An Emerging Role for isomiRs and the microRNA Epitranscriptome in Neovascularization

Abstract

Therapeutic neovascularization can facilitate blood flow recovery in patients with ischemic cardiovascular disease, the leading cause of death worldwide. Neovascularization encompasses both angiogenesis, the sprouting of new capillaries from existing vessels, and arteriogenesis, the maturation of preexisting collateral arterioles into fully functional arteries. Both angiogenesis and arteriogenesis are highly multifactorial processes that require a multifactorial regulator to be stimulated simultaneously. MicroRNAs can regulate both angiogenesis and arteriogenesis due to their ability to modulate expression of many genes simultaneously. Recent studies have revealed that many microRNAs have variants with altered terminal sequences, known as isomiRs. Additionally, endogenous microRNAs have been identified that carry biochemically modified nucleotides, revealing a dynamic microRNA epitranscriptome. Both types of microRNA alterations were shown to be dynamically regulated in response to ischemia and are able to influence neovascularization by affecting the microRNA’s biogenesis, or even its silencing activity. Therefore, these novel regulatory layers influence microRNA functioning and could provide new opportunities to stimulate neovascularization. In this review we will highlight the formation and function of isomiRs and various forms of microRNA modifications, and discuss recent findings that demonstrate that both isomiRs and microRNA modifications directly affect neovascularization and vascular remodeling.

Current Status of Angiogenic Cell Therapy and Related Strategies Applied in Critical Limb Ischemia

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miR-24 Targets the Transmembrane Glycoprotein Neuropilin-1 in Human Brain Microvascular Endothelial Cells

“…MicroRNAs (miRNAs, miRs) are small non-coding RNAs involved in post-transcriptional gene regulation [ 9 , 10 , 11 , 12 ]. They play crucial regulatory roles in a number of biological processes [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”

Critical roles of microRNA-141-3p and CHD8 in hypoxia/reoxygenation-induced cardiomyocyte apoptosis

“…MicroRNAs (miRNAs) are small, highly conserved, and non-coding RNA, which containing approximately 22 nucleotides [8][9][10]. MiRNAs promote the degradation of mRNA or inhibit the translation of mRNA by targeting the 3′ untranslated region of mRNA, thereby regulating gene expression at post-transcriptional level [10][11][12].…”