Disruption of NF-κB Signaling Reveals a Novel Role for NF-κB in the Regulation of TNF-Related Apoptosis-Inducing Ligand Expression

Abstract

The NF-κB family of transcription factors functions broadly in the host control of immunoregulatory gene expression, inflammation, and apoptosis. Using Jurkat T cells engineered to inducibly express a transdominant repressor of IκBα, we examined the role of NF-κB in the regulation of cytokine and apoptotic gene expression. In this T cell model, as well as in primary T lymphocytes, expression of TNF-related apoptosis-inducing ligand (TRAIL) apoptotic signaling protein was dramatically down-regulated by inhibition of NF-κB binding activity. TRAIL acts through membrane death receptors to induce apoptosis of activated T lymphocytes and can be up-regulated by a variety of physiological and pharmacological inducers. However, regulation of TRAIL gene expression has not been defined. Treatment with TCR mimetics (PMA/ionomycin, PHA, and anti-CD3/CD28 Abs) resulted in a rapid increase in the expression of TRAIL mRNA and cell surface TRAIL protein. Induction of the transdominant repressor of IκBα dramatically down-regulated surface expression of TRAIL, indicating an essential role for NF-κB in the regulation of TRAIL. The induced expression of TRAIL was linked to a c-Rel binding site in the proximal TRAIL promoter at position −256 to −265; mutation of this site or an adjacent κB site resulted in a complete loss of the inducibility of the TRAIL promoter. The regulation of TRAIL expression by NF-κB may represent a general mechanism that contributes to the control of TRAIL-mediated apoptosis in T lymphocytes.

TRAIL in the mandarin fish Siniperca chuatsi: Gene and its apoptotic effect in HeLa cells

“…7C, a broad distribution of SCTRAIL protein was detected in all organs, with predominant expression in organs such as in head kidney, kidney and gonad, but a very low level of expression in brain. There existed one main form in all examined organs with the molecular weight of about 40 kDa, similar to that in human [31].…”

“…Sp-1 plays a role in both basal and inducible TRAIL expression [26]. The promoter region of SCTRAIL also has an NF-kB binding site, which has an essential role for NF-kB in the regulation of TRAIL in human primary T lymphocytes [31]. All these important regulation sites existing in the SCTRAIL promoter region may imply that SCTRAIL has similar expression regulation mechanisms.…”

Current insights into the regulation of programmed cell death by NF-κB

“…A few proapoptotic NF-kB transcriptional target genes appear to be involved in this effect. These proapoptotic targets include the death receptors Fas(CD95), TRAIL receptors DR4, DR5 and DR6, the death-inducing ligands FasL, TNFa and TRAIL, tumor suppressor p53, the proapoptotic multidomain Bcl-2 family member Bax and the proapoptotic alternatively spliced form of Bcl-xL, Bcl-xS Shakhov et al, 1990;Wu and Lozano, 1994;Kasibhatla et al, 1998;Matsui et al, 1998;Chan et al, 1999;Kasibhatla et al, 1999;Baetu et al, 2001;Kasof et al, 2001;RiveraWalsh et al, 2001;Siegmund et al, 2001;Zheng et al, 2001;Kim et al, 2002;Shou et al, 2002;Kucharczak et al, 2003;Chen et al, 2003b;Grimm et al, 2005). A recent example of a proapoptotic NF-kB activity is the apoptosis of cortical neurons that occurs following serum withdrawal and K þ loss, which is associated with increased levels of NF-kB and the resultant upregulation of Bcl-xS (Tao et al, 2006).…”

Resveratrol sensitizes melanomas to TRAIL through modulation of antiapoptotic gene expression

“…Additional reporter constructs used included: 1.5 kb TRAIL-promoter-Luc [22], 1 kb cFLIP-promoter-Luc [23,24] and p53RE-Luc [25]. Transient transfection of different reporter constructs (1 μg) together with pCMV-βgal (0.25μg) into 5×10 5 melanoma cells was performed using Lipofectamine (Life Technologies-Invitrogen).…”