SLs and their downstream metabolites (such as ceramide) play important roles in mediating cell-stress response and cell proliferation and in regulating the cell cycle and apoptosis [ 1– 3].
At the M-band, the kinase domain of titin is a major player mediating cell responses to mechanical stress.
Mitogen-activated protein kinase (MAPK) cascades are conserved signal-transduction pathways that respond sensitively to diverse extracellular stimuli in mediating cell proliferation, differentiation, migration, stress responses, inflammation and apoptosis.
Although not fully elucidated, these mechanisms may represent an adaptive change mediating cell survival through a stress-induced increase in several antiapoptotic genes, which function like small heat shock proteins to chaperone and stabilise conformations of proteins at times of cell stress (Miyake et al, 1999, 2000a; Zoubeidi et al, 2010a).
However, with sustained cardiac stress, cellular processes mediating cell survival, metabolism, and the maintenance of normal cardiac architecture begin to fail.
Although DAPk mediates cell death following various stress stimuli, including both apoptosis and autophagic cell death during ER stress, not many molecular events downstream of DAPk activation have been elucidated.
A number of studies have demonstrated that several transient receptor potential (TRP) channels are regulated by oxidative stress and that calcium influx through TRP channels may be one mechanism by which oxidative stress mediates cell damage and physiological alterations (Miller, 2006; Poteser et al., 2006; Miller & Zhang, 2011; Takahashi et al., 2011).
It was of interest therefore to determine, whether salubrinal would also prevent classical, thapsigargin-mediated ER stress mediated cell death in K562 cells or whether the response to salubrinal would instead reflect cell type specific differences.
NO-S-nitrosylation-GAPDH-E3/2 cascade mediates cell death under oxidative stress conditions and thus represent an important mechanism of cytotoxicity [92], [93], [94].
Our findings therefore support the data from a previous study of Borner and co-workers [50] where Bid expression was not required for ER stress mediated cell death.
