Original ContributionSelective vulnerability of neurons to acute toxicity after proteasome inhibitor treatment: Implications for oxidative stress and insolubility of newly synthesized proteins
Section snippets
Materials
The antibodies to β-actin (SC-47778) and ubiquitin (SC - 8017) were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). MG132 was purchased from EMD Chemicals (Gibbstown, NJ, USA). The BCA reagent was purchased from Thermo Scientific (Waltham, IL, USA). The OxyBlot kit was purchased from Millipore (Billerica, MA, USA). [35S]Methionine was purchased from PerkinElmer (Cat. No. NEG009A500UC; Shelton, CT, USA). All the chemicals, including Hoechst, H33342 (bisbenzamide trihydrochloride)
Neuronal cells exhibit increased vulnerability to the toxicity of proteasome inhibitors
To begin to elucidate the relative susceptibilities of primary rat neuronal and astrocyte cultures to the toxicity of proteasome inhibitors, we conducted studies analyzing the severity of proteasome inhibition and induction of cell death after treatment with the proteasome inhibitor MG132. In these studies we observed that proteasome inhibitor treatment resulted in a robust dose-dependent impairment of 26S and 20S chymotrypsin-like activity in both neurons and astrocytes (Fig. 1).
Discussion
Our studies identify for the first time that primary rat neuron cultures undergo a greater degree of cytotoxicity after proteasome inhibitor treatment compared to primary rat astrocyte cultures. These data suggest that neurons may be preferentially affected by the proteasome inhibition reported to occur in the brain during aging and age-related diseases of the nervous system [30]. In this model the negative effects of proteasome inhibition in the brain during aging and age-related diseases are
Acknowledgments
This work was supported by grants from the NIA (AG029885, AG025771) and the Hibernia National Bank/Edward G. Schlieder Chair (J.N.K.).
References (44)
- et al.
Possible involvement of proteasome inhibition in aging: implications for oxidative stress
Mech. Ageing Dev.
(2000) - et al.
Molecular mechanisms of proteasome plasticity in aging
Mech. Ageing Dev.
(2010) - et al.
Proteasome dysfunction in mammalian aging: steps and factors involved
Exp. Gerontol.
(2005) - et al.
Aging process modulates nonlinear dynamics in liver cell metabolism
J. Biol. Chem.
(2007) - et al.
The neuronal ubiquitin–proteasome system: murine models and their neurological phenotype
Prog. Neurobiol.
(2008) - et al.
Role of proteasomes in the degradation of short-lived proteins in human fibroblasts under various growth conditions
Int. J. Biochem. Cell Biol.
(2003) - et al.
Reactive oxygen species generation and mitochondrial dysfunction in the apoptotic response to Bortezomib, a novel proteasome inhibitor, in human H460 non-small cell lung cancer cells
J. Biol. Chem.
(2003) - et al.
Proteasome inhibition induces both pro- and anti-cell death pathways in prostate cancer cells
Cancer Lett.
(2006) - et al.
Aging and dietary restriction alter proteasome biogenesis and composition in the brain and liver
Mech. Ageing Dev.
(2009) - et al.
Increased protein hydrophobicity in response to aging and Alzheimer disease
Free Radic. Biol. Med.
(2010)
Oxidative modification and inactivation of the proteasome during coronary occlusion/reperfusion
J. Biol. Chem.
Aggregates of oxidized proteins (lipofuscin) induce apoptosis through proteasome inhibition and dysregulation of proapoptotic proteins
Free Radic. Biol. Med.
Interplay between protein synthesis and degradation in the CNS: physiological and pathological implications
Trends Neurosci.
Quantitating protein synthesis, degradation, and endogenous antigen processing
Immunity
The relationship between oxidative/nitrative stress and pathological inclusions in Alzheimer's and Parkinson's diseases
Free Radic. Biol. Med.
Oxidative posttranslational modifications in Alzheimer disease: a possible pathogenic role in the formation of senile plaques and neurofibrillary tangles
Mol. Chem. Neuropathol.
Proteasome regulation of oxidative stress in aging and age-related diseases of the CNS
Antioxid. Redox Signaling
Proteasome function in aging and oxidative stress: implications in protein maintenance failure
Antioxid. Redox Signaling
Role of proteasomes in disease
BMC Biochem.
Ubiquitin, proteasomes, and the aging brain
Sci. Aging Knowledge Environ.
Proteasome inhibition in oxidative stress neurotoxicity: implications for heat shock proteins
J. Neurochem.
Inhibition of the ubiquitin–proteasome system in Alzheimer's disease
Proc. Natl. Acad. Sci. USA
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