The X-linked inhibitor of apoptosis protein (XIAP) is a potent caspase inhibitor, best known for its anti-apoptotic function in cancer. During apoptosis, XIAP is antagonized by SMAC, which is released from the mitochondria upon caspase-mediated activation of BID. Recent studies suggest that XIAP is involved in immune signaling. Here, we explore XIAP as an important mediator of an immune response against the enteroinvasive bacterium Shigella flexneri, both in vitro and in vivo. Our data demonstrate for the first time that Shigella evades the XIAP-mediated immune response by inducing the BID-dependent release of SMAC from the mitochondria. Unlike apoptotic stimuli, Shigella activates the calpain-dependent cleavage of BID to trigger the release of SMAC, which antagonizes the inflammatory action of XIAP without inducing apoptosis. Our results demonstrate how the cellular death machinery can be subverted by an invasive pathogen to ensure bacterial colonization.
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http://dx.doi.org/10.15252/embj.201387244 | DOI Listing |
Neurochem Res
November 2016
Department of Pharmacology, College of Medicine, and theBK21plus Skin Barrier Network Human Resources Development Team, Chung-Ang University, Seoul, 156-756, South Korea.
Impairment of proteasomal function has been shown to be implicated in neuronal cell degeneration. The compounds which have antioxidant and anti-inflammatory abilities appear to provide a neuroprotective effect. Flavone apigenin is known to exhibits antioxidant and anti-inflammatory effects.
View Article and Find Full Text PDFNeurochem Res
October 2016
Department of Pharmacology, College of Medicine, BK21(plus) Skin Barrier Network Human Resources Development Team, Chung-Ang University, Seoul, 156-756, South Korea.
Proteasome impairment has been shown to be involved in neuronal degeneration. Antiepileptic lamotrigine has been demonstrated to have a neuroprotective effect. However, the effect of lamotrigine on the proteasome inhibition-induced neuronal cell death has not been studied.
View Article and Find Full Text PDFNeurochem Int
October 2015
Department of Pharmacology, College of Medicine, and the BK21(plus) Skin Barrier Network Human Resources Development Team, Chung-Ang University, Seoul 156-756, South Korea. Electronic address:
Cholesterol oxidation products are suggested to be involved in neuronal degeneration. Apocynin has demonstrated to have anti-inflammatory and anti-oxidant effects. We assessed the effect of apocynin on the cholesterol oxidation product-induced programmed cell death in neuronal cells using differentiated PC12 cells in relation to NF-κB-mediated cell death process.
View Article and Find Full Text PDFNaunyn Schmiedebergs Arch Pharmacol
August 2015
Department of Pharmacology, College of Medicine, and the BK21plus Skin Barrier Network Human Resources Development Team, Chung-Ang University, Seoul, 156-756, South Korea.
Cholesterol oxidation products are suggested to be involved in neuronal cell degeneration. We examined the preventive effect of quercetin-3-O-(2″-galloyl)-α-L-rhamnopyranoside (QGR), a quercetin derivative, on the cholesterol oxidation product-induced neuronal cell death using differentiated PC12 cells in relation to nuclear factor (NF)-κB-mediated apoptotic process. 7-Ketocholesterol and 25-hydroxycholesterol induced a decrease in the levels of BH3 interacting-domain death agonist (Bid) and B cell lymphoma 2 (Bcl-2), increase in the levels of Bcl-2-associated X protein (Bax) and p53, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases, and cleavage of poly(ADP-ribose) polymerase 1 (PARP-1).
View Article and Find Full Text PDFEur J Pharmacol
February 2015
Department of Pharmacology, College of Medicine, and the BK21(plus) Skin Barrier Network Human Resources Development Team, Chung-Ang University, Seoul 156-756, South Korea. Electronic address:
The extract of from the barks of Ilex Rotunda Thunb has demonstrated anti-inflammatory and anti-oxidant effects. Nevertheless, the effect of rotundarpene (4-caffeoyl-3-methyl-but-2-ene-1,4-diol) on the neuronal cell death induced by cholesterol oxidation products is unclear. We assessed the preventive effect of rotundarpene on the cholesterol oxidation product-induced apoptosis in neuronal cells using differentiated PC12 cells.
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