Effect of the IL-6 trans-signaling pathway in the absence or presence of TGF-β2 on Schlemm's canal endothelial cells.

Intraocular pressure (IOP) is regulated through the balance of production and drainage of aqueous humor. The main route of aqueous-humor outflow comprises the trabecular meshwork (TM) and Schlemm's canal (SC). We reported that IL-6 trans-signaling can inhibit TGF-β signaling in TM cells and may affect regulation of IOP.

A ROCK inhibitor suppresses the transforming growth factor-beta-2-induced endothelial-mesenchymal transition in Schlemm's canal endothelial cells.

In the normal eye, most of the aqueous humor drains through the trabecular meshwork (TM) and Schlemm's canal (SC). The concentration of transforming growth factor beta 2 (TGF-β2) is increased in the aqueous humor of primary open angle glaucoma patients. TGF-β2 increases outflow resistance by affecting the TM and SC, and endothelial-mesenchymal transition (EndMT) of SC cells is involved in these changes.

Elevated soluble vascular endothelial growth factor receptor levels in aqueous humor from patients with different types of glaucoma.

We investigated the aqueous humor levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor (sVEGFR)1, and sVEGFR2 in glaucoma patients and the correlations among them. Aqueous humor was collected from the anterior chamber at the start of glaucoma or cataract surgery. The levels of VEGF and its receptors, sVEGFR1 and sVEGFR2, were measured using multiplex bead-based immunoassays.

Suberoylanilide hydroxamic acid (SAHA) inhibits transforming growth factor-beta 2-induced increases in aqueous humor outflow resistance.

Transforming growth factor-beta 2 (TGF-β2) is highly concentrated in the aqueous humor of primary open-angle glaucoma patients. TGF-β2 causes fibrosis of outflow tissues, such as the trabecular meshwork (TM), and increases intraocular pressure by increasing resistance to aqueous humor outflow. Recently, histone deacetylase (HDAC) activity was investigated in fibrosis in various tissues, revealing that HDAC inhibitors suppress tissue fibrosis.

Potential roles of the IL-6 family in conjunctival fibrosis.

Elevated intraocular pressure (IOP) is a significant risk factor for vision loss due to glaucoma, which is a major cause of blindness worldwide. Glaucoma filtration surgery (GFS) is an important method to reduce IOP by guidance of aqueous humor into a newly built filtration bleb in the conjunctiva; management of the wound healing mechanism is essential for the success of GFS. Here, we investigated the roles of interleukin (IL)-6 family members during the wound healing process after GFS.

Correction: TGF-β-induced activation of conjunctival fibroblasts is modulated by FGF-2 and substratum stiffness.

[This corrects the article DOI: 10.1371/journal.pone.

TGF-β-induced activation of conjunctival fibroblasts is modulated by FGF-2 and substratum stiffness.

Purpose: This study aimed to investigate the effects of substratum stiffness on the sensitivity of human conjunctival fibroblasts to transforming growth factor (TGF)-β, and to explore the molecular mechanism of action.

Methods: Human conjunctival fibroblasts were cultured on collagen-coated plastic or silicone plates. The stiffness of the silicone plates was 0.

DNA methyltransferase inhibitor suppresses fibrogenetic changes in human conjunctival fibroblasts.

Purpose: This study aimed to clarify the effects of a DNA methyltransferase inhibitor on fibrogenetic changes in human conjunctival fibroblasts (HConF).

Methods: HConF were pretreated with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza-dC) for 48 h. After one passage, the cells were treated with 5 ng/ml of transforming growth factor (TGF)-β2 for 48 h, and the expression levels of α-smooth muscle actin (α-SMA), extracellular matrix proteins, and phosphorylated Smad3 were evaluated with western blotting.

YAP/TAZ Are Essential for TGF-β2-Mediated Conjunctival Fibrosis.

Purpose: To investigate the roles of Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ), the major effector molecules of the Hippo pathway, in TGF-β2-mediated conjunctival fibrosis.

Methods: Primary human conjunctival fibroblasts were treated with TGF-β2. The expression of YAP/TAZ was examined by Western blot analyses and immunocytochemistry.

