Decreased FABP5 and DSG1 protein expression following PAX6 knockdown of differentiated human limbal epithelial cells.

PAX6 haploinsufficiency related aniridia is characterized by disorder of limbal epithelial cells (LECs) and aniridia related keratopathy. In the limbal epithelial cells of aniridia patients, deregulated retinoic acid (RA) signaling components were identified. We aimed to visualize differentiation marker and RA signaling component expression in LECs, combining a differentiation triggering growth condition with a small interfering RNA (siRNA) based aniridia cell model (PAX6 knock down). Primary LECs were isolated from corneoscleral rims of healthy donors and cultured in serum free low Ca2+ medium (KSFM) and in KSFM supplemented with 0.9 mmol/L Ca2+. In addition, LECs were treated with siRNA against PAX6. DSG1, PAX6, KRT12, KRT 3, ADH7, RDH10, ALDH1A1, ALDH3A1, STRA6, CYP1B1, RBP1, CRABP2, FABP5, PPARG, VEGFA and ELOVL7 expression was determined using qPCR and western blot. DSG1, FABP5, ADH7, ALDH1A1, RBP1, CRABP2 and PAX6 mRNA and FABP5 protein expression increased (p ≤ 0.03), PPARG, CYP1B1 mRNA expression decreased (p ≤ 0.0003) and DSG1 protein expression was only visible after Ca2+ supplementation. After PAX6 knock down and Ca2+ supplementation, ADH7 and ALDH1A1 mRNA and DSG1 and FABP5 protein expression decreased (p ≤ 0.04), compared to Ca2+ supplementation alone. Using our cell model, with Ca2+ supplementation and PAX6 knockdown with siRNA treatment against PAX6, we provide evidence that haploinsufficiency of the master regulatory gene PAX6 contributes to differentiation defect in the corneal epithelium through alterations of RA signalling. Upon PAX6 knockdown, DSG1 differentiation marker and FABP5 RA signaling component mRNA expression decreases. A similar effect becomes apparent at protein level though differentiation triggering Ca2+ supplementation in the siRNA-based aniridia cell model. Expression data from this cell model and from our siRNA aniridia cell model strongly indicate that FABP5 expression is PAX6 dependent. These new findings may lead to a better understanding of differentiation processes in LECs and are able to explain the insufficient cell function in AAK.

Ophthalmological evaluation and integrated intervention in a family with congenital aniridia in Alagoas, Brazil / Avaliação oftalmológica e intervenção integrada em família com aniridia congênita em Alagoas, Brasil

Abstract Objective: We aimed to describe the clinical and phenotypic manifestations as well as the visual prognosis of a family with CA in Northeastern Brazil. Methods: This was a cross-sectional study involving 31 individuals (56 eyes) from the same family presenting CA phenotypes. The study population resided in the municipality of Água Branca, in the backlands of the state of Alagoas, Northeastern Brazil. The clinical and phenotypic variables were analyzed. For the analysis, descriptive statistics (absolute and relative frequency and measures of central tendency and dispersion) and inferential statistics (Shapiro-Wilk and Student's t tests) were used, with 95% confidence intervals and significance set at 5%. Results: Of the 31 individuals, 18 (58.1%) were male, with a mean age of 27.45 ± 17.49 years, with no difference between sexes. Of the 56 eyes evaluated, 26 and 30 were right and left eyes, respectively; 61.3% (n = 19) individuals had complete bilateral aniridia and 25.8% (n = 8) reported a total loss of light perception in both the eyes. The most prevalent ocular abnormalities were nystagmus (n = 27; 87.09%), cataract (n = 20; 64.5%), strabismus (n = 14; 45.2%), corneal changes such as opacities and/or vascularization (n = 13; 41.93%), and ectopia lentis (n = 6; 19.4%). Further, 13 individuals underwent retinal optical coherence tomography, six man and seven women aged 9-48 (mean, 30.15 ± 15.9) years. All patients presented absence of foveal depression as well as reduced macular thickness and visual acuity. Nine subjects underwent phacoemulsification. Conclusion: The study showed wide phenotypic variation among the studied individuals, with poor visual prognosis. The study highlights the need to establish comprehensive care mechanisms for families with the disease.

