Genotypic and Phenotypic Analysis of 34 Cases of Inherited Junctional Epidermolysis Bullosa caused by COL17A1 Mutations.

Inherited epidermolysis bullosa defines a heterogeneous group of genodermatoses characterized by skin and/or mucosa fragility resulting in blistering. The junctional variant (JEB) is associated with mutations affecting the genes expressing the components of the dermo-epidermal junction (DEJ) [1-2]. We report 34 JEB patients with COL17A1 genetic mutations diagnosed in our Center between 1993 and 2019. Medical and biological records were collected with a standardized questionnaire.

A unique LAMB3 splice-site mutation with founder effect from the Balkans causes lethal epidermolysis bullosa in several European countries.

BACKGROUND: We have encountered repeated cases of recessive lethal generalized severe (Herlitz-type) junctional epidermolysis bullosa (JEB gen sev) in infants born to Hungarian Roma parents residing in a small region of Hungary. OBJECTIVES: To identify the disease-causing mutation and to investigate the genetic background of its unique carrier group. METHODS: The LAMB3 gene was analysed in peripheral-blood genomic DNA samples, and the pathological consequences of the lethal defect were confirmed by cutaneous LAMB3cDNA sequencing. A median joining haplotype network within the Y chromosome H1a-M82 haplogroup of individuals from the community was constructed, and LAMB3 single-nucleotide polymorphism (SNP) patterns were also determined. RESULTS: An unconventional intronic splice-site mutation (LAMB3, c.1133-22G>A) was identified. Thirty of 64 voluntarily screened Roma from the closed community carried the mutation, but none of the 306 Roma from other regions of the country did. The age of the mutation was estimated to be 548 ± 222 years. Within the last year, more patients with JEB gen sev carrying the same unusual mutation have been identified in three unrelated families, all immigrants from the Balkans. Two were compound heterozygous newborns, in Germany and Italy, and one homozygous newborn died in France. Only the French family recognized their Roma background. LAMB3SNP haplotyping confirmed the link between the apparently unrelated Hungarian, German and Italian male cases, but could not verify the same background in the female newborn from France. CONCLUSIONS: The estimated age of the mutation corresponds to the time period when Roma were wandering in the Balkans.

[Recessive epidermolysis bullosa due to composite heterozygote mutations in the COL7A1 gene]. / Épidermolyse bulleuse héréditaire dystrophique par hétérozygotie composite COL7A1.

BACKGROUND: Dystrophic epidermolysis bullosa (DEB) is a genodermatosis characterized by various abnormalities of anchoring fibrils, composed mainly of type VII collagen, at the dermal-epidermal junction. These changes are induced by mutations in the type VII collagen gene (COL7A1). PATIENTS AND METHODS: A new-born boy was diagnosed with recessive DEB on the basis of typical skin lesions composed of multiple blisters with erosions on trauma-exposed body sites, including the hands and feet and the navel. Diagnosis was confirmed by pathology examination and irregular immunofluorescence staining of type VII collagen. Genomic DNA from the patient and parents were subjected to direct sequencing for the COL7A1 gene. Two heterozygous mutations were detected in the affected child. Each parent was a carrier of one heterozygous mutation. DISCUSSION: Over 730 mutations of the COL7A1 gene have been identified as responsible for phenotypic polymorphism of EBD. The relatively mild phenotype seen in our patient, known as "non-Hallopeau-Siemens" or "mitis" EBD, is due to residual synthesis of collagen VII. The mutation present on the maternal allele that prevents synthesis of collagen VII is compensated by the mutation on the paternal allele, which enables more or less functional collagen VII synthesis.

Aplasia cutis congenita with dystrophic epidermolysis bullosa: clinical and mutational study.

