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1.
Amino Acids ; 47(6): 1107-15, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25715756

RESUMO

Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.


Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Estereoisomerismo
2.
FASEB J ; 27(9): 3741-52, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23756650

RESUMO

Management of painful peripheral neuropathies remains challenging, since patients with chronic pain respond poorly to the available pharmacopeia. In recent years, the G-protein-coupled receptor neurotensin (NT) type 2 (NTS2) emerged as an attractive target for treating transitory pain states. To date, however, there is no evidence for its role in the regulation of chronic peripheral neuropathies. Here, we found that NTS2 receptors were largely localized to primary afferent fibers and superficial dorsal horns. Changes in the time course of the gene expression profile of NT, NTS1, and NTS2 were observed over a 28-d period following the sciatic nerve constriction [chronic constriction injury (CCI) model]. We next determined the effects of central delivery of selective-NTS2 agonists to CCI-treated rats on both mechanical allodynia (evoked withdrawal responses) and weight-bearing deficits (discomfort and quality-of-life proxies). The NTS2 analogs JMV431, levocabastine, and ß-lactotensin were all effective in reducing ongoing tactile allodynia in CCI-treated rats. Likewise, amitriptyline, pregabalin, and morphine significantly attenuated CCI-induced mechanical hypersensitivity. NTS2 agonists were also efficient in reversing weight-bearing and postural deficits caused by nerve damage, unlike reference analgesics currently used in the clinic. Thus, NTS2 agonists may offer new treatment avenues for limiting pain associated with peripheral neuropathies and improve functional rehabilitation and well-being.


Assuntos
Neuralgia/tratamento farmacológico , Receptores de Neurotensina/metabolismo , Analgésicos/uso terapêutico , Animais , Western Blotting , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Masculino , Microscopia Eletrônica de Transmissão , Neuralgia/induzido quimicamente , Oligopeptídeos/uso terapêutico , Piperidinas/uso terapêutico , Ratos , Ratos Sprague-Dawley , Receptores de Neurotensina/agonistas , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo
3.
Data Brief ; 31: 105884, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32637491

RESUMO

Neurotensin (NT) is a tridecapeptide displaying interesting antinociceptive properties through its action on its receptors, NTS1 and NTS2. Neurotensin-like compounds have been shown to exert better antinociceptive properties than morphine at equimolar doses. In this article, we characterized the molecular effects of a novel neurotensin (8-13) (NT(8-13)) analog containing an unnatural amino acid. This compound, named JMV2009, displays a Silaproline in position 10 in replacement of a proline in the native NT(8-13). We first examined the binding affinities of this novel NT(8-13) derivative at both NTS1 and NTS2 receptor sites by performing competitive displacement of iodinated NT on purified cell membranes. Then, we evaluated the ability of JMV2009 to activate NTS1-related G proteins as well as to promote the recruitment of ß-arrestins 1 and 2 by using BRET-based cellular assays in live cells. We next assessed its ability to induce p42/p44 MAPK phosphorylation and NT receptors internalization using western blot and cell-surface ELISA, respectively. Finally, we determined the in vitro plasma stability of this NT derivative. This article is associated with the original article "Pain relief devoid of opioid side effects following central action of a silylated neurotensin analog" published in European Journal of Pharmacology[1]. The reader is directed to the associated article for results interpretation, comments, and discussion.

4.
Eur J Pharmacol ; 882: 173174, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32534076

RESUMO

Neurotensin (NT) exerts naloxone-insensitive antinociceptive action through its binding to both NTS1 and NTS2 receptors and NT analogs provide stronger pain relief than morphine on a molecular basis. Here, we examined the analgesic/adverse effect profile of a new NT(8-13) derivative denoted JMV2009, in which the Pro10 residue was substituted by a silicon-containing unnatural amino acid silaproline. We first report the synthesis and in vitro characterization (receptor-binding affinity, functional activity and stability) of JMV2009. We next examined its analgesic activity in a battery of acute, tonic and chronic pain models. We finally evaluated its ability to induce adverse effects associated with chronic opioid use, such as constipation and analgesic tolerance or related to NTS1 activation, like hypothermia. In in vitro assays, JMV2009 exhibited high binding affinity for both NTS1 and NTS2, improved proteolytic resistance as well as agonistic activities similar to NT, inducing sustained activation of p42/p44 MAPK and receptor internalization. Intrathecal injection of JMV2009 produced dose-dependent antinociceptive responses in the tail-flick test and almost completely abolished the nociceptive-related behaviors induced by chemical somatic and visceral noxious stimuli. Likewise, increasing doses of JMV2009 significantly reduced tactile allodynia and weight bearing deficits in nerve-injured rats. Importantly, repeated agonist treatment did not result in the development of analgesic tolerance. Furthermore, JMV2009 did not cause constipation and was ineffective in inducing hypothermia. These findings suggest that NT drugs can act as an effective opioid-free medication for the management of pain or can serve as adjuvant analgesics to reduce the opioid adverse effects.


Assuntos
Analgésicos/uso terapêutico , Neurotensina/análogos & derivados , Neurotensina/uso terapêutico , Dor/tratamento farmacológico , Receptores de Neurotensina/agonistas , Analgésicos/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Motilidade Gastrointestinal/efeitos dos fármacos , Hiperalgesia/tratamento farmacológico , Hiperalgesia/fisiopatologia , Masculino , Neurotensina/farmacologia , Dor/fisiopatologia , Ratos Sprague-Dawley , Receptores de Neurotensina/fisiologia
5.
J Med Chem ; 58(19): 7785-95, 2015 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-26348111

RESUMO

The silylated amino acid (l)-(trimethylsilyl)alanine (TMSAla) was incorporated at the C-terminal end of the minimal biologically active neurotensin (NT) fragment, leading to the synthesis of new hexapeptide NT[8-13] analogues. Here, we assessed the ability of these new silylated NT compounds to bind to NTS1 and NTS2 receptors, promote regulation of multiple signaling pathways, induce inhibition of the ileal smooth muscle contractions, and affect distinct physiological variables, including blood pressure and pain sensation. Among the C-terminal modified analogues, compound 6 (JMV2007) carrying a TMSAla residue in position 13 exhibits a higher affinity toward NT receptors than the NT native peptide. We also found that compound 6 is effective in reversing carbachol-induced contraction in the isolated strip preparation assay and at inducing a drop in blood pressure. Finally, compound 6 produces potent analgesia in experimental models of acute and persistent pain.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Neurotensina/análogos & derivados , Neurotensina/química , Analgésicos/química , Analgésicos/farmacologia , Animais , Ligação Competitiva , Pressão Sanguínea/efeitos dos fármacos , Células CHO , Técnicas de Química Sintética , Cricetulus , Meia-Vida , Masculino , Músculo Liso/efeitos dos fármacos , Ratos Sprague-Dawley , Receptores de Neurotensina/genética , Receptores de Neurotensina/metabolismo
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