miR-263b Controls Circadian Behavior and the Structural Plasticity of Pacemaker Neurons by Regulating the LIM-Only Protein Beadex

Circadian clocks drive rhythmic physiology and behavior to allow adaption to daily environmental changes. In Drosophila, the small ventral lateral neurons (sLNvs) are primary pacemakers that control circadian rhythms. Circadian changes are observed in the dorsal axonal projections of the sLNvs, but their physiological importance and the underlying mechanism are unclear. Here, we identified miR-263b as an important regulator of circadian rhythms and structural plasticity of sLNvs in Drosophila. Depletion of miR-263b (miR-263bKO) in flies dramatically impaired locomotor rhythms under constant darkness. Indeed, miR-263b is required for the structural plasticity of sLNvs. miR-263b regulates circadian rhythms through inhibition of expression of the LIM-only protein Beadex (Bx). Consistently, overexpression of Bx or loss-of-function mutation (BxhdpR26) phenocopied miR-263bKO and miR-263b overexpression in behavior and molecular characteristics. In addition, mutating the miR-263b binding sites in the Bx 3′ UTR using CRISPR/Cas9 recapitulated the circadian phenotypes of miR-263bKO flies. Together, these results establish miR-263b as an important regulator of circadian locomotor behavior and structural plasticity.

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miR-263b controls circadian rhythms and structural plasticity of small ventral lateral neurons by inhibition of Beadex

10.1101/368043 ◽

2018 ◽

Author(s):

Xiaoge Nian ◽

Wenfeng Chen ◽

Weiwei Bai ◽

Zhangwu Zhao ◽

Yong Zhang

Keyword(s):

Circadian Rhythms ◽

Environmental Changes ◽

Structural Plasticity ◽

Underlying Mechanism ◽

Molecular Characteristics ◽

Constant Darkness ◽

Physiological Importance ◽

Axonal Projections ◽

Important Regulator ◽

Lateral Neurons

Circadian clocks drive rhythmic physiology and behavior to allow adaption to daily environmental changes. In Drosophila , the small ventral lateral neurons (sLNvs) are the master pacemakers that control circadian rhythms. Circadian changes are observed in the dorsal axonal projections of the sLNvs, but their physiological importance and the underlying mechanism are unclear. Here we identified miR-263b as an important regulator of circadian rhythms in Drosophila . Flies depleted of miR-263b ( miR-263b KO ) exhibited dramatically impaired rhythms under constant darkness. Indeed, miR-263b is rhythmically expressed and controls circadian output by affecting the structural plasticity of sLNvs through inhibition of expression of the LIM-only protein Beadex ( Bx ). The misexpression of Bx in flies phenocopied miR-263b KO in behavior and molecular characteristics. In addition, the circadian phenotypes of miR-263b KO were recapitulated by mutating the miR-263b binding sites in the Bx 3′UTR. Together, these results establish miR-263b as an important regulator of circadian locomotor behavior.

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miR-210 controls the evening phase of circadian locomotor rhythms through repression of Fasciclin 2

10.1101/399873 ◽

2018 ◽

Author(s):

Wesley Leigh ◽

Zhenxing Liu ◽

Xiaoge Nian ◽

Yong Zhang

Keyword(s):

