Evaluation of human hepatocytes cultured by three-dimensional spheroid systems for drug metabolism.

We investigated the utility of three-dimensional (3D) spheroid cultures of human hepatocytes in discovering drug metabolites. Metabolites of acetaminophen, diclofenac, lamotrigine, midazolam, propranolol and salbutamol were analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS) to measure enzyme activities in this system cultured for 2 and 7 days. Sequential metabolic reactions by Phase I and then Phase II enzymes were found in diclofenac [CYP2C9 and UDP-glucuronyltransferases (UGTs)], midazolam (CYP3A4 and UGTs) and propranolol (CYP1A2/2D6 and UGTs).

Establishment and characterization of renal carcinoma cell lines from a Bhd gene mutant (Nihon) rat.

A germline insertion of a single nucleotide in the rat homologue of the human Birt-Hogg-Dubé (BHD) gene gives rise to dominantly inherited renal cell carcinoma (RCC) in the Nihon rat model. In this study, we established 7 lines (NR cell lines NR22, 24, 32, 45, 49, 54 and 64) from an RCC found in a Nihon rat. All cell lines consisted mainly of round or polygonal cells arranged in a cobblestone-like growth pattern.

PuraMatrix facilitates bone regeneration in bone defects of calvaria in mice.

Artificial bones have often used for bone regeneration due to their strength, but they cannot provide an adequate environment for cell penetration and settlement. We therefore attempted to explore various materials that may allow the cells to penetrate and engraft in bone defects. PuraMatrix is a self-assembling peptide scaffold that produces a nanoscale environment allowing both cellular penetration and engraftment.

Reversal of mouse hepatic failure using an implanted liver-assist device containing ES cell-derived hepatocytes.

Severe acute liver failure, even when transient, must be treated by transplantation and lifelong immune suppression. Treatment could be improved by bioartificial liver (BAL) support, but this approach is hindered by a shortage of human hepatocytes. To generate an alternative source of cells for BAL support, we differentiated mouse embryonic stem (ES) cells into hepatocytes by coculture with a combination of human liver nonparenchymal cell lines and fibroblast growth factor-2, human activin-A and hepatocyte growth factor.

Lentivirus-based gene delivery in mouse embryonic stem cells.

Background: Embryonic stem (ES) cells are widely used in therapeutic research as an unlimited source of cell therapy. Therefore, it is of great value to find a way to efficiently manipulate ES cells. HIV-1-derived lentiviral vectors are now considered to be an efficient vehicle for delivering genes into a variety of cells.

Lentiviral vector: a useful tool for transduction of human liver endothelial cells.

Endothelial cells play multiple roles in pathophysiologic processes and are increasingly being recognized as target cells of gene therapy. Lentiviral vectors derived from human immunodeficiency virus type 1 have an ability to infect both dividing and nondividing cells and currently receive a great deal of attention as an innovative tool for transduction of target cells. The purpose of the present work was to evaluate the efficacy of a lentiviral vector for transducing human liver endothelial cells (HLECs) in vitro.

Controlled expansion of human endothelial cell populations by Cre-loxP-based reversible immortalization.

Endothelial cells (ECs) play multiple physiological functions and are central to many pathological processes. Various biological studies as well as cell and gene therapy applications would benefit substantially from a procedure that would result in the expansion in culture of large numbers of highly differentiated human ECs. Here, we report the amplification in vitro of human EC populations, which occurred during the first phase of reversible immortalization resulting from the retroviral transfer of an oncogene that was subsequently excised by Cre-loxP-mediated site-specific recombination.