Pathological proliferation of retinal blood vessels commonly causes vision impairment in proliferative retinopathies, including retinopathy of prematurity. Dysregulated crosstalk between the vasculature and retinal neurons is increasingly recognized as a major factor contributing to the pathogenesis of vascular diseases. Class 3 semaphorins (SEMA3s), a group of neuron-secreted axonal and vascular guidance factors, suppress pathological vascular growth in retinopathy. However, the upstream transcriptional regulators that mediate the function of SEMA3s in vascular growth are poorly understood. Here we showed that retinoic acid receptor-related orphan receptor α (RORα), a nuclear receptor and transcription factor, is a novel transcriptional regulator of SEMA3E-mediated neurovascular coupling in a mouse model of oxygen-induced proliferative retinopathy. We found that genetic deficiency of RORα substantially induced Sema3e expression in retinopathy. Both RORα and SEMA3E were expressed in retinal ganglion cells. RORα directly bound to a specific ROR response element on the promoter of Sema3e and negatively regulated Sema3e promoter-driven luciferase expression. Suppression of Sema3e using adeno-associated virus 2 carrying short hairpin RNA targeting Sema3e promoted disoriented pathological neovascularization and partially abolished the inhibitory vascular effects of RORα deficiency in retinopathy. Our findings suggest that RORα is a novel transcriptional regulator of SEMA3E-mediated neurovascular coupling in pathological retinal angiogenesis.-Sun, Y., Liu, C.-H., Wang, Z., Meng, S. S., Burnim, S. B., SanGiovanni, J. P., Kamenecka, T. M., Solt, L. A., Chen, J. RORα modulates semaphorin 3E transcription and neurovascular interaction in pathological retinal angiogenesis.
Pathological neovessels growing into the normally avascular photoreceptors cause vision loss in many eye diseases, such as age-related macular degeneration and macular telangiectasia. Ocular neovascularization is strongly associated with inflammation, but the source of inflammatory signals and the mechanisms by which these signals regulate the disruption of avascular privilege in photoreceptors are unknown. In this study, we found that c-Fos, a master inflammatory regulator, was increased in photoreceptors in a model of pathological blood vessels invading photoreceptors: the very low-density lipoprotein receptor-deficient (Vldlr(-/-) ) mouse. Increased c-Fos induced inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor (TNF), leading to activation of signal transducer and activator of transcription 3 (STAT3) and increased TNFα-induced protein 3 (TNFAIP3) in Vldlr(-/-) photoreceptors. IL-6 activated the STAT3/vascular endothelial growth factor A (VEGFA) pathway directly, and elevated TNFAIP3 suppressed SOCS3 (suppressor of cytokine signaling 3)-activated STAT3/VEGFA indirectly. Inhibition of c-Fos using photoreceptor-specific AAV (adeno-associated virus)-hRK (human rhodopsin kinase)-sh_c-fos or a chemical inhibitor substantially reduced the pathological neovascularization and rescued visual function in Vldlr(-/-) mice. These findings suggested that the photoreceptor c-Fos controls blood vessel growth into the normally avascular photoreceptor layer through the inflammatory signal-induced STAT3/VEGFA pathway.
Reactive remodeling of optic nerve head astrocytes is consistently observed in glaucoma and other optic nerve injuries. However, it is unknown whether this reactivity is beneficial or harmful for visual function. In this study, we used the Cre recombinase (Cre)-loxP system under regulation of the mouse glial fibrillary acidic protein promoter to knock out the transcription factor signal transducer and activator of transcription 3 (STAT3) from astrocytes and test the effect this has on reactive remodeling, ganglion cell survival, and visual function after experimental glaucoma and nerve crush. After injury, STAT3 knockout mice displayed attenuated astrocyte hypertrophy and reactive remodeling; astrocytes largely maintained their honeycomb organization and glial tubes. These changes were associated with increased loss of ganglion cells and visual function over a 30-day period. Thus, reactive astrocytes play a protective role, preserving visual function. STAT3 signaling is an important mediator of various aspects of the reactive phenotype within optic nerve astrocytes.
