藏红花素抑制铁死亡改善糖尿病肾病的机制研究

[目的] 研究藏红花素（CRO）治疗糖尿病肾病（DN）的效果并从脂质过氧化与铁死亡角度探究其作用机制。[方法] 60只C57BL/6J小鼠适应性喂养1周，HFD继续喂养8周，之后链脲霉素（STZ）造模并随机平均分为正常组、模型组、铁死亡抑制剂组（铁死亡抑制剂Fer-1，10 mg/kg，灌胃）、低剂量CRO组（CRO 5 mg/kg，灌胃）、中剂量CRO组（CRO 10 mg/kg，灌胃）、高剂量CRO组（CRO 20 mg/kg，灌胃）。治疗8周后，收集小鼠24 h尿液样本、血液样本、肾脏进行分析测定。采用试剂盒测定小鼠24 h尿蛋白定量（24 h-UPQ），血清肌酐（Cr）、尿素氮（BUN），肾组织丙二醛（MDA）、活性氧（ROS）、4-羟基壬烯醛（4-HNE）水平，评估其肾功能与脂质过氧化水平。对肾脏同一部位进行苏木精-伊红（HE）、Masson以及TUNEL染色，观察其病理学变化以及细胞死亡情况。测定肾组织Fe水平并采用实时荧光定量反转录聚合酶连锁反应（RT-qPCR）以及蛋白质免疫印迹法（Western blot）检测前列腺六跨膜上皮抗原3（STEAP3）、转铁蛋白（TF）、重链铁蛋白（FTH1）、轻链铁蛋白（FTL）以及谷胱甘肽过氧化物酶4（GPX4）表达情况，以评估CRO对铁死亡的影响。[结果] 与模型组相比，CRO治疗后，DN小鼠Cr、BUN、24 h-UPQ有不同程度降低，肾组织病理损伤有不同程度的好转，MDA、ROS、4-HNE水平显著降低，肾组织中TUNEL荧光阳性反应明显减弱，肾组织Fe水平出现不同程度降低，STEAP3与TF表达下调，FTH1、FTL以及GPX4蛋白表达上调。[结论] CRO可以通过抑制脂质过氧化并减轻细胞铁死亡发挥对DN小鼠肾脏的保护作用。

Mechanism of crocin treatment on improving diabetic nephropathy by inhibiting ferroptosis

[Objective] To investigate the effect of crocin（CRO） on diabetic nephropathy（DN） and explore its mechanism from the perspective of lipid peroxidation and ferroptosis. [Methods] Sixty C57BL/6J mice were adaptively fed for 1 week and then HFD for 8 weeks. After STZ modeling，the mice were randomly divided into control group，model group，ferroptosis inhibitor group（Fe-1，10 mg/kg，gavage），low dose CRO group（CROL，5 mg/kg，gavage），middle dose CRO group（CROM，10 mg/kg，gavage），high dose CRO group（CROH，20 mg/kg，gavage）. After 8 weeks of treatment，24 h urine samples，blood samples and kidneys were collected for analysis and determination. The levels of 24 h-UPQ，Cr and BUN in serum，MDA，ROS and 4-HNE in renal tissue were measured by kits to evaluate renal function and lipid peroxidation. HE，Masson and TUNEL staining were used to observe the pathological changes and cell death in the same part of the kidney. Level of Fe in renal was measured，and the expressions of STEAP3，TF，FTH1，FTL，and GPX4 were detected by RT-qPCR and Western blot to evaluate the effect of CRO on ferroptosis. [Results] Compared with the model group，the levels of Cr，BUN，24 h-UPQ decreased different degrees，and the pathological damage of renal tissue has different degrees of improvement，and the levels of MDA，ROS，4-HNE were significantly reduced，and TUNEL fluorescence positive reaction in renal tissue were significantly weakened，and the level of Fe in renal tissue decreased in different degrees after CRO treatment. The expression of STEAP3 and TF was down-regulated，while the expression of FTH1，FTL and GPX4 was up-regulated. [Conclusion] CRO can protect the kidney of DN mice by inhibiting lipid peroxidation and reducing ferroptosis.