotes lipogenesis in white adipose tissue, inhibits lipolysis and browning of white adipose tissue, and suppresses thermogenesis in brown adipose tissue, thereby storing energy and increasing body weight. However, considering that most experimental results were obtained using mice and conducted under specific nutritional conditions, such as high-fat diets, whether serotonin acts in the same way in humans, whether it will act similarly in individuals with normal versus obese weights, and whether its effects vary depending on the type of food consumed, remain unknown.

• 동의생리병리학회지
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• 제27권6호
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• pp.802-808
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• 2013

Here we tried to uncover the potential anti-lipogenic effect and the underlying mechanism of Phaseolus angularis seed in a cellular model of nonalcoholic fatty liver disease (NAFLD) induced in HepG2 cells. Ethanol extract of Phaseolus angularis seed (JSD) was prepared. HepG2 cells were incubated in palmitate containing media to induce intracellular lipid accumulation, and co-treated with JSD for 16 hrs before examine intracellular lipid content. In control group, the cells were not co-treated with JSD. We measured the effects of JSD on liver X receptor ${\alpha}$ ($LXR{\alpha}$) and sterol regulatory element-binding transcription factor-1c (SREBP-1c) expression, transcription level of lipogenic genes, including acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), and AMP-activated protein kinase (AMPK) activation in HepG2 cells. JSD markedly reduced palmitate-induced intracellular lipid accumulation in HepG2 cells. JSD suppressed $LXR{\alpha}$/SREBP-1c expression, and SREBP-1c mediated induction of ACC, FAS, and SCD-1. Furthermore, JSD activated AMPK, which plays a major role in the control of hepatic lipid metabolism. Taken together, it is suggested that JSD has a potential to alleviate hepatic steatosis, at least in part, by suppressing $LXR{\alpha}$/SREBP-1c mediated induction of lipogenic genes. In addtion, the anti-lipogenic potential may be associated with activation of AMPK. Therefore, the Phaseolus angularis seed could be applied as a potential therapeutics for NAFLD with additional clinical studies.

• 대한본초학회지
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• 제21권4호
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• pp.27-36
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• 2006

Objectives : This study was performed for the investigation of anticancer effects of methanol extract of Rheum Rhizoma (MeOH-RR) on a human liver cancer cell line (HepG2). Methods : To study the cytotoxic effect of MeOH-RR on HepG2 cells, the cell viability was determined by XTT reduction method and trypan blue exclusion assay. The cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of procaspase-3, -8 and -9 were examined by western blot analysis. Furthermore, MeOH-RR-induced apoptosis was confirmed by DNA fragmentation. The release of cytochrome c from mitochondria to cytosol, the level of Bcl-2 and Bax were examined by western blot analysis. Results : MeOH-RR reduced proliferation of HepG2 cells in a dose-dependent manner at 24 h and 48 h treatment. MeOH-RR induced the activation of caspase-3, -8, and -9 and the cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3. Furthermore, treatment with MeOH-RR resulted in internucleosomal DNA fragmentation, evidenced by the formation of a DNA ladder on agarose gel, a hallmark of cells undergoing apoptosis. MeOH-RR downregulated Bcl-2, upregulated Bax, and increased the release of cytochrome c from the mitochondria into cytosol in a dose-dependent manner. Moreover, MeOH-RP increased caspase-3 activity. Conclusion : There results suggest that MeOH-RR induce apoptosis via mitochondrial pathway and caspase-3-dependent pathway in HepG2 cells. There results suggest that MeOH-RR is potentially useful as a chemotherapeutic agent in human liver cancer.