Interleukin-6-mediated trans-signaling inhibits transforming growth factor-β signaling in trabecular meshwork cells.

Glaucoma is one of the major causes of blindness, and transforming growth factor-β2 (TGF-β2) has been found to be elevated in the aqueous humor of eyes with primary open-angle glaucoma (POAG). TGF-β2 in aqueous humor causes the glaucoma-related fibrosis of human trabecular meshwork (HTM), suggesting an important role of TGF-β in POAG pathogenesis. Here, we sought to elucidate the effects of IL-6 trans-signaling on TGF-β signaling in HTM cells.

Stimulation of the adenosine A3 receptor, not the A1 or A2 receptors, promote neurite outgrowth of retinal ganglion cells.

Among candidate neuroprotective agents, adenosine is thought to be a possible treatment for central nervous system disorders. Adenosine elicits biological effects through four G protein-coupled receptors (A, A, A, and A). The A and A receptors stimulate adenylyl cyclase (AC) and increase cyclic adenosine monophosphate (cAMP) levels, whereas A and A receptors inhibit AC and decrease cAMP levels.

Decreased MCP-1/CCR2 axis-mediated chemotactic effect of conjunctival fibroblasts after transdifferentiation into myofibroblasts.

The purpose of this study is to investigate the change in chemotactic effects of human conjunctival fibroblasts (HConFs) after transdifferentiation into myofibroblasts, and to explore related molecular mechanisms. HConFs were treated with 5 ng/mL transforming growth factor (TGF)-β2 for 48 h to induce transdifferentiation into myofibroblasts. The cytokine concentrations in the conditioned media of HConFs were measured by multiplex bead-based immunoassays.

Inhibition of Rho Kinase Induces Antioxidative Molecules and Suppresses Reactive Oxidative Species in Trabecular Meshwork Cells.

Purpose: To investigate the effect of rho kinase inhibitors on oxidative stress in trabecular meshwork (TM) cells.

Methods: TM cells were isolated from the eyes of cynomolgus monkeys. Y-27632 and menadione were used to inhibit rho kinase and induce production of reactive oxygen species (ROS), respectively.

Molecular Mechanisms Underlying the Filtration Bleb-Maintaining Effects of Suberoylanilide Hydroxamic Acid (SAHA).

Purpose: Suberoylanilide hydroxamic acid (SAHA) has been shown to support the maintenance of experimental filtration blebs in animal models. This study was performed to investigate the molecular mechanisms underlying the bleb-maintaining effects of SAHA in modulating wound healing activities of conjunctival fibroblasts.

Methods: Human conjunctival fibroblasts (HConFs) were pretreated with SAHA before treatment with TGF-β2.

Vascular Endothelial Growth Factor-A Increases the Aqueous Humor Outflow Facility.

Purpose: Anti-vascular endothelial growth factor (VEGF) antibody therapy is an effective treatment for ocular angiogenesis. Although the intraocular pressure of some patients increases after anti-VEGF therapy, the effects of VEGF-A on the aqueous humor outflow pathway remain unknown. This study investigated the effects of VEGF-A on the aqueous humor outflow pathway.

The effects of ripasudil (K-115), a Rho kinase inhibitor, on activation of human conjunctival fibroblasts.

The most common cause of glaucoma surgery failure is scar formation induced by activation of wound-healing responses and resultant fibrosis at the surgical site. We investigated the effects of ripasudil, a Rho kinase inhibitor, on activation of human conjunctival fibroblasts (HConF). HConF were pretreated with different concentrations of ripasudil for 1 h before addition of transforming growth factor (TGF)-β2, followed by incubation for 48 h.

Live cell imaging of actin dynamics in dexamethasone-treated porcine trabecular meshwork cells.

