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2.
Int J Mol Sci ; 20(18)2019 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-31487785

RESUMEN

Kv7.2-Kv7.5 channels mediate the M-current (IKM), a K+-selective current regulating neuronal excitability and representing an attractive target for pharmacological therapy against hyperexcitability diseases such as pain. Kv7 channels interact functionally with transient receptor potential vanilloid 1 (TRPV1) channels activated by endogenous and/or exogenous pain-inducing substances, such as bradykinin (BK) or capsaicin (CAP), respectively; however, whether Kv7 channels of specific molecular composition provide a dominant contribution in BK- or CAP-evoked responses is yet unknown. To this aim, Kv7 transcripts expression and function were assessed in F11 immortalized sensorial neurons, a cellular model widely used to assess nociceptive molecular mechanisms. In these cells, the effects of the pan-Kv7 activator retigabine were investigated, as well as the effects of ICA-27243 and (S)-1, two Kv7 activators acting preferentially on Kv7.2/Kv7.3 and Kv7.4/Kv7.5 channels, respectively, on BK- and CAP-induced changes in intracellular Ca2+ concentrations ([Ca2+]i). The results obtained revealed the expression of transcripts of all Kv7 genes, leading to an IKM-like current. Moreover, all tested Kv7 openers inhibited BK- and CAP-induced responses by a similar extent (~60%); at least for BK-induced Ca2+ responses, the potency of retigabine (IC50~1 µM) was higher than that of ICA-27243 (IC50~5 µM) and (S)-1 (IC50~7 µM). Altogether, these results suggest that IKM activation effectively counteracts the cellular processes triggered by TRPV1-mediated pain-inducing stimuli, and highlight a possible critical contribution of Kv7.4 subunits.


Asunto(s)
Señalización del Calcio , Capsaicina/farmacología , Canales de Potasio KCNQ/metabolismo , Células Receptoras Sensoriales/metabolismo , Fármacos del Sistema Sensorial/farmacología , Canales Catiónicos TRPV/metabolismo , Animales , Bradiquinina/farmacología , Calcio/metabolismo , Carbamatos/farmacología , Línea Celular , Canales de Potasio de Gran Conductancia Activados por el Calcio/metabolismo , Moduladores del Transporte de Membrana/farmacología , Fenilendiaminas/farmacología , Ratas , Células Receptoras Sensoriales/efectos de los fármacos
3.
Int J Mol Sci ; 20(11)2019 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-31141957

RESUMEN

The transient receptor potential melastatin subtype 8 (TRPM8) is a nonselective, multimodal ion channel, activated by low temperatures (<28 °C), pressure, and cooling compounds (menthol, icilin). Experimental evidences indicated a role of TRPM8 in cold thermal transduction, different life-threatening tumors, and other pathologies, including migraine, urinary tract dysfunction, dry eye disease, and obesity. Hence, the modulation of the TRPM8 channel could be essential in order to understand its implications in these pathologies and for therapeutic intervention. This short review will cover recent progress on the TRPM8 agonists and antagonists, describing newly reported chemotypes, and their application in the pharmacological characterization of TRPM8 in health and disease. The recently described structures of the TRPM8 channel alone or complexed with known agonists and PIP2 are also discussed.


Asunto(s)
Moduladores del Transporte de Membrana/química , Canales Catiónicos TRPM/agonistas , Animales , Sitios de Unión , Humanos , Moduladores del Transporte de Membrana/farmacología , Unión Proteica , Canales Catiónicos TRPM/antagonistas & inhibidores , Canales Catiónicos TRPM/química , Canales Catiónicos TRPM/metabolismo
4.
Methods Mol Biol ; 1947: 361-376, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30969428

RESUMEN

Engineered G protein-coupled receptors (DREADDs, designer receptors exclusively activated by designer drugs) are convenient tools for specific activation of GPCR signaling in many cell types. DREADDs have been utilized as research tools to study numerous cellular and physiologic processes, including regulation of neuronal activity, behavior, and metabolism. Mice with random insertion transgenes and adeno-associated viruses have been widely used to express DREADDs in individual cell types. We recently created and characterized ROSA26-GsDREADD knock-in mice to allow Cre recombinase-dependent expression of a Gαs-coupled DREADD (GsD) fused to GFP in distinct cell populations in vivo. These animals also harbor a CREB-activated luciferase reporter gene for analysis of CREB activity by in vivo imaging, ex vivo imaging, or biochemical reporter assays. In this chapter, we provide detailed methods for breeding GsD animals, inducing GsD expression, stimulating GsD activity, and measuring basal and stimulated CREB reporter bioluminescence in tissues in vivo, ex vivo, and in vitro. These animals are available from our laboratory for non-profit research.


Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Genes Reporteros , Procesamiento de Imagen Asistida por Computador/métodos , Mediciones Luminiscentes/métodos , Moduladores del Transporte de Membrana/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Animales , Clozapina/análogos & derivados , Clozapina/farmacología , Integrasas/metabolismo , Ratones , Especificidad de Órganos , Receptores Acoplados a Proteínas G/efectos de los fármacos , Receptores Acoplados a Proteínas G/genética , Transducción de Señal
5.
PLoS Negl Trop Dis ; 13(2): e0007153, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30730880

RESUMEN

BACKGROUND: Tick feeding causes extreme morbidity and mortality to humans through transmission of pathogens and causes severe economic losses to the agricultural industry by reducing livestock yield. Salivary gland secretions are essential for tick feeding and thus, reducing or preventing saliva secretions into the vertebrate host is likely to reduce feeding and hinder pathogen life cycles. Unfortunately, the membrane physiology of tick salivary glands is underexplored and this gap in knowledge limits the development of novel therapeutics for inducing cessation of tick feeding. METHODOLOGY: We studied the influence of inward rectifier potassium (Kir) channel subtypes to the functional capacity of the isolated tick salivary gland through the use of a modified Ramsay assay. The secreted saliva was subsequently used for quantification of the elemental composition of the secreted saliva after the glands were exposed to K+ channel modulators as a measure of osmoregulatory capacity. Lastly, changes to blood feeding behavior and mortality were measured with the use of a membrane feeding system. PRINCIPAL FINDINGS: In this study, we characterized the fundamental role of Kir channel subtypes in tick salivary gland function and provide evidence that pharmacological inhibition of these ion channels reduces the secretory activity of the Amblyomma americanum salivary gland. The reduced secretory capacity of the salivary gland was directly correlated with a dramatic reduction of blood ingestion during feeding. Further, exposure to small-molecule modulators of Kir channel subtypes induced mortality to ticks that is likely resultant from an altered osmoregulatory capacity. CONCLUSIONS: Our data contribute to understanding of tick salivary gland function and could guide future campaigns aiming to develop chemical or reverse vaccinology technologies to reduce the worldwide burden of tick feeding and tick-vectored pathogens.


Asunto(s)
Ixodidae/fisiología , Canales de Potasio de Rectificación Interna/metabolismo , Animales , Conducta Alimentaria/fisiología , Ixodidae/efectos de los fármacos , Moduladores del Transporte de Membrana/farmacología , Pinacidilo/farmacología , Canales de Potasio de Rectificación Interna/genética , Glándulas Salivales/fisiología , Xantinas/farmacología
6.
Pharmacol Rep ; 71(1): 121-129, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30612046

RESUMEN

BACKGROUND: The osmolyte and antioxidant taurine plays an important role in regulation of cellular volume, oxidative status and Ca2+-homeostasis. Taurine uptake in human cells is regulated by the Na+- and Cl--dependent taurine transporter TauT. In order to gain deeper structural insights about the substrate binding pocket of TauT, a HEK293 cell line producing a GFP-TauT fusion protein was generated. METHODS: Transport activity was validated using cell-based [3H]-taurine transport assays. We determined the Km and IC50 values of taurine, ß-alanine and γ-aminobutyrate. Additionally we were able to identify structurally similar compounds as potential new substrates or inhibitors of the TauT transporter. Substrate induced cytotoxicity was analyzed using a cell viability assay. RESULTS: In this study we show competitive effects of the 3-pyridinesulfonate, 2-aminoethylhydrogen sulfate, 5-aminovalerate, ß-aminobutyrate, piperidine-4-sulfonate, 2-aminoethylphosphate and homotaurine. We demonstrate that taurine uptake can be inhibited by a phosphate. Furthermore our studies revealed that piperidine-4-sulfonate interacts with TauT with a higher affinity than γ-aminobutyrate and imidazole-4-acetate. CONCLUSION: We propose that piperidine-4-sulfonate may serve as a potential lead structure for the design of novel drug candidates required for specific modulation of the TauT transporter in therapy of neurodegenerative diseases.


