Abstract：
Random-pattern skin flaps are important method for skin reconstruction after defect; however, the distal end of flaps is not easily viable due to inadequate nutrient supply. Erastin is a well-established ferroptosis inducer, but our study found that low-dose of erastin (2 μM) may reduce nutrient deficiency induced cell death in human umbilical vein endothelial cells (HUVECs). RNA-seq analysis suggested that its role was related to autophagy regulation. Follow-up studies have shown that the use of autophagy inhibitors or the knockdown of TFEB in HUVECs can both reduce the anti-apoptotic effect of erastin in HUVECs. Mechanism study demonstrated that erastin can suppress mTORC1 and promote TFEB activity in HUVECs, suggesting that the effect of erastin on the survival of HUVECs under nutrient deprivation conditions is regulated by mTORC1/TFEB. Subsequently, we evaluated the effect of erastin on the survival of random-pattern skin flaps in mice in vivo. On the postoperative day 7, we observed a significant increase in flap survival area, blood perfusion, and microvascular density after erastin treatment; also, erastin treatment showed enhanced autophagy within the ischemic region. In summary, our study demonstrates that low-dose of erastin may suppress cell death in endothelial cells under nutrient deficiency condition, and its effects may relate to the mTORC1-TFEB medicated autophagy regulation, erastin treatment may be a potential therapy for random-pattern skin flaps.
摘要：
随机皮瓣是缺损后皮肤重建的重要方法,由于营养供应不足，皮瓣的远端不易存活。Erastin是一种公认的铁死亡诱导剂,但是我们的研究发现，低剂量的erastin（2μM）可以减少营养缺乏引起的人脐静脉内皮细胞（HUVEC）细胞死亡。RNA-seq分析表明其作用与自噬调节有关。后续研究表明，在HUVECs中使用自噬抑制剂或敲除TFEB都可以降低HUVECs中擦除素的抗凋亡作用。机制研究表明，在HUVECs中，擦除素可以抑制mTORC1并促进TFEB活性。提示erastin在营养剥夺条件下对HUVECs存活的影响受mTORC1/TFEB调节。随后，我们评估了erastin对小鼠体内随机皮瓣存活的影响。在术后第7天，我们观察到皮瓣存活面积显著增加，血液灌注，和erastin治疗后的微血管密度；还有，erastin治疗显示缺血区内自噬增强.总之,我们的研究表明，低剂量的erastin可能在营养缺乏的情况下抑制内皮细胞的细胞死亡，其作用可能与mTORC1-TFEB药物自噬调节有关，erastin治疗可能是随机皮瓣的潜在治疗方法。
