OBJECTIVETo investigate the mRNA and protein expressions of 11beta-Hydroxysteroid dehydrogenase type 2 (11betaHSD2) in patients with atrial fibrillation.

METHODSRight and left atrial lateral wall tissue samples were obtained during mitral/aortic valve replacement operation from 25 patients with rheumatic heart valve disease (12 in sinus rhythm and 13 in chronic atrial fibrillation). Realtime quantitative PCR and Western blot were used to determine the mRNA and protein expressions of 11betaHSD2 in atria specimens. The distribution of 11betaHSD2 in human atrial tissue was analyzed by specific immunohistochemical staining. Echocardiography examination was performed before operation.

RESULTSThe left atrial diameters were significantly higher in the atrial fibrillation group as compared to sinus rhythm group (P < 0.01). Similarly, mRNA expression of 11betaHSD2 (0.86 +/- 0.14 vs 0.33 +/- 0.12 in right atria, 0.95 +/- 0.15 vs 0.37 +/- 0.10 in left atria, all P < 0.01) and protein expression of 11betaHSD2 (1.18 +/- 0.64 vs 0.71 +/- 0.21 in right atria, P < 0.01; and 1.36 +/- 0.58 vs 0.85 +/- 0.15 in left atria, P < 0.05) were also significantly upregulated in atrial fibrillation groups than those in sinus rhythm groups. The mRNA and protein expressions of 11betaHSD2 were similar between left atria and right atria both in fibrillation and sinus groups (all P > 0.05). The special immunohistochemical staining demonstrated that 11betaHSD2 was abundant in the human atrial myocardium and located mainly in the cytoplasm.

CONCLUSIONThese findings suggested that upregulated 11betaHSD2 might be associated to the development and persistence of atrial fibrillation.