A murine model demonstrating reversal of structural and functional correlates of cirrhosis with progenitor cell transplantation

Cellular and Molecular Mechanisms of Toxic Liver Fibrosis in Rats Depending on the Stages of Its Development

The aim is to study the cellular and molecular features of toxic liver fibrosis in rats and its dependence on development stages of this pathological condition.

Materials and Methods

Liver fibrogenesis in male Wistar rats was induced with the thioacetamide solution by introducing into the stomach with a probe at a dose of 200 mg/kg of animal body weight 2 times per week. The process dynamics was studied at 5 time points (control, week 3, week 5, week 7, and week 9). The mRNA levels of tweak, fn14, ang, vegfa, cxcl12, and mmp-9 genes in liver were detected by real-time polymerase chain reaction. Immunohistochemical study was performed on paraffin sections. The CD31, CD34, CK19, α-SMA, FAP, CD68, CD206, CX3CR1, and CD45 cells were used as markers. Fibrosis degree was determined in histological sections, stained in line with the Mallory technique, according to the Ishak's semi-quantitative scale.

Results

Two simultaneously existing morphologically heterogeneous populations of myofibroblasts expressing different types of markers (FAP, α-SMA) were identified in rat liver. Prior to the onset of transformation of fibrosis into cirrhosis (F1-F4, weeks 3-7), FAP+ and SMA+ cells were localized in different places on histological specimens. All stages of liver fibrosis development were accompanied by an increase in the number (p=0.0000), a change in the phenotypic structure and functional properties of macrophages. The CK19+ cells of the portal areas differentiated into cholangiocytes that formed interlobular bile ducts and ductules, as well as hepatocytes that formed rudiments of new hepatic microlobules. Pathological venous angiogenesis and heterogeneity of endotheliocytes of the intrahepatic vascular bed were detected. Two options for changes in mRNA expression of the selected genes were identified. The level of the fn14 and mmp-9 mRNAs at all stages of fibrosis was higher (p=0.0000) than in control rats. For tweak, ang, vegfa, and cxcl12 mRNAs, the situation was the opposite - the level of genes decreased (p=0.0000). There were strong and moderate correlations between the studied target genes (p<0.05).

Conclusion

It was established that the stages of toxic fibrosis had morphological and molecular genetic features. The FAP+ cells make the main contribution to development of portal and initial stage of bridging fibrosis. The stellate macrophages and infiltrating monocytes/ macrophages can potentially be used for development of new therapeutic strategies for liver pathology treatment. One should take into account the features of the markers' expression by endothelial cells during the study of the intrahepatic vascular bed. Joint study of genes is a necessary ad-hoc parameter in fundamental and preclinical research.

Changes in Macrophage Subpopulations in Rat Liver at Different Stages of Experimental Fibrosis

The number, phenotypic composition, and functional properties of macrophages in the liver of Wistar rats change depending on the stages of fibrosis induced by thioacetamide. In the sinusoidal capillaries of the liver of control rats, CD68⁺ wing-shaped cells were mainly detected. The number of CD68⁺ cells at the stages of fibrosis before the process of its transformation into cirrhosis was 2-fold higher (p=0.0000) than in the control. At later terms of the experiment, no significant differences were found. Immunohistochemical method revealed two morphologically different groups of CD68⁺ cells differing in shape and localization. At all stages of the experiment, round and elongated CD206⁺ cells of were detected in the sinusoidal capillaries. At the stage of cirrhosis (13 weeks), the number of CD206⁺ cells was higher than during the third week of the experiment by 3.21 times (p=0.0000). Later, a decrease in the number of CD206⁺ cells was observed. At the same time, in the portal zones and connective tissue septa around the false hepatic lobules, round CX3CR1⁺ cells were noted. By the end of the experiment (17 weeks), their number exceeded that on the third week of the experiment by 5.66 times (p=0.0000).

Alcohol and HIV-Derived Hepatocyte Apoptotic Bodies Induce Hepatic Stellate Cell Activation

Recently, we found that both HIV and acetaldehyde, an alcohol metabolite, induce hepatocyte apoptosis, resulting in the release of large extracellular vesicles called apoptotic bodies (ABs). The engulfment of these hepatocyte ABs by hepatic stellate cells (HSC) leads to their profibrotic activation. This study aims to establish the mechanisms of HSC activation after engulfment of ABs from acetaldehyde and HIV-exposed hepatocytes (ABAGS+HIV). In vitro experiments were performed on Huh7.5-CYP (RLW) cells to generate hepatocyte ABs and LX2 cells were used as HSC. To generate ABs, RLW cells were pretreated for 24 h with acetaldehyde, then exposed overnight to HIV1ADA and to acetaldehyde for 96 h. Thereafter, ABs were isolated from cell suspension by a differential centrifugation method and incubated with LX2 cells (3:1 ratio) for profibrotic genes and protein analyses. We found that HSC internalized ABs via the tyrosine kinase receptor, Axl. While the HIV gag RNA/HIV proteins accumulated in ABs elicited no productive infection in LX2 and immune cells, they triggered ROS and IL6 generation, which, in turn, activated profibrotic genes via the JNK-ERK1/2 and JAK-STAT3 pathways. Similarly, ongoing profibrotic activation was observed in immunodeficient NSG mice fed ethanol and injected with HIV-derived RLW ABs. We conclude that HSC activation by hepatocyte ABAGS+HIV engulfment is mediated by ROS-dependent JNK-ERK1/2 and IL6 triggering of JAK-STAT3 pathways. This can partially explain the mechanisms of liver fibrosis development frequently observed among alcohol abusing PLWH.

