Yizhen Xu, Huanqing Liu, Shuang Liu, Peng Wu, Rui Wang, You Li, Xiaona Wang, Qiuyu Cao, Lei Duan, Ruobai Qiao, Hao Tang, Zhen Wang
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引用次数: 0
Abstract
Introduction: Mitochondrial redox homeostasis is of utmost significance in myocardial ischemia-reperfusion (I/R) injury. Irisin, a myokine, has drawn extensive attention in research regarding the protection against cardiovascular diseases.
Methods: This study utilized in vitro Hypoxia/Reoxygenation (H/R) models in H9c2 cardiomyocytes to simulate I/R injury. Cells were pretreated with irisin (20 ng/mL) prior to reoxygenation. UCP2 knockdown was achieved via siRNA/shRNA transfection. Cell viability and apoptosis were assessed using CCK-8 and flow cytometry (Annexin V-FITC/PI staining), respectively. Intracellular calcium dynamics were monitored by Fluo-3/AM confocal imaging, while ROS levels were quantified via DCFH-DA flow cytometry. Key oxidative stress markers (LDH, MDA, GSH-Px, and CAT) and protein expression (ASC, NLRP3, SIRT1, UCP2, and SOD2) were evaluated using commercial kits and Western blotting. Protein interactions were analyzed by coimmunoprecipitation, and ubiquitination levels were measured under proteasomal/lysosomal inhibition (MG132/Leupeptin).
Results: Irisin attenuated H/R injury in cardiomyocytes by suppressing apoptosis, calcium/ROS overload, and NLRP3 activation through a UCP2-dependent pathway. UCP2 knockdown significantly attenuated irisin's protection and reduced SOD2 protein stability. Mechanistically, UCP2 bound SOD2 and inhibited its ubiquitin-proteasomal degradation.
Discussion: This study reveals a novel mechanism where irisin enhances mitochondrial redox homeostasis by promoting UCP2's function, which stabilizes SOD2 against ubiquitin-proteasomal degradation. This UCP2-SOD2 axis attenuates oxidative stress and inhibits NLRP3 inflammasome activation during cardiac injury, offering a promising dual-targeted therapeutic strategy for I/R injury.
Conclusion: Irisin protects cardiomyocytes against H/R injury primarily via a novel UCP2-SOD2 axis.
期刊介绍：
Protein & Peptide Letters publishes letters, original research papers, mini-reviews and guest edited issues in all important aspects of protein and peptide research, including structural studies, advances in recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, and drug design. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallization and preliminary structure determination of biologically important proteins are considered only if they include significant new approaches or deal with proteins of immediate importance, and preliminary structure determinations of biologically important proteins. Purely theoretical/review papers should provide new insight into the principles of protein/peptide structure and function. Manuscripts describing computational work should include some experimental data to provide confirmation of the results of calculations.
Protein & Peptide Letters focuses on:
Structure Studies
Advances in Recombinant Expression
Drug Design
Chemical Synthesis
Function
Pharmacology
Enzymology
Conformational Analysis
Immunology
Biotechnology
Protein Engineering
Protein Folding
Sequencing
Molecular Recognition
Purification and Analysis
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