MS‐Based Screening of 5‐Substituted Nipecotic Acid Derived Hydrazone Libraries as Ligands of the GABA Transporter 1

ChemMedChem ◽  
2019 ◽  
Author(s):  
Tobias J. Hauke ◽  
Georg Höfner ◽  
Klaus T. Wanner
2020 ◽  
pp. 7-12
Author(s):  
Л. И. Хожай

Цель работы - исследование распределения уровня GAT-транспортера ГАМК в комплексе Бетцингера на разных сроках раннего постнатального развития крыс в норме и при пренатальном дефиците серотонина. Материал и методы. Работа проведена на лабораторных крысах линии Wistar. Снижение уровня эндогенного серотонина в эмбриональный период осуществляли методом ингибирования триптофан-гидроксилазы пара-хлорфенилаланином (пХФА). Выявление транспортного белка GAТпроводили посредством иммуногистохимической реакции с использованием первичных кроличьих поликлональных антител anti-GABA transporter1 (AbCam, Великобритания). Мозг исследовали на 5-, 10-е и 20-е сутки постнатального развития. Результаты. В комплексе Бетцингера на ранних сроках постнатального развития у контрольных животных отмечено колебание уровня GAT-транспортера ГАМК. На 1-й неделе жизни уровень GATбыл высоким как в сети отростков и терминалей, так и в синапсах. В течение 2-й недели жизни уровень GATснижался, а к концу 3-й недели - повышался вновь, достигая исходного уровня. Дефицит серотонина в пренатальный период вызывал у подопытных животных существенное увеличение уровня GATв нейропиле комплекса Бетцингера на всех изученных сроках постнатального развития. Выводы. Пренатальный дефицит серотонина приводит к существенному повышению уровня GAT-транспортера ГАМК в ранние сроки постнатального развития, что может приводить к изменению трансмиссии ГАМК и, как следствие, к нарушению баланса тормозных и возбуждающих эффектов в дыхательном ядре. Objective - to study the distribution of GABA transporter 1 (GAT) levels in the Bötzinger complex at the early stages of postnatal development in rats with prenatal serotonin deficiency. Materials and methods. The work was carried out on Wistar line laboratory rats. To reduce the level of endogenous serotonin in the embryonic period, the method of tryptophan hydroxylase inhibition by para-chlorophenylalanine (PCPA) (Sigma, USA) was used. The GAT1 transport protein was detected by immunohistochemical reaction with anti-GABA transporter1 primary rabbit polyclonal antibodies (AbCam, UK). The brain was examined on the 5, 10 and 20 day of postnatal development. Results. At the early stages of postnatal development, a fluctuation in the GAT1 level of the GABA transporter was noted in the Bötzinger complex of control animals. In the first postnatal week, the GAT level was high both in the network of neuronal processes and terminals, and in synapses. During the 2 week of life, the GAT1 level decreased, and by the end of the 3 week it increased again, reaching the initial level. Deficiency of serotonin in the prenatal period caused a significant increase in the level of GAT in the neuropil of the Bötzinger complex in experimental animals at all studied stages of postnatal development. Conclusions. Prenatal deficiency of serotonin leads to a significant increase in the GAT1 level at the early stages of postnatal development, which can lead to a change in the GABA transmission, and, as a result, to a disturbance in the balance of inhibitory and stimulatory effects in the respiratory nuclei.


2003 ◽  
Vol 90 (4) ◽  
pp. 2690-2701 ◽  
Author(s):  
Kimmo Jensen ◽  
Chi-Sung Chiu ◽  
Irina Sokolova ◽  
Henry A. Lester ◽  
Istvan Mody

After its release from interneurons in the CNS, the major inhibitory neurotransmitter GABA is taken up by GABA transporters (GATs). The predominant neuronal GABA transporter GAT1 is localized in GABAergic axons and nerve terminals, where it is thought to influence GABAergic synaptic transmission, but the details of this regulation are unclear. To address this issue, we have generated a strain of GAT1-deficient mice. We observed a large increase in a tonic postsynaptic hippocampal GABAA receptor-mediated conductance. There was little or no change in the waveform or amplitude of spontaneous inhibitory postsynaptic currents (IPSCs) or miniature IPSCs. In contrast, the frequency of quantal GABA release was one-third of wild type (WT), although the densities of GABAA receptors, GABAB receptors, glutamic acid decarboxylase 65 kDa, and vesicular GAT were unaltered. The GAT1-deficient mice lacked a presynaptic GABAB receptor tone, present in WT mice, which reduces the frequency of spontaneous IPSCs. We conclude that GAT1 deficiency leads to enhanced extracellular GABA levels resulting in an overactivation of GABAA receptors responsible for a postsynaptic tonic conductance. Chronically elevated GABA levels also downregulate phasic GABA release and reduce presynaptic signaling via GABAB receptors thus causing an enhanced tonic and a diminished phasic inhibition.


2020 ◽  
Vol 45 (7) ◽  
pp. 1551-1565
Author(s):  
Maria E. K. Lie ◽  
Stefanie Kickinger ◽  
Jonas Skovgaard-Petersen ◽  
Gerhard F. Ecker ◽  
Rasmus P. Clausen ◽  
...  

2011 ◽  
Vol 30 (4-6) ◽  
pp. 206-217 ◽  
Author(s):  
J. Hu ◽  
W. Reutter ◽  
H. Fan

2014 ◽  
Vol 6 ◽  
pp. JCNSD.S14012 ◽  
Author(s):  
Seok K. Kang ◽  
Shin Tae Kim ◽  
Michael V. Johnston ◽  
Shilpa D. Kadam

Rett syndrome (RTT), associated with mutations in methyl-CpG-binding protein 2 (Mecp2), is linked to diverse neurological symptoms such as seizures, motor disabilities, and cognitive impairments. An altered GABAergic system has been proposed as one of many underlying pathologies of progressive neurodegeneration in several RTT studies. This study for the first time investigated the temporal- and location-specific alterations in the expression of γ-amino butyric acid (GABA) transporter 1 (GAT-1), vesicular GABA transporter (vGAT), and glutamic acid decarboxylase 67kD (GAD67) in wild type (WT) and knockout (KO) mice in the Mecp2m1.1Bird/y mouse model of RTT. Immunohistochemistry (IHC) co-labeling of GAT-1 with vGAT identified GABAergic synapses that were quantitated for mid-sagittal sections in the frontal cortex (FC), hippocampal dentate gyrus (DG), and striatum (Str). An age-dependent increase in the expression of synaptic GABA transporters, GAT-1, and vGAT, was observed in the FC and DG in WT brains. Mecp2 KO mice showed a significant alteration in this temporal profile that was location-specific, only in the FC. GAD67-positive cell densities also showed an age-dependent increase in the FC, but a decrease in the DG in WT mice. However, these densities were not significantly altered in the KO mice in the regions examined in this study. Therefore, the significant location-specific downregulation of synaptic GABA transporters in Mecp2 KO brains with unaltered densities of GAD67-positive interneurons may highlight the location-specific synaptic pathophysiology in this model of RTT.


2018 ◽  
Vol 9 (11) ◽  
pp. 2767-2773 ◽  
Author(s):  
Alexandra R. Sowa ◽  
Allen F. Brooks ◽  
Xia Shao ◽  
Bradford D. Henderson ◽  
Philip Sherman ◽  
...  

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