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Cruz Flores VA, Menghani H, Mukherjee PK, Marrero L, Obenaus A, Dang Q, Khoutorova L, Reid MM, Belayev L, Bazan NG. Combined Therapy With Avastin, a PAF Receptor Antagonist and a Lipid Mediator Inhibited Glioblastoma Tumor Growth. Front Pharmacol 2021; 12:746470. [PMID: 34630114 PMCID: PMC8498947 DOI: 10.3389/fphar.2021.746470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/06/2021] [Indexed: 12/30/2022] Open
Abstract
Glioblastoma multiforme (GBM) is an aggressive, highly proliferative, invasive brain tumor with a poor prognosis and low survival rate. The current standard of care for GBM is chemotherapy combined with radiation following surgical intervention, altogether with limited efficacy, since survival averages 18 months. Improvement in treatment outcomes for patients with GBM requires a multifaceted approach due to the dysregulation of numerous signaling pathways. Recently emerging therapies to precisely modulate tumor angiogenesis, inflammation, and oxidative stress are gaining attention as potential options to combat GBM. Using a mouse model of GBM, this study aims to investigate Avastin (suppressor of vascular endothelial growth factor and anti-angiogenetic treatment), LAU-0901 (a platelet-activating factor receptor antagonist that blocks pro-inflammatory signaling), Elovanoid; ELV, a novel pro-homeostatic lipid mediator that protects neural cell integrity and their combination as an alternative treatment for GBM. Female athymic nude mice were anesthetized with ketamine/xylazine, and luciferase-modified U87MG tumor cells were stereotactically injected into the right striatum. On post-implantation day 13, mice received one of the following: LAU-0901, ELV, Avastin, and all three compounds in combination. Bioluminescent imaging (BLI) was performed on days 13, 20, and 30 post-implantation. Mice were perfused for ex vivo MRI on day 30. Bioluminescent intracranial tumor growth percentage was reduced by treatments with LAU-0901 (43%), Avastin (77%), or ELV (86%), individually, by day 30 compared to saline treatment. In combination, LAU-0901/Avastin, ELV/LAU-0901, or ELV/Avastin had a synergistic effect in decreasing tumor growth by 72, 92, and 96%, respectively. Additionally, tumor reduction was confirmed by MRI on day 30, which shows a decrease in tumor volume by treatments with LAU-0901 (37%), Avastin (67%), or ELV (81.5%), individually, by day 30 compared to saline treatment. In combination, LAU-0901/Avastin, ELV/LAU-0901, or ELV/Avastin had a synergistic effect in decreasing tumor growth by 69, 78.7, and 88.6%, respectively. We concluded that LAU-0901 and ELV combined with Avastin exert a better inhibitive effect in GBM progression than monotherapy. To our knowledge, this is the first study that demonstrates the efficacy of these novel therapeutic regimens in a model of GBM and may provide the basis for future therapeutics in GBM patients.
