hUCMSC-extracellular vesicles downregulated hepatic stellate cell activation and reduced liver injury in S. japonicum-infected mice

BACKGROUND: Accumulating evidence shows that mesenchymal stem cells (MSCs) have the potential as a cellular therapy avenue for schistosome-induced liver injury. Extracellular vesicles (EVs) are membranous vesicles released by almost all cell types, and EVs produced by MSCs (MSC-EVs) exert therapeutic effects in several disease models. However, the potential of MSC-EVs in schistosomiasis treatment remains unclear. METHODS: Using survival analysis, HE and Masson's trichrome staining, immunohistochemical, western blot analysis, real-time PCR, and EdU proliferation, we investigated the effects of human umbilical cord MSC-derived EVs (hUCMSC-EVs) on the survival and liver injury in the S. japonicum-infected mice and explored the underlying mechanism. RESULTS: Here, we found that like hUCMSCs, hUCMSC-EVs significantly ameliorated liver injury and improved the survival of schistosome-infected mice. Indeed, the hUCMSC-EV-mediated alleviation of liver injury is associated with decreased expression of α-smooth muscle actin (α-SMA), collagen 1, and collagen 3. More importantly, we showed that hUCMSC-EVs directly suppressed the proliferation of LX2 (human hepatic stellate cell) in vitro. In addition, hUCMSC-EVs significantly downregulated the activation of LX2 after transforming growth factor-β1 (TGF-β1) treatment. CONCLUSION: Our results provided the first evidence that hUCMSC-EVs reduced liver injury in S. japonicum-infected mice, potentially creating new avenues for the treatment of liver damage in schistosomiasis.