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Biomedical subjects

D Aberdam

Publications and source records attributed to D Aberdam.

At least 37 records · Page 2Linked to original sources
PubMed1997

Altered expression of the hemidesmosome-anchoring filament complex proteins in basal cell carcinoma: possible role in the origin of peritumoral lacunae.

Basal cell carcinoma (BCC) is a frequent skin cancer with low metastatic potential. Expression of the anchoring filament proteins, native laminin-5 and its individual alpha 3, beta 3 and gamma 2 chains, uncein. and linear IgA antigen was examined by immunostaining in 17 BCC with different histological subtypes. Immunoreactivity of the hemidesmosomal proteins, integrin alpha 6 beta 4, 230-kDa bullous pemphigoid antigen (BP-230 Ag) and plectin/HD-1, and that of dermal-epidermal junction (DEJ) components, integrin alpha 2 beta 1, laminin-1, collagen IV, and collagen VII was also analysed. Around tumour nests, the labelling of laminin-5 was absent or markedly reduced in 12 BCC (comprising eight solid BCC, three adenoid BCC and one keratotic BCC) and strong in five BCC (comprising three adenoid BCC, one keratotic BCC and one adenoid and keratotic BCC). Intriguingly, in tumour cells of 12 BCC including laminin-5 negative tumours, a cytoplasmic reactivity of the laminin gamma 2 chain was detected, but not that of the alpha 3 and beta 3 chains. In the basement membrane of the epidermis overlying tumour nests, the labelling of laminin-5 was always strong. Uncein, linear IgA disease antigen, and integrin alpha 6 beta 4 were absent in solid BCC and weakly expressed in adenoid or keratotic BCC. For plectin/HD-1 and BP-230 Ag, a cytoplasmic reactivity was detected in the majority of the tumour cells. The labelling of integrin alpha 2 beta 1, laminin-1, collagen IV and collagen VII indicated no alteration in the synthesis of these proteins. In peritumoral lacunae, immunoreactivity of hemidesmosome and anchoring filament proteins was absent, except for plectin/HD-1 on the tumour side and sometimes for laminin-5 on the stromal side, while laminin-1, collagen IV and collagen VII were detected on the stromal side. These findings suggest that the components of the hemidesmosome-anchoring filament complex are not synthetized or assembled properly in BCC, and that the alteration of these adhesion structures may be the cause of peritumoral lacunae.

Autoantigens↗
PubMed1996

Developmental expression of laminin-5 and HD1 in the intestine: epithelial to mesenchymal shift for the laminin gamma-2 chain subunit deposition.

We report the expression pattern of hemidesmosome-associated proteins laminin-5, composed of alpha 3 beta 3 gamma 2 chains, and HD1 in the developing mouse and human intestine, an organ in which variations in structure and function parallel morphogenesis and differentiation. Immunocytochemistry analysis revealed the coexpression of laminin-5 and HD1 at the basal pole of differentiating epithelial cells. Distinct noticeable variations occurring in the location of laminin alpha 3 chain in development of mouse gut were stressed by the reverse transcriptase-polymerase chain reaction data. A peculiar finding was also the location of laminin gamma 2 chain in the intestinal muscle coat. The cellular origin of laminin gamma 2 chain was examined by immunocytochemistry on interspecies hybrid intestines with specific antibodies recognizing mouse antigens. Complementary and sequential production of laminin gamma 2 chain was observed, by epithelial cells as establishment of the basement membrane occurs and by mesenchymal cells in the more differentiated organ. These results support the concept of mesenchymal involvement in deposition of basement membrane molecules, a crucial process for intestinal differentiation. Taken together these data provide the first evidence for the coexpression of hemidesmosome-associated proteins in the gut, a non-stratified tissue.

Aging↗
PubMed1996

Cicatricial pemphigoid autoantibodies react with multiple sites on the BP180 extracellular domain.

Cicatricial pemphigoid (CP) is an autoimmune blistering disease that primarily affects mucosal tissues. Autoantibodies to laminin-5 have previously been detected in certain patients with a CP-like disease; however, individuals that exhibit this reactivity profile apparently represent a small subset of CP patients. In the present investigation, 0 of 18 CP sera showed reactivity with laminin-5 by immunoblotting. In contrast, 18 of 23 CP sera (78%) recognized a 180-kDa epidermal antigen that, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, co-migrated with BP180, a hemidesmosomal glycoprotein associated with two other autoimmune blistering diseases, bullous pemphigoid and herpes gestationis. To investigate further the CP autoimmune response, various segments of human BP180 were expressed as bacterial fusion proteins and assayed by immunoblotting for reactivity with CP patients' sera. The results of this investigation demonstrated that the BP180 autoantigen is indeed a major target of CP autoantibodies. Further, two distinct CP-reactive sites were identified on the extracellular domain of the BP180 protein, one located in the non-collagenous (NC) 16A domain (at or near the previously defined autoantibody-reactive site recognized by bullous pemphigoid and herpes gestationis sera) and the other in the carboxy-terminal region of this protein. Sixteen of 23 CP sera (70%) reacted with one or both of these antigenic sites of BP180. Other immunologic data suggested that BP180 may harbor additional CP-reactive sites. In conclusion, there are now three bullous diseases, bullous pemphigoid, herpes gestationis, and cicatricial pemphigoid, that are known to be associated with an autoimmune response against the extracellular domain of the BP180 antigen.

