RESUMEN
Autism spectrum disorder (ASD) is known as a group of neurodevelopmental conditions including stereotyped and repetitive behaviors, besides social and sensorimotor deficits. Anatomical and functional evidence indicates atypical maturation of the striatum. Astrocytes regulate the maturation and plasticity of synaptic circuits, and impaired calcium signaling is associated with repetitive behaviors and atypical social interaction. Spontaneous calcium transients (SCT) recorded in the striatal astrocytes of the rat were investigated in the preclinical model of ASD by prenatal exposure to valproic acid (VPA). Our results showed sensorimotor delay, augmented glial fibrillary acidic protein -a typical intermediate filament protein expressed by astrocytes- and diminished expression of GABAA-ρ3 through development, and increased frequency of SCT with a reduced latency that resulted in a diminished amplitude in the VPA model. The convulsant picrotoxin, a GABAA (γ-aminobutyric acid type A) receptor antagonist, reduced the frequency of SCT in both experimental groups but rescued this parameter to control levels in the preclinical ASD model. The amplitude and latency of SCT were decreased by picrotoxin in both experimental groups. Nipecotic acid, a GABA uptake inhibitor, reduced the mean amplitude only for the control group. Nevertheless, nipecotic acid increased the frequency but diminished the latency in both experimental groups. Thus, we conclude that striatal astrocytes exhibit SCT modulated by GABAA-mediated signaling, and prenatal exposure to VPA disturbs this tuning.
Asunto(s)
Astrocitos , Cuerpo Estriado , Animales , Astrocitos/metabolismo , Astrocitos/efectos de los fármacos , Cuerpo Estriado/metabolismo , Cuerpo Estriado/efectos de los fármacos , Femenino , Embarazo , Ratas , Ácido Valproico/farmacología , Ratas Wistar , Picrotoxina/farmacología , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , Modelos Animales de Enfermedad , Masculino , Calcio/metabolismo , Trastorno del Espectro Autista/metabolismo , Trastorno Autístico/metabolismo , Efectos Tardíos de la Exposición Prenatal/metabolismoRESUMEN
Calcium is a secondary messenger that interacts with several cellular proteins, regulates various physiological processes, and plays a role in diseases such as viral infections. Next-generation probiotics and live biotherapeutic products are linked to the regulation of intracellular calcium levels. Some viruses can manipulate calcium channels, pumps, and membrane receptors to alter calcium influx and promote virion production and release. In this study, we examined the use of bacteria for the prevention and treatment of viral diseases, such as coronavirus of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Vaccination programs have helped reduce disease severity; however, there is still a lack of well-recognized drug regimens for the clinical management of COVID-19. SARS-CoV-2 interacts with the host cell calcium (Ca2+), manipulates proteins, and disrupts Ca2+ homeostasis. This article explores how viruses exploit, create, or exacerbate calcium imbalances, and the potential role of probiotics in mitigating viral infections by modulating calcium signaling. Pharmacological strategies have been developed to prevent viral replication and block the calcium channels that serve as viral receptors. Alternatively, probiotics may interact with cellular calcium influx, such as Lactobacillus spp. The interaction between Akkermansia muciniphila and cellular calcium homeostasis is evident. A scientific basis for using probiotics to manipulate calcium channel activity needs to be established for the treatment and prevention of viral diseases while maintaining calcium homeostasis. In this review article, we discuss how intracellular calcium signaling can affect viral replication and explore the potential therapeutic benefits of probiotics.
Asunto(s)
COVID-19 , Calcio , Probióticos , SARS-CoV-2 , Probióticos/uso terapéutico , Probióticos/farmacología , Humanos , COVID-19/metabolismo , COVID-19/virología , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Tratamiento Farmacológico de COVID-19RESUMEN
BACKGROUND: Astrocytes Ca2+ signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca2+ signals in astrocytes. Importantly, astrocytes express the Ca2+-dependent nitric oxide (NO)-synthetizing enzymes eNOS and nNOS, which might contribute to the Ca2+ signals by triggering Ca2+ influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca2+ homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca2+ signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex. RESULTS: Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca2+]i and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptor-dependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca2+ signaling. CONCLUSIONS: Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca2+ signaling.
