The extracellular matrix components osteopontin and tenascin-C are ligands of α9 integrin, and both play roles in corneal wound fibrosis and neovascularization. It has been shown that loss of osteopontin impairs closure of incisional wounds in the mouse cornea. Detailed analyses suggest that the loss of osteopontin reduces macrophage invasion and myofibroblast differentiation in the healing stroma in association with suppression of fibrogenic gene expression in response to injury. Cultured ocular fibroblasts derived from knockout mice showed an impairment of activation of p38 MAPK and Smad3 upon exposure to transforming growth factor β1. The loss of tenascin-C delays stromal healing in association with suppression of fibrogenic gene expression and macrophage invasion. With regard to neovascularization, the loss of either osteopontin or tenascin-C suppressed the growth of new blood vessels from the limbal region toward the central cornea in response to corneal cauterization in mice. Gene expression analysis further showed that lack of osteopontin or tenascin-C resulted in inhibition of angiogenic and proinflammatory gene expression. In conclusion, osteopontin or tenascin-C, α9 integrin ligands, play an important role in stromal healing (or fibrosis) and neovascularization in mouse cornea.

We investigated the effects of loss of tenascin C on the healing of the stroma using incision-injured mice corneas. Tenascin C was upregulated in the stroma following incision injury to the cornea. Wild-type (WT) and tenascin C-null (knockout (KO)) mice on a C57BL/6 background were used. Cell culture experiments were also conducted to determine the effects of the lack of tenascin C on fibrogenic gene expression in ocular fibroblasts. Histology, immunohistochemistry and real-time reverse transcription PCR were employed to evaluate the healing process in the stroma. The difference in the incidence of wound closure was statistically analyzed in hematoxylin and eosin-stained samples between WT and KO mice in addition to qualitative observation. Healing of incision injury in corneal stroma was delayed, with less appearance of myofibroblasts, less invasion of macrophages and reduction in expression of collagen Iα1, fibronectin and transforming growth factor β1 (TGFβ1) in KO mice compared with WT mice. In vitro experiments showed that the loss of tenascin C counteracted TGFβ1 acceleration of mRNA expression of TGFβ1, and of collagen Iα1 and of myofibroblast conversion in ocular fibroblasts. These results indicate that tenascin C modulates wound healing-related fibrogenic gene expression in ocular fibroblasts and is required for primary healing of the corneal stroma.

We examined whether absence or blocking of transient receptor potential vanilloid subtype 1 (TRPV1) affects the level of inflammation and fibrosis/scarring during healing of injured tissue using an alkali burn model of cornea in mice. A cornea burn was produced with 1 N NaOH instilled into one eye of TRPV1 -/- (KO) (n = 88) or TRPV1+1+ (n = 94) mice. Examinations of the corneal surface and eye globe size suggested that the loss of TRPV1 suppressed inflammation and fibrosis/scarring after alkali burn, and this was confirmed by histology, IHC, and gene expression analysis. The loss of TRPV1 inhibited inflammatory cell invasion and myofibroblast generation in association with reduction of expression of proinflammatory and profibrogenic components. Experiments of bone marrow transplantation between either genotype of mice showed that KO corneal tissue resident cells, but not KO bone marrow derived cells, are responsible for KO-type wound healing with reduced inflammation and fibrosis. The absence of TRPV1 attenuated expression of transforming growth factor beta 1 (TGF beta 1) and other proinflammatory gene expression in cultured ocular fibroblasts, but did not affect TGF beta 1 expression in macrophages. Loss of TRPV1 inhibited myofibroblast transdifferentiation in cultured fibroblasts. Systemic TRPV1 antagonists reproduced the KO type of healing. In conclusion, absence or blocking of TRPV1 healing of alkali-burned mouse cornea. TRPV1 is a potential drug target for improving the outcome of inflammatory/fibrogenic wound healing. (Am J Pathol 2011, 178:2654-2664; DOI: 10.1016/j.ajpath.2011.02.043)

METHODS. Ocular fibroblasts and macrophages from wild-type (WT) and TNC-null (KO) mice were used to study the role of TNC in the expression of VEGF and TGF 1. The effects of the absence of TNC on angiogenic gene expression, inflammatory cell invasion, and cornea neovascularization in the corneal stroma were then evaluated after cauterization of the center of the cornea in mice. Histologic, immunohistochemical, and mRNA expression analyses were performed.

