Therapeutic potential of TMSC-Exo for non-alcoholic fatty liver disease using the liver-on-a-chip model.

BACKGROUND AND OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) has become a growing global public health concern. Effective therapeutic strategies for NAFLD remain urgently needed. Liver-on-a-chip (LC) technology offers an innovative platform for NAFLD modeling and drug development. This study aimed to develop a biomimetic liver-chip using co-cultured human hepatocyte (HepaRG) with hepatic stellate and endothelial cells to model NAFLD, and evaluate the therapeutic potential of scalable telomerase reverse transcriptase (hTERT)-immortalized umbilical cord mesenchymal stem cell-derived exosomes (TMSC-Exo). METHODS: HepaRG cells, hepatic stellate cells, and endothelial cells were used to construct a dual-chamber biocompatible LC. The NAFLD model was induced by free fatty acid (FFA) and applied to evaluate the efficacy of resmetirom and TMSC-Exo for the treatment of NAFLD. Moreover, the high-fat (HF) diet-induced mouse model was analyzed to verify the in vitro results. Proteomic analyses were performed to explore the molecular mechanisms involved in the development of NAFLD and the effect of TMSC-Exo in treating NAFLD. RESULTS: Cells cultured in LC showed better viability compared to those in the Transwell system. The on-chip NAFLD model mimicked the characteristics of NAFLD in vivo, including intracellular lipid accumulation and impaired hepatocyte functions in albumin synthesis, levels of urea, CYP1A2, and CYP3A4. Both TMSC-Exo and resmetirom displayed a significant effect in reducing the lipid accumulation in the on-chip NAFLD model. The TMSC-Exo showed superior effects in elevating the levels of albumin, urea, CYP1A2, and CYP3A4. The therapeutic effects of TMSC-Exo were also confirmed in the NAFLD mouse models. Proteomic analysis found that the top 15 up- and down-regulated differentially expressed proteins in NAFLD models compared to the control group were mainly associated with lipid metabolism, endoplasmic reticulum stress, and inflammation. CONCLUSIONS: Our on-chip NAFLD model successfully recapitulated key pathological features of hepatic steatosis and functional impairment. Using this model, we evaluated TMSC-Exo and demonstrated its significant therapeutic efficacy against NAFLD.