Fibroblasts from two patients carrying a heterozygous mutation in the translation initiation codon (c.2 T > G) of the kelch-like protein 24 (KLHL24) gene were used to generate human induced pluripotent stem cells (hiPSCs), using non-integrating Sendai virus to deliver reprogramming factors. CRISPR-Cas9 editing was used for genetic correction of the mutation in the patient-hiPSCs. The top-predicted off-target sites were not altered. Patient and isogenic hiPSCs showed typical morphology, expressed pluripotency-associated markers, had the capacity for in vitro differentiation into the three germ layers and displayed a normal karyotype. These isogenic pairs will enable in vitro modelling of KLHL24-associated heart and skin conditions.
Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genodermatosis caused by mutations in the gene coding for type VII collagen (COL7A1). More than 800 different pathogenic mutations in COL7A1 have been described to date; however, the ancestral origins of many of these mutations have not been precisely identified. In this study, 32 RDEB patient samples from the Southwestern United States, Mexico, Chile, and Colombia carrying common mutations in the COL7A1 gene were investigated to determine the origins of these mutations and the extent to which shared ancestry contributes to disease prevalence. The results demonstrate both shared European and American origins of RDEB mutations in distinct populations in the Americas and suggest the influence of Sephardic ancestry in at least some RDEB mutations of European origins. Knowledge of ancestry and relatedness among RDEB patient populations will be crucial for the development of future clinical trials and the advancement of novel therapeutics.
Keywords: epidermolysis bullosa; genetics; genodermatoses.
Background: Epidermolysis bullosa (EB) corresponds to a series of conditions characterized by extreme fragility of the skin and/or mucous membranes. Of the four main types of EB, junctional EB (JEB) is the most associated with alterations in the teeth. The purposes of this study were to determine the clinical, histopathological, and ultrastructural characteristics of teeth with amelogenesis imperfecta (AI) in a patient with JEB, and compare them with control teeth, and correlate the findings with the mutations present in the patient.
Case Report: The study was conducted on a 10-year-old patient with JEB carrier of two recessive mutations in the LAMB3 gene and absence of the laminin-332 protein (LM-332), determined by immunofluorescence on a skin biopsy. The patient presents hypoplastic AI with very thin and yellow-brown colored enamel. Extraction of two permanent molars was performed due to pain and soft tissue covering the crown, resembling pulp polyp or hyperplastic gingiva. Light and scanning electron microscopy (SEM) revealed very thin enamel varying from complete absence to 60 μm, absence of normal prismatic structure, and presence of a cross-banding with a laminated appearance. The histopathological study revealed granulation tissue causing external crown resorption.
Conclusion: Although coronary resorption has been reported in patients with syndromic and non-syndromic AI, this is the first clinicopathological report of coronary resorption in partially erupted teeth in patients with JEB with mutations in the LAMB3 gene and hypoplastic AI. In patients with this condition, the presence of partially erupted teeth with soft tissue covering part of the crown, without a periodontal pocket, and with a radiographic image of partial coronal radiolucency should lead to suspicion of external coronary resorption.
Impaired wound healing complicates a wide range of diseases and represents a major cost to healthcare systems. Here we describe the use of discarded wound dressings as a novel, cost effective, accessible, and non-invasive method of isolating viable human cells present at the site of skin wounds. By analyzing 133 discarded wound dressings from 51 patients with the inherited skin-blistering disease epidermolysis bullosa (EB), we show that large numbers of cells, often in excess of 100 million per day, continually infiltrate wound dressings. We show, that the method is able to differentiate chronic from acute wounds, identifying significant increases in granulocytes in chronic wounds, and we show that patients with the junctional form of EB have significantly more cells infiltrating their wounds compared with patients with recessive dystrophic EB. Finally, we identify subsets of granulocytes and T lymphocytes present in all wounds paving the way for single cell profiling of innate and adaptive immune cells with relevance to wound pathologies. In summary, our study delineates findings in EB that have potential relevance for all chronic wounds, and presents a method of cellular isolation that has wide reaching clinical application.
Objectives: To present early teeth extractions as a treatment option in severe dental crowding in patients with generalized recessive dystrophic epidermolysis bullosa (RDEB).
Materials and methods: Three patients with generalized RDEB were treated with early teeth extractions to prevent severe dental crowding.
Results: Two patients had bilateral upper first premolars extraction, and the third patient had permanent maxillary canine extraction. Crowding was avoided, and no further orthodontic treatment was necessary.
Conclusion: Considering the challenges of severe mucosal fragility and microstomia in patients with generalized RDEB, early teeth extractions are a reasonable option as an orthodontic management. This approach reduces the severity of dental crowding as the child gets older and reduces the need for orthodontic appliances. Individual factors such as access to dental care, general health, and oral health have an important impact on the decision-making process. Orthodontic treatment planning should include a multidisciplinary team.
Keywords: orthodontic; rare diseases; skin diseases.
Background: Esophageal strictures are the common gastrointestinal complications in patients with epidermolysis bullosa (EB) requiring dilation. There is limited information on the best type of intervention, outcomes, and predictors for re-stenosis.
Objectives: We aimed to investigate the frequency, clinical presentation of esophageal strictures in EB patients, and to ascertain the predictors of re-stenosis.
