Expression of BRD4 in patients with nonvalvular atrial fibrillation and
its role in postoperative recurrence and the development of atrial
Objective: Through clinical studies and animal experiments, we
explored the expression of BRD4 in patients with NVAF and its role in
the postoperative recurrence and occurrence of atrial fibrosis.
Methods: 74 patients with NVAF and 73 patients with PSVT were
included. The BRD4 levels of the patients were measured. Thirty-Six
Sprague Dawley(SD) rats were randomly divided into three groups. The
incidence and duration of AF in each group were recorded. Masson’s
trichrome staining was performed. Western blot was used to detect the
expression of BRD4, TGF-β1, P-Smad2/3, Smad2/3, Smad7, Cx43, and type
III collagen in each group. Results: The BRD4 levels were
significantly higher in patients with AF than those of PSVT,especially
in patients with persistent AF and postoperative recurrence of AF and AF
with left atrial low voltage( P < 0.05). The collagen
volume fraction and average induced rate of AF and average duration of
AF and levels of BRD4, TGF-β1, P-Smad2/3, Smad2/3, and type III collagen
were significantly highest in the AF + CTL group than those of the CTL
group and AF + JQ-1 group( P < 0.05).
Conclusions: BRD4 was correlated with AF and atrial fibrosis.
Inhibition of BRD4 expression significantly improved the degree of left
atrial fibrosis in rats with AF and reduced the incidence of AF and the
duration of AF. BRD4 may be involved in atrial fibrosis and remodeling
through the TGF-β1/Smad signaling pathway, thus participating in the
occurrence and maintenance of AF.