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1.
J Am Chem Soc ; 145(18): 10015-10021, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37104712

RESUMEN

Caspases are a family of cysteine-dependent proteases with important cellular functions in inflammation and apoptosis, while also implicated in human diseases. Classical chemical tools to study caspase functions lack selectivity for specific caspase family members due to highly conserved active sites and catalytic machinery. To overcome this limitation, we targeted a non-catalytic cysteine residue (C264) unique to caspase-6 (C6), an enigmatic and understudied caspase isoform. Starting from disulfide ligands identified in a cysteine trapping screen, we used a structure-informed covalent ligand design to produce potent, irreversible inhibitors (3a) and chemoproteomic probes (13-t) of C6 that exhibit unprecedented selectivity over other caspase family members and high proteome selectivity. This approach and the new tools described will enable rigorous interrogation of the role of caspase-6 in developmental biology and in inflammatory and neurodegenerative diseases.


Asunto(s)
Caspasas , Cisteína , Humanos , Caspasa 6 , Apoptosis , Inhibidores de Cisteína Proteinasa/farmacología
2.
Nature ; 547(7663): 364-368, 2017 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-28693035

RESUMEN

Polymodal thermo- and mechanosensitive two-pore domain potassium (K2P) channels of the TREK subfamily generate 'leak' currents that regulate neuronal excitability, respond to lipids, temperature and mechanical stretch, and influence pain, temperature perception and anaesthetic responses. These dimeric voltage-gated ion channel (VGIC) superfamily members have a unique topology comprising two pore-forming regions per subunit. In contrast to other potassium channels, K2P channels use a selectivity filter 'C-type' gate as the principal gating site. Despite recent advances, poor pharmacological profiles of K2P channels limit mechanistic and biological studies. Here we describe a class of small-molecule TREK activators that directly stimulate the C-type gate by acting as molecular wedges that restrict interdomain interface movement behind the selectivity filter. Structures of K2P2.1 (also known as TREK-1) alone and with two selective K2P2.1 (TREK-1) and K2P10.1 (TREK-2) activators-an N-aryl-sulfonamide, ML335, and a thiophene-carboxamide, ML402-define a cryptic binding pocket unlike other ion channel small-molecule binding sites and, together with functional studies, identify a cation-π interaction that controls selectivity. Together, our data reveal a druggable K2P site that stabilizes the C-type gate 'leak mode' and provide direct evidence for K2P selectivity filter gating.


Asunto(s)
Canales de Potasio de Dominio Poro en Tándem/agonistas , Canales de Potasio de Dominio Poro en Tándem/química , Animales , Ácido Araquidónico/química , Ácido Araquidónico/metabolismo , Ácido Araquidónico/farmacología , Benzamidas/química , Benzamidas/metabolismo , Benzamidas/farmacología , Sitios de Unión/efectos de los fármacos , Células HEK293 , Humanos , Activación del Canal Iónico/efectos de los fármacos , Lípidos , Ratones , Modelos Moleculares , Pichia , Canales de Potasio de Dominio Poro en Tándem/metabolismo , Conformación Proteica/efectos de los fármacos , Sulfonamidas/química , Sulfonamidas/metabolismo , Sulfonamidas/farmacología , Tiofenos/química , Tiofenos/metabolismo , Tiofenos/farmacología , Xenopus laevis
3.
J Pharmacol Exp Ther ; 355(1): 2-12, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26224882

RESUMEN

Because no drug exists that halts or even slows any neurodegenerative disease, developing effective therapeutics for any prion disorder is urgent. We recently reported two compounds (IND24 and IND81) with the 2-aminothiazole (2-AMT) chemical scaffold that almost doubled the incubation times in scrapie prion-infected, wild-type (wt) FVB mice when given in a liquid diet. Remarkably, oral prophylactic treatment with IND24 beginning 14 days prior to intracerebral prion inoculation extended survival from ∼120 days to over 450 days. In addition to IND24, we evaluated the pharmacokinetics and efficacy of five additional 2-AMTs; one was not followed further because its brain penetration was poor. Of the remaining four new 2-AMTs, IND114338 doubled and IND125 tripled the incubation times of RML-inoculated wt and Tg4053 mice overexpressing wt mouse prion protein (PrP), respectively. Neuropathological examination of the brains from untreated controls showed a widespread deposition of self-propagating, ß-sheet-rich "scrapie" isoform (PrP(Sc)) prions accompanied by a profound astrocytic gliosis. In contrast, mice treated with 2-AMTs had lower levels of PrP(Sc) and associated astrocytic gliosis, with each compound resulting in a distinct pattern of deposition. Notably, IND125 prevented both PrP(Sc) accumulation and astrocytic gliosis in the cerebrum. Progressive central nervous system dysfunction in the IND125-treated mice was presumably due to the PrP(Sc) that accumulated in their brainstems. Disappointingly, none of the four new 2-AMTs prolonged the lives of mice expressing a chimeric human/mouse PrP transgene inoculated with Creutzfeldt-Jakob disease prions.


Asunto(s)
Encéfalo/efectos de los fármacos , Encéfalo/patología , Proteínas PrPSc/metabolismo , Tiazoles/química , Tiazoles/farmacología , Animales , Encéfalo/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Ratones , Proteínas PrPSc/genética , Scrapie/patología , Especificidad de la Especie , Análisis de Supervivencia , Tasa de Supervivencia , Tiazoles/farmacocinética , Tiazoles/uso terapéutico , Transgenes/genética , Resultado del Tratamiento
4.
Bioorg Med Chem Lett ; 25(21): 4834-4837, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26144347

RESUMEN

Inhibition of the cysteine protease cruzain from Trypanosoma cruzi has been studied pre-clinically as a new chemotherapeutic approach to treat Chagas' disease. Efficacious effects of vinylsulfone-based cruzain inhibitors in animal models support this therapeutic hypothesis. More recently, substrate-activity screening was used to identify nonpeptidic tetrafluorophenoxymethyl ketone inhibitors of cruzain that showed promising efficacy in animal models. Herein we report efforts to further optimize the in vitro potency and in vivo pharmacokinetic properties of this new class of cruzain inhibitors. Through modifications of the P1, P2 and/or P3 positions, new analogs have been identified with reduced lipophilicity, enhanced potency, and improved oral exposure and bioavailability.


Asunto(s)
Enfermedad de Chagas/tratamiento farmacológico , Inhibidores Enzimáticos/farmacocinética , Hidrocarburos Fluorados/farmacología , Hidrocarburos Fluorados/farmacocinética , Cetonas/farmacología , Cetonas/farmacocinética , Proteínas Protozoarias/antagonistas & inhibidores , Tripanocidas/farmacología , Tripanocidas/farmacocinética , Trypanosoma cruzi/efectos de los fármacos , Disponibilidad Biológica , Enfermedad de Chagas/metabolismo , Cisteína Endopeptidasas/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Hidrocarburos Fluorados/síntesis química , Hidrocarburos Fluorados/química , Cetonas/síntesis química , Cetonas/química , Estructura Molecular , Proteínas Protozoarias/metabolismo , Relación Estructura-Actividad , Tripanocidas/síntesis química , Tripanocidas/química
5.
Antimicrob Agents Chemother ; 58(7): 4138-44, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24820073

