Nucling, a novel protein associated with NF-κB, regulates endotoxin-induced apoptosis in vivo

Abstract

Nucling is a proapoptotic protein that regulates the apoptosome and nuclear factor-kappa B (NF-iB) signalling pathways. Strong stimuli, such as Gramnegative bacterial lipopolysaccharide (LPS), induce the simultaneous secretion of cytokines following the activation of NF-iB. Proinflammatory cytokines can induce liver damage through several mechanisms such as increases in oxidative stress and apoptotic reactions leading to tissue necrosis. Herein, we show that Nucling-knockout (KO) mice are resistant to LPS that consistently caused mortality in wild-type (WT) counterparts. Although serum levels of cytokines such as tumour necrosis factor (TNF)-a, interleukin (IL)-1b and IL-6 did not differ significantly between WT and Nucling-KO mice after the LPS challenge, hepatocytes of Nucling-KO mice were refractory to LPS-or TNF-a-induced cell death. These results were consistent with the decreased expression of proapoptotic proteins including apoptosis-inducing factor and cleaved form of poly (ADP-ribose) polymerase and terminal deoxynucleotidyl transferase dUTP nick end-labelling positive cells in the liver of Nucling-KO mice after the administration of a lethal dose of LPS. Moreover, the upregulation of NF-iB-regulated anti-apoptotic molecules including cellular inhibitor of apoptosis (cIAP) 1 and cIAP2 was observed in the liver of Nucling-KO mice after LPS treatment. These findings indicate that the Nucling deficiency leads to resistance to apoptosis in liver. We propose that Nucling is important for the induction of apoptosis in cells damaged by cytotoxic stressors through the NF-iB signalling pathway.

Roles of Macrophages in Advanced Liver Fibrosis, Identified Using a Newly Established Mouse Model of Diet-Induced Non-Alcoholic Steatohepatitis

“…EGFR signaling is required for estrogen-stimulated macrophage infiltration in the development of mammary tumorigenesis [ 48 ]. UACA is a proapoptotic protein that regulates NF-κB signaling [ 49 ], the expression of which is high in various cancers, including hepatocellular carcinoma [ 50 ]. KRT8 expression is high in patients with advanced liver fibrosis [ 51 ].…”

Minnelide: A Novel Therapeutic That Promotes Apoptosis in Non-Small Cell Lung Carcinoma In Vivo

“…However, there is some evidence that the uveal autoantigen with coiled-coil domains and ankyrin repeats (UACA)/nucling may be involved in this translocation [60]. It has been shown that UACA/nucling is associated with canonical NF-κ signaling pathway [61-63] and was described as a functional regulator of sensitivity to extracellular inducers of apoptosis in cancer cells [64]. …”

Nucling, a Novel Apoptosis-associated Protein, Controls Mammary Gland Involution by Regulating NF-κB and STAT3

“…Protein concentrations were determined using the BCA TM Protein Assay Kit (Pierce). Western blotting was performed as described previously (26). The following antibodies were used: anti-mouse middle portion of Nucling (m.Nucl.mid) (16); a phospho-NF-B-p65 (Ser-468) antibody (Cell Signaling); a phospho-STAT3 (Tyr-705) mouse antibody (Cell Signaling); caspase-3 antibody (Santa Cruz); a STAT3 antibody (sc482 Santa Cruz); anti-liver Arginase antibody (ab91279, Abcam); monoclonal anti-␤-actin (catalog number A5441, Sigma); HRP anti-mouse IgG (catalog number NA9310, GE Healthcare); and HRP anti-rabbit IgG (catalog number NA934, GE Healthcare).…”