Microvesicles from quiescent and TGF-β1 stimulated hepatic stellate cells: Divergent impact on hepatic vascular injury

by Jianlong Xie, Zhirong Ye, Xiaobing Xu, Anzhi Chang, Ziyi Yang, Qin Wu, Qunwen Pan, Yan Wang, Yanyu Chen, Xiaotang Ma, Huilai Miao

Background

This study evaluated the effect of microvesicles(MVs) from quiescent and TGF-β1 stimulated hepatic stellate cells (HSC-MVs, TGF-β1HSC-MVs) on H₂O₂-induced human umbilical vein endothelial cells (HUVECs) injury and CCl₄-induced rat hepatic vascular injury.

Methods

HUVECs were exposed to hydrogen peroxide (H₂O₂) to establish a model for vascular endothelial cell injury. HSC-MVs or TGF-β1HSC-MVs were co-cultured with H₂O₂-treated HUVECs, respectively. Indicators including cell survival rate, apoptosis rate, oxidative stress, migration, invasion, and angiogenesis were measured. Simultaneously, the expression of proteins such as PI3K, AKT, MEK1+MEK2, ERK1+ERK2, VEGF, eNOS, and CXCR4 was assessed, along with activated caspase-3. SD rats were intraperitoneally injected with CCl₄ twice a week for 10 weeks to induce liver injury models. HSC-MVs or TGF-β1HSC-MVs were injected into the tail vein of rats. Liver and hepatic vascular damage were also detected.

Results

In H₂O₂-treated HUVECs, HSC-MVs increased cell viability, reduced cytotoxicity and apoptosis, improved oxidative stress, migration, and angiogenesis, and upregulated protein expression of PI3K, AKT, MEK1/2, ERK1/2, VEGF, eNOS, and CXCR4. Conversely, ^TGF-β1HSC-MVs exhibited opposite effects. CCl₄- induced rat hepatic injury model, HSC-MVs reduced the release of ALT and AST, hepatic inflammation, fatty deformation, and liver fibrosis. HSC-MVs also downregulated the protein expression of CD31 and CD34. Conversely, TGF-β1HSC-MVs demonstrated opposite effects.

Conclusion

HSC-MVs demonstrated a protective effect on H₂O₂-treated HUVECs and CCl₄-induced rat hepatic injury, while TGF-β1HSC-MVs had an aggravating effect. The effects of MVs involve PI3K/AKT/VEGF, CXCR4, and MEK/ERK/eNOS pathways.