Serotonin, depression, and cardiovascular disease: sex-specific issues

Sex differences at the platelet-vascular interface

Platelets are multifunctional cells that ensure the integrity of the vascular wall and modulate the immune response at the blood/vascular interface. Their pathological activation results in both thrombosis and inflammation and implicates them in the pathogenesis of vascular disease. Vascular diseases are sexually dimorphic in terms of incidence, clinical presentation, outcome, and efficacy of anti-platelet therapy. We here provide an overview of what is known about the role of platelets in the initiation and progression of vascular diseases and summarize what is known about the sex differences in platelet reactivity and in the thromboinflammatory mechanisms that drive these diseases, with a particular focus on atherosclerosis, obstructive and non-obstructive coronary artery disease, and ischemic stroke. Understanding the sex differences at the platelet-vascular interface is clinically relevant as it will enable: (1) to design new therapeutic strategies that prevent the detrimental effects of the immune-modulatory function of platelets taking sex into account, and (2) to evaluate if sex-specific anti-platelet drug regimens should be used to reduce the risk not only of thrombosis but also of vascular disease progression.

The effects of exercise and diet on mental status, insulin signaling pathway, and microbiome in obese mice

The aim of this study was to investigate the effects of exercise and diet on mental status, insulin signaling pathway, serotonin synthesis, and microbiome in high-fat-induced obesity mice. Before the start of this experiment, obesity groups made obese mice by administering a high-fat diet containing 60% fat for 12 weeks. In the obesity with exercise group, after a high-fat diet for 12 weeks, exercise was performed with high-fat diet for 8 weeks. In the obesity with diet group, a high-fat diet for 12 weeks followed by a normal diet for 8 weeks. Depression and anxiety were determined by open field test and elevated plus maze test. Immunohistochemistry for tryptophan hydroxylase (TPH) in the dorsal raphe, western blot analysis for phosphorylated protein kinase B (p-ATK), total AKT (t-AKT), phosphorylated phosphoinositide 3-kinase (p-PI3K), and total PI3K (t-PI3K) in the hippocampus were performed. Analysis of microbiome was also conducted. Obesity-induced depression and anxiety status, suppressed ratio of p-AKT/t-AKT and p-PI3K/t-PI3K, and inhibited TPH synthesis. Exercise and diet improved depression and anxiety status, activated p-AKT/t-AKT and p-PI3K/t-PI3K, and increased TPH synthesis. Exercise and diet improved depression and anxiety status by increasing the insulin signaling pathway and promoting serotonin production. These effects of exercise and diet were almost similar. In addition, exercise and diet regulated the composition of gut microbiota.

Association Between Depression and Risk of Incident Cardiovascular Diseases and Its Sex and Age Modifications: A Prospective Cohort Study in Southwest China

To examine possible associations between depression and cardiovascular disease (CVD) incidence and whether demographic factors modified those associations in the Chinese population. This prospective cohort study comprised 7,735 adults aged 18 years or older in Guizhou, China from 2010 to 2020. The Patient Health Questionnaire-9 (PHQ-9) was used to measure the prevalence of depression. Cox proportional hazard models were used to estimated hazard ratios (HRs) and 95% confidence intervals (95%CIs) of depression and incident CVD. We identified 215 CVD cases (including 28 acute myocardial infarction (AMI) and 197 stroke cases) during an average follow-up of 7.07 years. In the multivariable-adjusted model, baseline PHQ-9 score was associated with incident CVD, AMI, and stroke. The HR per 1-SD increase for PHQ-9 score was 1.14 (95%CI: 1.03, 1.26) for CVD, 1.26 (95%CI: 1.01, 1.57) for AMI, and 1.12 (95%CI: 1.01, 1.25) for stroke. Compared with participants without depression, those with any mild or more advanced depression had a higher risk of incident CVD (HR: 1.69, 95%CI: 1.08, 2.64) and AMI (HR: 3.36, 95%CI: 1.17, 10.56). Associations between depression with CVD and stroke were suggested to be even stronger among women and participants aged <65 years (P for interaction <0.05). The effect of depression on stroke tended to be preserved in non-smokers. Depression was associated with a higher risk of incident CVD, AMI, and stroke in adults of Southwest, China, particularly in women, participants aged <65 years, and non-smokers. These findings highlighted the importance and urgency of depression healthcare.

