The novel tRF-23 promotes osteogenic differentiation of hBMSCs and protects against bone loss in ovariectomized mice

The pathogenesis of osteoporosis is closely related to the impaired human bone marrow-derived stromal cells (hBMSCs) osteogenic differentiation. No studies to date, however, have established whether tRNA-derived fragments (tRFs) can influence osteogenic differentiation of hBMSCs or the onset of osteoporosis. Here, tRF-23 was found to control hBMSC osteogenesis through its ability to target suppressor of cytokine signaling 1 (SOCS1) via the Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3) signaling pathway. tRF-23 was then further established as a potential target for efforts to protect against bone loss and marrow adipose tissue (MAT) accumulation in osteoporotic model mice, and its molecular mechanism was also verified in vivo. Together, these results suggest a model in which tRF-23 can protect against bone loss induced by ovariectomized (OVX) through the augmentation of hBMSC osteogenesis, providing a foundation for further characterizing the pathogenesis of osteoporosis and seeking new therapeutic targets for this disruptive condition. After using Trim Galore to remove any low-quality reads and adapter sequences, the remaining sequences 12-50 nucleotides long were aligned with miRBase (http://www.mirbase.org/). Known miRNAs were identified with BWA followed by the alignment of unmapped reads to rRNAs (https://rnacentral.org/). An in-house tRNA sequence database (using sequences from http://gtrnadb.ucsc.edu/ and https://cm.jefferson.edu/MINTbase/) was then employed for analyses of all other reads that were unmapped. Intronic sequences were initially removed, followed by the addition of CCA to the end of all tRNA sequences. Ultimately, 50 genomic nucleotides were added behind these CCA residues, and the resulting sequences were selected as possible tRFs, followed by classification with tRFdb (http://genome.bioch.virginia.edu/trfdb/) and MINTBase (https://cm.jefferson.edu/MINTbase/). Differentially expressed tRFs during osteogenesis (at days 0, 7, 14 and 21 of osteogenic differentiation) were identified with the EB-Seq algorithm based on the following criteria: fold change > 2 or < 0.5 and P < 0.05, FDR < 0.05. The miRanda and RNAhybrid tools were used to identify predicted targets of these tRFs of interest.