ROCK‐Mediated Actin Remodeling Contributes to the Reduced Proliferation and Migration of bEnd.3 Endothelial Cells Treated With Florfenicol

ABSTRACT Florfenicol (FLO), a widely used antibiotic, can cause early embryonic death and impaired angiogenesis. However, the mechanism by which FLO inhibits angiogenesis and its role in FLO‐induced embryonic toxicity are not yet fully understood. This study aimed to investigate the effect of FLO on the proliferation and migration of mouse bEnd.3 endothelial cells (bECs) and the underlying mechanism, given the crucial role of endothelial cells in angiogenesis. The results showed that FLO treatment at 7.5–15 μg/mL significantly inhibited proliferation and migration in a time‐dependent manner, with stronger effects observed after 48 h compared to 24 h. RNA sequencing analysis identified 1351 genes differentially expressed in response to FLO. Functional analysis indicated that FLO disrupted ATP metabolism, angiogenesis, vasculature development, and actin filament organization. The F‐actin cytoskeleton remodeling was morphologically confirmed, and activation of the ROCK/Cofilin signaling pathway was detected. Subsequent experiments demonstrated that pharmacological inhibition of the pathway normalized cytoskeletal rearrangement and promoted angiogenesis, as evidenced by enhanced wound closure and increased cell viability. Our results demonstrated that ROCK‐mediated F‐actin remodeling plays a crucial role in the FLO‐induced inhibition of proliferation and migration in bECs. These findings may explain why FLO inhibited angiogenesis. However, further investigations are necessary to validate our findings in in vivo experiments.