transforming-growth-factor-beta and Myopia

Marfan syndrome (MFS) is a rare, autosomal-dominant, multisystem disorder, presenting with skeletal, ocular, skin, and cardiovascular symptoms. Significant clinical overlap with other systemic connective tissue diseases, including Loeys-Dietz syndrome (LDS), Shprintzen-Goldberg syndrome (SGS), and the MASS phenotype, has been documented. In MFS and LDS, the cardiovascular manifestations account for the major cause of patient morbidity and mortality, rendering them the main target for therapeutic intervention. Over the past decades, gene identification studies confidently linked the aforementioned syndromes, as well as nonsyndromic aneurysmal disease, to genetic defects in proteins related to the transforming growth factor (TGF)-β pathway, greatly expanding our knowledge on the disease mechanisms and providing us with novel therapeutic targets. As a result, the focus of the developing pharmacological treatment strategies is shifting from hemodynamic stress management to TGF-β antagonism. In this review, we discuss the insights that have been gained in the molecular biology of MFS and related disorders over the past 25 years.

Topics: Angiotensin Receptor Antagonists; Animals; Arachnodactyly; Craniosynostoses; Gene Expression Regulation; Gene Regulatory Networks; Genetic Predisposition to Disease; Humans; Loeys-Dietz Syndrome; Marfan Syndrome; Mitral Valve Prolapse; Myopia; Signal Transduction; Skin Diseases; Transforming Growth Factor beta

Myopia is one of the most prevalent ocular conditions and is the result of a mismatch between the power of the eye and axial length of the eye. In the vast majority of cases the structural cause of myopia is an excessive axial length of the eye, or more specifically the vitreous chamber depth. In about 3% of the general population in Europe, USA and Australia, the degree of myopia is above 6 dioptres and is termed high myopia. In South East Asia the figure is closer to 20% of the general population with high myopia. The prevalence of sight threatening ocular pathology is markedly increased in eyes with high degrees of myopia (>-6 D). This results from the excessive axial elongation of the eye which, by necessity, must involve the outer coat of the eye, the sclera. Current theories of refractive development acknowledge the pivotal role of the sclera in the control of eye size and the development of myopia. This review details the major structural, biochemical and biomechanical changes that underlie abnormal development of the mammalian sclera in myopia. In describing the changes in regulation of sclera metabolism in myopia, the pivotal role of transforming growth factor-β signalling is highlighted as the responsible factor for certain critical events in myopia development that ultimately result in the scleral pathology observed in high myopia.

Topics: Animals; Axial Length, Eye; Collagen; Glycosaminoglycans; Humans; Myopia; Sclera; Transforming Growth Factor beta

To compare the incidence and degree of corneal haze formation following laser subepithelial keratomileusis (LASEK) and epithelial laser in situ keratomileusis (epi-LASIK), and examine its correlation with tear film transforming growth factor-beta1 (TGF-beta1) levels.. This prospective, interventional, clinical trial included 20 eyes (20 patients) randomly assigned to undergo LASEK or epi-LASIK. The level of TGF-beta1 in tear fluid was measured preoperatively and 1, 3, and 5 days postoperatively. Corneal haze was graded at 1 and 3 months after surgery, and the relationship with TGF-beta1 levels was determined.. Mean preoperative spherical equivalent refraction was -4.50 +/- 1.44 diopters (D) (range: -1.50 to -6.00 D) for LASEK eyes and -4.90 +/- 1.26 D (range: -1.75 to -6.00 D) for epi-LASIK eyes. Although mean corneal haze scores at 1 month were significantly higher in LASEK-treated eyes than in epi-LASIK treated eyes (P=.031), these scores were similar at 3 months (P=.608). Tear fluid TGF-beta1 levels were similar in LASEK and epi-LASIK eyes before surgery (P=.458) and significantly higher in the LASEK group at 1, 3, and 5 days postoperatively (P=.015, P=.023, and P=.039, respectively). A positive correlation was noted between tear TGF-beta1 levels on the first postoperative day and the degree of corneal haze at 1 month (r=0.501, P=.016).. Less corneal haze was noted after epi-LASIK than LASEK. A positive correlation between corneal haze and tear fluid TGF-beta1 levels on the first postoperative day suggest a possible mechanism for the observed difference.

Topics: Adult; Corneal Opacity; Female; Humans; Incidence; Keratectomy, Subepithelial, Laser-Assisted; Keratomileusis, Laser In Situ; Male; Myopia; Postoperative Complications; Prospective Studies; Tears; Transforming Growth Factor beta; Transforming Growth Factor beta1

Myopia is one of the most common eye diseases in children and adolescents worldwide. Currently, there is no effective treatment in clinical practice. Ocular tissue fibrosis is involved in the development of myopia and this study aimed to investigate the effect of miR-138-5p on choroidal fibrosis in myopic guinea pigs via regulating the HIF-1α signaling pathway. First, guinea pigs were randomly divided into a normal control (NC) group, a lens-induced myopia (LIM) group, a LIM + miR-138-5p-carried Lentivirus treatment (LV) group, and a LIM + miR-138-5p-Vector treatment (VECTOR) group. All animals were induced experimental myopia with a -6.0 diopter lens except those in the NC group. Meanwhile, animals in the LV group were supplemented with 5 μl of miR-138-5p-carried Lentivirus, while those in the VECTOR group were only supplemented with the same volume of miR-138-5p-Vector. After myopia induction for 2 and 4 weeks, the refractive status and other ocular parameters of the guinea pigs were measured. Further, the expression of hypoxia-inducible factor (HIF)-1α, transforming growth factor (TGF)-β, collagen I, hydroxyproline (HYP), interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and a-smooth muscle actin (α-SMA) in choroidal tissues was investigated. Results showed that the refraction and axial length of the experimental myopic guinea pigs increased, and choroid fibrosis aggravated after experimental myopic induction. miR-138-5p can efficiently decrease the refraction and ocular length, and ameliorate the choroidal fibrosis of the experimental myopic guinea pigs via downregulating the fibrosis-related TGF-β1, collagen I, HYP, IL-1β, TNF-α, and α-SMA expression through inhibiting the HIF-1α signaling pathway. Our results provide new insight into controlling myopic development using microRNAs in clinical practice.

Topics: Animals; Choroid; Collagen; Disease Models, Animal; Fibrosis; Guinea Pigs; Hypoxia-Inducible Factor 1, alpha Subunit; MicroRNAs; Myopia; Signal Transduction; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

The objective is to investigate the relationship and correlation between PEDF and TGF-. For each group of patients (namely, group A: patients with high myopia CNV (mCNV); group B: patients with high myopia without CNV; group C: patients with CNV caused by other eye diseases; and group D (control group): patients with simple cataract (without CNV and high myopia)), 20 patients were collected. A total of 40 patients have been collected since the beginning of the study in December 2020, including 7 patients in group A, 13 patients in group B, 10 patients in group C, and 10 patients in group D. Serum and aqueous humor samples were collected, and PEDF and TGF-. There were no significant differences in age, gender, and course of disease among all groups (. TGF-

Topics: Aqueous Humor; Cataract; Enzyme-Linked Immunosorbent Assay; Humans; Myopia; Serpins; Transforming Growth Factor beta

