Detection of inflammasome activation in liver tissue during the donation process as potential biomarker for liver transplantation

Abstract

Deceased donor liver transplantation (LT) is a crucial lifesaving option for patients with end-stage liver diseases. Although donation after brain death (DBD) remains the main source of donated organs, exploration of donation after circulatory death (DCD) addresses donor scarcity but introduces challenges due to warm ischemia. While technical advances have improved outcomes, challenges persist, with a 13% mortality rate within the first year. Delving into liver transplantation complexities reveals the profound impact of molecular signaling on organ fate. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation play a pivotal role, influencing inflammatory responses. The NLRP3 inflammasome, found in hepatocytes, contributes to inflammation, fibrosis, and liver cell death. This study explores these dynamics, shedding light on potential biomarkers and therapeutic targets. Samples from 36 liver transplant patients were analyzed for ASC specks detection and inflammasome-related gene expression. Liver biopsies, obtained before and after cold ischemia storage, were processed for immunofluorescence, qRT-PCR, and Western blot. One year post-LT clinical follow-up included diagnostic procedures for complications, and global survival was assessed. Immunofluorescence detected activated inflammasome complexes in fixed liver tissues. ASC specks were identified in hepatocytes, showing a trend toward more specks in DCD livers. Likewise, inflammasome-related gene expression analysis indicated higher expression in DCD livers, decreasing after cold ischemia. Similar results were found at protein level. Patients with increased ASC specks staining exhibited lower overall survival rates, correlating with IL1B expression after cold ischemia. Although preliminary, these findings offer novel insights into utilizing direct detection of inflammasome activation in liver tissue as a biomarker. They suggest its potential impact on post-transplant outcomes, potentially paving the way for improved diagnostic approaches and personalized treatment strategies in LT.