Jean-Michel Luccarini - Academia.edu (original) (raw)

Papers by Jean-Michel Luccarini

Research paper thumbnail of Pharmacological profile of LF 16-0687, a new potent non-peptide bradykinin B2 receptor antagonist

Immunopharmacology, 1999

LF 16-0687 (1-[[2,4-dichloro-3-[[(2,4-dimethylquinolin-8-yl)oxy] methyl]phenyl]sulfonyl]-N-[3-[[4... more LF 16-0687 (1-[[2,4-dichloro-3-[[(2,4-dimethylquinolin-8-yl)oxy] methyl]phenyl]sulfonyl]-N-[3-[[4-(aminoimethyl) phenyl] carbonylamino]propyl]-2(S)-pyrrolidinecarboxamide) has been selected from a large-scale medicinal chemistry program for further development. In competition binding studies using [3H]bradykinin (BK), LF 16-0687 bound to the human, rat and guinea-pig recombinant B2 receptor expressed in CHO cells giving K(i) values of 0.67 nM, 1.74 nM and 1.37 nM, respectively. It also bound to the native BK B2 receptor from human umbilical vein (HUV), rat uterus (RU) and guinea-pig ileum (GPI) giving K(i) values of 0.89 nM, 0.28 nM and 0.98 nM, respectively. It inhibited BK-induced IP1, IP2 and IP3 formation in INT407 cells yielding pK(B) values of 8.5, 8.6 and 8.7, respectively. In isolated organs experiments, LF 16-0687 behaved as a competitive antagonist of BK-mediated contractions giving pA2 values of 9.1 in HUV, 7.7 in RU and 9.1 in GPI. Binding and functional studies performed over 40 different receptors revealed that LF 16-0687 was selective for the BK B2 receptor. A continuous intravenous infusion of LF 16-0687 antagonized in a dose-dependent manner and with a rapid onset of action BK-induced hypotensive response. Subcutaneous administration of LF 16-0687 at 1.1 micromol/kg to rats markedly reduced BK-induced edema of the stomach (- 69%), duodenum (-65%) and pancreas (-56%).

Research paper thumbnail of Synthesis and in Vivo pharmacological profile of dimeric HOE 140 bradykinin antagonists

American Peptide Symposia, 2002

Research paper thumbnail of Design and Synthesis of Potent Bradykinin Agonists Containing a Benzothiazepine Moiety

Journal of Medicinal Chemistry, 1999

A bradykinin analogue (H-Arg-Pro-Pro-Gly-Phe-Ser-D-BT-Arg-OH, 3) in which the Pro-Phe dipeptide w... more A bradykinin analogue (H-Arg-Pro-Pro-Gly-Phe-Ser-D-BT-Arg-OH, 3) in which the Pro-Phe dipeptide was replaced by the (3S)[amino]-5-(carbonylmethyl)-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety has been synthesized. The same modification was performed on the potent bradykinin B(2) receptor antagonist HOE 140 (H-D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-Tic-Oic-Arg-OH), in which the -D-Tic-Oic- moiety was replaced by D-BT to yield H-D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-BT-Arg-OH, 1 (JMV1116). These compounds were examined in vitro for their binding affinity toward bradykinin B(1) and B(2) receptors as well as for their ability to interfere with bradykinin-induced contraction of both human umbilical vein and rat uterus. The two compounds 3 and 1 competed with [(3)H]bradykinin binding to the human cloned B(2) receptor giving K(i) values of 13 +/- 2 and 0.7 +/- 0.1 nM, respectively. Unexpectedly, both compounds were full bradykinin B(2) receptor agonists on the human umbilical vein (pD(2) = 6.60 +/- 0.07 for 3 and 6.80 +/- 0.08 for 1) and rat uterus (pD(2) = 7.20 +/- 0.09 for 3 and 7.50 +/- 0.09 for 1) preparations with the same efficacy as bradykinin. In addition 1 induced a concentration-dependent phosphoinositide production in CHO cells expressing the human cloned B(2) receptor. These data provide evidence for a bioactive conformation of bradykinin constrained at the dipeptide Pro-Phe.

Research paper thumbnail of Specific Nonpeptide Photoprobes as Tools for the Structural Study of the Angiotensin II AT 1 Receptor

Journal of Medicinal Chemistry, 1999

The aim of this work was to obtain photoactivatable nonpeptide antagonists of the angiotensin II ... more The aim of this work was to obtain photoactivatable nonpeptide antagonists of the angiotensin II AT(1) receptor. Based on structure-function relationships, two chemical structures as well as appropriate synthetic schemes were chosen as a frame for the design of radiolabeled azido probes. The feasibility of the strategy was first assessed by the synthesis of two tritiated ligands 21 and 22 possessing a high affinity for the AT(1) receptor and a low nonspecific binding to membrane or cell preparations. We then prepared two unlabeled azido derivatives 7 and 14 which retained a fairly high affinity for the AT(1) receptor. The latter compound proved to be suitable for receptor irreversible labeling and was prepared in its tritiated form 28. This tritiated azido nonpeptide probe displayed a K(d) value of 11.8 nM and a low nonspecific binding. It was suitable for specific and efficient covalent labeling of the recombinant AT(1A) receptor stably expressed in CHO cells. The electrophoretic pattern of the specifically labeled entity was strictly identical to that of purified receptor photolabeled with a biotinylated peptidic photoactivatable probe. This new tool should be useful for the mapping of the nonpeptide receptor binding site. These potential applications are discussed in light of the current knowledge of molecular mechanisms of G-protein coupled receptor activation and inactivation.

Research paper thumbnail of Synthesis and Biological Evaluation of Bradykinin B 1 /B 2 and Selective B 1 Receptor Antagonists

Journal of Medicinal Chemistry, 2000

We recently described a potent bradykinin B(2) receptor agonist (JMV1116) obtained by replacing t... more We recently described a potent bradykinin B(2) receptor agonist (JMV1116) obtained by replacing the D-Tic-Oic dipeptide moiety of HOE140 by a (3S)-amino-5-(carbonylmethyl)-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety. This compound inhibited the specific binding of [(3)H]BK on membranes of CHO cells expressing the human cloned B(2) receptor with nanomolar affinity and contracted both isolated rat uterus and human umbilical vein. These data demonstrated that D-BT could be a good mimic of the Pro-Phe dipeptide. In the present study we characterized B(1) receptor antagonists containing the D-BT moiety. We prepared an analogue of compound JMV1116 deleting the C-terminal arginine residue. The resulting compound (1) had an affinity of 83 nM for the human cloned B(1) receptor. The most remarkable property of 1 is its ability to bind also the B(2) receptor with an affinity of 4.4 nM despite the absence of the C-terminal arginine residue. Modifications at the N-terminal part of 1 associated with the substitution of the thienylalanine residue by alpha-(2-indanyl)glycine resulted in analogues selectively binding to the B(1) receptor with an affinity in the picomolar range.

