Association of serum nitric oxide levels with depressive symptoms: a study with end-stage renal failure patients

Different roles of microbiota and genetics in the prediction of treatment response in major depressive disorder

The roles of gut microbiota and susceptibility genes in patients with major depression disorder (MDD) are not well understood. Examining the microbiome and host genetics might be helpful for clinical decision-making. Patients with MDD were recruited in this study and subsequently treated for eight weeks. We identified the differences between the population with a response after two weeks and those with a response after eight weeks. The factors that were significantly correlated with efficacy were used to predict the treatment response. The differences in the importance of microbiota and genetics in prediction were analyzed. Our study identified rs58010457 as a potentially key locus affecting the treatment effect. Different microbiota and enriched pathways might play different roles in the response after two and eight weeks. We found that the area under the curve (AUC) value was greater than 0.8 for both random forest models. The contribution of different components to the AUC was evaluated by removing genetic information, microbiota abundance, and pathway data. The gut microbiome was an important predictor of the response after eight weeks, while genetics was an important predictor of the response after two weeks. These results suggested a dynamic effect of interaction among genetics and gut microbes on treatment. Furthermore, these results provide new guidance for clinical decisions: in cases of inadequate treatment effects after two weeks, the composition of the intestinal flora can be improved by diet therapy, which could ultimately affect the efficacy.

The Association Between Concentrations of Arginine, Ornithine, Citrulline and Major Depressive Disorder: A Meta-Analysis

Alterations in the peripheral (e.g., serum, plasma, platelet) concentrations of arginine and its related catabolic products (i.e., ornithine, citrulline) in the urea and nitric oxide cycles have been reported to be associated with major depressive disorder (MDD). The meta-analysis herein aimed to explore the association between the concentration of peripheral arginine, its catabolic products and MDD, as well as to discuss the possible role of arginine catabolism in the onset and progression of MDD. PubMed, EMBASE, PsycINFO and Web of Science were searched from inception to June 2020. The protocol for the meta-analysis herein has been registered at the Open Science Framework [https://doi.org/10.17605/osf.io/7fn59]. In total, 745 (47.5%) subjects with MDD and 823 (52.5%) healthy controls (HCs) from 13 articles with 16 studies were included. Fifteen of the included studies assessed concentrations of peripheral arginine, eight assessed concentrations of ornithine, and six assessed concentrations of citrulline. Results indicated that: (1) the concentrations of arginine, ornithine, and citrulline were not significantly different between individuals with MDD and HCs when serum, plasma and platelet are analyzed together, (2) in the subgroups of serum samples, the concentrations of arginine were lower in individuals with MDD than HCs, and (3) concurrent administration of psychotropic medications may be a confounding variable affecting the concentrations of arginine, ornithine, and citrulline. Our findings herein do not support the hypothesis that arginine catabolism between individuals with MDD and HCs are significantly different. The medication status and sample types should be considered as a key future research avenue for assessing arginine catabolism in MDD.

Clinical Evidence of Antidepressant Effects of Insulin and Anti-Hyperglycemic Agents and Implications for the Pathophysiology of Depression-A Literature Review

Close connections between depression and type 2 diabetes (T2DM) have been suggested by many epidemiological and experimental studies. Disturbances in insulin sensitivity due to the disruption of various molecular pathways cause insulin resistance, which underpins many metabolic disorders, including diabetes, as well as depression. Several anti-hyperglycemic agents have demonstrated antidepressant properties in clinical trials, probably due to their action on brain targets based on the shared pathophysiology of depression and T2DM. In this article, we review reports of clinical trials examining the antidepressant effect of these medications, including insulin, metformin, glucagon like peptide-1 receptor agonists (GLP-1RA), and peroxisome proliferator-activated receptor (PPAR)-γ agonists, and briefly consider possible molecular mechanisms underlying the associations between amelioration of insulin resistance and improvement of depressive symptoms. In doing so, we intend to suggest an integrative perspective for understanding the pathophysiology of depression.

Nitric oxide: Antidepressant mechanisms and inflammation

Millions of individuals worldwide suffers from mood disorders, especially major depressive disorder (MDD), which has a high rate of disease burden in society. Although targeting the biogenic amines including serotonin, and norepinephrine have provided invaluable links with the pharmacological treatment of MDD over the last four decades, a growing body of evidence suggest that other biologic systems could contribute to the pathophysiology and treatment of MDD. In this chapter, we highlight the potential role of nitric oxide (NO) signaling in the pathophysiology and thereby treatment of MDD. This has been investigated over the last four decades by showing that (i) levels of NO are altered in patients with major depression; (ii) modulators of NO signaling exert antidepressant effects in patients with MDD or in the animal studies; (iii) NO signaling could be targeted by a variety of antidepressants in animal models of depression; and (iv) NO signaling can potentially modulate the inflammatory pathways that underlie the pathophysiology of MDD. These findings, which hypothesize an NO involvement in MDD, can provide a new insight into novel therapeutic approaches for patients with MDD in the future.

Pathologic role of nitrergic neurotransmission in mood disorders

Mood disorders are chronic, recurrent mental diseases that affect millions of individuals worldwide. Although over the past 40 years the biogenic amine models have provided meaningful links with the clinical phenomena of, and the pharmacological treatments currently employed in, mood disorders, there is still a need to examine the contribution of other systems to the neurobiology and treatment of mood disorders. This article reviews the current literature describing the potential role of nitric oxide (NO) signaling in the pathophysiology and thereby the treatment of mood disorders. The hypothesis has arisen from several observations including (i) altered NO levels in patients with mood disorders; (ii) antidepressant effects of NO signaling blockers in both clinical and pre-clinical studies; (iii) interaction between conventional antidepressants/mood stabilizers and NO signaling modulators in several biochemical and behavioral studies; (iv) biochemical and physiological evidence of interaction between monoaminergic (serotonin, noradrenaline, and dopamine) system and NO signaling; (v) interaction between neurotrophic factors and NO signaling in mood regulation and neuroprotection; and finally (vi) a crucial role for NO signaling in the inflammatory processes involved in pathophysiology of mood disorders. These accumulating lines of evidence have provided a new insight into novel approaches for the treatment of mood disorders.

2, 3, 5, 4'-Tetrahydroxystilbene-2-O-β-D-glucoside prevention of lipopolysaccharide-induced depressive-like behaviors in mice involves neuroinflammation and oxido-nitrosative stress inhibition

Although numerous hypotheses have been raised in recent years, the exact mechanisms that promote the development of major depression are largely unknown. Recently, strategies targeting the process of neuroinflammation and oxidative stress in depression have been attracting greater attention. 2, 3, 5, 4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG), a compound purified from a traditional Chinese herbal medicine polygonummultiflorum, has been widely reported to inhibit neuroinflammation and oxidative stress. In this context, we investigated whether TSG affects lipopolysaccharide (LPS)-induced depressive-like behaviors in a manner associated with neuroinflammation and oxido-nitrosative stress. Results showed that administration of ICR mice with 0.83 mg/kg of LPS-induced typical depressive-like behaviors in the experiments of the tail-suspension test, the forced-swimming test, and sucrose preference, and these behaviors were prevented by TSG treatment (30 and 60 mg/kg). Further analysis showed that TSG pretreatment at the doses of 30 and 60 mg/kg not only inhibited the production of proinflammatory cytokines induced by LPS, such as interleukin-1β, interleukin-6, and tumor necrosis factor-α, but also prevented the LPS-induced enhancement of oxido-nitrosative stress in mouse hippocampus and prefrontal cortex. The LPS-induced decreases in brain-derived neurotrophic factor levels in the hippocampus and prefrontal cortex were also prevented by TSG treatment. Generally, our data provide evidence to show that TSG could be used to cope with depressive-like symptoms by inhibition of neuroinflammation and oxido-nitrosative stress.

