1. Aminoglycoside nephrotoxicity: from molecular pharmacology and pathology to some applications
Paul M. Tulkens, MD, PhD
Unité de Pharmacologie Cellulaire et Moléculaire
Université Catholique de Louvain
Brussels, Belgium

2. Aminoglycosides... highly bactericidal and wide spectrum
post-antibiotic effect
synergistic with beta-lactams
dose proportionate PKs
no metabolism and 95 % renal excretion
BUT…
neuro-muscular blockade (high doses)
nephrotoxicity
ototoxicity (irreversible)

3. Aminoglycosides...
cytological and molecular mechanisms of nephrotoxicity
the “once-a-day” schedule
polyaspartic acid
recent data on apoptosis

4. Evidence of apoptosis in proximal tubular cells
Gentamicin 10 mg/kg 10 days; HE staining

5. Evidence of apoptosis in proximal tubular cells: histology
HE staining
methyl green-pyronin
gentamicin 10 mg/kg, 10 days

6. Evidence of apoptosis in proximal tubular cells: TUNEL staining
gentamicin 10 mg/kg, 10 days

7. Apoptosis in proximal tubular cells: quantification and correlation between TUNEL and Brachet

8. Apoptosis in proximal tubular cells: correlation with tubular/peritubular proliferation

9. Apoptosis in cultured cells: EM
chromatin condensation
rat embryo
fibroblats
gentamicin
2 mM 4 days
apoptotic body

10. Apoptosis in cultured cells: DNA size analysis (agarose electrophoresis)
control GM 2mM
4 days
fibroboblats
MDCK cells
LLC-PK1 cells

11. Gentamicin-induced apoptosis in cultured cells: Quantification by TUNEL

12. Gentamicin-induced apoptosis in cultured cells: correlation with gentamicin accumulation

13. Gentamicin-induced apoptosis in cultured cells: correlation with phospholipidosis

14. Modulation of gentamicin-induced apoptosis in cultured cells
blocked by cycloheximide (fibroblasts and MDCK-cells) (LLC-PK1 cells show apoptosis with CH)
blocked by over-expression of BCl-2 protein in bcl-2 transfected cells (MDCK- and LLC-PK1 cells)
associated with increased caspase-3 activity (MDCK cells)
blocked by caspase-3 inhibitor ZVAD.fmk (MDCK-cells)

15. Aminoglycosides... cytological and molecular mechanisms of nephrotoxicity
G. Laurent
B. Carlier
R. Brasseur
J.M. Ruysschaert
Starting in the early 80’s ...

16. Aminoglycosides... The once-a-day story...
S. Ibrahim
P. Maldague
B. Carlier
G. Laurent
D. Beauchamp
… and many others
In the mid 80’s ...

17. Aminoglycosides... The poly-aspartic acid saga...
Z. Kallay
B.K. Kishore
J. Piret
S. Ibrahim
P. Maldague
D. Beauchamp
… and many others
Early 90’s ...

18. Aminoglycosides... The apoptosis finale ...
P. Maldague (+ 1994)
M. El Mouedden
H. Taper
M.P. Mingeot
G. Laurent
M. Dellale
The 90’s ...

19. Aminoglycosides... Where has that been published ?
So many papers, but start with two last reviews:
Mingeot-Leclercq, M.P. and Tulkens, P.M.: Aminoglycosides: nephrotoxicity. Antimicrob. Agents Chemother. 43: , 1999.
Mingeot-Leclercq, M.P., Glupczynski, Y. and Tulkens, P.M.: Aminoglycosides: activity and resistance. Antimicrob. Agents Chemother. 43: , 1999.

20. Aminoglycosides... Where has that been published ?
and then, make a Medline Search on the following names
(a selection):
Laurent-G
Kishore-BK
Mingeot-Leclercq-MP
Carlier-MB
Beauchamp-D
Piret-J
Van-der-Auwera-P ….
Lambricht-P
Wagner-R
Vanschepdael-A
Claes-JP
Vanderhaeghe-HJ
Langhendries-M
Porter-G
...

21. Aminoglycosides...
Or, just come and visit us...

22. Aminoglycosides... But, where is that ?
Cellular and Molecular Pharmacology Unit
Catholic University of Louvain, Belgium