title: MicroRNA-30a promotes B cell hyperactivity in patients with systemic lupus erythematosus by direct interaction with Lyn.
abstract: OBJECTIVE
  To investigate why the level of Lyn is significantly decreased in B cells from a majority of patients with systemic lupus erythematosus (SLE) and to determine the role of microRNA-30a (miR-30a) in SLE B cell hyperactivity.
  
  
  METHODS
  Luciferase reporter gene assays were performed to identify the interaction between miR-30a and the 3'-untranslated region (3'-UTR) of Lyn. Levels of miR-30a in B cells were determined by TaqMan quantitative polymerase chain reaction (qPCR), Lyn messenger RNA levels were tested with real-time qPCR, and protein levels of Lyn were determined using Western blotting. The quantity of IgG was determined by enzyme-linked immunosorbent assay. The proliferation of B cells was measured using (3) H-thymidine incorporation.
  
  
  RESULTS
  In B cell lines, miR-30a, but not miR-30b, miR-30c, miR-30d, or miR-30e, could specifically bind the 3'-UTR of Lyn, and overexpression of miR-30a inhibited the levels of Lyn. The level of miR-30a in B cells was significantly higher in SLE patients compared to healthy donors. The level of miR-30a was negatively associated with the level of Lyn in B cells. Overexpression of miR-30a was found to promote B cell proliferation and the production of IgG antibodies. The effect of miR-30a could be abrogated by inducing overexpression of Lyn in B cells.
  
  
  CONCLUSIONS
  These results reveal that elevated expression of miR-30a is responsible for the reduction in levels of Lyn in B cells from patients with SLE, suggesting that miR-30a plays an important role in B cell hyperactivity.
authors: Beijing Institute of Basic Medical Sciences, People's Hospital, and Peking University, Beijing, China.
authors: Yu
authors: Y
authors: Liu
authors: Jie
authors: J
authors: Dong
authors: Rong
authors: R
authors: Mu
authors: Yaping
authors: Y
authors: Gao
authors: Xiaorong
authors: X
authors: Tan
authors: Yuhui
authors: Y
authors: Li
authors: Zhanguo
authors: Z
authors: Li
authors: Guang
authors: G
authors: Yang
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D015153:Blotting, Western; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000235:genetics* / Q000276:immunology; D035683:MicroRNAs / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: C546086:MIRN30b microRNA, human; D035683:MicroRNAs; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases