Publications
Here is a selection of publications where different laminin isoforms were used to create more authentic cell culture systems.
Ablation of astrocytic laminin impairs vascular smooth muscle cell function and leads to hemorrhagic stroke
Chen Z-L., Yao Y., Norris E.H., Kruyer A., Jno-Charles O., Akhmerov A., Strickland S. J Cell Biol. 2013
Astrocytes express laminin-111 and 211 and assemble basement membranes (BMs) at their endfeet. Here the authors show that ablation of astrocytic laminin disrupted endfeet BMs and led to hemorrhage in deep brain regions of adult mice. The lack of astrocytic laminin led to impaired function of vascular smooth muscle cells, fragmentation and vascular wall disassembly where astrocytes have a closer association with VSMCs in small arterioles. Acute disruption of astrocytic laminin in the striatum of adult mice also impaired vascular smooth muscle cells function, indicating that laminin is necessary for vascular smooth muscle cell maintenance. In vitro, both astrocytes and astrocytic laminin promoted brain vascular smooth muscle cell differentiation.
Laminin 211 inhibits protein kinase A in Schwann cells to modulate neuregulin 1 type III-driven myelination.
Ghidinelli M., Poitelon Y., Shin YK., Ameroso D., Williamson C., Ferri C., Pellegatta M., Espino K., Mogha A., Monk K., Podini P., Taveggia C., Nave K.A., Wrabetz L., Park H.T., Feltri M.L.PLoS Biology, 2017
Ghidinelli and colleagues, through their in vivo and in vitro studies have clearly shown that Laminin 211, apart from promotion, can also inhibit myelination by modulating neuregulin 1 type III activity via PKA signaling and thereby prevent inappropriate and excessive myelin wrapping of small nerve fibers.
YAP and TAZ control peripheral myelination and the expression of laminin receptors in Schwann cells
Poitelon Y., Lopez-Anido C., Catignas K., Berti C., Palmisano M., Williamson C., Ameroso D., Abiko K., Hwang Y., Gregorieff A., Wrana JL., Asmani M., Zhao R., Sim FJ., Wrabetz L., Svaren J., Feltri ML. Nature Neuroscience, 2016
A mechanistic article just published by Poitelon and colleagues in Nat Neurosci, adding further evidence for the importance of laminin-211 for radial sorting and proper axon myelination by Schwann cells. The authors show that laminin-211 in combination with mechanical stimuli activate and modulate Yap and Taz, which are downstream effectors in the Hippo pathway, required for radial sorting fo axons and subsequent myelination.
Chronic stress induced disturbances in Laminin: a significant contributor to modulating microglial pro-inflammatory tone?
Pietrogrande G., Mabotuwana N., Zhao Z., Mahmoud A., Johnson S.J., Nilsson M., Walker F.R.Brain, Behavior, and Immunity, 2017.
In this study, Pietrogrande and colleagues have addressed the potential role of the extracellular matrix protein Laminin as a crucial factor to drive microglia into an inflamed state. Chronic restraint stress of C57BL6 adult mice over six weeks resulted in elevated levels of Laminin-α1 and pro-inflammatory markers such as TNF-α and iNOS, quantified by qPCR and western blot. Immunolabeling of Laminin-α1 identified pyramidal neurons and dentate gyrus to be their primary source within the hippocampus. Furthermore, Iba-1 staining of microglia revealed that chronic stress also strongly reduced the total branch length (15%), number of primary branches (47%) and number of branching points (68%) when compared to microglia of control mice. In vitro, primary microglia and BV2 cells grown on Laminin-111 expressed higher levels of TNF-α, IL-1β, and iNOS. In addition, LPS activation of microglia coated on Laminin-111 led to an increased pro-inflammatory state represented by higher pro-inflammatory cytokines level and phagocytic capability, both before and after stimulation. Interestingly, similar to observations made in vivo, microglia cultured on Laminin- 111 had fewer ramifications compared to control. These results, thus, expose the capability of chronic restraint stress in modulating Laminin within the CNS, an effect that has implications for understanding environmental mediated disturbances of microglial function.
Human diseases reveal novel roles for neural lamininsCortical deficiency of laminin γ1 impairs the AKT/GSK-3β signaling pathway and leads to defects in neurite outgrowth and neuronal migration
Chen Z.L., Haegeli V., Yu H., Strickland S.Developmental Biology, 2009
In this study, Chen and colleagues demonstrate the importance of laminin γ1 in the cerebral cortex and its absence leading to defects in neuritogenesis and neuronal migration. Mice lacking laminin γ1 gene expression suffered from disrupted cortical layers and impaired axonal pathfinding. Such loss during development has been shown to greatly affect the FAK and paxillin mediated integrin signaling mechanisms. Furthermore, mutant mice also display reduced phosphorylation of GSK-3β and AKT proteins. These data clearly show the participation of both integrin signaling and AKT/GSK-3β pathway in the regulation of neurite growth and neuronal migration by laminins.
