Durotaxis: The Hard Path from In Vitro to In Vivo

Durotaxis, the process by which cells follow gradients of extracellular mechanical stiffness, has been proposed as a mechanism driving directed migration. Despite lack evidence for its existence in vivo, durotaxis become an active field research, focusing on respond to stimuli from environment. In this review, we describe technical and conceptual advances study vitro, discuss what extent suggests may occur emphasize urgent need vivo demonstration durotaxis. Cell migration, translocate one distinct location another, is fundamental biological that underpins development, physiology, disease (Yamada Sixt, 2019Yamada K.M. Sixt M. Mechanisms 3D cell migration.Nat. Rev. Mol. Biol. 2019; 20: 738-752Crossref PubMed Scopus (54) Google Scholar). The basic mechanisms motility are well understood. Classical migration involves polarization, leading trailing edges defined (Figure 1). Polarized intracellular signaling permits actin polymerization near front 1A). Myosin motors pull rearward create retrograde flow. When flow resisted attachment underlying substrate, such focal adhesions, movement impeded, drives edge forward 1B). At rear cell, adhesions disassembled, retracts thanks myosin-II-dependent contraction 1C). These polarized events often lead asymmetric morphology. processes many migratory cells, stereotypically 2D surfaces (Ridley et al., 2003Ridley A.J. Schwartz M.A. Burridge K. Firtel R.A. Ginsberg M.H. Borisy G. Parsons J.T. Horwitz A.R. migration: integrating signals back.Science. 2003; 302: 1704-1709Crossref (3486) Scholar), transpire simultaneously highly complex inter-regulatory fashion (Case Waterman, 2015Case L.B. Waterman C.M. Integration dynamics adhesion three-dimensional, mechanosensitive molecular clutch.Nat. 2015; 17: 955-963Crossref (125) Scholar; Krause Gautreau, 2014Krause Gautreau A. Steering lamellipodium regulation directional persistence.Nat. 2014; 15: 577-590Crossref (264) However, research using more methods vitro led appreciation flexible: can exhibit wide variety modes Cells migrate collectively, whereby achieved while retaining intercellular (Mayor Etienne-Manneville, 2016Mayor R. Etienne-Manneville S. collective 2016; 97-109Crossref (294) also absence direct substrate. This amoeboid mode uses propulsive forces based cortex friction coordinate (Paluch 2016Paluch E.K. Aspalter I.M. Focal adhesion-independent migration.Annu. Dev. 32: 469-490Crossref (86) Alternatively, lobopodial use their nucleus mechanotransducer propel forward. case, myosin-II-based contractility pulls pressurize provide front-directed protrusions different machinery involved generating lamellipodial Petrie 2014Petrie R.J. Koo H. Yamada Generation compartmentalized pressure nuclear piston governs matrix.Science. 345: 1062-1065Crossref (174) Thus, flexible adaptive, depending situation. principles be driven intrinsically, but persistent regulated extracellularly (Shellard Mayor, 2020Shellard Mayor All roads migration.Trends 2020; 30: 852-868Abstract Full Text PDF (0) first intrinsic best understood means directing movement, chemotaxis. We then examine how environmental stiffness movement: called evaluate data assess current future challenges studying Motile move randomly, allows them explore local environments. with high persistence without turning (Petrie 2009Petrie Doyle A.D. Random versus directionally 2009; 10: 538-549Crossref (599) random or rely polarity, distinguished. polarity arise leads either randomly oriented strongest external come studies, whereas it impossible rule out role because enormously microenvironment. shown whether migrates straight changing directions result small changes GTPase Rac activating WAVE nucleator Arp2/3 complex, causes membrane outgrowth. Protrusions stabilized anchoring substrate via cell-matrix through traction applied movement. Competition between determine cellular direction (Trinkhaus, 1969Trinkhaus J.P. into Organs: Forces Shape Embryo. Prentice-Hall, 1969Google High levels supports promoting multiple peripheral lamellae directions, turning; intermediate support do not competitive (Pankov 2005Pankov Endo Y. Even-Ram Araki Clark Cukierman E. Matsumoto A switch regulates migration.J. 2005; 170: 793-802Crossref (346) activity regulatory motility. Mechanistically, protein Par3 targets TIAM1 front, promotes restriction activation (Pegtel 2007Pegtel D.M. Ellenbroek S.I.J. Mertens A.E.E. van der Kammen de Rooij J. Collard J.G. par-tiam1 controls stabilizing microtubule-dependent front-rear polarity.Curr. 2007; 1623-1634Abstract (138) Caveolin-1, principle component caveolae membranes, at locally GTPases RhoA, Rac1, Cdc42 (Nakayama 2008Nakayama Goto T.M. Sugimoto Nishimura T. Shinagawa Ohno Amano Kaibuchi Rho-kinase phosphorylates PAR-3 disrupts PAR formation.Dev. Cell. 2008; 14: 205-215Abstract (108) polarization these components reinforced mutual inhibition RhoA Hence, coordination regulate cytoskeleton. Although have inherent propensity persistently, common generated sustained signals, chemical, mechanical, electrical Haeger 2015Haeger Wolf Zegers M.M. Friedl P. Collective guidance hierarchies.Trends 25: 556-566Abstract described cues chemotaxis, along soluble chemoattractant. Chemotactic enhance stabilize pathways converge same downstream Typically, chemoattractants bind receptors present surface, like PI3K Akt, ultimately edge, thereby protrusions. chemotactic signal bias retention pre-existing, (Insall, 2010Insall R.H. Understanding eukaryotic chemotaxis: pseudopod-centred view.Nat. 2010; 11: 453-458Crossref (104) Weber, 2006Weber I. Is there pilot pseudopod?.Eur. 2006; 85: 915-924Crossref both cases, chemoattractant Rac, Rho, further polarize activities Chemotaxis very characterized documented types including immune neurons (Weber 2013Weber Hauschild Schwarz Moussion C. Vries Legler D.F. Luther S.A. Bollenbach Interstitial dendritic haptotactic chemokine gradients.Science. 2013; 339: 328-332Crossref (301) Marín 2010Marín O. Valiente Ge X.C. Tsai L.H. Guiding neuronal migrations.Cold Spring Harbor Perspect. 2: a001834Crossref (253) chemotaxis explain all environments those found vivo. potential environment mechanics dictate physical variables environment, confinement, adhesion, topology, rigidity (Janmey 2020Janmey P.A. Fletcher D.A. Reinhart-King C.A. Stiffness sensing cells.Physiol. 100: 695-724Crossref (18) profoundly impact function, (Charras Sahai, 2014Charras Sahai Physical influences 813-824Crossref (323) idea modulates originated cytoskeleton modified sense forces. proposal matrix might serve cue (Choquet 1997Choquet D. Felsenfeld D.P. Sheetz M.P. Extracellular strengthening integrin-cytoskeleton linkages.Cell. 1997; 88: 39-48Abstract Soon after, fibroblasts were discovered soft-to-stiff substrates, was named (Latin durus, hard; Greek taxis, arrangement; Box 1), guided rigidity; moving increasing (Lo 2000Lo Wang H.B. Dembo Y.L. substrate.Biophys. 2000; 79: 144-152Abstract Durotaxis since various other types, smooth muscle (Wong 2003Wong J.Y. Velasco Rajagopalan Pham Q. Directed vascular gradient-compliant hydrogels †.Langmuir. 19: 1908-1913Crossref (Bollmann 2015Bollmann L. Koser D.E. Shahapure Gautier H.O.B. Holzapfel G.A. Scarcelli Gather M.C. Ulbricht Franze Microglia mechanics: alters durotaxis.Front. Neurosci. 9: 363Crossref (37) Choi 2012Choi Y.S. Vincent L.G. Lee Kretchmer K.C. Chirasatitsin Dobke M.K. Engler alignment fusion assembly adipose-derived stem mechanically patterned matrices.Biomaterials. 2012; 33: 6943-6951Crossref (96) cancer (DuChez 2019DuChez B.J. Dimitriadis human cells.Biophys. 116: 670-683Abstract (28) McKenzie 2018McKenzie Hicks S.R. Svec K.V. Naughton Edmunds Z.L. Howe A.K. microenvironment ovarian morphology, spheroid disaggregation.Sci. Rep. 2018; 8: 7228Crossref (41) Lachowski 2017Lachowski Cortes Pink Chronopoulos Karim P Morton Del Río Hernández A.E. Substrate pancreatic stellate cells.Sci. 2017; 7: 2506Crossref (8) others (Evans 2018Evans E.B. Brady S.W. Tripathi Hoffman-Kim Schwann physiologically relevant gradients.Biomater. Res. 22: 14Crossref (5) 2018Lachowski Robinson B. Rice Rombouts A.E.D. FAK YAP, transcriptional regulator required durotaxis.FASEB 1099-1107Crossref (40) Tse Engler, 2011Tse J.R. mimicking tissue variation mesenchymal fate.PLoS One. 2011; 6: e15978Crossref (320) Scholar).Box 1Definitions TermsDurotaxis—Cell soft stiff following gradient. Reverse refers gradient opposite direction: could guide originally mechanotaxis, word