Epigenetic signals associated with delirium replicated across four independent cohorts.

Delirium is risky and indicates poor outcomes for patients. Therefore, it is crucial to create an effective delirium detection method. However, the epigenetic pathophysiology of delirium remains largely unknown. We aimed to discover reliable and replicable epigenetic (DNA methylation: DNAm) markers that are associated with delirium including post-operative delirium (POD) in blood obtained from patients among four independent cohorts. Blood DNA from four independent cohorts (two inpatient cohorts and two surgery cohorts; 16 to 88 patients each) were analyzed using the Illumina EPIC array platform for genome-wide DNAm analysis. We examined DNAm differences in blood between patients with and without delirium including POD. When we compared top CpG sites previously identified from the initial inpatient cohort with three additional cohorts (one inpatient and two surgery cohorts), 11 of the top 13 CpG sites showed statistically significant differences in DNAm values between the delirium group and non-delirium group in the same directions as found in the initial cohort. This study demonstrated the potential value of epigenetic biomarkers as future diagnostic tools. Furthermore, our findings provide additional evidence of the potential role of epigenetics in the pathophysiology of delirium including POD.

The Genome-wide DNA methylation changes in gastrointestinal surgery patients with and without postoperative delirium: Evidence of immune process in its pathophysiology.

AIM: The pathophysiological mechanisms of postoperative delirium (POD) are still unclear, and there is no reliable biomarker to distinguish between those with and without POD. Our aim was to discover DNAm markers associated with POD in blood collected from patients before and after gastrointestinal surgery. METHOD: We collected blood samples from 16 patients including 7 POD patients at three timepoints; before surgery (pre), the first and third postoperative days (day1 and day3). We measured differences in DNA methylation between POD and control groups between pre and day1 as well as between pre and day3 using the Illumina EPIC array method. Besides, enrichment analysis with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes terms were also performed after excluding influence of common factors related to surgery and anesthesia. RESULT: The results showed that pre and day1 comparisons showed that immune and inflammatory signals such as 'T-cell activation' were significantly different, consistent with our previous studies with non-Hispanic White subjects. In contrast, we found that these signals were not significant any more when pre was compared with day3. CONCLUSION: These results provide strong evidence for the involvement of inflammatory and immune-related epigenetic signals in the pathogenesis of delirium, including POD, regardless of ethnic background. These findings also suggest that DNAm, which is involved in inflammation and immunity, is dynamically altered in patients with POD. In summary, the present results indicate that these signals may serve as a new diagnostic tool for POD.

The Bispectral Electroencephalography Method Quantifies Postoperative Delirium-Like States in Young and Aged Male Mice After Head-Mount Implantation Surgery.

Delirium, a syndrome characterized by an acute change in attention, awareness, and cognition, is commonly observed in older adults, although there are few quantitative monitoring methods in the clinical setting. We developed a bispectral electroencephalography (BSEEG) method capable of detecting delirium and can quantify the severity of delirium using a novel algorithm. Preclinical application of this novel BSEEG method can capture a delirium-like state in mice following lipopolysaccharide administration. However, its application to postoperative delirium (POD) has not yet been validated in animal experiments. This study aimed to create a POD model in mice with the BSEEG method by monitoring BSEEG scores following EEG head-mount implantation surgery and throughout the recovery. We compared the BSEEG scores of C57BL/6J young (2-3 months old) with aged (18-19 months old) male mice for quantitative evaluation of POD-like states. Postoperatively, both groups displayed increased BSEEG scores and a loss of regular diurnal changes in BSEEG scores. In young mice, BSEEG scores and regular diurnal changes recovered relatively quickly to baseline by postoperative day (PO-Day) 3. Conversely, aged mice exhibited prolonged increases in postoperative BSEEG scores and it reached steady states only after PO-Day 8. This study suggests that the BSEEG method can be utilized as a quantitative measure of POD and assess the effect of aging on recovery from POD in the preclinical model.

Genome-wide DNA methylation analysis in female veterans with military sexual trauma and comorbid PTSD/MDD.

