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TRPM3 belongs to the melastatin sub-family of transient receptor potential (TRPM) cation channels and has been shown to function as a steroid-activated, heat-sensitive calcium ion (Ca2+) channel. A missense substitution (p.I65M) in the TRPM3 gene of humans (TRPM3) and mice (Trpm3) has been shown to underlie an inherited form of early-onset, progressive cataract. Here, we model the pathogenetic effects of this cataract-causing mutation using 'knock-in' mutant mice and human cell lines. Trpm3 and its intron-hosted micro-RNA gene (Mir204) were strongly co-expressed in the lens epithelium and other non-pigmented and pigmented ocular epithelia. Homozygous Trpm3-mutant lenses displayed elevated cytosolic Ca2+ levels and an imbalance of sodium (Na+) and potassium (K+) ions coupled with increased water content. Homozygous TRPM3-mutant human lens epithelial (HLE-B3) cell lines and Trpm3-mutant lenses exhibited increased levels of phosphorylated mitogen-activated protein kinase 1/extracellular signal-regulated kinase 2 (MAPK1/ERK2/p42) and MAPK3/ERK1/p44. Mutant TRPM3-M65 channels displayed an increased sensitivity to external Ca2+ concentration and an altered dose response to pregnenolone sulfate (PS) activation. Trpm3-mutant lenses shared the downregulation of genes involved in insulin/peptide secretion and the upregulation of genes involved in Ca2+ dynamics. By contrast, Trpm3-deficient lenses did not replicate the pathophysiological changes observed in Trpm3-mutant lenses. Collectively, our data suggest that a cataract-causing substitution in the TRPM3 cation channel elicits a deleterious gain-of-function rather than a loss-of-function mechanism in the lens. [ABSTRACT FROM AUTHOR]

The Emory cataract (Em) mouse mutant has long been proposed as an animal model for age-related or senile cataract in humans—a leading cause of visual impairment. However, the genetic defect(s) underlying the autosomal dominant Em phenotype remains elusive. Here, we confirmed development of the cataract phenotype in commercially available Em/J mice [but not ancestral Carworth Farms White (CFW) mice] at 6–8 months of age and undertook whole-exome sequencing of candidate genes for Em. Analysis of coding and splice-site variants did not identify any disease-causing/associated mutations in over 450 genes known to underlie inherited and agerelated forms of cataract and other lens disorders in humans and mice, including genes for lens crystallins, membrane/cytoskeleton proteins, DNA/RNA-binding proteins, and those associated with syndromic/systemic forms of cataract. However, we identified three cataract/lens-associated genes each with one novel homozygous variant including predicted missense substitutions in Prx (p.R167C) and Adamts10 (p.P761L) and a disruptive in-frame deletion variant (predicted missense) in Abhd12 (p.L30_A32delinsS) that were absent in CFW and over 35 other mouse strains. In silico analysis predicted that the missense substitutions in Prx and Adamts10 were borderline neutral/damaging and neutral, respectively, at the protein function level, whereas, that in Abhd12 was functionally damaging. Both the human counterparts of Adamts10 and Abhd12 are clinically associated with syndromic forms of cataract known as Weil-Marchesani syndrome 1 and polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract syndrome, respectively. Overall, while we cannot exclude Prx and Adamts10, our data suggest that Abhd12 is a promising candidate gene for cataract in the Em/J mouse. [ABSTRACT FROM AUTHOR]

Charged multivesicular body protein 4b (CHMP4B) is a core sub‐unit of the endosomal sorting complex required for transport III (ESCRT‐III) machinery that serves myriad remodeling and scission processes of biological membranes. Mutation of the human CHMP4B gene underlies rare forms of early‐onset lens opacities or cataracts, and CHMP4B is required for lens growth and differentiation in mice. Here, we determine the sub‐cellular distribution of CHMP4B in the lens and uncover a novel association with gap junction alpha‐3 protein (GJA3) or connexin 46 (Cx46) and GJA8 or Cx50. Immunofluorescence confocal microscopy revealed that CHMP4B localized to cell membranes of elongated fiber cells in the outer cortex of the lens—where large gap junction plaques begin to form—particularly, on the broad faces of these flattened hexagon‐like cells in cross‐section. Dual immunofluorescence imaging showed that CHMP4B co‐localized with gap junction plaques containing Cx46 and/or Cx50. When combined with the in situ proximity ligation assay, immunofluorescence confocal imaging indicated that CHMP4B lay in close physical proximity to Cx46 and Cx50. In Cx46‐knockout (Cx46‐KO) lenses, CHMP4B‐membrane distribution was similar to that of wild‐type, whereas, in Cx50‐KO lenses, CHMP4B localization to fiber cell membranes was lost. Immunoprecipitation and immunoblotting analyses revealed that CHMP4B formed complexes with Cx46 and Cx50 in vitro. Collectively, our data suggest that CHMP4B forms plasma membrane complexes, either directly and/or indirectly, with gap junction proteins Cx46 and Cx50 that are often associated with "ball‐and‐socket" double‐membrane junctions during lens fiber cell differentiation. [ABSTRACT FROM AUTHOR]

