Biology subjects

Yudin, Y.

Publications and source records attributed to Yudin, Y..

9 recordsLinked to original sources

bioRxiv2025

Omega-3 Fatty Acid Derived Neuroactive Lipids - Docosahexaenoyl-Glycine and Its Epoxide Metabolites are Multifunctional Lipid Mediators

Lipid mediators derived from {omega}-3 and {omega}-6 polyunsaturated fatty acids (PUFAs) support neurological health in part through their oxidative and non-oxidative transformation into a diverse array of bioactive molecules. Among these are lipidated neurotransmitters, formed via conjugation of neurotransmitters with fatty acids such as arachidonic acid (AA) or docosahexaenoic acid (DHA). Previous studies links these lipidated neurotransmitters to beneficial outcomes in neurological diseases. Here, we focus on two such endogenous lipidated neurotransmitters, arachidonoyl glycine (NA-Gly) and docosahexaenoyl glycine (DHA-Gly) and demonstrate their further biotransformation by cytochrome P450 enzymes into epoxidized metabolites. These metabolites are structurally multifunctional, combining both epoxide and glycine moieties. In lipopolysaccharide-stimulated microglial cells, we observe increased formation of NA-Gly and DHA-Gly, correlating with their anti-inflammatory effects. Functionally, these lipidated glycines are selective and act as inverse agonists of G protein-coupled receptor 55 (GPR55) and selectively potentiate transient receptor potential vanilloid 4 (TRPV4), but not TRPV1 or TRPM3 channels. Together, our findings identify NA-Gly, DHA-Gly, and their epoxide derivatives as multifunctional lipid mediators with anti-inflammatory properties and selective receptor modulation, positioning them as potential therapeutic leads in neuroinflammation and reinforce the critical side role of glycine in brain function. SignificanceLipidated neurotransmitters derived from omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) contribute to neurological health through their conversion into a diverse array of bioactive signaling molecules. In this study, we study docosahexaenoyl glycine (DHA-Gly) and demonstrate their further enzymatic transformation by cytochrome P450 epoxygenases into epoxidized derivatives. These structurally distinct metabolites exhibit anti-inflammatory activity in microglial cells and interact with GPR55 and TRPV4, but not TRPV1 or TRPM3. Our findings highlight a new class of multifunctional lipid mediators with therapeutic potential for targeting neuroinflammation and related neurological disorders.

biochemistry↗

bioRxiv2024

Phosphatidic acid is an endogenous negative regulator of PIEZO2 channels and mechanical sensitivity

Mechanosensitive PIEZO2 ion channels play roles in touch, proprioception, and inflammatory pain. Currently, there are no small molecule inhibitors that selectively inhibit PIEZO2 over PIEZO1. The TMEM120A protein was shown to inhibit PIEZO2 while leaving PIEZO1 unaffected. Here we find that TMEM120A expression elevates cellular levels of phosphatidic acid and lysophosphatidic acid (LPA), aligning with its structural resemblance to lipid-modifying enzymes. Intracellular application of phosphatidic acid or LPA inhibited PIEZO2, but not PIEZO1 activity. Extended extracellular exposure to the non-hydrolyzable phosphatidic acid and LPA analogue carbocyclic phosphatidic acid (ccPA) also inhibited PIEZO2. Optogenetic activation of phospholipase D (PLD), a signaling enzyme that generates phosphatidic acid, inhibited PIEZO2, but not PIEZO1. Conversely, inhibiting PLD led to increased PIEZO2 activity and increased mechanical sensitivity in mice in behavioral experiments. These findings unveil lipid regulators that selectively target PIEZO2 over PIEZO1, and identify the PLD pathway as a regulator of PIEZO2 activity.

