Jakobiec FA, Zakka FR, Papakostas TD, Fay A. Angiomyofibroma of the orbit: a hybrid of vascular leiomyoma and cavernous hemangioma. Ophthalmic Plast Reconstr Surg 2012;28(6):438-45.Abstract
PURPOSE: The aim of this study was to describe a novel primary orbital vascular tumor combining elements of a vascular leiomyoma (angioleiomyoma) and a cavernous hemangioma. METHODS: A critical review of clinical records, diagnostic tests, and radiographic studies combined with histopathologic evaluation with standard and special histochemical staining and immunohistochemical investigations was conducted. RESULTS: A 44-year-old man slowly developed 5 mm of well-tolerated relative right proptosis with minimal motility disturbance and no visual decline. Computed tomography and magnetic resonance imaging demonstrated a medial and intraconal rounded mass that perfused slowly and whose anterior surface was well circumscribed. At surgery, the tumor was solid and pink with intersecting white bands and densely attached to surrounding normal tissues. The most adherent apical portion of the mass was left behind after subtotal excision. Histopathologically, only a partial pseudocapsule was discovered. The tumor was composed of cavernous channels, capillary zones, compressed lumens with linear strands of endothelium, and collections of muscular veins devoid of an elastica. Striking smooth muscle actin positivity was identified in disorganized masses of smooth muscle cells in the intervascular spaces and around the cavernous vascular units; these myocytes were intermixed with bundles of interstitial keloidal collagen. The endothelium was CD31 and CD34 positive for vascular endothelium and D2-40 negative for lymphatic endothelium. CONCLUSIONS: The authors have classified this hybrid tumor an angiomyofibroma with low neoplastic potential and features of a malformation. It is a composite variant of cavernous hemangioma associated with a conspicuous proliferation of anomalous disorganized smooth muscle cells (leiomyoma). Most of the lesion lacked a pseudocapsule, which impeded surgical delivery. Incomplete excision is recommended in such cases as preferable to the complications that could ensue from overly aggressive efforts at complete removal, particularly at the orbital apex. Supporting this position is the observation that incompletely excised cavernous hemangioma generally does not recur.
Joyce NC. Proliferative capacity of corneal endothelial cells. Exp Eye Res 2012;95(1):16-23.Abstract
The corneal endothelial monolayer helps maintain corneal transparency through its barrier and ionic "pump" functions. This transparency function can become compromised, resulting in a critical loss in endothelial cell density (ECD), corneal edema, bullous keratopathy, and loss of visual acuity. Although penetrating keratoplasty and various forms of endothelial keratoplasty are capable of restoring corneal clarity, they can also have complications requiring re-grafting or other treatments. With the increasing worldwide shortage of donor corneas to be used for keratoplasty, there is a greater need to find new therapies to restore corneal clarity that is lost due to endothelial dysfunction. As a result, researchers have been exploring alternative approaches that could result in the in vivo induction of transient corneal endothelial cell division or the in vitro expansion of healthy endothelial cells for corneal bioengineering as treatments to increase ECD and restore visual acuity. This review presents current information regarding the ability of human corneal endothelial cells (HCEC) to divide as a basis for the development of new therapies. Information will be presented on the positive and negative regulation of the cell cycle as background for the studies to be discussed. Results of studies exploring the proliferative capacity of HCEC will be presented and specific conditions that affect the ability of HCEC to divide will be discussed. Methods that have been tested to induce transient proliferation of HCEC will also be presented. This review will discuss the effect of donor age and endothelial topography on relative proliferative capacity of HCEC, as well as explore the role of nuclear oxidative DNA damage in decreasing the relative proliferative capacity of HCEC. Finally, potential new research directions will be discussed that could take advantage of and/or improve the proliferative capacity of these physiologically important cells in order to develop new treatments to restore corneal clarity.
