title: Regulatory T cells in the pathogenesis of type 2 diabetes mellitus retinopathy by miR-155.
abstract: OBJECTIVE
  To explore the regulatory T cells (Treg) in the peripheral blood of diabetic retinopathy patients by microRNA-155 (miR-155), and investigate the mechanisms of regulatory T cells and miR-155 in the pathogenesis of diabetic retinopathy.
  
  
  METHODS
  The study explores the percentage of CD4+ CD25+ Foxp3+ T cells (Treg cells) and the expression of miR-155 in the peripheral blood of 20 cases with background diabetic retinopathy (BDR group) and 20 cases with proliferative diabetic retinopathy (PDR group). Flow cytometry and RT-PCR determined 18 cases with non-diabetic retinopathy (NDR group) and 20 cases of healthy control (NC group). ELISA determined the expression of TGF-β.
  
  
  RESULTS
  The percentages of Treg cells in the peripheral blood of patients in BDR group, PDR group, and NDR group had significantly decreased compared to that in the NC group (p < 0.05). The percentages of the Treg cells in the BDR and PDR groups were lower than those in NDR group (p < 0.05 in both cases). The percentage of Treg cells in the PDR group was lower than that in the BDR group (p < 0.05). The expression levels of miR-155 in the peripheral blood of the patients in the BDR group, PDR group, and NDR group had significantly increased compared to that in NC group (p < 0.05). The expression levels of miR-155 in the BDR group and PDR group were higher than that in the NDR group (p < 0.05 in both cases). The expression level of miR-155 in the PDR group was higher than that in the BDR group (p < 0.05). The expression levels of TGF-β in the BDR group and PDR group were significantly decreased compared to those in the NDR group and NC group (p < 0.05 in both cases). The expression of miR-155 was negatively related to the Treg cells and the expression level of TGF-β2 (r1 = -0.835, p1 = 0.000, r2 = -0.771, p2 = 0.000).
  
  
  CONCLUSIONS
  In type 2 diabetes mellitus (T2DM) retinopathy, miR-155 may play an important role in the pathogenesis of T2DM retinopathy by regulating the Treg cells with TGF-β.
authors.affiliation: Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China. songshoujun@126.com.
authors.forename: T-T
authors.initials: TT
authors.lastname: Yang
authors.forename: S-J
authors.initials: SJ
authors.lastname: Song
authors.forename: H-B
authors.initials: HB
authors.lastname: Xue
authors.forename: D-F
authors.initials: DF
authors.lastname: Shi
authors.forename: C-M
authors.initials: CM
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000209:etiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D035683:MicroRNAs / Q000097:blood / Q000378:metabolism*; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000097:blood*
chemical_list: C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D016212:Transforming Growth Factor beta