Opening the Possibility of Targeted Therapy for Cardiovascular Disease through Epigenetic Editing without DNA Sequence Damage
Background
Cardiovascular disease (CVD) is a refractory condition that ranks as the leading cause of death worldwide. It is triggered by the combination of genetic factors such as hypertension and diabetes, along with environmental factors like Westernized diets and smoking, which disrupt the genomic program of heart cells. The medical field has traditionally relied on drug therapies to manage symptoms, such as antihypertensive agents and lipid-lowering drugs. Recently, gene-editing technologies using gene scissors to directly cut disease-causing DNA sequences have been actively researched.
However, gene-editing methods that directly cut DNA sequences carry the risk of unexpected side effects. The process of directly modifying DNA sequences can induce permanent mutations and is often associated with off-target effects, leading to damage in other genes. Additionally, there is a limitation in selectively correcting only the cell populations that actually cause the disease among the diverse cell types that make up the heart and blood vessels. This has led to a growing demand for new epigenetic therapeutic technologies that can normalize the expression of disease-related genes in a cell-specific manner without altering the DNA sequence.
Key Findings
Recently, the academic community has shown interest in cell-specific epigenome editing techniques that preserve the DNA base sequence while correcting only the chemical genetic information within the cell. A representative example is the fusion of dead Cas9 (dCas9) proteins, which lack cutting activity, with writer or eraser enzymes that transfer or remove chemical groups. This correction tool binds to regulatory regions of target genes, such as promoters or enhancers, and induces DNA methylation or histone modifications to finely control gene expression.
A research team demonstrated therapeutic efficacy by targeting specific cell populations that cause atherosclerosis, such as vascular endothelial cells and macrophages. By delivering dCas9 fusion proteins to suppress the expression of disease-related genes, they observed significant and sustained effects lasting several months. This confirmed the ability to stably suppress target gene expression without permanently damaging the DNA sequence.
To maximize the therapeutic efficiency of epigenome editing, a precise validation system at the single-cell level is essential. The research team employed single-cell multi-omics analysis to comprehensively evaluate on-target activity in target cells and off-target safety in non-target cells. They confirmed that unwanted chromatin structure changes did not occur in other organs or non-target cells, thereby ensuring the safety of the treatment.
Significance and Prospects
Epigenome editing is expected to provide new breakthroughs for refractory cardiovascular conditions such as atherosclerosis, cardiomyopathy, and cardiac fibrosis. It allows for the control of disease-related gene activity in a non-genotoxic manner while preventing permanent alterations to the DNA sequence of heart cells.
However, several technical challenges must be overcome to implement this technology in clinical practice. Developing cardiac-selective delivery methods that can deliver gene editors only to target cells in the heart muscle or vascular wall is a key challenge. Research is also needed to minimize immune responses to the introduced dCas9 proteins or viral vectors. In the long term, establishing monitoring systems for subtle chromatin structure changes over time and setting up regulatory approval processes distinct from those for conventional gene therapies will be essential.
BACKGROUND: Cell-specific epigenetic editing provides a new approach to the therapy of cardiovascular disease (CVD) by rewriting pathological chromatin and RNA marks in exactly those cell populations responsible for causing disease. CVD is caused by interactions of genetics and environment on cell-type-specific epigenomic programs. Interventions that alter DNA methylation, histone marks, or RNA modifications can therefore correct maladaptive gene expression without altering DNA sequence. SUMMARY: Recently developed technologies such as dCas9 fused to writers/erasers allow programmable, locus-directed modulation of promoters, enhancers, and transcripts. Proof-of-principle in vivo work has shown durable target silencing, illustrating both the potency and persistence of epigenetic edits. To achieve therapeutic benefit, cell-targeting strategies and rigorous single-cell/multi-omic validation of on-target activity and off-target safety will be required. Major translational challenges include scalable, cardiac-selective delivery, immune responses to vectors/editors, long-term monitoring for unintended chromatin changes, and regulatory pathways for nongenotoxic but durable interventions. KEY MESSAGES: Altogether, cell-specific epigenetic editing holds very high therapeutic value for atherosclerosis, cardiomyopathy, and fibrosis, provided that delivery, specificity, and safety challenges are also addressed.
This technology is useful for personalized precision therapy in patients with atherosclerosis or chronic heart failure. For example, in atherosclerosis, where cholesterol accumulates in the vascular wall and causes inflammation, methylation enzymes can be delivered to macrophages with overactivated inflammatory genes to selectively block the transcription of those genes. A combined therapeutic strategy could also be developed by enhancing histone activity marks in vascular endothelial cells to maintain vascular elasticity. By not destroying the genome itself, this approach significantly improves safety, offering a safe targeted therapy for patient groups who previously found gene therapy difficult due to age or underlying conditions.