Cirbp suppression compromises DHODH-mediated ferroptosis defense and attenuates hypothermic cardioprotection in an aged donor transplantation model
Yifan Zhu, … , Hao Zhang, Yiwei Liu
Yifan Zhu, … , Hao Zhang, Yiwei Liu
Published May 1, 2024
Citation Information: J Clin Invest. 2024;134(9):e175645. https://doi.org/10.1172/JCI175645.
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Research Article

Cirbp suppression compromises DHODH-mediated ferroptosis defense and attenuates hypothermic cardioprotection in an aged donor transplantation model

Abstract

Hypothermia is commonly used to protect donor hearts during transplantation. However, patients transplanted with aged donor hearts still have severe myocardial injury and decreased survival rates, but the underlying mechanism remains unknown. Because aged hearts are not considered suitable for donation, the number of patients awaiting heart transplants is increasing. In this study, we examined whether hypothermic cardioprotection was attenuated in aged donor hearts during transplantation and evaluated potential therapeutic targets. Using a rat heart transplantation model, we found that hypothermic cardioprotection was impaired in aged donor hearts but preserved in young donor hearts. RNA-Seq showed that cold-inducible RNA-binding protein (Cirbp) expression was decreased in aged donor hearts, and these hearts showed severe ferroptosis after transplantation. The young donor hearts from Cirbp-KO rats exhibited attenuated hypothermic cardioprotection, but Cirbp overexpression in aged donor hearts ameliorated hypothermic cardioprotection. Cardiac proteomes revealed that dihydroorotate dehydrogenase (DHODH) expression was significantly decreased in Cirbp-KO donor hearts during transplantation. Consequently, DHODH-mediated ubiquinone reduction was compromised, thereby exacerbating cardiac lipid peroxidation and triggering ferroptosis after transplantation. A cardioplegic solution supplemented with CIRBP agonists improved hypothermic cardioprotection in aged donor hearts, indicating that this method has the potential to broaden the indications for using aged donor hearts in transplantation.

Authors

Yifan Zhu, Chenyu Jiang, Jian He, Chen He, Xingliang Zhou, Xu Huang, Yi Shen, Liwei Wu, Yongnan Li, Bei Feng, Yi Yan, Jun Li, Hao Zhang, Yiwei Liu

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Figure 8

CIRBP binds Dhodh mRNA and enhances its translation.

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CIRBP binds Dhodh mRNA and enhances its translation. (A) Proteomics anal...
(A) Proteomics analysis of donor hearts harvested from WT rats and Cirbp-KO rats was performed. IPA of differentially expressed proteins between the WT and KO groups. (B) Volcano plots showing the differentially expressed proteins between the WT and KO groups. Green dots represent genes whose expression were significantly decreased in KO groups. Red dots represent genes whose expression were significantly increased in KO groups. Gray dots represent genes whose expression did not reach the statistical significance. (C) Verification of significantly differentially expressed proteins that are involved in the ferroptosis signaling pathway between WT and KO groups after transplantation. (D) Real-time qPCR analysis of Dhodh mRNA expression in donor hearts from the WT and KO groups after transplantation. (E) The binding of CIRBP to Dhodh mRNA was investigated by ultraviolet cross-link RIP assay. (F) Biotin-pulldown assays were performed using biotinylated fragments of Dhodh mRNA to detect bound cellular CIRBP. (G) RNC mRNA and total RNA were isolated from donor hearts after transplantation and were both subjected to real-time qPCR analysis to assess the presence of Dhodh mRNA. The Dhodh mRNA in total RNA was used as input. (H) CoQH2/CoQ ratios in donor hearts from the WT and KO groups after transplantation. (I) Western blotting and quantification of DHODH in WT and Cirbp-KO cardiomyocytes after cold ischemia. (J) CoQH2/CoQ ratios in WT and Cirbp-KO cardiomyocytes after cold ischemia. (K) Western blotting and quantification of DHODH in young and aged donor hearts after transplantation. (L) CoQH2/CoQ ratios in young and aged donor hearts after transplantation. Quantitative data are shown as the mean ± standard deviation, with individual values presented in a dot plot. *P < 0.05, **P < 0.01, and ***P < 0.001, by 2-sided Student’s t test.