BACKGROUND: Military sexual trauma (MST) is a prevalent issue within the U.S. military. Victims are more likely to develop comorbid diseases such as posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). Nonetheless, not everyone who suffers from MST develops PTSD and/or MDD. DNA methylation, which can regulate gene expression, might give us insight into the molecular mechanisms behind this discrepancy. Therefore, we sought to identify genomic loci and enriched biological pathways that differ between patients with and without MST, PTSD, and MDD. METHODS: Saliva samples were collected from 113 female veterans. Following DNA extraction and processing, DNA methylation levels were measured through the Infinium HumanMethylationEPIC BeadChip array. We used limma and bump hunting methods to generate the differentially methylated positions and differentially methylated regions (DMRs), respectively. Concurrently, we used Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome to find enriched pathways. RESULTS: A DMR close to the transcription start site of ZFP57 was differentially methylated between subjects with and without PTSD, replicating previous findings and emphasizing the potential role of ZFP57 in PTSD susceptibility. In the pathway analyses, none survived multiple correction, although top GO terms included some potentially relevant to MST, PTSD, and MDD etiology. CONCLUSION: We conducted one of the first DNA methylation analyses investigating MST along with PTSD and MDD. In addition, we found one DMR near ZFP57 to be associated with PTSD. The replication of this finding indicates further investigation of ZFP57 in PTSD may be warranted.

NSAIDs use history: impact on the genome-wide DNA methylation profile and possible mechanisms of action.

BACKGROUND AND OBJECTIVE: NSAIDs inhibit cyclooxygenase, but their role in aging and other diseases is not well understood. Our group previously showed the potential benefit of NSAIDs in decreasing the risk of delirium and mortality. Concurrently, epigenetics signals have also been associated with delirium. Therefore, we sought to find differentially methylated genes and biological pathways related to exposure with NSAIDs by comparing the genome-wide DNA methylation profiles of patients with and without a history of NSAIDs use. METHODS: Whole blood samples were collected from 171 patients at the University of Iowa Hospital and Clinics from November 2017 to March 2020. History of NSAIDs use was assessed through a word-search function in the subjects' electronic medical records. DNA was extracted from the blood samples, processed with bisulfite conversion, and analyzed using Illumina's EPIC array. The analysis of top differentially methylated CpG sites and subsequent enrichment analysis were conducted using an established pipeline using R statistical software. RESULTS: Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) showed several biological pathways relevant to NSAIDs' function. The identified GO terms included "arachidonic acid metabolic process," while KEGG results included "linoleic acid metabolism," "cellular senescence," and "circadian rhythm." Nonetheless, none of the top GO and KEGG pathways and the top differentially methylated CpG sites reached statistical significance. CONCLUSION: Our results suggest a potential role of epigenetics in the mechanisms of the action of NSAIDs. However, the results should be viewed with caution as exploratory and hypothesis-generating given the lack of statistically significant findings.

Bispectral EEG (BSEEG) Algorithm Captures High Mortality Risk Among 1,077 Patients: Its Relationship to Delirium Motor Subtype.

OBJECTIVE: Delirium is dangerous and a predictor of poor patient outcomes. We have previously reported the utility of the bispectral EEG (BSEEG) with a novel algorithm for the detection of delirium and prediction of patient outcomes including mortality. The present study employed a normalized BSEEG (nBSEEG) score to integrate the previous cohorts to combine their data to investigate the prediction of patient outcomes. We also aimed to test if the BSEEG method can be applicable regardless of age, and independent of delirium motor subtypes. METHODS: We calculated nBSEEG score from raw BSEEG data in each cohort and classified patients into BSEEG-positive and BSEEG-negative groups. We used log-rank test and Cox proportional hazards models to predict 90-day and 1-year outcomes for the BSEEG-positive and -negative groups in all subjects and motor subgroups. RESULTS: A total of 1,077 subjects, the BSEEG-positive group showed significantly higher 90-day (hazard ratio 1.33 [95% CI 1.16-1.52] and 1-year (hazard ratio 1.22 [95% CI 1.06-1.40] mortality rates than the negative group after adjustment for covariates such as age, sex, CCI, and delirium status. Among patients with different motor subtypes of delirium, the hypoactive group showed significantly higher 90-day (hazard ratio 1.41 [95% CI 1.12-1.76] and 1-year mortality rates (hazard ratio 1.32 [95% CI 1.05-1.67], which remained significant after adjustment for the same covariates. CONCLUSION: We found that the BSEEG method is capable of capturing patients at high mortality risk.

