Role of Nlrp3 inflammasome signaling in alcoholic liver disease progression

• Applicant: Professor Dr. Alexander Wree
• Subject Area: Gastroenterology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 505980472

Alcoholic liver disease (ALD) is one of the major disease burdens in western society of our time. Although its prevalence has increased over recent years, disease progression towards severe liver inflammation, liver fibrosis and hepatocellular carcinoma are still not understood. The multi-protein complex NLR family pyrin domain containing 3 inflammasome has been implicated in the promotion of disease progression, boosting cellular inflammation and contributing to differentiation of hepatic stellate cells thereby accelerating the development of fibrosis. These studies fostered the development of novel Nlrp3 inflammasome-interfering compounds, which just entered in the first human studies for the treatment of non-alcoholic fatty liver disease. In previous published studies we demonstrate, that Nlrp3 inflammasome overactivation aggravates the development of liver inflammation and liver fibrosis in mice. In preliminary experiments, we discovered that IL-18 is a driver of hepatic stellate cell activation and alcohol incubation treatment increased hepatocellular IL-18 production. We also analyzed inflammasome-cascade related SNPs in two independent cohorts of patients with hepatocellular cancer and faced a total incidence of 10%. Logically, we propose the HYPOTHESIS that cell-specific Nlrp3 inflammasome activation is a central mechanism that triggers hepatic inflammation and liver fibrogenesis in alcoholic liver disease. Three work packages link evaluation of patient data with in vivo experiments in murine models and advance cell culture and organoid systems. For the latter we will integrate the knowledge and expertise of Prof. Soumita Das (University of California, San Diego), an expert in organoid systems, in our growing liver research unit at Charité Berlin. We will employ multi-celltype coculture with cells either deficient or extensively proficient in Nlrp3 signaling. Consequently, our in vivo experiments are similarly focused on cell specific activation or global deletion of Nlrp3 or IL-18. Combining alcohol in drinking water alongside a Western style diet fed to mice for 8 weeks, will allow a closer delineation of the individual disease components and their role in inflammatory signaling. More specifically, we will employ multi-colour flow cytometry to analyze the individual inflammatory cell subsets in order to project their role in disease progression and therapeutic interventions. Finally, we have established a collaborative effort with Prof. Andreas Heinz (spokesperson of the recently established Collaborative Research Center Transregio 265 – Losing and Regaining Control over Drug Intake) Charité Berlin to evaluate the full spectrum of (ALD) progression. In this cohort of we will evaluate a multiplicity of markers including cytokines, immune cell distribution and microRNA expression. As whole genome sequencing will be performed we will have the unique opportunity to uncover inflammasome cascade alteration in patients with ALD.

• DFG Programme: Research Grants