Publications by authors named "Fournie-Zaluski M"

Background: The first line pharmacological treatment of cancer pain is morphine and surrogates but a significant pain relief and a reduction of the side-effects of these compounds makes it necessary to combine them with other drugs acting on different targets. The aim of this study was to measure the antinociceptive effect on cancer-induced bone pain resulting from the association of the endogenous opioids enkephalin and non-opioid analgesic drugs. For this purpose, PL265 a new orally active single dual inhibitor of the two degrading enkephalins enzymes, neprilysin (NEP) and aminopeptidase N (APN) was used.

View Article and Find Full Text PDF

New neprilysin inhibitors containing an α-mercaptoketone HSC(RR)CO group, as zinc ligand were designed. Two parameters were explored for potency optimization: the size of the inhibitor which could interact with the S, S' or S' domain of the enzyme and the nature of the substituents R, R of the mercaptoketone group. Introduction of a cyclohexyl chain in R, R position and a (3-thiophen)benzyl group in position R (compound 12n) yielded to the most potent inhibitor of this series with a Ki value of 2±0.

View Article and Find Full Text PDF

Neuropathic pain remains difficult to treat due to the involvement of various pathophysiological mechanisms in its pathogeny. Among the different opioidergic systems the enkephalinergic one is primarily recruited via activation of delta opioid receptor (DOP) in chronic pain and of mu opioid receptor (MOP) in acute pain. To investigate the role of their endogenous ligands Met and Leu-enkephalin in neuropathic pain control, a dual inhibitor of their degrading enzymes, PL265, which acts restrictively at the level of peripheral nociceptors, was administered per os to assess its efficacy in pain prevention and alleviation using a partial sciatic nerve ligation model (PSNL) in mice.

View Article and Find Full Text PDF

The endogenous opioid system, essentially constituted by two opioid receptors which are stimulated by the natural internal effectors enkephalins (Met-enkephalin and Leu-enkephalin), is present at the different sites (peripheral, spinal, central) of the control of pain. We have demonstrated that the protection of the enkephalin inactivation by the two metallopeptidases (neprilysin and neutral aminopeptidase) increases their local concentration selectively induced by pain stimuli triggering analgesic responses. With the aim of increasing the orally antinociceptive responses of the previously described disulfide DENKIs ( [Formula: see text] CH(R1)CH2-S-S-CH2-C(R2R3)CONHCH(R4)COOR5), we designed new pro-drugs, in the same chemical series, with a transient protection of the free amino group by an acyloxyalkyl carbamate, giving rise to ((CH3)2CHCO2CH(CH3)OCONHCH(R1)CH2-S-S-CH2-C(R2R3)CONHCH(R4)COOR5) pro-drugs 2a-2g.

View Article and Find Full Text PDF

The peripheral endogenous opioid system is critically involved in neuropathic and inflammatory pain generation as suggested by the modulation of opioid receptors expression and enkephalins (ENKs) release observed in these painful conditions. Accordingly, an innovative approach in the treatment of these nocifensive events is to increase and maintain high local concentrations of extracellular pain-evoked ENKs, by preventing their physiological enzymatic inactivation by two Zn metallopeptidases, the neutral endopeptidase (NEP, neprilysin, EC 3.4.

View Article and Find Full Text PDF

Protecting enkephalins, endogenous opioid peptides released in response to nociceptive stimuli, is an innovative approach for acute and neuropathic pain alleviation. This is achieved by inhibition of their enzymatic degradation by two membrane-bound Zn-metallopeptidases, neprilysin (NEP, EC 3.4.

View Article and Find Full Text PDF

Leukotriene A4 hydrolase (LTA4H) is a bifunctional zinc-dependent metalloprotease bearing both an epoxide hydrolase, producing the pro-inflammatory LTB4 leukotriene, and an aminopeptidase activity, whose physiological relevance has long been ignored. Distinct substrates are commonly used for each activity, although none is completely satisfactory; LTA4, substrate for the hydrolase activity, is unstable and inactivates the enzyme, whereas aminoacids β-naphthylamide and para-nitroanilide, used as aminopeptidase substrates, are poor and nonselective. Based on the three-dimensional structure of LTA4H, we describe a new, specific, and high-affinity fluorigenic substrate, PL553 [L-(4-benzoyl)phenylalanyl-β-naphthylamide], with both in vitro and in vivo applications.

