Reversible Mitochondrial Fragmentation in iPSC-Derived Cardiomyocytes From Children With DCMA, a Mitochondrial...

Area of Science:

• Cardiovascular Biology
• Mitochondrial Medicine
• Genetics

Background:

• Dilated cardiomyopathy with ataxia syndrome (DCMA) is an understudied genetic disorder.
• DCMA is caused by DNAJC19 mutations and linked to mitochondrial dysfunction and cardiolipin (CL) maturation defects, similar to Barth syndrome.
• The exact mechanism of cardiac dysfunction in DCMA remains unknown.

Purpose of the Study:

• To develop a cellular model for studying DCMA.
• To investigate mitochondrial abnormalities in DCMA patient-derived cells.
• To explore potential therapeutic interventions for DCMA.

Main Methods:

• Induced pluripotent stem cells (iPSCs) were generated from DCMA patients.
• iPSCs were differentiated into cardiomyocytes (iPSC-CMs).
• Mitochondrial structure, cardiolipin content, and OPA1 protein were analyzed before and after treatment with SS-31.

Main Results:

• DCMA iPSC-CMs exhibited fragmented mitochondria with abnormal OPA1 ratios.
• Mitochondrial abnormalities were reversed by SS-31 treatment within 24 hours.
• While CL species increased upon differentiation, significant differences in total CL content were not observed between patients and controls.

Conclusions:

• A novel cellular model for DCMA was established using iPSC-CMs.
• Mitochondrial abnormalities in DCMA are characterized by structural defects and OPA1 imbalance.
• SS-31 shows promise as a potential therapeutic agent for DCMA.