scholarly journals Functional Recellularization of Acellular Rat Liver Scaffold by Induced Pluripotent Stem Cells: Molecular Evidence for Wnt/B-Catenin Upregulation

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2819
Author(s):  
Nesrine Ebrahim ◽  
Omnia Badr ◽  
Mohamed Yousef ◽  
Amira Hassouna ◽  
Dina Sabry ◽  
...  
Keyword(s):  
Growth Factors ◽  
Rat Liver ◽  
Three Dimensional ◽  
Molecular Evidence ◽  
Liver Development ◽  
Urea Synthesis ◽  
Adult Rat ◽  
Ecm Proteins ◽  
Induced Pluripotent ◽  
Rat Livers

Background. Liver transplantation remains the only viable therapy for liver failure but has a severely restricted utility. Here, we aimed to decellularize rat livers to form acellular 3D bio-scaffolds suitable for seeding with induced pluripotent cells (iPSCs) as a tool to investigate the role of Wnt/β-catenin signaling in liver development and generation. Methods. Dissected rat livers were randomly divided into three groups: I (control); II (decellularized scaffolds) and III (recellularized scaffolds). Liver decellularization was established via an adapted perfusion procedure and assessed through the measurement of extracellular matrix (ECM) proteins and DNA content. Liver recellularization was assessed through histological examination and measurement of transcript levels of Wnt/β-catenin pathway, hepatogenesis, liver-specific microRNAs and growth factors essential for liver development. Adult rat liver decellularization was confirmed by the maintenance of ECM proteins and persistence of growth factors essential for liver regeneration. Results. iPSCs seeded rat decellularized livers displayed upregulated transcript expression of Wnt/β-catenin pathway-related, growth factors, and liver specification genes. Further, recellularized livers displayed restored liver-specific functions including albumin secretion and urea synthesis. Conclusion. This establishes proof-of-principle for the generation of three-dimensional liver organ scaffolds as grafts and functional re-establishment.

scholarly journals Tissue- and developmental-stage-specific methylation in the two kidney promoters of the rat γ-glutamyl transpeptidase gene

1992 ◽  
Vol 287 (3) ◽  
pp. 691-694 ◽  
Author(s):  
J H Baik ◽  
S Siegrist ◽  
G Giuili ◽  
O Lahuna ◽  
F Bulle ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Developmental Stage ◽  
Rat Liver ◽  
Kidney Development ◽  
Rat Kidney ◽  
Liver Development ◽  
Gamma Glutamyl Transpeptidase ◽  
Site Specific ◽  
Adult Rat ◽  
Glutamyl Transpeptidase

We have investigated, using DNA methylation patterning, the site-specific methylation of promoters I and II of the rat gamma-glutamyl transpeptidase gene. This analysis was done in fetal, newborn and adult rat kidney, in which promoters I and II are progressively active during development, as well as in rat liver, which never expresses mRNAs from these two promoters. During kidney development, a progressive demethylation occurs in the promoter I and II region, specially at the level of the most proximal MspI site of promoter II. A progressive reorganization of the methylated sites within the 5′ end of the gene also occurs during liver development.

scholarly journals Expression of c-Ki-ras, c-Ha-ras, and c-myc in specific cell types during hepatocarcinogenesis.

1985 ◽  
Vol 5 (4) ◽  
pp. 780-786 ◽  
Author(s):  
P Yaswen ◽  
M Goyette ◽  
P R Shank ◽  
N Fausto
Keyword(s):  
Rat Liver ◽  
Cell Types ◽  
Isolated Hepatocytes ◽  
Specific Cell ◽  
Oval Cells ◽  
Deficient Diet ◽  
Adult Rat ◽  
Fetal Rat ◽  
Fetal Rat Liver ◽  
Rat Livers

