Development of a radioligand binding assay for serotonin 5-HT2B receptors
Athanasios Metaxas, Natalie Nanette Willadsen, Sanne Briting, Camilla Thygesen, Bente Finsen
Affiliations:
Institute of Molecular Medicine, Department of Neurobiology, University of Southern Denmark
Keywords:
Serotonin receptors, 5-HT2B, radioligand binding, inhibition studies
Abstract:
The neurotransmitter serotonin (5-HT) exerts its effects through at least 15 subtypes of 5-HT receptors. Among them, 5-HT2B receptors are considered to be promising therapeutic targets for schizophrenia and drug addiction. To date, the cellular localisation of 5-HT2B receptors in the central nervous system remains unknown. This study aims to develop a radioligand binding assay that can be used to quantify and map the distribution of 5-TH2B receptors in the mammalian brain. Inhibition binding studies were performed in porcine forebrain preparations using 10 nM [3H]5-HT. A series of displacing drugs with selectivity for distinct subtypes of 5-HT receptors were assayed in triplicate. [3H]5-HT was displaced in the rank order: 5-CT>5-HT>RS-127445>>Ketanserin>>SDZ 205-557>Paroxetine, which is consistent with high-affinity binding of [3H]5-HT to 5-HT1, 5-HT7 and 5-HT2B receptors. Further study is warranted, to determine the appropriate concentrations of ligands required to mask the binding of [3H]5-HT to receptors other than the 5-HT2B.
Erik Kaadt1, Birgitte Mumm1, Sanne Andersen1, Christian Damgaard2 and Betina Elfving1
Affiliations:
Keywords:
Depression, Biomarkers, Skin, Rat models of depression
Abstract:
Introduction
The current diagnosis of depression relies on the assessment of the symptomatic profile, which is obtained through direct interview with the patient. As symptoms between multiple psychiatric disorders are partly overlapping, the current diagnosis has been determined to be inaccurate. It is therefore of great clinical importance to identify objective biomarkers of depression that can aid the diagnosis. Recently, it has been shown that a list of 38 microRNAs (miRNAs) exhibit dysregulation in the dermal fibroblasts of human depressed subjects compared to controls.
Aims
To validate and specify the 38 miRNA alterations from the human study, we investigated their dysregulation in the skin from four distinct rat models of depression to identify overlaps.
Methods
Establishment of fibroblast cultures, miRNA extraction, cDNA synthesis, real-time qPCR, and statistical analysis.
Results
15 distinct miRNA-dysregulations were re-identified in the skin of the four rat models and 3 miRNAs overlapped between the models. The majority of the 15 miRNAs could be linked through their matched mRNA-targets, which indicate coordinated suppression of relevant depression targets.
Conclusion
We re-identified multiple miRNAs from the human study that were dysregulated in depressive-like rat models. This overlap could indicate that these specific miRNAs are correlated to the depressive phenotype.
Maiken K. Mikkelsen1, Nick Y. Larsen1, Connie Sanchez2,3, Jens Randel Nyengaard1
Affiliations:
Keywords:
Olanzapine, appetite regulation, opioid, hypothalamus
Abstract:
Antipsychotic medication used for the treatment of schizophrenia is associated with many adverse side effects. Although second generation atypical antipsychotics, such as Olanzapine, has less extrapyramidal side effects, they result in weight gain and metabolic dysfunction in up to 80% of treated patients. Studies have shown that the opioid system participates in the regulation of food intake in the hypothalamus, and a new study has found that patients treated with olanzapine and a µ opioid receptor antagonist results in less weight gain.
We are studying the effect of olanzapine treatment on appetite- and energy regulating neurons in the hypothalamus of female rats. Our results show a significant weight gain and increased food intake after only 72 hours of treatment. Using fluorescent in situ hybridization and quantitative image analysis, we have estimated µ, κ and δ opioid receptor RNA expression in the hypothalamus. The results show that 48 hours of olanzapine treatment results in a decreased expression of µ opioid receptor RNA in the hypothalamic arcuate nucleus.
