title: The Rho family GEF Asef2 regulates cell migration in three dimensional (3D) collagen matrices through myosin II.
abstract: Cell migration is fundamental to a variety of physiological processes, including tissue development, homeostasis, and regeneration. Migration has been extensively studied with cells on 2-dimensional (2D) substrates, but much less is known about cell migration in 3D environments. Tissues and organs are 3D, which is the native environment of cells in vivo, pointing to a need to understand migration and the mechanisms that regulate it in 3D environments. To investigate cell migration in 3D environments, we developed microfluidic devices that afford a controlled, reproducible platform for generating 3D matrices. Using these devices, we show that the Rho family guanine nucleotide exchange factor (GEF) Asef2 inhibits cell migration in 3D type I collagen (collagen I) matrices. Treatment of cells with the myosin II (MyoII) inhibitor blebbistatin abolished the decrease in migration by Asef2. Moreover, Asef2 enhanced MyoII activity as shown by increased phosphorylation of serine 19 (S19). Furthermore, Asef2 increased activation of Rac, which is a Rho family small GTPase, in 3D collagen I matrices. Inhibition of Rac activity by treatment with the Rac-specific inhibitor NSC23766 abrogated the Asef2-promoted increase in S19 MyoII phosphorylation. Thus, our results indicate that Asef2 regulates cell migration in 3D collagen I matrices through a Rac-MyoII-dependent mechanism.
authors.affiliation: a Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development ; Vanderbilt University ; Nashville , TN USA.
authors.forename: Léolène
authors.initials: L
authors.lastname: Jean
authors.forename: Lijie
authors.initials: L
authors.lastname: Yang
authors.forename: Devi
authors.initials: D
authors.lastname: Majumdar
authors.forename: Yandong
authors.initials: Y
authors.lastname: Gao
authors.forename: Mingjian
authors.initials: M
authors.lastname: Shi
authors.forename: Bryson M
authors.initials: BM
authors.lastname: Brewer
authors.forename: Deyu
authors.initials: D
authors.lastname: Li
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Webb
mesh_terms: D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects* / Q000235:genetics; D003094:Collagen / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D024462:Myosin Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D006576:Heterocyclic Compounds, 4 or More Rings; C525704:SPATA13 protein, human; C472645:blebbistatin; D003094:Collagen; D024462:Myosin Type II
keywords: 2D, 2-dimensional; 3D, 3-dimensional; Collagen I, type I collagen; DMEM, Dulbecco's Modified Eagle Medium; ECM, extracellular matrix; GEF, guanine nucleotide exchange factor; MyoII, non-muscle myosin II; PAK, p21-activated kinase; PBD, p21-binding domain; PBS, phosphate buffer saline; PDMS, polydimethylsiloxane; Rac; Rho family GTPases; UV, ultra-violet; guanine nucleotide exchange factor; microfluidics; myosin II; type I collagen