8 Migration induced by physical and chemical stimuli - Phylogeny Magnetic filedsElectric filedsMoistureLightTemperatureHydrotaxisMagnetotaxisElectrotaxisPhototaxisPhysicalstimuliThermotaxisPhysicalcontactChemotaxisChemicalsThigmotaxisBarotaxisRheotaxisMechanotaxisGeotaxiscímPressureFluid flowStiffnessGraviry
9 Chemotaxis – Significance in biology !Chemotaxis – Significance in biologyHelps to distinguish / to approach food moleculesHelps to avoid biologically harmful/toxic substancesSperm to approach oocyte - fertilizationTissue transformation processes (e.g. CNS)Immune reactions of multicellular organismsProliferation and growing of tumors, formationof metastasis
10 Main steps and objective of migration in tissues ?
11 ! Significant components to elicit cell migration A sejtvándorlás lépései és céljaReceptor – intracell signSubstanceinfluencingcell migrationCytoskeletonReceptors(intracellular signaling)
12 An important factor - Size of the cell !An important factor - Size of the cellBacteria (small to detect concentration):continuous scanning the environmentEukaryotes:Migration directed by concentration gradientsBig D conc.Small D conc.
16 Adhesion Chemotaxis Phagocytosis Chemotaxis is a cell physiological reaction and part of a three member process.Cell adhesion is (regularly) required for migration.Phagocytosis is the most essential target reaction of migratory cells.AdhesionChemotaxisPhagocytosis
17 Migratory cell typesMartin Bergert, Max Planck Institute of Molecular Cell Biology and Genetics
18 Cells with 3D migration – Fluid phase bacteriaCells migrating in the 3D space with no limiting factor.spermiumciliated eukaryotes
19 Cells with 2D migration – Solid surface monocyte / macrophageamoebaCells require solid or semi-solid surface for migration.fibroblastendothel
20 Migration in Extracellular matrix (ECM) e.g. tumor cellse.g. lymphocyteThe most fundamental way of migration in ECM.Polarized cell; on frontal edge enzyme releasee.g. macrophageGroups of cells kept together by cell adhesion molecules – migrating together.Amoboid? sorrendBLOOD, 1 NOVEMBER VOLUME 110, NUMBER 9
21 Micromotion activity of cells A constant rotation is detectableeven in confluent layers of cell cultures.Quality of ECM can influence ofcharacteristics of micromotion.Mi a zöld ?Ectracellular matrixLang, O., Kohidai, L., Wegener, J. Electrical noise analysis as a tool for screening the metastatic potential of tumor cells. In prep.
22 Cilia and flagellum – Structure and function propeller likemovementbeatingback-and-forthin motionpassive part9 x microtubulibasal bodyFlagellumCiliatubulin(13 or 11 protofilaments)CsillóATP-independent bindingnexinATP hydrolysisdynein armsArm moves toward the negative pole
23 Healthy body with migratory cells (immune system); Motile bacteria invading body.Tumor attacked by immune system;Metastasis formation.
28 Microtubule Polymerization of tubulins GTP dependentfast
29 Models of structural instability TreadmillingmodelDynamicinstabilityEssentialdefinicióTreadmilling model considers the changing balance between the polymerization and depolymerization of the cytoskeletal component.The dynamic instability model considers the polymerization or depolymerization of the same pole of the cytoskeletal component.
31 Cyclosis Immobile cytoplasm Circulating, cortical cytoplasm Surface membraneActin filamentsCell wallMotor proteinesChloroplastsForrás: Lodish, H. et al. Mol. Cell Biol. 2000Essential form of cellular movement.In diatomes cyclosis of the cortical cytoplasm helps the movement of the cells.- Sliding between motor proteins anchored to organels and cortical actin.
35 Length of actin – regulatory proteins GelsolinSeveringCap39CapZVillinTropomodulin-+CofilinSeverinGelsolincímCytoplasmic regulatory proteins of actin influence length of the molecule:Capping proteins can block growing or breakdownother truncating proteins reduce acting length of actin in the cortex
38 Force generation by actin F-ActinFilaminProfilin- G-actinArp2/3Cell membraneMyosin I.Integrin(Svitkina, TM és mts. J. Cell Biol munkája felhasználásávalPIP2Proteinrich inProbranching actincímF-actin generates force via different membrane conponents as Myosin I, PIP2 and integrins.Connecting molecules: Arp2/3, profilin and filamin.
