Real-time two- and three-dimensional imaging of monocyte motility and navigation on planar surfaces and in collagen matrices: roles of Rho.
We recently found that macrophages from RhoA/RhoB double knockout mice had increased motility of the cell body, but severely impaired retraction of the tail and membrane extensions, whereas RhoA- or RhoB-deficient cells exhibited mild phenotypes. Here we extended this work and investigated the roles of Rho signaling in primary human blood monocytes migrating in chemotactic gradients and in various settings. Monocyte velocity, but not chemotactic navigation, was modestly dependent on Rho-ROCK-myosin II signaling on a 2D substrate or in a loose collagen type I matrix. Viewed by time-lapse epi-fluorescence microscopy, monocytes appeared to flutter rather than crawl, such that the 3D surface topology of individual cells was difficult to predict. Spinning disk confocal microscopy and 3D reconstruction revealed that cells move on planar surfaces and in a loose collagen matrix using prominent, curved planar protrusions, which are rapidly remodeled and reoriented, as well as resorbed. In a dense collagen type I matrix, there is insufficient space for this mode and cells adopt a highly Rho-dependent, lobular mode of motility. Thus, in addition to its role in tail retraction on 2D surfaces, Rho is critical for movement in confined spaces, but is largely redundant for motility and chemotaxis in loose matrices.
Institut für Physiologie II, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Robert
R
Bzymek
Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Markus
M
Horsthemke
Institut für Physiologie II, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Katrin
K
Isfort
Institut für Physiologie II, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Simon
S
Mohr
Molekulare und Vaskuläre Kardiologie, Universitätsklinikum Münster, 48129 Münster, Germany.
Kerstin
K
Tjaden
Hämatologie und Onkologie, Universitätsklinikum Halle, 06120 Halle, Germany.
Carsten
C
Müller-Tidow
Analytical and Environmental Sciences Division, King's College London, United Kingdom.
Marlies
M
Thomann
Institut für Ernährungswissenschaft, Universität Potsdam, 14558 Nuthetal, Germany.
Tanja
T
Schwerdtle
Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Martin
M
Bähler
Institut für Physiologie II, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Albrecht
A
Schwab
Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität, 48149 Münster, Germany.
Peter J
PJ
Hanley
D002465:Cell Movement; D002478:Cells, Cultured; D006801:Humans; D021621:Imaging, Three-Dimensional; D008856:Microscopy, Fluorescence; D009000:Monocytes / Q000502:physiology*; D059008:Time-Lapse Imaging; D020741:rho GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*
D020741:rho GTP-Binding Proteins