BACKGROUND: Aplasia cutis congenita (ACC) has been associated with all clinical forms of inherited epidermolysis bullosa (EB), including dominant and recessive dystrophic EB (DDEB and RDEB). To date, only a few patients with DEB specifically combined with ACC have been described and genotyped and almost all cases represent dominant forms of the condition. OBJECTIVES: The aim of this study was to describe new mutations of COL7A1 in patients with DEB and ACC and investigate possible genotype-phenotype correlations. METHODS: Twenty-two patients with DEB and ACC were included among the 123 patients with DEB whose COL7A1 mutations have been identified in the Reference Centre in Nice. RESULTS: Seven patients presented a severe generalized RDEB phenotype (RDEB-sev-gen), while the other 15 suffered from milder phenotypes. We identified 28 mutations in COL7A1, of which nine are novel. Patients with severe phenotypes have mostly mutations leading to premature termination codon (PTC) and/or splice-site or missense mutations. Patients with the milder phenotypes have mostly glycine or arginine substitutions associated or not with other types of mutations. All amino acid substitutions fell within the carboxyl portion of the triple helix domain (THD) of collagen VII, close to the THD interruptions. CONCLUSIONS: Our findings suggest that ACC is a frequent manifestation in patients with DEB irrespective of the severity of the disease, and is due to leg rubbing in utero. In children with a moderate form of DEB with no or moderate skin fragility, a glycine substitution near the THD interruption domain of the collagen VII leading to thermolabile protein could explain this phenomenon.

Epidermolysis bullosa simplex with PLEC mutations: new phenotypes and new mutations.

BACKGROUND: Genetic mutations in the plectin gene (PLEC) cause autosomal recessive forms of epidermolysis bullosa simplex (EBS) associated with either muscular dystrophy (EBS-MD) or pyloric atresia (EBS-PA). Phenotype-genotype analysis has suggested that EBS-MD is due mostly to genetic mutations affecting the central rod domain of plectin, and EBS-PA to mutations outside this domain. OBJECTIVES: This study aimed to describe new phenotypes of patients with EBS-MD and EBS-PA, to identify novel PLEC mutations and to establish genotype-phenotype correlations. METHODS: Seven patients with a suspicion of EBS linked to PLEC mutations were included. A standardized clinical questionnaire was sent to the physicians in charge of each patient. Immunofluorescence studies of skin biopsies followed by molecular analysis of PLEC were performed in all patients. RESULTS: We report the first case of nonlethal EBS-PA improving with age, the first multisystemic involvement in a patient with lethal EBS-PA, and the first patients with EBS-MD with involvement of either the bladder or oesophagus. Eleven novel PLEC mutations are also reported. CONCLUSIONS: Our results confirm that EBS-PA is linked to mutations in the distal exons 1-30 and 32 of PLEC. Long-term survival is possible, with skin improvement, but a delayed onset of MD is probable. While EBS-MD is linked to PLEC mutations in all exons, in most cases one of the mutations affects exon 31. The precocity of MD seems to be linked to the type and localization of the PLEC mutation(s), but no correlation with mucosal involvement has been found.

The first COL7A1 mutation survey in a large Spanish dystrophic epidermolysis bullosa cohort: c.6527insC disclosed as an unusually recurrent mutation.

BACKGROUND: Dystrophic epidermolysis bullosa (DEB) is a genodermatosis caused by mutations in COL7A1. The clinical manifestations are highly variable from nail dystrophy to life-threatening blistering, making early molecular diagnosis and prognosis of utmost importance for the affected families. Mutation identification is mandatory for prenatal testing. OBJECTIVES: To conduct the first mutational analysis of COL7A1 in a Spanish cohort, to assess mutation consequences at protein/mRNA level and to establish genotype-phenotype correlations. METHODS: Forty-nine Spanish patients with DEB were studied. Antigen mapping was performed on patient skin biopsies. COL7A1 mutation screening in genomic DNA was performed by polymerase chain reaction (PCR) and direct sequencing. Mutation consequences were determined by reverse transcriptase-PCR. RESULTS: Eight patients belonged to three unrelated families with dominant DEB. Forty-one were affected with recessive DEB (RDEB). Specifically, 27 displayed the severe generalized subtype, eight the other generalized subtype and six a localized phenotype (two pretibial, three acral and one inversa). Thirty-five mutations were identified, 20 of which are novel. The pathogenic mutation c.6527insC accounted for 46.3% of Spanish RDEB alleles. A consistent genotype-phenotype correlation was established. CONCLUSIONS: Although the COL7A1 database indicates that most DEB mutations are family specific, the pathogenic mutation c.6527insC was highly recurrent in our cohort. This level of recurrence for a single genetic defect has never previously been reported for COL7A1. Our findings are essential to the clinicians caring for patients with DEB in Spain and in the large population of Spanish descendants in Latin America. They also provide geneticists a molecular clue for a priority mutation screening strategy.

