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Updated: Jul 22, 2026
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Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
Cardiovascular tissues contain independent circadian clocks
A J Davidson1, B London, G D Block
1Department of Biology, University of Virginia, Charlottesville, Virginia 22904-4328, USA ad2h@virginia.edu
Summary
Cardiovascular events show daily rhythms. Researchers found the clock gene mPer1 is rhythmic in rat heart, arteries, and veins, suggesting internal biological clocks regulate cardiovascular health.
Area of Science:
- Cardiovascular Biology
- Chronobiology
- Molecular Genetics
Background:
- Acute cardiovascular events display a circadian rhythm in occurrence frequency.
- The underlying mechanisms are not fully understood but may involve inherent cardiovascular system rhythmicity.
- Characterizing clock gene rhythmicity in the cardiovascular system is crucial.
Purpose of the Study:
- To characterize the rhythmicity of the clock gene mPer1 in the rat cardiovascular system.
- To investigate the in vitro circadian expression patterns of mPer1 in various cardiovascular tissues.
- To explore the influence of the light:dark cycle on cardiovascular circadian rhythms.
Main Methods:
- Utilized transgenic Per1-luc rats for in vitro bioluminescence assays.
- Cultured explants of heart, arteries, and veins to measure mPer1 promoter-driven luciferase activity.
- Assessed rhythmicity and phase relationships of gene expression over multiple circadian cycles.
- Varied culture initiation time relative to the animal's light:dark cycle.
Main Results:
- mPer1 promoter activity showed rhythmic expression in vitro in heart, artery, and vein explants.
- Peak mPer1 bioluminescence occurred during the late night in heart and arteries.
- Vein rhythm phases varied significantly by anatomical location.
- In vitro rhythm phases were influenced by culture time, but inter-tissue phase relationships remained consistent.
Conclusions:
- The cardiovascular system exhibits inherent circadian rhythmicity at the molecular level, involving the mPer1 clock gene.
- Diversity exists in circadian regulation among different components of the cardiovascular system (heart, arteries, veins).
- Understanding these tissue-specific rhythms may provide insights into the timing of cardiovascular events.
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