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Li Q, Wang L, Tang C, Wang X, Yu Z, Ping X, Ding M, Zheng L. Adipose Tissue Exosome circ_sxc Mediates the Modulatory of Adiposomes on Brain Aging by Inhibiting Brain dme-miR-87-3p. Mol Neurobiol 2024; 61:224-238. [PMID: 37597108 DOI: 10.1007/s12035-023-03516-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/14/2023] [Indexed: 08/21/2023]
Abstract
Aging of the brain usually leads to the decline of neurological processes and is a major risk factor for various neurodegenerative diseases, including sleep disturbances and cognitive decline. Adipose tissue exosomes, as adipocyte-derived vesicles, may mediate the regulatory processes of adipose tissue on other organs, including the brain; however, the regulatory mechanisms remain unclear. We analyzed the sleep-wake behavior of young (10 days) and old (40 days) Drosophila and found that older Drosophila showed increased sleep fragmentation, which is similar to mammalian aging characteristics. To investigate the cross-tissue regulatory mechanisms of adiposity on brain aging, we extracted 10-day and 40-day Drosophila adipose tissue exosomes and identified circRNAs with age-dependent expression differences by RNA-seq and differential analysis. Furthermore, by combining data from 3 datasets of the GEO database (GSE130158, GSE24992, and GSE184559), circ_sxc that was significantly downregulated with age was finally screened out. Moreover, dme-miR-87-3p, a conserved target of circ_sxc, accumulates in the brain with age and exhibits inhibitory effects in predicted binding relationships with neuroreceptor ligand genes. In summary, the current study showed that the Drosophila brain could obtain circ_sxc by uptake of adipose tissue exosomes which crossed the blood-brain barrier. And circ_sxc suppressed brain miR-87-3p expression through sponge adsorption, which in turn regulated the expression of neurological receptor ligand proteins (5-HT1B, GABA-B-R1, Rdl, Rh7, qvr, NaCP60E) and ensured brain neuronal synaptic signaling normal function of synaptic signaling. However, with aging, this regulatory mechanism is dysregulated by the downregulation of the adipose exosome circ_sxc, which contributes to the brain exhibiting sleep disturbances and other "aging" features.
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Affiliation(s)
- Qiufang Li
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Lingxiao Wang
- The Center for Heart Development, State Key Laboratory of Development Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China.
| | - Chao Tang
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Xiaoya Wang
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Zhengwen Yu
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Xu Ping
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Meng Ding
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China
| | - Lan Zheng
- Key Laboratory of Physical Fitness and Exercise Rehabilitation of Hunan Province, Hunan Normal University, Changsha, Hunan, China.
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Armour EM, Thomas CM, Greco G, Bhatnagar A, Elefant F. Experience-dependent Tip60 nucleocytoplasmic transport is regulated by its NLS/NES sequences for neuroplasticity gene control. Mol Cell Neurosci 2023; 127:103888. [PMID: 37598897 PMCID: PMC11337217 DOI: 10.1016/j.mcn.2023.103888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/22/2023] Open
Abstract
Nucleocytoplasmic transport (NCT) in neurons is critical for enabling proteins to enter the nucleus and regulate plasticity genes in response to environmental cues. Such experience-dependent (ED) neural plasticity is central for establishing memory formation and cognitive function and can influence the severity of neurodegenerative disorders like Alzheimer's disease (AD). ED neural plasticity is driven by histone acetylation (HA) mediated epigenetic mechanisms that regulate dynamic activity-dependent gene transcription profiles in response to neuronal stimulation. Yet, how histone acetyltransferases (HATs) respond to extracellular cues in the in vivo brain to drive HA-mediated activity-dependent gene control remains unclear. We previously demonstrated that extracellular stimulation of rat hippocampal neurons in vitro triggers Tip60 HAT nuclear import with concomitant synaptic gene induction. Here, we focus on investigating Tip60 HAT subcellular localization and NCT specifically in neuronal activity-dependent gene control by using the learning and memory mushroom body (MB) region of the Drosophila brain as a powerful in vivo cognitive model system. We used immunohistochemistry (IHC) to compare the subcellular localization of Tip60 HAT in the Drosophila brain under normal conditions and in response to stimulation of fly brain neurons in vivo either by genetically inducing potassium channels activation or by exposure to natural positive ED conditions. Furthermore, we found that both inducible and ED condition-mediated neural induction triggered Tip60 nuclear import with concomitant induction of previously identified Tip60 target genes and that Tip60 levels in both the nucleus and cytoplasm were significantly decreased in our well-characterized Drosophila AD model. Mutagenesis of a putative nuclear localization signal (NLS) sequence and nuclear export signal (NES) sequence that we identified in the Drosophila Tip60 protein revealed that both are functionally required for appropriate Tip60 subcellular localization. Our results support a model by which neuronal stimulation triggers Tip60 NCT via its NLS and NES sequences to promote induction of activity-dependent neuroplasticity gene transcription and that this process may be disrupted in AD.
