Could mRNA Vaccine Technology Help Repair Damaged Livers?

A short burst of cellular reprogramming helped damaged mouse livers recover, while targeted mRNA nanoparticles improved survival after severe liver injury, pointing toward a promising new strategy for liver repair.

Study: Enhanced liver regeneration via targeted mRNA delivery for partial in vivo reprogramming. Image credit: SvetaZi/Shutterstock.com

Unlike skin or the intestine, the adult liver renews its cells slowly and relies minimally on dedicated stem cells for routine maintenance. In a recent study published in Cell Reports Medicine, researchers tested whether a short course of reprogramming signals can turn mature liver cells into progenitor-like cells, and whether a nanoparticle targeted to the liver can deliver those signals with a transient effect. 

Why The Liver’s Natural Repair Capacity Remains Limited 

Mammals regenerate tissue less effectively than amphibians. However, single-cell analyses show that injured organs can produce temporary progenitor cells with features seen in fetal tissue. In the liver, these cells are called liver progenitor-like cells, and they can arise when hepatocytes lose their specialized identity after damage. Inflammatory signals from immune cells, including interleukin-6 from Kupffer cells, help drive this process.

Studies have found that brief activation of four genes called Yamanaka factors (Oct4, Sox2, Klf4, and c-Myc) promotes repair in several organs. Applying this idea to the liver has thus far been difficult because excessive or sustained expression of these factors can cause liver and intestinal failure, and viral delivery methods add safety concerns.

Researchers Test Two Approaches to Reprogram Liver Cells 

In this study, the researchers explored whether mature liver cells could be reprogrammed into progenitor-like cells. They used mice carrying all four Yamanaka factor genes under the control of doxycycline, an antibiotic that works as a genetic switch.

They used a low dose of doxycycline to activate the genes, while tracking body weight and liver enzymes to check tolerance. Hepatocyte identity and activity were assessed through tissue staining and gene and protein measurements, and flow cytometry was conducted to measure ploidy. The researchers also treated isolated hepatocytes in cultures in parallel.

To test repair, mice received a sublethal or lethal dose of acetaminophen to induce liver injury, followed by three days of doxycycline. The researchers compared tissue damage and cell division at several time points. In a separate model with 70% of the liver surgically removed, the recovery of liver mass with or without doxycycline was followed for six days.

The team conducted single-nucleus ribonucleic acid (RNA) sequencing of over 22,500 nuclei from reprogrammed and acetaminophen-injured livers to compare cell types and gene activity. Computational tools were also employed to infer developmental paths and signaling between cells.

Additionally, to test another non-viral approach, the team synthesized messenger RNA (mRNA) for the four Yamanaka factors with modified nucleotides and packaged each into lipid nanoparticles bearing galactose to target hepatocytes. After testing delivery and safety, they mixed the four formulations equally and injected them into mouse veins, with weekly dosing for four weeks and safety monitoring at 30 and 60 days. They also tested the ability of the lipid nanoparticle-packaged mRNA treatment to repair liver injury using mouse models with acetaminophen-induced liver damage.

Reprogramming Boosts Liver Repair and Improves Mouse Survival 

The study found that a brief course of reprogramming in mouse livers converted some mature hepatocytes into progenitor-like cells without injury, and that a liver-targeted lipid nanoparticle-based mRNA treatment improved outcomes after acetaminophen-induced liver damage.

Three days of doxycycline treatment lowered mature liver markers and increased cell division without raising liver enzymes or causing visible tissue damage. In cultured hepatocytes, the dedifferentiated state faded within 48 hours after the drug was withdrawn. In mice with acetaminophen-induced liver damage, the reprogramming left initial injury unchanged but reduced dead tissue by day four, indicating faster repair.

Moreover, in mice with surgically removed liver tissue, the liver mass recovered faster and then matched controls by six days, which suggested regeneration without overgrowth.

Single-nucleus RNA sequencing identified two liver progenitor-like cell (LPLC) populations, named LPLC1 and LPLC2. After injury, LPLC1 expanded 4.8-fold, while reprogramming increased LPLC1 and LPLC2 3.1- and 4.3-fold, respectively. LPLC1 showed gene-expression similarities to regenerative hepatocyte states observed in injured mouse livers and in patients with acetaminophen-induced liver injury, whereas LPLC2 carried stronger features of a flexible state. While induced liver injury increased Kupffer cells 4.5 times and monocyte-derived macrophages 16 times, these immune populations stayed small after reprogramming.

Furthermore, in the lipid nanoparticle experiments, a single dose increased progenitor and proliferation markers, and hepatic reprogramming mRNA levels of the Yamanaka factors fell within 54 hours, indicating a transient effect. When the nanoparticle-mRNA treatment was given 18 hours after a toxic acetaminophen dose, four of 14 treated mice survived the four-day observation period, compared with none of the 14 mice receiving control mRNA nanoparticles. The treatment also reduced liver enzymes and necrosis. Moreover, weekly dosing for four weeks and 60 days of monitoring showed no overt tumors or abnormal growth.

The authors acknowledged that small mouse test groups and short safety monitoring were limitations. They also noted that the direct contribution of the identified progenitor-like cells to liver regeneration remains unconfirmed, and that further studies are needed to determine whether nanoparticle-delivered mRNA produces the same cell states observed in genetically reprogrammed mice.

However, if these findings are validated in larger animal models and human studies, this approach could offer patients with acute liver injury a new way to support recovery.

Targeted mRNA Therapy Shows Promise for Liver Regeneration 

The study showed that a short, controlled burst of reprogramming could push mature liver cells into a progenitor-like state and speed repair in mice, with less immune activation than injury itself. Targeted delivery of reprogramming instructions as mRNA in nanoparticles enabled liver-directed treatment, while the transient nature of mRNA expression limited the duration of the reprogramming signals and improved survival after acetaminophen poisoning.

If these findings are validated in larger models and human systems, this strategy could give clinicians a new option for helping patients recover from acute liver injury.

Journal Reference

Jo, B.-K., Song, Y. S., Song, W., Eom, H.-J., Lee, Y. J., Kim, J., Hong, S., Cho, S.-W., & Cha, H.-J. (2026). Enhanced liver regeneration via targeted mRNA delivery for partial in vivo reprogramming. Cell Reports Medicine. 103084. DOI:10.1016/j.xcrm.2026.103084. https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791%2826%2900501-X