We defined how blood-derived vitronectin (VTN) rapidly and potently activates leukemia inhibitory factor (LIF) and pro-inflammatory interleukin 6 (IL-6) in vitro and after vascular injury in the brain. Treatment with VTN (but not fibrinogen, fibronectin, laminin-111 or collagen-I) substantially increased LIF and IL-6 within 4 h in C6-astroglioma cells, while VTN-/- mouse plasma was less effective than that from wild-type mice. LIF and IL-6 were induced by intracerebral injection of recombinant human (rh)VTN in mice, but induction seen upon intracerebral hemorrhage was less in VTN-/- mice than in wild-type littermates. In vitro, VTNeffects were inhibited by RGD, αvβ3 and αvβ5 integrin-blocking peptides and antibodies. VTN activated focal adhesion kinase (FAK; also known as PTK2), whereas pharmacological- or siRNA-mediated inhibition of FAK, but not PYK2, reduced the expression of LIF and IL-6 in C6 and endothelial cells and after traumatic cell injury.Dominant-negative FAK (Y397F) reduced the amount of injury-induced LIF and IL-6. Pharmacological inhibition or knockdown of uPAR (also known as PLAUR), which binds VTN, also reduced cytokine expression, possibly through a common target of uPAR and integrins. We propose that VTN leakage into tissues promotes inflammation. Integrin-FAKsignaling is therefore a novel IL-6 and LIF regulation mechanism relevant to the inflammation and stem cell fields.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-11596 |
| Date | 01 February 2018 |
| Creators | Keasey, Matthew P., Jia, Cuihong, Pimentel, Lylyan F., Sante, Richard R., Lovins, Chiharu, Hagg, Theo |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
Page generated in 0.002 seconds