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Biochimica Et Biophysica Acta Mar 2014Fatty acids in the epidermis can be incorporated into complex lipids or exist in a free form, and they are crucial to proper functions of the epidermis and its... (Review)
Review
Fatty acids in the epidermis can be incorporated into complex lipids or exist in a free form, and they are crucial to proper functions of the epidermis and its appendages, such as sebaceous glands. Epidermal fatty acids can be synthesized de novo by keratinocytes or taken up from extracutaneous sources in a process that likely involves protein transporters. Several proteins that are expressed in the epidermis have been proposed to facilitate the uptake of long-chain fatty acids (LCFA) in mammalian cells, including fatty acid translocase/CD36, fatty acid binding protein, and fatty acid transport protein (FATP)/very long-chain acyl-CoA synthetase. In this review, we will discuss the mechanisms by which these candidate transporters facilitate the uptake of fatty acids. We will then discuss the clinical implications of defects in these transporters and relevant animal models, including the FATP4 animal models and ichthyosis prematurity syndrome, a congenital ichthyosis caused by FATP4 deficiency. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.
Topics: Animals; Aniridia; Biological Transport, Active; Disease Models, Animal; Fatty Acid Transport Proteins; Fatty Acids; Female; Humans; Ichthyosis; Infant, Premature, Diseases; Kidney; Male; Psychomotor Disorders; Skin
PubMed: 24120574
DOI: 10.1016/j.bbalip.2013.09.016 -
The Ocular Surface Jan 2021To evaluate conjunctival cell microRNA (miRNAs) and mRNA expression in relation to observed phenotype of progressive limbal stem cell deficiency in a cohort of subjects...
Abnormal neovascular and proliferative conjunctival phenotype in limbal stem cell deficiency is associated with altered microRNA and gene expression modulated by PAX6 mutational status in congenital aniridia.
PURPOSE
To evaluate conjunctival cell microRNA (miRNAs) and mRNA expression in relation to observed phenotype of progressive limbal stem cell deficiency in a cohort of subjects with congenital aniridia with known genetic status.
METHODS
Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and miRNA and mRNA analyses were performed using microarrays. Results were related to severity of keratopathy and genetic cause of aniridia.
RESULTS
Of 2549 miRNAs, 21 were differentially expressed in aniridia relative to controls (fold change ≤ -1.5 or ≥ +1.5). Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold in severely vascularized corneas. At the mRNA level, 539 transcripts were differentially expressed (fold change ≤ -2 or ≥ +2), among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all being components of the AP-1 transcription factor complex. Pathway analysis revealed enrichment of PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several miRNAs and transcripts regulating retinoic acid metabolism, expression levels correlated with keratopathy severity and genetic status.
CONCLUSION
Strong dysregulation of key factors at the miRNA and mRNA level suggests that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, and these changes are expressed in a PAX6 mutation-dependent manner. Additionally, retinoic acid metabolism is disrupted in severe, but not mild forms of the limbal stem cell deficiency in aniridia.
Topics: Aniridia; Conjunctiva; Eye Proteins; Gene Expression; Humans; MicroRNAs; Mutation; PAX6 Transcription Factor; Phenotype; Phosphatidylinositol 3-Kinases; Stem Cells
PubMed: 32422284
DOI: 10.1016/j.jtos.2020.04.014 -
BMC Ophthalmology Jul 2017This study evaluates patients with congenital aniridia and cataract who underwent phacoemulsification, capsular tension ring placement, and foldable intraocular lens...
BACKGROUND
This study evaluates patients with congenital aniridia and cataract who underwent phacoemulsification, capsular tension ring placement, and foldable intraocular lens implantation.
METHODS
In this prospective case series, 10 patients (17 eyes) underwent cataract surgery via a 3.2 mm clear corneal incision. A continuous circular capsulorhexis with <6 mm diameter was employed. A capsular tension ring and HOYA yellow foldable posterior chamber intraocular lens was implanted. All patients wore color contact lenses postoperatively. Paired t test was used to compare visual acuity, intraocular pressure, and corneal endothelial changes before and after surgery.
RESULTS
A single surgeon performed all surgeries. The best-corrected visual acuity improved from value 1.03 ± 0.27LogMAR preoperatively to value 0.78 ± 0.26LogMAR postoperatively (p = 0.000). The photophobic symptoms improved significantly after surgery. The mean corneal endothelial cell density before and after surgery was 3280 ± 473 cells/mm2 and 2669 ± 850 cells/mm2, respectively (p = 0.006). None of the patients developed corneal endothelial decompensation or secondary glaucoma after surgery.
