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1.
BMC Public Health ; 21(1): 1985, 2021 11 02.
Article in English | MEDLINE | ID: mdl-34727895

ABSTRACT

BACKGROUND: During March of 2020 the Centers for Disease Control and Prevention (CDC) announced non-pharmaceutical intervention (NPI) guidance as the primary mitigation strategy against growing COVID-19 community spread due to the absence of a vaccine or effective treatment at that time. CDC guidance states that NPIs are most effective when instituted in an early, targeted, and layered fashion. NPIs are effective in slowing spread, and measures should be custom-tailored to each population. This study examines factors associated with implementation and timing of NPI interventions across large public and private U.S. universities at the onset of the COVID-19 pandemic. METHODS: NPI decisions of interest include when U.S. universities canceled international travel, shifted to online learning, moved faculty/staff to remote work, limited campus housing, and closed campus for all non-essential personnel. Cox proportional hazard analyses of retrospective data were conducted to assess the time to NPI events. Hazard ratios were calculated for university governance, campus setting, religious affiliation, health infrastructure, faculty diversity, and student demographics. The methods control for variance inflation factors, COVID case prevalence, and time varying covariates of spring break and states' state of emergency (SOE) orders. This study captures NPI decisions at 575 U.S. universities during spring of 2020 which affected the movement of seven million students and two million employees. RESULTS: Universities located in districts represented by Democratic party congressional members reported earlier NPI implementation than Republican (Cox proportional hazard ratio (HR) range 0.61-0.80). University religious affiliation was not associated with the timing any of the NPI decisions. Universities with more diverse faculty showed an association with earlier NPI implementation (HR range 0.65-0.76). The existence of university-affiliated health infrastructure was not associated with NPI timing. CONCLUSION: University NPI implementation was largely driven by local COVID-19 epidemiology, culture and political concerns. The timing of university NPI decisions varied by regional politics, faculty demographics, university governance, campus setting, and foreign student prevalence adjusting for COVID-19 state case prevalence and spring break timing. Religious affiliation and presence of university health infrastructure were not associated with timing.


Subject(s)
COVID-19 , Pandemics , Humans , Retrospective Studies , SARS-CoV-2 , Survival Analysis , Universities
2.
PLoS One ; 16(8): e0255778, 2021.
Article in English | MEDLINE | ID: mdl-34388189

ABSTRACT

Extracellular vesicles secreted from IFNγ-stimulated rat dendritic cells (referred to here as IFNγ-DC-EVs) contain miRNAs which promote myelination (including but not limited to miR-219), and preferentially enter oligodendrocytes in brain slice cultures. IFNγ-DC-EVs also increase myelination when nasally administered to naïve rats. While we can infer that these extracellular vesicles enter the CNS from functional studies, here we demonstrate biodistribution throughout the brain after nasal delivery by way of imaging studies. After nasal administration, Xenolight DiR-labelled IFNγ-DC-EVs were detected 30 minutes later throughout the brain and the cervical spinal cord. We next examined cellular uptake of IFNγ-DC-EVs by transfecting IFNγ-DC-EVs with mCherry mRNA prior to nasal administration. mCherry-positive cells were found along the rostrocaudal axis of the brain to the brainstem. These cells morphologically resembled oligodendrocytes, and indeed cell-specific co-staining for neurons, astrocytes, microglia and oligodendrocytes showed that mcherry positive cells were predominantly oligodendrocytes. This is in keeping with our prior in vitro results showing that IFNγ-DC-EVs are preferentially taken up by oligodendrocytes, and to a lesser extent, microglia. To confirm that IFNγ-DC-EVs delivered cargo to oligodendrocytes, we quantified protein levels of miR-219 mRNA targets expressed in oligodendrocyte lineage cells, and found significantly reduced expression. Finally, we compared intranasal versus intravenous delivery of Xenolight DiR-labelled IFNγ-DC-EVs. Though labelled IFNγ-DC-EVs entered the CNS via both routes, we found that nasal delivery more specifically targeted the CNS with less accumulation in the liver. Taken together, these data show that intranasal administration is an effective route for delivery of IFNγ-DC-EVs to the CNS, and provides additional support for their development as an EV-based neurotherapeutic that, for the first time, targets oligodendrocytes.