Maintenance of the transparency and regular shape of the cornea are essential to the normal vision, whereas opacification of the tissue impairs vision. Fibrogenic reaction leading to scarring in an injured cornea is characterized by appearance of myofibroblasts, the key player of the fibrogenic reaction, and excess accumulation of fibrous extracellular matrix. Inflammatory/fibrogenic growth factors/cytokines produced by inflammatory cells play a pivotal role in fibrogenic response. Signaling systems involved in myofibroblast formation and fibrogenesis are activated by various growth factors, i.e., transforming growth factor beta or others. Modulation of transforming growth factor beta signal transduction molecules, e.g., Smad and mitogen-activated protein kinases, by gene transfer and other technology provides a new concept of prevention/treatment of unfavorable fibrogenesis in the cornea.

Neurotropic keratopathy is one of the major refractory corneal disorders, which was first recognized in 1824. This category of diseases is caused by damage to the trigeminal nerve and the consequent loss of corneal sensation. It leads to various types of corneal disorder, including superficial keratopathy, persistent epithelial defects and corneal ulcers. In the present article, we review the pathobiology and prevention/treatment of neurotrophic corneal diseases. The goals of treatment of neurotrophic keratopathy are to prevent the progression of corneal damage to promote epithelial healing in case that the original damage in the trigeminal nerve or its braches is difficult. The therapy should be prompt and based on the clinical stage of the disease. Although at present, there are no accurate treatment methods for neurotrophic keratopathy, several effective treatments have been reported. Signals derived from TRP channels are involved in homeostasis of tissues by controlling cell behaviors, i. e., gene expression for inflammation, cell migration, or cell survival/cell death. Targeting TRP channel in the cornea is expected to contribute to the development of a new treatment method for neurotrophic keratopathy. Further study and clinical trial are need to establish this new treatment strategy.

The authors report two cases of congenital retrobulbar cyst or large peripapillary staphyloma with alcoholic mothers. In the first case, a 53-day-old newborn was referred for evaluation of microphthalmia in her left eye. Ophthalmic examination showed microcornea, microphthalmia, and an abnormally enlarged optic disc with an excavation in her left eye. Imaging revealed the presence of a cystic lesion in her left orbit that seemed to be communicated with the vitreous cavity. She did not have chromosomal abnormality. In the second case, a large peripapillary staphyloma was detected in the right eye of a 7-month-old newborn. The mother of each patient was an alcoholic. Retrobulbar cystic lesion or peripapillary staphyloma could be considered to be a series of abnormalities caused by the degree of the failure of the optic cup. Effects of each mother's alcohol intake on the development of the eye, especially the closure of the optic cup, is to be further investigated.

PURPOSE:To investigate the role of tenascin-C in epithelial-mesenchymal transition (EMT) of the lens epithelium during wound healing in mice. Tenascin-C is a component of the extracellular matrix in patients having post-operative capsular opacification.METHODS:The crystalline lens was injured by needle puncture in tenascin-C null (KO, n=56) and wild-type (WT, n=56) mice in a C57BL/6 background. The animals were killed at day 2, 5, or 10 post-injury. Immunohistochemistry was employed to detect alpha-smooth muscle actin (alphaSMA), a marker of EMT, collagen type I, transforming growth factor beta1 (TGFbeta1), phospho-Smad2, phospho-adducin, and phospho-myosin light chain 9 (MLC9). The expression levels of phospho-adducin and phospho-MLC9 were used as markers for the activation of protein kinase C and Rho kinase, respectively.RESULTS:The expression of tenascin-C was upregulated in WT lens epithelial cells adjacent to the capsular break at day 5. The results showed that injury-induced EMT of the mouse lens epithelium, as evaluated by histology and the expression patterns of alphaSMA and fibronectin, was attenuated in the absence of tenascin-C. Upregulation of TGFbeta1 expression in the epithelium was also inhibited, and loss of tenascin-C attenuated the phosphorylation of Smad2 and adducin in epithelial cells adjacent to the capsular break. The expression of phospho-adducin was suppressed, while the expression level of phospho-MLC9 was unchanged, in the healing epithelium in the absence of tenascin C.CONCLUSIONS:Tenascin-C is required for injury-induced EMT in the mouse lens epithelium. The mechanism behind this might involve impaired activation of cytoplasmic signaling cascades; i.e., TGFbeta/Smad and protein kinase C-adducing signaling, in the absence of tenascin-C.

