Detection of autophagy gene expression in T cells from patients with systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective In order to explore the role of autophagy in the development of systemic lupus erythematosus (SLE),we measured the expression of autophagy related gene microtubule-associated protein 1 light chain 3 (LC3),Atg5,Beclinl,Atg7 and the incidence of autophagy in T cells from patients with SLE.Methods The mRNA levels of LC3,Atg5,Beclinl,Atg7 in T cells from 67 SLE patients and 31 healthy individuals were detected by real-time quantitative polymerase chain reacton (qPCR) technique.Autophagy in T cells from 17 SLE patients and 11 healthy controls was also determined by flow cytometry (FACs).The correlation of Atg7 mRNA expression with clincal features was then analyzed.The differences between the two groups were tested by t-test and x2 tcst,all data were analyzed by statistical and service solutions (SPSS) 17.0 software.Results The mRNA levels of LC3 and Atg7 (ΔCT value) in SLE patients were obviously down-regulated as compared to healthy populations (P=0.010,P=0.002),paralleled with the decreased autophagy rate detected by flow cytometry in T cells of SLE patients [(3.7±1.9)％ vs (6.6±1.4)％,t=4.132,P=0.000].Also,the protein expression levels of LC3-Ⅱ in T cells of SLE patients (LC3-Ⅱ/GAPDH) was significantly lower than those in healthy controls (0.21±0.08 vs 0.34±0.11,t=1.846,P=0.047).Moreover,Atg7 mRNA expression levels were found to be negatively correlated to autophagy rate (r=-0.492,P=0.008).However,when comparing the clinical features of 24 SLE patients with decreased Atg7 mRNA expression (ΔCT value＞9.86) to 43 SLE patients with normal or high Atg7 mRNA expression (ΔCT value ＜9.86),increasing trend of incidence of arthritis,blood involvement and CNS was noted in patients with decreased Atg7 mRNA expression.However,there was a significant difference between the two groups in the incidence of renal involvement and anti-dsDNA antibody and SLEDAI (P=0.008,P=0.018,P=0.035).Conclusion The impaired autophagy resulted from down-regulated LC3 and Atg7 mRNA levels in T cells from SLE patients indicates that autophagy plays a role in mediating the occurrence and development of SLE,which might be through unable to clean harmful molecules effectively.