Activation of PPARdelta inhibits cardiac fibroblast proliferation and the transdifferentiation into myofibroblasts.

Autor: Teunissen BE; Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands., Smeets PJ, Willemsen PH, De Windt LJ, Van der Vusse GJ, Van Bilsen M
Jazyk: angličtina
Zdroj: Cardiovascular research [Cardiovasc Res] 2007 Aug 01; Vol. 75 (3), pp. 519-29. Date of Electronic Publication: 2007 May 03.
DOI: 10.1016/j.cardiores.2007.04.026
Abstrakt: Objective: The development of heart failure is invariably associated with extensive fibrosis. Treatment with Peroxisome Proliferator-Activated Receptor (PPAR) ligands has been shown to attenuate cardiac fibrosis, but the molecular mechanism underlying this protective effect has remained largely unknown. In this study the potential of each PPAR isoform (PPARalpha, delta, and gamma) to attenuate cardiac fibroblast proliferation, fibroblast (CF) to myofibroblast (CMF) transdifferentiation, and collagen synthesis was investigated.
Methods and Results: PPARdelta was found to be the most abundant isoform in both CF and CMF. Only the PPARdelta ligand GW501516, but not PPARalpha ligand Wy-14,643 or PPARgamma ligand rosiglitazone, significantly increased PPAR-dependent promoter activity and expression of the PPAR-responsive gene UCP2 ( approximately 5-fold). GW501516 reduced the proliferation rate of CF (-38%) and CMF (-26%), which was associated with increased expression of the cell cycle inhibitor gene G0/G1 switch gene 2 (G0S2). Exposure of CF to the PPARdelta ligand or adenoviral overexpression of PPARdelta significantly decreased alpha-smooth muscle actin (alpha-SMA) levels, indicating a reduced CF to CMF transition. The inhibition of transdifferentiation by PPARdelta correlated with an increase in PTEN (Phosphatase and Tensin Homolog Deleted on Chromosome ten) expression. (3)H-Proline incorporation assays demonstrated a GW501516 induced decline in collagen synthesis (-36%) in CF.
Conclusion: Cardiac fibroblast proliferation, fibroblast to myofibroblast differentiation and collagen synthesis were reduced after activation of PPARdelta, suggesting that PPARdelta represents an attractive molecular target for attenuating cardiac fibrosis.
Databáze: MEDLINE