Cytotoxicity of peroxisome proliferator-activated receptor alpha and gamma agonists in renal proximal tubular cell lines.
Fibrates and thiazolidinediones are agonists of peroxisome proliferator-activated receptors (PPAR) alpha and gamma, pharmacologically designed to control dyslipidemia and insulin resistance, respectively. Several works have reported the toxicity of some agonists in a number of tissues. In this work we have analyzed the toxicity of two PPARalpha (WY14643 and clofibrate) and two PPARgamma (pioglitazone and ciglitazone) agonists, using three different renal proximal tubular cell lines: Opossum OK, pig LLC-PK1, and murine MCT. Cell death was determined by the activity of intracellular lactate dehydrogenase. WY14643 and ciglitazone increased cell death with LC50 values of 92-124 microM and 8.6-14.8 microM, respectively, depending on the cell line. Clofibrate and pioglitazone were, however, non-cytotoxic even at concentrations of 10 and 100 higher than the corresponding EC50, which suggests that cell death is independent of PPAR activation. Discrimination between apoptosis or necrosis was analyzed by light microscopy and stress fiber morphology, double staining with acridine orange and ethidium bromide, binding of annexin V, caspase-3 activity, and DNA laddering. With these methods, no signs of apoptosis were observed, which suggests a direct necrosis of the compounds on these renal proximal tubular cell lines.
Giral
Héctor
H
Laboratory of Molecular Toxicology, University of Zaragoza, E50013 Zaragoza, Spain.
Villa-Bellosta
Ricardo
R
Catalán
Julia
J
Sorribas
Víctor
V
D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002994:Clofibrate / Q000494:pharmacology*; D053938:DNA Fragmentation; D007004:Hypoglycemic Agents / Q000494:pharmacology; D000960:Hypolipidemic Agents / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018374:LLC-PK1 Cells; D051379:Mice; D009893:Opossums; D047493:PPAR alpha / Q000819:agonists*; D047495:PPAR gamma / Q000819:agonists*; D020025:Peroxisome Proliferators / Q000494:pharmacology; D000077205:Pioglitazone; D011743:Pyrimidines / Q000494:pharmacology*; D013552:Swine; D045162:Thiazolidinediones / Q000494:pharmacology*
D007004:Hypoglycemic Agents; D000960:Hypolipidemic Agents; D047493:PPAR alpha; D047495:PPAR gamma; D020025:Peroxisome Proliferators; D011743:Pyrimidines; D045162:Thiazolidinediones; C006253:pirinixic acid; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3; D002994:Clofibrate; C039671:ciglitazone; D000077205:Pioglitazone