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Sinning, S.

Publications and source records attributed to Sinning, S..

2 recordsLinked to original sources

Antidepressants interact with sex steroid receptors and their intracellular signaling components

There is growing interest in understanding how hormonal signaling pathways contribute to the pathophysiology of mood disorders, based on the premise that fluctuations in sex hormones influence mood, a relationship particularly evident in conditions such as premenstrual dysphoric disorder, prenatal depression, postpartum depression, and perimenopausal depression. Estrogen receptor alpha (ER) is predominantly localized in the nucleus, but can also be associated with the cell membrane, thus mediating a broad range of genomic and non-genomic effects through distinct intracellular pathways. By employing a combination of computational simulations and in vitro biochemical and cell-based assays, we systematically evaluated the potential binding and functional interactions of antidepressant compounds with ER. Our results provide compelling evidence that antidepressants may not only affect classical monoaminergic targets but also modulate hormone receptor activity, particularly that of ER. These findings are consistent with the hypothesis that ER plays an important role in mood regulation and highlight it as a potential therapeutic target. Moreover, this work raises the possibility that the clinical efficacy of certain antidepressants may, at least in part, derive from their capacity to influence estrogen receptor-mediated signaling. Significance statementClinical observations suggest a link between female sex hormones and mood, highlighted by the higher prevalence of depression in women and increased vulnerability to depression during hormonal fluctuations. Here, we report that structurally diverse conventional and rapid-acting antidepressants directly interact with estrogen receptor alpha (ER). This interaction is associated with rapid intracellular signaling in cellular models. These findings indicate that, alongside their conventional targets, antidepressants may also engage sex steroid receptor components and signaling. This work broadens our basic understanding of antidepressant pharmacology at the cellular level, offering an additional perspective that may inform future research into the biological mechanisms of mood disorders and suggest a framework for developing targeted therapies for hormone-associated depressive disorders.

pharmacology and toxicology↗

Structural elements required for coupling ion and substrate transport in the neurotransmitter transporter homolog LeuT.

The coupled transport of ions and substrates allows transporters to accumulate substrates using the energy in transmembrane ion gradients and electrical potentials. During transport, conformational changes that switch accessibility of substrate and ion binding sites from one side of the membrane to the other must be controlled so as to prevent uncoupled movement of ions or substrates. In the Neurotransmitter:Sodium Symporter (NSS) family, Na+ stabilizes the transporter in an outward-open state, thus decreasing the likelihood of uncoupled Na+ transport. In a step essential for coupled transport, substrate binding must overcome the effect of Na+, allowing intracellular substrate and Na+ release from an inward-open state. However, it is unclear which specific elements of the protein mediate this conformational response to substrate binding. Previously, we showed that in the prokaryotic NSS transporter LeuT, the effect of Na+ on conformation occurs at the Na2 site, where it influences conformation by fostering interaction between two domains of the protein (JBC 291: 1456, 2016). Here, we identify a conserved tyrosine residue in the substrate binding site required for substrate to enable conversion to inward-open states by establishing an interaction between the two transporter domains. We further identify additional interactions between the two transporter domains in the extracellular pathway that are required. Together with our previous work on the conformational effect of Na+, these results identify mechanistic components underlying ion-substrate coupling in NSS transporters.

biochemistry↗