Category: 2016

JMV2894, a novel growth hormone secretagogue, accelerates body mass recovery in an experimental model of cachexia

Endocrine, 2016, Pages: Ahead of Print

E. Bresciani, L. Rizzi, L. Molteni, M. Ravelli, A. Liantonio, K. Ben Haj Salah, J. A. Fehrentz, J. Martinez, R. J. Omeljaniuk, G. Biagini, V. Locatelli, A. Torsello

Abstract

Oncol. patients subjected to chemotherapy frequently present aphagia, malnutrition, and cachexia. The purpose of this study was to investigate whether selected growth hormone secretagogues including hexarelin, JMV2894 and JMV2951 could antagonize body wt. loss and wasting induced by cisplatin administration in rats. The three growth hormone secretagogues behaved as full agonists of the growth hormone secretagogues receptor both in terms of ability to stimulate calcium mobilization in Chinese hamster ovary cells and stimulation of growth hormone release in neonatal rats. Adult rats were (i) treated with vehicle throughout (controls), or (ii) treated with cisplatin (days 1-3) and a growth hormone secretagogues or vehicle, (days 1-12). Body wt. and food consumption were measured daily. Although all growth hormone secretagogues caused initial transient acute increases in food intake, the total amt. of food eaten by controls and growth hormone secretagogues treated groups over the 12 exptl. days was not significantly different. All groups pre-treated with cisplatin lost up to 5-10 % body wt. in the first 4 days; they subsequently gained wt. at a rate comparable with controls. Interestingly, rats which received JMV2894 demonstrated a faster gain in body wt. than any other growth hormone secretagogues treated group and at the end of the protocol reached a wt. similar to that of controls. JMV2894 did not stimulate perirenal and epididymal fat accumulation but reduced MuRF mRNA levels in skeletal muscles. In conclusion, our findings demonstrate that JMV2894 antagonizes cisplatin induced wt. loss in rats and may prove useful in antagonizing cachexia assocd. with cancer and chemotherapy in humans.

Structure-Activity Relationships of JMV4463, a Vectorized Cathepsin D Inhibitor with Antiproliferative Properties: The Unique Role of the AMPA-Based Vector

ChemMedChem, 2016, Volume: 11, Issue: 3, Pages: 302-308, DOI: 10.1002/cmdc.201500457

L. Vezenkov, C. A. Sanchez, V. Bellet, V. Martin, M. Maynadier, N. Bettache, V. Lisowski, J. Martinez, M. Garcia, M. Amblard, J. F. Hernandez

Abstract

Cathepsin D (CathD) is overexpressed and secreted by several solid tumors and stimulates their growth, the mechanism of which is still not understood.  In this context, the pepstatin bioconjugate JMV4463 [Ac-arg-O2Oc-(Val)3-Sta-Ala-Sta-(AMPA)4-NH2; O2Oc=8-amino-3,6-dioxaoctanoyl, Sta=statine, AMPA=ortho-aminomethylphenylacetyl], contg. a new kind of cell-penetrating vector, was previously shown to exhibit potent antiproliferative effects in vitro and to delay the onset of tumors in vivo.  In this study, the authors performed a structure-activity relationship anal. to evaluate the significance of the inhibitor and vector moieties of JMV4463.  By modifying both statine residues of pepstatin the authors found that the antiproliferative activity is correlated with CathD inhibition, supporting a major role of the catalytic activity of intracellular CathD in cancer cell proliferation.  Replacing the vector composed of four AMPA units with other vectors was found to abolish cytotoxicity, although all of the conjugates enabled pepstatin transport into cells.  In addn., the AMPA4 vector must be localized at the C terminus of the bioconjugate.  The unexpected importance of the vector structure and position for cytotoxic action suggests that AMPA4 enables pepstatin to inhibit the proteolysis of crit. CathD substrates involved in cell proliferation via a unique mechanism of action.

