Purpose of Review: Small non-coding RNAs regulate gene expression and are highly implicated in heart failure. Recently, an additional level of post-transcriptional regulation has been identified,... Show morePurpose of Review: Small non-coding RNAs regulate gene expression and are highly implicated in heart failure. Recently, an additional level of post-transcriptional regulation has been identified, referred to as the epitranscriptome, which encompasses the body of post-transcriptional modifications that are placed on RNA molecules. In this review, we summarize the current knowledge on the small non-coding RNA epitranscriptome in heart failure. Recent Findings: With the rise of new methods to study RNA modifications, epitranscriptome research has begun to take flight. Over the past 3 years, the number of publications on the epitranscriptome in heart failure has significantly increased, and we expect many more highly relevant publications to come out over the next few years. Currently, at least six modifications on small non-coding RNAs have been investigated in heart failure-relevant studies, namely N6-adenosine, N5-cytosine and N7-guanosine methylation, 2'-O-ribose-methylation, adenosine-to-inosine editing, and isomiRs. Their potential role in heart failure is discussed. Show less
Cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and thus, novel therapies are required. CVDs generally result in local shortages in the blood supply, known as ischemia.... Show moreCardiovascular diseases (CVDs) remain the leading cause of death worldwide, and thus, novel therapies are required. CVDs generally result in local shortages in the blood supply, known as ischemia. Neovascularization is the body's innate response mechanism that stimulates the restoration of blood flow to ischemic tissues. During the last decade, microRNAs have emerged as critical regulators of both CVD and neovascularization. Recent studies demonstrated that microRNAs are altered in many ways; however, whether these microRNA modifications could be physiologically relevant remained unclear. We examined whether specific microRNAs with a known cardiovascular function are subject to particular microRNA-alterations and if they could be relevant in cardiovascular disease. Our experiments demonstrated that the level of specific microRNA alterations, including isomiR formation, adenosine-to-inosine editing, and N6-adenosine methylation, changed in response to cardiovascular pathology. Many of these alterations changed the microRNAs function, which had a direct effect on processes like neovascularization. For example, microRNA adenosine-to-inosine editing increased after ischemia in both mice and humans and promoted neovascularization. These findings suggest that microRNA modifications can potentially be harnessed as a biomarker for cardiovascular disease, or even a novel therapeutic target. Show less