Histone lysine demethylase inhibition is a disease-modifying therapy for hypertrophic cardiomyopathy

Verdict. Objective: To determine whether pharmacological inhibition of histone lysine demethylases (KDMs) with JIB-04 can prevent or reverse HCM progression and to identify the underlying epigenetic mechanisms. It intersects mitochondrial stress/dysfunction themes (mitochondrial dysfunction; disease context).

What the authors report

Rationale: Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder characterized by cardiac hypertrophy, fibrosis, arrhythmias, and sudden cardiac death (SCD). Although current therapies primarily target sarcomere dysfunction, the contribution of epigenetic dysregulation to HCM pathogenesis and its therapeutic potential remain poorly understood.

Key results stated in the abstract include the following. Objective: To determine whether pharmacological inhibition of histone lysine demethylases (KDMs) with JIB-04 can prevent or reverse HCM progression and to identify the underlying epigenetic mechanisms. Methods and Results: We evaluated the pan-KDM inhibitor JIB-04 in Myh6R403Q/+ mice carrying the murine equivalent of the pathogenic human MYH7 R403Q mutation. JIB-04 prevented disease progression, reduced cardiac hypertrophy and fibrosis, preserved cardiac function, and completely prevented SCD in cyclosporin A-accelerated HCM.

Why it matters for mitochondrial biology

Within mitochondrial research, this work maps primarily to redox biology, cardiovascular, immunology, therapeutics. It is relevant to mitochondrial dysfunction discourse because the abstract invokes mitochondrial dysfunction, disease context. That does not by itself establish a validated disease mechanism; it indicates thematic proximity. Because a therapeutic or interventional angle is present, the piece is of interest for mitochondrial-targeted drug hypothesis generation—subject to full-text validation of endpoints and safety context. Server: biorxiv. Posted 2026-08-13. Synthesis confidence is bounded by abstract completeness.

Study design (abstract-level)

Methods and Results: We evaluated the pan-KDM inhibitor JIB-04 in Myh6R403Q/+ mice carrying the murine equivalent of the pathogenic human MYH7 R403Q mutation. JIB-04 also reversed established disease, produced sustained therapeutic benefits after drug withdrawal, and improved cardiac function in aged mice with spontaneous HCM. Bulk RNA sequencing and ATAC-seq demonstrated partial restoration of disease-associated transcriptional programs and chromatin accessibility.

Principal findings

1. Objective: To determine whether pharmacological inhibition of histone lysine demethylases (KDMs) with JIB-04 can prevent or reverse HCM progression and to identify the underlying epigenetic mechanisms.
2. Methods and Results: We evaluated the pan-KDM inhibitor JIB-04 in Myh6R403Q/+ mice carrying the murine equivalent of the pathogenic human MYH7 R403Q mutation.
3. JIB-04 prevented disease progression, reduced cardiac hypertrophy and fibrosis, preserved cardiac function, and completely prevented SCD in cyclosporin A-accelerated HCM.
4. In MYH7 R403Q induced pluripotent stem cell-derived cardiomyocytes, JIB-04 normalized disease-associated gene expression, restored connexin-43 membrane localization, and improved mitochondrial respiration.
5. These findings identify KDM inhibition as a promising therapeutic strategy for HCM, establish PHF2 as a candidate mediator of disease pathogenesis, and support further development of KDM-targeted therapies.

Limitations of this brief

• This Mitos brief is an abstract-level synthesis of a preprint; it is not peer review and not a substitute for reading the full paper.
• Preprint status: findings may change with revision or journal review.
• Effect sizes, n numbers, statistics, and full experimental controls are typically incomplete at abstract resolution.
• Comparator/control language is weak or absent in the abstract, limiting causal inference from this brief alone.
• Primary source: biorxiv DOI 10.64898/2026.08.07.743611 (posted 2026-08-13).

Open scientific questions

• Which specific experimental panels in the full paper establish the strongest causal claim, and how robust are the controls?
• Are OXPHOS defects primary drivers or secondary consequences of broader cellular stress?
• What dose, timing, and off-target profile would be required to take the intervention seriously as a therapeutic hypothesis?
• How do these findings sit relative to prior literature on the same pathway—replication, contradiction, or incremental extension?

Bottom line

For mitochondrial biologists focused on redox biology, cardiovascular, immunology, this preprint is worth full-text review if the topic matches your program. Abstract-level takeaway: Objective: To determine whether pharmacological inhibition of histone lysine demethylases (KDMs) with JIB-04 can prevent or reverse HCM progression and to identify the underlying epigenetic mechanisms. Confirm methods, effect sizes, and controls in the full PDF before citing the result as established.

Bibliographic record

Abstract-based editorial synthesis by Mitos. Not peer review.