Subject(s)
Dendritic Cells/chemistry , Extracellular Vesicles/chemistry , Interferon-gamma/pharmacology , MicroRNAs/genetics , Administration, Intranasal , Administration, Intravenous , Animals , Astrocytes/drug effects , Brain/drug effects , Brain/metabolism , Cervical Cord/drug effects , Gene Expression Regulation/drug effects , Interferon-gamma/chemistry , Microglia/drug effects , Myelin Sheath/genetics , Neurons/drug effects , Oligodendroglia/drug effects , Rats
3.
PLoS One ; 15(10): e0240786, 2020.
Article in English | MEDLINE | ID: mdl-33064753

ABSTRACT

BACKGROUND: The Centers for Disease Control and Prevention (CDC) publishes COVID-19 non-pharmaceutical intervention (NPI) guidance for specific institutional audiences to limit community spread. Audiences include: business, clinical, public health, education, community, and state/local government. The swift, severe, and global nature of COVID-19 offers an opportunity to systematically obtain a national view of how larger institutions of higher education adopted NPI guidance at the onset of the pandemic. METHOD: An original database of COVID-19-related university NPI policy changes was compiled. Survey team members manually combed university websites and official statements capturing implementation decisions and dates for five NPI variables from 575 U.S. universities, across 50 states and the District of Columbia, during March of 2020. The universities included in this study were selected from the Department of Education Integrated Postsecondary Education Data System (IPEDS), which provides a set of university explanatory variables. Using IPEDS as the basis for the organizational data allows consistent mapping to event-time and institutional characteristic variables including public health announcements, geospatial, census, and political affiliation. RESULTS: The dataset enables event-time analysis and offers a variety of variables to support institutional level study and identification of underlying biases like educational attainment. A descriptive analysis of the dataset reveals that there was substantial heterogeneity in the decisions that were made and the timing of these decisions as they temporally related to key state, national, and global emergency announcements. The WHO pandemic declaration coincided with the largest number of university decisions to implement NPIs. CONCLUSION: This study provides descriptive observations and produced an original dataset that will be useful for future research focused on drivers and trends of COVID-19 NPIs for U.S. Universities. This preliminary analysis suggests COVID-19 university decisions appeared to be made largely at the university level, leading to major variations in the nature and timing of the responses both between and within states, which requires further study.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Infection Control/methods , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Universities , COVID-19 , Centers for Disease Control and Prevention, U.S. , Coronavirus Infections/virology , Decision Making , Education, Distance/methods , Humans , Pneumonia, Viral/virology , Public Health , SARS-CoV-2 , Students , Surveys and Questionnaires , Travel , United States/epidemiology
4.
Med Intensiva (Engl Ed) ; 44(3): 171-184, 2020 Apr.
Article in English, Spanish | MEDLINE | ID: mdl-31492476

ABSTRACT

Given the importance of the management of sedation, analgesia and delirium in Intensive Care Units, and in order to update the previously published guidelines, a new clinical practice guide is presented, addressing the most relevant management and intervention aspects based on the recent literature. A group of 24 intensivists from 9 countries of the Pan-American and Iberian Federation of Societies of Critical Medicine and Intensive Therapy met to develop the guidelines. Assessment of evidence quality and recommendations was made according to the Grading of Recommendations Assessment, Development and Evaluation Working Group. A systematic search of the literature was carried out using MEDLINE, Cochrane Library databases such as the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Effects, the National Health Service Economic Evaluation Database and the database of Latin American and Caribbean Literature in Health Sciences (LILACS). A total of 438 references were selected. After consensus, 47 strong recommendations with high and moderate quality evidence, 14 conditional recommendations with moderate quality evidence, and 65 conditional recommendations with low quality evidence were established. Finally, the importance of initial and multimodal pain management was underscored. Emphasis was placed on decreasing sedation levels and the use of deep sedation only in specific cases. The evidence and recommendations for the use of drugs such as dexmedetomidine, remifentanil, ketamine and others were incremented.


Subject(s)
Analgesia/methods , Anesthesia/methods , Critical Illness/therapy , Delirium/therapy , Analgesia/standards , Anesthesia/standards , Benzodiazepines/administration & dosage , Conscious Sedation/methods , Conscious Sedation/standards , Critical Care/methods , Critical Care/standards , Evidence-Based Medicine/standards , Humans , Hypnotics and Sedatives/administration & dosage , Intensive Care Units , Midazolam/administration & dosage , Pain Management/standards
5.
Front Neurosci ; 13: 942, 2019.
Article in English | MEDLINE | ID: mdl-31551696

