The forkhead transcription factor gene FKHL7 is responsible for glaucoma phenotypes which map to 6p25

Mutations of CYP1B1 and FOXC1 genes for childhood glaucoma in Japanese individuals

PURPOSE

To explore the frequency and positions of genetic mutations in CYP1B1 and FOXC1 in a Japanese population.

STUDY DESIGN

Molecular genetic analysis.

METHODS

Genomic DNA was extracted from 31 Japanese patients with childhood glaucoma (CG) from 29 families. We examined the CYP1B, FOXC1, and MYOC genes using Sanger sequencing and whole-exome sequencing (WES).

RESULTS

For CYP1B1, we identified 9 families that harbored novel mutations, p.A202T, p.D274E, p.Q340*, and p.V420G; the remaining mutations had been previously reported. When mapped to the CYP1B1 protein structure, all mutations appeared to influence the enzymatic activity of CYP1B1 by provoking structural deformity. Five patients were homozygotes or compound heterozygotes, supporting the recessive inheritance of the CYP1B1 mutations in CG. In contrast, four patients were heterozygous for the CYP1B1 mutation, suggesting the presence of regulatory region mutations or strong modifiers. For the FOXC1 gene, we identified 3 novel mutations, p.Q23fs, p.Q70R, and p.E163*, all of which were identified in a heterozygous state. No mutation was found in the MYOC gene in these CG patients. All individuals with CYP1B1 and FOXC1 mutations were severely affected by early-onset CG. In the CYP1B1-, FOXC1-, and MYOC-negative families, we also searched for variants in the other candidate genes reported for CG through WES, but could not find any mutations in these genes.

CONCLUSIONS

Our analyses of 29 CG families revealed 9 families with point mutations in the CYP1B1 gene, and four of those patients appeared to be heterozygotes, suggesting the presence of complex pathogenic mechanisms. FOXC1 appears to be another major causal gene of CG, indicating that panel sequencing of CYP1B1 and FOXC1 will be useful for diagnosis of CG in Japanese individuals.

Congenital anterior segment ocular disorders: Genotype-phenotype correlations and emerging novel mechanisms

Development of the anterior segment of the eye requires reciprocal sequential interactions between the arising tissues, facilitated by numerous genetic factors. Disruption of any of these processes results in congenital anomalies in the affected tissue(s) leading to anterior segment disorders (ASD) including aniridia, Axenfeld-Rieger anomaly, congenital corneal opacities (Peters anomaly, cornea plana, congenital primary aphakia), and primary congenital glaucoma. Current understanding of the genetic factors involved in ASD remains incomplete, with approximately 50% overall receiving a genetic diagnosis. While some genes are strongly associated with a specific clinical diagnosis, the majority of known factors are linked with highly variable phenotypic presentations, with pathogenic variants in FOXC1, CYP1B1, and PITX2 associated with the broadest spectrum of ASD conditions. This review discusses typical clinical presentations including associated systemic features of various forms of ASD; the latest functional data and genotype-phenotype correlations related to 25 ASD factors including newly identified genes; promising novel candidates; and current and emerging treatments for these complex conditions. Recent developments of interest in the genetics of ASD include identification of phenotypic expansions for several factors, discovery of multiple modes of inheritance for some genes, and novel mechanisms including a growing number of non-coding variants and alleles affecting specific domains/residues and requiring further studies.

Increasing the diagnostic yield of childhood glaucoma cases recruited into the 100,000 Genomes Project

Childhood glaucoma (CG) encompasses a heterogeneous group of genetic eye disorders that is responsible for approximately 5% of childhood blindness worldwide. Understanding the molecular aetiology is key to improving diagnosis, prognosis and unlocking the potential for optimising clinical management. In this study, we investigated 86 CG cases from 78 unrelated families of diverse ethnic backgrounds, recruited into the Genomics England 100,000 Genomes Project (GE100KGP) rare disease cohort, to improve the genetic diagnostic yield. Using the Genomics England/Genomic Medicine Centres (GE/GMC) diagnostic pipeline, 13 unrelated families were solved (13/78, 17%). Further interrogation using an expanded gene panel yielded a molecular diagnosis in 7 more unrelated families (7/78, 9%). This analysis effectively raises the total number of solved CG families in the GE100KGP to 26% (20/78 families). Twenty-five percent (5/20) of the solved families had primary congenital glaucoma (PCG), while 75% (15/20) had secondary CG; 53% of this group had non-acquired ocular anomalies (including iris hypoplasia, megalocornea, ectopia pupillae, retinal dystrophy, and refractive errors) and 47% had non-acquired systemic diseases such as cardiac abnormalities, hearing impairment, and developmental delay. CYP1B1 was the most frequently implicated gene, accounting for 55% (11/20) of the solved families. We identified two novel likely pathogenic variants in the TEK gene, in addition to one novel pathogenic copy number variant (CNV) in FOXC1. Variants that passed undetected in the GE100KGP diagnostic pipeline were likely due to limitations of the tiering process, the use of smaller gene panels during analysis, and the prioritisation of coding SNVs and indels over larger structural variants, CNVs, and non-coding variants.

Evaluating neural crest cell migration in a Col4a1 mutant mouse model of ocular anterior segment dysgenesis

The periocular mesenchyme (POM) is a transient migratory embryonic tissue derived from neural crest cells (NCCs) and paraxial mesoderm that gives rise to most of the structures in front of the eye. Morphogenetic defects of these structures can impair aqueous humor outflow, leading to elevated intraocular pressure and glaucoma. Mutations in collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) cause Gould syndrome - a multisystem disorder often characterized by variable cerebrovascular, ocular, renal, and neuromuscular manifestations. Approximately one-third of individuals with COL4A1 and COL4A2 mutations have ocular anterior segment dysgenesis (ASD), including congenital glaucoma resulting from abnormalities of POM-derived structures. POM differentiation has been a major focus of ASD research, but the underlying cellular mechanisms are still unclear. Moreover, earlier events including NCC migration and survival defects have been implicated in ASD; however, their roles are not as well understood. Vascular defects are among the most common consequences of COL4A1 and COL4A2 mutations and can influence NCC survival and migration. We therefore hypothesized that NCC migration might be impaired by COL4A1 and COL4A2 mutations. In this study, we used 3D confocal microscopy, gross morphology, and quantitative analyses to test NCC migration in Col4a1 mutant mice. We show that homozygous Col4a1 mutant embryos have severe embryonic growth retardation and lethality, and we identified a potential maternal effect on embryo development. Cerebrovascular defects in heterozygous Col4a1 mutant embryos were present as early as E9.0, showing abnormal cerebral vasculature plexus remodeling compared to controls. We detected abnormal NCC migration within the diencephalic stream and the POM in heterozygous Col4a1 mutants whereby mutant NCCs formed smaller diencephalic migratory streams and POMs. In these settings, migratory NCCs within the diencephalic stream and POM localize farther away from the developing vasculature. Our results show for the first time that Col4a1 mutations lead to cranial NCCs migratory defects in the context of early onset defective angiogenesis without affecting cell numbers, possibly impacting the relation between NCCs and the blood vessels during ASD development.

Research progress on the regulatory mechanisms of FOXC1 expression in cancers and its role in drug resistance

The Forkhead box C1 (FOXC1) transcription factor is an important member of the FOX family. After initially being identified in triple-negative breast cancer (TNBC) with significant oncogenic function, FOXC1 was subsequently demonstrated to be involved in the development of more than 16 types of cancers. In recent years, increasing studies have focused on the deregulatory mechanisms of FOXC1 expression and revealed that FOXC1 expression was regulated at multiple levels including transcriptional regulation, post-transcription regulation and post-translational modification. Moreover, dysregulation of FOXC1 is also implicated in drug resistance in various types of cancer, especially in breast cancer, which further emphasizes the translational and clinical significance of FOXC1 as a therapeutic target in cancer treatment. This review summarizes recent findings on mechanisms of FOXC1 dysregulation in cancers and its role in chemoresistance, which will help to better understand the oncogenic role of FOXC1, overcome FOXC1-mediated drug resistance and develop targeted therapy for FOXC1 in cancers.