RESUMEN

Entamoeba histolytica and Giardia lamblia are anaerobic protozoan parasites that cause amebiasis and giardiasis, two of the most common diarrheal diseases worldwide. Current therapy relies on metronidazole, but resistance has been reported and the drug has significant adverse effects. Therefore, it is critical to search for effective, better-tolerated antiamebic and antigiardial drugs. We synthesized several examples of a recently reported class of Hsp90 inhibitors and evaluated these compounds as potential leads for antiparasitic chemotherapy. Several of these inhibitors showed strong in vitro activity against both E. histolytica and G. lamblia trophozoites. The inhibitors were rescreened to discriminate between amebicidal and giardicidal activity and general cytotoxicity toward a mammalian cell line. No mammalian cytotoxicity was found at >100 µM for 48 h for any of the inhibitors. To understand the mechanism of action, a competitive binding assay was performed using the fluorescent ATP analogue bis-ANS (4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid dipotassium salt) and recombinant E. histolytica Hsp90 preincubated in both the presence and absence of Hsp90 inhibitors. There was significant reduction in fluorescence compared to the level in the control, suggesting that E. histolytica Hsp90 is a selective target. The in vivo efficacy and safety of one Hsp90 inhibitor in a mouse model of amebic colitis and giardiasis was demonstrated by significant inhibition of parasite growth at a single oral dose of 5 mg/kg of body weight/day for 7 days and 10 mg/kg/day for 3 days. Considering the results for in vitro activity and in vivo efficacy, Hsp90 inhibitors represent a promising therapeutic option for amebiasis and giardiasis.


Asunto(s)
Entamoeba histolytica/efectos de los fármacos , Entamebiasis/tratamiento farmacológico , Giardia lamblia/efectos de los fármacos , Giardiasis/tratamiento farmacológico , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Naftalenosulfonatos de Anilina/química , Animales , Antiprotozoarios/uso terapéutico , Benzamidas/uso terapéutico , Línea Celular Tumoral , Modelos Animales de Enfermedad , Entamebiasis/parasitología , Giardiasis/parasitología , Glicina , Humanos , Indazoles/uso terapéutico , Células Jurkat , Ratones , Pruebas de Sensibilidad Parasitaria , Trofozoítos/efectos de los fármacos
6.
Cell Chem Biol ; 31(7): 1305-1323.e9, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39029456

RESUMEN

K2P potassium channels regulate excitability by affecting cellular resting membrane potential in the brain, cardiovascular system, immune cells, and sensory organs. Despite their important roles in anesthesia, arrhythmia, pain, hypertension, sleep, and migraine, the ability to control K2P function remains limited. Here, we describe a chemogenetic strategy termed CATKLAMP (covalent activation of TREK family K+ channels to clamp membrane potential) that leverages the discovery of a K2P modulator pocket site that reacts with electrophile-bearing derivatives of a TREK subfamily small-molecule activator, ML335, to activate the channel irreversibly. We show that CATKLAMP can be used to probe fundamental aspects of K2P function, as a switch to silence neuronal firing, and is applicable to all TREK subfamily members. Together, our findings exemplify a means to alter K2P channel activity that should facilitate molecular and systems level studies of K2P function and enable the search for new K2P modulators.


Asunto(s)
Canales de Potasio de Dominio Poro en Tándem , Humanos , Canales de Potasio de Dominio Poro en Tándem/metabolismo , Canales de Potasio de Dominio Poro en Tándem/genética , Animales , Células HEK293 , Ratones , Potenciales de la Membrana/efectos de los fármacos , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Ratas
7.
J Pharmacol Exp Ther ; 347(2): 325-38, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23965382

RESUMEN

The only small-molecule compound demonstrated to substantially extend survival in prion-infected mice is a biaryl hydrazone termed "Compd B" (4-pyridinecarboxaldehyde,2-[4-(5-oxazolyl)phenyl]hydrazone). However, the hydrazone moiety of Compd B results in toxic metabolites, making it a poor candidate for further drug development. We developed a pharmacophore model based on diverse antiprion compounds identified by high-throughput screening; based on this model, we generated biaryl amide analogs of Compd B. Medicinal chemistry optimization led to multiple compounds with increased potency, increased brain concentrations, and greater metabolic stability, indicating that they could be promising candidates for antiprion therapy. Replacing the pyridyl ring of Compd B with a phenyl group containing an electron-donating substituent increased potency, while adding an aryl group to the oxazole moiety increased metabolic stability. To test the efficacy of Compd B, we applied bioluminescence imaging (BLI), which was previously shown to detect prion disease onset in live mice earlier than clinical signs. In our studies, Compd B showed good efficacy in two lines of transgenic mice infected with the mouse-adapted Rocky Mountain Laboratory (RML) strain of prions, but not in transgenic mice infected with human prions. The BLI system successfully predicted the efficacies in all cases long before extension in survival could be observed. Our studies suggest that this BLI system has good potential to be applied in future antiprion drug efficacy studies.