Methods: We conducted a retrospective, multicenter cohort study involving 7 specialized, international EB centers on patients who were 0 to 50 years of age. Descriptive statistics and hazard risks for re-stenosis were calculated.
Results: We identified 125 patients with 497 esophageal stricture episodes over a mean period of observation of 17 (standard deviation [SD] = 11.91) years. Dilations were attempted in 90.74% of episodes, using guided fluoroscopy 45.23%, retrograde endoscopy 33.04%, and antegrade endoscopy 19.07%. Successful dilation was accomplished in 99.33% of attempts. Patients experienced a median of 2 (interquartile range [IQR]: 1-7) stricture episodes with a median interval between dilations of 7 (IQR: 4-12) months. Predictors for re-stenosis included: number of strictures (2 vs 1 stricture: χ = 4.293, P = 0.038, hazard ratio [HR] = 1.294 (95% confidence interval [CI]: 1.014–1.652 and 3 vs 1 stricture:χ = 7.986, P = 0.005, HR = 1.785 [95% CI: 1.194, 2.667]) and a long (≥1 cm) segment stricture (χ = 4.599, P = 0.032, HR = 1.347 (95% CI: 1.026–1.769). Complications were more common with the endoscopic approach (8/86, antegrade endoscopy; 2 /149, retrograde endoscopy vs 2/204, fluoroscopy; χ = 17.39, P-value <0.000).
Conclusions: We found excellent dilation outcomes irrespective of the dilation procedure; however, with higher complications in the endoscopic approach. Long (>1 cm) segment involvement and multiple locations were predictive of stricture reoccurrence.
To the Editor: Classifying epidermolysis bullosa (EB) in the new-born period is important because each subtype has different morbidities and prognoses, and diagnostic tests take time to complete and might not be available worldwide. Denuded tongue, which is the complete absence of tongue papillae on the dorsal tongue surface, can be observed in patients with the generalized severe recessive dystrophic type (RDEB-gen-sev).
This prospective study included all 223 consecutive patients with an EB diagnosis5 confirmed by mutation analysis seen at DEBRA Chile between 2015 and 2018. Ethic committee approval and informed consent was obtained. The diagnostic criteria analyzed were complete absence, partial absence, and normal tongue papillae, also including normal papillae with a localized chronic ulcer (Fig 1). Age ranged from 2 hours to 75 years, the male-to-female sex ratio was 0.89. The distribution of EB type, subtype, gene affected, absence of tongue papillae, and patient flow diagram can be observed in Supplemental Tables I and II and Supplemental Fig 1 (available via Mendeley at https://doi.org/10.17632/j7fm33t6j2.2).
Regenerative responses predispose tissues to tumor formation by largely unknown mechanisms. High-mobility group box 1 (HMGB1) is a danger-associated molecular pattern contributing to inflammatory pathologies. We show that HMGB1 derived from keratinocytes, but not myeloid cells, delays cutaneous wound healing and drives tumor formation. In wounds of mice lacking HMGB1 selectively in keratinocytes, a marked reduction in neutrophil extracellular trap (NET) formation is observed. Pharmacological targeting of HMGB1 or NETs prevents skin tumorigenesis and accelerates wound regeneration. HMGB1-dependent NET formation and skin tumorigenesis is orchestrated by tumor necrosis factor (TNF) and requires RIPK1 kinase activity. NETs are present in the microenvironment of keratinocyte-derived tumors in mice and lesional and tumor skin of patients suffering from recessive dystrophic epidermolysis bullosa, a disease in which skin blistering predisposes to tumorigenesis. We conclude that tumorigenicity of the wound microenvironment depends on epithelial-derived HMGB1 regulating NET formation, thereby establishing a mechanism linking reparative inflammation to tumor initiation.
Keywords: HMGB1; TNF; diabetes; epidermolysis bullosa; innate immunity; neutrophil extracellular traps; skin inflammation; tumor microenvironment; wound healing.
Purpose: Squamous cell carcinoma (SCC) of the skin is the leading cause of death in patients with the severe generalized form of the genetic disease recessive dystrophic epidermolysis bullosa (RDEB). Although emerging data are identifying why patients suffer this fatal complication, therapies for treatment of RDEB SCC are in urgent need.Experimental Design: We previously identified polo-like kinase 1 (PLK1) as a therapeutic target in skin SCC, including RDEB SCC. Here, we undertake a screen of 6 compounds originally designated as PLK1 inhibitors, and detail the efficacy of the lead compound, the multipathway allosteric inhibitor ON-01910, for targeting RDEB SCC in vitro and in vivo.
Results: ON-01910 (or rigosertib) exhibited significant specificity for RDEB SCC: in culture rigosertib induced apoptosis in 10 of 10 RDEB SCC keratinocyte populations while only slowing the growth of normal primary skin cells at doses 2 orders of magnitude higher. Furthermore, rigosertib significantly inhibited the growth of two RDEB SCC in murine xenograft studies with no apparent toxicity. Mechanistically, rigosertib has been shown to inhibit multiple signaling pathways. Comparison of PLK1 siRNA with MEK inhibition, AKT inhibition, and the microtubule-disrupting agent vinblastine in RDEB SCC shows that only PLK1 reduction exhibits a similar sensitivity profile to rigosertib.
Conclusions: These data support a «first in RDEB» phase II clinical trial of rigosertib to assess tumor targeting in patients with late stage, metastatic, and/or unresectable SCC.