The use of viral vectors for inner ear gene therapy is receiving increased attention for treatment of genetic hearing disorders. Most animal studies to date have injected viral suspensions into neonatal ears, via the round window membrane. Achieving transduction of hair cells, or sensory neurons, throughout the cochlea has proven difficult, and no studies have been able to efficiently transduce sensory cells in adult ears while maintaining normal cochlear function. Here, we show, for the first time, successful transduction of all inner hair cells and the majority of outer hair cells in an adult cochlea via virus injection into the posterior semicircular canal. We used a "designer" AAV, AAV2/Anc80L65, in which the main capsid proteins approximate the ancestral sequence state of AAV1, 2, 8, and 9. Our injections also transduced ~10% of spiral ganglion cells and a much larger fraction of their satellite cells. In the vestibular sensory epithelia, the virus transduced large numbers of hair cells and virtually all the supporting cells, along with close to half of the vestibular ganglion cells. We conclude that this viral vector and this delivery route hold great promise for gene therapy applications in both cochlear and vestibular sense organs.
PURPOSE: In advanced Fuchs endothelial corneal dystrophy (FECD), central endothelial changes do not correlate with disease severity. The peripheral endothelial cell count (ECC) has not been studied as a marker of FECD severity. The goal of this study was to determine the relationship between the peripheral ECC and known clinical markers of FECD in advanced cases. METHODS: Patients with FECD examined between January 1, 2013, and September 1, 2016, by 1 cornea specialist were identified. Medical records from all previous visits were reviewed to include eyes with high-quality central and peripheral in vivo confocal microscopy images performed on the same day as a clinical evaluation. Endothelial photographs were used to perform manual cell counts centrally and peripherally. Clinical grading of FECD from 1 to 4 was performed at the slit-lamp. RESULTS: We identified 154 eyes of 126 patients that met criteria for inclusion. With higher disease grades, central ECC and peripheral ECC decreased, visual acuity worsened, and central corneal thickness (CCT) increased (all P < 0.05). In patients with advanced disease (defined as either grade 3 or 4, CCT >700, or central ECC <350), the peripheral ECC was the best predictor of disease severity and had the highest number of statistically significant correlations with other clinical markers compared with competing variables. CONCLUSIONS: In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and CCT. The peripheral ECC should be added to the clinical parameters used to evaluate FECD severity.
PURPOSE: Obstructive meibomian gland dysfunction is a leading cause of ocular morbidity and its treatment remains a challenge. Meibomian gland probing was initially described in 2010. Here, the authors describe a modified technique, dynamic intraductal meibomian probing, which offers several advantages over the traditional approach including increased magnification, greater eyelid stabilization, enhanced anesthesia, and easier identification of gland orifices through the expression of meibum. METHODS: The authors conducted a retrospective chart review of 70 eyelids with treatment-resistant obstructive meibomian gland dysfunction undergoing dynamic intraductal meibomian probing between January 2013 and April 2015. RESULTS: Immediately after the procedure, 91.4% of cases experienced symptomatic improvement, and no complications were noted. CONCLUSIONS: Dynamic intraductal meibomian probing is an effective and safe treatment for obstructive meibomian gland dysfunction that is resistant to traditional therapies.
Antigen-presenting cells (APCs) play an important role in transplant rejection and tolerance. In high-risk corneal transplantation, where the graft bed is inflamed and vascularized, immature APCs in the donor corneal stroma quickly mature and migrate to lymphoid tissues to sensitize host T cells. In this study, using a mouse model of corneal transplantation, we investigated whether enrichment of tolerogenic APCs (tolAPCs) in donor corneas can enhance graft survival in corneal allograft recipients with inflamed graft beds. Treatment of donor corneas with interleukin-10 (IL-10) and transforming growth factor-β1 (TGFβ1) altered the phenotype and function of tissue-residing APCs. Transplantation of these tolAPC-enriched corneas decreased frequencies of interferon gamma (IFNγ)(+) effector T cells (Teffs), as well as allosensitization in the hosts, diminished graft infiltration of CD45(+) and CD4(+) cells, and significantly improved corneal allograft survival compared to saline-injected controls. These data provide a novel approach for tolAPC-based immunotherapy in transplantation by direct cytokine conditioning of the donor tissue.
Transmembrane mucins are highly O-glycosylated glycoproteins that coat the apical glycocalyx on mucosal surfaces and represent the first line of cellular defense against infection and injury. Relatively low levels of N-glycans are found on transmembrane mucins, and their structure and function remain poorly characterized. We previously reported that carbohydrate-dependent interactions of transmembrane mucins with galectin-3 contribute to maintenance of the epithelial barrier at the ocular surface. Now, using MALDI-TOF mass spectrometry, we report that transmembrane mucin N-glycans in differentiated human corneal epithelial cells contain primarily complex-type structures with N-acetyllactosamine, a preferred galectin ligand. In N-glycosylation inhibition experiments, we find that treatment with tunicamycin and siRNA-mediated knockdown of the Golgi N-acetylglucosaminyltransferase I gene (MGAT1) induce partial loss of both total and cell-surface levels of the largest mucin, MUC16, and a concomitant reduction in glycocalyx barrier function. Moreover, we identified a distinct role for N-glycans in promoting MUC16's binding affinity toward galectin-3 and in causing retention of the lectin on the epithelial cell surface. Taken together, these studies define a role for N-linked oligosaccharides in supporting the stability and function of transmembrane mucins on mucosal surfaces.
