Vitreous M2 Macrophage-Derived Microparticles Promote RPE Cell Proliferation and Migration in Traumatic Proliferative Vitreoretinopathy.

Purpose: To characterize vitreous microparticles (MPs) in patients with traumatic proliferative vitreoretinopathy (PVR) and investigate their role in PVR pathogenesis. Methods: Vitreous MPs were characterized in patients with traumatic PVR, patients with rhegmatogenous retinal detachment (RRD) complicated with PVR, and control subjects by flow cytometry. The presence of M2 macrophages in epiretinal membranes was measured by immunostaining. Vitreous cytokines were quantified by ELISA assay. For in vitro studies, MPs isolated from THP-1 cell differentiated M1 and M2 macrophages, termed M1-MPs and M2-MPs, were used. The effects and mechanisms of M1-MPs and M2-MPs on RPE cell proliferation, migration, and epithelial to mesenchymal transition were analyzed. Results: Vitreous MPs derived from photoreceptors, microglia, and macrophages were significantly increased in patients with traumatic PVR in comparison with control and patients with RRD (PVR), whereas no significance was identified between the two control groups. M2 macrophages were present in epiretinal membranes, and their signature cytokines were markedly elevated in the vitreous of patients with traumatic PVR. Moreover, MPs from M2 macrophages were increased in the vitreous of patients with traumatic PVR. In vitro analyses showed that M2-MPs promoted the proliferation and migration of RPE cells via activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway. However, M2-MPs did not induce the expression of fibrotic proteins, including fibronectin, α-smooth muscle actin, and N-cadherin in RPE cells. Conclusions: This study demonstrated increased MP shedding in the vitreous of patients with traumatic PVR; specifically, MPs derived from M2 polarized macrophages may contribute to PVR progression by stimulating RPE cell proliferation and migration.

[Intraocular ferritin production due to an iron-containing intraocular foreign body]. / Synthèse intraoculaire de ferritine suite à un corps étranger intraoculaire ferrique.

INTRODUCTION: Ocular siderosis is a rare but severe complication of open globe trauma with intraocular retention of a metallic foreign body. CASE STUDY: We report a case of recurrent uveitis in a 37-year-old patient. The ophthalmic examination revealed poor vision in the left eye, lid edema, limbal scleromalacia, hyphema and severe ocular hypertension. Orbital CT showed the presence of a radio-opaque IOFB between the crystalline lens and vitreous body. An aqueous humor sample was obtained for iron and ferritin levels. The results came back 100 and 2000 times higher, respectively, than the serum reference values. DISCUSSION: The very high iron content is the result of a sustained release from the metallic INFB and is responsible for ocular siderosis in our patient. The extremely high ferritin level would be the result of in situ synthesis by the various cells of the ocular structures in order to preserve the components of the eye. Measurement of these two levels would improve the diagnosis, prognosis and treatment of metallic IOFBs.

Immunohistochemical Characterization of the Ectopic Epithelium Devoid of Goblet Cells From a Posttraumatic Iris Cyst Causing Mucogenic Glaucoma.

PURPOSE: Mucogenic glaucoma is an unusual form of secondary open-angle glaucoma caused by intracameral ectopic mucus-producing epithelium. To date, only 3 cases have been described in detail. Numerous goblet cells in the specimens indicated a possible conjunctival origin. We immunohistochemically characterized the implanted epithelium from an iris cyst responsible for mucogenic glaucoma. METHODS: A series of immunostaining analyses were performed on a sector-iridectomy specimen derived from an eye with mucogenic glaucoma and a history of limbal penetrating injury. An iris cyst was present in the inferonasal quadrant of the right eye of a 58-year-old man. The anterior chamber was filled with hazy, translucent material, and the chamber angle was gonioscopically open. The cyst was resected due to medically uncontrollable high intraocular pressure. RESULTS: The ectopic epithelium was mostly positive for CK19, a corneal and conjunctival epithelial marker. Negative staining for MUC5AC, a secretory mucin, and positive staining for MUC1, a membrane-bound mucin, corroborated the absence of goblet cells. Ectopic epithelial cells were abundantly positive for CK15, a limbal basal cell marker, but there was patchy immunostaining of CK13, a conjunctival epithelial marker, and sparse labeling with CK12, a corneal epithelial marker. Immunostaining patterns of CK15, CK13, and CK12 were nearly mutually exclusive. CONCLUSIONS: The ectopic epithelium of an iris cyst causing mucogenic glaucoma was most likely to originate from limbal basal cells, which showed dual direction of differentiation toward both the conjunctival and corneal epithelia. The membrane-bound mucin may have caused mucogenic glaucoma in the absence of goblet cells.

