Further Pharmacological Evidence of Nuclear Factor-B Pathway Involvement in Bradykinin B 1 Receptor-Sensitized Responses in Human Umbilical Vein SERGIO PABLO SARDI, 1 VER ´ ONICA REY-ARES, 2 VIRGINIA ANDREA PUJOL-LEREIS, SANTIAGO ALEJO SERRANO, and RODOLFO PEDRO ROTHLIN Departamento de Farmacologı´a, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina Received September 17, 2001; accepted March 4, 2002 This article is available online at http://jpet.aspetjournals.org ABSTRACT Bradykinin (BK) B 1 receptors are thought to exert a pivotal role in maintaining and modulating inflammatory processes. They are not normally present under physiological situations but are induced under physiopathological conditions. In isolated hu- man umbilical vein (HUV), a spontaneous BK B 1 receptor up- regulation and sensitization process has been demonstrated. Based on pyrrolidine-dithiocarbamate inhibition, it has been proposed that this phenomenon is dependent on nuclear fac- tor-B (NF-B) activation. The aim of this study was to further evaluate the NF-B pathway involvement on BK B 1 receptor sensitization in isolated HUV, using several pharmacological tools. In 5-h incubated rings, either the I-B kinase inhibitor 3-(4-methylphenylsulfonyl)-2-propenenitrile (Bay 11–7082) or the proteasome activity inhibitor Z-Leu-Leu-Leu-CHO (MG-132) inhibited the development of the BK B 1 receptor- sensitized contractile responses. Furthermore, pro-inflam- matory cytokine interleukin-6 (IL-6) produced a leftward shift of the concentration-response curve to the BK B 1 receptor agonist, whereas anti-inflammatory cytokines interleukin-4 (IL-4) and tumor growth factor-1 (TGF-1) produced a right- ward shift of the responses to des-Arg 9 -BK in our prepara- tions. Taken together, these results point to NF-B as a key intermediary in the activation of the expression of BK B 1 receptor-sensitized responses in HUV and support the role of inflammatory mediators in the modulation of this process. Vascular bradykinin (BK) B 1 receptors were first described in isolated rabbit anterior mesenteric vein by Regoli et al. (1978) after a long in vitro incubation. These authors postu- lated the de novo formation of BK B 1 receptors to account for this phenomenon. Thereafter, induction of BK B 1 responses was documented in different isolated tissue preparations (Marceau et al., 1998). BK B 1 receptors are not normally present in nontraumatized tissues, but their synthesis can be induced under certain physiopathological conditions such as tissue injury or inflammation, or during trauma tissue isola- tion and incubation (Marceau et al., 1998). In isolated human umbilical vein (HUV), the BK B 1 recep- tor-mediated contractile response develops from an initial null level and increases in magnitude as a function of the in vitro incubation time (Sardi et al., 1997). This up-regulation process is dependent on the de novo synthesis of receptors since it is abolished by translation, transcription, and protein trafficking or glycosylation inhibitors (Sardi et al., 2000a). On the other hand, in isolated HUV, BK B 2 receptors are constitutively expressed and do not undergo additional in- duction (Sardi et al., 1997, 1998). In vitro and in vivo studies have demonstrated a close link between inflammatory mediators and the expression of BK B 1 receptors (Campos et al., 1998; Marceau et al., 1998). In HUV, it has been reported that interleukin-1 (IL-1) or tumor ne- crosis factor- (TNF-) treatment potentiates BK B 1 receptor- mediated responses (Sardi et al., 1998, 1999). These cytokines have been linked to nuclear factor-B (NF-B) pathway activa- tion (Baldwin, 1996). Furthermore, in this human tissue, the development of BK B 1 receptor-sensitized responses has been inhibited by anti-inflammatory agents that could be linked to NF-B pathway inactivation, such as dexamethasone, pyrroli- dine-dithiocarbamate (PDTC), all-trans-retinoic acid or 9-cis- retinoic acid (Sardi et al., 1998, 1999, 2000b). NF-B is a ubiquitously expressed transcription factor that consists of homodimers or heterodimers of a family of struc- This research was supported by grants from the Universidad de Buenos Aires (UBA Grant TM-049) and by the Fundacio ´n A. J. Roemmers. 1 Current address: Department of Neuroscience, Children’s Hospital, Har- vard Medical School, 300 Longwood Avenue, Boston. MA. 02115. 2 Current address: Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077-Goettingen, Germany. ABBREVIATIONS: BK, bradykinin; 5-HT, 5-hydroxytryptamine or serotonin; HUV, human umbilical vein; IL, interleukin; NF-B, nuclear factor-B; PDTC, pyrrolidine-dithiocarbamate; Bay 11–7082, 3-(4-methylphenylsulfonyl)-2-propenenitrile; MG-132, Z-Leu-Leu-Leu-CHO; TGF-1, tumor growth factor-1; TNF-, tumor necrosis factor-. 0022-3565/02/3013-975–980$7.00 THE JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS Vol. 301, No. 3 Copyright © 2002 by The American Society for Pharmacology and Experimental Therapeutics 4546/987470 JPET 301:975–980, 2002 Printed in U.S.A. 975 at ASPET Journals on July 18, 2018 jpet.aspetjournals.org Downloaded from