Project description:Delirium is a common postoperative complication among older patients with many adverse outcomes. Due to lack of validated biomarkers, prediction and monitoring of delirium by biological testing is not currently feasible. Circulating proteins in cerebrospinal fluid (CSF) may reflect biological processes causing delirium. Our goal was to discover and investigate candidate protein biomarkers in preoperative CSF that were associated with development of postoperative delirium in older surgical patients. We employed a nested case–control study design coupled with high multiplex affinity proteomics analysis to measure 1305 proteins in preoperative CSF. Twenty-four matched delirium cases and non-delirium controls were selected from the Healthier Postoperative Recovery (HiPOR) cohort and the associations between preoperative protein levels and postoperative delirium were assessed using t-test statistics with further analysis by systems biology to elucidate delirium pathophysiology. Proteomics analysis identified 32 proteins in preoperative CSF that significantly associate with delirium (t-test p<0.05). Due to the limited sample size these proteins did not remain significant by multiple hypothesis testing using the Benjamini-Hochberg correction and q-value method. Three algorithms were applied to separate delirium cases from non-delirium controls. Hierarchical clustering classified 40/48 case-control samples correctly, principal components analysis separated 43/48. The receiver operating characteristic curve yielded an area under the curve [95% confidence interval] of 0.91 [0.80-0.97]. Systems biology analysis identified several key pathways associated with risk of delirium: inflammation, immune cell migration, apoptosis, angiogenesis, synaptic depression and neuronal cell death. Proteomics analysis of preoperative CSF identifies 32 proteins that might discriminate individuals who subsequently develop postoperative delirium from matched control samples. These proteins are potential candidate biomarkers for delirium and may play a role in its pathophysiology.
Project description:Postoperative delirium (POD) is a common postoperative complication in elderly patients. The exact mechanism of POD is still unclear. In order to reveal the effect of CircRNA on POD, We analyzed the differential expression profile of circRNAs by microarray technique in hippocampus of 12-month-old mice between tibial fracture and control group.
Project description:Delirium is a common serious complication that often occurs after major surgery. However, there is little known about the function of long non-coding RNAs (lncRNAs) in postoperative delirium (POD). The goals of this study were to explore the expression profiles and functional networks of lncRNAs and mRNAs in patients of POD.
Project description:Delirium is a common yet underdiagnosed condition in elderly hospitalized patients. The lack of effective diagnostic and therapeutic methods can be attributed to the limited understanding of its pathophysiology. Delirium has recently been reported to be linked to neuroinflammation and epigenetic changes. The aim of this study was to validate the pathways in a larger cohort with a uniform type of surgery, while rigorously adjusting for potential covariates. This study primarily investigated DNA methylation (DNAm) changes before and after surgery in postoperative delirium (POD) among older adults having undergone femoral fracture surgery. After propensity analysis, 65 subjects were divided into 2 subgroups; one consisted of subjects who had blood samples collected preoperatively and on postoperative day 0, and the other consisted of those who had samples collected preoperatively and on postoperative day 3. We performed differential methylation analysis and enrichment analysis on each subgroup. Enrichment analysis using CpGs that exhibited substantial DNAm changes between pre- and postoperative day 0 samples in POD cases showed inflammation- and immunity-related pathways such as "leukocyte mediated immunity" and "NF-kappa B signaling pathway." Inflammation- and immunity-related pathways became less noticeable between pre- and postoperative day 3 samples. Inflammation- and immunity-related pathways showed in this study align with previous studies across diverse populations, reinforcing the role of inflammation- and immunity-related epigenetic mechanisms in delirium including POD. Notably, these DNAm changes were potentially transient, corresponding to the typical onset of delirium, suggesting their potential as biomarkers for early diagnosis.
Project description:This dataset is part of the European BioCog project (EU602461) and comprises perioperative plasma samples from elderly patients (≥65 years) undergoing elective surgery. Proteomic profiling was conducted in a matched case-control design to investigate molecular mechanisms of postoperative delirium (POD). Samples were collected preoperatively (T0) and on postoperative day 1 (T1).
Project description:Postoperative delirium, is a notable and serious complication after surgery, commonly extending hospitalization by 2-3 days. In a cohort of 167 patients, elevated serum intestinal fatty acid binding protein (I-FABP) was identified as an independent risk factor for postoperative delirium. Complementary experiments conducted in murine models demonstrated that intestinal ischemia-reperfusion injury induced behaviors analogous to delirium, accompanied by disruption of the intestinal barrier and gut dysbiosis predominantly characterized by Enterobacteriaceae overgrowth. Fecal microbiota transplantation from healthy donors effectively restored the microbial homeostasis, improved cognitive performance, and preserved hippocampal synaptic integrity. Multiomics analyses further revealed that microbiome dysbiosis triggered intestinal expression of indoleamine-2,3-dioxygenase 1 (IDO1), leading to systemic accumulation of L-kynurenine. This accumulation activated microglia, leading to aberrant synaptic phagocytosis and consequent cognitive decline.