Publications
Here is a selection of publications where different laminin isoforms were used to create more authentic cell culture systems.
Laminin-411 Is a Vascular Ligand for MCAM and Facilitates TH17 Cell Entry into the CNS
Flanagan K., Fitzgerald K., Baker J., Regnstrom K., Gardai S., Bard F., Mocci S., Seto P., You M., Larochelle C., Prat A., Chow S., Li L., Vandevert C., Zago W., Lorenzana C., Nishioka C., Hoffman J., Botelho R., Willits C., Tanaka K., Johnston J., Yednock T.PLOS ONE, 2012
TH17 cells enter tissues to facilitate pathogenic autoimmune responses. Herein, they characterize MCAM (CD146) as an adhesion molecule that defines human TH17 cells. Parental CHO cells, lacking MCAM expression or CHO cells stably transfected with mouse MCAM were incubated in the presence of laminin-411 or laminin-511. They identify the MCAM ligand as laminin 411, an isoform of laminin expressed within the vascular endothelial basement membranes. hMCAM binds to a ligand in the ECM with identical staining to laminin a4. Moreover, mMCAM colocalizes with laminin 411 on the choroid plexus, and shows no specific binding to tissues from LAMA4 -/- mice. Their data suggest that MCAM and laminin-411 interact to facilitate TH17 cell entry into tissues and promote inflammation. The specific location of laminin 411 in the endothelial basement membrane may either function to augment adhesion of cells attempting CNS endothelial penetration or serve as an adhesion based gating system to signal appropriate entry mechanisms. As such, modulation of the interaction between MCAM and laminin 411 represents a novel and selective approach that may help to maintain or restore homeostasis to inflamed tissues in autoimmune diseases.
Adult SVZ Stem Cells Lie in a Vascular Niche: A Quantitative Analysis of Niche Cell-Cell Interactions
Shen Q., Wang Y., Kokovay E., Lin G., Chuang S-M. Goderie S.K., Roysam B., Temple S. Cell Stem Cell, 2008
Here, they examine the relationship of adult SVZ NSC lineage cells to blood vessels using confocal imaging of SVZ whole mounts in which the normal 3D relationships of cells are preserved. Neural stem cells (NSCs) in the adult subventricular zone (SVZ) lie close to blood vessels in a vascular-derived laminin-rich niche. Cells expressing stem cell markers, including GFAP, and proliferation markers are closely apposed to the laminin-containing extracellular matrix (ECM) surrounding vascular endothelial cells. Adult SVZ progenitor cells express the laminin receptor a6B1 integrin, and blocking this inhibits their adhesion to endothelial cells, altering their position and proliferation in vivo.
Characterization of a stereotypical cellular and extracellular adult liver progenitor cell niche in rodents and diseased human liver
Lorenzini S., Bird T.G., Boulter L., Bellamy C., Samuel K., Aucott R., Clayton E., Andreone P., Bernardi M., Golding M., Alison M.R., Iredale J.P., Forbes S.J.Gut, 2010
In this article, the composition and formation of stem progenitor cell niches were examined. The progenitor cell response in liver injury is intimately surrounded by myofibroblasts and macrophages, and to a lesser extent by endothelial cells. Hepatic progenitor cells are not of bone marrow origin; however, bone marrow-derived cells associate intimately with these cells and are macrophages. Laminin always surrounds the progenitor cells. In vitro studies showed that laminin aids the maintenance of progenitor and biliary cell phenotype and promotes their gene expression (Dlk1, Aquaporin 1, gammaGT) while inhibiting hepatocyte differentiation and gene expression (CEPB/alpha). During liver damage in rodents and humans, a stereotypical cellular and laminin niche forms around hepatic progenitor cells. Laminin helps the maintenance of undifferentiated progenitor cells. The niche links the intrahepatic progenitor cells with bone marrow-derived cells and links tissue damage with progenitor cell-mediated tissue repair.
The Vascular Basement Membrane: A Niche for Insulin Gene Expression and B Cell Proliferation
Nikolova G., Jabs N., Konstantinova I., Domogatskaya A., Tryggvason K., Sorokin L., Fässler R., Gu G., Gerber H-P., Ferrara N., Melton D.A., Lammert E.Developmental Cell, 2006
Mouse pancreatic islets intimately interact with endothelial cells and differentiation and delamination of insulin-producing b cells from pancreatic epithelium strictly require endothelial cells. Doug Melton and colleagues show that BMs within islets are formed and found exclusively around capillaries but not islet cells. Islet endothelial cells express laminin a4 and a5. Laminins promote insulin gene expression and proliferation in B-cells and B1-integrin is required for this laminin response. Laminin-411 and -511 worked well but also laminin-111 which shows that the applied laminin does not necessarily have to be endothelial cell-derived. Research on islet transplantation has shown that it takes about 1–2 weeks for transplanted islets to become revascularized in the host and the authors suggest that treating islets with these laminins prior to transplantation will help maintain insulin production until new capillaries are formed in transplanted islets.
