Gene Expression Profiling in Human Acute Ischemic Stroke

Background: Gene expression profiling of human acute ischemic stroke (AIS) has the potential to identify a diagnostic panel for differential diagnosis of AIS early in the treatment phase. Purpose: The objective of this dissertation was to identify peripheral blood biomarkers that could be further explored for use in differential diagnosis of AIS and the design of stroke therapeutics.Methods: A prospective gene expression profiling study of 39 patients and 25 healthy controls was conducted. Peripheral blood samples were collected in Paxgene Blood RNA tubes from patients who were ≥18 years of age with MRI diagnosed AIS after differential diagnosis and controls who were Non-stroke neurologically healthy. In stroke patients, blood was redrawn 24 hours following onset of symptoms to determine changes in gene expression profiles over time. RNA was hybridized to Illumina humanRef-8v2 bead chips. Validation was performed using Taqman Gene expression polymerase chain reaction on significant targets. Results: A nine gene profile has been identified for AIS. Five of these nine genes were identified in the previously published whole blood gene expression profiling study of stroke and therefore play a likely role in the response to AIS in humans. One of these nine genes (s100A12) was significantly associated with increasing age and therefore may be non-specific for stroke. Three genes were identified as the whole blood expression profile change over time (LY96, IL8, and SDPR). Pathway analysis revealed a robust innate immune response, with toll like receptor (TLR) signaling as a highly significant pathway present in the peripheral whole blood of AIS patients.Conclusion: The findings of this study support the claim that gene expression profiling of peripheral whole blood can be used to identify diagnostic markers of AIS. A plausible case for innate immunity through the activation of TLR4 as a mediator of response to AIS has been made from the results of this study. This study and those conducted by Moore et al (2005) and Tang et al (2006) provide the foundation of data that support the use of peripheral whole blood for future blood profiling studies of neurological disease; which significantly opens the door of opportunity

Military personnel with chronic symptoms following blast traumatic brain injury have differential expression of neuronal recovery and epidermal growth factor receptor genes

Objective: Approximately one-quarter of military personnel who deployed to combat stations sustained one or more blast-related, closed-head injuries. Blast injuries result from the detonation of an explosive device. The mechanisms associated with blast exposure that give rise to traumatic brain injury (TBI), and place military personnel at high risk for chronic symptoms of post-concussive disorder (PCD), post-traumatic stress disorder (PTSD), and depression are not elucidated. Methods: To investigate the mechanisms of persistent blast-related symptoms, we examined expression profiles of transcripts across the genome to determine the role of gene activity in chronic symptoms following blast-TBI. Active duty military personnel with (1) a medical record of a blast-TBI that occurred during deployment (n = 19) were compared to control participants without TBI (n = 17). Controls were matched to cases on demographic factors including age, gender, and race, and also in diagnoses of sleep disturbance, and symptoms of PTSD and depression. Due to the high number of PCD symptoms in the TBI+ group, we did not match on this variable. Using expression profiles of transcripts in microarray platform in peripheral samples of whole blood, significantly differentially expressed gene lists were generated. Statistical threshold is based on criteria of 1.5 magnitude fold-change (up or down) and p-values with multiple test correction (false discovery rate \u3c0.05). Results: There were 34 transcripts in 29 genes that were differentially regulated in blast-TBI participants compared to controls. Up-regulated genes included epithelial cell transforming sequence and zinc finger proteins, which are necessary for astrocyte differentiation following injury. Tensin-1, which has been implicated in neuronal recovery in pre-clinical TBI models, was down-regulated in blast-TBI participants. Protein ubiquitination genes, such as epidermal growth factor receptor, were also down-regulated and identified as the central regulators in the gene network determined by interaction pathway analysis. Conclusion: In this study, we identified a gene-expression pathway of delayed neuronal recovery in military personnel a blast-TBI and chronic symptoms. Future work is needed to determine if therapeutic agents that regulate these pathways may provide novel treatments for chronic blast-TBI-related symptoms

Monocyte-lymphocyte cross-communication via soluble CD163 directly links innate immune system activation and adaptive immune system suppression following ischemic stroke

