• BMB Reports
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• v.28 no.5
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• pp.427-432
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• 1995

Ganglioside GM3 and sialidase activities in human fetal liver have been investigated. Gangliosides were extracted from fetal livers by the Folch-Suzuki method and analyzed by high-performance thin layer chromatography (HPTLC). GM3 increased, but lactosylceramide (LacCer) decreased predominantly over the developmental stages. Sialidase in human fetal liver was mainly localized in the lysosomal fraction and its activity was high in the earlier stages of development. The optimum pH for this enzyme was 4.3~4.4. Sialidase was more active with the ganglioside mixture than with GM3, sialyllactose or fetuin. Fetal liver sialidase was still active (20% activity) in the presence of 25% methanol. These results suggested that the changes of the ganglioside GM3 and sialidase activity may be involved in the regulation of cell growth in human fetal liver during development.

• Toxicological Research
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• v.8 no.2
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• pp.285-302
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• 1992

Human and rat hepatocytes were isolated by nonperfusion method and cultured for longer than 5 days. Human liver biopsy sample and rat liver were used as hepatocyte source. Several physical and chemical factors which were influencing on hepatocyte isolation procedure were examined and a batch isolation procedure was established for small size sample of rat liver. Isolated hepatocytes showed normal morphlologica characteristics in microscopy and electron microscopical examinations and a morphologica response to phalloidin. Isolated cells were cultured as a monolayer and proven to have intact morphological characteristics for longer than 15 days. Because human liver sample is harder and tighter compared with rat liver, a standard procedure for rat hepatocytes was slightly modified to reduce mechanical damage. Similarly with rat hepatocytes, isolated human hepatocytes showed a normal morphological characteristics and could be cultured for longer than 15days. Human and rat hepatocytes were examined on their functional integrities including cytochrome-P450 related enzyme activity and it's inducibility, hormonal inducibility of AIB uptake and TAT activity, albumin synthesis, DNA synthesis, cellular protein maintenance. In all parameters used in the present study, human and rat hepatocytes showed normal functional characteristics.

• Applied Microscopy
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• v.28 no.3
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• pp.283-297
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• 1998

Hemopoiesis and morphogenesis of the human fetal liver through from 10 to 32 weeks of gestation were investigated by light and electron microscopy. The results obtained were as follows. Hemopoiesis of fetal liver tissue was found from 10 to 32 weeks of gestation, but the hemopoiesis was decreased at 32 weeks of gestation. At the 32 weeks of gestation, matured erythrocytes were observed in the sinusoid, and formation of liver cell cord and portal triad were established. Differentiation of hepatic cell was characterized by the increase of amount of cell organelles within cytoplasm, decrease of hemopoietic cell, morphological change of nuclear envelope from folding form to round form during the developmental period. These results suggest that human fetal liver plays a hematopoietic function until bone marrow and spleen play their function, but morphology of liver at 32 weeks of gestation was differed with structure observed in liver of adult.

• BMB Reports
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• v.30 no.4
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• pp.299-301
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• 1997

The asialoglycoprotein receptor (ASGPR) was the first described mammalian lectin that mediates the specific binding and internalization of galactose/N-acetylgalactosamine-terminating glycoproteins by hepatic parenchymal cells. H1 and H2 are known as essential subunits of the functional ASGPR. There were close similarities in ASGPR H2 subunits between cultured cell line HepG2 and normal human liver cells including identical sequences at both termini. It was therefore expected that there may be some similarities between the subunits from normal liver cells and fetal liver cells. The two subunits of human fetal liver ASGPR. designated FL-H1 and FL-H2. were cloned from cDNA library by peR and the sequences were compared with the known HI and H2 sequences of HepG2, and the H1 sequence of nornal human liver cells. The results showed that FL-H1 was identical to H1 of HepG2. Whereas FL-H2 contains a 15-bp miniexon, but missing 57-bp at the near upstream from the membrane-spanning domain compared to H2 of HepG2 and normal human liver cells indicating that FL-H2 resulted from a differential splicing compared to HepG2 and normal liver cells.

