title: Effects of interleukin-11 on the expression of human bone sialoprotein gene.
abstract: Interleukin-11 (IL-11) is a bone marrow stromal fibroblast-derived cytokine with a wide spectrum of activities in different biological systems. IL-11 and IL-6 are two cytokines known to rely on osteoblast-osteoclast communication for their effects on osteoclast differentiation. Bone sialoprotein (BSP) is a mineralized connective tissue-specific protein expressed in differentiated osteoblasts, odontoblasts, and cementoblasts. To determine the molecular basis of the transcriptional regulation of the human BSP gene by IL-11, we conducted real-time polymerase chain reactions (PCR), transient transfection analyses with chimeric constructs of the human BSP gene promoter linked to a luciferase reporter gene, gel mobility shift assays, and a chromatin immunoprecipitation assay using human osteoblast-like Saos2 cells. IL-11 (20 ng/ml) increased BSP, Runx2, and Osterix mRNA levels at 6 h and the alkaline phosphatase (ALP) mRNA level at 12 h in osteoblast-like Saos2 cells. In a transient transfection assay, IL-11 (20 ng/ml, 12 h) increased luciferase activities of constructs between -60LUC and -868LUC including the human BSP gene promoter. Transcriptional stimulations by IL-11 were partially inhibited in the constructs that included 2-bp mutations in the cAMP response element 1 (CRE1, -72 to -79) and CRE2 (-667 to -674). When mutations were made in pairs of CRE1 and CRE2 in -868LUC, the effect of IL-11 on luciferase activity was almost totally abrogated. Transcriptional activities induced by IL-11 were inhibited by protein kinase A, tyrosine kinase, ERK1/2, and PI3-kinase inhibitors. Gel mobility shift analyses showed that IL-11 increased nuclear proteins binding to CRE1 and CRE2. CREB1, phospho-CREB1, c-Fos, and c-Jun antibodies disrupted the formation of CRE1 and CRE2 protein complexes. These data demonstrate that IL-11 stimulates BSP gene transcription via CRE1 and CRE2 elements in the human BSP gene promoter.
authors.affiliation: Department of Periodontology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, 271-8587, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Matsumura
authors.forename: Yohei
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Hideki
authors.initials: H
authors.lastname: Takai
authors.forename: Yorimasa
authors.initials: Y
authors.lastname: Ogata
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics; D002460:Cell Line; D000242:Cyclic AMP / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000235:genetics*; D017370:Interleukin-11 / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010006:Osteoblasts / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D014162:Transfection / Q000379:methods
chemical_list: C508611:IL11 protein, human; D058574:Integrin-Binding Sialoprotein; D017370:Interleukin-11; D012333:RNA, Messenger; D000242:Cyclic AMP; D000469:Alkaline Phosphatase