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Biomedical subjects

L Bruckner-Tuderman

Publications and source records attributed to L Bruckner-Tuderman.

At least 19 recordsLinked to original sources
PubMed2007

[Erythema annulare centrifugum Darier. Successful therapy with topical calcitriol and 311 nm-ultraviolet B narrow band phototherapy].

Erythema annulare centrifugum is an acute dermatosis of unclear etiology, which presents with annular erythematous lesions with marginal scale. Therapeutically, systemic and topical glucocorticosteroids are used primarily. We treated a patient with large lesions in the area of the thighs resistant to a therapy with topical glucocorticosteroids, with topical calcitriol in combination with 311 nm ultraviolet B narrow band phototherapy. After four weeks of treatment the skin lesions had cleared nearly completely without any side effects. The combination topical vitamin D3-analogue calcitriol and 311 nm ultraviolet B narrow band phototherapy was effective and can be regarded as a useful alternative to glucocorticosteroids for erythema annulare centrifugum.

Administration, Topical↗
PubMed2006

[Bullous pemphigoid: diagnostics and new therapeutic strategies].

Bullous pemphigoid, the most frequent bullous autoimmune dermatosis of the adult, typically presents as disseminated tense blisters on normal or erythematous skin. The diagnosis can be confirmed by direct and indirect immunofluorescence, the detection of circulating autoantibodies against the basement membrane proteins collagen XVII/BP180 and BP230, and histopathology. Autoantibody reactivity against collagen XVII can be measured by ELISA and correlates with disease activity. The ELISA therefore provides a useful tool for monitoring disease activity. Treatment of bullous pemphigoid usually consists of topical and / or systemic steroids in combination with immunosuppressive agents. The intensity of skin involvement and the concurrent diseases and medications of the patient must be considered when selecting a certain treatment. Interdisciplinary cooperation between general practitioners, internists and other specialists facilitates the optimal adaptation of the medication and the early discovery of potential side effects.

Adrenal Cortex Hormones↗
PubMed2006

Collagen XVII promotes integrin-mediated squamous cell carcinoma transmigration--a novel role for alphaIIb integrin and tirofiban.

The expression of collagen XVII (BP180), a transmembrane hemidesmosomal component, is upregulated in invasive areas of epithelial tumors. The collagenous ectodomain of collagen XVII is cleaved from the plasma membrane of keratinocytes and malignant epithelial cells. The released ectodomain is predicted to regulate cell detachment, differentiation, and motility. We report that the cell adhesion domain of collagen XVII, Col15, is able to chemotactically attract invasive HSC-3 SCC cells but not keratinocytes. Analysis of integrin expression revealed that HSC-3 cells, unlike keratinocytes, express alphaIIb integrin, a platelet-specific fibrinogen receptor. We show that this novel chemotactic function is mediated by the known Col15-binding integrins alpha5beta1 and alphav and the platelet integrin alphaIIb. Moreover, we report that tirofiban, a FDA-proved alphaIIb integrin-blocking drug widely used for the therapy of acute coronary ischaemic syndrome and the prevention of thrombotic complications, inhibits the Col15 chemotaxis of HSC-3 carcinoma cells. Together, these data demonstrate a novel interaction between collagen XVII and alphaIIb integrin and also suggest a possibility to use tirofiban to inhibit the invasion and progression of alphaIIb expressing SCC tumors.

Adult↗
PubMed2005

High frequency of the 425A-->G splice-site mutation and novel mutations of the COL7A1 gene in central Europe: significance for future mutation detection strategies in dystrophic epidermolysis bullosa.

BACKGROUND: Mutations in the type VII collagen gene (COL7A1) are responsible for dominant and recessive forms of dystrophic epidermolysis bullosa (DEB). These mutations are usually specific for individual families; only a few cases of recurring mutations have been identified. OBJECTIVES: Forty-three unrelated Hungarian and German patients with different DEB phenotypes were screened for novel and recurrent COL7A1 mutations. METHODS: All patients were classified based on clinical and genetic findings, skin immunofluorescent antigen mapping, and electron microscopic studies. Mutation analysis was performed by amplification of genomic DNA with polymerase chain reaction using COL7A1-specific primers, heteroduplex analysis, and direct nucleotide sequencing. Restriction endonuclease digestion was used for family screening and mutation verification. Results In this group of patients, the splice-site mutation 425A-->G was observed frequently, in 11 of 86 alleles (12.8%), once in homozygous form and in nine cases in heterozygous form. One of 100 control alleles from clinically unaffected individuals also carried the mutation. We also identified three novel mutations: the 976-3C-->A splice-site mutation, and the 4929delT and 8441-15del20 deletions. CONCLUSIONS: High recurrence of the splice-site mutation 425A-->G in central European patients with DEB should be taken into account when designing COL7A1 mutation detection strategies. Reporting of three novel COL7A1 mutations in this study further emphasizes the molecular heterogeneity of DEB and provides more information for studies on genotype-phenotype correlations in different DEB subtypes.