PURPOSE: To quantitatively evaluate the angle anatomy in eyes with the Boston type I keratoprosthesis (B-KPro) differing in the back plate (BP) material and size using anterior segment optical coherence tomography. METHODS: B-KPro eyes with poly(methyl methacrylate) (PMMA) (7.0 and 8.5 mm) and titanium (7.0, 8.5, and 9.5 mm) BPs were imaged with anterior segment optical coherence tomography. The angle opening distance at 500 μm from the scleral spur (AOD500), trabecular iris surface area at 500 μm from the scleral spur (TISA500), and trabecular iris angle at 500 μm from the scleral spur (TIA500) were measured. Among the visible quadrants, the average, the temporal, the widest, and the narrowest angle of each eye were included in the analysis. Average time between B-KPro implantation and imaging was 7.5 ± 1.4 years for a PMMA BP and 2.4 ± 2.3 years for a titanium BP (P < 0.0001). RESULTS: We analyzed 17 B-KPro eyes with PMMA BPs and 24 B-KPro eyes with titanium BPs. The average AOD500 (394.1 ± 226.9 vs. 454.5 ± 255.6 μm, P = 0.44), average TIA500 (26.2 ± 14.2 vs. 29.8 ± 13.9 degrees, P = 0.43), and average TISA500 (0.15 ± 0.08 vs. 0.17 ± 0.10 μm, P = 0.52) were not statistically different between eyes with PMMA and titanium BPs, nor were the temporal, the narrowest, and the widest angle measurements of each eye (all P > 0.05). Similarly, no significant differences were found between the angle measurements of B-KPro eyes with a titanium BP diameter of 8.5 or 9.5 mm (all P > 0.05). CONCLUSIONS: We successfully visualized the angle anatomy in 66.1% of the imaged eyes, including all BPs studied. Neither the material nor the size of the B-KPro BP had a significant impact on the angle anatomy.
Horstick et al. (2013) previously reported a homozygous p.Trp284Ser variant in STAC3 as the cause of Native American myopathy (NAM) in 5 Lumbee Native American families with congenital hypotonia and weakness, cleft palate, short stature, ptosis, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia (MH). Here we present two non-Native American families, who were found to have STAC3 pathogenic variants. The first proband and her affected older sister are from a consanguineous Qatari family with a suspected clinical diagnosis of Carey-Fineman-Ziter syndrome (CFZS) based on features of hypotonia, myopathic facies with generalized weakness, ptosis, normal extraocular movements, cleft palate, growth delay, and kyphoscoliosis. We identified the homozygous c.851G>C;p.Trp284Ser variant in STAC3 in both sisters. The second proband and his affected sister are from a non-consanguineous, Puerto Rican family who was evaluated for a possible diagnosis of Moebius syndrome (MBS). His features included facial and generalized weakness, minimal limitation of horizontal gaze, cleft palate, and hypotonia, and he has a history of MH. The siblings were identified to be compound heterozygous for STAC3 variants c.851G>C;p.Trp284Ser and c.763_766delCTCT;p.Leu255IlefsX58. Given the phenotypic overlap of individuals with CFZS, MBS, and NAM, we screened STAC3 in 12 individuals diagnosed with CFZS and in 50 individuals diagnosed with MBS or a congenital facial weakness disorder. We did not identify any rare coding variants in STAC3. NAM should be considered in patients presenting with facial and generalized weakness, normal or mildly abnormal extraocular movement, hypotonia, cleft palate, and scoliosis, particularly if there is a history of MH.
PURPOSE: To report a novel presentation of dyskeratosis congenita masquerading as familial exudative vitreoretinopathy. METHODS: Observational case series involving single family and literature review. RESULTS: A brother and sister were diagnosed with familial exudative vitreoretinopathy at ages 4 and 2, respectively. Both patients were managed with laser photocoagulation. Eight years after the initial presentation, both siblings developed pancytopenia secondary to bone marrow failure. Laboratory work-up revealed severely shortened telomere length in both patients, and genetic testing revealed a missense mutation in the gene that encodes the reverse transcriptase component of telomerase, confirming the diagnosis of dyskeratosis congenita. The father of both children was a carrier of the same mutation, who exhibited marked retinal vascular tortuosity of the second-order vessels. CONCLUSION: Dyskeratosis congenita is a severe multisystem disorder, which should be considered in cases of pediatric exudative retinopathies with concurrent signs and/or symptoms of bone marrow failure.
