Long-range intercellular communication in collective cell migration

Abstract: From embryonic development, through synchronized beating of myocardiocytes to collective cell death - individual cells use basic cellular machinery to influence and respond to neighboring cells through a complex interplay of chemical and physical cues. How these local interactions are integrated in space and time to induce collective patterns is yet unknown. By designing and applying new analytical methods to migrating monolayers of epithelial cells, we discovered how local mechanical fluctuations induce long-range inter-cellular communication and identified potential molecular pathways driving this mechanism. We concluded that for effective collective migration contractility-mediating pathways must be optimally tuned to compromise between generation of motility forces and restriction of inter-cellular communication.

Papers:
http://jcb.rupress.org/content/early/2017/05/15/jcb.201609095
www.cell.com/biophysj/abstract/S0006-3495(15)01123-6

Source code: https://github.com/DanuserLab/MonolayerKymographs

Transcript

1. Assaf Zaritsky Long-range intercellular communication in collective cell migration @AssafZaritsky
2. Emergence of collective cell behavior from single cell action and cell-cell communication Collective cell death Planar cell polarity Overholtzer lab Nitsan et al. (2016) Synchronized cardiac cells Barlan et al. (2017) Sun et al. (2012) Collective calcium signaling
3. Collective cell migration Cai et al. (2014) Border cells migration, Drosophila Oogenesis Bettina Weigelin, Peter Friedl Collective tumor migration on “highways” in vivo
4. Cells migrate more efficiently in groups than individually Malet-Engra et al. (2015)
5. Tumor cell clusters as precursors of metastasis Cheung et al. (2016) Aceto et al. (2014)
6. mechanisms of long range communication between cells WANTED! ? ?
7. A simple model system to study intercellular long-range communication
8. The onset of monolayer migration
9. Two questions • How intercellular long-range communication is induced by local mechanical fluctuations? • What are the molecular players driving long- range communication?
10. Trepat et al. (2009) How (global) coordination emerges from (local) heterogeneous traction forces? Traction Tx (Pa ) Phase Contrast
11. Suggested model Time Stochastic force exertion transform to directional migration Strain on neighbors coordinate their movement Propagation in time and space to guide groups of cells
12. Measuring traction force, stress and velocity Phase contrast Traction Tx Average normal stress Trepat et al. (2009) Tambe et al. (2011) Serra-Picamal et al. (2012)
13. Region-growing segmentation for explicit detection of coordinated migration clusters Method from: Zaritsky et al. (2014)
14. Associating coordinated stress and motion Method from: Zaritsky et al. (2014)
15. Strain-induced motion coordinates cluster’s motility Red: motion clusters, Blue: stress, Magenta: both
16. Strain-induced motion coordinates cluster’s motility Red: motion clusters, Blue: stress Fraction of coordinated cells
17. Stress aligns motion Tight junction proteins play a role in effective transmission of aligned stress to aligned motion
18. Coordination migration emerges from cell-cell junctional transmission of mechanical guidance cues Time
19. mechanisms of long range communication between cells WANTED! ? ?
20. Time 1 2 3 Position Protruding cells kymograph
21. Protruding cells kymograph Time 1 2 3 Position
22. Protruding cells kymograph Time 1 2 3 Position
23. Protruding cells kymograph Time 1 2 3 Position
24. Lateral shear-strain waves x-axis
25. Interpretation of diagonal patterns Time 1 2 Position
26. Lateral shear-strain waves
27. Rear cells guided to location of shear- strain events at the front
28. Long range guidance of by leader cells Propagation
29. Two questions • How intercellular long-range communication is induced by local mechanical fluctuations? • What are the molecular players driving long- range communication?
30. Rho-GTPases and their activators
31. Down-regulation of Cdc42 and Rac1 but not RhoA disrupts monolayer migration
32. Spatiotemporal quantification Front cells Rear cells
33. Visualizing front-to-back propagation Front cells Rear cells m/hr Location (m)
34. Depleted RhoA enhances long-range communication
35. Control shRHOA Depleted RhoA enhances long-range communication
36. Comprehensive GEFs screen
37. Comprehensive GEFs screen • > 3,000 videos to analyze • Robust algorithmic pipeline • Variability, controls • Measures for screening
38. Encoding spatiotemporal dynamics
39. Information encoded in a wound healing experiment All controls (normalized)
40. Association with monolayer migration rate What do PC1, PC2, PC3 mean biologically?
41. Reverse engineering: what information is encoded in an experiment?
42. Measures
43. Greatest hits RhoA GEFs inhibit long-range communication
44. What about Myosin? Kevin Dean, @kD3AN
45. Downstream effectors of RhoA
46. Actomyosin contractility disturbs intercellular communication downstream of the ARHGEF18 - RHOA pathway
47. Differential functional roles of RhoA-GEFs down-stream of RhoA signaling Contractility inhibition
48. RhoC has an intermediate phenotype
49. Diverse roles of GEFs in regulating collective cell migration
50. RhoA-GEFs/RhoA/Myosin-II balances motile forces vs. mechanical guidance generation of motile forces transmission of guidance cues
51. RhoA-GEFs/RhoA/Myosin-II balances motile forces vs. mechanical guidance generation of motile forces transmission of guidance cues
52. Summary Coordination migration emerges from cell- cell junctional transmission of mechanical guidance cues RhoA-GEFs/RhoA/Myosin-II, balances generation of robust motile forces vs. transmission of mechanical guidance cues
53. Acknowledgments Alan Hall Gaudenz Danuser Mike Overholtzer Ángeles Rabadán Yun-Yu Tseng Shefali Krishna
54. References, resources References: – Zaritsky et al. Seeds of locally aligned motion and stress coordinate a collective cell migration (2015) http://jcb.rupress.org/content/early/2017/05/15/jcb.201609095 – Zaritsky, Tseng et al. Diverse roles of guanine nucleotide exchange factors in regulating collective cell migration (2017) www.cell.com/biophysj/abstract/S0006-3495(15)01123-6 Source code: – https://github.com/DanuserLab/MonolayerKymographs