Frameshift mutations in LRPAP1 are responsible for autosomal recessive high myopia in human beings but its underlying mechanism remains elusive. This study aims to investigate the effect of LRPAP1 defect on ocular refractive development and its involved mechanism.. A lrpap1 mutant zebrafish line with homozygous frameshift mutation was generated by CRISPR/Cas9 technology and confirmed by Sanger sequencing. The ocular refractive phenotype was analyzed by calculating the relative refractive error (RRE) with vivo photography and histological analysis at different development stages, together with examining ocular structure change via transmission electron microscopy. Further, RNA sequencing and bioinformatics analysis were performed. The potentially involved signaling pathway as well as the interacted protein were investigated in vivo.. The lrpap1 homozygous mutant zebrafish line showed myopic phenotype. Specifically, the mutant lines showed larger eye axial length-to-body length in one-month old individuals and a myopic shift with an RRE that changed after two months. Collagen fibers became thinning and disordered in the sclera. Further, RNA sequencing and bioinformatics analysis indicated that apoptosis signaling was activated in mutant line; this was further confirmed by acridine orange and TUNEL staining. Moreover, the expression of TGF-β protein was elevated in the mutant lines. Finally, the treatment of wild-type embryos with a TGF-β agonist aggravated the degree of eyeball apoptosis; conversely, the use of a TGF-β inhibitor mitigated apoptosis in mutant embryos.. The study provides functional evidence of a link between lrpap1 and myopia, suggesting that lrpap1 deficiency could lead to myopia through TGF-β-induced apoptosis signaling. Video abstract.

Topics: Acridine Orange; Animals; Apoptosis; Collagen; Humans; LDL-Receptor Related Protein-Associated Protein; Myopia; Sclera; Transforming Growth Factor beta; Zebrafish; Zebrafish Proteins

To analyze the expression of 440 human cytokines in aqueous humor of high myopic patients with cataracts.. Eighty-five patients with cataracts were recruited in this study. In the screening stage, the RayBio G-Series Human Cytokine Antibody Array 440 was used to assay the aqueous humor samples collected from nine high myopic patients with cataracts and eight non-myopic patients with cataracts right before the surgery. The array was further used for verification of the screened cytokines, with aqueous humor samples obtained from 34 eyes of high myopic patients with cataracts and 34 eyes of non-myopic patients with cataracts.. Compared with the non-myopic patients with cataracts, the expression levels of decorin, receptor activator of NF-kB (RANK), angiopoietin-1 (ANG-1), C-X-C motif ligand 16 (CXCL16), β-inducible gene-h3 (bIG-H3), insulin-like growth factor-binding protein 2 (IGFBP-2), and interleukin-17B (IL-17B) were statistically significantly higher in high myopic patients with cataracts (all p<0.000114). The matrix metalloproteinase-2 (MMP-2) level also increased in the aqueous humor of high myopic patients with cataracts (p = 0.0034). The concentrations of ANG-1 and MMP-2 were also increased in the aqueous humor of the confirmatory stage (all p<0.05).. In this study, numerous cytokines in aqueous humor were detected in high myopic patients with cataracts and non-myopic patients with cataracts, and it was confirmed that the MMP-2 level in the aqueous humor of patients with high myopia was statistically significantly increased. Further verification also revealed the elevation of ANG-1 in the aqueous humor of high myopic patients with cataracts, which suggests that ANG-1 may be related to the pathogenesis of high myopia.

Topics: Aged; Angiopoietin-1; Aqueous Humor; Cataract; Chemokine CXCL16; Cytokines; Decorin; Extracellular Matrix Proteins; Female; Gene Expression Regulation; Humans; Insulin-Like Growth Factor Binding Protein 2; Interleukin-17; Male; Matrix Metalloproteinase 2; Middle Aged; Myopia; NF-kappa B; Transforming Growth Factor beta

Loeys-Dietz syndrome (LDS), an autosomal-dominant connective tissue disorder, is characterised by systemic manifestations including arterial aneurysm and craniofacial dysmorphologies. Although ocular involvement in LDS has been reported, detailed information on those manifestations is lacking.. Retrospective chart review of patients with diagnosed LDS and comparison with age-matched control patients.. Mean age was 37.8±14.6 years (patients with LDS) and 38.4±13.5 years (controls). Patients with LDS less frequently had iris transillumination, cataract and glaucoma compared with controls. Scleral and retinal vascular abnormalities were not found in any of the LDS eyes. Ectopia lentis was found in one patient with LDS. The eyes of patients with LDS tended to be more myopic (spherical equivalent, -2.47±2.70 dioptres (dpt) vs -1.30±2.96dpt (controls); P=0.08) and longer (24.6±1.7mm vs 24.1±1.5mm (controls); P=0.10). Central corneal thickness was significantly reduced in LDS eyes (521±48µm vs 542±37µm (controls); P=0.02). Corneal curvature (43.06±1.90dpt (LDS) versus 43.00±1.37dpt (controls); P=0.72) and interpupillary distance (65.0±6.0mm (LDS) vs 64.3±4.8mm (controls); P=0.66) did not differ significantly between both groups. Visual acuity was similar between both groups (0.03±0.09logarithm of the minimum angle of resolution (logMAR) for LDS eyes and 0.05±0.17logMAR for control eyes, P=0.47).. Ocular features of LDS include decreased central corneal thickness and mild myopia. Ectopia lentis may be slightly more common than in controls but appears less common than in Marfan syndrome. Hypertelorism, scleral and retinal vascular abnormalities were not features of LDS.

Topics: Adolescent; Adult; Aged; Biometry; Cataract; Corneal Diseases; Ectopia Lentis; Female; Glaucoma; Humans; Iris Diseases; Loeys-Dietz Syndrome; Male; Middle Aged; Myopia; Receptor, Transforming Growth Factor-beta Type I; Receptor, Transforming Growth Factor-beta Type II; Retrospective Studies; Smad3 Protein; Transforming Growth Factor beta; Visual Acuity; Young Adult

Mitochondrial intracrines are extracellular signaling proteins, targeted to the mitochondria. The pathway for mitochondrial targeting of mitochondrial intracrines and actions in the mitochondria remains unknown. Megalin/LRP2 mediates the uptake of vitamins and proteins, and is critical for clearance of amyloid-β protein from the brain. Megalin mutations underlie the pathogenesis of Donnai-Barrow and Lowe syndromes, characterized by brain defects and kidney dysfunction; megalin was not previously known to reside in the mitochondria. Here, we show megalin is present in the mitochondria and associates with mitochondrial anti-oxidant proteins SIRT3 and stanniocalcin-1 (STC1). Megalin shuttles extracellularly-applied STC1, angiotensin II and TGF-β to the mitochondria through the retrograde early endosome-to-Golgi transport pathway and Rab32. Megalin knockout in cultured cells impairs glycolytic and respiratory capacities. Thus, megalin is critical for mitochondrial biology; mitochondrial intracrine signaling is a continuum of the retrograde early endosome-to-Golgi-Rab32 pathway and defects in this pathway may underlie disease processes in many systems.

