RESUMO
The physical and functional interaction between transient receptor potential channel ankyrin 1 (TRPA1) and neuronal calcium sensor 1 (NCS-1) was assessed. NCS-1 is a calcium (Ca2+) sensor found in many tissues, primarily neurons, and TRPA1 is a Ca2+ channel involved not only in thermal and pain sensation but also in conditions such as cancer and chemotherapy-induced peripheral neuropathy, in which NCS-1 is also a regulatory component.We explored the interactions between these two proteins by employing western blot, qRT-PCR, co-immunoprecipitation, Ca2+ transient monitoring with Fura-2 spectrophotometry, and electrophysiology assays in breast cancer cells (MDA-MB-231) with different levels of NCS-1 expression and neuroblastoma cells (SH-SY5Y).Our findings showed that the expression of TRPA1 was directly correlated with NCS-1 levels at both the protein and mRNA levels. Additionally, we found a physical and functional association between these two proteins. Physically, the NCS-1 and TRPA1 co-immunoprecipitate. Functionally, NCS-1 enhanced TRPA1-dependent Ca2+ influx, current density, open probability, and conductance, where the functional effects depended on PI3K. Conclusion: NCS-1 appears to act not only as a Ca2+ sensor but also modulates TRPA1 protein expression and channel function in a direct fashion through the PI3K pathway. These results contribute to understanding how Ca2+ homeostasis is regulated and provides a mechanism underlying conditions where Ca2+ dynamics are compromised, including breast cancer. With a cellular pathway identified, targeted treatments can be developed for breast cancer and neuropathy, among other related diseases.
Assuntos
Neoplasias da Mama , Proteínas Sensoras de Cálcio Neuronal , Neuropeptídeos , Canal de Cátion TRPA1 , Feminino , Humanos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cálcio/metabolismo , Sinalização do Cálcio , Linhagem Celular Tumoral , Proteínas Sensoras de Cálcio Neuronal/metabolismo , Proteínas Sensoras de Cálcio Neuronal/genética , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Neuropeptídeos/genética , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Canal de Cátion TRPA1/metabolismo , Canal de Cátion TRPA1/genéticaRESUMO
Fragile X syndrome (FXS) is caused by the loss of function of Fragile X mental retardation protein (FMRP). FXS is one of the leading monogenic causes of intellectual disability (ID) and autism. Although it is caused by the failure of a single gene, FMRP that functions as an RNA binding protein affects a large number of genes secondarily. All these genes represent hundreds of potential targets and different mechanisms that account for multiple pathological features, thereby hampering the search for effective treatments. In this scenario, it seems desirable to reorient therapies toward more general approaches. Neuronal calcium sensor 1 (NCS-1), through its interaction with the guanine-exchange factor Ric8a, regulates the number of synapses and the probability of the release of a neurotransmitter, the two neuronal features that are altered in FXS and other neurodevelopmental disorders. Inhibitors of the NCS-1/Ric8a complex have been shown to be effective in restoring abnormally high synapse numbers as well as improving associative learning in FMRP mutant flies. Here, we demonstrate that phenothiazine FD44, an NCS-1/Ric8a inhibitor, has strong inhibition ability in situ and sufficient bioavailability in the mouse brain. More importantly, administration of FD44 to two different FXS mouse models restores well-known FXS phenotypes, such as hyperactivity, associative learning, aggressive behavior, stereotype, or impaired social approach. It has been suggested that dopamine (DA) may play a relevant role in the behavior and in neurodevelopmental disorders in general. We have measured DA and its metabolites in different brain regions, finding a higher metabolic rate in the limbic area, which is also restored with FD44 treatment. Therefore, in addition to confirming that the NCS-1/Ric8a complex is an excellent therapeutic target, we demonstrate the rescue effect of its inhibitor on the behavior of cognitive and autistic FXS mice and show DA metabolism as a FXS biochemical disease marker.
