Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
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Neetu Tyagi
Abstract
Background: γ-Aminobutyric acid (GABA) is a known inhibitory neurotransmitter in the mammalian central nervous system, and homocysteine (Hcy) behaves as an antagonist for GABAA receptor. Although the properties and functions of GABAA receptors are well studied in mouse neural tissue, its presence and significance in non-neural tissue remains obscure. The aim of the present study was to examine the expression of GABAA receptor and its subunits in non-neural tissue.
Methods: The mice were analyzed. The presence of GABAA receptor and its subunits was evaluated using Western blot and reverse transcription polymerase chain reaction.
Results: We report that GABAA receptor protein is abundant in the renal medulla, cortex, heart, left ventricle, aorta and pancreas. Low levels of GABAA receptor protein were detected in the atria of the heart, right ventricle, lung and stomach. The mRNA protein expression of GABAA receptor subunit shows that α1, β1, β3 and γ1 subunits are present only in brain. The mRNA protein expression levels of GABAA receptor α2, α6, β2 and γ3 subunits were highly expressed in brain compared to other tested tissue, while GABAA receptor γ2 subunit was expressed only in brain and kidney. Treatment of microvascular endothelial cells with Hcy decreased GABAA receptor protein level, which was restored to its baseline level in the presence of GABAA receptor agonist, muscimol. The distribution of GABAA and GABAB receptors in wild type mice was determined and tissue-specific expression patterns were found showing that several receptor subtypes were also expressed in the central nervous system.
Conclusions: Hcy, a GABAA agonist, was found to decrease GABAA expression levels. These data enlarge knowledge on distribution of GABA receptors and give novel ideas of the effects of Hcy on different organs.
Clin Chem Lab Med 2007;45:1777–84.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Homocysteine research: alive and kicking!
- Homocysteine-lowering trials for prevention of vascular disease: protocol for a collaborative meta-analysis
- Perspective on the efficacy analysis of the Vitamin Intervention for Stroke Prevention trial
- Homocysteine-lowering vitamin B treatment decreases cardiovascular events in hemodialysis patients
- The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases
- Management of L-Dopa related hyperhomocysteinemia: catechol-O-methyltransferase (COMT) inhibitors or B vitamins? Results from a review
- Biomarkers of folate and vitamin B12 status in cerebrospinal fluid
- The role of hyperhomocysteinemia as well as folate, vitamin B6 and B12 deficiencies in osteoporosis – a systematic review
- Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
- Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?
- Hyperhomocysteinemia and high-density lipoprotein metabolism in cardiovascular disease
- Hyperhomocysteinemia, DNA methylation and vascular disease
- Measuring subclinical atherosclerosis: is homocysteine relevant?
- Plasma protein homocysteinylation in uremia
- Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
- Hyperhomocysteinemia – association with renal transsulfuration and redox signaling in rats
- Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine
- Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
- The molecular basis of homocysteine thiolactone-mediated vascular disease
- Importance of folate-homocysteine homeostasis during early embryonic development
- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
- Decreased p66Shc promoter methylation in patients with end-stage renal disease
- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
- Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
Articles in the same Issue
- Homocysteine research: alive and kicking!
- Homocysteine-lowering trials for prevention of vascular disease: protocol for a collaborative meta-analysis
- Perspective on the efficacy analysis of the Vitamin Intervention for Stroke Prevention trial
- Homocysteine-lowering vitamin B treatment decreases cardiovascular events in hemodialysis patients
- The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases
- Management of L-Dopa related hyperhomocysteinemia: catechol-O-methyltransferase (COMT) inhibitors or B vitamins? Results from a review
- Biomarkers of folate and vitamin B12 status in cerebrospinal fluid
- The role of hyperhomocysteinemia as well as folate, vitamin B6 and B12 deficiencies in osteoporosis – a systematic review
- Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
- Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?
- Hyperhomocysteinemia and high-density lipoprotein metabolism in cardiovascular disease
- Hyperhomocysteinemia, DNA methylation and vascular disease
- Measuring subclinical atherosclerosis: is homocysteine relevant?
- Plasma protein homocysteinylation in uremia
- Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
- Hyperhomocysteinemia – association with renal transsulfuration and redox signaling in rats
- Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine
- Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
- The molecular basis of homocysteine thiolactone-mediated vascular disease
- Importance of folate-homocysteine homeostasis during early embryonic development
- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
- Decreased p66Shc promoter methylation in patients with end-stage renal disease
- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
- Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
