Diabetologia (2996) 39:1055-1062 Diabetologia 9 Springer-Verlag1996 Regulatory role of eicosanoids in extracellular matrix overproduction induced by long-term exposure to high glucose in cultured rat mesangial cells E Pricci 1, G. Pugliese 1, P. Men~ 1, G. Romeo 1, G. Romano 1, G. Galli 2, A. Casini 2, C.M. Rotella 2, U. Di Mario 3, F. Pugliese ~ 1Clinica Medica II (Endocrinologia I and Nefrologia) and Dipartimento di Medicina Sperimentale (Patologia Generale I), "La Sapienza" University, Rome, Italy 2Dipartimento di Fisiopatologia Clinica (Endocrinologia and Gastroenterologia) and Clinica Medica III, University of Florence, Florence, Italy 3Dipartimento di Medicina Sperimentale e Clinica (Endocrinolgia), University of Reggio Calabria at Catanzaro, Catanzaro, Italy Summary Accumulation of extracellular matrix in the mesangium and altered renal eicosanoid synthesis are two prominent features of diabetic glomerular disease. We investigated the relationship between ei- cosanoid and extracellular matrix production in rat mesangial cells cultured under high glucose vs normal glucose conditions. Long-term exposure of rat mesan- gial cells to high glucose, but not to iso-osmolar man- nitol, significantly increased extracellular matrix ac- cumulation and gene expression and transforming growth factor-~ (TGF-~) mRNA levels, and de- creased prostaglandin (PG) E 2 synthesis without af- fecting production of either thromboxane (TX) B 2 or PGF2~ , with respect to cells incubated in normal glucose. Addition of exogenous PGE 2 resulted in a dose-dependent reduction of matrix protein and mRNA levels and TGF-[3 gene expression in cells cul- tured in either normal or high glucose conditions, whereas exposure to exogenous PGF2~ produced a significant increment in matrix production and matrix and TGF-[3 gene expression in cells grown in normal glucose, but only a slight increase in those cultured in high glucose. Stimulation of endogenous endoper- oxide metabolism towards PGE 2 and PGF2~ synthesis with FCE-22,178, a drug originally developed as TXA 2synthase inhibitor, resulted in a dose-dependent decrease in matrix accumulation and matrix and TGF-f3 gene expression which was suppressed by co- incubation with the cyclo-oxygenase inhibitor feno- profen blocking the FCE-22,178-enhanced PG pro- duction. In both cell lines, the rate of synthesis of TXA 2 was very low and the selective blockade of its synthesis (by two other TXA 2 synthase inhibitors, OKY-046 and Ridogrel) or action (by the TXA 2 re- ceptor antagonist BM-13,177) did not alter matrix production or TGF-[3 mRNA levels. These results suggest that the cyclo-oxygenase pathway is involved in the regulation of matrix changes induced by high glucose in rat mesangial cells; the reduced production of PGE 2 may enhance the synthesis or potentiate the effect of stimulators of ECM formation such as TGF-[3, whereas TXA 2 does not appear to be in- volved. These data also indicate that glucose-en- hanced mesangial matrix accumulation may be pre- vented by exogenous PGE 2 or by drugs capable of in- creasing endogenous PGE 2 synthesis. [Diabetologia (1996) 39: 1055-1062] Keywords Extracellular matrix, transforming growth factor- B, prostaglandins, thromboxane, mesangial cell, diabetes mellitus. Received: 22 January 1996 and in revised form: 10 April 1996 Corresponding author: Dr. E Pugliese, Clinica Medica II, Divi- sion of Nephrology, "La Sapienza" University of Rome, Poli- clinico Umberto I, Viale del Policlinico,1-00161 Rome, Italy Abbreviations: AGE, Advanced glycosylation end-products; ECM, extracellular matrix; PG, prostaglandin; RMC, rat me- sangial cells;TGF-[3,transforming growth factor-B;TX, throm- boxane; Cox, cyclo-oxygenase. Extracellular matrix (ECM) overproduction by me- sangial cells is believed to play a central role in the pathogenesis of glomerulosclerosis, the histologic picture common to all progressive renal diseases in- cluding diabetic glomerulopathy [1, 2]. Increased amounts of ECM may result in mesangial expansion, eventually leading to collapse of the capillary bed, with subsequent glomerular ischaemia and sclerosis. Both clinical [3, 4] and experimental [5, 6] studies