Myofibrillar architecture in engineered cardiac myocytes
Kevin Kit Parker1, John Tan, Christopher S Chen
1Disease Biophysics Group, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. kkparker@ seas.harvard.edu
Circulation Research
|July 19, 2008
Summary
Cell shape influences muscle cell development. Engineered myocyte shapes guided the organization of contractile myofibrillar arrays, revealing physical constraints as key regulators of cardiac muscle morphogenesis.
Area of Science:
- Cardiovascular Biology
- Cell Biology
- Biophysics
Background:
- Cardiac muscle morphogenesis is traditionally linked to gene expression and signaling molecules.
- The role of physical constraints from the cellular microenvironment in organizing subcellular structures is increasingly recognized.
Purpose of the Study:
- To investigate if myocyte shape acts as a distinct signal influencing myofibrillar array organization in cardiac muscle cells.
- To determine the impact of physical confinement on the self-assembly of subcellular contractile structures.
Main Methods:
- Neonatal rat ventricular myocytes were cultured on microfabricated fibronectin islands to engineer specific cell shapes.
- Cellular spreading and the subsequent assembly of actin networks and myofibrils were analyzed.
- The alignment and registration patterns of sarcomere Z-lines were examined in relation to engineered cell morphology.
Main Results:
- Myocyte shape directly influenced the spatial and temporal progression of myofibrillogenesis.
- The architecture of actin networks assembled within myocytes was predictable based on the engineered island shape.
- Distinct patterns of Z-line alignment were observed, enabling the engineering of orthogonal contraction axes.
Conclusions:
- Cellular microenvironment constraints, specifically cell shape, are significant regulators of myofibrillar organization in cardiac myocytes.
- Physical confinement by the extracellular matrix plays a crucial role in directing the self-assembly of contractile units within muscle cells.
- This study highlights a novel mechanism for controlling cardiac muscle structure and function through physical cues.
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Each myosin...
Each myosin...
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