Cell Adhesion ◽

Circadian Rhythms ◽

Binding Site ◽

Environmental Changes ◽

Fruit Flies ◽

Circadian Clocks ◽

Phase Advance ◽

Constant Darkness ◽

Circadian Regulation ◽

Anticipatory Behavior

AbstractCircadian clocks control the timing of animal behavior rhythms to anticipate daily environmental changes. Fruit flies gradually increase their activity and reach a peak of activity around dawn and dusk. microRNAs are small non-coding RNAs that play important roles in post-transcriptional regulation. Here we identify Drosophila miR-210 as a critical regulator of circadian rhythms. Under light-dark conditions, flies lacking miR-210 (miR-210KO) exhibit a dramatic phase advance of evening anticipatory behavior about 2 hours. However, circadian rhythms and molecular pacemaker function are intact in miR-210KO flies under constant darkness. Furthermore, we identify that miR-210 determines the evening phase of activity through repression of the cell adhesion molecule Fasciclin 2 (Fas2). Ablation of the miR-210 binding site within the 3’ UTR of Fas2 (Fas2ΔmiR-210) by CRISPR-Cas9 advances the evening phase as in miR-210KO. Indeed, miR-210 genetically interacts with Fas2. Moreover, Fas2 abundance is significantly increased in the optic lobe of miR-210KO and Fas2ΔmiR-210. In addition, overexpression of Fas2 in the miR-210 expressing cells recapitulates the phase advance behavior phenotype of miR-210KO. Together, these results reveal a novel mechanism by which miR-210 regulates circadian locomotor behavior.Author summaryCircadian clocks control the timing of animal physiology. Drosophila has been a powerful model in understanding the mechanisms of circadian regulation. Fruit flies anticipate daily environmental changes and exhibit two peaks of locomotor activity around dawn and dusk. Here we identify miR-210 as a critical regulator of evening anticipatory behavior. Depletion of miR-210 in flies advances evening anticipation. Futhermore, we identify the cell adhesion molecular Fas2 as miR-210’s target in circadian regulation. Fas2 abundance is increased in fly brain lacking of miR-210. Using CRISPR-Cas9 genome editing method, we deleted the miR-210 binding site on 3’ untranslated region of Fas2 and observed similar phenotype as miR-210 mutants. Altogether, our results indicate a novel mechanism of miR-210 in regulation of circadian anticipatory behavior through inhibition of Fas2.

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Nitric Oxide Mediates Neuro-Glial Interaction that Shapes Drosophila Circadian Behavior

10.1101/700971 ◽

2019 ◽

Author(s):

Anatoly Kozlov ◽

Emi Nagoshi

Keyword(s):

Nitric Oxide ◽

Circadian Rhythms ◽

Neural Circuit ◽

Critical Role ◽

Constant Darkness ◽

Molecular Clocks ◽

Loss Of Function ◽

Pacemaker Neurons ◽

Circadian Behavior ◽

First Time

AbstractDrosophila circadian behavior relies on the network of heterogeneous groups of clock neurons. Short -and long-range signaling within the pacemaker circuit coordinates molecular and neural rhythms of clock neurons to generate coherent behavioral output. The neurochemistry of circadian behavior is complex and remains incompletely understood. Here we demonstrate that the gaseous messenger nitric oxide (NO) is a signaling molecule linking circadian pacemaker to rhythmic locomotor activity. We show that two independent mutants lacking nitric oxide synthase (NOS) have severely disturbed locomotor behavior both in light-dark cycles and constant darkness, although molecular clocks in the main pacemaker neurons are unaffected. Behavioral phenotypes are due in part to the malformation of neurites of the main pacemaker neurons, s-LNvs. Using cell-type selective and stage-specific gain -and loss-of-function of NOS, we demonstrate that NO secreted from diverse cellular clusters non-cell-autonomously affect molecular and behavioral rhythms. We further identify glia as a major source of NO that regulates circadian locomotor output. These results reveal for the first time the critical role of NO signaling in the Drosophila circadian system and highlight the importance of neuro-glial interaction in the neural circuit output.Author summaryCircadian rhythms are daily cycles of physiological and behavioral processes found in most plants and animals on our planet from cyanobacteria to humans. Circadian rhythms allow organisms to anticipate routine daily and annual changes of environmental conditions and efficiently adapt to them. Fruit fly Drosophila melanogaster is an excellent model to study this phenomenon, as its versatile toolkit enables the study of genetic, molecular and neuronal mechanisms of rhythm generation. Here we report for the first time that gasotransmitter nitric oxide (NO) has a broad, multi-faceted impact on Drosophila circadian rhythms, which takes place both during the development and the adulthood. We also show that one of the important contributors of NO to circadian rhythms are glial cells. The second finding highlights that circadian rhythms of higher organisms are not simply controlled by the small number of pacemaker neurons but are generated by the system that consists of many different players, including glia.