Genetic variants in IL33 and IL1RL1 genes confer susceptibility to HBV-related liver cirrhosis in Chinese Han population

INTRODUCTION

Previous studies indicate that the IL-33/ST2 pathway is involved in hepatitis B virus (HBV) -related liver diseases. This study aimed to determine the relationship between genetic variants in IL-33/ST2 pathway with susceptibility to liver cirrhosis.

MATERIALS AND METHODS

A total of 2632 Han Chinese samples met the inclusion and exclusion criteria, including 840 negative controls (NeC), 691 chronic hepatitis B (CHB), 680 HBV-related liver cirrhosis (LC) and 421 HBV-related hepatocellular carcinoma (HCC) (without LC) patients. Four polymorphisms (IL33-rs4742170, rs1048274, rs10975519 and IL1RL1-rs1041973) were selected and genotyping was performed. All statistical analyses were performed by SPSS21.0, mainly using the Hardy-Weinberg equilibrium test, Pearson chi-square, unconditional Logistic regression and haplotype analysis.

RESULTS

After adjusting for age, sex, smoking and drinking, significant associations were observed between IL33-rs4742170, rs1048274 and rs10975519 polymorphisms with LC risk. NeC with IL33-rs4742170 CC genotype was 1.80 times more likely to develop LC compared with TT genotype, while NeC with rs10975519(TC + CC) genotype was 1.32 times more likely to develop LC when compared with the TT genotype. CHB cases with rs4742170(CC + TC) genotype had 1.30 times higher susceptibility to develop LC compared with the TT genotype. The IL33-rs1048274G allele occurred more frequently in the LC group compared with the HCC group in codominant model (AG/AA: P = 0.001, OR = 1.66, 95%CI = 1.22-2.25; GG/AA: P = 0.018, OR = 1.54, 95%CI = 1.08-2.20). The IL33 haplotype CG conformed by rs10975519C and rs1048274G was more frequent in the LC group than in the NeC group and CHB group. Moreover, the IL33 haplotype CCG conformed by rs4742170C, rs10975519C and rs1048274G was found to be more frequent in the LC group than the HCC group. However, there was no association between IL1RL1-rs1041973 and LC risk.

CONCLUSION

Our findings demonstrate the association between genetic variants in IL33 with susceptibility to liver cirrhosis. IL33-rs4742170C, rs1048274G and rs10975519C could serve as biomarkers of LC.

Predicting HCC Response to Multikinase Inhibitors With In Vivo Cirrhotic Mouse Model for Personalized Therapy

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) arises in a cirrhotic, pro-angiogenic microenvironment. Inhibiting angiogenesis is a key mode of action of multikinase inhibitors and current non-cirrhotic models are unable to predict treatment response. We present a novel mouse cirrhotic model of xenotransplant that predicts the natural biology of HCC and allows personalized therapy.

METHODS

Cirrhosis was induced in NOD Scid gamma mice with 4 months of thioacetamide administration. Patient derived xenografts (PDXs) were created by transplant of human HCC subcutaneously into non-cirrhotic mice and intra-hepatically into both cirrhotic and non-cirrhotic mice. The applicability of cirrhotic PDXs for drug testing was tested with 16 days of either sorafenib or lenvatinib. Treatment response was evaluated by MRI.

RESULTS

8 out of 19 (42%) human HCC engrafted in the cirrhotic model compared with only 3 out of 19 (16%) that engrafted in the subcutaneous non-cirrhotic model. Tumor vasculature was preserved in the cirrhotic model but was diminished in the non-cirrhotic models. Metastasis developed in 3 cirrhotic PDX lines and was associated with early HCC recurrence in all 3 corresponding patients (100%), compared with only 5 out of 16 (31%) of the other PDX lines, P = .027. The cirrhotic model was able to predict response and non-response to lenvatinib and sorafenib respectively in the corresponding patients. Response to lenvatinib in the cirrhotic PDX was associated with reduction in CD34, VEGFR2 and CLEC4G immunofluorescence area and intensity (all P ≤ .03).

CONCLUSIONS

A clinically relevant cirrhotic PDX model preserves tumor angiogenesis and allows prediction of response to multikinase inhibitors for personalized therapy.

Recompensation of Decompensated Hepatitis B Cirrhosis: Current Status and Challenges

Liver-function decompensation or hepatocellular carcinoma (HCC) gradually appears after chronic hepatitis B progresses to cirrhosis. Effective antiviral treatment can significantly improve the long-term prognosis of decompensated patients, and some patients present recompensation of decompensated hepatitis B cirrhosis. At present, there are limited research data on the recompensation of decompensated hepatitis B cirrhosis. There is still controversy regarding the evaluation time, evaluation indicators, influencing factors, and long-term prognosis of recompensation.