Asunto(s)
Astrocitos , Señalización del Calcio , Óxido Nítrico , Animales , Ratas , Astrocitos/metabolismo , Astrocitos/efectos de los fármacos , Calcio/metabolismo , Canales de Calcio/metabolismo , Señalización del Calcio/fisiología , Señalización del Calcio/efectos de los fármacos , Células Cultivadas , Conexina 43/metabolismo , Ácido Glutámico/metabolismo , Óxido Nítrico/metabolismo , Ratas WistarRESUMEN
La hipertensión arterial pulmonar se caracteriza por una presión arterial pulmonar media y resistencia vascular pulmonar elevadas y remodelado patológico de las arterias pulmonares. La entrada de calcio desde el espacio extracelular al intracelular a través de canales dependientes e independientes de voltaje juega un rol fundamental en el aumento de la contractilidad de las arterias pulmonares y la pérdida de regulación del comportamiento proliferativo de las células de las distintas capas de la pared de las arterias pulmonares. De esta manera, estos canales contribuyen con la vasoconstricción exacerbada de las arterias pulmonares y a su remodelado patológico. El objetivo de esta revisión es recapitular la evidencia obtenida desde modelos celulares y animales respecto a la contribución de los principales canales de calcio de membrana plasmática en estos mecanismos fisiopatológicos claves en el desarrollo de la hipertensión pulmonar, discutiendo su valor potencial como diana farmacológica para terapias presentes y futuras.
Pulmonary arterial hypertension is characterized by increased mean pulmonary arterial pressure, resistance, and pathological remodeling of pulmonary arteries. Calcium entry from the extracellular to the intracellular space through voltage-dependent and -independent channels play a major role in the increase of contractility of pulmonary arteries and in the loss of regulation of the proliferative behavior of the cells from the different layers of the pulmonary arterial wall. In doing so, these channels contribute to enhanced vasoconstriction of pulmonary arteries and their pathological remodeling. This review aims to summarize the evidence obtained from animal and cellular models regarding the involvement of the main plasma membrane calcium channels in these key pathophysiological processes for pulmonary arterial hypertension, discussing the potential value as pharmacological targets for therapies in the present and the future.
Asunto(s)
Humanos , Canales de Calcio/efectos de los fármacos , Canales de Calcio/fisiología , Hipertensión Pulmonar/fisiopatología , Hipertensión Pulmonar/tratamiento farmacológico , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/fisiopatología , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , Bloqueadores de los Canales de Calcio/uso terapéutico , Bloqueadores de los Canales de Calcio/farmacología , Transducción de Señal/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , AnimalesRESUMEN
Pulmonary arterial hypertension is characterized by increased mean pulmonary arterial pressure, resistance, and pathological remodeling of pulmonary arteries. Calcium entry from the extracellular to the intracellular space through voltage-dependent and -independent channels play a major role in the increase of contractility of pulmonary arteries and in the loss of regulation of the proliferative behavior of the cells from the different layers of the pulmonary arterial wall. In doing so, these channels contribute to enhanced vasoconstriction of pulmonary arteries and their pathological remodeling. This review aims to summarize the evidence obtained from animal and cellular models regarding the involvement of the main plasma membrane calcium channels in these key pathophysiological processes for pulmonary arterial hypertension, discussing the potential value as pharmacological targets for therapies in the present and the future.
Asunto(s)
Canales de Calcio , Hipertensión Pulmonar , Humanos , Hipertensión Pulmonar/tratamiento farmacológico , Hipertensión Pulmonar/fisiopatología , Canales de Calcio/fisiología , Canales de Calcio/efectos de los fármacos , Animales , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , Bloqueadores de los Canales de Calcio/uso terapéutico , Bloqueadores de los Canales de Calcio/farmacología , Transducción de Señal/efectos de los fármacos , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/fisiopatología , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiologíaRESUMEN
Throughout evolution, the need for single-celled organisms to associate and form a single cluster of cells has had several evolutionary advantages. In complex, multicellular organisms, each tissue or organ has a specialty and function that make life together possible, and the organism as a whole needs to act in balance and adapt to changes in the environment. Sensory organs are essential for connecting external stimuli into a biological response, through the senses: sight, smell, taste, hearing, and touch. The G-protein-coupled receptors (GPCRs) are responsible for many of these senses and therefore play a key role in the perception of the cells' external environment, enabling interaction and coordinated development between each cell of a multicellular organism. The malaria-causing protozoan parasite, Plasmodium falciparum, has a complex life cycle that is extremely dependent on a finely regulated cellular signaling machinery. In this review, we summarize strong evidence and the main candidates of GPCRs in protozoan parasites. Interestingly, one of these GPCRs is a sensor for K+ shift in Plasmodium falciparum, PfSR25. Studying this family of proteins in P. falciparum could have a significant impact, both on understanding the history of the evolution of GPCRs and on finding new targets for antimalarials.
