title: [Effect of spironolactone on the expression of Toll-like receptor 4 in renal tubular epithelia cells exposed to high glucose].
abstract: OBJECTIVE
  To study the expression of Toll-like receptor 4 (TLR4) in renal tubular epithelial cells exposed to high glucose and the effect of spironolactone on the TLR4 expression.
  
  
  METHODS
  In vitro renal tubular epithelial cells (NRK-52E) were randomly exposed to DMEM culture solution with low glucose (5 mmol /L), high glucose (25 mmol/L) or 10(-7) mol/L spironolactone plus 25 mmol/L glucose. Immunohistochemistry, RT-PCR and Western blot were used to determine TLR4 protein and mRNA expression. The levels of IL-6 and TNF-alpha in the cell culture supernatant were determined using ELISA.
  
  
  RESULTS
  The expression of TLR4 mRNA in the high glucose group began to increase 6 hrs and remained at a higher level up to 24 hrs after exposure as compared with the low glucose group. The TLR4 mRNA expression in the spironolactone treatment group was significantly lower than that in the high glucose group, although it was higher than that in the low glucose group between 6 and 24 hrs after exposure. TLR4 protein expression increased significantly in the high glucose group 24 and 48 hrs after exposure compared with that in the low glucose group. The TLR4 protein expression in the spironolactone treatment group was lower than that in the high glucose group, but higher than that in the low glucose group. IL-6 and TNF-alpha expression in the supernatant from the NRK-52E cells in the high glucose groups increased significantly as compared with the low glucose group. The spironolactone treatment group had significantly reduced IL-6 and TNF-alpha expression compared with the high glucose group.
  
  
  CONCLUSIONS
  High glucose triggers an increase in the expression of TLR4 and inflammatory factors in NRK-52E cells. TLR4 may participate in the progress of diabetic nephropathy. Spironolactone can reduce expression of TLR4 and inflammatory factors, which might be attributed to one of the mechanisms of protection by spironolactone against diabetic nephropathy.
authors.affiliation: Kidney Disease and Blood Purification Research Center/Department of Nephropathy, Xiangya Hospital of Central South University, Changsha 410008, China.
authors.forename: Kang-Han
authors.initials: KH
authors.lastname: Liu
authors.forename: Qiao-Ling
authors.initials: QL
authors.lastname: Zhou
authors.forename: Xiang
authors.initials: X
authors.lastname: Ao
authors.forename: Tian-Feng
authors.initials: TF
authors.lastname: Tang
authors.forename: Xue-Min
authors.initials: XM
authors.lastname: Hong
authors.forename: Rui-Lan
authors.initials: RL
authors.lastname: Bao
mesh_terms: D002478:Cells, Cultured; D003928:Diabetic Nephropathies / Q000209:etiology*; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000032:analysis; D007684:Kidney Tubules / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D013148:Spironolactone / Q000494:pharmacology*; D051197:Toll-Like Receptor 4 / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D013148:Spironolactone