Further experiments are in progress to determine olanzapine driven changes in opioid receptor and serotonin receptor expression in the hypothalamus, as well as estimations of neuroanatomical changes in appetite regulating neuron populations.
Estrid Thougaard Pedersen1, Ana Sanchez-Gonzalez2, Adolf Tobeña2, Bente Pakkenberg1, Alberto Fernandez-Teruel2 and Susana Aznar1
Affiliations:
Keywords:
Schizophrenia, animal model, astrocytes, mPFC
Abstract:
The Roman rat strains are a neurobehavioral animal model derived from selective breeding into an inbred Roman Low- (RLA-I) and Roman High-Avoidance (RHA-I) strain, based on their performance in the two-way active avoidance task in the shuttle box. The RHA-I strain presents behavioral phenotypes associated with schizophrenia and schizophrenia risk, making it an ideal model for investigating the underlying neurobiology behind these behavioral traits. The prefrontal cortex (PFC) is a central player in cognitive processes, which are known to be impaired in schizophrenia. The RHA-I strain, when compared to RLA-I, show enhanced expression of pre- and postsynaptic components and increased number of immature dendritic spines in PFC. The aim of this study is to investigate whether this is accompanied by differences in number of astrocytes and microglia, as these cells are involved in regulating synaptic pruning.
Coronally cut brain sections from male RHA-I and RLA-I rats were stained for GFAP and Iba1 for identification of astroglia and microglia respectively, using colorimetric immunohistochemistry. Stereology was used to estimate the volume and the total numbers of astrocytes and microglia in mPFC.
RHA-I rats had a significantly higher number of astrocytes in their mPFC than their RLA-I counterparts (P≤0.01). The number of microglia in mPFC did not differ between the two groups, neither did the mPFC volume.
Katrine Tang Stenz, Jesper Just, Kim Ryun Drasbek
Affiliations:
Keywords:
Ischemic stroke, Extracellular vesicles, Remote ischemic conditioning, Blood flow restricted exercise
Abstract:
Stroke is a leading cause of death and disability worldwide. An ischemic stroke is characterized by an instant reduction in oxygen delivery to the brain, leading to tissue damage. When treated, the recanalization of blood vessels can lead to reperfusion injury; together known as ischemia/reperfusion injury (I/R injury).
The aim of this study is to utilize the body’s own endogenous protective pathways against I/R injury by different conditioning methods. These include remote ischemic conditioning (RIC), blood flow restricted exercise (BFRE), and traditional resistance training (TRT). We hypothesize that RIC, BFRE and TRT can induce cytoprotection through conditioned extracellular vesicles (EVs) released into circulation.
EVs are important for cell-to-cell communication over long distances, as they are stable in blood. Upon conditioning, these EVs change characteristics including surface charge, surface proteins and miRNA content.
We have found that conditioned EVs from RIC and BFRE constitute protection of human brain microvascular endothelial cells in our in vitro stroke model. Furthermore, miRNA-182, which is present in RIC EVs, can target mRNA for genes involved in proliferation and apoptosis signaling for degradation.
With more studies, we want to utilize this for the futures treatment of ischemic strokes.
Jesper Just1, Yan Yan2, Jean Farup4,5, Peter Sieljacks3, Mette Sloth Larsen1, Morten Venø2, Tingting Gu1, Frank Vincenzo de Paoli, Rikke Bæk6, Malene Møller Jørgensen6, Jørgen Kjems2, Kristian Vissing3, Kim Ryun Drasbek1
Affiliations:
Keywords:
Exercise, micro-RNAs, extracellular vesicles
Abstract:
Transient sub-lethal ischemia can promote protective effect against tissue degradation inherent of lethal ischemia. The protective effects may involve miRNA derived from extracellular vesicles (EVs) to affect gene expression in remote tissues. EVs are released in plasma after ischemic conditioning and traditional exercise. Ischemic exercise conducted as low-load blood flow restricted resistance exercise (BFRE) can precondition skeletal muscle and promote muscle accretion. Muscle regenerative and growth processes are partly reliant on activation of muscle precursor cells. Extracellular miRNA elicited by BFRE may stimulate muscle precursor cells, to potentially exert effect on remote skeletal and cardiac tissue.
