Changes to hepatocyte ploidy and binuclearity profiles during human chronic viral hepatitis - PubMed (original) (raw)
Changes to hepatocyte ploidy and binuclearity profiles during human chronic viral hepatitis
H Toyoda et al. Gut. 2005 Feb.
Abstract
Background and aims: The importance of the hepatocyte ploidisation pattern to the control of cell proliferation and differentiation has been well established. However, there are no data that have characterised hepatocyte ploidy at various stages of chronic liver inflammation and fibrosis in vivo.
Methods: We therefore investigated hepatocyte ploidy/binuclearity patterns in 57 patients with chronic hepatitis, using a recently developed methodology which allows simultaneous hepatocyte ploidy and binuclearity analyses on the same liver section.
Results: The percentage of mononuclear diploid hepatocytes was significantly reduced in patients with high hepatitis activity and marked fibrosis (low activity: 75.1 (18.8)% v high activity: 61.8 (21.6)%, p=0.0111, and low fibrosis: 77.3 (13.8)% v high fibrosis: 57.4 (23.3)%, p=0.0002). Accordingly, the percentage of mononuclear polyploid hepatocytes increased in patients with high hepatitis activity and marked fibrosis (low activity: 11.9 (15.5)% v high activity: 22.2 (20.1)%, p=0.0166, and low fibrosis: 9.4 (10.7)% v high fibrosis: 26.4 (21.6)%, p=0.0001). In addition, the fraction of binuclear hepatocytes was significantly higher in patients with hepatitis B virus (HBV) than in those with hepatitis C virus (HCV) infections (HBV: 18.2 (7.6)% v HCV: 12.0 (4.8)%; p=0.0020). Under multivariate analysis, HBV infection was an independent factor accounting for the larger binuclear hepatocyte fraction (p=0.0294).
Conclusion: Our results revealed an increase in the polyploid hepatocyte fraction which correlates with the severity of chronic hepatitis; moreover, we demonstrated that HBV and HCV related chronic hepatitis exhibited distinctive hepatocyte ploidy patterns, thus allowing the suggestion that these two viral infections may modulate liver ploidy through different mechanisms.
Figures
Figure 1
In vivo analysis of hepatocyte ploidy/binuclearity in patients with chronic hepatitis. (A) Image of a liver section after double staining with Hoechst 33342 (nuclear labelling, pink) and cytokeratin (plasma membrane labelling, green) which enabled a distinction between mononuclear and binuclear hepatocytes. (B) Representative histogram of the DNA content distribution of mononuclear hepatocytes for one patient. DNA content was evaluated by recording either the area of each nucleus (left panel) or the intensity of Hoechst integrated fluorescence (right panel). The first peak is representative of hepatocytes with 2n DNA content. The second peak is positioned around twice the value of the first peak and is representative of hepatocytes with 4n DNA content. (C) Integrated fluorescence was correlated with the area of nucleus in each specimen analysed (example for one patient, p<0.0005). A significant correlation was observed between the two parameters (p<0.001 for the 57 patients, Spearman’s rank correlation 0.85).
Figure 2
Ploidy/binuclearity distributions, according to the progression of chronic hepatitis. (A, B) Fraction of mononuclear diploid hepatocyte; (C, D) fraction of mononuclear polyploid hepatocytes; and (E, F) fraction of binuclear hepatocytes. (A, C, E) Comparison between low and high activity of inflammation; and (B, D, F) comparison between low and high degrees of fibrosis. Box plots for the percentage of hepatocytes in each population (mononuclear diploid hepatocytes, mononuclear polyploid hepatocytes, and binuclear hepatocytes) out of the total number of hepatocytes analysed. The ends of each box represent the quartiles, and the median of distribution is indicated by a line within the box; n corresponds to the number of patients in each group. All p values were calculated using the Mann-Whitney U test.
Figure 3
Comparison of the fraction of mononuclear cells in the population of polyploid hepatocytes (FMP) in patients with chronic hepatitis. Four groups of patients were defined: low activity and low fibrosis; high activity and low fibrosis; low activity and high fibrosis; and high activity and high fibrosis. FMP percentages were calculated as follows: FMP = number of mononuclear polyploid hepatocytes/number of all polyploid hepatocytes (mononuclear polyploid hepatocytes+binuclear hepatocytes). The ends of each box represent the quartiles, and the median of distribution is indicated by a line within the box; n corresponds to the number of patients in each group. All p values were calculated using the Mann-Whitney U test.
Figure 4
Comparison of ploidy/binuclearity distributions between patients with chronic hepatitis B and C. (A) Fraction of mononuclear diploid hepatocyte; (B) fraction of mononuclear polyploid hepatocyte; and (C) fraction of binuclear hepatocyte levels. Box plots of the percentage of hepatocytes in each population (mononuclear diploid hepatocytes, mononuclear polyploid hepatocytes and binuclear hepatocytes) out of the total number of hepatocytes analysed. The ends of each box represent the quartiles, and the median of distribution is indicated by a line within the box; n corresponds to the number of patients in each group. All p values were calculated using the Mann-Whitney U test.
References
- Nadal C , Zajdela F. Hepatic polyploidy in the rat. IV. Experimental changes in the nucleolar volume of liver cells and their mechanisms of regulation. Exp Cell Res 1967;48:518–28. - PubMed
- Saeter G , Schwarze E, Seglen O. Shift from polyploidizing to nonpolyploidizing growth in carcinogen-treated rat liver. J Natl Cancer Inst 1988;80:950–8. - PubMed
- Wheatley DN. Binucleation in mammalian liver. Studies on the control of cytokinesis in vivo. Exp Cell Res 1972;74:455–65. - PubMed
- Koike Y , Suzuki Y, Nagata A, et al. Studies on DNA content of hepatocytes in cirrhosis and hepatoma by means of microspectrophotometry and radioautography. Histochemistry 1982;75:549–62. - PubMed
- Kudryavtsev BN, Kudryavtseva MV, Sakuta GA, et al. Human hepatocyte polyploidization kinetics in the course of life cycle. Virchows Arch B Cell Pathol Incl Mol Pathol 1993;64:387–93. - PubMed
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources