Inhibition of RANKL-induced osteoclast differentiation through the downregulation of c-Fos and NFATc1 by Eremochloa ophiuroides (centipedegrass) extract

Abstract

Osteoclasts, derived from hematopoietic stem cells, are specialized macrophages and have a homeostatic role in skeletal modeling and remodeling with bone-forming osteoblasts. However, excessive osteoclast activity induces bone diseases, including osteoporosis, periodontitis and rheumatoid arthritis. Natural substances have received attention as therapeutic drugs in human diseases. In the current study, cells isolated from mouse bone marrow, and a mouse model, were used to determine the effect of centipedegrass extract (CGE) on osteoclasts. Multiple concentrations of CGE were administered to bone marrow cells for 24‑72 hours and, for the in vivo study, mice were treated with CGE for 8 days. The effects of CGE on transcription and translation of osteoclast-associated molecules were then determined using reverse transcription-polymerase chain reaction and immunoblotting, respectively. In the present study it was shown that CGE extracted from Eremochloa ophiuroides (centipedegrass) inhibited receptor activator of nuclear factor κ‑B ligand (RANKL)‑mediated osteoclast differentiation in bone marrow macrophages, without cytotoxicity, in a dose‑dependent manner. CGE decreased the expression levels of osteoclast‑specific genes, including matrix metalloproteinase‑9, osteoclast‑associated immunoglobulin‑like receptor and cathepsin K, however, CGE had no inhibitory effect on the expression levels of mitogen‑activated protein kinases, nuclear factor‑κB and Akt. Furthermore, the protein and RNA levels of RANKL‑induced c‑Fos and nuclear factor of activated T-cell cytoplasmic 1 were suppressed by CGE. These results indicated that CGE may serve as a useful drug in the prevention of bone loss.

Leonurus�sibiricus L. ethanol extract promotes osteoblast differentiation and inhibits osteoclast formation

“…OSCAR is specifically expressed in early stage osteoclasts or in mature osteoclasts, and induces calcium activation to assist in the expression of RANKL-mediated NFATc1 (54). Similar to these results, the majority of osteoclast inhibition studies have reported that osteoclast-related genes are decreased by reduction of c-Fos and NFATc1 (55,56). OC-STAMP and ATP6v0d2 are expressed when the osteoclast precursor cells are fused, and when it is deficient, differentiation into osteoclasts is not completed.…”

Auraptene ameliorates osteoporosis by inhibiting RANKL/NFATc1 pathway-mediated bone resorption based on network pharmacology and experimental evaluation

“…32 DC-STAMP is a key regulator of the cell fusion of osteoclasts controlled by NFATc1. 33 Then, osteoclasts attach to the bone matrix containing type 1 collagen and noncollagenous proteins. 34 In the process of mature osteoclast-mediated bone resorption, transcription of NFATc1 upregulates the release of osteoclast-related genes including CTS-K, TRAP, and MMP-9.…”

N-[2-(4-Acetyl-1-Piperazinyl)Phenyl]-2-(3-Methylphenoxy)Acetamide (NAPMA) Inhibits Osteoclast Differentiation and Protects against Ovariectomy-Induced Osteoporosis

“…Similarly, Choi et al also reported that the CGE extract did not inhibit the MAPK and NF-kB signaling pathways, but suppressed RANKL-induced c-Fos and NFATc1. It also affected the expression of osteoclast-related genes, such as OSCAR , MMP9 , and cathepsin K [ 44 ].…”