1. MicroRNA-221 protects myocardial contractility in myocardial ischemia/reperfusion injury through phospholamban.
- Author
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Li H, Qiu J, Liu C, Yu G, Wu D, Chu Y, and Wang K
- Subjects
- Animals, Mice, Male, Calcium metabolism, Apoptosis, Sarcoplasmic Reticulum Calcium-Transporting ATPases metabolism, Sarcoplasmic Reticulum Calcium-Transporting ATPases genetics, Myocytes, Cardiac metabolism, Myocytes, Cardiac pathology, Caspase 3 metabolism, Caspase 3 genetics, Disease Models, Animal, Ryanodine Receptor Calcium Release Channel metabolism, Ryanodine Receptor Calcium Release Channel genetics, MicroRNAs genetics, MicroRNAs metabolism, Calcium-Binding Proteins metabolism, Calcium-Binding Proteins genetics, Myocardial Reperfusion Injury metabolism, Myocardial Reperfusion Injury genetics, Myocardial Reperfusion Injury pathology, Myocardial Contraction, Myocardium metabolism, Myocardium pathology
- Abstract
Objective: To investigate the effects and mechanisms of miRNA 221 on myocardial ischemia/reperfusion injury (MIRI) in mice through the regulation of phospholamban (PLB) expression., Methods: The MIRI mouse model was created and mice were divided into sham, MIRI, MIRI+ 221, and MIRI+ scr groups, with miRNA 221 overexpression induced in the myocardium of MIRI mice by targeted myocardial injection. Quantitative RT-PCR analysis was performed to observe the variation in miRNA 221, PLB, SERCA2, RYR2, NCX1, Cyt C and caspase 3 mRNA levels in myocardium, while Western blot assessed the levels of PLB, p-PLB (Ser16), p-PLB (Thr17), SERCA2, RYR2, NCX1, Cyt C and caspase 3 proteins. Changes in the structural integrity of the mouse heart were identified with HE and MASSON staining, while TUNEL staining was used to evaluate the TUNEL-positive cells of cardiomyocytes. Changes in myocardium calcium concentration were detected with reagent kits and the targeting interaction between miRNA 221 and PLB was evaluated using a luciferase reporter assay., Results: In the myocardium of MIRI mice, miRNA 221 level was significantly reduced, while the levels of PLB, p-PLB (Ser16), p-PLB (Thr17), and apoptosis-related genes caspase 3, and Cyt C were increased markedly, as well as calcium levels in myocardium. Following the overexpression of miRNA 221 in myocardium, there was a marked alleviation of myocardial injury and cardiomyocyte apoptosis and necrosis, significant enhancement of left ventricular systolic function, and marked decrease in the levels of PLB, p-PLB (Ser16), p-PLB (Thr17), caspase 3 and Cyt C, as well as a significant decrease in total calcium levels in myocardium., Conclusions: miRNA 221 can alleviate myocardial injury in mouse myocardial ischemia/reperfusion by suppressing the expression of PLB, thus reducing calcium overload in myocardium., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2025
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