University of Utah , Salt Lake City, Utah.
J Appl Physiol (1985). 2017 Dec 1;123(6):1671-1675. doi: 10.1152/japplphysiol.00119.2017. Epub 2017 May 18.
Hypoxia increases erythropoiesis mediated by hypoxia-inducible transcription factors (HIF), which regulate erythropoietin transcription. Neocytolysis is a physiological mechanism that corrects polycythemia from chronic sustained hypoxemia by transient, preferential destruction of young RBCs after normoxia is restored. We showed that neocytolysis is caused by excessive mitochondrial-derived reactive oxygen species in reticulocytes mediated by downregulation of HIF-controlled BNIP3L regulated mitophagy and a decrease in RBC antioxidant catalase (CAT) in hypoxia-produced erythrocytes. Decreased CAT results from hypoxia-induced miR-21 that downregulates CAT. This correlates with a transient acute decrease of HIF-1 at normoxic return that is associated with normalization of red cell mass.
低氧通过缺氧诱导转录因子 (HIF) 增加红细胞生成，HIF 调节促红细胞生成素的转录。网织红细胞新生溶解是一种生理性机制，通过在恢复正常氧合后短暂优先破坏年轻的 RBC，来纠正慢性持续低氧引起的红细胞增多症。我们表明，网织红细胞中的线粒体来源的活性氧过多是由 HIF 控制的 BNIP3L 调节的线粒体自噬下调和低氧产生的 RBC 中抗氧化酶 CAT 减少引起的。CAT 的减少是由于缺氧诱导的 miR-21 下调 CAT 所致。这与正常氧合恢复时 HIF-1 的短暂急性下降相关，这与红细胞量的正常化相关。