Intraocular penetration of systemic antibiotics in eyes with penetrating ocular injury.

PURPOSE: To determine whether penetrating scleral or corneal injury can enhance intraocular penetration of systemic moxifloxacin, vancomycin, and ceftazidime. METHODS: Thirty rabbits were divided into 3 groups for each antibiotic and then further subdivided to receive either scleral or corneal injury to the right eye. The left eye served as a control. Intravenous antibiotics were given following injury, and eyes were subsequently enucleated. Vitreous antibiotic concentration was determined by high-performance liquid chromatography analysis. Plasma concentration was measured for comparison. RESULTS: Intravitreal moxifloxacin concentration was unchanged by injury. Minimum inhibitory concentration (MIC90) was achieved in the vitreous against the most common gram-positive endophthalmitis-causing organisms. Intravitreal vancomycin levels were not enhanced by injury and did not reach the MIC90 for gram-positive organisms commonly causing intraocular infection. Intravitreal ceftazidime was increased in the injured eyes, 67% and 73% higher in scleral and corneal injury eyes. It reached MIC90 of many gram-negative bacteria. CONCLUSIONS: Intravitreal antibiotic penetration of systemic antibiotics with or without penetrating ocular injury varies depending on the antibiotic. For prevention or treatment of gram-positive-bacteria-causing endophthalmitis, intravitreal vancomycin is necessary and provides the most reliable coverage. Systemic ceftazidime can be used for many gram-negative bacteria, but intravitreal injection is recommended for better coverage, especially for more-potent organisms. Systemic moxifloxacin can be considered for most gram-positive and -negative infections due to its excellent intraocular penetration and broad coverage, but the patient's previous history of its topical use and increasing resistance patterns must be considered.

Apoptosis of rabbit retinal cell after eyeball rupture.

OBJECTIVE: To establish rabbit eyeball rupture model by air gun in order to observe and analyze the early injury condition and reasons of retinal cell after eyeball rupture. METHODS: Forty eight healthy rabbits were randomly divided into control group and 1, 3, 6, 12 and 24 h after injury groups. After anesthesia, the rabbit eyeball rupture model was established by air gun. Then the early pathological changes of rabbit retina were observed, and apoptotic index (AI), oncosis index (OI), the relationship between the expression amounts of apoptosis-related genes and AI were analyzed. RESULTS: Obvious pathological lesion appeared in retina 6 h after injury. Irreversible damage occurred 12-24 h after injury. The results of AI and OI indicated that the OI peak appeared 6 h after injury and then gradually declined, while the AI increased with the prolongation of time, and the AI was higher than OI in 12 h after injury. Immunohistochemical results indicated that there was no obvious bcl-2 protein expression change. Compared with the control group and the 3, 6, 12 and 24 h after the injury groups, the expressions of p53 and Caspase-3 were significantly improved and peaked at 12 h (P<0.01). Positive correlation existed among p53, Caspase-3 expression amount and cell apoptosis amount. CONCLUSIONS: Apoptosis and oncosis of visual cells are the main reasons of retinal cell injury. p53 and Caspase-3 are the important factors in promoting the retinal cell apoptosis after eyeball rupture.

Invasion of lymphatic vessels into the eye after open globe injuries.

