Endothelin-1 plasma concentrations in depressed patients and healthy controls

Crosstalk Among NLRP3 Inflammasome, ETBR Signaling, and miRNAs in Stress-Induced Depression-Like Behavior: a Modulatory Role for SGLT2 Inhibitors

Depression is an overwhelming health concern, and many patients fail to optimally respond to available standard therapies. Neuroplasticity and blood-brain barrier (BBB) integrity are the cornerstones of a well-functioning central nervous system, but they are vulnerable to an overly active NLRP3 inflammasome pathway that can also indirectly trigger the release of ET-1 and contribute to the ET system disturbance, which further damages stress resilience mechanisms. Here, the promising yet unexplored antidepressant potential of dapagliflozin (Dapa), a sodium-glucose co-transporter-2 inhibitor, was investigated by assessing its role in the modulation of the NLRP3 inflammasome pathway and ETBR signal transduction, and their impact on neuroplasticity and BBB integrity in an animal model of depression. Dapa (1 mg/kg/day; p.o.) with and without BQ-788 (1 mg/kg/day; i.p.), a specific ETBR blocker, were administered to adolescent male Wistar rats exposed to a 5-week chronic unpredictable stress protocol. The depressive animals demonstrated marked activation of the NLRP3 inflammasome pathway (NF-κB/NLRP3/caspase-1/IL/TNF-α), which was associated with both peripheral and central inflammatory responses. The ET system was disrupted, with noticeable reduction in miR-125a-5p and ETBR gene expression. Cortical ZO-1 expression was downregulated under the influence of NLRP3/TNF-α/miR-501-3p signaling, along with a prominent reduction in hippocampal BDNF and synapsin-1. With ETBR up-regulation being a cornerstone outcome, Dapa administration efficiently created an overall state of resilience, improved histopathological and behavioral variables, and preserved BBB function. These observations were further verified by the results obtained with BQ-788 co-administration. Thus, Dapa may exert its antidepressant action by reinforcing BBB integrity and promoting neuroplasticity through manipulation of the NLRP3/ET-1/ETBR/BDNF/ZO-1 axis, with a significant role for ETBR signaling. Graphical illustration for the proposed mechanisms of the anti-depressant potential of Dapa. Dapa suppressed NLRP3 inflammasome activation and assembly with subsequent inhibition of pro-inflammatory ILs. This results in attenuation of neuro-inflammation, BBB disruption, glial cell activation, TNF-α and ET-1 release, and the enhanced production of neurotrophins. The role of ETBR signaling was emphasized; Dapa possibly augmented ETBR expression, which is thought to boost neurotrophins production. The ETBR blocker, BQ-788, suppressed most of the positive outcomes of Dapa. Finally, miR-125a-5p and miR-501-3p that played major roles in these pathological pathways were modulated by Dapa. It is not yet clear whether Dapa has a direct or rather indirect effect on their expression. BBB, blood-brain barrier; Dapa, dapagliflozin; ET-1, endothelin-1; ETBR, endothelin B receptor; IL, interleukin; NF-κB, nuclear factor kappa B; NLRP3, nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3; TNF-α, tumor necrosis factor-α. Created with BioRender.com.

High platelet-to-lymphocyte ratio are associated with post-stroke depression

BACKGROUND

Post-stroke depression (PSD) is the most common psychological consequence among stroke patients, and inflammatory cytokines have cited as risk factors in PSD. We aimed to evaluate the predictive value of stratification of PLR (platelet-to-lymphocyte ratio), an inflammatory marker, in PSD patients.

METHODS

A total of 363 acute ischemic stroke (AIS) patients were screened in the study and received 1-month follow-up. All of the patients were categorized into equal tertiles according to the number of patients and the distribution of PLR. PSD status was evaluated by 17-item Hamilton Depression Rating Scale at 1 month after stroke RESULTS: The optimal cut-off points of PLR were: (T1) 42.15-99.60, (T2) 99.72-127.92, (T3) 127.93-259.84. A total of 77 patients (21.2%) were diagnosed with PSD at 1-month follow-up. Significant differences were found between the PSD and non-PSD groups in PLR tertiles of patients (P < 0.001). After adjustment for conventional confounding factors, the odds ratio of PSD was 5.154 (95% CI, 1.933-13.739) for the highest tertile of PLR compared with the lowest tertile. In multiple-adjusted spline regression, continuously PLR showed linear relation with PSD risk after 95 (P < 0.001 for linearity).

LIMITATIONS

We excluded patients with severe aphasia or serious conditions. In addition, the PLR was recorded only at admission, which limited us explore the correlation of the change of PLR over time with PSD CONCLUSIONS: Increased PLR at admission is a significant and independent biomarker to predict the development of PSD, and stratified PLR could strengthen the predictive power for PSD patients.

Endothelin-1 and psychosocial risk factors for cardiovascular disease: a systematic review

OBJECTIVES

Psychosocial factors (i.e., social environment and emotional factors) contribute to an increased risk of cardiovascular disease (CVD). Perturbation in a potent vasoconstrictive peptide endothelin (ET)-1 could be one of the mechanisms linking psychosocial factors to CVD. Our aim was to evaluate the literature on the relationship between plasma ET-1 and psychosocial risk factors for CVD.

METHODS

MEDLINE and PsycINFO databases were searched for articles on human studies published in peer-reviewed English-language journals through September 2012.