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Affiliation(s)
- Valerie A Cruz Flores
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Pediatrics, Hematology-Oncology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Hemant Menghani
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States.,Department of Pediatrics, Hematology-Oncology, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Pranab K Mukherjee
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Luis Marrero
- Department of Orthopaedic Surgery, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Andre Obenaus
- Department of Pediatrics, School of Medicine, University of California Irvin, Irvine, CA, United States
| | - Quan Dang
- Department of Pediatrics, School of Medicine, University of California Irvin, Irvine, CA, United States
| | - Larissa Khoutorova
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Madigan M Reid
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Ludmila Belayev
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, United States
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Dalmaso B, da Silva-Junior IA, Fragel-Madeira L, Jancar S, Del Debbio CB. Platelet activating factor in the eye: Physiological roles, diseases and future perspectives. Prostaglandins Other Lipid Mediat 2020; 153:106522. [PMID: 33358892 DOI: 10.1016/j.prostaglandins.2020.106522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/03/2020] [Accepted: 12/18/2020] [Indexed: 01/09/2023]
Abstract
Platelet Activating Factor (PAF) is a known phospholipid mediator of inflammation. Since its first description in 1972, it has emerged as a key regulator of vital cellular signaling functions, as proliferation, cell adhesion, and apoptosis. Evidence suggests that interactions between PAF and its receptor (PAFR) play a critical role in nervous system tissues, including the retina. The retina is a very important constituent of the visual system, along with the cornea, sclera, choroid, iris, and ciliary body, that acts synergistically to provide vision and to maintain optical homeostasis. There is evidence that PAF may regulate a wide range of physiological functions in the visual system tissues, such as eye development, inflammation, epithelial wound healing, and synapsis. Due to their multiple functions, PAF and PAFR also have important pathological and clinical implications in ocular disorders such as Choroidal Neovascularization (CNV), Age Macular Degeneration, (AMD), Diabetic Retinopathy (DR), transplant responses, and pharmacological interactions. Studies with PAFR antagonists have shown promising results such as inhibition of neovascularization and chloroquine-induced retinopathies, as well as reducing inflammation and retinal cell death. Due to the importance of PAFR signaling in the visual system and ophthalmology research, this review aims to provide a general overview of current and future perspectives about PAF in eye biology.
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Affiliation(s)
- Barbara Dalmaso
- Department of Cell and Developmental Biology, Biomedical Sciences Institute, University of Sao Paulo, São Paulo, Brazil
| | | | - Lucianne Fragel-Madeira
- Department of Neurobiology, Institute of Biology, Fluminense Federal University, Rio de Janeiro, Brazil
| | - Sonia Jancar
- Department of Immunology, Biomedical Sciences Institute, University of Sao Paulo, São Paulo, Brazil
| | - Carolina Beltrame Del Debbio
- Department of Cell and Developmental Biology, Biomedical Sciences Institute, University of Sao Paulo, São Paulo, Brazil.
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Nitoda E, Moschos MM, Mavragani CP, Koutsilieris M. Ocular actions of platelet-activating factor: clinical implications. Expert Opin Ther Targets 2012; 16:1027-39. [DOI: 10.1517/14728222.2012.712961] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Superior Neuroprotective Efficacy of LAU-0901, a Novel Platelet-Activating Factor Antagonist, in Experimental Stroke. Transl Stroke Res 2011; 3:154-63. [PMID: 22408693 PMCID: PMC3284672 DOI: 10.1007/s12975-011-0116-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/10/2011] [Accepted: 10/12/2011] [Indexed: 01/05/2023]
Abstract
Platelet-activating factor (PAF) accumulates during cerebral ischemia, and inhibition of this process plays a critical role in neuronal survival. Recently, we demonstrated that LAU-0901, a novel PAF receptor antagonist, is neuroprotective in experimental stroke. We used magnetic resonance imaging in conjunction with behavior and immunohistopathology to expand our understanding of this novel therapeutic approach. Sprague–Dawley rats received 2 h middle cerebral artery occlusion (MCAo) and were treated with LAU-0901 (60 mg/kg) or vehicle 2 h from MCAo onset. Behavioral function, T2-weighted imaging (T2WI), and apparent diffusion coefficients were performed on days 1, 3, and 7 after MCAo. Infarct volume and number of GFAP, ED-1, and NeuN-positive cells were conducted on day 7. Behavioral deficit was significantly improved by LAU-0901 treatment compared to vehicle on days 1, 3, and 7. Total lesion volumes computed from T2WI were significantly reduced by LAU-0901 on days 1, 3, and 7 (by 83%, 90%, and 96%, respectively), which was consistent with decreased edema formation. Histopathology revealed that LAU-0901 treatment resulted in significant reduction of cortical and subcortical infarct volumes, attenuated microglial infiltration, and promoted astrocytic and neuronal survival. These findings suggest LAU-0901 is a promising neuroprotectant and provide the basis for future therapeutics in patients suffering ischemic stroke.
