Genetic association of ANGPT2 with primary open-angle glaucoma.

BACKGROUND: To determine the association of the ANGPT2 gene with primary open-angle glaucoma (POAG) in Chinese. METHODS: Six single-nucleotide polymorphisms (SNPs) in ANGPT2 (rs2515487, rs2922869, rs13255574, rs4455855, rs13269021, and rs11775442) were genotyped in a total of 2601 study subjects from two cohorts. One is a Hong Kong Chinese cohort of 484 high tension glaucoma (HTG) and 537 normal tension glaucoma (NTG) patients, and 496 non-glaucoma control subjects. Another cohort is a Shantou Chinese cohort of 403 HTG and 135 NTG patients, and 543 non-glaucoma control subjects. Subgroup analysis by sex was conducted. Outcomes from different cohorts were combined for meta-analysis. RESULTS: The association of SNP rs11775442 with NTG in the Hong Kong cohort [P = 0.0498, OR = 1.24, 95% confidence interval (CI) 1.00-1.55] after adjusting for age and sex did not reach statistical significance after Bonferroni correction. Other SNPs were not significantly associated with NTG, HTG and POAG in individual cohort or in the combined analyses (P > 0.05). In the subgroup analysis by sex, SNP rs13269021 in the Shantou cohort, but not in the Hong Kong cohort, was significantly associated with NTG in males (P = 0.0081, OR = 1.67, 95% CI: 1.14-2.43) but not in females (P = 0.874). In the combined analyses by sex, no SNPs were significantly associated with NTG, HTG and POAG. CONCLUSIONS: In the subgroup analysis by sex, a significant association was shown in SNP rs13269021 with NTG in Shantou males, but not in Hong Kong males. Further studies are needed to verify the association between ANGPT2 locus (rs13269021) and NTG in Chinese males.

A Cohesin Subunit Variant Identified from a Peripheral Sclerocornea Pedigree.

BACKGROUND: Sclerocornea is a rare congenital disorder characterized with the opacification of the cornea. Here, we report a nonconsanguineous Chinese family with multiple peripheral sclerocornea patients spanning across three generations inherited in an autosomal dominant manner. METHODS: This is a retrospective case series of a peripheral sclerocornea pedigree. Comprehensive ophthalmic examinations were conducted and assessed on 14 pedigree members. Whole-exome sequencing was used to identify the genetic alterations in the affected pedigree members. Lymphoblastoid cell lines (LCLs) were established using blood samples from the family members. Functional tests were performed with these cell lines. RESULTS: Six affected and eight unaffected members of a family with peripheral sclerocornea were examined. All affected individuals showed features of scleralization over the peripheral cornea of both eyes. Mean horizontal and vertical corneal diameter were found significantly decreased in the affected members. Significant differences were also observed on the mean apex pachymetry between affected and unaffected subjects. These ophthalmic parameters did not resemble that of cornea plana. A RAD21C1348T variant was identified by whole-exome sequencing. Although this variant causes RAD21 R450C substitution at the separase cleavage site, cells from peripheral sclerocornea family members had no mitosis and ploidy defects. CONCLUSION: We report a family of peripheral sclerocornea with no association with cornea plana. A RAD21 variant was found cosegregating with peripheral sclerocornea. Our results suggest that RAD21 functions, other than its cell cycle and chromosome segregation regulations, could underline the pathogenesis of peripheral sclerocornea.

Coding Region Mutation Screening in Optineurin in Chinese Normal-Tension Glaucoma Patients.

