Toll-like receptor 4 (TLR4), a key member of the TLR family, has been well characterized by its function in the induction of inflammatory products of innate immunity. However, the involvement of TLR4 in a variety of apoptotic events by an unknown mechanism has been the focus of great interest. Our investigation found that TLR4 promoted apoptotic signalling by affecting the glycogen synthase kinase-3β (GSK-3β) pathway in a serum-deprivation- induced apoptotic paradigm. Serum deprivation induces GSK-3β activation in a pathway that leads to subsequent cell apoptosis. Intriguingly, this apoptotic cascade is amplified in presence of TLR4 but greatly attenuated by β-arrestin 2, another critical molecule implicated in TLR4-mediated immune responses. Our data suggest that the association of β-arrestin 2 with GSK-3β contributes to the stabilization of phospho-GSK-3β, an inactive form of GSK-3β. It becomes a critical determinant for the attenuation of TLR4-initiated apoptosis by β-arrestin 2. Taken together, we demonstrate that the TLR4 possesses the capability of accelerating GSK-3β activation thereby deteriorating serum-deprivation-induced apoptosis; β-arrestin 2 represents an inhibitory effect on the TLR4-mediated apoptotic cascade, through controlling the homeostasis of activation and inactivation of GSK-3β.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-17968 |
| Date | 01 August 2010 |
| Creators | Li, Hui, Sun, Xiuli, Lesage, Gene, Zhang, Yi, Liang, Zhihou, Chen, Jixiang, Hanley, Gregory, He, Lei, Sun, Shenggang, Yin, Deling |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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