Asunto(s)
Señalización del Calcio/fisiología , Interacciones Huésped-Parásitos/fisiología , Malaria Falciparum/metabolismo , Percepción/fisiología , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animales , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Humanos , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/parasitología , Terapia Molecular Dirigida/métodos , Percepción/efectos de los fármacos , Unión Proteica , Receptores Acoplados a Proteínas G/antagonistas & inhibidoresRESUMEN
Although monoaminergic-based antidepressant drugs are largely used to treat major depressive disorder (MDD), their mechanisms are still incompletely understood. Intracellular Ca2+ (iCa2+) and Calmodulin 1(CaM-1) homeostasis have been proposed to participate in the therapeutic effects of these compounds. We investigated whether intra-hippocampal inhibition of CaM-1 would modulate the behavioral responses to chronic treatment with imipramine (IMI) or 7-nitroindazole (7-NI), a selective inhibitor of the neuronal nitric oxide synthase 1 (NOS1) enzyme that shows antidepressant-like effects. We also investigated the interactions of IMI and CaM-1 on transient astrocyte iCa2+ evoked by glutamate stimuli. Intra-hippocampal microinjection of the lentiviral delivered (LV) short hairpin iRNA-driven against the CaM-1 mRNA (LV-shRNA-CaM-1) or the CaM-1 inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalene sulphonamide (W-7) blocked the antidepressant-like effect of chronic treatment with IMI or 7-NI. The shRNA also inhibited the mRNA expression of the tropomyosin receptor kinase B (TrkB) in the microinjection region. The iCa2+ in ex vivo hippocampus slices stained with fluorescent Ca2+indicator Oregon Green 488 BAPTA-1 revealed that IMI increased the intensity and duration of iCa2+ oscillation and reduced the number of events evoked by glutamate stimuli, evaluated by using CCD imaging and the % ΔF/Fo parameters. The pre-treatment with W-7 fully antagonized this effect. The present results indicate that the behavioral benefits of chronic antidepressant treatment might be associated with astrocyte intracellular Ca2+dynamics and TrkB mRNA expression in the hippocampus.
Asunto(s)
Antidepresivos/farmacología , Astrocitos/metabolismo , Señalización del Calcio/fisiología , Depresión/metabolismo , Hipocampo/metabolismo , Receptor trkB/biosíntesis , Animales , Astrocitos/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Depresión/tratamiento farmacológico , Depresión/psicología , Células HEK293 , Hipocampo/efectos de los fármacos , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Técnicas de Cultivo de Órganos , Ratas , Ratas Wistar , Resultado del TratamientoRESUMEN
Histamine H1 receptor ligands used clinically as antiallergics rank among the most widely prescribed and over-the-counter drugs in the world. They exert the therapeutic actions by blocking the effects of histamine, due to null or negative efficacy towards Gαq-phospholipase C (PLC)-inositol triphosphates (IP3)-Ca2+ and nuclear factor-kappa B cascades. However, there is no information regarding their ability to modulate other receptor responses. The aim of the present study was to investigate whether histamine H1 receptor ligands could display positive efficacy concerning receptor desensitization, internalization, signaling through Gαq independent pathways or even transcriptional regulation of proinflammatory genes. While diphenhydramine, triprolidine and chlorpheniramine activate ERK1/2 (extracellular signal-regulated kinase 1/2) pathway in A549 cells, pre-treatment with chlorpheniramine or triprolidine completely desensitize histamine H1 receptor mediated Ca2+ response, and both diphenhydramine and triprolidine lead to receptor internalization. Unlike histamine, histamine H1 receptor desensitization and internalization induced by antihistamines prove to be independent of G protein-coupled receptor kinase 2 (GRK2) phosphorylation. Also, unlike the reference agonist, the recovery of the number of cell-surface histamine H1 receptors is a consequence of de novo synthesis. On the other hand, all of the ligands lack efficacy regarding cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) mRNA regulation. However, a prolonged exposure with each of the antihistamines impaires the increase in COX-2 and IL-8 mRNA levels induced by histamine, even after ligand removal. Altogether, these findings demonstrate the biased nature of histamine H1 receptor ligands contributing to a more accurate classification, and providing evidence for a more rational and safe use of them.
Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Agonistas de los Receptores Histamínicos/farmacología , Antagonistas de los Receptores Histamínicos H1/farmacología , Receptores Histamínicos H1/efectos de los fármacos , Células A549 , Señalización del Calcio/efectos de los fármacos , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Agonismo Inverso de Drogas , Activación Enzimática , Quinasa 2 del Receptor Acoplado a Proteína-G/genética , Quinasa 2 del Receptor Acoplado a Proteína-G/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Inositol 1,4,5-Trifosfato/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Ligandos , Fosforilación , Transporte de Proteínas , Receptores Histamínicos H1/metabolismo , Fosfolipasas de Tipo C/metabolismoRESUMEN
Increasing evidence indicates that aquaporins (AQPs) exert an influence in cell signaling by the interplay with the transient receptor potential vanilloid 4 (TRPV4) channel. We previously found that TRPV4 physically and functionally interacts with AQP2 in cortical collecting ducts (CCD) cells, favoring cell volume regulation and cell migration. Because TRPV4 was implicated in ATP release in several tissues, we investigated the possibility that TRPV4/AQP2 interaction influences ATP release in CCD cells. Using two CCD cell lines expressing or not AQP2, we measured extracellular ATP (ATPe) under TRPV4 activation and intracellular Ca2+ under ATP addition. We found that AQP2 is critical for the release of ATP induced by TRPV4 activation. This ATP release occurs by an exocytic and a conductive route. ATPe, in turn, stimulates purinergic receptors leading to ATPe-induced ATP release by a Ca2+ -dependent mechanism. We propose that AQP2 by modulating Ca2+ and ATP differently could explain AQP2-increased cell migration.
Asunto(s)
Adenosina Trifosfato/metabolismo , Acuaporina 2/metabolismo , Señalización del Calcio , Calcio/metabolismo , Movimiento Celular , Túbulos Renales Colectores/metabolismo , Canales Catiónicos TRPV/metabolismo , Animales , Comunicación Autocrina , Señalización del Calcio/efectos de los fármacos , Línea Celular , Movimiento Celular/efectos de los fármacos , Exocitosis , Túbulos Renales Colectores/efectos de los fármacos , Leucina/análogos & derivados , Leucina/farmacología , Comunicación Paracrina , Ratas , Receptores Purinérgicos P2/metabolismo , Sulfonamidas/farmacología , Canales Catiónicos TRPV/agonistasRESUMEN
Allatotropin is a pleiotropic peptide originally characterized in insects. The existence of AT neuropeptide signaling was proposed in other invertebrates. In fact, we previously proposed the presence of an AT-like system regulating feeding behavior in Hydra sp. Even in insects, the information about the AT signaling pathway is incomplete. The aim of this study is to analyze the signaling cascade activated by AT in Hydra plagiodesmica using a pharmacological approach. The results show the involvement of Ca2+ and IP3 signaling in the transduction pathway of the peptide. Furthermore, we confirm the existence of a GPCR system involved in this pathway, that would be coupled to a Gq subfamily of Gα protein, which activates a PLC, inducing an increase in IP3 and cytosolic Ca2+. To the best of our knowledge, this work represents the first in vivo approach to study the overall signaling pathway and intracellular events involved in the myoregulatory effect of AT in Hydra sp.
Asunto(s)
Señalización del Calcio , Hydra/metabolismo , Hormonas de Insectos/metabolismo , Neuropéptidos/metabolismo , Orexinas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animales , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Estrenos/farmacología , Proteínas de Unión al GTP/metabolismo , Indoles/farmacología , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Maleimidas/farmacología , Meliteno/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Pirrolidinonas/farmacología , Fosfolipasas de Tipo C/antagonistas & inhibidores , Fosfolipasas de Tipo C/metabolismoRESUMEN
Pannexin-1 (Panx1) forms plasma membrane channels that allow the exchange of small molecules between the intracellular and extracellular compartments, and are involved in diverse physiological and pathological responses in the nervous system. However, the signaling mechanisms that induce their opening still remain elusive. Here, we propose a new mechanism for Panx1 channel activation through a functional crosstalk with the highly Ca2+ permeable α7 nicotinic acetylcholine receptor (nAChR). Consistent with this hypothesis, we found that activation of α7 nAChRs induces Panx1-mediated dye uptake and ATP release in the neuroblastoma cell line SH-SY5Y-α7. Using membrane permeant Ca2+ chelators, total internal reflection fluorescence microscopy in SH-SY5Y-α7 cells expressing a membrane-tethered GCAMP3, and Src kinase inhibitors, we further demonstrated that Panx1 channel opening depends on Ca2+ signals localized in submembrane areas, as well as on Src kinases. In turn, Panx1 channels amplify cytosolic Ca2+ signals induced by the activation of α7 nAChRs, by a mechanism that seems to involve ATP release and P2X7 receptor activation, as hydrolysis of extracellular ATP with apyrase or blockage of P2X7 receptors with oxidized ATP significantly reduces the α7 nAChR-Ca2+ signal. The physiological relevance of this crosstalk was also demonstrated in neuroendocrine chromaffin cells, wherein Panx1 channels and P2X7 receptors contribute to the exocytotic release of catecholamines triggered by α7 nAChRs, as measured by amperometry. Together these findings point to a functional coupling between α7 nAChRs, Panx1 channels and P2X7 receptors with physiological relevance in neurosecretion.
Asunto(s)
Células Cromafines/metabolismo , Conexinas/metabolismo , Exocitosis/fisiología , Proteínas del Tejido Nervioso/metabolismo , Receptor Cross-Talk/fisiología , Receptores Purinérgicos P2X7/metabolismo , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Animales , Quelantes del Calcio/farmacología , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , Bovinos , Línea Celular Tumoral , Células Cromafines/efectos de los fármacos , Exocitosis/efectos de los fármacos , Humanos , Ratones , Receptor Cross-Talk/efectos de los fármacosRESUMEN
Agents that modulate the activity of high-voltage gated calcium channels (HVCCs) exhibit experimentally and clinically significant effect by relieving visceral pain. Among these agents, the toxins Phα1ß and ω-conotoxin MVIIA effectively reduce chronic pain in rodent models. The molecular mechanisms underlying the chronic pain associated with acute pancreatitis (AP) are poorly understood. Hypercalcemia is a risk factor; the role of cytosolic calcium is considered to be a modulator of pancreatitis. Blockade of Ca2+ signals may be useful as a prophylactic treatment of pancreatitis. We explored the pathophysiological roles of three peptide toxins: Phα1ß and its recombinant form CTK 01512-2-blockers of TRPA1 receptor and HVCCs and ω-conotoxin MVIIA, a specific blocker of N-type calcium channels in cerulein-induced AP. Cerulein injection elicits AP in rats, evidenced by an increase in hyperalgesic pain, inflammatory infiltration, amylase and lipase secretion, and reactive oxygen species, TNF-α, and p65 NF-κB levels. These effects of cerulein-induced AP were abolished by Phα1ß and its recombinant form CTK 01512-2, whereas ω-conotoxin MVIIA had no effect on the induced increase in pancreatic enzyme secretion. Our results demonstrate that Phα1ß and CTK 01512-2 toxins-antagonists of HVCCs and TRPA1 receptor presented an effective response profile, in the control of nociception and inflammatory process in the AP model in rats, without causing changes in spontaneous locomotion of the rats.
Asunto(s)
Dolor Abdominal/prevención & control , Analgésicos/farmacología , Antiinflamatorios/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Hiperalgesia/prevención & control , Umbral del Dolor/efectos de los fármacos , Pancreatitis/prevención & control , Dolor Abdominal/etiología , Dolor Abdominal/metabolismo , Dolor Abdominal/fisiopatología , Animales , Conducta Animal/efectos de los fármacos , Canales de Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Ceruletida , Modelos Animales de Enfermedad , Conducta Exploratoria/efectos de los fármacos , Hiperalgesia/etiología , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatología , Mediadores de Inflamación/metabolismo , Masculino , Neuropéptidos/farmacología , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Pancreatitis/inducido químicamente , Pancreatitis/metabolismo , Pancreatitis/fisiopatología , Ratas Wistar , Venenos de Araña/farmacología , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Médula Espinal/fisiopatología , omega-Conotoxinas/farmacologíaRESUMEN
The lateral line (LL) is a sensory system that allows fish and amphibians to detect water currents. LL responsiveness is modulated by efferent neurons that aid in distinguishing between external and self-generated stimuli, maintaining sensitivity to relevant cues. One component of the efferent system is cholinergic, the activation of which inhibits afferent activity. LL hair cells (HCs) share structural, functional, and molecular similarities with those of the cochlea, making them a popular model for studying human hearing and balance disorders. Because of these commonalities, one could propose that the receptor at the LL efferent synapse is a α9α10 nicotinic acetylcholine receptor (nAChR). However, the identities of the molecular players underlying ACh-mediated inhibition in the LL remain unknown. Surprisingly, through the analysis of single-cell expression studies and in situ hybridization, we describe that α9, but not the α10, subunits are enriched in zebrafish HCs. Moreover, the heterologous expression of zebrafish α9 subunits indicates that homomeric receptors are functional and exhibit robust ACh-gated currents blocked by α-bungarotoxin and strychnine. In addition, in vivo Ca2+ imaging on mechanically stimulated zebrafish LL HCs show that ACh elicits a decrease in evoked Ca2+ signals, regardless of HC polarity. This effect is blocked by both α-bungarotoxin and apamin, indicating coupling of ACh-mediated effects to small-conductance Ca2+-activated potassium (SKs) channels. Our results indicate that an α9-containing (α9*) nAChR operates at the zebrafish LL efferent synapse. Moreover, the activation of α9* nAChRs most likely leads to LL HC hyperpolarization served by SK channels.SIGNIFICANCE STATEMENT The fish lateral line (LL) mechanosensory system shares structural, functional, and molecular similarities with those of the mammalian cochlea. Thus, it has become an accessible model for studying human hearing and balance disorders. However, the molecular players serving efferent control of LL hair cell (HC) activity have not been identified. Here we demonstrate that, different from the hearing organ of vertebrate species, a nicotinic acetylcholine receptor composed only of α9 subunits operates at the LL efferent synapse. Activation of α9-containing receptors leads to LL HC hyperpolarization because of the opening of small-conductance Ca2+-activated potassium channels. These results will further aid in the interpretation of data obtained from LL HCs as a model for cochlear HCs.
