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Updated: Jul 29, 2025
CRISPR-Cas9-Mediated Precise Knock-In Edits in Zebrafish Hearts
Published on: September 13, 2022
Cardiac RNase Z edited via CRISPR-Cas9 drives heart hypertrophy in Drosophila
Ekaterina Migunova1, Saathvika Rajamani1, Stefania Bonanni1
1Department of Biological Sciences, Fordham University, Bronx, NY, United States of America.
Insights
RNase Z deficiency causes severe cardiomyopathy. This study shows that RNase Z-linked heart disease arises from cell-autonomous mechanisms within heart muscle cells, not external factors.
Area of Science:
- Cardiology
- Molecular Biology
- Genetics
Background:
- Cardiomyopathy (CM) encompasses myocardial diseases with diverse causes.
- RNase Z endoribonuclease deficiency is linked to severe, often fatal, forms of CM.
- RNase Z is crucial for tRNA processing, and its variants cause symptoms like heart hypertrophy.
Purpose of the Study:
- To investigate whether RNase Z-linked cardiomyopathy (CM) is caused by cell-autonomous or non-autonomous mechanisms.
- To develop a model for studying RNase Z deficiency-related heart disease.
Main Methods:
- Utilized CRISPR-TRiM technology in Drosophila.
- Created Drosophila models with cardiomyopathy-linked RNase Z alleles specifically in cardiomyocytes.
- Analyzed cardiac morphology and function in the developed models.
Main Results:
- Cardiomyopathy-linked RNase Z alleles in cardiomyocytes were sufficient to induce heart hypertrophy and systolic dysfunction in Drosophila.
- The observed cardiac abnormalities support a cell-autonomous mechanism for RNase Z-linked CM.
- This indicates that RNase Z deficiency within heart cells directly drives the disease pathology.
Conclusions:
- RNase Z-linked cardiomyopathy is primarily driven by cell-autonomous mechanisms.
- Targeting RNase Z function within cardiomyocytes may offer novel therapeutic strategies for patients.
- Further research into tRNA processing defects in cardiac cells is warranted.
Abstract:
Cardiomyopathy (CM) is a group of diseases distinguished by morphological and functional abnormalities in the myocardium. It is etiologically heterogeneous and may develop via cell autonomous and/or non-autonomous mechanisms. One of the most severe forms of CM has been linked to the deficiency of the ubiquitously expressed RNase Z endoribonuclease. RNase Z cleaves off the 3'-trailer of both nuclear and mitochondrial primary tRNA (pre-tRNA) transcripts. Cells mutant for RNase Z accumulate unprocessed pre-tRNA molecules. Patients carrying RNase Z variants with reduced enzymatic activity display a plethora of symptoms including muscular hypotonia, microcephaly and severe heart hypertrophy; still, they die primarily due to acute heart decompensation. Determining whether the underlying mechanism of heart malfunction is cell autonomous or not will provide an opportunity to develop novel strategies of more efficient treatments for these patients. In this study, we used CRISPR-TRiM technology to create Drosophila models that carry cardiomyopathy-linked alleles of RNase Z only in the cardiomyocytes. We found that this modification is sufficient for flies to develop heart hypertrophy and systolic dysfunction. These observations support the idea that the RNase Z linked CM is driven by cell autonomous mechanisms.