Research paper thumbnail of From Bradykinin B2 Receptor Antagonists to Orally Active and Selective Bradykinin B1 Receptor Antagonists

Journal of Medicinal Chemistry, 2012

The bradykinin (BK) B1 receptor is an attractive target for the treatment of chronic pain and inf... more The bradykinin (BK) B1 receptor is an attractive target for the treatment of chronic pain and inflammation. Starting from a dual B1 and B2 antagonist, novel antagonists were designed that display low-nanomolar affinity for human B1 receptor and selectivity over B2. Initially, potent imidazoline derivatives were studied, but these compounds suffered from low bioavailability. This issue could be overcome by the use of less basic amino derivatives leading to orally active compounds.

Research paper thumbnail of Synthesis and Characterization of Bradykinin B 2 Receptor Agonists Containing Constrained Dipeptide Mimics

Journal of Medicinal Chemistry, 1999

We have previously shown that substitution of the D-Tic-Oic dipeptide by a (3S)-[amino]-5-(carbon... more We have previously shown that substitution of the D-Tic-Oic dipeptide by a (3S)-[amino]-5-(carbonylmethyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one (D-BT) moiety in the bradykinin B 2 receptor antagonist HOE 140 resulted in a full potent and selective bradykinin B 2 receptor agonist (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-D-BT-Arg-OH, JMV1116) exhibiting a high affinity for the human receptor (K i 0.7 nM). In the present study, we have investigated the effects of replacement of the D-Tic-Oic moiety by various constrained dipeptide mimetics. The resulting compounds were tested for their binding affinity toward the cloned human B 2 receptor and for their functional interaction with the bradykinin-induced contraction of isolated human umbilical vein. Subsequently, we have designed novel bradykinin B 2 receptor agonists which are likely to be resistant to enzymatic cleavage by endopeptidases and which might represent interesting new pharmacological tools. In an attempt to increase the potency of compound JMV1116, both its N-terminal part and the D-BT moiety were modified. Substitution of the D-arginine residue by a L-lysine residue led to a 10-fold more potent bradykinin B 2 ligand [compound 22 (JMV1465) (K i 0.07 nM)], retaining full agonist activity on human umbilical vein. Substitution of the D-BT moiety by a (3S)-[amino]-5-(carbonylmethyl)-2,3-dihydro-8-methyl-1,5-benzothiazepin-4(5H)one [D-BT(Me)] moiety led to compound 23 (JMV1609) which exhibited a higher agonist activity (pD 2 ) 7.4) than JMV1116 (pD 2 ) 6.8).

Research paper thumbnail of A Rational Approach to the Design and Synthesis of a New Bradykinin B 1 Receptor Antagonist

Journal of Medicinal Chemistry, 2000

We have previously synthesized a potent and selective B(1) bradykinin receptor antagonist, JMV164... more We have previously synthesized a potent and selective B(1) bradykinin receptor antagonist, JMV1645 (H-Lys-Arg-Pro-Hyp-Gly-Igl-Ser-D-BT-OH), containing a dipeptide mimetic ((3S)-amino-5-carbonylmethyl-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety) at the C-terminal. Analogues of this potent B(1) bradykinin receptor antagonist in which the central Pro(2)-Hyp(3)-Gly(4)-Igl(5) tetrapeptide has been replaced by constrained N-1-substituted-1,3,8-triazaspiro¿4. 5decan-4-one ring system were synthesized. Among these analogues, compound JMV1640 (1) was found to have an affinity of 24.10 +/- 9.48 nM for the human cloned B(1) receptor. It antagonized the ¿des-Arg(10)-kallidin-induced contraction of the human umbilical vein (pA(2) = 6.1 +/- 0.1). Compound 1 was devoid of agonist activity at the kinin B(1) receptor. Moreover, it did not bind to the human cloned B(2) receptor. Therefore, JMV1640 constitutes a lead compound for the rational search of nonpeptide B(1) receptor analogues based on the BK sequence.

Research paper thumbnail of In vitro and in vivo effects of the new nonpeptide bradykinin B 2 receptor antagonist, LF 16-0335C, on guinea-pig and rat kinin receptors

Fundamental & Clinical Pharmacology, 1999

Activation of the kinin-kallikrein system and stimulation of hradykinin (BK) B, receptors are tho... more Activation of the kinin-kallikrein system and stimulation of hradykinin (BK) B, receptors are thought to play an important role in the pathophysiology of inflammation and pain. In the present study, we report the pharmacological properties of a novel nonpeptide bradykinin B, receptor antagonist, L F 16-033SC, ( 1 -[[3-[(2,4-dimethylquinolin-8-yl)oxymethyl]-2,4-dichloro-phenyl]sulfonyl]-2(S)-[~4-~4-(aminoiminomethyl)-phenylcarbonyl]piperazin-1 -yl]carbonyl]pyrrolidine, 2HCI). In binding studies, L F 16-033SC competed with ['Hlbradykinin giving K, values of 1.65 f 0.36 nM and 2.20 t 0.30 nM in membrane preparations from rat uterus (RU) and guinea-pig ileum (GPI), respectively. In functional experiments, LF 16-033SC inhibited in a competitive manner BK-induced contractions of both isolated RU and GPI, leading to calculated PA, values of 7.70 k 0.70 and 8.30 k 0.30, respectively. The inhibitory effect of LF 16-033SC was

Research paper thumbnail of Characterisation of bradykinin receptors from juvenile pig coronary artery

