Ultrastructure of fetal mice hepatocytes exposed in utero to diazepam / Ultraestructura de hepatocitos fetales de ratón expuestos in utero a diazepam

Previous research has shown that fetal mice hepatic cells from females treated with diazepam (Valium) during pregnancy depict cytoplasmic and nuclear modifications when observed with photonic microscope. The purpose of this work is to investigate if diazepam administered subcutaneously (SC) to pregnant mice females induces ultraestructural alterations in the cytoplasmic organelles and nucleus to fetal hepatocytes. Transmission electron microscopy observations of fetal hepatocytes from pregnant females treated with a single daily dose of diazepam 2.7 mg/kg/bw/SC administered from 6th to 15th days of gestation revealed that they frequently presented disorganized and dilated rough endoplasmic reticulum cisterns, membranous elements, abundant Golgi complex and glycogen granules, around large vacuoles. The voluminous nucleus shows atypical distribution of chromatin. These alterations could modify the hepatocyte's physiology and probably persist after birth.

Estudios previos muestran que las células hepáticas de fetos de ratón, de hembras tratadas con diazepam (Valium) durante la gestación, presentan modificaciones citoplásmicas y nucleares que se pueden observar con el microscopio fotónico, por lo que el propósito de este trabajo es determinar si el diazepam administrado por vía subcutánea (SC) a hembras gestantes de ratón, induce alteraciones ultraestructurales de los organelos citoplásmicos y del núcleo de los hepatocitos fetales. En los fetos de ratón del grupo experimental de hembras gestantes, tratadas con dosis únicas diarias de 2,7 mg/kg de peso corporal administradas por vía SC del 6° al 15° día de la gestación, se observó con el microscopio electrónico de transmisión que los hepatocitos fetales presentaban con frecuencia retículo endoplásmico rugoso desorganizado, con cisternas dilatadas; había elementos membranosos y complejo de Golgi abundante, al igual que gránulos de glucógeno que rodeaban a grandes vacuolas. Los núcleos eran voluminosos, con la cromatina distribuida atípicamente. Estas alteraciones podrían modificar la fisiología de los hepatocitos y probablemente persistan después del nacimiento.

Conditional immortalization of human fetal hepatocytes using an amphotropic retrovirus encoding temperature - sensitive SV40 large T antigen / 대한내과학회지

BACKGROUND: Human cells are almost never spontaneously immortalized in vitro. We tried to immortalize human fetal hepatocytes (h-FH) and evaluate the differentiational status and its change. METHODS: Hepatocytes were isolated from a liver fragment of 20 week old fetus and infected with amphotropic recombinant retrovirus containing a temperature- sensitive mutant of SV40 large T antigen and neomycin phosphotransferase gene. G418 resistant colonies were cloned and expanded. The cells which were able to divide more than 30 times were used to analyze various functions. RESULTS: The immortalization rate was 3.3 x 10-8 and two cell lines (C11, D21) were established. C11-60, C11-80, D21-30 and D21-60 (suffix number means the cell division counts) were evaluated. D21-30 was thougt to be imcompletely immortalized because a considerable portion of cells died during culture. The morphology was similar to that of epithelial cells except for D21-30 which looked like fibroblast. The cells grew rapidly at 33oC but stopped growing at 39oC. T antigen and p53 was expressed at 33oC but disappeared at 39oC, which suggest that T antigen binds to p53. Chromosomal changes were so marked that it was impossible to discriminate exact number. Albumin was secreted as about 1/10 as that of h-FH, but alpha-fetoprotein secretion stopped after immortalization. Telomerase was activated in both cell lines except for the incompletely immortalized cells D21-30. Telomere was elongated in competely immortalized cell lines, but it was rather shortened in D21-30 compared to that of h-FH. Macroscopic colonies did not develop in soft agar assay. CONCLUSIONS: We successfully immortalized human fetal hepatocytes. Although the cells are not likely to have oncogenicity, the functions are not so good, possibly due to marked chromosomal changes which are thought to occur before telomerase is activated during immortalization step.

Effect of fibronectin on infection of primary human fetal hepatocytes with HBV in vitro / 解放军医学杂志

Objective This experiment was carried out to study the effect of fibronectin on the infection of primary human fetal hepatocytes with hepatitis B virus (HBV) in vitro. Method Human fetal hepatocytes were inoculated with HBV positive serum in culture dish coated with fibronectin (Fn) in vitro. HBsAg and HBeAg in supernatant were assayed with ELISA, HBcAg in nuclei by immunohistochemistry, HBV DNA in cells by fluorescence quantitative PCR, and cccDNA in cultured cells by nest PCR. The results were compared with the cells cultured in dishes without fibronectin coating. Results HBsAg and HBeAg in supernatants were positive on the fifth day in dishes without Fn coating, and on the first day in dishes with Fn coating. HBcAg in nuclei was positive on the second and the first day in dishes without and with Fn coating, respectively, and the positive rates were about 10%～15% and 90%, respectively. HBV DNA was detected in cells on the fourth day and first day in dishes without and with Fn coating, respectively. CccDNA in cells was positive on the eighth day and the first day in dishes without and with Fn coating, respectively. Conclusion Fibronectin coating could facilitate HBV infection in primary fetal hepatocytes in vitro. The infection time of HBV was shortened, and the number of infected cells was increased.