Kasaoka M, Ma J, Lashkari K. c-Met modulates RPE migratory response to laser-induced retinal injury. PLoS One 2012;7(7):e40771.Abstract
Retinal laser injuries are often associated with aberrant migration of the retinal pigment epithelium (RPE), which can cause expansion of the scar beyond the confines of the original laser burn. In this study, we devised a novel method of laser-induced injury to the RPE layer in mouse models and began to dissect the mechanisms associated with pathogenesis and progression of laser-induced RPE injury. We have hypothesized that the proto-oncogene receptor, c-Met, is intimately involved with migration of RPE cells, and may be an early responder to injury. Using transgenic mouse models, we show that constitutive activation of c-Met induces more robust RPE migration into the outer retina of laser-injured eyes, while abrogation of the receptor using a cre-lox method reduces these responses. We also demonstrate that retinal laser injury increases expression of both HGF and c-Met, and activation of c-Met after injury is correlated with RPE cell migration. RPE migration may be responsible for clinically significant anatomic changes observed after laser injury. Abrogation of c-Met activity may be a therapeutic target to minimize retinal damage from aberrant RPE cell migration.
Keating A, Pineda R. Trichosporon asahii keratitis in a patient with a type I Boston keratoprosthesis and contact lens. Eye Contact Lens 2012;38(2):130-2.Abstract
PURPOSE: The aim of the study was to report a case of Trichosporon asahii in a patient with a type I Boston keratoprosthesis and contact lens with review of the literature. METHODS: A case report and literature review are provided. RESULTS: A 70-year-old monocular South Asian man with light perception vision and dense corneal scarring from previously failed amniotic membrane grafting and one failed corneal transplant was evaluated for a keratoprosthesis for visual rehabilitation. Three months after undergoing uneventful implantation of a type I Boston keratoprosthesis and placement of a therapeutic contact lens, he was found on routine follow-up to have a corneal infiltrate that was culture positive for T. asahii. The fungal keratitis was successfully treated with topical amphotericin B and oral ketoconazole. CONCLUSIONS: Contact lens wear is a known risk factor for fungal keratitis. Trichosporon is an uncommon agent of fungal keratitis. We report the first known case of fungal keratitis caused by T.asahii in a patient with a keratoprosthesis and contact lens.
Khandelwal P, Liu S, Sullivan DA. Androgen regulation of gene expression in human meibomian gland and conjunctival epithelial cells. Mol Vis 2012;18:1055-67.Abstract
PURPOSE: Androgens exert a significant influence on the structure, function and/or pathophysiology of the meibomian gland and conjunctiva. We sought to determine whether this hormone action involves the regulation of epithelial cell gene expression in these tissues. METHODS: Immortalized human meibomian gland and conjunctival epithelial cells were treated with placebo or dihydrotestosterone (DHT) and processed for molecular biologic procedures. Gene expression was evaluated with BeadChips and data were analyzed with bioinformatic and statistical software. RESULTS: Androgen treatment significantly influenced the expression of approximately 3,000 genes in immortalized human meibomian gland and conjunctival epithelial cells. The nature of DHT action on gene activity was predominantly cell-specific. Similarly, DHT exerted a significant, but primarily cell-specific, influence on many gene ontologies and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These included groups of genes related, for example, to lipid dynamics, innate immunity, cell cycle, Janus kinase (JAK)-signal transducer and activator of transcription (stat) cascades, oxidative phosphorylation, the proteasome, and mammalian target of rapamycin (mTOR), Wnt, and peroxisome proliferator-activated receptor (PPAR) signaling. CONCLUSIONS: Our findings support our hypothesis that androgens regulate gene expression in human meibomian gland and conjunctival epithelial cells. Our ongoing studies are designed to determine whether many of these genes are translated and play a role in the health and well being of the eye.
Kim LA, D'Amore PA. A brief history of anti-VEGF for the treatment of ocular angiogenesis. Am J Pathol 2012;181(2):376-9.Abstract
In 1994, The American Journal of Pathology published a key article reporting that hypoxic retina produces vascular endothelial growth factor (VEGF), suggesting a role for VEGF in ocular neovascularization. Subsequent developments in anti-VEGF treatment for neovascular eye disease have improved visual outcomes and changed the standard of care in retinal medicine and ophthalmology.
