Molecular mechanisms of tumor invasion in three-dimensional collagen matrices

During metastasis, cells can use proteolytic activity to form tube-like “microtracks” within the extracellular matrix (ECM). Using these microtracks, cells can migrate unimpeded through the stroma. To investigate the molecular mechanisms of microtrack migration, we developed an in vitro three-dimensional (3D) micromolded collagen platform. When in microtracks, cells tend to migrate unidirectionally. Because focal adhesions are the primary mechanism by which cells interact with the ECM, we examined the roles of several focal adhesion molecules in driving unidirectional motion. Vinculin knockdown results in the repeated reversal of migration direction compared with control cells. Tracking the position of the Golgi centroid relative to the position of the nucleus centroid reveals that vinculin knockdown disrupts cell polarity in microtracks. Vinculin also directs migration on two-dimensional (2D) substrates and in 3D uniform collagen matrices, as indicated by reduced speed, shorter net displacement, and decreased directionality in vinculin-deficient cells. In addition, vinculin is necessary for focal adhesion kinase (FAK) activation in three dimensions, as vinculin knockdown results in reduced FAK activation in both 3D uniform collagen matrices and microtracks but not on 2D substrates, and, accordingly, FAK inhibition halts cell migration in 3D microtracks. Together these data indicate that vinculin plays a key role in polarization during migration.

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Structural Studies of Fibrinolysis by Electron and Light Microscopy

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615843 ◽

1999 ◽

Vol 82 (08) ◽

pp. 277-282 ◽

Cited By ~ 37

Author(s):

Yuri Veklich ◽

Jean-Philippe Collet ◽

Charles Francis ◽

John W. Weisel

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Plasminogen Activator ◽

Structural Changes ◽

Molecular Mechanisms ◽

Degradation Products ◽

Molecular Model ◽

Three Dimensional ◽

Tissue Type ◽

Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

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Dendritic Fibroblasts in Three-dimensional Collagen Matrices

Molecular Biology of the Cell ◽

10.1091/mbc.e02-08-0493 ◽

2003 ◽

Vol 14 (2) ◽

pp. 384-395 ◽

Cited By ~ 139

Author(s):

Frederick Grinnell ◽

Chin-Han Ho ◽

Elisa Tamariz ◽

David J. Lee ◽

Gabriella Skuta

Keyword(s):

Dimensional Space ◽

Human Fibroblasts ◽

Three Dimensional ◽

Rho Kinase ◽

Matrix Remodeling ◽

Dependent Manner ◽

Collagen Matrices ◽

Form And Function ◽

Metabolic Coupling ◽

Dendritic Network

Cell motility determines form and function of multicellular organisms. Most studies on fibroblast motility have been carried out using cells on the surfaces of culture dishes. In situ, however, the environment for fibroblasts is the three-dimensional extracellular matrix. In the current research, we studied the morphology and motility of human fibroblasts embedded in floating collagen matrices at a cell density below that required for global matrix remodeling (i.e., contraction). Under these conditions, cells were observed to project and retract a dendritic network of extensions. These extensions contained microtubule cores with actin concentrated at the tips resembling growth cones. Platelet-derived growth factor promoted formation of the network; lysophosphatidic acid stimulated its retraction in a Rho and Rho kinase-dependent manner. The dendritic network also supported metabolic coupling between cells. We suggest that the dendritic network provides a mechanism by which fibroblasts explore and become interconnected to each other in three-dimensional space.

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Angiogenesis: molecular mechanisms and functional interactions

Thrombosis and Haemostasis ◽

10.1055/s-0037-1613559 ◽

2003 ◽

Vol 89 (01) ◽

pp. 190-197 ◽

Cited By ~ 6

Author(s):

Georg Breier ◽

Hellmut Augustin

Keyword(s):