We examined the expression of six proto-oncogenes in (i) whole rat liver and isolated liver cell populations during the course of hepatocarcinogenesis induced by a choline-deficient diet containing 0.1% ethionine and (ii) fetal rat liver at different stages of development. The abundance of c-Ki-ras, c-Ha-ras, and c-myc transcripts in polysomal polyadenylated RNA from liver cells increased by 2 weeks after the start of the carcinogenic diet. c-Ki-ras and c-myc expression remained elevated during the 35 weeks of the diet, whereas c-Ha-ras transcripts increased transiently. A primary tumor sampled at 35 weeks after the carcinogenic diet was started contained high levels of both c-Ki-ras and c-myc RNA. The abundance of c-src transcripts was unchanged throughout carcinogenesis; c-abl and c-mos transcripts were not detected in either preneoplastic or neoplastic livers. To determine which cell types within the liver contained proto-oncogene transcripts, we isolated hepatocytes, oval cells, and bile duct cells from normal and preneoplastic livers. The results indicate that proto-oncogenes are expressed differentially in these cell types during hepatocarcinogenesis and that the expression of c-Ki-ras and c-myc is high in oval cells throughout carcinogenesis. In developing livers, c-Ki-ras, c-Ha-ras, and c-myc transcript levels were high at 17 days of gestation but reached the low values characteristic of adult rat livers between 20 days of gestation and 3 days after birth.

Changing activities of galactose-metabolizing enzymes during perfusion of suckling-rat liver

1981 ◽  
Vol 240 (3) ◽  
pp. E333-E339 ◽  
Author(s):  
S. Rogers ◽  
S. Segal
Keyword(s):  
Rat Liver ◽  
Uptake Rate ◽  
Specific Activity ◽  
Model System ◽  
Transferase Activity ◽  
Metabolizing Enzymes ◽  
Adult Rat ◽  
Specific Activities ◽  
Precipitous Decline ◽  
Rat Livers

The specific activities of the galactose-metabolizing enzymes, galactokinase (EC 2.7.1.6), galactose-1-phosphate uridyltransferase (EC 2.7.7.12), and UDPgalactose 4-epimerase (EC 5.1.3.2), in suckling-rat livers perfused for 90 min with 1 and 4 mM galactose fluctuate significantly with a different pattern of change for each enzyme. Perfusion for 30 min with galactose resulted in a significant increase of transferase specific activity followed by a precipitous decline to about one-fifth of the activity in unperfused liver at 90 min. The increase in transferase activity was also observed when D-glucose was perfused but not when L-glucose, D-fructose, D-xylose, or D-ribose was added to the perfusate. No such changes in transferase activity were observed when adult-rat liver was perfused with galactose. Epimerase activity in the suckling-rat liver was relatively low, and the changes in its activity correlated best with the uptake rate of galactose. The perfused suckling-rat liver may provide a model system for examination of factors that modulate the specific activity of galactose-metabolizing enzymes and effect the metabolism of galactose.

Expression of c-Ki-ras, c-Ha-ras, and c-myc in specific cell types during hepatocarcinogenesis

1985 ◽  
Vol 5 (4) ◽  
pp. 780-786
Author(s):  
P Yaswen ◽  
M Goyette ◽  
P R Shank ◽  
N Fausto
Keyword(s):  
Rat Liver ◽  
Cell Types ◽  
Isolated Hepatocytes ◽  
Specific Cell ◽  
Oval Cells ◽  
Deficient Diet ◽  
Adult Rat ◽  
Fetal Rat ◽  
Fetal Rat Liver ◽  
Rat Livers