ABSTRACT

Migraine is a common headache disorder characterized by unilateral, intense headaches. In migraine with aura, the painful headache is preceded by focal neurological symptoms that can be visual, sensory, or motor in nature. Spreading depression (the most likely cause of migraine with aura and perhaps related headache pain) results in increased neuronal excitability and related increases in inflammation and production of reactive oxygen species. This in turn can promote the transformation of low-frequency, episodic migraine into higher-frequency and eventually chronic migraine. Though migraine affects 11% of adults worldwide, with 3% experiencing chronic headache, existing therapies offer only modest benefits. Here, we focus on the mechanisms by which environmental enrichment (i.e., volitionally increased intellectual, social, and physical activity) mitigates spreading depression. In prior work, we have shown that exposure to environmental enrichment reduces susceptibility to spreading depression in rats. This protective effect is at least in part due to environmental enrichment-mediated changes in the character of serum exosomes produced by circulating immune cells. We went on to show that environmental enrichment-mimetic exosomes can be produced by stimulating dendritic cells with low levels of interferon gamma (a cytokine that is phasically increased during environmental enrichment). Interferon gamma-stimulated dendritic cell exosomes (IFNγ-DC-Exos) significantly improve myelination and reduce oxidative stress when applied to hippocampal slice cultures. Here, we propose that they may also be effective against spreading depression. We found that administration of IFNγ-DC-Exos reduced susceptibility to spreading depression in vivo and in vitro, suggesting that IFNγ-DC-Exos may be a potential therapeutic for migraine.

6.
Int J Immunopathol Pharmacol ; 33: 2058738419844932, 2019.
Article in English | MEDLINE | ID: mdl-30994016

ABSTRACT

The hydroferrate fluid MRN-100, an iron-based compound with potent antioxidant characteristics, was examined to identify its possible anti-inflammatory effects on human dendritic cells (DCs) in vitro. Human monocyte-derived DCs were treated with MRN-100 at two concentrations (50 and 100 µL/mL) for 24 h and then stimulated with or without lipopolysaccharides (LPS). The expression of DC maturation markers was assessed by flow cytometry and the production of cytokines was determined by enzyme-linked immunosorbent assay (ELISA). Functional assay was performed by co-culturing MRN-100-treated and untreated DCs with allogeneic naïve CD4+ T cells and assaying the T cells' cytokine production. Results show that treatment with MRN-100 significantly upregulated the co-stimulatory molecules CD80 and CD86 and increased human leukocyte antigen-DR (HLA-DR) though not significantly. MRN-100 treatment also significantly increased the production of the anti-inflammatory cytokine interleukin (IL)-10. On the other hand, MRN-100 significantly induced the secretion of pro-inflammatory cytokines such as IL-6 only at high concentrations. Furthermore, DCs pretreated with MRN-100 and either stimulated or not with LPS were able to prime CD4+ T cells to secrete significant amounts of IL-10 while inhibiting the secretion of pro-inflammatory cytokine tumor necrosis factor (TNF)-α. These results indicate that MRN-100 is a powerful anti-inflammatory agent that promotes the generation of an anti-inflammatory immune response in vitro. MRN-100 could be beneficial for treating patients with inflammatory diseases, including arthritis and type 1 diabetes, and its potential benefits should be examined in clinical trials.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Dendritic Cells/drug effects , Iron Compounds/pharmacology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/metabolism , Cells, Cultured , Cytokines/metabolism , Dendritic Cells/metabolism , Humans
7.
Int J Immunopathol Pharmacol ; 32: 2058738418797768, 2018.
Article in English | MEDLINE | ID: mdl-30270704

ABSTRACT

Marina crystal minerals (MCM) are a mixture that contains crystallized minerals along with trace elements extracted from seawater. It is a nutritional supplement that is capable of enhancing natural killer (NK) cell activity and increasing T and B cell proliferation in humans post ingestion. However, its effect on dendritic cells (DCs), the cells that bridge innate and adaptive immunity, is not yet known. In this study, we examine the stimulatory effects of MCM on DCs' maturation and function in vitro. Human monocyte-derived DCs were treated with MCM at two different concentrations (10 and 20 µg/mL) for 24 h. Results showed that MCM treatment activated DCs in a dose-dependent fashion. It caused the upregulation of costimulatory molecules CD80, CD86, and HLA-DR, and prompted the production of DC cytokines, including interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and IL-1ß, and chemokines (monocyte chemotactic protein-1 (MCP-1)) and interferon-gamma-inducible protein-10 (IP-10). In addition, activated DCs primed CD4+ T cells to secrete significant amounts of interferon gamma (IFN-γ), and they also stimulated CD8+ T cells to express higher amounts of CD107a. These results indicate that MCM is a potentially powerful adjuvant, from natural materials, that activates human DCs in vitro and therefore may suggest its possible use in immune-based therapies against cancer and viral infections.


