Identification of a cartilage specific novel miRNA which directly targets PRMT3 in rats.

UNLABELLED

Through experiments to testify a candidate novel miRNA previously discovered by us is a real miRNA and involved in cartilage development.

DESIGN

The and the newly hairpin miRNA transcribed sequence () was verified as a genuinely existing miRNA by northern blotting. The predicted secondary structure, sequence alignment and targets of were performed by "RNAstructure 5.3" program, LASTN2.8.0+/miRbase22 program and RNA hybird program, respective. GO/KEGG pathway analysis also were performed. The expression in cartilage tissue during development was detected by RT-qPCR and dot blotting. The chondrocyte differentiation model was established to examine whether is involved in cartilage development. The regulation of PRMT3 expression by novel miRNA was determined with the luciferase reporter gene assay and Western blotting after novel miRNA mimic or inhibitor transfection.

RESULTS

It's potential role in specifically regulating rodent cartilage development and associated cellular processes. Furthermore, the expression of protein arginine N-methyltransferase 3 (PRMT3), as a predicted target of the novel miRNA, was found consistently downregulated at rat cartilage during developmental stages and RCJ3.1C5.18 (C5.18) cells during the proliferating and hypertrophic phases of the cartilage development, where the expression was significantly up-regulated. Both the dual-luciferase reporter gene assay and the up- or down-regulation of suggest that the later can specifically bind with the .

CONCLUSION

Overall, this study provides the first comprehensive evidence that a genuine cartilage-specific novel miRNA directly targets PRMT3 and may regulate multitudinous cellular processes and signal transduction during cartilage development.