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Kenchegowda S, Bazan HEP. Significance of lipid mediators in corneal injury and repair. J Lipid Res 2010; 51:879-91. [PMID: 19965607 PMCID: PMC2853455 DOI: 10.1194/jlr.r001347] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 11/03/2009] [Indexed: 12/23/2022] Open
Abstract
Corneal injury induces an inflammatory reaction and damages the sensory nerves that exert trophic influences in the corneal epithelium. Alterations in normal healing disrupt the integrity and function of the tissue with undesirable consequences, ranging from dry eye and loss of transparency to ulceration and perforation. Lipids play important roles in this complex process. Whereas lipid mediators such as platelet activating factor (PAF) and cyclooxygenease-2 metabolites contribute to tissue damage and neovascularization, other mediators, such as the lipoxygenase (LOX) derivatives from arachidonic acid, 12- and 15-hydroxy/hydroperoxyeicosatetraenoic acids, and lipoxin A4, act as second messengers for epidermal growth factor to promote proliferation and repair. Stimulation of the cornea with pigment epithelial derived factor in the presence of docosahexaenoic acid gives rise to the synthesis of neuroprotectin D1, a derivative of LOX activity, and increases regeneration of corneal nerves. More knowledge about the role that lipids play in corneal wound healing can provide insight into the development of new therapeutic approaches for treating corneal injuries. PAF antagonists, lipoxins, and neuroprotectins can be effective therapeutic tools for maintaining the integrity of the cornea.
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Affiliation(s)
| | - Haydee E. P. Bazan
- Neuroscience Center of Excellence and Department of Ophthalmology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112
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Esquenazi S, Bazan HEP. Role of platelet-activating factor in cell death signaling in the cornea: A review. Mol Neurobiol 2010; 42:32-8. [PMID: 20431963 DOI: 10.1007/s12035-010-8129-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 04/05/2010] [Indexed: 11/28/2022]
Abstract
Platelet-activating factor (PAF) is a potent bioactive lipid generated in the cornea after injury whose actions are mediated through specific receptors. Studies from our laboratory have shown that PAF interactions with its receptors activate several transmembrane signals involved in apoptosis. Continuous exposure to PAF during prolonged inflammation increases keratocyte apoptosis and inhibition of epithelial adhesion to the basement membrane. As a consequence, there is a marked delay in wound healing, which is not countered by the action of growth factors. While apoptosis of stroma cells is rapid and potent, epithelial cells as well as myofibroblasts, which appear in the stroma during the repair phase, are resistant to apoptosis. However, PAF accelerates apoptosis of corneal epithelial cells exposed to oxidative stress by stimulating phospholipase A2, producing an early release of cytochrome C from mitochondria and activating caspase-3. In myofibroblasts, PAF has a synergistic action with tumor necrosis factor-alpha (TNF-alpha), increasing apoptosis of the cells to 85%. PAF antagonists block the effects of PAF and could have a therapeutic role in maintaining a healthy and transparent cornea.
