1. Toxicol Appl Pharmacol. 2016 Oct 15;309:24-36. doi: 10.1016/j.taap.2016.08.020.
Epub 2016 Aug 26.

Subcellular mechanisms involved in apoptosis induced by aminoglycoside
antibiotics: Insights on p53, proteasome and endoplasmic reticulum.

Denamur S(1), Boland L(1), Beyaert M(2), Verstraeten SL(1), Fillet M(3), Tulkens 
PM(1), Bontemps F(2), Mingeot-Leclercq MP(1).

Author information: 
(1)Université catholique de Louvain, Louvain Drug Research Institute, Cellular
and Molecular Pharmacology, UCL B1.73.05, avenue E. Mounier, 73 - B1200 Brussels,
Belgium. (2)Université catholique de Louvain, de Duve Institute, Laboratory of
Physiological Chemistry, UCL B1.75.08, avenue Hippocrate, 75 B -1200 Brussels,
Belgium. (3)University of Liege, CIRM, Department of Pharmacy, Laboratory for the
Analysis of Medicines, Quartier Hopital, Avenue Hippocrate, 15, B36, Tower 4,
4000 Liège 1, Belgium.

Gentamicin, an aminoglycoside used to treat severe bacterial infections, may
cause acute renal failure. In the renal cell line LLC-PK1, gentamicin accumulates
in lysosomes, induces alterations of their permeability, and triggers the
mitochondrial pathway of apoptosis via activation of caspase-9 and -3 and changes
in Bcl-2 family proteins. Early ROS production in lysosomes has been associated
with gentamicin induced lysosomal membrane permeabilization. In order to better
understand the multiple interconnected pathways of gentamicin-induced apoptosis
and ensuing renal cell toxicity, we investigated the effect of gentamicin on p53 
and p21 levels. We also studied the potential effect of gentamicin on proteasome 
by measuring the chymotrypsin-, trypsin- and caspase-like activities, and on
endoplasmic reticulum by determining phopho-eIF2α, caspase-12 activation and
GRP78 and 94. We observed an increase in p53 levels, which was dependent on ROS
production. Accumulation of p53 resulted in accumulation of p21 and of
phospho-eIF2α. These effects could be related to an impairment of proteasome as
we demonstrated an inhibition of trypsin-and caspase-like activities. Moderate
endoplasmic reticulum stress could also participate to cellular toxicity induced 
by gentamicin, with activation of caspase-12 without change in GRP74 and GRP98.
All together, these data provide new mechanistic insights into the apoptosis
induced by aminoglycoside antibiotics on renal cell lines.

Copyright © 2016 Elsevier Inc. All rights reserved.

DOI: 10.1016/j.taap.2016.08.020 
PMID: 27568863  [PubMed - in process]