PURPOSE: We analyzed whether lymphatic vessels can be detected in eyes enucleated after an open globe injury. METHODS: The presence of lymphatic vessels was analyzed immunohistochemically using podoplanin as a specific lymphatic endothelial marker in 21 globes that had been enucleated after open globe injury. The localization of pathologic lymphatic vessels (within the eye wall or inside the eye) was correlated with the mechanism of trauma, anatomic site of perforation or rupture, and time interval between trauma and enucleation. RESULTS: Pathologic lymphatic vessels were detected in 15 of 21 eyes (71%) enucleated after an open globe injury. In 5 globes (24%) they were found within the eye, located in retrocorneal membranes, underneath the sclera, and adjacent to uveal tissue (ciliary body, iris). No significant association was observed between the presence of pathologic lymphatic vessels and the mechanism of trauma (P = 0.598), anatomic site of perforation or rupture (P = 0.303), and time interval between trauma and enucleation (P = 0.145). CONCLUSIONS: The human eye can be invaded secondarily by lymphatic vessels if the eye wall is opened by trauma. This mechanism could be important for wound healing, immunologic defense against intruding microorganisms, and autoimmune reactions against intraocular antigens.

Pathological changes in rabbit retina and its relationship with glutamic acid after injuries from high-speed bullets.

PURPOSE: To observe the pathological changes in rabbit retinas and the measure of glutamic acid levels in the vitreous body after suffering from high-speed bullet injuries. METHODS: Rabbits eyeball contusion models were established with high-speed bullets, i.e., the rabbits eyes were shot with a fixed air rifle at a speed of 90m/s (using plastic bullets, weighing 0.20122g, on average). Retinal tissues treated with HE staining and were prepared for light microscopy examination and glutamate levels were tested at different points in time after the injury. RESULTS: Edema, exudation, hemorrhage, and rupture were evident in rabbit retinas following bullet injuries. Meanwhile, glutamate levels gradually increased as time proceeded. CONCLUSION: Visual impairment is related with retinal damages after high-speed bullet injuries. Increased glutamate concentration serves as a potential factor for aggravating retinal injuries.

Occult orbito-cranial penetrating injury by pencil: role of beta tracer protein as a marker for cerebrospinal fluid leakage.

Orbito-cranial foreign bodies present a treacherous situation that can escape detection. The only evidence of these foreign bodies may be the entry wound in the form of a small lid laceration. A two-year-old boy presented with right upper lid laceration following a fall two hours back. Analysis of the fluid around the wound revealed a beta-tracer protein (beta-TP) value of 33.5 mg/l suggestive of cerebrospinal fluid (CSF). Three-dimensional computed tomography (CT) scan revealed a foreign body measuring 4.2 cm x 0.8 cm passing from the orbital roof to the frontal lobe. The foreign body tract was explored through the eyelid laceration and a broken pencil was removed followed by dural patch graft. The patient developed no ocular or intracranial complications. Beta-TP, a highly specific marker of CSF is routinely used in screening patients of neurosurgery and otolaryngology with CSF leaks, however, its use has never been reported in ophthalmic literature based on an online PubMed search.

Connexin43 knockdown accelerates wound healing but inhibits mesenchymal transition after corneal endothelial injury in vivo.