Levels of nitric oxide, asymmetric dimethyl arginine, symmetric dimethyl arginine,and L-arginine in patients with obsessive-compulsive disorder

BACKGROUND/AIM

We aimed to investigate and compare to healthy controls the variations in the levels of nitric oxide (NO), asymmetric dimethyl arginine (ADMA), symmetric dimethyl arginine (SDMA), and L-arginine levels in patients with obsessive-compulsive disorder (OCD).

MATERIALS AND METHODS

We enrolled 30 patients with OCD and 30 healthy controls in the study consecutively. Diagnostic interviews of all participants were conducted with the Structured Clinical Interview for Axis I Disorders (SCID-I), and sociodemographic data of the participants were recorded. Patients scoring 10 points or more on the Yale-Brown Obsessive-Compulsive Scale were enrolled in the study.

RESULTS

The NO levels of patients with OCD were increased compared to the control group, but the increase was not statistically significant (P > 0.05). However, patients with OCD had significantly lower levels of ADMA, SDMA, and L-arginine compared with the controls (P < 0.001).

CONCLUSION

We found a significant decrease in ADMA, SDMA, and L-arginine as NO inhibitors between the groups, possibly because of an increase in NO. However, the insignificant increase in NO suggests that ADMA, SDMA, and L-arginine play direct and potentially important roles in OCD biology.

Possible role of adrenomedullin and nitric oxide in major depression

Adrenomedullin (ADM) and nitric oxide (NO) have been implicated in the pathogenesis of certain psychiatric disorders such as schizophrenia and bipolar disorder. ADM induces vasorelaxation by activating adenylate cyclase and stimulating the release of NO. These two molecules are known to influence cerebral activity. In this study, we aimed to examine the serum levels of ADM and NO in patients with major depression (MD). We enrolled 50 patients with MD and 50 healthy control subjects. The diagnosis of MD was established on the basis of a structured clinical interview using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The severity of depressive symptoms was evaluated using Hamilton's 17-item Depression Rating Scale. The mean serum levels of ADM and NO in patients with MD were significantly higher than those in healthy subjects (p=0.001, for both). The severity of psychomotor retardation in patients with MD was significantly correlated with the ADM (r=0.37, p=0.007) and NO levels (r=0.29, p=0.038). The patients with obvious psychomotor retardation had significantly higher levels of ADM and NO than did the patients with no psychomotor retardation (p=0.025, p=0.030). A significantly positive correlation was found between ADM and NO levels in patients with MD (r=0.79, p=0.001). Serum levels of ADM and NO levels were not correlated with the severity or duration of depression or depressive symptoms (except psychomotor retardation). In conclusion, our study indicates that serum levels of ADM and NO are elevated in patients with MD and that increased serum levels of ADM and NO may be associated with psychomotor retardation. The ADM-NO system may serve as a new target in the treatment of patients with MD and psychomotor retardation.

Plasma amino acid levels discriminate between control subjects and mildly depressed elderly women

BACKGROUND AND AIMS

Depression is the most common of all psychiatric disorders and the role of amino acid transmitters in this pathology has been recently studied. We undertook this study to investigate if the plasma levels of L-arginine, L-citrulline, L-glutamic acid, L-glutamine, L-asparagine and other amino acids, the L-citrulline/L-arginine and the L-tyrosine/L-phenylalanine ratios, and the nitrite levels are modified in mildly depressed women and if such changes are related to olfactory dysfunction.

METHODS

Plasma samples were obtained from elderly female subjects (n = 21) with mild depression and (n = 48) controls. Amino acids were analyzed with high-performance liquid chromatography, plasma nitrite levels were measured using the Griess method, and olfactory performance was assessed by the combined testing of odor identification, odor discrimination, odor recognition, and the olfactory threshold.

RESULTS

Compared to controls, depressed patients had a significantly higher concentration of L-arginine and a significantly lower L-citrulline/L-arginine ratio when the effect of other variables is not taken into account. A logistic regression model allowed us to identify two risk factors for mild depression, L-arginine and L-glutamic acid, and two protective factors, L-asparagine and the L-tyrosine/L-phenylalanine ratio. Additionally, a significant increase in nitrite levels in depressed women was found. No significant differences were found between the percentage of depressed and control women that identified the odors.