PURPOSE: To study the roles of sequence alterations in the optineurin (OPTN) gene-coding region in normal-tension glaucoma (NTG) among Chinese patients. METHODS: Genomic DNA was extracted from 190 NTG patients and 201 control subjects. The thirteen exons of OPTN were amplified by polymerase chain reaction and analyzed by direct sequencing. Detected sequence changes were compared between NTG patients and control subjects. RESULTS: Seven sequence changes in OPTN were identified in both NTG patients and control subjects. Among them, c.464G>A (T34 T), c.509C>T (T49T), c.806G>A (V148V), and c.959T>C (P199P) were synonymous codon changes, whilst c.655T>A (M98K), c.1996G>A (R545Q), and c.1582T>C (I407T) were missense changes. Two previously reported heterozygous mutations, c.458G>A (E50K) in exon 4 and c.691_692insAG in exon 6, were not found in this study. Out of these seven OPTN sequence variants, c.464G>A (T34T) was significantly associated with NTG in both the allelic and genotypic association analyses (allelic association: p = 0.0001, OR = 2.20, 95% CI: 1.46-3.31; genotypic association: p = 0.0001), whereas the association of other variants with NTG did not reach statistical significance (p > 0.05). Variants c.1582 T>C (I407T) and c.806G>A (V148V) were identified in one and two NTG patients, respectively, but not in the control subjects. CONCLUSIONS: This study confirmed the association of the OPTN T34T variant with NTG, suggesting that OPTN is a susceptibility gene for NTG in Chinese. Moreover, a variant with amino acid change (I407T) was identified in NTG but not in controls. Further studies are warranted to assess whether this variant is a causative mutation for NTG.

Mutant RAMP2 causes primary open-angle glaucoma via the CRLR-cAMP axis.

PURPOSE: Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide and mutations in known genes can only explain 5-6% of POAG. This study was conducted to identify novel POAG-causing genes and explore the pathogenesis of this disease. METHODS: Exome sequencing was performed in a Han Chinese cohort comprising 398 sporadic cases with POAG and 2010 controls, followed by replication studies by Sanger sequencing. A heterozygous Ramp2 knockout mouse model was generated for in vivo functional study. RESULTS: Using exome sequencing analysis and replication studies, we identified pathogenic variants in receptor activity-modifying protein 2 (RAMP2) within three genetically diverse populations (Han Chinese, German, and Indian). Six heterozygous RAMP2 pathogenic variants (Glu39Asp, Glu54Lys, Phe103Ser, Asn113Lysfs*10, Glu143Lys, and Ser171Arg) were identified among 16 of 4763 POAG patients, whereas no variants were detected in any exon of RAMP2 in 10,953 control individuals. Mutant RAMP2s aggregated in transfected cells and resulted in damage to the AM-RAMP2/CRLR-cAMP signaling pathway. Ablation of one Ramp2 allele led to cAMP reduction and retinal ganglion cell death in mice. CONCLUSION: This study demonstrated that disruption of RAMP2/CRLR-cAMP axis could cause POAG and identified a potential therapeutic intervention for POAG.

New loci and coding variants confer risk for age-related macular degeneration in East Asians.

Age-related macular degeneration (AMD) is a major cause of blindness, but presents differently in Europeans and Asians. Here, we perform a genome-wide and exome-wide association study on 2,119 patients with exudative AMD and 5,691 controls, with independent replication in 4,226 patients and 10,289 controls, all of East Asian descent, as part of The Genetics of AMD in Asians (GAMA) Consortium. We find a strong association between CETP Asp442Gly (rs2303790), an East Asian-specific mutation, and increased risk of AMD (odds ratio (OR)=1.70, P=5.60 × 10(-22)). The AMD risk allele (442Gly), known to protect from coronary heart disease, increases HDL cholesterol levels by 0.17 mmol l(-1) (P=5.82 × 10(-21)) in East Asians (n=7,102). We also identify three novel AMD loci: C6orf223 Ala231Ala (OR=0.78, P=6.19 × 10(-18)), SLC44A4 Asp47Val (OR=1.27, P=1.08 × 10(-11)) and FGD6 Gln257Arg (OR=0.87, P=2.85 × 10(-8)). Our findings suggest that some of the genetic loci conferring AMD susceptibility in East Asians are shared with Europeans, yet AMD in East Asians may also have a distinct genetic signature.

Genetic variants at 13q12.12 are associated with high myopia in the Han Chinese population.

