N-(1-pyrenyl) maleimide induces bak oligomerization and mitochondrial dysfunction in Jurkat Cells
Pei-Rong Huang1, Shu-Chen Hung2, Chia-Chu Pao3
1Department of Molecular and Cellular Biology, College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan 333, Taiwan.
Abstract:
N-(1-pyrenyl) maleimide (NPM) is a fluorescent reagent that is frequently used as a derivatization agent for the detection of thio-containing compounds. NPM has been shown to display a great differential cytotoxicity against hematopoietic cancer cells. In this study, the molecular mechanism by which NPM induces apoptosis was examined. Here, we show that treatment of Jurkat cells with NPM leads to Bak oligomerization, loss of mitochondrial membrane potential (Δψm), and release of cytochrome C from mitochondria to cytosol. Induction of Bak oligomerization appears to play a critical role in NPM-induced apoptosis, as downregulation of Bak by shRNA significantly prevented NPM-induced apoptosis. Inhibition of caspase 8 by Z-IETD-FMK and/or depletion of Bid did not affect NPM-induced oligomerization of Bak. Taken together, these results suggest that NPM-induced apoptosis is mediated through a pathway that is independent of caspase-8 activation.
Insights
N-(1-pyrenyl) maleimide (NPM) induces cancer cell death by triggering Bak oligomerization and cytochrome C release, independent of caspase-8 activation. This mechanism highlights NPM
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- N-(1-pyrenyl) maleimide (NPM) is a fluorescent reagent used for detecting thio-containing compounds.
- NPM exhibits differential cytotoxicity against hematopoietic cancer cells.
Purpose of the Study:
- To elucidate the molecular mechanism of NPM-induced apoptosis.
Main Methods:
- Treatment of Jurkat cells with NPM.
- Analysis of Bak oligomerization, mitochondrial membrane potential (Δψm), and cytochrome C release.
- Downregulation of Bak using shRNA.
- Inhibition of caspase-8 and depletion of Bid.
Main Results:
- NPM treatment induced Bak oligomerization, loss of Δψm, and cytochrome C release.
- Downregulation of Bak significantly inhibited NPM-induced apoptosis.
- Inhibition of caspase-8 or Bid depletion did not affect NPM-induced Bak oligomerization.
Conclusions:
- NPM-induced apoptosis is mediated by Bak oligomerization.
- The apoptotic pathway activated by NPM is independent of caspase-8 activation.