Glaucoma Animal Models beyond Chronic IOP Increase

Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP), other mechanisms play a pivotal role in glaucoma onset and progression. For example, it is known that excitotoxicity, immunological alterations, ischemia, and oxidative stress contribute to the neurodegeneration in glaucoma disease. To study these effects and to discover novel therapeutic approaches, appropriate animal models are needed. In this review, we focus on various glaucoma animal models beyond an elevated IOP. We introduce genetically modified mice, e.g., the optineurin E50K knock-in or the glutamate aspartate transporter (GLAST)-deficient mouse. Excitotoxicity can be mimicked by injecting the glutamate analogue N-methyl-D-aspartate intravitreally, which leads to rapid RGC degeneration. To explore the contribution of the immune system, the experimental autoimmune glaucoma model can serve as a useful tool. Here, immunization with antigens led to glaucoma-like damage. The ischemic mechanism can be mimicked by inducing a high IOP for a certain amount of time in rodents, followed by reperfusion. Thereby, damage to the retina and the optic nerve occurs rapidly after ischemia/reperfusion. Lastly, we discuss the importance of optic nerve crush models as model systems for normal-tension glaucoma. In summary, various glaucoma models beyond IOP increase can be utilized.

Neuroimaging Findings in Axenfeld-Rieger Syndrome: A Case Series

Axenfeld-Rieger syndrome is an autosomal dominant condition associated with multisystemic features including developmental anomalies of the anterior segment of the eye. Single nucleotide and copy number variants in the paired-like homeodomain transcription factor 2 (PITX2) and forkhead box C1 (FOXC1) genes are associated with Axenfeld-Rieger syndrome as well as other CNS malformations. We determined the association between Axenfeld-Rieger syndrome and specific brain MR imaging neuroradiologic anomalies in cases with or without a genetic diagnosis. This case series included 8 individuals with pathogenic variants in FOXC1; 2, in PITX2; and 2 without a genetic diagnosis. The most common observation was vertebrobasilar artery dolichoectasia, with 46% prevalence. Other prevalent abnormalities included WM hyperintensities, cerebellar hypoplasia, and ventriculomegaly. Vertebrobasilar artery dolichoectasia and absent/hypoplastic olfactory bulbs were reported in >50% of individuals with FOXC1 variants compared with 0% of PITX2 variants. Notwithstanding the small sample size, neuroimaging abnormalities were more prevalent in individuals with FOXC1 variants compared those with PITX2 variants.

The hidden hedgehog of the pituitary: hedgehog signaling in development, adulthood and disease of the hypothalamic-pituitary axis

Hedgehog signaling plays pivotal roles in embryonic development, adult homeostasis and tumorigenesis. However, its engagement in the pituitary gland has been long underestimated although Hedgehog signaling and pituitary embryogenic development are closely linked. Thus, deregulation of this signaling pathway during pituitary development results in malformation of the gland. Research of the last years further implicates a regulatory role of Hedgehog signaling in the function of the adult pituitary, because its activity is also interlinked with homeostasis, hormone production, and most likely also formation of neoplasms of the gland. The fact that this pathway can be efficiently targeted by validated therapeutic strategies makes it a promising candidate for treating pituitary diseases. We here summarize the current knowledge about the importance of Hedgehog signaling during pituitary development and review recent data that highlight the impact of Hedgehog signaling in the healthy and the diseased adult pituitary gland.

Congenital aniridia beyond black eyes: From phenotype and novel genetic mechanisms to innovative therapeutic approaches

Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.

Large-scale multitrait genome-wide association analyses identify hundreds of glaucoma risk loci

Glaucoma, a leading cause of irreversible blindness, is a highly heritable human disease. Previous genome-wide association studies have identified over 100 loci for the most common form, primary open-angle glaucoma. Two key glaucoma-associated traits also show high heritability: intraocular pressure and optic nerve head excavation damage quantified as the vertical cup-to-disc ratio. Here, since much of glaucoma heritability remains unexplained, we conducted a large-scale multitrait genome-wide association study in participants of European ancestry combining primary open-angle glaucoma and its two associated traits (total sample size over 600,000) to substantially improve genetic discovery power (263 loci). We further increased our power by then employing a multiancestry approach, which increased the number of independent risk loci to 312, with the vast majority replicating in a large independent cohort from 23andMe, Inc. (total sample size over 2.8 million; 296 loci replicated at P < 0.05, 240 after Bonferroni correction). Leveraging multiomics datasets, we identified many potential druggable genes, including neuro-protection targets likely to act via the optic nerve, a key advance for glaucoma because all existing drugs only target intraocular pressure. We further used Mendelian randomization and genetic correlation-based approaches to identify novel links to other complex traits, including immune-related diseases such as multiple sclerosis and systemic lupus erythematosus.

Chromosome 6p25 deletion syndrome: A case report and review of ophthalmic features

The 6p25 deletion syndrome is a rare genetic disorder characterized by a wide spectrum of congenital anomalies. Ophthalmic abnormalities appear to be highly associated with the syndrome, although this relationship has not been well characterized to date. We conducted a systematic literature review to highlight the ocular features in patients with this deletion syndrome and describe a 7-month-old female who has a 6.07 MB 6p25.1p25.3 deletion and a 4.25 MB 17q25.3 duplication. Our patient presented with multiple congenital anomalies, including macrocephaly, frontal bossing, low set ears, tent-shaped mouth, saddle nose, flat midface, and hearing impairment. Her ophthalmic features included proptosis, down-slanting palpebral fissures, hypertelorism, nystagmus, bilateral posterior embryotoxon, and decentered and abnormally shaped pupils. A systematic review of the published cases with sufficient clinical eye descriptions included 63 cases with a confirmed 6p25 deletion. The most common eye findings observed were posterior embryotoxon, iris hypoplasia, corectopia, cornea opacity, and glaucoma.

Efficiency of genotyping by sequencing in inferring genomic relatedness and molecular insights into fat tail selection in Tunisian sheep

In developing countries, the use of simple and cost-efficient molecular technology is crucial for genetic characterization of local animal resources and better development of conservation strategies. The genotyping by sequencing (GBS) technique, also called restriction enzyme- reduced representational sequencing, is an efficient, cost-effective method for simultaneous discovery and genotyping of many markers. In the present study, we applied a two-enzyme GBS protocol (PstI/MspI) to discover and genotype SNP markers among 197 Tunisian sheep samples. A total of 100 333 bi-allelic SNPs were discovered and genotyped with an SNP call rate of 0.69 and mean sample depth 3.33. The genomic relatedness between 183 samples grouped the samples perfectly to their populations and pointed out a high genetic relatedness of inbred subpopulation reflecting the current adopted reproductive strategies. The genome-wide association study contrasting fat vs. thin-tailed breeds detected 41 significant variants including a peak positioned on OAR20. We identified FOXC1, GMDS, VEGFA, OXCT1, VRTN and BMP2 as the most promising for sheep tail-type trait. The GBS data have been useful to assess the population structure and improve our understanding of the genomic architecture of distinctive characteristics shaped by selection pressure in local sheep breeds. This study successfully investigates a cost-efficient method to discover genotypes, assign populations and understand insights into sheep adaptation to arid area. GBS could be of potential utility in livestock species in developing/emerging countries.

Pediatric Glaucoma-From Screening, Early Detection to Management

Pediatric glaucoma (PG) covers a rare and heterogeneous group of diseases with variable causes and presentations. Delayed diagnosis of PG could lead to blindness, bringing emotional and psychological burdens to patients' caregivers. Recent genetic studies identified novel causative genes, which may provide new insight into the etiology of PG. More effective screening strategies could be beneficial for timely diagnosis and treatment. New findings on clinical characteristics and the latest examination instruments have provided additional evidence for diagnosing PG. In addition to IOP-lowering therapy, managing concomitant amblyopia and other associated ocular pathologies is essential to achieve a better visual outcome. Surgical treatment is usually required although medication is often used before surgery. These include angle surgeries, filtering surgeries, minimally invasive glaucoma surgeries, cyclophotocoagulation, and deep sclerectomy. Several advanced surgical therapies have been developed to increase success rates and decrease postoperative complications. Here, we review the classification and diagnosis, etiology, screening, clinical characteristics, examinations, and management of PG.

