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World J Gastroenterol. May 21, 2006; 12(19): 3077-3081
Published online May 21, 2006. doi: 10.3748/wjg.v12.i19.3077
Production of reactive oxygen species and expression of inducible nitric oxide synthase in rat isolated Kupffer cells stimulated by Leptospira interrogans and Borrelia burgdorferi
Antonella Marangoni, Silvia Accardo, Rita Aldini, Massimo Guardigli, Francesca Cavrini, Vittorio Sambri, Marco Montagnani, Aldo Roda, Roberto Cevenini
Antonella Marangoni, Silvia Accardo, Francesca Cavrini, Vittorio Sambri, Roberto Cevenini, Sezione di Microbiologia DMCSS, University of Bologna, Bologna, Italy
Rita Aldini, Istituto di Scienze Chimiche, University of Bologna, Bologna, Italy
Massimo Guardigli, Aldo Roda, Dipartimento di Scienze Farmaceutiche, University of Bologna, Bologna, Italy
Marco Montagnani, Dipartimento di Medicina Interna e Gastroenterologia, University of Bologna, Bologna, Italy
Author contributions: All authors contributed equally to the work
Supported by MIUR, PRIN 2003 to R.C.
Correspondence to: Roberto Cevenini, Sezione di Microbiologia DMCSS, University of Bologna, Policlinico S. Orsola, Via Massarenti 9, 40138 Bologna, Italy. roberto.cevenini@unibo.it
Telephone: +39-51-341632 Fax: +39-51-307397
Received: December 6, 2005
Revised: January 7, 2006
Accepted: January 14, 2006
Published online: May 21, 2006
Abstract

AIM: 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.

CONCLUSION: 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.

Keywords: Leptospira interrogans; Borrelia burgdorferi; Inducible nitric oxide synthase; Nitric oxide; Reactive oxygen species; Kupffer cells; Chemiluminescence