Tian Lan’s research while affiliated with Charité Universitätsmedizin Berlin and other places

Background Injured or reactive biliary epithelial cells participate in most chronic liver injuries in a process referred to as ductular reaction, which involves multicellular interactions with marked local infiltration of macrophages and fibrogenic cell activation. The direct roles of biliary epithelial cells in shaping their cellular niche remain unknown. Objective We aimed at investigating the effects of biliary epithelial cell-derived acute phase response protein orosomucoid 2 (ORM2) in shaping monocyte/macrophage response to liver injury. Design Transcriptome data sets from human and mouse livers were used, results were confirmed with multiplex immunofluorescence. A multicellular biliary-niche-on-a-chip derived from primary liver and blood cells (wild-type, Mdr2 −/− mice) was established to model ductular reaction. Human blood cells collected from healthy donors and intrahepatic cholangiocyte organoids derived from normal and cirrhotic liver patients were used. Results Our transcriptome data set and multiplex immunofluorescence analyses indicated a previously unrecognised involvement of the acute phase response protein ORM2 in ductular reactions in both human and mouse livers. ORM2 gene expression was increased in biliatresone-challenged, bile acid-challenged and acetaminophen-challenged cholangiocytes. Cholangiocyte-derived ORM2 induced unique transcriptome changes and functional adaptation of liver macrophages. ORM2-activated macrophages exacerbated cholangiocyte cell stress and Orm2 expression, but also tended to promote fibrogenic activation of hepatic stellate cells. Mechanistically, ORM2 effects were mediated by an inositol 1,4,5-trisphosphate receptor type 2-dependent calcium pathway. Conclusion This study reveals a paracrine communication circuit during ductular reaction, in which reactive cholangiocyte-derived ORM2 reprogrammes liver macrophages, participating in a pathogenic remodelling of the immune biliary niche.

Hepatic stellate cells (HSCs) have a central pathogenetic role in the development of liver fibrosis. However, their fibrosis-independent and homeostatic functions remain poorly understood1, 2, 3, 4–5. Here we demonstrate that genetic depletion of HSCs changes WNT activity and zonation of hepatocytes, leading to marked alterations in liver regeneration, cytochrome P450 metabolism and injury. We identify R-spondin 3 (RSPO3), an HSC-enriched modulator of WNT signalling, as responsible for these hepatocyte-regulatory effects of HSCs. HSC-selective deletion of Rspo3 phenocopies the effects of HSC depletion on hepatocyte gene expression, zonation, liver size, regeneration and cytochrome P450-mediated detoxification, and exacerbates alcohol-associated and metabolic dysfunction-associated steatotic liver disease. RSPO3 expression decreases with HSC activation and is inversely associated with outcomes in patients with alcohol-associated and metabolic dysfunction-associated steatotic liver disease. These protective and hepatocyte-regulating functions of HSCs via RSPO3 resemble the R-spondin-expressing stromal niche in other organs and should be integrated into current therapeutic concepts.

Background and Aims Ferroptosis plays an essential role in chronic liver diseases, and cyclooxygenase-2 (COX-2) affects liver fibrosis through multiple mechanisms. However, research on COX-2 regulation of ferroptosis in chronic liver injury remains limited. This study aimed to investigate whether and how COX-2 regulates ferroptosis in chronic liver injury. Methods In vivo, a thioacetamide (TAA)-induced chronic liver injury model, characterized by significant liver lipid peroxidation and oxidative stress, was used. COX-2+/+ and COX-2–/– mice were treated with TAA or normal saline. In vitro, primary mouse hepatocytes were isolated and treated with dimethyl sulfoxide (DMSO), erastin+DMSO, etoricoxib+erastin+DMSO, and tBHQ+erastin+DMSO. Mitochondrial morphology, iron metabolism, lipid peroxidation, and oxidative stress were assessed to verify ferroptosis. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway was measured to investigate the relationship between COX-2 and ferroptosis. Results TAA-treated COX-2–/– mice presented milder liver fibrosis, whereas TAA-treated COX-2–/– mice livers and etoricoxib+erastin+DMSO-treated primary hepatocytes exhibited alleviated mitochondrial damage compared with TAA-treated COX-2+/+ littermates and erastin+DMSO-treated primary hepatocytes, respectively. The knockout of COX-2 decreased ferrous ion concentration (p < 0.01) and mitigated lipid peroxidation in TAA-treated livers (p < 0.05). Furthermore, both COX-2 knockout and etoricoxib restored reduced glutathione (p < 0.05) and glutathione peroxidase 4 (p < 0.05), while decreasing malondialdehyde levels (p < 0.05). Additionally, COX-2 inhibition upregulated Nrf2, which helped alleviate erastin+DMSO-induced ferroptosis (p < 0.01). Conclusions Ferroptosis contributes to the progression of chronic liver injury. Inhibition of COX-2 upregulates Nrf2, mitigating hepatocyte ferroptosis in chronic liver injury.

We assessed the global incidence, mortality, and disability-adjusted life years (DALYs) associated with various liver diseases, including alcohol-related liver disease (ALD), hepatitis B/C virus infections (HBV or HCV), liver cancer, metabolic dysfunction-associated steatotic liver disease (MASLD), and other chronic liver diseases, from the 2019 Global Burden of Disease study. Additionally, we analyzed the global trends in hepatology research and drug development. From 2000 to 2019, prevalence rates increased for ALD, MASLD and other liver diseases, while they decreased for HBV, HCV, and liver cancer. Countries with a high socio-demographic index (SDI) exhibited the lowest mortality rates and DALYs. The burden of liver diseases varied due to factors like sex and region. In nine representative countries, MASLD, along with hepatobiliary cancer, showed highest increase in funding in hepatology research. Globally, the major research categories in hepatology papers from 2000 to 2019 were cancer, pathobiology, and MASLD. The United States (U.S.) was at the forefront of hepatology research, with China gradually increasing its influence over time. Hepatologists worldwide are increasingly focusing on studying the communication between the liver and other organs, while underestimating the research on ALD. Cancer, HCV, and MASLD were the primary diseases targeted for therapeutic development in clinical trials. However, the proportion of new drugs approved for the treatment of liver diseases was relatively low among all newly approved drugs in the U.S., China, Japan, and the European Union. Notably, there were no approved drug for the treatment of ALD in the world.

In recent years, advances have been made for treating ascites in patients with cirrhosis. Recent studies have indicated that several treatments that have been used for a long time in the management of portal hypertension may have beneficial effects that were not previously identified. Long‐term albumin infusion may improve survival in patients with cirrhosis and ascites while beta‐blockers may reduce ascites occurrence. Transjugular intrahepatic porto‐systemic shunt (TIPS) placement may also improve survival in selected patients in addition to the control with ascites. Low‐flow ascites pump insertion can be another option for some patients with intractable ascites. In this review, we summarize the latest data related to the management of ascites occurring in cirrhosis. There are still unanswered questions, such as the optimal use of albumin as a long‐term therapy, the place of beta‐blockers, and the best timing for TIPS placement to improve the natural history of ascites, as well as the optimal stent diameter to reduce the risk of shunt‐related side‐effects. These issued should be addressed in future studies.