The role of LncRNA MCM3AP-AS1 in human cancer

Long noncoding RNAs (lncRNA) play pivotal roles in every level of gene and genome regulation. MCM3AP-AS1 is a lncRNA that has an oncogenic role in several kinds of cancers. Aberrant expression of MCM3AP-AS1 has been reported to be involved in the progression of diverse malignancies, including colorectal, cervical, prostate, lymphoma, lung, ovary, liver, bone, and breast cancers. It is generally believed that MCM3AP-AS1 expression is associated with cancer cell growth, proliferation, angiogenesis, and metastasis. MCM3AP-AS1 by targeting various signaling pathways and microRNAs (miRNAs) presents an important role in cancer pathogenesis. MCM3AP-AS1 as a competitive endogenous RNA has the ability to sponge miRNA, inhibit their expressions, and bind to different target mRNAs related to cancer development. Therefore, MCM3AP-AS1 by targeting several signaling pathways, including the FOX family, Wnt, EGF, and VEGF can be a potent target for cancer prediction and diagnosis. In this review, we will summarize the role of MCM3AP-AS1 in various human cancers.

The clinical and genetic findings in a Chinese family with Axenfeld-Rieger syndrome

Objecive

To describe the clinical and genetic findings of an Axenfeld-Rieger syndrome (ARS) family with a new PITX2 splicing mutation.

Methods

A Chinese ARS family with five affected individuals was recruited. Exome sequencing was performed on the proband and the variant (C.253-9C > A) in PITX2 gene was detected as a pathogenic mutation. Sanger sequencing was performed for verification and cosegregation analysis. Real-time polymerase chain reaction (RT- PCR) and Western blotting were performed to verify the expression of the pathogenic gene.

Results

All the patients showed abnormalities in the anterior segment of both eyes including posterior embryotoxon, corectopia, iris dysplasia, and iridocorneal tissue adhesions. In addition, they all presented systemic features, including maxillary hypoplasia, underbite, hypodontia, conical teeth. Only III-7 showed obvious umbilical skin. In the PITX2 family, we identified a novel heterozygous splicing mutation (C.253-9C > A) which was confirmed by Sanger sequencing to be completely cosegregated with the ARS phenotype. Real-time quantitative PCR and Western results showed that PITX2 mRNA and protein expression were significantly lower in patients compared with unrelated normal controls.

Conclusion

In the ARS pedigree, we summarized the variable phenotype, described a novel PITX2 splicing mutation which expand the genetic spectrum of ARS. We further confirmed the possibility of development of ARS induced by this PITX2 gene deficiency.

Case report: Congenital mitral and tricuspid valve insufficiency in a patient with Axenfeld-Rieger syndrome

Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder that is primarily due to disruption of the development of neural crest cells. The onset of associated symptoms in both eyes accompanied by extraocular developmental defects is referred to as ARS. Cardiac defects associated with ARS have been reported, but the extent of the cardiac defects has yet to be defined. We report a case of a 17-year-old girl with ARS with typical facial malformations and severe mitral and tricuspid valve insufficiency. The patient was diagnosed with secondary glaucoma detected on ophthalmologic examination. Echocardiography showed severe mitral and tricuspid valve insufficiency. This case provides further evidence of the association of ARS with cardiac malformations and extends the reported range of cardiac malformations in patients with ARS.

Axenfeld-Rieger syndrome: orthopedic and orthodontic management in a pediatric patient: a case report

Axenfeld–Rieger Syndrome (ARS) is a rare autosomal dominant genetic disease with considerable expressive variability, characterized by ocular and non-ocular manifestations, cardiovascular, mild craniofacial abnormalities and dental malformations. Current data report an incidence of Xenfeld-Rieger syndrome in the population of 1: 200,000.

The case described is that of a 14-year-old female patient whose ARS is suspected and investigated following a dental specialist visit for orthodontic reasons, acquired the patient’s family and clinical data following a medical approach multidisciplinary, we proceed to the orthodontic involved the use of the Rapid Palatal Expander (RPE) and a fixed orthodontic treatment.

The aim of this study is to report the case of the orthopaedic and orthodontic treatment in a patient affected by ARS and with facial dysmorphism and teeth anomalies associated to ocular anomalies.

Interplay Between Stress and Reproduction: Novel Epigenetic Markers in Response to Shearing Patterns in Australian Merino Sheep (Ovis aries)

In this study, we determined the effect(s) of early shearing on Australian Merino ewes (Ovis aries) and their lambs. To test this research question, we used a suite of field and laboratory methods including GPS collars, wool cortisol, and epigenetic change between ewes and lambs identified using Illumina NovaSeq RRBS. Once shorn ewes (n = 24) were kept on their full fleece throughout the entire gestation period, whereas twice (early) shorn ewes (n = 24) had their wool shorn pre-joining. Top-knot wool sample was taken from ewes during pre-joining, day 50 (mid-gestation), and day 90 (late gestation) for laboratory analysis. Ewes were pregnancy scanned at mid-gestation to determine whether they were early or late parturition (this confirmation is provided by the pregnancy scanner based on fetus size). Top-knot wool sample was also taken from the lambs at weaning for hormone and wool quality testing. Ear tissue was taken from ewes at day 50 (mid-gestation) and from lambs at lamb marking for DNA analysis. Results showed that twice or early shorn ewes grazed 10% higher and maintained stronger body condition than once shorn ewes. Wool cortisol levels were also significantly lower in the early shorn ewes between mid- and late gestation. Lambs bred from twice shorn ewes had on average better visual wool quality parameters in terms of micron, spin finesses, and curvature. For the DNA methylation results, when comparing a group of once sheared with twice sheared ewes, we have discovered one locus (Chr20:50404014) that was significantly differentially methylated [False Discovery Rate (FDR) = 0.005]. This locus is upstream of a protein-coding gene (ENSOARG00000002778.1), which shows similarities to the forkhead box C1 (FOXC1) mRNA using BLAST searches. To further our understanding of the potential interaction between pregnancy status and shearing frequency of the ewes, we performed further differential methylation analysis using a combination of shearing treatment and pregnancy scanning status. The comparisons (1) late pregnancy vs. early pregnancy for ewes with one shearing treatment and (2) late pregnancy vs. early pregnancy for sheep with two shearing treatments were carried out to identify associations between loci and pregnancy duration for sheep with either one or two shearing events. We discovered that 36 gene loci were significantly modulated either between different shearing treatments or late vs. early pregnancy status of ewes. This result suggests that maternal pregnancy and nutritional status during gestation influence DNA methylation. We further investigated DNA methylation in lambs and identified 16 annotated gene loci that showed epigenetic modulation as a result of being born from an early or late stage pregnancy. From the genomics data, we pointed out that ewes go through epigenetic modifications during gestation, and there is a degree of intra-individual variation in the reproductive performance of ewes, which could be due to combination of intrinsic (genetic and physiological) and extrinsic (management and climatic) factors. Collectively, this research provides novel dataset combining physiological, molecular epigenetics, and digital tracking indices that advances our understanding of how Merino ewes respond to shearing frequency, and this information could guide further research on Merino sheep breeding and welfare.

The genetics of glaucoma: Disease associations, personalised risk assessment and therapeutic opportunities-A review

Glaucoma refers to a heterogenous group of disorders characterised by progressive loss of retinal ganglion cells and associated visual field loss. Both early-onset and adult-onset forms of the disease have a strong genetic component. Here, we summarise the known genetic associations for various forms of glaucoma and the possible functional roles for these genes in disease pathogenesis. We also discuss efforts to translate genetic knowledge into clinical practice, including gene-based tests for disease diagnosis and risk-stratification as well as gene-based therapies.

De novo PBX1 variant in a patient with glaucoma, kidney anomalies, and developmental delay: An expansion of the CAKUTHED phenotype

An infant was referred for evaluation of congenital glaucoma and corneal clouding. In addition, he had a pelvic kidney, hypotonia, patent ductus arteriosus, abnormal pinnae, and developmental delay. Exome sequencing identified a previously unpublished de novo single nucleotide insertion in PBX1 c.400dupG (NM_002585.3), predicted to cause a frameshift resulting in a truncated protein with loss of function (p.Ala134Glyfs*65). Identification of this loss of function variant supports the diagnosis of congenital anomalies of the kidney and urinary tract syndrome with or without hearing loss, abnormal ears, or developmental delay (CAKUTHED). Here, we propose glaucoma as an extra-renal manifestation associated with PBX1-related disease due to the relationship of PBX1 with MEIS1, MEIS2, and FOXC1 transcription factors associated with eye development.

