title: Increased levels of IL-6, sIL-6R, and sgp130 in the aqueous humor and serum of patients with diabetic retinopathy.
abstract: Trans-signaling of interleukin (IL)-6 through its soluble receptor (sIL-6R) is critically involved in the promotion of chronic inflammatory diseases. The aim of the present study was to estimate IL-6, sIL-6R, and soluble gp130 (sgp130, a natural antagonist of IL-6 trans-signaling) concentrations in the serum and aqueous humor (AqH) of patients with diabetic retinopathy (DR).
  
  
  
  Paired AqH and serum samples were collected from 152 consecutive diabetic patients (105 with DR and 47 without DR, NDR) and 51 healthy controls. The IL-6, sIL-6R, and sgp130 concentrations were measured with multiplex bead immunoassay.
  
  
  
  The sgp130 concentrations in the serum and AqH were statistically significantly elevated in patients with DR compared with the NDR patients and the healthy controls (p<0.001). The sgp130 concentrations in the serum and AqH increased as the DR severity increased (p = 0.008, p<0.001, respectively). Higher serum and AqH concentrations of IL-6 and sIL-6R were also observed in patients with DR when compared with the NDR patients and the healthy controls (p<0.001). The AqH concentration of sgp130 was found to be statistically significantly correlated with sIL-6R and IL-6. Similarly, the IL-6 concentration in the AqH was statistically significantly correlated with sIL-6R (p<0.001). Elevated sgp130, sIL-6R, and IL-6 concentrations in the AqH were associated with longer disease duration and higher body mass index, plasma glucose, and glycosylated hemoglobin (HbA1c).
  
  
  
  The sgp130, IL-6, and sIL-6R concentrations were statistically significantly elevated in patients with DR, suggesting a probable contributing role of the IL-6 trans-signaling pathway to the pathophysiology of DR.
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Hui
authors: H
authors: Chen
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Xiongze
authors: X
authors: Zhang
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Nanying
authors: N
authors: Liao
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Feng
authors: F
authors: Wen
mesh_terms: D001082:Aqueous Humor / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D050822:Cytokine Receptor gp130 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D003930:Diabetic Retinopathy / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D019947:Receptors, Interleukin-6 / Q000097:blood*
chemical_list: D001786:Blood Glucose; D050822:Cytokine Receptor gp130; D006442:Glycated Hemoglobin; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; C508600:IL6 protein, human; C517652:hemoglobin A1c protein, human