European Journal of Pharmacology, 1996

Coronary artery rings from juvenile male farm pigs were incubated for 6 h and precontracted with ... more Coronary artery rings from juvenile male farm pigs were incubated for 6 h and precontracted with U46619. The rings relaxed in response to des-Arg9-bradykinin (pD2, 7.78 +/- 0.13; Emax, 87.4 +/- 4.3%) and to bradykinin (pD2, 8.69 +/- 0.30; Emax, 104.2 +/- 4.4%). These responses were abolished by endothelium removal and unaffected by indomethacin whilst NG-nitro-L-arginine reduced the relaxation due to des-Arg9-bradykinin only. Preincubation with cycloheximide or actinomycin had no effect against relaxations mediated by kinins whilst the protein trafficking inhibitor, brefeldin A, reduced by 52% the maximum response to des-Arg9-bradykinin. The bradykinin receptor antagonists, des-Arg9-[Leu8]bradykinin, Hoe 140 (D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]bradykinin) and NPC 567 (D-Arg-[Hyp3,D-Phe7]bradykinin) antagonized competitively the response to des-Arg9-bradykinin, giving respective pA2 values of 6.82 +/- 0.34, 6.63 +/- 0.28 and 6.48 +/- 0.41 whereas the non-peptide bradykinin B2 receptor antagonist, WIN 64338 (phosphonium, [[4-[[2-[[bis(cyclohexylamino)methylene]amino]-3-(2- naphtalenyl) 1-oxopropyl]amino]-phenyl]-methyl]tributyl chloride, monohydrochloride), was inactive. Hoe 140 and WIN 64338 but not des-Arg9[Leu8]bradykinin behaved as competitive antagonists towards the relaxation due to bradykinin. In conclusion, both bradykinin B2 and B1 receptors are present on the endothelium of large coronary arteries from juvenile pig. The bradykinin B1 receptor subtype appears partly inducible and is coupled to the synthesis of nitric oxide.

Research paper thumbnail of Induction of kinin B1 receptor-dependent vasoconstriction following balloon catheter injury to the rabbit carotid artery

British Journal of Pharmacology, 1994

1 Balloon catheter injury to the rabbit carotid artery damaged the endothelium and induced neoint... more 1 Balloon catheter injury to the rabbit carotid artery damaged the endothelium and induced neointima formation over 7 days. The area of intima, expressed as a percentage of the media, was 16.2 ± 4.2% and 8.2 ± 0.1% in balloon catheter-injured and sham-operated arteries. 2 Seven days after arterial injury, carotid arteries were isolated and set up as ring preparations in organ baths for isometric tension measurements. Balloon catheter-injured arteries first contracted with noradrenaline (0.01-0.1 M), contracted further in a concentration-dependent manner to bradykinin (BK; pD2, 5.98 ± 0.22; Ema, 41.3 ± 5.2% of KCl) and to des-Arg9-BK (pD2, 7.12 ± 0.36; Emax, 46.0 ± 9.9% of KCI). In contrast, vessel segments with endothelium either intact or acutely removed were unresponsive to both BK receptor agonists. 3 The concentration-contraction curves for BK and for des-Arg9-BK were shifted to the right by the B1 receptor antagonist, [Leu8]des-Arg9-BK (3 AM), but not by the selective B2 receptor antagonist, Hoe 140 (1O M). 4 Thus, BK and its metabolite, des-Arg9-BK act as vasoconstrictor agents following balloon catheter injury. These effects appear to be mediated by activation of B1 receptors.

Research paper thumbnail of Haemodynamic and cardiac effects of kinin B1 and B2 receptor stimulation in conscious instrumented dogs

British Journal of Pharmacology, 1996

1 Mongrel dogs were chronically instrumented with an intra-aortic catheter, a K6nigsberg intraven... more 1 Mongrel dogs were chronically instrumented with an intra-aortic catheter, a K6nigsberg intraventricular pressure transducer and a D6ppler flow probe around the left coronary artery. After ganglionic blockade with hexamethonium, the cardiovascular effects of bradykinin B, and B2 receptor agonists, des-Arg9-bradykinin and bradykinin (BK), were investigated in the presence and absence of specific antagonists. The contribution of nitric oxide (NO) and prostanoids to the cardiovascular effects of kinins was also examined. 2 BK (1 gg kg-' min-') and des-Arg9-BK (1 Mug kg-' min-') both given as a 2 min i.v. infusion, produced a significant decrease in mean arterial pressure (MAP, -34+4% for BK and -45+2% for des-Arg9-BK) and coronary vascular resistance (CVR, -37+5% for BK and -50+2% for des-Arg9-BK), without affecting cardiac contractility, left ventricular end diastolic pressure, and coronary velocity. BK caused a significantly greater decrease in MAP and CVR than des-Arg9-BK (P<0.05). 3 Pretreatment with the B, receptor antagonist, des-Arg9-[Leu8]-BK (25 pg kg-') significantly inhibited the decrease in MAP and CVR produced by des-Arg9-BK but not by BK. Infusion of des-Arg9-[Leu8]-BK alone also induced a significant decrease in MAP and CVR (P<0.05). In the presence of the B2 receptor antagonist, Hoe 140 (25 jug kg-'), only the decreases in MAP and CVR caused by BK were significantly reduced (P<0.05). 4 Inhibition of NO synthase with Nw-nitro-L-arginine (L-NOARG, 45 mg kg-') significantly (P<0.05) prevented the decrease in CVR but not MAP induced by des-Arg9-BK, whilst responses to BK were not affected by L-NOARG pretreatment. Inhibition of prostanoid synthesis with indomethacin (25 mg kg-') did not affect the reductions in MAP and CVR induced by des-Arg9-BK or BK. 5 In conclusion, i.v. des-Arg9-BK and BK administration induced reductions in MAP and CVR suggesting that in conscious instrumented dogs both B, and B2 receptors are present and can affect systemic blood pressure and coronary resistance regulation. Our results also suggest that prostanoids are not involved in the vascular response to kinins and that coronary vascular B, receptors are at least in part coupled to the release of NO.

Research paper thumbnail of Pharmacological and molecular evidence for kinin B 1 receptor expression in urinary bladder of cyclophosphamide-treated rats