Growth Factors ◽

Research Program ◽

Tumor Invasion ◽

Molecular Mechanisms ◽

Precursor Cells ◽

Invasion And Metastasis ◽

Angiogenic Growth Factors ◽

Cell Contacts ◽

Functional Interactions ◽

Biannual Meeting

SummaryThe German Priority Research Program “Angiogenesis” (www.angiogenese.de) hosts a biannual meeting in the Kloster Seeon in Southern Germany. The 2nd Kloster Seeon Meeting “Angiogenesis: Molecular Mechanisms and Functional Interactions” was held in September 2002. It included sessions on hypoxia, the biology of endothelial precursor cells, angiogenic growth factors including VEGFs, the angiopoietins, ephrins, and FGFs, mechanisms of vascular sprouting and cell-cell contacts during angiogenesis, angiogenic signaling, lymphangiogenesis, angiogenesis during tumor invasion and metastasis, and on novel angiomanipulatory therapies. This report summarizes the key findings reported during the platform presentations of the meeting.

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Molecular Mechanisms Controlling Vascular Lumen Formation in Three-Dimensional Extracellular Matrices

Cells Tissues Organs ◽

10.1159/000331410 ◽

2012 ◽

Vol 195 (1-2) ◽

pp. 122-143 ◽

Cited By ~ 57

Author(s):

Anastasia Sacharidou ◽

Amber N. Stratman ◽

George E. Davis

Keyword(s):

Molecular Mechanisms ◽

Three Dimensional ◽

Extracellular Matrices ◽

Lumen Formation ◽

Vascular Lumen

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The differential regulation of cell motile activity through matrix stiffness and porosity in three dimensional collagen matrices

Biomaterials ◽

10.1016/j.biomaterials.2010.04.064 ◽

2010 ◽

Vol 31 (25) ◽

pp. 6425-6435 ◽

Cited By ~ 144

Author(s):

Miguel Miron-Mendoza ◽

Joachim Seemann ◽

Frederick Grinnell

Keyword(s):

Three Dimensional ◽

Differential Regulation ◽

Matrix Stiffness ◽

Collagen Matrices ◽

Motile Activity

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Apolar and polar transitions drive the conversion between amoeboid and mesenchymal shapes in melanoma cells

Molecular Biology of the Cell ◽

10.1091/mbc.e15-06-0382 ◽

2015 ◽

Vol 26 (22) ◽

pp. 4163-4170 ◽

Cited By ~ 17

Author(s):

Sam Cooper ◽

Amine Sadok ◽

Vicky Bousgouni ◽

Chris Bakal

Keyword(s):

Quantitative Imaging ◽

Three Dimensional ◽

Shape Space ◽

Melanoma Cells ◽

Collagen Matrices ◽

Morphological Heterogeneity ◽

Rho Family Gtpases ◽

Metastatic Process ◽

Rho Family ◽

Single Living

Melanoma cells can adopt two functionally distinct forms, amoeboid and mesenchymal, which facilitates their ability to invade and colonize diverse environments during the metastatic process. Using quantitative imaging of single living tumor cells invading three-dimensional collagen matrices, in tandem with unsupervised computational analysis, we found that melanoma cells can switch between amoeboid and mesenchymal forms via two different routes in shape space—an apolar and polar route. We show that whereas particular Rho-family GTPases are required for the morphogenesis of amoeboid and mesenchymal forms, others are required for transitions via the apolar or polar route and not amoeboid or mesenchymal morphogenesis per se. Altering the transition rates between particular routes by depleting Rho-family GTPases can change the morphological heterogeneity of cell populations. The apolar and polar routes may have evolved in order to facilitate conversion between amoeboid and mesenchymal forms, as cells are either searching for, or attracted to, particular migratory cues, respectively.

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Characterization of an A-type cyclin-dependent kinase gene from Dendrobium candidum

Biologia ◽

10.2478/s11756-012-0016-y ◽

2012 ◽

Vol 67 (2) ◽

Cited By ~ 1

Author(s):

Gang Zhang ◽

Chao Song ◽

Ming-Ming Zhao ◽

Biao Li ◽

Shun-Xing Guo

Keyword(s):