RESULTS

Of the 20 studies that met the inclusion criteria, 14 were experimental studies of acute psychological/mental challenges and 6 were observational studies of psychological and social factors. The inferences drawn from this review were as follows: a) laboratory-induced acute psychological/mental stress may result in exaggerated plasma ET-1 release in those with CVD and those at risk for CVD (positive studies: 5/10); b) chronic/episodic psychosocial factors may have a positive relationship to plasma ET-1 (positive studies: 3/5); and c) race (African American), sex (male), and individual differences in autonomic and hemodynamic responses to stress (parasympathetic withdrawal and elevated blood pressure responsiveness) may moderate the relationship between psychosocial factors and plasma ET-1.

CONCLUSIONS

This review indicates that psychosocial risk factors for CVD are associated with elevated plasma ET-1; however, the relatively small number of studies, methodological differences, and variable assessment tools preclude definitive conclusions about the strength of the association. Specific suggestions regarding the selection of psychosocial factors, optimization of acute challenge protocols, and standardization of methods and timing of the ET-1 measures are provided.

The effects of ethnic discrimination and socioeconomic status on endothelin-1 among blacks and whites

BACKGROUND

Ethnic disparities in cardiovascular disease (CVD) may partially reflect differences in chronic stress burden that vary by social class and exposure to ethnic discrimination. Stress is associated with increased endothelin-1 (ET-1). This study examined the relationship of ET-1 to socioeconomic status (SES) and to perceived ethnic discrimination among black (n = 51) and white (n = 65) adults (mean age 36.5).

METHODS

The Perceived Discrimination subscale of the Scale of Ethnic Experience measured exposure to discrimination and the Hollingshead Two-Factor Index of Social Position assessed SES. Plasma ET-1 was sampled upon awakening after an overnight admission.

RESULTS

SES and ET-1 levels were similar across ethnic groups, but mean discrimination scores were higher among blacks than whites (P < 0.001). Multiple regressions found that the SES x ethnicity interaction was associated with ET-1 (P < 0.05), after adjustment for gender, resting mean arterial pressure (MAP), body mass index (BMI), and exercise frequency. Regressions stratified by ethnicity revealed that lower SES correlated with higher ET-1 in whites (P < 0.001), but not blacks, and accounted for 21% of the variance. Another series of regressions revealed an interaction effect of ethnicity by discrimination on ET-1 (P < 0.05). Increased discrimination correlated with increased ET-1 among blacks (P < 0.05), but not whites, and explained 11% of the variance after adjustment for SES, gender, exercise frequency, and socially desirable response bias.

CONCLUSIONS

Thus, ET-1 levels increased in association with different psychosocial burdens in blacks and whites. Plasma ET-1 was higher among whites with lower SES and among blacks with higher levels of perceived ethnic discrimination, regardless of SES.

The platelet of the patients with ischemic cardiopathy and cardiac valve disease showed a reduction of 8OH-DPAT binding sites

Depression is prospectively associated with increased risk of coronary artery disease in individuals initially free of clinical cardiovascular disease probably by an increased platelet activity. The serotonergic receptors mainly implied in depression are 5-HT1A and 5-HT2 receptors. Activation of 5HT2 receptor induces platelet aggregation. Drugs with 5-HT1A receptor agonist and 5-HT2A receptor antagonist effects reduced the receptor-mediated platelet aggregation. There are only indirect data about 5-HT1A receptors presence in platelet membranes, thus our aims were to study the characteristics of the platelet membranes 5-HT1A binding sites of both healthy volunteers and patients with cardiac valve disease and ischemic cardiopathy. The bound of the 5-HT1A selective agonist 3H-8OH-DPAT to the platelet membranes 5-HT1A binding sites of patients with cardiac valve disease and ischemic cardiopathy were compared with a control group of healthy voluntaries using radioligand binding methods. The patients with cardiovascular disease showed a reduction (-50.40%) (p<0.01) of the 3H-8OH-DPAT bound to the platelet membranes 5-HT1A receptors (1.652+/-0.79 fmol/mg protein) with respect to the control group (3.331+/-0.16 fmol/mg protein). 3H-8OH-DPAT binding to human platelet membranes is saturable, of high affinity, and seems selective for 5-HT1A receptors, and similar to that described in animal brain and in other human cells. Patients with ischemic cardiopathy and cardiac valve disease showed a reduction of the 8OH-DPAT bound to the platelet membranes. Taken together, these findings suggest that the 8OH-DPAT bound to the human platelet membranes is modulated by modifications produced by cardiovascular disease conditions.

Platelet hyperactivity in clinical depression and the beneficial effect of antidepressant drug treatment: how strong is the evidence?

OBJECTIVE

Platelet hyperactivity is thought to contribute to the increased coronary artery disease (CAD) risk in depression. This study reviewed the evidence for hyperactive platelets and for effects of antidepressant drug treatment on platelet 'stickiness' in clinical depression.

METHOD

By means of PubMed electronic library search, 34 studies in English were identified (1983-2003) and critically reviewed.

RESULTS

In depression, flow cytometry studies allowing detection of subtle platelet activation states consistently found at least one platelet activation marker to be increased, while the bulk of platelet aggregation studies did not suggest increased platelet aggregability. Platelets seem to be more activated in depressed patients with CAD than in depressed individuals without CAD. The selective serotonin reuptake inhibitors normalized platelet hyperactivity in four studies.

CONCLUSION

Data on platelet activity in depression are inconclusive. To resolve this issue and its clinical implications, studies in larger sample sizes controlling for confounders of platelet functioning and prospectively designed are needed.