Resumo Objetivo: Descrever manifestações clínicas e fenotípicas e o prognóstico visual de uma família com aniridia congênita (AC). Métodos: Trata-se de estudo transversal envolvendo 31 indivíduos (56 olhos), de uma mesma família com fenótipo de AC residindo no município de Água Branca, no sertão do estado de Alagoas, região nordeste do Brasil. Foram analisadas variáveis clínicas e fenotípicas. Para a análise, foi utilizada a estatística descritiva (frequência absoluta e relativa e medidas de tendência central e de dispersão) e inferencial (testes de Shapiro-Wilk e t Student). Considerou-se o intervalo de confiança de 95% e a significância de 5%. Resultados: Dos 31 indivíduos, 18 (58,1%) eram do sexo masculino, com média de idade de 27,45±17,49, sem diferença entre os sexos. Dos 56 olhos avaliados, 26 eram olhos direitos e 30 olhos esquerdos: 61,3% (n=19) apresentavam aniridia bilateral total; 25,8% (n=8) referiam perda total de percepção da luz em ambos os olhos. As anormalidades oculares mais prevalentes foram o nistagmo (n=27; 87,09%), catarata (n=20; 64,5%), estrabismo 14 (45,2%), alterações opacidades ou vascularização corneanas (n=13; 41,93%) e ectopia lentis (n=6; 19,4%). Os 13 indivíduos submetidos à tomografia de coerência óptica (OCT) retiniana apresentavam perda da depressão foveal, redução da espessura macular e redução da acuidade visual. Nove indivíduos foram submetidos a cirurgia de facoemulsificação. Conclusão: O estudo mostrou ampla variação fenotípica entre os indivíduos estudados, com pobre prognóstico visual. O estudo destaca a necessidade de estabelecer mecanismos de cuidado integral para as famílias com a doença.

Early and late auditory information processing show opposing deviations in aniridia.

Aniridia is a congenital disorder, predominantly caused by heterozygous mutations of the PAX6 gene. While ocular defects have been extensively characterized in this population, brain-related anatomical and functional abnormalities are emerging as a prominent feature of the disorder. Individuals with aniridia frequently exhibit auditory processing deficits despite normal audiograms. While previous studies have reported hypoplasia of the anterior commissure and corpus callosum in some of these individuals, the neurophysiological basis of these impairments remains unexplored. This study provides direct assessment of neural activity related to auditory processing in aniridia. Participants were presented with tones designed to elicit an auditory steady-state response (ASSR) at 22 Hz, 40 Hz, and 84 Hz, and infrequent broadband target tones to maintain attention during electroencephalography (EEG) recording. Persons with aniridia showed increased early cortical responses (P50 AEP) in response to all tones, and increased high-frequency oscillatory entrainment (84 Hz ASSR). In contrast, this group showed a decreased cortical integration response (P300 AEP to target tones) and reduced neural entrainment to cortical beta-band stimuli (22 Hz ASSR). Collectively, our results suggest that subcortical and early cortical auditory processing is augmented in aniridia, while functional cortical integration of auditory information is deficient in this population.

Suprachoroidal hemorrhage after removal of releasable suture with globe massage post-trabeculectomy.

A 19-year-old female, having aniridia with secondary glaucoma, presented with uncontrolled intraocular pressure (IOP) in the right eye (RE) on maximal topical and systemic medications. On examination, RE had a subluxated cataractous lens with advanced cupping. She underwent trabeculectomy with mitomycin C. On postoperative day 1, as the IOP was 32 mmHg, one releasable suture was removed followed by gentle bleb massage. On postoperative day 2, suprachoroidal hemorrhage was noted, for which the patient underwent two drainage procedures. Hemorrhagic choroidals resolved completely 4 weeks after drainage.