Human Embryonic Hepatocytes Research Articles

Bavachin induces liver injury and cell apoptosis by targeting Wnt/β-catenin/DRP1 signaling pathway mediated mitochondrial dysfunction

Psraleae Fructus (PF) is a well-known traditional Chinese medicine in China. While numerous liver injury reports caused by PF limits its clinical application. Bavachin, a flavonoid compound isolated from the fruits of Psoralea corylifolia L., has been validated to induce direct apoptosis in hepatocytes and liver tissues in our previous studies. However, the subcellular mechanisms of bavachin induced liver injury is still elusive. Here, utilizing 6-week-old C57BL/6 J mice and human embryonic hepatocytes (L02 cells), we report that bavachin activates dynamic-related protein 1 (DRP1) mediated excess mitochondrial fission and endoplasmic reticulum (ER) stress related apoptosis via Wnt/β-catenin signaling pathway. Notably, DRP1 knockdown or XAV-939 induced Wnt/β-catenin inhibition decreased bavachin-induced ER stress and cell apoptosis in L02 cells. In addition, bavachin impaired mitochondrial structural and function in the mice liver tissues. Mdivi-1, a mitochondrial fission inhibitor targeting DRP1, prevented bavachin-induced mitochondrial and ER structural damage, ER stress, and liver injury. Our results demonstrated that bavachin induced mitochondrial fission plays a crucial role in bavachin induced ER stress related liver injury, via the mechanism that involved activation of Wnt/β-catenin signaling pathway.

Alendronate-decorated biodegradable polymeric micelles for potential bone-targeted delivery of vancomycin

Osteomyelitis is a bone infection disease which is caused by bacteria or other germs, and could cause serious impact on the health and working capacity of the patients. Alendronate (ALN) can chelate strongly with the calcium ion of hydroxyapatite (HA) which is commonly used to treat osteoporosis. Nanomedicine has attracted a lot of attention in that the nano-sized carrier can deliver drug molecules to specific site of interest with the aid of targeting moiety and achieve sustained release, resulting in improved therapeutic effect and reduced side effect. In this study, micelles self-assembled from poly(lactic acid-co-glycolic acid)-block-poly(ethylene glycol)-alendronate (PLGA-PEG-ALN) copolymer were prepared for bone-targeted delivery of vancomycin (Van). The chemical structure of PLGA-PEG-ALN was confirmed by proton nuclear magnetic resonance (1H-NMR) spectroscopy. The formation of the nanoparticles was characterized by dynamic light scattering, transmission electronic microscopy as well as the critical micelle concentration measurement. Release profiles from the micelles revealed that the conjugation of ALN to the surface of micelle did not pose adverse effect on the drug-loading capacity and release behaviors. The cytotoxicity of Van-loaded PLGA-PEG-ALN micelles as well as the blank micelles was evaluated via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay toward rat bone marrow stromal cells (rBMSCs) and human embryonic hepatocytes (L02 cells), and results showed that this Van-loaded micelle possesses appropriate cytotoxicity and is safe in the potential treatment of osteomyelitis. The in vitro affinity of PLGA-PEG-ALN micelles to the HA was also confirmed in vitro. The antibacterial effect of Van-loaded PLGA-PEG-ALN micelles was tested against Staphylococcus aureus (SA) which is the main pathogenic bacteria in osteomyelitis, and the results showed that the Van-loaded micelles can effectively inhibit the growth of SA. These results demonstrated that the PLGA-PEG-ALN micelles may be potentially used for the bone targeted delivery of Van.

Construction of Silver Nanoparticle-Loaded Micelles Via Coordinate Interaction and Their Antibacterial Activity

Silver nanoparticles (AgNPs) loaded antibacterial micelles were fabricated utilizing the coordinate interaction between silver ion (Ag+) and methoxy-poly(ethylene glycol)-block-poly(acrylamide-co-acrylonitrile) followed by in situ reduction. This micelle was characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, and dynamic light scattering. The upper critical solution temperature of Ag+-loaded micelles was dependent on Ag+ concentration. The AgNPs were approximately 4 nm in diameter and homogenously distributed in the micelles. The AgNPs-loaded micelle displayed high stability during a one week study and excellent antibacterial activity against gram-negative Escherichia coli and was of acceptable toxicity toward human embryonic hepatocytes.

