muramidase and Stress-Disorders--Post-Traumatic

Enhanced glucocorticoid receptor (GR) sensitivity is present in people with posttraumatic stress disorder (PTSD), but the molecular mechanisms of GR sensitivity are not understood. Epigenetic factors have emerged as one potential mechanism that account for how trauma exposure leads to sustained PTSD symptoms given that PTSD develops in only a subset of trauma survivors.. Cytosine methylation of a relevant promoter of the GR gene (NR3C1-1F promoter) and three functional neuroendocrine markers of hypothalamic-pituitary-adrenal axis function were examined in a sample of 122 combat veterans.. Lower NR3C1-1F promoter methylation in peripheral blood mononuclear cells (PBMCs) was observed in combat veterans with PTSD compared with combat-exposed veterans who did not develop PTSD. NR3C1-1F promoter methylation was also associated with three functional measures of glucocorticoid activity that have been associated with PTSD in combat veterans: PBMCs' lysozyme inhibition on the lysozyme suppression test, plasma cortisol decline on the low-dose (.50 mg) dexamethasone suppression test, and 24-hour urinary cortisol excretion. Finally, NR3C1-1F promoter methylation was inversely correlated with clinical markers and symptoms associated with PTSD.. Alterations in NR3C1-1F promoter methylation may reflect enduring changes resulting from combat exposure that lead to functional neuroendocrine alterations. Because epigenetic measures are thought to reflect enduring effects of environmental exposures, they may be useful in distinguishing combat-exposed veterans who do or do not develop PTSD.

Topics: Adult; Biomarkers; Cytosine; Depressive Disorder, Major; Dexamethasone; DNA Methylation; Epigenesis, Genetic; Humans; Hydrocortisone; Hypothalamus; Male; Monocytes; Muramidase; Pituitary-Adrenal System; Promoter Regions, Genetic; Receptors, Glucocorticoid; Stress Disorders, Post-Traumatic; Veterans

Posttraumatic stress disorder (PTSD) has been shown to be associated with altered glucocorticoid receptor (GR) activity. We studied the expression and functional properties of the receptor in peripheral blood mononuclear cells (PBMCs) from non-traumatized healthy individuals (healthy controls; n=85), and war trauma-exposed individuals with current PTSD (n=113), with life-time PTSD (n=61) and without PTSD (trauma controls; n=88). The aim of the study was to distinguish the receptor alterations related to PTSD from those related to trauma itself or to resilience to PTSD.. Functional status of the receptor was assessed by radioligand binding and lysozyme synthesis inhibition assays. The level of GR gene expression was measured by quantitative PCR and immunoblotting.. Current PTSD patients had the lowest, while trauma controls had the highest number of glucocorticoid binding sites (Bmax) in PBMCs. Hormone-binding potential (Bmax/KD ratio) of the receptor was diminished in the current PTSD group in comparison to all other study groups. Correlation between Bmax and KD that normally exists in healthy individuals was decreased in the current PTSD group. Contrasting Bmax data, GR protein level was lower in trauma controls than in participants with current or life-time PTSD.. Current PTSD is characterized by reduced lymphocyte GR hormone-binding potential and by disturbed compensation between Bmax and hormone-binding affinity. Resilience to PTSD is associated with enlarged fraction of the receptor molecules capable of hormone binding, within the total receptor molecule population in PBMCs.

Topics: Adult; Analysis of Variance; Blotting, Western; Dexamethasone; Diagnostic and Statistical Manual of Mental Disorders; Electrophoresis, Polyacrylamide Gel; Glucocorticoids; Hormones; Humans; Kinetics; Lymphocytes; Male; Middle Aged; Muramidase; Radioligand Assay; Real-Time Polymerase Chain Reaction; Receptors, Glucocorticoid; Serbia; Stress Disorders, Post-Traumatic; Warfare; Wounds and Injuries

