This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.

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Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME.

Vitamin D receptor polymorphisms and diseases.

https://aasldpubs.onlinelibrary.wiley.com/doi/epdf/10.1002/hep.31065

Diagnosis and Management of Autoimmune Hepatitis in Adults and Children: 2019 Practice Guidance and Guidelines From the American Association for the Study of Liver Diseases.

Advances in the Diagnosis, Pathogenesis, and Management of Autoimmune Hepatitis

Genome-wide association study identifies variants associated with autoimmune hepatitis type 1

Background: Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are two autoimmune diseases of unknown etiology. Genetic factors appear to be involved in the pathogenesis of both diseases. Vitamin D has been shown to exert multiple immunomodulatory effects, which acts through its own receptor (VDR). Polymorphisms of VDR had been implicated in several autoimmune diseases. In the present study, the association between Chinese patients with AIH, PBC and the polymorphisms in exon 2, intron 8 and exon 9 of vitamin D receptor genes was studied.



Methods: Four candidate gene loci were investigated in 49 patients with AIH, 58 patients with PBC, and 160 healthy controls. The VDR polymorphisms were assessed by FokI, BsmI, ApaI, and TaqI endonuclease digestion after specific polymerase chain reaction (PCR) amplification.



Results: The result show a significant difference in FokI polymorphism between AIH patients and controls (χ2 = 5.47, P = 0.019), and a significant association in BsmI polymorphisms between PBC patients and controls (χ2 = 6.52, P = 0.01). Furthermore the distribution of FokI, BsmI, ApaI, and TaqI gene types differered between Chinese healthy controls and Caucasian healthy controls.



Conclusion: It is suggested that there is a genetic link of VDR polymorphisms to autoimmune liver dieseses such as AIH and PBC in Chinese patients. Further studies are needed to elucidate the mechanisms by which VDR polymorphisms contribute to the lose of immune tolerance in autoimmune diseases.



© 2004 Blackwell Publishing Asia Pty Ltd

Genetic association of vitamin D receptor polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

AIM: To investigate the association between Chinese patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and the polymorphisms of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene promoter (-318) and exon 1 ( + 49).

METHODS: CTLA-4 promoter (-318 T/C) and exon1 ( + 49A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 62 Chinese AIH patients, 77 Chinese PBC patients and 160 healthy controls.

RESULTS: We found a significant association in CTLA-4 gene exon1 49 A/G polymorphism between PBC patients and controls (P = 0.006) and the frequency of G alleles was significantly increased in comparison with controls (P = 0.0046, OR = 1.8). We also found the frequency of C alleles in promoter -318 was significantly increased in AIH patients compared with controls (P = 0.02, OR = 0.41). Although the genotype distribution of the CTLA-4 exon 1-promoter gene was not significantly different between AIH and PBC patients and controls, the occurence of GG-CC was increased in two groups of patients (AIH: 32.3%, PBC: 37.7%, control: 22.5%).

CONCLUSION: Polymorphisms of CTLA-4 gene probably confer susceptibility to AIH and PBC in Chinese population.

Cytotoxic T lymphocyte associated antigen-4 gene polymorphisms confer susceptibility to primary biliary cirrhosis and autoimmune hepatitis in Chinese population.

AIM: To characterize gene polymorphism of several cytokine gene in-patients with AIH and PBC and to analyze the difference of the polymorphism distribution between Chinese patients and healthy controls.

METHODS: The study population consisted of 62 patients with AIH, and 77 patients with PBC. The genetic profile of four cytokines was analyzed by restriction fragment length polymorphism after specific PCR amplification (PCR-RFLP) or sequence-specific primers PCR (SSP-PCR). The analyzed gene polymorphism included interleukin-1 (IL-1) (at position +3 953 and IL-1RN intron 2), IL-6 (at position -174), IL-10 promoter (at position -1082, -819, and -592). The control group consisted of 160 healthy blood donors.

