Electrophilic PPAR[gamma] ligands inhibit corneal fibroblast to myofibroblast differentiation in vitro: A potentially novel therapy for corneal scarring

A critical component of corneal scarring is the TGF[beta]-induced differentiation of corneal keratocytes into myofibroblasts. Inhibitors of this differentiation are potentially therapeutic for corneal scarring. In this study, we tested the relative effectiveness and mechanisms of action of two electrophilic peroxisome proliferator-activated receptor gamma (PPAR[gamma]) ligands: cyano-3,12-dioxolean-1,9-dien-28-oic acid-methyl ester (CDDO-Me) and 15-deoxy-[DELTA].sup.-12,14-prostaglandin J.sub.2 (15d-PGJ.sub.2) for inhibiting TGF[beta]-induced myofibroblast differentiation in vitro. TGF[beta] was used to induce myofibroblast differentiation in cultured, primary human corneal fibroblasts. CDDO-Me and 15d-PGJ.sub.2 were added to cultures to test their ability to inhibit this process. Myofibroblast differentiation was assessed by measuring the expression of myofibroblast-specific proteins ([alpha]SMA, collagen I, and fibronectin) and mRNA ([alpha]SMA and collagen III). The role of PPAR[gamma] in the inhibition of myofibroblast differentiation by these agents was tested in genetically and pharmacologically manipulated cells. Finally, we assayed the importance of electrophilicity in the actions of these agents on TGF[beta]-induced [alpha]SMA expression via Western blotting and immunofluorescence. Both electrophilic PPAR[gamma] ligands (CDDO-Me and 15d-PGJ.sub.2) potently inhibited TGF[beta]-induced myofibroblast differentiation, but PPAR[gamma] was only partially required for inhibition of myofibroblast differentiation by either agent. Electrophilic PPAR[gamma] ligands were able to inhibit myofibroblast differentiation more potently than non-electrophilic PPAR[gamma] ligands, suggesting an important role of electrophilicity in this process. CDDO-Me and 15d-PGJ.sub.2 are strong inhibitors of TGF[beta]-induced corneal fibroblast to myofibroblast differentiation in vitro, suggesting this class of agents as potential novel therapies for corneal scarring warranting further study in pre-clinical animal models.Academi

Electrophilic PPARγ ligands inhibit corneal fibroblast to myofibroblast differentiation in vitro: A potentially novel therapy for corneal scarring

A critical component of corneal scarring is the TGFβ-induced differentiation of corneal keratocytes into myofibroblasts. Inhibitors of this differentiation are potentially therapeutic for corneal scarring. In this study, we tested the relative effectiveness and mechanisms of action of two electrophilic peroxisome proliferator-activated receptor gamma (PPARγ) ligands: cyano-3,12-dioxolean-1,9-dien-28-oic acid-metheyl ester (CDDO-Me) and 15-deoxy-Δ-12,14-prostaglandin J(2) (15d-PGJ(2)) for inhibiting TGFβ-induced myofibroblast differentiation in vitro. TGFβ was used to induce myofibroblast differentiation in cultured, primary human corneal fibroblasts. CDDO-Me and 15d-PGJ(2) were added to cultures to test their ability to inhibit this process. Myofibroblast differentiation was assessed by measuring the expression of myofibroblast-specific proteins (αSMA, collagen I, and fibronectin) and mRNA (αSMA and collagen III). The role of PPARγ in the inhibition of myofibroblast differentiation by these agents was tested in genetically and pharmacologically manipulated cells. Finally, we assayed the importance of electrophilicity in the actions of these agents on TGFβ-induced αSMA expression via Western blotting and immunofluorescence. Both electrophilic PPARγ ligands (CDDO-Me and 15d-PGJ(2)) potently inhibited TGFβ-induced myofibroblast differentiation, but PPARγ was only partially required for inhibition of myofibroblast differentiation by either agent. Electrophilic PPARγ ligands were able to inhibit myofibroblast differentiation more potently than non-electrophilic PPARγ ligands, suggesting an important role of electrophilicity in this process. CDDO-Me and 15d-PGJ(2) are strong inhibitors of TGFβ-induced corneal fibroblast to myofibroblast differentiation in vitro, suggesting this class of agents as potential novel therapies for corneal scarring warranting further study in pre-clinical animal models

Vascular and neuronal development: Intersecting parallelisms and rossroads

Two key events during evolution allowed vertebrates to develop specialized tissues able to perform complex tasks: the formation of a highly branched vascular system ensuring that all tissues receive adequate blood supply, and the development of a nervous system in which nerves branches to transmit electrical signal to peripheral organs. Both networks are laid down in a complex and stereotyped manner, which is tightly controlled by a series of shared developmental cues. Vessels and nerves use similar signals and principles to grow, differentiate and navigate toward their final targets. Moreover, the vascular and the nervous system cross-talk and, when deregulated, they contribute to medically relevant diseases. The emerging evidence that both systems share several molecular pathways not only provides an important link between vascular biology and neuroscience, but also promises to accelerate the discovery of new pathogenetic insights and therapeutic strategies