Subject(s)
Adjuvants, Immunologic/pharmacology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Dendritic Cells/drug effects , Lymphocyte Activation , Minerals/pharmacology , Paracrine Communication/drug effects , Seawater/chemistry , Adjuvants, Immunologic/isolation & purification , B7-1 Antigen/immunology , B7-1 Antigen/metabolism , B7-2 Antigen/immunology , B7-2 Antigen/metabolism , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Cells, Cultured , Coculture Techniques , Crystallization , Cytokines/immunology , Cytokines/metabolism , Dendritic Cells/immunology , Dendritic Cells/metabolism , HLA-DR Antigens/immunology , HLA-DR Antigens/metabolism , Humans , Lysosomal-Associated Membrane Protein 1/immunology , Lysosomal-Associated Membrane Protein 1/metabolism , Minerals/isolation & purification , Signal Transduction
9.
Cell Mol Neurobiol ; 36(3): 313-325, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26993508

ABSTRACT

Environmental enrichment (EE) consists of increased physical, intellectual, and social activity, and has wide-ranging effects, including enhancing cognition, learning and memory, and motor coordination. Animal studies have demonstrated that EE improves outcome of brain trauma and neurodegenerative disorders, including demyelinating diseases like multiple sclerosis, making it a promising therapeutic option. However, the complexity of applying a robust EE paradigm makes clinical use difficult. A better understanding of the signaling involved in EE-based neuroprotection may allow for development of effective mimetics as an alternative. In prior work, we found that exosomes isolated from the serum of rats exposed to EE impact CNS myelination. Exosomes are naturally occurring nanovesicles containing mRNA, miRNA, and protein, which play important roles in cell function, disease, and immunomodulation. When applied to hippocampal slice cultures or nasally administered to naïve rats, EE-serum exosomes significantly increase myelin content, oligodendrocyte precursor (OPC) and neural stem cell levels, and reduce oxidative stress (OS). We found that rat EE exosomes were enriched in miR-219, which is necessary and sufficient for OPC differentiation into myelinating cells. Thus, peripherally produced exosomes may be a useful therapy for remyelination. Here, we aim to better characterize the impact of EE on CNS health and to determine the cellular source of nutritive exosomes found in serum. We found that exosomes isolated from various circulating immune cell types all increased slice culture myelin content, contained miR-219, and reduced OS, suggesting that EE globally alters immune function in a way that supports brain health.


Subject(s)
Central Nervous System/pathology , Environment , Exosomes/metabolism , Inflammation/pathology , Leukocytes/metabolism , Myelin Sheath/metabolism , Animals , Axons/ultrastructure , B-Lymphocytes/cytology , Brain/metabolism , Brain/pathology , Cells, Cultured , Central Nervous System/metabolism , Dendritic Cells/cytology , Gene Expression Profiling , Gene Expression Regulation , Gliosis/pathology , Inflammation/genetics , Lipopolysaccharides , Lymph Nodes/cytology , Male , MicroRNAs/genetics , MicroRNAs/metabolism , Myelin Basic Protein/metabolism , Oxidative Stress , Rats, Wistar , Spleen/cytology , T-Lymphocytes/cytology
10.
J Extracell Vesicles ; 4: 27575, 2015.
Article in English | MEDLINE | ID: mdl-26320942

ABSTRACT

The NIH Extracellular RNA Communication Program's initiative on clinical utility of extracellular RNAs and therapeutic agents and developing scalable technologies is reviewed here. Background information and details of the projects are presented. The work has focused on modulation of target cell fate by extracellular vesicles (EVs) and RNA. Work on plant-derived vesicles is of intense interest, and non-mammalian sources of vesicles may represent a very promising source for different therapeutic approaches. Retro-viral-like particles are intriguing. Clearly, EVs share pathways with the assembly machinery of several other viruses, including human endogenous retrovirals (HERVs), and this convergence may explain the observation of viral-like particles containing viral proteins and nucleic acid in EVs. Dramatic effect on regeneration of damaged bone marrow, renal, pulmonary and cardiovascular tissue is demonstrated and discussed. These studies show restoration of injured cell function and the importance of heterogeneity of different vesicle populations. The potential for neural regeneration is explored, and the capacity to promote and reverse neoplasia by EV exposure is described. The tremendous clinical potential of EVs underlies many of these projects, and the importance of regulatory issues and the necessity of general manufacturing production (GMP) studies for eventual clinical trials are emphasized. Clinical trials are already being pursued and should expand dramatically in the near future.