Self‐assembled UCST‐Type Micelles as Potential Drug Carriers for Cancer Therapeutics

A methoxy‐poly(ethylene glycol)‐block‐poly(acrylamide‐co‐acrylonitrile) (mPEG‐b‐P(AAm‐co‐AN)) amphiphilic copolymer exhibiting upper critical solution temperature (UCST) behavior is synthesized, and micelles from this copolymer are fabricated. It is found that the thermal responses of these micelles are tunable through balancing the hydrophobic/hydrophilic blocks in the copolymer. The size of the doxorubicin (DOX)‐loaded micelles is dependent on the hydrophobic interaction as well as hydrogen bonding between polymer and drug molecules. As a proof of concept, the drug release behavior is studied in vitro, and the cumulative release of DOX increases at temperature above the UCST of blank micelles. 3‐(4,5‐dimethyl‐thiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assays indicate that these polymers are non‐toxic towards human hepatic carcinoma cells (Bel 7402 cells) as well as human embryonic hepatocytes (L02 cells). DOX‐loaded micelles could effectively enter Bel 7402 cells in 2 h, and display much lower half inhibitory concentration compared with free DOX. These micelles may be exploited as a promising drug carrier for cancer therapeutics. image

Novel heparin-mimicking polymer brush grafted carbon nanotube/PES composite membranes for safe and efficient blood purification

Nowadays, polymeric membrane based hemodialysis is considered to be the most practical approach for the treatment of kidney failure. To develop advanced hemodialysis membrane integrated with favorable blood and cell compatibilities and efficient blood purification ability, novel biocompatible composite membranes consisting of heparin-mimicking polymer brush functionalized carbon nanotubes (f-CNTs) and polyethersulfone (PES) are designed. Firstly, surface initiated atom transfer polymerization (SI-ATRP) is applied to synthesize heparin-mimicking polymer brush (contained the sodium styrene sulfonate (SS) and methyl ether methacrylate (EGMA) units) grafted CNT. Then, the f-CNT/PES composite membranes are prepared by a liquid–liquid phase separation technique. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) results indicated that the f-CNT would not cause severe damage on the membrane morphologies. Systemic protein ultrafiltration experiment indicated that the heparin-mimicking composite membranes owned satisfied antifouling property and protein rejection ratio. Further blood compatibility evaluation revealed that the composite membranes had decreased protein adsorption, prolonged clotting time, and suppressed platelet adhesion compared to pristine PES membrane. The results of human embryonic hepatocytes (LO-2) culture revealed that the cyto-compatibility of the modified membrane was enhanced by the blending of heparin mimicking polymer functionalized CNT. Furthermore, with the addition of f-CNT, the composite membranes showed remarkably increased removal efficiency of uremic toxin. In general, the fabricated heparin-mimicking f-CNT/PES composite membranes exhibited anti-fouling ability in ultrafiltration, excellent blood and cell compatibility and efficient toxic molecules removal ratio, thus present great potential for various applications, such as hemodialysis and bio-artificial liver support. Furthermore, the proposed method might forward the fabrication of advanced hemodialysis membrane by integrating functional nanomaterials and bioactive polymers.

Expression of miR-145 in hepatocellular carcinoma and its significance

Objective To explore the role of miR-145 in human hepatocellular carcinoma ( HCC). We investigate the expression of miR-145 in human embryonic hepatocytes ( L02 cells),hepatocellular carcinoma cell lines (MHCC97 ,SMMC7721) ,HCC tissues and normal liver. Methods We detected the expressions of miR-145 in human embryonic hepatocytes, hepatocellular carcinoma cell lines ( MHCC97,SMMC7721) ,HCC tissues,cancer organizations and normal liver by real-time PCR. Result The expression of miR-145 in hepatocellular carcinoma cell lines ( MHCC97,SMMC7721) is significantly lower than the human embryonic hepatocytes ( 0. 312 ± 0. 025,0. 396 ± 0. 076,0. 954 ± 0. 037, P ＜ 0. 05), and compared with the cancer organizations and normal liver,the expression of miR-145 in HCC tissues is significantly decreased (0. 162 ±0.002,0. 972 ±0.054,0.956 ±0. 018,P＜0. 05). Conclusion These results indicate that the miR-145 probably involved in HCC pathogenesis and was the indicator of diagnosis and prognosis of the HCC. Key words: miR-145; HCC; Real-time PCR

Chitooligosaccharides Protect Human Embryonic Hepatocytes Against Oxidative Stress Induced by Hydrogen Peroxide

Chitooligosaccharides (COS) has many biological activities, such as antitumor activity and hepatoprotective effect. Herein, we investigated the protective effect of COS against hydrogen peroxide (H2O2)-induced oxidative stress on human embryonic hepatocytes (L02 cells) and its scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical in vitro. The results showed that the lost cell viability induced by H2O2 was markedly restored after 24 h pre-incubation with COS (0.1-0.4 mg/ml). This rescue effect could be related to the antioxidant property of COS, in which we showed that the radical scavenging activity of COS reached 80% at concentration of 2 mg/ml. In addition, COS could prevent cell apoptosis induced by H2O2, as shown by the inhibition of the cleavage of poly (adenosine diphosphate-ribose) polymerase and increased expression of the anti-apoptotic protein Bcl-xL. Furthermore, we have utilized confocal laser microscopy to observe cellular uptake of COS, an important step for COS to exert its effects on target cells. Taken together, our findings suggested that COS could effectively protect L02 cells against oxidative stress, which might be useful in clinical setting during the treatment of oxidative stress-related liver damages.