We examined the expression of six proto-oncogenes in (i) whole rat liver and isolated liver cell populations during the course of hepatocarcinogenesis induced by a choline-deficient diet containing 0.1% ethionine and (ii) fetal rat liver at different stages of development. The abundance of c-Ki-ras, c-Ha-ras, and c-myc transcripts in polysomal polyadenylated RNA from liver cells increased by 2 weeks after the start of the carcinogenic diet. c-Ki-ras and c-myc expression remained elevated during the 35 weeks of the diet, whereas c-Ha-ras transcripts increased transiently. A primary tumor sampled at 35 weeks after the carcinogenic diet was started contained high levels of both c-Ki-ras and c-myc RNA. The abundance of c-src transcripts was unchanged throughout carcinogenesis; c-abl and c-mos transcripts were not detected in either preneoplastic or neoplastic livers. To determine which cell types within the liver contained proto-oncogene transcripts, we isolated hepatocytes, oval cells, and bile duct cells from normal and preneoplastic livers. The results indicate that proto-oncogenes are expressed differentially in these cell types during hepatocarcinogenesis and that the expression of c-Ki-ras and c-myc is high in oval cells throughout carcinogenesis. In developing livers, c-Ki-ras, c-Ha-ras, and c-myc transcript levels were high at 17 days of gestation but reached the low values characteristic of adult rat livers between 20 days of gestation and 3 days after birth.

Plasminogen Receptors in Human Malignancies: Effects on Prognosis and Feasibility as Targets for Drug Development

2020 ◽  
Vol 21 (7) ◽  
pp. 647-656
Author(s):  
Steven L. Gonias ◽  
Carlotta Zampieri
Keyword(s):  
Growth Factors ◽  
Drug Development ◽  
Plasminogen Activator ◽  
Human Cancer ◽  
Annexin A2 ◽  
The Cancer Genome Atlas ◽  
Tissue Type ◽  
Cell Surfaces ◽  
Ecm Proteins ◽  
Type Plasminogen Activator

The major proteases that constitute the fibrinolysis system are tightly regulated. Protease inhibitors target plasmin, the protease responsible for fibrin degradation, and the proteases that convert plasminogen into plasmin, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). A second mechanism by which fibrinolysis is regulated involves exosite interactions, which localize plasminogen and its activators to fibrin, extracellular matrix (ECM) proteins, and cell surfaces. Once plasmin is generated in association with cell surfaces, it may cleave transmembrane proteins, activate growth factors, release growth factors from ECM proteins, remodel ECM, activate metalloproteases, and trigger cell-signaling by cleaving receptors in the Proteaseactivated Receptor (PAR) family. These processes are all implicated in cancer. It is thus not surprising that a family of structurally diverse but functionally similar cell-surface proteins, called Plasminogen Receptors (PlgRs), which increase the catalytic efficiency of plasminogen activation, have received attention for their possible function in cancer and as targets for anticancer drug development. In this review, we consider four previously described PlgRs, including: α-enolase, annexin-A2, Plg-RKT, and cytokeratin-8, in human cancer. To compare the PlgRs, we mined transcriptome profiling data from The Cancer Genome Atlas (TCGA) and searched for correlations between PlgR expression and patient survival. In glioma, the expression of specific PlgRs correlates with tumor grade. In a number of malignancies, including glioblastoma and liver cancer, increased expression of α-enolase or annexin-A2 is associated with an unfavorable prognosis. Whether these correlations reflect the function of PlgRs as receptors for plasminogen or other activities is discussed.

Hepatic uptake of intact glutathione S-conjugate, inhibition by organic anions, and sinusoidal catabolism

1993 ◽  
Vol 265 (3) ◽  
pp. G547-G554
Author(s):  
C. A. Hinchman ◽  
A. T. Truong ◽  
N. Ballatori
Keyword(s):  
Guinea Pig ◽  
Rat Liver ◽  
Marked Decrease ◽  
Hepatic Uptake ◽  
Half Time ◽  
High Concentrations ◽  
Rat Livers ◽  
Dose Dependent ◽  
Uptake And Metabolism ◽  
Guinea Pig Liver

