Department of Mechanical and Aerospace Engineering (MAE)

University of California
 San Diego
  
 9500 Gilman Dr.
    La Jolla, CA 92093-0411




Quantitative Analysis of the Chemotactic Motility of Amoeboid Cells.

Grant #: Pending

Funding Agency: NIH. Lead PI with Professor Richard Firtel (co-PI).

Researchers  
Motility of eukaryotic cells is essential for many physiological processes such as embryonic development and tissue renewal, as well as for the function of the immune system. Incorrect regulation of motility plays an important part in many diseases such as cancer, destructive inflammation, osteoporosis, and mental retardation. Basic research and future therapeutic approaches will benefit from a precise quantitative understanding of the biophysical processes controlling cell motility. Our aim is to establish the precise mechanisms whereby each individual stage of the motility cycle is related to specific biochemical signaling events, and to elucidate the effects that the regulation of these signaling pathways has on cell motility. We base our research on the joint quantitative analysis of the physical properties of the cells, such as traction forces or cytoplasm rheology, and the biochemical pathways that control each step in the motility cycle. We employ analytical techniques that allow us to provide finely-resolved, spatio-temporal maps of these properties that are statistically-representative of a given phenotype. The ultimate goal is to improve the understanding of the biomechanical processes which will lead to better prediction and control of cell motility.



Composite image of a Dictyostelium discoideum cell crawling on a elastic substrate seeded with green fluorescent marker beads at the times t=0s, t= 100s and t= 200s. The solid black contours show the cells' outline at these time points, and the blue curve indicates the trajectory which the cell follows up the chemoattractant gradient. The magnitude of the traction forces (black arrows) and the stresses (color contours) exerted by the cell at each instant was calculated from the displacement of the marker beads using our traction force microscopy method.




Bright field image of a moving Dictyostelium cell that has been injected with 0.5-micron gold microbeads (black dots). The curves show the trajectories of three microbeads tracked during 10 seconds. The cell is moving in the direction pointed by the arrow. The scale bar is 5 microns long. This experiment was performed in collaboration with Alex Groisman and Orit Shefi (Macagno Lab).

Related papers


DEL ALAMO, J. C., MEILI, R., ALONSO-LATORRE, B. RODRIGUEZ-RODRIGUEZ, J., ALISEDA, A., FIRTEL, R. & LASHERAS, J. C., 2007. “Spatio-temporal analysis of eukaryotic cell motility by improved force cytometry”. Proc. Natl. Acad. Sci. PDF .