Topics: Agenesis of Corpus Callosum; Amyloid beta-Peptides; Animals; Brain; Cell Membrane; Glycoproteins; Hearing Loss, Sensorineural; HEK293 Cells; Hernias, Diaphragmatic, Congenital; Humans; Low Density Lipoprotein Receptor-Related Protein-2; Mice; Mitochondria; Myopia; Oculocerebrorenal Syndrome; Proteinuria; rab GTP-Binding Proteins; RAW 264.7 Cells; Renal Tubular Transport, Inborn Errors; Signal Transduction; Sirtuin 3; Transforming Growth Factor beta

This study investigated the gene expression of TGFβ isoforms and their receptors in chick retina, retinal pigment epithelium (RPE), and choroid and the effects of short-term imposed optical defocus.. The expression of TGFβ isoforms (TGF-β1, 2, 3) and TGFβ receptors (TGFBR1, 2, 3) was examined in the retina, RPE, and choroid of young White-Leghorn untreated chicks (19 days-old). The effects on the expression of the same genes of monocular +10 and -10 D defocusing lenses, worn for either 2 or 48 h by age-matched chicks, were also examined by comparing expression in treated and untreated fellow eyes. RNA was purified, characterized and then reverse transcribed to cDNA. Differential gene expression was quantified using real-time PCR.. All 3 isoforms of TGFβ and all 3 receptor subtypes were found to be expressed in all 3 ocular tissues, with apparent tissue-dependent differences in expression profiles. Data are reported as mean normalized expression relative to GAPDH. Sign-dependent optical defocus effects were also observed. Optical defocus did not affect retinal gene expression but in the RPE, TGF-β2 expression was significantly up-regulated with +10 D lenses, worn for either 2 h (349% increase ± 88%, p < 0.01) or 48 h (752% increase ± 166%, p < 0.001), and in the choroid, the expression of TGF-β3 was up-regulated with -10 D lenses, worn for 48 h (147% increase ± 9%, p < 0.01).. The effects of short term exposure to optical defocus on TGFβ gene expression in the RPE and choroid, which were sign-dependent and isoform specific, provide further supporting evidence for important roles of members of the TGFβ family and these two tissues in local signal cascades regulating ocular growth.

Topics: Animals; Chickens; Choroid; Fixation, Ocular; Myopia; Optic Nerve; Protein Isoforms; Receptors, Transforming Growth Factor beta; Retina; Retinal Pigment Epithelium; Transforming Growth Factor beta; Up-Regulation; Vision, Ocular

Previously, we demonstrated that scleral stem/progenitor cells (SSPCs) from mice have a chondrogenic differentiation potential, which is stimulated by transforming growth factor-β (TGF-β). In the present study, we hypothesized that chondrogenesis in the sclera could be a possible mechanism in myopia development. Therefore, we investigated the association of form-deprivation myopia (FDM) with expressions in mice sclera representing the chondrogenic phenotype: collagen type II (Col2) and α-smooth muscle actin (α-SMA).. The mRNA levels of α-SMA and Col2 in cultured murine SSPCs during chondrogenesis stimulated by TGF-β2 were determined by real-time quantitative RT-PCR (qRT-PCR). The expression patterns of α-SMA and Col2 were assessed by immunohistochemistry in a three dimensional pellet culture. In an FDM mouse model, a western blot analysis and immunofluorescence study were used to detect the changes in the α-SMA and Col2 protein expressions in the sclera. In the RPE-choroid complex, qRT-PCR was used to detect any changes in the TGF-β mRNA expression.. The treatment of SSPCs in vitro with TGF-β2 for 24 h at 1 or 10 ng/ml led to increased levels of both the α-SMA and Col2 expressions. In addition, we observed the formation of cartilage-like pellets from TGF-β2-treated SSPCs. Both α-SMA and Col2 were expressed in the pellet. In an in-vivo study, the α-SMA and Col2 protein expressions were significantly increased in the sclera of FDM eyes in comparison to contralateral control eyes. Similarly, the levels of TGF-β in the RPE-choroid complex of an FDM eye were also significantly elevated.. Based on the concept of stem cells possessing multipotent differentiation potentials, scleral chondrogenesis induced by SSPCs may play a role in myopia development. The increased expressions of the cartilage-associated proteins Col2 and α-SMA during scleral chondrogenesis may be potential markers for myopia development. In addition, the increased levels of TGF-β mRNA in the RPE-choroid complex might induce the chondrogenic change in the sclera during myopia development.

Topics: Actins; Animals; Cells, Cultured; Chondrogenesis; Choroid; Collagen Type II; Disease Models, Animal; Gene Expression; Male; Mice; Mice, Inbred C57BL; Myopia; Retinal Pigment Epithelium; RNA, Messenger; Sclera; Stem Cells; Transforming Growth Factor beta; Transforming Growth Factor beta2

High myopia, with the characteristic feature of refractive error, is one of the leading causes of blindness worldwide. It has a high heritability, but only a few causative genes have been identified and the pathogenesis is still unclear.. We used whole genome linkage and exome sequencing to identify the causative mutation in a non-syndromic high myopia family. Direct Sanger sequencing was used to screen the candidate gene in additional sporadic cases or probands. Immunofluorescence was used to evaluate the expression pattern of the candidate gene in the whole process of eye development. Real-time quantitative PCR and immunoblot was used to investigate the functional consequence of the disease-associated mutations.. We identified a nonsense mutation (c.141C>G:p.Y47*) in SLC39A5 co-segregating with the phenotype in a non-syndromic severe high myopia family. The same nonsense mutation (c.141C>G:p.Y47*) was detected in a sporadic case and a missense mutation (c.911T>C:p.M304T) was identified and co-segregated in another family by screening additional cases. Both disease-associated mutations were not found in 1276 control individuals. SLC39A5 was abundantly expressed in the sclera and retina across different stages of eye development. Furthermore, we found that wild-type, but not disease-associated SLC39A5 inhibited the expression of Smadl, a key phosphate protein in the downstream of the BMP/TGF-β (bone morphogenic protein/transforming growth factor-β) pathway.. Our study reveals that loss-of-function mutations of SLC39A5 are associated with the autosome dominant non-syndromic high myopia, and interference with the BMP/TGF-β pathway may be one of the molecular mechanisms for high myopia.

Topics: Animals; Bone Morphogenetic Proteins; Cation Transport Proteins; Child; Child, Preschool; Embryo, Mammalian; Eye; Female; Genotyping Techniques; Humans; Male; Mice; Mutation; Myopia; Pedigree; Transforming Growth Factor beta

Myopia is an extremely common eye disorder but the pathogenesis of its isolated form, which accounts for the overwhelming majority of cases, remains poorly understood. There is strong evidence for genetic predisposition to myopia, but determining myopia genetic risk factors has been difficult to achieve. We have identified Mendelian forms of myopia in four consanguineous families and implemented exome/autozygome analysis to identify homozygous truncating variants in LRPAP1 and CTSH as the likely causal mutations. LRPAP1 encodes a chaperone of LRP1, which is known to influence TGF-β activity. Interestingly, we observed marked deficiency of LRP1 and upregulation of TGF-β in cells from affected individuals, the latter being consistent with available data on the role of TGF-β in the remodeling of the sclera in myopia and the high frequency of myopia in individuals with Marfan syndrome who characteristically have upregulation of TGF-β signaling. CTSH, on the other hand, encodes a protease and we show that deficiency of the murine ortholog results in markedly abnormal globes consistent with the observed human phenotype. Our data highlight a role for LRPAP1 and CTSH in myopia genetics and demonstrate the power of Mendelian forms in illuminating new molecular mechanisms that may be relevant to common phenotypes.

Topics: Adolescent; Animals; Cathepsin H; Child; Child, Preschool; Female; Gene Expression; Genetic Predisposition to Disease; Homozygote; Humans; Infant; LDL-Receptor Related Protein-Associated Protein; Low Density Lipoprotein Receptor-Related Protein-1; Male; Marfan Syndrome; Mice; Mutation; Myopia; Pedigree; Phenotype; Sclera; Severity of Illness Index; Transforming Growth Factor beta

Visual environment plays an important role in the occurrence of myopia. We previously showed that the different flashing lights could result in distinct effects on the ocular growth and development of myopia. CCN2 has been reported to regulate various cellular functions and biological processes. However, whether CCN2 signaling was involved in the red flashing light-induced myopia still remains unknown. In the present study, we investigated the effects of the red flashing lights exposure on the refraction and axial length of the eyes in vivo and then evaluated their effects on the expression of CCN2 and TGF- β in sclera tissues. Our data showed that the eyes exposed to the red flashing light became more myopic with a significant increase of the axial length and decrease of the refraction. Both CCN2 and TGF- β , as well as p38 MAPK and PI3K, were highly expressed in the sclera tissues exposed to the red flashing light. Both CCN2 and TGF- β were found to have the same gene expression profile in vivo. In conclusion, our findings found that CCN2 signaling pathway plays an important role in the red flashing light-induced myopia in vivo. Moreover, our study establishes a useful animal model for experimental myopia research.

Topics: Animals; Connective Tissue Growth Factor; Disease Models, Animal; Eye; Gene Expression Regulation; Guinea Pigs; Light; Myopia; p38 Mitogen-Activated Protein Kinases; Signal Transduction; Transcriptome; Transforming Growth Factor beta

In the chicken model of myopia, it has first been shown that imposing defocus to the retina results in active remodelling of the sclera which, in turn, results in axial length changes of the eye. Transforming growth factor-beta (TGF-beta) is one of the scleral growth modulators but its cellular localization in the fundal layers, colocalization and function are not well known. The aim of the current study was to investigate the cellular distribution of the three isoforms TGF-beta1, 2 and 3 by immunohistochemical labelling. Furthermore, the effects of visual experience that induces refractive errors on TGF-beta2 labelling were examined. Transversal cryostat sections of the fundal layers were analyzed by indirect immunofluorescent labelling and cell counts. Visual experience was changed by having the chicks wear either diffusers, or positive or negative lenses of 7D power in front of the right eyes for various periods of time. Left eyes served as uncovered controls. All TGF-beta isoforms were localized in both scleral layers. In choroid, diffuse labelling of all isoforms was found. In retina, TGF-beta1 and 3 were detected in bipolar, amacrine and ganglion cells and TGF-beta2 in amacrine and ganglion cells. To further characterize these cells, double-labelling with known amacrine and bipolar cell markers was performed (calbindin, cellular retinoic acid binding protein (CRABP), Islet1, Lim3 and protein kinase C (PKC)). TGF-beta1, 2 and 3 could be colocalized with calbindin and CRABP in single amacrine cells. TGF-beta1-positive bipolar cells were immunoreactive to Lim3. TGF-beta1 and 3 were never colocalized with PKC in bipolar cells. Also, colocalization with peptides known to be involved in myopia development in chicks, such as glucagon, or vasointestinal polypeptide and the key enzyme for dopamine synthesis, tyrosine hydroxylase, was not observed. Lenses or diffusers, worn by the chicks for various periods of time, had no effect on TGF-beta2 immunoreactivity in choroid or sclera, or on the number of TGF-beta2 (active and latent form) expressing amacrine cells. This result did not change when the two identified populations of TGF-beta2 expressing amacrine cells (one calbindin-positive and the other CRABP-positive) were separately considered. Also no modulation was seen in choroid, although an earlier study had found changes in TGF-beta2 mRNA after lens treatment. The lack of any visually-induced changes in retina or choroid suggests that TGF-beta may not repr

Topics: Animals; Antibody Specificity; Biomarkers; Cell Count; Chickens; Choroid; Disease Models, Animal; Fluorescent Antibody Technique, Indirect; Fundus Oculi; Male; Myopia; Retina; Retinal Neurons; Sclera; Sensory Deprivation; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2; Transforming Growth Factor beta3

Reduced extracellular matrix accumulation in the sclera of myopic eyes leads to increased ocular extensibility and is related to reduced levels of scleral transforming growth factor-beta (TGF-beta). The current study investigated the impact of this extracellular environment on scleral cell phenotype and cellular biomechanical characteristics. Scleral cell phenotype was investigated in vivo in a mammalian model of myopia using the myofibroblast marker, alpha-smooth muscle actin (alpha-SMA). In eyes developing myopia alpha-SMA levels were increased, suggesting increased numbers of contractile myofibroblasts, and decreased in eyes recovering from myopia. To understand the factors regulating this change in scleral phenotype, the competing roles of TGF-beta and mechanical stress were investigated in scleral cells cultured in three-dimensional collagen gels. All three mammalian isoforms of TGF-beta altered scleral cell phenotype to produce highly contractile, alpha-SMA-expressing myofibroblasts (TGF-beta3>TGF-beta2>TGF-beta1). Exposure of cells to the reduced levels of TGF-beta found in the sclera in myopia produced decreased cell-mediated contraction and reduced alpha-SMA expression. These findings are contrary to the in vivo gene expression data. However, when cells were exposed to both the increased stress and the reduced levels of TGF-beta found in myopia, increased alpha-SMA expression was observed, replicating in vivo findings. These results show that although reduced scleral TGF-beta is a major contributor to the extracellular matrix remodeling in the myopic eye, it is the resulting increase in scleral stress that dominates the competing TGF-beta effect, inducing increased alpha-SMA expression and, hence, producing a larger population of contractile cells in the myopic eye.

Topics: Actins; Animals; Cell Shape; Cells, Cultured; Myopia; Protein Isoforms; Sclera; Stress, Physiological; Transforming Growth Factor beta; Tupaia

A visually evoked signalling cascade, which begins in the retina, transverses the choroid, and mediates scleral remodelling, is considered to control eye growth. The ubiquitous cytokine TGF-beta has been associated with alterations in ocular growth, where alterations in scleral TGF-beta isoforms mediate the scleral remodelling that results in myopia. However, while the TGF-beta isoforms have been implicated in the scleral change during myopia development, it is unclear whether alterations in retinal and choroidal isoforms constitute part of the retinoscleral cascade. This study characterised the retinal and choroidal TGF-beta isoform profiles and TGF-beta2 activation during different stages of myopia development, as induced by form deprivation, in a mammalian model of eye growth. Using quantitative real-time PCR, the mRNA for all three mammalian isoforms of TGF-beta was detected in tree shrew retina and choroid. Distinct tissue-specific isoform profiles were observed for the retina (TGF-beta1:TGF-beta2:TGF-beta3=20:2085:1) and choroid (TGF-beta1:TGF-beta2:TGF-beta3=16:23:1), which remained constant over the development period under investigation. The active and latent pools of retinal TGF-beta2 were quantified using ELISA with the majority (>94%) of total TGF-beta2 found in the latent form. Unlike previous scleral data showing early and continuous decreases in TGF-beta isoform expression during myopia development, the levels of the three isoforms remained within normal ranges for retinal (TGF-beta1, -14 to +14%; TGF-beta2, -2 to +20%; TGF-beta3, -10 to +26%) and choroidal (TGF-beta1, -19 to +21%; TGF-beta2, -26 to +8%; TGF-beta3, -11 to +28%) tissues during myopia development (induction times of 3h, 7h, 11h, 24h, and 5 days). A 40% decrease in retinal TGF-beta2 activation was observed after 5 days of myopia development, however, there was no functional correlate of altered TGF-beta2 activity, as assessed by the retinal ERG response. Overall, these data highlight the specific nature of TGF-beta isoform expression, which reflects the differences in tissue structure and function. While TGF-beta isoforms are involved in scleral regulation during myopia development in mammals, they do not have a primary role in the retinal and choroidal signals. Thus, the regulation of eye growth via the retinoscleral cascade involves more than one factor, which is likely to be tissue-specific in nature.