CD163 is a scavenger receptor expressed on innate immune cell populations which can be shed from the plasma membrane via the metalloprotease ADAM17 to generate a soluble peptide with lympho-inhibitory properties. The purpose of this study was to investigate CD163 as a possible effector of stroke-induced adaptive immune system suppression. Liquid biopsies were collected from ischemic stroke patients (n = 39), neurologically asymptomatic controls (n = 20), and stroke mimics (n = 20) within 24 hours of symptom onset. Peripheral blood ADAM17 activity and soluble CD163 levels were elevated in stroke patients relative to non-stroke control groups, and negatively associated with post-stroke lymphocyte counts. Subsequent in vitro experiments suggested that this stroke-induced elevation in circulating soluble CD163 likely originates from activated monocytic cells, as serum from stroke patients stimulated ADAM17-dependant CD163 shedding from healthy donor-derived monocytes. Additional in vitro experiments demonstrated that stroke-induced elevations in circulating soluble CD163 can elicit direct suppressive effects on the adaptive immune system, as serum from stroke patients inhibited the proliferation of healthy donor-derived lymphocytes, an effect which was attenuated following serum CD163 depletion. Collectively, these observations provide novel evidence that the innate immune system employs protective mechanisms aimed at mitigating the risk of post-stroke autoimmune complications driven by adaptive immune system overactivation, and that CD163 is key mediator of this phenomenon

The Ohio State University Dream Team: Innovation for Well-being fellowship and coaching program

Abstract Background: Nearly 70% of faculty experience very high levels of stress. Integrative Nurse Coaching (INC) can help by assisting clients in establishing goals and embarking on new lifestyle behaviors that help to decrease perceived stress, achieve work life integration, and enhance life satisfaction. Our goal was to evaluate a faculty coaching and fellowship program to support faculty well-being while developing innovation competency. Methods: We employed an INC paradigm to coach five faculty to build confidence and competence in innovation and enhance well-being. We offered monthly group and individual coaching and used a qualitative research thematic analysis to determine themes important for the fellow and group experiences, identify outcomes, and create recommendations for the future. Results: We identified the following themes as outcomes for our program: (1) enhanced connection, comradery, and support; (2) increased confidence and competence in navigating academia; (3) shift from a fixed mindset to an innovation mindset; and (4) increased ability to identify and manage stress and burnout. Fellows also experienced a shift from focusing on individual needs to addressing the needs of the community at the college. Conclusion: Nurse coaching is an effective strategy to address faculty stress and burnout. Additional research is needed to evaluate the Innovation for Well-being faculty fellowship program and its impact on the academic community

Machine-Learning Approach Identifies a Pattern of Gene Expression in Peripheral Blood that can Accurately Detect Ischaemic Stroke

Early and accurate diagnosis of stroke improves the probability of positive outcome. The objective of this study was to identify a pattern of gene expression in peripheral blood that could potentially be optimised to expedite the diagnosis of acute ischaemic stroke (AIS). A discovery cohort was recruited consisting of 39 AIS patients and 24 neurologically asymptomatic controls. Peripheral blood was sampled at emergency department admission, and genome-wide expression profiling was performed via microarray. A machine-learning technique known as genetic algorithm k-nearest neighbours (GA/kNN) was then used to identify a pattern of gene expression that could optimally discriminate between groups. This pattern of expression was then assessed via qRT-PCR in an independent validation cohort, where it was evaluated for its ability to discriminate between an additional 39 AIS patients and 30 neurologically asymptomatic controls, as well as 20 acute stroke mimics. GA/kNN identified 10 genes (ANTXR2, STK3, PDK4, CD163, MAL, GRAP, ID3, CTSZ, KIF1B and PLXDC2) whose coordinate pattern of expression was able to identify 98.4% of discovery cohort subjects correctly (97.4% sensitive, 100% specific). In the validation cohort, the expression levels of the same 10 genes were able to identify 95.6% of subjects correctly when comparing AIS patients to asymptomatic controls (92.3% sensitive, 100% specific), and 94.9% of subjects correctly when comparing AIS patients with stroke mimics (97.4% sensitive, 90.0% specific). The transcriptional pattern identified in this study shows strong diagnostic potential, and warrants further evaluation to determine its true clinical efficacy

Syndactyly in Pigs: A Review of Previous Research and the Presentation of Eight Archaeological Specimens

This paper reviews evidence for the rare condition of porcine syndactyly. It describes eight archaeological examples from Britain, Northern Ireland and France. Syndactyly refers to the partial or complete fusion of two or more adjacent phalanges on the medio-lateral border. The degree and character of fusion are variable, but phalanges frequently unite to create a single skeletal element. This condition has been identified by veterinarians, zoologists and naturalists in individuals and populations in a range of species, but in spite of substantial research on the condition in humans and to a lesser extent cattle, it remains relatively poorly understood in other mammals. Syndactyly is generally agreed to be primarily congenital in origin, although factors affecting its incidence remain far from fully understood. In light of the general paucity of discussion of specific conditions of animal palaeopathology, this paper presents an analysis of these newly discovered syndactyle pig specimens, offers a review of research with particular reference to pigs and discusses the etiology of the condition

Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes

AbstractObjectiveWe sought to assess whether genetic risk factors for atrial fibrillation can explain cardioembolic stroke risk.MethodsWe evaluated genetic correlations between a prior genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously-validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors.ResultsWe observed strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson’s r=0.77 and 0.76, respectively, across SNPs with p &lt; 4.4 × 10−4 in the prior AF meta-analysis). An AF PRS, adjusted for clinical AF risk factors, was associated with cardioembolic stroke (odds ratio (OR) per standard deviation (sd) = 1.40, p = 1.45×10−48), explaining ∼20% of the heritable component of cardioembolic stroke risk. The AF PRS was also associated with stroke of undetermined cause (OR per sd = 1.07, p = 0.004), but no other primary stroke subtypes (all p &gt; 0.1).ConclusionsGenetic risk for AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.</jats:sec

Stroke-associated pattern of gene expression previously identified by machine-learning is diagnostically robust in an independent patient population

Our group recently employed genome-wide transcriptional profiling in tandem with machine-learning based analysis to identify a ten-gene pattern of differential expression in peripheral blood which may have utility for detection of stroke. The objective of this study was to assess the diagnostic capacity and temporal stability of this stroke-associated transcriptional signature in an independent patient population. Publicly available whole blood microarray data generated from 23 ischemic stroke patients at 3, 5, and 24 h post-symptom onset, as well from 23 cardiovascular disease controls, were obtained via the National Center for Biotechnology Information Gene Expression Omnibus. Expression levels of the ten candidate genes (ANTXR2, STK3, PDK4, CD163, MAL, GRAP, ID3, CTSZ, KIF1B, and PLXDC2) were extracted, compared between groups, and evaluated for their dis- criminatory ability at each time point. We observed a largely identical pattern of differential expression between stroke patients and controls across the ten candidate genes as reported in our prior work. Furthermore, the coordinate expression levels of the ten candidate genes were able to discriminate between stroke patients and controls with levels of sensitivity and specificity upwards of 90% across all three time points. These findings confirm the diagnostic robustness of the previously identified pattern of differential expression in an in- dependent patient population, and further suggest that it is temporally stable over the first 24 h of stroke pa- thology

Rapid mitochondrial dysfunction mediates TNF-alpha-induced neurotoxicity

Tumor necrosis factor alpha (TNF-α) is known to exacerbate ischemic brain injury; however, the mechanism is unknown. Previous studies have evaluated the effects of TNF-α on neurons with long exposures to high doses of TNF-α, which is not pathophysiologically relevant. We characterized the rapid effects of TNF-α on basal respiration, ATP production, and maximal respiration using pathophysiologically relevant, post-stroke concentrations of TNF-α. We observed a reduction in mitochondrial function as early as 1.5 h after exposure to low doses of TNF-α, followed by a decrease in cell viability in HT-22 cells and primary neurons. Subsequently, we used the HT-22 cell line to determine the mechanism by which TNF-α causes a rapid and profound reduction in mitochondrial function. Pre-treating with TNF-R1 antibody, but not TNF-R2 antibody, ameliorated the neurotoxic effects of TNF-α, indicating that TNF-α exerts its neurotoxic effects through TNF-R1. We observed an increase in caspase 8 activity and a decrease in mitochondrial membrane potential after exposure to TNF-α which resulted in a release of cytochrome c from the mitochondria into the cytosol. These novel findings indicate for the first time that an acute exposure to pathophysiologically relevant concentrations of TNF-α has neurotoxic effects mediated by a rapid impairment of mitochondrial function

Nursing genetics and genomics: The International Society of Nurses in Genetics (ISONG) survey

Background: The International Society of Nursing in Genetics (ISONG) fosters scienti fi c and professional de- velopment in the discovery, interpretation, and application of genomic information in nursing research, edu- cation, and clinical practice. Objectives: Assess genomic-related activities of ISONG members in research, education and practice, and com- petencies to serve as global leaders in genomics. Design: Cross-sectional survey (21-items) assessing genomic-related training, knowledge, and practice. Settings: An email invitation included a link to the anonymous online survey. Participants: All ISONG members ( n = 350 globally) were invited to partake. Methods: Descriptive statistics and Wilcoxon Rank Sum Test for between-group comparisons. Results: Respondents ( n = 231, 66%), were mostly Caucasian, female, with a master's degree or higher. Approximately 70% wanted to incorporate genomics in research, teaching, and practice. More than half reported high genomic competency, and over 95% reported that genomics is relevant the next 5 years. Conclusions: Findings provide a foundation for developing additional educational programs for an international nursing workforce in genomic