Distribution of cytokeratins and vimentin in rats liver at various stages of ontogenesis

Abstract

In recent years, there has been increasing understanding that the molecular mechanisms of liver morphogenesis are also involved in the mechanisms of regeneration and pathogenesis of some organ diseases. Epithelial-mesenchymal and mesenichymal-epithelial transitions play a significant role in embryogenesis, morphogenesis and regeneration. The aim of the study was to characterize the localization and ratio of epithelial and mesenchymal cells in the liver tissue during embryonic and postnatal development of rat liver as a possible criterion for mesenchymal-epithelial transition. We have analyzed immunohistochemically the production and distribution of vimen-tin (mesenchymal marker) and cytokeratin 18 (epithelial marker) in the liver tissue of rats from day 1 0 of embryonic development to adults. The relative area of hybrid cells has determined by double immunofluorescence followed by morphometry. The study showed that as the liver develops, the content of the epithelial marker (cy-tokeratin 18) increases, while the production of the mesenchymal marker (vimentin) decreases, with the exception of the period from 1 to 17 days after birth, when the amount of vimentin increases. In addition, hybrid cells were found in the liver of embryos on days 10 and 17 of gestation, which synthesized both intermediate microfilaments - vimentin and cytokeratin 1 8. Thus, based on the ratio of vimentin and cytokeratin 18 in the process of embryonic and postnatal liver morphogenesis and the presence of hybrid cells allow make an assumption about the origin of a part of hepatocytes by mesenchymal-epithelial transition.