Topics: Animals; Choroid; Disease Models, Animal; Disease Progression; Electroretinography; Eye Proteins; Gene Expression; Myopia; Protein Isoforms; Retina; Transforming Growth Factor beta; Transforming Growth Factor beta2; Tupaiidae

To report a photorefractive keratectomy (PRK)-treated patient who first developed stromal opacities with a typical granular pattern 9 years after surgery, which was confirmed as heterozygous Avellino dystrophy by DNA analysis.. A 37-year-old woman, who had undergone PRK 17 years ago, has been followed for glaucoma and corneal dystrophy. She had preoperative clear corneas in both eyes.. Nine years after PRK, at the age of 29 years, 2-3 small, white, anterior stromal corneal opacities were first detected in both eyes. Seventeen years postoperatively, multiple anterior stromal corneal deposits with a dot, crumb, or snowflake appearance were noted to the same degree in both eyes. The intervening cornea was relatively clear. Her DNA was heterozygous for the R124H mutation.. Slowly developing, mild corneal deposits occurred after PRK in this patient with heterozygote Avellino corneal dystrophy. Various clinical manifestations can occur after excimer laser refractive surgery in patients with Avellino corneal dystrophy.

Topics: Adult; Corneal Dystrophies, Hereditary; Corneal Opacity; Corneal Stroma; DNA Mutational Analysis; Extracellular Matrix Proteins; Female; Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Postoperative Complications; Transforming Growth Factor beta

To report a case of granular corneal dystrophy after radial keratotomy (RK).. A 32-year-old man presented with white radial lines in both corneas. He had a history of uncomplicated RK in both eyes 8 years ago. Preoperative refraction had been OD -3.5-0.75 x 180 and OS -3.0-0.5 x 175. The cornea was reported to be clear on postoperative examinations.. Postoperative uncorrected visual acuity was OD 20/30 and OS 20/40. Best-corrected visual acuity was 20/25 in both eyes with OD -0.5-0.5 x 60 and OS -0.75-0.5 x 80. Slit-lamp examination revealed discrete well-demarcated whitish lesions with clear intervening stroma in the central anterior cornea consistent with granular dystrophy. Similar opacities were present within the RK incisions.. Production and deposition of such abnormal material could be due to keratocyte activation after RK or proliferation and migration of epithelial cells with a tendency to express abnormal keratoepithelin.

Topics: Adult; Corneal Dystrophies, Hereditary; Extracellular Matrix Proteins; Heterozygote; Humans; Keratotomy, Radial; Male; Myopia; Pedigree; Point Mutation; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Transforming Growth Factor beta

Induction of myopia leads to a decreased glycosaminoglycan synthesis and smaller collagen fibrillar diameters, increased levels of gelatinase-A (MMP-2) and decreased amounts of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the fibrous sclera of both chicks and tree shrews. Another factor found to be involved in altered eye growth is the transforming growth factor beta-2 (TGFbeta-2). The aim of the current study was to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA expression changes separately in the two scleral layers of chicks, following myopic and hyperopic defocus. Chicks were treated unilaterally with positive and negative lenses for different time periods. All contralateral eyes wore plano lenses and additional controls, treated binocularly with plano lenses, were included. Real-time PCR was used to measure MMP-2, TIMP-2 and TGFbeta-2 mRNA levels. Few changes in MMP-2 and TIMP-2 mRNA levels were measured following treatment with plus and minus lenses for up to 3 days. The mRNA levels of MMP-2 and TIMP-2 were either unchanged or co-regulated in both eyes, even though only the eye with the powered lens actually displayed changes in growth. In contrast, TGFbeta-2 mRNA was significantly up-regulated in the cartilaginous layer following treatment with plus lenses after 24 hr, compared to all other groups. These changes were confined to the eyes that also displayed reduced growth, suggesting a role of TGFbeta-2 in the final steps of visual eye growth regulation.

Topics: Animals; Cartilage; Chickens; Gene Expression Regulation; Hyperopia; Male; Matrix Metalloproteinase 2; Myopia; Refractive Errors; RNA, Messenger; Sclera; Time Factors; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta

To report the first case of Avellino corneal dystrophy exacerbation after LASIK in a white or North American patient.. Case report and literature review.. A 25-year-old white female developed progressive corneal opacities after LASIK. Preoperative examination had revealed only subtle white corneal opacities in each eye. The patient's mother had similar corneal opacities. DNA analysis of the patient revealed a heterozygous mutation at the R124H location in the BIGH3 gene.. LASIK can exacerbate Avellino corneal dystrophy and should be avoided in patients with this condition. A careful history and genetic analysis can identify affected patients and those at risk.

Topics: Adult; Corneal Dystrophies, Hereditary; Corneal Opacity; Disease Progression; Extracellular Matrix Proteins; Female; Georgia; Humans; Keratomileusis, Laser In Situ; Mutation; Myopia; Transforming Growth Factor beta

Transforming growth factor-beta (TGFbeta), a multifunctional growth factor that plays a key role in the remodeling of scleral tissue, may be involved in the predisposition and pathophysiology of high myopia. Our aim was to examine the association between myopia and the polymorphisms within codon 10 of the TGFbeta1 gene.. This was a case control study. The study group contained participants who had high myopia and a spherical equivalent greater than -6.00 D. The control group was composed of medical students whose spherical equivalent was less then -0.5 D. All volunteers in this study were over 16 years old and had never undergone ocular surgery. Genotyping was conducted by restriction fragment length polymorphism, and the results were compared between myopia patients and control subjects.. The frequency of the CC genotype in TGFbeta1 codon 10 differed significantly between patients in the high myopia group (n=201) and individuals in the control group (n=86; p<0.001). People with either the CT or TT genotype had a lower probability of having high myopia with a spherical equivalent greater than -6.00 D than those with the CC genotype. Furthermore, there was a higher frequency of the C allele in the high myopia group than with the control group (p<0.001, OR=1.83, CI=1.27-2.63).. The frequency of the CC homozygote in the high myopia group was much higher than in the control group, indicating people with the CC homozygote may be at a higher risk of developing high myopia. Varied expression of this gene may contribute to the genetic predisposition to high myopia in Chinese Taiwanese.

Topics: Adolescent; Adult; Asian People; Case-Control Studies; Codon; Gene Frequency; Genetic Predisposition to Disease; Genotype; Homozygote; Humans; Myopia; Polymorphism, Genetic; Severity of Illness Index; Taiwan; Transforming Growth Factor beta; Transforming Growth Factor beta1

A previous study in China first indicated that the transforming growth factor-induced factor (TGIF) is a probable candidate gene for high myopia. The purpose of our study was to investigate whether there are significant associations between high myopia and single nucleotide polymorphism (SNP) variants in the TGIF gene of Japanese subjects. Genomic DNA was collected from 330 Japanese subjects with high myopia and at a level refractive error was less than -9.25 Dsph and 330 randomized controls without high myopia. Thirteen SNPs were detected by polymerase chain reaction (PCR) and primer extension or by PCR and SNP-specific fluorogenic probes in all of the cases and controls. Thirteen SNPs were found within the TGIF genes of the cases and controls. Two of the SNPs were monomorphic and none of the 13 SNPs showed a significant result. The pairwise linkage disequilibrium (LD) mapping confirmed that these alleles have a comparatively strong LD index of >0.8 for D' and >0.4 for r(2). We found no statistical association between any of the 13 SNPs located on the TGIF gene and high myopia in Japanese subjects. Based on our study using Japanese subjects and the previous studies of TGIF gene polymorphism in Chinese and northern European subjects with myopia, there is no convincing evidence to prove a connection between nucleotide sequence variations in TGIF and high myopia.

