-
American Journal of Human Genetics Dec 1999Junctional epidermolysis bullosa (JEB), a genetically heterogeneous group of blistering skin diseases, can be caused by mutations in the genes encoding laminin 5 or...
Junctional epidermolysis bullosa (JEB), a genetically heterogeneous group of blistering skin diseases, can be caused by mutations in the genes encoding laminin 5 or collagen XVII, which are components of the hemidesmosome-anchoring filament complex in the skin. Here, a family with severe nonlethal JEB and with mutations in genes for both proteins was identified. The index patient was compound heterozygous for the COL17A1 mutations L855X and R1226X and was heterozygous for the LAMB3 mutation R635X. As a consequence, two functionally related proteins were affected. Absence of collagen XVII and attenuated laminin 5 expression resulted in rudimentary hemidesmosome structure and separation of the epidermis from the basement membrane, with severe skin blistering as the clinical manifestation. In contrast, single heterozygotes carrying either (1) one or the other of the COL17A1 null alleles or (2) a double heterozygote for a COL17A1 and a LAMB3 null allele did not have a pathological skin phenotype. These observations indicate that the known allelic heterogeneity in JEB is further complicated by interactions between unlinked mutations. They also demonstrate that identification of one mutation in one gene is not sufficient for determination of the genetic basis of JEB in a given family.
Topics: Alleles; Autoantigens; Carrier Proteins; Cell Adhesion Molecules; Child, Preschool; Codon, Terminator; Collagen; Cytoskeletal Proteins; Dystonin; Epidermolysis Bullosa, Junctional; Female; Genes, Lethal; Genetic Heterogeneity; Genetic Linkage; Heterozygote; Humans; Infant; Male; Mutation; Nerve Tissue Proteins; Non-Fibrillar Collagens; Pedigree; RNA Stability; RNA, Messenger; Skin; Kalinin; Collagen Type XVII
PubMed: 10577906
DOI: 10.1086/302672 -
The Journal of Cell Biology Oct 2003Disruption of the BPAG1 (bullous pemphigoid antigen 1) gene results in progressive deterioration in motor function and devastating sensory neurodegeneration in the null...
Disruption of the BPAG1 (bullous pemphigoid antigen 1) gene results in progressive deterioration in motor function and devastating sensory neurodegeneration in the null mice. We have previously demonstrated that BPAG1n1 and BPAG1n3 play important roles in organizing cytoskeletal networks in vivo. Here, we characterize functions of a novel BPAG1 neuronal isoform, BPAG1n4. Results obtained from yeast two-hybrid screening, blot overlay binding assays, and coimmunoprecipitations demonstrate that BPAG1n4 interacts directly with dynactin p150Glued through its unique ezrin/radixin/moesin domain. Studies using double immunofluorescent microscopy and ultrastructural analysis reveal physiological colocalization of BPAG1n4 with dynactin/dynein. Disruption of the interaction between BPAG1n4 and dynactin results in severe defects in retrograde axonal transport. We conclude that BPAG1n4 plays an essential role in retrograde axonal transport in sensory neurons. These findings might advance our understanding of pathogenesis of axonal degeneration and neuronal death.
Topics: Animals; Animals, Newborn; Autoantigens; Axonal Transport; Axons; COS Cells; Carrier Proteins; Chlorocebus aethiops; Collagen; Cytoskeletal Proteins; Dynactin Complex; Dyneins; Dystonin; Ganglia, Spinal; Mice; Mice, Knockout; Microtubule-Associated Proteins; NIH 3T3 Cells; Nerve Tissue Proteins; Neurons, Afferent; Non-Fibrillar Collagens; Pemphigoid, Bullous; Protein Isoforms; Protein Structure, Tertiary; Collagen Type XVII
PubMed: 14581450
DOI: 10.1083/jcb.200306075 -
Transmembrane collagen XVII, an epithelial adhesion protein, is shed from the cell surface by ADAMs.The EMBO Journal Oct 2002Collagen XVII, a type II transmembrane protein and epithelial adhesion molecule, can be proteolytically shed from the cell surface to generate a soluble collagen. Here...
