ABSTRACT
Lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) are important membrane constituents implicated in signaling and immune regulation. Synthesis of LPCs is challenging due to rapid acyl migration, e.g., induced by chromatography. We here report a highly regioselective synthesis of LPC and mixed PC via an intermediate allowing specific terminal acyl introduction, yielding the pure LPC without chromatography by an exceedingly mild TBS deprotection, using 1 equiv of TFA in aqueous solution. The method enabled the synthesis of glycerol-, acyl-, and choline-labeled LPC.
Subject(s)
Lysophosphatidylcholines , Phosphatidylcholines , Lysophosphatidylcholines/chemistry , Lysophosphatidylcholines/pharmacology , Phosphatidylcholines/chemistry , WaterABSTRACT
We developed a versatile stereoselective route for the synthesis of new 2'-(S)-CCG-IV analogues. The route allows for late stage diversification and thereby provides access to a great variety of conformationally restricted cyclopropyl glutamate analogues. A selection of the 2'-(S)-CCG-IV analogues were evaluated using two-electrode voltage-clamp electrophysiology at recombinant GluN1/GluN2A-D receptors, demonstrating that agonists can be developed with GluN2 subunit-dependent potency and agonist efficacy. We also describe a crystal structure of the GluN2A agonist binding domain in complex with 2'-butyl-(S)-CCG-IV that determines the position of 2'-substituents in (S)-CCG-IV agonists in the glutamate binding site and provides further insight to the structural determinants of their agonist efficacy. The stereoselective synthesis described here enables versatile and straight-forward modifications to diverse analogues of interest for the development of potent subtype-specific NMDA receptor agonists and other applications.
Subject(s)
Amino Acids, Dicarboxylic/pharmacology , Receptors, N-Methyl-D-Aspartate/agonists , Amino Acids, Dicarboxylic/chemical synthesis , Amino Acids, Dicarboxylic/chemistry , Crystallography, X-Ray , Dose-Response Relationship, Drug , Humans , Models, Molecular , Molecular Structure , Stereoisomerism , Structure-Activity RelationshipABSTRACT
Hypothalamic adult neurogenesis provides the basis for renewal of neurons involved in the regulation of whole-body energy status. In addition to hormones, cytokines and growth factors, components of the diet, particularly fatty acids, have been shown to stimulate hypothalamic neurogenesis; however, the mechanisms behind this action are unknown. Here, we hypothesized that GPR40 (FFAR1), the receptor for medium and long chain unsaturated fatty acids, could mediate at least part of the neurogenic activity in the hypothalamus. We show that a GPR40 ligand increased hypothalamic cell proliferation and survival in adult mice. In postnatal generated neurospheres, acting in synergy with brain-derived neurotrophic factor (BDNF) and interleukin 6, GPR40 activation increased the expression of doublecortin during the early differentiation phase and of the mature neuronal marker, microtubule-associated protein 2 (MAP2), during the late differentiation phase. In Neuro-2a proliferative cell-line GPR40 activation increased BDNF expression and p38 activation. The chemical inhibition of p38 abolished GPR40 effect in inducing neurogenesis markers in neurospheres, whereas BDNF immunoneutralization inhibited GPR40-induced cell proliferation in the hypothalamus of adult mice. Thus, GPR40 acts through p38 and BDNF to induce hypothalamic neurogenesis. This study provides mechanistic advance in the understating of how a fatty acid receptor regulates adult hypothalamic neurogenesis.
Subject(s)
Brain-Derived Neurotrophic Factor/physiology , Hypothalamus/cytology , Hypothalamus/physiology , Neurogenesis/physiology , Receptors, G-Protein-Coupled/physiology , p38 Mitogen-Activated Protein Kinases/physiology , Animals , Cell Line , Cell Proliferation/drug effects , Cell Proliferation/physiology , Cell Survival/drug effects , Cell Survival/physiology , Hypothalamus/drug effects , Imidazoles/pharmacology , Interleukin-6/physiology , Ligands , Male , Methylamines/pharmacology , Mice , Mice, Inbred C57BL , Models, Neurological , Neurons/drug effects , Neurons/physiology , Propionates/pharmacology , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Receptors, G-Protein-Coupled/agonists , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitorsABSTRACT
A series of analogues based on serine as lead structure were designed, and their agonist activities were evaluated at recombinant NMDA receptor subtypes (GluN1/2A-D) using two-electrode voltage-clamp (TEVC) electrophysiology. Pronounced variation in subunit-selectivity, potency, and agonist efficacy was observed in a manner that was dependent on the GluN2 subunit in the NMDA receptor. In particular, compounds 15a and 16a are potent GluN2C-specific superagonists at the GluN1 subunit with agonist efficacies of 398% and 308% compared to glycine. This study demonstrates that subunit-selectivity among glycine site NMDA receptor agonists can be achieved and suggests that glycine-site agonists can be developed as pharmacological tool compounds to study GluN2C-specific effects in NMDA receptor-mediated neurotransmission.
