Targeted elimination of senescent cells by engineered extracellular vesicles attenuates atherosclerosis in ApoE-/- mice with minimal side effects

Senescent cells in plaques emerge as a detrimental factor for atherosclerosis (AS), for which targeted senolysis might be a promising therapeutic strategy. The development of safe and efficient senolytics for senescent cell eradication by targeted delivery is greatly needed. Methods: Pro-apoptotic intelligent Bax (iBax)-overexpressing plasmid was constructed by molecular cloning, in which Bax CDS was fused to miR-122 recognition sites. Extracellular vesicle-based senolytics (EViTx) were developed to be conjugated with magnetic nanoparticles on the surface, iBax mRNA encapsulated inside, and BAX activator BTSA1 incorporated into the membrane. EViTx was characterized, and in vivo distribution was tracked via fluorescence imaging. The therapeutic effects of EViTx on AS and its systemic side effects were analyzed in ApoE-/- mice. Results: Magnetic nanoparticles, iBax mRNA and BAX activator BTSA1 were efficiently loaded into/onto EViTx. With external magnetic field navigation, EViTx was delivered into atherosclerotic plaques and induced significant apoptosis in senescent cells regardless of origins. Repeated delivery of EViTx via tail vein injection has achieved high therapeutic efficacy in ApoE-/- mice. Notably, EViTx is inevitably accumulated in liver cells, while the iBax mRNA was translationally repressed by miR-122, an endogenous miRNA highly expressed in hepatocytes, and thus the liver cells are protected from the potential toxicity of Bax mRNA. Conclusion: Our work demonstrated that magnetic EV-based delivery of iBax mRNA and the BAX activator BTSA1, efficiently induced apoptosis in recipient senescent cells in atherosclerotic plaques. This strategy represents a promising treatment approach for AS and other age-related diseases.

Effects of granulosa cells on steroidogenesis, proliferation and apoptosis of stromal cells and theca cells derived from the goat ovary

The aim of this study was to investigate the effect of granulosa cells from small antral follicles on steroidogenesis, proliferation and apoptosis of goat ovarian stromal and theca cells in vitro. Using Transwell co-culture system, we evaluated androgen production, LH responsiveness, cell proliferation and apoptosis and some molecular expression regarding steroidogenic enzyme and apoptosis-related genes in stromal and theca cells. The results indicated that the co-culture with granulosa cells increased steroidogenesis, LH responsiveness and bcl-2 gene expression as well as decreased apoptotic bax and bad expressions in stromal and theca cells. Thus, granulosa cells had a capacity of promoting steroidogenesis in stromal cell and LH responsiveness in cortical stromal cells, maintaining steroidogenesis in theca cells, inhibiting apoptosis of cortical stromal cells and improving anti-apoptotic abilities of stromal and theca cells.