11.
J Interferon Cytokine Res ; 35(10): 795-807, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26083947

ABSTRACT

The detrimental effects of T-cell-secreted interferon gamma (IFNγ) on oxidative stress (OS) and demyelination in multiple sclerosis (MS) are well recognized. Recently, we demonstrated that IFNγ-mediated damage to myelin also increases susceptibility to spreading depression (SD; the likely basis of migraine with aura). However, before onset of MS, induction of physiological levels of IFNγ, like that produced by environmental enrichment (EE), protects against demyelination and OS. Accordingly, we focused on the potential for physiological levels of IFNγ to protect against SD. EE, which occurs with a moderate and phasic increase in proinflammatory cytokines, reduces migraine frequency. Thus, we applied phasic or pulsed IFNγ to brain slice cultures to emulate EE. This treatment reduced OS, increased myelin basic protein, a marker for myelin, and reduced susceptibility to SD. Building on our research on exosomes in EE-based neuroprotection, we found that IFNγ stimulation of slice cultures induced release of exosomes, likely from the microglia that produce the same protective effects as IFNγ treatment when applied to naive cultures. Finally, nasal administration of IFNγ to rats recapitulated in vitro effects, reducing OS, increasing myelin, and reducing SD. These results support phasic IFNγ signaling as a therapeutic target for prevention of SD and, by extension, migraine.


Subject(s)
Depression/metabolism , Exosomes/metabolism , Interferon-gamma/pharmacology , Animals , Cells, Cultured , Depression/drug therapy , Depression/genetics , Disease Models, Animal , Gene Expression Profiling , Glutathione/metabolism , Hippocampus/drug effects , Hippocampus/metabolism , Interferon-gamma/administration & dosage , MicroRNAs/genetics , Microglia/drug effects , Microglia/metabolism , Oxidative Stress/drug effects , Rats , Tissue Culture Techniques
12.
Exp Neurol ; 264: 43-54, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25500111

ABSTRACT

Multiple sclerosis and migraine with aura are clinically correlated and both show imaging changes suggestive of myelin disruption. Furthermore, cortical myelin loss in the cuprizone animal model of multiple sclerosis enhances susceptibility to spreading depression, the likely underlying cause of migraine with aura. Since multiple sclerosis pathology involves inflammatory T cell lymphocyte production of interferon-gamma and a resulting increase in oxidative stress, we tested the hypothesis that spreading depression disrupts myelin through similar signaling pathways. Rat hippocampal slice cultures were initially used to explore myelin loss in spreading depression, since they contain T cells, and allow for controlled tissue microenvironment. These experiments were then translated to the in vivo condition in neocortex. Spreading depression in slice cultures induced significant loss of myelin integrity and myelin basic protein one day later, with gradual recovery by seven days. Myelin basic protein loss was abrogated by T cell depletion, neutralization of interferon-gamma, and pharmacological inhibition of neutral sphingomyelinase-2. Conversely, one day after exposure to interferon-gamma, significant reductions in spreading depression threshold, increases in oxidative stress, and reduced levels of glutathione, an endogenous neutral sphingomyelinase-2 inhibitor, emerged. Similarly, spreading depression triggered significant T cell accumulation, sphingomyelinase activation, increased oxidative stress, and reduction of gray and white matter myelin in vivo. Myelin disruption is involved in spreading depression, thereby providing pathophysiological links between multiple sclerosis and migraine with aura. Myelin disruption may promote spreading depression by enhancing aberrant excitability. Thus, preservation of myelin integrity may provide novel therapeutic targets for migraine with aura.


Subject(s)
Cortical Spreading Depression/physiology , Interferon-gamma/metabolism , Myelin Sheath/metabolism , Neocortex/physiology , Signal Transduction/physiology , Aniline Compounds/pharmacology , Animals , Antibodies/pharmacology , Benzylidene Compounds/pharmacology , Cytokines/immunology , Cytokines/metabolism , Enzyme Inhibitors/pharmacology , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Hippocampus/physiology , In Vitro Techniques , Interferon-gamma/immunology , Male , Myelin Basic Protein/metabolism , Myelin Sheath/ultrastructure , Neocortex/ultrastructure , Rats , Rats, Sprague-Dawley , Rats, Wistar , Sphingomyelin Phosphodiesterase/metabolism , T-Lymphocytes/metabolism
13.
Glia ; 62(7): 1176-94, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24723305

