Project description:Few have characterized miRNA expression during the transition from injury to neural repair and secondary neurodegeneration following stroke in humans. We compared expression of 754 miRNAs from plasma samples collected 5, 15, and 30 days post-ischemic stroke from a discovery cohort (n=55) and 15-days post-ischemic stroke from a validation cohort (n=48) to healthy control samples (n=55 and 48 respectively) matched for age, sex, race and cardiovascular comorbidities using qRT-PCR. Eight miRNAs remained significantly altered across all time points in both cohorts including many described in acute stroke. The number of significantly dysregulated miRNAs more than doubled from post-stroke day 5 (19 miRNAs) to days 15 (50 miRNAs) and 30 (57 miRNAs). Twelve brain-enriched miRNAs were significantly altered at one or more time points (decreased expression, stroke versus controls: miR-107; increased expression: miR-99-5p, miR-127-3p, miR-128-3p, miR-181a-3p, miR-181a-5p, miR-382-5p, miR-433-3p, miR-491-5p, miR-495-3p, miR-874-3p, and miR-941). Many brain-enriched miRNAs were associated with apoptosis over the first month post-stroke whereas other miRNAs suggested a transition to synapse regulation and neuronal protection by day 30. These findings suggest that a program of decreased cellular proliferation may last at least 30 days post-stroke, and points to specific miRNAs that could contribute to neural repair in humans.
Project description:Few have characterized miRNA expression during the transition from injury to neural repair and secondary neurodegeneration following stroke in humans. We compared expression of 754 miRNAs from plasma samples collected 5, 15, and 30 days post-ischemic stroke from a discovery cohort (n = 55) and 15-days post-ischemic stroke from a validation cohort (n = 48) to healthy control samples (n = 55 and 48 respectively) matched for age, sex, race and cardiovascular comorbidities using qRT-PCR. Eight miRNAs remained significantly altered across all time points in both cohorts including many described in acute stroke. The number of significantly dysregulated miRNAs more than doubled from post-stroke day 5 (19 miRNAs) to days 15 (50 miRNAs) and 30 (57 miRNAs). Twelve brain-enriched miRNAs were significantly altered at one or more time points (decreased expression, stroke versus controls: miR-107; increased expression: miR-99-5p, miR-127-3p, miR-128-3p, miR-181a-3p, miR-181a-5p, miR-382-5p, miR-433-3p, miR-491-5p, miR-495-3p, miR-874-3p, and miR-941). Many brain-enriched miRNAs were associated with apoptosis over the first month post-stroke whereas other miRNAs suggested a transition to synapse regulation and neuronal protection by day 30. These findings suggest that a program of decreased cellular proliferation may last at least 30 days post-stroke, and points to specific miRNAs that could contribute to neural repair in humans.
Project description:Stroke is a prevalent disorder representing the third leading cause of death and major cause of disability. Post-stroke epilepsy (PSE) has been recognized as a common clinical issue after stroke, accounting for 30-40% of the causes of epilepsy among older adults. In this study, we determined GABAA receptor-mediated seizure susceptibility after PT cerebral stroke in aged mice. Young adult mice around 10 weeks of age are widely used in stroke experiments. However, as most strokes are diagnosed in the elderly and PSE has been recognized as a common clinical incidence after stroke, we utilized photothrombosis (PT) model of cerebral ischemia and examined seizure susceptibility and brain injury using combined behavioral (video) and EEG monitoring and histological (MRI) assessments. To investigate GABAA receptor-mediated convulsive/non-convulsive seizures, lower-doses of pentylenetetrazol (PTZ) was injected. PTZ susceptibility in aging mice increased compared to young adults. One month after PT stroke, aged PT stroke mice exhibited severe convulsive seizures (late-onset). These findings exhibited the increase of GABAA receptor-mediated seizures susceptibility in PT stroke aging mice, but not in young adults.
Project description:To date, miRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models. In this study presented here, Middle Cerebral Artery Occlusion stroke model was established by using embolus and the brain samples of stroke model were harvested at 0hrs, 3hrs, 6hrs, 12hrs, 24hrs, 48hrs, 72hrs, 120hrs and 168hrs. RNAs were extracted from these samples and microRNA array and mRNA array were performed.
Project description:To date, miRNA and mRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models. In this study presented here, Middle Cerebral Artery Occlusion stroke model was established by using embolus and the brain samples of stroke model were harvestd at 0hrs, 3hrs, 6hrs, 12hrs, 24hrs, 48hrs, 72hrs, 120hrs and 168hrs. RNAs were extracted from these samples and microRNA array and mRNA array were performed.
