T. Wiederholt

Allelic loss underlies type 2 segmental Hailey-Hailey disease, providing molecular confirmation of a novel genetic concept

Hailey-Hailey disease (HHD) is an autosomal dominant trait characterized by erythematous and oozing skin lesions preponderantly involving the body folds. In the present unusual case, however, unilateral segmental areas along the lines of Blaschko showing a rather severe involvement were superimposed on the ordinary symmetrical phenotype. Based on this observation and similar forms of mosaicism as reported in other autosomal dominant skin disorders, we postulated that in such cases, 2 different types of segmental involvement can be distinguished. Accordingly, the linear lesions as noted in the present case would exemplify type 2 segmental HHD. In the heterozygous embryo, loss of heterozygosity occurring at an early developmental stage would have given rise to pronounced linear lesions reflecting homozygosity or hemizygosity for the mutation. By analyzing DNA and RNA derived from blood and skin samples as well as keratinocytes of the index patient with various molecular techniques including RT-PCR, real-time PCR, and microsatellite analysis, we found a consistent loss of the paternal wild-type allele in more severely affected segmental skin regions, confirming this hypothesis for the first time, to our knowledge, at the molecular and cellular level.

Expression and Induction of Cytochrome P450 Isoenzymes in Human Skin Equivalents

Organotypic skin models are frequently used for a wide range of applications and latterly also for dermatotoxicological studies. To evaluate their practicability for the investigation of xenobiotic metabolism in human skin we compared three types of organotypic skin models, acquired by purchase from different manufacturers, to a self-constructed in-house model with regard to cytochrome P450 (CYP) isoenzyme expression on mRNA and protein level and the inducibility of these enzymes by aryl hydrocarbon receptor ligands. To induce enzyme activity, models were treated with benzanthracene, liquor carbonis detergens, pix lithanthracis or dimethyl sulfoxide as a solvent control. RNA was isolated by phenol-chloroform extraction and purified. Gene expression patterns were studied by cDNA microarray analysis. Microarray data were confirmed by real-time PCR. For quality control of the models and to detect and localize enzyme expression, immunofluorescence staining was performed with antibodies against CYPs and structure proteins. The immunofluorescence staining demonstrated the regular structure of our models. We could provide evidence for the expression of CYP types 1A1, 1B1, 2E1, 2C and 3A5 in organotypic skin models. The expression of CYP1A1 and CYP1B1 was highly inducible by treatment with liquor carbonis detergens. The proof of the expression and inducibility of CYP enzymes in organotypic skin models suggests that skin equivalents are a valuable tool that can emulate CYP-dependent metabolism of drugs and other xenobiotics in human skin.

Calcium pantothenate modulates gene expression in proliferating human dermal fibroblasts.

Abstract:  Topical application of pantothenate is widely used in clinical practice for wound healing. Previous studies identified a positive effect of pantothenate on migration and proliferation of cultured fibroblasts. However, these studies were mainly descriptive with no molecular data supporting a possible model of its action. In this study, we first established conditions for an in vitro model of pantothenate wound healing and then analysed the molecular effects of pantothenate. To test the functional effect of pantothenate on dermal fibroblasts, cells were cultured and in vitro proliferation tests were performed using a standardized scratch test procedure. For all three donors analysed, a strong stimulatory effect of pantothenate at a concentration of 20 μg/ml on the proliferation of cultivated dermal fibroblasts was observed. To study the molecular mechanisms resulting in the proliferative effect of pantothenate, gene expression was analysed in dermal fibroblasts cultivated with 20 μg/ml of pantothenate compared with untreated cells using the GeneChip® Human Exon 1.0 ST Array. A number of significantly regulated genes were identified including genes coding for interleukin (IL)‐6, IL‐8, Id1, HMOX‐1, HspB7, CYP1B1 and MARCH‐II. Regulation of these genes was subsequently verified by quantitative real‐time polymerase chain reaction analysis. Induction of HMOX‐1 expression by pantothenol and pantothenic acid in dermal cells was confirmed on the protein level using immunoblots. Functional studies revealed the enhanced suppression of free radical formation in skin fibroblasts cultured with panthenol. In conclusion, these studies provided new insight in the molecular mechanisms linked to the stimulatory effect of pantothenate and panthenol on the proliferation of dermal fibroblasts.