British Journal of Pharmacology, 1999

1 In the present study, we developed an experimental model of cystitis induced by cyclophosphamid... more 1 In the present study, we developed an experimental model of cystitis induced by cyclophosphamide (CYP). In order to characterize des-Arg 9 -BK-induced contraction on the urinary bladder (UB) during the development of in¯ammation and to quantify kinin B 1 receptor gene expression using a quantitative RT ± PCR technique. 2 In the presence of peptidase inhibitors captopril (10 mM), DL-thiorphan (1 mM) and DL-2mercaptomethyl-3-guanidino-ethylthiopropanoic acid (MERGEPTA 5 mM), bradykinin (BK) (0.3 ± 3,000 nM) evoked a concentration-dependent contraction of rat UB which was not dierent between the CYP-and vehicle-treated groups. Unlike BK, des-Arg 9 -BK (0.3 ± 100,000 nM) did not contract UB from vehicle-treated rats but contracted vigorously bladder strips from CYP-treated rats 14, 24 and 168 h after treatment. In UB of 24 h treated rat, the pD 2 value of des-Arg 9 -BK was 7.3+0.1. 3 The cyclo-oxygenase inhibitor indomethacin (3 mM) reduced by 30% the maximal response of des-Arg 9 -BK. Both the kinin B 1 receptor antagonists des-Arg 9 -[Leu 8 ]BK (10 mM) and des-Arg 10 -Hoe 140 (10 mM) produced a rightward shift of the concentration-response curve to des-Arg 9 -BK yielding pK B values of 6.8+0.2 and 7.2+0.1, respectively, whilst the kinin B 2 receptor antagonist Hoe 140 (1 mM) had no eect. 4 After CYP treatment, mRNA coding for the kinin B 1 receptor appeared predominantly in UB. In this organ, the induction was progressive, reaching a maximum 48 h after CYP treatment. 5 In conclusion, the present study provides strong evidence for an induction of kinin B 1 receptors in UB of CYP-treated rats. This was associated at a molecular level with an increase in mRNA expression of the gene coding for the kinin B 1 receptor. This kinin receptor displayed the whole features of a classical rat kinin B 1 receptor. 2 P. Belichard and J.M. Luccarini equally contributed to this work.

Research paper thumbnail of LF 16.0335, a novel potent and selective nonpeptide antagonist of the human bradykinin B 2 receptor

British Journal of Pharmacology, 1998

1. In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1-[[3... more 1. In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1-[[3-[(2,4-dimethylquinolin-8-yl)oxymethyl]-2,4-dichloro-p henyl]sulphonyl] -2(S) - [[4 -[4-(aminoiminomethyl)phenylcarbonyl]piperazin-1-yl]ca rbonyl]pyrrolidine), a novel and potent nonpeptide antagonist of the human bradykinin (BK) B2 receptor. 2. LF 16.0335 displaced [3H]-BK binding to membrane preparations from CHO cells expressing the cloned human B2 receptor, INT 407 cells and human umbilical vein with Ki values of 0.84+/-0.39 nM, 1.26+/-0.68 nM and 2.34+/-0.36 nM, respectively. 3. In saturation binding studies performed in INT 407 cell membranes in the presence or absence of LF 16.0335, max values of [3H]-BK were not significantly changed suggesting that LF 16.0335 behaves as a competitive antagonist. 4. LF 16.0335 had no affinity for the cloned human kinin B1 receptor stably expressed in 293 cells. In addition, this compound at 1 microM did not significantly bind to a range of 40 different membrane receptors and eight ion channels except muscarinic M2 and M1 receptors for which an IC50 value of 0.9 and 1 microM was obtained. 5. BK stimulates in a concentration-dependent manner phosphoinositosides (IPs) production in cultured INT 407 cells. Concentration-response-curves to BK were shifted to the right in the presence of LF 16.0335 (0.1 microM) without reduction of the maximum. LF 16.0335 inhibited the concentration-contraction curve to BK in the human umbilical vein giving a pA2 value of 8.30+/-0.30 with a Schild plot slope that was not different from unity. 6. These results demonstrate that LF 16.0335 is a potent, selective and competitive antagonist of the human bradykinin B2 receptor.

Research paper thumbnail of Cloning and characterization of guinea pig interleukin-8 receptor

Biochemical Pharmacology, 2003

CXC-chemokine receptors 1 and 2 and their ligands (CXCL1, induce the selective recruitment of neu... more CXC-chemokine receptors 1 and 2 and their ligands (CXCL1, induce the selective recruitment of neutrophils during inflammation. Such receptors have not been characterized yet in guinea pig, an animal inflammation model of interest. We report the identification, cloning, and characterization of a CXCL8 receptor in guinea pig. Human CXCL8 produced in vivo neutrophilia, chemotaxis and intracellular calcium release of guinea pig neutrophils. The expression of this receptor at their neutrophil surface was investigated. The cDNA encoding a functional CXCL8 receptor was cloned from guinea pig neutrophils and sequenced. It was synthesized using RT-PCR, with oligonucleotide primers derived from well conserved regions of published CXCL8 receptors. This sequence presented an open reading frame coding for 352 amino acids and shares, at the amino acid level, 70 and 69% identity with human and rabbit CXCR2, respectively. The receptor was mainly expressed in neutrophils but it was also present in kidney, lung, spleen and, to a less extent, in heart. Cloned receptor transfected cells showed that this receptor displayed high affinity for human CXCL8, slightly lower than the affinity observed with guinea pig neutrophils. CXC chemokines from both rabbit and human were shown to induce inositol phosphate accumulation in these transfected cells. Receptor binding and activation characteristics together with sequence homology suggested that we identified a guinea pig equivalent of the human CXCR2 receptor. #

Research paper thumbnail of Pan PPAR agonist IVA337 is effective in prevention and treatment of experimental skin fibrosis

Annals of the Rheumatic Diseases, 2016

The pathogenesis of systemic sclerosis (SSc) involves a distinctive triad of autoimmune, vascular... more The pathogenesis of systemic sclerosis (SSc) involves a distinctive triad of autoimmune, vascular and inflammatory alterations resulting in fibrosis. Evidence suggests that peroxisome proliferator-activated receptors (PPARs) play an important role in SSc-related fibrosis and their agonists may become effective therapeutic targets. To determine the expression of PPARs in human fibrotic skin and investigate the effects of IVA337, a pan PPAR agonist, in in vitro and in vivo models of fibrosis. The antifibrotic effects of IVA337 were studied using a bleomycin-induced mouse model of dermal fibrosis. The in vivo effect of IVA337 on wound closure and inflammation were studied using an excisional model of wound healing. Low levels of PPARα and PPARγ were detected in the skin of patients with SSc compared with controls. In mice, IVA337 was associated with decreased extracellular matrix (ECM) deposition and reduced expression of phosphorylated SMAD2/3-intracellular effector of transforming growth factor (TGF)-β1. Although the antifibrotic effect of pan PPAR was similar to that of PPARγ agonist alone, a significant downregulation of several markers of inflammation was associated with IVA337. Despite its anti-inflammatory and antifibrotic properties, IVA337 did not interfere with wound closure. In vitro effects of IVA337 included attenuation of transcription of ECM genes and alteration of canonical and non-canonical TGF-β signalling pathways. These findings indicate that simultaneous activation of all three PPAR isoforms exerts a dampening effect on inflammation and fibrosis, making IVA337 a potentially effective therapeutic candidate in the treatment of fibrotic diseases including SSc.