Topics: Adult; Asian People; Extracellular Matrix Proteins; Female; Humans; Linkage Disequilibrium; Male; Middle Aged; Myopia; Polymorphism, Single Nucleotide; Transforming Growth Factor beta

To quantify central corneal regrowth and haze development after LASIK in rabbits.. New Zealand White rabbits received an 89 microm (-8 diopters) myopic LASIK and were evaluated during 4 months using slit-lamp and in vivo confocal microscopy to monitor changes in central corneal morphology, epithelial and stromal thickness, flap and bed thickness, and corneal light backscattering (haze). At various time-points, corneas were processed for histology.. Using in vivo confocal microscopy, LASIK induced no detectable morphological changes besides a slightly elevated light backscattering at the interface. Correspondingly, all corneas remained clear with no haze development by slit-lamp biomicroscopy. Corneal thickness was stable by 8 weeks after an increase of 17 +/- 4 microm that consisted of a 13 +/- 3 microm stromal regrowth and a 4 +/- 2 microm epithelial hyperplasia. At the LASIK interface, less than 4 microm new extracellular matrix was deposited. Accordingly, all LASIK flaps were easily pulled off by 6 months.. LASIK induces a minimal wound healing response in rabbit corneas with no haze development and a regrowth (regression) of only 17 microm of an 89-microm photoablation. Three main factors contributed to the observed regrowth: epithelial hyperplasia (approximately 4 microm), matrix deposition at the LASIK interface (approximately 4 microm), and stromal growth outside the interface within the flap and wound bed (approximately 9 microm).

Topics: Actins; Animals; Cornea; Corneal Opacity; Corneal Stroma; Epithelium, Corneal; Extracellular Matrix; Fibroblasts; Fibronectins; Keratomileusis, Laser In Situ; Light; Microscopy, Confocal; Microscopy, Fluorescence; Myopia; Rabbits; Scattering, Radiation; Surgical Flaps; Transforming Growth Factor beta; Wound Healing

The development of high myopia is associated with altered scleral extracellular matrix biochemistry. Previous studies highlight the importance of collagen turnover in this process, yet it is unclear which factors control scleral remodeling. This study used a mammalian model of myopia to investigate the capacity of TGF (transforming growth factor)-beta1, -beta2, and -beta3 to influence scleral remodeling in myopia. RT-PCR confirmed the presence of all mammalian TGF-beta isoforms in scleral tissue and scleral fibroblasts. Myopia was experimentally induced via monocular deprivation of pattern vision, and animals were allocated to two groups depending on the duration of treatment (1 or 5 days). Down-regulation of each isoform was apparent after only 1 day of myopia development (TGF-beta1, -32%; TGF-beta2, -27%; TGF-beta3, -42%). Whereas the decrease in TGF-beta1 and -beta3 expression was relatively constant between the two time points, differential down-regulation of TGF-beta2 was found between days 1 (-27%) and 5 (-50%). In vitro experiments, using primary scleral fibroblasts, demonstrated the capacity of all isoforms to increase collagen production in a dose-dependent manner. Changes in TGF-beta levels, which mimicked those during myopia induction, caused an approximately 15% reduction in collagen synthesis, which is qualitatively similar to those previously reported in vivo. These data represent the first demonstration of TGF-beta3 expression in the sclera and implicate all three TGF-beta isoforms in the control of scleral remodeling during myopia development. In addition, the early alterations in TGF-beta expression levels may reflect a role for these cytokines in mediating the retinoscleral signal that controls myopic eye growth.

Topics: Animals; Animals, Newborn; Collagen; Disease Progression; Fibroblasts; Gene Expression Regulation; Myopia; Protein Isoforms; RNA, Messenger; Sclera; Time Factors; Transforming Growth Factor beta; Tupaiidae

To investigate the coding exons of transforming growth factor (TGF)-beta-induced factor (TGIF) for mutations in Chinese patients with high myopia.. 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.. 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).. TGIF is a probable candidate gene for high myopia. Further studies are needed to identify the underlying mechanism.

Topics: Adult; Asian People; Chromosomes, Human, Pair 18; Exons; Female; Genes, Homeobox; Homeodomain Proteins; Hong Kong; Humans; Male; Mutation; Myopia; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Repressor Proteins; Sequence Analysis, DNA; Transforming Growth Factor beta

To describe histopathological and immunohistochemical findings in human corneas after myopic laser in situ keratomileusis (LASIK) followed by iatrogenic keratectasia and after hyperopic LASIK.. Department of Ophthalmology, University of Innsbruck, Innsbruck, Austria.. Clinical, histological, and immunohistochemical investigations were performed of 1 human cornea with iatrogenic keratectasia following myopic LASIK and 1 human cornea with irregular astigmatism and central scar formation after hyperopic LASIK. Corneal buttons were obtained during penetrating keratoplasty in both patients.. Histopathological examination showed thinning of the central stroma with a posterior residual thickness of 190 microm in the patient with iatrogenic keratectasia after myopic LASIK and significant midperipheral thinning in the patient who had hyperopic LASIK. However, this characteristic ablation profile of the stroma after hyperopic LASIK was partially mitigated and compensated by the epithelium, which was significantly thinned in the center and markedly thickened in the midperiphery. Traces of wound healing with minimal scar tissue were present at the flap margin after myopic and hyperopic LASIK. In a few sections of the cornea with keratectasia after myopia LASIK, only a few collagen lamellae were visible crossing between the posterior residual stroma and the superficial flap. Immunohistochemical examination revealed minimally increased staining of dermatan sulfate proteoglycan within the stroma adjacent to the interface of the microkeratome incision. Increased staining of hepatocyte growth factor was found on keratocytes/fibroblasts at the flap margin in both corneas.. The wound-healing response is generally poor after LASIK, which may result in significant weakening of the tensile strength of the cornea after myopic LASIK, probably due to biomechanically ineffective superficial lamella. After LASIK in patients with high hyperopia, compensatory epithelial thickening in the annular midperipheral ablation zone might be partly responsible for regression.

Topics: Adult; Chondroitin Sulfate Proteoglycans; Collagen; Cornea; Corneal Diseases; Dermatan Sulfate; Dilatation, Pathologic; Female; Hepatocyte Growth Factor; Humans; Hyperopia; Iatrogenic Disease; Immunoenzyme Techniques; Keratan Sulfate; Keratomileusis, Laser In Situ; Keratoplasty, Penetrating; Male; Middle Aged; Myopia; Platelet-Derived Growth Factor; Transforming Growth Factor beta

To report a case of Avellino corneal dystrophy that increased in severity 1 year after uncomplicated laser in situ keratomileusis (LASIK) for myopia.. Avellino dystrophy was confirmed by polymerase chain reaction sequencing of DNA from the patient and her parents.. Best spectacle-corrected visual acuity decreased from 20/20 to 20/30 12 to 20 months after LASIK owing to opacities that appeared centrally in the corneal stroma and the LASIK flap and remaining posterior stroma interface.. LASIK is contraindicated in patients with Avellino corneal dystrophy because vision may be reduced by corneal opacities that appear in the interface of the flap and remaining posterior stroma postoperatively.