Asunto(s)
Riñón/efectos de los fármacos , Glicoproteínas de Membrana/antagonistas & inhibidores , Moduladores del Transporte de Membrana/farmacología , Taurina/metabolismo , Sitios de Unión , Unión Competitiva , Transporte Biológico , Células HEK293 , Humanos , Riñón/metabolismo , Cinética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Moduladores del Transporte de Membrana/química , Moduladores del Transporte de Membrana/toxicidad , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Estructura Molecular , Unión Proteica , Relación Estructura-Actividad
7.
Acta Pharmacol Sin ; 40(6): 746-754, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30315249

RESUMEN

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play a critical role in controlling pacemaker activity in both heart and nervous system. Developing HCN channel inhibitors has been proposed to be an important strategy for the treatment of pain, heart failure, arrhythmias, and epilepsy. One HCN channel inhibitor, ivabradine, has been clinically approved for the treatment of angina pectoris and heart failure. In this study, we designed and synthesized eight alkanol amine derivatives, and assessed their effects on HCN channels expressed in COS7 cells using a whole-cell patch clamp method. Among them, compound 4e displayed the most potent inhibitory activity with an IC50 of 2.9 ± 1.2 µM at - 120 mV on HCN2 channel expressed in COS7 cells. Further analysis revealed that application of compound 4e (10 µM) caused a slowing of activation and a hyperpolarizing shift (ΔV1/2 = - 30.2 ± 2.9 mV, n = 5) in the voltage dependence of HCN2 channel activation. The inhibitory effect of compound 4e on HCN1 and HCN4 channel expressed in COS7 cells was less potent with IC50 of 17.2 ± 1.3 and 7.3 ± 1.2 µM, respectively. Besides, we showed that application of compound 4e (10 µM) inhibited Ih and action potential firing in acutely dissociated mouse small dorsal root ganglion neurons. Our study provides a new strategy for the design and development of potent HCN channel inhibitors.


Asunto(s)
Amino Alcoholes/farmacología , Canales Regulados por Nucleótidos Cíclicos Activados por Hiperpolarización/antagonistas & inhibidores , Moduladores del Transporte de Membrana/farmacología , Potenciales de Acción/efectos de los fármacos , Amino Alcoholes/síntesis química , Amino Alcoholes/química , Animales , Células COS , Humanos , Masculino , Moduladores del Transporte de Membrana/síntesis química , Moduladores del Transporte de Membrana/química , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Canales de Potasio
8.
Pflugers Arch ; 471(1): 53-65, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30535512

RESUMEN

The control of inorganic phosphate homeostasis is mediated through the activity of sodium-coupled Pi transporters located in the intestine, kidneys, and bone. To study these transporters in either the native tissue or after heterologous expression, it is very important to use specific inhibitors of the studied transporter, in order to know the corresponding relevance in the total Pi uptake and to differentiate from the activity of other transporters. Inhibitors are also necessary as drugs for treating Pi homeostasis disorders. Under normal physiological conditions, the renal and intestinal excretion of Pi matches dietary intestinal absorption, but when the number of non-functional nephrons increase in chronic kidney disease and end-stage renal disease, the excretion of surplus Pi is progressively impaired, thereby increasing the risk of hyperphosphatemia and Pi toxicity. When the compensatory mechanisms that increase Pi excretion fail, Pi toxicity can only be prevented by reducing the intestinal absorption of Pi through phosphate binders that reduced the free Pi concentration in the lumen, and inhibitors of intestinal Pi transporters and of the paracellular absorption route. Although many potentially interesting inhibitors have been reported to date, only a few are available for experimental purposes, and even fewer have been used in independent clinical trials. In this review, we summarize the different groups of compounds reported to date as inhibitors of Pi transport. To help understand and characterize the inhibition mechanisms, we also summarize the kinetic analysis approaches and screening methods that could be applied.


