Voluntary Wheel Running Exercise Does Not Attenuate Circadian and Cardiac Dysfunction Caused by Conditional Deletion of Bmal1

Circadian misalignment occurs with age, jet lag, and shift work, leading to maladaptive health outcomes including cardiovascular diseases. Despite the strong link between circadian disruption and heart disease, the cardiac circadian clock is poorly understood, prohibiting identification of therapies to restore the broken clock. Exercise is the most cardioprotective intervention identified to date and has been suggested to reset the circadian clock in other peripheral tissues. Here, we tested the hypothesis that conditional deletion of core circadian gene Bmal1 would disrupt cardiac circadian rhythm and function and that this disruption would be ameliorated by exercise. To test this hypothesis, we generated a transgenic mouse with spatial and temporal deletion of Bmal1 only in adult cardiac myocytes (Bmal1 cardiac knockout [cKO]). Bmal1 cKO mice demonstrated cardiac hypertrophy and fibrosis concomitant with impaired systolic function. This pathological cardiac remodeling was not rescued by wheel running. While the molecular mechanisms responsible for the profound cardiac remodeling are unclear, it does not appear to involve activation of the mammalian target of rapamycin (mTOR) signaling or changes in metabolic gene expression. Interestingly, cardiac deletion of Bmal1 disrupted systemic rhythms as evidenced by changes in the onset and phasing of activity in relationship to the light/dark cycle and by decreased periodogram power as measured by core temperature, suggesting cardiac clocks can regulate systemic circadian output. Together, we suggest a critical role for cardiac Bmal1 in regulating both cardiac and systemic circadian rhythm and function. Ongoing experiments will determine how disruption of the circadian clock causes cardiac remodeling in an effort to identify therapeutics to attenuate the maladaptive outcomes of a broken cardiac circadian clock.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:38

Enthalten in:

Journal of biological rhythms - 38(2023), 3 vom: 17. Juni, Seite 290-304

Sprache:

Englisch

Beteiligte Personen:

Yusifova, Musharraf [VerfasserIn]
Yusifov, Aykhan [VerfasserIn]
Polson, Sydney M [VerfasserIn]
Todd, William D [VerfasserIn]
Schmitt, Emily E [VerfasserIn]
Bruns, Danielle R [VerfasserIn]

Links:

Volltext

Themen:

ARNTL Transcription Factors
BMAL1
Cardiac dysfunction
Circadian rhythm
Exercise
Journal Article
Mouse

Anmerkungen:

Date Completed 19.06.2023

Date Revised 16.11.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1177/07487304231152398

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM353093823