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Affiliation(s)
- Salomon Esquenazi
- Neuroscience Center of Excellence and Department of Ophthalmology, LSU Health Sciences Center, New Orleans, LA, USA
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Esquenazi S, Esquenazi I, Grunstein L, He J, Bazan H. Immunohistological Evaluation of the Healing Response at the Flap Interface in Patients with LASIK Ectasia Requiring Penetrating Keratoplasty. J Refract Surg 2009; 25:739-46. [DOI: 10.3928/1081597x-20090707-09] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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He J, Bazan HEP. Epidermal growth factor synergism with TGF-beta1 via PI-3 kinase activity in corneal keratocyte differentiation. Invest Ophthalmol Vis Sci 2008; 49:2936-45. [PMID: 18579759 DOI: 10.1167/iovs.07-0900] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE To investigate the action of epidermal growth factor (EGF) on corneal keratocyte differentiation and its effects in conjunction with transforming growth factor (TGF)-beta1. METHODS Rabbit corneal keratocytes (RCKs) were treated with EGF, TGF-beta1, or EGF plus TGF-beta1 in the presence or absence of inhibitors of EGF-receptor (EGF-R), neutralizing concentrations of EGF antibody and of signaling kinases for 2 days to 1 week. RCK differentiation to myofibroblasts was identified with anti-aldehyde dehydrogenase (ALDH)-1 and alpha-smooth muscle actin (alpha-SMA) antibodies. Cell proliferation was evaluated with anti-Ki-67 antibody. Extracellular matrix (ECM) components were assayed by immunochemistry and Western blot. Cell migration images were captured with a camera attached to the microscope, and the area of the wound was calculated using imaging software. RESULTS RCKs cultured in serum-free DMEM/F12 without frequent changes of medium maintained the phenotype for more than 1 month. EGF stimulated differentiation into a proto-myofibroblast phenotype with the loss of dendritic shape and the expression of alpha-SMA. Treatment with TGF-beta1 stimulated 12% of the cells to differentiate to defined myofibroblasts, but in the presence of EGF, TGF-beta1 induced 90% of RCKs to transform into myofibroblasts. Inhibition of EGF-R activation and of the phosphatidylinositol-3 kinase (PI-3K)/Akt-1 pathway prevented the action of EGF on TGF-beta1 cell differentiation. TGF-beta1 in the presence of EGF also increased cell migration, which is inhibited by blocking EGF-R activation. CONCLUSIONS These data show that EGF contributes to the differentiation and migration of myofibroblasts induced by TGF-beta1 through EGF-R activation and that it is an important modulator of wound healing and scar tissue formation.
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Affiliation(s)
- Jiucheng He
- Department of Ophthalmology and Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, Louisiana 70112, USA
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Boetkjaer A, Boedker M, Cui JG, Zhao Y, Lukiw WJ. Synergism in the repression of COX-2- and TNFalpha-induction in platelet activating factor-stressed human neural cells. Neurosci Lett 2007; 426:59-63. [PMID: 17881124 PMCID: PMC2083574 DOI: 10.1016/j.neulet.2007.08.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 08/14/2007] [Accepted: 08/15/2007] [Indexed: 11/25/2022]
Abstract
Platelet activating factor (PAF; beta-acetyl-gamma-O-hexadecyl-l-alpha-phosphatidylcholine) triggers a rapid pro-inflammatory gene expression program in primary cultures of human neural (HN) cells. Two genes and gene products consistently induced after PAF treatment are the cytosoluble prostaglandin synthase cycloooxygenase-2 (COX-2) and the pro-apoptotic tumor necrosis factor alpha (TNFalpha). Both of these mediators are associated with the activation of inflammatory signaling, neural cell dysfunction, apoptosis and brain cell death, and both have been found to be up-regulated after brain injury in vivo. In this study we investigated the effects of the non-halogenated synthetic glucocorticoid budesonide epimer R (BUDeR), the novel PAF antagonist LAU-0901, and the electron spin trap and free radical scavenger phenyl butyl nitrone (PBN), upon early COX-2 and TNFalpha gene activation and prostaglandin E(2) (PGE(2)) release in PAF-stressed primary HN cells. The data indicate that these three biochemically unrelated classes of inflammatory repressors act synergistically in modulating PAF-induced up-regulation of COX-2, TNFalpha, and PGE(2) by quenching oxidative stress or inflammatory signaling, resulting in increased HN cell survival. These, or analogous classes of compounds, may be useful in the design of more effective combinatorial pharmacotherapeutic strategies in the treatment of complex neuro-inflammatory disorders.