Unambiguous and Controlled One-Pot Synthesis of Multifunctional Silica Nanoparticles

Chemistry of Materials, 2016, Volume: 28, Issue: 3, Pages: 885-889, DOI: 10.1021/acs.chemmater.5b04398

J. Ciccione, T. Jia, J .L. Coll, K. Parra, M. Amblard, S. Jebors, J. Martinez, A. Mehdi, G. Subra 

Abstract

A method for obtaining in a single step well-defined tunable multifunctional fluorescent particles having their surface functionalized with multiple covalently linked ligands is reported.  The strategy relies on the synthesis of hybrid bioorg.-inorg. peptide ligands, greatly simplifying the design of multifunctional nanoparticles.  It was possible to tune the ratio of two grafted ligands on the surface of the SiNPs simply by adjusting the relative concn. of hybrid species in the starting soln.  An original fluorine NMR method was applied to the dissolved SiNPs to demonstrate our hypothesis.

A switchable stapled peptide

Journal of Peptide Science, 2016, Volume: 22, Issue: 3, Pages: 143-148, DOI: 10.1002/psc.2851

A. Kalistratova, B. Legrand, P. Verdie, E. Naydenova, M. Amblard, J. Martinez, G. Subra

Abstract

The O-N acyl transfer reaction has gained significant popularity in peptide and medicinal chem.  This reaction has been successfully applied to the synthesis of difficult sequence-contg. peptides, cyclic peptides, epimerization-free fragment coupling and more recently, to switchable peptide polymers.  Herein, we describe a related strategy to facilitate the synthesis and purifn. of a hydrophobic stapled peptide.  The staple consists of a serine linked through an amide bond formed from its carboxylic acid function and the side chain amino group of diaminopropionic acid and through an ester bond formed from its amino group and the side chain carboxylic acid function of aspartic acid.  The α-amino group of serine was protonated during purifn.  Interestingly, when the peptide was placed at physiol. pH, the free amino group initiated the O-N shift reducing the staple length by one atom, leading to a more hydrophobic stapled peptide.

Easy Synthesis of Tunable Hybrid Bioactive Hydrogels

Chemistry of Materials, 2016, Volume: 28, Issue: 5, Pages: 1261-1265,  DOI: 10.1021/acs.chemmater.5b04881

C. Echalier, C. Pinese, X. Garric, H. Van Den Berghe, E. Jumas Bilak, J. Martinez, A. Mehdi, G. Subra 

Abstract

Hydrogels are raising an increasing interest in the biomedical field and have found applications in tissue engineering and regenerative medicine.  In order to mimic the complexity of natural tissues, functionalization of hydrogels with bioactive mols. is of first importance.  In this context, we developed a bottom-up approach based on the synthesis of hybrid silylated blocks that can be combined to obtain covalently functionalized gels.  In this study, hybrid silylated PEG and hybrid silylated bioactive peptides were synthesized and mixed in desired ratio before being simply dissolved in phosphate buff-er at physiol. pH to form a gel.  The soln. turns quickly into a covalent functional gel at 37 °C.  Mech. properties of these hydrogels were studied and their biocompatibility was demonstrated.  Depending on the type of bioactive peptides introduced within the gels, they exhibited either antibacterial or cell adhesion properties demonstrating the potency of this sol-gel modular strategy for fine tuning of gel properties.

Selective homodimerization of unprotected peptides using hybrid hydroxydimethylsilane derivatives

RSC Advances, 2016, Volume: 6, Issue: 39, Pages: 32905-32914, DOI: 10.1039/C6RA06075G

C. Echalier, A. Kalistratova, J. Ciccione, A. Lebrun, B. Legrand, E. Naydenova, D. Gagne, J. A. Fehrentz , J. Marie, M. Amblard, A. Mehdi, J. Martinez, G. Subra 

Abstract

We developed a simple and straightforward way to dimerize unprotected peptide sequences that relies on a chemoselective condensation of hybrid peptides bearing a hydroxydimethylsilyl group at a chosen position (either C-ter, N-ter or side-chain linked) to generate siloxane bonds upon freeze-drying. Interestingly, the siloxane bond sensitivity to hydrolysis is strongly pH-dependent. Thus, we investigated the stability of siloxane dimers in different exptl. conditions. For that purpose, 29Si, 13C and 1H NMR spectra were recorded to accurately quantify the ratio of dimer/monomer. More interestingly, we showed that 1H resonances of the methylene and Me groups connected to the Si can be used as sensitive probes to monitor siloxane hydrolysis and to det. the half-lives of the dimers. Importantly, we showed that the dimers were rather stable at pH 7.4 (t1/2 ≈ 400 h) and we applied the dimerization strategy to bioactive sequences. Once optimized, three dimers of the growth hormone releasing hexapeptide (GHRP-6) were prepd. Interestingly, their pharmacol. evaluation revealed that the activity of the dimeric ligands could be switched from agonist to inverse agonist depending on the position of dimerization.

