Abstract
Background & Aims
Acute liver failure (ALF) is a critical inflammatory condition characterized by rapid hepatocyte death, impaired liver regeneration due to the delayed removal of necroptotic cells, and high mortality rates. This study introduces a novel dual-mode action therapeutic approach using extracellular vesicles expressing Signal Regulatory Protein Alpha (SIRP-EVs) derived from genetically engineered mesenchymal stem cells (MSCs). These SIRP-EVs are designed to concurrently resolve necroptosis and promote liver regeneration. Methods
We evaluated CD47 expression across diverse ALF models using histological analysis, flow cytometry, western blot, confocal microscopy, and spatial transcriptomics. EVs were harvested through a 3D bioreactor-based process and subsequently purified. These purified EVs underwent various established characterization assays. After a single systemic injection, CD47-dependent accumulation of SIRP-EVs in liver tissues was evaluated using the in vivo imaging system. The therapeutic efficacy of SIRP-EVs was determined by measuring liver enzyme levels, examining histological changes, tracking survival rates, and analyzing inflammatory cytokine profiles. Results
Our studies identified CD47 and SIRPα as promising therapeutic targets for ALF. We developed a scalable 3D bioreactor-based process that produces high-purity SIRP-EVs, which preserve MSC properties and achieve significant production levels. SIRP-EVs effectively bind to and block CD47, a ‘don’t eat me’ signal on necroptotic hepatocytes, while concurrently delivering MSC-derived regenerative proteins to the damaged tissue. Comprehensive in vitro and in vivo studies demonstrate that SIRP-EVs effectively target CD47-overexpressing hepatocytes, reduce liver damage markers, and enhance survival rates in ALF models. Conclusions
These findings highlight the potential of SIRP-EVs as a dual-mode action therapeutic for ALF, offering promising prospects for their application in other inflammatory diseases. Moreover, these results pave the way for advancing engineered EV-based therapies toward clinical implementation. Impact and implications
Developing extracellular vesicles expressing Signal Regulatory Protein Alpha, derived from engineered mesenchymal stem cells (MSCs), offers a promising dual-mode action therapy for acute liver failure (ALF). This innovative approach uniquely combines blocking CD47 ‘don’t eat me’ signal to resolve necroptosis with promoting liver regeneration through the delivery of MSC-derived regenerative cargos. Our findings are pivotal for advancing the management of ALF and other severe acute inflammatory diseases, offering a new therapeutic strategy that could significantly improve patient survival and reduce liver damage more effectively than existing treatments. Graphical abstract