ABSTRACT

Microglia play an important role in fine-tuning neuronal activity. In part, this involves their production of tumor necrosis factor-alpha (TNFα), which increases neuronal excitability. Excessive synaptic activity is necessary to initiate spreading depression (SD). Increased microglial production of proinflammatory cytokines promotes initiation of SD, which, when recurrent, may play a role in conversion of episodic to high frequency and chronic migraine. Previous work shows that this potentiation of SD occurs through increased microglial production of TNFα and reactive oxygen species, both of which are associated with an M1-skewed microglial population. Hence, we explored the role of microglia and their M1 polarization in SD initiation. Selective ablation of microglia from rat hippocampal slice cultures confirmed that microglia are essential for initiation of SD. Application of minocycline to dampen M1 signaling led to increased SD threshold. In addition, we found that SD threshold was increased in rats exposed to environmental enrichment. These rats had increased neocortical levels of interleukin-11 (IL-11), which decreases TNFα signaling and polarized microglia to an M2a-dominant phenotype. M2a microglia reduce proinflammatory signaling and increase production of anti-inflammatory cytokines, and therefore may protect against SD. Nasal administration of IL-11 to mimic effects of environmental enrichment likewise increased M2a polarization and increased SD threshold, an effect also seen in vitro. Similarly, application of conditioned medium from M2a polarized primary microglia to slice cultures also increased SD threshold. Thus, microglia and their polarization state play an essential role in SD initiation, and perhaps by extension migraine with aura and migraine.


Subject(s)
Environment , Hippocampus/physiology , Membrane Potentials/physiology , Microglia/physiology , Neocortex/physiology , Signal Transduction , Animals , Cells, Cultured , Central Nervous System Agents/pharmacology , Cytokines/metabolism , Hippocampus/drug effects , Housing, Animal , Interleukin-11/metabolism , Male , Membrane Potentials/drug effects , Microelectrodes , Microglia/drug effects , Minocycline/pharmacology , Neocortex/drug effects , Oxidative Stress/physiology , Rats, Wistar , Signal Transduction/drug effects , Tissue Culture Techniques , Tumor Necrosis Factor-alpha/metabolism
14.
Expert Rev Neurother ; 14(4): 353-5, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24552578

ABSTRACT

Current treatment options for multiple sclerosis are limited and consist of immunosuppressors or agents to prevent immune infiltration of the brain. These therapies have potentially harmful side effects and do little to promote myelin repair. Instead, we suggest using exosomes, naturally occurring small vesicles that exert influence through the delivery of mRNA, microRNA and protein. Dendritic cells can be cultured from bone marrow and stimulated to release exosomes. When administered to the brain, these exosomes significantly increase myelination and improve remyelination following injury by prompting preoligodendrocytes to differentiate into myelin producing cells. Additionally, they are non-toxic and can easily cross the blood-brain barrier and, thus, have great potential as a therapeutic.


Subject(s)
Exosomes/physiology , Immunologic Factors/therapeutic use , Multiple Sclerosis/immunology , Multiple Sclerosis/therapy , Humans , MicroRNAs/administration & dosage , Proteins/administration & dosage , RNA, Messenger/administration & dosage
15.
J Neuroimmunol ; 266(1-2): 12-23, 2014 Jan 15.
Article in English | MEDLINE | ID: mdl-24275061

ABSTRACT

Dendritic cells (DCs) release exosomes with different characteristics based on stimulus. Here, we showed that DC cultures stimulated with low-level IFNγ released exosomes (IFNγ-DC-Exos) that contained microRNA species that can increase baseline myelination, reduce oxidative stress, and improve remyelination following acute lysolecithin-induced demyelination. Furthermore, nasally administered IFNγ-DC-Exos increased CNS myelination in vivo. IFNγ-DC-Exos were preferentially taken up by oligodendrocytes, suggesting that they directly impact oligodendrocytes to increase myelination. Thus, our results show great potential for use of these IFNγ-DC-Exos as a therapeutic to promote remyelination in multiple sclerosis and dysmyelinating syndromes.


