Project description:Background. Women account for 60% of all stroke deaths and are more often permanently disabled than men, despite their higher observed stroke incidence. Considering the clinical population affected by stroke, an obvious drawback is that many pre-clinical and clinical studies only investigate young males. To improve therapeutic translation from bench to bedside, we believe that it is advantageous to include both sexes in experimental models of stroke. The aims of this study were to identify early cerebral vascular responses to ischemic stroke in females, compare the differential gene expression patterns with those seen in males, and identify potential new therapeutic targets. Results. Transient middle cerebral artery occlusion (tMCAO) was used to induce stroke in both female and male rats, the middle cerebral arteries (MCAs) were isolated 3 hours post reperfusion and RNA was extracted. Affymetrix whole transcriptome expression profiling was performed on female (n = 12) MCAs to reveal differentially expressed genes. In total, 1076 genes had an increased expression and 879 genes a decreased expression in the occluded MCAs as compared with the control MCAs from female rats. An enrichment of genes related to apoptosis, regulation of transcription, protein autophosphorylation, inflammation, oxidative stress, and tissue repair and recovery were seen in the occluded MCA. The high expression genes chosen for qPCR verification (Adamts4, Olr1, JunB, Fosl1, Serpine1, S1pr3, Ccl2 and Socs3) were all shown to be upregulated in the same manner in both females and males after tMCAO (p < 0.05; n = 23). When comparing the differentially expressed genes in female MCAs (occluded and non-occluded) with our previous findings in males after tMCAO, a total of 297 genes overlapped (all groups had 32 genes in common). Conclusions. The cascades of processes initiated in the vasculature following reperfusion are complex. Dynamic gene expression alterations were observed in the occluded MCAs, and to a less pronounced degree in the non-occluded MCAs. Dysregulation of inflammation and blood-brain barrier breakdown are possible pharmacological targets. The sample of genes (<1% of differentially expressed genes) validated for this microarray did not reveal any sex differences.
Project description:The purpose of this project was to elucidate gene expression in the peripheral whole blood of acute ischemic stroke patients to identify a panel of genes for the diagnosis of acute ischemic stroke. Peripheral blood samples were collected in Paxgene Blood RNA tubes from stroke patients who were >18 years of age with MRI diagnosed ischemic stroke and controls who were non-stroke neurologically healthy. The results suggest a panel of genes can be used to diagnose ischemic stroke, and provide information about the biological pathways involved in the response to acute ischemic stroke in humans. Total RNA extracted from whole blood in n=39 ischemic stroke patients compared to n=24 healthy control subjects.
Project description:The purpose of this project was to elucidate gene expression in the peripheral whole blood of acute ischemic stroke patients to identify a panel of genes for the diagnosis of acute ischemic stroke. Peripheral blood samples were collected in Paxgene Blood RNA tubes from stroke patients who were >18 years of age with MRI diagnosed ischemic stroke and controls who were non-stroke neurologically healthy. The results suggest a panel of genes can be used to diagnose ischemic stroke, and provide information about the biological pathways involved in the response to acute ischemic stroke in humans.
Project description:Cerebral ischemia and aging induce local and systemic effects, and impact severity of stroke outcome. We performed comprehensive metabolic profiling to detect metabolites in brain, plasma, and liver as a function of aging and ischemia/reperfusion (IR). Ischemic stroke was induced by middle cerebral artery occlusion. Abundant metabolites were identified and quantified by 1H-NMR. Older rats aged 12 months showed significant changes in metabolic profiles in the brain, but only a few metabolites were changed in the liver and plasma as compared to younger rats aged 3 months. However, I/R injury at day 2 resulted in major changes in metabolites in liver and plasma of older rats. In younger rats, focal cerebral ischemia induced reperfusion-time dependent changes in metabolites in brain, plasma, and liver. Metabolic changes were seen in brain as early as day 2 of I/R, plasma showed significant changes at day 3 of reperfusion, and liver exhibited delayed response after day 3 that continued to remain at week 2 of reperfusion-time. Pathways involved in energy and amino acid metabolism, inflammation, and oxidative stress were altered as a result of aging and I/R. Thus, age, tissue, and I/R time affect changes in metabolites and may have implications in stroke outcome.
Project description:Sleep deprivation (SD) performed before stroke induces an ischemic tolerance state as observed in other forms of preconditioning. As the mechanisms underlying this effect are not well understood we used DNA oligonucleotide microarray analysis, to identify the genes and the gene-pathways underlying SD preconditioning. Gene expression was analyzed 3 days after stroke surgery in four experimental groups: i) SD performed before focal cerebral ischemia induction; ii) SD performed before Sham surgery; iii) IS without SD; and iv) Sham surgery without SD. SD was performed by gentle handling during the last 6h of the light period and ischemia was induced immediately after. Stroke induced a massive alteration in gene expression both in sleep deprived and non-sleep deprived animals. However, compared to animals that underwent ischemia alone, SD induced a general reduction in transcriptional changes with a reduction in the upregulation of genes involved in cell cycle regulation and immune response. Moreover an upregulation of a new neuroendocrine pathway which included melanin concentrating hormone, glycoprotein hormones-M-kM-1-polypeptide and hypocretin was observed exclusively in rats sleep deprived before stroke. Our data indicate that SD before stroke reprogrammed the signaling response to injury. The inhibition of cell cycle regulation and inflammation are neuroprotective mechanisms reported also for other forms of preconditioning treatment whereas the implication of the neuroendocrine function is novel and has never been described before. These results therefore provide new insights into neuroprotective mechanisms involved in ischemic tolerance mechanisms.