Asunto(s)
Amidas/química , Amidas/uso terapéutico , Hidrazonas/química , Hidrazonas/uso terapéutico , Proteínas PrPSc/patogenicidad , Enfermedades por Prión/tratamiento farmacológico , Amidas/síntesis química , Amidas/farmacocinética , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Descubrimiento de Drogas , Hidrazonas/síntesis química , Hidrazonas/farmacocinética , Periodo de Incubación de Enfermedades Infecciosas , Estimación de Kaplan-Meier , Ratones , Ratones Transgénicos , Modelos Moleculares , Estructura Molecular , Proteínas PrPSc/genética , Relación Estructura-Actividad
8.
Beilstein J Org Chem ; 9: 15-25, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23400640

RESUMEN

Inhibition of the Trypanosoma cruzi cysteine protease cruzain has been proposed as a therapeutic approach for the treatment of Chagas' disease. Among the best-studied cruzain inhibitors to date is the vinylsulfone K777 (1), which has proven effective in animal models of Chagas' disease. Recent structure-activity studies aimed at addressing potential liabilities of 1 have now produced analogues such as N-[(2S)-1-[[(E,3S)-1-(benzenesulfonyl)-5-phenylpent-1-en-3-yl]amino]-3-(4-methylphenyl)-1-oxopropan-2-yl]pyridine-4-carboxamide (4), which is trypanocidal at ten-fold lower concentrations than for 1. We now find that the trypanocidal activity of 4 derives primarily from the inhibition of T. cruzi 14-α-demethylase (TcCYP51), a cytochrome P450 enzyme involved in the biosynthesis of ergosterol in the parasite. Compound 4 also inhibits mammalian CYP isoforms but is trypanocidal at concentrations below those required to significantly inhibit mammalian CYPs in vitro. A chemical-proteomics approach employing an activity-based probe derived from 1 was used to identify mammalian cathepsin B as a potentially important off-target of 1 and 4. Computational docking studies and the evaluation of truncated analogues of 4 reveal structural determinants for TcCYP51 binding, information that will be useful in further optimization of this new class of inhibitors.

9.
bioRxiv ; 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37905049

RESUMEN

K2P potassium channels regulate excitability by affecting cellular resting membrane potential in the brain, cardiovascular system, immune cells, and sensory organs. Despite their important roles in anesthesia, arrhythmia, pain, hypertension, sleep, and migraine, the ability to control K2P function remains limited. Here, we describe a chemogenetic strategy termed CATKLAMP (Covalent Activation of TREK family K+ channels to cLAmp Membrane Potential) that leverages the discovery of a site in the K2P modulator pocket that reacts with electrophile-bearing derivatives of a TREK subfamily small molecule activator, ML335, to activate the channel irreversibly. We show that the CATKLAMP strategy can be used to probe fundamental aspects of K2P function, as a switch to silence neuronal firing, and is applicable to all TREK subfamily members. Together, our findings exemplify a new means to alter K2P channel activity that should facilitate studies both molecular and systems level studies of K2P function and enable the search for new K2P modulators.

