Novel insights into the roles of tRNA-derived small RNAs.

tRNA-derived small RNA (tsRNA) is a novel class of non-coding RNA that is usually produced from tRNA following endonuclease cleavage which occurs under stress conditions. There are two types of tsRNAs: tRNA-derived fragments (tRFs) and stress-induced tRNA halves (tiRNAs), which differ in their cleavage position. Many studies have demonstrated that tsRNAs are involved in various physiological and pathological processes apart from cancer and gene expression. In this review, we briefly described the biogenesis, classification, and characteristics of tsRNAs and summarized the current research progress of tsRNAs in metabolic diseases, senescence, reproduction, stress, and organ injury, and finally put forward some problems to be solved.