Publications by authors named "Noël C Derecki"

13 Publications

  • Page 1 of 1

High-throughput-compatible assays using a genetically-encoded calcium indicator.

Sci Rep 2019 09 3;9(1):12692. Epub 2019 Sep 3.

Janssen Research & Development, LLC, San Diego, CA, 92121, USA.

Measurement of intracellular calcium in live cells is a key component of a wide range of basic life science research, and crucial for many high-throughput assays used in modern drug discovery. Synthetic calcium indicators have become the industry standard, due their ease of use, high reliability, wide dynamic range, and availability of a large variety of spectral and chemical properties. Genetically-encoded calcium indicators (GECIs) have been optimized to the point where their performance rivals that of synthetic calcium indicators in many applications. Stable expression of a GECI has distinct advantages over synthetic calcium indicators in terms of reagent cost and simplification of the assay process. We generated a clonal cell line constitutively expressing GCaMP6s; high expression of the GECI was driven by coupling to a blasticidin resistance gene with a self-cleaving cis-acting hydrolase element (CHYSEL) 2A peptide. Here, we compared the performance of the GECI GCaMP6s to the synthetic calcium indicator fluo-4 in a variety of assay formats. We demonstrate that the pharmacology of ion channel and GPCR ligands as determined using the two indicators is highly similar, and that GCaMP6s is viable as a direct replacement for a synthetic calcium indicator.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-49070-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722131PMC
September 2019

Structural and functional features of central nervous system lymphatic vessels.

Nature 2015 Jul 1;523(7560):337-41. Epub 2015 Jun 1.

1] Center for Brain Immunology and Glia, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA [2] Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA [3] Medical Scientist Training Program, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA.

One of the characteristics of the central nervous system is the lack of a classical lymphatic drainage system. Although it is now accepted that the central nervous system undergoes constant immune surveillance that takes place within the meningeal compartment, the mechanisms governing the entrance and exit of immune cells from the central nervous system remain poorly understood. In searching for T-cell gateways into and out of the meninges, we discovered functional lymphatic vessels lining the dural sinuses. These structures express all of the molecular hallmarks of lymphatic endothelial cells, are able to carry both fluid and immune cells from the cerebrospinal fluid, and are connected to the deep cervical lymph nodes. The unique location of these vessels may have impeded their discovery to date, thereby contributing to the long-held concept of the absence of lymphatic vasculature in the central nervous system. The discovery of the central nervous system lymphatic system may call for a reassessment of basic assumptions in neuroimmunology and sheds new light on the aetiology of neuroinflammatory and neurodegenerative diseases associated with immune system dysfunction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature14432DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4506234PMC
July 2015

Unexpected cellular players in Rett syndrome pathology.

Neurobiol Dis 2016 08 14;92(Pt A):64-71. Epub 2015 May 14.

Center for Brain Immunology and Glia, Department of Neuroscience, Graduate Program in Neuroscience and Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22908, USA. Electronic address:

Rett syndrome is a devastating neurodevelopmental disorder, primarily caused by mutations of methyl CpG-binding protein 2 (MeCP2). Although the genetic cause of disease was identified over a decade ago, a significant gap still remains in both our clinical and scientific understanding of its pathogenesis. Neurons are known to be primary players in pathology, with their dysfunction being the key in Rett syndrome. While studies in mice have demonstrated a clear causative - and potential therapeutic - role for neurons in Rett syndrome, recent work has suggested that other tissues also contribute significantly to progression of the disease. Indeed, Rett syndrome is known to present with several common peripheral pathologies, such as osteopenia, scoliosis, gastrointestinal problems including nutritional defects, and general growth deficit. Mouse models assessing the potential role of non-neuronal cell types have confirmed both roles in disease and potential therapeutic targets. A new picture is emerging in which neurons both initiate and drive pathology, while dysfunction of other cell types and peripheral tissues exacerbate disease, possibly amplifying further neurologic problems, and ultimately result in a positive feedback loop of progressively worsening symptoms. Here, we review what is known about neuronal and non-neuronal cell types, and discuss how this new, integrative understanding of the disease may allow for additional clinical and scientific pathways for treating and understanding Rett syndrome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nbd.2015.05.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4644494PMC
August 2016

Methyl-CpG Binding Protein 2 Regulates Microglia and Macrophage Gene Expression in Response to Inflammatory Stimuli.

