Recovery of Mature Hepatocytic Phenotype following Bile Ductular Transdifferentiation of Rat Hepatocytes in Vitro

Abstract

We previously demonstrated that mature rat hepatocytes transdifferentiate to bile ductular cells when cultured in a three-dimensional collagen-rich matrix. Here, we show that the phenotype of transdifferentiated hepatocytes can be reversed by modulating culture conditions. Spheroidal aggregates of hepatocytes were cultured within a collagen gel matrix in the presence of serum and tumor necrosis factor-α. Spheroids transformed into ductular structures composed of small cuboidal cells, lost the expression of hepatocytic markers, while aberrantly expressed bile ductular markers. The transdifferentiated cells were then retrieved from the gels, plated on Matrigel-coated surfaces, and cultured in serum-free media. Cells spontaneously formed spheroidal aggregates and recovered hepatocytic phenotype. While Dexamethasone (Dex), which suppressed the phosphorylation of ERK and Jun N-terminal kinase, facilitated the recovery, the combination with interleukin-6 or oncostatin M resulted in the recovery of HNF-4α protein expression and the typical hepatocytic morphology and a decrease in the expression of bile ductular markers. A cDNA microarray analysis revealed that the hepatocyte-specific mRNA expression profile was recovered in these cells. Our results demonstrate that hepatocytes are able to recover their phenotypes following bile ductular transdifferentiation, suggesting that hepatocytic and bile ductular phenotypes may be mutually reversible.4

Tumor necrosis factor‐α promotes bile ductular transdifferentiation of mature rat hepatocytes in vitro

“…The expression of secretin receptors has been demonstrated in the bile ductular cells appeared in CCl 4 ‐induced chronic liver injury in rats [LeSage et al, 1999]. We also found that secretin receptor mRNA was highly expressed in hepatocytes cultured within the collagen gel in the presence of TNF‐α [Sone et al, 2012].…”

“…In conclusion, we have shown that, within a collagen‐rich matrix, TNF‐α strongly enhances the bile ductular transdifferentiation of hepatocytes, especially through the suppression of hepatocytic differentiation and enhancement of ductular morphogenesis. Recently, we also have observed phenotypic reversion of transdifferentiated ductular cells to mature hepatocytes when cells are retrieved from the collagen gel matrix and cultured serum‐free on Matrigel in the presence of IL‐6 or oncostatin M [Sone et al, 2012]. These results suggest that there might be phenotypic plasticity between hepatocytes and bile ductular cells in the adult liver, depending on the microenvironment into which they are placed (Fig.…”

Contributions of Hepatocytes and Bile Ductular Cells in Ductular Reactions and Remodeling of the Biliary System after Chronic Liver Injury

“…11,12 Furthermore, we have recently demonstrated that, under modulated culture conditions, rat hepatocytes can recover their original phenotype after bile ductular transdifferentiation. 13 This suggests that hepatocytic and bile ductular phenotypes are mutually reversible.…”

Biliary fibrosis drives liver repopulation and phenotype transition of transplanted hepatocytes

“…However, it has been demonstrated in vitro that IL-6 reverses biliary “transdifferentiation” of cultured hepatocytes (18), so we did not perform experiments with this cytokine. Moreover, a pilot experiment with mature hepatocytes incubated with FGF18 showed no effect on mRNA expression of genes that are involved in the development of bile ducts ( data not shown ) and published studies have shown that this agent is a hepatocyte mitogen without obvious phenotypic effects (19).…”