Asunto(s)
Moduladores del Transporte de Membrana/farmacología , Fosfatos/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo II/metabolismo , Animales , Humanos , Absorción Intestinal , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Proteínas Cotransportadoras de Sodio-Fosfato de Tipo II/antagonistas & inhibidores
9.
Drug Des Devel Ther ; 12: 4129-4138, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30584277

RESUMEN

Introduction: Six years after the US Food and Drug Administration approval of the broad-spectrum antibiotic ofloxacin (OFLX), the chiral switching of this racemic mixture resulted in a drug composed of the L-optical isomer levofloxacin (LVFX). Since both fluoroquinolones (FQs) were introduced to the pharmaceutical market, they have been widely prescribed by physicians, with careful administration during pregnancy and breastfeeding. Therefore, the role of the influx and efflux placental transporters in the concentrations of these drugs that permeate through human placental barrier model was investigated in this study. Methods: The contribution of major carriers on the transplacental flux of OFLX and LVFX uptake into choriocarcinoma BeWo cells was evaluated in the presence vs absence of well-known inhibitors. Results: Our results reveal that neither the influx transporters such as organic cation transporters, organic anion transporters, and monocarboxylate transporters nor the efflux transporters such as P-glycoprotein or breast cancer resistance protein significantly affected the transport of OFLX. In contrast, multiple transporters revealed pronounced involvement in the transfer of the levorotatory enantiomer in and out of the in vitro placental barrier. These data suggest a non-carrier-mediated mechanism of transport of the racemic mixture, while LVFX is subjected to major influx and efflux passage through the placental brush border membranes. Conclusion: This study provides underlying insights to elucidate the governing factors that influence the flux of these FQs through organ barriers, in view of the controversial safety profile of these drugs in pregnant population.


Asunto(s)
Antibacterianos/metabolismo , Vellosidades Coriónicas/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Ofloxacino/metabolismo , Trofoblastos/metabolismo , Antibacterianos/química , Transporte Biológico , Línea Celular Tumoral , Vellosidades Coriónicas/efectos de los fármacos , Humanos , Cinética , Moduladores del Transporte de Membrana/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Ofloxacino/química , Permeabilidad , Estereoisomerismo , Trofoblastos/efectos de los fármacos
10.
Clin Pharmacol Ther ; 104(5): 836-864, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30347454

RESUMEN

Drug transporters can govern the absorption, distribution, metabolism, and excretion of substrate drugs and endogenous substances. Investigations to examine their potential impact to pharmacokinetic (PK) drug-drug interactions (DDIs) are an integral part of the risk assessment in drug development. To evaluate a new molecular entity as a potential perpetrator of transporters, use of well characterized and/or clinically relevant probe substrates with good selectivity and sensitivity are critical for robust clinical DDI assessment that could inform DDI management strategy in the product labeling. The availability of endogenous biomarkers to monitor transporter-mediated DDIs in early phases of clinical investigations would greatly benefit downstream clinical plans. This article reviews the state-of-the-art in transporter clinical probe drugs and emerging biomarkers, including current challenges and limitations, delineates methods and workflows to identify and validate novel endogenous biomarkers to support clinical DDI evaluations, and proposes how these probe drugs or biomarkers could be used in drug development.


Asunto(s)
Biomarcadores/metabolismo , Desarrollo de Medicamentos/métodos , Interacciones de Drogas , Moduladores del Transporte de Membrana/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Sondas Moleculares/metabolismo , Farmacocinética , Animales , Humanos , Moduladores del Transporte de Membrana/metabolismo , Modelos Biológicos , Técnicas de Sonda Molecular , Medición de Riesgo , Flujo de Trabajo
11.
J Gen Physiol ; 150(10): 1432-1443, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30166313