Primary congenital glaucoma (PCG) is a leading cause of blindness in children worldwide and is caused by developmental defects in 2 aqueous humor outflow structures, Schlemm's canal (SC) and the trabecular meshwork. We previously identified loss-of-function mutations in the angiopoietin (ANGPT) receptor TEK in families with PCG and showed that ANGPT/TEK signaling is essential for SC development. Here, we describe roles for the major ANGPT ligands in the development of the aqueous outflow pathway. We determined that ANGPT1 is essential for SC development, and that Angpt1-knockout mice form a severely hypomorphic canal with elevated intraocular pressure. By contrast, ANGPT2 was dispensable, although mice deficient in both Angpt1 and Angpt2 completely lacked SC, indicating that ANGPT2 compensates for the loss of ANGPT1. In addition, we identified 3 human subjects with rare ANGPT1 variants within an international cohort of 284 PCG patients. Loss of function in 2 of the 3 patient alleles was observed by functional analysis of ANGPT1 variants in a combined in silico, in vitro, and in vivo approach, supporting a causative role for ANGPT1 in disease. By linking ANGPT1 with PCG, these results highlight the importance of ANGPT/TEK signaling in glaucoma pathogenesis and identify a candidate target for therapeutic development.
Pseudotumor cerebri syndrome refers to elevated intracranial pressure associated with papilledema without an identified etiology for intracranial hypertension. Over the past few decades, several medications have been described to be associated with this syndrome. We searched the literature for those case reports and series and evaluated the evidence for the association of such medications with pseudotumor cerebri syndrome.
Phagocytosis of daily shed photoreceptor outer segments is an important function of the retinal pigment epithelium (RPE) and it is essential for retinal homeostasis. RPE dysfunction, especially impairment of its phagocytic ability, plays an essential role in the pathogenesis of age-related macular degeneration (AMD). Statins, or HMG CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors, are drugs with multiple properties that have been extensively used to treat hyperlipidemia. However, their effect on RPE cells has not been fully elucidated. Here we report that high dose atorvastatin increased the phagocytic function of ARPE-19 cells, as well as rescue the cells from the phagocytic dysfunction induced by cholesterol crystals and oxidized low-density lipoproteins (ox-LDL), potentially by increasing the cellular membrane fluidity. Similar effects were observed when evaluating two other hydrophobic statins, lovastatin and simvastatin. Furthermore, atorvastatin was able to block the induction of interleukins IL-6 and IL-8 triggered by pathologic stimuli relevant to AMD, such as cholesterol crystals and ox-LDL. Our study shows that statins, a well-tolerated class of drugs with rare serious adverse effects, help preserve the phagocytic function of the RPE while also exhibiting anti-inflammatory properties. Both characteristics make statins a potential effective medication for the prevention and treatment of AMD.
Dural cerebral veins (CV) are required for cerebrospinal fluid reabsorption and brain homeostasis, but mechanisms that regulate their growth and remodeling are unknown. We report molecular and cellular processes that regulate dural CV development in mammals and describe venous malformations in humans with craniosynostosis and TWIST1 mutations that are recapitulated in mouse models. Surprisingly, Twist1 is dispensable in endothelial cells but required for specification of osteoprogenitor cells that differentiate into preosteoblasts that produce bone morphogenetic proteins (BMPs). Inactivation of Bmp2 and Bmp4 in preosteoblasts and periosteal dura causes skull and CV malformations, similar to humans harboring TWIST1 mutations. Notably, arterial development appears normal, suggesting that morphogens from the skull and dura establish optimal venous networks independent from arterial influences. Collectively, our work establishes a paradigm whereby CV malformations result from primary or secondary loss of paracrine BMP signaling from preosteoblasts and dura, highlighting unique cellular interactions that influence tissue-specific angiogenesis in mammals.
