Gene expression profiles in the spinal cord below the lesion level and influence of treadmill locomotor training
ABSTRACT: Traumatic spinal cord injury (SCI) often leads to loss of locomotor function. Neuroplasticity of spinal circuitry underlies some functional recovery and therefore represents a therapeutic target to improve locomotor function following SCI. However, the cellular and molecular mechanisms mediating neuroplasticity below the lesion level are not fully understood. The present study performed a gene expression profiling in the rat lumbar spinal cord at 1 and 3 weeks after contusive SCI at T9. The below-level gene expression profiles were compared with those of animals that were subjected to treadmill locomotor training. Rat lumbar spinal cords were taken for the microarray analysis at 1 and 3 weeks after contusive spinal cord injury at the T9 level. Another group of rats received treadmill locomotor training for 3 weeks, and theirs spinal cords were harvested for the microarray. The changes in gene expression after spinal cord injury were analyzed at the two time points. The influence of treadmill locomotor training was evaluated by comparing gene expression profiles between animals with or without treadmill training.
Project description:Spinal cord injury (SCI) is one of the most disabling health problems facing adults today. Locomotor training has been shown to induce substantial recovery in muscle size and muscle function in both transected and contusion injury animal models of SCI. The overall objective of this study is to implement genome wide expression profiling of skeletal muscle to define the molecular pathways associated with muscle remodeling after SCI and during locomotor training (TM). We profiled rat soleus of total 36 samples including controls; 3, 8 and 14 days after SCI; 8 and 14 days after SCI with locomotor treadmill training (TM).
Project description:Summary: Spinal cord injury (SCI) is a damage to the spinal cord induced by trauma or disease resulting in a loss of mobility or feeling. SCI is characterized by a primary mechanical injury followed by a secondary injury in which several molecular events are altered in the spinal cord often resulting in loss of neuronal function. Analysis of the areas directly (spinal cord) and indirectly (raphe and sensorimotor cortex) affected by injury will help understanding mechanisms of SCI. Hypothesis: Areas of the brain primarily affected by spinal cord injury are the Raphe and the Sensorimotor cortex thus gene expression profiling these two areas might contribute understanding the mechanisms of spinal cord injury. Specific Aim: The project aims at finding significantly altered genes in the Raphe and Sensorimotor cortex following an induced moderate spinal cord injury in T9.
Project description:Summary: Spinal cord injury (SCI) is a damage to the spinal cord induced by trauma or disease resulting in a loss of mobility or feeling. SCI is characterized by a primary mechanical injury followed by a secondary injury in which several molecular events are altered in the spinal cord often resulting in loss of neuronal function. Hypothesis: Spinal cord injury (SCI) induces a cascade of molecular events including the activation of genes associated with transcription factors, inflammation, oxidative stress, ionic imbalance, apoptosis and neuroregeneration which suggests the existance of endogenous reparative attempts. However, not all mechanisms following SCI are well known. Specific Aim: The goal of this project is to analyze the molecular events following spinal cord injury 1 cm above, below, and at the site of injury (T9), aiming at finding potential new targets to improve recovery and therapy.
Project description:Sensorimotor dysfunction following incomplete spinal cord injury (SCI) is often characterized by paralysis, spasticity and pain. Previously, we showed that intrathecal (i.t.) administration of the albumin-oleic acid (A-OA) complex in rats with SCI produced partial improvement of these symptoms and that oral 2-hydroxyoleic acid (HOA), a non-hydrolyzable OA analogue), was efficacious in the modulation and treatment of nociception and pain-related anxiety, respectively. Here we observed that intrathecal treatment with the complex albumin-HOA (A-HOA) every 3 days following T9 spinal contusion injury promoted significant recovery in locomotor function and marked an inhibition of TA noxious reflex activity (i.e., nociception) in Wistar rats. To investigate the mechanism of action of A-HOA, microarray analysis was carried out in the spinal cord lesion area. Representative genes involved in pain and neuroregeneration were selected to validate the changes observed in the microarray analysis by quantitative real-time RT-PCR. Comparison of the expression between healthy rats, SCI rats, and SCI treated with A-HOA rats revealed relevant changes in the expression of genes associated with neuronal morphogenesis and growth, neuronal survival, pain and inflammation. Thus, treatment with A-HOA not only induced a significant overexpression of growth and differentiation factor 10 (GDF10), tenascin C (TNC), aspirin (ASPN) and sushi-repeat-containing X-linked 2 (SRPX2), but also a significant reduction in the expression of prostaglandin E synthase (PTGES) and phospholipases A1 and A2 (PLA1/2). Currently, SCI has very important unmet clinical needs. A-HOA proved to downregulate genes involved in inflammation and upregulate genes involved in neuron growth, which balanced the important body response to medular lesion and allowed recovery from paralysis and pain. Overall design: We use four different animals for each experimental group which were extracted and processed separately
Project description:We asked what genes are significantly differentially regulated in the spinal cord of SCI trkB.T1 WT and trkB.T1 KO mice. TrkB.T1 is upregulated shortly after SCI although the precise mechanisms underyling this upregulation are poorly understood. In the trkB.T1 null, we show less mechanical allodynia and better locomotor recovery following SCI. The microarray studies helped us to elucidate a signaling pathway that is differently regulated in the WT versus KO mice at 1 day after SCI. In this study, we did not examine gene changes within a genotype after SCI. Rather, we examined DGE by genotype at each time point. Spinal cord tissue from WT and KO mice in a sham condition (intact spinal cord) versus 1D, 3D and 7D following SCI was harvested for microarray analyses.
