Hypermethylation at CREBBP Is Associated with Cognitive Impairment in a Mexican American Cohort.

BACKGROUND: The aging Mexican American (MA) population is the fastest growing ethnic minority group in the US. MAs have a unique metabolic-related risk for Alzheimer's disease (AD) and mild cognitive impairment (MCI), compared to non-Hispanic whites (NHW). This risk for cognitive impairment (CI) is multifactorial involving genetics, environmental, and lifestyle factors. Changes in environment and lifestyle can alter patterns and even possibly reverse derangement of DNA methylation (a form of epigenetic regulation). OBJECTIVE: We sought to identify ethnicity-specific DNA methylation profiles that may be associated with CI in MAs and NHWs. METHODS: DNA obtained from peripheral blood of 551 participants from the Texas Alzheimer's Research and Care Consortium was typed on the Illumina Infinium® MethylationEPIC chip array, which assesses over 850K CpG genomic sites. Within each ethnic group (N = 299 MAs, N = 252 NHWs), participants were stratified by cognitive status (control versus CI). Beta values, representing relative degree of methylation, were normalized using the Beta MIxture Quantile dilation method and assessed for differential methylation using the Chip Analysis Methylation Pipeline (ChAMP), limma and cate packages in R. RESULTS: Two differentially methylated sites were significant: cg13135255 (MAs) and cg27002303 (NHWs) based on an FDR p < 0.05. Three suggestive sites obtained were cg01887506 (MAs) and cg10607142 and cg13529380 (NHWs). Most methylation sites were hypermethylated in CI compared to controls, except cg13529380 which was hypomethylated. CONCLUSION: The strongest association with CI was at cg13135255 (FDR-adjusted p = 0.029 in MAs), within the CREBBP gene. Moving forward, identifying additional ethnicity-specific methylation sites may be useful to discern CI risk in MAs.

Transcriptomic predictors of inflammation-induced depressed mood.

Inflammation plays a significant role in the pathophysiology of depression. However, not all individuals exposed to inflammatory challenge develop depression, and identifying those at risk is necessary to develop targeted monitoring, prevention, and treatment strategies. Within a randomized double-blind placebo-controlled study (n = 115), we examined whether leukocyte transcriptome profiles predicted inflammation-induced depressed mood in volunteers who received low-dose intravenous endotoxin (n = 58; aged 18-50). At baseline, transcription factor (TF) activities were assessed using genome-wide transcriptional profiling of peripheral blood mononuclear cells and promoter-based bioinformatic analyses. Then, participants were administered endotoxin. Self-reported depressed mood was assessed using the Profile of Mood States. Based on extant studies linking transcriptional profiles to depressive disorder, we examined whether post-endotoxin depressed mood is predicted by baseline activity of TFs related to immune activation, sympathetic activation, and glucocorticoid insensitivity: respectively, nuclear factor kappa B (NF-kB), cAMP response element-binding protein (CREB), and glucocorticoid receptor (GR). Twenty-one participants (36%) experienced an increase in depressed mood from baseline to 2 h post endotoxin, when depressive response peaks. Bioinformatics analyses controlling for age, sex, ethnicity, body mass index, and physical sickness response revealed that post-endotoxin depressed mood was predicted by increased baseline activity of TFs related to inflammation (NF-kB) and beta-adrenergic signaling (CREB) and by decreased activity of GR-related TFs (P's < 0.001). Inflammation-induced depressed mood is predicted by peripheral transcriptome profiles related to immune activation, sympathetic activation, and glucocorticoid insensitivity. With further replication, these stress-related molecular profiles could be used for a novel genomic approach for identifying individuals at high-risk for the inflammatory subtype of depression.

Reduced pCREB in Alzheimer's disease prefrontal cortex is reflected in peripheral blood mononuclear cells.

Cyclic-AMP response element-binding protein (CREB) signaling has a critical role in the formation of memories. CREB signaling is dysfunctional in the brains of mouse models of Alzheimer's disease (AD), and evidence suggests that CREB signaling may be disrupted in human AD brains as well. Here, we show that both CREB and its activated form pCREB-Ser(133) (pCREB) are reduced in the prefrontal cortex of AD patients. Similarly, the transcription cofactors CREB-binding protein (CBP) and p300 are reduced in the prefrontal cortex of AD patients, indicating additional dysfunction of CREB signaling in AD. Importantly, we show that pCREB expression is reduced in peripheral blood mononuclear cells (PBMC) of AD subjects. In addition, pCREB levels in PBMC positively correlated with pCREB expression in the postmortem brain of persons with AD. These results suggest that pCREB expression in PBMC may be indicative of its expression in the brain, and thus offers the intriguing possibility of pCREB as a biomarker of cognitive function and disease progression in AD.