Asunto(s)
Vías Eferentes/fisiología , Sistema de la Línea Lateral/fisiología , Sistema Nervioso Parasimpático/fisiología , Sinapsis/fisiología , Animales , Bungarotoxinas/farmacología , Señalización del Calcio/efectos de los fármacos , Regulación de la Expresión Génica , Células Ciliadas Auditivas/fisiología , Antagonistas Nicotínicos/farmacología , Oocitos , Estimulación Física , Receptores Nicotínicos/efectos de los fármacos , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/efectos de los fármacos , Estricnina/farmacología , Xenopus , Pez CebraRESUMEN
Coumarins exhibit a wide variety of biological effects, including activities in the cardiovascular system and the aim of this study was to evaluate the vascular therapeutic potential of 7-Hydroxicoumarin (7-HC). The vascular effects induced by 7-HC (0.001 µM-300 µM), were investigated by in vitro approaches using isometric tension measurements in rat superior mesenteric arteries and by in silico assays using Ligand-based analysis. Our results suggest that the vasorelaxant effect of 7-HC seems to rely on potassium channels, notably through large conductance Ca2+-activated K+ (BKCa) channels activation. In fact, 7-HC (300 µM) significantly reduced CaCl2-induced contraction as well as the reduction of intracellular calcium mobilization. However, the relaxation induced by 7-HC was independent of store-operated calcium entry (SOCE). Moreover, in silico analysis suggests that potassium channels have a common binding pocket, where 7-HC may bind and hint that its binding profile is more similar to quinine's than verapamil's. These results are compatible with the inhibition of Ca2+ release from intracellular stores, which is prompted by phenylephrine and caffeine. Taken together, these results demonstrate a therapeutic potential of 7-HC on the cardiovascular system, making it a promising lead compound for the development of drugs useful in the treatment of cardiovascular diseases.
Asunto(s)
Señalización del Calcio/efectos de los fármacos , Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio/agonistas , Arterias Mesentéricas/efectos de los fármacos , Umbeliferonas/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Animales , Señalización del Calcio/fisiología , Línea Celular , Relación Dosis-Respuesta a Droga , Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio/química , Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio/fisiología , Masculino , Arterias Mesentéricas/fisiología , Técnicas de Cultivo de Órganos , Estructura Secundaria de Proteína , Ratas , Ratas Wistar , Vasodilatación/fisiologíaRESUMEN
Monocytes can develop immunological memory, a functional characteristic widely recognized as innate immune training, to distinguish it from memory in adaptive immune cells. Upon a secondary immune challenge, either homologous or heterologous, trained monocytes/macrophages exhibit a more robust production of pro-inflammatory cytokines, such as IL-1ß, IL-6, and TNF-α, than untrained monocytes. Candida albicans, ß-glucan, and BCG are all inducers of monocyte training and recent metabolic profiling analyses have revealed that training induction is dependent on glycolysis, glutaminolysis, and the cholesterol synthesis pathway, along with fumarate accumulation; interestingly, fumarate itself can induce training. Since fumarate is produced by the tricarboxylic acid (TCA) cycle within mitochondria, we asked whether extra-mitochondrial fumarate has an effect on mitochondrial function. Results showed that the addition of fumarate to monocytes induces mitochondrial Ca2+ uptake, fusion, and increased membrane potential (Δψm), while mitochondrial cristae became closer to each other, suggesting that immediate (from minutes to hours) mitochondrial activation plays a role in the induction phase of innate immune training of monocytes. To establish whether fumarate induces similar mitochondrial changes in vivo in a multicellular organism, effects of fumarate supplementation were tested in the nematode worm Caenorhabditis elegans. This induced mitochondrial fusion in both muscle and intestinal cells and also increased resistance to infection of the pharynx with E. coli. Together, these findings contribute to defining a mitochondrial signature associated with the induction of innate immune training by fumarate treatment, and to the understanding of whole organism infection resistance.
