帮忙修改以下英文To date the mechanism of TGFβ in suppressing physiological angiogenesis is poorly understood Although many studies have involved TGFβ and angiogenesis the researches about the underlying mecha

Currently, the mechanism by which TGFβ suppresses physiological angiogenesis is poorly understood. Despite numerous studies involving TGFβ and angiogenesis, research on the direct role of TGFβ in underlying mechanisms is still limited. One study found that PAI-1, an inhibitor of plasminogen activators, was the downstream anti-angiogenic target of TGFβ, which inhibited EC function [12]. This paper has been widely cited in other papers on the anti-angiogenic role of TGFβ [28, 29]. In this study, we found that TGFβ inhibited the migration and tube formation of EC in vitro and suppressed zebrafish angiogenesis in vivo. Mechanistically, we discovered that the level of TSP1, a critical anti-angiogenic factor that suppresses EC proliferation, migration, and tube formation [30], was up-regulated by TGFβ treatment or TGFβR1 activation, but reduced by TGFβR1 inhibitor or Smad2 silencing. Knockdown of TSP1 weakened the inhibitory effect of TGFβ on EC migration. The downstream effector that mediated the anti-angiogenesis function of TGFβ was identified as TSP1. The role of anti-angiogenic factors in mediating the function of TGFβ in angiogenesis has not been previously reported