Morphology, differentiation and matrix production of liver cells in organoid cultures high density cultures of fetal rat livers

Abstract

Tlie aim of this study \\as to dcn~ons t ratetl ie morpl~ologya nd matrix synthesis of ernl~ryonicr at liver cc.11\ (clay IS of gestation) in organoid cultures (high densit!, cultures) with electron microscopic and imm~~nomorphologictaelc hniclues. For this purpose tlie cells of embryonic rat livers were isolated enzyniaticall! and g r o ~i1~1 ;iin organoid culture (high clensit!, c ~ ~ l t u r e ) l'or .; weeks in n Trowell systern. During the first 48 h n sor t ing-o~~ptr ocess took place. i.e. liver and bloodforming cells met to form aggregates. In between mescncliynial cells were seen. Vessel-like cavities cleceloped. Electron microscopic inspection of the hepatocytes did not reveal any lesions of the cell organelles after 14 days in culture. As late as after a 3-week culture period niitochondrial s\~cllings ancl an increasecl number of autopliagic cacuole\ \\.ere ohse~.vccl. A rim of collagenous fibrils or fibrillar hun~llcs ancl granular matrix structul-es uas perceptible ;I\ earl! as after 7 days in culture. Immunofluoresccnce microscopic t e c h n i q~~eresv ealed collagen types 111. IV and V1 as well as laminin. nidogen. lieparansulfateproteoglycan and fibronectin in these areas. Thus, the composition of the matrix in this c u l t ~ ~ rsey stem corresponds (apart from the absence of collagen type 1 ) to tlie embryonic situation. Therefore. the organoid culture appears to be a n appropriate technicl~let o stuciy the l > c l i a ~ i oo~f~ lri epatocytes in \,itro. It is especially suited to clenionstrate the formation of matrix coliiponents in liver cells and their extracellular occurrence.