New ligands of the ghrelin receptor based on the 1,2,4-triazole scaffold by introduction of a second chiral center

Bioorganic & Medicinal Chemistry Letters, 2016, Volume: 26, Issue: 10, Pages: 2408-2412, DOI: 10.1016/j.bmcl.2016.04.003

M. Maingot, A. L Blayo, S. Denoyelle, C. M’Kadmi, M. Damian, S. Mary, D. Gagne, P. Sanchez, B. Aicher, P. Schmidt, G. Muller, M. Teifel, E. Gunther, J. Marie, J.-L. Baneres, J. Martinez, J. A. Fehrentz, 

Abstract

Introducing a second chiral center on the previously described 1,2,4-triazole, allowed us to increase diversity and elongate the ‘C-terminal part’ of the mol.  Therefore, the authors were able to explore mimics of the substance P analogs described as inverse agonists.  Some compds. presented affinities in the nanomolar range and potent biol. activities, while one exhibited a partial inverse agonist behavior similar to a Substance P analog.

Novel 1H-Pyrrolo[3,2-c]quinoline Based 5-HT6 Receptor Antagonists with Potential Application for the Treatment of Cognitive Disorders Associated with Alzheimer’s Disease

ACS Chemical Neuroscience, 2016, Volume: 7, Issue: 7, Pages: 972-983,  DOI: 10.1021/acschemneuro.6b00090

K. Grychowska, G. Satala, T. Kos, A. Partyka, E. Colacino, S. Chaumont-Dubel, X. Bantreil, A. Wesolowska, M. Pawlowski, J. Martinez, P. Marin, G. Subra, A. J. Bojarski, F. Lamaty, P. Popik, P. Zajdel 

Abstract

Modulators of the serotonin 5-HT6 receptor (5-HT6R) offer a promising strategy for the treatment of the cognitive deficits that are assocd. with dementia and Alzheimer’s disease.  Herein, we report the design, synthesis, and characterization of a novel class of 5-HT6R antagonists that is based on the 1H-pyrrolo[3,2-c]quinoline core.  The most active compds. exhibited comparable binding affinity to the ref. compd., SB-742457, and markedly improved selectivity.  Lead optimization led to the identification of (S)-1-[(3-chlorophenyl)sulfonyl]-4-(pyrrolidine-3-yl-amino)-1H-pyrrolo[3,2-c]quinoline (14) (Ki = 3 nM and Kb = 0.41 nM).  Pharmacol. characterization of the 5-HT6R’s constitutive activity at Gs signaling revealed that 14 behaved as a neutral antagonist, while SB-742457 was classified as an inverse agonist.  Both compds. 14 and SB-742457 reversed phencyclidine-induced memory deficits and displayed distinct procognitive properties in cognitively unimpaired animals (3 mg/kg) in NOR tasks.  Compds. 14 and SB-742457 were also active in the Vogel test, yet the anxiolytic effect of 14 was 2-fold higher (MED = 3 mg/kg).  Moreover, 14 produced, in a 3-fold higher dose (MED = 10 mg/kg), antidepressant-like effects that were similar to those produced by SB-742457 (MED = 3 mg/kg).  Together, these data suggest that the 4-(pyrrolidine-3-yl-amino)-1H-pyrrolo[3,2-c]quinoline scaffold is an attractive mol. framework for the development of procognitive agents.  The results are promising enough to warrant further detailed mechanistic studies on the therapeutic potential of 5-HT6R antagonists and inverse agonists for the treatment of cognitive decline and depression/anxiety symptoms that are comorbidities of Alzheimer’s disease.