Adolescent↗
PubMed2004

[Hereditary blistering disorders].

Epidermolysis bullosa (EB) is a group of genetic skin disorders whose common feature is the formation of blisters following minor trauma. They present with a wide clinical spectrum of manifestations because of a variety of molecular defects. In patients with mild phenotypes, only skin is affected. The most severe EB forms are multiorgan disorders with a poor prognosis. EB arises from abnormalities in proteins of the dermal-epidermal junction. These specialized protein components aggregate to form anchoring complexes, which attach the epidermis to the dermis. Three major EB-forms can be distinguished on the basis of ultrastructural blistering level: EB simplex--epidermolytic, junctional EB--in the lamina lucida and dystrophic EB--dermolytic. To establish a provisional diagnosis for an EB patient, clinical data, family history and morphologic examination of the skin, e.g. by antigen-mapping, are needed. Complete knowledge of the genetic defect provides the basis to a rational genetic counseling and prenatal testing. Treatment of EB is based on wound care; multidisciplinary management of cases with severe course is required.

Epidermolysis Bullosa↗
PubMed2003

Dystrophic epidermolysis bullosa complicated by cutaneous squamous cell carcinoma and pulmonary and renal amyloidosis.

A 25-year-old woman with Hallopeau-Siemens recessive dystrophic epidermolysis bullosa had generalized blistering, scarring and milia since birth. In the course of the disease, acral pseudosyndactyly developed, and the patient suffered from corneal erosions, oesophageal strictures, malabsorption, recurrent severe pneumonias and nephrotic syndrome. In addition, she had severe anaemia, sideropaenia, hypocalcaemia, heavy proteinuria and hypoalbuminaemia. A rapidly growing skin squamous cell carcinoma developed on the neck that spread to axillary and cervical lymph nodes. Recurrent hypocalcaemic tetanic convulsions and dyspnoea and a pneumonia refractory to antibiotics led to the premature demise of the patient. Autopsy revealed extensive amyloidosis of the renal, hepatic and splenic tissues. AA type amyloid deposits were detected in the renal glomeruli and in the lung, explaining the patient's unusually severe pulmonary infections. In essence, the patient had severe recessive dystrophic epidermolysis bullosa, complicated by squamous cell carcinoma, recurrent pneumonias and nephrotic syndrome due to secondary amyloidosis of the kidney and lung. The possibility of secondary pulmonary amyloidosis should be considered in severe dystrophic epidermolysis bullosa patients with recurrent pulmonary infections.

Adult↗
PubMed2002

Childhood epidermolysis bullosa acquisita: a novel variant with reactivity to all three structural domains of type VII collagen.

Most patients with epidermolysis bullosa acquisita develop an autoimmune response to the non-collagenous (NC) 1 domain of type VII collagen. We report a 4-year-old girl of white European descent presenting with widespread blistering disease involving the face, hands, genital area and oral mucosa. Histopathology revealed subepidermal blisters, and linear deposits of IgG and C3 were seen along the dermal-epidermal junction on direct immunofluorescence (IF) microscopy of a perilesional skin biopsy. On indirect IF microscopy, circulating autoantibodies exclusively stained the dermal side of 1 mol L-1 NaCl-split skin. The patient's IgG autoantibodies labelled a 290-kDa protein on Western blotting of dermal extracts, and reacted with the NC1, NC2 and triple helical domains of type VII collagen on immunoblotting of recombinant and cell-derived fragments obtained by pepsin and collagenase digestion of the full-length protein. Oral methylprednisolone and dapsone led to clearance of lesions, which healed with mild scarring and milia formation. Treatment was discontinued after 1 year and the patient has now been in remission for more than 3 years.