PURPOSE: To explore connexin43 (Cx43) knockdown as an efficient treatment for corneal endothelial injury in an in vivo rat corneal scrape injury model. METHODS: Scrape injury was induced in the corneal endothelium, and immunolabeling (ZO-1, alpha-SMA, Cx43) was performed to analyze changes in Cx43 expression during wound healing. Single injection of Cx43 antisense oligodeoxynucleotide (AS-ODN), small interfering RNA (siRNA), or adenovirus (CMV-Cx43-mRFP1) was applied into the anterior chamber simultaneously with the injury, and wound closure was examined by immunolabeling (ZO-1, Cx43) and propidium iodide staining. Corneal endothelium proliferation on day 1 after injury was studied by Ki67-immunolabeling. Cx43-knockdown treatment was performed also without injury, and its effect on Cx43 expression and Ki67 immunolabeling was examined. The postinjury appearance of myofibroblasts in Cx43 AS-ODN- and sense-ODN-treated corneas was compared by alpha-SMA-immunolabeling. RESULTS: Complete wound closures were observed in five of six corneas on day 3 after injury with either Cx43 AS-ODN or siRNA treatment, whereas no complete closure was observed on day 3 in the control corneas (S-ODN, zero of six; or nonsense siRNA, zero of six). Consistently, Cx43 overexpression using adenovirus delayed wound closure. Cx43 knockdown increased the number of Ki67-positive proliferating cells on day 1, whereas it decreased the number of alpha-SMA-positive myofibroblasts on day 5. Cx43 knockdown without injury decreased Cx43 expression and induced endothelial proliferation in vivo. CONCLUSIONS: These results show that Cx43 knockdown induces corneal endothelium proliferation but inhibits endothelial-mesenchymal transition/transformation after injury, suggesting that Cx43 knockdown is a new therapeutic approach for acceleration of wound closure and for prevention of retrocorneal fibrous membrane formation.

Vascular endothelial growth factor in aqueous humor of patients with perforative eye injuries.

Considering that VEGF is the key factor for angiogenesis stimulation, we wanted to establish if VEGF level is increased in aqueous humor of patients with open globe eye injury. The study included 20 patients with open globe injury. During the surgery, aqueous humor samples were taken out and VEGF levels were measured by ELISA. VEGF levels were significantly higher in the aqueous humor of patients with open globe eye injury and uveitis, in patients with wound bigger than 2 mm and in patients where from injury to surgery passed more than 4 hours. VEGF levels were also higher, but not significantly, in patients with intrabulbar foreign body. Considering that VEGF levels were significantly higher in patients with open globe eye injury with uveitis, wound larger than 2 mm and in patients where from injury to surgery passed more than 4 hours, anti VEGF therapy might have application in these conditions.

Reelin expression is upregulated following ocular tissue injury.

PURPOSE: Reelin is important in the guidance of neuronal stem cells in the central nervous system during normal development. We wished to determine whether reelin is expressed in the retina and cornea after injury. METHODS: Mice underwent laceration of their retina as well as corneal epithelial debridement. The mice were sacrificed at 3 days, and eyes were fixed and stained for reelin expression and reelin messenger ribonucleic acid (mRNA). RESULTS: In normal eyes, reelin was expressed only at very low levels in the ganglion cell layer of the retina and the endothelial cell layer of the cornea. In injured eyes, there was marked expression in reelin immunoreactivity in the retina and cornea. Reelin gene expression was seen in the retina and cornea. CONCLUSIONS: Reelin is expressed during normal retinogenesis. This study shows that reelin is also upregulated following injury to the retina and cornea. The expression of reelin following injury suggests that reelin may play an important role in regulating stem cell trafficking in neuronal and nonneuronal tissues following injury similar to its role in normal organogenesis.

Role of angiotensin II receptor subtypes in conjunctival wound healing.

PURPOSE: To investigate the role of angiotensin II (Ang II) receptor subtypes in subconjunctival injury. METHODS: A wound-healing model was developed by subconjunctival blunt dissection in male wild-type, AT1a receptor-deficient (AT1aKO) and AT2 receptor-deficient (AT2KO) mice. Collagen deposition and cell infiltration were evaluated histologically. Expression of collagen, matrix metalloproteinase (MMP), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were determined by real-time PCR. RESULTS: Subconjunctival injury increased the infiltration of inflammatory cells, collagen deposition in the subconjunctival space, and the expression of collagen type I and type III, TIMP-1 and MMP2. In AT1aKO mice, collagen deposition, cell infiltration, and expression of collagen and TIMP-1 were inhibited, but MMP2 expression was enhanced. In contrast, in AT2KO mice, the increase in collagen deposition, cell infiltration, and expression of collagen and TIMP-1 were further enhanced. CONCLUSIONS: These results indicate that AT1a and AT2 receptor stimulation may in addition to other mechanisms be antagonistically involved in the wound-healing process after subconjunctival injury.

