Three polymorphisms of the eNOS gene and plasma levels of metabolites of nitric oxide in depressed Japanese patients: A preliminary report
Depression is a risk factor for coronary heart disease. Nitric oxide (NO) plays an important role in both coronary heart disease and depression.
Fifty-one inpatients and outpatients who met the Diagnostic and Statistical Manual of Mental Disorders--Fourth Edition criteria for major depressive disorder (MDD) in the university hospital of the University of Occupational and Environmental Health and 58 age-matched and sex-matched healthy controls enrolled in this study. We investigated the association between the three polymorphisms of the endothelial nitric oxide synthase (eNOS) gene (single-nucleotide polymorphism (SNP); rs2070744, rs1799983, variable number tandem repeat (VNTR) in intron 4) and scores on the Hamilton Rating Scale for Depression, plasma metabolites of NO (NO(x) ) or ankle brachial index in patients with MDD and healthy controls.
We did not find significant differences in the genotype distributions between patients with MDD and healthy volunteers. No associations were observed between any of the polymorphisms of the eNOS gene and the Hamilton Rating Scale for Depression or ankle brachial index in patients with MDD. However, plasma NO(x) level was significantly associated with a polymorphism of the eNOS gene (rs207044 and variable number tandem repeat in intron 4).
These results suggest that the direct association was not observed between the polymorphisms of the eNOS gene and the pathogenesis of depression.
Available from: Yiming Wang
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There is an increased incidence of major depressive disorder (MDD) in individuals after myocardial infarction (MI), but the pathophysiological processes mediating this association are unclear. Our previous study demonstrated an increase in pro-apoptotic pathways in the myocardium and hippocampus in MDD, which was reversed by venlafaxine. This study aimed to attempt to confirm the effects of apoptosis vulnerability markers on the myocardium in a model of depression after myocardial infarction.
Rats were divided into four groups: sham (N = 8), depression (N = 8, chronic mild unpredictable stress and separation were used in the depression group), MI (N = 13) and post-MI depression (N = 7). The rats in all four groups underwent the same open field and sucrose preference behavioral tests. Evan Blue staining was used to determine the area at risk of myocardial infarction in the left ventricle, and 2,3,5-triphenyl tetrazolium chloride (1.5% TTC) dye was used to detect the size of the myocardial infarction. The expression of bax and bcl-2 protein in the myocardium was investigated by immunohistochemistry, and the mRNA expression of bax, bcl-2 and caspase-3 in the myocardium was investigated by real time RT-PCR. Apoptosis was estimated in the myocardium by measuring the Bax:Bcl-2 ratio.
In the depression and post-MI depression rats, there were significantly decreased movements and total sucrose consumption, modeling behavioral deficits and an anhedonic-like state. In terms of myocardial infarction size, no difference was seen between the MI and post-MI depression groups. There was an up-regulated Bax:Bcl-2 ratio in the depression, MI and post-MI depression groups. Furthermore, in the latter group, there was a greater up-regulated Bax:Bcl-2 ratio. However, caspase-3 did not differ among the four groups.
These results of this animal model suggest that active pro-apoptotic pathways may be involved in the nexus between myocardial infarction and depression. This mechanism may be germane to understanding this relationship in humans.
BMC Medicine 02/2013; 11(1):32. DOI:10.1186/1741-7015-11-32 · 7.25 Impact Factor
Available from: Daniel M. Pearlman
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ABSTRACT: About one-third of people with major depressive disorder (MDD) fail at least two antidepressant drug trials at 1 year. Together with clinical and experimental evidence indicating that the pathophysiology of MDD is multifactorial, this observation underscores the importance of elucidating mechanisms beyond monoaminergic dysregulation that can contribute to the genesis and persistence of MDD. Oxidative stress and neuroinflammation are mechanistically linked to the presence of neurovascular dysfunction with blood-brain barrier (BBB) hyperpermeability in selected neurological disorders, such as stroke, epilepsy, multiple sclerosis, traumatic brain injury, and Alzheimer's disease. In contrast to other major psychiatric disorders, MDD is frequently comorbid with such neurological disorders and constitutes an independent risk factor for morbidity and mortality in disorders characterized by vascular endothelial dysfunction (cardiovascular disease and diabetes mellitus). Oxidative stress and neuroinflammation are implicated in the neurobiology of MDD. More recent evidence links neurovascular dysfunction with BBB hyperpermeability to MDD without neurological comorbidity. We review this emerging literature and present a theoretical integration between these abnormalities to those involving oxidative stress and neuroinflammation in MDD. We discuss our hypothesis that alterations in endothelial nitric oxide levels and endothelial nitric oxide synthase uncoupling are central mechanistic links in this regard. Understanding the contribution of neurovascular dysfunction with BBB hyperpermeability to the pathophysiology of MDD may help identify novel therapeutic and preventative approaches.
Journal of Neuroinflammation 12/2013; 10(1):142. DOI:10.1186/1742-2094-10-142 · 5.41 Impact Factor
Available from: Orrin Devinsky
Neurology Psychiatry and Brain Research 02/2014; 20(1):18–19. DOI:10.1016/j.npbr.2014.01.161 · 0.10 Impact Factor
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