The effect of lentivirus-mediated SIRT1 gene knockdown in the ATDC5 cell line via inhibition of the Wnt signaling pathway.

SIRT1 is a highly conserved type III acetyltransferase gene located on chromosome 10 in mammals that belong to the Sirtuins family. In order to explore the effects of the SIRT1 gene in the ATDC5 cell line, an RNAi SIRT1 target sequence was designed and synthesized, aimed to knockdown the expression of SIRT1 in ATDC5 by a lentivirus. Gene chip, qrt-PCR, and WES analyses were used to detect the expression of SIRT1 and changes to the Wnt signaling pathway, while detecting any changes in proliferation and differentiation factors. The results showed that the expressions of the SIRT1 gene, mRNA, and protein were lower after transfection of the RNAi SIRT1sequence into ATDC5 cells. The Wnt signaling pathway, especially the classical pathway, was inhibited by the knockdown of SIRT1. The cartilaginous proliferation and differentiation of ATDC5 cells were simultaneously inhibited, and apoptosis was accelerated. In summary, knocking down SIRT1 gene increased the degeneration of ATDC5 cells via inhibiting the Wnt signaling pathway. We also found some novel factors related to the Wnt signaling pathway after SIRT1 gene knockdown (BIRC3, IL1RAP, PPP3CA, PPP2R2A, PPP2R5E, GSN, PPP2R1B, etc), which might provide new clues in disease research related to chondrocyte degeneration.