The aim of the study was to investigate the effect of low intensity BFRE on EV profile, miRNA cargo and skeletal muscle precursor cell proliferation.
EVs were isolated from plasma collected from 6 healthy human subjects before and 1 hour after a single bout of BFRE. EVs were characterized by NTA, TRPS, western blotting and electron microscopy. Small EV RNAs were isolated and sequenced by NGS. Isolated EVs were applied in an in vitro proliferation assay on primary muscle stem cells and fatty acid progenitor cells, to test the ability BFRE primed EVs to stimulate proliferation.
No difference in EV quantity or size was observed after BFRE. Expression of 12 miRNAs was significantly altered after BFRE. Target prediction and functional enrichment analysis of these miRNAs revealed several target genes and association to several biological pathways involved in skeletal muscle protein turnover. Interestingly, BFRE-conditioned EVs significantly increased the proliferation of muscle precursor cells. The results support that BFRE promote EV-derived miRNA to engage in muscle remodeling and/or growth processes. Moreover, this suggest for a way for ischemia and/or exercise to exert protective effects in remote tissues.
Carina Jørgensen1,2, Livia Rosa Fernandes1,2, Anders Bach3, Kate Lykke Lambertsen1,2
Kristian Strømgaard3, Bettina Hjelm Clausen1,2
Affiliations:
Keywords:
Stroke, neuroprotection, PSD-95
Abstract:
Background:
Ischemic stroke is a leading cause of death and disability and with limited options for treatment. Ischemic stroke comprises a complex series of pathophysiological events with glutamate induced excitotoxicity taking place immediately after stroke-onset. The compound AVLX-144 specifically inhibits the postsynaptic density protein-95 (PSD-95) thereby decoupling downstream N-methyl-D-aspartate (NMDA) receptor signaling, a strategy resulting in neuroprotection after focal cerebral ischemia in mice. Here we test the dose-response effect of AVLX-144 treatment on infarct development in the permanent (p) and transient (t) middle cerebral artery occlusion (MCAO) model.
Results:
Administration of AVLX-144 30 minutes after MCAO affects infarct development in a positive manner in both stroke models. In the pMCAO model administration of 18 nmol/g AVLX-144 leads to a significantly smaller infarct compared to saline. In the tMCAO model administration of 18 nmol/g and 30 nmol/g AVLX both leads to significant smaller infarcts compared to saline.
Conclusion:
AVLX-144 has a wide therapeutic dose-window ranging from 3 nmol/g (previously shown) to 30 nmol/g following tMCAO. It reduces infarct size in two experimental stroke models but, whether this leads to increased functional recovery remains to be evaluated. AVLX-144 could be a promising drug candidate for the treatment of ischemic stroke.
Pall Karlsson1,2, S Gylfadottir, J Ramirez, P Shillo, S Tesfaye, A Rice, N Finnerup, JR Nyengaard, TS Jensen, D Bennett, A Themistocleous
Affiliations:
Keywords:
Diabetes, neuropathy, skin biopsies, nerve fibers, swellings
Abstract:
Diabetic peripheral neuropathy (DPN) is one of the most common complications to diabetes. DPN is associated with a loss of intra-epidermal nerve fibers structural changes to the nerve fibers such as axonal swellings may also be present. This study investigated the presence of axonal swellings in non-diabetics, patients with type 2 diabetes without signs or symptoms of neuropathy and DPN patients with and without neuropathic pain.
Jonas Olsen Dall, Thomas Alrik Sørensen
Affiliations:
Keywords:
Expertise; Working Memory; Attention; Short-Term Memory Capacity, Complexity, Expertise
Abstract:
Visual complexity of an object can vary in different degrees, and if we have a limited short-term memory capacity (e.g. Cowan, 2001), how does memory deal with objects of high visual complexity? While early studies demonstrated that visual complexity increase the load on both processing time and memory capacity (Alvarez & Cavanagh 2004), later studies indicate that memory capacity is highly influenced by stimulus specific expertise (Sørensen, & Kyllingsbæk, 2012). Nevertheless, complexity can be divided into two types based on either visual elements or familiarity. The current aim is to examine the relationship between the visual complexity and what we term the perceived complexity. In an experiment we used Chinese characters (radicals) divided into four groups based on visual complexity or stroke count (high vs low) and perceived complexity or word frequency (high vs low). We examined this using a whole report paradigm (Sperling, 1960) with varying exposure rates and modeled the results according to the Theory of Visual Attention (Bundesen, 1990). This procedure allows us to isolate specific attentional components and the results reveal that for experienced observers differences in processing speed and memory capacity is driven solely by the perceived complexity of an object.
Carsten Gleesborg1, Casper Schmidt1-2, Valerie Voon2, Arne Møller1
Affiliations:
Keywords:
Gambling disorder, DTI, fingerprinting, striatum, orbitofrontal cortex
Abstract:
Introduction:
Gambling disorder (GD) is a relatively frequent behavioral addiction marked by severe impairments in impulsive and repetitive engagement with risk-seeking gambling behaviors, and is associated with personal, social and occupational dysfunction as well as the highest suicide rate of any addictive disorder. Although an abundance of studies within GD exist, none have yet examined the white matter (WM) integrity of GD through a novel fingerprinting technique developed recently to identify subtle abnormalities in clinical disorders.
Methods:
Here we examine structural connectivity in GD, contrasting 18 treatment-active GD patients with 24 healthy volunteers (HV). We employed probabilistic tractography using a novel method developed in Oxford. Further analysis employed graph theoretical measures.
Results:
We found that there was a restructuring of striatal connections, with loss of connectivity to areas found less active in GD, and increases to areas reported to have increased activity in GD, relative to HV. Further, we observed distinct right-hemisphere losses of frontal lobe connectivity, and a general increase in connectivity between GD subjects and HV. Modularity analysis demonstrated very similar community structure for both groups, understating a behavioral indication of treatment status in GD, yet hub classification differences underlined regional differences across GD and HV groups.
Conclusions:
The results in this study successfully synthesize many sporadic findings into a whole-brain mapping of structural imbalance in GD. We urge future studies to replicate our findings, preferably with treatment naïve GD subjects in order to better trace the effect of treatment within the disorder.
Supportive drug therapy trials in Gambling Disorder
Authors:
Per Mikkelsen, Catharina Blocher, Arne Møller
Affiliations:
Nuclear Medicine and PET, Aarhus University Hospital
Keywords:
Gambling Disorder, Compulsivity, Impulsivity, Serotonin, Dopamine
Abstract:
This project is a pilot study on the effects of supportive drug therapy Gambling Disorder that will hopefully improve treatment efficacy for disordered gamblers by reducing the immediate urge to gamble and making patients more susceptible to psychotherapy and other long-term solutions to their problem. This project will be used to prove the methodology viable and solidify an infrastructure of recruitment of gamblers for future projects.
From the data obtained we hypothesized that gamblers can be subdivided into at least 2 distinct groups (compulsive and impulsive) based on their mode of gambling and personality traits. Based on this, we theorize these groups may have different background or pathophysiology for gambling. In a double-blinded randomized design would they be divided into a compulsive- and impulse group, and receive a serotonergic acting (compulsive group) or a dopaminergic acting (impulsive group) compound – or placebo.
To prove the existence of these two groups we use validated structured psychiatric interview methods and questionnaires to examine the personality, degree for addiction etc. of the test subjects.
Subgrouping is done on a consensus assessment of two investigators supported by results from questionnaires (MINI, SOGS, AUDIT, UPPS-P, BDI, STAI and OCI-R).
Participants are treatment-seeking gamblers at Center of Ludomani and Forskningsklinikken for Ludomani.
