Delivery of Synthetic Interleukin-22 mRNA to Hepatocytes via Lipid Nanoparticles Alleviates Liver Injury

Hepatocellular injury, a pivotal contributor to liver diseases, particularly hepatitis, lacks effective pharmacological treatments. Interleukin-22 (IL-22), crucial for liver cell survival, shows potential in treating liver diseases by regulating repair and regeneration through signal transducer and activator of transcription 3 (STAT3) activation. However, the short half-life and off-target effects limit its clinical applications. To address these issues, lipid nanoparticles are employed to deliver synthetic IL-22 mRNA (IL-22/NP) for in situ IL-22 expression in hepatocytes. The study reveals that IL-22/NP exhibits liver-targeted IL-22 expression, with increased IL-22 levels detected in the liver as early as 3 h postintravenous injection, lasting up to 96 h. Furthermore, IL-22/NP activates STAT3 signaling in an autocrine or paracrine manner to upregulate downstream factors Bcl-xL and CyclinD1, inhibiting hepatocyte apoptosis and promoting cell proliferation. The therapeutic efficacy of IL-22/NP is demonstrated in both chronic and acute liver injury models, suggesting IL-22 mRNA delivery as a promising treatment strategy for hepatitis and liver diseases involving hepatocellular injury.