Noncoding RNAs: Bridging Regulation of Circadian Rhythms and Inflammation

Rüdiger Hardeland

doi:10.3233/nib-190159

Daily Expression Pattern of Protein-Encoding Genes and Small Noncoding RNAs in Synechocystis sp. Strain PCC 6803

Applied and Environmental Microbiology ◽

10.1128/aem.01086-14 ◽

2014 ◽

Vol 80 (17) ◽

pp. 5195-5206 ◽

Cited By ~ 36

Author(s):

Christian Beck ◽

Stefanie Hertel ◽

Anne Rediger ◽

Robert Lehmann ◽

Anika Wiegard ◽

...

Keyword(s):

Circadian Rhythms ◽

Noncoding Rnas ◽

Continuous Light ◽

Circadian Clocks ◽

Dark Phase ◽

Content Type ◽

Antisense Rnas ◽

Small Noncoding Rnas ◽

Gene Copies ◽

Pcc 6803

ABSTRACTMany organisms harbor circadian clocks with periods close to 24 h. These cellular clocks allow organisms to anticipate the environmental cycles of day and night by synchronizing circadian rhythms with the rising and setting of the sun. These rhythms originate from the oscillator components of circadian clocks and control global gene expression and various cellular processes. The oscillator of photosynthetic cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, linked to a complex regulatory network.Synechocystissp. strain PCC 6803 possesses the standard cyanobacterialkaiABCgene cluster plus multiplekaiBandkaiCgene copies and antisense RNAs for almost everykaitranscript. However, there is no clear evidence of circadian rhythms inSynechocystissp. PCC 6803 under various experimental conditions. It is also still unknown if and to what extent the multiplekaigene copies andkaiantisense RNAs affect circadian timing. Moreover, a large number of small noncoding RNAs whose accumulation dynamics over time have not yet been monitored are known forSynechocystissp. PCC 6803. Here we performed a 48-h time series transcriptome analysis ofSynechocystissp. PCC 6803, taking into account periodic light-dark phases, continuous light, and continuous darkness. We found that expression of functionally related genes occurred in different phases of day and night. Moreover, we found day-peaking and night-peaking transcripts among the small RNAs; in particular, the amounts ofkaiantisense RNAs correlated or anticorrelated with those of their respectivekaitarget mRNAs, pointing toward the regulatory relevance of these antisense RNAs. Surprisingly, we observed that the amounts of 16S and 23S rRNAs in this cyanobacterium fluctuated in light-dark periods, showing maximum accumulation in the dark phase. Importantly, the amounts of all transcripts, including small noncoding RNAs, did not show any rhythm under continuous light or darkness, indicating the absence of circadian rhythms inSynechocystis.

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The Biological Clock and Sleep in the Elderly

Zeitschrift für Gerontopsychologie & -psychiatrie ◽

10.1024/1011-6877.19.1.45 ◽

2006 ◽

Vol 19 (1) ◽

pp. 45-51 ◽

Cited By ~ 1

Author(s):

Myriam Juda ◽

Mirjam Münch ◽

Anna Wirz-Justice ◽

Martha Merrow ◽

Till Roenneberg

Keyword(s):

Circadian Rhythms ◽

Biological Clock ◽

The Elderly ◽

Early Morning ◽

Behavioral Changes ◽

Older Age ◽

Age Related ◽

Theoretical Considerations ◽

Sleep Difficulties ◽

Circadian Biology

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.

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