Histone hypoacetylation and increased histone deacetylases in peripheral blood mononuclear cells from patients with Graves' disease.

The objective of this study was to investigate histone modification patterns in peripheral blood mononuclear cells (PBMCs) of patients with Graves' disease (GD). Thirty GD patients and 20 healthy controls were enrolled in this study. Global histone H3/H4 acetylation levels of PBMCs in all subjects were detected by enzyme-linked immunosorbent assay. mRNA levels of histone-related chromatin modifier genes were measured by real-time quantitative reverse transcription-polymerase chain reaction. Global histone H4 acetylation level in PBMCs of GD patients was significantly decreased compared with controls (p=0.005). The mRNA expression of histone deacetylases HDAC1 and HDAC2 were significantly increased in PBMCs of GD patients compared with controls (p=0.004 and 0.018; respectively). No significant difference was observed either in SIRT1 or in HATs mRNA including p300, CREBBP between GD patients and controls (p>0.05). Our findings firstly suggested that histone acetylation modifications are aberrant in PBMCs of GD patients, possibly due to the deregulation of epigenetic modifier genes.

Clinical recovery from surgery correlates with single-cell immune signatures.

Delayed recovery from surgery causes personal suffering and substantial societal and economic costs. Whether immune mechanisms determine recovery after surgical trauma remains ill-defined. Single-cell mass cytometry was applied to serial whole-blood samples from 32 patients undergoing hip replacement to comprehensively characterize the phenotypic and functional immune response to surgical trauma. The simultaneous analysis of 14,000 phosphorylation events in precisely phenotyped immune cell subsets revealed uniform signaling responses among patients, demarcating a surgical immune signature. When regressed against clinical parameters of surgical recovery, including functional impairment and pain, strong correlations were found with STAT3 (signal transducer and activator of transcription), CREB (adenosine 3',5'-monophosphate response element-binding protein), and NF-κB (nuclear factor κB) signaling responses in subsets of CD14(+) monocytes (R = 0.7 to 0.8, false discovery rate <0.01). These sentinel results demonstrate the capacity of mass cytometry to survey the human immune system in a relevant clinical context. The mechanistically derived immune correlates point to diagnostic signatures, and potential therapeutic targets, that could postoperatively improve patient recovery.

Resveratrol reverses the effects of chronic unpredictable mild stress on behavior, serum corticosterone levels and BDNF expression in rats.

Depression is one of the most common neuropsychiatric disorders and has been associated with the neuroendocrine system and alterations in specific brain proteins. Resveratrol is a natural polyphenol enriched in polygonum cuspidatum and has diverse biological activities, including potent antidepressant-like effects. The present study attempts to explore the mechanisms underlying the antidepressant-like action of resveratrol by measuring serum corticosterone levels and the content of brain derived neurotrophic factor (BDNF) in the hippocampus and amygdala of rats exposed to the chronic unpredictable mild stress (CUMS). Male Wistar rats were subjected to the CUMS protocol for a period of 5 weeks to induce depressive-like behavior. Resveratrol treatment (20, 40 and 80mg/kg/i.p. 5 weeks) significantly reversed the CUMS-induced behavioral abnormalities (reduced sucrose preference, increased immobility time and decreased locomotor activity) and the elevated serum corticosterone levels observed in stressed rats. Additionally, 5-weeks of CUMS exposure significantly decreased BDNF levels in the hippocampus and amygdala, and was accompanied by decreased phosphorylation of extracellular signal-regulated kinase (pERK) and cAMP response element-binding protein (pCREB), while resveratrol treatment normalized these levels. All of these effects of resveratrol were essentially identical to that observed with the established antidepressant, desipramine. In conclusion, our study shows that resveratrol exerted antidepressant-like effects in CUMS rats, mediated in part by normalizing serum corticosterone levels while up-regulating pERK, pCREB and BDNF levels in the hippocampus and amygdala.

GSK3ß, CREB, and BDNF in peripheral blood of patients with Alzheimer's disease and depression.