instead mainly adopted response fluidic shear stress.Stiffness—The object resists deformation force. term interchangeable rigidity, inversely proportional flexibility, material deflects under given load. Tissue measured Young’s modulus, known elastic modulus. Stiff materials modulus requires loads elastically deform it. deforming surroundings forces.Young’s Modulus—Measures resistance (recoverable) measure material. Elastic varies few hundred pascals brain gigapascals cortical bone determined ECM architecture properties. Durotaxis—Cell stress. Stiffness—The groups: MDCK monolayers, A431 carcinoma spheroids, keratocyte sheets (Martinez 2016Martinez J.S. Schlenoff J.B. Keller T.C.S. epithelial sheet polyelectrolyte multilayers uniform compliance.Exp. 346: 17-29Crossref Sunyer 2016Sunyer Conte V. Escribano Elosegui-Artola Labernadie Valon Navajas García-Aznar J.M. Muñoz J.J. Roca-Cusachs al.Collective emerges long-range force transmission.Science. 353: 1157-1161Crossref (198) Like observations electrotaxis (Zhu 2020aZhu Hum N.R. Reid Sun Loots G.G. Zhao Electric fields breast galvanotaxis.Sci. 8712Crossref Malet-Engra 2015Malet-Engra Yu W.M. Oldani Rey-Barroso Gov N.S. Scita Dupré prowess chemorepulsion.Curr. 242-250Abstract (62) Theveneau 2010Theveneau Marchant Kuriyama Gull Moepps contact-dependent polarity.Dev. 39-53Abstract (345) efficient than individual constituent emergent property groups. data, remained elusive. studies relatively simplistic, primarily due fabricating substrates precise reproducible upon cultured studied (Sunyer Trepat, 2020Sunyer Trepat X. Durotaxis. Curr. R383-R387Abstract Scholar) (Box 2). Partly reason, attempts infer operate during strict experiments. therefore, any experimental approach test should expose gradient; unfortunately, reports claim comparing behaviors exposed analyzing interface motile, persistent, morphologically axis stiffer softer sufficient conclude they will differences, followed integrated across happen only when On basis, some attributes summarized follows.Box 2Fabricating Gradients VitroTo culture stiffnesses approximate native solid produced hydrophilic polymer chains replacing plastic glass petri dishes traditionally used research. Hydrogels made materials; most popular polyacrylamide. ratio crosslinking agent dictates properties hydrogel; crosslinked acrylamide is, becomes (Pelham Wang, 1997Pelham Y.l. locomotion flexibility.Proc. Natl. Acad. Sci. USA. 94: 13661-13665Crossref (2249) Fabricating varying strength range manner precise, reproducible, varied according user’s needs major challenge Scholar).Initial performed “step gradients” drops solutions polymerized adjacent creating sharp transition Only spanning analyzed, method does generate continuous much less steep. method, microfluidic device splits recombines polyacrylamide (Zaari 2004Zaari N. Kim S.K. Wong Photopolymerization generators: microscale control compliance manipulate response.Adv. Mater. 2004; 16: 2133-2137Crossref produces well-defined, discrete inputs, although achievable limited pathological range, large. Also, technique costly, labor intensive, time consuming.The accessible utilize differential diffusion pre-polymerized gel thickness second top (Hadden 2017Hadden W.J. Young J.L. Holle A.W. McFetridge M.L. D.Y. Wijesinghe Taylor-Weiner Wen J.H. Bieback al.Stem mechanotransduction linear hydrogels.Proc. 114: 5647-5652Crossref (164) somewhat small, large limits observation microscopy, reliable. technique, variations introduced microfabricated molds, generates steeper gradients, swell, topological influence (Pieuchot 2018Pieuchot Marteau Guignandon Dos Santos Brigaud Chauvy P.F. Cloatre Ponche Petithory Rougerie al.Curvotaxis directs cell-scale curvature landscapes.Nat. Commun. 3995Crossref (47) difficult attribute results solely durotaxis.The advanced photolithographically patterned, photomask graded transparency (Tse sliding mask Marklein Burdick, 2010Marklein Burdick J.A. Spatially controlled hydrogel modulate interactions.Soft Matter. 136-143Crossref Photoinitiator reactions suboptimal impaired transmission light, light diffraction, lateral radicals, resolution gradients. photopolymerization versatile obtain ranges physiological relevance. To Initial consuming.