Overexpression of Foxc1 ameliorates sepsis‑associated encephalopathy by inhibiting microglial migration and neuroinflammation through the IκBα/NF‑κB pathway

Sepsis-associated encephalopathy (SAE) is a common and severe complication of sepsis. The cognitive dysfunction that ensues during SAE has been reported to be caused by impairments of the hippocampus. Microglia serves a key role in neuroinflammation during SAE through migration. Forkhead box C1 (Foxc1) is a member of the forkhead transcription factor family that has been found to regulate in cell migration. However, the role of Foxc1 in neuroinflammation during SAE remains unknown. In the present study, the mechanistic role of Foxc1 on microglial migration, neuroinflammation and neuronal apoptosis during the occurrence of cognitive dysfunction in SAE was investigated. A microglia-mediated inflammation model was induced by LPS in BV-2 microglial cells in vitro, whilst a SAE-related cognitive impairment model was established in mice using cecal ligation and perforation (CLP) surgery. Cognitive function in mice was evaluated using the Morris Water Maze (MWM) trial. Lipopolysaccharide (LPS) treatment was found to trigger BV-2 cell migration, inflammation and neuronal apoptosis. In addition, CLP surgery induced cognitive injury, which was indicated by longer latencies and shorter dwell times in the goal quadrant compared with those in the Sham group in the MWM trial. LPS treatment or CLP induction decreased the expression of Foxc1 and inhibitor of NF-κB (IκΒα) whilst increasing that of p65, IL-1β and TNF-α. After Foxc1 was overexpressed, the cognitive dysfunction of mice that underwent CLP surgery was improved, with the expression of IκBα also increased, microglial cell migration, the expression of p65, IL-1β and TNF-α and neuronal apoptosis were all decreased in vivo and in vitro, which were in turn reversed by the inhibition of IκBα in vitro. Overall, these results suggest that the overexpression of Foxc1 inhibited microglial migration whilst suppressing the inflammatory response and neuronal apoptosis by regulating the IκBα/NF-κB pathway, thereby improving cognitive dysfunction during SAE.

miR-149 Suppresses the Proliferation and Metastasis of Human Gastric Cancer Cells by Targeting FOXC1

Purpose

Gastric cancer is one of the most common cancers in the world. miRNAs play an important role in regulating gene expression by binding with 3'-UTR of the target gene. The aim of this study was to investigate the function of miRNA-149 and FOXC1 in gastric cancer. Patients and Methods. qRT-PCR was used to detect the expression of miRNA-149 and FOXC1 in gastric cancer tissues and cells. Human gastric cancer cell lines AGS and MKN28 were cultured and transfected with miR-149 overexpression plasmid and its control or FOXC1 siRNA and its control. The MTT, colony formation, flow cytometry, wound healing, transwell, and western blotting were performed to examine the function of miRNA-149 and FOXC1 in the development of gastric cancer. What is more, dual-luciferase assay and western blotting were used to demonstrated the relationship between miRNA-149 and FOXC1.

Results

miRNA-149 was underexpressed in gastric cancer tissues and cells, while overexpression of miRNA-149 promoted cell apoptosis, retarded cell cycle, and inhibited proliferation and migration in AGS and MKN28 cells. In addition, we showed that miRNA-149 targeted FOXC1. What is more, FOXC1 was highly expressed in gastric cancer tissues and cells; the silencing of FOXC1 inhibited the biological function of AGS and MKN28 cells.

Conclusion

miRNA-149 inhibits the biological behavior of gastric cancer by targeting FOXC1, providing a promising target in the treatment of human gastric cancer.

Heterogeneity of Axenfeld-Rieger Syndrome: Molecular and Clinical Findings in Chinese Patients

Axenfeld–Rieger Syndrome (ARS) is a rare disease with a wide spectrum of ocular and systemic manifestations. The genetic spectrum of Chinese patients with ARS and genotype-phenotype correlations have yet to be described. To explore the molecular and clinical features in Chinese patients, fifty-five patients clinically diagnosed with ARS from independent families were recruited. Complete ophthalmic examinations and next generation sequencing of anterior segment dysgenesis associated genes were performed in all patients, and segregation in available relatives was verified using Sanger sequencing. 18 FOXC1 variants, 13 PITX2 variants, and two gross deletions spanning FOXC1 were detected in 35 out of 55 (63.6%) patients. 12 FOXC1 variants, 9 PITX2 variants, and two gross deletions were novel. There was a wide range of variability and severity in ocular and systemic manifestations displayed in our patients. Patients with FOXC1 variants were diagnosed at a younger age and had a lower prevalence of systemic manifestations than patients harboring PITX2 variants and those without variants. To our best knowledge, this is the largest study of Chinese patients with ARS to date. Our findings expand the genetic spectrum of ARS and reveal genotype-phenotype correlations in Chinese patients with ARS. Genetic and clinical heterogeneity were present in our patients. Awareness of the extensive characterization may aid in the clinical management and genetic counseling of patients with this rare disease.

Identification and functional study of FOXC1 variants in Chinese families with glaucoma

This study aimed to identify the disease-causing gene of three Chinese families with glaucoma. Whole exome sequencing was performed on the probands and detected three different variants (c.405C>A (p.Cys135Ter), c.851G>T (p.Ser284Ile), and c.392C>T (p.Ser131Leu)) in FOXC1 as a causative gene of glaucoma, and Sanger sequencing was performed for verification and cosegregation analysis. Three in silico tools all predicted these two missense variants to be probably disease-causing. Western blot analysis, immunofluorescence, and dual-luciferase assay were further used to evaluate the effect of FOXC1 missense variants, and demonstrated that the two variants resulted in decreased transactivation activity of FOXC1 although the variants had no effect on the protein amount and the nucleus subcellar localization of FOXC1 compared with the wild type, which implies that both of two variants may be probably pathogenic. In this study, we reported two novel FOXC1 variants as well as a reported variant and the phenotypes associated to these variants, which expands the spectrum and relevant phenotypes of FOXC1 variants. Additionally, the functional analysis of FOXC1 variants provides further insight into the possible pathogenesis of anterior segment anomaly related to FOXC1.

Therapeutically Targeting Cancers That Overexpress FOXC1: A Transcriptional Driver of Cell Plasticity, Partial EMT, and Cancer Metastasis

Metastasis accounts for more than 90% of cancer related mortality, thus the most pressing need in the field of oncology today is the ability to accurately predict future onset of metastatic disease, ideally at the time of initial diagnosis. As opposed to current practice, what would be desirable is that prognostic, biomarker-based detection of metastatic propensity and heightened risk of cancer recurrence be performed long before overt metastasis has set in. Without such timely information it will be impossible to formulate a rational therapeutic treatment plan to favorably alter the trajectory of disease progression. In order to help inform rational selection of targeted therapeutics, any recurrence/metastasis risk prediction strategy must occur with the paired identification of novel prognostic biomarkers and their underlying molecular regulatory mechanisms that help drive cancer recurrence/metastasis (i.e. recurrence biomarkers). Traditional clinical factors alone (such as TNM staging criteria) are no longer adequately prognostic for this purpose in the current molecular era. FOXC1 is a pivotal transcription factor that has been functionally implicated to drive cancer metastasis and has been demonstrated to be an independent predictor of heightened metastatic risk, at the time of initial diagnosis. In this review, we present our viewpoints on the master regulatory role that FOXC1 plays in mediating cancer stem cell traits that include cellular plasticity, partial EMT, treatment resistance, cancer invasion and cancer migration during cancer progression and metastasis. We also highlight potential therapeutic strategies to target cancers that are, or have evolved to become, “transcriptionally addicted” to FOXC1. The potential role of FOXC1 expression status in predicting the efficacy of these identified therapeutic approaches merits evaluation in clinical trials.

Glaucoma Syndromes: Insights into Glaucoma Genetics and Pathogenesis from Monogenic Syndromic Disorders

Monogenic syndromic disorders frequently feature ocular manifestations, one of which is glaucoma. In many cases, glaucoma in children may go undetected, especially in those that have other severe systemic conditions that affect other parts of the eye and the body. Similarly, glaucoma may be the first presenting sign of a systemic syndrome. Awareness of syndromes associated with glaucoma is thus critical both for medical geneticists and ophthalmologists. In this review, we highlight six categories of disorders that feature glaucoma and other ocular or systemic manifestations: anterior segment dysgenesis syndromes, aniridia, metabolic disorders, collagen/vascular disorders, immunogenetic disorders, and nanophthalmos. The genetics, ocular and systemic features, and current and future treatment strategies are discussed. Findings from rare diseases also uncover important genes and pathways that may be involved in more common forms of glaucoma, and potential novel therapeutic strategies to target these pathways.