10.
PLoS Comput Biol ; 7(6): e1002083, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21731480

RESUMEN

P-glycoprotein (P-gp) is an ATP-dependent transport protein that is selectively expressed at entry points of xenobiotics where, acting as an efflux pump, it prevents their entering sensitive organs. The protein also plays a key role in the absorption and blood-brain barrier penetration of many drugs, while its overexpression in cancer cells has been linked to multidrug resistance in tumors. The recent publication of the mouse P-gp crystal structure revealed a large and hydrophobic binding cavity with no clearly defined sub-sites that supports an "induced-fit" ligand binding model. We employed flexible receptor docking to develop a new prediction algorithm for P-gp binding specificity. We tested the ability of this method to differentiate between binders and nonbinders of P-gp using consistently measured experimental data from P-gp efflux and calcein-inhibition assays. We also subjected the model to a blind test on a series of peptidic cysteine protease inhibitors, confirming the ability to predict compounds more likely to be P-gp substrates. Finally, we used the method to predict cellular metabolites that may be P-gp substrates. Overall, our results suggest that many P-gp substrates bind deeper in the cavity than the cyclic peptide in the crystal structure and that specificity in P-gp is better understood in terms of physicochemical properties of the ligands (and the binding site), rather than being defined by specific sub-sites.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Simulación de Dinámica Molecular , Subfamilia B de Transportador de Casetes de Unión a ATP , Algoritmos , Animales , Sitios de Unión , Línea Celular , Inhibidores de Cisteína Proteinasa/química , Inhibidores de Cisteína Proteinasa/metabolismo , Perros , Descubrimiento de Drogas , Humanos , Ratones , Farmacocinética , Docilidad , Unión Proteica , Curva ROC
11.
Pharmaceuticals (Basel) ; 15(2)2022 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-35215301

RESUMEN

Onchocerciasis and lymphatic filariasis are neglected tropical diseases caused by infection with filarial worms. Annual or biannual mass drug administration with microfilaricidal drugs that kill the microfilarial stages of the parasites has helped reduce infection rates and thus prevent transmission of both infections. However, success depends on high population coverage that is maintained for the duration of the adult worm's lifespan. Given that these filarial worms can live up to 14 years in their human hosts, a macrofilaricidal drug would vastly accelerate elimination efforts. Here, we have evaluated the repurposed drug pyrvinium pamoate as well as newly synthesized analogs of pyrvinium for their efficacy against filarial worms in vitro and in vivo. We found that pyrvinium pamoate, tetrahydropyrvinium and one of the analogs were highly potent in inhibiting worms in in vitro whole-worm screening assays, and that all three compounds reduced female worm fecundity and inhibited embryogenesis in the Brugia pahangi-gerbil in vivo model of infection.

12.
Bioorg Med Chem Lett ; 21(6): 1670-4, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21324685

RESUMEN

There is an urgent need for the development of novel antimicrobial agents that offer effective treatment against MRSA. Using a new class of dipeptide antibiotic TAN-1057A/B as lead, we designed, synthesized and evaluated analogs of TAN-1057A/B. Several novel dihydropyrimidinone antibiotics demonstrating comparable antibiotic efficacy while possessing favorable selectivity were identified.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Pirimidinas/química , Pirimidinas/farmacología , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad
13.
Bioorg Med Chem Lett ; 19(21): 6218-21, 2009 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-19773167

RESUMEN

We describe here the identification of non-peptidic vinylsulfones that inhibit parasite cysteine proteases in vitro and inhibit the growth of Trypanosoma brucei brucei parasites in culture. A high resolution (1.75 A) co-crystal structure of 8a bound to cruzain reveals how the non-peptidic P2/P3 moiety in such analogs bind the S2 and S3 subsites of the protease, effectively recapitulating important binding interactions present in more traditional peptide-based protease inhibitors and natural substrates.