RESUMEN

KCNQ2-5 (Kv7.2-Kv7.5) channels are strongly influenced by an emerging class of small-molecule channel activators. Retigabine is the prototypical KCNQ activator that is thought to bind within the pore. It requires the presence of a Trp side chain that is conserved among retigabine-sensitive channels but absent in the retigabine-insensitive KCNQ1 subtype. Recent work has demonstrated that certain KCNQ openers are insensitive to mutations of this conserved Trp, and that their effects are instead abolished or attenuated by mutations in the voltage-sensing domain (VSD). In this study, we investigate the stoichiometry of a VSD-targeted KCNQ2 channel activator, ICA-069673, by forming concatenated channel constructs with varying numbers of drug-insensitive subunits. In homomeric WT KCNQ2 channels, ICA-069673 strongly stabilizes an activated channel conformation, which is reflected in the pronounced deceleration of deactivation and leftward shift of the conductance-voltage relationship. A full complement of four drug-sensitive subunits is required for maximal sensitivity to ICA-069673-even a single drug-insensitive subunit leads to significantly weakened effects. In a companion article (see Yau et al. in this issue), we demonstrate very different stoichiometry for the action of retigabine on KCNQ3, for which a single retigabine-sensitive subunit enables near-maximal effect. Together, these studies highlight fundamental differences in the site and mechanism of activation between retigabine and voltage sensor-targeted KCNQ openers.


Asunto(s)
Canales de Potasio KCNQ/efectos de los fármacos , Moduladores del Transporte de Membrana/farmacología , Células HEK293 , Humanos , Canales de Potasio KCNQ/genética , Mutación
12.
J Nutr Sci Vitaminol (Tokyo) ; 64(4): 287-291, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30175793

RESUMEN

[6]-Gingerol possesses various beneficial pharmacological and therapeutic properties, including anti-carcinogenic and anti-inflammatory properties and the ability to regulate intestinal contraction. Recently, our group observed that the serosal administration of [6]-gingerol stimulated electrogenic sodium absorption in the rat colon via the capsaicin receptor, TRPV1. TRPV1 is known to be expressed in both the mucosal epithelium and the muscle layers in the colon. In the present study, we assessed whether [6]-gingerol stimulated sodium absorption via TRPV1 in the colonic mucosal epithelium. We compared the effect of [6]-gingerol on TRPV1-dependent colonic sodium absorption in the colon preparation with or without muscle layer. All experiments were performed by measuring the transmural potential difference (ΔPD) in an Ussing chamber system. [6]-Gingerol induced positive ΔPD when administered to the serosal side of the colon, and this effect was significantly larger in the colon preparation without muscle layer than in that with the muscle layer. In the colon preparation without muscle layer, the [6]-gingerol-dependent induction of ΔPD was markedly suppressed by mucosal addition of amiloride, a selective inhibitor of epithelial sodium channel. ΔPD induction by [6]-gingerol was considerably diminished by capsazepine, an inhibitor of the capsaicin receptor TRPV1, but not by AP-18, an inhibitor of TRPA1. These results suggest that [6]-gingerol induces amiloride-sensitive electrogenic sodium absorption in the rat colon via TRPV1 expressed in the colonic mucosal epithelium, and that this effect is independent of TRPV1 in the colonic muscle layer.


Asunto(s)
Catecoles/farmacología , Colon/efectos de los fármacos , Alcoholes Grasos/farmacología , Fármacos Gastrointestinales/farmacología , Absorción Intestinal/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Sodio en la Dieta/metabolismo , Canales Catiónicos TRPV/agonistas , Amilorida/farmacología , Animales , Capsaicina/análogos & derivados , Capsaicina/farmacología , Colon/fisiología , Bloqueadores del Canal de Sodio Epitelial/farmacología , Técnicas In Vitro , Mucosa Intestinal/fisiología , Potenciales de la Membrana/efectos de los fármacos , Moduladores del Transporte de Membrana/farmacología , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Oximas/farmacología , Ratas Sprague-Dawley , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/metabolismo
13.
eNeuro ; 5(4)2018.
Artículo en Inglés | MEDLINE | ID: mdl-30225345

