Heterogeneous micromechanical properties of the extracellular matrix in healthy and infarcted hearts.
Infarcted hearts are macroscopically stiffer than healthy organs. Nevertheless, although cell behavior is mediated by the physical features of the cell niche, the intrinsic micromechanical properties of healthy and infarcted heart extracellular matrix (ECM) remain poorly characterized. Using atomic force microscopy, we studied ECM micromechanics of different histological regions of the left ventricle wall of healthy and infarcted mice. Hearts excised from healthy (n=8) and infarcted mice (n=8) were decellularized with sodium dodecyl sulfate and cut into 12 μm thick slices. Healthy ventricular ECM revealed marked mechanical heterogeneity across histological regions of the ventricular wall with the effective Young's modulus ranging from 30.2 ± 2.8 to 74.5 ± 8.7 kPa in collagen- and elastin-rich regions of the myocardium, respectively. Infarcted ECM showed a predominant collagen composition and was 3-fold stiffer than collagen-rich regions of the healthy myocardium. ECM of both healthy and infarcted hearts exhibited a solid-like viscoelastic behavior that conforms to two power-law rheology. Knowledge of intrinsic micromechanical properties of the ECM at the length scale at which cells sense their environment will provide further insight into the cell-scaffold interplay in healthy and infarcted hearts.
CEIT and TECNUN (University of Navarra), 20018 San Sebastián, Spain.
Ion
I
Andreu
Unit of Biophysics and Bioengineering, School of Medicine, University of Barcelona, 08036 Barcelona, Spain; Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain; Ciber Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Spain.
Tomás
T
Luque
CEIT and TECNUN (University of Navarra), 20018 San Sebastián, Spain.
Ana
A
Sancho
Laboratory of Cell Therapy, Division of Oncology, Foundation for Applied Medical Research, University of Navarra, 31080 Pamplona, Spain.
Beatriz
B
Pelacho
Laboratory of Cell Therapy, Division of Oncology, Foundation for Applied Medical Research, University of Navarra, 31080 Pamplona, Spain.
Olalla
O
Iglesias-García
Unit of Biophysics and Bioengineering, School of Medicine, University of Barcelona, 08036 Barcelona, Spain; Ciber Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Spain.
Esther
E
Melo
Unit of Biophysics and Bioengineering, School of Medicine, University of Barcelona, 08036 Barcelona, Spain; Ciber Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Spain; Institut d'Investigacions Biomèdiques August Pi Sunyer, 08036 Barcelona, Spain.
Ramon
R
Farré
Clínica Universitaria de Navarra, 31080 Pamplona, Spain.
Felipe
F
Prósper
CEIT and TECNUN (University of Navarra), 20018 San Sebastián, Spain. Electronic address: relizalde@ceit.es.
M Reyes
MR
Elizalde
Unit of Biophysics and Bioengineering, School of Medicine, University of Barcelona, 08036 Barcelona, Spain; Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain; Ciber Enfermedades Respiratorias (CIBERES), 07110 Bunyola, Spain. Electronic address: dnavajas@ub.edu.
Daniel
D
Navajas
D000818:Animals; D005109:Extracellular Matrix / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018625:Microscopy, Atomic Force; D009203:Myocardial Infarction / Q000503:physiopathology*; D012212:Rheology
Atomic force microscopy; Extracellular matrix; Heart scaffold; Nanoindentation; Viscoelasticity