Topics: Adult; Contraindications; Corneal Dystrophies, Hereditary; Corneal Opacity; Disease Progression; DNA Mutational Analysis; Extracellular Matrix Proteins; Female; Humans; Keratomileusis, Laser In Situ; Myopia; Neoplasm Proteins; Polymerase Chain Reaction; Transforming Growth Factor beta; Vision Disorders; Visual Acuity

The aim was to determine the association of tear fluid cytokine levels and post-PRK corneal haze evaluated by in vivo confocal microscopy. In addition, the possible association between subbasal neural regeneration and haze formation, or epithelial regeneration were investigated. Twenty eyes of 20 patients (16 women and four men, age 30.7 +/- 7.5 years, range 21-48 years) underwent a myopic PRK. The spherical equivalent (SE) of the intended correction was -4.7 +/- 1.5 D (range -2.75 to -9.00 D). ELISA-methods were used to assess tear fluid concentrations of TGF-beta1, PDGF-BB and TNF-alpha pre-operatively, and post-operatively on day 2 and at 3 months. Tear fluid flow in the collection capillary was recorded, and rates of cytokine release (= tear fluid flow-corrected concentrations) were calculated. In vivo confocal microscopy was performed at 3 months to evaluate the corneal morphology and to determine numerical haze estimate. There was wide interindividual variation between pre-operative and post-operative concentrations and rates of release of TGF-beta1, PDGF-BB and TNF-alpha. Subepithelial haze was observed in all corneas and the mean haze estimate was 506 +/- 401 U (100-1410 U). However, no association was found between tear fluid cytokine levels and post-PRK haze. Regenerating subbasal nerve plexus was found in 18 out of 20 corneas; in two corneas it was absent or could not be visualized due to subepithelial haze. The density of the subbasal nerve fiber bundles had a positive correlation with the epithelial thickness (Pearson correlation, r = 0.56, P = 0.011), but not with the haze estimate or the thickness of the haze area. At 3 months post-PRK, haze could be observed in all patients. The results suggest that tear fluid cytokine analysis, as measured, may not be suitable for screening the potential candidates for haze formation. We did not find any correlation between haze and regeneration of subbasal nerve plexus, but we demonstrated that the regeneration of subbasal nerve plexus might have significant influence on regulation of epithelial healing.

Topics: Adult; Cornea; Enzyme-Linked Immunosorbent Assay; Epithelium, Corneal; Female; Humans; Immunoassay; Lasers, Excimer; Male; Microscopy, Confocal; Middle Aged; Myopia; Nerve Regeneration; Normal Distribution; Photorefractive Keratectomy; Proto-Oncogene Proteins c-sis; Statistics, Nonparametric; Tears; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Wound Healing

Form deprivation myopia in chicks is a widely accepted model to study visually-regulated postnatal ocular growth. The chick sclera has a cartilaginous layer as well as the fibrous layer found in mammals. It appears that a dynamic relationship exists between these two layers during visual deprivation-induced growth. The changes in the fibrous sclera of myopic eyes, however, have not been previously described. This investigation is focused on the comparative morphological analyses of the cartilaginous and fibrous scleral changes in myopic chick eyes. The fibrous scleral changes in the posterior segment of myopic eyes were examined in detail using light and electron microscopy, and the expression of growth factors was analysed by immunohistochemistry. In the posterior segment of myopic eyes the border between the cartilaginous and fibrous layers was indistinct because of collagen bundles of the fibrous sclera that spread into the cartilaginous sclera, whereas in control eyes the distinction was clear. Various types of transitional cells, from fibroblast-like mesenchymal cells to chondrocytes, were found in the border between the cartilaginous and fibrous layers. Collagen fibrillar diameters of the fibrous sclera in the posterior segment of myopic eyes were smaller than in control, whereas those in the equatorial segment were almost the same in myopic and control eyes although the distribution of sizes was obviously different. Thus, changes in the fibrous sclera in myopic eyes of chicks seem to be similar to scleral changes in myopic eyes of mammals. The cells in the posterior sclera of myopic eyes were more intensely immunostained for TGF-beta and IGF-II than control, whereas no immunoreaction of TGF-alpha could be detected in either control or myopic eyes. These results suggest that the structural characteristics of the posterior sclera are different from those of the anterior and equatorial segments. Undifferentiated mesenchymal cells might be concentrically distributed exclusively in the innermost layer of posterior fibrous sclera. TGF-beta and IGF-II might influence cell growth, differentiation, and migration in the exaggerated scleral growth accompanying myopia.

Topics: Animals; Chickens; Collagen; Decorin; Extracellular Matrix Proteins; Fibrosis; Insulin-Like Growth Factor II; Microscopy, Electron; Microscopy, Electron, Scanning; Myopia; Proteoglycans; Sclera; Sensory Deprivation; Transforming Growth Factor alpha; Transforming Growth Factor beta

To observed the effect of amniotic membrane transplantation (AMT) on expressions of transforming growth factor-beta 1(TGF-beta 1), collagens I, III and fibronectin (FN) in rabbit corneal healing after photorefractive keratectomy (PRK), and investigate the anti-scarring formation mechanism of AMT.. Ten rabbits underwent bilateral PRK to correct 8 diopters of myopia. One eye was randomly transplanted with preserved human amniotic membrane, and the other eye served as the control. The expressions of TGF-beta 1, collagens I, III and FN were studied by immunohistochemistry at 4 weeks after operation.. The expression of TGF-beta 1 in corneal epithelium and keratocytes and collegans in anterior stroma was significantly less in AMT group than in the control group. The expressions of collagens III and FN in anterior stroma of ablation area were also significantly less in AMT group than in the control group. The staining of collagen I had no significant difference between the AMT group and the control group.. The expressions of TGF-beta 1, collagens III and FN can be suppressed by amniotic membrane after PRK. These data suggest that part of the anti-scarring effect of AMT may be mediated through the suppression of TGF-beta 1, collagens III and FN expression.

Topics: Amnion; Animals; Collagen Type I; Collagen Type III; Cornea; Female; Fibronectins; Humans; Lasers, Excimer; Male; Myopia; Photorefractive Keratectomy; Rabbits; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transplantation, Heterologous; Wound Healing

To evaluate the outcomes of macular hole surgery in highly myopic eyes and to compare these outcomes with a control group of eyes that were not severely myopic.. The study design was a matched, case-control, retrospective chart review. The participants included 26 eyes of 24 patients who had vitreous surgery for macular holes. The eyes were divided into two groups: 13 consecutive eyes with severe myopia (defined as -6.00 diopters of refractive error or greater) and 13 control eyes without severe myopia that were operated on immediately before or after each study eye, with the most recently operated eye chosen. The main outcome parameters were preoperative and final follow-up visual acuity, macular hole closure rates, reoperation rates, duration of preoperative symptoms, and follow-up time.. Using the Snellen equivalent of logarithm of minimal angle of resolution (logMAR) units, visual acuity improved after macular hole surgery in severely myopic eyes from 20/152 to 20/89 (P =.041) and in control eyes from 20/152 to 20/47 (P <.001). At final follow-up, visual acuities were lower in severely myopic eyes compared with control eyes (P =.048). Macular hole closure rates, reoperation rates, duration of pre-operative symptoms, and follow-up intervals were not significantly different statistically between groups.. Macular hole surgery results in anatomical and visual improvements in severely myopic eyes but generally yields poorer visual acuity outcomes compared with eyes that are not severely myopic.

Topics: Adult; Aged; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myopia; Reoperation; Retinal Perforations; Retrospective Studies; Transforming Growth Factor beta; Treatment Outcome; Visual Acuity

Colchicine has been reported to destroy ganglion cells (GCs) in the retina of hatchling chicks. We tested whether colchicine influences normal ocular growth and form-deprivation myopia, and whether it affects cells other than GCs. Colchicine greatly increased axial length, equatorial diameter, eye weight, and myopic refractive error, while reducing corneal curvature. Colchicine caused DNA fragmentation in many GCs and some amacrine cells and photoreceptors, ultimately leading to the destruction of most GCs and particular sub-sets of amacrine cells. Colchicine-induced ocular growth may result from the destruction of amacrine cells that normally suppress ocular growth, and corneal flattening may result from the destruction of GCs whose central pathway normally plays a role in shaping the cornea.

