Abnormal brain function in photophobic patients with dry eye disease: An fMRI study.

BACKGROUND AND OBJECTIVES: Photophobia, a frequent and disabling symptom observed in various neurological conditions and eye diseases, is thought to involve maladaptive brain functioning. We assessed this hypothesis, using functional magnetic resonance imaging (fMRI) in photophobic patients with minimal-to-severe dry eye disease (DED), as compared to healthy controls. METHODS: This prospective, monocentric, comparative, cohort study included eleven photophobic DED patients compared to eight controls. Photophobic patients had a complete evaluation of DED to exclude any other cause of photophobia. All participants were scanned with fMRI under intermittent light stimulation with a LED lamp (27s. ON, 27 s. OFF), and cerebral activations were studied with univariate contrasts between the ON and OFF conditions, and with functional connectivity methods. RESULTS: Firstly, stimulation activated the occipital cortex more strongly in patients than in controls. Moreover, stimulation deactivated the superior temporal cortex in patients less than in controls. Secondly, functional connectivity analysis showed that light stimulation induced lesser decoupling between the occipital cortex and the salience and visual networks in patients than in controls. DISCUSSION: The current data shows that DED patients with photophobia have maladaptive brain anomalies. There is hyperactivity in the cortical visual system, associated with abnormal functional interactions, both within the visual cortex, and between visual areas and salience control mechanisms. Such anomalies show similarities with other conditions such as tinnitus, hyperacusis, and neuropathic pain. Those findings support novel neurally oriented methods for the care of patients with photophobia.

Matrix metalloproteinase 14 overexpression reduces corneal scarring.

Once a corneal scar develops, surgical management remains the only option for visual rehabilitation. Corneal transplantation is the definitive treatment for a corneal scar. In addition to the challenges posed by graft rejections and other postoperative complications, the lack of high-quality donor corneas can limit the benefits possible with keratoplasty. The purpose of our study was to evaluate a new therapeutic strategy for treating corneal scarring by targeting collagen deposition. We overexpressed a fibril collagenase (matrix metalloproteinase 14 (MMP14)) to prevent collagen deposition in the scar tissue. We demonstrated that a single and simple direct injection of recombinant adeno-associated virus-based vector expressing murine MMP14 can modulate gene expression of murine stromal keratocytes. This tool opens new possibilities with regard to treatment. In a mouse model of corneal full-thickness incision, we observed that MMP14 overexpression reduced corneal opacity and expression of the major genes involved in corneal scarring, especially type III collagen and α-smooth muscle actin. These results represent proof of concept that gene transfer of MMP14 can reduce scar formation, which could have therapeutic applications after corneal trauma.

Pediatric cataract, myopic astigmatism, familial exudative vitreoretinopathy and primary open-angle glaucoma co-segregating in a family.

PURPOSE: To describe an Australian pedigree of European descent with a variable autosomal dominant phenotype of: pediatric cortical cataract (CC), asymmetric myopia with astigmatism, familial exudative vitreoretinopathy (FEVR), and primary open-angle glaucoma (POAG). METHODS: Probands with CC, FEVR, and POAG were enrolled in three independent genetic eye studies in Tasmania. Genealogy confirmed these individuals were closely related and subsequent examination revealed 11 other family members with some or all of the associated disorders. RESULTS: Twelve individuals had CC thought to be of childhood onset, with one child demonstrating progressive lenticular opacification. One individual had severe retinal detachment while five others had dragged retinal vessels. Seven individuals had POAG. Seven individuals had myopia in at least one eye ≤-3 Diopters. DNA testing excluded mutations in myocilin, trabecular meshwork inducible glucocorticoid response (MYOC) and tetraspanin 12 (TSPAN12). Haplotype analysis excluded frizzled family receptor 4 (FZD4) and low density lipoprotein receptor-related protein 5 (LRP5), but only partly excluded EVR3. Multipoint linkage analysis revealed multiple chromosomal single-nucleotide polymorphisms (SNPs) of interest, but no statistically significant focal localization. CONCLUSIONS: This unusual clustering of ophthalmic diseases suggests a possible single genetic cause for an apparently new cataract syndrome. This family's clinical ocular features may reflect the interplay between retinal disease with lenticular changes and axial length in the development of myopia and glaucoma.

Management of ocular involvement in the acute phase of Stevens-Johnson syndrome and toxic epidermal necrolysis: french national audit of practices, literature review, and consensus agreement.

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) can lead to severe ophthalmologic sequelae. The main risk factor is the severity of the initial ocular involvement. There are no recommendations for ocular management during acute phase.We conducted a national audit of current practice in the 11 sites of the French reference center for toxic bullous dermatoses and a review of the literature to establish therapeutic consensus guidelines. We sent a questionnaire on ocular management practices in SJS/ TEN during acute phase to ophthalmologists and dermatologists. The survey focused on ophthalmologist opinion, pseudomembrane removal, topical ocular treatment (i.e. corticosteroids, antibiotics, antiseptics, artificial tear eye drops, vitamin A ointment application), amniotic membrane transplantation, symblepharon ring use, and systemic corticosteroid therapy for ophthalmologic indication. Nine of 11 centers responded. All requested prompt ophthalmologist consultation. The majority performed pseudomembrane removal, used artificial tears, and vitamin A ointment (8/9, 90%). Combined antibiotic-corticosteroid or corticosteroid eye drops were used in 6 centers (67%), antibiotics alone and antiseptics in 3 centers (33%). Symblepharon ring was used in 5 centers (55%) if necessary. Amniotic membrane transplantation was never performed systematically and only according to the clinical course. Systemic corticosteroid therapy was occasionally used (3/9, 33%) and discussed on a case-by-case basis.The literature about ocular management practice in SJS/ TEN during acute phase is relatively poor. The role of specific treatments such as local or systemic corticosteroid therapy is not consensual. The use of preservatives, often present in eye drops and deleterious to the ocular surface, is to be restricted. Early amniotic membrane transplantation seems to be promising.

Confirmation of RAX gene involvement in human anophthalmia.

Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. Mutations in several genes have been involved in syndromic and non-syndromic anophthalmia. Previously, RAX recessive mutations were implicated in a single patient with right anophthalmia, left microphthalmia and sclerocornea. In this study, we report the findings of novel compound heterozygous RAX mutations in a child with bilateral anophthalmia. Both mutations are located in exon 3. c.664delT is a frameshifting deletion predicted to introduce a premature stop codon (p.Ser222ArgfsX62), and c.909C>G is a nonsense mutation with similar consequences (p.Tyr303X). This is the second report of a patient with anophthalmia caused by RAX mutations. These findings confirm that RAX plays a major role in the early stages of eye development and is involved in human anophthalmia.

[Evaluation of the nurse triage at the ophtalmology emergency department of Pierre-Paul-Riquet Hospital]. / Évaluation du questionnaire de tri infirmier aux urgences ophtalmologiques de l'hôpital Pierre-Paul-Riquet au CHU de Toulouse.

INTRODUCTION: The steady increase in the number of visits to the various emergency services combined with the decrease in medical demographics, make it necessary to optimize triage of patients to improve their care. The purpose of this study was to evaluate the pertinence of our triage questionnaire in the classification of ophthalmologic emergencies by severity. METHODS: We used a monocentric cross-sectional study. From September 5 through September 25 2017, 858 patients who had all been seen in the ophthalmology emergency department of Pierre Paul Riquet Hospital of Toulouse university medical center and had responded to the triage nurse questionnaire were included. According to the symptoms presented or not by the patient, a color code was attributed (GREEN, ORANGE or RED) in order of increasing level of emergency. For each patient, we compared the severity of the final diagnosis by Base Score with the level of emergency established by our questionnaire. RESULTS: There were 118 "GREEN" patients, 606 "ORANGE" patients and 134 "RED." We were able to analyze 822 patients. 21.65% of patients were correctly classified, 73.36% were overestimated (of which 87.06% by one level and 12.94% by two levels of severity), and 4.99% were underestimated (of which 90.24% by one level and 9.76% by two levels). CONCLUSION: Our current triage questionnaire is not sufficiently discriminating for effective triage of ophthalmologic emergencies. It often overestimates minor emergencies, causing a delay in treating other emergencies. We propose a new questionnaire modified according to the results obtained during our study.

[Assessment of astigmatism associated with the iris-fixated ARTISAN aphakia implant: Anterior fixation versus posterior fixation, study of postoperative follow-up at one year]. / Évaluation de l'astigmatisme associé à l'implant ARTISAN Aphakia fixé à l'iris en face antérieure versus face postérieure : étude du suivi postopératoire sur un an.

PURPOSE: The goal of our retrospective, single-center study of a case series was to compare the total, corneal, and internal astigmatism, and the visual acuity at one year after combined or stand-alone surgery consisting of iris fixation of an iris-claw intraocular lens (ARTISAN aphakia) in aphakic patients, according to whether the lens was fixated to the anterior (n=21) or posterior (n=51) surface of the iris. RESULTS: We did not find a significant difference between these two types of fixation for any of the studied variables. The surgically induced astigmatism was 1.67 D at 176° in group A versus 1.19 D at 11° in group P. CONCLUSION: Although this surgery creates additional corneal astigmatism, it has not been proven that it differs depending on the type of fixation of the iris-claw. If we adhere to the notion that the posterior fixated iris-claw decreases the risk of endothelial decompensation in case the implant becomes disenclavated, then reverse iris fixation of the iris-claw makes sense.

Overexpression of the myristoylated alanine-rich C kinase substrate in human choroidal melanoma cells affects cell proliferation.

Reduced expression of the myristoylated alanine-rich C kinase substrate (MARCKS) has been described in various cell lines after oncogenic or chemical transformation, leading to the question of whether this protein may be involved in cell proliferation. Here we compare the expression of MARCKS in human tumor-derived choroidal melanoma cells (OCM-1) and in primary cultures of normal choroidal melanocytes. We found an important down-regulation of the protein in the melanoma cell line. Stable transfection of these cells with the cDNA coding for MARCKS led to the selection of several clones expressing variable levels of the protein. Proliferation experiments performed with four of these clones revealed that cell growth was reduced by 35-40% when compared with control cells. Upon serum starvation, cell proliferation was almost abolished when the expression level of MARCKS was high, whereas it was only partially reduced in the controls. MARCKS overexpression induced a higher percentage of cells in the G0-G1 phase of the cell cycle upon serum starvation, as well as the inhibition of colony formation in soft agar. Finally, the expression of the CDK inhibitor p27 was increased in the cells presenting a high level of MARCKS protein. Altogether, these data suggest that the expression of this protein kinase C substrate affects the proliferation and partially reverts the transformed phenotype of the OCM-1 cells.

[Efficacy of corneal cross-linking for the treatment of keratoconus]. / Efficacité du cross-linking du collagène cornéen pour le traitement du kératocône.

Keratoconus (KC) is a complex disease whose pathophysiology is only partially understood. The priority in management is to halt the progression of corneal deformation as soon as possible in the course of KC disease. Corneal cross-linking (CXL) is at present the only dedicated treatment for this purpose. Its biochemical mechanism of action leads to changes in the viscoelastic properties of the cornea induced by matrix bonding and renewal of keratocytes. The effect of CXL is difficult to quantify when measured in in-vivo conditions because of a lack of consistent tools adapted for clinical practice. Nevertheless, a large amount of evidence has been collected so far confirming the positive action of CXL on corneal structural reinforcement, and numerous studies have demonstrated significant efficacy in halting progression of KC with long-term follow-up. Published studies, however, are of relatively low scientific power given the great heterogeneity of the disease and the numerous associated biases in evaluation. The purpose of this paper is to summarize the consistent evidence of efficacy of CXL and to justify its role in our therapeutic armamentarium for management of progressive KC.

[High myopic patients: A survey of their history, feelings, beliefs and needs]. / Enquête sur l'histoire, le ressenti, les croyances et les besoins des patients myopes forts.

BACKGROUND AND OBJECTIVES: High myopia (HM), which affects 0.9 to 3.1% of the population, is a major cause of vision loss. The purpose of this investigation was to study and evaluate the impact of their high myopia on the daily lives of patients and to better understand their expectations in order to better meet their needs. MATERIALS AND METHODS: The survey was conducted between February 19 and March 21, 2014. To be eligible, patients had to have myopia of at least -8 diopters and be over 40 years of age, with or without myopic complications. Patients' degree of myopia was defined as the optical prescription of their worse eye. The 123 patients included were interviewed by phone using a questionnaire developed and validated by a scientific committee composed of experts and members of the patients' Association against myopic maculopathy (AMAM). The phone interview, semi-structured, lasted 20 minutes. RESULTS: On average, myopia was -11.7 diopters. Women accounted for 71% of the population, 89% of patients were under 65 years and were mostly professionals (65%). Over half of the subjects reported myopic complications; 5% of patients had choroidal neovascularization (CNV). Only 29% had been informed of the risk of CNV or maculopathy. HM was a handicap in sports for 64% of patients, in leisure activities for 51%, and in professional activities for more than a quarter (28%). Only 56% of HM patients reported living perfectly well with their condition. CONCLUSIONS: This survey is the first study on the daily life of people with HM aiming to analyze their social and emotional environment. It shows that HM has a profound impact on the daily lives of patients and may affect social life and professional activity. Most myopic patients possess incomplete or unclear information about the nature and risk of myopic complications. They expressed the desire to be better informed about their condition earlier, before the onset of complications.

Visual Impairment Screening at the Geriatric Frailty Clinic for Assessment of Frailty and Prevention of Disability at the Gérontopôle.

OBJECTIVES: To evaluate visual performance and factors associated with abnormal vision in patients screened for frailty at the Geriatric Frailty Clinic (GFC) for Assessment of Frailty and Prevention of Disability at Toulouse University Hospital. DESIGN: Retrospective, observational cross-sectional, single-centre study. SETTING: Institutional practice. PARTICIPANTS: Patients were screened for frailty during a single-day hospital stay between October 2011 and October 2014 (n = 1648). MEASUREMENTS: Collected medical records included sociodemographic data (including living environment and educational level), anthropometric data, and clinical data. The general evaluation included the patient's functional status using the Activities of Daily Living (ADL) scale and the Instrumental Activity of Daily Living (IADL) scale, the Mini-Mental State Examination (MMSE) for cognition testing, and the Short Physical Performance Battery (SPPB) for physical performance. We also examined Body Mass Index (BMI), the Mini-Nutritional Assessment (MNA), and the Hearing Handicap Inventory for the Elderly Screening (HHIE-S) tool. The ophthalmologic evaluation included assessing visual acuity using the Snellen decimal chart for distant vision, and the Parinaud chart for near vision. Patients were divided into groups based on normal distant/near vision (NDV and NNV groups) and abnormal distant/near vision (ADV and ANV groups). Abnormal distant or near vision was defined as visual acuity inferior to 20/40 or superior to a Parinaud score of 2, in at least one eye. Associations with frailty-associated factors were evaluated in both groups. RESULTS: The mean age of the population was 82.6 ± 6.2 years. The gender distribution was 1,061 females (64.4%) and 587 males (35.6%). According to the Fried criteria, 619 patients (41.1%) were pre-frail and 771 (51.1%) were frail. Distant and near vision data were available for 1425 and 1426 patients, respectively. Distant vision was abnormal for 437 patients (30.7%). Near vision was abnormal for 199 patients (14%). Multiple regression analysis showed that abnormal distant vision as well as abnormal near vision were independently associated with greater age (P < 0.01), lower educational level (P < 0.05), lower performance on the MMSE (P < 0.001), and lower autonomy (P < 0.02), after controlling for age, gender, educational level, Fried criteria, and MMSE score. CONCLUSION: The high prevalence of visual disorders observed in the study population and their association with lower autonomy and cognitive impairment emphasises the need for systematic screening of visual impairments in the elderly. Frailty was not found to be independently associated with abnormal vision.

Overexpression of vascular endothelial growth factor induces cell transformation in cooperation with fibroblast growth factor 2.

Vascular endothelial growth factor (VEGF) is a family of homodimeric proteins produced from a single gene by alternative splicing of the VEGF transcript. VEGF induces in vivo angiogenesis and vascular permeability. We have recently demonstrated that VEGF is an autocrine growth factor for retinal pigment epithelial (RPE) cells. To further understand the role of VEGF, we overexpressed VEGF in rat RPE cells. The transfected cells exhibited a growth advantage in vitro and an increased response to the mitogenic effect of fibroblasts growth factor-2 (FGF-2), and formed colonies in soft agar upon FGF-2 addition. Moreover, analysis of FGF-receptors evidenced a dramatic increase in FGFR-1 mRNA and protein level, supporting the hypothesis that this receptor mediates the transforming effect of FGF-2. These results reveal that the oncogenic role of VEGF is exerted through a cross regulation between VEGF and FGF signal transduction pathways.

[What were the obstacles to the development of outpatient cataract surgery in Toulouse University Hospital in 2013?]. / Quels obstacles au développement de la chirurgie ambulatoire de la cataracte au CHU de Toulouse en 2013?

INTRODUCTION: Cataract surgery is an ideal candidate for outpatient care. In 2013, in the Toulouse University Hospital, outpatient care rate for phacoemulsification was 75.8%. We conducted this study to identify the barriers that limit the development of outpatient cataract surgery in our establishment. MATERIAL AND METHODS: A retrospective observational study was conducted. We included all patients who underwent phacoemulsification (Medical Act Code BFGA004) as a traditional inpatient in 2013. We excluded admissions for which the medical, anesthesia or nursing records, as well as scheduling sheets, were incomplete. Patients were classified according to the reason for inpatient hospitalization and the type of surgery: cataract as primary surgery or cataract as combined procedure. RESULTS: Two hundred and ninety-eight stays were included with a mean age of 66.8 ± 16.8 years, and a male/female ratio of 0.76. The indication for inpatient hospitalization was a social, surgical or anesthetic reason in the following respective proportions: 41, 34 and 8% of cases. Failure of ambulatory care represented 7% of cases. Social isolation represented 89% of social reasons. In a combined gesture, the reason was surgical in 89% of cases. CONCLUSION: Development of outpatient surgery requires the participation of all involved. Taking into account the social factors is an essential element for developing ambulatory surgery. Social isolation is a frequent situation requiring a societal response. With regard to surgical considerations, practice patterns must target outpatient combined procedures in particular.

Peptides derived from the dependence receptor ALK are proapoptotic for ALK-positive tumors.

ALK is a receptor tyrosine kinase with an oncogenic role in various types of human malignancies. Despite constitutive activation of the kinase through gene alterations, such as chromosomal translocation, gene amplification or mutation, treatments with kinase inhibitors invariably lead to the development of resistance. Aiming to develop new tools for ALK targeting, we took advantage of our previous demonstration identifying ALK as a dependence receptor, implying that in the absence of ligand the kinase-inactive ALK triggers or enhances apoptosis. Here, we synthesized peptides mimicking the proapoptotic domain of ALK and investigated their biological effects on tumor cells. We found that an ALK-derived peptide of 36 amino acids (P36) was cytotoxic for ALK-positive anaplastic large-cell lymphoma and neuroblastoma cell lines. In contrast, ALK-negative tumor cells and normal peripheral blood mononuclear cells were insensitive to P36. The cytotoxic effect was due to caspase-dependent apoptosis and required N-myristoylation of the peptide. Two P36-derived shorter peptides as well as a cyclic peptide also induced apoptosis. Surface plasmon resonance and mass spectrometry analysis of P36-interacting proteins from two responsive cell lines, Cost lymphoma and SH-SY5Y neuroblastoma, uncovered partners that could involve p53-dependent signaling and pre-mRNA splicing. Furthermore, siRNA-mediated knockdown of p53 rescued these cells from P36-induced apoptosis. Finally, we observed that a treatment combining P36 with the ALK-specific inhibitor crizotinib resulted in additive cytotoxicity. Therefore, ALK-derived peptides could represent a novel targeted therapy for ALK-positive tumors.

Adenovirus-mediated suicide gene transduction: feasibility in lens epithelium and in prevention of posterior capsule opacification in rabbits.

The most common complication of cataract surgery is the development of posterior capsule opacification (PCO). Hyperplasia of the lens epithelium is one of the main cellular events following phacoemulsification, and has been found to be an important feature contributing to opacification of the posterior capsule. Adenoviral vector-mediated transfer is a suitable method for transducing the herpes simplex virus thymidine kinase gene (HSV-tk) into proliferating cells, allowing for the selective killing of these cells by ganciclovir (GCV) treatment. To determine the potential of gene transduction for lens epithelial cells, we studied the transduction of rabbit lens epithelial cells with adenoviral vectors containing either the Escherichia coli beta-galactosidase (lacZ) gene or the HSV-tk gene in vitro and in vivo in an experimental model of PCO. The efficiency of lacZ gene transfer in rabbit lens epithelial cells was at least 95% both in vitro and in vivo. In vivo transduction with HSV-tk adenoviral vector followed by GCV treatment significantly inhibited the development of PCO (p<0.001). These results suggest that adenoviral vector-mediated transfer of HSV-tk into the proliferating lens epithelial cells is feasible and may provide a novel therapeutic strategy for PCO.

The major myristoylated PKC substrate (MARCKS) is involved in cell spreading, tyrosine phosphorylation of paxillin, and focal contact formation.

The expression of the myristoylated PKC substrate MARCKS is reduced in tumor-derived choroidal melanoma cells (OCM-1). We transfected the OCM-1 cells with MARCKS cDNA and we selected clones with stable overexpression of the protein. Tyrosine phosphorylation of paxillin, a biochemical marker of focal contact formation, was conserved upon serum starvation when MARCKS was overexpressed, while it was almost abolished in the control cells. Immunofluorescent labelling of paxillin and vinculin, another component of focal contact, revealed that these structures were conserved upon serum starvation when MARCKS was overexpressed but not in the control cells. Furthermore, the cell morphology was affected by the ectopic expression of MARCKS, leading to increased spreading and formation of membrane processes. These data suggest the involvement of MARCKS in cell spreading and focal contact formation.

G1 phase arrest by the phosphatidylinositol 3-kinase inhibitor LY 294002 is correlated to up-regulation of p27Kip1 and inhibition of G1 CDKs in choroidal melanoma cells.

We have investigated the effect of the flavonoid derivative LY 294002, a potent and selective phosphatidylinositol 3-kinase inhibitor, on cell cycle progression in human choroidal melanoma cells. We demonstrate that LY 294002 induces a specific G1 block in asynchronously growing cells leading to an almost complete inhibition of cell proliferation after three days of treatment. When melanoma cells are released from a nocodazole-induced G2/M block, LY 294002 is shown to delay and greatly restrain the G1/S transition. The inhibitor is able to exert its action as long as it is added during the G1 progression and before the cells enter in S phase. We report that the LY 294002-induced G1 arrest is closely correlated to inhibition of CDK4 and CDK2 activities leading to the impairment of pRb phosphorylation which normally occurs during G1 progression. While the inhibition of CDK4 may be attributed at least in part to the decline in CDK4 protein level, CDK2 activity reduction is rather due to the up-regulation of the CDK inhibitor p27Kip1 and to its increased association to CDK2.

Cyclin-dependent kinase inhibitory protein expression in human choroidal melanoma tumors.

PURPOSE: Recent studies have demonstrated the close link between oncogenesis and cell cycle machinery. Cyclin-dependent kinase inhibitory proteins (CKIs) have been shown to play a critical role in the regulation of cell cycle progression. Alteration of CKI levels and/or functions could be implicated in cell transformation. The three CKIs-p16, p21, and p27-were investigated in human uveal melanoma tumors, and an attempt was made to correlate their levels with clinicopathologic parameters, as well as to p53 and Ki-67 (Mib-1) protein levels. METHODS: Immunochemistry was performed on 32 formalin-fixed, paraffin-embedded specimens of malignant choroidal melanoma. Immunoblot was performed to confirm the immunochemistry study. Prognostic histologic markers such as cell typing, pigmentation, larger tumor dimension, mitotic figures, nucleolar size, scleral invasion, and optic nerve head invasion were reported. RESULTS: Nuclear positivity for p16 was observed in 11 tumors (34%) without any association with clinicopathologic parameters. Tumor cells positive for p21 were detected in 12 choroidal melanomas (37%). Unexpectedly, a positive relationship was seen between p21 and scleral invasion (P: = 0.008). Nuclear positivity for p27 was observed in nine tumors (28%). An inverse correlation was observed between the number of mitotic figures and p27 immunoreactivity (P: = 0.03), as well as between Mib-1 positivity and p27 expression (P: = 0.02). Western blot assays of tumor extracts confirmed overexpression of p21 and p27. CONCLUSIONS: The results suggest that p21 and p27 may be involved in tumorigenesis in choroidal melanoma.

Vasculotropin-VEGF stimulates retinal capillary endothelial cells through an autocrine pathway.

PURPOSE: To determine whether bovine retinal endothelial cells (BRECs) bind, synthesize, and respond to vasculotropin-vascular endothelial growth factor (VAS-VEGF). METHODS: Cultured BRECs were tested for their ability to bind 125I VAS-VEGF and their response to the growth and migration-promoting effect of VAS-VEGF. Total RNAs extracted from BRECs were reverse transcribed and amplified by polymerase chain reaction using VAS-VEGF primers. The translation was assessed by a Western blot analysis and a radioreceptor assay in the BREC-conditioned medium. Neutralization with anti-VAS-VEGF antibodies ascertained the autocrine role of VAS-VEGF. RESULTS: BRECs bind VAS-VEGF on two high-affinity binding sites (apparent Kd of 2 and 56 pM) and can proliferate and migrate upon the addition of recombinant VAS-VEGF. Furthermore, BRECs synthesize and secrete into their own culture medium a mitogen related to VAS-VEGF as far as two factors are concerned: chromatographic behavior on heparin-affinity columns, and cross-reactivity with recombinant VAS-VEGF to the binding to its receptors or antibodies. Neutralization of the purified conditioned medium with anti-VAS-VEGF antibodies revealed that VAS-VEGF can act on BRECs through an autocrine pathway. CONCLUSIONS: This is the first description of an autocrine regulation of endothelial cell growth by VAS-VEGF that could be involved in the pathogenesis of retinal neovascularization.

Differential expression of G1 cyclins and cyclin-dependent kinase inhibitors in normal and transformed melanocytes.

PURPOSE: To investigate the levels of the different regulatory proteins involved in the G1 progression and G1/S transition in normal and transformed human choroidal melanocytes (CM). METHODS: Three choroidal melanoma cell lines and three CM cultures were used. The purity of the CM cultures was assessed by different approaches, including morphologic study, specific immunostaining, cell proliferation behavior, and transforming growth factor-beta1 responsiveness. The cell cycle protein levels were evaluated by specific immunoblotting of total extracts obtained from the different cell lines. RESULTS: Alterations were observed in the expression of cylins D1 and E in the transformed cells, whereas the amounts of the cyclin-dependent kinases (CDKs) CDK2 and CDK4 were almost identical in both cell types. Although the expression of cyclin H was slightly increased in transformed cells, neither the CDK7 level nor the CDK7 and cyclin H localizations were altered when compared with those in normal CM. The results suggest the absence of the CDK inhibitor (CKI) p21 in two of the three melanoma cell lines and, as a main feature, a striking underexpression of p27 in the three transformed cell lines. Finally, although the p16 level was almost the same in normal and transformed cells, a loss of p16-CDK4 interaction was observed in two of the three melanoma cell lines. CONCLUSIONS: Deregulated expression of G1 cyclins and CKIs and alteration in the interaction of CKIs with CDKs may be implicated in the neoplastic transformation of human ocular melanocytes to malignant melanoma cells.