BACKGROUND: Glycogen synthase kinase-3ß (GSK3ß), cAMP-response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) play critical roles in neuronal survival, synaptic plasticity and memory and participate in the pathophysiology of both depressive disorder and Alzheimer's disease (AD). METHODS: This study was designed to determine the association of GSK3ß activity, CREB activity and BDNF concentration in peripheral blood of patients with AD with or without depressive symptoms and in depressive patients without AD. GSK3ß activity in platelets, CREB activity in lymphocytes and BDNF concentration in plasma, platelet-rich plasma or platelets were measured in 85 AD patients (36 of whom displayed co-morbid depressive symptoms), 65 non-AD patients with depressive disorder and 96 healthy controls. AD patients were clinically assessed for stage of dementia, cognitive impairment and severity of depressive symptoms. Depressive patients were clinically assessed for severity of depression. RESULTS: We observed increased CREB activity and GSK3ß activity in AD with depressive symptoms or in AD at mild stage of dementia. Decreased BDNF concentration was found in platelet-rich plasma of AD patients at moderate to severe stages of dementia or in AD without depressive symptoms. An association was revealed of the severity of cognitive impairment with the increase of GSK3ß in the platelets of AD patients with mild dementia. In depressive patients, a lower concentration of phosphorylated GSK3ß was associated with a higher severity of depression. Association was confirmed between severity of depression, CREB activation, and BDNF concentration in drug-naïve depressive patients. CONCLUSION: Our data demonstrated that AD is accompanied by increased CREB activity in lymphocytes and a decreased concentration of BDNF in platelet-rich plasma. The decreased BDNF concentration appears to correlate with moderate to severe stages of dementia in AD. Observation of decreased phosphorylation of GSK3ß in platelets of both AD patients with depressive symptoms and depressive patients after treatment confirms the role of increased GSK3ß activity in the pathophysiology of both AD and depressive disorder. Associations were confirmed between AD and platelet GSK3ß activity, lymphocyte CREB activity and plasma BDNF. CREB activity and platelet BDNF concentration seems to be related to depressive disorder.

Increased vascular permeability after cardiopulmonary bypass in patients with diabetes is associated with increased expression of vascular endothelial growth factor and hepatocyte growth factor.

BACKGROUND: Several inflammatory mediators such as vascular endothelial growth factor and hepatocyte growth factor are known to play a critical role in the regulation of vascular permeability and angiogenesis. We studied the serum levels of growth factors and gene expression profiles of genes involved in growth factor signaling in the peripheral blood of patients with and patients without diabetes following cardiopulmonary bypass and cardioplegic arrest. METHODS: Serum and total RNA were obtained from the blood samples collected from patients with diabetes and matched patients without diabetes (n = 7 patients each) who had coronary artery bypass graft before and 6 hours and 4 days after cardiopulmonary bypass/cardioplegic arrest. The cytokine panel, consisting of growth factors such as vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, and epidermal growth factor, was quantified in patients with diabetes and patients without diabetes before and 6 hours and 4 days post-cardiopulmonary bypass/cardioplegic arrest using multiplex cytokine quantification system. cDNA microarray analysis was performed and fold-change was calculated. RESULTS: Length of hospitalization (10 vs 6 days; P = .04) and weight gain (5 vs 2.5 kg; P = .001) were significantly greater for patients with diabetes compared with patients without diabetes. The serum levels of vascular endothelial growth factor and hepatocyte growth factor were significantly elevated in patients with diabetes when compared with patients without diabetes before versus 6 hours post-cardiopulmonary bypass/cardioplegic arrest. In addition, significantly elevated mRNA expression of hypoxia-inducible factor-1alpha, cyclic adenosine monophosphate response element binding protein, and E1A binding protein p300 (more than twofold) was observed 4 days post-cardiopulmonary bypass/cardioplegic arrest exclusively in patients with diabetes. CONCLUSIONS: The differential profile of gene and protein expression of growth factors and their related genes in patients with diabetes and patients without diabetes could be associated with increased edema and weight gain in patients with diabetes after cardiopulmonary bypass/cardioplegic arrest.

Sleep in bipolar patients.

