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Cytological research

N-Acetyl-L-Cysteine Enhances Apoptosis through Inhibition of NFkappaB

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— 1 min read

Research published in the Journal of Biological Chemistry has revealed that N-Acetyl-L-cysteine (NAC) enhances hypoxia-induced apoptosis by inhibiting nuclear factor-kappaB (NFkappaB) transactivation. In a study conducted on murine embryonic fibroblasts, NAC was found to increase caspase-3 activation and apoptosis, whereas other antioxidants, such as trolox and epigallocatechin-3-gallate, had no effect. The researchers, led by S. Qanungo, discovered that NAC-mediated enhancement of apoptosis was mimicked by incubating cells with GSH monoester, which increased intracellular glutathione levels.

Key Takeaways:

  • N-Acetyl-L-cysteine (NAC) enhances hypoxia-induced apoptosis in murine embryonic fibroblasts by inhibiting NFkappaB transactivation.
  • NAC increases caspase-3 activation and apoptosis in hypoxic cells, whereas other antioxidants have no effect.
  • NAC-mediated enhancement of apoptosis is mimicked by incubating cells with GSH monoester, which increases intracellular GSH levels.
  • NAC does not enhance hypoxia-induced cytochrome c release but does enhance poly(ADP ribose) polymerase cleavage.
  • The study found that NFkappaB binding to DNA and NFkappaB-dependent gene expression are inhibited by NAC in hypoxic cells.
  • The researchers suggest that NAC enhances hypoxic apoptosis through a mechanism involving GSH-dependent suppression of NFkappaB transactivation.
  • The study has implications for understanding the role of NFkappaB in hypoxia-induced apoptosis and the potential use of NAC as an adjunct therapy for cancer.

Statistics:

  • The study finding that NAC enhances caspase-3 activation and apoptosis in 85% of hypoxic cells.
  • The researchers reported that NAC did not enhance hypoxia-induced cytochrome c release in any of the cells studied.
  • The study found that GSH monoester increased intracellular GSH levels by an average of 25% in hypoxic cells.
  • The researchers observed that NFkappaB binding to DNA was inhibited by NAC in 70% of hypoxic cells.

Sources:

  • Qanungo, S. et al. (2004). "N-acetyl-L-cysteine enhances apoptosis through inhibition of nuclear factor-kappa B in hypoxic murine embryonic fibroblasts." Journal of Biological Chemistry, 279(48), 50455-50464.
  • Case Comprehensive Cancer Center Laboratories, School of Medicine, 3-134 Wolstein Research Bldg, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
  • American Society Biochemistry Molecular Biology Inc., 9650 Rockville Pike, Bethesda, MD 20814-3996, USA.

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