Zhang Xiaoming, McLendon Jared M, Peck Bailey D, Chen Biyi, Song Long-Sheng, Boudreau Ryan L
Department of Internal Medicine, Fraternal Order of Eagles Diabetes Research Center, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
Mol Ther Nucleic Acids. 2023 Nov 17;34:102081. doi: 10.1016/j.omtn.2023.102081. eCollection 2023 Dec 12.
MicroRNAs (miRNAs) control the expression of diverse subsets of target mRNAs, and studies have found miRNA dysregulation in failing hearts. Expression of miR-29 is abundant in heart, increases with aging, and is altered in cardiomyopathies. Prior studies demonstrate that miR-29 reduction via genetic knockout or pharmacologic blockade can blunt cardiac hypertrophy and fibrosis in mice. Surprisingly, this depended on specifically blunting miR-29 actions in cardiomyocytes versus fibroblasts. To begin developing more translationally relevant vectors, we generated a novel transgene-encoded miR-29 inhibitor (TuD-29) that can be incorporated into a viral-mediated gene therapy for cardioprotection. Here, we corroborate that miR-29 expression and activity is higher in cardiomyocytes versus fibroblasts and demonstrate that TuD-29 effectively blunts hypertrophic responses in cultured cardiomyocytes and mouse hearts. Furthermore, we found that adeno-associated virus (AAV)-mediated miR-29 overexpression in mouse hearts induces early diastolic dysfunction, whereas AAV:TuD-29 treatment improves cardiac output by increasing end-diastolic and stroke volumes. The integration of RNA sequencing and miRNA-target interactomes reveals that miR-29 regulates genes involved in calcium handling, cell stress and hypertrophy, metabolism, ion transport, and extracellular matrix remodeling. These investigations support a likely versatile role for miR-29 in influencing myocardial compliance and relaxation, potentially providing a unique therapeutic avenue to improve diastolic function in heart failure patients.
微小RNA(miRNA)控制着多种靶mRNA子集的表达,研究发现衰竭心脏中存在miRNA失调。miR-29在心脏中表达丰富,随年龄增长而增加,且在心肌病中发生改变。先前的研究表明,通过基因敲除或药物阻断降低miR-29可减轻小鼠的心脏肥大和纤维化。令人惊讶的是,这取决于特异性地减弱心肌细胞和成纤维细胞中miR-29的作用。为了开始开发更具转化相关性的载体,我们构建了一种新型转基因编码的miR-29抑制剂(TuD-29),它可被整合到用于心脏保护的病毒介导基因治疗中。在此,我们证实miR-29在心肌细胞中的表达和活性高于成纤维细胞,并证明TuD-29可有效减轻培养的心肌细胞和小鼠心脏中的肥大反应。此外,我们发现腺相关病毒(AAV)介导的miR-29在小鼠心脏中过表达会诱导早期舒张功能障碍,而AAV:TuD-29治疗可通过增加舒张末期容积和每搏输出量来改善心输出量。RNA测序和miRNA-靶标相互作用组的整合揭示,miR-29调节参与钙处理、细胞应激和肥大、代谢、离子转运以及细胞外基质重塑的基因。这些研究支持miR-29在影响心肌顺应性和舒张方面可能具有多种作用,这可能为改善心力衰竭患者的舒张功能提供一条独特的治疗途径。