Reprogramming cardiomyocyte mechanosensing by crosstalk between integrins and hyaluronic acid receptors

Abstract

The elastic modulus of bioengineered materials has a strong influence on the phenotype of many cells including cardiomyocytes. On polyacrylamide (PAA) gels that are laminated with ligands for integrins, cardiac myocytes develop well organized sarcomeres only when cultured on substrates with elastic moduli in the range of 10 kPa to 30 kPa, near those of the healthy tissue. On stiffer substrates (>60 kPa) approximating the damaged heart, myocytes form stress fiber-like filament bundles but lack organized sarcomeres or an elongated shape. On soft (<1 kPa) PAA gels myocytes exhibit disorganized actin networks and sarcomeres. However, when the polyacrylamide matrix is replaced by hyaluronic acid (HA) as the gel network to which integrin ligands are attached, robust development of functional neonatal rat ventricular myocytes occurs on gels with elastic moduli of 200 Pa, a stiffness far below that of the neonatal heart and on which myocytes would be amorphous and dysfunctional when cultured on polyacrylamide-based gels. The HA matrix by itself is not adhesive for myocytes, and the myocyte phenotype depends on the type of integrin ligand that is incorporated within the HA gel, with fibronectin, gelatin, or fibrinogen being more effective than collagen 1. These results show that HA alters the integrin-dependent stiffness response of cells in vitro and suggests that expression of HA within the extracellular matrix (ECM) in vivo might similarly alter the response of cells that bind the ECM through integrins. The integration of HA with integrin-specific ECM signaling proteins provides a rationale for engineering a new class of soft hybrid hydrogels that can be used in therapeutic strategies to reverse the remodeling of the injured myocardium.

Enhanced Schwann Cell Attachment and Alignment Using One-Pot “Dual Click” GRGDS and YIGSR Derivatized Nanofibers

“…58 Endothelial cell alignment to shear stress was approximately 42% using similar measurements. 66 To further confirm the impact of the nanofibers on cell morphology, the aspect ratio of the nuclei of individual cells was determined (Figure 4E). Aligned scaffolds had a significantly increased aspect ratio over random scaffolds.…”

Contractility of single cardiomyocytes differentiated from pluripotent stem cells depends on physiological shape and substrate stiffness

“…In contrast, engineered cells on 6-and 35-kPa substrates had defects in myofibril organization through overtension and myofibril rupture (35 kPa) or undertension and myofibril buckling (6 kPa) (48). Previous studies found that 10-kPa substrates yield useful cultures of immature primary neonatal murine CMs with physiological shape (21,23). Increasing substrate stiffness without controlling cell shape increases the force output of neonatal murine CMs (25) and unpatterned hPSC-CMs (24).…”

Ultrasound-induced modulation of cardiac rhythm in neonatal rat ventricular cardiomyocytes

“…Neonatal ventricular rat cardiomyocytes were harvested from excised hearts of 1-to 3-day-old euthanized Sprague-Dawley rat pups using a cell isolation kit (Cellutron Life Technology, Baltimore, MD, cellutron.com) (7). Briefly, cells were isolated from the cardiac tissue of both ventricles.…”