Research paper thumbnail of Pharmacological profile of LF 16-0687, a new potent non-peptide bradykinin B2 receptor antagonist

Immunopharmacology, 1999

LF 16-0687 (1-[[2,4-dichloro-3-[[(2,4-dimethylquinolin-8-yl)oxy] methyl]phenyl]sulfonyl]-N-[3-[[4... more LF 16-0687 (1-[[2,4-dichloro-3-[[(2,4-dimethylquinolin-8-yl)oxy] methyl]phenyl]sulfonyl]-N-[3-[[4-(aminoimethyl) phenyl] carbonylamino]propyl]-2(S)-pyrrolidinecarboxamide) has been selected from a large-scale medicinal chemistry program for further development. In competition binding studies using [3H]bradykinin (BK), LF 16-0687 bound to the human, rat and guinea-pig recombinant B2 receptor expressed in CHO cells giving K(i) values of 0.67 nM, 1.74 nM and 1.37 nM, respectively. It also bound to the native BK B2 receptor from human umbilical vein (HUV), rat uterus (RU) and guinea-pig ileum (GPI) giving K(i) values of 0.89 nM, 0.28 nM and 0.98 nM, respectively. It inhibited BK-induced IP1, IP2 and IP3 formation in INT407 cells yielding pK(B) values of 8.5, 8.6 and 8.7, respectively. In isolated organs experiments, LF 16-0687 behaved as a competitive antagonist of BK-mediated contractions giving pA2 values of 9.1 in HUV, 7.7 in RU and 9.1 in GPI. Binding and functional studies performed over 40 different receptors revealed that LF 16-0687 was selective for the BK B2 receptor. A continuous intravenous infusion of LF 16-0687 antagonized in a dose-dependent manner and with a rapid onset of action BK-induced hypotensive response. Subcutaneous administration of LF 16-0687 at 1.1 micromol/kg to rats markedly reduced BK-induced edema of the stomach (- 69%), duodenum (-65%) and pancreas (-56%).

Research paper thumbnail of Synthesis and in Vivo pharmacological profile of dimeric HOE 140 bradykinin antagonists

American Peptide Symposia, 2002

Research paper thumbnail of Design and Synthesis of Potent Bradykinin Agonists Containing a Benzothiazepine Moiety

Journal of Medicinal Chemistry, 1999

A bradykinin analogue (H-Arg-Pro-Pro-Gly-Phe-Ser-D-BT-Arg-OH, 3) in which the Pro-Phe dipeptide w... more A bradykinin analogue (H-Arg-Pro-Pro-Gly-Phe-Ser-D-BT-Arg-OH, 3) in which the Pro-Phe dipeptide was replaced by the (3S)[amino]-5-(carbonylmethyl)-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety has been synthesized. The same modification was performed on the potent bradykinin B(2) receptor antagonist HOE 140 (H-D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-Tic-Oic-Arg-OH), in which the -D-Tic-Oic- moiety was replaced by D-BT to yield H-D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-BT-Arg-OH, 1 (JMV1116). These compounds were examined in vitro for their binding affinity toward bradykinin B(1) and B(2) receptors as well as for their ability to interfere with bradykinin-induced contraction of both human umbilical vein and rat uterus. The two compounds 3 and 1 competed with [(3)H]bradykinin binding to the human cloned B(2) receptor giving K(i) values of 13 +/- 2 and 0.7 +/- 0.1 nM, respectively. Unexpectedly, both compounds were full bradykinin B(2) receptor agonists on the human umbilical vein (pD(2) = 6.60 +/- 0.07 for 3 and 6.80 +/- 0.08 for 1) and rat uterus (pD(2) = 7.20 +/- 0.09 for 3 and 7.50 +/- 0.09 for 1) preparations with the same efficacy as bradykinin. In addition 1 induced a concentration-dependent phosphoinositide production in CHO cells expressing the human cloned B(2) receptor. These data provide evidence for a bioactive conformation of bradykinin constrained at the dipeptide Pro-Phe.

Research paper thumbnail of Specific Nonpeptide Photoprobes as Tools for the Structural Study of the Angiotensin II AT 1 Receptor

Journal of Medicinal Chemistry, 1999

The aim of this work was to obtain photoactivatable nonpeptide antagonists of the angiotensin II ... more The aim of this work was to obtain photoactivatable nonpeptide antagonists of the angiotensin II AT(1) receptor. Based on structure-function relationships, two chemical structures as well as appropriate synthetic schemes were chosen as a frame for the design of radiolabeled azido probes. The feasibility of the strategy was first assessed by the synthesis of two tritiated ligands 21 and 22 possessing a high affinity for the AT(1) receptor and a low nonspecific binding to membrane or cell preparations. We then prepared two unlabeled azido derivatives 7 and 14 which retained a fairly high affinity for the AT(1) receptor. The latter compound proved to be suitable for receptor irreversible labeling and was prepared in its tritiated form 28. This tritiated azido nonpeptide probe displayed a K(d) value of 11.8 nM and a low nonspecific binding. It was suitable for specific and efficient covalent labeling of the recombinant AT(1A) receptor stably expressed in CHO cells. The electrophoretic pattern of the specifically labeled entity was strictly identical to that of purified receptor photolabeled with a biotinylated peptidic photoactivatable probe. This new tool should be useful for the mapping of the nonpeptide receptor binding site. These potential applications are discussed in light of the current knowledge of molecular mechanisms of G-protein coupled receptor activation and inactivation.

Research paper thumbnail of Synthesis and Biological Evaluation of Bradykinin B 1 /B 2 and Selective B 1 Receptor Antagonists

Journal of Medicinal Chemistry, 2000

We recently described a potent bradykinin B(2) receptor agonist (JMV1116) obtained by replacing t... more We recently described a potent bradykinin B(2) receptor agonist (JMV1116) obtained by replacing the D-Tic-Oic dipeptide moiety of HOE140 by a (3S)-amino-5-(carbonylmethyl)-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety. This compound inhibited the specific binding of [(3)H]BK on membranes of CHO cells expressing the human cloned B(2) receptor with nanomolar affinity and contracted both isolated rat uterus and human umbilical vein. These data demonstrated that D-BT could be a good mimic of the Pro-Phe dipeptide. In the present study we characterized B(1) receptor antagonists containing the D-BT moiety. We prepared an analogue of compound JMV1116 deleting the C-terminal arginine residue. The resulting compound (1) had an affinity of 83 nM for the human cloned B(1) receptor. The most remarkable property of 1 is its ability to bind also the B(2) receptor with an affinity of 4.4 nM despite the absence of the C-terminal arginine residue. Modifications at the N-terminal part of 1 associated with the substitution of the thienylalanine residue by alpha-(2-indanyl)glycine resulted in analogues selectively binding to the B(1) receptor with an affinity in the picomolar range.

