Biomedical subjects

Victor M Elner

Publications and source records attributed to Victor M Elner.

32 records · Page 2Linked to original sources

PubMed2004

Differential involvement of phosphoinositide 3-kinase/Akt in human RPE MCP-1 and IL-8 expression.

PURPOSE: To investigate the role of the phosphatidylinositol 3-kinase (PI3K) pathway and the signal mediator AP-1 in monocyte chemotactic protein (MCP)-1 and interleukin (IL)-8 gene expression in human retinal pigment epithelial (hRPE) cells. METHODS: hRPE cells were stimulated with IL-1beta and TNF-alpha and by coculturing with monocytes in the presence or absence of a series of kinase inhibitors. The induction of MCP-1 and IL-8 protein and mRNA was determined by ELISA and RT-PCR, respectively. Western blot analysis, kinase assays, and electrophoretic mobility shift assays were used to detect the activation of signaling mediators and transcription factors. RESULTS: Concomitant with the induction of chemokine expression by the stimuli, there was phosphorylation of PI3K and its downstream targets-namely, Akt, GSK, and FKHR. Ly294002, a specific inhibitor of PI3K, resulted in time- and dose-dependent blockade of MCP-1 mRNA expression and protein production. The IC(50) for inhibition of MCP-1 secretion induced by IL-1beta, TNF-alpha, and hRPE-monocyte binding was 16, 12, and less than 3 micro M, respectively. In contrast, Ly294002 did not inhibit the IL-8 expression induced by any of the stimuli. Ly294002 as well as U0126, SB202190, and SP600125, the selective inhibitors of MEK, p38, and JNK, respectively, strongly inhibited induced c-fos expression, whereas Ly294002 did not inhibit induction of MEK, p38, or JNK. Blockade of PI3K/Akt abolished IL-1beta-induced nuclear translocation of AP-1, whereas the induction of IkappaB degradation was unchanged. CONCLUSIONS: The Ly294002-sensitive PI3K/Akt pathway regulates MCP-1, but not IL-8 expression in hRPE cells independent of MAPK and IkappaB. PI3K-dependent induction of hRPE c-fos and AP-1 nuclear translocation may be a target for therapies aimed at modulating MCP-1 in retinal diseases.

Blotting, Western↗

PubMed2003

Clinicopathologic correlation and genetic analysis in a case of posterior polymorphous corneal dystrophy.

PURPOSE: To evaluate the clinical history, histopathology, and genetics of posterior polymorphous corneal dystrophy (PPMD) in a woman with a prominent retrocorneal membrane. DESIGN: Observational case report and genetic analysis of her family, UM:139. METHODS: Records were reviewed from a case and associated family members. The diagnosis of PPMD was based on clinical examination, immunohistochemical staining, electron microscopy, and screening of genetic markers from regions previously reported to be associated with PPMD. RESULTS: Over 17 years, the proband with PPMD had 25 ocular procedures performed for glaucoma, cataract, cornea, retina, and postoperative problems. A prominent retrocorneal membrane grew onto the crystalline lens and intraocular lens (IOL). Histopathology revealed stratified epithelial-like cells on iris from an iridectomy and stratified corneal endothelium on a corneal button. Electron microscopy on the cornea revealed microvilli, tonofilaments, and desmosomes consistent with endothelial transformation, which was confirmed by positive anticytokeratin (CK) AE1/AE3 and CAM 5.2 immunoreactivity. Negative immunoreactivity in epithelium and positive in endothelium with anti-CK 7 supported the diagnosis of PPMD rather than epithelial downgrowth. Multiple relatives were affected with PPMD with apparent autosomal dominant inheritance, but surprisingly, the PPMD, congenital hereditary endothelial dystrophy 1 (CHED1) and CHED2 loci on chromosome 20 and the collagen, type VIII, alpha-2 (COL8A2) gene were excluded by linkage and haplotype analyses. CONCLUSIONS: We are unaware of previous PPMD reports describing the unusual feature of a retrocorneal membrane extending onto the crystalline lens and IOL. In addition, this family suggests another PPMD locus.

Biomarkers↗

PubMed2003

RPE CD14 immunohistochemical, genetic, and functional expression.

