Altered expression of microRNA-27a-3p in the thymus tissue of patients with myasthenia gravis / 中华神经科杂志

ABSTRACT

Objective To investigate the expression level of thymus microRNA-27a-3p in patients with myasthenia gravis (MG) and to explore the pathogenesis of MG.Methods Thymus tissue samples from 36 cases were collected from December 2014 to February 2015 in the Second Affiliated Hospital of Harbin Medical University.Nineteen thymus tissue samples of MG group were collected from department of chest surgery,17 thymus tissue samples of control group were collected from department of chest surgery or congenital heart disease patients from department of cardiac surgery.The expression of microRNA-27a-3p in the thymus from 36 patients was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR),using U6 as housekeeping control.The Wilcoxon Rank-Sum test was used to analyze the relative expression of microRNA-27a-3p of the two groups.Spearman rank correlation was used to determine the correlation coefficient between microRNA-27a-3p and Quantitative Myasthenia Gravis Score (QMGS).Results (1) The expression level of microRNA-27a-3p in thymus was significantly higher in MG group (0.195(0.049,0.714)) compared with control group (0.045(0.004,0.088),Z =-2.646,P =0.008).(2) Nineteen MG patients were included in the study,out of which 7 were ocular myasthenia gravis (OMG) patients and 12 were generalized myasthenia gravis (GMG) patients.The expression of microRNA-27a-3p in GMG patients (0.493 (0.157,1.123)) was significantly higher than that in OMG patients (0.035 (0.008,0.103),Z =-2.620,P =0.009).(3) There was a positive correlation between the expression of microRNA-27a-3p and QMGS (r =0.576,P =0.010).Conclusions The expression of microRNA-27a-3p in thymus is significantly up-regulated in the patients with MG.MicroRNA-27a-3p may be associated with MG severity and significantly elevated in GMG patients compared with OMG patients.