Insulating materials are ubiquitous in a built environment and play a critical role in reducing the energy consumed to maintain habitable indoor environments. Mineral wool insulation (MWI) products, including glass, stone, and slag variants, are the most widely used class of insulating materials in Europe and account for more than 50% of the total market by volume. MWI typically consists of two key components: a mesh of inorganic fibers that are several micrometers in diameter, and an organic thermosetting adhesive commonly referred to as the "binder." Traditional phenol‐formaldehyde‐urea (PFU) binders used in the manufacture of MWI are increasingly being scrutinized for the formaldehyde released during their manufacture and service lifetime. The recent classification of formaldehyde as a carcinogen by various safety organizations has accelerated a paradigm shift within the industry toward alternative binder technologies that minimize or indeed eliminate formaldehyde emissions. This review examines more recent strategies for achieving low‐ or zero‐added formaldehyde binders for MWI, with a particular focus on the patent literature. The chemistry underpinning traditional PFU binders is presented and compared to new strategies involving scavenging molecules that decrease formaldehyde emissions, as well as zero‐added formaldehyde binder technologies such as polyester, Maillard, and epoxide thermosets. [ABSTRACT FROM AUTHOR]

Transient‐receptor‐potential cation channel, subfamily M, member 3 (TRPM3) serves as a polymodal calcium sensor in diverse mammalian cell‐types. Mutation of the human TRPM3 gene (TRPM3) has been linked with inherited forms of early‐onset cataract with or without other eye abnormalities. Here, we have characterized the ocular phenotypes of germline “knock‐in” mice that harbor a human cataract‐associated isoleucine‐to‐methionine mutation (p.I65M) in TRPM3 (Trpm3‐mutant) compared with germline “knock‐out” mice that functionally lack TRPM3 (Trpm3‐null). Despite strong expression of Trpm3 in lens epithelial cells, neither heterozygous (Trpm3+/−) nor homozygous (Trpm3−/−) Trpm3‐null mice developed cataract; however, the latter exhibited a mild impairment of lens growth. In contrast, homozygous Trpm3‐M/M mutants developed severe, progressive, anterior pyramid‐like cataract with microphthalmia, whereas heterozygous Trpm3‐I/M and hemizygous Trpm3‐M/‐ mutants developed anterior pyramidal cataract with delayed onset and progression–consistent with a semi‐dominant lens phenotype. Histochemical staining revealed abnormal accumulation of calcium phosphate‐like deposits and collagen fibrils in Trpm3‐mutant lenses and immunoblotting detected increased αII‐spectrin cleavage products consistent with calpain hyper‐activation. Immunofluorescent confocal microscopy of Trpm3‐M/M mutant lenses revealed fiber cell membrane degeneration that was accompanied by accumulation of alpha‐smooth muscle actin positive (α‐SMA+ve) myofibroblast‐like cells and macrosialin positive (CD68+ve) macrophage‐like cells. Collectively, our mouse model data support an ocular disease association for TRPM3 in humans and suggest that (1) Trpm3 deficiency impaired lens growth but not lens transparency and (2) Trpm3 dysfunction resulted in progressive lens degeneration and calcification coupled with pro‐fibrotic (α‐SMA+ve) and immune (CD68+ve) cell responses. [ABSTRACT FROM AUTHOR]

Devices featuring electrophoretic displays (EPD) have become extremely popular in recent years because of their low power consumption, high readability and thin display designs, but a product with a full colour gamut comparable with liquid crystal displays (LCDs) has not yet been commercialised. In this article, we demonstrate that staggering the addition of methyl methacrylate (MMA) monomer and low quantities of a coloured dye crosslinker is an effective route to producing well-defined and covalently-linked, strongly coloured PMMA microparticles in one-pot, via dispersion polymerisation in supercritical carbon dioxide (scCO2). This novel methodology is synthetically simple, readily scalable and has the added cachet of being cost effective because the functional molecules can be confined on the microparticle surface such that even at low concentrations, the resulting materials are brightly coloured. We then demonstrate the applicability of this approach to another functional comonomer/crosslinker system in 2-dimethylaminoethyl methacrylate (DMAEMA)/ethyleneglycol dimethacrylate (EGDMA), in this case allowing hierarchically structured 'pomegranate-like' microparticles with polarisable charge to be produced over a range of DMAEMA loadings as high as 44 wt%. Finally, the performance of these materials in out-of-plane EPD test cells is compared against analogues synthesised in dodecane. These tests revealed that the coloured microparticles fabricated in scCO2 performed as well as or better than their dodecane synthesised counterparts, consistently producing the cleanest white state and achieving effective colour switching over ten cycles. [ABSTRACT FROM AUTHOR]

Rare germ-line mutations in the coding regions of the human EPHA2 gene (EPHA2) have been associated with inherited forms of pediatric cataract, whereas, frequent, non-coding, single nucleotide variants (SNVs) have been associated with age-related cataract. Here we sought to determine if germ-line EPHA2 coding SNVs were associated with age-related cataract in a case-control DNA panel (> 50 years) and if somatic EPHA2 coding SNVs were associated with lens aging and/or cataract in a post-mortem lens DNA panel (> 48 years). Micro-fluidic PCR amplification followed by targeted amplicon (exon) next-generation (deep) sequencing of EPHA2 (17-exons) afforded high read-depth coverage (1000x) for > 82% of reads in the cataract case-control panel (161 cases, 64 controls) and > 70% of reads in the post-mortem lens panel (35 clear lens pairs, 22 cataract lens pairs). Novel and reference (known) missense SNVs in EPHA2 that were predicted in silico to be functionally damaging were found in both cases and controls from the age-related cataract panel at variant allele frequencies (VAFs) consistent with germ-line transmission (VAF > 20%). Similarly, both novel and reference missense SNVs in EPHA2 were found in the post-mortem lens panel at VAFs consistent with a somatic origin (VAF > 3%). The majority of SNVs found in the cataract case-control panel and post-mortem lens panel were transitions and many occurred at di-pyrimidine sites that are susceptible to ultraviolet (UV) radiation induced mutation. These data suggest that novel germ-line (blood) and somatic (lens) coding SNVs in EPHA2 that are predicted to be functionally deleterious occur in adults over 50 years of age. However, both types of EPHA2 coding variants were present at comparable levels in individuals with or without age-related cataract making simple genotype-phenotype correlations inconclusive. [ABSTRACT FROM AUTHOR]

Major intrinsic protein or aquaporin-0 (MIP/AQP0) functions as a water channel and a cell-junction molecule in the vertebrate eye lens. Loss of MIP function in the lens leads to degraded optical quality and cataract formation by pathogenic mechanisms that are unclear. Here we have used microarray-hybridization analysis to detect lens transcriptome changes during cataract formation in mice that are functionally null for MIP ( Mip−/− ). In newborn Mip−/− lenses (P1) 11 genes were up-regulated and 18 were down-regulated (>2-fold, p=<0.05) and a similar number of genes was differentially regulated at P7. The most up-regulated genes (>6-fold) in the Mip−/− lens at P1 included those coding for a mitochondrial translocase ( Timmdc1 ), a matrix metallopeptidase ( Mmp2 ), a Rho GTPase-interacting protein ( Ubxn11 ) and a transcription factor ( Twist2 ). Apart from Mip , the most down-regulated genes (>4-fold) in the Mip−/− lens at P1 included those coding for a proteasome sub-unit ( Psmd8 ), a ribonuclease ( Pop4 ), and a heat-shock protein ( Hspb1 ). Lens fiber cell degeneration in the Mip−/− lens was associated with increased numbers of TUNEL-positive cell nuclei and dramatically elevated levels of calpain-mediated proteolysis of αII-spectrin. However red-ox status, measured by glutathione and free-radical levels, was similar to that of wild-type. These data suggest that while relatively few genes (∼1.5% of the transcriptome) were differentially regulated >2-fold in the Mip−/− lens, calpain hyper-activation acts as a terminal pathogenic event during lens fiber cell death and cataract formation. [ABSTRACT FROM AUTHOR]