Aged↗
PubMed1996

Localization of laminin-5 in the epidermal basement membrane.

Laminin-5 (kalinin/nicein/BM600) is a component of the epidermal basement membrane zone. Previous en bloc pre-embedding immunogold electron microscopy (EM) has shown that the epitope of GB3, a monoclonal antibody against laminin-5, is present in the lamina lucida (LL). However, precise localization of the entire laminin-5 molecule was unclear because of uneven and limited penetration of gold-labeled antibody in pre-embedding immunolabeling. In addition, the location of the GB3 epitope may not directly represent the location of the laminin-5 moelcule itself. To elucidate the precise ultrastructural distribution of the entire laminin-5 molecule, we used polyclonal antibodies against different sites of laminin-5. Dual staining immunofluorescence with anti-laminin-5 and anti-melanocyte antibodies and immunoperoxidase EM showed that laminin-5 was present only beneath keratinocytes and not beneath melanocytes. Both cryoultramicrotomy and postembedding immunogold EM demonstrated that laminin-5 was localized to the lamina densa (LD) and the lower LL, with major labeling beneath the hemidesmosome. Quantitative analysis showed that 67-69% of gold particles were distributed to the LD and 88-90% were distributed beneath the hemidesmosome. Our results indicate that laminin-5 is localized mainly to the LD and partially to the lower LL, and is associated predominantly with hemidesmosomes.

Basement Membrane↗
PubMed1995

Cloning and complete primary structure of the mouse laminin alpha 3 chain. Distinct expression pattern of the laminin alpha 3A and alpha 3B chain isoforms.

We have isolated and characterized overlapping cDNA clones encoding the alpha 3A and alpha 3B chains of mouse laminin 5. Sequence analysis of the cDNA for the alpha 3B predicts a polypeptide of 2541 amino acids (279,510 Da) comprising a truncated short arm and a carboxyl-terminal long arm common to the laminin alpha chains identified thus far. The short arm of the alpha 3B chain harbors two alternating epidermal growth factor-like domains and two globular domains. The amino-terminal globular domain, thought to mediate interactions with molecules of the extracellular matrix, shows no significant homology to any globular domain at the tips of the known laminin isoforms. The alpha 3A cDNA predicts a polypeptide of 1711 amino acids (186,230 Da) that substitutes a short sequence of 43 amino acids for the short arm seen in the alpha 3B isoform and displays 77% conservative homology to the alpha 3Ep chains of the adhesion ligand epiligrin. Northern and Western blot analyses of skin and lung epithelial cells demonstrated the tissue-specific expression of the laminin alpha 3A and alpha 3B isoforms, and in situ hybridization on mouse embryos revealed a focal localization of alpha 3B in areas of the central nervous system.

Amino Acid Sequence↗
PubMed1995

Integrin beta 4 mutations associated with junctional epidermolysis bullosa with pyloric atresia.

Pyloric atresia associated with junctional epidermolysis bullosa (PA-JEB), is a rare inherited disorder characterized by pyloric stenosis and blistering of the skin as primary manifestations. We demonstrate that in one PA-JEB patient the disease resulted from two distinct mutations in the beta 4 integrin gene alleles. The paternal mutation consists of a one base pair deletion causing a shift in the open reading frame, and a downstream premature termination codon. The maternal mutation occurs in a donor splice site, and results in in-frame exon skipping involving the cytoplasmic domain of the polypeptide. Our results implicate mutations in the beta 4 integrin gene in some forms of PA-JEB.

Alleles↗
PubMed1995

A homozygous nonsense mutation in the alpha 3 chain gene of laminin 5 (LAMA3) in lethal (Herlitz) junctional epidermolysis bullosa.

