RANKL interferes with osteoclastogenesis in PEG-fused U937 cells through LGR4

ABSTRACT

Introduction

RANKL plays an important role in the differentiation and maturation process of preosteoclast cells. The osteoclast is a multinucleated cell that can have various sizes and a variable number of nuclei. However, there are no models that allow us to understand how successive cell fusions have a limit, or how cell fusion is regulated.

Methodology

The present investigation was aimed to determine whether fusing U937 cells with PEG to generate osteoclast-like cells expresses LGR4 and whether applying RANKL to these cells modifies osteoclastic activity compared to non-PEG-fused and RANKL-treated cells.

Results

By fusing U937 cells with PEG, it was found that the LGR4 receptor expression was promoted as early as 24 hours of culture. Applying RANKL before or after fusion inhibits osteoclastic activity. Interfering RANKL interaction with LGR4 in PEG-treated cells recovers and increases cell fusion and osteoclastic activity. PEG-fused U937 cells show osteoclast markers similar to those observed in the classical RANKL-stimulated cell model.

Conclusion

Our model allows us to understand that RANKL has fusogenic activity during the first days of culture and in fused cells modulates fusion, contributing to differentiate the role of RANKL before and after fusion through LGR4.

KEYWORDS:

• Osteoclast
• LGR4
• RANKL
• cell fusion
• PEG

Acknowledgments

Regarding the authorship of the manuscript, we declare that Juan A. Arteaga contribute to conducting experiments, analysis, and interpretation of data, and writing of paper draft; Guerrero CA contributes to conception and design of the study, and analysis and interpretation of data.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03008207.2022.2090350.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.