BACKGROUND: Sleep disturbance has been described in bipolar disorder (BPD). Specific complaints may include frequent nighttime awakenings, poor quality of sleep, reduction in total sleep time, and nightmares. Most patients with BPD also report insomnia when in depression, but a significant percentage of patients report hypersomnia symptoms with prolonged nighttime sleep, difficulty in wakening, and excessive daytime sleepiness. OBJECTIVES: The present study aims to investigate whether bipolar patients with sleep disorders presented impairment in quality of life, disability, and global function. METHODS: One hundred ninety bipolar patients type-I diagnosed by application of Structured Clinician Interview for DSM-IV Disorders (SCID), were distributed in two groups based on absence or presence of sleep disorders. Quality of life, disability, and global dysfunction were evaluated using the Health Organization's Quality of Life instrument (WHOQOL-Brief), the Sheehan Disability Scale, and the Global Assessment of Functioning (GAF), respectively. RESULTS: Sleep complaints have negative influence on general quality of life, observed by decreased scores in WHOQOL and GAF domains and increased Sheehan scores, indicating the importance of maintenance of normal sleep in bipolar patients. CONCLUSION: Our results suggest that sleep complains impair quality of life and global function. Collectively, further studies are warranted to investigate the impairment of sleep disturbance on others neurotrophic factors and neurochemical pathways.

Negative signaling contributes to T-cell anergy in trauma patients.

OBJECTIVE: Maintenance of postinjury T-lymphocyte immune paralysis or anergy could result from failure to activate costimulatory receptors during T-cell receptor activation and/or from chronic stimulation of a competing set of elevated corepressor receptors. Our objective was to assess whether elevated posttrauma T-lymphocyte surface expression of corepressor receptors was associated with immunodepressed lymphocyte responses and corresponded to increased inhibitory and decreased activating signal transduction molecules. DESIGN: Prospective observational study. SETTING: University trauma intensive care unit and research laboratory. PATIENTS: Sixty-one severe thermal and mechanical trauma patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Isolated trauma patients' and controls' peripheral blood T cells were assayed for negative and positive costimulation receptor expression. These receptor expression levels were compared (flow cytometry) between the two groups and correlated to T-cell levels of inhibitory and activating signal transduction molecules and proliferation capacity. Patients' proliferation hyporesponsive (anergic) T cells had increased expression of novel inhibitory receptors (corepressors) PD-1 (p < .05) and CD47 (p < .05) vs. patients' T-cell proliferation competent or controls' T cells. Patients' T-cell CD152 (CTLA-4) expression was also elevated vs. controls. Only patients' anergic T cells had simultaneously increased levels of the inhibitory signal transduction proteins, c-Cbl, a ubiquitin-ligase (p < .01) and SHP-1, a phosphatase (p < .01), concomitant to depressed phosphorylation of the activating signal kinases Erk, Zap70, and CD3Euro. T-cell receptor complex phosphorylation and activation of the interleukin-2 pivotal transcriptional complex protein CREB were also simultaneously depressed as c-Cbl and SHP-1 were elevated. CONCLUSIONS: Up-regulated corepressor receptor expression is novelly shown to characterize trauma patients' anergic T cells and correlate with predominance of inhibitory overactivating signal transduction molecules during T-cell stimulation. This could contribute to postinjury immunosuppression.

Interferon regulatory factor 3-dependent responses to lipopolysaccharide are selectively blunted in cord blood cells.

The synthesis of interferon-beta (IFNbeta) and IFN-inducible factors elicited by lipopolysaccharide (LPS) depends on the transcriptional activity of interferon regulatory factor 3 (IRF-3) downstream of Toll-like receptor-4 (TLR4). To examine the ability of human newborns to mount TLR4-mediated IRF-3-dependent responses, we analyzed the pattern of genes expressed on the addition of LPS to cord blood or cord blood monocyte-derived dendritic cells (moDCs). Expression of IFNbeta and IFN-inducible genes was selectively impaired in neonatal blood and moDCs as compared with their adult counterparts. This selective defect was confirmed by microarray experiments on moDCs. Altered expression of IFN-inducible genes was related to impaired IFNbeta synthesis because IFNbeta signaling was functional in neonatal moDCs. However, addition of exogenous IFNbeta failed to restore LPS-induced IL-12p70 synthesis which was previously shown to be defective in neonatal moDCs. Although LPS-induced IRF-3 nuclear translocation was observed both in adult and neonatal moDCs, IRF-3 DNA-binding activity and association with the coactivator CREB-binding protein (CBP) were decreased in neonatal as compared with adult moDCs. We conclude that impaired IRF-3/CBP interaction in neonatal blood cells exposed to LPS is associated with impaired expression of IFNbeta and IFN-inducible genes. Because IRF-3 activity is also required for IL-12p70 synthesis, our findings provide a molecular basis for the decreased ability of LPS-stimulated neonatal moDCs to elicit Th1-type responses.