Reza Khorooshi1, Emil Ulrikkaholm Tofte-Hansen1, Camilla Tygesen1, Roser Montanana-Rosell1, Hannah Liska Limburg1, Joanna Marczynska1, Nasrin Asgari1,2, Ulrike Muscha Steckelings3 and Trevor Owens1
Affiliations:
Abstract:
Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing inflammatory CNS disease for which there is no cure. Immunoglobulin-G autoantibodies specific for the water channel aqua-porin-4 are a serum biomarker, believed to induce complement-dependent astrocyte damage with secondary demyelination. To investigate the effect of angiotensin AT2-receptor (AT2R) stimulation on NMOSD-like pathology and its underlying mechanism, NMOSD-like pathology was induced in mice by intracerebral injection of Immunoglobulin-G isolated from NMOSD patient serum, with complement. This mouse model produces the characteristic histological features of NMOSD. A specific AT2R agonist, Compound 21 (C21), was given intrac-erebrally at day 0 and by intrathecal injection at day 2. Loss of aquaporin-4 and glial fibrillary acidic protein was attenuated by treatment with C21. Administration of C21 induced mRNA for interleukin-10 in the brain. NMOSD-like pathology was exacerbated in interleukin-10-deficient mice, suggesting a protective role. C21 treatment did not attenuate NMOSD-like pathology in interleukin-10-deficient mice, indicating the protective effect of AT2R stimulation was depend-ent on interleukin-10. Our findings identify AT2R as a novel potential therapeutic target for the treatment of NMOSD. Interleukin-10 signaling is an essential part of the protective mechanism counteracting NMOSD pathology.
Pernille Vinther Nielsen
Affiliations:
Keywords:
Spinal cord injury, microglia, TNF inhibitors
Abstract:
Spinal cord injury (SCI) is one of the most common forms of traumatic injury to the central nervous system (CNS). When an injury occurs on the spinal cord, it often initiates from a prima-ry mechanical insult of the spinal cord, leading to neuronal and glial death followed by second-ary injury. The secondary injury is, among other things, characterized by gliatoxic and neuronal sequelae, leading to further cell death and activation of the immune system.
Microglia are resident macrophages of the CNS and are activated in almost all neurological diseases and injuries, including SCI. Once activated, microglia secrete inflammatory cytokines, including tumor necrosis factor (TNF), followed by migration to the injured area to phagocytose damaged cells and cell debris.
In this project, microglia were isolated from C57BL/6 mice (0-2 days old) and from border zone tissue from patients undergoing surgery for brain tumor. The aim of the project was to deter-mine if microglia become more phagocytic when inhibiting only solTNF using the double nega-tive inhibitor XPro1595, or when inhibiting both solTNF and tmTNF using Etanercept. Increased phagocytotic activity was seen upon inhibition of solTNF, however, inhibition of both solTNF and tmTNF showed decreased phagocytotic activity.
Sanne Lindberg1, Senior Researcher Tomasz Brudek – external supervisor2, Post.doc Sylwia Owczarek2, PhD student Jonas Folke2, Head of molecular biology lab Susana Aznar2, Head of laboratory Prof Bente Pakkenberg2
Affiliations:
Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital
Keywords:
Natural antibodies, TDP-43 protein, Amyotrophic Lateral Sclerosis, ELISA
Abstract:
Amyotrophic lateral sclerosis is a terminal neurodegenerative disorder affecting both the upper and the lower motor neurons. It is a relatively rare disease with a prevalence of approximately 5 people out of 100.000 every year worldwide, and a prognosis of death within 3-5 years from the diagnosis. The disease is defined by gradually breaking down the muscles, leading to loss of respiratory functions. It is known, that for only 5-10% ALS cases it is genetic inherited, while 90-95% are sporadic ALS (sALS). 97 % of ALS patients displays a common histopathological phenotype in disease-affected tissues, namely aggregation of the TAR-DNA binding protein (TDP)-43.