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Affiliation(s)
- Ellen M Armour
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Christina M Thomas
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Gabrielle Greco
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Akanksha Bhatnagar
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, PA, United States of America.
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Ruan H, Ueda A, Xing X, Wan X, Strub B, Mukai S, Certel K, Green D, Belozerov K, Yao WD, Johnson W, Jung-Ching Lin J, Hilliker AJ, Wu CF. Generation and characterization of new alleles of quiver (qvr) that encodes an extracellular modulator of the Shaker potassium channel. J Neurogenet 2017; 31:325-336. [PMID: 29117754 DOI: 10.1080/01677063.2017.1393076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Our earlier genetic screen uncovered a paraquat-sensitive leg-shaking mutant quiver1 (qvr1), whose gene product interacts with the Shaker (Sh) K+ channel. We also mapped the qvr locus to EY04063 and noticed altered day-night activity patterns in these mutants. Such circadian behavioral defects were independently reported by another group, who employed the qvr1 allele we supplied them, and attributed the extreme restless phenotype of EY04063 to the qvr gene. However, their report adopted a new noncanonical gene name sleepless (sss) for qvr. In addition to qvr1 and qvrEY, our continuous effort since the early 2000s generated a number of novel recessive qvr alleles, including ethyl methanesulfonate (EMS)-induced mutations qvr2 and qvr3, and P-element excision lines qvrip6 (imprecise jumpout), qvrrv7, and qvrrv9 (revertants) derived from qvrEY. Distinct from the original intron-located qvr1 allele that generates abnormal-sized mRNAs, qvr2, and qvr3 had their lesion sites in exons 6 and 7, respectively, producing nearly normal-sized mRNA products. A set of RNA-editing sites are nearby the lesion sites of qvr3 and qvrEY on exon 7. Except for the revertants, all qvr alleles display a clear ether-induced leg-shaking phenotype just like Sh, and weakened climbing abilities to varying degrees. Unlike Sh, all shaking qvr alleles (except for qvrf01257) displayed a unique activity-dependent enhancement in excitatory junction potentials (EJPs) at larval neuromuscular junctions (NMJs) at very low stimulus frequencies, with qvrEY displaying the largest EJP and more significant NMJ overgrowth than other alleles. Our detailed characterization of a collection of qvr alleles helps to establish links between novel molecular lesions and different behavioral and physiological consequences, revealing how modifications of the qvr gene lead to a wide spectrum of phenotypes, including neuromuscular hyperexcitability, defective motor ability and activity-rest cycles.
