DataSheet2_Tetramethylpyrazine nitrone activates hypoxia-inducible factor and regulates iron homeostasis to improve renal anemia.PDF

Renal anemia is one of the most common complications of chronic kidney disease and diabetic kidney disease. Despite the progress made in recent years, there is still an urgent unmet clinical need for renal anemia treatment. In this research, we investigated the efficacy and mechanism of action of the novel tetramethylpyrazine nitrone (TBN). Animal models of anemia including the streptozotocin (STZ)-induced spontaneously hypertensive rats (SHR) and the cisplatin (CDDP)-induced C57BL/6J mice are established to study the TBN’s effects on expression of hypoxia-inducible factor and erythropoietin. To explore the mechanism of TBN’s therapeutic effect on renal anemia, cobalt chloride (CoCl2) is used in Hep3B/HepG2 cells to simulate a hypoxic environment. TBN is found to increase the expression of hypoxia-inducible factor HIF-1α and HIF-2α under hypoxic conditions and reverse the reduction of HIFs expression caused by saccharate ferric oxide (SFO). TBN also positively regulates the AMPK pathway. TBN stimulates nuclear transcription and translation of erythropoietin by enhancing the stability of HIF-1α expression. TBN has a significant regulatory effect on several major biomarkers of iron homeostasis, including ferritin, ferroportin (FPN), and divalent metal transporter-1 (DMT1). In conclusion, TBN regulates the AMPK/mTOR/4E-BP1/HIFs pathway, and activates the hypoxia-inducible factor and regulates iron homeostasis to improve renal anemia.

肾性贫血（Renal anemia）是慢性肾脏病（chronic kidney disease）与糖尿病肾病（diabetic kidney disease）最常见的并发症之一。尽管近年来相关研究取得了一定进展，但肾性贫血的临床治疗仍存在迫切的未被满足的医疗需求。本研究探讨了新型四甲基吡嗪硝酮（tetramethylpyrazine nitrone, TBN）的疗效及其作用机制。本研究构建了贫血动物模型，包括链脲佐菌素（streptozotocin, STZ）诱导的自发性高血压大鼠（spontaneously hypertensive rats, SHR）以及顺铂（cisplatin, CDDP）诱导的C57BL/6J小鼠，以探究TBN对缺氧诱导因子（hypoxia-inducible factor, HIF）与促红细胞生成素（erythropoietin, EPO）表达的调控作用。为阐明TBN治疗肾性贫血的作用机制，本研究采用氯化钴（cobalt chloride, CoCl2）处理Hep3B/HepG2细胞以模拟缺氧环境。研究发现，TBN可在缺氧条件下上调缺氧诱导因子HIF-1α与HIF-2α的表达，并逆转蔗糖铁（saccharate ferric oxide, SFO）所致的HIFs表达下调。TBN同时可正向调控腺苷酸活化蛋白激酶（AMPK）信号通路。TBN通过增强HIF-1α的表达稳定性，促进促红细胞生成素的核转录与翻译过程。TBN对铁稳态的多项关键生物标志物——包括铁蛋白（ferritin）、铁转运蛋白（ferroportin, FPN）以及二价金属离子转运体1（divalent metal transporter-1, DMT1）——均具有显著的调控作用。综上，TBN可通过调控腺苷酸活化蛋白激酶（AMPK）/哺乳动物雷帕霉素靶蛋白（mTOR）/真核翻译起始因子4E结合蛋白1（4E-BP1）/缺氧诱导因子（HIFs）信号通路，激活缺氧诱导因子并调控铁稳态，从而改善肾性贫血。