Effects on protein and mRNA expression levels of p53 induced by fluoride in human embryonic hepatocytes

We investigated the effects of protein and mRNA expression levels on p53 induced by fluoride in human embryo hepatocyte L-02 cells. The protein and mRNA levels of p53 in L-02 cells were measured after in vitro cultured L-02 was exposed to sodium fluoride at different doses (40, 80, and 160 μg/ml) for 24 h. The results showed that the cell survival rate of L-02 cells in the high dose fluoride group was significantly lower than that of the control group. The protein expression levels of p53 in the middle and high dose fluoride group were significantly higher than in the control group and elevated with increasing fluoride concentration. The mRNA expression levels of p53 in the fluoride groups were markedly higher than in the control group. The mRNA expression level of p53 in the high dose fluoride group was however lower compared to the middle dose fluoride group, but similar to the low dose fluoride group. These finding suggest that fluoride can decrease the L-02 cells survival rate and induce protein and mRNA expressions of p53; however, there is no consistency between the protein expression level of p53 and the mRNA expression level.

Способ получения и культивирования эмбриональных гепатоцитов человека

Способ получения и культивирования эмбриональных гепатоцитов человека

Regulation of Hepatocyte-Specific Gene Expression in Cultures of Human Embryonic Hepatocytes

The aim of this study was to see whether the rat embryo can serve as a model system for hepatocyte-specific gene expression in the human embryo. Carbamoylphosphate synthetase was used as a hepatocyte-specific marker molecule. Despite the earlier developmental appearance of this enzyme in human than in murine liver, the hormonal regulation of gene expression in cultures of embryonic hepatocytes was found to be the same. Therefore, a relatively early developmental appearance of regulatory hormones rather than differences in regulatory mechanisms of gene expression appears to be responsible for the early accumulation of the enzyme in human liver, when compared to murine liver.

Verteilung und enzymatische Hypermethylierung invers repetitiver DNA-Sequenzen in verschiedenen Mäuse-und menschlichen Zellen / Distribution and Enzymic Hypermethylation of Inverted DNA Repeats in Different Murine and Human Cells

A specific class of DNA sequences, the inverted repetitive sequences, forms a double-stranded structure within a single linear polynucleotide chain in denatured DNA. The reassociation process is unimolecular and occurs very fast. Quantitative analyses have shown that these sequences comprise about 4--5% of the nuclear DNA of various mammalian cells (P815 mouse mastocytoma, Hela, L cells, Raji and Chang cells, and human embryonic hepatocytes) and are interspersed within sequences of other degrees of repetitiveness. After labeling the cells with L-[Methyl-3H]methionine and [14C]deoxycytidine, relative rates of enzymic DNA methylation were computed on the basis of 3H and 14C radioactivities found in pyrimidine residues of the nuclear DNA. The results indicate that DNA of inverted repetitive sequences is methylated to a level about 50% higher than the ordinary repetitive sequences and to about 300% higher than the unique and intermediary sequences. The biological function of the inverted repeats as well as the role of their enzymic hypermethylation is unknown.

Synthesis of ?-fetoprotein and albumin by human embryonic hepatocytes

Population aspects of the production of specific secreted proteins (serum albumin and α-fetoprotein) were studied in cultures of hepatocytes from human embryos at 6–12 weeks of development. A method based on local hemolysis in gel using sheep's erythrocytes conjugated with antibodies against the proteins for testing, was used. The overwhelming majority of hepatocytes were shownto synthesize both proteins.

Characteristics of human embryonic hepatocytes cultivated in vitro

A simple and reproducible method for cultivation of human embryo (7--12-week) hepatocytes in a monolayer is presented. The culture showed the capacity for limited growth, displayed a viability for 4 to 6 weeks without being subcultured, and retained some specific characteristics: synthesis of serum protein (albumin and alpha-fetoprotein), a significant amount of glycogen, a high activity of monaminooxidase, and a characteristics response to a high concentration of glucocorticoids. These properties are useful as markers for genetic experiments or for selection.

Tissue culture of adult liver biopsies.

AND J. STUBBS (London School of Hygiene and Tropical Medicine and St. Mary Abbot's Hospital, London) The tissue culture method for human embryonic hepatocytes described by Zuckerman, Tsiquaye, and Fulton (1967) has been extended to fragments of human adult liver obtained from biopsies taken for diagnostic purposes. The liver was cut into very small pieces and allowed to stand in 0-2% trypsin solution for 30 min. before stirring magnetically for five min. Small pieces of the softened tissue were washed and then teased out with two needles before implantation. Clotted mouse plasma was used as