Primary open-angle glaucoma (POAG) is a clinically important and genetically heterogeneous cause of progressive vision loss as a result of retinal ganglion cell death. Here we have utilized trio-based, whole-exome sequencing to identify the genetic defect underlying an autosomal dominant form of adult-onset POAG segregating in an African-American family. Exome sequencing identified a novel missense variant (c.418C>T, p.Arg140Trp) in exon-5 of the gene coding for epidermal growth factor (EGF) containing ibulin-like xtracellular atrix rotein (EFEMP1) that co-segregated with disease in the family. Linkage and haplotype analyses with microsatellite markers indicated that the disease interval overlapped a known POAG locus (GLC1H) on chromosome 2p. The p.Arg140Trp substitution was predicted in silico to have damaging effects on protein function and transient expression studies in cultured cells revealed that the Trp140-mutant protein exhibited increased intracellular accumulation compared with wild-type EFEMP1. In situ hybridization of the mouse eye with oligonucleotide probes detected the highest levels of EFEMP1 transcripts in the ciliary body, cornea, inner nuclear layer of the retina, and the optic nerve head. The recent finding that a common variant near EFEMP1 was associated with optic nerve-head morphology supports the possibility that the EFEMP1 variant identified in this POAG family may be pathogenic. [ABSTRACT FROM AUTHOR]

Background: Inherited cataract is a clinically important and genetically heterogeneous cause of visual impairment. Typically, it presents at an early age with or without other ocular/systemic signs and lacks clear phenotype-genotype correlation rendering both clinical classification and molecular diagnosis challenging. Here we have utilized trio-based whole exome sequencing to discover mutations in candidate genes underlying autosomal dominant cataract segregating in three nuclear families. Results: In family A, we identified a recurrent heterozygous mutation in exon-2 of the gene encoding γD-crystallin (CRYGD; c.70C > A, p.Pro24Thr) that co-segregated with ‘coralliform’ lens opacities. Families B and C were found to harbor different novel variants in exon-2 of the gene coding for gap-junction protein α8 (GJA8; c.20T > C, p.Leu7Pro and c.293A > C, p.His98Pro). Each novel variant co-segregated with disease and was predicted in silico to have damaging effects on protein function. Conclusions: Exome sequencing facilitates concurrent mutation-profiling of the burgeoning list of candidate genes for inherited cataract, and the results can provide enhanced clinical diagnosis and genetic counseling for affected families. [ABSTRACT FROM AUTHOR]

Inherited forms of cataract are a clinically important and genetically heterogeneous cause of visual impairment that usually present at an early age with or without systemic and/or other ocular abnormalities. Here we have identified a new locus for inherited cataract and high-tension glaucoma with variable anterior segment defects, and characterized an underlying mutation in the gene coding for transient receptor potential cation channel, subfamily M, member-3 (TRPM3, melastatin-2). Genome-wide linkage analysis mapped the ocular disease locus to the pericentric region of human chromosome 9. Whole exome and custom-target next-generation sequencing detected a heterozygous A-to-G transition in exon-3 of TRPM3 that co-segregated with disease. As a consequence of alternative splicing this missense mutation was predicted to result in the substitution of isoleucine-to-methionine at codon 65 (c.195A>G; p.I65 M) of TRPM3 transcript variant 9, and at codon 8 (c.24A>G; p.I8 M) of a novel TRPM3 transcript variant expressed in human lens. In both transcript variants the I-to-M substitution was predicted in silico to exert damaging effects on protein function. Furthermore, transient expression studies of a recombinant TRPM3-GFP reporter product predicted that the I-to-M substitution introduced an alternative translation start-site located 89 codons upstream from the native initiator methionine found in eight other TRPM3 transcript variants (1–8). Collectively, these studies have provided the first evidence that TRPM3 is associated with inherited ocular disease in humans, and further provide support for the important role of this cation channel in normal eye development. [ABSTRACT FROM AUTHOR]

Directed self-assembly (DSA) is a promising approach for extending conventional lithographic techniques by being able to print features with critical dimensions under 10 nm. The most widely studied block copolymer system is polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA). This system is well understood in terms of its synthesis, properties, and performance in DSA. However, PS-b-PMMA also has a number of limitations that impact on its performance and hence scope of application. The primary limitation is the low Flory-Huggins polymer-polymer interaction parameter (χ), which limits the size of features that can be printed. Another issue with block copolymers in general is that specific molecular weights need to be synthesized to achieve desired morphologies and feature sizes. Here we explore blending ionic liquid (IL) additives with PS-b-PMMA to increase the χ parameter. ILs have a number of useful properties that include negligible vapor pressure, tunable solvent strength, thermal stability, and chemical stability. The blends of PS-b-PMMA with an IL selective for the PMMA block allowed the resolution of the block copolymer to be improved. Depending on the amount of additive, it is also possible to tune the domain size and the morphology of the systems. These findings may expand the scope of PS-b-PMMA for DSA. [ABSTRACT FROM AUTHOR]

