Bacterial Lipopeptides Induce Nitric Oxide Synthase and Promote Apoptosis through Nitric Oxide-independent Pathways in Rat Macrophages

doi:10.1074/jbc.270.11.6017

Bacterial Lipopeptides Induce Nitric Oxide Synthase and Promote Apoptosis through Nitric Oxide-independent Pathways in Rat Macrophages (*)

From the (1)Instituto de Bioquímica (CSIC-UCM), Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain and
the (2)Dipartimento di Biologia Cellulare e dello Sviluppo, Universitá “La Sapienza,” 00185 Roma, Italy

^§ To whom correspondence should be addressed:
Instituto de Bioquímica, Facultad de Farmacia, 28040 Madrid, Spain.

Abstract

Stimulation of resident peritoneal macrophages with S-[2,3-bis(pamitoyloxy)-(2R,2S)-propyl]-N-palmytoyl-(R)-CysSerLys₄ or S-[2,3-bis(pamitoyloxy)-(2R,2S)-propyl]-N-palmytoyl-(R)-CysAlaLys₄, two synthetic bacterial lipopeptides, promoted the expression of the inducible form of nitric oxide synthase, exhibiting a temporal pattern of nitric oxide release that was delayed with respect to the induction elicited by bacterial lipopolysaccharide. Treatment of macrophages with genistein blocked the nitric oxide synthesis triggered by the lipopeptides or lipopolysaccharide. Simultaneous incubation with lipopolysaccharide and lipopeptide resulted in an antagonistic effect on nitric oxide synthase mRNA levels and on nitrite plus nitrate release to the medium.

Triggering with bacterial lipopeptides induced macrophage programmed cell death. In macrophages activated with lipopeptide, apoptosis was observed even in the absence of nitric oxide synthesis, therefore indicating the existence of alternative pathways in the control of programmed cell death in these cells.

Footnotes

↵* This work was supported by Grant PM92-070 from CICYT, Spain. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

LPS

lipopolysaccharide

TPP

S-[2,3-bis(pamitoyloxy)-(2R,2S)-propyl]-N-palmytoyl-(R)-CysSerLys₄

TPP-Ala

S-[2,3-bis(pamitoyloxy)-(2R,2S)-propyl]-N-palmytoyl-(R)-CysAlaLys₄

NMA

N^G-methyl-L-arginine

M

macrophage

NOS

nitric oxide synthase

IFN-

interferon

TNF-α

tumor necrosis factor α

PBS

phosphate-buffered saline

PDBu

phorbol 12,13-dibutyrate

MAP

mitogen-activated protein.
- Received July 13, 1994.
- Revision received January 16, 1995.