In vivo stabilization of a gastrin-releasing peptide receptor antagonist enhances PET imaging and radionuclide therapy of prostate cancer in preclinical studies

Theranostics, 2016, Volume: 6, Issue: 1, Pages: 104-117, DOI: 10.7150/thno.13580

K. L. S. Chatalic, M. Konijnenberg, J. Nonnekens, H. de Blois, S. Erik, C. de Ridder, L. Brunel, J. A. Fehrentz, J. Martinez, D. C. van Gent, B. A. Nock, T. Maina, W. M. van Weerden, M. de Jong

Abstract

A single tool for early detection, accurate staging, and personalized treatment of prostate cancer (PCa) would be a major breakthrough in the field of PCa.  Gastrin-releasing peptide receptor (GRPR) targeting peptides are promising probes for a theranostic approach for PCa overexpressing GRPR.  However, the successful application of small peptides in a theranostic approach is often hampered by their fast in vivo degrdn. by proteolytic enzymes, such as neutral endopeptidase (NEP).  Here we show for the first time that co-injection of a NEP inhibitor (phosphoramidon (PA)) can lead to an impressive enhancement of diagnostic sensitivity and therapeutic efficacy of the theranostic 68Ga-/177Lu-JMV4168 GRPR-antagonist.  Co-injection of PA (300 μg) led to stabilization of 177Lu-JMV4168 in murine peripheral blood.  In PC-3 tumor-bearing mice, PA co-injection led to a two-fold increase in tumor uptake of 68Ga-/177Lu-JMV4168, 1 h after injection.  In positron emission tomog. (PET) imaging with 68Ga-JMV4168, PA co-injection substantially enhanced PC-3 tumor signal intensity.  Radionuclide therapy with 177Lu-JMV4168 resulted in significant regression of PC-3 tumor size.  Radionuclide therapy efficacy was confirmed by prodn. of DNA double strand breaks, decreased cell proliferation and increased apoptosis.  Increased survival rates were obsd. in mice treated with 177Lu-JMV4168 plus PA as compared to those without PA.  This data shows that co-injection of the enzyme inhibitor PA greatly enhances the theranostic potential of GRPR-radioantagonists for future application in PCa patients.

12/14/14-Helix Formation in 2:1 α/β-Hybrid Peptides Containing Bicyclo[2.2.2]octane Ring Constraints

Chemistry – A European Journal, 2016, Volume: 22, Issue: 34, Pages: 11986-11990, DOI: 10.1002/chem.201602746

B. Legrand, C. Andre, L. Moulat, C. Didierjean, P. Hermet, J. L. Bantignies, J. Martinez, M. Amblard, M. Calmes 

Abstract

In the search for new peptide ligands contg. selenium in their sequences, we investigated L-4-selenazolidine-carboxylic acid (selenazolidine, Sez) as a proline analog with the chalcogen atom in the γ-position of the ring.  In contrast to proteinogenic selenocysteine (Sec) and selenomethionine (SeMet), the incorporation within a peptide sequence of such a non-natural amino acid has never been studied.  There is thus a great interest in increasing the possibility of selenium insertion within peptides, esp. for sequences that do not possess a sulfur contg. amino acid (Cys or Met), by offering other selenated residues suitable for peptide synthesis protocols.  Herein, we have evaluated selenazolidine in Boc/Bzl (Boc = tert-butoxycarbonyl) and Fmoc/tBu (Fmoc = 9-fluorenylmethoxycarbonyl) strategies through the synthesis of a model tripeptide, both in soln. and on a solid support.  Special attention was paid to the stability of the Sez residue in basic conditions.  Thus, generic protocols have been optimized to synthesize Sez-contg. peptides, through the use of an Fmoc-Xxx-Sez-OH dipeptide unit.  As an example, a new analog of the vasopressin receptor-1A antagonist was prepd., in which Pro was replaced with Sez [3-(4-hydroxyphenyl)-propionyl-D-Tyr(Me)-Phe-Gln-Asn-Arg-Sez-Arg-NH2].  Both proline and such pseudo-proline contg. peptides exhibited similar pharmacol. properties and endopeptidase stabilities indicating that the presence of the selenium atom has minimal functional effects.  Taking into account the straightforward handling of Sez as a dipeptide building block in a conventional Fmoc/tBu SPPS strategy, this result suggested a wide range of potential uses of the Sez amino acid in peptide chem., for instance as a viable proline surrogate as well as a selenium probe, complementary to Sec and SeMet, for NMR and mass spectrometry anal. purposes.