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 Transplantation

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 9

Cardioplegic solution supplemented with Cirbp agonist improves hypothermic cardioprotection of aged donor hearts during cold storage in transplantation.

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Cardioplegic solution supplemented with Cirbp agonist improves hypotherm...
(A) Experimental design. Aged donor hearts were harvested and transplanted into young rats. UW solution was used to induce cardiac arrest in the control group, and UW solution supplemented with the Cirbp agonist Zr17-2 was used in the experimental group (n = 5 in each group). Hypothermia was used to protect donor hearts during cold storage. (B) Western blotting and quantification of CIRBP in donor hearts after transplantation. (C) Assessment of cardiac resuscitation after transplantation. (D) Cardiac function of donor hearts measured by echocardiography after transplantation. (E) Representative LVP traces and cardiac function parameters of donor hearts determined via cardiac catheterization after transplantation. (F) Serum cardiac enzymes in recipients after transplantation. (G) MPO staining of donor hearts after transplantation. Scale bars: 50 μm. (H) H&E and PTAH staining of donor hearts after transplantation. Arrows indicate myocardial contraction band necrosis. Scale bars: 100 μm (H&E images); 50 μm (PTAH images). (I) Western blotting and quantification of DHODH in donor hearts after transplantation. (J) CoQH2/CoQ ratio in donor hearts after transplantation. (K) Peroxidation parameters and iron overload in donor hearts after transplantation. (L) Arachidonic acid metabolite levels in donor hearts after transplantation. (M) Prussian blue staining of donor hearts after transplantation. Arrows indicate iron deposition in myocardium. Scale bars: 50 μm. (N) Western blotting and quantification of PTGS2 in donor hearts after transplantation. (O) Immunofluorescence staining for PTGS2 in donor hearts after transplantation and quantification. Scale bars: 100 μm. (P) TEM images of donor hearts after transplantation. Arrowheads indicate mitochondrial shrinkage (blue), crista loss (black), and membrane rupture (red). Scale bars: 1 μm. Original magnification (enlarged insets), ×100,000. Data shown are the mean ± standard deviation, with individual values presented as a dot plot. *P < 0.05, **P < 0.01, and ***P < 0.001, by 2-sided Student’s t test.