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

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.

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

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 923 ◽  
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 ◽  
Loss Of Function ◽  
Physiological Importance ◽  
Important Regulator ◽  
Locomotor Rhythms

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.

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

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.

Endocrinology, sleep and circadian rhythms

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).

scholarly journals Wearable Vibration Sensor for Measuring the Wing Flapping of Insects

Sensors ◽  
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.

scholarly journals Circadian Rhythm: Potential Therapeutic Target for Atherosclerosis and Thrombosis

2021 ◽  
Vol 22 (2) ◽  
pp. 676
Author(s):  
Andy W. C. Man ◽  
Huige Li ◽  
Ning Xia
Keyword(s):  
Circadian Rhythm ◽  
Cardiovascular Diseases ◽  
Circadian Rhythms ◽  
Circadian Clock ◽  
Therapeutic Target ◽  
Environmental Changes ◽  
Clock Genes ◽  
Vascular System ◽  
Peripheral Tissues ◽  
Inflammatory Processes

Every organism has an intrinsic biological rhythm that orchestrates biological processes in adjusting to daily environmental changes. Circadian rhythms are maintained by networks of molecular clocks throughout the core and peripheral tissues, including immune cells, blood vessels, and perivascular adipose tissues. Recent findings have suggested strong correlations between the circadian clock and cardiovascular diseases. Desynchronization between the circadian rhythm and body metabolism contributes to the development of cardiovascular diseases including arteriosclerosis and thrombosis. Circadian rhythms are involved in controlling inflammatory processes and metabolisms, which can influence the pathology of arteriosclerosis and thrombosis. Circadian clock genes are critical in maintaining the robust relationship between diurnal variation and the cardiovascular system. The circadian machinery in the vascular system may be a novel therapeutic target for the prevention and treatment of cardiovascular diseases. The research on circadian rhythms in cardiovascular diseases is still progressing. In this review, we briefly summarize recent studies on circadian rhythms and cardiovascular homeostasis, focusing on the circadian control of inflammatory processes and metabolisms. Based on the recent findings, we discuss the potential target molecules for future therapeutic strategies against cardiovascular diseases by targeting the circadian clock.

Disrupted circadian rhythms in VIP- and PHI-deficient mice

2003 ◽  
Vol 285 (5) ◽  
pp. R939-R949 ◽  
Author(s):  
Christopher S. Colwell ◽  
Stephan Michel ◽  
Jason Itri ◽  
Williams Rodriguez ◽  
J. Tam ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Wheel Running ◽  
Activity Rhythm ◽  
Activity Patterns ◽  
Circadian System ◽  
Diurnal Rhythms ◽  
Constant Darkness ◽  
Light Cycle ◽  
Wild Type ◽  
Deficient Mice

The related neuropeptides vasoactive intestinal peptide (VIP) and peptide histidine isoleucine (PHI) are expressed at high levels in the neurons of the suprachiasmatic nucleus (SCN), but their function in the regulation of circadian rhythms is unknown. To study the role of these peptides on the circadian system in vivo, a new mouse model was developed in which both VIP and PHI genes were disrupted by homologous recombination. In a light-dark cycle, these mice exhibited diurnal rhythms in activity which were largely indistinguishable from wild-type controls. In constant darkness, the VIP/PHI-deficient mice exhibited pronounced abnormalities in their circadian system. The activity patterns started ∼8 h earlier than predicted by the previous light cycle. In addition, lack of VIP/PHI led to a shortened free-running period and a loss of the coherence and precision of the circadian locomotor activity rhythm. In about one-quarter of VIP/PHI mice examined, the wheel-running rhythm became arrhythmic after several weeks in constant darkness. Another striking example of these deficits is seen in the split-activity patterns expressed by the mutant mice when they were exposed to a skeleton photoperiod. In addition, the VIP/PHI-deficient mice exhibited deficits in the response of their circadian system to light. Electrophysiological analysis indicates that VIP enhances inhibitory synaptic transmission within the SCN of wild-type and VIP/PHI-deficient mice. Together, the observations suggest that VIP/PHI peptides are critically involved in both the generation of circadian oscillations as well as the normal synchronization of these rhythms to light.

Organization of rat circadian rhythms during daily infusion of melatonin or S20098, a melatonin agonist

1999 ◽  
Vol 277 (3) ◽  
pp. R812-R828 ◽  
Author(s):  
B. Pitrosky ◽  
R. Kirsch ◽  
A. Malan ◽  
E. Mocaer ◽  
P. Pevet
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Phase Response Curve ◽  
Constant Darkness ◽  
Time Interval ◽  
General Activity ◽  
Activity Peak ◽  
Free Running ◽  
Wheel Activity ◽  
Free Running Period