Asunto(s)
Caenorhabditis elegans/efectos de los fármacos , Infecciones por Escherichia coli/prevención & control , Escherichia coli/patogenicidad , Fumaratos/farmacología , Inmunidad Innata/efectos de los fármacos , Memoria Inmunológica/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Monocitos/efectos de los fármacos , Animales , Caenorhabditis elegans/inmunología , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/microbiología , Señalización del Calcio/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Escherichia coli/inmunología , Infecciones por Escherichia coli/inmunología , Infecciones por Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Interacciones Huésped-Patógeno , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/inmunología , Mitocondrias/metabolismo , Dinámicas Mitocondriales/efectos de los fármacos , Monocitos/inmunología , Monocitos/metabolismoRESUMEN
Elevated plasma concentrations of the ketone body ß-hydroxybutyrate (BHB), an endogenous agonist of the hydroxycarboxylic acid receptor 2 (HCA2), is associated with an increased incidence of inflammatory diseases during lactation in dairy cows. In the early stages of this pathology, an increase in neutrophil recruitment is observed; however, the role of BHB remains elusive. This study characterized the effect of BHB and synthetic agonists of the HCA2 receptor on bovine neutrophil chemotaxis and the signaling pathways involved in this process. We demonstrated that treatment with BHB concentrations between 1.2 and 10 mM and two full selective agonists of the HCA2 receptor, MK-1903 and nicotinic acid, increased bovine neutrophil chemotaxis. We also observed that BHB and HCA2 agonists induced calcium release and phosphorylation of AKT, ERK 1/2 and AMPKα. To evaluate the role of these pathways in bovine neutrophil chemotaxis, we used the pharmacological inhibitors BAPTA-AM, pertussis toxin, U73122, LY294002, U0126 and compound C. Our results suggest that these pathways are required for HCA2 agonist-induced bovine neutrophil chemotaxis in non-physiological condition. Concentrations around 1.4 mM of BHB after calving may exert a chemoattractant effect that is key during the onset of the inflammatory process associated with metabolic disorders in dairy cows.
Asunto(s)
Ácido 3-Hidroxibutírico/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Quimiotaxis , Sistema de Señalización de MAP Quinasas , Neutrófilos/citología , Neutrófilos/enzimología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Animales , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Bovinos , Quimiotaxis/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Niacina/farmacología , Fosforilación/efectos de los fármacos , Pirazoles/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Fosfolipasas de Tipo C/metabolismoRESUMEN
Population aging, as well as the handling of age-associated diseases, is a worldwide increasing concern. Among them, Alzheimer's disease stands out as the major cause of dementia culminating in full dependence on other people for basic functions. However, despite numerous efforts, in the last decades, there was no new approved therapeutic drug for the treatment of the disease. Calcium-activated potassium channels have emerged as a potential tool for neuronal protection by modulating intracellular calcium signaling. Their subcellular localization is determinant of their functional effects. When located on the plasma membrane of neuronal cells, they can modulate synaptic function, while their activation at the inner mitochondrial membrane has a neuroprotective potential via the attenuation of mitochondrial reactive oxygen species in conditions of oxidative stress. Here we review the dual role of these channels in the aging phenotype and Alzheimer's disease pathology and discuss their potential use as a therapeutic tool.
Asunto(s)
Envejecimiento/metabolismo , Enfermedad de Alzheimer/metabolismo , Inflamación/metabolismo , Mitocondrias/metabolismo , Neuronas/metabolismo , Canales de Potasio Calcio-Activados/metabolismo , Envejecimiento/patología , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/terapia , Animales , Calcio/metabolismo , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/genética , Muerte Celular/genética , Humanos , Memoria/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/fisiología , Estrés Oxidativo/genética , Canales de Potasio Calcio-Activados/agonistas , Canales de Potasio Calcio-Activados/antagonistas & inhibidores , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Acute ethanol treatment induces neurodegeneration in cultured neurons and can lead to brain damage in animal models. Neuronal cells exposed to ethanol showed an increase in reactive oxygen species (ROS), oxidative damage and mitochondrial impairment contributing to synaptic failure. However, the underlying mechanisms of these events are not well understood. Here, we studied the contribution of NADPH oxidase, as a relevant source of ROS production in the brain, to mitochondrial impairment and oxidative stress induced by ethanol. We used primary hippocampal neurons subjected to an acute treatment of ethanol at increasing concentrations (25, 50, and 75 mM, 24 h), and we evaluated ROS production, mitochondrial function, and synaptic vesicle activity. Our studies showed that after ethanol administration, hippocampal neurons presented an increase in ROS levels, mitochondrial dysfunction, calcium handling defects, and synaptic impairment. Interestingly, treatment with the NADPH inhibitor, apocynin, significantly prevented oxidative stress, mitochondrial dysfunction, and the impairment of synaptic vesicle activity induced by ethanol treatment. These results indicate that NADPH oxidase could be a key participant in the molecular mechanism by which alcohol affects the brain.
