Ben Dou,
Xiaohui Wu,
Yisong Xie,
Hongliang Ruan,
Xiaolan Liu
Department of Orthopedics, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, Hunan 410005, China;
For correspondence:- Xiaolan Liu
Email: onorouj@yahoo.com Tel:+8613627489118
Accepted: 24 January 2020
Published: 29 February 2020
Citation:
Dou B, Wu X, Xie Y, Ruan H, Liu X.
Epigallocatechin gallate activates miR-193a-3p and protects mice against glucocorticoid-induced osteoporosis by targeting NFATC1 expression. Trop J Pharm Res 2020; 19(2):227-232
doi:
10.4314/tjpr.v19i2.2
© 2020 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..
Abstract
Purpose: To investigate the effect of epigallocatechin gallate (EGCG) on microRNAs in a mouse model of glucocorticoid-induced osteoporosis (GIOP), and the mechanism involved.
Methods: Osteoclast-specific marker mRNA expressions, receptor activator of nuclear factor kappa-B ligand (RANKL), receptor activator of nuclear factor κ B (RANK), and miRNA expressions were determined using reverse transcription polymerase chain reaction (RT-qPCR) analysis. Western blotting was used to assay protein expressions, while miRNA and 3’UTR interaction studies were carried out with reporter assay.
Results: Treatment with EGCG resulted in downregulation of glucocorticoid-induced expressions of RANKL, RANK and osteoclast-specific markers i.e. tumor necrosis factor receptor-associated factor 6, (TRAF6), nuclear factor of activated T cells 1 (NFATc1), cathepsin K, matrix metallopeptidase 9 (MMP9) and tartrate-resistant acid phosphatase (TRAP). Furthermore, EGCG treatment significantly reduced reactive oxygen species (ROS) levels and inflammatory cytokine expressions in GIOP mice. The expression of miRNA-targeting osteoclast marker mmu-mir-193-3p was significantly down-regulated in GIOP mice. However, EGCG treatment increased mmu-mir-193-3p expression and had specific interaction with NFATc1 3’UTR (3’-untranslated region). In vitro results showed that mmu-mir-193-3p mimics downregulated dexamethasone (DXM)-induced osteoclast-specific marker expressions.
Conclusion: These results show that EGCG exerts a protective role against GIOP by upregulating miR-193a-3p expressions.
Keywords: Epigallocatechin gallate, Glucocorticoids, RANKL, Osteoporosis