The regulation of the actin cytoskeleton in trabecular meshwork (TM) cells is important for controlling outflow of the aqueous humor. In some reports, dexamethasone (DEX) increased the aqueous humor outflow resistance and induced unusual actin structures, such as cross-linked actin networks (CLAN), in TM cells. However, the functions and dynamics of CLAN in TM cells are not completely known, partly because actin stress fibers have been observed only in fixed cells.

p38 MAP kinase inhibitor suppresses transforming growth factor-β2-induced type 1 collagen production in trabecular meshwork cells.

Glaucoma is an age-related neurodegenerative disease of retinal ganglion cells, and appropriate turnover of the extracellular matrix in the trabecular meshwork is important in its pathology. Here, we report the effects of Rho-associated kinase (ROCK) and p38 MAP kinase on transforming growth factor (TGF)-β2-induced type I collagen production in human trabecular meshwork cells. TGF-β2 increased RhoA activity, actin polymerization, and myosin light chain 2 phosphorylation.

Oxidative stress response signaling pathways in trabecular meshwork cells and their effects on cell viability.

Purpose: To clarify the primary oxidative stress response signaling pathways in trabecular meshwork (TM) cells and their effects on cell viability.

Methods: Porcine TM cells were treated with 600 μM or 800 μM H₂O₂, and their time-dependent morphologic changes were observed. Phosphorylation of protein kinase B (Akt), extracellular regulated kinase (ERK)1/2, p38, and c-Jun NH2-terminal kinase (JNK) was evaluated by western blot analysis.

Involvement of RhoA/Rho-associated kinase signal transduction pathway in dexamethasone-induced alterations in aqueous outflow.

Purpose: We investigated the involvement of the RhoA/Rho kinase (ROCK) signal transduction pathway in dexamethasone (DEX)-induced changes in aqueous outflow.

Methods: Using trabecular meshwork (TM) and Schlemm's canal endothelial (SCE) cells, RhoA activation was evaluated with a pull-down assay and myosin light chain phosphorylation was evaluated by Western blot analysis. Outflow facility was measured in perfused porcine anterior segment organ cultures treated with DEX and/or Y-27632, a selective ROCK inhibitor.

The effect of monocyte chemoattractant protein-1/CC chemokine ligand 2 on aqueous humor outflow facility.

Purpose: To investigate the effect of monocyte chemoattractant protein-1 (MCP-1)/CC chemokine ligand 2 on aqueous humor outflow facility.

Methods: Aqueous humor outflow facility was measured in enucleated porcine eyes in a constant pressure perfusion system with or without MCP-1 (1600 ng/mL). Expression of CCR2, an MCP-1 receptor, in Schlemm's canal endothelial (SCE) cells was examined by reverse transcription-polymerase chain reaction (RT-PCR) assay.

The effect of Rho-associated protein kinase inhibitor on monkey Schlemm's canal endothelial cells.

Purpose: To investigate the effect of a specific inhibitor of Rho-associated protein kinase, Y-27632, on monkey Schlemm's canal endothelial (SCE) cells.

Methods: SCE cells were isolated from cynomolgus monkey eyes. The effects of Y-27632 on aqueous outflow facility were evaluated using enucleated monkey eyes and a constant-pressure perfusion system.

Involvement of the Hipk family in regulation of eyeball size, lens formation and retinal morphogenesis.

Members of the homeodomain-interacting protein kinase (HIPK) family are involved in various intracellular regulatory mechanisms. The present study focused on clarifying the functions of HIPK family members in ocular organization during late embryogenesis. HIPK1 and HIPK2 were expressed in the inner retina during late embryogenesis.

RGS2-deficient mice exhibit decreased intraocular pressure and increased retinal ganglion cell survival.

Purpose: Contractile activity of the trabecular meshwork (TM) and ciliary muscle (CM) influences aqueous humor drainage; however, the mechanisms linking tissue contractility and regulation of aqueous humor drainage are not well understood. Regulator of G Protein Signaling 2 (RGS2), a GTPase-activating protein of the Galphaq family of proteins, plays a critical role in regulation of contractile activity of vascular smooth muscle and in blood pressure homeostasis. To explore a potential role for RGS2 in intraocular pressure (IOP) homeostasis, we evaluated RGS2 knockout (RGS2(-/-)) mice for changes in IOP.