• 한국조리학회지
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• 제15권1호
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• pp.120-127
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• 2009

석류씨, 석류 외피 분말 추출물 및 석류 과즙(주스 1과 주스 2) 추출물을 DPPH 라디컬 소거활동에 HepG-2 세포 그리고 항산화 활동에 추출물의 성장억제를 측정하였다. 높은 농도를 가진 모든 샘플은 HepG-2 세포에 대하여 성장 억제를 보였으며, 2,500 ppm의 처리구에서는 2회 감압 농축한 과즙 농축물(43%)>석류씨 분말 추출물(42%)>석류외피 분말 추출물(38%)>1회 감압 농축한 과즙 농축물(29%) 순으로 나타났다. BHT와 시료들 모두 농도 의존적으로 DPPH 라티칼 소거 활성이 증가하는 경향을 보였고, 12.5 ppm의 처리구에서 석류외피 분말 추출물(60.8%)>BHT(29.9%)>석류씨 분말 추출물(16.2%)>2회 감압 농축한 과즙 농축물(15.1%)>1회 감압 농축한 과즙 농축물(12.6%)의 순으로 나타났으며, 25, 50, 100 및 200 ppm처리구에서는 석류외피 분말 추출물(81.9$\sim$85.3%)>석류씨 분말 추출물(33.4$\sim$83.0%)>BHT(31.3$\sim$47.8%)>2회 감압 농축한 과즙 농축물(15.4$\sim$36.8%)>1회 갑압 농축한 과즙 농축물(13.4$\sim$36.1 %)의 순으로 나타났다.

• 한국산학기술학회논문지
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• 제17권10호
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• pp.432-438
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• 2016

본 연구는 야관문 추출물이 알코올 투여된 생쥐의 간장에 미치는 영향을 알아보고자 시행하였다. 대조군(Con), 알코올투여군(AL) 알코올-야관문 200 mg/kg 투여군 (AL-LC 200군), 알코올-야관문 400 mg/kg투여군 (AL-LC 400군)으로 나누어 구분하였다. 대조군과 알코올투여군은 1차 증류수를 알코올-야관문 투여군은 야관문을 각각 200 mg/kg과 400 mg/kg 농도로 10 일간 경구투여 하였다. 모든 실험군은 경구투여 7일후 12시간 절식시킨 다음 대조군은 1차 증류수, 알코올투여군과 알코올-야관문투여군은 50% ethanol (MERCK, USA)을 10 g/kg농도로 12시간 간격으로 5회 경구투여 하였다. 혈액의 AST, ALT 효소활성과 간장의 조직학적 실험을 하여 다음과 같은 결론을 얻었다. AST, ALT은 AL군 보다 알코올-야관문 복합투여군에서 수치가 감소하였다. 특히 AST 활성은 AL군에 대하여 AL-LC 200군과 AL-LC 400군 모두 활성이 유의적으로 감소하였다. 조직학적 결과는 간장에서 AL군은 대부분에서 괴사와 변형이 일어났고 중심정맥 주변 간세포 내에 지방방울이 축적되었다. AL-LC 200군에서는 중심정맥의 일부가 부풀어진 모습을 보였고 간세포의 팽창과 작은 지방 방울이 축적되었다. AL-LC 400군에서는 중심정맥은 정상적인 모습을 보이며 일부 간세포내의 작은 지방 방울이 축적 되었고 대부분은 정상적인 모습을 보였다. 이상의 연구결과로 보아 야관문 추출물이 알코올투여한 생쥐의 간장손상에 대한 보호 효과가 있어 기능성 건강 소재로서의 활성 용도가 높을 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제18권4호
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• pp.333-339
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• 2014

Exendin-4 (Ex-4), a glucagon-like peptide-1 receptor (GLP-1R) agonist, has been known to reverse hepatic steatosis in ob/ob mice. Although many studies have evaluated molecular targets of Ex-4, its mechanism of action on hepatic steatosis and fibrosis has not fully been determined. In the liver, glucose transporter 4 (GLUT4) is mainly expressed in hepatocytes, endothelial cells and hepatic stellate cells (HSCs). In the present study, the effects of Ex-4 on GLUT4 expression were determined in the liver of ob/ob mice. Ob/ob mice were treated with Ex-4 for 10 weeks. Serum metabolic parameters, hepatic triglyceride levels, and liver tissues were evaluated for hepatic steatosis. The weights of the whole body and liver in ob/ob mice were reduced by long-term Ex-4 treatment. Serum metabolic parameters, hepatic steatosis, and hepatic fibrosis in ob/ob mice were reduced by Ex-4. Particularly, Ex-4 improved hepatic steatosis by enhancing GLUT4 via GLP-1R activation in ob/ob mice. Ex-4 treatment also inhibited hepatic fibrosis by decreasing expression of connective tissue growth factor in HSCs of ob/ob mice. Our data suggest that GLP-1 agonists exert a protective effect on hepatic steatosis and fibrosis in obesity and type 2 diabetes.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.183-194
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• 2008