Kirzhner M, Jakobiec FA, Borodic G. Desmoplastic trichoepithelioma: report of a unique periocular case. Ophthalmic Plast Reconstr Surg 2012;28(5):e121-3.Abstract
In a 58-year-old woman with blepharospasm, a slowly enlarging left inferomedial eyelid lesion developed. It measured 3 × 5 mm and was nonulcerated, well-circumscribed, whitish, upraised, and firm. An initial incomplete excision followed by a total repeated excision revealed small squamous microcysts, often exhibiting calcifications and cords of nonclefting basaloid cells embedded in a scirrhous stroma characteristic of desmoplastic trichoepithelioma (DTE). Immunohistochemical investigations disclosed CD34-positive stromal fibroblasts and many CK20-positive Merkel cells located among the epithelial cells, features absent in mimicking sclerosing basal cell carcinoma (BCC). The tumor has not recurred during 6 months of follow up. Besides BCC, the differential diagnosis chiefly concerns syringoma and microcystic adnexal carcinoma. Surgical therapy should aim at complete excision but does not have to be as extensive or aggressive as that used for morpheic or sclerosing BCC because of its lack of diffusely infiltrating margins.
Kohanim S, Daniels AB, Huynh N, Eliott D, Chodosh J. Utility of ocular ultrasonography in diagnosing infectious endophthalmitis in patients with media opacities. Semin Ophthalmol 2012;27(5-6):242-5.Abstract
Assessment of patients with infectious endophthalmitis is frequently limited by media opacities, and ocular ultrasonography is routinely performed in this setting. We examined the literature to assess the level of evidence for the utility of ocular ultrasonography in these patients. Common ultrasonographic findings reported include low amplitude mobile echoes, vitreous membranes, and thickening of the retina and choroid. Based on the available evidence, we conclude that ocular ultrasound may be a useful adjunct in guiding treatment and minimizing complications. While positive findings may be confirmatory in cases in which the clinical suspicion is high, ocular ultrasound alone cannot be used to prove or to exclude the diagnosis of infectious endophthalmitis.
Kos VN, Desjardins CA, Griggs A, Cerqueira G, Van Tonder A, Holden MTG, Godfrey P, Palmer KL, Bodi K, Mongodin EF, Wortman J, Feldgarden M, Lawley T, Gill SR, Haas BJ, Birren B, Gilmore MS. Comparative genomics of vancomycin-resistant Staphylococcus aureus strains and their positions within the clade most commonly associated with Methicillin-resistant S. aureus hospital-acquired infection in the United States. MBio 2012;3(3)Abstract
UNLABELLED: Methicillin-resistant Staphylococcus aureus (MRSA) strains are leading causes of hospital-acquired infections in the United States, and clonal cluster 5 (CC5) is the predominant lineage responsible for these infections. Since 2002, there have been 12 cases of vancomycin-resistant S. aureus (VRSA) infection in the United States-all CC5 strains. To understand this genetic background and what distinguishes it from other lineages, we generated and analyzed high-quality draft genome sequences for all available VRSA strains. Sequence comparisons show unambiguously that each strain independently acquired Tn1546 and that all VRSA strains last shared a common ancestor over 50 years ago, well before the occurrence of vancomycin resistance in this species. In contrast to existing hypotheses on what predisposes this lineage to acquire Tn1546, the barrier posed by restriction systems appears to be intact in most VRSA strains. However, VRSA (and other CC5) strains were found to possess a constellation of traits that appears to be optimized for proliferation in precisely the types of polymicrobic infection where transfer could occur. They lack a bacteriocin operon that would be predicted to limit the occurrence of non-CC5 strains in mixed infection and harbor a cluster of unique superantigens and lipoproteins to confound host immunity. A frameshift in dprA, which in other microbes influences uptake of foreign DNA, may also make this lineage conducive to foreign DNA acquisition. IMPORTANCE: Invasive methicillin-resistant Staphylococcus aureus (MRSA) infection now ranks among the leading causes of death in the United States. Vancomycin is a key last-line bactericidal drug for treating these infections. However, since 2002, vancomycin resistance has entered this species. Of the now 12 cases of vancomycin-resistant S. aureus (VRSA), each was believed to represent a new acquisition of the vancomycin-resistant transposon Tn1546 from enterococcal donors. All acquisitions of Tn1546 so far have occurred in MRSA strains of the clonal cluster 5 genetic background, the most common hospital lineage causing hospital-acquired MRSA infection. To understand the nature of these strains, we determined and examined the nucleotide sequences of the genomes of all available VRSA. Genome comparison identified candidate features that position strains of this lineage well for acquiring resistance to antibiotics in mixed infection.