Modafinil normalized hyperreflexia after spinal transection in adult rats.

STUDY DESIGN: Hyperreflexia occurs after spinal cord injury and can be assessed by measuring low frequency-dependent depression of the H-reflex in the anesthetized animal. OBJECTIVE: To determine the effects of Modafinil (MOD), given orally, following a complete SCI compared with animals receiving MBET and transected untreated animals and examine if changes exist in Connexin 36 (Cx-36) protein levels in the lumbar enlargement of animals for the groups described. SETTING: Center for Translational Neuroscience, Little Rock, AR, USA. METHODS: Adult female rats underwent complete transection (Tx) at T10 level. H-reflex testing was performed 30 days following Tx in one group, and after initiation of treatment with MOD in another group, and after MBET training in the third group. The Lumbar enlargement tissue was harvested and western blots were performed after immunoprecipitation techniques to compare Cx-36 protein levels. RESULTS: Statistically significant decreases in low frequency-dependent depression of the H-reflex were observed in animals that received MOD and those that were treated with MBET compared with the Tx, untreated group. Statistically significant changes in Cx-36 protein levels were not observed in animals treated with MOD compared with Tx, untreated animals. CONCLUSION: Normalization of the loss of low frequency -dependent depression of the H-reflex was demonstrated in the group receiving MOD and the group receiving MBET compared with the Tx, untreated group. Further work is needed to examine if Cx-36 protein changes occur in specific subregions of the spinal cord.

[Localised de novo dominant dystrophic epidermolysis bullosa]. / Epidermolyse bulleuse dystrophique localisée dominante de novo.

INTRODUCTION: Dystrophic epidermolysis bullosa is a hereditary heterogeneous blistering disease. Clinical examination and additional tests are not always sufficient to identify the subtype or mode of transmission. We describe a case of de novo dominant inherited dystrophic epidermolysis bullosa localised strictly to the knees. CASE REPORT: A 3-year-old boy presented symmetrical lesions on the anterior aspect of the knees since starting to walk. No nail, dental or mucous dystrophy was observed and the parents presented no clinical abnormalities. Optical microscopy, electron microscopy and immunofluorescence analysis suggested dystrophic epidermolysis bullosa. The genealogical tree allowed no distinction between the dominant de novo and mitis recessive forms. Genetic analysis identified a missense G 1776W mutation at exon 61 of gene COL 7A1 in the child's DNA but not the parents'. DISCUSSION: Dystrophic epidermolysis bullosa may present in generalized or localized forms and the disease may be inherited in either autosomal dominant or recessive mode. Genetic analysis shows mutations in COL 7A1. While the clinical features often allow different types to be distinguished when the parents do not have the disease (with the recessive forms being more severe), genetic analysis is essential to confirm the mode of inheritance. In the dominant forms, and more recently in recessive cases, glycine substitutions have been implicated, although the precise role of glycine substitution has yet to be clarified. Localised involvement of the skin alone, as seen in our case report, is very rare. CONCLUSION: Genetic analysis is important for genetic counselling and determination of risk of recurrence.

The mitogen-activated protein kinase signaling pathway stimulates mos mRNA cytoplasmic polyadenylation during Xenopus oocyte maturation.