CD14 is the primary receptor for lipopolysaccharide (LPS)that plays important roles in host defense and subserves other host-related biological functions. We previously identified CD14 on cultured human retinal pigment epithelial (HRPE) cells using immunocytochemical techniques. In this study, we investigated immunoreactive HRPE CD14 expression by immunohistochemically staining HRPE cells and HRPE cells in sections of human eyes with anti-CD14 monoclonal antibodies (mAb). Constitutive HRPE gene and protein expression were confirmed by semiquantitative PCR and western blotting. ELISA for cell-associated and secreted (s) HRPE CD14 revealed that specific digestion by phosphoinositol-specific phospholipase C (PI-PLC) significantly reduced (P<0.01) cell-associated HRPE CD14 which was not modulated by LPS or gamma-IFN. ELISA of the conditioned media (CM) of HRPE cells treated with PI-PLC contained significantly more (P<0.001) sCD14, but sCD14 was not modulated by LPS or gamma-IFN. FACS analysis confirmed HRPE cell surface CD14. To show functional CD14, fluorescently-labelled LPS and CD14 were demonstrated to show significant co-localization on live, cultured HRPE cells in close proximity (<7A) as demonstrated by resonance energy transfer of the fluorescent ligands (P<0.0001). Significant inhibition (P<0.001) of LPS-induced IL-8 secretion, as measured by ELISA, occurred in the presence of function blocking anti-CD14 mAb. Significant inhibition of LPS-induced HRPE IL-8 secretion by PKC, PTK, PI3 kinase, and p38 kinase inhibitors indicated cell mediators responsible for LPS-induced HRPE chemokine secretion. This study demonstrates that HRPE cells express functional CD14 in vitro and in situ along at the outer blood-retina barrier.

Antibodies, Monoclonal↗

PubMed2003

Human RPE cell lysis of extracellular matrix: functional urokinase plasminogen activator receptor (uPAR), collagenase and elastase.

Age-related macular degeneration (ARMD), proliferative vitreoretinopathy (PVR) and uveitis are characterized by RPE motility through the ECM of retinal lesions. The purpose of this study was to test the hypothesis that multiple proteolytic systems are functionally intact at the HRPE surface and peri-cellular region and that these activities are differentially modulated by IL-1beta. HRPE cells were evaluated: (1). as individual cells or cell extracts, (2). during migration across three-dimensional ECM-like layers and (3). in tissue sections. The urokirase plasminogen activator receptor (uPAR; CD87) was detected on HRPE cells as well as its functional activity. Although uPAR was associated with CD11b (CR3) on live resting cells, polarized migratory HRPE cells were found to dissociate uPAR from CR3; uPAR then translocated to anterior pole of the cell, where it enhanced PAI-1-inhibitable local proteolytic activity. The relative contribution of uPAR and collagenase in HRPE migration was evaluated using three-dimensional gelatin matrices. Interestingly, uPAR/uPA was found to play a key role in migration across these layers. IL-1 upregulated uPAR, collagenase, and elastase activities, suggesting that cytokines may affect the invasive program of HRPE cells in vivo. Immunohistochemistry for uPAR was performed in sections of human retina. Immunoreactive uPAR was present along the HRPE basolateral membrane in retinal sections and in sections of diseased retinal tissue at an enhanced level. Our results suggest that multiple proteolytic systems are present in association with HRPE and that the uPAR/uPA system may be particularly important.

Albumins↗

PubMed2003

Human RPE-monocyte co-culture induces chemokine gene expression through activation of MAPK and NIK cascade.

