Subclinical depressive symptoms affect responses to acute psychosocial stress in healthy premenopausal women

Impact of Acute and Chronic Stress on Thrombosis in Healthy Individuals and Cardiovascular Disease Patients

Psychological stress induces different alterations in the organism in order to maintain homeostasis, including changes in hematopoiesis and hemostasis. In particular, stress-induced hyper activation of the autonomic nervous system and hypothalamic–pituitary–adrenal axis can trigger cellular and molecular alterations in platelets, coagulation factors, endothelial function, redox balance, and sterile inflammatory response. For this reason, mental stress is reported to enhance the risk of cardiovascular disease (CVD). However, contrasting results are often found in the literature considering differences in the response to acute or chronic stress and the health condition of the population analyzed. Since thrombosis is the most common underlying pathology of CVDs, the comprehension of the mechanisms at the basis of the association between stress and this pathology is highly valuable. The aim of this work is to give a comprehensive review of the studies focused on the role of acute and chronic stress in both healthy individuals and CVD patients, focusing on the cellular and molecular mechanisms underlying the relationship between stress and thrombosis.

Stress and inflammation - The need to address the gap in the transition between acute and chronic stress effects

Stress responses help us navigate our environment and respond appropriately to threats. Stress systems communicate threats to the entire organism, and as such, also stimulate inflammatory mechanisms. This modulation might serve protective functions in the short term, but sustained low-grade inflammation has severe long-term health consequences. While we have reached a reasonable level of understanding of acute, as well as chronic stress effects on inflammatory mechanisms, there is a significant gap in our understanding of the transitional phase between acute and chronic stress. The purpose of this review is to first summarize current knowledge of our understanding of acute stress effects on inflammation, as well as of chronic stress effects on inflammation, and to then analyze the state of knowledge about the transitional phase between acute and chronic stress. Research discussed here shows that we are beginning to understand the early phase of repeated acute stress, but lack information on longer term exposure to repeated acute stress experiences. More research is needed to bridge this important gap und our conceptualization and understanding of the stress and health relationship.

A dimensional approach to determine common and specific neurofunctional markers for depression and social anxiety during emotional face processing

Major depression disorder (MDD) and anxiety disorder are both prevalent and debilitating. High rates of comorbidity between MDD and social anxiety disorder (SAD) suggest common pathological pathways, including aberrant neural processing of interpersonal signals. In patient populations, the determination of common and distinct neurofunctional markers of MDD and SAD is often hampered by confounding factors, such as generally elevated anxiety levels and disorder-specific brain structural alterations. This study employed a dimensional disorder approach to map neurofunctional markers associated with levels of depression and social anxiety symptoms in a cohort of 91 healthy subjects using an emotional face processing paradigm. Examining linear associations between levels of depression and social anxiety, while controlling for trait anxiety revealed that both were associated with exaggerated dorsal striatal reactivity to fearful and sad expression faces respectively. Exploratory analysis revealed that depression scores were positively correlated with dorsal striatal functional connectivity during processing of fearful faces, whereas those of social anxiety showed a negative association during processing of sad faces. No linear relationships between levels of depression and social anxiety were observed during a facial-identity matching task or with brain structure. Together, the present findings indicate that dorsal striatal neurofunctional alterations might underlie aberrant interpersonal processing associated with both increased levels of depression and social anxiety.

Physiological responses to psychological stress: importance of adiposity in men aged 50-70 years

We tested the hypothesis that overweight/obese men aged 50-70 years will have a greater salivary cortisol, salivary alpha amylase and heart rate (HR) responses to psychological stress compared with age matched lean men. Lean (BMI=20-25 kg/m(2); n=19) and overweight/obese (BMI=27-35 kg/m(2); n=17) men (50-70 years) were subjected to a well-characterised psychological stress (Trier Social Stress Test, TSST) at 1500 h. Concentrations of cortisol and alpha amylase were measured in saliva samples collected every 7-15 min from 1400 to 1700 h. HR was recorded using electrocardiogram. Body weight, BMI, percentage body fat, resting systolic and diastolic blood pressure and mean arterial pressure were significantly higher (P<0.05) in overweight/obese men compared with lean men. Both groups responded to the TSST with a substantial elevation in salivary cortisol (372%), salivary alpha amylase (123%) and HR (22%). These responses did not differ significantly between the groups (time×treatment interaction for salivary cortisol, salivary alpha amylase and HR; P=0.187, P=0.288, P=0.550, respectively). There were no significant differences between the groups for pretreatment values, peak height, difference between pretreatment values and peak height (reactivity) or area under the curve for salivary cortisol, salivary alpha amylase or HR (P>0.05 for all). The results showed that, for men with a moderate level of overweight/obesity who were otherwise healthy, the response of salivary cortisol, salivary alpha amylase and HR to acute psychological stress was not impaired.