Angiostatic effect of penetrating ocular injury: role of pigment epithelium-derived factor.

PURPOSE: To characterize the angiostatic effect of penetrating ocular injury and to begin to explore its mechanism, with an emphasis on the role of pigment epithelium-derived factor (PEDF). METHODS: Using the rat model of oxygen-induced retinopathy (OIR), single or multiple dry needle injuries were made, penetrating the globe of one eye; the opposite eye served as a control. Eyes were harvested from rats killed 1, 3, and 6 days after injury, and retinas were dissected and processed for assessment of neovascularization and microglial activation or were processed for genetic and proteomic analysis. Temporal and spatial expression patterns of PEDF were analyzed by in situ hybridization. RESULTS: Penetrating ocular injury resulted in a 30% decrease in neovascular area in the retinas of OIR rats. At day 1 after injury, needle insertion caused a 4.1-fold increase in retinal PEDF mRNA and a 1.5-fold increase in retinal PEDF protein. Vitreous PEDF protein increased 3.4-fold in injured eyes compared with noninjured eyes. In situ hybridization showed an increase in PEDF mRNA in areas surrounding the puncture site. Concentrated vitreous protein from injured eyes caused a 60% decrease in retinal neovascularization when injected into the vitreous cavity of OIR rats. Preincubation of vitreous samples with anti-PEDF partially abolished this efficacy. CONCLUSIONS: The pattern of angiostasis resulting from penetrating ocular injury is consistent with the release of an endogenous antiangiogenic factor from the wound site. Preliminary studies show a possible role for PEDF in this effect. Further characterization of this role and the identification of other factors may lead to new therapeutic strategies for angiogenic eye conditions.

Absence of scar formation in human donor cornea with prior laser in situ keratomileusis.

PURPOSE: To investigate transglutaminases (enzymes capable of cross-linking extracellular matrix proteins to proteolysis-resistant complexes during scar tissue formation) in a human donor cornea after successful laser in situ keratomileusis (LASIK) without clinical complications and to compare with the results in a human donor cornea with corneal scarring after corneal injury. SETTING: Department of Ophthalmology, Ludwig-Maximilians University, Munich, Germany. METHODS: A donor cornea with prior uneventful LASIK treatment and 1 with corneal scarring after penetrating injury were investigated. Cryostat sections were stained immunohistochemically for tissue transglutaminase (tTG), keratocyte transglutaminase (kTG), and their reaction product epsilon-(gamma-glutamyl)-lysine. RESULTS: With light microscopy, the flap interface of the LASIK-treated eye could hardly be detected, while in the injured eye, infiltration of cells and a clear margin next to the scar formation were present. Immunohistochemistry demonstrated a distinct staining for tTG, kTG, and epsilon-(gamma-glutamyl)-lysine in the corneal scar. In contrast, neither transglutaminase nor epsilon-(gamma-glutamyl)-lysine staining could be observed at the flap margin or in the interface of the LASIK-treated donor eye. CONCLUSIONS: Irreversible protein cross-linking of transglutaminases via epsilon-(gamma-glutamyl)-lysine connections seem to be indicators for scarring in corneal wound healing. The absence of transglutaminases and their reaction product epsilon-(gamma-glutamyl)-lysine in a LASIK-treated cornea supports the idea of missing scar tissue formation after LASIK surgery.

Fibroblast growth factor 2: roles of regulation of lens cell proliferation and epithelial-mesenchymal transition in response to injury.