High myopia, which is extremely prevalent in the Chinese population, is one of the leading causes of blindness in the world. Genetic factors play a critical role in the development of the condition. To identify the genetic variants associated with high myopia in the Han Chinese, we conducted a genome-wide association study (GWAS) of 493,947 SNPs in 1088 individuals (419 cases and 669 controls) from a Han Chinese cohort and followed up on signals that were associated with p < 1.0 × 10(-4) in three independent cohorts (combined, 2803 cases and 5642 controls). We identified a significant association between high myopia and a variant at 13q12.12 (rs9318086, combined p = 1.91 × 10(-16), heterozygous odds ratio = 1.32, and homozygous odds ratio = 1.64). Furthermore, five additional SNPs (rs9510902, rs3794338, rs1886970, rs7325450, and rs7331047) in the same linkage disequilibrium (LD) block with rs9318086 also proved to be significantly associated with high myopia in the Han Chinese population; p values ranged from 5.46 × 10(-11) to 6.16 × 10(-16). This associated locus contains three genes-MIPEP, C1QTNF9B-AS1, and C1QTNF9B. MIPEP and C1QTNF9B were found to be expressed in the retina and retinal pigment epithelium (RPE) and are more likely than C1QTNF9B-AS1 to be associated with high myopia given the evidence of retinal signaling that controls eye growth. Our results suggest that the variants at 13q12.12 are associated with high myopia.

Ethnicity-based subgroup meta-analysis of the association of LOXL1 polymorphisms with glaucoma.

PURPOSE: To investigate the association and ethnic heterogeneity of lysyl oxidase-like 1 (LOXL1) single nucleotide polymorphisms (SNPs) with exfoliation syndrome (XFS)/exfoliation glaucoma (XFG) and other types of glaucoma. METHODS: We performed meta-analysis and ethnicity-based subgroup analyses according to published studies. Allele and genotype frequencies of SNPs rs1048661, rs2165241, and rs3825942 were extracted for analysis in Reviewer Manager: (1) comparison of the allelic distributions between XFS and XFG, (2) allelic association of LOXL1 SNPs with XFS/XFG, (3) associations in homozygote, heterozygote, and dominant and recessive models, and (4) allelic association with primary open angle glaucoma (POAG). RESULTS: In total 24 reported articles were retrieved, including Caucasian, African, Japanese, Indian, and Chinese populations. There was no significant difference in the distributions of rs1048661, rs2165241, and rs3825942 between XFS and XFG. The G allele of rs3825942 was the common at-risk allele for XFS/XFG in all populations with a total odds ratio (OR) of 10.89. The total homozygote OR of rs3825942 was 9.06 for XFS/XFG combined, but the total heterozygote OR was not significant. We also found that in the recessive model, the total OR was 14.70. There was no association of the three SNPs with POAG. CONCLUSIONS: The association of rs3825942, but not rs2165241 or rs1048661, with XFS/XFG is consistent in different ethnic populations in the recessive model. LOXL1 is not associated with POAG in all study populations.

AC and AG dinucleotide repeats in the PAX6 P1 promoter are associated with high myopia.

PURPOSE: The PAX6 gene, located at the reported myopia locus MYP7 on chromosome 11p13, was postulated to be associated with myopia development. This study investigated the association of PAX6 with high myopia in 379 high myopia patients and 349 controls. METHODS: High myopia patients had refractive errors of -6.00 diopters or greater and axial length longer than 26 mm. Control subjects had refractive errors less than -1.00 diopter and axial length shorter than 24 mm. The P1 promoter, all coding sequences, and adjacent splice-site regions of the PAX6 gene were screened in all study subjects by polymerase chain reaction and direct sequencing. PAX6 P1 promoter-luciferase constructs with variable AC and AG repeat lengths were prepared and transfected into human ARPE-19 cells prior to assaying for their transcriptional activities. RESULTS: No sequence alterations in the coding or splicing regions showed an association with high myopia. Two dinucleotide repeats, (AC)(m) and (AG)(n), in the P1 promoter region were found to be highly polymorphic and significantly associated with high myopia. Higher repeat numbers were observed in high myopia patients for both (AC)(m) (empirical p = 0.013) and (AG)(n) (empirical p = 0.012) dinucleotide polymorphisms, with a 1.327-fold increased risk associated with the (AG)(n) repeat (empirical p = 0.016; 95% confidence interval: 1.059-1.663). Luciferase-reporter analysis showed elevated transcription activity with increasing individual (AC)(m) and (AG)(n) and combined (AC)(m)(AG)(n) repeat lengths. CONCLUSIONS: Our results revealed an association between high myopia and AC and AG dinucleotide repeat lengths in the PAX6 P1 promoter, indicating the involvement of PAX6 in the pathogenesis of high myopia.