Kovacs K, Wagley S, Quirk MT, Ceron OM, Silva PA, Singh RJ, Gukasyan HJ, Arroyo JG. Pharmacokinetic study of vitreous and serum concentrations of triamcinolone acetonide after posterior sub-tenon's injection. Am J Ophthalmol 2012;153(5):939-48.Abstract
PURPOSE: To compare a theoretical pharmacokinetic model of triamcinolone acetonide after posterior sub-Tenon's injection with experimental serum and undiluted vitreous triamcinolone acetonide concentrations obtained during pars plana vitrectomy. DESIGN: Clinical-practice, prospective, interventional case series study. METHODS: This study compared computer-modeled triamcinolone acetonide diffusion after posterior sub-Tenon's injection with triamcinolone acetonide levels in experimental undiluted vitreous and serum samples from 57 patients undergoing vitrectomy assessed via mass spectrometry and high-pressure liquid chromatography. At least 5 pairs of samples were collected at each of 7 time points (1 day, 3 days, and 1, 2, 3, 4, and 8 weeks) after triamcinolone acetonide injection, with 6 controls without injection. Cortisol levels were measured in 31 sets of samples. RESULTS: The theoretical model predicted that triamcinolone acetonide levels in systemic blood, vitreous, and choroidal extracellular matrix would plateau after 3 days at 15 ng/mL, 227 ng/mL and 2230 ng/mL, respectively. Experimental vitreous levels of triamcinolone peaked at 111 ng/mL at day 1, then reached a plateau in the range 15 to 25 ng/mL, while serum triamcinolone levels peaked at day 3 near 35 ng/mL and plateaued near 2 to 8 ng/mL. Serum triamcinolone and cortisol levels were inversely correlated (Spearman -0.42, P = .02). CONCLUSIONS: The theoretical model predicts efficient delivery of triamcinolone acetonide from the posterior sub-Tenon's space to the extracellular choroidal matrix. The experimental findings demonstrate low levels of serum triamcinolone that alter systemic cortisol levels and higher vitreous levels lasting at least 1 month. Both assessments support trans-scleral delivery of posterior sub-Tenon's triamcinolone.
Kruger JM, Lessell S, Cestari DM. Neuro-imaging: a review for the general ophthalmologist. Semin Ophthalmol 2012;27(5-6):192-6.Abstract
The diagnosis of many neuro-ophthalmic conditions is facilitated with neuro-imaging. The two main modalities are Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Clinicians who refer patients for either of these techniques must not only know which of them to choose, but also where the imaging should be performed (e.g. brain, orbit), whether or not contrast is indicated, and if angiography should be supplemented. These complexities often result in imaging studies that are either unneeded or unhelpful. The goal of this manuscript is to provide a practical set of guidelines for the general ophthalmologist of how to choose the correct parameters for neuro-imaging studies.
Kumar R, Dohlman CH, Chodosh J. Oral acetazolamide after Boston keratoprosthesis in Stevens-Johnson syndrome. BMC Res Notes 2012;5:205.Abstract
BACKGROUND: Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare but severe and sometimes fatal condition associated with exposure to medications; sulfamethoxazole is among the most common causes. We sought to address the safety of acetazolamide, a chemically related compound, in patients with prior SJS/TEN and glaucoma. A retrospective case series is described of patients at the Massachusetts Eye and Ear Infirmary who underwent keratoprosthesis surgery for corneal blindness from SJS/TEN, and later required oral acetazolamide for elevated intraocular pressure. FINDINGS: Over the last 10 years, 17 patients with SJS/TEN received a Boston keratoprosthesis. Of these, 11 developed elevated intraocular pressure that required administration of oral acetazolamide. One of 11 developed a mild allergic reaction, but no patient experienced a recurrence of SJS/TEN or any severe adverse reaction. CONCLUSION: Although an increase in the rate of recurrent SJS/TEN due to oral acetazolamide would not necessarily be apparent after treating only 11 patients, in our series, acetazolamide administration was well tolerated without serious sequela.