A variety of stem cells has been emerging as therapeutic cells that can replace organ transplantation in human liver diseases. The present study focused on whether human eyelid adipose-derived stem cells (HAD) might differentiate into functional hepatocyte-like cells in vitro. HAD were isolated from human eyelid adipose tissue. Effect of dimethyl sulfoxide (DMSO), fibroblast growth factor (FGF)-2 and FGF-4 on the hepatic differentiation of HAD have been examined in vitro. Immunocytochemical analysis and PAS staining showed that HAD cultured in both DMSO and FGF-4 exhibited the most intense staining than HAD of the other experimental groups. These HAD expressed numerous hepatocyte-related genes. Immunoblotting analyses showed that HAD cultured in the presence of DMSO and FGF-4 secreted higher amount of human albumin than HAD cultured in other conditions. Urea analysis also demonstrated that these HAD produced higher amount of urea than any other groups of HAD. In conclusion, combined treatment of DMSO and FGF-4 could effectively induce the functional differentiation of HAD into hepatocyte-like cells.

• BMB Reports
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• 제31권5호
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• pp.453-458
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• 1998

Human thrombopoietin (hTPO) was expressed to high levels in insect cells using the baculovirus expression system. Full-length hTPO cDNA containing a native signal peptide sequence was amplified by PCR from a human fetal liver cDNA library and cloned into the Autographa californica nuclear polyhedrosis virus (AcNPV) expression vector. Immunoblot analysis with antiserum against hTPO indicated that an approximately 55 kDa protein was produced in recombinant AcNPV infected insect cells. Recombinant hTPO was produced 4-fold higher in Trichoplusia ni (Tn5) cells than in Spodoptera frugiperda (Sf9) cells. with most of the hTPO produced in Tn5 cells secreted into the culture medium. Addition of tunicamycin in the culture medium resulted in the reduction of the size of hTPO to 35-38 kDa, and most of the protein remained within the cell. These results suggest that N-glycosylation of hTPO is required for the secretion of the protein into the culture medium in insect cells. hTPO produced in insect cells induced proliferation and maturation of megakaryocyte progenitors, indicating that it is in a biologically active form.

• 한국발생생물학회지:발생과생식
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• 제23권2호
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• pp.79-92
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• 2019

Humanized mice, containing engrafted human cells and tissues, are emerging as an important in vivo platform for studying human diseases. Since the development of Nod scid gamma (NSG) mice bearing mutations in the IL-2 receptor gamma chain, many investigators have used NSG mice engrafted with human hematopoietic stem cells (HSCs) to generate functional human immune systems in vivo, results in high efficacy of human cell engraftment. The development of NSG mice has allowed significant advances to be made in studies on several human diseases, including cancer and graft-versus-host-disease (GVHD), and in regenerative medicine. Based on the human HSC transplantation, organ transplantation including thymus and liver in the renal capsule has been performed. Also, immune reconstruction of cells, of the lymphoid as well as myeloid lineages, has been partly accomplished. However, crosstalk between pluripotent stem cell derived therapeutic cells with human leukocyte antigen (HLA) mis/matched types and immune CD3 T cells have not been fully addressed. To overcome this hurdle, human major histocompatibility complex (MHC) molecules, not mouse MHC molecules, are required to generate functional T cells in a humanized mouse model. Here, we briefly summarize characteristics of the humanized mouse model, focusing on development of CD3 T cells with MHC molecules. We also highlight the necessity of the humanized mouse model for the treatment of various human diseases.