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Ng FS, Sengupta S, Huang Y, Yu AM, You S, Roberts MA, Iyer LK, Yang Y, Jackson FR. TRAP-seq Profiling and RNAi-Based Genetic Screens Identify Conserved Glial Genes Required for Adult Drosophila Behavior. Front Mol Neurosci 2016; 9:146. [PMID: 28066175 PMCID: PMC5177635 DOI: 10.3389/fnmol.2016.00146] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/30/2016] [Indexed: 01/06/2023] Open
Abstract
Although, glial cells have well characterized functions in the developing and mature brain, it is only in the past decade that roles for these cells in behavior and plasticity have been delineated. Glial astrocytes and glia-neuron signaling, for example, are now known to have important modulatory functions in sleep, circadian behavior, memory and plasticity. To better understand mechanisms of glia-neuron signaling in the context of behavior, we have conducted cell-specific, genome-wide expression profiling of adult Drosophila astrocyte-like brain cells and performed RNA interference (RNAi)-based genetic screens to identify glial factors that regulate behavior. Importantly, our studies demonstrate that adult fly astrocyte-like cells and mouse astrocytes have similar molecular signatures; in contrast, fly astrocytes and surface glia-different classes of glial cells-have distinct expression profiles. Glial-specific expression of 653 RNAi constructs targeting 318 genes identified multiple factors associated with altered locomotor activity, circadian rhythmicity and/or responses to mechanical stress (bang sensitivity). Of interest, 1 of the relevant genes encodes a vesicle recycling factor, 4 encode secreted proteins and 3 encode membrane transporters. These results strongly support the idea that glia-neuron communication is vital for adult behavior.
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Affiliation(s)
- Fanny S Ng
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Sukanya Sengupta
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Yanmei Huang
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Amy M Yu
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Samantha You
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Mary A Roberts
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Lakshmanan K Iyer
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - Yongjie Yang
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
| | - F Rob Jackson
- Department of Neuroscience, Sackler Program in Biomedical Sciences, Tufts University School of Medicine Boston, MA, USA
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202
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Zheng JY, Liang KS, Wang XJ, Zhou XY, Sun J, Zhou SN. Chronic Estradiol Administration During the Early Stage of Alzheimer's Disease Pathology Rescues Adult Hippocampal Neurogenesis and Ameliorates Cognitive Deficits in Aβ 1-42 Mice. Mol Neurobiol 2016; 54:7656-7669. [PMID: 27838872 DOI: 10.1007/s12035-016-0181-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/28/2016] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia and has become an important public health concern. Accumulating evidence indicates that estradiol can both facilitate and impair memory-related processes and, as a result, the precise nature of the role that estradiol plays during AD pathology remains elusive. Therefore, the present study established a mouse model of AD using stereotactic brain injection of Aβ1-42 in which the mice were bilaterally ovariectomized to investigate the effects of 17β-estradiol (E2) treatment during different stages of the AD process (early and late stages). The cognitive deficits associated with this AD model were significantly ameliorated, and there was a significant increase in hippocampal neurogenesis in Aβ1-42 mice that received E2 treatment during the early stage of AD pathology. On the other hand, Aβ1-42 mice that received E2 treatment during the late stage of AD pathology did not exhibit any improvements in cognitive function or hippocampal neurogenesis. To reveal the mechanisms, underlying these effects, levels of oxidative stress, activity in death-associated pathways, gliosis, and synaptic function were assessed in the hippocampus. The Aβ1-42 mice that received E2 treatment during the early stage of AD pathology exhibited significant reductions in the production of nitric oxide (NO) and reactive oxygen species (ROS), a marked decrease in the activation of Cytochrome-c/Bax/Bcl-2/caspase-3 pathway, a notable decrease in the level of gliosis a significant increase in the number of synapses (ultrastructural investigation), and a marked upregulation in synaptic function-related proteins compared to mice that received E2 treatment during the late stage of AD pathology. Taken together, these findings indicate that E2 treatment during the early stage of AD pathology might be an efficient approach to ameliorate the development of this disease.