The molecular basis of porphyria cutanea tarda in Chile: Identification and functional characterization of mutations in the uroporphyrinogen decarboxylase gene

Abstract:  The porphyrias are heterogeneous disorders arising from predominantly inherited catalytic deficiencies of specific enzymes in heme biosynthesis. Porphyria cutanea tarda (PCT) results from a decreased activity of uroporphyrinogen decarboxylase, the fifth enzyme in heme biosynthesis. The disorder represents the only porphyria that is not exclusively inherited monogenetically. In PCT, at least two different types can be distinguished: acquired/sporadic (type I) PCT, in which the enzymatic deficiency is limited to the liver and inherited/familial (type II) PCT, which is inherited as an autosomal dominant trait with a decrease of enzymatic activity in all tissues. In an effort to characterize the molecular basis of PCT in Chile, we identified eight mutations in 18 previously unclassified PCT families by polymerase chain reaction, heteroduplex analysis, and automated sequencing. To study the role of these mutations in disease causality, in vitro expression of all novel missense mutations was studied. Our results indicate that the frequency of familial PCT in Chile is approximately 50%, thus, to our knowledge, representing the highest incidence of familial PCT reported to date. The data further emphasize the molecular heterogeneity in type II PCT and demonstrate the advantages of molecular genetic techniques as a diagnostic tool and in the detection of clinically asymptomatic mutation carriers.

Labordiagnostik und Therapie der Porphyrien

ZusammenfassungBei Porphyrien handelt es sich um eine heterogene Gruppe überwiegend hereditär bedingter metabolischer Erkrankungen, die aus Funktionsstörungen der Hämbiosynthese resultieren. Die meisten Porphyrieformen können sich mit einer Vielzahl kutaner Symptome an den lichtexponierten Arealen der Haut manifestieren, andere hingegen mit akuten lebensbedrohlichen neurologischen Attacken, wobei auch Mischformen vorkommen. Da neben der Haut auch andere Organe wie die Leber und das zentrale Nervensystem betroffen sein können, kommt der interdisziplinären Betreuung dieser Patienten eine wichtige Rolle zu. In diesem Übersichtsartikel werden zunächst Klinik und Diagnostik der Porphyrieerkrankungen dargestellt, einschließlich der spezifischen biochemischen Laboruntersuchungen und eines Algorithmus für die Diagnostik. Danach werden kurz die derzeitigen Behandlungsmöglichkeiten vorgestellt und abschließend die Europäische Porphyrie-Initiative (European Porphyria Initiative, EPI), ein Verbund zahlreicher europäischer Porphyrie-Zentren, der es sich zur Aufgabe gemacht hat, die langjährige Erfahrung international ausgewiesener Porphyrieexperten zu bündeln, um europäische Konsensusrichtlinien zu Diagnostik und Therapie dieser Stoffwechselerkrankungen zu erarbeiten.AbstractThe porphyrias are a heterogeneous group of predominantly hereditary metabolic diseases resulting from a dysfunction of heme biosynthesis. Most of the porphyrias can manifest with a broad range of cutaneous symptoms on the sun-exposed areas of the body, whereas other variants reveal life-threatening acute neurological attacks. Further, mixed types of porphyrias exist. Besides the skin, other organs can be affected, such as the liver and the central nervous system. Therefore, interdisciplinary supervision of these patients is mandatory. In this review we will first present the clinical picture and diagnosis of the porphyrias, including the specific biochemical laboratory tests and a diagnostic algorithm. Thereafter, the current therapeutic concepts will be briefly addressed. Finally, we introduce the European Porphyria Initiative (EPI), an association of various European porphyria centers that is aiming at gathering the broad experience of internationally renowned porphyria experts for the development of European consensus guidelines for diagnosis and treatment of these metabolic disorders.

