Publications
Here is a selection of publications where different laminin isoforms were used to create more authentic cell culture systems.
Vascular laminins in physiology and pathology
Di Russo J., Hannocks M-J., Luik A-L., Song J., Zhang X., Yousif L., Aspite G., Hallmann R., Sorokin L. Matrix biology, 2016
Review on vascular laminins. In the healthy vessel, basement membranes (BMs) are the main ECM structures found in the vessel wall, underlying endothelium and surrounding vascular smooth muscle cells. Laminin α4 and α5 chains are the major α chains occurring in endothelial BMs and in vascular smooth muscle BMs. In most cases, laminins α4 and α5 combine with laminin β1 and γ1 chains to form laminins-411 and -511 in endothelial BMs; however, there is also evidence for the expression of laminin β2 in several tissues suggesting the additional existence of laminins-421 and -521 in endothelial BMs. While laminin α2 does not occur in endothelial BMs it can occur in association with perivascular cells including smooth muscle BMs of large arteries, such as the aorta, but not of smaller arterioles. There is no laminin α1 in endothelial or smooth muscle BMs regardless of tissue or species.
Laminin isoforms in endothelial and perivascular basement membranes
Yuosif L., Russo J.D., Sorokin L.Cell Adh Migr., 2013
α4 and α5 chain laminins are the predominant isoforms in the basal lamina of vascular endothelial cells. While the α4 chain is expressed ubiquitously throughout different developmental stages, the prominent expression of α5 chain appears postnatally and its distribution varies with vessel type.
Differentiation of Human Embryonic Stem Cells to Endothelial Progenitor Cells on Laminins in Defined and Xeno-free Systems
Nguyen M.T.X., Okina E., Chai X., Tan K.H., Hovatta O., Ghosh S., Tryggvason K. Stem Cell Reports, 2016
Here, the authors developed a chemically defined, xeno-free protocol for differentiation of hESCs to endothelial progenitor cells (EPCs) using LN521 as the main culture substrate. The EPCs derived are functional and expressed both progenitor and mature endothelial markers. The authors were able to generate about 95% functional EPCs defined as VEGFR2+CD34+CD31+VE-Cadherin+. RNA-sequencing analyses of hESCs, EPCs, and primary human umbilical vein endothelial cells show differentiation-related EC expression signatures, regarding basement membrane composition, cell-matrix interactions, and changes in endothelial lineage markers. Six-week continuous culturing allows the hESC derived EPSs to mature further, relative to HUVECs. These results may facilitate the production of stable ECs for the treatment of vascular diseases and in vitro cell modeling.
Switch in Laminin β2 to Laminin β1 Isoforms During Aging Controls Endothelial Cell Functions
Wagner J.U.G., Chavakis E., Rogg E.M, Muhly-Reinholz M., Glaser S.F., Günther S., John D., Bonini F, Zeiher A.M., Schaefer L., Hannocks M-J, Boon R.A., Dimmeler S.Arterioscler Thromb Vasc Biol, 2018
Here, the authors aim to decipher the role of the microenvironment underlying the impairment of endothelial cell functions by aging. RNA sequencing of isolated cardiac endothelial cells derived from young and 18-month-old mouse hearts revealed that aging affects the endothelial expression of genes encoding extracellular matrix proteins, specifically the laminin β1 (Lamb1) and laminin β2 (Lamb2) chains. Whereas Lamb1 was upregulated, Lamb2 was decreased in endothelial cells in old mice compared with young controls. A similar change in expression patterns was observed after induction of acute myocardial infarction. Mimicking aging and injury conditions by plating endothelial cells on laminin β1–containing laminin 411 matrix impaired endothelial cell adhesion, migration, and tube formation and augmented endothelial-to-mesenchymal transition and endothelial detachment compared with laminin 421, which contains the laminin β2 chain. Because laminins can signal via integrin receptors, the authors determined the activation of ITGB1 (integrin β1). Laminin 421 coating induced a higher activation of ITGB1 compared with laminin 411. siRNA-mediated silencing of ITGB1 reduced laminin β2–dependent adhesion, suggesting that laminin β2 more efficiently activates ITGB1. Mimicking age-related modulation of laminin β1 versus β2 chain expression changes the functional properties and phenotype of endothelial cells. The dysregulation of the extracellular matrix during vascular aging may contribute to an age-associated impairment of organ function and fibrosis.
Laminin a5 chain is required for intestinal smooth muscle development
Bolcato-Bellemin A-L., Lefebvre O., Arnold C., Sorokin L., Miner J. H., Kedinger M., Simon-Assmann P. Developmental Biology, 2003
Here, the function of the laminin a5 chain in the developing intestine was defined by analyzing laminin a5 -/- mutants and by grafting experiments. The authors show that laminin a5 plays a major role in smooth muscle organization and differentiation, as excessive folding of intestinal loops and delay in the expression of specific markers are observed in laminin a5 -/- mice. Loss of a5 expression was paralleled by ectopic or accelerated deposition of laminin a2 and a4 chains; this may explain why no obvious defects were observed in the villous form and enterocytic differentiation. Lack of the laminin a5 chain was accompanied by a decrease in epithelial a3B1 integrin receptor expression adjacent to the epithelial basement membrane and of Lutheran blood group glycoprotein in the smooth muscle cells, indicating that these receptors are likely mediating the a5 interactions. Taken together, the laminin a5 chain is essential for the normal development of the intestinal smooth muscle.