CONCLUSIONS
Treatment of congenital aniridia and coexistent cataract by phacoemulsification, posterior chamber foldable lens implantation, capsular tension ring placement was safe and effective. Use of colored contact lenses in the postoperative period can reduce photophobic symptoms in this group of patients.
TRIAL REGISTRATION
ChiCTR-OOC-17011638 (retrospectively registered at 12,June,2017).
Topics: Adolescent; Adult; Aniridia; Cataract; Child; Child, Preschool; Female; Humans; Lenses, Intraocular; Male; Middle Aged; Phacoemulsification; Prospective Studies; Tomography, Optical Coherence; Visual Acuity; Young Adult
PubMed: 28676040
DOI: 10.1186/s12886-017-0503-6 -
The British Journal of Ophthalmology Dec 2023To evaluate changes in the ocular surface and tear film with age and mutational status in congenital aniridia.
AIM
To evaluate changes in the ocular surface and tear film with age and mutational status in congenital aniridia.
METHODS
45 participants with congenital aniridia (89 eyes) in a prospective, cross-sectional study. Whole-exome sequencing identified the causative mutation. Examinations included slit-lamp biomicroscopy, in vivo confocal microscopy, Ocular Surface Disease Index (OSDI) score, blink rate, Schirmer I test, Oxford Staining Score (OSS), tear film break-up time (TFBUT) and Ocular Protection Index (OPI).
RESULTS
There were age-dependent increases in OSDI (β=0.34, 95% CI 0.03 to 0.66; p=0.030), blink rate (β=0.18, 95% CI 0.08 to 0.27; p<0.001) and OSS (β=0.05, 95% CI 0.03 to 0.07; p<0.001) and age-dependent reductions in tear production (β=-0.23, 95% CI -0.43 to 0.02; p=0.029) and TFBUT (β=-0.10, 95% CI -0.17 to -0.04; p<0.001). Perturbed OSDI, OSS, blink rate, tear production and TFBUT were noted after the age of ten and OSDI, OSS, blink rate and TFBUT correlated with deficient corneal nerves and limbal stem cell function. OSDI, blink rate, Schirmer, OSS, TFBUT and OPI were not associated with type of mutation, but OSDI, OSS and blink rate associated with grade of aniridia-associated keratopathy.
CONCLUSIONS
Ocular surface damage and dry eye signs appear in congenital aniridia regardless of mutation, appearing after 10 years of age and progressing thereafter. An early treatment window may exist for therapies to protect the ocular surface homoeostasis and limbal function, to possibly delay keratopathy development and progression.
Topics: Humans; Cross-Sectional Studies; Prospective Studies; Cornea; Tears; Dry Eye Syndromes; Corneal Diseases; Aniridia
PubMed: 36517210
DOI: 10.1136/bjo-2021-320774 -
Pharmaceutics Dec 2020Congenital aniridia is a rare and severe panocular disease characterized by a complete or partial iris defect clinically detectable at birth. The most common form of...
Congenital aniridia is a rare and severe panocular disease characterized by a complete or partial iris defect clinically detectable at birth. The most common form of aniridia occurring in around 90% of cases is caused by PAX6 haploinsufficiency. The phenotype includes ptosis, nystagmus, corneal limbal insufficiency, glaucoma, cataract, optic nerve, and foveal hypoplasia. Ataluren eye drops aim to restore ocular surface PAX6 haploinsufficiency in aniridia-related keratopathy (ARK). However, there are currently no available forms of the ophthalmic solution. The objective of this study was to assess the physicochemical and microbiological stability of ataluren 1% eye drop in preservative-free low-density polyethylene (LDPE) bottle with an innovative insert that maintains sterility after opening. Because ataluren is a strongly lipophilic compound, the formulation is complex and involves a strategy based on co-solvents in an aqueous phase or an oily formulation capable of totally dissolving the active ingredient. The visual aspect, ataluren quantification by a stability-indicating chromatographic method, and microbiological sterility were analyzed. The oily formulation in castor oil and DMSO (10%) better protects ataluren hydrolysis and oxidative degradation and permits its complete solubilization. Throughout the 60 days period, the oily solution in the LDPE bottle remained clear without any precipitation or color modification, and no drug loss and no microbial development were detected. The demonstrated physical and microbiological stability of ataluren 1% eye drop formulation at 22-25 °C might facilitate clinical research in aniridia.
PubMed: 33375041
DOI: 10.3390/pharmaceutics13010007 -
PloS One 2022Classical aniridia is a congenital and progressive panocular disorder almost exclusively caused by heterozygous loss-of-function variants at the PAX6 locus. We report...
