Positive feedback regulation between MMP-9 and VEGF in human RPE cells

PURPOSE: The proteolytic activity of matrix metalloproteinases (MMPs) is involved in pathologic angiogenesis in the eye. However, it is unknown whether MMPs may stimulate the production of the major angiogenic factor, vascular endothelial growth factor (VEGF). The authors investigated whether MMP-2 and MMP-9 alter the expression of VEGF by retinal pigment epithelial (RPE) cells. They also sought to determine the effects of MMPs on cellular proliferation and migration and the effect of triamcinolone acetonide on MMP-9-evoked cellular responses. METHODS: Human RPE cell cultures were stimulated with MMP-2 or MMP-9. The gene expression and secretion of MMP-9 and VEGF were determined by real-time RT-PCR and ELISA, respectively. Cellular proliferation was investigated with a bromodeoxyuridine immunoassay, and chemotaxis was examined with a Boyden chamber assay. RESULTS: Under control conditions, RPE cells in vitro expressed a significantly higher amount of mRNA for MMP-2 than for MMP-9. Chemical hypoxia caused upregulation of the gene expression of both MMPs, whereas VEGF increased the gene expression and secretion of MMP-9. The hypoxic expression of MMP-9 was mediated by autocrine VEGF signaling. Exogenous MMP-9 increased the gene expression and secretion of VEGF, whereas MMP-2 reduced the secretion of VEGF. MMP-2 and MMP-9 did not alter the proliferation but stimulated the migration of RPE cells. Triamcinolone fully inhibited the stimulatory effect of MMP-9 on the expression of VEGF and the VEGF-evoked increase in the expression of MMP-9. However, triamcinolone had no effect on the motogenic effect of MMP-9. CONCLUSIONS: There is a positive feedback regulation between MMP-9 and VEGF in RPE cells. The hypoxic expression of MMP-9 may stimulate the production and secretion of VEGF under pathologic conditions. Triamcinolone inhibits the positive feedback regulation between MMP-9 and VEGF under hypoxic conditions through inhibition of the gene expression of MMP-9 and the secretion of VEGF.     

Long-term results of surgery in childhood glaucoma

Purpose The aim of this study is to assess the functional results and morphological parameters in children surgically treated for glaucoma. Methods Data from 43 patients and 68 eyes who were operated in our department between 1990 and 2002 were collected. This retrospective trial included primary congenital glaucoma (n=36), and secondary glaucoma (n=7) in Rieger-Axenfeld syndrome and Sturge Weber syndrome. Intraocular pressure (IOP), axial length of the eyeball, visual acuity, refractive errors and orthoptic status were analysed. Results The age of patients at the first surgery was 6.0±5.3 months (range 0.7 to 28.0 months). The mean period of follow-up was 57.3±36.8 months (6.0–161.0).The mean number of surgical procedures performed on one eye was 2.5±2.4 procedures (1–11). The mean IOP before the first surgery was 31.0±7.9 mmHg (17.5–52.0), and was 15.0±3.9 mmHg (7.0–28.0) at the last visit. 49 eyes (72.1%) did not need any further medical treatment after the last surgical procedure. The IOP was 18 mmHg or lower without medication in 29 eyes (42.6%) after just one surgical procedure (21 trabeculotomy, 8 combined trabeculotomy/trabeculectomy with or without mitomycin-C). At the first examination, the mean axial length of the eyeball was 22.6±1.8 mm (the mean normal value at this age is 20.3±0.7 mm), and was 24.4±2.0 mm at the last visit (the mean normal value at this age is 22.2±0.6 mm). The best corrected visual acuity at the last visit was 0.25±4.6 lines; the normal range of visual acuity at this age is from 0.4±4.0 lines to 0.8±3.0 lines. Visual acuity was 0.32 or more in 53.0% of the eyes. Visual acuity was lower than 0.1 in only 15.2% of the eyes. Myopia was present in 57.4% of the eyes with a mean spherical equivalent of −6.1±3.9 dioptres. 15 patients (34.9%) developed strabismus. 22 patients (51.2%) were treated with part-time occlusion. Binocular function as assessed with the Lang-1 test was positive in 17 of 30 patients (56.7%). Conclusions Although a good long-term IOP-control can often be achieved in childhood glaucoma, the visual acuity remains below the normal range in most cases despite close orthoptic follow-up. Excerpts presented at the meeting of the German Society of Ophthalmology (DOG), Berlin, 2004.     

Comparison of visual acuity measurements and Purkinje's vessel shadow perception for prediction of postoperative visual acuity in different ophthalmological diseases

PURPOSE: Prediction of postoperative visual acuity (VA) is extremely important to the patient and highly relevant to the surgeon. However, objective evaluation of the macula is frequently impossible in cases such as mature cataract, cataract in high myopia or vitreous haemorrhage. This study compares different preoperative examination techniques used to predict postoperative VA. METHODS: We retrospectively evaluated the charts of all patients who underwent any of the following procedures at our hospital in 2004: phacoemulsification for mature cataract or cataract in high myopia; vitrectomy for diabetic vitreous haemorrhage; macular pucker, and macular hole. The following methods were evaluated: preoperative distance and reading VA; laser interferential VA; Purkinje's vessel shadow perception, and postoperative distance VA. RESULTS: Complete documentation was available for 136 patients (29 mature cataracts, 25 immature cataracts in high myopia, 42 vitreous haemorrhages, 19 macular puckers, 21 macular holes). In cases of preoperative mature cataract, a positive Purkinje's vessel shadow perception predicted a postoperative VA >or= 20/50 (odds ratio 11.2). In cases of high myopia, interferential VA correlated best with visual outcome (p < 0.05). In macular surgery laser interferential VA predicted postoperative VA to be better and preoperative reading VA predicted it to be worse than it actually turned out after surgery. Laser interferential VA and last known VA prior to vitreous haemorrhage (mean of 20 months previously) correlated best with postoperative VA (p < 0.05) in cases of vitreous haemorrhage. Purkinje's vessel shadow perception--if positive--predicted a postoperative VA >or= 20/300 in these cases (odds ratio 15.0). CONCLUSIONS: Postoperative VA after vitrectomy for macular pucker or macular hole and in cases of cataract in high myopia is best predicted by laser interferential VA. Postoperative VA after vitrectomy for diabetic vitreous haemorrhage is best predicted by prehaemorrhage VA or laser interferential VA, especially when prehaemorrhage VA is unknown. Positive Purkinje's vessel shadow perception is an excellent method of predicting postoperative VA >or= 20/300 in cases of vitreous haemorrhage and VA = 20/50 in mature cataract.     

Autoantibodies to bullous pemphigoid antigen 180 induce dermal-epidermal separation in cryosections of human skin

Bullous pemphigoid is a subepidermal autoimmune blistering disease associated with autoantibodies to the hemidesmosomal bullous pemphigoid antigens 180 and 230. Most sera from bullous pemphigoid patients recognize epitopes within the N-terminal NC16A portion of the bullous pemphigoid 180 ectodomain. Using cryosections of human skin, patients' sera were shown to generate dermal-epidermal separation when coincubated with leukocytes and complement from healthy volunteers; however, the specificity of pathogenic autoantibodies in bullous pemphigoid patients has not yet been elucidated. In this study, by the use of a modified version of the cryosection model, we show that sera from all of 13 bullous pemphigoid patients and from two rabbits, immunized against bullous pemphigoid 180 NC16A, induced dermal-epidermal separation. This finding was confirmed with the use of IgG purified from patients' sera, whereas sera and purified IgG from healthy controls were not pathogenic. The induction of subepidermal splits in this experimental model was shown to be dependent on the presence of neutrophils, but not complement. Interestingly, patients' autoantibodies affinity purified against a recombinant form of bullous pemphigoid 180 NC16A retained their blister-inducing capacity, whereas patients' IgG depleted of reactivity to NC16A lost this ability. F(ab')2 fragments of antibodies specific to NC16A, lacking the Fc portion, did not induce splits. In addition, patients' autoantibodies purified against a recombinant fragment of the C-terminus of bullous pemphigoid 180 as well as rabbit antibodies to the intracellular portion of bullous pemphigoid 180 and to bullous pemphigoid 230 did not cause dermal-epidermal separation. Our in vitro results support the idea that autoantibodies to bullous pemphigoid 180 from patients with bullous pemphigoid are of pathogenic relevance.     

Sorafenib, but not sunitinib, affects function of dendritic cells and induction of primary immune responses

The tyrosine kinase inhibitors sorafenib and sunitinib are approved for the treatment of patients with malignant diseases. To analyze the possible use of these compounds in combination with immunotherapeutic approaches, we analyzed the effects of both inhibitors on the immunostimulatory capacity of human dendritic cells (DCs) and the induction of primary immune responses in vivo. Sorafenib, but not sunitinib, inhibits function of DCs, characterized by reduced secretion of cytokines and expression of CD1a, major histocompatibility complex, and costimulatory molecules in response to TLR ligands as well as by their impaired ability to migrate and stimulate T-cell responses. These inhibitory effects are mediated by inhibition of PI3 and MAP kinases and NFB signaling. In contrast, sorafenib had no influence on the phenotype and proliferation of T cells. To analyze the effects of both TKIs on cytotoxic T-cell induction in vivo, C57BL/6 mice were pretreated with sorafenib or sunitinib and immunized with OVA_257-264 peptide. Sorafenib, but not sunitinib, application significantly reduced the induction of antigen-specific T cells. Numbers of regulatory T cells were reduced in peripheral blood mononuclear cells from mice treated with sunitinib. These results indicate that sunitinib, but not sorafenib, is suitable for combination with immunotherapeutic approaches for treatment of cancer patients.     

Obsessive–Compulsive Disorder is Characterized by a Lack of Adaptive Coping Rather than an Excess of Maladaptive Coping

The present study aimed to elucidate the profile of coping in patients with obsessive–compulsive disorder (OCD) in order to discern whether the disorder is characterized by an excess of maladaptive coping skills and/or a lack of adaptive coping skills. Sixty individuals with OCD were compared with 110 individuals with depression and 1050 nonclinical controls on the Maladaptive and Adaptive Coping Styles Questionnaire (MAX). Psychopathology was assessed with the Obsessive–Compulsive Inventory-Revised (OCI-R), the Yale-Brown Obsessive–Compulsive Scale (Y-BOCS), and the Patient Health Questionnaire-9 for depression (PHQ-9). Individuals with OCD and depression displayed more maladaptive coping and avoidance as well as less adaptive coping than nonclinical controls. Importantly, adaptive coping was significantly lower in individuals with OCD than in those with depression at a medium effect size, whereas the clinical groups were indistinguishable on maladaptive coping and avoidance. Lack of adaptive coping was strongly correlated with resistance to symptoms and poor insight in OCD (Y-BOCS), even after controlling for depression. Lack of adaptive coping skills may represent a specific pathogenetic factor in OCD. Longitudinal studies need to clarify whether strengthening adaptive skills during childhood and adolescence may help to prevent the progression from subclinical to manifest OCD.