Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


The Profile of miRNA Expression during the Differentiation of Murine Osteoclast.

Ahn1,  Inhye E., Ju2,  Ji Hyeon, Park3,  Jin Sil

Department of Internal Medicine, The Methodist Hospital, Houston, TX
Division of Rheumatology, Department of Internal Medicine, Catholic University of Korea, Seoul, Korea, Republic of
Rheumatology Research Center, Catholic University of Korea, Seoul, Korea, Republic of

Objectives:

By identifying chronological patterns of miRNA expression during the differentiation of murine osteoclast, this study aimed to reveal clusters of non-coding genes involved in the regulation of bone metabolism.

Methods:

Murine bone marrow-derived monocytes were stimulated with M-CSF only or with the combination of RANKL. Cultured cells were harvested at the designated time points critical for osteoclastogenesis, which ranged from the 24-hour after the monocyte culture, at the point of precursor cells (day 3), when cell-to-cell fusion occurred (day 5), and when mature osteoclasts were formed (day 7). Isolated miRNA underwent microarray analysis. Types and patterns of miRNA expression were compared between two stimulation groups and also between chronological points within each stimulation group.

Results:

At the point of cell fusion, six miRNAs were identified to be expressed significantly higher in monocytes stimulated with both M-CSF and RANKL than in those with M-CSF only (p<0.05). This number of differentially expressed genes between two stimulation groups increased to 35 as osteoclast matured. Patterns of miRNA expression in M-CSF plus RANKL-stimulated monocytes were categorized into nine clusters by K-mean clustering analysis.

Figure 1. Patterns of gene expression patterns during the differentiation of osteoclast stimulated with M-CSF plus RANKL. Critical time points for osteoclastogenesis were designated for analysis, which ranged from the 24-hour after the monocyte culture (day 0), at the point of precursor cells (day 3), when cell-to-cell fusion occurred (day 5), and when mature osteoclasts were formed (day 7).

In all clusters, the most distinctive change of differential gene expression was observed during cell fusion. Two clusters showed declining patterns throughout the differentiation which included miR-20b, 92a, 93, 130b, 450a and 709.

Conclusion:

The number of differentially expressed genes in murine osteoclastogenesis increased as cell maturation progressed. The most critical time point with marked changes in miRNA expression was when cell fusion occurred.

To cite this abstract, please use the following information:
Ahn, Inhye E., Ju, Ji Hyeon, Park, Jin Sil; The Profile of miRNA Expression during the Differentiation of Murine Osteoclast. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :842
DOI: 10.1002/art.28610

Abstract Supplement

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