Asunto(s)
Amidas/química , Proteasas de Cisteína/química , Inhibidores de Proteasas/química , Sulfonas/química , Tripanocidas/química , Amidas/farmacología , Sitios de Unión , Cristalografía por Rayos X , Proteasas de Cisteína/metabolismo , Humanos , Células Jurkat , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/toxicidad , Estructura Terciaria de Proteína , Sulfonas/síntesis química , Sulfonas/farmacología , Sulfonas/toxicidad , Tripanocidas/síntesis química , Tripanocidas/toxicidad , Trypanosoma brucei brucei/efectos de los fármacos
14.
ACS Chem Neurosci ; 9(12): 3153-3165, 2018 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-30089357

RESUMEN

K2P potassium channels generate leak currents that stabilize the resting membrane potential of excitable cells. Various K2P channels are implicated in pain, ischemia, depression, migraine, and anesthetic responses, making this family an attractive target for small molecule modulator development efforts. BL-1249, a compound from the fenamate class of nonsteroidal anti-inflammatory drugs is known to activate K2P2.1(TREK-1), the founding member of the thermo- and mechanosensitive TREK subfamily; however, its mechanism of action and effects on other K2P channels are not well-defined. Here, we demonstrate that BL-1249 extracellular application activates all TREK subfamily members but has no effect on other K2P subfamilies. Patch clamp experiments demonstrate that, similar to the diverse range of other chemical and physical TREK subfamily gating cues, BL-1249 stimulates the selectivity filter "C-type" gate that controls K2P function. BL-1249 displays selectivity among the TREK subfamily, activating K2P2.1(TREK-1) and K2P10.1(TREK-2) ∼10-fold more potently than K2P4.1(TRAAK). Investigation of mutants and K2P2.1(TREK-1)/K2P4.1(TRAAK) chimeras highlight the key roles of the C-terminal tail in BL-1249 action and identify the M2/M3 transmembrane helix interface as a key site of BL-1249 selectivity. Synthesis and characterization of a set of BL-1249 analogs demonstrates that both the tetrazole and opposing tetralin moieties are critical for function, whereas the conformational mobility between the two ring systems impacts selectivity. Together, our findings underscore the landscape of modes by which small molecules can affect K2P channels and provide crucial information for the development of better and more selective K2P modulators of the TREK subfamily.


Asunto(s)
Canales de Potasio de Dominio Poro en Tándem/efectos de los fármacos , Tetrahidronaftalenos/farmacología , Tetrazoles/farmacología , Animales , Células HEK293 , Humanos , Proteínas del Tejido Nervioso/efectos de los fármacos , Proteínas del Tejido Nervioso/metabolismo , Oocitos , Técnicas de Placa-Clamp , Canales de Potasio/efectos de los fármacos , Canales de Potasio/metabolismo , Canales de Potasio de Dominio Poro en Tándem/metabolismo , Xenopus laevis
15.
J Med Chem ; 48(24): 7520-34, 2005 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-16302794

RESUMEN

We have prepared a series of achiral aminoacetonitriles, bearing tri-ring benzamide moieties and an aminocyclohexanecarboxylate residue at P2. This combination of binding elements resulted in sub-250 pM, reversible, selective, and orally bioavailable cathepsin K inhibitors. Lead compounds displayed single digit nanomolar inhibition in vitro (of rabbit osteoclast-mediated degradation of bovine bone). The best compound in this series, 39n (CRA-013783/L-006235), was orally bioavailable in rats, with a terminal half-life of over 3 h. 39n was dosed orally in ovariectomized rhesus monkeys once per day for 7 days. Collagen breakdown products were reduced by up to 76% dose-dependently. Plasma concentrations of 39n above the bone resorption IC50 after 24 h indicated a correlation between functional cellular and in vivo assays. Inhibition of collagen breakdown by cathepsin K inhibitors suggests this mechanism of action may be useful in osteoporosis and other indications involving bone resorption.