RESUMEN

Action potentials propagating along axons are often followed by prolonged afterdepolarization (ADP) lasting for several tens of milliseconds. Axonal ADP is thought to be an important factor in modulating the fidelity of spike propagation during repetitive firings. However, the mechanism as well as the functional significance of axonal ADP remain unclear, partly due to inaccessibility to small structures of axon for direct electrophysiological recordings. Here, we examined the ionic and electrical mechanisms underlying axonal ADP using whole-bouton recording from mossy fiber terminals in mice hippocampal slices. ADP following axonal action potentials was strongly enhanced by focal application of veratridine, an inhibitor of Na+ channel inactivation. In contrast, tetrodotoxin (TTX) partly suppressed ADP, suggesting that a Na+ channel-dependent component is involved in axonal ADP. The remaining TTX-resistant Na+ channel-independent component represents slow capacitive discharge reflecting the shape and electrical properties of the axonal membrane. We also addressed the functional impact of axonal ADP on presynaptic function. In paired-pulse stimuli, we found that axonal ADP minimally affected the peak height of subsequent action potentials, although the rising phase of action potentials was slightly slowed, possibly due to steady-state inactivation of Na+ channels by prolonged depolarization. Voltage clamp analysis of Ca2+ current elicited by action potential waveform commands revealed that axonal ADP assists short-term facilitation of Ca2+ entry into the presynaptic terminals. Taken together, these data show that axonal ADP maintains reliable firing during repetitive stimuli and plays important roles in the fine-tuning of short-term plasticity of transmitter release by modulating Ca2+ entry into presynaptic terminals.


Asunto(s)
Potenciales de Acción/fisiología , Señalización del Calcio/fisiología , Moduladores del Transporte de Membrana/farmacología , Fibras Musgosas del Hipocampo/fisiología , Canales de Sodio/efectos de los fármacos , Veratridina/farmacología , Potenciales de Acción/efectos de los fármacos , Animales , Señalización del Calcio/efectos de los fármacos , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Fibras Musgosas del Hipocampo/efectos de los fármacos
14.
Pflugers Arch ; 470(11): 1583-1596, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30194638

RESUMEN

Transient receptor potential (TRP) channels comprise a family of cation channels implicated in a variety of cellular processes including light, mechanical or chemical stimuli, temperature, pH, or osmolarity. TRP channel proteins are a diverse family of proteins that are expressed in many tissues. We debated our recent knowledge about the expression, function, and regulation of TRP channels in the different parts of the male urogenital system in health and disease. Emerging evidence suggests that dysfunction of TRP channels significantly contributes to the pathophysiology of urogenital diseases. So far, there are many efforts underway to determine if these channels can be used as drug targets to reverse declines in male urogenital function. Furthermore, developing safe and efficacious TRP channel modulators is warranted for male urogenital disorders in a clinical setting.


Asunto(s)
Disfunción Eréctil/metabolismo , Moduladores del Transporte de Membrana/uso terapéutico , Canales Catiónicos TRPV/metabolismo , Vejiga Urinaria Hiperactiva/metabolismo , Animales , Disfunción Eréctil/tratamiento farmacológico , Humanos , Masculino , Moduladores del Transporte de Membrana/farmacología , Canales Catiónicos TRPV/agonistas , Canales Catiónicos TRPV/antagonistas & inhibidores , Vejiga Urinaria Hiperactiva/tratamiento farmacológico
16.
Clin Pharmacol Ther ; 104(5): 890-899, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30091177

RESUMEN

This white paper provides updated International Transporter Consortium (ITC) recommendations on transporters that are important in drug development following the 3rd ITC workshop. New additions include prospective evaluation of organic cation transporter 1 (OCT1) and retrospective evaluation of organic anion transporting polypeptide (OATP)2B1 because of their important roles in drug absorption, disposition, and effects. For the first time, the ITC underscores the importance of transporters involved in drug-induced vitamin deficiency (THTR2) and those involved in the disposition of biomarkers of organ function (OAT2 and bile acid transporters).


Asunto(s)
Desarrollo de Medicamentos/métodos , Moduladores del Transporte de Membrana/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Preparaciones Farmacéuticas/metabolismo , Farmacocinética , Animales , Interacciones de Drogas , Humanos , Moduladores del Transporte de Membrana/metabolismo , Modelos Biológicos , Medición de Riesgo
17.
Biomed Pharmacother ; 106: 1563-1569, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30119231