The Mos protein kinase is a key regulator of vertebrate oocyte maturation. Oocyte-specific Mos protein expression is subject to translational control. In the frog Xenopus, the translation of Mos protein requires the progesterone-induced polyadenylation of the maternal Mos mRNA, which is present in the oocyte cytoplasm. Both the Xenopus p42 mitogen-activated protein kinase (MAPK) and maturation-promoting factor (MPF) signaling pathways have been proposed to mediate progesterone-stimulated oocyte maturation. In this study, we have determined the relative contributions of the MAPK and MPF signaling pathways to Mos mRNA polyadenylation. We report that progesterone-induced Mos mRNA polyadenylation was attenuated in oocytes expressing the MAPK phosphatase rVH6. Moreover, inhibition of MAPK signaling blocked progesterone-induced Mos protein accumulation. Activation of the MAPK pathway by injection of RNA encoding Mos was sufficient to induce both the polyadenylation of synthetic Mos mRNA substrates and the accumulation of endogenous Mos protein in the absence of MPF signaling. Activation of MPF, by injection of cyclin B1 RNA or purified cyclin B1 protein, also induced both Mos protein accumulation and Mos mRNA polyadenylation. However, this action of MPF required MAPK activity. By contrast, the cytoplasmic polyadenylation of maternal cyclin B1 mRNA was stimulated by MPF in a MAPK-independent manner, thus revealing a differential regulation of maternal mRNA polyadenylation by the MAPK and MPF signaling pathways. We propose that MAPK-stimulated Mos mRNA cytoplasmic polyadenylation is a key component of the positive-feedback loop, which contributes to the all-or-none process of oocyte maturation.

Regulation and expression of a growth arrest-specific gene (gas5) during growth, differentiation, and development.

The growth arrest-specific gas5 gene was isolated from mouse genomic DNA and structurally characterized. The transcriptional unit is divided into 12 exons that span around 7 kb. An alternative splicing mechanism gives rise to two mature mRNAs which contain either 11 or 12 exons, and both are found in the cytoplasm of growth-arrested cells. In vivo, the gas5 gene is ubiquitously expressed in mouse tissues during development and adult life. In Friend leukemia and NIH 3T3 cells, the levels of gas5 gene mRNA were high in saturation density-arrested cells and almost undetectable in actively growing cells. Run-on experiments indicated that the gas5 gene is transcribed at the same level in both growing and arrested cells. On the other hand, in dimethyl sulfoxide-induced differentiating cells a sharp decrease in the rate of transcription was observed shortly before the cells reached the postmitotic stage. These results indicate that in density-arrested cells accumulation of gas5 mRNA is controlled at the posttranscriptional level while in differentiating cells expression is regulated transcriptionally.

Inherited epidermolysis bullosa and squamous cell carcinoma: a systematic review of 117 cases.

BACKGROUND: Inherited epidermolysis bullosa (EB) comprises a highly heterogeneous group of rare diseases characterized by exacerbated skin and/or mucosal fragility and blister formation after minor mechanical trauma. Level of cleavage in the skin, clinical features with immunofluorescence antigen mapping and/or electron microscopy examination of a skin biopsy and/or gene involved, type(s) of mutation present and sometimes specific mutation(s), allow to define the EB type and subtype. This family of genodermatoses exposes patients to several complications, cutaneous squamous cell carcinoma (cSCC) being the most severe of them. OBJECTIVE: The aim of this systematic review was to document patients with EB who developed cSCC. METHODS: A systematic literature search was performed, from inception to March 2014, using Medline, Embase, Cochrane and ClinicalTrials.gov databases. Only articles published in English and French were selected. The diagnosis of EB had to be confirmed by EM and/or IFM and/or mutation analysis, while cSCC had to be confirmed by histological analysis. RESULTS: Of 167 references in the original search, 69 relevant articles were identified, representing 117 cases. cSCCs were identified in all types of EB, though predominantly in recessive dystrophic EB (RDEB) forms (81 cases (69.2 %)). The median age at diagnosis was 36 years old (interquartile range (IQR), 27-48 years and range, 6-71 years) for all forms. Of those with measurements in the literature (88 cases (75.2 %)), tumor size was greater than 2 centimeters in 52 cases (59.1 %). The histopathological characteristics were specified in 88 cases (75.2 %) and well-differentiated forms predominated (73.9 %). No conclusion could be drawn on the choice of surgical treatment or the management in advanced forms. LIMITATIONS: This study was retrospective and statistical analysis was not included due to various biases. This study design did not allow to infer prevalence, nor EB subtype risk for cSCC occurrence. CONCLUSIONS: Our study correlated with historical data shows that most of the cSCCs occurred in subjects with the RDEB subtype, however reports also show that cSCCs can present in any patients with EB. The first signs of cSCC developed at a younger age in EB patients than in non-EB patients. Interestingly, the cSCC duration, before its diagnosis, was shorter in individuals with RDEB than with junctional EB (JEB) and dominant dystrophic EB (DDEB). This study further emphasizes the importance of regular monitoring of EB patients, particularly with the RDEB subtype as they developed cSCC at a younger age.