An alphaA-crystallin gene mutation, Arg12Cys, causing inherited cataract-microcornea exhibits an altered heat-shock response.

PURPOSE: To investigate the clinical features and molecular basis of inherited cataract-microcornea caused by an alphaA-crystallin gene (CRYAA) mutation in a Chinese family. METHODS: A three-generation Chinese family with members having autosomal dominant cataract and microcornea was recruited. Genomic DNA from peripheral blood or buccal swab samples of five affected and five unaffected members were obtained. Based on 15 genes known to cause autosomal dominant cataract, single nucleotide polymorphisms (SNPs) or microsatellite markers were selected and genotyped for two-point linkage analysis. Direct sequencing was performed to identify the disease-causing mutation. The expression construct coding for recombinant COOH-terminal myc-His-tagged wild type or R12C alphaA-crystallin protein (CRYAA) was expressed in COS-7 cells. Detergent solubility and subcellular distribution of wild type and R12C CRYAA were examined by western blotting and immunofluorescence, respectively. Heat-shock response was monitored by quantitative polymerase chain reaction (qPCR) of heat-shock proteins 70 and 90alpha (HSP70 and HSP90alpha). RESULTS: The five affected family members showed variable lens opacities and microcornea. Clinical features of cataract were asymmetric in two eyes of some affected subjects. A heterozygous missense substitution, c.34C>T, in CRYAA, which is responsible for the R12C amino acid change, segregated with autosomal dominant cataract (ADCC) in this family. This substitution was absent in 103 unrelated controls. When expressed in COS-7 cells, the R12C mutant CRYAA resembled the wild type protein in its solubility when extracted with 0.5% Triton X-100 and with its cytoplasmic localization. However, mutant cells exhibited an altered heat-shock response, evidenced by the delayed expression of HSP70, when compared to cells expressing wild type CRYAA. CONCLUSIONS: The R12C mutation in CRYAA was responsible for a variable type of inherited cataract associated with microcornea in this Chinese family. The altered heat-shock response of mutant cells suggested a change of chaperoning capacity and networking, which could be associated with the pathogenesis of hereditary cataract-microcornea syndrome.

Multiple gene polymorphisms analysis revealed a different profile of genetic polymorphisms of primary open-angle glaucoma in northern Chinese.

PURPOSE: To evaluate the individual and interactive effects of polymorphisms in the myocilin (MYOC),optineurin (OPTN), WD repeat domain 36 (WDR36), and apolipoprotein E (APOE) genes on primary open-angle glaucoma (POAG) in northern Chinese. METHODS: Northern Chinese study subjects, 176 POAG patients and 200 controls, were recruited for screening of the coding exons and splicing regions of MYOC. Five single nucleotide polymorphisms (SNPs) in OPTN (M98K, R545Q, IVS5+38T>G, IVS8-53T>C, and IVS15+10G>A), one SNP in WDR36 (IVS5+30C>T) as well as the APOE promoter and epsilon2/epsilon3/epsilon4 polymorphisms were also examined. Association analysis was performed by using chi(2) analysis. High-order gene-gene interaction was also analyzed using the multifactor dimensionality reduction (MDR) method. RESULTS: In MYOC, 22 variants were identified. Four of them were novel but found in controls only. The missense mutation, Val53Ala, is likely a glaucoma causing mutation, accounting for 0.6% of cases. No individual polymorphism in OPTN, WDR36, or APOE was associated with POAG. MDR analysis identified a best 6-factor model for POAG: MYOC IVS2+35A>G, OPTN Met98Lys, OPTN IVS5+38T>G, OPTN IVS8-53T>C, WDR36 IVS5+30C>T, and APOE -491A>T. CONCLUSIONS: The association pattern between the genes, MYOC, OPTN, WDR36, and APOE, and POAG in northern Chinese is different from that of southern Chinese. Disease-causing mutations in MYOC accounted for a small proportion of northern Chinese POAG patients. Common polymorphisms in these genes were not associated with POAG individually but might interactively contribute to the disorder, supporting a polygenic etiology.