Asunto(s)
Intoxicación Alcohólica/enzimología , Intoxicación Alcohólica/patología , Hipocampo/efectos de los fármacos , Hipocampo/patología , Mitocondrias/efectos de los fármacos , NADPH Oxidasas , Neuronas/efectos de los fármacos , Neuronas/patología , Estrés Oxidativo , Adenosina Trifosfato/metabolismo , Animales , Señalización del Calcio/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Embarazo , Cultivo Primario de Células , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno , Sinapsis/efectos de los fármacos , Vesículas Sinápticas/efectos de los fármacosRESUMEN
Exocytosis of spermatozoon's secretory vesicle, named acrosome reaction (AR), is a regulated event that plays a central role in fertilization. It is coupled to a complex calcium signaling. Ceramide is a multitasking lipid involved in exocytosis. Nevertheless, its effect on secretion is controversial and the underlying cellular and molecular mechanisms remain unknown. Human spermatozoa are useful to dissect the role of ceramide in secretion given that the gamete is not capable to undergo any trafficking mechanisms other than exocytosis. We report for the first time, the presence of sphingolipid metabolism enzymes such as neutral-sphingomyelinase and ceramide synthase in sperm. Ceramidases are also present and active. Both the addition of cell-permeable ceramide and the rise of the endogenous one, increase intracellular calcium acting as potent inducers of exocytosis. Ceramide triggers AR in capacitated spermatozoa and enhances the gamete response to progesterone. The lipid induces physiological ultrastructural changes in the acrosome and triggers an exocytosis-signaling cascade involving protein tyrosine phosphatase 1B and VAMP2. Real-time imaging showed an increment of calcium in the cytosol upon ceramide treatment either in the absence or in the presence of extracellular calcium. Pharmacological experiments demonstrate that at early stages the process involves ryanodine receptors, CatSper (calcium channel of sperm), and store-operated calcium channels. We set out the signaling sequence of events that connect ceramide to internal calcium mobilization and external calcium signals during secretion. These results allow the coordination of lipids and proteins in a pathway that accomplishes secretion. Our findings contribute to the understanding of ceramide's role in regulated exocytosis and fertilization.
Asunto(s)
Reacción Acrosómica/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 1/genética , Espermatozoides/efectos de los fármacos , Proteína 2 de Membrana Asociada a Vesículas/genética , Acrosoma/efectos de los fármacos , Acrosoma/metabolismo , Reacción Acrosómica/efectos de los fármacos , Adulto , Calcio/química , Canales de Calcio/genética , Señalización del Calcio/efectos de los fármacos , Ceramidas/farmacología , Citoplasma/efectos de los fármacos , Citoplasma/genética , Exocitosis/genética , Fertilización/genética , Humanos , Masculino , Canal Liberador de Calcio Receptor de Rianodina/genética , Vesículas Secretoras/efectos de los fármacos , Vesículas Secretoras/genética , Espermatozoides/patologíaRESUMEN
BACKGROUND: The interactions between Alzheimer's Disease (AD) and major depression can be translated into clinical data showing that depressive patients have had an enhanced risk for developing AD (later in life). The cellular mechanisms involved in these interactions remain under intensive debate in the literature. In addition, the role of a Ca2+ homeostasis dysregulation in the pathogenesis of neurodegenerative diseases, like AD, and major depression has been under intensive discussion. OBJECTIVE: Thus, revealing the interplay between AD and major depression may provide novel insights into the pathogenesis of these diseases. METHODS: Publications involving Ca2+ signalling pathways, AD, and major depression (alone or combined) were collected by searching multiple databases to find the maximum number of relevant citations (using a search strategy with high sensitivity for studies of etiology). RESULTS: Ca2+ Channel Blockers (CCBs), classically prescribed for hypertensive patients, have been demonstrating neuroprotective effects, such as decreasing the incidence of AD in hypertensive patients, including alleviating major depression symptoms. A mechanism under debate is focused on the restoration of the Ca2+ homeostasis. Indeed, previous studies of our own have correlated Ca2+ and cAMP signalling pathways (Ca2+/cAMP signalling) in controlling both the neurotransmitter release and neuronal death. These studies also observed that CCBs can affect Ca2+/cAMP signalling. CONCLUSION: This review discussed the plausible role of Ca2+/cAMP signalling in the neuroprotective effects of CCBs, including the participation of Ca2+/cAMP signalling in the interactions between major depression and AD. Considering both AD and major depression have become highly prevalent medical problems in the world, the comprehension of the interactions between these diseases could improve drug development.