Absence of inflammatory changes induced by PPAR β/δ antagonists in skin after topical application.

<p>(a) C57Bl/6j wild type mice were treated with ointments containing GSK0660 or compound 3 h applied twice daily to shaved dorsal skin for one week. Mice were sacrificed 1 h after the last ointment application and skin tissue processed for H&E based histology and mass spectrometry, as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">Methods</a>. Data shown represent average ± s.d. of n = 3 mice per data point (left) treated with GSK (blue columns) or compound 3 h (red). Representative histology sections of all treated mice are shown on right. The inset in the middle panel shows a section of GSK0660-treated epidermis showing apoptotic looking cells (marked by red arrow head). Horizontal bar represents 5 µm. (b) Representative H&E sections of C57Bl/6j wild type mice treated for one week with either GSK0660 (top) or GSK3787 (bottom). Red arrow-heads denoting apoptotic looking cells.</p

Prevention of epidermal hyperplasia by transdermal application of selective PPAR β/δ antagonists.

<p>Both the PPAR β/δ agonist GW501516 (GW) and the antagonists GSK0660 (GSK) or compound 3 h were applied topically to the skin, as described in the text. Left: representative H&E-stained paraffin-sections of dorsal skin from PPAR β/δ transgenic mice after treatment with ointments containing the indicated drugs for twenty days, as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">Methods</a>. Horizontal bar represents 5 µm. Right: quantification of H&E-based epidermal thickness observed in n = 4 mice per group, performed as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">Methods</a>. * p<0.05 in a two-sided independent t-test.</p

Low systemic absorption of topically applied PPAR β/δ antagonists.

<p><b>A</b>. Peak blood concentrations of PPAR β/δ agonist GW501516, and antagonists GSK0660 and compound 3 h, respectively, at 1 h after topical application to skin. Left: Amount of drugs detected in systemic circulation, expressed as fraction of total amount applied, was calculated as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">methods</a>. Right: Drug concentration expressed as molar concentration. <b>B</b>. GSK0660 concentration in blood (left) and total amount of circulating drug as fraction of amount applied (right, calculated as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">Methods</a>) at the indicated time points after drug application. The horizontal dashed line represents the reported IC50 for GSK0660 acting on PPAR β/δ reported previously (300 nmol/L). Data shown represent average ± s.d. of n = 3 mice per data point.</p

Half – life of GSK0660 after topical application to skin.

<p>42 mg of GSK0660 ointment was applied to dorsal skin of C57Bl/6j wild type mice. Mice were sacrificed at the time after drug application indicated in the figure and drug concentration determined by mass spectrometry, as detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037097#s4" target="_blank">Methods</a>. Data shown represent average ± s.d. of n = 3 mice per data point.</p

PPAR β/δ selective antagonists used in this study.

<p>Chemical structures and in vitro pharmacodynamic data shown are taken from the references listed. The structure of the PPAR β/δ selective agonist GW501516 used in this study is given for comparison.</p

Control of PPAR β/δ – mediated skin disease using reduced-frequency application of ointment containing an irreversible PPAR β/δ antagonist.

<p>Skin disease in PPAR β/δ transgenic mice was induced by i.p. injection of the agonist GW501516. Additionally, mice were shaved on their abdomen and were treated with vehicle-ointment or ointment containing either GSK0660 (twice daily) or GSK3787 at the indicated frequencies. Red arrow denotes apoptotic cells noted in the GW-only treatment group. <b>A</b>. Top: Representative H&E stains from 3 different mice in each treatment group. Horizontal bar represents 5 µm. Bottom: Quantification of epidermal thickness (p<0.01 in all treatment groups vs. GW-only). <b>B</b>. Quantification of dermal infiltrate. Data shown represent average ± s.d. of five mice per group.</p