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Loro E, Ramaswamy G, Chandra A, Tseng WJ, Mishra MK, Shore EM, Khurana TS. IL15RA is required for osteoblast function and bone mineralization. Bone 2017; 103:20-30. [PMID: 28602725 PMCID: PMC5598756 DOI: 10.1016/j.bone.2017.06.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022]
Abstract
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.
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Affiliation(s)
- Emanuele Loro
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Girish Ramaswamy
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Abhishek Chandra
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA; Division of Geriatric Medicine and Gerontology, Mayo Clinic, Rochester, MN, USA
| | - Wei-Ju Tseng
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Manoj K Mishra
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Eileen M Shore
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Tejvir S Khurana
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Bae JS, Shim SH, Hwang SD, Kim JW, Park DW, Park CI. Molecular cloning and expression analysis of interleukin (IL)-15 and IL-15 receptor α from rock bream, Oplegnathus fasciatus. Fish Shellfish Immunol 2013; 35:1209-1215. [PMID: 23911652 DOI: 10.1016/j.fsi.2013.07.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/19/2013] [Accepted: 07/24/2013] [Indexed: 06/02/2023]
Abstract
Mammalian interleukin (IL)-15 plays an important role in the activation of CD8(+) T cells and natural killer (NK) cells along with its receptor α (IL-15Rα). To understand the potential roles of IL-15 and IL-15Rα in fish, we identified IL-15 and IL-15Rα cDNA from rock bream (Oplegnathus fasciatus) and investigated their gene expression profiles after bacterial and viral infection. Coding regions of rock bream (Rb) IL-15 and RbIL-15Rα cDNAs were 534 and 402 bp encoding 177 and 133 amino acid residues, respectively. The sushi domain of IL-15Rα was highly conserved between rock bream and other species. Unlike other IL-15Rαs, RbIL-15Rα does not have a transmembrane region. Gene expression of RbIL-15 and RbIL-15Rα was widely expressed in different tissues of healthy fish, especially immune-related tissues. RbIL-15 and RbIL-15Rα were highly induced in the kidney and spleen after infection with Edwardsiella tarda, Streptococcus iniae and red seabream iridovirus. Gene expression patterns of RbIL-15 and RbIL-15Rα were similar in the kidney and spleen after pathogen infection. However, these genes were differentially induced in the liver after pathogen infection. These results suggest that the different responses of RbIL-15 and RbIL-15Rα to pathogen infection may be induced by different tissues or cell types.
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Affiliation(s)
- Jin-Sol Bae
- Department of Marine Biology & Aquaculture, College of Marine Science, Gyeongsang National University, 445, Inpyong-dong, Tongyeong, Gyeongnam 650-160, Republic of Korea
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