46 Main groups of chemoattractant ligands !Main groups of chemoattractant ligandsions of inorganic salts (K+, Cl-)amino acids (methionine, serine)biogenic aminesoligopeptides (bacterial tripeptides – e.g. fMLF)hormones (insulin)chemokines (e.g. interleukin 8)pheromonessynthetic substances (drugs)
47 and their chemotactic effects Sequence of appearence of amino acids in the primordial soupand their chemotactic effectsChemotactic responsiveness proved to be decisive in early levels of cell phylogeny.
48 Models of chemotactic signaling: Yeast Induction of chemotaxis receptors results more responses via activation different intracellular pathways.
49 Models of chemotactic signaling : Dictyostelium Crosstalk between ligands inducingdifferent signaling pathways can result also chemotactic responses.
50 Chemotaxis +cAMP Changing number of actin filaments - induced by cAMP treatmentin DictyosteliumChemotaxisTwo-peak response.Reorganization of actin network.+cAMP
51 Formyl-Met-Leu-Phe (fMLF) Chemotactic effects of the bacterial tripeptide (fMLF) is elicited via surface membrane receptors (FPR) composed by 7 transmembrane domains. Special parts of the receptor are responsible for binding of the peptide (red, brown), other parts (15AA loop) is responsible for the signal transfer into the cell.
52 Intracellular signaling network of Formyl-Met-Leu-Phe (fMLF) Signaling via FPR is achieved by activation of different signaling pathways.
53 Complement system - C5a receptor Receptor of complement C5a is also a 7TM structure. Its extracellular loops (red) are binding C5a, while the intracellular 18AA and 16AA loops have a role in signal transfer.
54 Complement system - C5aComplement 5a (C5a) is the most chemoattractant member of the complement system.Its chemoattractant moiety is elicited by the C-terminal pentapeptide (red) while other parts are responsible for the optimal conformation.
55 ? CHIPS = chemotaxis inhibitory protein of Staphylococci CHIPS = C5a receptorCHIPSNeutrofil gr.c.C5aBacteriumCHIPSFormyl peptidreceptorfMLFReceptors of C5a, fMLF are inhibitedNeutrofil grc. responses are blockedBacteria survive in human bodyForrás: Foster TJ. Nature Reviews Microbiology 2005
56 CHIPS are multipotent inhibitors. The same CHIPS can block fMLF and C5a receptorsCHIPS-NH2CHIPS-NH2Formyl-peptidreceptorC5areceptor-COOH-COOHForrás: Foster TJ. Nature Reviews Microbiology 2005
57 Classification of chemokines !Classification of chemokinesC chemokinesCC chemokinesCXC chemokinesCX3C chemokinesPeptide chaindisulfide-boundmucin-likedomainhydrophobeGroup of molecules responsible for migration in several motile cells of the body ( neutrophil grc., monocyte, lymphocyte).Class CX3C is responsible for haptotactic responses as it has hydrophobe domain which can fix the molecule to the surface membranes.
59 ! Chemokine receptors G-protein phosphorylation chemokine NH2- HOOC-GAGG-proteinCellular and Molecular Immunology 1999phosphorylationInteraction between chemokine and its receptor: it is shown that only some parts of the chemokine participate in the interaction and that chemokine develops contact with other membrane components (e.g. GAG)Phosphorylation of the intracellular C-terminal part and induction of G-proteins are significant parts of intracellular signaling.