Dual porphyrias revisited

Abstract:  The porphyrias are clinically and genetically heterogeneous metabolic diseases, which predominantly result from a hereditary dysfunction in the pathway of haeme biosynthesis. Currently, at least eight different forms of porphyrias can be differentiated, all of them characterized by a specific enzyme deficiency that is either inherited in an autosomal‐dominant fashion, autosomal recessively or, in the case of porphyria cutanea tarda, might also be acquired. All genes encoding these enzymes have been cloned and several mutations underlying the different types of porphyrias have been reported. Traditionally, the diagnosis of porphyria is made on the basis of clinical symptoms, characteristic biochemical findings and enzyme assays. In some porphyria patients and families, however, these diagnostic tools can reveal simultaneous findings compatible with two different forms of porphyria, a phenomenon referred to as dual porphyria. Here, we give an overview on what is currently known about these peculiar variants of porphyria and suggest that, whenever feasible, molecular genetic analysis should complement the analytical techniques used to characterize patients and families in which a double enzymatic deficiency within the haeme biosynthetic pathway is assumed.

Genetisch bedingte Haarerkrankungen

ZusammenfassungDurch die stetig wachsenden Erkenntnisse auf dem Gebiet der Molekulargenetik erhielten Ärzte und Wissenschaftler in den zurückliegenden Jahren neue Einblicke in die Ätiologie und Pathogenese zahlreicher monogener und polygener Erbkrankheiten des Menschen. Diese Fortschritte führten neben bemerkenswerten Ergebnissen in der Genodermatosenforschung im Allgemeinen insbesondere auf dem Gebiet genetisch bedingter Haarerkrankungen zur Entschlüsselung molekularer Mechanismen und Entdeckung zahlreicher krankheitsverursachender Mutationen in verschiedenen Genen. Nachfolgend geben wir einen Überblick zu den molekulargenetischen Grundlagen und klinischen Merkmalen einiger hereditärer Hyper- und Hypotrichosen.AbstractOver the last years, the rapid advance of discoveries in the field of molecular genetics has provided physicians and scientists with new insights into etiology and pathogenesis of several monogenetic and polygenetic human diseases. Along with remarkable progress regarding genodermatoses in general, different molecular mechanisms involved in hair growth have been elucidated and mutations causing several genetic hair disorders have been identified. We provide an overview of the molecular genetic basis and the clinical hallmarks of some diseases associated with hypertrichosis and hypotrichosis.

Laboratory tests and therapeutic strategies for the porphyrias

ZusammenfassungBei Porphyrien handelt es sich um eine heterogene Gruppe überwiegend hereditär bedingter metabolischer Erkrankungen, die aus Funktionsstörungen der Hämbiosynthese resultieren. Die meisten Porphyrieformen können sich mit einer Vielzahl kutaner Symptome an den lichtexponierten Arealen der Haut manifestieren, andere hingegen mit akuten lebensbedrohlichen neurologischen Attacken, wobei auch Mischformen vorkommen. Da neben der Haut auch andere Organe wie die Leber und das zentrale Nervensystem betroffen sein können, kommt der interdisziplinären Betreuung dieser Patienten eine wichtige Rolle zu. In diesem Übersichtsartikel werden zunächst Klinik und Diagnostik der Porphyrieerkrankungen dargestellt, einschließlich der spezifischen biochemischen Laboruntersuchungen und eines Algorithmus für die Diagnostik. Danach werden kurz die derzeitigen Behandlungsmöglichkeiten vorgestellt und abschließend die Europäische Porphyrie-Initiative (European Porphyria Initiative, EPI), ein Verbund zahlreicher europäischer Porphyrie-Zentren, der es sich zur Aufgabe gemacht hat, die langjährige Erfahrung international ausgewiesener Porphyrieexperten zu bündeln, um europäische Konsensusrichtlinien zu Diagnostik und Therapie dieser Stoffwechselerkrankungen zu erarbeiten.AbstractThe porphyrias are a heterogeneous group of predominantly hereditary metabolic diseases resulting from a dysfunction of heme biosynthesis. Most of the porphyrias can manifest with a broad range of cutaneous symptoms on the sun-exposed areas of the body, whereas other variants reveal life-threatening acute neurological attacks. Further, mixed types of porphyrias exist. Besides the skin, other organs can be affected, such as the liver and the central nervous system. Therefore, interdisciplinary supervision of these patients is mandatory. In this review we will first present the clinical picture and diagnosis of the porphyrias, including the specific biochemical laboratory tests and a diagnostic algorithm. Thereafter, the current therapeutic concepts will be briefly addressed. Finally, we introduce the European Porphyria Initiative (EPI), an association of various European porphyria centers that is aiming at gathering the broad experience of internationally renowned porphyria experts for the development of European consensus guidelines for diagnosis and treatment of these metabolic disorders.

