25] Evaluation of biological role of c-Jun N-terminal kinase using an antisense approach

Abstract

Publisher Summary The mammalian mitogen-activated protein (MAP) kinase signaling pathway links extracellular stimuli to the regulation of cellular responses, including cellular growth, differentiation, and apoptosis. MAP kinase family members are a conserved group of serine/threonine protein kinases that include c-Jun N-terminal kinase (JNK), extracellular regulated kinase (ERK), and p38 MAP kinases. An antisense approach is a useful strategy to potently and specifically inhibit gene expression to delineate the precise functional role of a target protein and identify potential pharmacological targets. Treatment of cultured cells with oligonucleotides targeted to either human JNK1 or human JNK2 results in a potent inhibition of JNK messenger ribonucleic acid (mRNA) and protein expression, as well as JNK kinase activity. Inhibition of JNK gene expression by antisense oligonucleotides reveals a significant suppression of hypoxia/reoxygenation-induced apoptosis in human kidney cells and tumor necrosis factor (TNF)- α -induced E-selectin expression in human endothelial cells. These results suggest that the activation of JNK is an important signal transduction protein for apoptosis induced by the cellular stress of hypoxia/reoxygenation. In addition, the results demonstrate that JNK2 is the JNK isoform responsible for TNF- α -mediated induction of E-selectin in endothelial cells.