Depression and Cardiovascular Disease: The Viewpoint of Platelets

Depression is a major cause of morbidity and low quality of life among patients with cardiovascular disease (CVD), and it is now considered as an independent risk factor for major adverse cardiovascular events. Increasing evidence indicates not only that depression worsens the prognosis of cardiac events, but also that a cross-vulnerability between the two conditions occurs. Among the several mechanisms proposed to explain this interplay, platelet activation is the more attractive, seeing platelets as potential mirror of the brain function. In this review, we dissected the mechanisms linking depression and CVD highlighting the critical role of platelet behavior during depression as trigger of cardiovascular complication. In particular, we will discuss the relationship between depression and molecules involved in the CVD (e.g., catecholamines, adipokines, lipids, reactive oxygen species, and chemokines), emphasizing their impact on platelet activation and related mechanisms.

Sex-discrete role of depressive symptomatology on 10-year first and recurrent cardiovascular disease incidence: results from ATTICA and GREECS prospective studies

OBJECTIVE

The sex-specific effect of depressive symptomatology on 10-year first and recurrent cardiovascular disease (CVD) events was evaluated.

METHODS

The Greek samples from ATTICA (2002-2012, n = 845 free-of-CVD subjects) and GREECS (2004-2014, n = 2,172 subjects with acute coronary syndrome (ACS)) prospective epidemiological studies with baseline psychological assessments were used for the first and the recurrent event, respectively. Depressive symptomatology was assessed at baseline, through Zung Self-Rating Depression Scale in the ATTICA study, and through the Center for Epidemiological Studies-Depression scale in the GREECS study.

RESULTS

ACS as well as free-of-CVD women scored significantly higher for depressive symptomatology. Men scored higher than women against first (19.7% vs. 11.7%) and subsequent CVD events (38.8% vs. 32.9%). In participants with depressive symptoms man-to-woman first and recurrent CVD event rate ratio was below 1, confirming that depressive women were more likely to have a CVD event than depressive men. Multiadjusted analysis revealed that depressive symptomatology had an independent aggravating effect on the first (hazard ratio (HR) = 2.72, 95% confidence interval (95% CI) 1.50, 9.12) and recurrent (HR = 1.31, 95% CI 1.01, 1.69) CVD events only in women. Mediation analysis in women revealed that 35% (23%, 44%) of excess first-CVD-event risk of depressive symptoms was attributed to conventional risk factors. The respective number for recurrent CVD events was 46% (23%, 53%); different patterns of ranking regarding the mediating effect corresponding to each adjustment factor were observed.

CONCLUSIONS

The present work augments prior evidence that psychological stressors possess important drivers of CVD onset and progression mainly in women, while it gives rise to research toward unidentified paths behind this claim.

The association between low level of high-density lipoprotein cholesterol and mood disorder using time-dependent analysis

BACKGROUND

Although many studies have identified factors associated with mood disorder, the association between high-density lipoprotein cholesterol (HDL-C) and mood disorder is still controversial. The aim of our study was to evaluate the association between low HDL-C and onset of mood disorder in Korea based on different cut-off levels.

METHODS

We used National Health Examinations Service cohort data from 2009 to 2013. We used time-dependent Cox regression analysis to evaluate the association between low level of HDL-C and onset of mood disorder. Hazard ratios (HRs) for onset of mood disorder were estimated for 1- to 2-year time intervals, starting at the first health examination and accounting for the duration until the next health examination.

RESULTS

A total of 400,803 participants (male: 220,573; female: 180,230) were included in our study. A total of 4576 (2.07%) males and 7598 (4.22%) females developed mood disorder. Based on dyslipidemia (< 40mg/dL), low level of HDL-C was associated with the risk of mood disorder in both male and female, however, only females showed statistically significant (HR: 1.097, 95% CI: 1.012-1.189). Based on quartile-based approach, females with low levels of HDL-C (< 47mg/dL) and males with high levels of HDL-C (≥ 59mg/dL) were associated with subsequent risk of mood disorder.

CONCLUSIONS

Our findings suggest that level of HDL-C is associated with potential risk factors in mood disorder. However, a flexible threshold value in HDL-C level would be needed to evaluate the subsequent risk of mood disorder. Thus, further studies are needed to help improve the mental health in susceptible individuals.