CONCLUSIONS

We identified that the amino acids L-arginine and L-glutamic acid are risk factors for mild depression, whereas L-asparagine and the L-tyrosine/L-phenylalanine ratio are protective factors.

A follow-up case-control association study of tractable (druggable) genes in recurrent major depression

The High-Throughput Disease-specific target Identification Program (HiTDIP) aimed to study case-control association samples for 18 common diseases. Here we present the results of a follow-up case-control association study of HiTDIP in major depressive disorder (MDD). The HiTDIP in MDD was conducted in a sample of 974 cases of recurrent MDD of white German origin collected at the Max-Planck Institute (MP-GSK) and 968 ethnically matched controls screened for lifetime absence of depression. Six genes were identified as of interest for a follow-up, based on the strength of the association and based on the interest as potential candidate target for developing new treatment for depression: Solute Carrier Family 4 Member 10 (SLC4A10), Dipeptidyl Peptidase IV (DPP4), Dopamine Receptor D3 (DRD3), Zinc Finger Protein 80 (ZNF80), Nitric Oxide Synthase 2A (NOS2A) and Peroxisome Proliferator-Activated Receptor-Gamma, Coactivator 1, Alpha (PPARGC1A). Within the current study, we attempted to follow-up these findings in a sample from the UK, the Depression Case Control (DeCC) sample consisting of 1,196 cases and 842 screened controls, phenotyped using exactly the same methods as the MP-GSK sample. Performing Cochran-Mantel-Haenzel statistics to test for genotypic and/or allelic differences between the DeCC and MP-GSK samples, we found no significant differences, thus being able to combine the two samples for association testing. In the combined sample of 2,170 MDD cases and 1,810 controls, there were positive findings in the Nitric Oxide Synthase 2A (NOS2A) gene both using single SNP analysis and haplotype analysis.

The course of nitric oxide and superoxide dismutase during treatment of bipolar depressive episode

BACKGROUND AND AIMS

Studies have already pointed out a possible pathophysiological role of oxidative and antioxidative molecules in bipolar disorder. We aimed to evaluate the activity and levels of antioxidant superoxide dismutase (SOD), and oxidant nitric oxide (NO), in bipolar I depressive episode (BD-DE) patients in a prospective design.

METHOD

30 BD-DE patients, diagnosed according to DSM IV, and 30 healthy volunteer controls were included. The serum levels of NO and SOD have been studied when admitted to hospital (1st) and on the 30th days. Clinical outcome was measured by Hamilton Depression Scale (HAM-D). The patients were allowed to have their treatments. One patient was dropped out due to insufficient sampling.

RESULTS

As in the previous studies, NO 1st day levels were significantly higher in patients and SOD 1st day activity was significantly low (p<0.01). NO levels significantly decreased (p<0.01) and normalized, as SOD activity significantly increased but did not reach to the controls' levels (p<0.01) on the 30th day.

CONCLUSION

Despite normalized NO levels, persistent low SOD activity might point out an oxidative imbalance in BD-DE. Chronic low SOD activity may be associated with incapacity of coping with oxidative stress. This research connotes the probable oxidative imbalance in BD-DE and discusses that phenomenon within the continuum of the disease state.