Daily administration of melatonin or S20098, a melatonin agonist, is known to entrain the free-running circadian rhythms of rats. The effects of the duration of administration on entrainment were studied. The animals demonstrated free-running circadian rhythms (running-wheel activity, body temperature, general activity) in constant darkness. Daily infusions of melatonin or S20098 for 1, 8, or 16 h entrained the circadian rhythms to 24 h. Two daily infusions of 1 h (separated by 8 h) entrained the activity peak within the shorter time interval. The entraining properties of melatonin and S20098 were similar and were affected neither by pinealectomy nor by infusion of 1- or 8-h duration. However, with 16-h infusion, less than half of the animals became entrained. Once entrained, the phase angle between the onset of infusion and the rhythms (onset of activity or acrophase of body temperature) increased with the duration of infusion. Before entrainment, the free-running period increased with the duration of infusion, an effect that was not predictable from the phase response curve.

scholarly journals Interaction between photoperiod and variation in circadian rhythms in tomato

2022 ◽  
Author(s):  
Yanli Xiang ◽  
Thomas Sapir ◽  
Pauline Rouillard ◽  
Marina Ferrand ◽  
Jose M Jimenez-Gomez
Keyword(s):  
Seasonal Variation ◽  
Circadian Rhythms ◽  
Phase Shift ◽  
Circadian Clock ◽  
Environmental Changes ◽  
Circadian Clocks ◽  
Biological Processes ◽  
Near Isogenic Lines ◽  
Transcriptomic Profiling ◽  
Isogenic Lines

Many biological processes follow circadian rhythmicity and are controlled by the circadian clock. Predictable environmental changes such as seasonal variation in photoperiod can modulate circadian rhythms, allowing organisms to adjust to the time of the year. Modification of circadian clocks is especially relevant in crops to enhance their cultivability in specific regions by changing their sensibility to photoperiod. In tomato, the appearance of mutations in EMPFINDLICHER IM DUNKELROTEN LICHT 1 (EID1, Solyc09g075080) and NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED GENE 2 (LNK2, Solyc01g068560) during domestication delayed its circadian rhythms, and allowed its expansion outside its equatorial origin. Here we study how variation in circadian rhythms in tomato affects its perception of photoperiod. To do this, we create near isogenic lines carrying combinations of wild alleles of EID1 and LNK2 and perform transcriptomic profiling under two different photoperiods. We observe that EID1, but not LNK2, has a large effect on the tomato transcriptome and its response to photoperiod. This large effect of EID1 is likely a consequence of the global phase shift elicited by this gene in tomato's circadian rhythms.

scholarly journals Arginine-Vasopressin Expressing Neurons in the Murine Suprachiasmatic Nucleus Exhibit a Circadian Rhythm in Network Coherence in vivo

2021 ◽  
Author(s):  
Adam Stowie ◽  
Zhimei Qiao ◽  
Daniella Do Carmo Buonfiglio ◽  
J. Christopher Ehlen ◽  
Morris Benveniste ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Suprachiasmatic Nucleus ◽  
Arginine Vasopressin ◽  
Single Cells ◽  
Circadian Variation ◽  
Population Level ◽  
Correlational Analysis ◽  
Constant Darkness ◽  
Peak Time

AbstractThe Suprachiasmatic Nucleus (SCN) is composed of functionally distinct sub-populations of GABAergic neurons such as vasoactive intestinal polypeptide (VIP)-, arginine vasopressin (AVP)-, gastrin releasing peptide (GRP)-, and neuromedin S (NMS)-expressing neurons which form a neural network responsible for synchronizing most physiological and behavioral circadian rhythms in mammals. To date, little is known regarding which aspects of SCN rhythmicity are generated by individual SCN neurons or neuronal sub-populations and which aspects result from neuronal interaction within a network. In this study, we address this question utilizing in vivo miniaturized microscopy to measure fluorescent GCaMP-mediated calcium dynamics in AVP neurons in the intact SCN of awake, behaving mice. This approach permits analysis of rhythms of single cells, populations, and correlational analysis among groups of AVP neurons in a field of view across the circadian and diurnal day and night. We report that AVP neurons in the murine SCN exhibit a periodic oscillatory increase in calcium of approximately 14 seconds across the day and night, in both constant darkness and under a 12:12 light-dark (LD) cycle. Using in vivo optogentically-targeted single unit activity recording, we demonstrated that these slow calcium waves are likely the result of burst-firing characteristic of AVP neurons previously reported for other brain regions. Rhythmicity analysis of several fluorescence measures suggests that individual AVP neurons exhibit unstable and stochastic rhythms, with approximately 30% of the neurons rhythmic during any given day across lighting conditions, and weak or absent rhythmicity at the population level. Network-level cross-correlational analysis revealed that coherence among neuron pairs also exhibited stochastic rhythms with about 25% of pairs rhythmic at any time. Notably, this analysis revealed a stronger rhythm at the population level than was observed in single cell analysis. The peak time of maximal coherence among AVP neuronal pairs occurs between CT/ZT 6 and 9, coinciding with the timing of maximal neuronal activity with the SCN as a whole. These results are the first to demonstrate robust circadian variation in the coordination between apparently weakly rhythmic or arrhythmic neurons suggesting that, for AVP neurons, interactions between neurons in the SCN are more influential than individual or single subpopulation activity in the regulation of mammalian circadian rhythms.

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