Stimulation of systemic low-grade inflammation by psychosocial stress

Psychosocial stress is an important precursor of disease and reduced quality of life in humans. The biological pathways between stress exposure and pathophysiological processes underlying disease have received substantial scientific attention, although the roles of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system remain insufficiently understood. Recent attention has focused on chronic systemic low-grade inflammation as a promising pathway because elevated inflammation often accompanies chronic psychosocial distress. These alterations of inflammatory activity play a key role in the pathophysiology of diseases that are adversely affected by chronic distress, such as cardiovascular disease. Transient increases in systemic inflammation are observed in response to acute psychosocial stress, with larger responses among individuals reporting adverse psychosocial states or conditions such as depression, lower self-esteem, or lower self-compassion. Recent evidence shows that lower subjective social status and perceived purpose in life are associated with sensitization of inflammatory stress responses to repeated stress exposure. The aims of this selective review article are to summarize current knowledge of the role of acute and chronic psychosocial stress on low-grade inflammation in humans and to discuss potential relationships between inflammatory responses to acute psychosocial stress and long-term development of disease.

PKCγ receptor mediates visceral nociception and hyperalgesia following exposure to PTSD-like stress in the spinal cord of rats

BACKGROUND

Clinical studies indicate that patients with post-traumatic stress disorder (PTSD) frequently share comorbidity with numerous chronic pain conditions. However, the sustained effects of PTSD-like stress over time on visceral nociception and hyperalgesia have been rarely studied, and the underlying mechanisms of stress-induced modulation of visceral hyperalgesia remain elusive. The purpose of this study was to investigate the characterization of visceral nociception and hyperalgesia over time in rats exposed to PTSD-like stress, and to explore the potential role of protein kinase C gamma (PKCγ) in mediating visceral hyperalgesia following exposure to PTSD-like stress.

RESULTS

On day 1, the rats exposed to single-prolonged stress (SPS, an established animal model for PTSD) exhibited an analgesic response and its visceromotor response (VMR) to graded colorectal distention (CRD) at 40 and 60 mmHg was reduced compared with the control group (all P < 0.05). On day 6, the VMR returned to the baseline value. However, as early as 7 days after SPS, VMR dramatically increased compared with its baseline value and that in the controls (all P < 0.001) and this increase persisted for 28 days, with the peak on day 9. Abdominal withdrawal reflex (AWR) scores were higher in SPS rats than in controls on days 7, 9, 14, 21 and 28 (all P < 0.001). Intrathecal administration of GF109203X (an inhibitor of PKC gamma), attenuated the SPS-induced increase in both VMR and AWR scores on days 7, 14, 21 and 28 (all P < 0.05). PKCγ protein expression determined by immunofluorescence was reduced in the spinal cord within 3 days after the exposure to SPS (P < 0.01), which returned to normal levels between days 4 and 6, and significantly increased from day 7, and this increase was maintained on days 14, 21, and 28 (all P < 0.001), with the peak on day 9. In addition, Western blotting showed a consistent trend in the changes of PKCγ protein expression.

CONCLUSIONS

The modified SPS alters visceral sensitivity to CRD, and contributes to the maintenance of visceral hyperalgesia, which is associated with enhanced PKCγ expression in the spinal cord. Functional blockade of the PKCγ receptors attenuates SPS-induced visceral hyperalgesia. Thus, the present study identifies a specific molecular mechanism for visceral hyperalgesia which may pave the way for novel therapeutic strategies for PTSD-like conditions.