Classical aniridia is a congenital and progressive panocular disorder almost exclusively caused by heterozygous loss-of-function variants at the PAX6 locus. We report nine individuals from five families with severe aniridia and/or microphthalmia (with no detectable PAX6 mutation) with ultrarare monoallelic missense variants altering the Arg51 codon of MAB21L1. These mutations occurred de novo in 3/5 families, with the remaining families being compatible with autosomal dominant inheritance. Mice engineered to carry the p.Arg51Leu change showed a highly-penetrant optic disc anomaly in heterozygous animals with severe microphthalmia in homozygotes. Substitutions of the same codon (Arg51) in MAB21L2, a close homolog of MAB21L1, cause severe ocular and skeletal malformations in humans and mice. The predicted nucleotidyltransferase function of MAB21L1 could not be demonstrated using purified protein with a variety of nucleotide substrates and oligonucleotide activators. Induced expression of GFP-tagged wildtype and mutant MAB21L1 in human cells caused only modest transcriptional changes. Mass spectrometry of immunoprecipitated protein revealed that both mutant and wildtype MAB21L1 associate with transcription factors that are known regulators of PAX6 (MEIS1, MEIS2 and PBX1) and with poly(A) RNA binding proteins. Arg51 substitutions reduce the association of wild-type MAB21L1 with TBL1XR1, a component of the NCoR complex. We found limited evidence for mutation-specific interactions with MSI2/Musashi-2, an RNA-binding proteins with effects on many different developmental pathways. Given that biallelic loss-of-function variants in MAB21L1 result in a milder eye phenotype we suggest that Arg51-altering monoallelic variants most plausibly perturb eye development via a gain-of-function mechanism.
Topics: Humans; Animals; Mice; Microphthalmos; PAX6 Transcription Factor; Aniridia; Mutation, Missense; Heterozygote; Transcription Factors; Homeodomain Proteins; RNA-Binding Proteins; Eye Proteins; Intracellular Signaling Peptides and Proteins
PubMed: 36413568
DOI: 10.1371/journal.pone.0268149 -
International Journal of Molecular... Jun 2022Genome-wide sequencing metadata allows researchers to infer bias in the relative frequencies of mutational events and to predict putative mutagenic models. In addition,... (Review)
Review
Genome-wide sequencing metadata allows researchers to infer bias in the relative frequencies of mutational events and to predict putative mutagenic models. In addition, much less data could be useful in the evaluation of the mutational frequency spectrum and the prevalent local mutagenic process. Here we analyzed the gene locus for mutational spectra obtained in our own and previous studies and compared them with data on other genes as well as the whole human genome. MLPA and Sanger sequencing were used for mutation searching in a cohort of 199 index patients from Russia with aniridia and aniridia-related phenotypes. The relative frequencies of different categories of mutations were consistent with those previously reported by other researchers. The ratio between substitutions, small indels, and chromosome deletions in the 11p13 locus was within the interval previously published for 20 disease associated genomic loci, but corresponded to a higher end due to very high frequencies of small indels and chromosome deletions. The ratio between substitutions, small indels, and chromosome deletions for disease associated genes, including the gene as well as the share of missense mutations, differed considerably from those typical for the whole genome.
Topics: Aniridia; Chromosome Deletion; Eye Proteins; Genome, Human; Homeodomain Proteins; Humans; Mutation; PAX6 Transcription Factor; Paired Box Transcription Factors; Pedigree; Repressor Proteins
PubMed: 35743132
DOI: 10.3390/ijms23126690 -
Cancer Feb 2021WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and range of developmental delays) is a rare contiguous gene deletion syndrome with a 45% to 60% risk of...
BACKGROUND
WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and range of developmental delays) is a rare contiguous gene deletion syndrome with a 45% to 60% risk of developing Wilms tumor (WT). Currently, surveillance and treatment recommendations are based on limited evidence.
METHODS
Clinical characteristics, treatments, and outcomes were analyzed for patients with WAGR and WT/nephroblastomatosis who were identified through International Society of Pediatric Oncology Renal Tumor Study Group (SIOP-RTSG) registries and the SIOP-RTSG network (1989-2019). Events were defined as relapse, metachronous tumors, or death.
RESULTS
Forty-three patients were identified. The median age at WT/nephroblastomatosis diagnosis was 22 months (range, 6-44 months). The overall stage was available for 40 patients, including 15 (37.5%) with bilateral disease and none with metastatic disease. Histology was available for 42 patients; 6 nephroblastomatosis without further WT and 36 WT, including 19 stromal WT (52.8%), 12 mixed WT (33.3%), 1 regressive WT (2.8%) and 2 other/indeterminable WT (5.6%). Blastemal type WT occurred in 2 patients (5.6%) after prolonged treatment for nephroblastomatosis; anaplasia was not reported. Nephrogenic rests were present in 78.9%. Among patients with WT, the 5-year event-free survival rate was 84.3% (95% confidence interval, 72.4%-98.1%), and the overall survival rate was 91.2% (95% confidence interval, 82.1%-100%). Events (n = 6) did not include relapse, but contralateral tumor development (n = 3) occurred up to 7 years after the initial diagnosis, and 3 deaths were related to hepatotoxicity (n = 2) and obstructive ileus (n = 1).
