Recombinant dsAAV9-mediated Endogenous Overexpression of Macrophage Migration Inhibitory Factor Alleviates Myocardial
Xiao-Cui Chen1,2, Min-Tao Gai1, Chun-Hui He1
1State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute, Xinjiang Medical University, No. 137 Liyushan South Road, Urumqi, 830054, China.
Purpose:
To investigate the protective effect and mechanism of enhanced expression of endogenous macrophage migration inhibitory factor (MIF) on cardiac ischemia-reperfusion (I/R) injury.
Methods:
A recombinant double-stranded adeno-associated virus serotype 9 with MIF or green fluorescent protein (GFP) genes (dsAAV9-MIF/GFP) was transduced into mice and neonatal rat ventricular myocytes (NRVMs). The models of cardiac 60 min ischemia and 24 h reperfusion and 12 h hypoxia/12 h reoxygenation (H/R) were established in mice and NRVMs, respectively. Infarct size, cardiac remodeling, and related signaling pathways were assessed.
Results:
The dsAAV9 vector demonstrated strong transduction efficacy and cardiac affinity. Cardiac overexpression of MIF led to a 35.3% reduction in infarct size and improved cardiac function following I/R injury. In the dsAAV9-MIF group, the AMP-activated protein kinase (AMPK) signaling pathway was activated, and autophagy was enhanced during the ischemic period. During reperfusion, the extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling pathway was upregulated, leading to reduced cardiac apoptosis. In vitro, transfection with MIF in NRVMs also upregulated AMPK and ERK1/2 signaling during hypoxia and reoxygenation, respectively. Furthermore, MIF overexpression significantly improved autophagy and mitochondrial function, evidenced by an increased LC3-II/I ratio and enhanced mitochondrial membrane potential (ΔΨm), with these effects reversed by the AMPK inhibitor compound C. Additionally, MIF overexpression led to a 60% reduction in the apoptosis rate of cardiomyocytes subjected to H/R and decreased the Bax/Bcl-2 ratio, partially through the ERK1/2 signaling pathway.
Conclusion:
Enhanced endogenous MIF expression via the dsAAV9 vector provides significant cardioprotection against I/R injury by activating the AMPK and ERK1/2 signaling pathways. Our findings suggest that targeting MIF may represent a viable therapeutic strategy for severe and prolonged I/R injury.
Insights
Enhanced macrophage migration inhibitory factor (MIF) expression protects the heart from ischemia-reperfusion (I/R) injury. This involves activating AMP-activated protein kinase (AMPK) and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathways, offering a potential therapeutic strategy.
Area of Science:
- Cardiovascular Biology
- Molecular Medicine
- Gene Therapy
Background:
- Cardiac ischemia-reperfusion (I/R) injury remains a significant clinical challenge.
- Understanding endogenous protective mechanisms is crucial for developing novel therapies.
Purpose of the Study:
- To investigate the protective effects of enhanced endogenous macrophage migration inhibitory factor (MIF) expression against cardiac I/R injury.
- To elucidate the underlying molecular mechanisms involving key signaling pathways.
Main Methods:
- Utilized a recombinant adeno-associated virus serotype 9 (dsAAV9) vector for cardiac-specific overexpression of MIF in mouse models of I/R injury.
- Established in vitro models using neonatal rat ventricular myocytes (NRVMs) subjected to hypoxia/reoxygenation (H/R).
- Assessed infarct size, cardiac function, apoptosis, autophagy, and activation of AMPK and ERK1/2 signaling pathways.
Main Results:
- Cardiac overexpression of MIF significantly reduced infarct size by 35.3% and improved cardiac function post-I/R.
- MIF activated the AMPK pathway during ischemia and the ERK1/2 pathway during reperfusion, enhancing autophagy and reducing apoptosis.
- MIF improved mitochondrial function and decreased cardiomyocyte apoptosis by 60% in vitro, partly via ERK1/2 signaling.
Conclusions:
- Enhanced endogenous MIF expression confers significant cardioprotection against I/R injury.
- Targeting MIF through gene therapy, activating AMPK and ERK1/2 pathways, presents a promising therapeutic strategy for severe I/R injury.