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Affiliation(s)
- Anja Boetkjaer
- The Danish University of Pharmaceutical Sciences, Universitetsparken 2, DK 2100 Copenhagen, Denmark
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de Rojas Silva MV, Abraldes MJ, Díez-Feijóo E, Yáñez PM, Javaloy J, Sánchez-Salorio M. Confocal Microscopy and Histopathological Examination of Diffuse Lamellar Keratitis in an Experimental Animal Model. J Refract Surg 2007; 23:299-304. [PMID: 17385297 DOI: 10.3928/1081-597x-20070301-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the cell populations and structural alterations of the cornea in an experimental model of diffuse lamellar keratitis (DLK) using confocal microscopy and histopathology. METHODS A corneal flap was cut in 22 eyes of 11 New Zealand rabbits and the stromal interface was exposed to balanced salt solution (BSS, BSS group) and Pseudomonas aeruginosa lipopolysaccharide (LPS) endotoxin (5 mg/mL) (LPS 5 mg/mL group) and (3.5 mg/mL) (LPS 3.5 mg/mL group). Postoperatively, eyes were examined with a slit-lamp microscope (DLK grading) and confocal microscopy. Animals were sacrificed on day 3 (BSS group and LPS 5 mg/mL group) and day 4 (LPS 3.5 mg/mL group). Corneoscleral buttons were excised and processed for histopathologic examination. RESULTS Seven eyes were excluded. Slit-lamp microscopy revealed no cellular infiltration in the BSS group (five eyes). In the LPS groups, all eyes developed DLK, with iritis only observed in grade III eyes. In the LPS 5 mg/mL group, four eyes had DLK grade III, with iritis in three eyes. In the LPS 3.5 mg/mL group, three eyes had grade II and three eyes had grade III with iritis. On confocal microscopy, the BSS group had no cellular infiltration. Dense accumulation of inflammatory cells at the interface was noted in both LPS groups. Histopathology in the BSS group had a normal appearance. In the LPS groups, an inflammatory infiltrate was present at the interface that consisted of three cell populations--eosinophils, neutrophils, and lymphocytes. CONCLUSIONS Lipopolysaccharide endotoxin induced DLK in all exposed eyes, with iritis in a considerable proportion of eyes. The infiltrate consisted of three cell populations. Confocal microscopy showed the infiltrate in all affected eyes. Histopathological and confocal microscopic findings correlated well with the clinical appearance.
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Affiliation(s)
- Ma Victoria de Rojas Silva
- Fundación Instituto Galego de Oftalmología, Rúa Ramón Baltar, s/n (Hospital Provincial de Conxo), 15706 Santiago de Compostela, Spain.
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Esquenazi S, He J, Kim DB, Bazan NG, Bui V, Bazan HEP. Wound-healing response and refractive regression after conductive keratoplasty. J Cataract Refract Surg 2006; 32:480-6. [PMID: 16631062 DOI: 10.1016/j.jcrs.2005.12.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 08/15/2005] [Indexed: 11/18/2022]
Abstract
PURPOSE To characterize the histological changes that occur after conductive keratoplasty (CK) using a rabbit model. SETTING LSU Eye Center and Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, School of Medicine, New Orleans, Louisiana, USA. METHODS Conductive keratoplasty was performed on 24 eyes of 12 New Zealand albino rabbits. In each eye, 24 spots were placed in a cross-corneal manner using 3 optical zones at 6.0, 7.0, and 8.0 mm. Eyes were assessed with corneal topography weekly. Rabbits were humanely killed 2, 4, 6, and 8 weeks postoperatively. The eyes were then enucleated and processed for histopathology and immunohistochemical analysis. RESULTS All eyes showed an initial mean steepening of the corneal curvature of 2.24 diopters (D) 2 weeks postoperatively. Corneal topography revealed a 26%, 36%, and 39% regression of the refractive results at 4, 6, and 8 weeks, respectively. Immunohistochemical analysis demonstrated keratocyte apoptosis, myofibroblast appearance, and upregulation of chondroitin sulfate, MMP-1, and collagen III in the area surrounding the tip in each spot. CONCLUSION The histological changes that occur after CK may be responsible for the well-established regression of its refractive effect. A better understanding of the wound-healing response after CK is necessary to improve the long-term stability of the procedure.
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Affiliation(s)
- Salomon Esquenazi
- LSU Eye Center, LSU Health Sciences Center, School of Medicine, New Orleans, Louisiana 70112, USA.