Purpose To examine the effects of a histone deacetylase inhibitor, Trichostatin A (TSA), on the behavior of macrophages and subconjunctival fibroblasts in vitro and on ocular surface inflammation and scarring in vivo using an alkali burn wound healing model. Methods Effects of TSA on expression of inflammation-related growth factors or collagen I were examined by real-time RT–PCR or immunoassay in mouse macrophages or human subconjunctival fibroblasts. Effects of TSA on trans forming growth factor β (TGFβ)/Smad signaling were evaluated with western blotting and/or immunocytochemistry. Alkali-burn injuries on the eyes of mice were performed with three µl of 0.5 N NaOH under general and topical anesthesia. TSA (600 µg/Kg daily) or vehicle was administered to animals via intraperitoneal (i.p.) injection. Histology and real-time RT–PCR investigations evaluated the effects of TSA on the healing process of the cornea. Results TSA inhibited TGFβ 1 and vascular endothelial growth factor (VEGF) expression in macrophages, and TGFβ1 and collagen I in ocular fibroblasts. It elevated the expression of 5′-TG-3′-interacting factor (TGIF) and Smad7 in fibroblasts and blocked nuclear translocation of phospho-Smad2. Real-time PCR and immunocytochemistry studies showed that systemic administration of TSA suppressed the inflammation and fibrotic response in the stroma and accelerated epithelial healing in the alkali-burned mouse cornea. Conclusions Systemic administration of TSA reduces inflammatory and fibrotic responses in the alkali-burned mouse ocular surface in vivo. The mechanisms of action involve attenuation of Smad signal in mesenchymal cells and reduction in the activation and recruitment of macrophages. TSA has the potential to treat corneal scarring in vivo.

PURPOSE:To investigate the effects of loss of osteopontin (OPN) in the development of neovascularization in corneal stroma in mice. Cell culture study was also conducted to clarify the effects of OPN in transforming growth factor (TGF) beta1-driven cell signaling and expression of vascular endothelial growth factor (VEGF).METHODS:Ocular fibroblasts from wild-type and OPN-null mice were used to study the role of OPN in TGFbeta1 signal and VEGF expression. The effect of the absence of OPN on corneal neovascularization was evaluated in mice.RESULTS:In ocular fibroblast culture, loss of OPN attenuated TGFbeta1 signals (Smad3 and p38) and reduced expression of VEGF. Loss of OPN attenuated neovascularization in corneal stroma in mice.CONCLUSIONS:OPN is involved in VEGF expression in cultured fibroblasts and is required for neovascularization in corneal stroma in vivo.

Transforming growth factor b (TGF beta) is believed to be the most important ligand in the pathogenesis of fibrotic diseases in the eye. Such ocular fibrotic diseases include scarring in the cornea and conjunctiva, fibrosis in the corneal endothelium, post-cataract surgery fibrosis of the lens capsule, excess scarring the tissue around the extraocular muscles in the strabismus surgery and proliferative vitreoretinopathy. In the proliferative stage of diabetic retinopathy, fibrogenic reaction causes tractional retinal detachment in association with contraction of the tissue. A myofibroblast, the major cellular component in the fibrotic lesions, is derived from both mesenchymal cells (in cornea and conjunctiva) and epithelial cell types (lens or retinal pigment epithelium or corneal endothelium) through epithelial-mesenchymal transition (EMT). The myofibroblasts cause excess accumulation of fibrogenic extracellular matrix with resultant tissue contraction and impaired functions. Although various cytokine signaling pathways are involved in the fibrogenic reaction in tissues, TGF beta/Smad signal is the critical one. Blocking Smad signal by chemical or natural inhibitors or anti-Smad gene introduction effectively suppress fibrogenic reaction; inhibition of both fibroblast-myofibroblast conversion or EMT. Such strategies can be clinically tested.

