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Updated: Jun 22, 2026

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
Published on: December 27, 2016
Adrenoreceptor-coupled signal-transduction mechanisms mediating lymphocyte apoptosis induced by endogenous
Jian-Lan Jiang1, Yu-Ping Peng, Yi-Hua Qiu
1Department of Biological Science and Technology, School of Life Sciences, Mailbox 426, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
Abstract:
Our previous work has shown that lymphocytes synthesize catecholamines (CAs) and the endogenous CAs accelerate apoptosis of concanavalin A (Con A)-activated lymphocyte. Here, we explored the involvement of adrenoreceptors (ARs) and signal molecules coupled to the ARs in the endogenous CA-mediated modulation of lymphocyte apoptosis. Pargyline, an inhibitor of CA degradation, up-regulated the expression of cleaved caspase-3 protein and increased the number of apoptotic cells. Antagonists of alpha(1)-ARs and beta(2)-ARs, not antagonists of alpha(2)-ARs or beta(1)-ARs, blocked these effects of pargyline. The facilitating effects of pargyline on lymphocyte apoptosis were mimicked by activators of adenylate cyclase and PKC, but reversed by inhibitors of PKA, PLC and PKC. Pargyline-stimulated CREB activation and Smac/DIABLO expression were prevented by the inhibitors of PKA, PLC and PKC. These results imply that endogenous CA-induced lymphocyte apoptosis is mediated by cAMP-PKA- and PLC-PKC-linked CREB-Smac/DIABLO pathways coupled with alpha(1)-ARs and beta(2)-ARs.
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