Molecular tools to study melatonin pathways and actions

Boutin, Jean A.; Audinot, Valérie; Ferry, Gilles; Delagrange, Philippe

doi:10.1016/j.tips.2005.06.006

Cited by 207 publications

(145 citation statements)

References 69 publications

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“…Os efeitos da melatonina são mediados por receptores de baixa afinidade, sendo possível a identificação de diferentes subtipos: receptores de baixa afinidade (MT3), identificado em mamíferos, corresponde a 'quinona redutase-2', uma enzima citosólica que pode estar envolvida nos processos de desintoxicação (Vanecek, 1998, Barrett et al, 2003, Boutin et al, 2005. Os receptores de alta afinidade pertencem à família proteo-G (GPC), com sete receptores do comando transmembranar.…”

Section: Melatoninaunclassified

Visão geral sobre reprodução de peixes teleósteos: da anatomia à sinalização molecular

Souto

Faria

Oliveira

et al. 2017

Pubvet

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RESUMO.Um dos principais objetivos da na reprodução e peixes é a produção de um grande número de gametas viáveis e alta sobrevivência da prole. Nos últimos anos, foram realizados importantes progressos na melhoria da eficiência na produção de gametas e viabilidade da prole. No entanto, existem lacunas importantes no que diz respeito à compreensão dos processos dinâmicos fisiológicos associados à gametogênese. O conhecimento das estruturas que compõe as gônadas, bem como o todos os mecanismos neuroendócrinos e de sinalização molecular é de extrema importância na elaboração de protocolos reprodutivos de peixes. Entre os desafios encontrados, destaca-se a ampla gama de espécies de peixes de diferentes famílias, os quais, na maioria das vezes, possuem mecanismos fisiológicos espécie-específico. No mecanismo neuroendócrino da reprodução de peixes é dado ênfase ao Hormônio liberador de gonadotrofinas (GnRH), neurotransmissor produzido e secretado pelo hipotálamo, que atua como fator estimulador na liberação de LH e, em menor grau, do FSH. Os hormônios gonadotróficos folículo estimulante e luteinizante (FSH e LH) atuam como os principais reguladores durante a vitelogênese e maturação dos gametas. Acreditava-se que a melatonina estaria envolvida no mecanismo neuroendócrino como resposta ao foto-período, inibindo a liberação de GnRH. Recentemente, estudos evidenciaram que a melatonina atua também acelerando a ação do hormônio indutor da maturação (MIH) e, consequentemente, a retomada do ciclo celular meiótico. Desta forma, o objetivo desta revisão é esclarecer os mecanismos fisiológicos da reprodução de peixes teleósteos, partindo da descrição da morfologia das gônadas, compreensão dos mecanismos neuroendócrinos e da sinalização molecular.Palavras chave: Gametogênese, hormônio indutor de maturação, melatonina, sinalização molecular Overview on reproduction of teleosteal fish: from anatomy to molecular signaling ABSTRACT. One of the main goals of reproduction and fish is the production of a large number of viable gametes and high survival of offspring. In recent years, significant progress has been made in improving the efficiency of gametes production and progeny viability. However, there are still important gaps in the understanding of the physiological dynamic processes associated with gametogenesis. The knowledge of the structures that make up the gonads, as well as the all the neuroendocrine and molecular signaling

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Section: Melatoninaunclassified

Visão geral sobre reprodução de peixes teleósteos: da anatomia à sinalização molecular

Souto

Faria

Oliveira

et al. 2017

Pubvet

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“…Melatonin stimulates several antioxidative enzymes (19) and acts on bone metabolism (20). The hormone exerts its effects both through activation of its receptors (21), through the circulating levels of the hormone or in a more autocrine/paracrine fashion near target tissues (22,23). In addition, melatonin brings about vasoconstriction through the MT1 and vasodilation through the MT2 receptors (24).…”

Section: Melatonin and Its Functionmentioning

confidence: 99%

The role of melatonin in diabetes: therapeutic implications

Sharma

Singh

Ahmad

et al. 2015

Arch. Endocrinol. Metab.

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Melatonin referred as the hormone of darkness is mainly secreted by pineal gland, its levels being elevated during night and low during the day. The effects of melatonin on insulin secretion are mediated through the melatonin receptors (MT1 and MT2). It decreases insulin secretion by inhibiting cAMP and cGMP pathways but activates the phospholipaseC/IP3 pathway, which mobilizes Ca 2+ from organelles and, consequently increases insulin secretion. Both in vivo and in vitro, insulin secretion by the pancreatic islets in a circadian manner, is due to the melatonin action on the melatonin receptors inducing a phase shift in the cells. Melatonin may be involved in the genesis of diabetes as a reduction in melatonin levels and a functional interrelationship between melatonin and insulin was observed in diabetic patients. Evidences from experimental studies proved that melatonin induces production of insulin growth factor and promotes insulin receptor tyrosine phosphorylation. The disturbance of internal circadian system induces glucose intolerance and insulin resistance, which could be restored by melatonin supplementation. Therefore, the presence of melatonin receptors on human pancreatic islets may have an impact on pharmacotherapy of type 2 diabetes. Arch Endocrinol Metab.2015;59(5):391-9

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“…MT2 is also expressed in the brain including the suprachiasmatic nucleus, where it mediates the phase shifting responses to melatonin (Liu et al, 1997;Dubocovich et al, 1998). Moreover, melatonin may act on other binding sites (MT3) (Boutin et al, 2005). The receptor type that mediates the action of melatonin as photoperiodic signal remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Melatonin Transmits Photoperiodic Signals through the MT1 Melatonin Receptor

Yasuo¹,

Yoshimura²,

Ebihara³

et al. 2009

J. Neurosci.

107

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Melatonin transmits photoperiodic signals that regulate reproduction. Two melatonin receptors (MT1 and MT2) have been cloned in mammals and additional melatonin binding sites suggested, but the receptor that mediates the effects of melatonin on the photoperiodic gonadal response has not yet been identified. We therefore investigated in mice whether and how targeted disruption of MT1, MT2, or both receptor types affects the expression level of two key genes for the photoperiodic gonadal regulation, type 2 and 3 deiodinase (Dio2 and Dio3, respectively). These are expressed in the ependymal cell layer lining the infundibular recess of the third ventricle and regulated by thyrotropin produced in the pars tuberalis. In wild-type C3H mice, Dio2 expression was constantly low, and no photoperiodic changes were observed, whereas Dio3 expression was upregulated under short-day conditions. In C3H with targeted disruption of MT1 and MT1/MT2, Dio2 expression was constitutively upregulated, Dio3 expression was constitutively downregulated, and the photoperiodic effect on Dio3 expression was abolished. Under short-day conditions, C3H with targeted disruption of MT2 displayed similar expression levels of Dio2 and Dio3 as wild-type animals, but they responded to long-day condition with a stronger suppression of Dio3 than wild-type mice. Melatonin injections into wild-type C57BL mice suppressed Dio2 expression and induced Dio3 expression under long-day conditions. These effects were abolished in C57BL mice with targeted disruption of MT1. All data suggest that the melatonin signal that transmits photoperiodic information to the hypothalamo-hypophysial axis acts on the MT1 receptor.

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Molecular tools to study melatonin pathways and actions

Cited by 207 publications

References 69 publications

Visão geral sobre reprodução de peixes teleósteos: da anatomia à sinalização molecular

Visão geral sobre reprodução de peixes teleósteos: da anatomia à sinalização molecular

The role of melatonin in diabetes: therapeutic implications

Melatonin Transmits Photoperiodic Signals through the MT1 Melatonin Receptor

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