Research paper thumbnail of From Bradykinin B2 Receptor Antagonists to Orally Active and Selective Bradykinin B1 Receptor Antagonists

Journal of Medicinal Chemistry, 2012

The bradykinin (BK) B1 receptor is an attractive target for the treatment of chronic pain and inf... more The bradykinin (BK) B1 receptor is an attractive target for the treatment of chronic pain and inflammation. Starting from a dual B1 and B2 antagonist, novel antagonists were designed that display low-nanomolar affinity for human B1 receptor and selectivity over B2. Initially, potent imidazoline derivatives were studied, but these compounds suffered from low bioavailability. This issue could be overcome by the use of less basic amino derivatives leading to orally active compounds.

Research paper thumbnail of Synthesis and Characterization of Bradykinin B 2 Receptor Agonists Containing Constrained Dipeptide Mimics

Journal of Medicinal Chemistry, 1999

We have previously shown that substitution of the D-Tic-Oic dipeptide by a (3S)-[amino]-5-(carbon... more We have previously shown that substitution of the D-Tic-Oic dipeptide by a (3S)-[amino]-5-(carbonylmethyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one (D-BT) moiety in the bradykinin B 2 receptor antagonist HOE 140 resulted in a full potent and selective bradykinin B 2 receptor agonist (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-D-BT-Arg-OH, JMV1116) exhibiting a high affinity for the human receptor (K i 0.7 nM). In the present study, we have investigated the effects of replacement of the D-Tic-Oic moiety by various constrained dipeptide mimetics. The resulting compounds were tested for their binding affinity toward the cloned human B 2 receptor and for their functional interaction with the bradykinin-induced contraction of isolated human umbilical vein. Subsequently, we have designed novel bradykinin B 2 receptor agonists which are likely to be resistant to enzymatic cleavage by endopeptidases and which might represent interesting new pharmacological tools. In an attempt to increase the potency of compound JMV1116, both its N-terminal part and the D-BT moiety were modified. Substitution of the D-arginine residue by a L-lysine residue led to a 10-fold more potent bradykinin B 2 ligand [compound 22 (JMV1465) (K i 0.07 nM)], retaining full agonist activity on human umbilical vein. Substitution of the D-BT moiety by a (3S)-[amino]-5-(carbonylmethyl)-2,3-dihydro-8-methyl-1,5-benzothiazepin-4(5H)one [D-BT(Me)] moiety led to compound 23 (JMV1609) which exhibited a higher agonist activity (pD 2 ) 7.4) than JMV1116 (pD 2 ) 6.8).

Research paper thumbnail of A Rational Approach to the Design and Synthesis of a New Bradykinin B 1 Receptor Antagonist

Journal of Medicinal Chemistry, 2000

We have previously synthesized a potent and selective B(1) bradykinin receptor antagonist, JMV164... more We have previously synthesized a potent and selective B(1) bradykinin receptor antagonist, JMV1645 (H-Lys-Arg-Pro-Hyp-Gly-Igl-Ser-D-BT-OH), containing a dipeptide mimetic ((3S)-amino-5-carbonylmethyl-2,3-dihydro-1, 5-benzothiazepin-4(5H)-one (D-BT) moiety) at the C-terminal. Analogues of this potent B(1) bradykinin receptor antagonist in which the central Pro(2)-Hyp(3)-Gly(4)-Igl(5) tetrapeptide has been replaced by constrained N-1-substituted-1,3,8-triazaspiro¿4. 5decan-4-one ring system were synthesized. Among these analogues, compound JMV1640 (1) was found to have an affinity of 24.10 +/- 9.48 nM for the human cloned B(1) receptor. It antagonized the ¿des-Arg(10)-kallidin-induced contraction of the human umbilical vein (pA(2) = 6.1 +/- 0.1). Compound 1 was devoid of agonist activity at the kinin B(1) receptor. Moreover, it did not bind to the human cloned B(2) receptor. Therefore, JMV1640 constitutes a lead compound for the rational search of nonpeptide B(1) receptor analogues based on the BK sequence.

Research paper thumbnail of In vitro and in vivo effects of the new nonpeptide bradykinin B 2 receptor antagonist, LF 16-0335C, on guinea-pig and rat kinin receptors

Fundamental & Clinical Pharmacology, 1999

Activation of the kinin-kallikrein system and stimulation of hradykinin (BK) B, receptors are tho... more Activation of the kinin-kallikrein system and stimulation of hradykinin (BK) B, receptors are thought to play an important role in the pathophysiology of inflammation and pain. In the present study, we report the pharmacological properties of a novel nonpeptide bradykinin B, receptor antagonist, L F 16-033SC, ( 1 -[[3-[(2,4-dimethylquinolin-8-yl)oxymethyl]-2,4-dichloro-phenyl]sulfonyl]-2(S)-[~4-~4-(aminoiminomethyl)-phenylcarbonyl]piperazin-1 -yl]carbonyl]pyrrolidine, 2HCI). In binding studies, L F 16-033SC competed with ['Hlbradykinin giving K, values of 1.65 f 0.36 nM and 2.20 t 0.30 nM in membrane preparations from rat uterus (RU) and guinea-pig ileum (GPI), respectively. In functional experiments, LF 16-033SC inhibited in a competitive manner BK-induced contractions of both isolated RU and GPI, leading to calculated PA, values of 7.70 k 0.70 and 8.30 k 0.30, respectively. The inhibitory effect of LF 16-033SC was

Research paper thumbnail of Characterisation of bradykinin receptors from juvenile pig coronary artery