Collagen XVII, a type II transmembrane protein and epithelial adhesion molecule, can be proteolytically shed from the cell surface to generate a soluble collagen. Here we investigated the release of the ectodomain and identified the enzymes involved. After surface biotinylation of keratinocytes, the ectodomain was detectable in the medium within minutes and remained stable for >48 h. Shedding was enhanced by phorbol esters and inhibited by metalloprotease inhibitors, including hydroxamates and TIMP-3, but not by inhibitors of other protease classes or by TIMP-2. This profile implicated MMPs or ADAMs as candidate sheddases. MMP-2, MMP-9 and MT1-MMP were excluded, but TACE, ADAM-10 and ADAM-9 were shown to be expressed in keratinocytes and to be actively involved. Transfection with cDNAs for the three ADAMs resulted in increased shedding and, vice versa, in TACE-deficient cells shedding was significantly reduced, indicating that transmembrane collagen XVII represents a novel class of substrates for ADAMs. Functionally, release of the ectodomain of collagen XVII from the cell surface was associated with altered keratinocyte motility in vitro.
Topics: Antibody Specificity; Autoantigens; Base Sequence; Biotinylation; Carrier Proteins; Cell Adhesion Molecules; Cell Membrane; Cells, Cultured; Collagen; Cytoskeletal Proteins; DNA Primers; Dystonin; Endopeptidases; Humans; Keratinocytes; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Nerve Tissue Proteins; Non-Fibrillar Collagens; Protease Inhibitors; Recombinant Proteins; Tissue Inhibitor of Metalloproteinase-2; Tissue Inhibitor of Metalloproteinase-3; Transfection; Collagen Type XVII
PubMed: 12356719
DOI: 10.1093/emboj/cdf532 -
Frontiers in Genetics 2020Hereditary sensory and autonomic neuropathies (HSANs) are a rare and severe group of sensory axonal neuropathies. HSANs have been classified into eight groups based on...
Hereditary sensory and autonomic neuropathies (HSANs) are a rare and severe group of sensory axonal neuropathies. HSANs have been classified into eight groups based on mode of inheritance, clinical features, and the involved genes. HSAN-VI, perhaps the most notable type, is an autosomal recessive disease, which manifests as the severely impaired pain sensitivity, autonomic disturbances, distal myopathy, spontaneous or surgical amputations, and sometimes early death. Mutations in have been identified as the cause of HSAN-VI. encodes dystonin, a member of the plakin protein family that is involved in cytoskeletal filament networks. Dystonin has seven major isoforms in nerve, muscle, and epithelium. The present study investigated a Chinese family with HSAN and explored potential pathogenic variants using whole-exome sequencing (WES). Variants were screened and filtered through bioinformatics analysis and prediction of variant pathogenicity. Co-segregation analysis was subsequently conducted. We identified compound heterozygous variants of (c.3304G>A, p.V1102I and c.13796G>A, p.R4599H) in two patients. We reported on a Chinese family with HSAN-VI family and detected the disease-causing variants. Our description expands the spectrum of known variants and contributes to the clinical diagnosis of HSAN-VI.
PubMed: 32528525
DOI: 10.3389/fgene.2020.00492 -
Frontiers in Immunology 2019Bullous pemphigoid (BP) is a common autoimmune blistering disease in which autoantibodies target the hemidesmosomal components BP180 and/or BP230 in basal keratinocytes....