Lipoproteins obtained from anorexia nervosa patients induce higher oxidative stress in U373MG astrocytes through nitric oxide production

Eating disorders (ED) are a group of important psychiatric disorders that affect young men and women, and can have serious consequences. Among all ED, anorexia nervosa (AN) is the most typical but also the most severe. The pathogenesis of AN is multifactorial and a great variety of cognitive deficits may contribute to its pathogenesis. The present study is aimed to measure NO and peroxynitrite production, iNOS and nNOS expression by Western immunoblot after incubation of AN lipoproteins at different times with human astrocytoma cells. The AN-HDL treated cells showed an increased production of NO at 3 h versus control-HDL treated cells and a decreased production at 24 h. Regarding LDL, a significant increase of NO production was obtained both at 3 and 24 h. The AN-HDL and AN-LDL treated cells showed an increased production of peroxynitrite both at 3 and 24 h compared to control lipoproteins. Densitometric analysis of bands indicated that both iNOS and nNOS protein levels were significantly higher in the cells incubated with AN lipoproteins compared to cells incubated with control lipoproteins both at 3 and 24 h. Although the pathogenesis of AN remains uncertain, evidence exists that modifications to the lipoprotein profile and cholesterol, structural alterations of phospholipids and integral constituents of myelin and synaptosomes may be related to psychotic disorders and body image distortion common to AN. Thus, a relevant pathophysiological association between NO and depression is certainly a possibility, as well as a central role played by NO in the pathogenesis.

Changes in nitric oxide level and superoxide dismutase activity during antimanic treatment

Oxidant nitric oxide (NO) and antioxidant superoxide dismutase (SOD) have been implicated to play a role in the pathogenesis of bipolar disorders. This is the first prospective study aimed to evaluate NO levels and SOD activity in bipolar disorder (type I manic episode) (BD-ME). 29 inpatient subjects with BD-ME and 30 healthy controls were included. Serum NO levels and SOD activity have been studied at 1st (NO [1st] and SOD [1st] respectively) and 30th days (NO [30th] and SOD [30th] respectively) after treatment. The clinical outcome was measured by Bech-Rafaelson Mania Scale (BRMS). The mean NO [1st] (p<.001) and NO [30th] levels (p<.001) were higher than controls, but SOD [1st] (p<.001) and SOD [30th] (p<.001) activities in BD-ME were lower than controls. SOD(1) activity was higher than SOD [30th] (p<.001), while there was no significance in comparison between NO [1st] and NO [30th] (p>.05). SOD [30th] activity is negatively correlated with the number of previous manic attacks and NO [1st] was negatively correlated with sleep item score of BRMS at first day. Also there was a significant correlation between NO [1st] levels and with the existence of a delusion. NO and SOD appear to play a role in the pathophysiological events occurring in BD, especially in BD-ME. This study for the first time showed the possible role of NO on sleep and the generation of delusions in the pathophysiology of BD. In the light of literature, induced glutamate pathway might be responsible for delusions in BD. The results of this research need further investigation to understand the oxidative vs antioxidative process in BD.

Adenosine Deaminase, Nitric Oxide, Superoxide Dismutase, and Xanthine Oxidase in Patients with Major Depression: Impact of Antidepressant Treatment

BACKGROUND

There has been much evidence in recent years that free oxygen radicals and nitric oxide (NO) may play an important role in the pathophysiology of neuropsychiatric disorders. In this study, we aimed to investigate whether NO, xanthine oxidase (XO), superoxide dismutase (SOD), and adenosine deaminase (ADA) levels are associated with major depression (MD) and to evaluate the impact of antidepressant treatments on NO, SOD, ADA and XO levels in MD.

METHODS

Thirty-six patients who were diagnosed as MD according to DSM-IV criteria and 20 healthy controls were included. The serum levels of NO, XO, SOD, and ADA were measured by spectrophotometric methods both in patients and controls. Patients were treated with antidepressant drugs for 8 weeks. All patients were assessed by Hamilton Depression Rating Scale (HDRS) both before and after antidepressant treatment.

RESULTS

ADA and XO levels of the patients were significantly higher than the controls. SOD level of the patients was significantly lower than the controls. Although NO levels of the patients were higher than the controls, the difference was not statistically significant. There was no correlation between HDRS and the parameters studied (SOD, ADA, XO, and NO) of the patients. After 8 weeks of antidepressant treatment, ADA and SOD activities were increased, whereas NO and, XO levels decreased significantly.

