Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Iwata, M. et al.

Human marrow stromal cells activate monocytes to secrete osteopontin, which down-regulates Notch1 gene expression in CD34+ cells.

The hematopoietic microenvironment, approximated in vitro by long-term marrow cultures (LTCs), consists of both nonhematopoietic-derived stromal elements and hematopoietic-derived monocyte/macrophages. To better understand the consequences of monocyte-stroma interactions, we compared gene expression profiles of CD14+ peripheral blood monocytes and HS-27a stromal cells cultured alone and together in cocultures. Results from 7 separate experiments revealed 22 genes were significantly up- or down-regulated in the cocultures, with osteopontin (OPN) up-regulated more than 15-fold. The microarray OPN data were confirmed by Northern blot, real-time polymerase chain reaction (PCR), and by detection of OPN protein. High levels of OPN gene expression were also detected in 2- to 3-week-old primary LTCs. Using Transwells we determined that stromal cells were secreting a factor that up-regulated OPN gene expression in CD14+ cells. When CD34+ cells were cultured in the presence of purified OPN, tyrosine phosphorylation of a 34-kDa molecule was increased 2- to 3-fold, an effect that was diminished in the presence of an OPN neutralizing monoclonal antibody. In addition, Notch1 gene expression was decreased 5-fold in OPN-treated CD34+ cells. We conclude that interactions between stroma and monocytes can result in activities that limit the role of Notch signaling in hematopoietic regulation.[1]

References

Human marrow stromal cells activate monocytes to secrete osteopontin, which down-regulates Notch1 gene expression in CD34+ cells. Iwata, M., Awaya, N., Graf, L., Kahl, C., Torok-Storb, B. Blood (2004) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.