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Hyperthermal sarcomeric oscillations generated in warmed cardiomyocytes control amplitudes with chaotic properties
1Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi, 487-8501, Japan.
Biochemical and Biophysical Research Communications
|April 25, 2022
Summary
Heartbeat-simulating oscillations (HSOs) in sarcomeres exhibit chaotic amplitude fluctuations while maintaining a constant cycle. This dynamic behavior, influenced by calcium concentration, is crucial for sarcomere development and function.
Area of Science:
- Cardiology
- Cell Biology
- Biophysics
Background:
- Previous studies demonstrated that heating cardiomyocytes to 38-42°C induces intracellular sarcomere oscillations (HSOs) mimicking heartbeat rhythms.
- Sarcomeres during HSOs previously showed homeostasis in contraction rhythm, maintaining a constant cycle despite varying amplitudes influenced by calcium levels.
Purpose of the Study:
- To investigate the amplitude dynamics of sarcomeres during heat-induced sarcomere oscillations (HSOs).
- To explore the relationship between sarcomere oscillation amplitude, cycle, synchronization, and calcium concentration.
- To understand the role of these dynamic properties in sarcomere development and function.
Main Methods:
- Primary cultured cardiomyocytes were subjected to controlled warming (38-42°C) to induce HSOs.
- Sarcomere oscillation amplitude, cycle, and synchronization were analyzed.
- The influence of varying calcium concentrations on these parameters was assessed.
Main Results:
- Sarcomeres during HSOs were found to chaotically fluctuate in oscillation amplitude.
- While the oscillation cycle remained constant, sarcomere synchronization states changed flexibly.
- Amplitude fluctuations were responsive to changes in intracellular calcium concentration.
Conclusions:
- The chaotic fluctuation of sarcomere oscillation amplitude, coupled with flexible synchronization and a constant cycle, is a key characteristic of HSOs.
- These dynamic properties, influenced by calcium concentration, are essential for the smooth developmental changes in sarcomere population tension.
- This adaptability is vital for sarcomeres, enabling rapid relaxation post-contraction even with residual calcium.
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