Project description:T cells undergo autoimmunization following spinal cord injury (SCI) and play both protective and destructive roles during the recovery process. T-cell deficient athymic nude (AN) rats recover better than immunocompetent Sprague-Dawley (SD) rats following spinal cord transection. In the present study, we evaluated locomotor recovery in SD and AN rats following moderate spinal cord contusion. To explain variable locomotor outcome, we assessed whole-genome expression using RNA sequencing, in the acute (1 week post-injury) and chronic (8 weeks post-injury) phases of recovery. AN rats demonstrated greater locomotor function than SD rats only at 1 week post-injury, coinciding with peak T cell infiltration in immunocompetent rats. Genetic markers for T cells and helper T cells were acutely enriched in SD rats, while AN rats expressed genes for Th2 cells, cytotoxic T cells, NK cells, mast cells, IL-1a, and IL-6 at higher levels. Acute enrichment of cell death-related genes suggested that SD rats undergo secondary tissue damage from T cells. Additionally, SD rats exhibited increased acute expression of voltage-gated potassium (Kv) channel-related genes. However, AN rats demonstrated greater chronic expression of cell death-associated genes and less expression of axon-related genes. We put forth a model in which T cells facilitate early tissue damage, demyelination, and Kv channel dysregulation in SD rats following contusion SCI. However, compensatory features of the immune response in AN rats cause delayed tissue death and limit long-term recovery. T cell inhibition combined with other neuroprotective treatment may thus be a promising therapeutic avenue. 2x2 model with 4 groups and 12 total samples. 2 rat strains (athymic nude [AN] and Sprague-Dawley [SD]) and 2 time points (1 week post-injury [acute] and 8 weeks post-injury [chronic]). 3 samples per group, for a total of 12 samples. No technical replicates were performed. Acute SD group = rats 618, 619, and 620. Chronic SD group = rats 605, 606, and 608. Acute AN group = rats 714, 715, and 717. Chronic AN group = rats 707, 712, and 713.
Project description:The aneurysm clip impact-compression model of spinal cord injury (SCI) in animals mimics the primary mechanism of SCI in human, i.e. acute impact and persisting compression; and its histo-pathological and behavioural outcomes are extensively similar to the human SCI. In order to understand the distinct molecular events underlying this injury model, an analysis of global gene expression of the acute, subacute and chronic stages of a moderate to severe injury to the rat spinal cord was conducted using a microarray gene chip approach. Rat thoracic spinal cord (T7) was injured using aneurysm clip impact-compression injury model and the epicenter area of injured spinal cord was isolated for RNA extraction and processing and hybridization on Affymetrix GeneChip arrays.
Project description:Spinal cord injury (SCI) represents a major debilitating health issue with a direct socioeconomic burden on the public and private sectors worldwide. Although several studies have been conducted to identify the molecular progression of injury sequel due from the lesion site, still the exact underlying mechanisms and pathways of injury development have not been fully elucidated. In this work, based on OMICs, 3D MALDI imaging, cytokines arrays, confocal imaging we established for the first time that molecular and cellular processes occurring after spinal cord injury (SCI) are altered between the lesion proximity, i.e., rostral and caudal segments nearby the lesion (R1-C1) whereas segments distant from R1-C1, i.e., R2-C2 and R3-C3 levels co-expressed factors implicated in neurogenesis. Delay in T regulators recruitment between R1 and C1 favor discrepancies between the two segments. This is also reinforced by presence of neurites outgrowth inhibitors in C1, absent in R1. Moreover, the presence of immunoglobulins (IgGs) in neurons at the lesion site at 3 days, validated by mass spectrometry, may present additional factor that contributes to limited regeneration. Treatment in vivo with anti-CD20 one hour after SCI did not improve locomotor function and IgG expression. These results open the door of a novel view of the SCI treatment by considering the C1 as the therapeutic target.
Project description:To determine whether the expression levels of circular RNAs were altered and lay a foundation for future work, we used high-throughput microarray analysis to screen circular RNAs expression patterns in the spinal cord of adult rats after traumatic spinal cord injury (SCI), finally to evaluate the potential rat models as a platform for the development of novel therapeutic targets for spinal cord injury in future clinical studies. Overall six rats at 3 days post-SCI in two groups were used to perform the microarray. Overall design: Six rats were randomly assigned to two groups: rats in the sham control group (n=3) were treated with laminectomy alone without contusion; rats in the SCI group (n=3) were subjected to laminectomy plus contusion. Rats were anesthetized at 3 days post-SCI, and a 1cm long segment of spinal cord, including the injury epicenter, was dissected and collected for the experiment.
Project description:The leg of healthy volunteers was locally deconditioned using three weeks of unilateral lower limb suspension (ULLS). The extremely deconditioned legs of subjects with a spinal cord injury (SCI) were trained using eight weeks of functional electrical stimulation (FES) exercise, 2-3 times per week (total 20 sessions). These models for local (in)activity were used to study changes in gene expression level of: A) Long-term deconditioning: before FES versus before ULLS (=SCI versus control); B) Short-term deconditioning: after ULLS versus before ULLS; and C) Exercise training: after FES versus before FES. RNA was isolated from six healthy subjects before and after ULLS deconditioning, and three subjects with SCI before and after FES exercise training.