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Affiliation(s)
- Jin-Yu Zheng
- Department of Neurosurgery, The Affiliated Huai'an Hospital of Xuzhou Medical College, No. 62 South Huaihai Road, Huai'an, Jiangsu Province, 223002, People's Republic of China
| | - Ke-Shan Liang
- Department of Neurology, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, No. 107 Wenhuaxi Road, Jinan, Shandong, 250012, People's Republic of China
- Department of Neurology, Pingyi Branch of Qilu Hospital, Shandong University, No. 07 Jinhua Road, Pingyi, Shandong Province, 273300, People's Republic of China
| | - Xian-Jun Wang
- Department of Neurology, Linyi People's Hospital, No. 49 Yizhou Road, Linyi, Shandong, 276000, People's Republic of China
| | - Xue-Ying Zhou
- Department of Neurology, Shangdong University of Traditional Chinese Medicine, Jinan, Shandong, 250031, China
| | - Jian Sun
- Department of Anesthesiology, Maternal and Child Health Hospital of Huai'an, No. 104 South Renmin, Huai'an, Jiangsu Province, 223002, China.
| | - Sheng-Nian Zhou
- Department of Neurology, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, No. 107 Wenhuaxi Road, Jinan, Shandong, 250012, People's Republic of China.
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203
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Stogsdill JA, Eroglu C. The interplay between neurons and glia in synapse development and plasticity. Curr Opin Neurobiol 2016; 42:1-8. [PMID: 27788368 DOI: 10.1016/j.conb.2016.09.016] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/26/2016] [Indexed: 12/21/2022]
Abstract
In the brain, the formation of complex neuronal networks amenable to experience-dependent remodeling is complicated by the diversity of neurons and synapse types. The establishment of a functional brain depends not only on neurons, but also non-neuronal glial cells. Glia are in continuous bi-directional communication with neurons to direct the formation and refinement of synaptic connectivity. This article reviews important findings, which uncovered cellular and molecular aspects of the neuron-glia cross-talk that govern the formation and remodeling of synapses and circuits. In vivo evidence demonstrating the critical interplay between neurons and glia will be the major focus. Additional attention will be given to how aberrant communication between neurons and glia may contribute to neural pathologies.
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Affiliation(s)
- Jeff A Stogsdill
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
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204
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Krencik R, van Asperen JV, Ullian EM. Human astrocytes are distinct contributors to the complexity of synaptic function. Brain Res Bull 2016; 129:66-73. [PMID: 27570101 DOI: 10.1016/j.brainresbull.2016.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/07/2016] [Accepted: 08/22/2016] [Indexed: 01/03/2023]
Abstract
Cellular components of synaptic circuits have been adjusted for increased human brain size, neural cell density, energy consumption and developmental duration. How does the human brain make these accommodations? There is evidence that astrocytes are one of the most divergent neural cell types in primate brain evolution and it is now becoming clear that they have critical roles in controlling synaptic development, function and plasticity. Yet, we still do not know how the precise developmental appearance of these cells and subsequent astrocyte-derived signals modulate diverse neuronal circuit subtypes. Here, we discuss what is currently known about the influence of glial factors on synaptic maturation and focus on unique features of human astrocytes including their potential roles in regenerative and translational medicine. Human astrocyte distinctiveness may be a major contributor to high level neuronal processing of the human brain and act in novel ways during various neuropathies ranging from autism spectrum disorders, viral infection, injury and neurodegenerative conditions.
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Affiliation(s)
- Robert Krencik
- Departments of Ophthalmology and Physiology, Neuroscience Program, University of California San Francisco, United States.
| | - Jessy V van Asperen
- Departments of Ophthalmology and Physiology, Neuroscience Program, University of California San Francisco, United States
| | - Erik M Ullian
- Departments of Ophthalmology and Physiology, Neuroscience Program, University of California San Francisco, United States
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205
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Inability to activate Rac1-dependent forgetting contributes to behavioral inflexibility in mutants of multiple autism-risk genes. Proc Natl Acad Sci U S A 2016; 113:7644-9. [PMID: 27335463 DOI: 10.1073/pnas.1602152113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The etiology of autism is so complicated because it involves the effects of variants of several hundred risk genes along with the contribution of environmental factors. Therefore, it has been challenging to identify the causal paths that lead to the core autistic symptoms such as social deficit, repetitive behaviors, and behavioral inflexibility. As an alternative approach, extensive efforts have been devoted to identifying the convergence of the targets and functions of the autism-risk genes to facilitate mapping out causal paths. In this study, we used a reversal-learning task to measure behavioral flexibility in Drosophila and determined the effects of loss-of-function mutations in multiple autism-risk gene homologs in flies. Mutations of five autism-risk genes with diversified molecular functions all led to a similar phenotype of behavioral inflexibility indicated by impaired reversal-learning. These reversal-learning defects resulted from the inability to forget or rather, specifically, to activate Rac1 (Ras-related C3 botulinum toxin substrate 1)-dependent forgetting. Thus, behavior-evoked activation of Rac1-dependent forgetting has a converging function for autism-risk genes.
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206
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