Liver-specific physiology of immortal, functionally differentiated hepatocytes and of deficient hepatocyte-like variants.

Five different immortalized transgenic hepatocyte cell lines derived from mice were investigated with respect to their potential to maintain the physiological properties of primary hepatocytes using chemically defined medium. This research completes a previous study by Klocke and coworkers in 2002, using gene expression analysis of the same cell lines by the respective physiological analysis for investigating the hepatocyte-like function. Three transgenic cell lines harboring a fusion gene derivative (construct 202) consisting of the complete SV40 early region, including the coding sequences for the transforming large and small tumor antigens, placed under the control of the murine metallothioneine 1-promotor/enhancer element, showed a hepatocyte-like function and physiology.

Vascularization and gene regulation of human endothelial cells growing on porous polyethersulfone (PES) hollow fiber membranes.

Open-cell hollow fibers made of polyethersulfone (PES) manufactured in the absence of solvents with pore diameters smaller than 100 microm were examined for vascularization by human endothelial cells. The goal of this study was to determine whether the 3-D porous character of the PES surface affected human endothelial cell morphology and functions. Freshly isolated human endothelial cells from the skin (HDMEC), from the lung (HPMEC) and from umbilical cords (HUVEC) and two human endothelial cell lines, HPMEC-ST1.

Remodeling of fibrinogen by endothelial cells in dependence on fibronectin matrix assembly. Effect of substratum wettability.

The endothelization of cardiovascular implants is desirable to improve their blood compatibility. The capacity of the endothelial cells to attach, migrate, proliferate and function on the implant surface depends on the presence of matrix proteins such as fibronectin (FN) and fibrinogen (FNG). In this study, we show that the deposition of fibrinogen into extracellular matrix-like structures by human umbilical vein endothelial cells (HUVEC) is dependent on FN matrix formation.

Progressive paralysis associated with diffuse astrocyte anaplasia in delta 202 mice homozygous for a transgene encoding the SV40 T antigen.

A convenient transgenic astrocytoma model in delta202 mice, homozygous for a construct encoding the early region of the SV40 virus genome, is described. In the offspring of crosses between delta202 mice heterozygous for the transgene nearly 60% were transgenic; one third of these developed progressive paralysis starting in the hindlimbs at approximately 35 days of age and died at 90 +/- 30 days of age. In affected mice proliferating-non-neuronal cells immunostained with antibodies to the GFAP, an astrocyte marker, whose number increased with age were found in the white matter of the brain, cerebellum and spinal cord, and progressive degeneration and necrosis of spinal motoneurons was observed that-may explain the paralysis.

entla, a novel epileptic and ataxic Cacna2d2 mutant of the mouse.

entla (ent) is a novel recessive phenotype of mice. The underlying mutation was mapped to chromosome 9 (60.1 centimorgans) and identified as an allele of the Cacna2d2 gene encoding the alpha2delta-2 subunit of voltage-gated calcium channels.

Fibrinogen adsorption and platelet interactions on polymer membranes.

The hemocompatibility of four different wettable polymer membranes, namely Cuprophan (CE), polyether-polycarbonate (PC-PE), polysulfone (PSU), and polyetherimide (PEI), was investigated with respect to fibrinogen (Fng) adsorption and platelet adhesion/activation. In order to estimate the polar and dispersion components of the surface free energy, contact angles using water/vapor and water/n-hexadecane systems were measured. Adsorption of fibrinogen was studied using fluorescence-labeled protein.

Cell cycle synchronization of porcine fetal fibroblasts by serum deprivation initiates a nonconventional form of apoptosis.

The success of somatic nuclear transfer depends upon the cell cycle stage of the donor nucleus and the recipient cytoplast. Recently, we established efficient cell cycle synchronization protocols for porcine fetal fibroblasts and found that serum withdrawal leads to cell death. Here, we examined whether the specific cell death induced by serum deprivation follows the conventional apoptotic pathway in porcine fibroblasts.

Generation and characterization of transgenic mice expressing cobra venom factor.

Cobra venom factor (CVF), the anticomplementary protein in cobra venom, activates the alternative complement pathway, eventually leading to complement consumption. Here, we describe the development of a transgenic mouse model for CVF. We generated a DNA construct containing the full-length cDNA for single-chain pre-pro-CVF.

Establishment and characterization of immortal hepatocytes derived from various transgenic mouse lines.

The potential of three genetic changes introduced into mice by the transgenic or knockout technology aimed at immortalizing hepatocytes in vitro and concomitantly preserving their differentiated hepatic functions was analyzed. Six hepatocyte lines were isolated from neonatal and adult transgenic mice expressing either IgEGF (a secretable variant of hEGF) or SV40 T antigen in the liver and from neonatal and adult p53 knockout (KO) mice and have been subcultured >150 times in serum-free, arginine-deficient medium. Only in SV40 T antigen transgenic lines profiles of mRNAs encoding serum proteins, transcription factors, and liver-specific enzymes were similar to those found in livers and primary hepatocytes.

Interaction of human skin fibroblasts with moderate wettable polyacrylonitrile--copolymer membranes.

The development of a bioartificial skin is a step toward the treatment of patients with deep burns or nonhealing skin ulcers. One possible approach is based on growing dermal cells on membranes to obtain appropriate living cellular stroma (sheets) to cover the wound. New membrane-forming copolymers were synthesized, based on acrylonitrile (AN) copolymerization with hydrophilic N-vinylpyrrolidone (NVP) monomer, in different percentage ratios, such as 5, 20, and 30% w/w, and with two other relatively high polar comonomers--namely, sodium 2-methyl-2-propene-1-sulfonic acid (NaMAS) and aminoethylmethacrylate (AeMA).