• Toxicological Research
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• v.11 no.2
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• pp.329-335
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• 1995

Incubation of aflatoxin $B_1$ $(AFB_1)$ with microsomes isolated from human liver number 110 yielded two metabolite peaks which were aflatoxin $Q_1$ $(AFQ_1)$ and $(AFB_1)$-exo-8, 9-epoxide (exo-epoxide) in high performance liquid chromatography. Production ratio of $AFQ_1$ to exo-epoxide was 2.43$\pm $0.04. Metabolism of $(AFB_1)$ to $(AFQ_1)$ and exo-epoxide was inhibited by troleandomycin in a same degree although troleandomycin was not activated as a mechanism-based inhibitor. The inhibitory effect was dependent upon either the incubation time with $(AFB_1)$ or the preincubation time before the addition of $(AFB_1)$. Incubation of troleandomycin and NADPH by the microsomes resulted in the formation of a cytochrome P 450 (P450)-metabollc intermediate (MI) complex and the level was approximately 80% of total P450 3A4 in the microsomes. This figure was similar to that of the inhibitory effect of troleandomycin on $AFB_1$ metabolism. Glutathione which was reported that it prevented the formation of MI complex in rat liver microsomes did not inhibit the formation of MI complex in human liver microsomes. These results suggested that the inhibitory effect of troleandomycin on $AFB_1$ metabolism is due to the formation of MI complex with P450 3A4. And the reaction mechanism of troleandomycin by human liver microsomes might be dlfferent from that one by rat liver microsomes.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.2
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• pp.258-272
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• 2000

The cytotoxic activities of Pinellia ternate, Aconitum carmichaeli, Arisaema amurense, Aconitum kusnezoffii and Scutellaria baicalensis on monkey kidney cell (Vero) and human liver cell (WRL68) were evaluated by Sulforhodamine B Protein (SRB) and Tetrazolium-based (MTT) colorimetric assay methods The results were as fellows : 1 The Pinellia ternate and Arisaema amurense did not show the cytotoxic activities at any concentration without processing or natural drugs. 2 The extracts of Aconitum carmichaeli, Aconitum kusnezoffii and Scutellaria baicalensis showed cytotoxic activities. However, the cytotoxic activities of processing drugs were less effective than the natural drugs. 3. The cytotoxic activities on monkey kidney cell (Vero) and human liver cell (WRL68) of Aconitum carmichaeli was determined by MTT assay. The Kyungpo(京?) of Aconitum carmichaeli showed less concentrate than that of the Dangpo(唐?). The $IC_{50}$ value on monkey kidney cell (Vero) and human liver cell (WRL68) of Kyungpo was $937{\pm}29\;and\;731{\pm}31{\mu}g/ml$, respectively 4. The cytotoxicity on monkey kidney cell (Vero) and human liver cell (WRL68) of Scutellaria baicalensis showed strong activities without processing or natural drugs.

• BMB Reports
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• v.29 no.3
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• pp.236-240
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• 1996

A 23-kDa molecular mass of antioxidant protein was purified from human liver. This protein exhibited the preventive effect against the inactivation of glutamine synthetase by a metal-catalyzed oxidation system. This antioxidant activity was supported by a thiol-reducing equivalent such as dithiothreitol in a similar manner to that of the 25-kDa thiol-specific antioxidant protein (TSA) from human red blood cells (HR). However, a thioredoxin-linked peroxidase activity of thiol-specific antioxidant protein of human liver (HLTSA) (0.91 ${\mu}mol/min/nmol$ of HLTSA) was much lower than that of thiol-specific antioxidant protein of human red blood cells (HRTSA) (16.4 ${\mu}mol/min/nmol$ of HRTSA). This HLTSA is also immnologically distinct from HRTSA Amino acid sequences of the three tryptic peptides (P1, P2, P3) of HLTSA were found to be completely homologous to segments of the known Mer5-like protein, which belongs to the known TSA family.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.342-349
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• 2023

Backgrounds/Aims: Liver organoids have emerged as a powerful tool for studying liver biology and disease and for developing new therapies and regenerative medicine approaches. For organoid culture, Matrigel, a type of extracellular matrix, is the most commonly used material. However, Matrigel cannot be used for clinical applications due to the presence of unknown proteins that can cause immune rejection, batch-to-batch variability, and angiogenesis. Methods: To obtain human primary hepatocytes (hPHs), we performed 2 steps collagenase liver perfusion protocol. We treated three small molecules cocktails (A83-01, CHIR99021, and HGF) for reprogramming the hPHs into human chemically derived hepatic progenitors (hCdHs) and used hCdHs to generate liver organoids. Results: In this study, we report the generation of liver organoids in a collagen scaffold using hCdHs. In comparison with adult liver (or primary hepatocyte)-derived organoids with collagen scaffold (hALO_C), hCdH-derived organoids in a collagen scaffold (hCdHO_C) showed a 10-fold increase in organoid generation efficiency with higher expression of liver- or liver progenitor-specific markers. Moreover, we demonstrated that hCdHO_C could differentiate into hepatic organoids (hCdHO_C_DM), indicating the potential of these organoids as a platform for drug screening. Conclusions: Overall, our study highlights the potential of hCdHO_C as a tool for liver research and presents a new approach for generating liver organoids using hCdHs with a collagen scaffold.