Asunto(s)
Benzamidas/síntesis química , Conservadores de la Densidad Ósea/síntesis química , Catepsinas/antagonistas & inhibidores , Nitrilos/síntesis química , Tiazoles/síntesis química , Administración Oral , Animales , Benzamidas/química , Benzamidas/farmacología , Disponibilidad Biológica , Biomarcadores/orina , Conservadores de la Densidad Ósea/química , Conservadores de la Densidad Ósea/farmacología , Resorción Ósea/orina , Catepsina K , Catepsinas/química , Bovinos , Colágeno/antagonistas & inhibidores , Colágeno/metabolismo , Cristalografía por Rayos X , Diseño de Fármacos , Humanos , Cinética , Macaca mulatta , Modelos Moleculares , Estructura Molecular , Nitrilos/química , Nitrilos/farmacología , Conejos , Ratas , Relación Estructura-Actividad , Tiazoles/química , Tiazoles/farmacología
16.
J Biomol Screen ; 20(1): 101-11, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25281737

RESUMEN

Chagas disease affects 8 million people worldwide and remains a main cause of death due to heart failure in Latin America. The number of cases in the United States is now estimated to be 300,000, but there are currently no Food and Drug Administration (FDA)-approved drugs available for patients with Chagas disease. To fill this gap, we have established a public-private partnership between the University of California, San Francisco and the Genomics Institute of the Novartis Research Foundation (GNF) with the goal of delivering clinical candidates to treat Chagas disease. The discovery phase, based on the screening of more than 160,000 compounds from the GNF Academic Collaboration Library, led to the identification of new anti-Chagas scaffolds. Part of the screening campaign used and compared two screening methods, including a colorimetric-based assay using Trypanosoma cruzi expressing ß-galactosidase and an image-based, high-content screening (HCS) assay using the CA-I/72 strain of T. cruzi. Comparing molecules tested in both assays, we found that ergosterol biosynthesis inhibitors had greater potency in the colorimetric assay than in the HCS assay. Both assays were used to inform structure-activity relationships for antiparasitic efficacy and pharmacokinetics. A new anti-T. cruzi scaffold derived from xanthine was identified, and we describe its development as lead series.


Asunto(s)
Descubrimiento de Drogas/métodos , Ensayos Analíticos de Alto Rendimiento , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Línea Celular , Enfermedad de Chagas/tratamiento farmacológico , Colorimetría/métodos , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Humanos , Ratones , Enfermedades Desatendidas/tratamiento farmacológico , Bibliotecas de Moléculas Pequeñas , Tripanocidas/química , Xantina/química , Xantina/farmacología
17.
ChemMedChem ; 8(5): 847-57, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23509039

RESUMEN

Recently, we described the aminothiazole lead (4-biphenyl-4-ylthiazol-2-yl)-(6-methylpyridin-2-yl)-amine (1), which exhibits many desirable properties, including excellent stability in liver microsomes, oral bioavailability of ∼40 %, and high exposure in the brains of mice. Despite its good pharmacokinetic properties, compound 1 exhibited only modest potency in mouse neuroblastoma cells overexpressing the disease-causing prion protein PrP(Sc) . Accordingly, we sought to identify analogues of 1 with improved antiprion potency in ScN2a-cl3 cells while retaining similar or superior properties. Herein we report the discovery of improved lead compounds such as (6-methylpyridin-2-yl)-[4-(4-pyridin-3-yl-phenyl)thiazol-2-yl]amine and cyclopropanecarboxylic acid (4-biphenylthiazol-2-yl)amide, which exhibit brain exposure/EC50 ratios at least tenfold greater than that of compound 1.


