HIF-1? Mediates TRAIL-Induced Neuronal Apoptosis via Regulating DcR1 Expression Following Traumatic Brain Injury.
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ABSTRACT: Background: Neuronal apoptosis involved in secondary injury following traumatic brain injury (TBI) significantly contributes to the poor outcomes of patients with TBI. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis of tumor cells. Hypoxia factor (HIF) 1? is a controversial factor that mediates the neuronal apoptotic pathway. Herein, we hypothesize that HIF-1? may mediate the TRAIL-induced neuronal apoptosis after TBI. Methods: We used Western blots and immunofluorescence to study the expression and cell localization of TRAIL and death receptor 5 (DR5) after TBI in rats. Soluble DR5 (sDR5) administration was used to block the TRAIL-induced neuronal death and neural deficits. HIF-1? inhibitor 2ME and agonist DMOG were used to study the role of HIF-1? in TRAIL-induced neuronal death. Meanwhile, HIF-1? siRNA was used to investigate the role of HIF-1? in TRAIL-induced neuronal death in vitro. Results: The expressions of microglia-located TRAIL and neuron-located DR5 were significantly upregulated after TBI. sDR5 significantly attenuated TRAIL-induced neuronal apoptosis and neurological deficits. 2ME decreased neuronal apoptosis, lesion area, and brain edema and improved neurological function via increased expression of TRAIL decoy receptor 1 (DcR1), which inhibited TRAIL-induced apoptosis after TBI. The administration of DMOG produced the opposite effect than did 2ME. Similarly, HIF-1? siRNA attenuated TRAIL-induced neuronal death via increased DcR1 expression in vitro. Conclusion: Our findings suggested that the TRAIL/DR5 signaling pathway plays an important role after neuronal apoptosis after TBI. HIF-1? mediates TRAIL-induced neuronal apoptosis by regulating DcR1 expression following TBI.
SUBMITTER: Fang Y
PROVIDER: S-EPMC7416670 | biostudies-literature | 2020
REPOSITORIES: biostudies-literature
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