The inherited mechanobullous disorder, junctional epidermolysis bullosa (JEB), is characterized by extensive blistering and erosions of the skin and mucous membranes. The diagnostic hallmarks of JEB include ultrastructural abnormalities in the hemidesmosomes of the cutaneous basement membrane zone, as well as an absence of staining with antibodies against the anchoring filament protein, laminin 5. Therefore, the three genes encoding alpha 3, beta 3 and gamma 2 chains of laminin 5, known as LAMA3, LAMB3 and LAMC2, are candidate genes for JEB. We have previously demonstrated mutations in the LAMB3 and LAMC2 genes in several families with JEB. We initiated mutation analysis from an affected child by PCR amplification of individual LAMA3 exons, followed by heteroduplex analysis. Nucleotide sequencing of heteroduplexes identified a homozygous nonsense mutation within domain I/II of the alpha 3 chain. These findings provide the first evidence that nonsense mutations within the LAMA3 gene are also involved in the pathogenesis of JEB, and indicate that mutations of all three genes of laminin 5 can result in the JEB phenotype.

Base Sequence↗
PubMed1994

The 100-kDa chain of nicein/kalinin is a laminin B2 chain variant.

We have isolated the basement membrane component nicein and performed rotary-shadow analyses using electron microscopy that showed the presence of two forms (I and II) of the protein. Molecular cloning of the cDNA that codes for the 100-kDa chain of the protein revealed that the sequence matches those independently identified for the 105-155-kDa subunit of kalinin, a recently identified basement membrane component. These data demonstrate that nicein and kalinin contain an identical chain. The length of the open reading frame in the cDNA (approximately 5200 nucleotides) and amino acid sequence obtained from the N-terminus of the 105-kDa kalinin chain showed the occurrence of a precursor polypeptide. This immature polypeptide is probably related to form I, observed by rotary shadowing, while the mature form is related to form II. It is noteworthy that nicein/kalinin subunits share discrete sequence similarities with the B2 chain of human laminin, but with a cleavage occurring within domain III that eliminates domains IV and V from the final product. The sequence of this subunit is nearly identical to that of B2t, a recently described polypeptide supposed to be related to a new laminin variant. Since nicein/kalinin expression is specifically impaired in the severe genodermatosis Herlitz junctional epidermolysis bullosa, the role and structure of this tissue-restricted laminin variant is crucial for the understanding of epidermal-dermal adhesion.

Amino Acid Sequence↗
PubMed1994

Herlitz's junctional epidermolysis bullosa is linked to mutations in the gene (LAMC2) for the gamma 2 subunit of nicein/kalinin (LAMININ-5).

We have linked Herlitz's junctional epidermolysis bullosa (H-JEB) to the gene (LAMC2) encoding the gamma 2 subunit of nicein/kalinin, an isolaminin (laminin-5) expressed by basal keratinocytes. In four H-JEB kindreds, a maximum two-point lod score of 5.33 at theta = 0 was observed between a microsatellite near LAMC2 at 1q25-31 and the disease. In one family, a homozygous point mutation leading to a premature stop codon (CGA to TGA) was identified in exon 3 of the gene. The segregation of the mutated allele implicates the mutation in the pathology of the disorder and corroborates the linkage results.

Base Sequence↗
PubMed1994

Developmental expression of nicein adhesion protein (laminin-5) subunits suggests multiple morphogenic roles.

Nicein/kalinin (laminin-5) is a heterotrimeric laminin-like adhesion protein, which is secreted at the basement membrane of subsets of epithelia and is involved in the etiology of junctional epidermolysis bullosa, a severe human blistering disease characterized by disadhesion of epidermis from dermis. cDNA clones encoding the three chains of mouse nicein and antibodies specific to each polypeptide were used to examine the expression of the protein in the developing mouse embryo from 10.5 day post coitum to 7 days after birth. At various stages of development, co-expression of the three chains of nicein was observed in amnion, skin, and in epithelia of respiratory, urinary and digestive systems. High level expression of nicein was seen in enamel-secreting ameloblasts in developing teeth. Cell-specific distribution of nicein was also detected in other specialized tissues representative of the three primary embryonic germ layers with prominent secretory or protective functions. Differential and focal expression of nicein subunits was observed in the choroid plexus and the floor plate of the neural tube. Messenger for the heavy chain of nicein was detected in the floor plate, where mouse s-laminin messengers were also found. This suggests that nicein genes may play a role in the migration and polarization of motor neurons in the developing spinal cord.

Amino Acid Sequence↗
PubMed1993

Nicein (BM-600) in junctional epidermolysis bullosa: polyclonal antibodies provide new clues for pathogenic role.