A novel deletion variant of gammaD-crystallin responsible for congenital nuclear cataract.

PURPOSE: To investigate a novel deletion variant of gammaD-crystallin (CRYGD) identified in a Chinese family with nuclear congenital cataract. METHODS: A Chinese family with five affected members diagnosed with nuclear cataract and four unaffected members were recruited for the mutational screening of 15 known candidate genes for autosomal dominant congenital cataract. Two-point linkage analysis with single nucleotide polymorphism markers and microsatellite markers flanking these genes together with direct sequencing was applied to identify the disease-causing mutation. Recombinant NH(2)-terminal FLAG-tagged wildtype or mutant gammaD-crystallin was expressed in COS-7 cells. The expression pattern, protein solubility and intracellular distribution were analyzed by western blotting and confocal double immunofluorescence. RESULTS: Linkage analysis located the candidate region in the gammaC-crystallin and gammaD-crystallin gene cluster. Direct sequencing identified a c.494delG in CRYGD, which cosegregated with the disease in all affected members. Neither the unaffected family members nor the 103 unrelated controls carried this deletion mutation, which causes a frameshift and an early termination of polypeptide to become G165fs. A significantly reduced solubility was observed for this mutant. Unlike wildtype gammaD-crystallin, which existed in both the nucleus and cytoplasm, G165fs was colocalized with lamin A/C on the nuclear envelope. CONCLUSIONS: We have identified a novel mutation, c.494delG, in CRYGD, which was associated with nuclear cataract. This is the first deletion mutation of CRYGD found to cause autosomal dominant congenital cataract. The mutant protein with loss of solubility and localization to the nuclear envelope is hypothesized to impair nuclear transfiguration and degradation in lens fiber cell differentiation, leading to opacity formation during lens development.

Association of apolipoprotein E polymorphisms with normal tension glaucoma in a Chinese population.

PURPOSE: To evaluate the role of apolipoprotein E (APOE) polymorphisms in primary open angle glaucoma (POAG). METHODS: A cohort of 400 unrelated Chinese POAG patients was examined, including 294 cases of high tension glaucoma (HTG) and 106 with normal tension glaucoma (NTG). Also studied were 300 unrelated Chinese control subjects. The genotypes of the APOE polymorphisms in exon 4 and in the promoter at positions -491, -427, and -219 were determined by polymerase chain reaction and restriction endonuclease analysis. Frequencies of the genotypes were compared between patients and controls by chi test or Fisher exact test. The association of APOE polymorphisms with POAG phenotypes including age at diagnosis, intraocular pressure (IOP) at diagnosis, highest IOP, cup-disc ratio, and visual field score was investigated by the Kruskal-Wallis test. RESULTS: No significant difference was detected in the frequencies of APOE promoter polymorphisms between POAG patients and control subjects (P>0.0125). For the exon 4 polymorphism, when compared with control subjects, the frequency of epsilon 4 carriers was significantly lower in patients with NTG (P=0.008; odds ratio=0.36, 95% confidence interval=0.17, 0.79) but not in HTG (P=0.07). Compared with -219TT, the -219G carriers had a significant higher age at diagnosis (P=0.0046). No significant association was found between other APOE polymorphisms and POAG phenotypes (P>0.07). CONCLUSIONS: Our findings suggest that the APOE epsilon 4 allele confers a protective effect against NTG, whereas the APOE promoter polymorphisms do not contribute to POAG risk. However, the APOE -219G carriers tended to have later-onset POAG.