Laminin α5 influences the architecture of the mouse small intestinal mucosa
Mahoney Z.X., Stappenbeck T.S., Miner J.HJ Cell Sci. 2008
The villus basement membrane is rich in laminin α5. Here the authors show that diminution of laminin α5 in a mouse model led to a compensatory deposition of colonic laminins that resulted in a transformation from a small intestinal to a colonic mucosal architecture. The alteration in mucosal architecture was associated with reduced levels of nuclear p27Kip1, a cell cycle regulator, and altered intestinal epithelial cell proliferation, migration, and differentiation. The results suggest that laminin α5 plays a crucial role in establishing and maintaining the specific mucosal pattern of the mouse small intestine.
Laminins in the Developing and Adult Human Small Intestine: Relation With the Functional Absorptive Unit
Teller I.C., Auclair J., Herring E., Gauthier R., Ménard D., Beaulieu J-F.Developmental dynamics, 2007
Here, the expression of the five laminin a-chains was analyzed in the developing and mature human small intestine at the protein and transcript levels in order to further delineate specific involvement of individual laminins in relation to the epithelial cell state as defined along the functional crypt-villus axis. The results show that all of the a-laminins are expressed in significant amounts in the small intestine relative to a panel of other tissues and organs. Distinct epithelial and mesenchymal origins, as well as a differential occurrence in intestinal basement membranes according to developmental stage, along the crypt-villus axis and in compartment-related experimental intestinal cell models. Taken together, the data point out the prime importance of a2-, a3-, and a5-containing laminins for the development and maintenance of the functional human intestinal epithelium.
Functional diversity of laminins
Domogatskaya A., Rodin S., Tryggvason K. Annu Rev Cell Dev Biol, 2012
In this review, the authors elucidate the evolution of laminins, describe their molecular complexity, and explore the current knowledge of their diversity and functional aspects, including laminin-mediated signaling via membrane receptors, in vitro cell biology, and involvement in various tissues gained from animal model and human disease studies. The potential use of laminins in cell biology research and biotechnology is discussed.
Integrin-linked kinase regulates the niche of quiescent epidermal stem cells
Morgner J., Ghatak S., Jakobi T., Dieterich C., Aumailley M., Wickström S.A.Nat Commun., 2015
In the present study the authors conclude that the precise ratio between LN-332 and LN-511 adjusts activities of key signalling pathways that determine SC activation within the hair follicle bulge niche. They suggest that integrin-linked kinase (ILK) is required for the maintenance of quiescent bulge SCs through remodelling of the ECM niche, thereby governing the activation and maintenance of hair follicle stem cells (HFSCs). ILK mediates deposition of inverse laminin-332 and -511 gradients within the basement membrane (BM) wrapping the hair follicles. The precise ratio of LN-511 and LN-332 regulates core SC fate-determining signalling pathways and that this ratio is disturbed in the absence of ILK, leading to aberrant SC activation and failure to re-establish quiescence. The BM composition tunes activities of Wnt and transforming growth factor-β pathways and subsequently regulates HFSC activation. LN-511, present at low levels around the bulge and at higher levels around the hair germ/TACs, promotes Tgf-β signalling, whereas LN-332, highly expressed along the IFE and to a lesser extent along the upper regions of HFs, suppresses Wnt/β-catenin signalling. Notably, reconstituting an optimal laminin microenvironment restores the altered signalling in ILK-deficient cells.
FOXC1 maintains the hair follicle stem cell niche and governs stem cell quiescence to preserve long-term tissue-regenerating potential
Lay K., Kumeb T., Fuchsa E.PNAS, 2016
Here, the authors suggest that hair follicle stem cells (HFSCs) have restricted potential in vivo, which they conserve by coupling quiescence to adhesion-mediated niche maintenance, thereby achieving long-term tissue homeostasis. They examine whether parsimonious stem cells use is essential to conserve long-term tissue-regenerating potential during normal homeostasis by conditionally ablating a key transcription factor Forkhead box C1 (FOXC1). FOXC1-deficient HFSCs spend less time in quiescence, leading to markedly shortened resting periods between hair cycles. The enhanced hair cycling accelerates HFSC expenditure, and impacts hair regeneration in aging mice. Interestingly, although FOXC1-deficient HFs can still form a new bulge that houses HFSCs for the next hair cycle, the older bulge is left unanchored. Hair follicle stem cells lacking the protein FOXC1 can only retain one old bulge in their hair follicles, while normal stem cells can keep up to four. In vitro cell adhesion assay they show that FACS-purified WT and Foxc1-KO HFSCs attach very well to LN-511 with about 6 times higher well area coverage compared to collagen I, fibronectin or Matrigel-coated plates.