Anti-inflammatory medication use associated with reduced delirium risk and all-cause mortality: A retrospective cohort study.

OBJECTIVE: To investigate the relationship between history of anti-inflammatory medication use and delirium risk, as well as long-term mortality. METHODS: In this retrospective cohort study, subjects recruited between January 2016 and March 2020 were analyzed. Information about anti-inflammatory medication use history including aspirin, NSAIDs, glucosamine, and other anti-inflammatory drugs, was collected. Logistic regression analysis investigated the relationship between anti-inflammatory medications and delirium. Log-rank analysis and cox proportional hazards model investigated the relationship between anti-inflammatory medications and one-year mortality. RESULTS: The data from 1274 subjects were analyzed. The prevalence of delirium was significantly lower in subjects with NSAIDs usage (23.0%) than in those without NSAIDs usage (35.0%) (p < 0.001). Logistic regression analysis controlling for age, sex, dementia status, and hospitalization department showed that the risk of delirium tended to be reduced by a history of NSAIDs use (OR, 0.76 [95% CI, 0.55 to 1.03]). The one-year mortality in the subjects with NSAIDs (survival rate, 0.879 [95% CI, 0.845 to 0.906]) was significantly lower than in the subjects without NSAIDs (survival rate, 0.776 [95% CI, 0.746 to 0.803]) (p < 0.001). A history of NSAIDs use associated with the decreased risk of one-year mortality even after adjustment for age, sex, Charlson Comorbidity Index, delirium status, and hospitalization department (HR, 0.70 [95% CI, 0.51 to 0.96]). CONCLUSION: This study suggested that NSAIDs usage was associated with decreased delirium prevalence and lower one-year mortality. The potential benefit of NSAIDs on delirium risk and mortality were shown.

Genome-wide DNA methylation analysis of post-operative delirium with brain, blood, saliva, and buccal samples from neurosurgery patients.

OBJECTIVE: No previous study demonstrates the difference in the genome-wide DNA methylation status of post-operative delirium (POD) using human brain tissue obtained from neurosurgery and multiple peripheral tissues such as blood, saliva, and buccal samples from the same individuals. We aimed to identify epigenetic marks of DNA methylation in the brain and peripheral tissues to elucidate the potential pathophysiological mechanism of POD. METHODS: The four tissue types (brain, blood, saliva, buccal) of DNA samples from up to 40 patients, including 11 POD cases, were analyzed using Illumina EPIC array. DNAm differences between patients with and without POD were examined. We also conducted enrichment analysis based on the top DNAm signals. RESULTS: The most different CpG site between control and POD was found at cg16526133 near the ADAMTS9 gene from the brain tissue(p = 8.66E-08). However, there are no CpG sites to reach the genome-wide significant level. The enrichment analysis based on the 1000 top hit CpG site (p < 0.05) on the four tissues showed several intriguing pathways. In the brain, there are pathways including "positive regulation of glial cell differentiation". Blood samples showed also pathways related to immune function. Besides, both saliva and the buccal sample showed pathways related to circadian rhythm, although these findings were not FDR significant. CONCLUSION: Enrichment analysis found several intriguing pathways related to potential delirium pathophysiology. Present data may further support the role of epigenetics, especially DNA methylation, in the molecular mechanisms of delirium pathogenesis.

rTMS Therapy Reduces Hypofrontality in Patients With Depression as Measured by fNIRS.

