Connexin43 mediates direct intercellular communication in human osteoblastic cell networks.
AUTOR(ES)
Civitelli, R
RESUMO
We have examined cell coupling and expression of gap junction proteins in monolayer cultures of cells derived from human bone marrow stromal cells (BMC) and trabecular bone osteoblasts (HOB), and in the human osteogenic sarcoma cell line, SaOS-2. Both HOB and BMC cells were functionally coupled, since microinjection of Lucifer yellow resulted in dye transfer to neighboring cells, with averages of 3.4 +/- 2.8 (n = 131) and 8.1 +/- 9.3 (n = 51) coupled cells per injection, respectively. In contrast, little diffusion of Lucifer yellow was observed in SaOS-2 monolayers (1.4 +/- 1.8 coupled cells per injection, n = 100). Dye diffusion was inhibited by octanol (3.8 mM), an inhibitor of gap junctional communication. All of the osteoblastic cells expressed mRNA for connexin43 and connexin45, but not for connexins 26, 32, 37, 40, or 46. Whereas all of the osteoblastic cells expressed similar quantities of mRNA for connexin43, the poorly coupled SaOS-2 cells produced significantly less Cx43 protein than either HOB or BMC, as assessed by immunofluorescence and immunoprecipitation. Conversely, more Cx45 mRNA was expressed by SaOS-2 cells than by HOB or BMC. Thus, intercellular coupling in normal and transformed human osteoblastic cells correlates with the level of expression of Cx43, which appears to mediate intercellular communication in these cells. Gap junctional communication may serve as a means by which osteoblasts can work in synchrony and propagate locally generated signals throughout the skeletal tissue.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=288182Documentos Relacionados
- Connexin43 and connexin45 form gap junctions with different molecular permeabilities in osteoblastic cells.
- TLR2 Mediates Gap Junctional Intercellular Communication through Connexin-43 in Intestinal Epithelial Barrier Injury*
- Epidermal growth factor disrupts gap-junctional communication and induces phosphorylation of connexin43 on serine.
- Wnt-1 regulation of connexin43 in cardiac myocytes
- Intramolecular interactions mediate pH regulation of connexin43 channels.