Autoantibodies↗
PubMed2001

The cell adhesion domain of type XVII collagen promotes integrin-mediated cell spreading by a novel mechanism.

Type XVII collagen (BP180) is a keratinocyte transmembrane protein that exists as the full-length protein in hemidesmosomes and as a 120-kDa shed ectodomain in the extracellular matrix. The largest collagenous domain of type XVII collagen, COL15, has been described previously as a cell adhesion domain (Tasanen, K., Eble, J. A., Aumailley, M., Schumann, H., Baetge, J, Tu, H., Bruckner, P., and Bruckner-Tuderman, L. (2000) J. Biol. Chem. 275, 3093-3099). In the present work, the integrin binding of triple helical, human recombinant COL15 was tested. Solid phase binding assays using recombinant integrin alpha(1)I, alpha(2)I, and alpha(10)I domains and cell spreading assays with alpha(1)beta(1)- and alpha(2)beta(1)-expressing Chinese hamster ovary cells showed that, unlike other collagens, COL15 was not recognized by the collagen receptors. Denaturation of the COL15 domain increased the spreading of human HaCaT keratinocytes, which could migrate on the denatured COL15 domain as effectively as on fibronectin. Spreading of HaCaT cells on the COL15 domain was mediated by alpha(5)beta(1) and alpha(V)beta(1) integrins, and it could be blocked by RGD peptides. The collagen alpha-chains in the COL15 domain do not contain RGD motifs but, instead, contain 12 closely related KGD motifs, four in each of the three alpha-chains. Twenty-two overlapping, synthetic peptides corresponding to the entire COL15 domain were tested; three peptides, all containing the KGD motif, inhibited the spreading of HaCaT cells on denatured COL15 domain. Furthermore, this effect was lost by mutation from D to E (KGE instead of KGD). We suggest that the COL15 domain of type XVII collagen represents a specific collagenous structure, unable to interact with the cellular receptors for other collagens. After being shed from the cell surface, it may support keratinocyte spreading and migration.

Amino Acid Motifs↗
PubMed2001

[Large melanocytic nevi in generalized atrophic benign epidermolysis bullosa (epidermolysis bullosa nevi)].

Generalized atrophic benign epidermolysis bullosa (GABEB) is a nonlethal form of junctional epidermolysis bullosa. The expression of type XVII collagen (180 kDa bullous pemphigoid antigen) or of laminin 5 is markedly reduced in the skin. A 13-year-old patient with GABEB, developed several large, asymmetric, irregularly pigmented melanocytic nevi with poorly defined borders. They had appeared following blister formation since 8 years of age. Histological examination revealed an irregular proliferation of monomorphous melanocytes at the dermoepidermal junction. Small nests of melanocytes were focally present. This case further emphasizes the difficulty in differentiating nevi appearing in GABEB from malignant melanoma.

Adolescent↗
PubMed2001

Altered expression of collagen XVII in ameloblastomas and basal cell carcinomas.

BACKGROUND: Collagen XVII (BP180) is an epithelial transmembrane protein, which presumably plays a role in cell migration and differentiation under both physiological and pathological conditions. Ameloblastoma, the most common odontogenic neoplasm, and basal cell carcinoma (BCC) of the skin exhibit similar growth patterns and share histological features. METHODS: Here, we examined the distribution and expression of collagen XVII in ameloblastomas and BCCs using immunohistochemistry and non-radioactive in situ hybridization. In both tumors, the distribution of collagen XVII varied in different parts of the lesions. RESULTS: In ameloblastomas, immunostaining for collagen XVII was usually localized in the basal and suprabasal cells of the tumor nests, although in some tumors, a diffuse intracellular staining was detected in the central cells of the neoplastic islands. In BCCs, collagen XVII was mostly seen as diffuse cytoplasmic staining in some central and peripheral cells of the tumor islands and also at the cell membranes in the basal keratinocytes of the epidermis overlying the tumor nests. Double immunostaining with antibody against gamma2 chain of laminin-5 showed that these two components of the keratinocyte adhesion complex are usually co-localized in ameloblastomas and BCCs. In both tumors, collagen XVII mRNA was found in the basal epithelial cells and in some central and peripheral cells of the tumor islands, while the stromal cells were negative. CONCLUSIONS: These findings indicate that the expression of collagen XVII may be differentially regulated in various parts of the tumor. Diffuse intracellular distribution of collagen XVII and a consequent loss of critical cellular attachments may contribute to the infiltrative and progressive growing potential of tumors.

