Publications

Identification of laminin domains involved in branching morphogenesis: Effects of anti-laminin monoclonal antibodies on mouse embryonic lung development

Schuger L., Skubitz A.P.N, O'Shea K.S., Chang J.F., Varani J.Developmental biology, 1991

Using a series of monoclonal anti-laminin antibodies, the deposition and functional involvement of different laminin domains in the developing lung were investigated. Immunohistochemistry reactivity was largely localized to the basement membrane but was also present diffusely in the extracellular matrix throughout the mesenchyme. Organ cultures of lung explants from Day 12 embryos were used. Although all antibodies penetrated the tissues in culture, only laminin alpha-1 and a-5 antibodies inhibited branching activity. Laminin alpha-2, -3, and -4 antibodies did not alter lung morphogenesis.

Monoclonal antibodies to human laminin α4 chain globular domain inhibit tumor cell adhesion and migration on laminins 411 and 421, and binding of α6β1 integrin and MCAM to α4-laminins

Ishikawa T., Wondimu Z., Oikawa Y., Ingerpuu S., Virtanen I., Patarroyo M.Matrix Biology, 2014

α4-Laminins, such as laminins -411 and -421, are mesenchymal laminins expressed by vascular and lymphatic endothelial cells, leukocytes and other normal cell types. These laminins are recognized by α6β1 and α6β4 integrins and MCAM (CD146) and promote adhesion and migration of the cells. α4-Laminins are also expressed and secreted by some tumor cells and strongly promote tumor cell migration. Moreover, the abluminal side of blood and/or lymphatic vessels and the nerve perineurium, common tracks of tumor cell dissemination, express α4-laminins, and these laminin isoforms, when expressed in the stroma, may contribute to tumor invasion. In the present study, we examined ten mAbs to human laminin α4 chain for their reactivity with the isolated laminin α4 globular domain, their ability to inhibit tumor cell adhesion and migration on laminin-411 and -421, and their effect on the binding of α6β1 integrin and MCAM to both α4-laminins. The results indicate that mAbs to the laminin α4 globular domain are able to inhibit tumor cell adhesion and migration on laminin-411 and -421 and that α6β1 integrin and MCAM bind α4-laminins at very close sites on the globular domain. These reagents contribute to a better understanding of the biology of α4-laminins and may have a therapeutic potential in malignant and inflammatory diseases.

Clonal culturing of human embryonic stem cells on laminin-521/E-cadherin matrix in defined and xeno-free environment

Rodin S., Antonsson L., Niaudet C., Simonson O.E., Salmela E., Hansson E.M., Domogatskaya A., Xiao Z., Damdimopoulou P., Sheikhi M., Inzunza J., Nilsson A.S., Baker D., Kuiper R., Sun Y., Blennow E., Nordenskjöld M., Grinnemo K.H., Kere J., Betsholtz C., Hovatta O., Tryggvason K.Nature Communications 2014 (a)

This article provides scientific evidence that LN-521 is the optimal matrix for the generation and culture of human pluripotent stem cells. Laminin-521 successfully recreates the biologically relevant hPSC milieu in vitro and via integrin binding, laminin-521 induces the PI3K/Akt signaling pathway, promoting survival and robust self-renewal of human embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC). Clonal derivation and single-cell expansion of hPSCs on laminin-521.This article provides scientific evidence that LN-521 is the optimal matrix for the generation and culture of human pluripotent stem cells. It is described in detail how this physiologically relevant laminin establishes genetically stable hESC lines in an efficient, defined, xeno-free and feeder-free procedure, suitable for stem cell banking and regenerative medicine applications. It is even possible to derive embryonic stem cells from a single blastomere, thereby avoiding the ethical dilemma associated with the destruction of donated embryos. LN-511 binds the same integrin but the α6β1 integrin mediating effects of LN-521 is much stronger than that of LN-511 which results in a more robust PSC expansion on LN-521.

Protocol for the derivation, culturing, and differentiation of human iPS-cell-derived neuroepithelial stem cells to study neural differentiation in vitro

Javier Calvo-Garrido, Dania Winn, Camilla Maffezzini, Anna Wedell, Christoph Freyer, Anna Falk, Anna Wredenberg. STAR Protocols, 2021

This protocol describes the derivation of neuroepithelial stem (NES) cells from human induced pluripotent stem cells. NES cells can be further differentiated into neurons and glia. The PSC culture and NES differentiation were done on plates coated with Biolaminin 521 (laminin-521). To avoid clonal selection of isolated NES cells, it is recommended to follow the culture conditions described. The protocol is expected to result in highly proliferate NES cells providing a good source of cells of a neuronal cell lineage. Glial cells are formed after approximately 45 days of differentiation.

Methods for Automated Single Cell Isolation and Sub-Cloning of Human Pluripotent Stem Cells

Valeria Fernandez Vallone, Narasimha Swamy Telugu, Iris Fischer,Duncan Miller, Sandra Schommer, Sebastian Diecke, Harald Stachelscheid. Current Protocols in Stem Cell Biology, 2020

This publication describes automated workflows to facilitate high-throughput hPSC clonal selection and expansion, which is required for example after genome editing. Three different automated single cell dispensing devices were applied with Biolaminin 521 coating of plates and multiwells. Laminin-521 increases single cell cloning efficiency compared to other commonly used matrices. Single cell−derived hPSC sub-clones from each system maintained pluripotency and genetic stability.