Kurbanyan K, Hoesl LM, Schrems WA, Hamrah P. Corneal nerve alterations in acute Acanthamoeba and fungal keratitis: an in vivo confocal microscopy study. Eye (Lond) 2012;26(1):126-32.Abstract
PURPOSE: To study sub-basal corneal nerve alterations in patients with acute Acanthamoeba keratitis (AK) and fungal keratitis (FK), using laser in vivo confocal microscopy (IVCM). METHODS: A retrospective analysis of IVCM (Heidelberg Retina Tomograph 3/Rostock Cornea Module) images of 10 AK corneas and 4 FK corneas was performed, and the results compared with those of 10 normal and 12 acute herpetic keratitis (HK) corneas. Sub-basal corneal nerves were analyzed with respect to total number of nerves, main nerve trunks, branching pattern and total length of nerves per image, as well as tortuosity. For each variable, results for three frames were averaged and analyzed using analysis of variance. RESULTS: Total corneal nerve length was significantly (P < 0.0001) reduced in patients with AK (193.4 ± 124.5 μm) and FK (268.6 ± 257.4 μm) when compared with normal controls (3811.84 ± 911.4 μm). Total nerve counts in patients with AK (3.9 ± 1.2) and FK (3.6 ± 3.2) were significantly (P < 0.0001) decreased in comparison with normal controls (24.7 ± 5.5). The number of main nerve trunks and nerve branching was found to be significantly lower in AK and FK corneas, when compared with controls. There was a statistically significant decrease in the above parameters when compared with HK controls. CONCLUSIONS: The sub-basal corneal nerve plexus is significantly diminished in eyes with AK and FK, as demonstrated by IVCM. These results are more profound than previously reported findings of a diminished nerve plexus in HK.
Lan Y, Kodati S, Lee HS, Omoto M, Jin Y, Chauhan SK. Kinetics and function of mesenchymal stem cells in corneal injury. Invest Ophthalmol Vis Sci 2012;53(7):3638-44.Abstract
PURPOSE: Bone marrow-derived mesenchymal stem cells (MSCs) hold great promise for wound healing and tissue regeneration. In the present study, we investigated the impact of corneal injury on the homeostasis of endogenous MSCs, and the potential of MSCs to home to injured tissue and promote corneal repair. METHODS: Corneal injury in mice was induced by thermal cauterization. Circulating MSCs were quantified by flow cytometric analysis. Ex vivo expanded red Q-dot-labeled or GFP+ bone marrow-derived MSCs were intravenously injected after injury and detected using epifluorescence microscopy. Corneal fluorescein staining was performed to evaluate epithelial regeneration. RESULTS: Following the induction of corneal injury in mice, a 2-fold increase in the frequency of circulating endogenous MSCs was observed within 48 hours of injury, which was accompanied by increased levels of the stem cell chemoattractants, substance P and SDF-1, in both the injured cornea and blood. Systemically administered MSCs homed to the injured cornea, but not to the normal cornea, and showed long-term survival. In addition, in the setting of corneal injury, MSC administration showed significant and rapid corneal epithelial regeneration. CONCLUSIONS: These findings provide novel evidence that corneal injury causes significant mobilization of endogenous MSCs into blood, and that MSCs home specifically to the injured cornea and promote regeneration, highlighting the therapeutic implications of MSC-mediated tissue repair in corneal injury.
Lefebvre DR, Freitag SK. Update on imaging of the lacrimal drainage system. Semin Ophthalmol 2012;27(5-6):175-86.Abstract
Epiphora is a common problem seen by the ophthalmologist. There are numerous etiologies of a watering eye, and the underlying diagnosis is not always clear. A variety of in-office examination techniques and procedures exist to aid with diagnosis and determination of appropriate therapy, but sometimes the diagnosis remains elusive, or an instituted therapy fails. Lacrimal imaging, particularly in these cases, can be helpful in assessing the function and anatomy of the lacrimal drainage system. This review serves to examine the literature of the last 10 years concerning imaging of the lacrimal drainage system.
