Circadian nuclear receptor Rev-erbα is expressed by platelets and potentiates platelet activation and thrombus formation

Abstract

Aims Adverse cardiovascular events have day/night patterns with peaks in the morning, potentially related to endogenous circadian clock control of platelet activation. Circadian nuclear receptor Rev-erbα is an essential and negative component of the circadian clock. To date, the expression profile and biological function of Rev-erbα in platelets have never been reported. Methods and results Here, we report the presence and functions of circadian nuclear receptor Rev-erbα in human and mouse platelets. Both human and mouse platelet Rev-erbα showed a circadian rhythm that positively correlated with platelet aggregation. Global Rev-erbα knockout and platelet-specific Rev-erbα knockout mice exhibited defective in haemostasis as assessed by prolonged tail-bleeding times. Rev-erbα deletion also reduced ferric chloride-induced carotid arterial occlusive thrombosis, prevented collagen/epinephrine-induced pulmonary thromboembolism, and protected against microvascular microthrombi obstruction and infarct expansion in an acute myocardial infarction model. In vitro thrombus formation assessed by CD41-labelled platelet fluorescence intensity was significantly reduced in Rev-erbα knockout mouse blood. Platelets from Rev-erbα knockout mice exhibited impaired agonist-induced aggregation responses, integrin αIIbβ3 activation, and α-granule release. Consistently, pharmacological inhibition of Rev-erbα by specific antagonists decreased platelet activation markers in both mouse and human platelets. Mechanistically, mass spectrometry and co-immunoprecipitation analyses revealed that Rev-erbα potentiated platelet activation via oligophrenin-1-mediated RhoA/ERM (ezrin/radixin/moesin) pathway. Conclusion We provided the first evidence that circadian protein Rev-erbα is functionally expressed in platelets and potentiates platelet activation and thrombus formation. Rev-erbα may serve as a novel therapeutic target for managing thrombosis-based cardiovascular disease. Key question Adverse cardiovascular events have day/night patterns with peaks in the morning, potentially related to endogenous circadian clock control of platelet activation. Whether circadian nuclear receptor Rev-erba is present in platelets and regulates platelet function remains unknown. Key finding We provide the first evidence that Rev-erba is functionally expressed in platelets and acts as a positive regulator of platelet activation/thrombus formation through the oligophrenin-1-mediated RhoA/ERM signalling pathway. Take home message Our observations highlight the importance of circadian clock machinery in platelet physiology and support the notion that Rev-erba may serve as a novel therapeutic target for managing thrombosis-based cardiovascular diseases.

Nuclear Receptor NR1D1 Regulates Abdominal Aortic Aneurysm Development by Targeting the Mitochondrial Tricarboxylic Acid Cycle Enzyme Aconitase-2

“…The identification of NR1D1 as a novel functional receptor in mitochondrial metabolism regulation in vascular cells might broaden our understanding of the multiple biological functions of NR1D1. 38 Our observations, along with recent findings about the role of NR1D1 in cardiovascular tissues from several research groups, 8 , 9 , 12 , 50 provide support for NR1D1 as an essential regulator of cardiovascular biology. It is important that our study unveils a previously undescribed NR1D1-ACO2-αKG axis in regulating mitochondrial metabolism, and provides proof-of-concept evidence indicating the therapeutic value of αKG supplementation in AAA prevention and treatment.…”

“… 37 , 38 It is important that emerging evidence has shown that NR1D1 regulates cardiovascular physiology/pathology. 8 , 9 , 13 Although NR1D1 has been reported to inhibit atherosclerotic development, 13 we unexpectedly found a profound detrimental effect of NR1D1 on AAA development. NR1D1 was upregulated in human and MASMCs from AAA tissues, with its gene expression ranked the highest in fold change among all 49 NRs.…”

“…NR1D1 (NR subfamily 1 group D member 1), also known as Rev-erbα, belongs to the NR superfamily, which was first cloned in pituitary tissue and recognized as a vital regulator of circadian rhythms. [7][8][9] Recently, several new functions of NR1D1 beyond its roles in circadian rhythms were identified (ie, regulating cell metabolism and inflammatory responses) and implicated in the pathogenesis of several metabolic diseases 10,11 and cardiovascular diseases. 8,9,12,13 Although NR1D1 has recently been demonstrated to be expressed in vascular cells, the functional role of NR1D1 in the pathology of AAA has never been investigated.…”

An Overview of the Circadian Clock in the Frame of Chronotherapy: From Bench to Bedside

“…It is now long known that acute myocardial infarctions occur more frequently in the morning [ 75 ]. This correlates with a peak in platelet activation during the morning, associated with the expression of REV-ERBα in platelets [ 76 ]. Anti-aggregative drugs such as acetylsalicylic acid (ASA) are therefore used for secondary prevention of coronary artery disease.…”

5-Hydroxyindoleacetic acid, a new ligand for GPR35, plays an important role in inflammatory disease

“…How does GPR35 promote neutrophil adhesion with platelets? We suspect that GPR35 is involved in the receptor-induced neutrophil shape change and promotes the cytoskeleton remodeling of neutrophils through G12/G13-mediated or Gai-mediated Rho/Rho kinase-dependent ERM (ezrin/radixin/moesin) phosphorylation regulation [ 7 , 8 ] . We believe that there is a close relationship between platelet activation and neutrophil recruitment.…”