Immunity 2015 Apr;42(4):679-91

Center for Brain Immunology and Glia, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Graduate Program in Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; Medical Scientist Training Program, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA. Electronic address:

Mutations in MECP2, encoding the epigenetic regulator methyl-CpG-binding protein 2, are the predominant cause of Rett syndrome, a disease characterized by both neurological symptoms and systemic abnormalities. Microglial dysfunction is thought to contribute to disease pathogenesis, and here we found microglia become activated and subsequently lost with disease progression in Mecp2-null mice. Mecp2 was found to be expressed in peripheral macrophage and monocyte populations, several of which also became depleted in Mecp2-null mice. RNA-seq revealed increased expression of glucocorticoid- and hypoxia-induced transcripts in Mecp2-deficient microglia and peritoneal macrophages. Furthermore, Mecp2 was found to regulate inflammatory gene transcription in response to TNF stimulation. Postnatal re-expression of Mecp2 using Cx3cr1(creER) increased the lifespan of otherwise Mecp2-null mice. These data suggest that Mecp2 regulates microglia and macrophage responsiveness to environmental stimuli to promote homeostasis. Dysfunction of tissue-resident macrophages might contribute to the systemic pathologies observed in Rett syndrome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2015.03.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4407145PMC
April 2015

Microglia as a critical player in both developmental and late-life CNS pathologies.

Acta Neuropathol 2014 Sep 24;128(3):333-45. Epub 2014 Jul 24.

Department of Neuroscience and Center for Brain Immunology and Glia (BIG), School of Medicine, University of Virginia, Charlottesville, VA, 22908, USA,

Microglia, the tissue-resident macrophages of the brain, are attracting increasing attention as key players in brain homeostasis from development through aging. Recent works have highlighted new and unexpected roles for these once-enigmatic cells in both healthy central nervous system function and in diverse pathologies long thought to be primarily the result of neuronal malfunction. In this review, we have chosen to focus on Rett syndrome, which features early neurodevelopmental pathology, and Alzheimer's disease, a disorder associated predominantly with aging. Interestingly, receptor-mediated microglial phagocytosis has emerged as a key function in both developmental and late-life brain pathologies. In a mouse model of Rett syndrome, bone marrow transplant and CNS engraftment of microglia-like cells were associated with surprising improvements in pathology-these benefits were abrogated by block of phagocytic function. In Alzheimer's disease, large-scale genome-wide association studies have been brought to bear as a method of identifying previously unknown susceptibility genes, which highlight microglial receptors as promising novel targets for therapeutic modulation. Multi-photon in vivo microscopy has provided a method of directly visualizing the effects of manipulation of these target genes. Here, we review the latest findings and concepts emerging from the rapidly growing body of literature exemplified for Rett syndrome and late-onset, sporadic Alzheimer's disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00401-014-1321-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4131160PMC
September 2014

From neurons to microglia, with complements.

Nat Neurosci 2013 Dec;16(12):1712-3

Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nn.3579DOI Listing
December 2013

The role of microglia in brain maintenance: implications for Rett syndrome.

Trends Immunol 2013 Mar 31;34(3):144-50. Epub 2012 Oct 31.

Center for Brain Immunology and Glia and Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA.

The role of microglia in central nervous system (CNS) pathology has been studied extensively, and more recently, examination of microglia in the healthy brain has yielded important insights into their many functions. It was long assumed that microglia were essentially quiescent cells, unless provoked into activation, which was considered a hallmark of disease. More recently, however, it has become increasingly clear that they are extraordinarily dynamic cells, constantly sampling their environment and adjusting to exquisitely delicate stimuli. Along these lines, our laboratory has identified a new and unexpected role for microglial phagocytosis - or lack thereof - in the pathophysiology of Rett syndrome, a neurodevelopmental disease caused by mutation of the gene encoding methyl-CpG binding protein (MECP)2. We have shown that specific expression of wild type Mecp2 in myeloid cells of Mecp2-null mice is sufficient to arrest major symptoms associated with this devastating disease. This beneficial effect, however, is abolished if phagocytic activity of microglia is inhibited. Here, we discuss microglial origins, the role of microglia in brain development and maintenance, and the phenomenon of microglial augmentation by myeloid progenitor cells in the adult brain. Finally, we address in some detail the beneficial roles of microglia as clinical targets in Rett syndrome and other neurological disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.it.2012.10.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3566274PMC
March 2013

Pro-cognitive properties of T cells.

Nat Rev Immunol 2012 09 20;12(9):663-9. Epub 2012 Aug 20.

Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA.

Interactions between the central nervous system and the immune system have been studied primarily in the context of pathology, popularizing the view that interplay between these two systems is inherently detrimental. However, recent experimental data have demonstrated productive neuroimmune interactions that occur under normal physiological conditions. In this Essay, we outline our current understanding of contemporary neuroimmunology, describe a working model of T cell function in support of learning and memory, and offer ideas regarding the selective advantages of immune-mediated effects on brain function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nri3280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4032225PMC
September 2012

Wild-type microglia arrest pathology in a mouse model of Rett syndrome.

Nature 2012 Mar 18;484(7392):105-9. Epub 2012 Mar 18.

Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia 22908, USA.

Rett syndrome is an X-linked autism spectrum disorder. The disease is characterized in most cases by mutation of the MECP2 gene, which encodes a methyl-CpG-binding protein. Although MECP2 is expressed in many tissues, the disease is generally attributed to a primary neuronal dysfunction. However, as shown recently, glia, specifically astrocytes, also contribute to Rett pathophysiology. Here we examine the role of another form of glia, microglia, in a murine model of Rett syndrome. Transplantation of wild-type bone marrow into irradiation-conditioned Mecp2-null hosts resulted in engraftment of brain parenchyma by bone-marrow-derived myeloid cells of microglial phenotype, and arrest of disease development. However, when cranial irradiation was blocked by lead shield, and microglial engraftment was prevented, disease was not arrested. Similarly, targeted expression of MECP2 in myeloid cells, driven by Lysm(cre) on an Mecp2-null background, markedly attenuated disease symptoms. Thus, through multiple approaches, wild-type Mecp2-expressing microglia within the context of an Mecp2-null male mouse arrested numerous facets of disease pathology: lifespan was increased, breathing patterns were normalized, apnoeas were reduced, body weight was increased to near that of wild type, and locomotor activity was improved. Mecp2(+/-) females also showed significant improvements as a result of wild-type microglial engraftment. These benefits mediated by wild-type microglia, however, were diminished when phagocytic activity was inhibited pharmacologically by using annexin V to block phosphatydilserine residues on apoptotic targets, thus preventing recognition and engulfment by tissue-resident phagocytes. These results suggest the importance of microglial phagocytic activity in Rett syndrome. Our data implicate microglia as major players in the pathophysiology of this devastating disorder, and suggest that bone marrow transplantation might offer a feasible therapeutic approach for it.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature10907DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321067PMC
March 2012

Alternatively activated myeloid (M2) cells enhance cognitive function in immune compromised mice.

Brain Behav Immun 2011 Mar 18;25(3):379-85. Epub 2010 Nov 18.

Graduate Program in Neuroscience, Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA.

It was recently shown that adaptive immunity plays a key role in cognitive function. T cells appear to be major players in learning and memory; thus, mice devoid of functional T cells are impaired in performance of cognitive tasks such as Morris water maze (MWM), Barnes maze and others. This is a reversible phenomenon; injection of immune deficient mice with T cells from wild type counterparts improves their cognitive function. Recently we described a critical role for T cell-derived IL-4 as having beneficial effects on learning and memory through regulation of meningeal myeloid cell phenotype. In the absence of IL-4, meningeal myeloid cells acquire a pro-inflammatory skew. Thus, the presence of IL-4 in the meningeal spaces maintains a delicate balance of pro- and anti-inflammatory myeloid cell phenotype. Here we show that macrophages alternatively activated in vitro (M2 cells) can circumvent the need for 'pro-cognitive' T cells when injected intravenously into immune deficient mice. These results show for the first time that M2 myeloid cells are new and unexpected players in cognitive function, conferring beneficial effects on learning and memory without adaptive immune influence. These results might lead to development of new therapeutic approaches for cognitive pathologies associated with malfunction of adaptive immunity, such as chemo-brain, age-related dementia, HIV-dementia, and others.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbi.2010.11.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3039052PMC
March 2011

Regulation of learning and memory by meningeal immunity: a key role for IL-4.

J Exp Med 2010 May 3;207(5):1067-80. Epub 2010 May 3.

Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA.

Proinflammatory cytokines have been shown to impair cognition; consequently, immune activity in the central nervous system was considered detrimental to cognitive function. Unexpectedly, however, T cells were recently shown to support learning and memory, though the underlying mechanism was unclear. We show that one of the steps in the cascade of T cell-based support of learning and memory takes place in the meningeal spaces. Performance of cognitive tasks led to accumulation of IL-4-producing T cells in the meninges. Depletion of T cells from meningeal spaces skewed meningeal myeloid cells toward a proinflammatory phenotype. T cell-derived IL-4 was critical, as IL-4(-/-) mice exhibited a skewed proinflammatory meningeal myeloid cell phenotype and cognitive deficits. Transplantation of IL-4(-/-) bone marrow into irradiated wild-type recipients also resulted in cognitive impairment and proinflammatory skew. Moreover, adoptive transfer of T cells from wild-type into IL-4(-/-) mice reversed cognitive impairment and attenuated the proinflammatory character of meningeal myeloid cells. Our results point to a critical role for T cell-derived IL-4 in the regulation of cognitive function through meningeal myeloid cell phenotype and brain-derived neurotrophic factor expression. These findings might lead to the development of new immune-based therapies for cognitive impairment associated with immune decline.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20091419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2867291PMC
May 2010