We have raised polyclonal antibodies against each of three subunits of the new basement membrane component nicein (formerly BM-600), the antigen recognized by the monoclonal antibody GB3 (Biochem Biophys Acta 942:45-56, 1988). Preparation of such antibodies was achieved from gel electrophoresis purification of nicein isolated by immuno-affinity chromatography. These antibodies were reactive with each transblotted denatured nicein subunit and recognized the native protein both in cultured keratinocytes and in all normal human basement membranes where the GB3 antigen is located. A reciprocal immuno-cross-reactivity was detected with the antibodies directed against the 100-kD and 150-kD (sometimes resolved as a 146-150-kD doublet) subunits of nicein, showing that they share some identical epitopes. In tissues and keratinocyte cultures from patients with the Herlitz form of junctional epidermolysis bullosa (H-JEB), GB3 is unable to recognize nicein, and the question arises whether this is due to an absence of synthesis or a structural abnormality of the protein. We report here that the polyclonal antibody directed against the 150-kD subunit of nicein binds its antigen in H-JEB patients (although usually less intensely than in control skin), whereas the other two antibodies either do not recognize or recognize only weakly their respective antigen subunits. These data suggest that nicein is present but structurally altered in basement membranes from H-JEB tissues. Furthermore, in non-Herlitz junctional and dystrophic types of epidermolysis bullosa, all three polyclonal antibodies recognize their antigens normally. Consequently, such antibodies should serve as potentially useful molecular tools for studying the expression of nicein in H-JEB.

Antibodies↗
PubMed1992

Kalinin is abnormally expressed in epithelial basement membranes of Herlitz's junctional epidermolysis bullosa patients.

Kalinin is an extracellular adhesion molecule specific to epithelial basement membranes (BM) identified as a component of anchoring filaments of hemidesmosomes. This heterotrimeric protein is synthesized by cultured normal human keratinocytes and is involved in cell attachment. In indirect immunofluorescence studies, the epidermal BM of patients with junctional epidermolysis bullosa (JEB) of Herlitz's type were found not to be reactive with the anti-kalinin monoclonal antibodies ka146 and K140 and displayed a decreased immunoreactivity to two anti-kalinin antibodies cross-reacting with K-laminin, an anchoring filament component recently described. The intrinsic defect of JEB keratinocytes in the synthesis of kalinin was further documented by indirect immunofluorescence on in vitro cultures of these cells. In non-Herlitz JEB patients, staining of BM was constantly detected. Impairment of expression of kalinin correlated with the lack of reactivity to the monoclonal antibody GB3, which detects the BM component nicein/BM600. These results clearly demonstrate a defect of kalinin expression in epithelial basement membranes of Herlitz JEB patients and suggest that kalinin may play a role in the pathogenesis of the disease. Further studies are in progress to define possible relationships between kalinin and nicein.

Basement Membrane↗
PubMed1991

A deletion and a rearrangement distinguish between the intracisternal A-particle of Hox-2.4 and that of interleukin-3 in the same leukemic cells.

Two intracisternal A-particle (IAP) insertions have been identified in WEHI-3B myeloid leukemic cells, one at the interleukin-3 (IL-3) gene and another at the homeobox gene Hox-2.4. In contrast to the 5-kb IL-3-IAP, the Hox-2.4-IAP is only 2.1 kb in size and contains a rearrangement. The homology throughout the remaining sequences suggests that both IAPs originated from a common progenitor molecule. Both proviral insertions have resulted in transcriptional activation of the adjacent genes, which appears to be a significant step in the leukemogenic process in these leukemic cells.

Amino Acid Sequence↗
PubMed1991

The oncogenic potential of an activated Hox-2.4 homeobox gene in mouse fibroblasts.

The homeobox gene Hox-2.4 is transcriptionally activated in cells of the mouse myeloid leukemia WEHI-3B. The constitutive Hox-2.4 expression in WEHI-3B cells is due to insertion of a transposable element belonging to the family of intracisternal A particles. In this study, we demonstrated the oncogenic potential of this activated homeobox gene. NIH 3T3 fibroblast clones bearing the activated Hox-2.4 gene produced fibrosarcomas in nude mice.

Animals↗
PubMed1988

DNA rearrangement of a homeobox gene in myeloid leukaemic cells.

A homeobox gene rearrangement has been detected in WEHI-3B mouse myeloid leukaemic cells. The rearranged gene was identified as Hox-2.4 which is a member of the Hox-2 gene cluster on mouse chromosome 11. Both the normal and the rearranged genes were cloned and analysed, and the rearranged genomic Hox-2.4 gene was sequenced. The results indicate that the rearrangement is due to insertion of an intracisternal A particle 5' upstream to Hox-2.4 and that this resulted in constitutive expression of the homeobox gene. It is suggested that constitutive expression of the homeobox gene may interrupt the normal development program in these leukaemic cells.

Amino Acid Sequence↗