Laminin/β1 integrin signal triggers axon formation by promoting microtubule assembly and stabilization
Lei W.L., Xing S.G., Deng C.Y., Ju X.C., Jiang X.Y., Luo Z.G.Cell Research 2012
In this study, the authors present several lines of evidence implicating the indispensable role of laminin in promoting neural polarization through integrin b1 (Itgb1) mediated microtubule assembly and stabilization. Laminin coated substrates (either in stripes or gradient) could initiate directional axon growth in undifferentiated neurites of both cultured hippocampal neurons and cortical slices in an Itgb1 dependent manner. Impairing endogenous laminin function either by treatment with exogenous laminins or by abolishing Itgb1 signaling using siRNA, resulted in defective axonal formation. Conditional knock out mice with abrogated Itgb1 expression in dorsal telencephalic progenitors displayed defective expression/activity of neuronal polarity related proteins, SAD and LKB1 kinases in addition to abnormal axonal development of cortical pyramidal neurons. These results not only identify laminin/ integrin b1 signaling as a crucial step in axon initiation and development but also link extracellular matrix adhesion to cytoskeleton remodeling that occurs during neuronal polarization.
β2 and γ3 laminins are critical cortical basement membrane components ablation of Lamb2 and Lamc3 genes disrupt cortical lamination and produces dysplasia
Radner S., Banos C., Bachay G., Li Y.N., Hunter D.D., Brunken W.J., Yee K.T.Developmental Neurobiology 2012
Here, the authors demonstrate the significance of laminin b2 and g3 expression in maintaining a functional cortical pial basement membrane to which Cajal Retzius and radial glial cells attach and in turn guide neural development. Several isoforms of laminins, those containing b2 and g3 in particular, have been isolated from the brain underlining their importance in CNS functions. In the present study, the authors employ a reverse genetic approach where mice with a homozygous deletion of b2 and g3 genes displayed cortical laminar disorganization. In addition, the ablation of both these laminin chains resulted in the incidence of human cobblestone lissencephaly. Interestingly, heterozygous mice also exhibited disruption of cortical neurons with lesser severity. In fact, similar to b2 distribution, g3 was also observed to be localized in the developing cortex. Mutation in the binding site of the laminin g1 gene results in abnormal cortex lamination.
Axon guidance of rat cortical neurons by microcontact printed gradients
Fricke R., Zentis P.D., Rajappa L.T., Hofmann B., Banzet M., Offenhäusser A., Meffert S.H.Biomaterials, 2011
Substrate-bound gradients play a crucial role in the axon guidance mechanism eventually leading to the development of complex neural circuits. In this study, the authors have grown single embryonic rat cortical neurons on a discontinuous substrate-bound gradient primarily comprising of laminin/poly-L-lysine (PLL) or PLL alone and examined the corresponding effects on neurite growth and axon guidance. Though different patterns of the substrate-bound gradient in terms of slope, width, and length had varying outcomes, they allowed neural adhesion, controlled neurite growth and guided up to 84% of the axons. The presence of laminin clearly had additional effects on both neurite growth and axon directionality when compared to PLL alone. The authors have thus mimicked the in vivo protein gradient conditions involved in creating defined neural networks during CNS development and successfully established an optimal model that could be used to guide axons of single multipolar neurons in vitro.
Modulation of Synapsin I Gene Expression in Rat Cortical Neurons by Extracellular Matrix
Savettieri G., Mazzola G.A., Rodriguez Sanchez M.B., Caruso G., Di Liegro I., Cestelli A.Cellular and Molecular Neurobiology, 1998
Here the authors have attempted to dissect the complex interaction between the genetic program and environmental cues involved in neuronal differentiation. In this study, neurons isolated from fetal rat brain (embryonic day 16) cortices were cultured on six different extracellular components, such as laminin-111, collagen, and poly-D-lysine in a chemically defined, neuron-specific medium. Among the ECM components tested, laminin allowed both firm attachment and extensive neurite outgrowth from neuronal cell bodies. Furthermore, laminin strongly increased gene expression the synapse-specific protein, Synapsin I, a well-known central marker for neuronal differentiation. These results highlight the significance of extracellular matrix components, particularly laminins, for the extension of neurite networks and neuronal differentiation of primary cortical neurons.
Neurons From Human Pluripotent Stem Cells Under Xeno-Free Conditions Restore Motor Deficits in Parkinsonian Rodents
Niclis J.C., Gantner C.W., Alsanie W.F., McDougall S.J., Bye C.R., Elefanty A.G., Stanley E.G., Haynes J.M., Pouton C.W., Thompson L.H., Parish C.L.Stem cells translational medicine, 2016
In this study, the authors describe the first fully defined feeder- and xenogeneic-free protocol for the generation of vmDA neurons from hPSCs. The protocol is translational across multiple embryonic and induced hPSC lines. hPSCs were cultured xeno-free on laminin-521 in TeSR2. For vmDA differentiation, two xeno-free matrix proteins, vitronectin, and human laminin-521 were compared for their ability to replace Matrigel. Both matrices facilitated appropriate patterning, however, only laminin-521 supported the long-term attachment of neural precursors. This “next-generation” protocol consistently increases both the yield and proportion of vmDAneural progenitors (OTX2/FOXA2/LMX1A) and neurons (FOXA2/TH/PITX3) that display classical vmDA metabolic and electrophysiological properties. The mechanism underlying these improvements are identified and demonstrate clinical applicability with the first report of scalability and cryopreservation of bona fide vmDA progenitors at a time amenable to transplantation. Finally, transplantation of xeno-free vmDA progenitors from LMX1A- and PITX3-eGFP reporter lines into Parkinsonian rodents demonstrate improved engraftment outcomes and restoration of motor deficits.