Genomics-based treatment in a patient with two overlapping heritable skin disorders: Epidermolysis bullosa and acrodermatitis enteropathica

Next-generation sequencing (NGS) is helpful in diagnosing complex genetic disorders and phenotypes, particularly when more than one overlapping condition is present. From a large cohort of 362 families with clinical manifestations of skin and mucosal fragility, referred by several major medical centers, one patient was found by NGS to have two overlapping heritable skin diseases, recessive dystrophic epidermolysis bullosa (RDEB; COL7A1 mutations) and acrodermatitis enteropathica (AE; SLC39A4 mutations). The pathogenicity of the variants was studied at gene expression as well as ultrastructural and tissue levels. Although there is no specific treatment for RDEB except avoiding trauma, supplementation with oral zinc (3 mg·kg^-1 ·day^-1 ) for the AE resulted in rapid amelioration of the skin findings. This case demonstrates the power of NGS in identifying two genetically unlinked diseases that led to effective treatment with major clinical benefits as an example of genomics-guided treatment.

Safety and early efficacy outcomes for lentiviral fibroblast gene therapy in recessive dystrophic epidermolysis bullosa

BACKGROUNDRecessive dystrophic epidermolysis bullosa (RDEB) is a severe form of skin fragility disorder due to mutations in COL7A1 encoding basement membrane type VII collagen (C7), the main constituent of anchoring fibrils (AFs) in skin. We developed a self-inactivating lentiviral platform encoding a codon-optimized COL7A1 cDNA under the control of a human phosphoglycerate kinase promoter for phase I evaluation.METHODSIn this single-center, open-label phase I trial, 4 adults with RDEB each received 3 intradermal injections (~1 × 106 cells/cm2 of intact skin) of COL7A1-modified autologous fibroblasts and were followed up for 12 months. The primary outcome was safety, including autoimmune reactions against recombinant C7. Secondary outcomes included C7 expression, AF morphology, and presence of transgene in the injected skin.RESULTSGene-modified fibroblasts were well tolerated, without serious adverse reactions or autoimmune reactions against recombinant C7. Regarding efficacy, there was a significant (P < 0.05) 1.26-fold to 26.10-fold increase in C7 mean fluorescence intensity in the injected skin compared with noninjected skin in 3 of 4 subjects, with a sustained increase up to 12 months in 2 of 4 subjects. The presence of transgene (codon-optimized COL7A1 cDNA) was demonstrated in the injected skin at month 12 in 1 subject, but no new mature AFs were detected.CONCLUSIONTo our knowledge, this is the first human study demonstrating safety and potential efficacy of lentiviral fibroblast gene therapy with the presence of COL7A1 transgene and subsequent C7 restoration in vivo in treated skin at 1 year after gene therapy. These data provide a rationale for phase II studies for further clinical evaluation.TRIAL REGISTRATIONClincalTrials.gov NCT02493816.FUNDINGCure EB, Dystrophic Epidermolysis Bullosa Research Association (UK), UK NIHR Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, and Fondation René Touraine Short-Exchange Award.

Next generation sequencing identifies double homozygous mutations in two distinct genes (EXPH5 and COL17A1) in a patient with concomitant simplex and junctional epidermolysis bullosa

Epidermolysis bullosa (EB) is a heterogeneous group of heritable blistering diseases. We developed a next generation sequencing (NGS) panel covering 21 genes associated with skin fragility disorders, and it was applied to DNA from 91 probands with the diagnosis of EB. In one patient, novel homozygous mutations were disclosed in two different, unlinked EB-associated genes: EXPH5, chr11 g.108510085G > A; p.Arg1808Ter and COL17A1, chr10 g.104077423delT; p.Thr68LeufsTer106. Consequences of the COL17A1 mutation were examined by RNAseq which revealed a complex splicing pattern predicting synthesis of a truncated polypeptide (85%) or in-frame deletion of exon 4 (15% of transcripts). Transmission electron microscopy (TEM) and immunostaining revealed findings consistent with EB simplex (EBS) and junctional EB (JEB), and clinical examination revealed a complex phenotype with features of both subtypes. This case illustrates the power of next generation sequencing in identifying mutations in patients with complex EB phenotype, with implications for genotype-phenotype correlations, prenatal testing, and genetic counseling of families at risk for recurrence.

