Anti-OCSTAMP polyclonal antibody

Gene expression is dependent not only on genomic sequences, but also epigenetic control, in which the regulation of chromatin by histone modification plays a crucial role. Histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) are related to transcriptionally activated and silenced sequences, respectively. Osteoclasts, the multinucleated cells that resorb bone, are generated by the fusion of precursor cells of monocyte/macrophage lineage. To elucidate the molecular and epigenetic regulation of osteoclast differentiation, we performed a chromatin immunoprecipitation sequencing (ChIP-seq) analysis for H3K4me3 and H3K27me3 in combination with RNA sequencing. We focused on the histone modification change from H3K4me3(+)H3K27me3(+) to H3K4me3(+)H3K27me3(-) and identified the protocadherin-7 gene (Pcdh7) to be among the genes epigenetically regulated during osteoclastogenesis. Pcdh7 was induced by RANKL stimulation in an NFAT-dependent manner. The knockdown of Pcdh7 inhibited RANKL-induced osteoclast differentiation due to the impairment of cell-cell fusion, accompanied by a decreased expression of the fusion-related genes Dcstamp, Ocstamp and Atp6v0d2. This study demonstrates that Pcdh7 plays a key role in osteoclastogenesis by promoting cell-cell fusion. (C) 2014 Elsevier Inc. All rights reserved.

Sphingosine-1-phosphate receptor 2 (S1PR2) couples with the Gi, Gq, and G(12/13) group of proteins, which modulate an array of cellular signaling pathways and affect immune responses to multiple stimuli. In this study, we demonstrated that knockdown of S1PR2 by a specific S1PR2 shRNA lentiviral vector significantly inhibited IL-1 beta, IL-6, and TNF-alpha protein levels induced by oral pathogen Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in murine bone marrow-derived monocytes and macrophages (BMMs) compared with controls. In addition, knockdown of S1PR2 by the S1PR2 shRNA lentiviral vector suppressed p-PI3K, p-ERK, p-JNK, p-p38, and p-NF-kappa Bp65 protein expressions induced by A. actinomycetemcomitans. Furthermore, bone marrow cells treated with the S1PR2 shRNA lentiviral vector inhibited osteoclastogenesis induced by RANKL compared with controls. The S1PR2 shRNA suppressed the mRNA levels of six osteoclastogenic factors including nuclear factor of activated T-cells cytoplasmic calcineurin-dependent 1 (NFATc1), cathepsin K (Ctsk), acid phosphatase 5 (Acp5), osteoclast-associated receptor (Oscar), dendritic cells specific transmembrane protein (Dcstamp), and osteoclast stimulatory transmembrane protein (Ocstamp) in bone marrow cells. We conclude that S1PR2 plays an essential role in modulating proinflammatory cytokine production and osteoclastogenesis. Blocking S1PR2 signaling might be a novel therapeutic strategy to treat inflammatory bone loss diseases.