Establishment of ornithine transcarbamylase deficiency-derived primary human hepatocyte with hepatic functions (original) (raw)

Establishment, characterization, and long-term maintenance of cultures of human fetal hepatocytes

Hepatology, 2003

Cultured human hepatocytes have broad research and clinical applications; however, the difficulties in culturing rodent and human hepatocytes are well known. These problems include the rapid loss of the hepatocytic phenotype in primary culture and the limited replicating capacity of the cultured cells. We describe the establishment of serum-free primary cultures of human fetal hepatocytes (HFHs) that retain hepatocytic morphology and gene expression patterns for several months and maintain sufficient proliferative activity to permit subculturing for at least 2 passages. Initially, HFH cultures contained 2 main cell types that morphologically resembled large and small hepatocytes. The fetal hepatocytes expressed ␣-fetoprotein (AFP), cytokeratin (CK) 19, albumin, and other hepatic proteins. , CD34, and OV-6 but do not stain with antibodies to ␤ 2 -microglobulin. HFH cultures maintained for 9 to 12 months produced grossly visible organoids containing ductular structures that stained for CK18, CK19, and AFP. In conclusion, HFH cultures, which might contain a population of hepatic stem cells, constitute an excellent tool for a variety of studies with human hepatocytes, including the mechanisms of viral infection. (HEPATOLOGY 2003;38:1095-1106 Abbreviations: HFH, human fetal hepatocyte; OSM, oncostatin M; BrdU, bro-

Evaluation of a new immortalized human fetal liver cell line (cBAL111) for application in bioartificial liver

Journal of Hepatology, 2008

Background/Aims: Clinical use of bioartificial livers (BAL) relies heavily on the development of human liver cell lines. The aim of this study was to assess the potential of the recently developed human fetal liver cell line cBAL111 for application in the AMC-BAL. Methods: Laboratory-scale AMC-BAL bioreactors were loaded with 20 or 200 million cBAL111 cells and were cultured for 3 days. Parameters for hepatocyte-specific function and general metabolism were determined daily using tests with culture medium or 100% human serum. The bioreactors were also analyzed for mRNA levels of liver-specific genes and histology. Results: cBAL111 eliminated ammonia at a rate up to 49% of that in primary porcine hepatocytes (PPH), despite a low (1.1%) urea production. Transcript levels of glutamine synthetase (GS) were 570% of that in human liver, whereas genes of the urea cycle showed low expression. GS expression was confirmed immunohistochemically, and glutamine was produced by the cells. cBAL111 eliminated galactose (90.1% of PPH) and lidocaine (0.1% of PPH) and produced albumin (6% of PPH). Human serum did not increase function of cBAL111. Conclusions: cBAL111 showed liver-specific functionality when cultured inside the AMC-BAL and eliminated ammonia mainly by the activity of GS, and not through the urea cycle.

Establishment of a human neonatal hepatocyte cell line

In Vitro Cellular & Developmental Biology - Animal, 2009

Hepatocytes are routinely used to generate and identify drug metabolites and hepatic toxicity. Primary cultures of human hepatocytes are the model cell of choice for most of these pharmacological and toxicological studies. However, major problems are encountered with primary liver cell cultures: the dwindling availability of viable livers, hepatocytes having a limited life span, the loss of liver-specific functions in culture, and the donor to donor variability. These limitations have created a significant need for an in vitro hepatocyte system, which has both the potential for use in toxicological and pharmaceutical studies as well as clinical applications. Ectopic expression of human telomerase reverse transcriptase (hTERT) is one of the major strategies used to develop immortalized cells. Immortalization of primary cells using hTERT allows retention of the original cellular characteristics and functions and avoids some of the genetic and phenotypic instabilities associated with using known oncogenes. In the present study, we developed a cell line from human neonatal hepatocytes by transduction with a recombinant retrovirus expressing the hTERT gene. Induction of stable expression of hTERT in the neonatal cells led to immortalization of these cells. The cell line was cultured continuously for more than 25 passages, equivalent to >25 population doublings, whereas the parental cells senesced within five passages. Analysis of telomerase activity as measured by telomeric repeat amplification protocol assay indicated elevated levels of telomerase activity in immortalized cells compared to the parental cells. These immortalized human hepatocytes cells maintained a normal diploid karyotype as well as the gene expression profile similar to that of human normal neonatal hepatocytes. The data suggest that these immortalized cells preserved some of the biological characteristics of hepatic progenitor cells and might be useful as an in vitro model for pharmacological and toxicity studies.

Characterization and engraftment of long-term serum-free human fetal liver cell cultures

Cytotherapy, 2010

Background aims. Cultured human hepatocytes have extensive diagnostic and clinical applications. However, the setting-up of new in vitro culture techniques allowing the long-term survival and functional maintenance of adult human hepatocytes represents a formidable challenge. Fetal liver cells (FLC) are attractive candidate donor cells because of their high proliferative capacity. Methods. Using cell culture and molecular techniques, we studied the in vitro and in vivo characteristics of FLC grown long-term in serum-free conditions. Results. Serum-free FLC obtained from 6-10-week-old human fetal livers grew as multiple clusters in suspension and could be subcultured for at least six passages. These cells maintained stable hepatocyte phenotypes and gene expression patterns in culture for up to 6 months. When a cluster of these cells in various passages was placed on collagen-coated plates, they formed a monolayer and morphologically resembled hepatocytes. The cells expressed α -fetoprotein, cytokeratin (CK) 8, CK18 and CK19 and albumin (ALB). Hepatocyte nuclear factor 4α and 1β and cytochrome P450 (CYP) 3A4 and CYP3A7 mRNA expression was demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR). Cells at different passages, when transplanted into nude mice with liver injury, engrafted successfully, as detected by in situ hybridization using a human-specifi c DNA probe. Colonies of humanspecifi c CK8, CK18, c-Met nuclear antigen (Ag), mitochondrial Ag, hepatocyte-specifi c Ag and ALB-expressing cells were present in the livers of recipient animals. Conclusions. Primary human FLC can be kept in culture consistently over a long time period and are potential candidates for cell therapy and in vitro diagnostics.