Bullous pemphigoid (BP) is a common autoimmune blistering disease in which autoantibodies target the hemidesmosomal components BP180 and/or BP230 in basal keratinocytes. In BP, 80 to 90% of autoantibodies target the juxtamembranous extracellular non-collagenous 16th A (NC16A) domain of BP180. Recently, the administration of dipeptidyl peptidase-IV inhibitors (DPP4i), which are widely used as antihyperglycemic drugs, has been recognized to be a causative factor for BP. DPP4i-associated BP (DPP4i-BP) autoantibodies tend to target epitopes on non-NC16A regions of BP180, and the pathomechanism for the development of the unique autoantibodies remains unknown. To address the characteristics of DPP4i-BP autoantibodies in detail, we performed epitope analysis of 18 DPP4i-BP autoantibodies targeting the non-NC16A domains of BP180 using various domain-specific as well as plasmin-digested polypeptides derived from recombinant BP180. Firstly, Western blotting showed that only one DPP4i-BP serum reacted with the epitopes on the intracellular domain of BP180, and no sera reacted with the C-terminal domain of the molecule. In addition, only 2 DPP4i-BP sera reacted with BP230 as determined by enzyme-linked immunosorbent assay. Thus, DPP4i-BP autoantibodies were found to mainly target the non-NC16A mid-portion of the extracellular domain of BP. Interestingly, Western blotting using plasmin-digested BP180 as a substrate revealed that all of the DPP4i-BP sera reacted more intensively with the 97-kDa processed extracellular domain of BP180, which is known as the LABD97 autoantigen, than full-length BP180 did. All of the DPP4i-BP autoantibodies targeting the LABD97 autoantigen were IgG1, and IgG4 was observed to react with the molecule in only 7 cases (38.9%). In summary, the present study suggests that IgG1-class autoantibodies targeting epitopes on the processed extracellular domain of BP180, i.e., LABD97, are the major autoantibodies in DPP4i-BP.
Topics: Aged; Aged, 80 and over; Antibody Specificity; Autoantibodies; Autoantigens; Blotting, Western; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dystonin; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Fibrinolysin; Humans; Immunoglobulin G; Male; Middle Aged; Non-Fibrillar Collagens; Pemphigoid, Bullous; Peptide Fragments; Protein Domains; Recombinant Proteins; Collagen Type XVII
PubMed: 31191560
DOI: 10.3389/fimmu.2019.01224 -
The Journal of Cell Biology Jan 1991Two hemidesmosomal plaque components of 230 and 180 kD have recently been characterized using autoantibodies in the serum samples of bullous pemphigoid (BP) patients...
Two hemidesmosomal plaque components of 230 and 180 kD have recently been characterized using autoantibodies in the serum samples of bullous pemphigoid (BP) patients (Klatte, D. H., M. A. Kurpakus, K. A. Grelling, and J. C. R. Jones. 1989, J. Cell Biol. 109:3377-3390). These BP autoantibodies generate the type of staining patterns that one would predict for formed hemidesmosomes, i.e., a punctate staining pattern towards the substratum; in less than 50% of various primary epithelial and transformed epidermal cell lines even when such cells are maintained in culture for prolonged periods. In contrast, affinity-purified human autoantibodies against the 230-kD hemidesmosomal plaque component generate intense immunofluorescence staining along the region of cell-substratum interaction in the rat bladder tumor cell line 804G maintained on uncoated glass cover-slips. This pattern is distinct from that observed in the 804G cells using an antibody preparation directed against vinculin, a component of adhesion plaques. Ultrastructural analyses of the 804G cells reveals that hemidesmosome-like structures occur along the basal surface of cells where they abut the substratum. These structures are present in 804G cells maintained in culture in reduced levels of Ca2+ and are recognized by autoantibodies directed against the 230-kD hemidesmosomal plaque component as determined by immunogold ultrastructural localization. To study hemidesmosome appearance in this cell line, 804G cells were trypsinized and then allowed to readhere to glass coverslips. In rounded, unattached 804G cells, hemidesmosome-like plaque structures occur along the cell surface. These structures are recognized by the 230-kD autoantibodies. At 1 h after plating, hemidesmosomes are observed along the substratum attached surface of cells. Protein synthesis is not required for the appearance of these hemidesmosomes. Within 4 h of plating, autoantibody staining and hemidesmosomes appear towards the cell periphery. Subsequently, the polypeptide recognized by the BP autoantibodies becomes concentrated in the perinuclear region, where there are numerous hemidesmosomes. We propose that the hemidesmosomes in 804G cells are involved in cell-substratum adhesion. We discuss possible mechanisms of assembly of hemidesmosomes in the 804G cells. Indeed, the 804G cells should prove an invaluable cell line for the biochemical and molecular dissection of hemidesmosome structure, function, and assembly.
