AGEs induce oxidative stress and activate protein kinase C-beta(II) in neonatal mesangial cells.
Increased activation of specific protein kinase C (PKC) isoforms and increased nonenzymatic glycation of intracellular and extracellular proteins [the accumulation of advanced glycation end products (AGEs)] are major mechanistic pathways implicated in the pathogenesis of diabetic complications. Blocking PKC-beta(II) has been shown to decrease albuminuria in animal models of diabetes. To demonstrate a direct relationship between AGEs and the induction and translocation of PKC-beta(II), studies were carried out in rat neonatal mesangial cells, known to express PKC-beta(II) in association with rapid proliferation in post-natal development. Oxidative stress was studied by using the fluorescent probe dichlorfluorescein diacetate. Translocation of PKC-beta(II) was demonstrated by using immunofluorescence and Western blotting of fractionated mesangial cells. Induction of intracellular oxidative stress, increase in intracellular calcium, and cytosol to membrane PKC-beta(II) translocation (with no change in PKC-alpha) were demonstrated after exposure to AGE-rich proteins. These data support the hypothesis that AGEs cause mesangial oxidative stress and alterations in PKC-beta(II), changes that may ultimately contribute to phenotypic abnormalities associated with diabetic nephropathy.
Scivittaro
V
V
Division of Nephrology, Department of Medicine, Case Western Reserve University and University Hospitals of Cleveland, OH 44106,USA.
Ganz
M B
MB
Weiss
M F
MF
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000502:physiology; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D007425:Intracellular Membranes / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D018384:Oxidative Stress; D011493:Protein Kinase C / Q000378:metabolism*; D064546:Protein Kinase C beta; D051381:Rats; D017207:Rats, Sprague-Dawley
D017127:Glycation End Products, Advanced; D007527:Isoenzymes; D011493:Protein Kinase C; D064546:Protein Kinase C beta