The ability of inner-cell-mass cells to self-renew as embryonic stem cells is acquired following epiblast specification

Boroviak T., Loos R., Bertone P., Smith A. and Nichols J.Nature Cell Biology, 2014

The authors show that mouse ICM cells from early blastocysts can progress to ERK independence if provided with a specific laminin substrate. We show by RNA sequencing that Laminin-511 is expressed in the early ICM, as is B1-integrin, which mediates laminin binding in ESCs. No expression of Laminin-521 in mouse ICM. Single ESC derivation in 2i-LIF on a fibronectin-LN511 mix and clonal ESC lines expansion on LN511.

Laminin-211 controls thymocyte—thymic epithelial cell interactions

Laminin-211 controls thymocyte—thymic epithelial cell interactions

Ocampo J.S.P., de Brito J.M,  Corrêa-de-Santana E., Borojevic R., Serra Villa-Verde D.M., Savino W.
Cellular Immunology, 2008

Thymocyte differentiation occurs within the thymic microenvironment. Previous experiments showed that laminin mediates interactions between thymocytes and thymic epithelial cells (TEC) in mice. Here, the authors show constitutive gene expression of various laminin chains in TEC preparations, comprising laminin-111 and laminin-211 isoforms. Immunocytochemistry revealed a selective laminin-211 distribution in the thymic lobules. In vitro, functional assays revealed that laminin-211 enhances TEC/thymocyte adhesion and thymocyte release from thymic nurse cells, as well as the reconstitution of these complexes. Conversely, these interactions are blocked by monoclonal antibodies specific for laminin-211 and the laminin receptor VLA-6. The results show that distinct laminin isoforms in the human thymus are relevant for lymphoepithelial interactions.

Laminin chains in the basement membranes of human thymus

Virtanen I., Lohi J., Tani T., Sariola H., Burgeson R.E., Lehto V-P Histochemical Journal, 1996

The laminin a2 chain has been suggested to be the only laminin a chain expressed in mouse and human thymus. Here, the authors use monoclonal antibodies to study the expression of laminin chains in samples of fetal and 6-year-old human thymus. The subepithelial basement membrane of the capsule of fetal 16- to 18-week thymus presented a bright immunoreactivity for laminin a1, a3, B1, B3 and g1 chains but not for a2 chain, suggesting the expression of laminin-111 and -332. Most cortical and medullary epithelial cells, including Hassall's corpuscles, however, lacked laminin immunoreactivity. In thymic specimens from 6-year-old children, immunoreactivity for the laminin a1, a3, B1, B3 and g1 chains were invariably found in the subepithelial basement membrane of the capsule and that for laminin a2 chain was now also distinct but more heterogeneous. The present results show that the thymic subepithelial basement membrane of the capsule presents properties that are commonly seen in stratified and combined epithelia, and are compatible with suggestions of the antigenic similarity of thymic epithelial cells and keratinocytes.

Laminin α1 Chain Synthesis in the Mouse Developing Lung: Requirement for Epithelial–Mesenchymal Contact and Possible Role in Bronchial Smooth muscle Development

Schuger L., Skubitz A.P.N., Zhang J., Sorokin L., He L. The Journal of Cell Biology, 1997

The present study shows that whereas a1 and a2 laminins are synthesized in the mouse developing lung and in epithelial-mesenchymal co-cultures derived from it, epithelial and mesenchymal monocultures lose their ability to synthesize the laminin α1 chain. Synthesis of laminin α1 chain, however, returns upon re-establishment of epithelial-mesenchymal contact. Cell-cell contact is critical since laminin α1 chain is not detected in monocultures exposed to coculture-conditioned medium or in epithelial-mesenchymal cocultures in which heterotypic cell-cell contact is prevented by an interposing filter. Immunohistochemical studies on cocultures treated with brefeldin A, an inhibitor of protein secretion, indicated both epithelial and mesenchymal cells synthesize laminin α1 chain upon heterotypic cell-cell contact. Lung explants exposed to monoclonal antibodies to laminin α1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle a actin and desmin. Taken together, the data suggest that laminin α1 chain synthesis is regulated by epithelial-mesenchymal interaction and may play a role in airway smooth muscle development.

Laminin-332 sustains chemoresistance and quiescence as part of the human hepatic cancer stem cell niche

Govaere O. et al. Journal of hepatology, 2015

This study demonstrates that tumor behavior is plastic and depends on the microenvironment of the tumor cell. The authors identified an important role for laminin-332 - more specifically its gamma2-chain - as part of the specialized cancer stem cell niche in maintaining and supporting stemness, e.g. quiescence and chemo-resistance. Laminin-332 not only protects hepatic cancer cells against chemotherapy but even stimulates cell proliferation upon sorafenib exposure. Therefore, monoclonal antibody treatment targeting the gamma2-chain of laminin-332 could provide an innovative therapy for hepatic cancer.