Expression and regulation of a novel identified TNFAIP8 family is associated with diabetic nephropathy

Biochim Biophys Acta. 2010 Nov;1802(11):1078-86. doi: 10.1016/j.bbadis.2010.08.003. Epub 2010 Aug 8.

Abstract

Tumor necrosis factor-α-inducible protein 8 (TNFAIP8) family are very recently identified proteins which share considerable sequence homology to regulate cellular and immune homeostasis. However, it is unknown whether TNFAIP8 family is expressed in the kidney and contributes to the regulation of renal functions. Therefore, the present study was designed to characterize the members of TNFAIP8 family in the kidney and to explore their possible roles in the development and progression of diabetic nephropathy. By RT-PCR and Western blot analyses, we found that all members of TNFAIP8 family were detected in the kidney. TNFAIP8 and TIPE2 expression was significantly increased in glomeruli from streptozotocin (STZ)-induced diabetic rats, and this upregulation was further confirmed in renal biopsies of diabetic patients. In in vitro study, TNFAIP8 was upregulated in response to high glucose in mesangial cells rather than podocytes. Moreover, a direct correlation was observed between expression of TNFAIP8 and mesangial cell proliferation and this regulation was associated with NADPH oxidase-mediated signaling pathway. However, we failed to observe the upregulation of TIPE2 in both mesangial cells and podocytes in response to high glucose. In conclusion, the present study addressed the role of TNFAIP8 family in diabetic nephropathy. These findings for the first time demonstrate that TNFAIP8 is one of critical components of a signal transduction pathway that links mesangial cell proliferation to diabetic renal injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / genetics*
  • Apoptosis Regulatory Proteins / metabolism
  • Blotting, Western
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / complications*
  • Diabetic Nephropathies / etiology
  • Diabetic Nephropathies / genetics*
  • Diabetic Nephropathies / metabolism
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation / drug effects
  • Genetic Predisposition to Disease*
  • Glucose / pharmacology
  • Humans
  • Immunohistochemistry
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Kidney / metabolism
  • Kidney / pathology
  • Kidney Glomerulus / metabolism
  • Kidney Glomerulus / pathology
  • Male
  • Mesangial Cells / metabolism
  • NADPH Oxidases / metabolism
  • RNA Interference
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Apoptosis Regulatory Proteins
  • Intracellular Signaling Peptides and Proteins
  • TIPE2 protein, rat
  • TNFAIP8 protein, human
  • TNFAIP8 protein, rat
  • NADPH Oxidases
  • Glucose