Abstract: Objective Study whether the transfer RNA (tRNA) derived fragments (tRFs) was expression in myocardium. Methods The anterior wall of left ventricle tissues which are matched to infarct zone and border zone were isolated and extracted the total RNA. The small RNA sequencing was conducted by the illumina sequencer. The sequences and dosage of expression were acquired. The software of Fastax and Bowtie, and perl language program were applied to annotate small RNAs with length between 30 and 36nt and compare the difference between the two area cardiac tissues. Results The tRFs were found to be expressed in the anterior wall of left ventricle tissues which are matched to infarct zone and border zone. In addition, it was found that the percentage of tRFs in matched to infarct zone and border zone was 9.15% and 7.30% comparing with total small RNA. The identified 28 tRFs and their expression are similar between the two areas. The percentage of two tRFs, GlyGC and ValCAC, were 84.73％和84.66％ between the two areas. The expression difference between each tRFs in two areas was less than 4%. Conclusions tRFs were expressed in myocardium. The expressional profile of tRFs in the myocardial tissues which are matched to infarct zone and border zone in myocardium was similar.

Key words: tRFs, small RNAs, left ventricular free wall, myocardial infarction