RESUMO
NCS-1 es una proteína unidora de calcio, que regula el funcionamiento de otras proteínas, con las cuales interactúa a nivel molecular. Su expresión es amplia y no limitada a neuronas. Sus efectos incluyen la regulación de receptores, canales iónicos y enzimas que intervienen en múltiples funciones neuronales. NCS-1 regula la actividad del receptor D2 de dopamina y del receptor A2A de adenosina, ambos fundamentales en diversos procesos de comunicación que involucran control emocional y control de movimientos en varios circuitos. NCS-1 también regula la actividad del receptor de IP3, un canal de calcio intracelular fundamental en la regulación de la homeostasis de este ion, interactúa con IP kinasas, las cuales a su vez desencadenan cascadas de señalización intracelular y modula la actividad de canales de calcio presinápticos; todos estos efectos redundan en regulación de la liberación de neurotransmisores y por ende, de la plasticidad sináptica, lo cual ha sido probado en diversos modelos experimentales. NCS-1 también parece estar involucrada en la regulación de otros canales iónicos de calcio y de potasio que podrían influir en la homeostasis eléctrica de las neuronas y en la supervivencia neuronal a través de la regulación de vías proapoptóticas. Estos amplios efectos de NCS-1 motivan a profundizar la investigación en los mecanismos involucrados en la regulación que ejerce sobre sus proteínas blanco y en nuevos efectos que ayuden a entender el rol de esta proteína en diversos procesos fisiológicos y fisiopatológicos(AU)
NCS-1 is a calcium-binding protein, which regulates the functioning of diverse proteins, with which interacts to a molecular level. Its expression is widespread and it is not limited to neurons. Its effects include the regulation of receptors, ion channels and enzymes, which intervene in multiple neuronal functions. NCS-1 regulates the functioning of D2 dopamine receptor and adenosine A2A receptor, both fundamental in diverse communication processes that involve emotional and movement control in a variety of neural circuits. NCS-1 also regulates the activity of IP 3 receptor, an intracellular calcium ion channel (which is crucial in the regulation of calcium homeostasis), interacts with the IP kinases, which trigger intracellular signaling cascades, and modulates the activity of presynaptic calcium channels. All these effects lead to the regulation of neurotransmitters release and thus, synaptic plasticity, which had been proved in diverse experimental models. NCS-1 also appears to be involved in the regulation of other calcium and potassium channels, which can influence the neuron electric homeostasis and survival through the modulation of proapoptotic pathways. These broad NCS-1 effects motivates further research of the specific mechanisms that are involved in the regulation that this protein exerts on its target proteins and in new effects that may help to understand the role of this protein in physiological and pathophysiological processes(AU)
Assuntos
Humanos , Masculino , Receptores Purinérgicos P1 , Agonistas de Dopamina , Peptídeos e Proteínas de Sinalização Intracelular , NeurôniosRESUMO
Sensing and regulating intracellular levels of calcium are essential for proper cellular function. In neurons, calcium sensing plays important roles in neuronal plasticity, neurotransmitter release, long-term synapse modification and ion channel activity. Neuronal calcium sensor-1 (NCS-1) is a member of the highly conserved neuronal calcium sensor family. Although NCS-1 has been associated with psychiatric conditions including autism, bipolar disorder and schizophrenia, it is unclear which role NCS-1 plays in behavior. To understand the involvement of NCS-1 in psychiatric conditions, we provided a comprehensive behavioral characterization of NCS-1 knockout (KO) mice. These mice grow and develop normally without apparent abnormalities in comparison to wild type littermates. However, open field showed that NCS-1 deficiency impairs novelty-induced exploratory activity in both KO and heterozygote (HT) mice. Moreover, NCS-1-deficiency also resulted in anxiety- and depressive-like behaviors as demonstrated by elevated plus maze, large open field, forced swim and tail suspension tasks. Furthermore, based on spontaneous object recognition test, non-aversive long-term memory was impaired in NCS-1 KO mice. In contrast, neither social behavior nor a kind of aversive memory was affected under NCS-1 deficiency. These data implicate NCS-1 in exploratory activity, memory and mood-related behaviors, suggesting that NCS-1 gene ablation may result in phenotypic abnormalities associated with neuropsychiatric disorders.