A genome-wide scan maps a novel juvenile-onset primary open angle glaucoma locus to chromosome 5q.

PURPOSE: To map the disease-associated locus of a family with autosomal dominant juvenile-onset primary open angle glaucoma (JOAG) and to screen the novel glaucoma gene WD repeat domain 36 (WDR36). METHODS: Complete ophthalmic examination and genomic DNA were obtained from 27 family members, in which nine were confirmed JOAG patients. Myocilin (MYOC), optineurin (OPTN), and WDR36 were screened for mutations by polymerase chain reaction and direct sequencing. Genome-wide scanning was carried out using the ABI PRISM Linkage Mapping Set MD-10. Two-point and multipoint linkage analyses were performed with the MLINK, ILINK, and LINKMAP programs. For fine mapping, additional markers flanking the most promising region on chromosome 5q were also analyzed. The significance of LOD scores was tested with simulation analyses using FASTLINK. Haplotypes were constructed using Simwalk2. RESULTS: MYOC or OPTN mutations were excluded in all family members. A maximum LOD score value of 4.82 at theta=0.00 was obtained for the marker D5S2011. Markers D5S2065, D5S1384, D5S471, D5S503, D5S2098, and D5S638 had LOD score values over 4.0 at theta=0.00. Haplotype analysis and recombination mapping further confined this region to 5q22.1-q32 within a region of 36 Mb flanked by D5S2051 and D5S2090. Screening of the novel WDR36 glaucoma-associated gene, which lies centromeric to the disease interval, revealed no mutations within any of the 23 coding exons or splicing junctions. CONCLUSIONS: Our results provided the mapping of a novel locus for JOAG at 5q and excluded coding or splicing junctions mutations within the WDR36 gene.

Molecular diagnostics of genetic eye diseases.

Eye diseases can be simple or complex, and mostly of heterogeneous molecular genetics. Some eye diseases are caused by mutations in a single gene, but some diseases, such as primary open angle glaucoma, can be due to sequence variations in multiple genes. In some diseases, both genetic and epigenetic mechanisms are involved, as was recently revealed in the mechanism of retinoblastoma. Disease causative mutations and phenotypes may vary by ethnicity and geography. To date, more than a hundred candidate genes for eye diseases are known, although less than 20 have definite disease-causing mutations. The three common genetic eye diseases, primary open angle glaucoma, age-related macular degeneration, and retinitis pigmentosa, all have known gene mutations, but these account for only a portion of the patients. While the search for eye disease genes and mutations still goes on, known mutations have been utilized for diagnosis. Genetic markers for pre-symptomatic and pre-natal diagnosis are available for specific diseases such as primary open angle glaucoma and retinoblastoma. This paper reviews the molecular basis of common genetic eye diseases and the available genetic markers for clinical diagnosis. Difficulties and challenges in molecular investigation of some eye diseases are discussed. Establishment of ethnic-specific disease databases that contain both clinical and genetic information for identification of genetic markers with diagnostic, prognostic, or pharmacological value is strongly advocated.

SNPs and interaction analyses of myocilin, optineurin, and apolipoprotein E in primary open angle glaucoma patients.

