Downregulation of miR-21 gene expression by CRE-Ter to modulate osteoclastogenesis: De Novo mechanism

• Published in: Biochemistry and biophysics reports Vol. 26; p. 101002
• Main Authors: Pengjam, Yutthana, Prajantasen, Thanet, Tonwong, Natda, Panichayupakaranant, Pharkphoom
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-07-2021; Elsevier
• Subjects: Akt; CRE-Ter; miR-21; NFκB; Osteoclastogenesis; Osteoclastogenesis; CRE-Ter; miR-21; Akt; NFκB
• ISSN: 2405-5808; 2405-5808
• DOI: 10.1016/j.bbrep.2021.101002

miR-21 expression stimulates osteoclast cells in the context of osteoclastogenesis. A previous report showed that NFκB-miR-21 pathway could serve as an innovative alternative to devise therapeutics for healing diabetic ulcers. Furthermore, our study demonstrated that a highly water-soluble curcuminoids-rich extract (CRE-Ter) inhibits osteoclastogenesis through NFκB pathway. The interplay between miR-21 and CRE-Ter in osteoclastogenesis has not yet been investigated. In this study, we examined the relation of CRE-Ter and miR-21 gene expression in receptor of the nuclear factor κB (NFκB) ligand (RANKL) - induced murine monocyte/macrophage RAW 264.7 cells, osteoclast cells, in osteoclastogenesis. Effect of CRE-Ter on generation of intracellular reactive oxygen species (ROS) was estimated by dichlorofluorescein diacetate (DCFH-DA). The results reveal that CRE-Ter reduced expression levels of miR-21 gene in osteoclasts. The inhibitory effects of CRE-Ter on in vitro osteoclastogenesis were evaluated by reduction in tartrate-resistant acid phosphatase (TRAP) content, and by reduction in expression levels of an osteoclast-specific gene, cathepsin K. Treatment of the osteoclast cells with CRE-Ter suppressed RANKL-induced NFκB activation including phospho-NFκB-p65, and phospho IκBα proteins. Western blot analysis revealed that NFκB inhibitor up-regulated CRE-Ter-promoted expression of phospho-NFκB-p65. In addition, CRE-Ter dose-dependently inhibited phospho-Akt expression. CRE-Ter also dose-dependently reduced DNA binding activity of NFκB and Akt as revealed by EMSA. ChIP assay revealed binding of NFκB-p65 to miR-21 promoters. In conclusion, our results demonstrate that CRE-Ter downregulates miR-21 gene expression in osteoclasts via a de novo mechanism, NFκB- Akt-miR-21 pathway.