Li D, Carozza RB, Shatos MA, Hodges RR, Dartt DA. Effect of histamine on Ca(2+)-dependent signaling pathways in rat conjunctival goblet cells. Invest Ophthalmol Vis Sci 2012;53(11):6928-38.Abstract
PURPOSE: The purpose of this study was to determine the Ca(2+)-dependent cellular signaling pathways used by histamine to stimulate conjunctival goblet cell secretion. METHODS: Cultured rat goblet cells were grown in RPMI 1640. Goblet cell secretion of high molecular weight glycoconjugates was measured by an enzyme-linked lectin assay. Intracellular [Ca(2+)] ([Ca(2+)](i)) was measured by loading cultured cells with the Ca(2+) sensitive dye fura-2. The level of [Ca(2+)](i) was measured using fluorescence microscopy. Extracellular regulated kinase (ERK) 2 was depleted using small interfering RNA (siRNA). RESULTS: Histamine-stimulated conjunctival goblet cell secretion of high molecular weight glycoproteins was blocked by removal of extracellular Ca(2+) and depletion of ERK2 by siRNA. Histamine increase in [Ca(2+)](i) was desensitized by repeated addition of agonist and blocked by a phospholipase C antagonist. Histamine at higher doses increased [Ca(2+)](i) by stimulating influx of extracellular Ca(2+), but at a lower dose released Ca(2+) from intracellular stores. Activation of each histamine receptor subtype (H(1)-H(4)) increased [Ca(2+)](i) and histamine stimulation was blocked by antagonists of each receptor subtype. The H(2) receptor subtype increase in [Ca(2+)](i) was cAMP dependent. CONCLUSIONS: We conclude that histamine activates phospholipase C to release intracellular Ca(2+) that induces the influx of extracellular Ca(2+) and activates ERK1/2 to stimulate conjunctival goblet cell mucous secretion, and that activation of all four histamine receptor subtypes can increase [Ca(2+)](i).
Liu Q, Collin RWJ, Cremers FPM, den Hollander AI, van den Born IL, Pierce EA. Expression of wild-type Rp1 protein in Rp1 knock-in mice rescues the retinal degeneration phenotype. PLoS One 2012;7(8):e43251.Abstract
Mutations in the retinitis pigmentosa 1 (RP1) gene are a common cause of autosomal dominant retinitis pigmentosa (adRP), and have also been found to cause autosomal recessive RP (arRP) in a few families. The 33 dominant mutations and 6 recessive RP1 mutations identified to date are all nonsense or frameshift mutations, and almost exclusively (38 out of 39) are located in the 4(th) and final exon of RP1. To better understand the underlying disease mechanisms of and help develop therapeutic strategies for RP1 disease, we performed a series of human genetic and animal studies using gene targeted and transgenic mice. Here we report that a frameshift mutation in the 3(rd) exon of RP1 (c.686delC; p.P229QfsX35) found in a patient with recessive RP1 disease causes RP in the homozygous state, whereas the heterozygous carriers are unaffected, confirming that haploinsufficiency is not the causative mechanism for RP1 disease. We then generated Rp1 knock-in mice with a nonsense Q662X mutation in exon 4, as well as Rp1 transgenic mice carrying a wild-type BAC Rp1 transgene. The Rp1-Q662X allele produces a truncated Rp1 protein, and homozygous Rp1-Q662X mice experience a progressive photoreceptor degeneration characterized disorganization of photoreceptor outer segments. This phenotype could be prevented by expression of a normal amount of Rp1 protein from the BAC transgene without removal of the mutant Rp1-Q662X protein. Over-expression of Rp1 protein in additional BAC Rp1 transgenic lines resulted in retinal degeneration. These findings suggest that the truncated Rp1-Q662X protein does not exert a toxic gain-of-function effect. These results also imply that in principle gene augmentation therapy could be beneficial for both recessive and dominant RP1 patients, but the levels of RP1 protein delivered for therapy will have to be carefully controlled.