PURPOSE: To evaluate the efficacy and safety of a sustained-release dexamethasone intracanalicular insert (Dextenza™) in a model of allergic conjunctivitis. METHODS: This was a randomized, double-masked, vehicle-controlled, Phase 2 study. Subjects had to have a positive conjunctival allergen challenge (CAC) reaction to allergen (bilateral +2 itching and redness on 5-point, 0-4 scales) at Visit 1, and for 2 of 3 time points on subsequent visits. Subjects who met entry criteria were randomized to receive Dextenza or PV (vehicle insert). Challenges occurred over 42 days, with efficacy assessed at 14 (primary endpoint visit), 28, and 40 days postinsertion. Outcome measures included the evaluation of ocular itching, redness, tearing, chemosis, eyelid swelling, rhinorrhea, and congestion. RESULTS: Twenty-eight subjects completed the study in the Dextenza group and 31 in the vehicle group. At 14 days postinsertion, Dextenza was statistically superior to PV, with least square mean differences for ocular itching of -0.76, -0.97, and -0.87 at 3, 5, and 7 min post-CAC, and for conjunctival redness of -0.46, -0.66, and -0.68 at 7, 15, and 20 min post-CAC. Clinical significance, defined as a 1-U decrease from PV, was not met for primary efficacy. Secondary endpoints, including number of subjects reporting itching and conjunctival redness, indicated superior performance of Dextenza compared with vehicle. Eleven Dextenza-treated (35.5%) and 10 vehicle-treated (30.3%) subjects each experienced a single adverse event. CONCLUSION: This Phase 2 study demonstrated preliminary efficacy and safety data of Dextenza for treatment of allergic conjunctivitis.
PURPOSE: To describe new software tools for quantifying optic nerve head drusen volume using 3-dimensional (3D) swept-source optical coherence tomography (SS-OCT) volumetric scans. MATERIALS AND METHODS: SS-OCT was used to acquire raster volume scans of 8 eyes of 4 patients with bilateral optic nerve head drusen. The scans were manually segmented by 3 graders to identify the drusen borders, and thereafter total drusen volumes were calculated. Linear regression was performed to study the relationships between drusen volume, retinal nerve fiber layer thickness, and Humphrey visual field mean deviation. RESULTS: In the 8 study eyes, drusen volumes ranged between 0.24 to 1.05 mm. Visual field mean deviation decreased by ∼20 dB per cubic millimeter increase in drusen volume, and the coefficient of correlation of the linear regression was 0.92. In this small patient series, visual field defects were detected when drusen volume was larger than about 0.2 mm. CONCLUSIONS: Software tools have been developed to quantify the size of OHND using SS-OCT volume scans.
PURPOSE: The purpose of this study was to develop an algorithm to automatically standardize the brightness, contrast, and color balance of digital color fundus photographs used to grade AMD and to validate this algorithm by determining the effects of the standardization on image quality and disease grading. METHODS: Seven-field color photographs of patients (>50 years) with any stage of AMD and a control group were acquired at two study sites, with either the Topcon TRC-50DX or Zeiss FF-450 Plus cameras. Field 2 photographs were analyzed. Pixel brightness values in the red, green, and blue (RGB) color channels were adjusted in custom-built software to make the mean brightness and contrast of the images equal to optimal values determined by the Age-Related Eye Disease Study (AREDS) 2 group. RESULTS: Color photographs of 370 eyes were analyzed. We found a wide range of brightness and contrast values in the images at baseline, even for those taken with the same camera. After processing, image brightness variability (brightest image-dimmest image in a color channel) was reduced 69-fold, 62-fold, and 96-fold for the RGB channels. Contrast variability was reduced 6-fold, 8-fold, and 13-fold, respectively, after adjustment. Of the 23% images considered nongradable before adjustment, only 5.7% remained nongradable. CONCLUSIONS: This automated software enables rapid and accurate standardization of color photographs for AMD grading. TRANSLATIONAL RELEVANCE: This work offers the potential to be the future of assessing and grading AMD from photos for clinical research and teleimaging.
An orbital neoplasm in children is an uncommon clinical finding. Clinical suspicion should be based on many factors, including its location, the nature of onset, associated systemic signs and symptoms, family and social histories, examination findings, and radiographic characteristics. We present two cases of young children of similar age with a rapid-onset orbital mass. In both cases, a circumscribed round lesion was found in the superomedial orbit. An orbital schwannoma, a benign and usually slow growing tumor, was found in the first patient. In contrast, the biopsy of the second patient, who was nearly asymptomatic, revealed a rhabdomyosarcoma. In this review, we have explored the differential diagnosis of relatively common circumscribed round orbital tumors in the pediatric population from both the radiographic (magnetic resonance imaging, MRI) and histopathologic perspectives. A review of highly unusual orbital tumors in children is also provided.