RESUMEN

Araloside A is a triterpenoid saponin,which exhibits a broad spectrum of pharmacological activities, such as stimulating fibrinolysis, preventing coagulant, inhibiting renin, and decreasing blood pressure. Our previous report found that the compound exhibits a poor absolute bioavailability. However the underlying mechanisms of its absorption have not been investigated in the small intestine or in a Caco-2 cell model. In this study, the absorption mechanisms of araloside A were investigated in a Caco-2 cell monolayer and in a single-pass intestinal perfusion in situ model with Sprague-Dawley rats. The effects of basic parameters, such as compound concentration, time, temperature, paracellular pathway, different intestinal segments were analyzed, and the susceptibility of araloside A absorption process to treatment with various inhibitors, such as the P-gp inhibitor verapamil, the multidrug resistance protein2 inhibitors (MRP2) MK571 and indomethacin, the breast cancer resistance protein (BCRP) inhibitors Ko143 and reserpine, and endocytosis inhibitor chlorpromazine were assessed. It can be found that the mechanisms of intestinal absorption of araloside A may involve multiple transport pathways, such as passive diffusion, the paracellular pathway, as well as the participation of efflux transporters.


Asunto(s)
Colon/metabolismo , Absorción Intestinal , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Ácido Oleanólico/análogos & derivados , Saponinas/metabolismo , Animales , Disponibilidad Biológica , Transporte Biológico , Células CACO-2 , Colon/efectos de los fármacos , Difusión , Humanos , Técnicas In Vitro , Absorción Intestinal/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Intestino Delgado/efectos de los fármacos , Cinética , Masculino , Moduladores del Transporte de Membrana/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Ácido Oleanólico/metabolismo , Ácido Oleanólico/farmacocinética , Perfusión , Permeabilidad , Ratas Sprague-Dawley , Saponinas/farmacocinética
18.
J Neurophysiol ; 120(4): 1893-1905, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30067136

RESUMEN

This overview compares the activity of wide dynamic range (WDR) and nociceptive specific (NS) neurons located in the deep dorsal horn across different rat models of pathological pain and following modulation by diverse pharmacology. The data were collected by our group under the same experimental conditions over numerous studies to facilitate comparison. Spontaneous firing of WDR neurons was significantly elevated (>3.7 Hz) in models of neuropathic, inflammation, and osteoarthritic pain compared with naive animals (1.9 Hz) but was very low (<0.5 Hz) and remained unchanged in NS neurons. WDR responses to low-intensity mechanical stimulation were elevated in neuropathic and inflammation models. WDR responses to high-intensity stimuli were enhanced in inflammatory (heat) and osteoarthritis (mechanical) models. NS responses to high-intensity stimulation did not change relative to control in any model examined. Several therapeutic agents reduced both evoked and spontaneous firing of WDR neurons (e.g., TRPV1, TRPV3, Nav1.7, Nav1.8, P2X7, P2X3, H3), other targets affected neither evoked nor spontaneous firing of WDR neurons (e.g., H4, TRPM8, KCNQ2/3), and some only modulated evoked (e.g, ASIC1a, Cav3.2) whereas others decreased evoked but affected spontaneous activity only in specific models (e.g., TRPA1, CB2). Spontaneous firing of WDR neurons was not altered by any peripherally restricted compound or by direct administration of compounds to peripheral sites, although the same compounds decreased evoked activity. Compounds acting centrally were effective against this endpoint. The diversity of incoming/modulating inputs to the deep dorsal horn positions this group of neurons as an important intersection within the pain system to validate novel therapeutics. NEW & NOTEWORTHY Data from multiple individual experiments were combined to show firing properties of wide dynamic range and nociceptive specific spinal dorsal horn neurons across varied pathological pain models. This high-powered analysis describes the sensitization following different forms of injury. Effects of diverse pharmacology on these neurons is also summarized from published and unpublished data all recorded under the same conditions to facilitate comparison. This comprehensive overview describes the function and utility of these neurons.


Asunto(s)
Potenciales Evocados , Neuralgia/fisiopatología , Células del Asta Posterior/fisiología , Analgésicos/farmacología , Animales , Calor/efectos adversos , Masculino , Moduladores del Transporte de Membrana/farmacología , Neuralgia/etiología , Neuralgia/patología , Nocicepción , Osteoartritis/complicaciones , Osteoartritis/fisiopatología , Células del Asta Posterior/clasificación , Células del Asta Posterior/efectos de los fármacos , Ratas , Ratas Sprague-Dawley
19.
Clin Pharmacol Ther ; 104(5): 818-835, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29981151