Topics: Animals; Autoantibodies; Autoantigens; Carrier Proteins; Collagen; Cytoskeletal Proteins; Dystonin; Epithelium; Immunoblotting; Intercellular Junctions; Nerve Tissue Proteins; Non-Fibrillar Collagens; Pemphigoid, Bullous; Rats; Trypsin; Tumor Cells, Cultured; Urinary Bladder Neoplasms; Collagen Type XVII
PubMed: 1986003
DOI: 10.1083/jcb.112.1.159 -
The Journal of Comparative Neurology Jun 2005The ectoderm gives rise not only to the skin but also to the entire CNS. This common embryonic lineage suggests that some molecular isoforms might serve analogous... (Comparative Study)
Comparative Study
The ectoderm gives rise not only to the skin but also to the entire CNS. This common embryonic lineage suggests that some molecular isoforms might serve analogous functions in both tissues. Indeed, not only are laminins important components of dermal adhesion mechanisms, but they also regulate some aspects of synaptic development in both the CNS and the PNS. In the skin, laminins are part of a hemidesmosome complex essential for basal keratinocyte adhesion that includes collagen XVII (BP180) and BPAG1 (dystonin/BP230). Here, we show that CNS neurons also express collagen XVII and BPAG1 and that these molecules are expressed in the adult and developing retina. In the retina, isoforms of collagen XVII and BPAG1 are colocalized with laminins at photoreceptor synapses and around photoreceptor outer segments; both molecules are expressed by rods, whereas cones express collagen XVII but not BPAG1. Moreover, biochemical data demonstrate that collagen XVII complexes with retinal laminins. We propose that collagen XVII and BPAG1 isoforms may help to anchor elements of the rod photoreceptor cytomatrix to the extracellular matrix.
Topics: Animals; Animals, Newborn; Aspartic Acid Endopeptidases; Autoantigens; Blotting, Northern; Blotting, Western; Calcium-Binding Proteins; Cattle; Cell Line; Central Nervous System; Collagenases; Gene Expression Regulation, Developmental; Immunohistochemistry; Immunoprecipitation; Keratinocytes; Kinesins; Laminin; Membrane Glycoproteins; Mice; Models, Molecular; Muscle Proteins; Nerve Tissue Proteins; Neuroglia; Non-Fibrillar Collagens; Peanut Agglutinin; Pregnancy Proteins; RNA, Messenger; Rats; Retina; Reverse Transcriptase Polymerase Chain Reaction; Synaptosomes; Vimentin; Collagen Type XVII
PubMed: 15880472
DOI: 10.1002/cne.20549 -
The Journal of Investigative Dermatology Oct 1991The seroreactivity of patients with bullous pemphigoid (BP) to recombinant proteins representing sequences in the carboxyl domain of the murine 230-kD BP antigen (BPA)...
The seroreactivity of patients with bullous pemphigoid (BP) to recombinant proteins representing sequences in the carboxyl domain of the murine 230-kD BP antigen (BPA) was determined. Sera from 133 patients with BP, 20 patients with pemphigus, and 21 normal subjects were examined by Western blotting by using two recombinant proteins: RP120 (MW = 120 kD), representing the C-terminal half of the 230-kD BPA, and RP60 (MW = 60 kD), representing the C-terminal quarter. These RP120 and RP60 were recognized by 84% and 61%, respectively, of the BP sera that reacted with the 230-kD BPA in epidermal extract, and not by any of pemphigus or normal sera. Furthermore, these RP120 and RP60 were not recognized by any BP sera that reacted only with the 170-kD BPA, which is known to be another major BPA. These findings indicate that one or more of the major antigenic regions localizes in the carboxyl-half domain of the 230-kD BPA, and also suggest that the 230-kD BPA may be distinct from the 170-kD BPA.
Topics: Animals; Autoantibodies; Autoantigens; Carrier Proteins; Collagen; Cytoskeletal Proteins; Dystonin; Humans; Immunoblotting; Mice; Molecular Weight; Nerve Tissue Proteins; Non-Fibrillar Collagens; Pemphigoid, Bullous; Recombinant Proteins; Collagen Type XVII
PubMed: 1940445
DOI: 10.1111/1523-1747.ep12484223 -
Rat bladder epithelium: a sensitive substrate for indirect immunofluorescence of bullous pemphigoid.Acta Dermato-venereologica May 2000Serological diagnosis of bullous pemphigoid is based on immunoblotting or indirect immunofluorescence on normal human salt-split skin. These methods are expensive or...