CONCLUSIONS
Patients with WAGR have a high rate of bilateral disease and no metastatic or anaplastic tumors. Although they can be treated according to existing WT protocols, intensive monitoring of toxicity and surveillance of the remaining kidney(s) are advised.
LAY SUMMARY
WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and range of developmental delays) is a rare genetic condition with an increased risk of developing Wilms tumor. In this study, 43 patients with WAGR and Wilms tumor (or Wilms tumor precursor lesions/nephroblastomatosis) were identified through the international registry of the International Society of Pediatric Oncology Renal Tumor Study Group (SIOP-RTSG) and the SIOP-RTSG network. In many patients (37.5%), both kidneys were affected. Disease spread to other organs (metastases) did not occur. Overall, this study demonstrates that patients with WAGR syndrome and Wilms tumor can be treated according to existing protocols. However, intensive monitoring of treatment complications and surveillance of the remaining kidney(s) are advised.
Topics: Anaplasia; Antineoplastic Protocols; Child, Preschool; Drug-Related Side Effects and Adverse Reactions; Female; Gene Deletion; Humans; Infant; Kidney; Liver; Male; Progression-Free Survival; Risk Factors; WAGR Syndrome; Wilms Tumor
PubMed: 33146894
DOI: 10.1002/cncr.33304 -
Survey of Ophthalmology 2023Congenital aniridia is a rare, panocular disorder with a main phenotypic characteristic of a partial or complete absence of the iris existing alongside other ocular...
Congenital aniridia is a rare, panocular disorder with a main phenotypic characteristic of a partial or complete absence of the iris existing alongside other ocular morbidities such as cataract, keratopathy, optic nerve and foveal hypoplasia, and nystagmus. The iris abnormality, however, often leads to symptoms such as photophobia, glare, and decreased visual acuity, as well as cosmetic dissatisfaction. Current management options for the iris deficit include colored iris contact lenses, corneal tattooing, and tinted contact lenses. Symptoms arising from small iris defects can be resolved with surgical management using micro-tying suture techniques such as McCannel or Siepser. Currently, larger iris defects can be treated with artificial iris implants. New prosthetic options range from colored intraocular lenses to flexible custom-made silicone iris implants. With a range of therapeutic options available and given the challenges of multiple comorbidities in aniridia, we evaluate the literature relating to the use of artificial iris implants in congenital aniridia, with a focus on the different surgical implantation techniques, the clinical outcomes achieved, complications occurred, and risk of bias of the studies included.
Topics: Humans; Visual Acuity; Aniridia; Iris; Lenses, Intraocular; Prosthesis Implantation; Vision Disorders
PubMed: 36379301
DOI: 10.1016/j.survophthal.2022.11.001 -
BMC Ophthalmology Jan 2022Aniridia is a congenital, panocular disease that can affect the cornea, anterior chamber angle, iris, lens, retina and optic nerve. PAX6 loss-of-function variants are...
BACKGROUND
Aniridia is a congenital, panocular disease that can affect the cornea, anterior chamber angle, iris, lens, retina and optic nerve. PAX6 loss-of-function variants are the most common cause of aniridia, and variants throughout the gene have been linked to a range of ophthalmic abnormalities. Furthermore, particular variants at a given site in PAX6 lead to distinct phenotypes. This study aimed to characterize genetic variants associated with congenital aniridia in a Chinese family.
METHODS
The proband and family underwent ophthalmologic examinations. DNA was sampled from the peripheral blood of all 6 individuals, and whole-exome sequencing was performed. Sanger sequencing was used to verify the variant in this family members.
RESULTS
A novel variant (c.114_119delinsAATTTCC: p.Pro39llefsTer17) in the PAX6 gene was identified in subjects II-1, III-1 and III-2, who exhibited complete aniridia and cataracts. The proband and the proband's brother also had glaucoma, high myopia, and foveal hypoplasia.
CONCLUSIONS
We identified that a novel PAX6 frameshift heterozygous deletion variant is the predominant cause of aniridia in this Chinese family.
TRIAL REGISTRATION
We did not perform any health-related interventions for the participants.
Topics: Aniridia; China; Eye Proteins; Heterozygote; Humans; Male; Mutation; PAX6 Transcription Factor; Pedigree
PubMed: 35034608
DOI: 10.1186/s12886-022-02256-7