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Updated: Jan 13, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Co-regulatory crosstalk between m5C, m7G, and o8G RNA modifications via QKI/YBX1 axis in myocardial
Ziqiang Yang1, Suyun Chen1, Siman Shen1
1Department of Anesthesiology, The Second Affiliated Hospital of Guangdong Medical University, Zhanjiang 524000, Guangdong, China.
Background:
Ischemia-reperfusion (I/R) injury in the heart triggers oxidative stress and alters post-transcriptional gene regulation. Reactive oxygen species (ROS) generated during oxidative stress induce RNA modifications such as 8-oxo-guanosine (o8G). Other modifications including 5-methylcytosine (m5C) and 7-methylguanosine (m7G) may also contribute to cardiac dysfunction. While the roles of individual RNA modifications in I/R injury are increasingly recognized, the global dynamics and crosstalk among these modifications under oxidative stress remain largely unexplored.
Methods:
We performed high-throughput sequencing specific to each modification, integrated with mRNA transcriptome profiling of an IR injury mouse model. Differentially modified transcripts were subjected to GO and KEGG enrichment analyses to elucidate their functional relevance. Mechanistically, we demonstrated that RNA modification regulators with distinct functional roles can physically interact with each other, as shown by co-immunoprecipitation and immunofluorescence assays. Global changes in RNA modification levels under the model conditions were assessed using dot blot analysis. Furthermore, the regulatory effects of these enzymes on target mRNA stability were evaluated via Actinomycin D transcriptional inhibition assays.
Results:
We found that the levels of all three modifications, m5C, m7G, and o8G were increased in IR by dot blot and observed a significant upregulation of three modification peaks under I/R by MeRIP-seq. Both m5C and o8G were predominantly enriched in CDS, while m7G displayed a dynamic redistribution. Our study focuses on the co-regulation crosstalk among three modifications. Functionally, singly or combinatorially modified transcripts were enriched in actin cytoskeleton regulation. Mechanistically, the transcripts of the regulators can be modified by each other and QKI can modulate the global modification level of o8G. QKI and YBX1 interact with each other to cooperatively stabilize ACTN4 mRNA, thereby maintaining cytoskeletal integrity.
Conclusion:
Our results establish that QKI and YBX1 modulate the actin cytoskeleton via a coordinated network of m5C, m7G, and o8G in I/R injury.
Insights
This study reveals how RNA modifications 5-methylcytosine (m5C), 7-methylguanosine (m7G), and 8-oxo-guanosine (o8G) are globally altered in heart ischemia-reperfusion (I/R) injury. QKI and YBX1 proteins coordinate these modifications to regulate the actin cytoskeleton, impacting cardiac function.
Area of Science:
- Molecular Biology
- Cardiovascular Research
- Epigenetics
Background:
- Ischemia-reperfusion (I/R) injury induces cardiac oxidative stress, altering post-transcriptional gene regulation.
- Reactive oxygen species (ROS) generate RNA modifications like 8-oxo-guanosine (o8G), 5-methylcytosine (m5C), and 7-methylguanosine (m7G), potentially causing cardiac dysfunction.
- The global dynamics and interplay of these RNA modifications during oxidative stress in I/R injury are not well understood.
Purpose of the Study:
- To investigate the global changes and crosstalk of m5C, m7G, and o8G RNA modifications in the heart during I/R injury.
- To elucidate the functional roles of these modifications and their regulators in cardiac dysfunction.
- To understand the mechanistic interplay between RNA modification enzymes and their targets.
Main Methods:
- Integrated high-throughput sequencing of RNA modifications (MeRIP-seq) with mRNA transcriptome profiling in an I/R mouse model.
- Performed GO and KEGG enrichment analyses on differentially modified transcripts.
- Utilized co-immunoprecipitation, immunofluorescence, dot blot analysis, and Actinomycin D assays to investigate enzyme interactions and regulatory effects on mRNA stability.
Main Results:
- Levels of m5C, m7G, and o8G were elevated in I/R injury, with specific enrichment patterns observed.
- Modified transcripts were significantly enriched in pathways regulating the actin cytoskeleton.
- RNA modification regulators QKI and YBX1 physically interact and cooperatively stabilize ACTN4 mRNA, influencing cytoskeletal integrity.
Conclusions:
- QKI and YBX1 play a crucial role in modulating the actin cytoskeleton through a coordinated network of m5C, m7G, and o8G modifications during I/R injury.
- This coordinated network is essential for maintaining cardiac function under stress conditions.
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