J Biol Chem

Collagen XXIII is a member of the transmembranous subfamily of collagens containing a cytoplasmic domain, a membrane-spanning hydrophobic domain, and three extracellular triple helical collagenous domains interspersed with non-collagenous domains. We cloned mouse, chicken, and human{alpha}1(XXIII) collagen cDNAs and showed that this non-abundant collagen has a limited tissue distribution in non-tumor tissues. Lung, cornea, brain, skin, tendon, and kidney are the major sites of expression. In contrast, five transformed cell lines were tested for collagen XXIII expression, and all expressed the mRNA. In vivo the {alpha}1(XXIII) mRNA is found in mature and developing organs, the latter demonstrated using stages of embryonic chick cornea and mouse embryos. Polyclonal antibodies were generated in guinea pig and rabbit and showed that collagen XXIII has a transmembranous form and a shed form. Comparison of collagen XXIII with its closest relatives in the transmembranous subfamily of collagens, types XIII and XXV, which have the same number of triple helical and non-collagenous regions, showed that there is a discontinuity in the alignment of domains but that striking similarities remain despite this

Human amnion contains a novel laminin variant, laminin 7, which like laminin 6, covalently associates with laminin 5 to promote stable epithelial-stromal attachment.

International audienceStable attachment of external epithelia to the basement membrane and underlying stroma is mediated by transmembrane proteins such as the integrin alpha6beta4 and bullous pemphigoid antigen 2 within the hemidesmosomes along the basolateral surface of the epithelial cell and their ligands that include a specialized subfamily of laminins. The laminin 5 molecule (previously termed kalinin/nicein/epiligrin) is a member of this epithelial-specific subfamily. Laminin 5 chains are not only considerably truncated within domains III-VI, but are also extensively proteolytically processed in vitro and in vivo. As a result, the domains expected to be required for the association of laminins with other basement membrane components are lacking in the mature laminin 5 molecule. Therefore, the tight binding of laminin 5 to the basement membrane may occur by a unique mechanism. To examine laminin 5 in tissue, we chose human amnion as the source, because of its availability and the similarity of the amniotic epithelial basement membrane with that of skin. We isolated the laminin 5 contained within the basement membrane of human amnion. In addition to monomeric laminin 5, we find that much of the laminin 5 isolated is covalently adducted with laminin 6 (alpha3beta1gamma1) and a novel laminin isotype we have termed laminin 7 (alpha3beta2gamma1). We propose that the association between laminin 5 and laminins 6 and 7 is a mechanism used in amnion to allow stable association of laminin 5 with the basement membrane. The beta2 chain is seen at the human amniotic epithelial-stromal interface and at the dermal-epidermal junction of fetal and adult bovine skin by immunofluorescence, but is not present, or only weakly present, in neonatal human skin.Stable attachment of external epithelia to the basement membrane and underlying stroma is mediated by transmembrane proteins such as the integrin alpha6beta4 and bullous pemphigoid antigen 2 within the hemidesmosomes along the basolateral surface of the epithelial cell and their ligands that include a specialized subfamily of laminins. The laminin 5 molecule (previously termed kalinin/nicein/epiligrin) is a member of this epithelial-specific subfamily. Laminin 5 chains are not only considerably truncated within domains III-VI, but are also extensively proteolytically processed in vitro and in vivo. As a result, the domains expected to be required for the association of laminins with other basement membrane components are lacking in the mature laminin 5 molecule. Therefore, the tight binding of laminin 5 to the basement membrane may occur by a unique mechanism. To examine laminin 5 in tissue, we chose human amnion as the source, because of its availability and the similarity of the amniotic epithelial basement membrane with that of skin. We isolated the laminin 5 contained within the basement membrane of human amnion. In addition to monomeric laminin 5, we find that much of the laminin 5 isolated is covalently adducted with laminin 6 (alpha3beta1gamma1) and a novel laminin isotype we have termed laminin 7 (alpha3beta2gamma1). We propose that the association between laminin 5 and laminins 6 and 7 is a mechanism used in amnion to allow stable association of laminin 5 with the basement membrane. The beta2 chain is seen at the human amniotic epithelial-stromal interface and at the dermal-epidermal junction of fetal and adult bovine skin by immunofluorescence, but is not present, or only weakly present, in neonatal human skin

