GSE121320
Zscan10 suppresses osteoclastgenesis by regulating expression of osteoclast differentiation inhibitory factors
Zinc finger and SCAN domain containing 10 (Zscan10) was identified as a novel transcription factor in osteoclast differentiation by our previous study. However, the biological functions of Zscan10 have not been fully understood except its role in maintenance of genome stability and pluripotency in embryonic stem cells. Therefore, the purpose of this study is clarification of Zscan10 function in somatic cells, especially during osteoclast differentiation. First, Zscan10 KO RAW264 (KO) cells were established using CRISPR/Cas9 system and single cell sorting. Then, Control (Ctrl) and KO cells were differentiated into osteoclast by RANKL stimulation. As a result, TRAP activity and expression levels of differentiation marker genes, such as Nfatc1, were significantly increased and the expression of inhibitory factors, such as Irf8, was decreased in KO cells as compared to Ctrl cells. These results suggested that Zscan10 might regulate transcription of the genes which negatively control osteoclastogenesis. To understand the transcriptomes controlled by Zscan10, RNA-seq was performed and the stringent analyses identified significantly down-regulated Haptoglobin (Hp) in KO cells. Additionally, Zscan10 binding sequence was located near the genomic region of Hp gene locus. ChIP against Zscan10 followed by qPCR for the region revealed that Zscan10 binds to the region located near Hp gene locus and transcript start site, suggesting that Zscan10 may regulate transcription of Hp. Next, to examine the effect of Hp under Zscan10 mediated osteoclastogenesis, KO cells were treated with recombinant Hp (rHp). As a result, Hp treatment could suppress the elevated TRAP activity of KO cells without affecting cell viability. Furthermore, Hp KO mice exhibit decreased bone mass and increased osteoclast number, and Hp has been reported to be involved in suppression of osteoclastogenesis. Also, In hemolytic disease, Hp had been decreased and also bone density. These facts suggested that Zscan10 negatively regulates osteoclast differentiation through transcription of Hp. Overall design: mRNA profiles of Control and Zscan10 KO cells established by CRISPR/Cas9 system with RAW264 cells were generated by deep sequencing, in triplicate, using Illumina Miseq.