PURPOSE:To examine the effects of introduction of the adenoviral peroxisome proliferator-activated receptor (PPAR)-gamma gene on postinjury conjunctival scarring in mice. Its effects on fibrogenic reaction of cultured human subconjunctival fibroblasts (hSCFs) were also evaluated.METHODS:The effects of PPARgamma gene introduction on expression of type I collagen, fibronectin, and connective tissue growth factor (CTGF) in hSCFs were examined. A circumferential incision was made in the equatorial conjunctiva of the right eye of generally anesthetized adult C57BL/6 mice (n = 72). PPARgamma cDNA-expressing adenoviral vector was topically applied; the control eye received nonfunctioning adenoviral vector. At 2, 5, 7, and 14 days (each, n = 18), the eyes were processed for histologic or immunohistochemical examination to evaluate tissue scarring. Expression of type I collagen and growth factors was evaluated by real-time reverse transcription-polymerase chain reaction in 32 eyes from control and treatment groups.RESULTS:PPARgamma overexpression suppressed type I collagen, fibronectin, and CTGF in cultured hSCFs at the mRNA or protein level. In vivo experiments showed that PPARgamma gene introduction suppressed monocyte/macrophage invasion, generation of myofibroblasts, and mRNA upregulation of cytokines/growth factors and collagen Ialpha2 chain (Col 1A2) in healing conjunctiva.CONCLUSIONS:PPARgamma gene transfer suppresses the fibrogenic reaction in hSCFs as well as the injury-induced scarring of conjunctival tissue in mice, suggesting the effectiveness of this strategy in preventing excess scarring after filtration surgery. The mechanism may include suppression of activation of fibroblasts and reduction of macrophage invasion.

Roberto Adani (Verona, Italy) Ezio Adriani (Rome, Italy) Annunziato Amendola (Iowa, USA) Antonio Andreacchio (Turin, Italy) Alessandro Aprato (Turin, Italy) Paolo Arrigoni (San Donato Milanese, Italy) Stefano Artiaco (Turin, Italy) Andrea Baldini (Florence, Italy) Massimo Balsano (Vicenza, Italy) Giovanni Barbanti Brodano (Bologna, Italy) Stefano Bastoni (Milan, Italy) Vittorio Bellotti (Barcelona, Spain) Teresa Benigno (Turin, Italy) Celeste Bertone (San Donato Milanese, Italy) Giuseppe Bianchi (Bologna, Italy) Amin Sadegh Bigham (Shahrekor, Iran) Kristian Bjorgul (Fredrikstad, Norway) Davide Blonna (Turin, Italy) Elena Maria Brach del Prever (Turin, Italy) Matteo Cadossi (Bologna, Italy) Filippo Calderazzi (Parma, Italy) Domenico Campanacci (Florence, Italy) Marco Cassini (Legnago, Italy) Riccardo Ciatti (Rome, Italy) Norberto Confalonieri (Milan, Italy) Landino Cugola (Verona, Italy) Walter Daghino (Turin, Italy) Arpit Dave (Gurgaon, India) Orazio De Lucia (Milan, Italy) Luigi De Palma (Ancona, Italy) Marco De Peppo (Rome, Italy) Giacomo Delle Rose (Rozzano, Italy) Laura Deriu (Rome, Italy) Angelo Dettoni (Turin, Italy) Shabir A. Dhar (Srinagar, India) Giovanni Luigi Di Gennaro (Bologna, Italy) Alberto Di Martino (Rome, Italy) Onofrio Donzelli (Bologna, Italy) Pasquale Farsetti (Rome, Italy) Flavio Fazioli (Naples, Italy) Florian Fischer (Milan, Italy) Olimpio Galasso (Catanzaro, Italy) Eduardo Garcı́a-Rey (Madrid, Spain) Alessandro Gasbarrini (Bologna, Italy) Giorgio Gasparini (Catanzaro, Italy) Federico Grassi (Novara, Italy) Tetsuo Hagino (Kofu Yamanashi, Japan) Marco Innocenti (Florence, Italy) Ernesto Ippolito (Rome, Italy) Sujith Konan (London, UK) Renato Laforgia (Bari, Italy) Danilo Leonetti (Bologna, Italy) Giandomenico Logroscino (Rome, Italy) Pietro Maniscalco (Siena, Italy) Sergio Mapelli (Milan, Italy) Ignazio Marcoccio (Brescia, Italy) Marcos Almeida Matos (Salvador de Bahia, Brasil) Cyril Mauffrey (Birmingham, UK) Giovanni Merolla (Cattolica, Italy) Jane Christiane Messina (Milan, Italy) Maria Teresa Miscione (Bologna, Italy) Matteo Nanni (Bologna, Italy) Thomasz Nizegorodcew (Rome, Italy) Angela Notarnicola (Bari, Italy) Masahiko Nozawa (Tokyo, Japan) Matthew E. Oetgen (New Haven, CT, USA) Antonio Pace (Ancona, Italy) Paolo Paladini (Cattolica, Italy)