60 Ligandspecificity – Overlapping effect of chemokines The same chemokine acts on different receptorsPossibility of regulatory networks and fine tuning of responses
61 Diversity of cellular responses induced by chemokines WortmanninU73122ChemotaxisAdh. mol. expr.ProliferationCytokine releaseIL-2 receptor expr.Anti HIV infection effectFormation uropodiumFUNCTIONAL RESPONSES- Induction of a chemokine receptorresults diverse functional responses- Responses are chemotaxis related, while others have more general significance
63 Cytoskeleton has a significant role in mechanotaxis cell, its cytoskeleton and surrounding materials perform significant systemchanging condition of environment has significant effect on migratory behaviour of cellsmechanotransductionmaterial - cytoskeletoncytoskeleton - responsematerial - responsebiochemical, topographicaland mechanical signalscell instructive materialscellular response
64 Larger resistive force Smaller resistive force !Preferences of migratory cellLeading EdgeHigher density of adhesion proteinsRetrograde flow of F-actinCell RearLower density of adhesion proteinsAnterograde flow of F-actinHard substrateLarger resistive forceper adhesion moleculeSoft substrateSmaller resistive force
65 Preferences of migratory cell – Tissues of the human body Cells belonging to different tissues express diverse mechanical preferences.
67 Fertilization: Chemotaxis as guiding factor !Fertilization: Chemotaxis as guiding factorMale and female origin factors are present in the proximity of oocyte.The cascade like process results also a positive selection of spermiums.
68 Membrane level regulation of flagellar beating of sperm Receptor-ligand interaction induced cascaderesults hyper- and depolarization and consecutiveasymmetry of flagellum .
69 Chemotaxis as significant factor - Inflammation calor rubor tumor dolor + functio laesaCelsus(Kr.e. 3０～Kr. u ３８)Virchow( )
70 Dual regulation of interaction between vascular endothel and neutrofil grc.Connection between vascular endothel and neutrophil grc. is regulated on two mechanisms by tumor necrosis factor (TNF):Influences release of complement 5a (C5a) in neutrophil grc.Induces expression of new receptors on endothel by interleukin-1 (IL-1) synthesis in endothel.TNF = tumor necrosis factorC5a = complement 5aIL-1 = interleukin 1
71 Inflammation - Transmigration !Inflammation - TransmigrationInteracting cells change expressed molecules (adhesion molecules – e.g. selectins, integrins and their receptors) on the surface step-by-step
72 Significance of chemokines in development of diseases In the background of several serious diseases we can find inflammatory processes regulated by chemokines.Every group of diseases is characterized by specific chemokine-target cell activation process.
73 Infections: Chemotaxis and cholera Development of some infections (e.g. cholera) depends on the chemotactic ability (or the lack of it) of the microbe.
74 Trapped macrophages - Atherosclerosis monocytein blood‘rolling’firmadhesionMIGRATIONendothelcellstunicaintimamediamacrophagedifferentiationscavengerreceptorsA pathological signal induced macrophage migration is in the background of atherosclerosis. The macrophages crossing the endothel are trapped and as a result their phathological metabolic processes turn to foam cells. The mass of foam cells forms the well known plaques.Nature Medicine 8, (2002)
75 Tumor cellsTumor cells express diverse adhesion and migratory responses in the primary and in the metastatic tumor.
76 Tumor cells – Migration of metastatic cells 1 In metastatic process the ratio of adhesion and migratory character of the tumor cell determines the release of the cell as well as its homing to the new tissue.
77 Tumor cells – Migration of metastatic cells 2 !Tumor cells – Migration of metastatic cells 2Matching of the chemokine receptors of the metastatic tumor cell and chemokine environment of the target tissue is a targeting factor in development of tumor metastasis.
78 Treatment with targeting of migratory cells Dentures of maxilla/mandibula with scaffold filled chemoattractantsubstance (PDGF)Increased migration and proliferation of osteoblasts, fibroblasts and cementoblastspromotes the ossification
79 Cellular movement and mechano-transduction: Cell movement, its significance in biology and in medicine.Main types of cell movement: taxis and kinesis (chemotaxis, haptotaxis and necrotaxis).Main groups of substances with cell motility inducer ability (formyl peptides chemokines) and their receptors.Structure and function of cilia and flagellum. Basal body.Molecular mechanism of ciliary movement (sliding of microtubules). Amoeboid movement.Differences in tissue elasticity.Characteristics of the mechanical property of the migrating cell, preferences of cells.(ECB: 569 – 604 OR )