CONCLUSIONS

ADA, XO, and SOD activity may have a pathophysiological role in MD and may predict prognosis of MD. Activity of these enzymes may be used to monitor effects of the antidepressant treatment.

Elevated serum nitric oxide and superoxide dismutase in euthymic bipolar patients: impact of past episodes

Nitric oxide (NO) has been implicated to play a role in the pathogenesis of many neuropsychiatric disorders. NO level was found high in acute manic inpatients. In this study, we aimed to assess NO level and activity of the antioxidant enzyme, superoxide dismutase (SOD), in euthymic bipolar patients. Twenty-seven patients with bipolar disorder (BD) in euthymic phase, and 20 healthy volunteers were included in this study. A semi-structured form was used to note social, demographic and clinical parameters of the patients. NO level and SOD activity were studied in the serum samples obtained from the patients and controls. The mean serum NO level in BD was significantly higher than in controls. Mean serum SOD activity was found to be elevated in patients with BD compared to controls. Total number of the manic episodes correlated with NO levels, but not with SOD activity. In conclusion, the number of manic episodes is positively associated with NO levels. NO and SOD appear to have a pathophysiological role in BD, especially in Type I euthymic phase, and may be considered an available trait marker for BD.

Nitric oxide, adenosine deaminase, xanthine oxidase and superoxide dismutase in patients with panic disorder: alterations by antidepressant treatment

OBJECTIVE

In the present study, we aimed to investigate whether nitric oxide (NO) levels and activities of xanthine oxidase (XO), superoxide dismutase (SOD), and adenosine deaminase (ADA) are associated with Panic disorder (PD) as well as impact of psychopharmacological treatments on NO, SOD, ADA, and XO levels in PD.

METHOD

In this study, 32 patients and 20 healthy controls were included. The serum levels of NO, XO, SOD, and ADA were measured in the patients and controls. The patients were treated with antidepressant.

RESULTS

ADA and XO levels of the patients were significantly higher than the controls. SOD levels of the patients were significantly lower than the controls but the difference was not statistically significant. Although NO levels of the patients were higher than the controls, the difference was not statistically significant. There was no correlation between PAS and the parameters studied (SOD, ADA, XO, and NO) of the patients. After 8 weeks of antidepressant treatment, ADA and SOD activities were increased whereas NO and XO levels decreased significantly.

CONCLUSION

ADA, XO activity may have a pathophysiological role in PD, and prognosis of PD. Activity of these enzymes may be used to monitor effects of the antidepressant treatment.

Possible role of nitric oxide and adrenomedullin in bipolar affective disorder

Nitric oxide (NO) has been implicated to play a role in the pathogenesis of depressive disorders. Adrenomedullin (AM) induces vasorelaxation by activating adenylate cyclase and also by stimulating the release of NO. AM immune reactivity is present in the brain, consistent with a role as neurotransmitter. Therefore, it is suggested that these two molecules may play a role together in the brain. We aimed to examine AM and NO in bipolar affective disorder (BPAD). Forty-four patients with BPAD and 21 healthy control subjects were included in this study. DSM-IV diagnosis of bipolar affective disorder (type I, manic episodes) was independently established by two psychiatrists and the Turkish version of the Bech-Rafaelson Mania Scale was administered. Also, a semistructured form was used to ascertain several sociodemographic and clinical variables of the patients. AM and NO were studied in plasma. The mean value of plasma NO levels in the BPAD group of 46.58 +/- 13.97 micromol/l was significantly higher than that of controls (31.81 +/- 8.14 micromol/l) (z = -4.15, p = 0.000). Mean plasma AM levels were found to be increased in patients with BPAD (35.13 +/- 5.26 pmol/l) compared to controls (16.22 +/- 3.02 pmol/l) (z = -6.16, p = 0.000). AM levels of BPAD patients were approximately 2-fold higher than controls. AM levels were positively correlated with the duration of hospitalization for the current episode and negatively correlated with the total duration of illness. Both NO and AM may have a pathophysiological role in BPAD (type I, manic episodes) and the clinical symptomatology and prognosis of BPAD.