Asunto(s)
Enfermedades por Prión/tratamiento farmacológico , Tiazoles/farmacología , Administración Oral , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Ratones , Modelos Moleculares , Estructura Molecular , Proteínas Gestacionales/biosíntesis , Enfermedades por Prión/metabolismo , Teoría Cuántica , Relación Estructura-Actividad , Tiazoles/administración & dosificación , Tiazoles/química , Tiazoles/uso terapéutico
18.
J Med Chem ; 52(16): 5005-8, 2009 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-19637873

RESUMEN

A docking screen identified reversible, noncovalent inhibitors (e.g., 1) of the parasite cysteine protease cruzain. Chemical optimization of 1 led to a series of oxadiazoles possessing interpretable SAR and potencies as much as 500-fold greater than 1. Detailed investigation of the SAR series subsequently revealed that many members of the oxadiazole class (and surprisingly also 1) act via divergent modes of inhibition (competitive or via colloidal aggregation) depending on the assay conditions employed.


Asunto(s)
Inhibidores de Cisteína Proteinasa/química , Proteínas Protozoarias/antagonistas & inhibidores , Tripanocidas/química , Trypanosoma cruzi/efectos de los fármacos , Coloides , Cisteína Endopeptidasas/química , Inhibidores de Cisteína Proteinasa/síntesis química , Inhibidores de Cisteína Proteinasa/farmacología , Bases de Datos Factuales , Glicolatos/síntesis química , Glicolatos/química , Glicolatos/farmacología , Modelos Moleculares , Oxadiazoles/síntesis química , Oxadiazoles/química , Oxadiazoles/farmacología , Pruebas de Sensibilidad Parasitaria , Proteínas Protozoarias/química , Relación Estructura-Actividad , Tripanocidas/síntesis química , Tripanocidas/farmacología , Trypanosoma cruzi/enzimología
19.
J Opt Soc Am A Opt Image Sci Vis ; 20(2): 357-67, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12570303

RESUMEN

We describe a new semiautomatic image processing method for detecting the cartilage boundaries in optical coherence tomography (OCT). In particular, we focus on rabbit cartilage since this is an important animal model for testing both chondroprotective agents and cartilage repair techniques. The novel boundary-detection system presented here consists of (1) an adaptive filtering technique for image enhancement and speckle reduction, (2) edge detection, and (3) edge linking by graph searching. The procedure requires several steps and can be automated. The quantitative measurements of cartilage thickness on OCT images correlated well with measurements from histology.


Asunto(s)
Cartílago Articular/anatomía & histología , Procesamiento de Imagen Asistido por Computador/métodos , Óptica y Fotónica , Tomografía , Algoritmos , Animales , Articulación de la Rodilla , Conejos
20.
Bioorg Med Chem ; 10(10): 3277-84, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12150873

RESUMEN

1-Cyanopyrrolidines have previously been reported to inhibit cysteinyl cathepsins (Falgueyret, J.-P. et al., J. Med. Chem. 2001, 44, 94). In order to optimize binding interactions for a given cathepsin and simultaneously reduce interactions with the other closely related enzymes, small peptidic substituents were introduced to the 1-cyanopyrrolidine scaffold, either at the 2-position starting with proline or at the 3-position of aminopyrrolidines. The resulting novel compounds proved to be micromolar inhibitors of cathepsin B (Cat B) but nanomolar to picomolar inhibitors of cathepsins K, L, and S (Cat K, Cat L, Cat S). Several of the compounds were >20-fold selective versus the other three cathepsins. SAR trends were observed, most notably the remarkable potency of Cat L inhibitors based on the 1-cyano-D-proline scaffold. The selectivity of one such compound, the 94 picomolar Cat L inhibitor 12, was demonstrated at higher concentrations in DLD-1 cells. Although none of the compounds in the proline series that was tested proved to be submicromolar in the in vitro bone resorption assay, two Cat K inhibitors in the 3-substituted pyrrolidine series, 24 and 25 were relatively potent in that assay.


Asunto(s)
Catepsinas/antagonistas & inhibidores , Dipéptidos/síntesis química , Pirrolidinas/síntesis química , Animales , Resorción Ósea/tratamiento farmacológico , Dipéptidos/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Ratones , Nitrilos/síntesis química , Nitrilos/farmacología , Pirrolidinas/farmacología , Relación Estructura-Actividad
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