This study examined the effects of sertraline (SER) on glucocorticoid sensitivity in mononuclear leukocytes (MNL) from eight subjects with current post-traumatic stress disorder (PTSD) and nine comparison subjects. In all, 60 ml of blood was withdrawn by venipuncture at 0800, and MNL were isolated from blood and divided into two portions: the first contained live cells incubated with a series of concentrations of dexamethasone (DEX); the second contained cells incubated with similar concentrations of DEX+2 muM SER. Group difference in the concentrations of DEX required to inhibit lysozyme activity by 50% were evaluated under conditions of DEX-only and DEX+SER using analysis of covariance (ANCOVA). A significant Group x Condition interaction reflected that SER altered the lysozyme IC(50-DEX) in the direction of decreasing sensitivity to glucocorticoids in PTSD while having no uniform effect in cells from comparison subjects. The data provide support for the idea that glucocorticoid receptors might be more responsive to antidepressants in PTSD than in persons without PTSD. Insofar as increased sensitivity to glucocorticoids has been linked with PTSD, the actions of SER on the lysozyme IC(50-DEX) suggest that this medication may target a biologic alteration associated with PTSD pathophysiology.

Topics: Adult; Dexamethasone; Female; Glucocorticoids; Humans; Hydrocortisone; Leukocytes, Mononuclear; Lymphocytes; Male; Muramidase; Receptors, Glucocorticoid; Selective Serotonin Reuptake Inhibitors; Sertraline; Stress Disorders, Post-Traumatic

This study examined the effects of topiramate (TPM) on glucocorticoid receptors (GRs) in mononuclear leukocytes of nine men and four women with chronic and recurring post-traumatic stress disorder (PTSD) and a group of comparison subjects (nine men, four women). A measure of 60 ml of blood was withdrawn by venipuncture at 0800 and mononuclear leukocytes were isolated. The cells were incubated with a series of concentrations of dexamethasone (DEX) without or with 50 micromol/l of TPM to evaluate the effects of DEX to inhibit lysozyme activity and the effect of TPM on it. ANCOVA compared the IC(50) for lysozyme inhibition under conditions of DEX only and TPM+DEX. TPM affected lysozyme IC(50) in the direction of increasing the sensitivity of the receptor in the sample as a whole. This effect was more pronounced in the mononuclear leukocytes from participants in the PTSD group, particularly in cells from subjects whose pretreatment lysozyme IC(50) was relatively higher (eg, reflecting decreased glucococorticoid receptor responsiveness), compared to the rest of the sample. In conclusion, further investigation of the actions of TPM on GR and other neuroendocrine systems may prove useful in understanding some of the other established clinical effects of this agent.

Topics: Adult; Aged; Anticonvulsants; Binding Sites; Case-Control Studies; Demography; Dexamethasone; Drug Interactions; Female; Fructose; Glucocorticoids; Humans; Inhibitory Concentration 50; Leukocytes, Mononuclear; Male; Middle Aged; Muramidase; Receptors, Glucocorticoid; Stress Disorders, Post-Traumatic; Surveys and Questionnaires; Topiramate

The aim of this study was to determine whether there is increased responsiveness to corticosteroids in posttraumatic stress disorder (PTSD) by examining the differential effects of dexamethasone (DEX) on the inhibition of lysozyme activity.. 60 mL of blood was withdrawn at 8:00 am, and mononuclear leukocytes were isolated from the blood of 26 men with, and 18 men without, PTSD. An aliquot of live cells was incubated with a series of concentrations of DEX to determine the rate of inhibition of lysozyme activity; a portion of cells was frozen for the determination of glucocorticoid receptors (GR).. Subjects with PTSD showed evidence of a greater sensitivity to glucocorticoids as reflected by a significantly lower mean concentration (nmol/L) of dexamethasone at which 50% of lysozyme activity is inhibited (IC(50-DEX)) (PTSD+ = 4.9 +/-.53; PTSD- group = 7.2 +/-.64). The lysozyme IC(50-DEX) was significantly correlated with age at exposure to the first traumatic event in subjects with PTSD (r =.44, n = 26, p =.025). The number of cytosolic glucocorticoid receptors was also correlated with age at exposure to the focal traumatic event (r = -.44, n = 25, p =.03) in PTSD.. This is the first in vitro demonstration of an alteration in target tissue sensitivity to glucocorticoids in PTSD. The lower lysozyme IC(50-DEX) might be related to the risk factor of prior exposure to trauma.

Topics: Adult; Age Factors; Age of Onset; Aged; Aged, 80 and over; Cell Count; Dexamethasone; Glucocorticoids; Humans; Hydrocortisone; Inhibitory Concentration 50; Leukocytes, Mononuclear; Male; Middle Aged; Muramidase; Radioligand Assay; Receptors, Glucocorticoid; Stress Disorders, Post-Traumatic