Long-term culture and characterization of patient-derived primary hepatocytes using conditional reprogramming

Experimental Biology and Medicine, 2019

Cultivation of primary human hepatocytes (PHHs) often faces obstacles including failure of long-term in vitro culture, weak proliferation ability, rapid loss of liver-specific function and morphology, and tendency of fibrosis. Previous research focused on immortalization methods, such as telomerase and viral, to culture immortalized primary human hepatocytes, which may lose some of the normal properties. However, non-immortalized PHHs often fail to maintain long-term viability and functionality. These highlight the urgent need for developing new culture strategy for PHHs. In the present study, we isolated PHHs from fresh human liver tissues representing different liver diseases and age groups. We used conditional reprogramming, without permanent immortalization, for long-term in vitro primary human hepatocytes cultivation and characterization. For functional characterization, we assessed CYP3A4, 1A1 and 2C9 activities and measured the mRNA expression of albumin, s100a4, krt8, krt18,...

In Vitro Functionality of Human Fetal Liver Cells and Clonal Derivatives Under Proliferative Conditions

Cell Transplantation, 2006

Mature human hepatocytes are not suitable for large-scale in vitro applications that rely on hepatocyte function, due to their limited availability and insufficient proliferation capacity in vitro. In contrast, human fetal liver cells (HFLC) can be easily expanded in vitro. In this study we evaluated the hepatic function of HFLCs under proliferative conditions, to determine whether HFLCs can replace mature hepatocytes for in vitro applications. HFLCs were isolated from fetal livers of 16 weeks gestation. Hepatic functions of HFLCs were determined in primary culture and after expansion in vitro. Clonal derivatives were selected and tested for hepatic functionality. Results were compared to primary mature human hepatocytes in vitro. No differences were observed between primary HFLCs and mature human hepatocytes in albumin production and mRNA levels of various liver-specific genes. Ureagenesis was 4.4-fold lower and ammonia elimination was absent in HFLCs. Expanding HFLCs decreased hepatic functions and increased cell stretching. In contrast, clonal derivatives had stable functionality and morphology and responded to differentiation stimuli. Although their hepatic functions were higher than in passaged HFLCs, functionality was at least 20 times lower compared to mature human hepatocytes. HFLCs cannot replace mature human hepatocytes in in vitro applications requiring extensive in vitro expansion, because this is associated with decreased hepatic functionality. Selecting functional subpopulations can, at least partly, prevent this. In addition, defining conditions that support hepatic differentiation is necessary to obtain HFLC cultures suitable for in vitro hepatic applications.

Serum-Free, Long-Term Cultures of Human Hepatocytes: Maintenance of Cell Morphology, Transcription Factors, and Liver-Specific Functions

Biochemical and Biophysical Research Communications, 2000

Since human hepatocytes are available only in limited number, the development of a serum-free culture system for long-term cultivation of differentiated and functional hepatocytes is of great importance. Here we describe the culture of human hepatocytes in a chemically defined serum-free medium for up to 5 weeks. Cell morphology was assayed by light and electron microscopy and revealed a well-preserved cellular morphology. Marker proteins for epithelial and bile duct cells, cytokeratin (CK) 18 and 19, and liver-specific proteins, like phosphoenolpyruvate carboxykinase-2 (PCK2) and serum proteins, were expressed. Liver-enriched transcription factors CCAAT/enhancer binding protein ␣ (C/ EBP␣) and hepatocyte nuclear factor-4 (HNF-4), cytokine and mitogen activated factors (nuclear factor kappa B) NFB, and activator protein-1 (AP-1) were maintained and active for several weeks in our cultures. In summary, our serum-free culture system allows the culture of differentiated human hepatocytes for several weeks. It may serve as a model system for metabolic, pharmacologic-toxicologic studies, and studies on human pathogens under defined chemical conditions.

Recent advances in human hepatocyte culture systems

The liver fulfills many vital processes in mammals. It is the central organ of energy metabolism, biotransformation of xenobiotics, and synthesis of plasma proteins under physiological and pathophysiological conditions. Primary cultures of hepatocytes have been and still are an important tool to study liver-specific processes and functions. So far, most of the studies with hepatocyte cultures have primarily been performed with rat hepatocytes. However, interspecies differences in all aspects of hepatocyte function exist and are recognized and investigated since more than 30 years: Differences have been reported for the intracellular distribution of gluconeogenic enzymes (1-4), for apolipoprotein A-IV expression (5), metabolic regulation of cholesterol and triacylglycerol synthesis (6), and cytochrome P450 induction . Therefore, primary human hepatocytes should be the system of choice for the evaluation of liver specific processes in human: (i) the biology of human viral pathogens or parasites and (ii) drug metabolism in phase I and II reactions (9, 10).