Inhibition of apoptosis by the expression of antisense Nedd2

Abstract

Nedd2 belongs to a family of mammalian cysteine proteases which share similarity with the Caenorhabditis elegans cell death protein, Ced-3. Overexpression of Nedd2 has been shown to induce apoptosis in mammalian cells but in the absence of a specific known inhibitor, it remains to be seen whether this represents cytotoxic effects of the Nedd2 protease or the specific activation of an apoptotic pathway. The present work shows that the factor-dependent cell line FDC-P1 expressing mouse antisense Nedd2 mRNA, exhibits significant inhibition of cell death upon removal of the cytokines, thus providing evidence for a direct role of Nedd2 in mediating apoptosis.

Nedd2 Is Required for Apoptosis after Trophic Factor Withdrawal, But Not Superoxide Dismutase (SOD1) Downregulation, in Sympathetic Neurons and PC12 Cells

“…Previous studies have shown that overexpression of Nedd2 can induce apoptotic death and that an antisense construct can rescue cells from apoptosis (Kumar et al, 1994;Kumar, 1995). The observations presented here extend these findings by demonstrating directly that Nedd2 protein levels are downregulated in neuronal cells by antisense treatment and, more significantly, that Nedd2 is required for neuronal cell death resulting from trophic factor withdrawal and not required when neuronal death is induced by SOD1 downregulation.…”

“…The major species recognized by both our N-terminal Nedd2 antiserum and a commercial Nedd2 C-terminal antiserum on Western blots migrated at an apparent M r of 53 kDa. This corresponds closely to the predicted M r of the Nedd2 protein, based on the sequence of the nedd2 transcript from mouse (Kumar, 1995) as well as rat (H. Qi and L. Stefanis, unpublished data). Recognition of this species by anti-N-Nedd2 was abolished in the presence of excess immunizing peptide.…”

“…The cysteine aspartase Nedd2 is the rodent homolog of the human Ich-1/ NEDD2 ICE family member and is highly expressed in neurons and PC12 cells (Kumar et al, 1994;Wang et al, 1994). Overexpression of Nedd2/ Ich-1 causes apoptosis in fibroblasts and neu-roblastoma cells (Kumar et al, 1994), and expression of a NEDD2 antisense construct protects a hematopoietic-derived cell line from death evoked by cytokine deprivation (Kumar, 1995). In the experiments reported here, we used a novel vector-linked antisense oligonucleotide to suppress Nedd2 expression in cultured PC12 cells and sympathetic neurons.…”

Caspase function in programmed cell death

“…112 Caspase-2 activation occurs rapidly and acute ablation of caspase-2 in a multitude of cell lines inhibits apoptosis in response to a range of stimuli including anticancer drugs. 106,[113][114][115][116][117][118][119][120] Caspase-2 has also been shown to promote MAPK and NFkB activation and may have some functions independent of its protease activity (see review by Lamkanfi et al in this issue). Curiously, casp2-null mice develop normally with only minor apoptotic defects in some cell types, suggesting that the function of caspase-2 in developmental cell death and in the adult animal is either redundant, or compensated by other caspases in the KO animals.…”

Caspase-2 is required for cell death induced by cytoskeletal disruption

“…In the case of Bid, caspase-2 can directly cleave full-length Bid to activated tBid (Guo et al, 2002;Bonzon et al, 2006). Caspase-2 activation has been implicated in apoptosis in response to a range of signals, including DNA damage, withdrawal of trophic support, heat shock, treatment with chemotherapeutic agents and tumor necrosis factor-related apoptosis-inducing ligand (Kumar, 1995;Troy et al, 2001;Lassus et al, 2002;Panaretakis et al, 2005;Shin et al, 2005;Bonzon et al, 2006;Yeung et al, 2006;Mhaidat et al, 2007). Caspase-2 has also been shown to associate with CD95 DISC and is activated within this complex but seems not to be essential for CD95-mediated cell death (Lavrik et al, 2006).…”