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Affiliation(s)
- Hongyu Ruan
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Atsushi Ueda
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Xiaomin Xing
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Xuxuan Wan
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Benjamin Strub
- b Department of Biology , York University , Toronto , ON , Canada
| | - Spencer Mukai
- b Department of Biology , York University , Toronto , ON , Canada
| | - Kaan Certel
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , IA , USA
| | - David Green
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Kyle Belozerov
- b Department of Biology , York University , Toronto , ON , Canada
| | - Wei-Dong Yao
- a Department of Biology , University of Iowa , Iowa City , IA , USA
| | - Wayne Johnson
- c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , IA , USA
| | | | | | - Chun-Fang Wu
- a Department of Biology , University of Iowa , Iowa City , IA , USA
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Lithium-Responsive Seizure-Like Hyperexcitability Is Caused by a Mutation in the Drosophila Voltage-Gated Sodium Channel Gene paralytic. eNeuro 2016; 3:eN-NWR-0221-16. [PMID: 27844061 PMCID: PMC5103163 DOI: 10.1523/eneuro.0221-16.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/06/2016] [Indexed: 01/01/2023] Open
Abstract
Shudderer (Shu) is an X-linked dominant mutation in Drosophila melanogaster identified more than 40 years ago. A previous study showed that Shu caused spontaneous tremors and defects in reactive climbing behavior, and that these phenotypes were significantly suppressed when mutants were fed food containing lithium, a mood stabilizer used in the treatment of bipolar disorder (Williamson, 1982). This unique observation suggested that the Shu mutation affects genes involved in lithium-responsive neurobiological processes. In the present study, we identified Shu as a novel mutant allele of the voltage-gated sodium (Nav) channel gene paralytic (para). Given that hypomorphic para alleles and RNA interference-mediated para knockdown reduced the severity of Shu phenotypes, Shu was classified as a para hypermorphic allele. We also demonstrated that lithium could improve the behavioral abnormalities displayed by other Nav mutants, including a fly model of the human generalized epilepsy with febrile seizures plus. Our electrophysiological analysis of Shu showed that lithium treatment did not acutely suppress Nav channel activity, indicating that the rescue effect of lithium resulted from chronic physiological adjustments to this drug. Microarray analysis revealed that lithium significantly alters the expression of various genes in Shu, including those involved in innate immune responses, amino acid metabolism, and oxidation-reduction processes, raising the interesting possibility that lithium-induced modulation of these biological pathways may contribute to such adjustments. Overall, our findings demonstrate that Nav channel mutants in Drosophila are valuable genetic tools for elucidating the effects of lithium on the nervous system in the context of neurophysiology and behavior.
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Wu M, Liu CZ, Joiner WJ. Structural Analysis and Deletion Mutagenesis Define Regions of QUIVER/SLEEPLESS that Are Responsible for Interactions with Shaker-Type Potassium Channels and Nicotinic Acetylcholine Receptors. PLoS One 2016; 11:e0148215. [PMID: 26828958 PMCID: PMC4735452 DOI: 10.1371/journal.pone.0148215] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/13/2016] [Indexed: 12/16/2022] Open
Abstract
Ly6 proteins are endogenous prototoxins found in most animals. They show striking structural and functional parallels to snake α-neurotoxins, including regulation of ion channels and cholinergic signaling. However, the structural contributions of Ly6 proteins to regulation of effector molecules is poorly understood. This question is particularly relevant to the Ly6 protein QUIVER/SLEEPLESS (QVR/SSS), which has previously been shown to suppress excitability and synaptic transmission by upregulating potassium (K) channels and downregulating nicotinic acetylcholine receptors (nAChRs) in wake-promoting neurons to facilitate sleep in Drosophila. Using deletion mutagenesis, co-immunoprecipitations, ion flux assays, surface labeling and confocal microscopy, we demonstrate that only loop 2 is required for many of the previously described properties of SSS in transfected cells, including interactions with K channels and nAChRs. Collectively our data suggest that QVR/SSS, and by extension perhaps other Ly6 proteins, target effector molecules using limited protein motifs. Mapping these motifs may be useful in rational design of drugs that mimic or suppress Ly6-effector interactions to modulate nervous system function.
