Targeting canonical and non-canonical NF-κB deubiquitinating mediators for individualized therapy to improve the outcome in alcohol-intoxicated trauma

• Applicant: Professorin Dr. Borna Relja
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465409392

A significant percentage of deaths after trauma is attributed to secondary local and systemic inflammatory complications in the later clinical course, causing organ failure and mortality. Among important factors influencing the course of trauma, most frequently reoccurring is alcohol. It relates to 25% of deaths in the European population of young adults and 6-45% of hospital admissions. While acute alcohol intoxication can alleviate injury intensity, it can also modify posttraumatic inflammation to an immune-suppressive but also to a pro-inflammatory stage affecting organ damage, secondary complications and outcomes. This peculiar contradiction suggests double-edging properties of alcohol on the immune system. Yet, it remains to be fully elucidated where lies the suspected molecular switch, which nudges both anti- and pro-inflammatory properties of alcohol after trauma. This project will address this research question. Molecular key player mediating posttraumatic inflammation is the transcription factor NF-κB, which stimulates the transcription of pro- and anti-inflammatory genes, depending on the activation pattern. Alcohol can effectively both stimulate and down-regulate NF-κB activation, and thus accordingly modify inflammation. Thus, there must be a molecular switch that allows the transition between anti- or pro-inflammatory functions of NF-κB. The family of deubiquitinating enzymes (DUBs) as one of the most prominent NF-κB regulators are physiological key players in posttranslational protein modifications. Here, as key regulator A20 constitutes a negative feedback loop on NF-κB activity. We will assess the role of DUBs as potential target and influencing factors in relation with pro- and anti-inflammatory effects of alcohol on NF-κB activity after trauma. We suggest that DUBs act as a switch between canonical and non-canonical NF-κB signaling. No group worldwide has yet addressed the issue related to alcohol influence on their expression pattern and how it affects the inflammatory state sustained by NF-κB upregulated activity after trauma. We aim for engineering immortalized liver and lung cells, to knock-out the full-length DUBs and then evaluate NF-κB-driven inflammation in DUBs absence and presence of alcohol, in which the cells will be subjected to and treated with (time- and dose-dependently). Also, cells will be co-treated with sera from alcohol-toxicated and non-toxicated trauma patients to evaluate NF-κB-driven inflammation (e.g. apoptosis, phagocytosis, killing-assay, endotoxin tolerance, oxidative burst, migratory capacity of cells and release of cytokines and extracellular vesicles). Progression of inflammation severity in an in vivo model of thoracic trauma and hemorrhagic shock in WT and DUB KO mice will be assessed, as well as the therapeutic approach with targeting MALT1 paracaspase (as DUB-modulator). We will describe the mechanism for the regulation of both NF-κB pathways in order to alleviate posttraumatic complications.

• DFG Programme: Research Units
• Subproject of: FOR 5417: Translational Polytrauma Research to Provide Diagnostic and Therapeutic Tools for Improving Outcomes
• Co-Investigator: Privatdozent Dr. Nils Wagner