Using the ELISA competition assay method, the avidity/affinity of anti-TDP-43 Nabs in serum samples from prodromal ALS patients and healthy individuals will be investigated. The key event of a competitive reaction results from occupation of antibody binding sites with increasing concentrations of free antigen (TDP-43) and a subsequent measurement of free antibodies on plates with immobilized antigen (TDP-43).
Unrelated studies suggest that lower levels of naturally occurring autoantibodies (Nabs) towards pathological proteins are implicated in the impaired clearing mechanism in neurodegenerative diseases.
Anna Kaihøj1, Anna Ulstein Odland2, Jesper Tobias Andreasen2, Jesper Kristensen2, Susana Aznar2
Affiliations:
Keywords:
5-HT2A, cognitive flexibility, glutamate receptors, gene expression
Abstract:
Psychedelics, such as psilocybin, seem to have promising therapeutic effects on disorders characterized by reduced cognitive flexibility. The mechanisms behind this are yet unknown but studies have suggested that psychedelics may induce neuroplasticity and that this is 5-HT2A receptor mediated. To prove this, we want to make use of a highly selective 5-HT2A receptor agonist, N-(2-Hydroxybenzyl)-2,5-Dimethoxy-4-Cyanophenylethylamine (25CN-NBOH) and investigate the effect of serotonin 2A receptor activation by 25CN-NBOH on long-term synaptic changes in vivo.
Mice will be subcutaneously injected with either VEH (negative control), DOI (positive control) or a high (5 mg/kg) or a low (1 mg/kg) dose of 25CN-NBOH. The animals will be euthanized at different time points (30 min, 1 h, 2 h and 24 h) post drug administration. PFC, hippocampus and striatum will be disected and qPCR performed for ex vivo expression analysis of arc and several NMDA and AMPA receptor subunits.
This project is part of a larger ongoing PhD project which aim to investigate, by use of behavioral tests, the effect of 25CN-NBOH on compulsive behavior and cognitive flexibility. Our studies will show whether a behavioral effect of 25CN-NBOH is accompanied by neurobiological changes.
Alisha Shahzad Chauhan, Jonas Folke, Rasmus Rydbirk, Tomasz Brudek og Susana Aznar
Affiliations:
Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital
Keywords:
Parkinson’s disease (PD), Multiple system atrophy (MSA), α-synuclein (AS), Fc receptors (FcRs), complement system
Abstract:
Parkinson’s disease (PD) and Multiple system atrophy (MSA) are progressive neurodegenerative movement disorders characterized by cell loss in the brain, due to excessive accumulation of α-synuclein (AS). The loss of cells causes problems with balance, movement and/or autonomic functions. It has previously been suggested that a dysfunctional immune system plays a role in the development of the both disorders. It is hypothesized that a family of immunoglobulin-like receptors known as Fc receptors (FcRs), may play a role in the disease pathology. Hence, we aim to investigate FcRs and their role in PD and MSA. FcRs (FcγR, FcμR and FcnR) are found on a number of immune cells facilitating protective functions of the innate and adaptive immune system. Our objective of this study is to investigate the gene and protein expression of several FcRs and downstream complement system in the putamen and prefrontal cortex of PD and MSA brains to evaluate the immunological cross-talk between the central nervous system and the peripheral immune system, we further wish to evaluate the same pathways in peripheral blood mononuclear cells including innate and adaptive immune cells.
Aurore Zelazny & Thomas Alrik Sørensen
Affiliations:
Centre for Cognitive Neuroscience, Aalborg University
Keywords:
Synaesthesia, Multisensory Perception, Culture, Learning
Abstract:
Synaesthesia is a rare neurological phenomenon by which a sensory input triggers sensation in other modalities. Despite the large variety of reported experiences (Day, 2005), most triggering inputs are acquired concepts (e.g., graphemes, weekdays, pitches), setting learning as mechanism of interest.
Multimodal learning is a complex process modulated by factors that are both idiosyncratic and also environmental (e.g., type of information, teaching method). The present project is divided into 3 different subsections that investigate those aspects.
Regarding the general influences of environment, spontaneous multimodal associations involving basic concepts such as shapes, pitches, graphemes, colours, months and space will be investigated in both Europe and Asia.
