butaprost and Glaucoma

Prostaglandin F2α analogues are the first-line medication for the treatment of ocular hypertension (OHT), and prostanoid EP2 receptor agonists are under clinical development for this indication. The goal of this study was to investigate the effects of F prostanoid (FP) and EP2 receptor activation on the myofibroblast transition of primary trabecular meshwork (TM) cells, which could be a causal mechanism of TM dysfunction in glaucoma.. Human primary TM cells were treated with either latanoprost or butaprost and TGF-β2. Trabecular meshwork contraction was measured in a three-dimensional (3D) TM cell-populated collagen gel (CPCG) model. Expression of α-smooth muscle actin (α-SMA) and phosphorylation of myosin light chain (MLC) were determined by Western blot. Assembly of actin stress fibers and collagen deposition were evaluated by immunocytochemistry. Involvement of p38, extracellular signal-regulated kinase (ERK), and Rho-associated kinase (ROCK) pathways as well as matrix metalloproteinase activation was tested with specific inhibitors.. In one source of validated adult TM cells, latanoprost induced cell contraction as observed by CPCG surface reduction and increased actin polymerization, α-SMA expression, and MLC phosphorylation, whereas butaprost inhibited TGF-β2-induced CPCG contraction, actin polymerization, and MLC phosphorylation. Both agonists inhibited TGF-β2-dependent collagen deposition. The latanoprost effects were mediated by p38 pathway.. Latanoprost decreased TM collagen accumulation but promoted a contractile phenotype in a source of adult TM cells that could modulate the conventional outflow pathway. In contrast, butaprost attenuated both TM contraction and collagen deposition induced by TGF-β2, thereby inhibiting myofibroblast transition of TM cells. These results open new perspectives for the management of OHT.

Topics: Actins; Adult; Alprostadil; Animals; Antihypertensive Agents; Blotting, Western; Cell Survival; Cells, Cultured; Dinoprost; Glaucoma; Humans; Immunohistochemistry; Latanoprost; Male; Myofibroblasts; Myosin Light Chains; Neuroprotective Agents; Prostaglandins E, Synthetic; Prostaglandins F, Synthetic; Rats; Real-Time Polymerase Chain Reaction; Receptors, Prostaglandin; Receptors, Prostaglandin E, EP2 Subtype; RNA; Signal Transduction; Trabecular Meshwork

Connective tissue growth factor (CTGF) and Cyr61 (cysteine-rich angiogenic protein 61) are members of the CCN gene family that encode multifunctional, extracellular matrix-associated signaling proteins. Because the mechanism of action of certain anti-glaucoma drugs involves extracellular matrix remodeling of ocular ciliary muscle, with a resultant increase in drainage of aqueous humor from the eye, we compared the effects of three pharmacologically distinct ocular hypotensive agents on Cyr61 and CTGF gene expression. Thus, prostaglandin F2alpha (PGF2alpha) (FP receptor agonist), Butaprost (EP2 receptor agonist), and Bimatoprost (a prostamide) were compared. Using Affymetrix gene chip technology, we first identified that PGF2alpha dramatically up-regulated Cyr61 and CTGF mRNA expression in HEK 293/EBNA cells (hFP-HEK 293/EBNA). Northern blot further confirmed the Cyr61 and CTGF up-regulation is in a dose- and time-dependent manner. PGF2alpha-induced up-regulation of Cyr61 appeared to exclusively involve the Rho pathway, and up-regulation of CTGF was via multiple intracellular pathways. Because prostamide receptors are, to date, defined only at the pharmacological level, Bimatoprost effects on Cyr61 and CTGF were studied in the isolated feline iris sphincter preparation, a tissue highly responsive to prostamides. Both PGF2alpha and Bimatoprost up-regulated Cyr61 mRNA expression in the cat iris tissue. Only PGF2alpha up-regulated CTGF mRNA expression in the cat iris. Therefore, PGF2alpha and Bimatoprost appear to interact with different receptors populations in the cat iris, according to their markedly different effects on CTGF. Activation of prostaglandin EP2 receptors (Gs-coupled) also up-regulated Cyr61 but not CTGF mRNA expression in the isolated cat iris. Similar data were observed in human primary ciliary smooth muscle cells. Thus, despite quite different signal transduction pathways, FP receptor stimulation up-regulates CTGF and Cyr61. The prostamide analog Bimatoprost and an EP2-selective agonist affects only Cyr61.

Topics: Alprostadil; Amides; Animals; Bimatoprost; Cats; Cell Line; Cells, Cultured; Ciliary Body; Cloprostenol; Connective Tissue Growth Factor; Cysteine-Rich Protein 61; Dinoprost; Gene Expression; Glaucoma; Humans; Immediate-Early Proteins; In Vitro Techniques; Intercellular Signaling Peptides and Proteins; Iris; Kinetics; Lipids; Oligonucleotide Array Sequence Analysis; Promoter Regions, Genetic; RNA, Messenger; Signal Transduction; Trabecular Meshwork; Up-Regulation