View Article and Find Full Text PDF

Detection and quantification of low doses of botulinum toxin serotype A (BoNT/A) in medicinal preparations require precise and sensitive methods. With mounting pressure from governmental authorities to replace the mouse LD50 assay, interest in alternative methods such as the endopeptidase assay, quantifying the toxin active moiety, is growing. Using internal collision-induced fluorescence quenching, Pharmaleads produced peptides encompassing the SNAP-25 cleavage site: a 17-mer (PL63) and a 48-mer (PL50) reaching the previously identified α-exosite, with PL50 showing higher apparent affinity for BoNT/A.

View Article and Find Full Text PDF

Inflammatory pain can be controlled by endogenous opioid peptides. Here we blocked the degradation of opioids in peripheral injured tissue to locally augment this physiological system. In rats with hindpaw inflammation, inhibitors of aminopeptidase N (APN; bestatin) or neutral endopeptidase (NEP; thiorphan), and a dual inhibitor, NH(2)-CH-Ph-P(O)(OH)CH(2)-CH-CH(2)Ph(p-Ph)-CONH-CH-CH(3)-COOH (P8B), were applied to injured paws.

View Article and Find Full Text PDF

Legionella pneumophila has been shown to secrete a protease termed major secretory protein (Msp). This protease belongs to the M4 family of metalloproteases and shares 62.9% sequence similarity with pseudolysin (EC 3.

View Article and Find Full Text PDF

Chronic pain remains unsatisfactorily treated, and few novel painkillers have reached the market in the past century. Increasing the levels of the main endogenous opioid peptides - enkephalins - by inhibiting their two inactivating ectopeptidases, neprilysin and aminopeptidase N, has analgesic effects in various models of inflammatory and neuropathic pain. Stemming from the same pharmacological concept, fatty acid amide hydrolase (FAAH) inhibitors have also been found to have analgesic effects in pain models by preventing the breakdown of endogenous cannabinoids.

View Article and Find Full Text PDF

Protease inhibitors represent a major class of drugs, even though a large number of proteases remain unexplored. Consequently, a great interest lies in the identification of highly sensitive substrates useful for both the characterization and the validation of these enzyme targets and for the design of inhibitors as potential therapeutic agents through high-throughput screening (HTS). With this aim, a synthetic substrate library, in which the highly fluorescent (L)-pyrenylalanine residue (Pya) is efficiently quenched by its proximity with the p-nitro-(L)-phenylalanine (Nop) moiety, was designed.

View Article and Find Full Text PDF

Endothelin-converting enzyme-2 (ECE-2) is a membrane-bound zinc-dependent metalloprotease that shares a high degree of sequence homology with ECE-1, but displays an acidic pH optimum characteristic of maturing enzymes acting late in the secretory pathway. Although ECE-2, like ECE-1, can cleave the big endothelin intermediate to produce the vasoconstrictive endothelin peptide, its true physiological function remains to be elucidated, a task that is hampered by the lack of specific tools to study and discriminate ECE-2 from ECE-1, i.e.

View Article and Find Full Text PDF

Leukotriene A4 hydrolase (LTA4H) is a key enzyme in the inflammatory process of mammals. It is an epoxide hydrolase and an aminopeptidase of the M1 family of the MA clan of Zn-metallopeptidases. We have solved the crystal structure of LTA4H in complex with N-[3(R)-[(hydroxyamino)carbonyl]-2-benzyl-1-oxopropyl]-L-alanine, a potent inhibitor of several Zn-metalloenzymes, both endopeptidases and aminopeptidases.

View Article and Find Full Text PDF

The preferred ligand of angiotensin (Ang) II type 2 (AT(2)R)-mediated natriuresis is Ang III. The major enzyme responsible for the metabolism of Ang III is aminopeptidase N, which is selectively inhibited by compound PC-18. In this study, urine sodium excretion rates (U(Na)V), fractional excretion of sodium, fractional excretion of lithium, glomerular filtration rate, and mean arterial pressures were studied in prehypertensive and hypertensive spontaneously hypertensive rats (SHRs) and compared with age-matched Wistar-Kyoto rats (WKYs).

