Dai Yuanyuan, Ignatyeva Nadezda, Xu Hang, Wali Ruheen, Toischer Karl, Brandenburg Sören, Lenz Christof, Pronto Julius, Fakuade Funsho E, Sossalla Samuel, Zeisberg Elisabeth M, Janshoff Andreas, Kutschka Ingo, Voigt Niels, Urlaub Henning, Rasmussen Torsten Bloch, Mogensen Jens, Lehnart Stephan E, Hasenfuss Gerd, Ebert Antje
Heart Research Center Goettingen, Clinic for Cardiology and Pneumology, University Medical Center Goettingen, Georg-August University of Goettingen, Germany (Y.D., N.I., H.X., R.W., K.T., S.B., S.S., E.M.Z., S.E.L., G.H., A.E.).
DZHK (German Center for Cardiovascular Research), partner site Goettingen, Germany (Y.D., N.I., H.X., R.W., K.T., S.B., C.L., J.P., F.E.F., E.M.Z., I.K., N.V., S.E.L., G.H., A.E.).
Circ Res. 2023 Jul 7;133(2):e19-e46. doi: 10.1161/CIRCRESAHA.122.321157. Epub 2023 Jun 14.
Systemic defects in intestinal iron absorption, circulation, and retention cause iron deficiency in 50% of patients with heart failure. Defective subcellular iron uptake mechanisms that are independent of systemic absorption are incompletely understood. The main intracellular route for iron uptake in cardiomyocytes is clathrin-mediated endocytosis.
We investigated subcellular iron uptake mechanisms in patient-derived and CRISPR/Cas-edited induced pluripotent stem cell-derived cardiomyocytes as well as patient-derived heart tissue. We used an integrated platform of DIA-MA (mass spectrometry data-independent acquisition)-based proteomics and signaling pathway interrogation. We employed a genetic induced pluripotent stem cell model of 2 inherited mutations ( []-R141W and []-L185F) that lead to dilated cardiomyopathy (DCM), a frequent cause of heart failure, to study the underlying molecular dysfunctions of DCM mutations.
We identified a druggable molecular pathomechanism of impaired subcellular iron deficiency that is independent of systemic iron metabolism. Clathrin-mediated endocytosis defects as well as impaired endosome distribution and cargo transfer were identified as a basis for subcellular iron deficiency in DCM-induced pluripotent stem cell-derived cardiomyocytes. The clathrin-mediated endocytosis defects were also confirmed in the hearts of patients with DCM with end-stage heart failure. Correction of the mutation in DCM patient-derived induced pluripotent stem cells, treatment with a peptide, Rho activator II, or iron supplementation rescued the molecular disease pathway and recovered contractility. Phenocopying the effects of the mutation into WT induced pluripotent stem cell-derived cardiomyocytes could be ameliorated by iron supplementation.
Our findings suggest that impaired endocytosis and cargo transport resulting in subcellular iron deficiency could be a relevant pathomechanism for patients with DCM carrying inherited mutations. Insight into this molecular mechanism may contribute to the development of treatment strategies and risk management in heart failure.
肠道铁吸收、循环和潴留的系统性缺陷导致50%的心力衰竭患者出现缺铁。与全身吸收无关的亚细胞铁摄取机制缺陷尚不完全清楚。心肌细胞摄取铁的主要细胞内途径是网格蛋白介导的内吞作用。
我们研究了患者来源的和经CRISPR/Cas编辑的诱导多能干细胞衍生的心肌细胞以及患者来源的心脏组织中的亚细胞铁摄取机制。我们使用了基于数据非依赖采集（DIA-MA）的蛋白质组学和信号通路询问的综合平台。我们采用了一种遗传诱导多能干细胞模型，该模型存在两种导致扩张型心肌病（DCM，心力衰竭的常见病因）的遗传突变（[]-R141W和[]-L185F），以研究DCM突变潜在的分子功能障碍。
我们确定了一种可药物治疗的亚细胞缺铁受损的分子发病机制，该机制独立于全身铁代谢。网格蛋白介导的内吞缺陷以及内体分布和货物转运受损被确定为DCM诱导多能干细胞衍生心肌细胞中亚细胞缺铁的基础。在终末期心力衰竭的DCM患者心脏中也证实了网格蛋白介导的内吞缺陷。纠正DCM患者来源的诱导多能干细胞中的突变、用肽Rho激活剂II治疗或补充铁可挽救分子疾病途径并恢复收缩力。将突变的影响模拟到野生型诱导多能干细胞衍生的心肌细胞中，补充铁可改善这种情况。
我们的研究结果表明，内吞和货物运输受损导致亚细胞缺铁可能是携带遗传突变的DCM患者的相关发病机制。深入了解这一分子机制可能有助于心力衰竭治疗策略的制定和风险管理。