Controlled sparse and percolating cross-linking in waterborne soft adhesives

The effect of low levels of cross-linking on the adhesive and mechanical properties of waterborne pressure-sensitive adhesives was investigated. We have taken advantage of a core-shell latex particle morphology obtained by emulsion polymerization to create a heterogeneous structure of cross-links without major modification of the monomer composition. The latex particles comprise a shell containing cross-linkable diacetone acrylamide (DAAM) repeat units localized on the periphery of a slightly softer core copolymer of very similar composition. Adipic acid dihydrazide was added to the latex prior to film formation to react with DAAM repeat units and affect interfacial cross-linking between particles in the adhesive films. The honeycomb-like structure obtained after drying of the latex results in a good balance between the dissipative properties required for adhesion and the resistance to creep. The characterization of the mechanical properties of the films shows that the chosen cross-linking method creates a percolating lightly cross-linked network, swollen with a nearly un-cross-linked component. With this cross-linking method, the linear viscoelastic properties of the soft films are nearly unaffected by the cross-linking while the nonlinear tensile properties are greatly modified. As a result, the long-term shear resistance of the adhesive film improves very significantly while the peel force remains nearly the same. A simple rheological model is used to interpret qualitatively the changes in the material parameters induced by cross-linking.

Autosomal dominant junctional epidermolysis bullosa

BACKGROUND

Epidermolysis bullosa (EB) encompasses a heterogeneous group of inherited skin disorders associated with trauma-induced blistering. The junctional forms of EB (JEB), Herlitz JEB, non-Herlitz JEB and JEB associated with pyloric atresia have all been attributed to autosomal recessive inheritance. We describe a 7-year-old girl with defective dental enamel, trauma-induced blistering and subsequent scarring. Her mother, a carrier of the mutation p.G627V in the collagen XVII gene (COL17A1) had evidence of hypoplastic dental enamel without skin blistering. Her grandmother had non-Herlitz JEB as a result of a compound heterozygous mutation in COL17A1 (p.G627V and c.3514ins25).

OBJECTIVES

To explore the molecular, ultrastructural and immunofluorescence findings of the first case of dominant JEB.

METHODS

Mutational analysis of COL17A1 was performed on the proband's genomic DNA. In addition, transmission electron microscopy and immunofluorescence microscopy were performed on a nonlesional skin biopsy from the proband and an unrelated healthy control.

RESULTS

Direct sequencing revealed a heterozygous glycine substitution mutation, p.G627V, in COL17A1. No discernible morphological abnormalities were found on transmission electron microscopy; however, immunofluorescence microscopy revealed findings of an altered distribution pattern for type XVII collagen epitopes close to the dermal-epidermal junction.

CONCLUSION

This report describes the first case of dominant JEB. Although some heterozygous mutations in COL17A1 are known to cause dental abnormalities none were associated with skin fragility. The dominant-negative interference between the proband's mutated type XVII collagen and the wild-type allele appears to render the skin prone to trauma-induced blister formation. Alternatively, other undisclosed modifying genetic or epigenetic factors might explain why the patient gets blistering whereas her mother, who has the same COL17A1 mutation, has no skin fragility.

Preparation, Morphology and Thermal Properties of Rubber-Modified Polyester Resins

The preparation of polyester resin blends consisting of an unsaturated polyester resin matrix and rubbery particles comprising three radially-alternating glassy and rubbery layers is described. The morphology of the resin blends was examined by transmission electron microscopy (TEM) while thermal properties were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The results show that the particles were prepared with good control of particle size and morphology. DMTA results showed no reduction in the Tg of the matrix whilst the shear modulus of modified materials was found to be lower than that of the matrix material.

Normal and SV40 transfected human peritoneal mesothelial cells produce IL-6 and IL-8: implication for gynaecological disease

High levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) have been demonstrated in the peritoneal fluid of benign and malignant gynaecological disease. Peritoneal monocytes and macrophages, endometrial cells, endometrial and peritoneal stromal cells and tumour cells produce these cytokines in vitro. To investigate whether normal human peritoneal mesothelial cells (HPMC) produce IL-6 and IL-8, HPMC were isolated from omental biopsies. Primary HPMC (P-HPMC) were transfected with pSV3-neo encoding SV40 large T antigen (T-HPMC) to generate sufficient cells. T-HPMC preserved the characteristics of P-HPMC as assessed by phase contrast microscopy, electron microscopy, immunocytochemistry and flow cytometry (FACS) analysis. T-HPMC retained a stable phenotype up to passage 14-19, whereas P-HPMC proliferated poorly and became senescent by passage 4-6. T-HPMC and P-HPMC constitutively expressed IL-6 and IL-8 at both protein and mRNA level. IL-6 and IL-8 production was stimulated by recombinant human interleukin-1beta (hIL-1beta) or human tumour necrosis factor-alpha (hTNF-alpha) alone in a dose-dependent manner. Moreover, hIL-1beta or hTNF-alpha up-regulated IL-6 and IL-8 gene expression as determined by competitive PCR. In contrast, human interferon-gamma (hIFN-gamma) or lipopolysaccharide (LPS) showed no effect. These data indicate that (1) T-HPMC lines mimic the morphological and functional features of P-HPMC, (2) P-HPMC and T-HPMC constituitively produce IL-6 and IL-8, which is enhanced by hIL-1beta and hTNF-alpha and (3) HPMC in vivo may participate in the pathogenesis of benign and malignant gynaecological disease.