EZH2 regulates expression of FOXC1 by mediating H3K27me3 in breast cancers

Triple-negative breast cancer (TNBC) is characterized by low expression of human epidermal growth factor receptor-2 (HER2), estrogen receptor (ER), and progesterone receptor (PR), which is the most aggressive subtype with poor outcome among breast cancers. The underlying mechanisms of TNBC remain unclear and there is a lack of biomarkers. In this study we conducted an in silico assay and found that FOXC1 was highly expressed in ER^-/PR^-/HER2^- breast cancers, which was confirmed by qRT-PCR, immunohistochemistry, and Western blot analysis. FOXC1 was more highly expressed in TNBCs than the other breast cancers. Kaplan-Meier plotter revealed that expression of FOXC1 was associated with overall survival (OS) of patients with breast cancers. Expression of FOXC1 was reversely associated with level of H3K27me3, which was methylated by EZH2. In MCF-7 and T47D cells, inhibition of EZH2 by DZNeP or GSK343 concentration- and time-dependently increased expression of FOXC1. Finally, we demonstrated that the expression of FOXC1 was associated with resistance of doxorubicin treatment of breast cancer cells. In conclusion, these results suggest that FOXC1 may be a potential biomarker or drug target for TNBCs, and that downregulation of FOXC1 could have therapeutic value in treatment of TNBCs.

Gene-specific facial dysmorphism in Axenfeld-Rieger syndrome caused by FOXC1 and PITX2 variants

Axenfeld-Rieger syndrome is a genetic condition characterized by ocular and systemic features and is most commonly caused by variants in the FOXC1 or PITX2 genes. Facial dysmorphism is part of the syndrome but the differences between both genes have never been systematically assessed. Here, 11 facial traits commonly reported in Axenfeld-Rieger syndrome were assessed by five clinical geneticists blinded to the molecular diagnosis. Individuals were drawn from the Australian and New Zealand Registry of Advanced Glaucoma in Australia or recruited through the Genetic and Ophthalmology Unit of l'Azienda Socio-Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Italy. Thirty-four individuals from 18 families were included. FOXC1 variants were present in 64.7% of individuals and PITX2 variants in 35.3% of individuals. A thin upper lip (55.9%) and a prominent forehead (41.2%) were common facial features shared between both genes. Hypertelorism/telecanthus (81.8% vs 25.0%, p = 0.002) and low-set ears (31.8% vs 0.0%, p = 0.036) were significantly more prevalent in individuals with FOXC1 variants compared with PITX2 variants. These findings may assist clinicians in reaching correct clinical and molecular diagnoses, and providing appropriate genetic counseling.

The Axenfeld-Rieger Syndrome Gene FOXC1 Contributes to Left-Right Patterning

Precise spatiotemporal expression of the Nodal-Lefty-Pitx2 cascade in the lateral plate mesoderm establishes the left–right axis, which provides vital cues for correct organ formation and function. Mutations of one cascade constituent PITX2 and, separately, the Forkhead transcription factor FOXC1 independently cause a multi-system disorder known as Axenfeld–Rieger syndrome (ARS). Since cardiac involvement is an established ARS phenotype and because disrupted left–right patterning can cause congenital heart defects, we investigated in zebrafish whether foxc1 contributes to organ laterality or situs. We demonstrate that CRISPR/Cas9-generated foxc1a and foxc1b mutants exhibit abnormal cardiac looping and that the prevalence of cardiac situs defects is increased in foxc1a^−/−; foxc1b^−/− homozygotes. Similarly, double homozygotes exhibit isomerism of the liver and pancreas, which are key features of abnormal gut situs. Placement of the asymmetric visceral organs relative to the midline was also perturbed by mRNA overexpression of foxc1a and foxc1b. In addition, an analysis of the left–right patterning components, identified in the lateral plate mesoderm of foxc1 mutants, reduced or abolished the expression of the NODAL antagonist lefty2. Together, these data reveal a novel contribution from foxc1 to left–right patterning, demonstrating that this role is sensitive to foxc1 gene dosage, and provide a plausible mechanism for the incidence of congenital heart defects in Axenfeld–Rieger syndrome patients.

FOXC1 variant in a family with anterior segment dysgenesis and normal-tension glaucoma

Our study describes the glaucoma phenotype in a family with Axenfeld-Rieger syndrome (ARS) and a FOXC1 variant. Included were 20 subjects from a large three generation family of Jewish Indian ancestry. Subjects underwent a comprehensive ophthalmic examination including automated perimetry and optical coherence tomography. Eight subjects were available for molecular analysis which included whole genome sequencing on selected patients and Sanger sequencing for variant screening. Eleven patients demonstrated a wide spectrum of Axenfeld-Rieger anomaly signs and symptoms. These ranged from subtle angle abnormalities to remarkable anterior segment abnormalities such as corectopia, iris adhesions and strands. Among them, six had glaucoma and two were glaucoma suspects. Of the six subjects with glaucoma three had high-tension glaucoma and two had normal-tension glaucoma. Molecular analysis revealed a previously described pathogenic variant in the FOXC1 gene (c.378C > G p.I126M; rs104893958), in six affected patients which was not identified in two healthy siblings. Molecular analysis also revealed a PITX2 missense variant (c.28T > A p.L10M; rs755864040) which did not segregate with clinical findings and was considered likely benign. In conclusion, patients with ARS due to FOXC1 variants may present with glaucomatous optic nerve damage without apparent elevation in IOP. Normal-tension glaucoma is less commonly reported in individuals with ARS and a comprehensive glaucoma assessment may be warranted in these individuals even with normal IOP. These findings raise the possibility that glaucomatous damage associated with FOXC1 is not only due to high IOP.

Ocular genetics in the genomics age

Current genetic screening methods for inherited eye diseases are concentrated on the coding exons of known disease genes (gene panels, clinical exome). These tests have a variable and often limited diagnostic rate depending on the clinical presentation, size of the gene panel and our understanding of the inheritance of the disorder (with examples described in this issue). There are numerous possible explanations for the missing heritability of these cases including undetected variants within the relevant gene (intronic, up/down-stream and structural variants), variants harbored in genes outside the targeted panel, intergenic variants, variants undetectable by the applied technology, complex/non-Mendelian inheritance, and nongenetic phenocopies. In this article we further explore and review methods to investigate these sources of missing heritability.

Axenfeld-Rieger syndrome-associated mutants of the transcription factor FOXC1 abnormally regulate NKX2-5 in model zebrafish embryos

FOXC1 is a member of the forkhead family of transcription factors, and whose function is poorly understood. A variety of FOXC1 mutants have been identified in patients diagnosed with the autosomal dominant disease Axenfeld-Rieger syndrome, which is mainly characterized by abnormal development of the eyes, particularly those who also have accompanying congenital heart defects (CHD). However, the role of FOXC1 in CHD, and how these mutations might impact FOXC1 function, remains elusive. Our previous work provided one clue to possible function, demonstrating that zebrafish foxc1a, an orthologue of human FOXC1 essential for heart development, directly regulates the expression of nkx2.5, encoding a transcriptional regulator of cardiac progenitor cells. Abnormal expression of Nkx2-5 leads to CHD in mice and is also associated with CHD patients. Whether this link extends to the human system, however, requires investigation. In this study, we demonstrate that FOXC1 does regulate human NKX2-5 expression in a dose-dependent manner via direct binding to its proximal promoter. A comparison of FOXC1 mutant function in the rat cardiac cell line H9c2 and zebrafish embryos suggested that the zebrafish embryos might serve as a more representative model system than the H9c2 cells. Finally, we noted that three of the Axenfeld-Rieger syndrome FOXC1 mutations tested increased, whereas a fourth repressed the expression of NKX2-5 These results imply that mutant FOXC1s might play etiological roles in CHD by abnormally regulating NKX2-5 in the patients. And zebrafish embryos can serve as a useful in vivo platform for rapidly evaluating disease-causing roles of mutated genes.

Exome Sequencing in a Swiss Childhood Glaucoma Cohort Reveals CYP1B1 and FOXC1 Variants as Most Frequent Causes

Purpose

The aim of this study was to investigate the molecular basis of childhood glaucoma in Switzerland to recommend future targeted genetic analysis in the Swiss population.

Methods

Whole-exome sequencing and copy number variation (CNV) analysis was performed in a Swiss cohort of 18 patients from 14 unrelated families. Identified variants were validated by Sanger sequencing and multiplex ligation-dependent probe amplification. Breakpoints of structural variants were determined by a microarray. A minigene assay was conducted for functional analysis of a splice site variant.