The influence of teaching methods on multimodal knowledge will be explored through the musical teaching technique of the (i.e., ABC song) in childhood. Additionally, the possibility of enriching the knowledge of letter identities at a non-linguistic level in expert adult readers using music will also be investigated. Finally, reading performances and colour naming processes will be compared in synaesthetes and non-synaesthetes.
The various subsections involve collaborations with museums in Denmark and Japan, along with data collections in Beijing. The aim of the project is to better understanding the role of senses in the learning process.
Elisabeth H. Lynnerup Rusholt1,2, Lisette Salvesen1, Tomasz Brudek1, Betel Tesfay1, Bente Pakkenberg1,2, Mikkel V. Olesen1
Affiliations:
Keywords:
Cell number, Cerebellum, Multiple System Atrophy, Parkinson’s disease, Stereology
Abstract:
Multiple System Atrophy (MSA) and Parkinson’s disease (PD) are synucleinopathies characterized by aggregation of α-synuclein in brain cells. Recent studies have shown that morphological changes in terms of cerebral nerve cell loss and increase in glia cell numbers, the degree of brain atrophy and molecular and epidemiological findings are more severe in MSA than PD.
In the present study, we used Cavalieri’s method, optical disectors and the rotator to quantify cerebellar volumes, the total number of granule- and Purkinje cells, and the mean volume of Purkinje cell perikarya and nucleus in cerebellar subregions of nine patients diagnosed with MSA, 10 PD patients and 15 age-matched control subjects.
Only brains from MSA patients displayed a reduction in the total number of Purkinje cells and Purkinje cell volumes (perikaryons and nuclei volume), while a reduction in the white matter volume was observed in both MSA and PD brains, compared to controls. The number of granule cells was unaffected in both diseases. Analyses of cell type-specific mRNA expression supported our structural data.
This study of the cerebellum is in line with previous findings in the cerebrum and demonstrates that the degree of morphological changes is more pronounced in MSA than PD. Further, our results support an explicit involvement of cerebellar Purkinje cells and white matter connectivity in MSA and points to the potential importance of white matter alterations in PD pathology.
Sarah Mujinga Kateta, Bettina Hjelm Claussen
Affiliations:
Department of Neurology Research, Institute of Molecular Medicine, University of Southern Denmark
Keywords:
Acute ischemic stroke, Glatiramer acetate , Inflammation , Neurodegeneration
Abstract:
Background:
Ischemic stroke is a devastating disease with a complex pathophysiology. The role of the immune system in the pathophysiology of acute ischemic stroke is increasingly recognized. However, targeted treatment strategies to modulate rather than eliminate immunological pathways in stroke are still lacking. Glatiramer acetate (GA) is a multifaceted immunomodulation approved for the treatment of human multiple sclerosis. GA induces the production of secreted IL-1 receptor antagonist (sIL-1Ra), a natural inhibitor of IL-1β, in human monocytes. Studies suggest that IL-1Ra plays a neuroprotective role in experimental stroke.
Methods:
Permanent middle cerebral artery occlusion (pMCAo) was performed using adult male mice. Thirty minutes after pMCAo GA or saline were administered intravenously. Outcomes such as infarct size and pro-inflammatory cytokine levels within the brain were evaluated 24 after pMCAo.
Results:
Treatment with GA 30 min after occlusion surprisingly showed a tendency towards bigger infarct volumes, while significant down-regulation of key inflammatory cytokines like IL-1β, TNF-α, IL-6.
Conclusions:
Glatiramer acetate administered 30 min after cerebral ischemia failed to reduce infarct volume in mice despite a significant reduction in pro-inflammatory cytokines that are known to play an important role in infarct development.
