György Váró

Institute of Biophysics, Biological Research CenterSzeged, Hungary

Lamorlaye, May 2011

2

Mannitol treatment of the cerebral endothelial cells

Blood-brain barrier:

Mannitol:

HO - CH2 – (CHOH)4 – CH2 - OH

3

Before treatment After treatment

4

Before treatment

After treatment

5

0.0

0.5

1.0

1.5

2.0

2.5

Cell region

Hei

ght

(µm

)

Control

Mannitol

Over the nucleus Out of nucleus

6

8 kPa

0.9 kPa

0

0.2

0.4

0.6

200 0-200-400-600

forc

e (n

N)

distance (nm)

SM C

A

indentation (nm)

forc

e (n

N)

0

0.2

0.4

0.6

6004002000

MC

B

7

Z. Bálint, I.a. Krizbai, I. Wilhelm, A.E. Farkas, Á. Párducz,Z. Szegletes and G. Váró (2007)

Changes induced by hyperosmotic mannitol in cerebral endothelialcells: an atomic force microscopic study.

Eur. Biophys. J. 36. 113-120

8

Effect of the calcium starvation on the cells:

Healthy endothelial cells-Ca2+

Ca starved cells

9

Ca starved cells

+Ca2+

10

I. Wilhelm, A.E. Farkas, P. Nagyőszi, G. Váró, Z. Bálint, G.A. Végh,P.O. Couraud, I.A. Romero, B. Weksler and I.A. Krizbai (2007)

Regulation of cerebral endothelial cell morphology by extracellular calcium.

Phys. Med. Biol. 52. 6261-6274

11

Petri Dish

8 µm Filter

AFM cantilever

Matrigel

RBEC LayerA2058

Transmigration of the melanoma cells

12

A2058 on RBEC layer

13

3

AFM cantilever tip on hard surface

Petri dish

AFM cantilever tip on hard surface

dwell time

load

AFM cantilever tip on living cells

AFM cantilever tip on living cells

Stress relaxation

AFM tipless cantilever with melanoma cell on living cells

AFM tipless cantilever with melanoma cell on living cells

AFM tipless cantilever with melanoma cell on living cells

AFM tipless cantilever with melanoma cell on fixed cells

Adhesion force: Melanoma cell on

hard surface

Melanoma cell onliving cell layer

Melanoma cell onfixed cell layer

Stress relaxationforce

Melanoma cell on hard surface

Melanoma cell onliving cell layer

Melanoma cell onfixed cell layer

Adhesion force properties:

Numbers of jumps

Size of the jumps

25

Living cells

Fixed cells

Size of the jumps

Stress relaxationfast exp.

Stress relaxationslow exp.

28