Results

A diagnosis of primary congenital glaucoma was made in 14 patients, of which six (43%) harbored pathogenic variants in CYP1B1, one (7%) a frameshift variant in FOXC1, and seven (50%) remained without a genetic diagnosis. Three patients were diagnosed with glaucoma associated with nonacquired ocular anomalies, of which two patients with mild ocular features of Axenfeld-Rieger syndrome harbored a FOXC1 duplication plus an additional FOXC1 missense variant, and one patient with a Barkan membrane remained without genetic diagnosis. A diagnosis of juvenile open-angle glaucoma was made in one patient, and genetic analysis revealed a FOXC1 duplication.

Conclusions

Sequencing of CYP1B1 and FOXC1, as well as analysis of CNVs in FOXC1, should be performed before extended gene panel sequencing.

Translational Relevance

The identification of the molecular cause of childhood glaucoma is a prerequisite for genetic counseling and personalized care for patients and families.

Phenotype expansion of heterozygous FOXC1 pathogenic variants toward involvement of congenital anomalies of the kidneys and urinary tract (CAKUT)

PURPOSE

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in childhood and adolescence. We aim to identify novel monogenic causes of CAKUT.

METHODS

Exome sequencing was performed in 550 CAKUT-affected families.

RESULTS

We discovered seven FOXC1 heterozygous likely pathogenic variants within eight CAKUT families. These variants are either never reported, or present in <5 alleles in the gnomAD database with ~141,456 controls. FOXC1 is a causal gene for Axenfeld-Rieger syndrome type 3 and anterior segment dysgenesis 3. Pathogenic variants in FOXC1 have not been detected in patients with CAKUT yet. Interestingly, mouse models for Foxc1 show severe CAKUT phenotypes with incomplete penetrance and variable expressivity. The FOXC1 variants are enriched in the CAKUT cohort compared with the control. Genotype-phenotype correlations showed that Axenfeld-Rieger syndrome or anterior segment dysgenesis can be caused by both truncating and missense pathogenic variants, and the missense variants are located at the forkhead domain. In contrast, for CAKUT, there is no truncating pathogenic variant, and all variants except one are located outside the forkhead domain.

CONCLUSION

We thereby expanded the phenotype of FOXC1 pathogenic variants toward involvement of CAKUT, which can potentially be explained by allelism.

Mapping the cis-regulatory architecture of the human retina reveals noncoding genetic variation in disease

The interplay of transcription factors and cis-regulatory elements (CREs) orchestrates the dynamic and diverse genetic programs that assemble the human central nervous system (CNS) during development and maintain its function throughout life. Genetic variation within CREs plays a central role in phenotypic variation in complex traits including the risk of developing disease. We took advantage of the retina, a well-characterized region of the CNS known to be affected by pathogenic variants in CREs, to establish a roadmap for characterizing regulatory variation in the human CNS. This comprehensive analysis of tissue-specific regulatory elements, transcription factor binding, and gene expression programs in three regions of the human visual system (retina, macula, and retinal pigment epithelium/choroid) reveals features of regulatory element evolution that shape tissue-specific gene expression programs and defines regulatory elements with the potential to contribute to Mendelian and complex disorders of human vision.

CPAMD8 loss-of-function underlies non-dominant congenital glaucoma with variable anterior segment dysgenesis and abnormal extracellular matrix

Abnormal development of the ocular anterior segment may lead to a spectrum of clinical phenotypes ranging from primary congenital glaucoma (PCG) to variable anterior segment dysgenesis (ASD). The main objective of this study was to identify the genetic alterations underlying recessive congenital glaucoma with ASD (CG-ASD). Next-generation DNA sequencing identified rare biallelic CPAMD8 variants in four patients with CG-ASD and in one case with PCG. CPAMD8 is a gene of unknown function and recently associated with ASD. Bioinformatic and in vitro functional evaluation of the variants using quantitative reverse transcription PCR and minigene analysis supported a loss-of-function pathogenic mechanism. Optical and electron microscopy of the trabeculectomy specimen from one of the CG-ASD cases revealed an abnormal anterior chamber angle, with altered extracellular matrix, and apoptotic trabecular meshwork cells. The CPAMD8 protein was immunodetected in adult human ocular fluids and anterior segment tissues involved in glaucoma and ASD (i.e., aqueous humor, non-pigmented ciliary epithelium, and iris muscles), as well as in periocular mesenchyme-like cells of zebrafish embryos. CRISPR/Cas9 disruption of this gene in F0 zebrafish embryos (96 hpf) resulted in varying degrees of gross developmental abnormalities, including microphthalmia, pharyngeal maldevelopment, and pericardial and periocular edemas. Optical and electron microscopy examination of these embryos showed iridocorneal angle hypoplasia (characterized by altered iris stroma cells, reduced anterior chamber, and collagen disorganized corneal stroma extracellular matrix), recapitulating some patients' features. Our data support the notion that CPAMD8 loss-of-function underlies a spectrum of recessive CG-ASD phenotypes associated with extracellular matrix disorganization and provide new insights into the normal and disease roles of this gene.

Identification of a novel microRNA-141-3p/Forkhead box C1/β-catenin axis associated with rheumatoid arthritis synovial fibroblast function in vivo and in vitro

Rationale: Rheumatoid arthritis (RA) is a prototype of inflammatory arthritis in which synovial fibroblasts (SFs) play key roles in cartilage and bone destruction through tumor-like proliferation, migration, invasion and inflammation. This study aimed to research forkhead box protein C1 (FoxC1) and microRNA (miR)-141-3p, which modulate pathological changes in the synovial membrane, to find possible strategies for treating RA.

Methods: FoxC1, β-catenin and miR-141-3p gene expression in synovial tissues and SFs was quantified by real-time PCR; FoxC1 and β-catenin protein levels were evaluated by immunohistochemistry, immunofluorescence, and Western blotting. We transiently transfected human SFs with FoxC1 and β-catenin overexpression and silencing vectors and assessed proliferation, migration, invasion and inflammation by cell function and enzyme-linked immunosorbent assays. We also assessed downstream signaling activation using immunofluorescence, real-time PCR and Western blotting. Double luciferase, coimmunoprecipitation and chromatin immunoprecipitation assays were used to verify miR-141-3p, FoxC1 and β-catenin gene and protein combinations. Finally, the therapeutic effects of FoxC1 silencing and miR-141-3p overexpression were evaluated in type II collagen-induced arthritis (CIA) rats.

Results: We found that FoxC1 expression was significantly upregulated in synovium and SFs in both RA patients and rats with collagen-induced arthritis (CIA). FoxC1 overexpression increased β-catenin messenger RNA (mRNA) and protein levels and upregulated cyclin D1, c-Myc, fibronectin and matrix metalloproteinase 3 (MMP3) mRNA and protein expression in RA SFs (RASFs). In contrast, FoxC1 knockdown reduced β-catenin mRNA and protein levels as well as cyclin D1, c-Myc, and fibronectin mRNA and protein levels in RASFs. Furthermore, altering FoxC1 expression did not significantly change GSK3β and pGSK3β levels. FoxC1 overexpression promoted proliferation, migration, invasion and proinflammatory cytokine (interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α)) production and reduced anti-inflammatory cytokine (IL-10) levels in RASFs. FoxC1 bound to the β-catenin promoter, and β-catenin mediated the FoxC1-induced pathological changes. We also observed downregulated microRNA (miR)-141-3p expression in SFs from both RA patients and CIA rats and further found that miR-141-3p bound to the FoxC1 3′UTR and suppressed FoxC1 expression. Intra-ankle miR-141-3p agomir or FoxC1-specific siRNA injection hindered CIA development in rats.

Conclusions: FoxC1 and miR-141-3p participate in RA pathogenesis by mediating inflammation and SF proliferation, migration, and invasion and thus could be novel targets for RA therapy as a nonimmunosuppressive approach.