Minna Christiansen Lund1, Ditte Gry Ellman1, Matilda Degn2 and Kate Lykke Lambertsen1,3,4
Affiliations:
Keywords:
Spinal cord injury, Neuroinflammation, Cytokines, Tumor Necrosis Factor
Abstract:
Spinal cord injury (SCI) has very detrimental consequences for the patient and it initiates many pathological events in the cord, one of these being the inflammatory response. The inflammatory response is initiated rapidly after SCI, with activation of both resident and blood borne immune-cells and the release of different cytokines, including tumor necrosis factor (TNF). TNF is important for inflammation, demyelination and remyelination following an injury to the CNS. It exists in two forms, membrane-bound TNF and soluble TNF (solTNF). We have previously shown that epidural inhibition of solTNF with XPro1595 increases functional recovery and decreases the lesion size following moderate SCI in mice.
The purpose of this study was to investigate the effect of XPro1595 on the inflammatory response following SCI, to see if there is a change in the recruitment of immune-cells and/or expression of inflammatory mediators following SCI.
Multiplex analysis revealed a tendency to decreased IL-1β expression 24 hours after SCI, and flow cytometry showed a decline in macrophages infiltration 7 days after SCI when inhibiting the solTNF with XPro1595, and a higher percentage of resident microglia in perilesion 14 days after SCI.
Thus, it appears that XPro1595 might affect macrophages and microglia infiltration and activation and needs to be further investigated.
Tingting Gu1, Yan Yan2, Jørgen Kjems2, Kim Ryun Drasbek1
Affiliations:
Keywords:
Ischemia, remote ischemic conditioning, extracellular vesicles
Abstract:
Remote ischemic conditioning (RIC) is a non-invasive treatment induced by repeated cycles of controlled ischemia-reperfusion in the limb. It has been proven to protect brain from ischemia-reperfusion injury. However, the protective mechanism of RIC remains unclear. It is hypothesized that RIC might stimulate the release of extracellular vesicles (EVs), which are cell-derived nano-particles that can carry effective cargos to remote area. In this study, we tested the biodistribution of EVs derived from conditioned myoblast cells in a stroke mouse model to see if they have a specific accumulation in the ischemic area. Mice were subjected to 45 min middle cerebral artery occlusion in the left hemisphere. EVs were isolated from hypoxia-reoxygenation (H-EVs) or normoxia (N-EVs) conditioned myoblast cells, labeled and then injected intravenously during occlusion. After 10 minutes reperfusion, mice were sacrificed. Organs were taken out for later IVIS scan. The results showed that, after i.v injection, most of EVs accumulated in the liver, kidney and spleen. More H-EVs seem to accumulate in the stroke brain and the ischemic hemisphere, but neither of them was significant. These results indicate a potential role of myoblast-EVs in RIC.
Binda, KH¹; Venega, RAG¹; Britto, LRG³; Real, CC²; Chacur, M¹
Affiliations:
Keywords:
Cannabinoid receptors; painful symptoms; analgesia; treadmill exercise; 6-OHDA Parkinson’s disease model
Abstract:
In addition to motor symptoms, Parkinson's disease (PD) has a high prevalence of painful symptoms responsible for worsening patients’ quality of life. Physical exercise can improve painful symptoms. We evaluated the effects of exercise on the nociceptive threshold in a unilateral Parkinson's disease rat model, as well as the role of the cannabinoid receptor type 2 (CB2) in areas responsible for pain pathways. For such, 15 days after PD induction, the animals either remained sedentary (SED) or were forced to exercise three times a week for 40 min (EX). Motor and nociceptive behavior was evaluated by the cylinder and mechanical hyperalgesia tests, respectively. Animals were euthanized for analysis of the CB2 receptors in the anterior cingulate cortex (ACC) by immunohistochemistry (IHC) analysis. Results showed that our model presented a decrease in the nociceptive threshold in both front paws after surgery; on the other hand, after the exercise protocol, there was an improvement in painful symptoms. Nociceptive threshold increase can occur by the modulation of CB2, since there is an increase in this receptor expression in the anterior cingulate cortex (ACC). Thus, physical exercise seems to be an important non-pharmacological intervention to reduce painful symptoms in a model of PD and thus contribute to understand and promote better interventions aimed at improving PD patients’ quality of life.
