Global Profile of tRNA-Derived Small RNAs in Pathological Cardiac Hypertrophy Plasma and Identification of tRF-21-NB8PLML3E as a New Hypertrophy Suppressor

Background: It remains unclear whether transfer RNA-derived small RNAs (tsRNAs) play a role in pathological cardiac hypertrophy (PCH). We aimed to clarify the expression profile of tsRNAs and disclose their relationship to the clinical phenotype of PCH and the putative role. Methods: Small RNA sequencing was performed in the plasma of PCH patients and healthy volunteers. In a larger sample size and angiotensin Ⅱ (Ang II)-stimulated H9c2 cells, the data were validated by real-time qPCR. The atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were examined in Ang II-stimulated H9c2 cells. The role of tsRNAs in the pathogenesis of PCH was explored by bioinformatics analysis. Results: A total of 4185 differentially expressed tsRNAs were identified, of which 4 and 5 tsRNAs were observed to be significantly differentially upregulated and downregulated expressed. Of the 5 down-regulated tsRNAs, 4 of them were verified to be significantly down-regulated in the larger sample group, among which tRF-30-3JVIJMRPFQ5D, tRF-16-R29P4PE, tRF-21-NB8PLML3E, and tRF-21-SWRYVMMV0 had areas under the curve to diagnose concentric hypertrophy. The 4 down-regulated tsRNAs were negatively correlated with left ventricular posterior wall dimensions in PCH patients (r=-0.4227; r=-0.4517; r=-0.5567; r=-0.4223). The levels of ANP and BNP as well as cell size were decreased in Ang II-stimulated H9c2 cells with 21-NB8PLML3E mimic transfection. Bioinformatics analysis revealed that the target genes of tRF-21-NB8PLML3E were mainly enriched in the metabolic pathway and involved in the regulation of ribosomes. Conclusion: The plasma tsRNAs tRF-21-NB8PLML3E might be considered biomarkers in patients with PCH with early screening potential.