Hepatic oxygen supplementation as therapy in cirrhotic liver disease

Hepatocellular organellar abnormalities following elimination of hepatitis C virus

BACKGROUND AND AIMS

The future development of hepatocellular carcinoma (HCC) in patients after sustained virologic response (SVR) is an important issue. The purposes of this study were to investigate pathological alterations in organelle of the liver of SVR patients and to characterize organelle abnormalities that may be related to carcinogenesis after SVR.

METHODS

The ultrastructure of liver biopsy specimens from patients with chronic hepatitis C (CHC) and SVR were compared to cell and mouse models and assessed semi-quantitatively using transmission electron microscopy.

RESULTS

Hepatocytes in patients with CHC showed abnormalities in the nucleus, mitochondria, endoplasmic reticulum, lipid droplet, and pericellular fibrosis, comparable to those seen in hepatitis C virus (HCV)-infected mice and cells. DAA treatment significantly reduced organelle abnormalities such as the nucleus, mitochondria, and lipid droplet in the hepatocytes of patients and mice after SVR, and cured cells, but it did not change dilated/degranulated endoplasmic reticulum and pericellular fibrosis in patients and mice after SVR. Further, samples from patients with a post-SVR period of >1 year had significantly larger numbers of abnormalities in the mitochondria and endoplasmic reticulum than those of <1 year. A possible cause of organelle abnormalities in patients after SVR could be oxidative stress of the endoplasmic reticulum and mitochondria associated with abnormalities of the vascular system due to fibrosis. Interestingly, abnormal endoplasmic reticulum was associated with patients with HCC for >1 year after SVR.

CONCLUSIONS

These results indicate that patients with SVR exhibit a persistent disease state and require long-term follow-up to detect early signs of carcinogenesis.

Hypoxia potentiates transforming growth factor-beta expression of hepatocyte during the cirrhotic condition in rat liver

BACKGROUND/AIMS

Many studies have reported that hypoxia might be associated with angiogenesis and fibrogenesis, and the level of transforming growth factor-beta1 (TGF-beta1) was increased in fibrotic liver and maximal at cirrhosis. Therefore, we examined the expression of TGF-beta1, phosphorylated-Smad2/3 (p-Smad2/3) of the TGF-beta immediate down stream signaling system and hypoxic status during hepatic fibrogenesis.

METHODS

Fibrosis of rats was induced by carbon tetrachloride. Collagens were detected with Azan stain. Immunohistochemistry and immunoblotting was used.

RESULTS

TGF-beta1 was mainly produced by hypoxic hepatocytes at cirrhosis although myofibroblasts (MFBs) and macrophages producing TGF-beta1 were decreased. Moreover, distribution of p-Smad2/3 in hepatocytes was consistent with those of hypoxic hepatocytes regardless of MFBs. Furthermore, in recovery, most MFBs disappeared, whereas positive reactions of p-Smad2/3 still existed in the hepatocytes of hypoxic areas. Therefore, TGF-beta1 expression in hepatocytes might have been associated with hypoxia.

CONCLUSIONS

We put forward the hypothesis that TGF-beta1 is mainly produced by MFBs and macrophages at early and middle stages of fibrotic processes, but it is predominantly released by hypoxic hepatocytes in the last fibrotic stage or cirrhosis.

Age-related pseudocapillarization of the human liver

Age-related changes in liver function are important because they may promote susceptibility to adverse drug reactions, neurotoxicity, atherosclerosis, and other important diseases in older people. Age-related changes in the rat hepatic sinusoidal endothelium, termed pseudocapillarization, have been described recently and these may contribute to hepatic impairment. The present study has examined surgical and post-mortem specimens with immunohistochemistry and transmission electron microscopy to determine whether pseudocapillarization also occurs in older humans. The age of the subject, independent of systemic disease or hepatic pathology in surgical and post-mortem samples of human liver, was associated with increased peri-sinusoidal expression of von Willebrand's factor, collagen I, collagen IV, and staining with Masson's trichrome. Electron microscopy revealed significant age-related thickening of the sinusoidal endothelium (young 165 +/- 17 nm, middle age 222 +/- 11 nm, older 289 +/- 9 nm, p < 0.001) with loss of fenestrations (young 7.7 +/- 0.7 per 10 micro m, middle age 3.6 +/- 0.5 per 10 micro m, older 1.5 +/- 0.4 per 10 micro m, p < 0.001), and age-related deposition of basal lamina and collagen. In conclusion, ageing in humans is associated with morphological changes in the sinusoidal endothelium and space of Disse which are presumptively related to the ageing process and potentially represent an important link between the ageing process and disease susceptibility.