PURPOSE: To evaluate the association of myocilin (MYOC), optineurin (OPTN), and apolipoprotein E (APOE) genes and their interactions in primary open angle glaucoma (POAG). METHODS: A cohort of 400 unrelated POAG patients (294 high tension glaucoma, HTG, and 106 normal tension glaucoma, NTG) and 281 unrelated control subjects were recruited. All coding exons and splicing junctions in MYOC and OPTN were screened for sequence alterations. Common polymorphisms in APOE were genotyped. Single genes were investigated by univariate and haplotype analysis, and gene-gene interactions by logistic regression and stratified analysis. Multiple comparisons were corrected by the Bonferroni method. Bioinformatics analysis was performed to assess the conservation of mutation sites across species and to predict putative motifs and secondary structures in mutated proteins. RESULTS: Disease-causing mutations in MYOC and OPTN were identified in 1.75% and 1% of POAG patients, respectively. Most of these mutations were highly conserved across species, many predicted to create new motifs or change protein secondary structures. No individual MYOC polymorphisms significantly contributed to HTG or NTG. A haplotype containing the minor allele of the MYOC IVS2+35A>G increased NTG risk (p=0.0001). Three OPTN polymorphisms, T34T, IVS5+38T>G, and IVS8-53T>C increased NTG risk (p<0.0008), while IVS5+38T>G increased HTG risk (p=0.0006). One haplotype that contains the minor alleles of 3 OPTN polymorphisms, T34T, IVS5+38T>G, and IVS7+24G>A, increased NTG risk (p=0.0002). APOE epsilon4 carriers had a decreased NTG risk (p=0.007). Possible gene-gene interactions were found between MYOC, OPTN, and APOE. CONCLUSIONS: Disease-causing mutations in MYOC and OPTN accounted for only a small proportion of Chinese POAG patients. Common polymorphisms in MYOC, OPTN, and APOE might interactively contribute to POAG, indicating a polygenic etiology.

The dual role of dexamethasone on anti-inflammation and outflow resistance demonstrated in cultured human trabecular meshwork cells.

PURPOSE: Dexamethasone (DEX) is a glucocorticoid commonly used in topical eyedrops to treat eye inflammation. It has an undesirable effect of inducing glaucoma in certain patients. In human Trabecular Meshwork (TM) cells DEX regulates a number of genes but its global influence on TM gene expression is still elusive. In the present work, DEX effects on global gene expressions of an established human TM cell line were studied by microarray. METHODS: The whole experiment of microarray was repeated three times. Differentially expressed genes were identified by an empirical Bayes approach and confirmed by Reverse Transcription Polymerase Chain Reaction. RESULTS: Eight genes (GAS1, CDH4, MT1L, CST3, ATF4, ASNS/TS11, CHOP, HSPA5) were identified that are at least a thousand times more likely to be differentially expressed due to DEX treatment and six genes (TSC22, LDHA, IGFBP2, TAGLN, SCG2, WARS) were identified that are at least a hundred times more likely to be differentially expressed due to DEX treatment. Except for MT1L, ASNS/TS11, IGFBP2, SCG2, and WARS, all the other genes are first reported here to be regulated by DEX in TM. Intriguingly, several of them have overlapping roles in anti-inflammatory response and outflow resistance. CONCLUSIONS: The results of our experiments on cultured human TM cells indicate that the increase in outflow resistance and ultimate ocular hypertension may be byproducts of the favorable anti-inflammatory response triggered by DEX.

TGFbeta-induced factor: a candidate gene for high myopia.

PURPOSE: To investigate the coding exons of transforming growth factor (TGF)-beta-induced factor (TGIF) for mutations in Chinese patients with high myopia. METHODS: Seventy-one individuals with high myopia of -6.00 D or less and 105 control subjects were screened by DNA sequencing for sequence alterations. Univariate analysis and logistic regression were performed to identify single-nucleotide polymorphisms (SNPs) and their interactions in TGIF that may be associated with myopia. RESULTS: Six SNPs showed a significant difference (P < 0.05) between patient and control subject in univariate analysis. Four of them cause codon changes: G223R, G231S, P241T, and A262G. Among all the SNPs that entered multivariate analysis, only 657(T-->G) showed statistical significance in the logistic regression model (odds ratio 0.133; 95% confidence interval 0.037-0.488; P = 0.002). CONCLUSIONS: TGIF is a probable candidate gene for high myopia. Further studies are needed to identify the underlying mechanism.