Subject(s)
Demyelinating Diseases/drug therapy , Dendritic Cells/drug effects , Exosomes/drug effects , Interferon-alpha/pharmacology , Animals , Animals, Newborn , Cell Differentiation/drug effects , Cells, Cultured , Demyelinating Diseases/chemically induced , Dendritic Cells/ultrastructure , Female , Glutathione/metabolism , Hippocampus/cytology , Hippocampus/ultrastructure , In Vitro Techniques , Lysophosphatidylcholines/toxicity , Male , MicroRNAs/metabolism , Microglia/drug effects , Microglia/metabolism , Microglia/ultrastructure , Oligodendroglia/drug effects , Oligodendroglia/metabolism , Oxidative Stress/drug effects , Pregnancy , Rats , Rats, Sprague-Dawley , Rats, Wistar , Stem Cells/drug effects
16.
Glia ; 62(2): 284-99, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24339157

ABSTRACT

Although commonly considered a disease of white matter, gray matter demyelination is increasingly recognized as an important component of multiple sclerosis (MS) pathogenesis, particularly in the secondary progressive disease phase. Extent of damage to gray matter is strongly correlated to decline in memory and cognitive dysfunction in MS patients. Aging likewise occurs with cognitive decline from myelin loss, and age-associated failure to remyelinate significantly contributes to MS progression. However, recent evidence demonstrates that parabiotic exposure of aged animals to a youthful systemic milieu can promote oligodendrocyte precursor cell (OPC) differentiation and improve remyelination. In the current study, we focus on this potential for stimulating remyelination, and show it involves serum exosomes that increase OPCs and their differentiation into mature myelin-producing cells-both under control conditions and after acute demyelination. Environmental enrichment (EE) of aging animals produced exosomes that mimicked this promyelinating effect. Additionally, stimulating OPC differentiation via exosomes derived from environmentally enriched animals is unlikely to deplete progenitors, as EE itself promotes proliferation of neural stem cells. We found that both young and EE serum-derived exosomes were enriched in miR-219, which is necessary and sufficient for production of myelinating oligodendrocytes by reducing the expression of inhibitory regulators of differentiation. Accordingly, protein transcript levels of these miR-219 target mRNAs decreased following exosome application to slice cultures. Finally, nasal administration of exosomes to aging rats also enhanced myelination. Thus, peripheral circulating cells in young or environmentally enriched animals produce exosomes that may be a useful therapy for remyelination.


Subject(s)
Central Nervous System/metabolism , Exosomes/metabolism , MicroRNAs/metabolism , Myelin Sheath/metabolism , Oligodendroglia/cytology , Aging , Animals , Axons/metabolism , Axons/pathology , Cell Differentiation/physiology , Demyelinating Diseases/metabolism , Environmental Exposure , Male , Myelin Sheath/pathology , Neural Stem Cells/cytology , Oligodendroglia/metabolism , Rats, Inbred WKY
17.
Exp Neurol ; 234(2): 398-404, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22281105

ABSTRACT

Preeclampsia is a hypertensive disorder of pregnancy that affects many organs including the brain. Neurological complications occur during preeclampsia, the most serious of which is seizure known as eclampsia. Although preeclampsia can precede the eclamptic seizure, it often occurs during normal pregnancy, suggesting that processes associated with normal pregnancy can promote neuronal excitability. Here we investigated whether circulating inflammatory mediators that are elevated late in gestation when seizure also occurs are hyperexcitable to neuronal tissue. Evoked field potentials were measured in hippocampal slices in which control horse serum that slices are normally grown in, was replaced with serum from nonpregnant or late-pregnant Wistar rats for 48 h. We found that serum from pregnant, but not nonpregnant rats, caused hyperexcitability to hippocampal neurons and seizure activity that was abrogated by inhibition of tumor necrosis factor alpha (TNFα) signaling. Additionally, application of TNFα mimicked this increased excitability. Pregnant serum also caused morphological changes in microglia characteristic of activation, and increased TNFα mRNA expression that was not seen with exposure to nonpregnant serum. However, TNFα protein was not found to be elevated in pregnant serum itself, suggesting that other circulating factors during pregnancy caused activation of hippocampal slice cells to produce a TNFα-mediated increase in neuronal excitability. Lastly, although pregnant serum caused neuroinflammation and hyperexcitability of hippocampal slices, it did not increase blood-brain barrier permeability, nor were pregnant rats from which the serum was taken undergoing seizure. Thus, the BBB has an important role in protecting the brain from circulating neuroinflammatory mediators that are hyperexcitable to the brain during pregnancy. These studies provide novel insight into the underlying cause of eclampsia without elevated blood pressure and the protective role of the BBB that prevents exposure of the brain to hyperexcitable factors.