Physical exercise ameliorates mood disorder-like behavior on high fat diet-induced obesity in mice

Obesity is associated with mood disorders such as depression and anxiety. The aim of this study was to investigate whether treadmill exercise had any benefits on mood disorder by high fat diet (HFD) induced obesity. Mice were randomly divided into four groups: control, control and exercise, high fat diet (HFD), and HFD and exercise. Obesity was induced by a 20-week HFD (60%). In the exercise groups, exercise was performed 6 times a week for 12 weeks, with the exercise duration and intensity gradually increasing at 4-week intervals. Mice were tested in tail suspension and elevated plus maze tasks in order to verify the mood disorder like behavior such as depression and anxiety on obesity. In the present study, the number of 5-HT- and TPH-positive cells, and expression of 5-HT_1A and 5-HTT protein decreased in dorsal raphe, and depression and anxiety like behavior increased in HFD group compared with the CON group. In contrast, treadmill exercise ameliorated mood disorder like behavior by HFD induced obesity and enhanced expression of the serotonergic system in the dorsal raphe. We concluded that exercise increases the capacity of the serotonergic system in the dorsal raphe, which improves the mood disorders associated with HFD-induced obesity.

The steroid metabolome in men with mood and anxiety disorders

The mood and behavior of individuals result from an orchestra of many factors. Among them steroids play an important role; however, only several common hormones have been investigated in this respect. It has been demonstrated that some steroid metabolites long considered merely the products of steroid hormone metabolism in fact possess considerable activity in the CNS. For this reason we studied the steroid metabolome including 50 analytes in 20 men with depression, 20 men with anxiety and 30 healthy controls. Significant differences were found not only between controls and men with either depression or anxiety, but also between men with depression and anxiety. Particularly striking were those steroids until now not generally associated with depression or anxiety, namely conjugated steroid forms, especially sulfates.

Climacteric symptoms in middle-aged women with chronic somatic diseases

OBJECTIVES

Chronic diseases may aggravate or simulate climacteric symptoms. Although acknowledged in clinical practice, there is a lack of research systematically analysing the association between chronic diseases and climacteric symptoms.

STUDY DESIGN AND MAIN OUTCOME MEASURES

Our study was a cross-sectional population-based study, which included 3421 women, aged 41-54 years. Climacteric symptoms were evaluated using the Women's Health Questionnaire (WHQ), of which we included seven symptom domains (vasomotor, sleep, depressive, anxiety/fears, cognitive, sexual, and menstrual) and a question concerning whether the women were worried about growing old. The occurrence of various diseases (cardiovascular, neurological, sensory organ, bronchopulmonary, musculoskeletal, gastrointestinal, urological, dermatological, and thyroid disease, diabetes, and cancer) was recorded. The associations between the diseases and symptoms were defined with multivariable analyses, adjusting for various confounding factors.

RESULTS

The women with the diseases had more symptoms. Vasomotor symptoms and sleep problems were associated only with gastrointestinal diseases, and lower sexual functioning only with diabetes. The remaining symptoms were associated with several diseases, except being worried about growing old, which was not associated with any.

CONCLUSIONS

Many symptoms connected to the climacteric may manifest also due to chronic diseases. Thus, health-care professionals should consider the origin of the symptoms when treating middle-aged women with chronic diseases.

Is there any association of personality traits with vascular endothelial function or systemic inflammation?

Background:

Evidences showed association of some personality traits with increased risk of cardiovascular diseases, but mediated mechanisms are not entirely described. In this study, we investigated the association of different personality traits with systemic inflammation and endothelial function as probable mediators.

Methods:

This cross-sectional study was conducted in 2011 on 40-60 years old employees of an industrial company located in Isfahan city (central Iran). Participants were selected through simple random sampling. Personality types were evaluated using the neuroticism-extroversion-openness personality inventory and systemic inflammatory status was determined with high sensitive C-reactive protein (hs-CRP) level. To evaluate endothelial function flow mediated dilation (FMD) were measured. The obtained data were analyzed with univariate correlation and multiple linear regression tests.

Results:

A total of 254 cases with mean age of 51.4 ± 6.1 years were evaluated. There was no significant relationship between hs-CRP level and FMD with the personality traits in univariate analysis. In multivariate analysis, no association was found between the scores of personality traits and FMD with controlling the factors such as age, body mass index dyslipidemia, hypertension and diabetes. Only there was an inverse association between conscientiousness score and hs-CRP (β = −0.241, P = 0.013).

Conclusions:

In our population who were the employees of an industrial company, no relationship was found between specific personality trait and endothelial dysfunction. However, we found that the personality trait of responsibility (conscientiousness) is negatively associated with inflammation. Further multi-center studies and also cohort studies are recommended in this regard.