neuroscience↗

bioRxiv2021

TMEM120A/TACAN inhibits mechanically activated Piezo2 channels

Mechanically activated Piezo2 channels are key mediators of light touch and proprioception in mice and humans. Relatively little is known about what other proteins regulate Piezo2 activity in a cellular context. TACAN (TMEM120A) was proposed to act as a high threshold mechanically activated ion channel in nociceptive dorsal root ganglion (DRG) neurons. Here we find that TACAN co-expression robustly reduced mechanically activated Piezo2 currents, but did not inhibit mechanically activated Piezo1 and TREK1 currents. TACAN co-expression did not affect cell surface expression of either Piezo1 or Piezo2 and did not have major effects on the cortical actin or tubulin cytoskeleton. TACAN expression alone did not result in the appearance of mechanically activated currents above background. In addition, TACAN and Piezo2 expression in DRG neurons overlapped, and siRNA mediated knockdown of TACAN did not decrease the proportion of slowly adapting mechanically activated currents, but resulted in an increased proportion of rapidly adapting currents. Our data do not support TACAN being a mechanically activated ion channel, and identify it as a negative modulator of Piezo2 channel activity.

neuroscience↗

bioRxiv2020

Disease-associated mutations in TRPM3 render the channel overactive via two distinct mechanisms

Transient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+ permeable non-selective cation channel activated by heat and chemical agonists such as pregnenolone sulfate and CIM0216. TRPM3 mutations in humans were recently reported to be associated with intellectual disability and epilepsy; the functional effects of those mutations however were not reported. Here we show that both disease-associated mutations of TRPM3 render the channel overactive, but likely via different mechanisms. The Val to Met substitution in the S4-S5 loop induced a larger increase in basal activity and agonist sensitivity at room temperature than the Pro to Gln substitution in the extracellular segment of S6. In contrast, heat activation was increased more by the S6 mutant than by the S4-S5 segment mutant. Both mutants were inhibited by the TRPM3 antagonist primidone, suggesting a potential therapeutic intervention to treat this disease.

neuroscience↗

bioRxiv2019

Gi-Coupled Receptor Activation Potentiates Piezo2 Currents via Gβγ

SUMMARYDysregulation of mechanosensitive Piezo2 channels is a hallmark of mechanical allodynia, yet the cellular mechanisms that sensitize mechanoreceptors are still poorly understood. Activation of Gi-coupled receptors sensitizes Piezo2 currents, but whether Gi-coupled receptors regulate the activity of Piezo2 channels is not known. Here, we found that activation of Gi-coupled receptors potentiates Piezo2 currents in dorsal root ganglion (DRG) neurons and in heterologous systems, but inhibits Piezo1 currents in heterologous systems. The potentiation, or inhibition of Piezo currents is abolished when blocking G{beta}{gamma} with the c-terminal domain of the beta-adrenergic kinase ({beta}ARKct). Pharmacological inhibition of kinases downstream of G{beta}{gamma}, phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK), also abolished the potentiation of Piezo2 currents. Hence, our studies illustrate an indirect mechanism of action of G{beta}{gamma} to sensitize Piezo2 currents after activation of Gi-coupled receptors.

neuroscience↗

bioRxiv2019

Molecular mechanism of TRPV2 channel modulation by cannabidiol

Transient receptor potential vanilloid 2 (TRPV2) plays a critical role in neuronal development, cardiac function, immunity, and cancer. Cannabidiol (CBD), the non-psychotropic therapeutically active ingredient of Cannabis sativa, is a potent activator of TRPV2 and also modulates other transient receptor potential (TRP) channels. Here, we determined structures of the full-length TRPV2 channel in a CBD-bound state in detergent and in PI(4,5)P2 enriched nanodiscs by cryo-electron microscopy. CBD interacts with TRPV2 through a hydrophobic pocket located between S5 and S6 helices of adjacent subunits, which differs from known ligand and lipid binding sites in other TRP channels. Comparison between apo- and two CBD-bound TRPV2 structures reveals that the S4-S5 linker plays a critical role in channel gating upon CBD binding. The TRPV2 \"vanilloid\" pocket, which is critical for ligand-dependent gating in other TRPV channels, stays unoccupied by annular lipids, PI(4,5)P2, or CBD. Together these results provide a foundation to further understand TRPV channel gating properties and their divergent physiological functions and to accelerate structure-based drug design.