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Endothelin-1 Regulates H+-ATPase-Dependent Transepithelial H+ Secretion in Zebrafish

Endocrinology ◽

10.1210/en.2013-1775 ◽

2014 ◽

Vol 155 (5) ◽

pp. 1728-1737 ◽

Cited By ~ 6

Author(s):

Ying-Jey Guh ◽

Yung-Che Tseng ◽

Chao-Yew Yang ◽

Pung-Pung Hwang

Keyword(s):

Underlying Mechanism ◽

Loss Of Function ◽

Atpase Inhibitor ◽

Acid Base ◽

Endothelin 1 ◽

Secretion Expression ◽

Important Regulator ◽

Embryonic Skin ◽

Electrode Technique

Endothelin-1 (EDN1) is an important regulator of H+ secretion in the mammalian kidney. EDN1 enhances renal tubule H+-ATPase activity, but the underlying mechanism remains unclear. To further elucidate the role of EDN1 in vertebrates' acid-base regulation, the present study used zebrafish as the model to examine the effects of EDN1 and its receptors on transepithelial H+ secretion. Expression of EDN1 and one of its receptors, EDNRAa, was stimulated in zebrafish acclimated to acidic water. A noninvasive scanning ion-selective electrode technique was used to show that edn1 overexpression enhances H+ secretion in embryonic skin at 3 days post fertilization. EDNRAa loss of function significantly decreased EDN1- and acid-induced H+ secretion. Abrogation of EDN1-enhanced H+ secretion by a vacuolar H+-ATPase inhibitor (bafilomycin A1) suggests that EDN1 exerts its action by regulating the H+-ATPase-mediated H+ secretion. EDN1 does not appear to affect H+ secretion through either altering the abundance of H+-ATPase or affecting the cell differentiation of H+-ATPase-rich ionocytes, because the reduction in secretion upon ednraa knockdown was not accompanied by decreased expression of H+-ATPase or reduced H+-ATPase-rich cell density. These findings provide evidence that EDN1 signaling is involved in acid-base regulation in zebrafish and enhance our understanding of EDN1 regulation of transepithelial H+ secretion in vertebrates.

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Endocrinology, sleep and circadian rhythms

Oxford Textbook of Endocrinology and Diabetes ◽

10.1093/med/9780199235292.003.2235 ◽

2011 ◽

pp. 273-279

Author(s):

G. Brabant

Keyword(s):

Circadian Rhythms ◽

Environmental Changes ◽

Biological Effects ◽

Underlying Mechanism ◽

Reciprocal Relation ◽

Common Denominator ◽

Energy Demands ◽

Causative Relationship ◽

Natural Time ◽

Activity Temperature

Endogenous circadian rhythms enable organisms to prepare for environmental changes and to temporally modify behavioural and physiological functions. A variation in energy demands appears to be the most important common denominator of these circadian changes, which renders the intimate reciprocal relation of circadian behaviour and endocrine rhythms no surprise. One of the most obvious examples of circadian behaviour is the sleep–wake cycle, closely linked to diurnal variations of locomotor activity, temperature regulation, and water/food intake. Already subtle changes in these circadian cycles may lead to detrimental effects in human biology. Such causative relationship between these changes and adverse biological effects have been obtained not only from mutations characterized in genes responsible for the generation and the integration of circadian rhythms but also from observational studies where circadian rhythmicity was experimentally changed. Life in modern societies tends to increasingly ignore the natural time cues and these environmental insults are increasingly recognized as the underlying mechanism for many pathophysiological changes and a higher susceptibility to disease. Focusing on endocrine-related effects, this chapter will highlight our current understanding of the genetic background of circadian rhythms, their integration with the light–dark cycle and their links to sleep-related changes (1).