(5S)-4-(2,2-Dimethyl­prop­yl)-5-isopropyl-1,3,4-oxadiazinan-2-one

The title compound, C11H22N2O2, has one chiral center and packs in the monoclinic space group P21. The asymmetric unit has five crystallographically independent mol­ecules, four of which engage in inter­molecular N—H⋯O hydrogen bonding

Laminin database: a tool to retrieve high-throughput and curated data for studies on laminins

The Laminin(LM)-database, hosted at http://www.lm.lncc.br, is the first database focusing a non-collagenous extracellular matrix protein family, the LMs. Part of the knowledge available in this website is automatically retrieved, whereas a significant amount of information is curated and annotated, thus placing LM-database beyond a simple repository of data. In its home page, an overview of the rationale for the database is seen and readers can access a tutorial to facilitate navigation in the website, which in turn is presented with tabs subdivided into LMs, receptors, extracellular binding and other related proteins. Each tab opens into a given LM or LM-related molecule, where the reader finds a series of further tabs for ‘protein’, ‘gene structure’, ‘gene expression’ and ‘tissue distribution’ and ‘therapy’. Data are separated as a function of species, comprising Homo sapiens, Mus musculus and Rattus novergicus. Furthermore, there is specific tab displaying the LM nomenclatures. In another tab, a direct link to PubMed, which can be then consulted in a specific way, in terms of the biological functions of each molecule, knockout animals and genetic diseases, immune response and lymphomas/leukemias. LM-database will hopefully be a relevant tool for retrieving information concerning LMs in health and disease, particularly regarding the hemopoietic system

Space- and time-resolved investigation on diffusion kinetics of human skin following macromolecule delivery by microneedle arrays

Microscale medical devices are being developed for targeted skin delivery of vaccines and the extraction of biomarkers, with the potential to revolutionise healthcare in both developing and developed countries. The effective clinical development of these devices is dependent on understanding the macro-molecular diffusion properties of skin. We hypothesised that diffusion varied according to specific skin layers. Using three different molecular weights of rhodamine dextran (RD) (MW of 70, 500 and 2000 kDa) relevant to the vaccine and therapeutic scales, we deposited molecules to a range of depths (0–300 µm) in ex vivo human skin using the Nanopatch device. We observed significant dissipation of RD as diffusion with 70 and 500 kDa within the 30 min timeframe, which varied with MW and skin layer. Using multiphoton microscopy, image analysis and a Fick’s law analysis with 2D cartesian and axisymmetric cylindrical coordinates, we reported experimental trends of epidermal and dermal diffusivity values ranging from 1–8 µm2 s-1 to 1–20 µm2 s-1 respectively, with a significant decrease in the dermal-epidermal junction of 0.7–3 µm2 s-1. In breaching the stratum corneum (SC) and dermal-epidermal junction barriers, we have demonstrated practical application, delivery and targeting of macromolecules to both epidermal and dermal antigen presenting cells, providing a sound knowledge base for future development of skin-targeting clinical technologies in humans

Mouse Acetylcholinesterase Enhances Neurite Outgrowth of Rat R28 Cells Through Interaction With Laminin-1

The enzyme acetylcholinesterase (AChE) terminates synaptic transmission at cholinergic synapses by hydrolyzing the neurotransmitter acetylcholine, but can also exert ‘non-classical’, morpho-regulatory effects on developing neurons such as stimulation of neurite outgrowth. Here, we investigated the role of AChE binding to laminin-1 on the regulation of neurite outgrowth by using cell culture, immunocytochemistry, and molecular biological approaches. To explore the role of AChE, we examined fiber growth of cells overexpressing different forms of AChE, and/or during their growth on laminin-1. A significant increase of neuritic growth as compared with controls was observed for neurons over-expressing AChE. Accordingly, addition of globular AChE to the medium increased total length of neurites. Co-transfection with PRIMA, a membrane anchor of AChE, led to an increase in fiber length similar to AChE overexpressing cells. Transfection with an AChE mutant that leads to the retention of AChE within cells had no stimulatory effect on neurite length. Noticeably, the longest neurites were produced by neurons overexpressing AChE and growing on laminin-1, suggesting that the AChE/laminin interaction is involved in regulating neurite outgrowth. Our findings demonstrate that binding of AChE to laminin-1 alters AChE activity and leads to increased neurite growth in culture. A possible mechanism of the AChE effect on neurite outgrowth is proposed due to the interaction of AChE with laminin-1