Publications
Here is a selection of publications where different laminin isoforms were used to create more authentic cell culture systems.
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.
Release of Matrix Metalloproteinase-8 During Physiological Trafficking and Induced Mobilization of Human Hematopoietic Stem Cells
Steinl C., Essl M., Schreiber T.D., Geiger K., Prokop L., Stevanovic´ S., Pötz O., Abele H., Wessels J.T, Aicher W.K., Klein G.Stem Cells Dev., 2013
In the present study, we provide evidence that the collagenase MMP-8 is involved in stem cell mobilization. Cell–matrix adhesion assays were performed with LM-511 where MACS-isolated CD34+ cells were allowed to attach to immobilized LM-511. A rapid release of MMP-8 from isolated neutrophil granulocytes can be observed during an in vitro culture. Activated MMP-8 degrades LM-511 but without influencing the HSC progenitor–matrix adhesion. This since MMP-8 strongly digests the LM-a5 chain but leaves the LG1–3 domains intact.
Superior Red Blood Cell Generation from Human Pluripotent Stem Cells Through a Novel Microcarrier-Based Embryoid Body Platform
Sivalingam J., Lam A.T., Chen H.Y., Yang B.X., Chen A.K., Reuveny S., Loh Y.H, Oh S.K. Tissue Eng Part C Methods, 2016
Conventional methods for hematopoietic differentiation of human pluripotent stem cells (hPSC) rely on embryoid body (EB) formation and/or co-culture with xenogeneic cell lines. In this study, the authors describe the development of a scalable, serum-free, xeno-free, and chemically defined microcarrier-based platform using human recombinant laminin-521 as an extracellular matrix (ECM) for hPSC expansion, EB formation, and subsequently hematopoietic differentiation of hPSC to red blood cells (RBS). Improved survival and better quality EBs generated with the microcarrier-based method resulted in significantly improved mesoderm induction and, when combined with hematopoietic differentiation, resulted in at least a 6-fold improvement in hematopoietic precursor expansion, potentially culminating in an 80-fold improvement in the yield of RBS generation compared to a conventional EB-based differentiation method. In addition, they show efficient terminal maturation and generation of mature enucleated RBCs using a co-culture system that comprised primary human mesenchymal stromal cells.
Characterization and functional analysis of laminin isoforms in human bone marrow
Siler U., Seiffert M., Puch S., Richards A., Torok-Storb B., Müller C.A, Sorokin L., Klein G.Blood, 2000
Based on gene expression, laminin-411/421 and laminin-511/521 are the most abundant laminin isoforms synthesized by human bone marrow stromal cells. Laminin-511/521 preparations showed strong adhesive interactions with human CD34+ cell lines. Antibodies against the B1 integrin subunit inhibited these interactions. In addition to its adhesion-mediating properties, laminin-511/521 preparations also showed a mitogenic activity for human hematopoietic progenitor cells. Other laminin isoforms tested, especially laminin-111 and laminin-211 and 221, showed only weak or no adhesive interactions with the hematopoietic cell lines tested and are suggested to play a minor role in the hematopoietic microenvironment. In the bone marrow, LN‐511 and 521 are the major laminins and show strongly adhesive and mitogenic activities toward early developing HSCs.
Laminin isoform-specific promotion of adhesion and migration of human bone marrow progenitor cells
Gu Y-C., Kortesmaa J., Tryggvason K., Persson J., Ekblom P., Jacobsen S-E., Ekblom M.HEMATOPOIESIS, 2003
Here they studied human bone marrow cell adhesion to laminin-511/521, laminin-411, laminin-111, and fibronectin. About 35% to 40% of CD34+ and CD34+CD38- stem and progenitor cells adhered to laminin-511/521, and 45% to 50% adhered to fibronectin, whereas they adhered less to laminin-411 and laminin-111. Adhesion of CD34+CD38- cells to laminin-511/521 was maximal without integrin activation, whereas adhesion to other proteins was dependent on protein kinase C activation. Integrin a6 chain expressed on most CD34+ and CD34+CD38-cells. Laminin-511/521 was highly adhesive to lineage-committed myelomonocytic and erythroid progenitor cells and most lymphoid and myeloid cell lines studied, whereas fibronectin and laminin-411 were less adhesive. Laminin-511/521was a ubiquitous adhesive protein for differentiated precursors of both B-lymphocytic, erythroid, megakaryocytic, and myelomonocytic cell lineages, whereas adhesion to laminin-411 and laminin-111 was restricted to a few cell lines. CD34+ cell migration was greatly enhanced through membranes coated with Laminin-511/521 and laminin-411. Our findings raise the possibility that a4 and a5 laminins are involved in mobilization and homing of hematopoietic progenitor cells.