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A Toll-receptor map underlies structural brain plasticity

eLife ◽

10.7554/elife.52743 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 6

Author(s):

Guiyi Li ◽

Manuel G Forero ◽

Jill S Wentzell ◽

Ilgim Durmus ◽

Reinhard Wolf ◽

...

Keyword(s):

Critical Period ◽

Brain Size ◽

Brain Plasticity ◽

Structural Plasticity ◽

Underlying Mechanism ◽

Cell Number ◽

Adult Brain ◽

Loss Of Function ◽

Fiber Number ◽

Destructive Processes

Experience alters brain structure, but the underlying mechanism remained unknown. Structural plasticity reveals that brain function is encoded in generative changes to cells that compete with destructive processes driving neurodegeneration. At an adult critical period, experience increases fiber number and brain size in Drosophila. Here, we asked if Toll receptors are involved. Tolls demarcate a map of brain anatomical domains. Focusing on Toll-2, loss of function caused apoptosis, neurite atrophy and impaired behaviour. Toll-2 gain of function and neuronal activity at the critical period increased cell number. Toll-2 induced cycling of adult progenitor cells via a novel pathway, that antagonized MyD88-dependent quiescence, and engaged Weckle and Yorkie downstream. Constant knock-down of multiple Tolls synergistically reduced brain size. Conditional over-expression of Toll-2 and wek at the adult critical period increased brain size. Through their topographic distribution, Toll receptors regulate neuronal number and brain size, modulating structural plasticity in the adult brain.

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Wearable Vibration Sensor for Measuring the Wing Flapping of Insects

Sensors ◽

10.3390/s21020593 ◽

2021 ◽

Vol 21 (2) ◽

pp. 593

Author(s):

Ryota Yanagisawa ◽

Shunsuke Shigaki ◽

Kotaro Yasui ◽

Dai Owaki ◽

Yasuhiro Sugimoto ◽

...

Keyword(s):

High Speed ◽

Environmental Changes ◽

Underlying Mechanism ◽

Indirect Measurement ◽

Feedback Mechanism ◽

The Body ◽

Vibration Sensor ◽

Wingbeat Frequency ◽

Film Sensor ◽

Insect Wing

In this study, we fabricated a novel wearable vibration sensor for insects and measured their wing flapping. An analysis of insect wing deformation in relation to changes in the environment plays an important role in understanding the underlying mechanism enabling insects to dynamically interact with their surrounding environment. It is common to use a high-speed camera to measure the wing flapping; however, it is difficult to analyze the feedback mechanism caused by the environmental changes caused by the flapping because this method applies an indirect measurement. Therefore, we propose the fabrication of a novel film sensor that is capable of measuring the changes in the wingbeat frequency of an insect. This novel sensor is composed of flat silver particles admixed with a silicone polymer, which changes the value of the resistor when a bending deformation occurs. As a result of attaching this sensor to the wings of a moth and a dragonfly and measuring the flapping of the wings, we were able to measure the frequency of the flapping with high accuracy. In addition, as a result of simultaneously measuring the relationship between the behavior of a moth during its search for an odor source and its wing flapping, it became clear that the frequency of the flapping changed depending on the frequency of the odor reception. From this result, a wearable film sensor for an insect that can measure the displacement of the body during a particular behavior was fabricated.

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EGCG modulates PKD1 and ferroptosis to promote recovery in ST rats

Translational Neuroscience ◽

10.1515/tnsci-2020-0119 ◽

2020 ◽

Vol 11 (1) ◽

pp. 173-181 ◽

Cited By ~ 1

Author(s):

Jianjun Wang ◽

Ying Chen ◽

Long Chen ◽

Yanzhi Duan ◽

Xuejun Kuang ◽

...