• Journal of Life Science
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• v.10 no.2
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• pp.45-49
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• 2000

Long terminal repeat (LTR) of human endogenous retrovirus K family (HERV-K) has been found to be coexpressed with sequences of closely located genes. We examined the transcribed HERV-K LTR elements in human liver and kidney tissues. Using the cDNA synthesized from mRNA of human liver and kidney, we performed PCR amplification and identified six HERV-K LTR elements. Those LTR elements showed a high degree of sequence similarity (93.3∼96.6%) with human-specific LTR. A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-K LTR elements (Liv-1, 2, 3 and Kid-1, 2, 3) were belonged to group I. Our data suggests that HERV-K LTR elements are active on human liver and kidney tissues and may represent a source of genetic variation connected to human disease.

• Journal of Embryo Transfer
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• v.13 no.2
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• pp.159-172
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• 1998

사람 성장호르몬 수용체(hGHR) cDNA는 PCR방법에 의하여 fagment로서 보고되어진 바 있으나, liver cDNA로 부터 전장을 cloning한 보고는 없는 실정으로 본 연구에서는 기능을 가진 약 4.6kbp의 cDNA hGHR을 cloning 하는데 성공하였다. 먼저 cloning하기 위하여 human liver mRNA와 human breast cancer tissue로부터 회수한 mRNA를 RT-PCR방법에 의하여 human cDNA library와 cloning에 필요한 probe를 제작하였다. human library mRNA는 GT-PCR방법에 의하여 증폭하여 증폭되어진 산물은 λZAP Vector를 이용하여 cDNA library를 구축하였고,screeing을 위하여 임 보고 되어진 hGHR fragment native sequence를 기초로 N-terminal부분의 primer를 설계하여 950bp의 probe를 얻는데 성공하였다. 이 probe를 이용하여 준비된 human liver cDNA library로부터 2.5$\times$10 6개의 plaque로부터 6개의 positive clone을 획득하였고, 이들중 poly Asignal인 "AATAAA"를 포함하고 있는 가장 긴 약 3.8kbp의 clone을 sequencing한 결과 open reading frame을 포함하고 있었으나, 5'부분의 결손되어 있었다. 그리하여 이 부분은 human breast cancer tissue로 부터 회수한 mRNA를 RT-PCR에 의하여 증폭하였고, sequencing결과 이미 보고되어진 native hGHR와 비교한 결과 하나의 nucleotide가 silent mutation으로 판명되었다.한편 human liver cDNA library로부터 cloning한 3.8cp의 positive clone의 5'end의 결손된 부분에 silent mutation된 PCR 산물을 연결함으로써 native hGHR와 유사한 cDNA hGHR subcloning에 성공하였다. 이러한 cDNA hGHR의 clone이 function을 가지고 있는지를 검토하기 위하여 eukaryotic 발현 vector인 pCXN2에 의거 ligation한 후 chinese hamster ovary cell[CHO-KI]에 transfect를 실시하였다. Dexamethasone은 첨가하지 않고 hGH만의 존재하에서 이들 cell을 배양시키고 cell menbrane에서 발현 여부를 판정키 위하여 hGHR monocloual antibody를 사용하여 flow cytometery해석을 실시하는 한편 125I-hGH binding assay에 의하여 hGH binding activity를 측정하였다. 최종적으로 GH signal transduction의 target genedf으로 알려져 있는 serine protease inhibitor 2.1(Spi 2.1) gene의 promotor activity를 검토한 결과 hGHR을 transfect한 CHO Cell에 있어서 hGH의 농도에 의존적으로 증가되었다. 따라서 본 실험에서 cloning한 cDNA hGHR는 native hGHR와 같은 기능을 가지는 것으로 판명되었다.것으로 판명되었다.