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Human Hepatocyte Spheroids Show Plasticity-enabling Extended Culture and Pretransplant Conditioning

The conception and animal modeling of hepatocyte transplantation along with a partial listing of human hepatocyte infusions over the last 13 years have been detailed in authoritative reviews. However, to adequately best represent the worldwide effort of moving from highly successful clinical solid liver transplants "back to" isolated hepatocyte therapy requires repeating important concepts with explanations of how or why not animal experimental data translate to human experience. This overview summarizes 78 human clinical hepatocyte transplant experiences authenticated by the authors. The human cell infusion experiences are categorized by liver disease treated (metabolic, chronic, and acute liver failure), and these are accompanied by seminal in vitro and in vivo experimental data.

An in vitro approach was undertaken to investigate the metabolite profile of dihydro-alpha-ergocryptine,9,10-[9,10 ( -3 ) H(N)] in humans by comparison with two species, rat and monkey, for toxicological studies. Hepatocytes (rat and human) and microsomes (rat, monkey, and human) were used in this study, and a high-performance liquid chromatography system was developed to determine the metabolic profiles. From the two in vitro metabolizing systems it was concluded that the compound was extensively metabolized in all species, with a similar overall rate of 4.5 ng/min/mg protein in the microsomal system. The human metabolite profile in hepatocytes showed an intersubject variability that was not confirmed with microsomes. The more complex human pattern consisted of eight metabolites (based on chromatographic properties) that were produced in rats (major part) or in monkeys. Of these eight metabolites, seven were produced by rat microsomes and six by the monkey microsomes. Because of qualitative and quantitative differences, it was not possible to show that the human metabolite profile was closer to the rat's or to the monkey's. The conclusion is that all the observed metabolites in human are produced either in rats (for a major part) or in monkeys, so that these two species cover the human metabolic pattern for toxicological studies.

We have found a hepatotrophic factor in plasma or sera of patients with fulminant hepatic failure and have purified human hepatocyte growth factor from plasma of these patients. In this study we developed an enzyme-linked immunosorbent assay with high specificity and sensitivity for human hepatocyte growth factor in human serum. This assay for serum human hepatocyte growth factor is a sandwich method consisting of three steps. The standard curve for human hepatocyte growth factor appeared to be linear in the range of 0.20 to 12.50 ng purified human hepatocyte growth factor/ml (2.35 to 147 pmol/L). The assay took about 4 hr. Serum human hepatocyte growth factor values in patients with fulminant hepatic failure measured by enzyme-linked immunosorbent assay showed a strong positive correlation with that by bioassay using rat hepatocytes in primary culture. The mean value of serum human hepatocyte growth factor for 30 normal subjects was 0.24 +/- 0.12 (S.D.) ng/ml; that for 23 patients with fulminant hepatic failure was 8.06 +/- 1.76 (S.E.M.) ng/ml- greater than 30 times greater than the mean value for normal subjects. Serum human hepatocyte growth factor levels in patients with acute hepatitis, chronic hepatitis and cirrhosis were found to be slightly higher than those in normal subjects, but only the increase in serum human hepatocyte growth factor of acute hepatitis patients was statistically significant. The enzyme-linked immunosorbent assay for serum human hepatocyte growth factor should prove useful for serum human hepatocyte growth factor level measurement in patients with various liver diseases.