European Journal of Pharmacology, 1996

Coronary artery rings from juvenile male farm pigs were incubated for 6 h and precontracted with ... more Coronary artery rings from juvenile male farm pigs were incubated for 6 h and precontracted with U46619. The rings relaxed in response to des-Arg9-bradykinin (pD2, 7.78 +/- 0.13; Emax, 87.4 +/- 4.3%) and to bradykinin (pD2, 8.69 +/- 0.30; Emax, 104.2 +/- 4.4%). These responses were abolished by endothelium removal and unaffected by indomethacin whilst NG-nitro-L-arginine reduced the relaxation due to des-Arg9-bradykinin only. Preincubation with cycloheximide or actinomycin had no effect against relaxations mediated by kinins whilst the protein trafficking inhibitor, brefeldin A, reduced by 52% the maximum response to des-Arg9-bradykinin. The bradykinin receptor antagonists, des-Arg9-[Leu8]bradykinin, Hoe 140 (D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]bradykinin) and NPC 567 (D-Arg-[Hyp3,D-Phe7]bradykinin) antagonized competitively the response to des-Arg9-bradykinin, giving respective pA2 values of 6.82 +/- 0.34, 6.63 +/- 0.28 and 6.48 +/- 0.41 whereas the non-peptide bradykinin B2 receptor antagonist, WIN 64338 (phosphonium, [[4-[[2-[[bis(cyclohexylamino)methylene]amino]-3-(2- naphtalenyl) 1-oxopropyl]amino]-phenyl]-methyl]tributyl chloride, monohydrochloride), was inactive. Hoe 140 and WIN 64338 but not des-Arg9[Leu8]bradykinin behaved as competitive antagonists towards the relaxation due to bradykinin. In conclusion, both bradykinin B2 and B1 receptors are present on the endothelium of large coronary arteries from juvenile pig. The bradykinin B1 receptor subtype appears partly inducible and is coupled to the synthesis of nitric oxide.

Research paper thumbnail of Induction of kinin B1 receptor-dependent vasoconstriction following balloon catheter injury to the rabbit carotid artery

British Journal of Pharmacology, 1994

1 Balloon catheter injury to the rabbit carotid artery damaged the endothelium and induced neoint... more 1 Balloon catheter injury to the rabbit carotid artery damaged the endothelium and induced neointima formation over 7 days. The area of intima, expressed as a percentage of the media, was 16.2 ± 4.2% and 8.2 ± 0.1% in balloon catheter-injured and sham-operated arteries. 2 Seven days after arterial injury, carotid arteries were isolated and set up as ring preparations in organ baths for isometric tension measurements. Balloon catheter-injured arteries first contracted with noradrenaline (0.01-0.1 M), contracted further in a concentration-dependent manner to bradykinin (BK; pD2, 5.98 ± 0.22; Ema, 41.3 ± 5.2% of KCl) and to des-Arg9-BK (pD2, 7.12 ± 0.36; Emax, 46.0 ± 9.9% of KCI). In contrast, vessel segments with endothelium either intact or acutely removed were unresponsive to both BK receptor agonists. 3 The concentration-contraction curves for BK and for des-Arg9-BK were shifted to the right by the B1 receptor antagonist, [Leu8]des-Arg9-BK (3 AM), but not by the selective B2 receptor antagonist, Hoe 140 (1O M). 4 Thus, BK and its metabolite, des-Arg9-BK act as vasoconstrictor agents following balloon catheter injury. These effects appear to be mediated by activation of B1 receptors.

Research paper thumbnail of Haemodynamic and cardiac effects of kinin B1 and B2 receptor stimulation in conscious instrumented dogs

British Journal of Pharmacology, 1996

1 Mongrel dogs were chronically instrumented with an intra-aortic catheter, a K6nigsberg intraven... more 1 Mongrel dogs were chronically instrumented with an intra-aortic catheter, a K6nigsberg intraventricular pressure transducer and a D6ppler flow probe around the left coronary artery. After ganglionic blockade with hexamethonium, the cardiovascular effects of bradykinin B, and B2 receptor agonists, des-Arg9-bradykinin and bradykinin (BK), were investigated in the presence and absence of specific antagonists. The contribution of nitric oxide (NO) and prostanoids to the cardiovascular effects of kinins was also examined. 2 BK (1 gg kg-' min-') and des-Arg9-BK (1 Mug kg-' min-') both given as a 2 min i.v. infusion, produced a significant decrease in mean arterial pressure (MAP, -34+4% for BK and -45+2% for des-Arg9-BK) and coronary vascular resistance (CVR, -37+5% for BK and -50+2% for des-Arg9-BK), without affecting cardiac contractility, left ventricular end diastolic pressure, and coronary velocity. BK caused a significantly greater decrease in MAP and CVR than des-Arg9-BK (P<0.05). 3 Pretreatment with the B, receptor antagonist, des-Arg9-[Leu8]-BK (25 pg kg-') significantly inhibited the decrease in MAP and CVR produced by des-Arg9-BK but not by BK. Infusion of des-Arg9-[Leu8]-BK alone also induced a significant decrease in MAP and CVR (P<0.05). In the presence of the B2 receptor antagonist, Hoe 140 (25 jug kg-'), only the decreases in MAP and CVR caused by BK were significantly reduced (P<0.05). 4 Inhibition of NO synthase with Nw-nitro-L-arginine (L-NOARG, 45 mg kg-') significantly (P<0.05) prevented the decrease in CVR but not MAP induced by des-Arg9-BK, whilst responses to BK were not affected by L-NOARG pretreatment. Inhibition of prostanoid synthesis with indomethacin (25 mg kg-') did not affect the reductions in MAP and CVR induced by des-Arg9-BK or BK. 5 In conclusion, i.v. des-Arg9-BK and BK administration induced reductions in MAP and CVR suggesting that in conscious instrumented dogs both B, and B2 receptors are present and can affect systemic blood pressure and coronary resistance regulation. Our results also suggest that prostanoids are not involved in the vascular response to kinins and that coronary vascular B, receptors are at least in part coupled to the release of NO.

Research paper thumbnail of Pharmacological and molecular evidence for kinin B 1 receptor expression in urinary bladder of cyclophosphamide-treated rats

