scholarly journals Nitric Oxide-Mediated Posttranslational Modifications: Impacts at the Synapse

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Sophie A. Bradley ◽  
Joern R. Steinert

Nitric oxide (NO) is an important gasotransmitter molecule that is involved in numerous physiological processes throughout the nervous system. In addition to its involvement in physiological plasticity processes (long-term potentiation, LTP; long-term depression, LTD) which can include NMDAR-mediated calcium-dependent activation of neuronal nitric oxide synthase (nNOS), new insights into physiological and pathological consequences of nitrergic signalling have recently emerged. In addition to the canonical cGMP-mediated signalling, NO is also implicated in numerous pathways involving posttranslational modifications. In this review we discuss the multiple effects of S-nitrosylation and 3-nitrotyrosination on proteins with potential modulation of function but limit the analyses to signalling involved in synaptic transmission and vesicular release. Here, crucial proteins which mediate synaptic transmission can undergo posttranslational modifications with either pre- or postsynaptic origin. During normal brain function, both pathways serve as important cellular signalling cascades that modulate a diverse array of physiological processes, including synaptic plasticity, transcriptional activity, and neuronal survival. In contrast, evidence suggests that aging and disease can induce nitrosative stressviaexcessive NO production. Consequently, uncontrolled S-nitrosylation/3-nitrotyrosination can occur and represent pathological features that contribute to the onset and progression of various neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s.

2018 ◽  
Vol 17 (9) ◽  
pp. 654-670 ◽  
Author(s):  
Mohit Kumar ◽  
Rajat Sandhir

Background & Objective: Hydrogen sulfide [H2S] has been widely known as a toxic gas for more than 300 years in the scientific community. However, the understanding about this small molecule has changed after the discovery of involvement of H2S in physiological and pathological mechanisms in brain. H2S is a third gasotransmitter and neuromodulator after carbon monoxide [CO] and nitric oxide [NO]. H2S plays an important role in memory and cognition by regulating long-term potentiation [LTP] and calcium homeostasis in neuronal cells. The disturbances in endogenous H2S levels and trans-sulfuration pathway have been implicated in neurodegenerative disorders like Alzheimer’s disease, Parkinson disease, stroke and traumatic brain injury. According to the results obtained from various studies, H2S not only behaves as neuromodulator but also is a potent antioxidant, anti-inflammatory and anti-apoptotic molecule suggesting its neuroprotective potential. Conclusion: Recently, there is an increased interest in developing H2S releasing pharmaceuticals to target various neurological disorders. This review covers the information about the involvement of H2S in neurodegenerative diseases, its molecular targets and its role as potential therapeutic molecule.


Hippocampus ◽  
1997 ◽  
Vol 7 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Tzu-Ping Yu ◽  
Jeffrey Fein ◽  
Tien Phan ◽  
Christopher J. Evans ◽  
Cui-Wei Xie

2003 ◽  
Vol 63 (6) ◽  
pp. 1322-1328 ◽  
Author(s):  
Wei-Lin Chien ◽  
Keng-Chen Liang ◽  
Che-Ming Teng ◽  
Sheng-Chu Kuo ◽  
Fang-Yu Lee ◽  
...  

1999 ◽  
Vol 6 (1) ◽  
pp. 63-76 ◽  
Author(s):  
Min Zhuo ◽  
Jarmo T. Laitinen ◽  
Xiao-Ching Li ◽  
Robert D. Hawkins

Perfusion of hippocampal slices with an inhibitor nitric oxide (NO) synthase blocked induction of long-term potentiation (LTP) produced by a one-train tetanus and significantly reduced LTP by a two-train tetanus, but only slightly reduced LTP by a four-train tetanus. Inhibitors of heme oxygenase, the synthetic enzyme for carbon monoxide (CO), significantly reduced LTP by either a two-train or four-train tetanus. These results suggest that NO and CO are both involved in LTP but may play somewhat different roles. One possibility is that NO serves a phasic, signaling role, whereas CO provides tonic, background stimulation. Another possibility is that NO and CO are phasically activated under somewhat different circumstances, perhaps involving different receptors and second messengers. Because NO is known to be activated by stimulation of NMDA receptors during tetanus, we investigated the possibility that CO might be activated by stimulation of metabotropic glutamate receptors (mGluRs). Consistent with this idea, long-lasting potentiation by the mGluR agonist tACPD was blocked by inhibitors of heme oxygenase but not NO synthase. Potentiation by tACPD was also blocked by inhibitors of soluble guanylyl cyclase (a target of both NO and CO) or cGMP-dependent protein kinase, and guanylyl cyclase was activated by tACPD in hippocampal slices. However, biochemical assays indicate that whereas heme oxygenase is constitutively active in hippocampus, it does not appear to be stimulated by either tetanus or tACPD. These results are most consistent with the possibility that constitutive (tonic) rather than stimulated (phasic) heme oxygenase activity is necessary for potentiation by tetanus or tACPD, and suggest that mGluR activation stimulates guanylyl cyclase phasically through some other pathway.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Razika Zeghir-Bouteldja ◽  
Manel Amri ◽  
Saliha Aitaissa ◽  
Samia Bouaziz ◽  
Dalila Mezioug ◽  
...  

Hydatidosis is characterized by the long-term coexistence of larvaEchinococcus granulosusand its host without effective rejection. Previous studies demonstrated nitric oxide (NO) production (in vivo and in vitro) during hydatidosis. In this study, we investigated the direct in vitro effects of NO species: nitrite (NO2−), nitrate (NO3−) and peroxynitrite (ONOO−) on protoscolices (PSCs) viability and hydatid cyst layers integrity for 24 hours and 48 hours. Our results showed protoscolicidal activity ofNO2−andONOO−24 hours and 3 hours after treatment with 320 μM and 80 μM respectively. Degenerative effects were observed on germinal and laminated layers. The comparison of the in vitro effects of NO species on the PSCs viability indicated thatONOO−is more cytotoxic thanNO2−. In contrast,NO3−has no effect. These results suggest possible involvement ofNO2−andONOO−in antihydatic action and point the efficacy of these metabolites as scolicidal agents.


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