Cell-cell contact between human retinal pigment epithelium (hRPE) cells and monocytes occurs in many retinal diseases involving blood-retinal barrier breakdown. This study investigates chemokine secretion induced by co-culture of hRPE cells and monocytes and illustrates the roles of p38 kinase, ERK, JNK/SAPK and NF-kappaB-inducing kinase signaling pathways for hRPE IL-8 and MCP-1 secretion induced in hRPE by co-culture with monocytes. Co-culture of hRPE cells with monocytes increased steady-state IL-8 and MCP-1 mRNA and protein secretion. Stimulation of hRPE cells by monocytes resulted in prominent increases in p38, ERK1/2 and JNK/SAPK phosphorolation, IkappaBalpha degradation, and NF-kappaB nuclear translocation. The induced IL-8 and MCP-1 proteins were almost completely supporessed by U0126, a specific mitogen-activated protein kinase kinase (MEK) inhibitor, or by SB203580, a selective p38 inhibitor. Chemokine secretion was completely blocked by simultaneous administration of U0126 and SB203580. Induction of IL-8 and MCP-1 was abrogated by Ro318220, an inhibitor of PKC, as well as by genistein or herbimycin A, inhibitors of PTK. In addition, anti-inflammatory drugs dexamethasone (DEX) and cyclosporin A (CSA) both blocked activation of JNKS/SAPK and the cell-cell contact induced production of hRPE IL-8 and MCP-1, while activation of p38 and ERK was only inhibited by DEX, but not by CSA. These results suggest that activation of DEX-sensitive, CSA-resistant MEK/ERK and p38 pathways, and activation of NF-kappaB, PKC, and PTK are essential for IL-8 and MCP-1 expression by hRPE cells.

Cell Communication↗

PubMed2003

Atopy: a patient-specific risk factor for diffuse lamellar keratitis.

OBJECTIVE: To identify whether atopy is a patient-specific risk factor for the development of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK). DESIGN: Retrospective survey study. PARTICIPANTS: Three hundred sixty consecutive patients who underwent same-day bilateral myopic astigmatic primary LASIK procedures during March 1, 2000, through July 31, 2000. METHODS: We collected data for 360 consecutive patients undergoing LASIK during a 4-month period. On preoperative medical history questionnaires, patients self-identified whether they were atopic. All patients also indicated whether they were taking antiallergy medications or were untreated for allergy. MAIN OUTCOME MEASURES: The incidence of DLK after LASIK surgery. RESULTS: The risk of DLK in untreated atopic patients was much greater than the risk of DLK among nonatopics (odds ratio, 5.85; 95% confidence interval, 2.89-11.85; P = 0.001). However, the risk of DLK among atopic patients taking an oral systemic nonsedating histamine receptor 1 antagonist and among nonatopic patients did not differ significantly (odds ratio, 0.54; 95% confidence interval, 0.12-2.46; P = 0.43). CONCLUSIONS: Atopy is a patient-specific risk factor for the development of DLK after primary bilateral LASIK for either myopia or myopic astigmatism. Atopic individuals benefit from preoperative treatment to minimize the incidence of DLK and the potential for visual loss.

Adult↗

PubMed2003

Activated monocytes induce human retinal pigment epithelial cell apoptosis through caspase-3 activation.

Dysfunction and loss of human retinal pigment epithelial (HRPE) cells is a significant component of many ocular diseases, in which mononuclear phagocyte infiltration at the HRPE-related interface is also observed. In this study, we investigated whether HRPE cell apoptosis may be induced by overlay of IFN-gamma-activated monocytes. Human monocytes primed with IFN-gamma overlaid directly onto HRPE cells elicited significant increases in terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive HRPE cells (p < 0.0001) and decreases of proliferating cell nuclear antigen-positive (p < 0.0001) HRPE cells. The activated monocytes also induced HRPE cell caspase-3 activation, which was inhibited by the caspase-3 inhibitor, Z-DEVD-fmk. However, co-incubations in which activated monocytes were prevented from direct contact with HRPE cells or in which the monocytes were separated from the HRPE cells after 30 minutes of direct contact, did not induce significant HRPE cell apoptosis. Function-blocking anti-CD18 and anti-intercellular adhesion molecule-1 (ICAM-1) antibodies significantly reduced activated monocyte-induced TUNEL-positive HRPE cells by 48% (p = 0.0051) and 38% (p = 0.046), respectively. Anti-CD18 and anti-ICAM-1 antibodies significantly inhibited caspase-3 activity by 56% (p < 0.0001) and 45% (p < 0.0001), respectively. However, antibodies to vascular cell adhesion molecule-1, TNF-alpha, IL-1beta, or TNF-related apoptosis-inducing ligand did not inhibit apoptosis or caspase-3 activation. Direct overlay of monocytes also induced reactive oxygen metabolites (ROM) within HRPE cells. The intracellular HRPE cell ROM production was inhibited by the anti-CD18 and anti-ICAM-1 antibodies, but not by superoxide dismutase, presumably due to its failure to penetrate into HRPE cells. Accordingly, neither superoxide dismutase nor N(G)-monomethyl-L-arginine had significant effects on HRPE cell apoptosis or caspase-3 activation. Our results suggest that activated monocytes may induce ROM in HRPE cells through cell-to-cell contact, in part via CD18 and ICAM-1, and promote HRPE cell apoptosis. These mechanisms may compromise HRPE cell function and survival in a variety of retinal diseases.

Apoptosis↗

PubMed2003

Role of MCP-1 and MIP-1alpha in retinal neovascularization during postischemic inflammation in a mouse model of retinal neovascularization.

Macrophages are important participants in neovascularization. This study was designed to examine the role of the monocyte/macrophage chemotactic proteins, monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1alpha (MIP-1alpha) in a mouse model of oxygen-induced ischemic retinopathy and to determine whether the morphology and distribution of macrophages/microglia are concomitantly altered. The MCP-1, MIP-1alpha mRNA levels increased at 3 h after ischemia. MCP-1, MIP-1alpha, and vascular endothelial growth factor protein levels were also increased markedly and were maximal on days 1, 0.5, and 1, respectively, after ischemia. In situ hybridization showed that MCP-1 and MIP-1alpha were localized in the hypoxic inner retina. Immunostaining demonstrated that the macrophages/microglia in the retina had morphological changes with enlarged processes, and some were closely associated with neovascular tufts at postnatal day 17. Coadministration of the neutralizing antibodies against MCP-1 and MIP-1alpha inhibited retinal neovascularization by 30%. Our data suggest that MCP-1 and MIP-1alpha are involved in the induction of retinal neovascularization and play a role in the inflammation induced by the ischemic retinopathy, possibly by modulating or attracting macrophages/microglia.

Animals↗

PubMed2003

Graded full-thickness anterior blepharotomy for upper eyelid retraction.

PURPOSE: A chief morbidity of Graves' eye disease (GED) is upper lid retraction that results in exposure keratopathy and cosmetic deformity. This study was conducted to assess the efficacy of graded anterior blepharotomy to treat upper lid retraction. METHODS: Fifty eyelids of 32 patients with GED-associated upper lid retraction causing symptomatic ocular exposure were treated with graded, transcutaneous, full-thickness, anterior blepharotomy. Preoperative and postoperative ocular exposure symptoms, upper lid position, lagophthalmos, and keratopathy were compared. RESULTS: At an average of 8.5 +/- 8.1 months (range, 2 to 35 months) follow-up, more than 90% of preoperative symptoms resolved or improved. Upper eyelid position (P < .00001), lagophthalmos (P < .0001), and keratopathy (P < .01) were significantly improved. Mild contour abnormalities (all < or = 1 mm) occurred in 7 of 50 eyelids. Eyelid crease recession or asymmetry occurred in 4 of 22 patients with postoperative lid crease measurements. Complications of ptosis, wound dehiscence, and full-thickness hole each occurred once. The average time for performing the procedure was 31.5 +/- 8.9 minutes per eyelid. CONCLUSIONS: Graded anterior blepharotomy for upper lid retraction is a safe and highly effective surgical treatment for symptomatic GED-associated upper eyelid retraction. This technique achieves excellent functional and cosmetic outcomes.

Adult↗

PubMed2003

Human RPE cell apoptosis induced by activated monocytes is mediated by caspase-3 activation.

PURPOSE: To determine the effects of activated monocytes on the induction of human retinal pigment epithelial (HRPE) cell reactive oxygen metabolite (ROM) production and apoptosis. METHODS: HRPE cells were co-cultured with interferon-gamma (IFN-gamma)-stimulated human monocytes. HRPE apoptosis was detected by propidium iodide, proliferating cell nuclear antigen (PCNA) and TdT-mediated dUTP nick end labeling (TUNEL) staining, caspase-3 activation, and Western blot analysis. HRPE cell ROMs were imaged using the fluorescent marker dihydrotetramethylrosamine (H2TMRos). RESULTS: IFN-gamma-activated monocytes in direct contact with HRPE cells elicited significant increases in TUNEL-positive (P < .0001) and decreases in PCNA-positive (P < .0001) HRPE cells. The activated monocytes also induced HRPE cell caspase-3 activation, which was inhibited by inhibitor Z-DEVD-fmk. Co-incubations, in which monocytes were either prevented from direct contact with HRPE cells or separated from HRPE cells after 30 minutes of direct contact, did not induce significant HRPE cell apoptosis. Anti-CD18 and anti-ICAM-1 antibodies significantly reduced activated monocyte-induced TUNEL-positive HRPE cells, by 48% (P = .0051) and 38% (P = .046), respectively, and caspase-3 activity by 56% (P < .0001) and 45% (P < .0001), respectively. Overlay of monocytes induced HRPE cell ROM that was inhibited by anti-CD18 and anti-ICAM-1 antibodies, but not by superoxide dismutase (SOD) or nitric oxide (NO) inhibitors. Accordingly, neither SOD nor NO inhibitors had significant effects on HRPE cell apoptosis or caspase-3 activation. CONCLUSIONS: We demonstrated that IFN-gamma-activated monocytes may induce ROM in HRPE cells through cell-to-cell contact, in part via CD18 and ICAM-1, and promote HRPE cell apoptosis via caspase-3 activation. These mechanisms may compromise HRPE cell function and survival in retinal diseases in which mononuclear phagocyte infiltration at the HRPE interface is observed.

Apoptosis↗

PubMed2002

Macrophage and retinal pigment epithelium expression of angiogenic cytokines in choroidal neovascularization.

PURPOSE: To determine the expression of angiogenic cytokines in macrophages and retinal pigment epithelium cells in choroidal neovascularization (CNV). METHODS: Ten surgically-excised subfoveal CNV specimens and ten eye bank eyes with subfoveal CNV were routinely processed, serially sectioned, and immunostained for factor VIII (F8), CD68 (KP1), cytokeratin 18 (CK18), vascular endothelial growth factor (VEGF), tissue factor (TF), and monocyte chemotactic protein (MCP). The CNV was classified as "inflammatory active" (more inflammation than fibrosis) or "inflammatory inactive" (morefibrosis than inflammation). The immunostaining was graded as none, mild (+), moderate (++), or heavy (+++). Five additional surgically-excised CNV specimens were dual labeled with CK18/MCP or CD68/TF and confocal scanning laser microscopy was performed. RESULTS: Vascular endothelium, macrophages, and RPE expressed F8, KP1, and CK18 respectively. Macrophages expressed + to ++ VEGF and ++ to +++ TF; RPE expressed ++ to +++ VEGF and ++ to +++ MCP. Staining for angiogenic cytokines was stronger in inflammatory active versus inflammatory inactive CNV. RPE dual labeled for CK18/MCP and macrophages dual labeled for CD68/TF. CONCLUSIONS: This study shows that RPE cells express MCP, a cytokine involved with macrophage recruitment, and that macrophages express TF in CNV. Macrophages and RPE express VEGF, thus perpetuating angiogenesis. TF is involved with fibrin formation and provides a scaffold effect for growth of the CNV complex. CNV likely represents a dynamic process with inflammatory active and inflammatory inactive (involutional) stages.

Adult↗

PubMed2002

Retinal pigment epithelial acid lipase activity and lipoprotein receptors: effects of dietary omega-3 fatty acids.

PURPOSE: To show that fish oil-derived omega-3 polyunsaturated fatty acids, delivered to the retinal pigment epithelium (RPE) by circulating low-density lipoproteins (LDL), enhance already considerable RPE lysosomal acid lipase activity, providing for more efficient hydrolysis of intralysosomal RPE lipids, an effect that may help prevent development of age-related macular degeneration (ARMD). METHODS: Colorimetric biochemical and histochemical techniques were used to demonstrate RPE acid lipase in situ, in vitro, and after challenge with phagocytic stimuli. Receptor-mediated RPE uptake of fluorescently labeled native, aceto-acetylated, and oxidized LDL was studied in vitro and in vivo. LDL effects on RPE lysosomal enzymes were assessed. Lysosomal enzyme activity was compared in RPE cells from monkeys fed diets rich in fish oil to those from control animals and in cultured RPE cells exposed to sera from these monkeys. RESULTS: RPE acid lipase activity was substantial and comparable to that of mononuclear phagocytes. Acid lipase activity increased significantly following phagocytic challenge with photoreceptor outer segment (POS) membranes. Receptor-mediated RPE uptake of labeled lipoproteins was determined in vitro. Distinctive uptake of labeled lipoproteins occurred in RPE cells and mononuclear phagocytes in vivo. Native LDL enhanced RPE lysosomal enzyme activity. RPE lysosomal enzymes increased significantly in RPE cells from monkeys fed fish oil-rich diets and in cultured RPE cells exposed to their sera. CONCLUSIONS: RPE cells contain substantial acid lipase for efficient metabolism of lipids imbibed by POS phagocytosis and LDL uptake. Diets rich in fish oil-derived omega-3 fatty acids, by enhancing acid lipase, may reduce RPE lipofuscin accumulation, RPE oxidative damage, and the development of ARMD.

Acyltransferases↗

PubMedDate not supplied

Comprehensive midfacial elevation for ocular complications of facial nerve palsy.

BACKGROUND: A chief morbidity of facial nerve palsy is ocular exposure, which is largely due to lower lid retraction and ectropion. OBJECTIVE: To assess the role of midfacial elevation in the comprehensive surgical treatment of paralytic lower lid malposition and ocular exposure. METHODS: Eleven patients with chronic facial nerve palsy causing symptomatic ocular exposure were treated with subperiosteal midface elevation as a component of comprehensive lower lid elevation. Other procedures were performed concomitantly to treat lower lid ligament laxity and reduced lower lid rigidity, as required. Preoperative and postoperative ocular exposure symptoms, visual acuity, lower lid position, lagophthalmos, and keratopathy were compared. RESULTS: At an average of 17 months of follow-up, all patients reported improvement in symptoms. Visual acuity was maintained or improved in all patients. Lower eyelid position (P =.003), lagophthalmos (P =.07), and keratopathy (P<.001) were also improved. CONCLUSIONS: Midfacial elevation is a safe and effective surgical adjunct in the treatment of lower eyelid retraction in chronic facial palsy. Its use reduces the need for tarsorrhaphy, which limits the binocular visual field and negatively impacts cosmesis.

Adult↗

PubMedDate not supplied

Local corticosteroid treatment of eyelid and orbital xanthogranuloma.

PURPOSE: To demonstrate the efficacy of local corticosteroid therapy for the treatment of eyelid and orbital xanthogranuloma in adults. METHODS: The authors performed a retrospective chart review of 6 patients receiving local triamcinolone acetonide (40 mg/ml) injections for the treatment of eyelid and orbital xanthogranuloma at the University of Michigan. All patients underwent diagnostic biopsy before treatment. The effects of this therapy on symptoms and signs of the disease were assessed. RESULTS: All 6 patients had eyelid swelling or nodularity and 5 had yellow discoloration of their eyelids. All lesions involved the eyelids and anterior orbit and 5 were present bilaterally. Biopsy revealed necrobiotic xanthogranuloma in 4 patients and adult-onset xanthogranuloma in 2 patients. Triamcinolone acetonide was administered intralesionally as series of 2 to 25 injections. Local control was obtained in all 6 cases, with the reduction of symptoms and signs of the disease in 5 cases. Two patients with necrobiotic xanthogranuloma had development of non-Hodgkin lymphoma. Average follow-up of patients whose treatment was not truncated by systemic chemotherapy was 52 months (range, 30 to 86 months). No complications occurred as a result of this treatment. CONCLUSIONS: Intralesional injection of triamcinolone acetonide is an effective, safe treatment for orbital xanthogranuloma in adults. This modality avoids the side effects associated with systemic corticosteroid or cytotoxic agent therapy.

Adult↗