Effects of chronic mental stress and atherogenic diet on the immune inflammatory environment in mouse aorta

Abstract

Inflammation and stress are regarded as two important atherogenic factors. Because stress can affect leukocyte distribution, we hypothesized that stress-mediated leukocyte extravasation can modify the inflammatory environment of the arterial wall possibly contributing to atherogenesis. To test this hypothesis we evaluated the inflammatory environment of the aorta in C57Bl/6 mice subjected to 3 and to 12 months of chronic stress and compared it to age matched non-stressed animals. Experiments were carried out in mice fed regular chow or atherogenic diets. Both treatments increased the expression of vascular and leukocyte adhesion molecules and leukocyte accumulation. At 3 months, stress but not an atherogenic diet elevated the number of CD4 cells, CD8 cells, macrophages, dendritic cells and neutrophils. These changes were associated with elevation of transcripts for ICAM-1 and VCAM-1, E-Selectin and Neuropeptide Y. At 12 months, stress or high cholesterol acted similarly to elevate the number of CD8 and macrophages, and synergistically on the number of all cell types investigated. At this time-point, strong synergism was also observed on the level of E-selectin and NPY in the aorta, but not in the circulation. Despite these effects, histological and morphological alterations of the arterial wall were severe in the atherogenic diet, but not in the stress groups. Thus, although stress and an atherogenic diet may both affect leukocyte accumulation in the aorta, they may contribute differently to atherogenesis.

Acute Psychological Stress Accelerates Reverse Cholesterol Transport via Corticosterone-Dependent Inhibition of Intestinal Cholesterol Absorption

“…66 In contrast, it was recently reported that up to 12 months of exposure to chronic stress in C57Bl/6J mice fed an atherogenic diet suppressed the development of intimal foam cells and attenuated the atherogenic histological changes in the aorta. 67 Although the cited studies have shown that the effect of stress on atherosclerosis is related to the particular type of stressor, the present finding that acute stress actually accelerates RCT was unanticipated. If we consider that a shortterm stress period enables the body with adaptive responses to protect against a threat/risk of injury, then increased synthesis of glucocorticoids may represent one of the body's auto pharmacological protective mechanisms in various disease processes.…”

Autonomic Dysfunction Determines Stress‐Induced Cardiovascular and Immune Complications in Mice

“…13 Interestingly, VCAM-1 is a key vascular inflammatory marker that increases under more severe stress protocols in ApoE À/À or C57BL/6 mice. 36,37 The studies also suggest that stress and an atherogenic diet increase vascular inflammation but have different effects on atherogenesis. In the current study, we confirmed elevated expression of VCAM-1 in carotids from SJL inbred mice or recipient SJL chimeras.…”

Chronic intermittent mental stress promotes atherosclerotic plaque vulnerability, myocardial infarction and sudden death in mice

“…At 10 weeks WD, a mental stress protocol adapted from Marcondes et al [18], was initiated and consisted of 3 different triggers: water avoidance, damp bedding and restraint stress. To induce water avoidance stress, mice were placed in an empty cage filled with 0.3 cm of water.…”