RESUMEN

Membrane transporters play diverse roles in the pharmacokinetics and pharmacodynamics of small-molecule drugs. Understanding the mechanisms of drug-transporter interactions at the molecular level is, therefore, essential for the design of drugs with optimal therapeutic effects. This white paper examines recent progress, applications, and challenges of molecular modeling of membrane transporters, including modeling techniques that are centered on the structures of transporter ligands, and those focusing on the structures of the transporters. The goals of this article are to illustrate current best practices and future opportunities in using molecular modeling techniques to understand and predict transporter-mediated effects on drug disposition and efficacy.Membrane transporters from the solute carrier (SLC) and ATP-binding cassette (ABC) superfamilies regulate the cellular uptake, efflux, and homeostasis of many essential nutrients and significantly impact the pharmacokinetics of drugs; further, they may provide targets for novel therapeutics as well as facilitate prodrug approaches. Because of their often broad substrate selectivity they are also implicated in many undesirable and sometimes life-threatening drug-drug interactions (DDIs).5,6.


Asunto(s)
Moduladores del Transporte de Membrana/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Preparaciones Farmacéuticas/metabolismo , Farmacocinética , Animales , Interacciones de Drogas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/genética , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/metabolismo , Genotipo , Humanos , Ligandos , Moduladores del Transporte de Membrana/metabolismo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Variantes Farmacogenómicas , Fenotipo , Conformación Proteica , Relación Estructura-Actividad Cuantitativa , Medición de Riesgo
20.
Mol Pain ; 14: 1744806918793229, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30027794

RESUMEN

Background Diabetic neuropathic pain is poorly controlled by analgesics, and the precise molecular mechanisms underlying hyperalgesia remain unclear. The KCNQ2/3/5 channels expressed in dorsal root ganglion neurons are important in pain transmission. The expression and activity of KCNQ2/3/5 channels in dorsal root ganglion neurons in rats with diabetic neuropathic pain were investigated in this study. Methods The mRNA levels of KCNQ2/3/5 channels were analyzed by real-time polymerase chain reaction. The protein levels of KCNQ2/3/5 channels were evaluated by Western blot assay. KCNQ2/3/5 channel expression in situ in dorsal root ganglion neurons was detected by double fluorescent labeling technique. M current (IM) density and neuronal excitability were determined by whole-cell voltage and current clamp recordings. Mechanical allodynia and thermal hyperalgesia were assessed by von Frey filaments and plantar analgesia tester, respectively. Results The mRNA and protein levels of KCNQ2/3/5 channels significantly decreased, followed by the reduction of IM density and elevation of neuronal excitability of dorsal root ganglion neurons from diabetic rats. Activation of KCNQ channels with retigabine reduced the hyperexcitability and inhibition of KCNQ channels with XE991 enhanced the hyperexcitability. Administration of retigabine alleviated both mechanical allodynia and thermal hyperalgesia, while XE991 augmented both mechanical allodynia and thermal hyperalgesia in diabetic neuropathic pain in rats. Conclusion The findings elucidate the mechanisms by which downregulation of the expression and reduction of the activity of KCNQ2/3/5 channels in diabetic rat dorsal root ganglion neurons contribute to neuronal hyperexcitability, which results in hyperalgesia. These data provide intriguing evidence that activation of KCNQ2/3/5 channels might be the potential new targets for alleviating diabetic neuropathic pain symptoms.


Asunto(s)
Neuropatías Diabéticas/patología , Ganglios Espinales/patología , Canales de Potasio KCNQ/metabolismo , Neuronas/metabolismo , Animales , Antracenos/farmacología , Carbamatos/farmacología , Carbamatos/uso terapéutico , Células Cultivadas , Neuropatías Diabéticas/inducido químicamente , Neuropatías Diabéticas/tratamiento farmacológico , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de los fármacos , Canales de Potasio KCNQ/genética , Moduladores del Transporte de Membrana/farmacología , Moduladores del Transporte de Membrana/uso terapéutico , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Umbral del Dolor/efectos de los fármacos , Umbral del Dolor/fisiología , Técnicas de Placa-Clamp , Fenilendiaminas/farmacología , Fenilendiaminas/uso terapéutico , Bloqueadores de los Canales de Potasio/farmacología , ARN Mensajero/metabolismo , Ratas , Estreptozocina/toxicidad , Canales Catiónicos TRPV/metabolismo
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