Circadian gene expression of clock genes and plasminogen activator inhibitor-1 in heart and aorta of spontaneously hypertensive and Wistar–Kyoto rats

Abstract

Enhanced expression of clock genes may increase PAI-1 expression in concert with activated renin-angiotensin system in SHR heart. Rather than clock genes, the renin-angiotensin system induces daily fluctuation and increased expression of aortic PAI-1 mRNA in SHR.

Rhythm changes of clock genes, apoptosis-related genes and atherosclerosis-related genes in apolipoprotein E knockout mice

“…Recent studies showed that circadian variation is also related to diseases (18). In some cardiovascular diseases, circadian expression of clock genes may change (19,20). Our results showed that the clock genes exhibited daily oscillations at the mRNA level (except mClock) in C57BL/6J mice, as previously reported (21).…”

“…Interestingly, abnormities of circadian genes were more severe in ApoE-/-mice at the advanced stage of atherosclerosis than in mice at the early stage. These results suggest that atherosclerosis may affect the expression of circadian genes, as with the other cardiovascular diseases mentioned above (19,20). Aside from clock genes, expression of many other genes show circadian rhythms (22).…”

Aryl hydrocarbon receptor nuclear translocator-like (BMAL1) is associated with susceptibility to hypertension and type 2 diabetes

“…The circadian expression of plasminogen activator inhibitor-1, a clock-regulated gene that participates in the regulation of thrombolysis and are associated with increased risk of myocardial infarction (9), is compromised in the heart of SHR (10). Although circadian oscillations of the expression of genes of the renin-angiotensin system are conserved in cardiac tissue of SHR, their expression are up-regulated in SHR when compared with normotensive Wistar-Kyoto (WKY) rats (11).…”

“…Inactivation of Bmal1 in mice is associated with a wide range of phenotypes, including decreased body weight; shortened life span; increased sleep time and sleep fragmentation; and altered regulation of blood pressure, glucose homeostasis, lipid metabolism, and adipogenesis (16)(17)(18)(19). Changes in Bmal1 circadian expression have been reported in hypertensive models (10). Therefore Bmal1 has an important role in a variety of functions other than regulating circadian rhythm, and its role depends on the tissue type in which it is expressed.…”

Mechanism of the circadian clock in physiology

“…139). Expression of the plasminogen activator inhibitor 1 (PAI-1) is a circadian target in rodents and humans (92,121) and is downregulated in the CLOCK mutant mouse (⌬19) (153). This mutation prevents circadian transcriptional activity of the CLOCK protein, but because CLOCK can still interact with BMAL1 and DNA, the mutation has a dominant negative effect.…”