Bombesin and neuromedin B stimulate the activation of p42(mapk) and p74(raf-1) via a protein kinase C-independent pathway in Rat-1 cells.

The mechanisms by which seven transmembrane receptors activate p42-(mapk)/p44(mapk) are not well defined although p21ras- and protein kinase C (PKC)-dependent pathways have been implicated, typically for Gi- and Gq-coupled receptors, respectively. Here, we demonstrate that in Rat-1 cells transfected with the Gq-coupled bombesin/gastrin releasing peptide receptor, bombesin stimulated activation of p42(mapk) that was not inhibited by the specific PKC inhibitor GF 109203X or by down regulation of phorbol ester-sensitive PKC isoforms. In addition, bombesin rapidly stimulated p74(raf-1) activity that was also independent of PKC activity and insensitive to inhibition by pertussis toxin. Furthermore, addition of neuromedin B to Rat-1 cells transfected with the neuromedin B preferring receptor also activated p42(mapk) and p74(raf-1) in a PKC-independent and pertussis toxin-insensitive manner. Finally we show that addition of bombesin to Rat-1 cells stimulated the GTP loading of p21ras. Our results reveal a novel PKC-independent pathway in the action of Gq-coupled receptors and stress the importance of cell context in defining the signal transduction pathway(s) that link specific receptors to the activation of the mitogen-activated protein kinase cascade.

The bombesin/GRP receptor transfected into Rat-1 fibroblasts couples to phospholipase C activation, tyrosine phosphorylation of p125FAK and paxillin and cell proliferation.

Bombesin elicits multiple signalling pathways in various cell types. It is not clear, however, whether these responses are mediated by a single receptor subtype or by different subtypes that couple preferentially to specific pathways. To resolve this we transfected the mouse bombesin/GRP receptor into Rat-1 fibroblasts and investigated the pathways activated by bombesin. Expression of the transfected receptors was verified by binding of (125I)GRP and two clones were selected, BOR5 and BOR15. Bombesin stimulation of BOR5 and BOR15 cells caused intracellular Ca2+ mobilisation and increased the phosphorylation of 80K/MARCKS, a prominent protein kinase C substrate. The transfected receptor conferred a proliferative response to bombesin demonstrated by incorporation of (3H) thymidine after 18 h and an increase in total cell numbers after 1-2 days. In BOR5 and BOR15 cells, bombesin rapidly stimulated the tyrosine phosphorylation of multiple proteins Mr 110 000-130 000 and 70 000-80 000 including p125fak and paxillin, at low concentrations (half maximum 0.3 nM). The specific bombesin/GRP receptor antagonist, D-F5-Phe6, D-Ala11-Bombesin (6-13)OMe, inhibited all the above responses. These results show that phospholipase C activation, cell growth and tyrosine phosphorylation emanate from a single class of bombesin receptor.

Renal function, neurohormonal activation, and survival in patients with chronic heart failure.

BACKGROUND: Because renal function is affected by chronic heart failure (CHF) and it relates to both cardiovascular and hemodynamic properties, it should have additional prognostic value. We studied whether renal function is a predictor for mortality in advanced CHF, and we assessed its relative contribution compared with other established risk factors. In addition, we studied the relation between renal function and neurohormonal activation. METHODS AND RESULTS: The study population consisted of 1906 patients with CHF who were enrolled in a recent survival trial (Second Prospective Randomized study of Ibopamine on Mortality and Efficacy). In a subgroup of 372 patients, plasma neurohormones were determined. The baseline glomerular filtration rate (GFR(c)) was calculated using the Cockroft Gault equation. GFR(c) was the most powerful predictor of mortality; it was followed by New York Heart Association functional class and the use of angiotensin-converting enzyme inhibitors. Patients in the lowest quartile of GFR(c) values (<44 mL/min) had almost 3 times the risk of mortality (relative risk, 2. 85; P<0.001) of patients in the highest quartile (>76 mL/min). Impaired left ventricular ejection fraction (LVEF) was only modestly predictive (P=0.053). GFR(c) was inversely related with N-terminal atrial natriuretic peptide (ANP; r=-0.53) and, to a lesser extent, with ANP itself (r=-0.35; both P<0.001). CONCLUSIONS: Impaired renal function (GFR(c)) is a stronger predictor of mortality than impaired cardiac function (LVEF and New York Heart Association class) in advanced CHF, and it is associated with increased levels of N-terminal ANP. Moreover, impaired renal function was not related to LVEF, which suggests that factors other than reduced cardiac output are causally involved.

