IL15RA is required for osteoblast function and bone mineralization. Bone 2017 Oct;103:20-30
Date
06/13/2017Pubmed ID
28602725Pubmed Central ID
PMC5598756DOI
10.1016/j.bone.2017.06.003Scopus ID
2-s2.0-85020916567 (requires institutional sign-in at Scopus site) 30 CitationsAbstract
Interleukin-15 receptor alpha (IL15RA) is an important component of interleukin-15 (IL15) pro-inflammatory signaling. In addition, IL15 and IL15RA are present in the circulation and are detected in a variety of tissues where they influence physiological functions such as muscle contractility and overall metabolism. In the skeletal system, IL15RA was previously shown to be important for osteoclastogenesis. Little is known, however, about its role in osteoblast function and bone mineralization. In this study, we evaluated bone structural and mechanical properties of an Il15ra whole-body knockout mouse (Il15ra-/-) and used in vitro and bioinformatic analyses to understand the role IL15/IL15RA signaling on osteoblast function. We show that lack of IL15RA decreased bone mineralization in vivo and in isolated primary osteogenic cultures, suggesting a cell-autonomous effect. Il15ra-/- osteogenic cultures also had reduced Rankl/Opg mRNA ratio, indicating defective osteoblast/osteoclast coupling. We analyzed the transcriptome of primary pre-osteoblasts from normal and Il15ra-/- mice and identified 1150 genes that were differentially expressed at a FDR of 5%. Of these, 844 transcripts were upregulated and 306 were downregulated in Il15ra-/- cells. The largest functional clusters, highlighted using DAVID analysis, were related to metabolism, immune response, bone mineralization and morphogenesis. The transcriptome analysis was validated by qPCR of some of the most significant hits. Using bioinformatic approaches, we identified candidate genes, including Cd200 and Enpp1, that could contribute to the reduced mineralization. Silencing Il15ra using shRNA in the calvarial osteoblast MC3T3-E1 cell line decreased ENPP1 activity. Taken together, these data support that IL15RA plays a cell-autonomous role in osteoblast function and bone mineralization.
Author List
Loro E, Ramaswamy G, Chandra A, Tseng WJ, Mishra MK, Shore EM, Khurana TSMESH terms used to index this publication - Major topics in bold
AnimalsCalcification, Physiologic
Gene Expression Regulation
Interleukin-15 Receptor alpha Subunit
Male
Mice
Mice, Knockout
Osteoblasts
Osteogenesis