Project description:Aim of the present study is to identify all circulating miRNAs that are modulated in patients with stroke, to select specific miRNAs to be used as disease biomarkers to improve both diagnosis and prognosis. Background. Stroke is the second-most common cause of death worldwide. The major factor limiting prognosis in patients affected by acute stroke is the very limited therapeutic window, so that most patients are not able receive the most successful treatments because of delays in diagnosis and to differentiate between ischemic and hemorrhagic etiology. Circulating levels of selected microRNAs (miRNAs) were found to be modulated both in animal experimental models and in patients with stroke, opening up new avenues for the identification of more effective and specific biomarkers to identify and risk-stratify stroke patients. Study aim. Aim of the present study is to identify all circulating miRNAs that are modulated in patients with stroke, to select specific miRNAs to be used as disease biomarkers to improve both diagnosis and prognosis. Methods. RNA was extracted from plasma samples using a commercial RNA extraction kit and quality of extracted material was assessed using a fluorometric electrophoretic assay (Agilent 4200 TapeStation, Santa Clara, CA, USA). MiRNA profiling was performed using the Affymetrix platform using GeneChip 4.0 (Thermo Fischer Scientific, Waltham, MA, USA). RT-PCR was performed using the Taqman protocol. MiRNA were chosen among those with the most relevant modulation between the groups. Results. Among the circulating miRNAs that were most down-regulated in stroke patients, we identified miR-3135b (20-fold, p<0.001), associated with vascular calcifications and heart failure; miR-1275 (18-fold, p=0.028), involved in cardiovascular atherosclerotic diseases and a sponge for circMAN2B2 in cancer; miR-4467 (13-fold, p=0.003), modulated in neurodegenerative diseases; and miR-7170 (7-fold, p<0.001). Among the circulating miRNAs that were most up-regulated in stroke patients, we identified miR-18a (35-fold, p=0.004), associated with stroke in the Framingham Cohort; the platelet-enriched miR-22-5p (24-fold, p=0.004), that is modulated in Huntington Disease; miR-199a (11-fold, p=0.012), a marker of brain microvascular injury and of stroke severity in rats, and miR-106b (10-fold, p=0.009), a regulator of neural stem-cell proliferation/differentiation whose level are modulated in patients with neurodegenerative diseases. Conclusions. Our results identified several circulating miRNAs that are down- of up-regulated in stroke patients. Among those with the most relevant differential expression, several miRNAs were identified that are known to play a role in the pathophysiology of neurovascular diseases, paving the way to a new class of smart pathophysiology-based biomarkers in stroke.
Project description:In order to determine the serum microRNAs profile from middle-old aged patients with acute ischemic stroke and investigate possible diagnostic value of these differential microRNAs.The blood samples of 117 IS patients and 82 healthy people were collected. Differential miRNAs in serum from IS and control were screened with miRNA microarray analysis, and the expression of selected miRNAs were validated by quantitative reverse-transcriptase polymerase chain reaction assays (qRT-PCR). Results: We discovered 115 differentially expressed miRNAs, among which miR-32-3p, miR-106-5p, miR-532-5p were found be related to IS for the first time. Conclusions: In the present study, we identified the changed expression pattern of miRNAs in IS. Serum miR-32-3p, miR-106-5p, miR-1246 and miR-532-5p may serve as potential diagnostic biomarkers for IS. During the initial screening stage, we divided the serum samples into five groups (10 serum samples were pooled to form a group). Group A1: A denotes thrombotic stroke and 1 denotes hepertension. Group A14: A denotes thrombotic stroke, 1 denotes hepertension and 4 denotes hyperlipidemia. Group B2: B denotes embolic stroke and 2 denotes heart disease. Group B12: B denotes embolic stroke, 1 denotes hepertension and 2 denotes heart disease. Group 0: healthy control group.
Project description:We sought to identify alterations in the quantity of plasma brain-derived extracellular vesicles (EV) over the first month post-stroke to shed light on related injury and repair mechanisms. We assessed plasma levels of presumed neuron-derived EVs (NDEs), astrocyte-derived EVs (ADEs), and oligodendrocyte-derived EVs (ODEs) in 58 patients 5, 15, and 30 days post-ischemic stroke and 46 controls matched for cardiovascular risk factors using sandwich immunoassays. Subsets of brain-derived EVs were identified by co-expression of the general EV marker CD9 and markers for neurons (L1CAM, CD171), astrocytes (EAAT1), and oligodendrocytes (MOG) respectively. Clinical MRIs assessed lesion volume and presence of hemorrhagic transformation. ADE levels were elevated 5, 15, and 30 days post-stroke compared to controls (p = 0.002, p = 0.002, and p = 0.005 respectively) with no significant change for NDE or ODE. ADEs were increased 15 days post-stroke in patients with hemorrhagic transformation (p = 0.04) compared to patients with no hemorrhage. We conclude that ADE levels are preferentially increased over the first month post-stroke in humans, possibly to provide trophic support to injured neurons following ischemia. ADEs hold potential as biomarkers of blood-brain barrier breakdown and hemorrhagic transformation, but this requires further study at earlier time points post-stroke.
Project description:To date, miRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models.
Project description:To date, miRNA and mRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models.