Depression and cardiovascular disease in women: is there a common immunological basis? A theoretical synthesis

Clinical studies have established an inherent comorbidity between depression and the development of cardiovascular disease (CVD). Furthermore, this comorbidity seems to be more amplified in women than in men. To further investigate this comorbidity, a thorough literature review was conducted on studies from 1992 to date. The PubMed database was accessed using the keywords: cardiovascular disease, inflammation, depression, and sex differences. Both human and animal studies were considered. This review takes the standpoint that depression and CVD are both inflammatory disorders, and that their co-occurrence may be related to how the hypothalamic–pituitary–adrenal axis, serotonergic transmission and circulation, and the renin–angiotensin–aldosterone system via angiotensin II are affected by the excess secretion of proinflammatory cytokines. More recently, preliminary research attributes this systemic inflammation to a global deficiency in CD4+CD25+FOXP3 regulatory T cells. 17-β estradiol and progesterone mediated modulation of cytokine secretion may partially explain the sex differences observed. These hormones and reproductive events associated with hormonal fluctuations are discussed in depth, including the analysis of perinatal models of depression and CVD, including preeclampsia. However, as evidenced by this review, there is a need for mechanistic research in humans to truly understand the nature and directionality of the relationship between depression and CVD.

The predictive value of somatic and cognitive depressive symptoms for cytokine changes in patients with major depression

CONTEXT

Elevated concentrations of proinflammatory cytokines have been hypothesized as an important factor in the pathophysiology of depression. Depression itself is considered to be a heterogeneous disorder. Current findings suggest that "cognitive" and "somatic" symptom dimensions are related to immune function in different ways. So far, little research has been done on the longitudinal aspects of inflammation in patients with major depression, especially with respect to different symptom dimensions of depression. Therefore, we investigated which aspects of depression may predict changes in tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 over 4 weeks.

METHODS

Forty-one patients with major depression diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and 45 healthy controls were enrolled. Serum measurements of TNF-alpha and IL-6 were conducted at baseline and 4 weeks later. Psychometric measures included the assessment of cognitive-affective depressive symptoms and somatic symptoms during the last 7 days as well as somatic symptoms during the last 2 years.

RESULTS

Patients with depression showed increased levels of TNF-alpha (P<0.05) compared to healthy controls. Hierarchical regression analyses indicated that neither depressive nor somatic symptoms predict changes in proinflammatory cytokines in the whole sample of depressed patients. Moderation analyses and subsequent sex-stratified regression analyses indicated that higher somatoform symptoms during the last 2 years significantly predict an increase in TNF-alpha in women with major depression (P<0.05) but not in men. Exploratory analyses indicated that the stability of TNF-alpha and IL-6 (as indicated by intraclass correlation coefficients) over 4 weeks was high for TNF-alpha but lower for IL-6.

CONCLUSION

The present study demonstrated that a history of somatoform symptoms may be important for predicting future changes in TNF-alpha in women with major depression.

Not all depression is created equal: sex interacts with disease to precipitate depression

Depression is a common mental disorder that co-occurs in other neurological and somatic diseases. Further, sex differences exist in the prevalence rates of many of these diseases, as well as within non-disease associated depression. In this review, the case is made for needing a better recognition of the source of the symptoms of depression with respect to the sex of the individual; in that, some disease states, which includes the neuroendocrine and immune reactions to the underlying pathophysiology of the disease, may initiate depressive symptoms more often in one sex over the other. The diseases specifically addressed to make this argument are: epilepsy, Alzheimer’s disease, cancer, and cardiovascular disease. For each of these conditions, a review of the following are presented: prevalence rates of the conditions within each sex, prevalence rates of depressive symptoms within the conditions, identified relationships to gonadal hormones, and possible interactions between gonadal hormones, adrenal hormones, and immune signaling. Conclusions are drawn suggesting that an evaluation of the root causes for depressive symptoms in patients with these conditions is necessary, as the underlying mechanisms for eliciting the depressive symptoms may be qualitatively different across the four diseases discussed. This review attempts to identify and understand the mechanisms of depression associated with these diseases, in the context of the known sex differences in the disease prevalence and its age of onset. Hence, more extensive, sex-specific model systems are warranted that utilize these disease states to elicit depressive symptoms in order to create more focused, efficient, and sex-specific treatments for patients suffering from these diseases and concurrent depressive symptoms.

Secondhand cigarette smoke exposure causes upregulation of cerebrovascular 5-HT(1) (B) receptors via the Raf/ERK/MAPK pathway in rats

AIM

Cigarette smoke exposure increases the risk of stroke. Upregulation of 5-hydroxytryptamine 1B (5-HT(1) (B) ) receptors is associated with the pathogenesis of cerebral ischaemia. This study examined the hypothesis that the expression of 5-HT(1) (B) receptors is altered in brain vessels after secondhand smoke (SHS) exposure.