PURPOSE: To examine the role of fibroblast growth factor 2 (FGF2) in regulating lens cell proliferation and epithelial-mesenchymal transition (EMT) in response to injury. METHODS: The amount of FGF2 protein was determined in healing, injured rat lenses by enzyme immunoassay. The effects of FGF2 and transforming growth factor beta2 (TGFbeta2) on cell proliferation of alphaTN4 cells (a mouse lens epithelial cell line) were determined. FGF2-knockout mice were used to further examine the role of endogenous FGF2 on injury-induced epithelial cell proliferation and EMT. The anterior lens capsule was injured by a hypodermic needle under both general and topical anesthesia in one eye of 34 fgf2+/+ mice and 42 fgf2-/- mice. At days 2, 5, and 10 post-injury the mice were sacrificed following a 2 h labeling period with bromo-deoxyuridine (BrdU). The number of BrdU-positive cells in each specimen was determined. RESULTS: A capsular break caused a 10 fold increase of FGF2 protein accumulated in rat lens 14 days after injury. Addition of 3.43 ng/ml FGF2 enhanced proliferation of alphaTN4 cells. This occurred in the presence or absence of exogenous TGFbeta2, that has an inhibitory effect on alphaTN4 cell proliferation. Significantly fewer BrdU-labeled cells were found in fgf2-/- mice than in fgf2+/+ mice during healing post-injury. However, lacking FGF2 did not alter the expression patterns of alpha-smooth muscle actin and collagen type I, markers of EMT in lens cells. CONCLUSIONS: Endogenous FGF2 is required for increased cell proliferation but not essential for EMT during the lens response to injury.

Ocular wounding prevents pre-retinal neovascularization and upregulates PEDF expression in the inner retina.

PURPOSE: Perforation injury to the eye can protect against retinal degeneration and pigment epithelial derived factor (PEDF) may play a role in this neuro-protective effect. PEDF has also been shown to possess potent anti-angiogenic properties. The current study has investigated a possible anti-angiogenic effect of penetrating ocular injury in a murine model of oxygen induced proliferative retinopathy (OIR) and determined if such a procedure alters PEDF expression in the retina. METHODS: OIR was produced by exposure of neonatal mice to 75% oxygen between postnatal days 7 and 12 (P7-P12). Mice were separated into various groups, with one group receiving a penetrating injury in a single eye. Pre-retinal neovascularization and intra-retinal ischaemia was quantified at P17 and PEDF protein expression was determined using immunofluorescence in retinal flatmounts and sections. PEDF mRNA was quantified using real-time RT-PCR. RESULTS: Punctured eyes showed less pre-retinal neovascularization at P17 when compared to the non-punctured eyes (p<0.001) although there was no effect on retinal ischaemia. PEDF immunreactivity was strongest in the ganglion cells of the retina, and intensity increased in punctured eyes at P13. There was more immunoreactive PEDF in ganglion cells adjacent to retinal venules than arterioles. At P13, retinal PEDF mRNA was also increased in punctured eyes compared to non-punctured controls (p<0.05), although there was no differential at P17. CONCLUSIONS: Penetrating ocular injury suppresses retinal neovascularization and modulates expression of PEDF. These findings have implications for intra-vitreal delivery of angiostatic agents since ocular perforation may provoke an acute, endogenous anti-angiogenic response that should be taken into account.

The structure and swelling of corneal scar tissue in penetrating full-thickness wounds.

OBJECTIVE: The purpose of this study was to determine corneal thickness and to examine the collagen and proteoglycans in full-thickness corneal scars up to 16 months following wounding. METHODS: Ultrasound pachymetry was used to measure the depths of penetrating central scars and their surrounding areas in 16 rabbit corneas. Measurements were taken at regular intervals: 5, 10, 12, and 16 months after healing. Transmission electron microscopy was then used to study the stroma of the resulting scars to observe the collagen organization and the amount, as well as the size, of cuprolinic blue-stained proteoglycan filaments within the stroma. Furthermore, ex vivo swelling of selected wounded contralateral excised corneas was undertaken by the measured addition of distilled water. RESULTS: In vivo, the thickness of the scar tissue was significantly less than that of the surrounding tissue throughout the period studied. By 12 months the proteoglycan filaments within the scar were of a similar size and number to those within the adjacent tissue, whereas the collagen fibrils within the scar were still disorganized (collagen interweaving, lack of a lamellar structure). Once excised and allowed to swell in water, scar tissue thickness remained relatively unchanged, whereas the surrounding tissue swelled considerably. CONCLUSION: Disorganized fibril arrangement inhibits the normal swelling of the scar tissue, which remains reduced. Furthermore, even after many months of healing, collagen remodeling in corneal scar tissue is not complete.