Multichannel functional near-infrared spectroscopy (fNIRS) is a tool used to capture changes in cerebral blood flow. A consistent result for depression is a decrease in blood flow in the frontal cortex leading to hypofrontality, which indicates multidomain functional impairment. Repetitive transcranial magnetic stimulation (rTMS) and elective convulsive therapy (ECT) are alternatives to antidepressant drugs for the treatment of depression but the underlying mechanism is yet to be elucidated. The aim of the current study was to evaluate cerebral blood flow using fNIRS following rTMS treatment in patients with depression. The cerebral blood flow of 15 patients with moderate depression after rTMS treatment was measured using fNIRS. While there was clear hypofrontality during pre-treatment (5 ± 2.5), a notable increase in oxygenated hemoglobin was observed after 30 sessions with rTMS (50 ± 15). This increased blood flow was observed in a wide range of channels in the frontal cortex; however, the centroid values were similar between the treatments. Increased blood flow leads to the activation of neuronal synapses, as noted with other neuromodulation treatments such as electroconvulsive therapy. This study describes the rTMS-induced modulation of blood oxygenation response over the prefrontal cortex in patients with depression, as captured by fNIRS. Future longitudinal studies are needed to assess cerebral blood flow dynamics during rTMS treatment for depression.

fNIRS Assessment during an Emotional Stroop Task among Patients with Depression: Replication and Extension.

OBJECTIVE: Accumulated evidence collected via functional near-infrared spectroscopy (fNIRS) has been reported with regard to mental disorders. A previous finding revealed that emotional words evoke left frontal cortex activity in patients with depression. The primary aim of the current study was to replicate this finding using an independent dataset and evaluate the brain region associated with the severity of depression using an emotional Stroop task. METHODS: Oxygenized and deoxygenized hemoglobin recording in the brain by fNIRS on 14 MDD patients and 20 normal controls. RESULTS: Hyperactivated oxygenized hemoglobin was observed in the left frontal cortex on exposure to unfavorable stimuli, but no significant difference was found among patients with depression compared with healthy controls on exposure to favorable stimuli. This result is consistent with previous findings. Moreover, an evoked wave associated with the left upper frontal cortex on favorable stimuli was inversely correlated with the severity of depression. CONCLUSION: Our current work using fNIRS provides a potential clue regarding the location of depression symptom severity in the left upper frontal cortex. Future studies should verify our findings and expand them into a precise etiology of depression.

Correlation between frontal lobe oxy-hemoglobin and severity of depression assessed using near-infrared spectroscopy.

INTRODUCTION: The search for objective biomarkers of psychiatric disorders has a long history. Despite this, no universally accepted instruments or methods to detect biomarkers have been developed. One potential exception is near-infrared spectroscopy, although interpreting the measures of blood flow recorded with this technique remains controversial. In this study, we aimed to investigate the relationship between recorded blood flow and depression severity assessed using the Hamilton depression scale in patients with various psychiatric disorders. METHODS: Enrolled patients (n=43) had DSM-IV diagnoses of major depressive disorder (n=25), bipolar disorder I (n=5), schizophrenia (n=3), dysthymic disorder (n=3), psychotic disorder (n=3), panic disorder (n=2), and Obsessive Compulsive Disorder (n=2). The verbal fluency task was administered during blood flow recording from the frontal and temporal lobes. RESULTS: We found that severity of depression was negatively correlated with the integral value of blood flow in the frontal lobe, irrespective of psychiatric diagnosis (F=5.94, p=0.02). DISCUSSION: Our results support blood flow in the frontal lobe as a potential biomarker of depression severity across various psychiatric disorders. LIMITATION: Limited sample size, no replication in the second set.

Microarray Analysis of Human Blood During Electroconvulsive Therapy.

INTRODUCTION: Electroconvulsive therapy (ECT) is currently regarded as a significant treatment option for intractable psychiatric disorders, such as catatonic schizophrenia or treatment-resistant depression; however, the underlying molecular mechanism for its therapeutic effect remains obscure. METHODS: Employing microarray analysis (Human Genome U133 Plus 2.0 Array; Affymetrix, United States) of cDNA derived from the peripheral blood of patients with catatonic schizophrenia (n = 5), we detected a significant change in 145 genes (0.68%) before and after modified ECT (mECT). Moreover, we performed quantitative polymerase chain reaction validation of genes that had previously been suggested to be functionally related to schizophrenia. RESULTS: Of 4 genes examined (AKT3, TCF7, PPP3R1, and GADD45B), only TCF7 was increased during the mECT procedure (P = 0.0025). DISCUSSION: This study describes the first attempt to uncover the molecular mechanism of mECT using a microarray assay of mRNA derived from peripheral blood, and our results suggest that the TCF family may play a role in the functional mechanism of mECT.