To identify potential mechanisms for hepatic removal of circulating glutathione (GSH) conjugates, uptake and metabolism of S-2,4-dinitrophenylglutathione (DNP-SG) were examined in isolated perfused livers from rat and guinea pig. Guinea pig livers perfused with 5 mumol of DNP-SG in a recirculating system (50 microM initial concn) rapidly cleared the conjugate from the perfusate (half time 3.7 min), whereas clearance was considerably slower in rat liver (half time 35 min). Disappearance of DNP-SG from the perfusate was accompanied by a simultaneous appearance of DNP-SG and its metabolites in bile. Addition of acivicin, an inhibitor of gamma-glutamyltransferase (gamma-GT), to the perfusate resulted in a marked decrease in DNP-SG clearance by guinea pig liver but had no effect in rat liver, suggesting that in the guinea pig this process is largely dependent on sinusoidal gamma-GT activity. However, even in the presence of acivicin, rat and guinea pig livers removed nearly one-half of the administered DNP-SG from the recirculating perfusate over 30 min. High concentrations of DNP-SG were found in bile (up to 3.7 mM), indicating that the liver is capable of transporting the intact conjugate from the circulation. When rat livers were perfused with higher concentrations of DNP-SG (100 and 250 microM), biliary excretion of DNP-SG increased dose dependently, with concentrations in bile reaching 10 mM at the higher dose. This was accompanied by a dose-dependent choleresis.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Induction of amino acid transport in primary cultures of adult rat liver parenchymal cells by insulin.

1976 ◽  
Vol 251 (10) ◽  
pp. 3014-3020 ◽  
Author(s):  
R F Kletzien ◽  
M W Pariza ◽  
J E Becker ◽  
V R Potter ◽  
F R Butcher
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Amino Acid Transport ◽  
Primary Cultures ◽  
Acid Transport ◽  
Liver Parenchymal ◽  
Adult Rat ◽  
Parenchymal Cells

Influence of Slice Thickness and Culture Conditions on the Metabolism of 7-Ethoxycoumarin in Precision-cut Rat Liver Slices

1998 ◽  
Vol 26 (4) ◽  
pp. 541-548
Author(s):  
Roger J. Price ◽  
Anthony B. Renwick ◽  
Paula T. Barton ◽  
J. Brian Houston ◽  
Brian G. Lake
Keyword(s):  
Gas Phase ◽  
Rat Liver ◽  
Xenobiotic Metabolism ◽  
Culture Conditions ◽  
Slice Thickness ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Liver Slices ◽  
Sprague Dawley Rats ◽  
Rat Livers

This study investigated the effects of some experimental variables on the rate of xenobiotic metabolism in precision-cut rat liver slices. Liver slices of 123 ± 8μm (mean ± SEM of six slices), 165 ± 3μm, 238 ± 6μm and 515 ± 14μm thickness were prepared from male Sprague-Dawley rats, and incubated in RPMI 1640 medium in an atmosphere of 95% O2/5% CO2 by using a dynamic organ culture system. Liver slices of all thicknesses metabolised 10μM 7-ethoxycoumarin to total (free and conjugated) 7-hydroxycoumarin in a time-dependent manner. The rate of 7-ethoxycoumarin metabolism was greatest in 165μm thick slices and slowest in 515μm thick slices, being 2.74 ± 0.19pmol/minute/mg slice protein and 0.69 ± 0.07pmol/minute/mg slice protein, respectively. No marked effects on the rate of 7-ethoxycoumarin metabolism in liver slices were observed either by changing the medium to Earle's balanced salt solution (EBSS) or by changing the gas phase to 95% air/5% CO2. Moreover, the perfusion of rat livers with EBSS at 2–4°C, prior to preparation of tissue cores, did not enhance 7-ethoxycoumarin metabolism in rat liver slices. In this study, the optimal slice thickness was 175μm, with higher rates of 7-ethoxycoumarin metabolism being observed than with 250μm thick slices, which are often used for studies of xenobiotic metabolism. Variable results were obtained with slices of around 100–120μm thickness, which may be attributable to the ratio between intact hepatocytes and cells damaged by the slicing procedure in these very thin slices.

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