RESULTS: The majority of Chinese people including patients and healthy controls exhibited IL-1B 1,1 genotype, and there was no significant difference in AIH, PBC patients and controls. There were highly statistically significant differences in the distribution of the IL-1RN gene polymorphism between the patients with PBC compared with controls. The frequency of IL-1RN 1,1 was significantly higher (90.9% vs 79.4%, P = 0.03) and the frequency of IL-1RN 1,2 was significantly lower in PBC patients (6.5% vs 17.5%, P = 0.01). No statistical difference was observed between AIH patients and controls. All of the 160 healthy controls and 62 cases of AIH patients exhibited IL-6-174GG genotype, and there were four cases, which expressed IL-6-174GC genotype in 77 cases of PBC patients. The frequency of IL-6-174GC was markedly significantly higher in PBC patients compared with controls (5.2% vs 0%, P = 0.004). No statistically significant difference was found in the distribution of IL-10 promoter genotype in AIH and PBC patients compared with controls.

CONCLUSION: The polymorphisms of IL-1RN and IL-6 -174G/C appear to be associated with PBC in Chinese patients.

Genetic association of cytokines polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

Objective Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are two autoimmune diseases of unknown etiology. Genetic factors appear to be involved in the pathogenesis of both diseases. Tumor necrosis factor (TNF)-alpha is one of the proinflammatory cytokines and immunomodulators, and is implicated in the pathogenesis of AIH and PBC. In this study, we studied the association between Chinese patients with AIH, PBC and the polymorphisms in promoter-region polymorphisms of the TNF-alpha gene at position -308 and -238. Methods We have investigated four candidate gene loci in 49 patients with AIH, 58 patients with PBC, and 160 healthy controls. The polymorphisms were assessed by the PCR specifically for the single-nucleotide polymorphisms. Results We found the difference in the TNF-alpha gene at position -308 genotype distributions between Chinese health controls and Caucasian health controls. Although the percent of TNF-alpha*2 was decrease on PBC patient group (10.34% vs. 16.88%), there was no significant difference between PBC patients and health control in the Chinese. There were also no significant differences between AIH and health control on the TNF-alpha gene at position -308 and -238. Conclusion Our findings suggest that the TNF-alpha promoter-region polymorphisms distribution is different between differe of ethnic groups; there are no genetic links of the TNF-alpha promoter-region polymorphisms to AIH and PBC in Chinese.

[Genetic association of tumor necrosis factor (TNF)-alpha polymorphisms with primary biliary cirrhosis and autoimmune liver diseases in a Chinese population].

AIM: To evaluate the association between Chlamydia pneumoniae (Cpn) infection and primary biliary cirrhosis (PBC).

METHODS: Cpn IgG and IgM were determined by enzyme-linked immunosorbent assay (ELISA) in 41 well-established PBC patients and two race-matched control groups (post-hepatitis cirrhosis, n = 70; healthy controls, n = 57).

RESULTS: The mean level and seroprevalence of Cpn IgG in PBC group and post-hepatitis cirrhosis (PHC) group were significantly higher than those in healthy controls (46.8 ± 43.4 RU/mL, 49.5 ± 45.2 RU/mL vs 28.3 ± 32.7 RU/mL; 68.3%, 71.4%, 42.1%, respectively; P 0.05), Cpn IgM was related with the abnormally high concentrations of total IgM in PBC group.

CONCLUSION: The results of this study do not support the hypothesis that infection with Chlamydia pneumoniae may be a triggering agent or even a causative agent in PBC, but suggest that Chlamydia pneumoniae infection probably contributes to the high level of IgM present in most patients with PBC.

Lie-ying Fan

Papers

Genetic association of vitamin D receptor polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

Cytotoxic T lymphocyte associated antigen-4 gene polymorphisms confer susceptibility to primary biliary cirrhosis and autoimmune hepatitis in Chinese population.

Genetic association of cytokines polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in the Chinese.

[Genetic association of tumor necrosis factor (TNF)-alpha polymorphisms with primary biliary cirrhosis and autoimmune liver diseases in a Chinese population].

Correlation of Chlamydia pneumoniae infection with primary biliary cirrhosis.