Topics: Animals; Biomarkers; Calbindin 2; Cell Death; Chickens; Choline O-Acetyltransferase; Colchicine; Cornea; DNA Damage; Enkephalins; Eye; Form Perception; Glucagon; Immunohistochemistry; Isomerism; Male; Myopia; Neurofilament Proteins; Retina; Retinal Ganglion Cells; S100 Calcium Binding Protein G; Transforming Growth Factor beta; Tyrosine 3-Monooxygenase; Vasoactive Intestinal Peptide

Topics: Cicatrix; Collagen; Corneal Opacity; Corneal Ulcer; Epithelium, Corneal; Humans; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Recurrence; Transforming Growth Factor beta

Transforming growth factor beta (TGF-beta) plays an important role in anterior segment wound healing, by controlling the cell proliferation and differentiation, angiogenesis, extracellular matrix composition and mediating the immunosuppressive properties of the aqueous humor. The present study was undertaken to clarify the possible changes of aqueous humor TGF-betaI levels after excimer laser photoablation. Twenty-eight New Zealand rabbits were divided into four groups of 7 rabbits each. Group 1 served as control, the central 7 mm of corneal epithelium was removed in groups 2, 3 and 4. We performed 50-microm corneal photoablation in group 3, and 100-microm ablation in group 4. After 48 h we measured the TGF-betaI levels of the aqueous humor by ELISA method. The mean TGF-betaI value of the aqueous humor was found to be 162.94+/-13.73 pg/ml in the control group. Mechanical deepithelialization did not change the TGF-betaI levels of the aqueous humor (p > 0.05). There was no significant difference between the 50-microm photoablated group and the controls (p > 0.05), but the TGF-betaI levels of the 100-microm photoablated group were found to be significantly higher than those of both the control group and 50-microm photoablated group (p < 0.05). Many factors and cytokines may induce corneal haze and myopic regression after excimer laser photoablation; our study demonstrated that TGF-betaI is one of these factors and there is a positive correlation between the depth of corneal photoablation and aqueous TGF-betaI concentrations.

Topics: Animals; Aqueous Humor; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Epithelium, Corneal; Lasers, Excimer; Myopia; Photorefractive Keratectomy; Rabbits; Transforming Growth Factor beta; Wound Healing

The purpose of this study is to clarify the role of retinoic acid (RA) in the mechanism of form-deprivation myopia (FDM) in the chick. FDM was induced in two-day old chicks by placement of a translucent plastic goggle over one eye, with the contralateral eye used as a control. After 12 days, the chicks were euthanized. RNA was extracted from scleras in the posterior segments, transcribed into cDNA, and amplified by PCR with primers specific for retinoic acid receptor (RAR) beta. G3PDH was used as a reference gene for normalization. The effects of RA, with or without TGF-beta, on the proliferation of scleral chondrocytes and scleral fibroblasts from 17-day chick embryos were studied by use of a colorimetric assay, and the alkaline phosphatase activities of those cells also studied. Furthermore, RAR beta expression in response to RA in cultured scleral cells was studied. As a result, RT-PCR products of the expected sizes were obtained from scleras from the myopic and control eyes. Expression of RAR beta in the myopic scleras was significantly higher than that in the controls. The proliferation of scleral chondrocytes and scleral fibroblasts was inhibited by treatment with RA in a dose-dependent manner (in 10% FBS). In the presence of TGF-beta (in 0.5% FBS), RA treatment stimulated the proliferation of scleral chondrocytes but inhibited the proliferation of scleral fibroblasts. RA induced alkaline phosphatase activities in both the scleral chondrocytes and scleral fibroblasts. RAR beta expression was induced by RA in cultured scleral cells. These results demonstrate that RA appears to play a role in the mechanism of FDM in the chick. However, it is also possible that the changes in the expression of RAR beta were secondary events related to other mechanisms responsible for ocular enlargement.

Topics: Alkaline Phosphatase; Animals; Cell Culture Techniques; Cell Division; Chickens; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Male; Myopia; Polymerase Chain Reaction; Receptors, Retinoic Acid; Sclera; Sensory Deprivation; Transforming Growth Factor beta; Tretinoin

To determine factors that control ocular enlargement in experimental form-deprivation myopia and to clarify the mechanism of form-deprivation myopia.. After the left eyes of 20 chicks were monocularly occluded for 2 weeks, protein, basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta 2 contents in samples of constant area (circular button, diameter = 8.5 mm) in the retina-retinal pigment epithelium (RPE)-choroid and the sclera in the posterior region of control and myopic eyes were determined by enzyme-linked immunosorbent assay.. The bFGF content (per circular button) and bFGF concentration (per mg protein) were significantly lower in the sclera in the posterior region of the myopic eyes than in control eyes. The bFGF content and concentration were similar in the retina-RPE-choroid in myopic and control eyes. The TGF-beta 2 content and concentration were significantly higher in myopic eyes in both the retina-RPE-choroid and the sclera (P < 0.05).. These results are consistent with the possibility that bFGF and TGF-beta 2 regulate ocular enlargement or respond to myopiagenic mechanisms in form-deprivation myopia.

Topics: Animals; Chickens; Disease Models, Animal; Eye; Fibroblast Growth Factor 2; Male; Myopia; Sensory Deprivation; Transforming Growth Factor beta

Occlusion of the eye (form deprivation) during post-natal development leads to ocular enlargement and myopia. The chick model of form deprivation myopia (FDM) has been used to identify candidate factors that underly the control of ocular growth. The major biochemical change associated with eye enlargement is an increase in scleral cartilage proteoglycan production (Rada et al., 1991) which is reduced in recovering eyes. Thus increasing evidence suggests that in the chicken eye, two different signals are involved, one for stop (occluder off) and one for go (occluder on). Because transforming growth factor-beta (TGF-beta) and basic fibroblast growth factor (bFGF) are known to act in a push-pull manner in regulating extracellular matrix, their possible roles in FDM were tested. Chicks were occluded monocularly for 8 days, after which axial dimensions were assessed using A-scan ultrasonography, and refractive errors using streak retinoscopy. Under light halothane anesthesia, the control group received daily vehicle injections into both eyes whereas the experimental groups were treated with growth factors in the occluded eye and vehicle in the unoccluded eye. It was shown that: (1) bFGF reduced FDM in a dose-dependent manner, with a 50% effective dose (ED50) of 1.05 and 1.67 ng for subconjunctival and intravitreal delivery, respectively. Both axial eye length and refraction were similarly affected. The effects were mainly confined to a decrease in vitreous chamber depth. The anterior chamber was less deep but only after intravitreal injections, whereas lens thickness was not affected at all. At maximum effect, after subconjunctival applications the bFGF-treated occluded eyes were only 0.09 +/- 0.16 mm longer than controls, which corresponded to a refractive error of -0.67 +/- 0.82 diopters (D), whereas after intravitreal applications the difference in axial eye length was -0.07 +/- 0.19 mm, corresponding to -0.3 +/- 0.52 D. (2) This effect could be mimicked by aFGF, but with a potency approximately 160 times less than that of bFGF. The aFGF rescue effect could only be demonstrated for subconjunctival delivery; high intravitreal doses (> or = 300 ng per injection) induced retinal detachment and photoreceptor degeneration, while doses of aFGF close to the ED50 for bFGF (3 ng per injection) were completely ineffective. (3) TGF-beta 1 was not found to induce myopia in unoccluded eyes, or to increase myopia in occluded eyes. It was, however, a potent inhibitor of t

Topics: Animals; Chickens; Dose-Response Relationship, Drug; Eye; Fibroblast Growth Factor 2; Male; Myopia; Recombinant Proteins; Sensory Deprivation; Transforming Growth Factor beta