Production of reactive oxygen species and expression of inducible nitric oxide synthase in rat isolated Kupffer cells stimulated by Leptospira interrogans and Borrelia burgdorferi.
OBJECTIVE
To evaluate the production of reactive oxygen species (ROS) and the expression of inducible nitric oxide synthase (iNOS) in rat isolated Kupffer cells (KCs) stimulated by Leptospira interrogans and Borrelia burgdorferi.


METHODS
Rat Kupffer cells were separated by perfusion of the liver with 0.05% collagenase, and purified by Percoll gradients. Purified Kupffer cells were tested in vitro with alive L. interogans and B. burgdorferi preparations. The production of ROS was determined by chemiluminescence, whereas iNOS protein expression was evaluated by Western blot assay using anti-iNOS antibodies.


RESULTS
B. burgdorferi and to a less extent L. interrogans induced ROS production with a peak 35 min after infection. The chemiluminescence signal progressively diminished and was undetectable by 180 min of incubation. Leptospirae and borreliae induced an increased iNOS expression in Kupffer cells that peaked at 6 hours and was still evident 22 h after infection.


CONCLUSIONS
Both genera of spirochetes induced ROS and iNOS production in rat Kupffer cells. Since the cause of liver damage both in leptospiral as well as in borrelial infections are still unknown, we suggest that leptospira and borrelia damage of the liver can be initially mediated by oxygen radicals, and is then maintained at least in part by nitric oxide.
Marangoni
Antonella
A
Sezione di Microbiologia DMCSS, University of Bologna, Policlinico S. Orsola, Via Massarenti 9, 40138 Bologna, Italy.
Accardo
Silvia
S
Aldini
Rita
R
Guardigli
Massimo
M
Cavrini
Francesca
F
Sambri
Vittorio
V
Montagnani
Marco
M
Roda
Aldo
A
Cevenini
Roberto
R
D000818:Animals; D015153:Blotting, Western; D025065:Borrelia burgdorferi / Q000502:physiology*; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D007728:Kupffer Cells / Q000201:enzymology / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D007921:Leptospira interrogans / Q000502:physiology*; D007922:Leptospirosis / Q000378:metabolism / Q000473:pathology; D049449:Luminescence; D008193:Lyme Disease / Q000378:metabolism / Q000473:pathology; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
D017382:Reactive Oxygen Species; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat