Effects of anti-glaucoma medications on gangion cell survival: the DBA/2J mouse model

AbstractWe studied whether several agents, approved or undergoing trials in human glaucoma, were effective in preventing ganglion cell loss in the DBA/2J mouse. Adult DBA/2J mice were treated with timolol, pilocarpine, brimonidine, dorzolamide, or NMDA-receptor antagonist memantine. Surviving retinal ganglion cells of treated and control mice were retrogradely labeled with fluorogold and counted after whole mount preparation. In treated mice, only memantine and timolol had significant effects on retinal ganglion cell survival (P<0.0001, analysis of variance). Brimonidine was lethal to these mice, and these retinae were not analyzed further. The DBA/2J mouse represents a promising candidate for further experimentation in ocular hypertension

Novel mutations of FOXC1 and PITX2 in patients with Axenfeld-Rieger malformations. Invest Ophthalmol Vis Sci 47

PURPOSE. To determine the prevalence of FOXC1 and PITX2 mutations and to assess clinical phenotypes in a cohort of German patients with Axenfeld-Rieger malformations. METHODS. All coding exons of the FOXC1 and PITX2 genes were amplified by PCR from genomic DNA and subjected to direct DNA sequencing. Analysis of mutations in control subjects was performed by restriction fragment length polymorphism (RFLP) analysis. RESULTS. Sequence variants were identified by DNA sequencing in 15 of 19 cases. Mutation screening identified four potentially pathogenic FOXC1 mutations causing amino acid substitutions (P79R, Y115S, G149D, and M161V) that were not present in 100 control subjects. In addition, two different 1-bp deletions causing a frameshift and subsequent premature stop codon were identified in two subjects. One patient harbored a FOXC1 nonsense mutation (S48X). Mutation screening also identified two potentially pathogenic PITX2 mutations (P64L and P64R) in two index patients that were excluded in 100 healthy control subjects. CONCLUSIONS. The findings in the present study clearly demonstrate that FOXC1 and PITX2 mutations are responsible for a significant proportion of Axenfeld-Rieger malformations in Germany. (Invest Ophthalmol Vis Sci. 2006;47:3846 -3852) DOI:10.1167/iovs.06-0343 A xenfeld-Rieger (AR) malformations comprise a series of clinically and genetically heterogeneous conditions. Affected individuals display a spectrum of classic ocular anomalies such as iris hypoplasia; a prominent Schwalbe line; adhesion of iris and cornea, microcornea, and corneal opacity, and increased intraocular pressure (IOP). In addition to the ocular phenotype, systemic features may also be associated with the disorder, including maxillary hypoplasia, hypodontia, microdontia, umbilical abnormalities, hearing defects, and congenital cardiac or kidney abnormalities. 1 These syndromic features are seen with incomplete penetrance and variable expressivity. Because of the severe changes in eye morphology, glaucoma develops in roughly half of all patients. The mode of inheritance is autosomal dominant and the incidence of the disease is estimated to be approximately 1:200,000. 2 Until now, four genetic loci have been associated with AR, including the genes FOXC1 and PITX2 located on 6p25 and 4q25, respectively. 3,4 A third locus was mapped to 13q14, but the gene has not yet been identified. 3,10 -20 The mutation spectrum comprises frameshift and nonsense as well as missense mutations in the forkhead domain (for an overview, see 23 From experimental data it seems likely that the molecular basis of tooth anomalies in AR is the inability of mutant PITX2 to activate genes involved in tooth morphogenesis, 25 To date, 30 mutations of the PITX2 gene have been associated with AR 4,26 -33 and other cases of anterior segment malformations, such as iridogoniodysgenesis, 34 iris hypoplasia, 37 The purpose of this study was to determine the prevalence of FOXC1 and PITX2 mutations in a cohort of German patients with AR malformations. MATERIALS AND METHODS Ascertainment of Patients and Clinical Evaluation Written informed consent was obtained from all subjects, and the study was approved by the ethics committees of the University Hospital Tübingen and the University Hospital Würzburg and conducted in accordance with the Declaration of Helsinki. Ophthalmic examinations included slit lamp biomicroscopy, gonioscopy, and measurement of intraocular pressure (IOP), visual acuity, and visual fields. Diagnosis of hypodontia was based on panoramic radiographs. Other diagnoses were obtained from the patients&apos; attending specialists. Mutation Detection by Direct Sequencing Patient DNA was extracted from peripheral blood lymphocytes using a standard salting-out procedure. Individual exons of the PITX2 gene were amplified by polymerase chain reaction (PCR) using appropriate amplification protocols. Amplification of the single FOXC1 exon was performed with a set of four overlapping primers. Primer pairs for amplification and sequencing are available on request. PCR fragments were purified (ExoSAP-IT enzyme cleanup; USB, Cleveland, OH) and From th

Neuroprotective effects of cardiotrophin-like cytokine on retinal ganglion cells

Premature neuronal cell death is a feature of numerous central nervous system and eye diseases, including glaucoma. Neurons (including retinal ganglion cells, RGCs) are protected by several neurotrophic factors, among those the IL-6 family of cytokines. Lately, a novel member of the IL-6 family of cytokines has been identified and cloned. This cytokine is known as novel neurotrophin-1/B-cell-stimulating factor-3 (NNT-1/BSF-3) or cardiotrophin-like cytokine (CLC). It shows neurotrophic as well as B-cell stimulatory effects.In this study, the neuroprotective properties of CLC on RGC loss in vivo were investigated.CLC significantly protected RGCs from degeneration in both chosen models of retinal neuronal damage: optic nerve crush (P<0.01) and N-methyl-D-aspartate (NMDA) injection (P<0.001).CLC shows neuroprotective effects on RGCs in vivo and might be a treatment option for chronic neurodegenerative eye diseases such as glaucoma. Clinical feasibility for the substance requires further investigation since the immunomodulatory and possible adverse effects have not yet been thoroughly characterized