Our research, supported by this grant over the years, has focused on identifying and characterizing novel neural messenger molecules and their roles in psychotropic drug actions. We propose new studies based on recent advances in this area involving, in particular, gasotransmitters and D-amino acids. Based on our earlier work on NO and CO, we have recently identified hydrogen sulfide (H2S) as a notable signaling molecule. We established its biosynthesis by cystathionine-gamma-lyase (CSE) and cystathionine- beta-synthase (CBS) by demonstrating its depletion with CSE and CBS knockout. We showed that H2S signals by sulfhydrating cysteines in target proteins, analogous to NO acting by nitrosylation. We will map CBS/CSE and their catalytic activity via a novel histochemical stain for H2S generation from cysteine. We will characterize new sulfhydrated targets. Based on our findings regarding CSE's transcriptional induction, we will elucidate the enzyme's turnover under diverse conditions. Recently we discovered a profound depletion of CSE in Huntington's Disease (HD) reflecting mutant huntingtin affecting the CSE transcription factor SP1. Pathophysiologic relevance was evident in the alleviation of the HD phenotype by rescue in cultures and intact mice by cysteine supplementation. We will further characterize cysteine/H2S dynamics in HD mice and neural cultures. The cysteine depletion may also account for the inanition of HD patients. Accordingly, we will also investigate the regulation by CSE of adiposity. We established D-serine as an endogenous agonist for glutamate-NMDA receptors, identifying, cloning and characterizing its biosynthetic enzyme serine racemase (SR). Recently, we discovered that SR can link AMPA and NMDA glutamate transmission. SR binds the AMPA receptor accessory protein stargazin leading to membrane association and SR inhibition. SR also binds PSD-95 from which it is dissociated by NMDA treatment. We will elucidate the physiologic significance of SR in an apparent cross-talk between AMPA and NMDA receptor systems. We recently identified substantial levels of D-cysteine in mammalian brain and other tissues. We have developed a novel sensitive and specific assay for tissue D-cysteine. We will monitor D-cysteine levels in diverse tissues under varying circumstances. We will seek biosynthetic mechanisms for D-cysteine via known or hitherto unidentified enzymes.

Public Health Relevance

Our research under this grant addresses synaptic and other signaling systems that mediate psychotropic drug influences. We propose work on hydrogen sulfide, D-serine, and D-cysteine and their impact on neuropsychiatric disorders.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Research Project (R01)
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Molecular Neuropharmacology and Signaling Study Section (MNPS)
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Nadler, Laurie S
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Johns Hopkins University
Schools of Medicine
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Harraz, Maged M; Snyder, Solomon H (2017) Antidepressant Actions of Ketamine Mediated by the Mechanistic Target of Rapamycin, Nitric Oxide, and Rheb. Neurotherapeutics 14:728-733
Fu, Chenglai; Tyagi, Richa; Chin, Alfred C et al. (2017) Inositol Polyphosphate Multikinase Inhibits Angiogenesis via Inositol Pentakisphosphate-Induced HIF-1? Degradation. Circ Res :
Peng, Ying-Jie; Zhang, Xiuli; Gridina, Anna et al. (2017) Complementary roles of gasotransmitters CO and H2S in sleep apnea. Proc Natl Acad Sci U S A 114:1413-1418
Paul, Bindu D; Snyder, Solomon H (2017) Gasotransmitter hydrogen sulfide signaling in neuronal health and disease. Biochem Pharmacol :
Sbodio, Juan I; Snyder, Solomon H; Paul, Bindu D (2016) Transcriptional control of amino acid homeostasis is disrupted in Huntington's disease. Proc Natl Acad Sci U S A 113:8843-8
Kim, Hyo Jung; Cha, Jiyoung Y; Seok, Jo Woon et al. (2016) Dexras1 links glucocorticoids to insulin-like growth factor-1 signaling in adipogenesis. Sci Rep 6:28648
Choi, Hyong Woo; Tian, Miaoying; Manohar, Murli et al. (2015) Human GAPDH Is a Target of Aspirin's Primary Metabolite Salicylic Acid and Its Derivatives. PLoS One 10:e0143447
Tyagi, Richa; Shahani, Neelam; Gorgen, Lindsay et al. (2015) Rheb Inhibits Protein Synthesis by Activating the PERK-eIF2? Signaling Cascade. Cell Rep :
Paul, Bindu D; Snyder, Solomon H (2015) H2S: A Novel Gasotransmitter that Signals by Sulfhydration. Trends Biochem Sci 40:687-700
Paul, Bindu D; Snyder, Solomon H (2015) Modes of physiologic H2S signaling in the brain and peripheral tissues. Antioxid Redox Signal 22:411-23

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