Keyword(s):

Spinal Cord ◽

Functional Recovery ◽

Antioxidant Properties ◽

Underlying Mechanism ◽

Maximal Effect ◽

Loss Of Function ◽

Protein Kinase D1 ◽

Erk Phosphorylation ◽

Cord Injury ◽

Novel Strategy

AbstractBackgroundSpinal cord injury (SCI) causes devastating loss of function and neuronal death without effective treatment. (−)-Epigallocatechin-3-gallate (EGCG) has antioxidant properties and plays an essential role in the nervous system. However, the underlying mechanism by which EGCG promotes neuronal survival and functional recovery in complete spinal cord transection (ST) remains unclear.MethodsIn the present study, we established primary cerebellar granule neurons (CGNs) and a T10 ST rat model to investigate the antioxidant effects of EGCG via its modulation of protein kinase D1 (PKD1) phosphorylation and inhibition of ferroptosis.ResultsWe revealed that EGCG significantly increased the cell survival rate of CGNs and PKD1 phosphorylation levels in comparison to the vehicle control, with a maximal effect observed at 50 µM. EGCG upregulated PKD1 phosphorylation levels and inhibited ferroptosis to reduce the cell death of CGNs under oxidative stress and to promote functional recovery and ERK phosphorylation in rats following complete ST.ConclusionTogether, these results lay the foundation for EGCG as a novel strategy for the treatment of SCI related to PKD1 phosphorylation and ferroptosis.

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NCMP-17. MISMATCH REPAIR MUTATIONS AND THE CENTRAL NERVOUS SYSTEM: A CASE SERIES OF GERMLINE MUTATIONS AND CNS MALIGNANCY

Neuro-Oncology ◽

10.1093/neuonc/noaa215.528 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii126-ii126

Author(s):

Amber Ruiz ◽

Jerome Graber

Keyword(s):

Treatment Response ◽

Mismatch Repair ◽

Case Series ◽

Germline Mutations ◽

Molecular Characteristics ◽

Loss Of Function ◽

Dna Mismatch ◽

Mutational Burden ◽

Increased Risk ◽

Tumor Mutational Burden

Abstract Our understanding of genetic predispositions for malignancy is continually evolving. One family of germline mutations well described in the literature is that of the DNA mismatch repair mechanism (MMR). Lynch syndrome (LS) is due to a loss of function mutation of several MMR genes- MSH2, MLH1, MSH6, and PMS2. Germline MMR mutations lead to microsatellite instability and loss of genomic integrity resulting in an increased risk for various cancers (colorectal, genitourinary, etc). LS may be as common as 1 in 400 people and some MMR mutations have been associated with gliomas. There is a paucity of information regarding frequency of glioma subtypes as well as tumor genetic and molecular characteristics which have important clinical implications. We describe a case series of 6 individuals with germline MMR mutations and brain tumors. Those with MSH2 and PMS2 mutations (n=3) developed glioblastomas at a mean age at diagnosis of 48 years. These tumors expressed MGMT hyper-methylation and high tumor mutational burden. Only one had IDH-1 mutation. Those with MLH1 mutations (n=3), did not develop gliomas. This raises the question of differential glioma subtype development based on MMR gene. It also highlights the possibility of Lynch-associated gliomas having more favorable treatment response due to MGMT methylation and potential response to immunotherapy based on high tumor mutational burden. Though the sample size is small, there appears to be a preponderance of women compared to men (5:1 respectively). Larger studies are needed to verify CNS involvement in germline MMR mutations. In doing so, we hope to identify factors that may influence clinical management and lead to a better understanding of treatment response and disease prognosis.

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Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos

International Journal of Molecular Sciences ◽

10.3390/ijms22126497 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6497

Author(s):

Anna Ghilardi ◽

Alberto Diana ◽

Renato Bacchetta ◽

Nadia Santo ◽

Miriam Ascagni ◽

...

Keyword(s):

Hearing Loss ◽

Inner Ear ◽

Hair Cells ◽

Muscle Fibers ◽

Underlying Mechanism ◽

Loss Of Function ◽

Zebrafish Model ◽

Developmental Defects ◽

Inner Ear Development ◽

Syndromic Hearing Loss

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.

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