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Esquenazi S, Bui V. Long-term Refractive Results of Myopic LASIK Complicated With Intraoperative Epithelial Defects. J Refract Surg 2006; 22:54-60. [PMID: 16447937 DOI: 10.3928/1081-597x-20060101-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the long-term refractive results of LASIK for myopia complicated with intraoperative epithelial defects. METHODS Twenty-six eyes with epithelial defects on the LASIK flap were compared with the contralateral eye that had no intraoperative complications. Pre- and postoperative data were compared between the two groups including 3-, 6- and 12-month postoperative spherical equivalent refraction, amount of undercorrection, and complications. RESULTS Eyes with intraoperative epithelial defects showed more undercorrection at 3 and 6 months postoperatively (P < .05). No statistically significant difference was noted at 12 months. Twenty (76%) eyes in the epithelial defect group lost best spectacle-corrected visual acuity (BSCVA) at 3 months postoperatively compared with 2 (7%) eyes in the control group. By 1 year, however, only 2 (7%) eyes in the epithelial defect group and no eyes in the control group lost > 1 line of BSCVA. Diffuse lamellar keratitis was observed in 15 (58%) of 26 eyes with epithelial defects and these eyes had more undercorrections at 6 and 12 months (P < .05) and higher corneal irregularity index at 6 and 12 months compared with controls (P < .05). Eyes with small epithelial defects (> 1 mm2 to < 3 mm2) had more undercorrections at 6 months (-1.08 +/- 0.76 diopters [D]) compared with the control group (-0.46 +/- 0.87 D). Eyes with centrally located epithelial defects had more undercorrections and increased corneal irregularity index compared with controls (P < .05). CONCLUSIONS Intraoperative epithelial defects after LASIK should be considered a severe complication that may result in diffuse lamellar keratitis, induce loss of BSCVA, prolong recovery of visual acuity, and induce undercorrection.
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Affiliation(s)
- Salomon Esquenazi
- Department of Ophthalmology and Neuroscience Center for Excellence, LSU Health Sciences Center, New Orleans, La 70112, USA.
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Abstract
PURPOSE To evaluate the efficacy of an autologous serum treatment of post-LASIK (laser in situ keratomileusis) corneal epithelial defects in a rabbit model. METHODS Five milliliters blood samples from 10 New Zealand rabbits were obtained by venepuncture. The serum was aseptically separated and diluted with saline solution to 20%. The final preparation was placed into 3-mL bottles with ultraviolet protection and maintained at 4 degrees C. Corneas were de-epithelialized using a 7-mm optical zone marker. A 160-microm thick flap was created in both eyes of all rabbits using an automatic corneal shaper microkeratome. Right eyes were treated with serum drops 6 times per day. Left eyes were treated with preservative-free artificial tears. Vital staining of the ocular surface and the area of corneal epithelial defect was measured daily for 1 week. Rabbits were humanely euthanized at postoperative day 7, and corneas were fixed and sectioned. Hematoxylin and eosin staining and immunohistochemical analysis were performed. RESULTS Corneas treated with autologous serum had a statistically significant increase in the epithelial healing rate compared with those treated with artificial tears. Serum-treated corneas showed significantly less terminal transferase-mediated dUTP nick-end labeling (TUNEL) staining in the interface, minimal inflammatory cell infiltration, and less induced synthesis of stromal chondroitin sulfate than did corneas treated with preservative-free artificial tears. CONCLUSIONS Treatment with autologous serum could be an efficient way to provide essential components to the ocular surface in the treatment of post-LASIK epithelial defects. Autologous serum induces faster epithelial healing than do artificial tears, leading to (1) a decrease in keratocyte apoptosis and migration of fibroblasts and myofibroblasts in the wound site, (2) a decrease in the migration of inflammatory cells, and (3) a consequent inhibition of cytokine release. This treatment could improve long-term refractive results post-LASIK.
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Affiliation(s)
- Salomon Esquenazi
- Department of Ophthalmology and Neuroscience Center of Excellence, LSU Health Sciences Center, New Orleans, LA 70112, USA.
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Esquenazi S, He J, Bazan NG, Bazan HEP. Comparison of corneal wound-healing response in photorefractive keratectomy and laser-assisted subepithelial keratectomy. J Cataract Refract Surg 2005; 31:1632-9. [PMID: 16129303 DOI: 10.1016/j.jcrs.2005.01.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate in a rabbit model the differences in cellular and matrix stromal response in low and high attempted corrections between photorefractive keratectomy (PRK) and laser-assisted subepithelial keratectomy (LASEK). SETTING Louisiana State University Health Sciences Center, Department of Ophthalmology and Neuroscience Center, New Orleans, Louisiana, USA. METHODS Twenty-four eyes of 12 New Zealand albino rabbits were used. Photorefractive keratectomy was performed in 1 eye and LASEK was performed in the contralateral eye of all rabbits. In 5 animals, a low refractive correction (--3 diopters [D]) was attempted. In the other 5 rabbits, a high refractive correction (--7 D) was attempted. Two rabbits served as controls. The animals were followed for 7 days, after which they were humanely killed. The eyes were enucleated and processed for histopathology and immunohystochemical analysis. RESULTS All eyes showed an inflammatory response in the anterior stroma adjacent to the ablated area, with greater inflammatory cell infiltration with higher attempted corrections. Similar keratocyte apoptosis was found with low attempted corrections in PRK-treated and LASEK-treated eyes. However, there was a significant increase in keratocyte apoptosis in the PRK group at higher attempted corrections. Increased transformation to myofibroblasts and synthesis of chondroitin sulfate were observed adjacent to the ablated stroma in all eyes. With low corrections, no differences were observed between LASEK-treated and PRK-treated eyes. With higher attempted corrections, there was a significant increase in myofibroblast transformation and chondroitin sulfate synthesis in the PRK group. An irregular and discontinued collagen IV component of the epithelial basement membrane was observed in all PRK-treated and LASEK-treated eyes regardless of the attempted correction. CONCLUSIONS At higher attempted corrections, LASEK-treated eyes showed less keratocyte apoptosis, myofibroblast transformation, and up-regulation in the synthesis of chondroitin sulfate than PRK-treated eyes. These differences may account for better visual acuities and less stromal haze in higher attempted corrections in LASEK-treated eyes.
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Affiliation(s)
- Salomon Esquenazi
- Department of Ophthalmology and Neuroscience Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
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Bazan HEP. Cellular and molecular events in corneal wound healing: significance of lipid signalling. Exp Eye Res 2005; 80:453-63. [PMID: 15781273 DOI: 10.1016/j.exer.2004.12.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Accepted: 12/28/2004] [Indexed: 11/29/2022]
Abstract
Alterations in the normal healing process after corneal injury can produce undesirable outcomes that range from corneal haze to ulceration and perforation. Lipids play important roles in the complex inflammatory processes that occur after corneal wounding. While some lipid mediators, such as the lipoxygenase derivatives of arachidonic acid, 12-hydroxyeicosatetraenoic acid (12[S]-HETE and 15[S]-HETE), act as second messengers to promote cell proliferation and are possibly involved in the synthesis of other molecules that suppress inflammation, others, such as platelet-activating factor (PAF), exert their actions through specific receptors, play key roles during sustained corneal inflammation (as might occur with chemical burns), and contribute to tissue destruction and neovascularization. PAF is also a strong inducer of selective metalloproteinases (MMPs) that degrade the extracellular matrix. The use of a new PAF antagonist has shown great promise for the treatment of diffuse lamellar keratitis (DLK) and alkali-burned corneas.
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Affiliation(s)
- Haydee E P Bazan
- Department of Ophthalmology and Neuroscience Center of Excellence, Louisiana State University Health Sciences Center School of Medicine, New Orleans, LA 70112, USA.
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