Project description:Treatments that stimulate neuronal excitability enhance motor performance after stroke.cAMP-response-element binding protein (CREB) is a transcription factor that plays a key rolein neuronal excitability. Increasing the levels of CREB with a viral vector in a small pool ofmotor neurons enhances motor recovery after stroke, while blocking CREB signaling preventsstroke recovery. Silencing CREB-transfected neurons in the peri-infarct region with thehM4di-DREADD blocks motor recovery. Reversing this inhibition allows recovery to continue,demonstrating that it is possible to turn off and on stroke recovery by manipulating theactivity of CREB-transfected neurons. CREB transfection enhances re-mapping of injuredsomatosensory and motor circuits, and induces the formation of new connections withinthese circuits. CREB is a central molecular node in the circuit responses after stroke that leadto recovery from motor deficits.
Project description:In response to cortical stroke and unilateral corticospinal tract degeneration, compensatory sprouting of spared corticospinal fibers is associated with recovery of skilled movement in rodents. To date, little is known about the molecular mechanisms orchestrating this spontaneous rewiring. In this study, we provide insights into the molecular changes in the spinal cord tissue after large ischemic cortical injury in adult female mice, with a focus on factors that might influence the re-innervation process by contralesional corticospinal neurons. We mapped the area of cervical grey matter re-innervation by sprouting contralesional corticospinal axons after unilateral photothrombotic stroke of the motor cortex in mice using anterograde tracing. The mRNA profile of this re-innervation area was analyzed using whole-genome sequencing to identify differentially expressed genes at selected time points during the recovery process. Bioinformatic analysis revealed two phases of processes: Early after stroke (4-7 days post injury), the spinal transcriptome is characterized by inflammatory processes, including phagocytic processes as well as complement cascade activation. Microglia are specifically activated in the denervated corticospinal projection fields in this early phase. In a later phase (28-42 days post injury), biological processes include tissue repair pathways with up-regulated genes related to neurite outgrowth. Thus, the stroke-denervated spinal grey matter, in particular its intermediate laminae, represents a growth-promoting environment for sprouting corticospinal fibers originating from the contralesional motor cortex. This data set provides a solid starting point for future studies addressing key elements of the post-stroke recovery process, with the goal to improve neuroregenerative treatment options for stroke patients.
Project description:Treatments that stimulate neuronal excitability enhance motor performance after stroke. cAMP-response-element binding protein (CREB) is a transcription factor that plays a key role in neuronal excitability. Increasing the levels of CREB with a viral vector in a small pool of motor neurons enhances motor recovery after stroke, while blocking CREB signaling prevents stroke recovery. Silencing CREB-transfected neurons in the peri-infarct region with the hM4Di-DREADD blocks motor recovery. Reversing this inhibition allows recovery to continue, demonstrating that by manipulating the activity of CREB-transfected neurons it is possible to turn off and on stroke recovery. CREB transfection enhances remapping of injured somatosensory and motor circuits, and induces the formation of new connections within these circuits. CREB is a central molecular node in the circuit responses after stroke that lead to recovery from motor deficits.
Project description:Stroke causes death of brain tissue leading to long-term deficits. Behavioral evidence from neurorehabilitative therapies suggest learning-induced neuroplasticity can lead to beneficial outcomes. However, molecular and cellular mechanisms that link learning and stroke recovery are unknown. We show that in mouse models of stroke, with enhanced recovery of function from genetic perturbations of learning and memory genes, express activity-dependent transcriptional programs that are normally active during formation or storage of new memories. The expression of neuronal activity-dependent genes are predictive of recovery and occupy a molecular latent space unique to motor recovery. With motor recovery, networks of activity-dependent genes are co-expressed with their transcription factor targets forming gene regulatory networks that support activity-dependent transcription, that are normally diminished after stroke. Neuronal activity-dependent changes at the circuit level are influenced by interactions with microglia. At the molecular level, we show that enrichment of activity-dependent programs in neurons lead to transcriptional changes in microglia where they differentially interact to support intercellular signaling pathways for axon guidance, growth and synaptogenesis. Together, these studies identify activity-dependent transcriptional programs as a fundamental mechanism for neural repair post-stroke.
Project description:It has been unclear whether ischemic stroke induces neurogenesis or neuronal DNA-rearrangements in the human neocortex. We show here that neither is the case, using immunohistochemistry, transcriptome-, genome- and ploidy-analyses, and determination of nuclear bomb test-derived 14C-concentration in neuronal DNA. A large proportion of cortical neurons display DNA-fragmentation and DNA-repair short time after stroke, whereas neurons at chronic stages after stroke show DNA-integrity, demonstrating the relevance of an intact genome for survival. Analyze of potential fusion transcripts in 13 samples, seven cortical ischemic stroke tissue and six control cortex, by deep sequencing using Illumina HiSeq 2000
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:High salt diet-induced functional adaptions in bone marrow progenitor cells, which subsequently reduced monocyte-derived macrophage reparative phenotype and impeded stroke recovery
Project description:This transcriptomic study investigates the effect of therapeutic short-chain fatty acids (SCFA) administration on post-stroke recovery.
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.