Molecular Mechanisms ◽

Three Dimensional ◽

Postembryonic Development ◽

Kinase Domain ◽

Dimensional Structure ◽

Pcr Analysis ◽

Kinase Gene ◽

Multiple Sequence ◽

Dendrobium Candidum ◽

Rapid Amplification

AbstractCyclin-dependent kinases (CDKs) play an essential role in cell cycle regulation during the embryonic and postembryonic development of organisms. To better understand the molecular mechanisms of CDKs involved in embryogenesis regulation in the endangered medicinal plant Dendrobium candidum Wall. ex Lindl., a 1229-bp full-length cDNA of an A-type CDK gene, Denca;CDKA;1, was identified using 3′ rapid amplification of cDNA end (RACE) PCR. Denca;CDKA;1 was predicted to encode a 294 amino acid residue-long protein of 33.76 kDa with an isoelectric point of 7.72. The deduced Denca;CDKA;1 protein contained a conserved serine/threonine-protein kinase domain (S-TKc) and a canonical cyclinbinding “PSTAIRE” motif. Multiple sequence alignment indicated that members of CDKA family from various plants exhibited a high degree of sequence identity ranging from 82% to 93%. A neighbor-joining phylogenetic tree showed that Denca;CDKA;1 was clustered into the plant group and was distant from the animal and fungal groups. The modeled three-dimensional structure of Denca;CDKA;1 exhibited the similar functional structure of a fold consisting of β-sheets and α-helices joined by discontinuous random coils forming two relatively independent lobes. Quantitative real-time PCR analysis revealed that Denca;CDKA;1 transcripts were the most abundant in protocorm-like bodies with 4.76 fold, followed by that in roots (4.19 fold), seeds (2.57 fold), and stems (1.57 fold). This study characterized the novel Denca;CDKA;1 gene from D. candidum for the first time and the results will be useful for further functional determination of the gene.

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Human platelet lysate improves human cord blood derived ECFC survival and vasculogenesis in three dimensional (3D) collagen matrices

Microvascular Research ◽

10.1016/j.mvr.2015.06.006 ◽

2015 ◽

Vol 101 ◽

pp. 72-81 ◽

Cited By ~ 24

Author(s):

Hyojin Kim ◽

Nutan Prasain ◽

Sasidhar Vemula ◽

Michael J. Ferkowicz ◽

Momoko Yoshimoto ◽

...

Keyword(s):

Cord Blood ◽

Human Platelet ◽

Three Dimensional ◽

Platelet Lysate ◽

Human Cord Blood ◽

Collagen Matrices ◽

Human Platelet Lysate ◽

3D Collagen

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Role of the HSP70 Co-Chaperone SIL1 in Health and Disease

International Journal of Molecular Sciences ◽

10.3390/ijms22041564 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1564

Author(s):

Viraj P. Ichhaporia ◽

Linda M. Hendershot

Keyword(s):

Molecular Mechanisms ◽

Three Dimensional ◽

Dependent Manner ◽

Nucleotide Exchange ◽

Multisystem Disorder ◽

Nucleotide Exchange Factors ◽

Precise Understanding ◽

Health And Disease ◽

Client Proteins ◽

Er Homeostasis

Cell surface and secreted proteins provide essential functions for multicellular life. They enter the endoplasmic reticulum (ER) lumen co-translationally, where they mature and fold into their complex three-dimensional structures. The ER is populated with a host of molecular chaperones, associated co-factors, and enzymes that assist and stabilize folded states. Together, they ensure that nascent proteins mature properly or, if this process fails, target them for degradation. BiP, the ER HSP70 chaperone, interacts with unfolded client proteins in a nucleotide-dependent manner, which is tightly regulated by eight DnaJ-type proteins and two nucleotide exchange factors (NEFs), SIL1 and GRP170. Loss of SIL1′s function is the leading cause of Marinesco-Sjögren syndrome (MSS), an autosomal recessive, multisystem disorder. The development of animal models has provided insights into SIL1′s functions and MSS-associated pathologies. This review provides an in-depth update on the current understanding of the molecular mechanisms underlying SIL1′s NEF activity and its role in maintaining ER homeostasis and normal physiology. A precise understanding of the underlying molecular mechanisms associated with the loss of SIL1 may allow for the development of new pharmacological approaches to treat MSS.

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