biophysics↗

bioRxiv2018

The G protein-biased PZM21 and TRV130 act as partial agonists of μ-opioid receptors signaling to ion channel targets

Opioids exert many of their acute effects through modulating ion channels via G{beta}{gamma} subunits. Some of their side effects are attributed to {beta}-arrestin recruitment, and several biased agonists that do not activate this pathway have been developed recently. Here we tested the effects of TRV130, PZM21 and herkinorin, three G-protein biased agonists of -opioid receptors (OR), on ion channel targets. Compared to the full OR agonist DAMGO, all three biased agonists induced smaller activation of G protein-coupled inwardly rectifying potassium channels (GIRK2), and smaller inhibition of Transient Receptor Potential Melastatin (TRPM3) channels. Furthermore, co-application of TRV130 or PZM21, but not herkinorin reduced the effects of DAMGO on both ion channels. CaV2.2 was also inhibited less by PZM21 and TRV130 than by DAMGO. TRV130, PZM21 and herkinorin were also less effective than DAMGO in inducing dissociation of the Gi /G{beta}{gamma} complex. We conclude that TRV130, PZM21 are partial agonists of OR.

pharmacology and toxicology↗

bioRxiv2018

Gαq sensitizes TRPM8 to inhibition by PI(4,5)P2 depletion upon receptor activation

Activation of G-protein coupled receptors (GPCRs) was proposed to inhibit the cold and menthol sensitive Transient Receptor Potential Melastatin 8 (TRPM8) channels via direct binding of Gq to the channel. It is well documented that TRPM8 requires the plasma membrane phospholipid phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2 or PIP2] for activity. It was claimed however that a decrease in cellular levels of this lipid does not contribute to channel inhibition upon receptor activation. Here we show that supplementing the whole cell patch pipette with PI(4,5)P2 reduced inhibition of TRPM8 by activation of Gq-coupled receptors in mouse dorsal root ganglion (DRG) neurons. Activation of the same receptors induced Phospholipase C (PLC) activation and decreased plasma membrane PI(4,5)P2 levels in these neurons. PI(4,5)P2 also reduced inhibition of TRPM8 by activation of heterologously expressed Gq-coupled muscarinic M1 receptors. Co-expression of a constitutively active Gq protein that does not couple to PLC inhibited TRPM8 activity, and in cells expressing this protein decreasing PI(4,5)P2 levels using a voltage sensitive 5-phosphatase induced a stronger inhibition of TRPM8 activity than in control cells. Our data indicate that PI(4,5)P2 depletion plays an important role in TRPM8 inhibition upon GPCR activation, and Gq inhibits the channel by reducing its apparent affinity for PI(4,5)P2 and thus sensitizes the channel to inhibition by decreasing PI(4,5)P2 levels.

neuroscience↗

bioRxiv2018

A consistent picture of TRPV1 activation emerges from molecular simulations and experiments

Although the structure of TRPV1 has been experimentally determined in both the closed and open states, very little is known about its activation mechanism. In particular, the conformational changes occurring in the pore domain and resulting in ionic conduction have not been identified yet. Here, we suggest a hypothetical molecular mechanism for TRPV1 activation, which involves the rotation of a conserved asparagine in S6 from the S4-S5 linker toward the pore. This rotation is correlated with the dehydration of four peripheral cavities located between S6 and the S4-S5 linker and the hydration of the pore. In light of our hypothesis, we perform bioinformatics analyses of TRP and other evolutionary related ion channels, analyze newly available structures and re-examine previously reported water accessibility and mutagenesis experiments. Overall, we provide several independent lines of evidence that corroborate our hypothesis. Finally, we show that the proposed molecular mechanism is compatible with the currently existing idea that in TRPV1 the selectivity filter acts as a secondary gate.

biophysics↗