Project description:Many hospitals lack facilities for accurate diagnosis of acute ischemic stroke (AIS). Circular RNA (circRNA) is highly expressed in the brain and is closely associated with stroke. In this study, we examined whether the blood-borne circRNAs can be promising candidates as adjunctive diagnostic biomarkers and their pathophysiological roles after stroke. We profiled the blood circRNA expression in mice subjected to experimental focal cerebral ischemia, and validated the selected circRNAs in AIS patients. We demonstrated that 128, 198 and 789 circRNAs were significantly altered at 5 min, 3 h and 24 h after ischemic stroke, respectively.
Project description:Stroke is a leading cause of mortality and long-term disability and ischemic stroke accounts for 87% of all strokes. Though timely recanalization of the occluded vessel is essential in the treatment of ischemic stroke, it is well known to cause ischemia-reperfusion (I/R) injury which result in neuronal cell death, brain tissue loss and severe neurological deficits. In this work, we employed a global proteomic approach to examine the changes of cerebral cortex proteins in rats undergoing acute and long-term I/R injury. In vivo middle cerebral artery occlusion (MCAO) model of focal cerebral I/R injury in rats was established. The animals were divided into three model groups with 2 h-MCAO followed with different reperfusion time, 1 day, 7 days and 14 days, respectively. For each model group a sham group was correspondingly set. Each group included four animals. For proteomic analysis, cerebral cortex proteins were extracted and analyzed by SDS-PAGE, whole-lane slicing, in-gel digestion and label-free quantitative LC-MS/MS. A total of 5621 proteins were identified and their quantities between the surgery and corresponding sham groups and across the three reperfusion time points were compared for mechanism investigation. This dataset includes all the raw files of the 840 LC-MS runs (6 groups x 4 animals x 35 gel squares/sample), as well as their identification and quantitation results at the levels of peptide fragments, peptides and proteins, respectively.
Project description:Blood monocytes/macrophages infiltrate the brain after ischemic stroke and critically influence brain injury and regeneration. We investigated stroke-induced transcriptomic changes of monocytes/macrophages by RNA sequencing profiling, using a mouse model of permanent focal cerebral ischemia. Compared to non-ischemic conditions, brain ischemia induced only moderate genomic changes in blood monocytes, but triggered robust genomic reprogramming in monocytes/macrophages invading the brain. Surprisingly, functional enrichment analysis of the transcriptome of brain macrophages revealed significant overrepresentation of biological processes linked to neurovascular remodeling, such as angiogenesis and axonal regeneration, as early as 5 days after stroke, suggesting a previously underappreciated role for macrophages in initiating post-stroke brain repair. Upstream Regulator analysis predicted peroxisome proliferator-activated receptor gamma (PPARγ) as a master regulator driving the transcriptional reprogramming in post-stroke brain macrophages. Importantly, myeloid cell-specific PPARγ knockout (mKO) mice demonstrated lower post-stroke angiogenesis and neurogenesis than wild-type mice, which correlated significantly with the exacerbation of post-stroke neurological deficits in mKO mice. Collectively, our findings reveal a novel repair-enhancing transcriptome in brain macrophages during post-stroke neurovascular remodeling. As a master switch controlling genomic reprogramming, PPARγ is a rational therapeutic target for promoting and maintaining beneficial macrophage functions, facilitating neurorestoration, and improving long-term functional recovery after ischemic stroke.
Project description:Large clinical studies have shown that AT1 receptor blockers (ARBs) reduce the incidence of stroke in patients at risk. However, there is controversy about the underlying pathomechanisms. To get a closer insight into the effects of ARBs in stroke on molecular level, gene expression pattern was compared in the ischemic brain areas of Candesartan pre-treated (0,2 mg/kg bwt., 5 days, s.c.) versus vehicle treated, normotensive, adult rats after middle carotid artery occlusion (MCAO). Candesartan significantly improved neurological outcome (as estimated by Garcia-scale) 24 h and 48 h after stroke and reduced infarct volume by about 40% compared to vehicle. Keywords: disease state analysis
Project description:We performed a genome-wide methylation study in whole-blood DNA from 404 ischemic stroke patient cohort, distributed across 3 ischemic stroke subtypes: Large-artery atherosclerosis (n=132), Small-artery disease (n=141) and Cardio embolic (n=127) . Illumina HumanMethylation450 BeadChip array was used to measure DNA methylation in CpG sites. We performed a genome-wide methylation study in whole-blood DNA from 185 ischemic stroke patient cohort. Illumina HumanMethylation450 BeadChip array was used to measure DNA methylation in CpG sites.