MOTS-c preserves mitochondrial bioenergetics and genome integrity, attenuating cardiac ischemia-reperfusion injury
Background
Myocardial ischemia-reperfusion (IR) injury, a major contributor to heart failure, is exacerbated by mitochondrial dysfunction. This dysfunction manifests as impaired bioenergetics, excessive oxidative stress, and disruption of mitochondrial homeostasis, leading to cardiomyocyte death. Current treatments often fall short in directly addressing these mitochondrial pathologies. MOTS-c, a mitochondrial-derived peptide, has shown promise in metabolic stress adaptation, but its specific role and mechanisms in mitigating cardiac IR injury, particularly concerning mitochondrial subpopulations, remained underexplored.
Study Design
Researchers utilized an isolated female Wistar rat heart model (n=6/group) subjected to 30 min global ischemia followed by 60 min reperfusion using the Langendorff perfusion system. MOTS-c (53 µM) was administered either before ischemia or at the onset of reperfusion. The study evaluated cardiac mechanical function, myocardial injury markers, mitochondrial bioenergetics, oxidative stress, mtDNA copy number, and mitochondrial regulatory gene expression in both subsarcolemmal and interfibrillar mitochondrial populations via ELISA, qPCR, and enzymatic assays.
Results
Ischemia-reperfusion injury significantly impaired cardiac mechanical recovery, increased oxidative stress, and reduced electron transport chain and dehydrogenase enzyme activities. It also disrupted mitochondrial membrane potential and decreased mtDNA copy number, alongside reduced expression of mitochondrial regulatory genes. MOTS-c treatment consistently improved post-ischemic mechanical recovery, demonstrating a cardioprotective effect. It also attenuated oxidative stress, partially preserved crucial mitochondrial enzyme activities, and stabilized mitochondrial membrane potential. Furthermore, MOTS-c mitigated the reductions in mtDNA copy number and the expression of mitochondrial regulatory genes. These protective effects were observed across both subsarcolemmal and interfibrillar mitochondrial subpopulations, although the specific responses varied depending on the parameter assessed. This suggests a broad impact on mitochondrial health.
MOTS-c treatment was associated with preservation of mitochondrial functional integrity and improved cardiac recovery following IR injury.
Key Findings
- MOTS-c treatment improved post-ischemic cardiac mechanical recovery in isolated rat hearts.
- MOTS-c attenuated oxidative stress induced by ischemia-reperfusion injury.
- Mitochondrial enzyme activities and membrane potential were partially preserved by MOTS-c.
- Reductions in
mtDNAcopy number and mitochondrial gene expression were mitigated by MOTS-c. - Protective effects were observed in both subsarcolemmal and interfibrillar mitochondrial populations.
Why It Matters
This study highlights MOTS-c as a promising therapeutic candidate for cardiac ischemia-reperfusion injury, offering a novel approach to directly target mitochondrial dysfunction. For biohackers and clinicians, this suggests a potential peptide intervention to protect the heart during events like heart attack or cardiac surgery. While the specific dose of 53 µM was effective in an ex vivo model, further in-vivo studies are crucial to establish optimal dosing, route, and timing for human translation. The findings underscore the importance of mitochondrial-derived peptides in modulating cellular stress responses, potentially opening avenues for combination therapies that enhance mitochondrial resilience and improve post-ischemic outcomes.
mots-c
cardiac ischemia-reperfusion injury
mitochondrial dysfunction
cardioprotection
oxidative stress
preclinical-animal