TIMI risk score for ST-elevation myocardial infarction: A convenient, bedside, clinical score for risk assessment at presentation: An intravenous nPA for treatment of infarcting myocardium early II trial substudy.

BACKGROUND: Considerable variability in mortality risk exists among patients with ST-elevation myocardial infarction (STEMI). Complex multivariable models identify independent predictors and quantify their relative contribution to mortality risk but are too cumbersome to be readily applied in clinical practice. METHODS AND RESULTS: We developed and evaluated a convenient bedside clinical risk score for predicting 30-day mortality at presentation of fibrinolytic-eligible patients with STEMI. The Thrombolysis in Myocardial Infarction (TIMI) risk score for STEMI was created as the simple arithmetic sum of independent predictors of mortality weighted according to the adjusted odds ratios from logistic regression analysis in the Intravenous nPA for Treatment of Infarcting Myocardium Early II trial (n=14 114). Mean 30-day mortality was 6.7%. Ten baseline variables, accounting for 97% of the predictive capacity of the multivariate model, constituted the TIMI risk score. The risk score showed a >40-fold graded increase in mortality, with scores ranging from 0 to >8 (P:<0.0001); mortality was <1% among patients with a score of 0. The prognostic discriminatory capacity of the TIMI risk score was comparable to the full multivariable model (c statistic 0. 779 versus 0.784). The prognostic performance of the risk score was stable over multiple time points (1 to 365 days). External validation in the TIMI 9 trial showed similar prognostic capacity (c statistic 0.746). CONCLUSIONS: The TIMI risk score for STEMI captures the majority of prognostic information offered by a full logistic regression model but is more readily used at the bedside. This risk assessment tool is likely to be clinically useful in the triage and management of fibrinolytic-eligible patients with STEMI.

Oral glycoprotein IIb/IIIa inhibition with orbofiban in patients with unstable coronary syndromes (OPUS-TIMI 16) trial.

BACKGROUND: Although intravenous glycoprotein IIb/IIIa inhibitors are beneficial in patients with acute coronary syndromes, prolonged oral IIb/IIIa inhibition might provide an additional reduction in recurrent events. METHODS AND RESULTS: Investigators at 888 hospitals in 29 countries enrolled 10 288 patients with acute coronary syndromes, which was defined as ischemic pain at rest within 72 hours of randomization, associated with positive cardiac markers, electrocardiographic changes, or prior cardiovascular disease. Patients received aspirin and were randomized to receive, for the duration of the trial, (1) 50 mg of orbofiban twice daily (50/50 group), (2) 50 mg of orbofiban twice daily for 30 days followed by 30 mg of orbofiban twice daily (50/30 group), or (3) a placebo. The primary composite end point was death, myocardial infarction, recurrent ischemia requiring rehospitalization, urgent revascularization, or stroke. The trial was terminated prematurely because of an unexpected increase in 30-day mortality in the 50/30 orbofiban group. Mortality through 10 months was 3.7% for the placebo group versus 5.1% in the 50/30 group (P=0.008) and 4.5% in the 50/50 group (P=0.11). There were no differences in the primary end point (22.9%, 23.1%, and 22.8%, for the placebo, 50/30, and 50/50 groups, respectively). Major or severe bleeding (but not intracranial hemorrhage) was higher with orbofiban; it occurred in 2. 0%, 3.7% (P=0.0004), and 4.5% (P<0.0001) of patients, respectively. Exploratory subgroup analyses found that patients who underwent percutaneous coronary intervention had a lower mortality and a significant reduction in the composite end point (P=0.001) with orbofiban. CONCLUSIONS: -Fixed-dose orbofiban failed to reduce major cardiovascular events and was associated with increased mortality in this broad population of patients with acute coronary syndromes; however, a benefit was observed among patients who underwent percutaneous coronary intervention.