A case of childhood glaucoma with a combined partial monosomy 6p25 and partial trisomy 18p11 due to an unbalanced translocation

Background: Chromosomal deletion involving the 6p25 region results in a clinically recognizable syndrome characterized by anterior eye chamber anomalies with risk of glaucoma and non-ocular malformations (6p25 deletion syndrome). We report a newborn infant case of childhood glaucoma with a combination of partial monosomy 6p25 and partial trisomy 18p11 due to an unbalanced translocation.Materials and methods: The patient was a 0-year-old girl. Both eyes showed aniridia and left eye Peters anomaly with multiple malformations. To identify the chromosomal aberrations in the patient with clinically suspected 6p25 deletion syndrome, we performed cytogenetic analysis (G-banding and multicolor fluorescent in-situ hybridization) and array-based comparative genomic hybridization (array-CGH) analysis.Results: Cytogenetic analyses revealed a derivative chromosome 6 with its distal short arm replaced by an extra copy of the short arm of chromosome 18. Array-CGH analysis detected a 4.6-Mb deletion at 6pter to 6p25.1 and 8.9-Mb duplication at 18pter to 18p11.22. To determine the breakpoint of the unbalanced rearrangement at the single-base level, we performed a long-range PCR for amplifying the junctional fragment of the translocation breakpoint. By sequencing the junctional fragment, we defined the unbalanced translocation as g.chr6:pter_4594783delinschr18:pter_8911541.Conclusions: A phenotype corresponding to combined monosomy 6p25 and trisomy 18p11 presented as childhood glaucoma associated with non-acquired (congenital) ocular anomalies consist of aniridia and Peters anomaly and other systemic malformations. To the best of our knowledge, this is the first report which demonstrated the breakpoint sequence of an unbalanced translocation in a Japanese infant with childhood glaucoma.

MIR-138-5P inhibits the progression of prostate cancer by targeting FOXC1

Background

Studies have suggested that micro‐RNAs (miRNAs) can function as an oncogene or a tumor suppressor in cancers. However, the role of MIR‐138‐5P (613394) in prostate cancer (PCa) remains unclear.

Methods

Expression level of MIR‐138‐5P in PCa cell lines and normal cell line was analyzed with the quantitative real‐time PCR method. Cell counting kit‐8 assay, colony formation assay, wound‐healing assay, and transwell invasion assay were performed to analyze the biological functions of MIR‐138‐5P.

Results

We showed MIR‐138‐5P expression level was significantly decreased in PCa cell lines compared with the normal cell line. Overexpression of MIR‐138‐5P inhibits PCa cell proliferation, colony formation, cell migration, and cell invasion in vitro. Mechanistically, we showed Forkhead box C1 (FOXC1, 601090) was a direct target for MIR‐138‐5P in PCa. We confirmed that overexpression of FOXC1 partially reversed the effects of MIR‐138‐5P on PCa cell behaviors.

Conclusions

Collectively, we showed that MIR‐138‐5P functions as a tumor suppressor gene in PCa via targeting FOXC1.

Prevalence of FOXC1 Variants in Individuals With a Suspected Diagnosis of Primary Congenital Glaucoma

Importance

Both primary and secondary forms of childhood glaucoma have many distinct causative mechanisms, and in many cases a cause is not immediately clear. The broad phenotypic spectrum of secondary glaucoma, particularly in individuals with variants in FOXC1 or PITX2 genes associated with Axenfeld-Rieger syndrome, makes it more difficult to diagnose patients with milder phenotypes. These cases are occasionally classified and managed as primary congenital glaucoma.

Objective

To investigate the prevalence of FOXC1 variants in participants with a suspected diagnosis of primary congenital glaucoma.

Design, Setting, and Participants

Australian and Italian cohorts were recruited from January 1, 2007, through March 1, 2016. Australian individuals were recruited through the Australian and New Zealand Registry of Advanced Glaucoma and Italian individuals through the Genetic and Ophthalmology Unit of l'Azienda Socio-Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Milan, Italy. We performed exome sequencing, in combination with Sanger sequencing and multiplex ligation-dependent probe amplification, to detect variants of FOXC1 in individuals with a suspected diagnosis of primary congenital glaucoma established by their treating specialist. Data analysis was completed from June 2015 to November 2017.

Main Outcome and Measures

Identification of single-nucleotide and copy number variants in FOXC1, along with phenotypic characterization of the individuals who carried them.

Results

A total of 131 individuals with a suspected diagnosis of primary congenital glaucoma were included. The mean (SD) age at recruitment in the Australian cohort was 24.3 (18.1) years; 37 of 84 Australian participants (44.0%) were female, and 71 of 84 (84.5%) were of European ancestry. The mean (SD) age at recruitment was 22.5 (18.4) years in the Italian cohort; 21 of 47 Italian participants (44.7%) were female, and 45 of 47 (95.7%) were of European ancestry. We observed rare, predicted deleterious FOXC1 variants in 8 of 131 participants (6.1%), or 8 of 166 participants (4.8%) when including those explained by variants in CYP1B1. On reexamination or reinvestigation, all of these individuals had at least 1 detectable ocular and/or systemic feature associated with Axenfeld-Rieger syndrome.

Conclusions and Relevance

These data highlight the genetic and phenotypic heterogeneity of childhood glaucoma and support the use of gene panels incorporating FOXC1 as a diagnostic aid, especially because clinical features of Axenfeld-Rieger syndrome can be subtle. Further replication of these results will be needed to support the future use of such panels.

Biallelic CPAMD8 Variants Are a Frequent Cause of Childhood and Juvenile Open-Angle Glaucoma

PURPOSE

Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.

DESIGN

Retrospective, multicenter case series.

PARTICIPANTS

A total of 268 probands and their relatives with a diagnosis of childhood or juvenile open-angle glaucoma.

PURPOSE

Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.

METHODS

Patients underwent a comprehensive ophthalmic assessment, with DNA from patients and their relatives subjected to genome, exome, or capillary sequencing. CPAMD8 RNA expression analysis was performed on tissues dissected from cadaveric human eyes.

MAIN OUTCOME MEASURES

Diagnostic yield within a cohort of childhood and juvenile open-angle glaucoma, prevalence and risk of ophthalmic phenotypes, and relative expression of CPAMD8 in the human eye.

RESULTS

We identified rare (allele frequency < 4×10^-5) biallelic CPAMD8 variants in 5.7% (5/88) of probands with childhood glaucoma and 2.1% (2/96) of probands with juvenile open-angle glaucoma. When including family members, we identified 11 individuals with biallelic variants in CPAMD8 from 7 unrelated families. Nine of these individuals were diagnosed with glaucoma (9/11, 81.8%), with a mean age at diagnosis of 9.22±14.89 years, and all individuals with glaucoma required 1 or more incisional procedures to control high intraocular pressure. Iris abnormalities were observed in 9 of 11 individuals, cataract was observed in 8 of 11 individuals (72.7%), and retinal detachment was observed in 3 of 11 individuals (27.3%). CPAMD8 expression was highest in neural crest-derived tissues of the adult anterior segment, suggesting that CPAMD8 variation may cause malformation or obstruction of key drainage structures.

CONCLUSIONS

Biallelic CPAMD8 variation was associated with a highly heterogeneous phenotype and in our cohorts was the second most common inherited cause of childhood glaucoma after CYP1B1 and juvenile open-angle glaucoma after MYOC. CPAMD8 sequencing should be considered in the investigation of both childhood and juvenile open-angle glaucoma, particularly when associated with iris abnormalities, cataract, or retinal detachment.

Forkhead box C1 promotes the pathology of osteoarthritis by upregulating β-catenin in synovial fibroblasts

Osteoarthritis (OA) is a joint disease characterized by articular cartilage degeneration, and no effective treatment is available. The OA classification has shifted from a cartilage-only disease to a whole-joint disease, and the synovial membrane plays an important role. Therefore, studies are needed to identify additional genes that regulate the pathological changes in the synovial membrane to develop a promising therapeutic strategy for OA. Here, we validated that the expression of forkhead box protein C1 (FoxC1) and β-catenin was upregulated in OA synovial membranes and synovial fibroblasts (SFs). Gain- and loss-of-function studies revealed that FoxC1 overexpression promoted, whilst silencing inhibited OA synovial fibroblast (OASF) proliferation and pro-inflammatory cytokine [interleukin 6 (IL-6), interleukin 8 (IL-8) and tumour necrosis factor-α (TNF-α)] production. FoxC1 overexpression increased β-catenin mRNA, total and nuclear protein expression in OASFs and upregulated a disintegrin and metalloproteinase with thrombospondin motif 5 (ADAMTS-5), fibronectin, matrix metalloproteinase 3 (MMP3) and matrix metalloproteinase 13 (MMP13) mRNA and total protein expression in OASFs. Conversely, FoxC1 knockdown reduced β-catenin mRNA, total and nuclear protein expression in OASFs and reduced ADAMTS-5, fibronectin, MMP3 and MMP13 mRNA and total protein expression in OASFs. β-catenin mediates FoxC1-induced pathological changes (proliferation, catabolic regulation and inflammation) in OASFs. MicroRNA-200a-3p (miR-200a-3p) binds to the 3'-UTR of FoxC1 and mediates FoxC1 expression. Intra-articular FoxC1-specific siRNA transfection hindered OA development in mice. Therefore, our results demonstrate the key role FoxC1 plays in vivo and in vitro in OA synovial pathology, possibly identifying a potential novel therapeutic target for OA.