High expression of chemokines Gro-alpha (CXCL-1), IL-8 (CXCL-8), and MCP-1 (CCL-2) in inflamed human corneas in vivo.

OBJECTIVE: To investigate in vivo expression of chemokines in normal and inflamed human corneas, to determine whether chemokines are responsible for the recruitment of inflammatory cells. METHODS: In situ hybridization of the CXC chemokines growth-related oncogene-alpha (Gro-alpha) (CXCL-1), interleukin 8 (CXCL-8), macrophage interferon-gamma inducible gene (CXCL-9), and interferon-gamma inducible protein 10 (CXCL-10) and of the CC chemokines macrophage chemoattractant protein 1 (MCP-1) (CCL-2), macrophage inflammatory protein 1alpha (CCL-3), and regulated on activation, normal T-cell expressed and secreted (CCL-5) was performed to localize chemokine messenger RNA. Immunohistochemistry was used to identify the cellular infiltrate within the cornea. Three normal human eyes were compared with eyes enucleated because of chronic inflammation (n = 10), secondary to perforating injuries. RESULTS: In normal corneas, no chemokine expression was detected. In inflamed lesions, a high intensity of signals from Gro-alpha (CXCL-1) and MCP-1 (CCL-2) messenger RNA was observed in limbal epithelium and from Gro-alpha (CXCL-1), interleukin 8 (CXCL-8), and MCP-1 (CCL-2) in corneal stroma. The Gro-alpha (CXCL-1) was the only chemokine expressed by central corneal epithelium. All other examined chemokines were only moderately expressed in limbus and corneal stroma, or barely detectable. CONCLUSIONS: These cytokines are important agents in the cytokine network and contribute to the cell-specific and spatially restricted recruitment of neutrophils and mononuclear cells in acute inflammatory lesions of the human cornea. Clinical Relevance Understanding the role of chemokines in corneal inflammation may lead to the development of a selective receptor blockage of highly expressed chemokines to inhibit the recruitment of leukocyte subsets.

Response of lens epithelial cells to injury: role of lumican in epithelial-mesenchymal transition.

PURPOSE: Lens epithelial cells (LECs) undergo epithelial-mesenchcymal transition (EMT) after injury and transform into myofibroblasts positive for alpha-smooth muscle actin (alphaSMA), an established marker of this process. Lumican is a keratan sulfate proteoglycan core protein. This study was conducted to examine whether human and mouse LECs express lumican after injury. To determine whether lumican may modulate EMT of LECs in response to injury or to exposure to transforming growth factor-beta2 (TGFbeta2), alphaSMA expression by the LECs was examined in lumican (Lum)-knockout mice in vivo and in organ culture. METHODS: Human postoperative capsular specimens and healing, injured mouse lenses at various intervals were immunostained for lumican or alphaSMA. alphaSMA was also immunolocalized in healing, injured lenses of Lum-knockout mice. Finally, expression of lumican and alphaSMA was examined in lenses of Lum-knockout mice incubated with TGFbeta2. RESULTS: Lumican was immunolocalized in matrix in human postoperative capsular opacification. Lumican and alphaSMA were upregulated in mouse LECs from 8 hours and day 5 after an injury, respectively. LECs accumulated adjacent to the capsular break were of epithelial shape in Lum(-/-) mice and fibroblast-like in Lum(+/-) mice during healing. alphaSMA expression by LECs was significantly delayed in Lum(-/-) mice, indicating that lumican may modulate injury-induced EMT in LECs. TGFbeta2-induced EMT appeared to be suppressed in organ-cultured lenses of Lum(-/-) mice compared with those of Lum(+/+) mice. CONCLUSIONS: Human capsular opacification contains lumican, and mouse LECs upregulate lumican and alphaSMA in response to injury. Loss of lumican perturbs EMT of mouse LECs.