Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models.Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis.Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis.Previous studies have shown that,when used to treat cardiovascular and digestive system diseases,metformin can also upregulate heme oxygenase-1 expression.Therefore,we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury.To test this,we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury.Next,we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis.Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury.Subsequently,we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord,and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury.Taken together,these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury,and that this effect is partially dependent on upregulation of heme oxygenase-1.

铁死亡抑制剂预培养的大鼠心肌细胞抵抗素诱导后细胞肥大程度及铁死亡相关蛋白表达观察

目的观察铁死亡抑制剂Fer-1预培养的大鼠心肌细胞系H9c2抵抗素诱导后细胞肥大程度及铁死亡相关蛋白的表达情况。方法将H9c2细胞饥饿培养16 h,随机分为1、2、3、4组。1组用含1μmmol/L的Fer-1的培养基培养16 h,后换为含50 ng/mL抵抗素的培养基培养32 h;2组用含1μmmol/L的Fer-1培养基培养16 h,后换为0.1%FBS培养基培养32 h;3组用含50 ng/mL抵抗素的培养基培养48 h;4组(正常对照组)用0.1%FBS培养基培养48 h。取各组细胞,采用Image J软件测量细胞表面积,采用BCA法测算单细胞蛋白含量,采用RT-qPCR法检测心肌细胞肥大相关胚胎基因ANP、BNP和β-MHC;采用WESTERN Blotting法检测各组铁死亡相关蛋白谷胱甘肽过氧化物酶4(Glutathione Peroxidase 4,GPX4)、酰基辅酶A合成酶长链家族成员4(Acyl-CoA synthetase long-chain family member,ACSL4)及环氧合酶2(COX2)。结果与4组比较,3组H9c2细胞表面积增大,单细胞蛋白含量高,ANF、BNF及β-MHC基因相对表达量高,GPX4蛋白相对表达量低、ACSL4及COX2蛋白相对表达量高(P均<0.05)。与3组相比,1组细胞表面积小,单细胞蛋白含量低,ANF、BNF及β-MHC基因相对表达量低(P均<0.05);与3组相比,1组细胞GPX4蛋白相对表达量高、ACSL4及COX2蛋白相对表达量低(P均<0.05)。结论Fer-1能抑制抵抗素诱导的H9c2细胞肥大。Fer-1可能通过促进铁死亡相关蛋白GPX4表达、抑制ACSL4及COX2蛋白表达,抑制抵抗素诱导的H9c2肥大。