ABSTRACT
Objective To investigate the expression of α-smooth muscle actin (α-SMA)in patients with valvular atrial fibrillation and study the relationship betweenα-SMA and atrial fibrosis in patients with valvular atrial fibrillation (AF).Methods For this study we enrolled 84 consecutive patients with rheumatic heart disease who were to receive cardiac surgery.The patients were divided into AF group (AF,n=39)and sinus rhythm group (SR, n=45).Their clinical data including baseline demographics,routine laboratory test and echocardiographics were collected before surgery.The right atrial tissue (0 .3-0 .5 cm3 )was disserted during the surgery.Right atrial fibrosis was observed by Masson staining.The mRNA expression ofα-SMA in atrial tissue were determined by Real-time quantitative PCR.Western blot was used to measure the protein expression ofα-SMA in atrial tissue.Results The two groups did not significantly differ in sex ratio,age,blood pressure,blood biochemical indicators or other aspects of medical history (P>0.05).However,left and right atrium diameters in AF group were significantly larger than those in SR group (P<0 .05 ).Masson staining suggested that collagen volume fraction and collagen content were significantly higher in AF group than in SR group (P<0 .05 ).The mRNA and protein expressions ofα-SMA in right atrial tissue were obviously higher in AF group than in SR group (coefficients P<0 .05 ).The mRNA and protein expressions ofα-SMA from right atrial tissue in the 84 patients were positively correlated with collagen content (coefficients of 0.587 and 0.607;P=0.029,0.014,respectively).Conclusion There is significant atrial fibrosis in patients with valvular atrial fibrillation,which is closely related to up-regulated expression ofα-SMA gene.
ABSTRACT
Objective:To investigate the expression of fibrillin-1 (FBN-1) in the atrium tissue of the patients with rheumatic heart valve disease complicated with atrial fibrillation(AF), and to explore its relationship with atrial fibrosis in the patients with valvular atrial fibrillation.Methods:Eighty-four consecutive patients with rheumatic heart valve disease underwent cardiac surgery were enrolled in this study.The patients were divided into AF group(n=39) and sinus rhythm group(SR group, n=45).The clinical data of patients were collected before operation.The right atrium tissue (0.3-0.5 mm3) was disserted during operation.The degrees of right atrial fibrosis of the patients in two groups were observed by Masson staining.Western blotting method was used to measure the protein expressions of FBN-1 in atrium tissue of the patients in two groups.Results:There were no significant differences in the gender ratio, age, blood pressure, blood biochemical indicators and other aspects of medical history between two groups(P>0.05);the diameters of left and right atrium of the patients in AF group were significantly larger than those in SR group(P<0.05).The Masson staining results showed that there was obvious fibrosis in AF group, and the collagen volume fraction and collagen level in AF group were significantly higher than those in SR group (P<0.05).The expression level of FBN-1 in right atrium tissue in AF group was obviously higher than that in SR group(P<0.05).The expression level of FBN-1 protein in right atrium tissue of the patients with valvular atrial fibrillation was positively correlated with the collagen level(r=0.544,P=0.021).Conclusion:There is obvious atrium fibrosis in the patients with valvular atrial fibrillation;it is closely related to the up-regulation of the expression of FBN-1 gene.