Childhood glaucoma genes and phenotypes: Focus on FOXC1 mutations causing anterior segment dysgenesis and hearing loss

Childhood glaucoma is an important cause of blindness world-wide. Eleven genes are currently known to cause inherited forms of glaucoma with onset before age 20. While all the early-onset glaucoma genes cause severe disease, considerable phenotypic variability is observed among mutations carriers. In particular, FOXC1 genetic variants are associated with a broad range of phenotypes including multiple forms of glaucoma and also systemic abnormalities, especially hearing loss. FOXC1 is a member of the forkhead family of transcription factors and is involved in neural crest development necessary for formation of anterior eye structures and also pharyngeal arches that form the middle ear bones. In this study we review the clinical phenotypes reported for known FOXC1 mutations and show that mutations in patients with reported ocular anterior segment abnormalities and hearing loss primarily disrupt the critically important forkhead domain. These results suggest that optimal care for patients affected with anterior segment dysgenesis should include screening for FOXC1 mutations and also testing for hearing loss.

The identification and stereochemistry analysis of a novel mutation p.(D367Tfs*61) in the CYP1B1 gene: A case report

Purpose:

To investigate the presence of a probable genetic defect(s) that may cause primary congenital glaucoma (PCG) in a seven-year-old female patient.

Methods:

A seven-year-old female patient and her family received genetic counseling and underwent full clinical examinations by an expert ophthalmologist. The patient's genomic DNA was subjected to the targeted gene capture and next-generation sequencing (NGS) along with Sanger sequencing method. The 3D structure prediction and stereochemistry analysis were performed for both mutant and wild-type forms of the CYP1B1 protein.

Results:

The clinical examinations indicated that the diagnosis of PCG was correctly made. We identified a novel homozygous deletion in which a “C” nucleotide was deleted from the final exon of the Cytochrome P450 Family 1 Subfamily B Member 1 (CYP1B1) gene. The 3D molecular modeling of the CYP1B1 protein predicted significant structural changes could occur in this protein as a result of the mutation mentioned earlier. The stereochemistry analysis revealed mutant features of the protein, as well as significant misfolding and possible malfunctions in the mutant form of the CYP1B1 protein.

Conclusions:

This mutation might cause a frameshift in the translation process, leading to the malfunction of the CYP1B1 protein and development of glaucoma. This newly-identified mutation could be regarded as potential deletion mutation in genetic counseling and molecular examination for the detection of PCG disease in Iran.

Exploring specific prognostic biomarkers in triple-negative breast cancer

Lacking of both prognostic biomarkers and therapeutic targets, triple-negative breast cancer (TNBC) underscores pivotal needs to uncover novel biomarkers and viable therapies. MicroRNAs have broad biological functions in cancers and may serve as ideal biomarkers. In this study, by data mining of the Cancer Genome Atlas database, we screened out 4 differentially-expressed microRNAs (DEmiRNAs) between TNBC and normal samples: miR-135b-5p, miR-9-3p, miR-135b-3p and miR-455-5p. They were specially correlated with the prognosis of TNBC but not non-TNBC. The weighted correlation network analysis (WGCNA) for potential target genes of 3 good prognosis-related DEmiRNAs (miR-135b-5p, miR-9-3p, miR-135b-3p) identified 4 hub genes with highly positive correlation with TNBC subtype: FOXC1, BCL11A, FAM171A1 and RGMA. The targeting relationships between miR-9-3p and FOXC1/FAM171A1, miR-135b-3p and RGMA were validated by dual-luciferase reporter assays. Importantly, the regulatory functions of 4 DEmiRNAs and 3 verified target genes on cell proliferation and migration were explored in TNBC cell lines. In conclusion, we shed lights on these 4 DEmiRNAs (miR-135b-5p, miR-9-3p, miR-135b-3p, miR-455-5p) and 3 hub genes (FOXC1, FAM171A1, RGMA) as specific prognostic biomarkers and promising therapeutic targets for TNBC.

Role of FOXC1 in regulating APSCs self-renewal via STI-1/PrPC signaling

Forkhead box protein C1 (FOXC1) is known to regulate developmental processes in the skull and brain. Methods: The unique multipotent arachnoid-pia stem cells (APSCs) isolated from human and mouse arachnoid-pia membranes of meninges were grown as 3D spheres and displayed a capacity for self-renewal. Additionally, APSCs also expressed the surface antigens as mesenchymal stem cells. By applying the FOXC1 knockout mice and mouse brain explants, signaling cascade of FOXC1-STI-1-PrP^C was investigated to demonstrate the molecular regulatory pathway for APSCs self-renewal. Moreover, APSCs implantation in stroke model was also verified whether neurogenic property of APSCs could repair the ischemic insult of the stroke brain. Results: Activated FOXC1 regulated the proliferation of APSCs in a cell cycle-dependent manner, whereas FOXC1-mediated APSCs self-renewal was abolished in FOXC1 knockout mice (FOXC1^-/- mice). Moreover, upregulation of STI-1 regulated by FOXC1 enhanced cell survival and self-renewal of APSCs through autocrine signaling of cellular prion protein (PrP^C). Mouse brain explants STI-1 rescues the cortical phenotype in vitro and induces neurogenesis in the FOXC1 ^-/- mouse brain. Furthermore, administration of APSCs in ischemic brain restored the neuroglial microenvironment and improved neurological dysfunction. Conclusion: We identified a novel role for FOXC1 in the direct regulation of the STI-1-PrP^C signaling pathway to promote cell proliferation and self-renewal of APSCs.

FOXF2 is required for cochlear development in humans and mice

Molecular mechanisms governing the development of the human cochlea remain largely unknown. Through genome sequencing, we identified a homozygous FOXF2 variant c.325A>T (p.I109F) in a child with profound sensorineural hearing loss (SNHL) associated with incomplete partition type I anomaly of the cochlea. This variant is not found in public databases or in over 1000 ethnicity-matched control individuals. I109 is a highly conserved residue in the forkhead box (Fox) domain of FOXF2, a member of the Fox protein family of transcription factors that regulate the expression of genes involved in embryogenic development as well as adult life. Our in vitro studies show that the half-life of mutant FOXF2 is reduced compared to that of wild type. Foxf2 is expressed in the cochlea of developing and adult mice. The mouse knockout of Foxf2 shows shortened and malformed cochleae, in addition to altered shape of hair cells with innervation and planar cell polarity defects. Expressions of Eya1 and Pax3, genes essential for cochlear development, are reduced in the cochleae of Foxf2 knockout mice. We conclude that FOXF2 plays a major role in cochlear development and its dysfunction leads to SNHL and developmental anomalies of the cochlea in humans and mice.

foxc1 is required for embryonic head vascular smooth muscle differentiation in zebrafish

Vascular smooth muscle of the head derives from neural crest, but developmental mechanisms and early transcriptional drivers of the vSMC lineage are not well characterized. We find that in early development, the transcription factor foxc1b is expressed in mesenchymal cells that associate with the vascular endothelium. Using timelapse imaging, we observe that foxc1b expressing mesenchymal cells differentiate into acta2 expressing vascular mural cells. We show that in zebrafish, while foxc1b is co-expressed in acta2 positive smooth muscle cells that associate with large diameter vessels, it is not co-expressed in capillaries where pdgfrβ positive pericytes are located. In addition to being an early marker of the lineage, foxc1 is essential for vSMC differentiation; we find that foxc1 loss of function mutants have defective vSMC differentiation and that early genetic ablation of foxc1b or acta2 expressing populations blocks vSMC differentiation. Furthermore, foxc1 is expressed upstream of acta2 and is required for acta2 expression in vSMCs. Using RNA-Seq we determine an enriched intersectional gene expression profile using dual expression of foxc1b and acta2 to identify novel vSMC markers. Taken together, our data suggests that foxc1 is a marker of vSMCs and plays a critical functional role in promoting their differentiation.