Cataracts are a clinically diverse and genetically heterogeneous disorder of the crystalline lens and a leading cause of visual impairment. Here we report linkage of autosomal dominant ‘progressive childhood posterior subcapsular’ cataracts segregating in a white family to short tandem repeat (STR) markers D20S847 (LOD score [Z] 5.50 at recombination fraction [θ] 0.0) and D20S195 ( at Z = 3.65 at θ = 0.0) on 20q, and identify a refined disease interval (rs2057262-(3.8Mb)-rs1291139) by use of single-nucleotide polymorphism (SNP) markers. Mutation profiling of positional-candidate genes detected a heterozygous transversion (c.386A→T) in exon 3 of the gene for chromatin modifying protein-4B (CHMP4B) that was predicted to result in the nonconservative substitution of a valine residue for a phylogenetically conserved aspartic acid residue at codon 129 (p.D129V). In addition, we have detected a heterozygous transition (c.481G→A) in exon 3 of CHMP4B cosegregating with autosomal dominant posterior polar cataracts in a Japanese family that was predicted to result in the missense substitution of lysine for a conserved glutamic acid residue at codon 161 (p.E161K). Transfection studies of cultured cells revealed that a truncated form of recombinant D129V-CHMP4B had a different subcellular distribution than wild type and an increased capacity to inhibit release of virus-like particles from the cell surface, consistent with deleterious gain-of-function effects. These data provide the first evidence that CHMP4B, which encodes a key component of the endosome sorting complex required for the transport-III (ESCRT-III) system of mammalian cells, plays a vital role in the maintenance of lens transparency. [ABSTRACT FROM AUTHOR]

Genetic variations in ephrin type-A receptor 2 (EPHA2) have been associated with inherited and age-related forms of cataract in humans. Here, we have characterized the eye lens phenotype and transcript profile of germline Epha2 knock-in mutant mice homozygous for either a missense variant associated with age-related cataract in humans (Epha2-Q722) or a novel insertion-deletion mutation (Epha2-indel722) that were both located within the tyrosine-kinase domain of EPHA2. Confocal imaging of ex vivo lenses from Epha2-indel722 mice on a fluorescent reporter background revealed misalignment of epithelial-to-fiber cell meridional-rows at the lens equator and severe disturbance of Y-suture formation at the lens poles, whereas Epha2-Q722 lenses displayed mild disturbance of posterior sutures. Immunofluorescent labeling showed that EPHA2 was localized to radial columns of hexagonal fiber cell membranes in Epha2-Q722 lenses, whereas Epha2-indel722 lenses displayed disorganized radial cell columns and cytoplasmic retention of EPHA2. Immunoprecipitation/blotting studies indicated that EPHA2 formed strong complexes with Src kinase and was mostly serine phosphorylated in the lens. RNA sequencing analysis revealed differential expression of several cytoskeleton-associated genes in Epha2-mutant and Epha2-null lenses including shared downregulation of Lgsn and Clic5. Collectively, our data suggest that mutations within the tyrosine-kinase domain of EPHA2 result in lens cell patterning defects and dysregulated expression of several cytoskeleton-associated proteins. [ABSTRACT FROM AUTHOR]

This work presents a robust method to achieve the synthesis of low molecular weight polyesters via ring‐opening polymerization (ROP) initiated by 2‐hydroxyethyl‐methacrylate (HEMA) when using triazabicyclodecene (TBD) as catalyst. The effect that the HEMA:TBD ratio has upon the final reaction rate and final polymer molecular architecture is discussed. The optimum HEMA:TBD ratio and reaction conditions required to minimize competing transesterification reactions are determined, in order to synthesize successfully the target ROP macromonomer species containing only a single 2‐methacryloyloxyethyl end‐group. Additionally, to confirm the terminal end‐group fidelity of the product macromonomers and confirm TBD utility for block copolymer manufacture, a small series of di‐block polyesters are synthesized using TBD and shown to exhibit good control over the final polymer structure whilst negating the side transesterification reactions, irrespective of the monomers used. Methacrylated block co‐polyesters are synthesized via triazabicyclodecene (TBD) catalyzed ring‐opening polymerization (ROP). TBD has been successfully employed as an active and selective catalyst for HEMA‐initiated ROP of D,L‐lactide (LA), trimethylene carbonate (TMC), and ε‐caprolactone (CL) in order to synthesize, under mild and standard laboratory conditions, homopolymers, and block copolymers with controlled molecular weight, low polydispersity, and a mono‐methacrylate final architecture. [ABSTRACT FROM AUTHOR]