ABSTRACT
Objective To investigate the association between myasthenia gravis (MG) and single nucleotide polymorphisms (SNPs) of PTPN22 + 1858C/T,CTLA-4 (+ 49A/G;-1772C/T;-1661A/G),KRAS(rs9226),BCL2(rs4987855) and IGF-1R(rs34804698) genes.Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was adopted to detect the gene types of SNPs in 76 MG patients who were enrolled in the Second Affiliated Hospital of Harbin Medical University from July 2011 to June 2015 and 59 healthy blood donors.Results In MG patients,the frequences of CTLA-4 +49A/G(rs231775) (57.9％) and-1772C/T (rs733618) (43.4％) were higher than that in the healthy controls (22.1％) (x2 =35.252,P =0.000; x2 =4.098,P =0.043).The frequence of CTLA-4 +49A/G in MG patients combined with thymoma (25.6％) was higher than other subgroups (thymic hyperplasia group:13.8％; normal thymus group:18.4％)(x2 =7.564,P=0.006; x2 =7.155,P=0.007).Meanwhile,the frequence of the C-1772 allele was higher in thymoma group (19.7％) compared with other two groups (thymic hyperplasia group:9.86％ ; normal thymus group:13.8％) (x2 =5.331,P =0.021 ;x2 =4.411,P =0.036).However,the other SNPs were not associated with the risk of MG.Conclusion There are associations of MG with CTLA-4 + 49A/G and-1772C/T SNPs,but not with PTPN,KRAS,BC12 and IGF-1R SNPs.
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.