Inherited metabolic disorders with cutaneous manifestations

ZusammenfassungIn den letzten Jahren konnte die genetische Basis zahlreicher monogen vererbter Stoffwechselerkrankungen aufgeklärt werden. Interessanterweise manifestieren sich einige dieser Erkrankungen mit charakteristischen kutanen Symptomen, die oftmals diagnostisch wegweisend sind. Zumeist sind neben der Haut aber auch weitere Organe betroffen, sodass der interdisziplinären Betreuung dieser Patienten eine wichtige Rolle zukommt. Nachfolgend werden in diesem Übersichtsartikel einige Erkrankungen vorgestellt, die sowohl für den Dermatologen, als auch für Ärzte aus anderen Fachbereichen eine Herausforderung darstellen. Besonders hervorgehoben werden die genetischen und klinischen Merkmale sowie derzeit existierende Therapiekonzepte.AbstractOver the last years, the genetic basis of several monogenic inherited metabolic diseases has been elucidated. Interestingly, some of these disorders manifest with characteristic cutaneous symptoms that are often crucial for diagnosis. In most cases, however, besides the skin other organs are affected. Therefore, an interdisciplinary supervision of these patients is highly important. In this review we will discuss diseases that constitute a challenge not only for dermatologists but also for physicians from other specialties. A particular emphasis is put on genetic and clinical features of these disorders as well as current therapeutic concepts.

Labordiagnostik und Therapie der Porphyrien@@@Laboratory tests and therapeutic strategies for the porphyrias

ZusammenfassungBei Porphyrien handelt es sich um eine heterogene Gruppe überwiegend hereditär bedingter metabolischer Erkrankungen, die aus Funktionsstörungen der Hämbiosynthese resultieren. Die meisten Porphyrieformen können sich mit einer Vielzahl kutaner Symptome an den lichtexponierten Arealen der Haut manifestieren, andere hingegen mit akuten lebensbedrohlichen neurologischen Attacken, wobei auch Mischformen vorkommen. Da neben der Haut auch andere Organe wie die Leber und das zentrale Nervensystem betroffen sein können, kommt der interdisziplinären Betreuung dieser Patienten eine wichtige Rolle zu. In diesem Übersichtsartikel werden zunächst Klinik und Diagnostik der Porphyrieerkrankungen dargestellt, einschließlich der spezifischen biochemischen Laboruntersuchungen und eines Algorithmus für die Diagnostik. Danach werden kurz die derzeitigen Behandlungsmöglichkeiten vorgestellt und abschließend die Europäische Porphyrie-Initiative (European Porphyria Initiative, EPI), ein Verbund zahlreicher europäischer Porphyrie-Zentren, der es sich zur Aufgabe gemacht hat, die langjährige Erfahrung international ausgewiesener Porphyrieexperten zu bündeln, um europäische Konsensusrichtlinien zu Diagnostik und Therapie dieser Stoffwechselerkrankungen zu erarbeiten.AbstractThe porphyrias are a heterogeneous group of predominantly hereditary metabolic diseases resulting from a dysfunction of heme biosynthesis. Most of the porphyrias can manifest with a broad range of cutaneous symptoms on the sun-exposed areas of the body, whereas other variants reveal life-threatening acute neurological attacks. Further, mixed types of porphyrias exist. Besides the skin, other organs can be affected, such as the liver and the central nervous system. Therefore, interdisciplinary supervision of these patients is mandatory. In this review we will first present the clinical picture and diagnosis of the porphyrias, including the specific biochemical laboratory tests and a diagnostic algorithm. Thereafter, the current therapeutic concepts will be briefly addressed. Finally, we introduce the European Porphyria Initiative (EPI), an association of various European porphyria centers that is aiming at gathering the broad experience of internationally renowned porphyria experts for the development of European consensus guidelines for diagnosis and treatment of these metabolic disorders.