Ameloblastoma↗
PubMed2001

Generalized dystrophic epidermolysis bullosa: identification of a novel, homozygous glycine substitution, G2031S, in exon 73 of COL7A1 in monozygous triplets.

We report monozygous triplets affected with dystrophic epidermolysis bullosa (DEB). The female triplets were delivered by Caesarean section and skin fragility of each child, which was partly induced by trauma, was apparent from the third to fourth day of life. Clinically, the triplets were equally affected. Mutation analysis in this family revealed a novel recessively expressed glycine substitution, G2031S, in exon 73 of the collagen VII gene COL7A1. Most glycine substitutions in this gene region encoding for the triple helical domain of collagen VII are associated with milder, dominantly inherited phenotypes. By contrast, the novel point mutation of this study is clinically silent in the heterozygous state and leads to a severe DEB subtype when homozygous.

Collagen↗
PubMed2001

Junctional epidermolysis bullosa gravis (Herlitz): diagnostic and genetic aspects.

We report on a boy suffering from lethal junctional epidermolysis bullosa gravis (JEBH) (Herlitz-type) (OMIM 226700). Screening for mutations of LAMB3 gene with polymerase chain reaction (PCR) amplification of all exons from genomic DNA and subsequent heteroduplex analysis and dideoxynucleotide sequencing of heteroduplex forming PCR products disclosed two mutations: the recurrent maternal mutation R635X and the novel paternal mutation 1629insG, both in exon 14 of LAMB3. Both mutations lead to a premature termination code, non-sense mediated mRNA decay and to absence of the synthesis of the beta3 chain of laminin 5. During the mutation screening of the index patient a second pregnancy was ascertained. After amniocentesis (14 + 1 week of pregnancy), prenatal diagnosis from fetal cells was performed and compound heterozygosity for both mutations was evident. The consultants decided to have a termination of pregnancy shortly after the diagnosis. Remarkable skin fragility of the fetus was evident by clinical examination. Complete absence of laminin 5 could be demonstrated by immunofluorescence staining. By the third pregnancy of this couple so far screened for mutations by chorionic villus sampling for prenatal molecular diagnosis a healthy but heterozygous child is expected.

Epidermolysis Bullosa, Junctional↗
PubMed2001

Latent TGF-beta binding protein LTBP-1 contains three potential extracellular matrix interacting domains.

Latent TGF-beta binding proteins (LTBPs) are components of the extracellular matrix (ECM). They belong to the fibrillin/LTBP-superfamily, and are high molecular weight glycoproteins characterized by EGF-like repeats and 8-Cys repeats. Most LTBPs associate with the small latent forms of TGF-beta. Their roles include to facilitate the secretion of latent TGF-beta and to target it to the ECM. In order to identify new matrix-binding domains of LTBP-1 and to characterize their association with the extracellular matrix, we have produced (in a mammalian expression system) partly overlapping recombinant fragments of its shorter form, LTBP-1S, and analyzed the binding of the purified fusion proteins to extracellular matrices of cultured human dermal and lung fibroblasts. Recombinant fragments from three different regions of the N- and C-termini showed affinity to the matrix. These interacting regions contain either the first (hybrid), second or fourth 8-Cys domains of the LTBP-1S molecule. They bound independently to the matrix. Each of them had an ability to inhibit the association of native exogenous LTBP-1 with fibroblast extracellular matrix. The interactions of the LTBP-1 fragments with the extracellular matrix resisted treatment with sodium deoxycholate, suggesting strong, possibly covalent binding. The binding occurred in a time- and dose-dependent fashion. The N-terminal fragments bound more readily to the matrices. With all fragments the binding took place both with intact fibroblast matrices and with matrices isolated by sodium deoxycholate. When using CHO cell layers, which form sparse matrices, only the N-terminal fragment of LTBP-1 was efficiently incorporated. The association of the binding fragments with isolated matrices was enhanced by soluble, cell-derived factors. The current data suggest that LTBP-1 contains three different domains with an ability to associate with the extracellular matrix.

Animals↗