Unique basement membrane structure of human pancreatic islets: implications for b-cell growth and differentiation
Otonkoski T., Banerjee M., Korsgren O., Thornell L.-E., Virtanen I.Diabetes, Obesity and Metabolism, 2008
The authors showed that in the human islets, a double BM structure surrounding each blood vessel within the islet. In addition, a continuous peri-islet BM was surrounding the entire islet, invaginating into the islet tissue together with the arterioles. The capillaries are surrounded by a double BM both in fetal and adult tissues. The B-cells are facing a BM that is separate from the endothelia, unlike the situation in mouse where the B-cells interact directly with BMs of capillary endothelial cells. Here they show that (i) a1 is not expressed in the adult human pancreas; (ii) a2 is only expressed in the exocrine pancreas; (iii) a4 is expressed in the blood vessel BMs; (iv) a5 and b1 are expressed similarly, both in the endocrine and endothelial BMs in the islets. Taken together, this suggested that there is a double-layered BM organization around the vascular channels of human islets: the inner vascular leaflet of the duplex contains Lms-411/421 and -511/521 whereas the outer leaflet facing the parenchymal endocrine cells contains only Lm-511. In contrast to the adult pancreas, a laminin a1 chain could be found in the acinar BMs of the fetal pancreas and faintly also in the developing islets. Similarly, as in the adult pancreas, immunoreactivity for laminin a5 chain was distinctly surrounding the developing islets and also in BMs of intra-islet vessels. Strong expression of laminin B1 and g1 in the fetal pancreas. a3 and b1 integrin subunits were found both on the vascular channels and the endocrine cells. However, the integrin a6 subunit was clearly absent from the endocrine cells and only expressed in the endothelial cells. The islet cells facing this BM have a strong and polarized expression of Lutheran glycoprotein, which is a well-known receptor for the laminin a5 chain. Dispersed human islet cells adhere to purified human laminin-511 and the binding is equally effectively blocked by a soluble form of Lutheran as by antibody against integrin B1. The results reveal that the BM structure of human islets, different from rodents.
N-Terminomics identifies HtrA1 cleavage of thrombospondin-1 with generation of a proangiogenic fragment in the polarized retinal pigment epithelial cell model of age-related macular degeneration
Chen C-Y., Melo E., Jakob P., Friedlein A., Elsässer B., Goettig P., Kueppers V., Delobel F., Stucki C., Dunkley T., Fauser S., Schilling O., Iacone R. Matrix Biology, 2018
Here, the authors investigate the impact of elevated HtrA1 levels on the retinal pigment epithelial (RPE) secretome using a polarized culture system. The authors suggest a mechanism by which increased levels of HtrA1 may contribute to AMD pathogenesis. Human primary Retinal Pigmented Epithelium (RPE) cells (Sciencell, 6540) were seeded in transwells coated with Laminin 521. A model that recapitulates the structural, molecular and apical/basolateral signatures of adult RPE cells was achieved. The upregulation of HtrA1 alters the abundance of key proteins involved in angiogenesis and extracellular matrix remodeling. Thrombospondin-1, an angiogenesis modulator, was identified as a substrate for HtrA1 using terminal amine isotope labeling of substrates in conjunction with HtrA1 specificity profiling. HtrA1 cleavage of thrombospondin-1 was further corroborated by in vitro cleavage assays and targeted proteomics together with small-molecule inhibition of HtrA1. While thrombospondin-1 is anti-angiogenic, the proteolytically released N-terminal fragment promotes the formation of a tube-like structure by endothelial cells.
Contribution of α6 integrins to hematopoietic stem and progenitor cell homing to bone marrow and collaboration with α4 integrins
Qian H., Tryggvason K., Jacobsen S.E., Ekblom M.Blood, 2006
The integrin a6 chain is ubiquitously expressed in human and mouse hematopoietic stem and progenitor cells. The integrin a6 chain is ubiquitously expressed in human HPCs. Laminin-411 and -511, are present in subendothelial basement membranes of sinusoids in bone marrow, at sites of hematopoietic cell development and trafficking and might, therefore, regulate HSC functions. In this paper, they show that mouse HSC and progenitors express a6B1 integrin which mediates high cell adhesion to laminin-511 and 521 and to laminin-411 to a lower extent. Blocking of a6 significantly reduced progenitor cell homing to bone marrow in mice. Integrin a4 receptors are also important for homing of HSCs to bone marrow (but not to the spleen). The first data showing that a6 integrins (LN521/511 binding) function in vivo as hematopoietic stem and progenitor cell homing receptors. Also, show the role of integrin a4 receptor for homing of long-term multilineage reconstituting HSCs and collaboration of these 2 integrins in homing of short-term HSCs.
Laminin-511 is an epithelial message promoting dermal papilla development and function during early hair morphogenesis
Jing Gao, Mindy C. DeRouen, Chih-Hsin Chen, Michael Nguyen, Ngon T. Nguyen, Hiroyuki Ido, Kenji Harada, Kiyotoshi Sekiguchi, Bruce A. Morgan, Jeffery H. Miner, Anthony E. Oro, and M. Peter Marinkovich. Genes Dev, 2008
Abnormal adhesion of grafted corneal endothelial cells (CECs) affects the application of intracameral injection for corneal endothelial dysfunction therapy. The authors explored whether laminin 511 (LN511) improves the therapeutic function of the intracameral CEC injection. Injected LN511 was found to be able to settle and form a coating on the posterior surface of Descemet's membrane (DM). The data suggests that the strategy of LN511 precoating and CECs' intracameral injection could be a potential method for the therapy of corneal endothelial dysfunction.