Inhibitory Effects of Astaxanthin on CML-HSA-Induced Inflammatory and RANKL-Induced Osteoclastogenic Gene Expression in RAW 264.7 Cells.

A N M Mamun-Or-Rashid,Tanzima Tarannum Lucy,Masayuki Yagi,Yoshikazu Yonei

doi:10.3390/biomedicines10010054

A N M Mamun-Or-Rashid, Tanzima Tarannum Lucy + Show 2 more

Open Access

https://doi.org/10.3390/biomedicines10010054

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Journal: Biomedicines	Publication Date: Dec 27, 2021
Citations: 8	License type: CC BY 4.0

Affiliation: Doshisha University

Abstract

Objective: Elevated levels of serum Nε-carboxymethyllysine (CML), a well-known advanced glycation end-product (AGE), were observed in patients with inflammation or osteoporosis. Astaxanthin was reported to possess anti-inflammatory and antioxidant effects. In the present study, we investigated the effects of commercially available dietary supplement AstaReal ACTR (ASR) capsule content as astaxanthin on CML-HSA-induced inflammatory and receptor activator of nuclear factor-kappa-Β ligand (RANKL)-induced osteoclastogenic gene expression. Methods: RAW 264.7 murine macrophage cells were stimulated with CML-HSA to trigger inflammatory gene expression and treated with either a vehicle control or varied concentrations of astaxanthin. Inflammatory gene expression was measured using an enzyme-linked immunosorbent assay (ELISA) or qPCR. We triggered osteoclastogenesis using RANKL, and osteoclastogenic gene expression was measured through tartrate-resistant acid phosphatase (TRAP) activity, staining, immunofluorescence, and qPCR analyses. Results: CML-HSA showed a stimulatory effect on inflammatory gene expression, and astaxanthin reduced the expression by at least two-fold. The levels of autoinflammatory gene expression were reduced by astaxanthin. The RANKL-induced osteoclastogenesis was significantly inhibited by astaxanthin, with reductions in the activation of nuclear factor-κB (NF-κB), the expression of NFATc1 (nuclear factor of activated T cells 1), multinucleated cell formation, and the expression of mature osteoclast marker genes. Conclusion: Astaxanthin has potential as a remedy for CML-HSA-induced inflammation and RANKL-induced excessive bone loss.

Highlights

Inflammatory cytokines play a crucial role in inducing bone loss, resulting in bone diseases, such as osteoporosis [1], rheumatoid arthritis (RA) [2], osteoarthritis [3], periodontitis [4], and so on
receptor activator of nuclear factor-kappa-B ligand (RANKL) is a member of the family of tumor necrosis factors, which binds to its receptor
We investigated the impact of ASR supplements on CML-HSA-induced inflammatory gene expression and RANKL-induced osteoclastogenic gene expression in RAW 264.7 cells

Summary

Introduction

Inflammatory cytokines play a crucial role in inducing bone loss, resulting in bone diseases, such as osteoporosis [1], rheumatoid arthritis (RA) [2], osteoarthritis [3], periodontitis [4], and so on. The tumor necrosis factor alpha (TNFα) [5,6,7], Interleukin (IL)-1 family [8,9,10,11], and IL-6 [12,13,14,15] are reported to be directly or indirectly involved in inducing osteoclast formation and bone resorption by upregulating RANKL and other osteoclastinducing factors that are usually secreted by osteoblasts and osteocytes and are expressed highly by the lymph nodes, thymus, and lungs and indigently by the spleen, bone marrow, peripheral blood, placenta, thyroid, leucocytes, stomach, skeletal muscle, and heart [16]. To maintain the integrity of the bone tissue, a balance between the activities of osteoblasts and osteoclasts is critical. It has been observed in osteoporosis-like diseases that bone resorption exceeds bone formation, leaving the bone weaker, fragile, and prone to fracture resulting from minor trauma [1]

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