Subject(s)
Evoked Potentials/physiology , Hippocampus/physiopathology , Neurons/physiology , Tumor Necrosis Factor-alpha/metabolism , Animals , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Female , Inflammation Mediators/metabolism , Microglia/physiology , Pregnancy , Rats , Rats, Wistar , Serum , Signal Transduction/physiology
18.
J Vis Exp ; (52)2011 Jun 13.
Article in English | MEDLINE | ID: mdl-21694695

ABSTRACT

Migraine and its transformation to chronic migraine are healthcare burdens in need of improved treatment options. We seek to define how neural immune signaling modulates the susceptibility to migraine, modeled in vitro using spreading depression (SD), as a means to develop novel therapeutic targets for episodic and chronic migraine. SD is the likely cause of migraine aura and migraine pain. It is a paroxysmal loss of neuronal function triggered by initially increased neuronal activity, which slowly propagates within susceptible brain regions. Normal brain function is exquisitely sensitive to, and relies on, coincident low-level immune signaling. Thus, neural immune signaling likely affects electrical activity of SD, and therefore migraine. Pain perception studies of SD in whole animals are fraught with difficulties, but whole animals are well suited to examine systems biology aspects of migraine since SD activates trigeminal nociceptive pathways. However, whole animal studies alone cannot be used to decipher the cellular and neural circuit mechanisms of SD. Instead, in vitro preparations where environmental conditions can be controlled are necessary. Here, it is important to recognize limitations of acute slices and distinct advantages of hippocampal slice cultures. Acute brain slices cannot reveal subtle changes in immune signaling since preparing the slices alone triggers: pro-inflammatory changes that last days, epileptiform behavior due to high levels of oxygen tension needed to vitalize the slices, and irreversible cell injury at anoxic slice centers. In contrast, we examine immune signaling in mature hippocampal slice cultures since the cultures closely parallel their in vivo counterpart with mature trisynaptic function; show quiescent astrocytes, microglia, and cytokine levels; and SD is easily induced in an unanesthetized preparation. Furthermore, the slices are long-lived and SD can be induced on consecutive days without injury, making this preparation the sole means to-date capable of modeling the neuroimmune consequences of chronic SD, and thus perhaps chronic migraine. We use electrophysiological techniques and non-invasive imaging to measure neuronal cell and circuit functions coincident with SD. Neural immune gene expression variables are measured with qPCR screening, qPCR arrays, and, importantly, use of cDNA preamplification for detection of ultra-low level targets such as interferon-gamma using whole, regional, or specific cell enhanced (via laser dissection microscopy) sampling. Cytokine cascade signaling is further assessed with multiplexed phosphoprotein related targets with gene expression and phosphoprotein changes confirmed via cell-specific immunostaining. Pharmacological and siRNA strategies are used to mimic and modulate SD immune signaling.


Subject(s)
Migraine Disorders/immunology , Migraine Disorders/pathology , Models, Immunological , Models, Neurological , Neurons/immunology , Neurons/pathology , Animals , Chronic Disease , Hippocampus/cytology , Hippocampus/immunology , Signal Transduction/immunology
19.
Afr Link ; : 20-2, 1998 May.
Article in English | MEDLINE | ID: mdl-12295892

ABSTRACT

PIP: There are an estimated 87,000 deaf people in Kenya; yet campaigns against HIV/AIDS have failed to address the communication needs of this special segment of the population. This paper examines the communication environment of deaf Kenyans. Though a minor group, the deaf community exists as a distinct cultural entity in the country. The Kenyan deaf culture has evolved from within the deaf communities, mainly in the 38 academic institutions and associations of the deaf. The isolation of these communities helped them to cultivate a unique way of life complete with a language--the Kenya Sign Language (KSL). Greatly bypassed by the information on AIDS, there is danger that the deaf Kenyan community will be wiped out by the epidemic because of the many obstacles. Among these obstacles are the use of the English language in literatures on HIV/AIDS, the lack of KSL interpretation on the television and on many AIDS related programs as well as in local public meetings. In addition, deaf people cannot benefit from the services that are offered by some organizations such as telephone hotline for counseling purposes, as well as for medical counseling services unless there is an interpreter. However, the presence of an interpreter beats the main purpose of these services, which is to offer anonymity and confidentiality. Providing relevant HIV/AIDS information to this forgotten segment of the population is a challenge to the health care community. In this regard, a number of recommendations are discussed.^ieng


Subject(s)
Acquired Immunodeficiency Syndrome , Communication , Disabled Persons , HIV Infections , Research , Africa , Africa South of the Sahara , Africa, Eastern , Demography , Developing Countries , Disease , Kenya , Population , Population Characteristics , Virus Diseases
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