Liu Y, Biarnés Costa M, Gerhardinger C. IL-1β is upregulated in the diabetic retina and retinal vessels: cell-specific effect of high glucose and IL-1β autostimulation. PLoS One 2012;7(5):e36949.Abstract
Many molecular and cellular abnormalities detected in the diabetic retina support a role for IL-1β-driven neuroinflammation in the pathogenesis of diabetic retinopathy. IL-1β is well known for its role in the induction and, through autostimulation, amplification of neuroinflammation. Upregulation of IL-1β has been consistently detected in the diabetic retina; however, the mechanisms and cellular source of IL-1β overexpression are poorly understood. The aim of this study was to investigate the effect of high glucose and IL-1β itself on IL-1β expression in microglial, macroglial (astrocytes and Müller cells) and retinal vascular endothelial cells; and to study the effect of diabetes on the expression of IL-1β in isolated retinal vessels and on the temporal pattern of IL-1β upregulation and glial reactivity in the retina of streptozotocin-diabetic rats. IL-1β was quantified by RealTime RT-PCR and ELISA, glial fibrillar acidic protein, α2-macroglobulin, and ceruloplasmin by immunoblotting. We found that high glucose induced a 3-fold increase of IL-1β expression in retinal endothelial cells but not in macroglia and microglia. IL-1β induced its own synthesis in endothelial and macroglial cells but not in microglia. In retinal endothelial cells, the high glucose-induced IL-1β overexpression was prevented by calphostin C, a protein kinase C inhibitor. The retinal vessels of diabetic rats showed increased IL-1β expression as compared to non-diabetic rats. Retinal expression of IL-1β increased early after the induction of diabetes, continued to increase with progression of the disease, and was temporally associated with upregulation of markers of glial activation. These findings point to hyperglycemia as the trigger and to the endothelium as the origin of the initial retinal upregulation of IL-1β in diabetes; and to IL-1β itself, via autostimulation in endothelial and macroglial cells, as the mechanism of sustained IL-1β overexpression. Interrupting the vicious circle triggered by IL-1β autostimulation could limit the progression of diabetic retinopathy.
Lobo A-M, Rhee DJ. Delayed interval of involvement of the second eye in a male patient with bilateral Chandler's syndrome. Br J Ophthalmol 2012;96(1):134-5, 146-7.
Lucas K, Karamichos D, Mathew R, Zieske JD, Stein-Streilein J. Retinal laser burn-induced neuropathy leads to substance P-dependent loss of ocular immune privilege. J Immunol 2012;189(3):1237-42.Abstract
Inflammation in the eye is tightly regulated by multiple mechanisms that together contribute to ocular immune privilege. Many studies have shown that it is very difficult to abrogate the immune privileged mechanism called anterior chamber-associated immune deviation (ACAID). Previously, we showed that retinal laser burn (RLB) to one eye abrogated immune privilege (ACAID) bilaterally for an extended period of time. In an effort to explain the inflammation in the nonburned eye, we postulated that neuronal signals initiated inflammation in the contralateral eye. In this study, we test the role of substance P, a neuroinflamatory peptide, in RLB-induced loss of ACAID. Histological examination of the retina with and without RLB revealed an increase of the substance P-inducible neurokinin 1 receptor (NK1-R) in the retina of first, the burned eye, and then the contralateral eye. Specific antagonists for NK1-R, given locally with Ag within 24 h, but not 3, 5, or 7 d post-RLB treatment, prevented the bilateral loss of ACAID. Substance P knockout (KO) mice retained their ability to develop ACAID post-RLB. These data support the postulate that substance P transmits early inflammatory signals from the RLB eye to the contralateral eye to induce changes to ocular immune privilege and has a central role in the bilateral loss of ACAID. The possibility is raised that blocking of the substance P pathway with NK1-R antagonists postocular trauma may prevent unwanted and perhaps extended consequences of trauma-induced inflammation in the eye.