Serological diagnosis of bullous pemphigoid is based on immunoblotting or indirect immunofluorescence on normal human salt-split skin. These methods are expensive or time-consuming and not available as a routine test in all laboratories. We used rat bladder epithelium as substrate for indirect immunofluorescence and compared it with other substrates and with immunoblotting. Twenty-nine bullous pemphigoid sera were studied on rat bladder epithelium, monkey oesophagus, salt-split skin and with immunoblotting on human keratinocyte cultures. Indirect immunofluorescence on rat bladder epithelium proved to be more sensitive (72%) than on monkey oesophagus alone (45%) and less sensitive than on salt-split skin (97%). Rat bladder epithelium, when tested on 41 sera of a control group, showed a very high specificity: 2/41 (95%). In combination with immunoblotting on keratinocyte extracts, indirect immunofluorescence on rat bladder epithelium allowed 93% of sera to be recognized, a value close to the salt-split skin alone. Rat bladder epithelium appears to be a more sensitive substrate than monkey oesophagus for the diagnosis of bullous pemphigoid and, although less specific, it is easier and faster than using salt-split skin, which remains indispensable to distinguish bullous pemphigoid from epidermolysis bullosa acquisita.
Topics: Aged; Aged, 80 and over; Animals; Autoantibodies; Autoantigens; Basement Membrane; Carrier Proteins; Cells, Cultured; Collagen; Cytoskeletal Proteins; Dystonin; Epithelium; Esophagus; Female; Fluorescent Antibody Technique, Indirect; Haplorhini; Humans; Immunoblotting; Keratinocytes; Male; Middle Aged; Nerve Tissue Proteins; Non-Fibrillar Collagens; Paraneoplastic Syndromes; Pemphigoid, Bullous; Rats; Sensitivity and Specificity; Serologic Tests; Skin; Urinary Bladder; Collagen Type XVII
PubMed: 10954206
DOI: 10.1080/000155500750042916 -
Clinical & Developmental Immunology 201239 bullous pemphigoid (BP) patients were studied to assess the clinical significance of anti-BP180 and anti-BP230 circulating autoantibodies of BP and correlate their...
39 bullous pemphigoid (BP) patients were studied to assess the clinical significance of anti-BP180 and anti-BP230 circulating autoantibodies of BP and correlate their titers with the clinical scores of the BP Disease Area Index (BPDAI) and the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) as well as with the intensity of pruritus measured by the BPDAI pruritus component. All parameters were evaluated by the time of diagnosis (baseline), month 3, and month 6. Titers of anti-BP180 autoantibodies were strongly correlated with BPDAI (r = 0.557, P value < 0.0001) and ABSIS (r = 0.570, P value < 0.0001) values, as well as with BPDAI component for the intensity of pruritus (rho = 0.530, P value = 0.001) at baseline. At month 3, titers of anti-BP180 autoantibodies were strongly correlated with BPDAI (rho = 0.626, P value = 0.000) and ABSIS (rho = 0.625, P value = 0.000) values, as well as with the BPDAI component for the intensity of pruritus (rho = 0.625, P value = 0.000). At month 6, titers of anti-BP180 autoantibodies were strongly correlated with BPDAI (rho = 0.527, P value = 0.001) and ABSIS (rho = 0.526, P value = 0.001) values, as well as with the BPDAI component for the intensity of pruritus (rho = 0.525, P value = 0.001). There was no statistically significant correlation between titers of anti-BP230 autoantibodies and the BPDAI, ABSIS, and BPDAI component for the intensity of pruritus at the same time points.
Topics: Adult; Aged; Aged, 80 and over; Autoantibodies; Autoantigens; Carrier Proteins; Cohort Studies; Cytoskeletal Proteins; Dystonin; Female; Follow-Up Studies; Greece; Humans; Male; Membrane Glycoproteins; Middle Aged; Nerve Tissue Proteins; Non-Fibrillar Collagens; Pemphigoid, Bullous; Prospective Studies; Pruritus; Collagen Type XVII
PubMed: 23227089
DOI: 10.1155/2012/854795