View Article and Find Full Text PDF

Although previous studies describe the up-regulation of purinergic P2X(3) receptors expressed at peripheral nociceptive fibers in experimental painful neoplastic processes, the analgesic efficacy of P2X(3) receptor antagonists has not been tested in these settings. We study here the effect of the P2X(3) receptor antagonist, A-317491, on thermal hyperalgesia produced by the intratibial inoculation of NCTC 2472 fibrosarcoma cells to C3H/HeJ mice. The peritumoral administration of A-317491 (10-100 microg) dose-dependently attenuated osteosarcoma-induced thermal hyperalgesia without modifying thermal latencies measured in the contralateral paws.

View Article and Find Full Text PDF

Botulinum neurotoxin type A (BoNT/A), the most poisonous substance known to humans, is a potential bioterrorism agent. The light-chain protein induces a flaccid paralysis through cleavage of the 25-kDa synaptosome-associated protein (SNAP-25), involved in acetylcholine release at the neuromuscular junction. BoNT/A is widely used as a therapeutic agent and to reduce wrinkles.

View Article and Find Full Text PDF

Several lines of data previously indicated that N-terminally truncated forms of amyloid-beta (Abeta) peptides are likely the earliest and more abundant species immunohistochemically detectable in Alzheimer's disease-affected brains. It is noteworthy that the free N-terminal residue of full-length Abeta (fl-Abeta) is an aspartyl residue, suggesting that Abeta could be susceptible to exopeptidasic attack by aminopeptidase A (APA)-like proteases. In this context, we have examined whether APA could target Abeta peptides in both cell-free and cellular models.

View Article and Find Full Text PDF

M1 aminopeptidases comprise a large family of biologically important zinc enzymes. We show that peptide turnover by the M1 prototype, leukotriene A4 hydrolase/aminopeptidase, involves a shift in substrate position associated with exchange of zinc coordinating groups, while maintaining the overall coordination geometry. The transition state is stabilized by residues conserved among M1 members and in the final reaction step, Glu-296 of the canonical zinc binding HEXXH motif shuffles a proton from the hydrolytic water to the leaving group.

View Article and Find Full Text PDF

We have previously shown that stimulation of peripheral opioid receptors by exogenous opiates counteracts the thermal hyperalgesia elicited by a tibial osteosarcoma due to intraosteal inoculation of NCTC 2472 cells to mice. Aiming to study whether pheripheral endogenous enkephalins could also counteract this painful symptom, we assayed in this model the effects of PL37, an orally active dual inhibitor of enkephalin inactivating enzymes. Oral administration of PL37 (25 mg/kg) completely supressed osteosarcoma-induced thermal hyperalgesia through the activation of micro-opioid receptors, since the administration of cyprodime (1 mg/kg) inhibited its antihyperalgesic effect.

View Article and Find Full Text PDF

In the kidney, angiotensin II (Ang II) is metabolized to angiotensin III (Ang III) by aminopeptidase A (APA). In turn, Ang III is metabolized to angiotensin IV by aminopeptidase N (APN). Renal interstitial (RI) infusion of Ang III, but not Ang II, results in angiotensin type-2 receptor (AT(2)R)-mediated natriuresis.

View Article and Find Full Text PDF

The renal angiotensin angiotensin type 2 receptor has been shown to mediate natriuresis, and angiotensin III, not angiotensin II, may be the preferential angiotensin type 2 receptor activator of this response. Angiotensin III is metabolized to angiotensin IV by aminopeptidase N. The present study hypothesizes that inhibition of aminopeptidase N will augment natriuretic responses to intrarenal angiotensin III in angiotension type 1 receptor-blocked rats.

View Article and Find Full Text PDF

Little is known about the production and function of metallopeptidases in embryonic development. One such enzyme, aminopeptidase N (APN), is present in several epithelia, the brain and angiogenic vessels in adults. APN promotes vascular growth and endothelial cell proliferation in physiological and pathological models of angiogenesis.

View Article and Find Full Text PDF