Knockdown of Clock gene induces thrombotic potential reduction by inhibiting α1-antitrypsin with promotion of fibronectin

Our previous study indicated that Clock gene could affect the thrombotic potential. In this present study, we examined the differential expression of proteins in Clock knockdown mice’s plasma, including α1-antitrypsin as a potential target. The proteins were examined in AML12 cells with Clock gene being knocked down to confirm the differential expressions. RNAs of those cells were extracted every 3 h in 24 h. The transcriptional levels of α1-antitrypsin (Serpina1a) and fibronectin (Fn1) were analyzed with the least-squares fit of a 24-h cosine function by single cosinor method, but no circadian rhythm was determined in neither of these genes. The expressions of α1-antitrypsin and fibronectin in Clock knockdown cells were found upregulated in both transcriptional and translational levels. Then, we applied ELISA assay to detect the concentration of activated protein C in Clock knockdown plasma and found a risen concentration. Fibronectin was reported to play a role in inhibiting the platelet aggregation, while activated protein C was demonstrated to inhibit PAI-1. All these results indicated that downregulation of the Clock gene in the circulatory system might have effects on PAI-1 by upregulating α1-antitrypsin, and might play some roles in platelet aggregation by increased fibronectin.