METHODS

Rats were exposed to SHS in vivo for 200 min daily for 8 weeks. The contractile responses of isolated cerebral arteries were studies by a sensitive myograph. The mRNA and protein expression for 5-HT(1) (B) receptors were examined by real-time PCR, Western blot and immunofluorescence respectively. In addition, the phosphorylation of Raf/extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway was evaluated.

RESULTS

The results showed that SHS exposure shifted the 5-HT(1) (B) receptor-mediated concentration-contraction curve towards the left with a markedly increased maximal contraction. Furthermore, there were significant elevations in mRNA level and protein expression of 5-HT(1) (B) receptors in SHS-exposed rats. Immunostaining revealed that the 5-HT(1) (B) receptors were localized to the smooth muscle cells of cerebral arteries. SHS was also found to induce the phosphorylation of Raf-1 and ERK1/2 proteins. The administration of a Raf-1 inhibitor GW5074 attenuated the 5-HT(1) (B) receptor upregulation.

CONCLUSION

Secondhand smoke exposure upregulates cerebrovascular 5-HT(1) (B) receptors in rats. The receptor upregulation is associated with Raf/ERK/MAPK activation.

Association of in vivo β-adrenergic receptor sensitivity with inflammatory markers in healthy subjects

OBJECTIVE

Several stress-related states and conditions that are considered to involve sympathetic overactivation are accompanied by increased circulating levels of inflammatory immune markers. Prolonged sympathetic overactivity involves increased stimulation of the β-adrenergic receptor (β-AR). Although prior research suggests that one mechanism by which sympathetic stimulation may facilitate inflammation is via β-AR activation, little work has focused on the relationship between circulating inflammatory immune markers and β-AR function within the human body (in vivo). We examined whether decreased β-AR sensitivity, an indicator of prolonged β-adrenergic overactivation and a physiological component of chronic stress, is related to elevated levels of inflammatory immune markers.

METHODS

Ninety-three healthy participants aged 19 to 51 years underwent the chronotropic 25 dose isoproterenol test to determine in vivo β-AR function. Circulating levels of C-reactive protein, interleukin 6, and soluble tumor necrosis factor receptor 1 were determined.

RESULTS

β-AR sensitivity was lower in people with higher C-reactive protein concentrations (r = 0.326, p = .003). That relationship remained significant after controlling for sociodemographic and health variables such as age, sex, ethnicity, body mass index, mean arterial blood pressure, heart rate, leisure-time exercise, and smoking status. No significant relationship was found between chronotropic 25 dose and interleukin 6 or soluble tumor necrosis factor receptor 1.

CONCLUSIONS

This study demonstrates a link between in vivo β-adrenergic receptor function and selected circulating inflammatory markers (CRP) in humans. Future studies in specific disease states may be promising.

Strategies and methods to study sex differences in cardiovascular structure and function: a guide for basic scientists

Background

Cardiovascular disease remains the primary cause of death worldwide. In the US, deaths due to cardiovascular disease for women exceed those of men. While cultural and psychosocial factors such as education, economic status, marital status and access to healthcare contribute to sex differences in adverse outcomes, physiological and molecular bases of differences between women and men that contribute to development of cardiovascular disease and response to therapy remain underexplored.

Methods

This article describes concepts, methods and procedures to assist in the design of animal and tissue/cell based studies of sex differences in cardiovascular structure, function and models of disease.

Results

To address knowledge gaps, study designs must incorporate appropriate experimental material including species/strain characteristics, sex and hormonal status. Determining whether a sex difference exists in a trait must take into account the reproductive status and history of the animal including those used for tissue (cell) harvest, such as the presence of gonadal steroids at the time of testing, during development or number of pregnancies. When selecting the type of experimental animal, additional consideration should be given to diet requirements (soy or plant based influencing consumption of phytoestrogen), lifespan, frequency of estrous cycle in females, and ability to investigate developmental or environmental components of disease modulation. Stress imposed by disruption of sleep/wake cycles, patterns of social interaction (or degree of social isolation), or handling may influence adrenal hormones that interact with pathways activated by the sex steroid hormones. Care must be given to selection of hormonal treatment and route of administration.

Conclusions

Accounting for sex in the design and interpretation of studies including pharmacological effects of drugs is essential to increase the foundation of basic knowledge upon which to build translational approaches to prevent, diagnose and treat cardiovascular diseases in humans.