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Affiliation(s)
- Meilin Wu
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America
| | - Clifford Z Liu
- UCSD undergraduate program, Marshall College, University of California San Diego, La Jolla, California, United States of America
| | - William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, California, United States of America.,Center for Circadian Biology, University of California San Diego, La Jolla, California, United States of America
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Iyengar A, Wu CF. Flight and seizure motor patterns in Drosophila mutants: simultaneous acoustic and electrophysiological recordings of wing beats and flight muscle activity. J Neurogenet 2014; 28:316-28. [PMID: 25159538 PMCID: PMC5555410 DOI: 10.3109/01677063.2014.957827] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Abstract Tethered flies allow studies of biomechanics and electrophysiology of flight control. We performed microelectrode recordings of spikes in an indirect flight muscle (the dorsal longitudinal muscle, DLMa) coupled with acoustic analysis of wing beat frequency (WBF) via microphone signals. Simultaneous electrophysiological recording of direct and indirect flight muscles has been technically challenging; however, the WBF is thought to reflect in a one-to-one relationship with spiking activity in a subset of direct flight muscles, including muscle m1b. Therefore, our approach enables systematic mutational analysis for changes in temporal features of electrical activity of motor neurons innervating subsets of direct and indirect flight muscles. Here, we report the consequences of specific ion channel disruptions on the spiking activity of myogenic DLMs (firing at ∼5 Hz) and the corresponding WBF (∼200 Hz). We examined mutants of the genes enconding: 1) voltage-gated Ca(2+) channels (cacophony, cac), 2) Ca(2+)-activated K(+) channels (slowpoke, slo), and 3) voltage-gated K(+) channels (Shaker, Sh) and their auxiliary subunits (Hyperkinetic, Hk and quiver, qvr). We found flight initiation in response to an air puff was severely disrupted in both cac and slo mutants. However, once initiated, slo flight was largely unaltered, whereas cac displayed disrupted DLM firing rates and WBF. Sh, Hk, and qvr mutants were able to maintain normal DLM firing rates, despite increased WBF. Notably, defects in the auxiliary subunits encoded by Hk and qvr could lead to distinct consequences, that is, disrupted DLM firing rhythmicity, not observed in Sh. Our mutant analysis of direct and indirect flight muscle activities indicates that the two motor activity patterns may be independently modified by specific ion channel mutations, and that this approach can be extended to other dipteran species and additional motor programs, such as electroconvulsive stimulation-induced seizures.
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Affiliation(s)
- Atulya Iyengar
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Chun-Fang Wu
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
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Potdar S, Sheeba V. Lessons From Sleeping Flies: Insights fromDrosophila melanogasteron the Neuronal Circuitry and Importance of Sleep. J Neurogenet 2013; 27:23-42. [DOI: 10.3109/01677063.2013.791692] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.
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Affiliation(s)
- Björn Rasch
- Division of Biopsychology, Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland.
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Drosophila QVR/SSS modulates the activation and C-type inactivation kinetics of Shaker K(+) channels. J Neurosci 2011; 31:11387-95. [PMID: 21813698 DOI: 10.1523/jneurosci.0502-11.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The quiver/sleepless (qvr/sss) gene encodes a small, glycosylphosphatidylinositol-anchored protein that plays a critical role in the regulation of sleep in Drosophila. Loss-of-function mutations in qvr/sss severely suppress sleep and effect multiple changes in in situ Shaker K(+) currents, including decreased magnitude, slower time-to-peak, and cumulative inactivation. Recently, we demonstrated that SLEEPLESS (SSS) protein modulates Shaker channel activity, possibly through a direct interaction at the plasma membrane. We show here that SSS accelerates the activation of heterologously expressed Shaker channels with no effect on deactivation or fast N-type inactivation. Furthermore, this SSS-induced acceleration is sensitive to the pharmacological disruption of lipid rafts and sufficiently accounts for the slower time-to-peak of in situ Shaker currents seen in qvr/sss mutants. We also find that SSS decreases the rate of C-type inactivation of heterologously expressed Shaker channels, providing a potential mechanism for the cumulative inactivation phenotype induced by qvr/sss loss-of-function mutations. Kinetic modeling based on the in vitro results suggests that the SSS-dependent regulation of channel kinetics accounts for nearly 40% of the decrease in Shaker current magnitude in flies lacking SSS. Sleep duration in qvr/sss-null mutants is restored to normal by a qvr/sss transgene that fully rescues the Shaker kinetic phenotypes but only partially rescues the decrease in current magnitude. Together, these results suggest that the role of SSS in the regulation of sleep in Drosophila correlates more strongly with the effects of SSS on Shaker kinetics than current magnitude.
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Abstract
Drosophila melanogaster is one of the most well studied genetic model organisms, nonetheless its genome still contains unannotated coding and non-coding genes, transcripts, exons, and RNA editing sites. Full discovery and annotation are prerequisites for understanding how the regulation of transcription, splicing, and RNA editing directs development of this complex organism. We used RNA-Seq, tiling microarrays, and cDNA sequencing to explore the transcriptome in 30 distinct developmental stages. We identified 111,195 new elements, including thousands of genes, coding and non-coding transcripts, exons, splicing and editing events and inferred protein isoforms that previously eluded discovery using established experimental, prediction and conservation-based approaches. Together, these data substantially expand the number of known transcribed elements in the Drosophila genome and provide a high-resolution view of transcriptome dynamics throughout development.
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