Morphological changes induced by extracellular matrix are correlated with maturation of rat small hepatocytes

Abstract

Small hepatocytes (SHs), which are known to be hepatic progenitor cells, were isolated from an adult rat liver. SHs in a colony sometimes change their shape from small to large and from flat to rising/piled-up. The aim of the present study is to clarify whether the alteration of cell shape is correlated with the maturation of SHs and whether extracellular matrix (ECM) can induce the morphological changes of SHs. We used liver-enriched transcription factors (LETFs) such as hepatocyte nuclear factor (HNF) 4 alpha, HNF6, CCAAT/enhancer binding proteins (C/EBP) alpha, and C/EBP beta, tryptophan 2,3-dioxygenase (TO), and serine dehydratase (SDH) as markers of hepatic maturation. To enrich the number of SH colonies, the colonies were isolated from dishes and replated. Replated colonies proliferated and the average number of cells per colony was about five times larger at day 9 than at day 1. When the cells were treated with laminin, type IV collagen, a mixture of laminin and type IV collagen, Matrigel or collagen gel (CG), only the cells treated with Matrigel dramatically changed their shape within several days and had reduced growth activity, whereas the cells treated with other ECM did not. HNF4 alpha, HNF6, C/EBP alpha, C/EBP beta, and TO were well expressed in the cells treated with Matrigel. Furthermore, addition of both glucagon and dexamethasone dramatically induced the expression of SDH mRNA and protein in the cells treated with Matrigel. In conclusion, morphological changes of SHs may be correlated with hepatic maturation and basement membrane (BM)-like structure may induce the morphological changes of SHs.

Selective proliferation of rat hepatocyte progenitor cells in serum-free culture

“…Next, we examined whether SHs could proliferate in serum-free medium. Although we reported that SH colonies could expand in serumfree medium after re-plating SH colonies 4,16 , it was very difficult for SHs in serum-free medium to grow to form colonies on conventional dishes. When we used serum-free DMEM/F12 and HA-coated dishes, many colonies developed (Fig.…”

“…Although the cells are less than half the size of mature hepatocytes (MHs), they possess hepatic characteristics 1 . SHs can clonally proliferate to form a colony and can differentiate into MHs by interacting with hepatic non-parenchymal cells (NPCs) 2,3 or as a result of treatment with gel derived from Engelbreth-Holm-Swarm sarcoma 4 . Thus, we consider that SHs may be 'committed progenitor cells' that can further differentiate into MHs.…”

Cell shape regulates global histone acetylation in human mammary epithelial cells

“…The following Lightcycler PCR amplification protocol was used: 95°C for 10 minutes, and 45 amplification cycles (95°C for 5 seconds, 60°C for 10 seconds, 72°C for 5 seconds). Amplification was followed by melting curve analysis to verify the presence of a single PCR product [34]; 18S was amplified as a reference gene using the same protocol.…”

Downregulation in the expression of the serine dehydratase in the rat liver during chronic metabolic acidosis

“…This stimulation is maximal in the presence of glucocorticoids (19). Also, SerDH is considered a marker of liver maturation and is involved in regulating the development of different tissues (48). Previously (30), we have demonstrated that SerDH activity, as well as the protein and mRNA levels, fell in rat liver during chronic liver injury induced by thioacetamide.…”