British Journal of Pharmacology, 1999

1 In the present study, we developed an experimental model of cystitis induced by cyclophosphamid... more 1 In the present study, we developed an experimental model of cystitis induced by cyclophosphamide (CYP). In order to characterize des-Arg 9 -BK-induced contraction on the urinary bladder (UB) during the development of in¯ammation and to quantify kinin B 1 receptor gene expression using a quantitative RT ± PCR technique. 2 In the presence of peptidase inhibitors captopril (10 mM), DL-thiorphan (1 mM) and DL-2mercaptomethyl-3-guanidino-ethylthiopropanoic acid (MERGEPTA 5 mM), bradykinin (BK) (0.3 ± 3,000 nM) evoked a concentration-dependent contraction of rat UB which was not dierent between the CYP-and vehicle-treated groups. Unlike BK, des-Arg 9 -BK (0.3 ± 100,000 nM) did not contract UB from vehicle-treated rats but contracted vigorously bladder strips from CYP-treated rats 14, 24 and 168 h after treatment. In UB of 24 h treated rat, the pD 2 value of des-Arg 9 -BK was 7.3+0.1. 3 The cyclo-oxygenase inhibitor indomethacin (3 mM) reduced by 30% the maximal response of des-Arg 9 -BK. Both the kinin B 1 receptor antagonists des-Arg 9 -[Leu 8 ]BK (10 mM) and des-Arg 10 -Hoe 140 (10 mM) produced a rightward shift of the concentration-response curve to des-Arg 9 -BK yielding pK B values of 6.8+0.2 and 7.2+0.1, respectively, whilst the kinin B 2 receptor antagonist Hoe 140 (1 mM) had no eect. 4 After CYP treatment, mRNA coding for the kinin B 1 receptor appeared predominantly in UB. In this organ, the induction was progressive, reaching a maximum 48 h after CYP treatment. 5 In conclusion, the present study provides strong evidence for an induction of kinin B 1 receptors in UB of CYP-treated rats. This was associated at a molecular level with an increase in mRNA expression of the gene coding for the kinin B 1 receptor. This kinin receptor displayed the whole features of a classical rat kinin B 1 receptor. 2 P. Belichard and J.M. Luccarini equally contributed to this work.

Research paper thumbnail of LF 16.0335, a novel potent and selective nonpeptide antagonist of the human bradykinin B 2 receptor

British Journal of Pharmacology, 1998

1. In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1-[[3... more 1. In the present paper, we describe the in vitro pharmacological properties of LF 16.0335 (1-[[3-[(2,4-dimethylquinolin-8-yl)oxymethyl]-2,4-dichloro-p henyl]sulphonyl] -2(S) - [[4 -[4-(aminoiminomethyl)phenylcarbonyl]piperazin-1-yl]ca rbonyl]pyrrolidine), a novel and potent nonpeptide antagonist of the human bradykinin (BK) B2 receptor. 2. LF 16.0335 displaced [3H]-BK binding to membrane preparations from CHO cells expressing the cloned human B2 receptor, INT 407 cells and human umbilical vein with Ki values of 0.84+/-0.39 nM, 1.26+/-0.68 nM and 2.34+/-0.36 nM, respectively. 3. In saturation binding studies performed in INT 407 cell membranes in the presence or absence of LF 16.0335, max values of [3H]-BK were not significantly changed suggesting that LF 16.0335 behaves as a competitive antagonist. 4. LF 16.0335 had no affinity for the cloned human kinin B1 receptor stably expressed in 293 cells. In addition, this compound at 1 microM did not significantly bind to a range of 40 different membrane receptors and eight ion channels except muscarinic M2 and M1 receptors for which an IC50 value of 0.9 and 1 microM was obtained. 5. BK stimulates in a concentration-dependent manner phosphoinositosides (IPs) production in cultured INT 407 cells. Concentration-response-curves to BK were shifted to the right in the presence of LF 16.0335 (0.1 microM) without reduction of the maximum. LF 16.0335 inhibited the concentration-contraction curve to BK in the human umbilical vein giving a pA2 value of 8.30+/-0.30 with a Schild plot slope that was not different from unity. 6. These results demonstrate that LF 16.0335 is a potent, selective and competitive antagonist of the human bradykinin B2 receptor.

Research paper thumbnail of Cloning and characterization of guinea pig interleukin-8 receptor

Biochemical Pharmacology, 2003

CXC-chemokine receptors 1 and 2 and their ligands (CXCL1, induce the selective recruitment of neu... more CXC-chemokine receptors 1 and 2 and their ligands (CXCL1, induce the selective recruitment of neutrophils during inflammation. Such receptors have not been characterized yet in guinea pig, an animal inflammation model of interest. We report the identification, cloning, and characterization of a CXCL8 receptor in guinea pig. Human CXCL8 produced in vivo neutrophilia, chemotaxis and intracellular calcium release of guinea pig neutrophils. The expression of this receptor at their neutrophil surface was investigated. The cDNA encoding a functional CXCL8 receptor was cloned from guinea pig neutrophils and sequenced. It was synthesized using RT-PCR, with oligonucleotide primers derived from well conserved regions of published CXCL8 receptors. This sequence presented an open reading frame coding for 352 amino acids and shares, at the amino acid level, 70 and 69% identity with human and rabbit CXCR2, respectively. The receptor was mainly expressed in neutrophils but it was also present in kidney, lung, spleen and, to a less extent, in heart. Cloned receptor transfected cells showed that this receptor displayed high affinity for human CXCL8, slightly lower than the affinity observed with guinea pig neutrophils. CXC chemokines from both rabbit and human were shown to induce inositol phosphate accumulation in these transfected cells. Receptor binding and activation characteristics together with sequence homology suggested that we identified a guinea pig equivalent of the human CXCR2 receptor. #

Research paper thumbnail of Pan PPAR agonist IVA337 is effective in prevention and treatment of experimental skin fibrosis

Annals of the Rheumatic Diseases, 2016

The pathogenesis of systemic sclerosis (SSc) involves a distinctive triad of autoimmune, vascular... more The pathogenesis of systemic sclerosis (SSc) involves a distinctive triad of autoimmune, vascular and inflammatory alterations resulting in fibrosis. Evidence suggests that peroxisome proliferator-activated receptors (PPARs) play an important role in SSc-related fibrosis and their agonists may become effective therapeutic targets. To determine the expression of PPARs in human fibrotic skin and investigate the effects of IVA337, a pan PPAR agonist, in in vitro and in vivo models of fibrosis. The antifibrotic effects of IVA337 were studied using a bleomycin-induced mouse model of dermal fibrosis. The in vivo effect of IVA337 on wound closure and inflammation were studied using an excisional model of wound healing. Low levels of PPARα and PPARγ were detected in the skin of patients with SSc compared with controls. In mice, IVA337 was associated with decreased extracellular matrix (ECM) deposition and reduced expression of phosphorylated SMAD2/3-intracellular effector of transforming growth factor (TGF)-β1. Although the antifibrotic effect of pan PPAR was similar to that of PPARγ agonist alone, a significant downregulation of several markers of inflammation was associated with IVA337. Despite its anti-inflammatory and antifibrotic properties, IVA337 did not interfere with wound closure. In vitro effects of IVA337 included attenuation of transcription of ECM genes and alteration of canonical and non-canonical TGF-β signalling pathways. These findings indicate that simultaneous activation of all three PPAR isoforms exerts a dampening effect on inflammation and fibrosis, making IVA337 a potentially effective therapeutic candidate in the treatment of fibrotic diseases including SSc.