What is mechanical stress? The difference between mechanical stress and mechanobiology explained simply by a culture device manufacturer.
- Tokaihit
- 6 days ago
- 6 min read
Updated: 5 days ago
In recent years, "mechanical stress" has gained attention in unraveling life phenomena.
This time, an engineer from a culture device manufacturer will explain everything from the definition of "mechanical stress" working within the body to its usefulness in cell culture. We will also clarify the differences between "mechanobiology" and mechanical stress, which are often confused. We hope you read through to the end.
Table of Contents
What is mechanical stress? 1-1）Definition of Mechanical Stress 1-2）Differences between Mechanical Stress and Mechanobiology
Research on Mechanical Stress 2-1）Purpose of Research on Mechanical Stress 2-2）Research Content on Mechanical Stress
The usefulness of mechanical stress in cell culture 3-1）Advantages of Using Mechanical Stress 3-2）Cells Compatible with Mechanical Stress 1．Vascular Endothelial Cells 2．Fibroblasts 3．Muscle Cells
Responses of Cells to Applied Pressure
Summary
1．What is mechanical stress?
1-1）Definition of Mechanical Stress
Mechanical stress refers to various physical stimuli that cells and tissues experience within the body. It is a term used in the field of cell biology, and in simple terms, it means "forces acting within the body."
In our bodies, forces are constantly at work everywhere. When we exercise, muscles and bones are subjected to loads, and even when we are at rest, the heart is affected by the force of its beating. Blood flow within blood vessels creates pressure, and the skin experiences friction from air and contact with objects.
Thus, cells within the body are subjected to all kinds of forces, and these forces are considered very important factors in studying the internal workings of living organisms.
1-2）Differences between Mechanical Stress and Mechanobiology
A term closely related to mechanical stress is "mechanobiology." While mechanical stress refers to the forces acting within the body, mechanobiology is the study of how these forces affect cells and tissues.
In recent years, research perspectives aiming to elucidate the body's internal mechanics have become increasingly active, and studies in the field of mechanobiology are accelerating. Future applications in medicine and drug development are anticipated, and the establishment of the Japan Society for Mechanobiology indicates that this is a very hot research field.
2．Research on Mechanical Stress
2-1）Purpose of Research on Mechanical Stress
First, the following three aspects are expected in the research of mechanical stress:
Elucidation of Cellular Responses
Understanding Tissue Development and Function
Disease Elucidation and Development of Therapies and Drug Discovery
Elucidation of Cellular Responses
Cells sense mechanical stress from external sources and exhibit various responses such as morphological changes, proliferation, and differentiation. The process from sensing to response is called "mechanotransduction." For example, vascular endothelial cells sense shear stress from blood flow to regulate vascular function, and muscle growth due to exercise is considered to be influenced by mechanical stress on muscle cells.
Understanding Tissue Development and Function
Mechanical stress is believed to be related to tissue development and function. In terms of development, external pressure and tension during fetal growth can influence tissue formation. Regarding function, mechanical stress controls processes such as heart expansion and contraction, and lung ventilation.
Mechanical stress is also crucial for tissue repair and regeneration. One reason for rehabilitation after a fracture is that proper mechanical stimulation is necessary for the correct healing of the fractured bone.
Disease Elucidation and Development of Therapies and Drug Discovery
Mechanical stress can be involved in the onset and progression of diseases. In heart and lung diseases, mechanical loads on blood vessels and tissues can have an impact. Understanding the effects of mechanical stress on diseases may lead to the development of new therapies and drug discovery.
Thus, mechanical stress is expected to yield various research outcomes, particularly in the medical field, and is considered an essential factor in understanding health and disease in living organisms.
2-2）Research Content on Mechanical Stress
Next, I will introduce the types of research being conducted on mechanical stress, including some papers.
Mechanical stress research and regenerative rehabilitation after mesenchymal stem cell treatment in people with knee osteoarthritis
Sources：J-Stage
This paper, published in the Journal of Basic Physical Therapy, Volume 22, Issue 1 (2019), explains the perspectives on the treatment of musculoskeletal disorders, specifically osteoarthritis of the knee, based on research data on exercises that apply mechanical stress.
Mechanical Stress and Transcriptional Regulation
Sources：JBSOC
This is a research presentation published in the "Special Issue: Mechanisms of Response to the Internal Environment from Gene Expression Regulation" by the Japan Society for Biochemistry in 2009.
3．The usefulness of mechanical stress in cell culture
3-1）Advantages of Using Mechanical Stress
One of the major advantages of applying mechanical stress in cell culture is the ability to mimic the in vivo environment.
As explained earlier, cells throughout the body are subjected to various forces, and these forces cause cells to behave in different ways. Therefore, by adding mechanical stress as a physical element during culture, it is possible to create an experimental environment that closely resembles the in vivo conditions.
3-2）Cells Compatible with Mechanical Stress
Different types of cells tend to show different responses to various mechanical stresses, but there are cells that are more notably compatible with mechanical stress.
In this article, I would like to highlight three representative cells among them.
Vascular Endothelial Cells
Fibroblasts
Muscle Cells
1．Vascular Endothelial Cells
Vascular endothelial cells are located on the innermost layer of the blood vessel wall and maintain the health of blood vessels.
Our bodies are designed to keep blood volume and blood pressure constant in response to changes in exercise and health conditions in daily life, and mechanical stress plays a significant role in this mechanism.
Within blood vessels, mechanical stresses such as pressure and shear stress from blood flow occur. Vascular endothelial cells sense these mechanical stresses and release signals related to the expansion and contraction of blood vessels, thereby regulating the environment within the blood vessels to maintain an appropriate state.
2．Fibroblasts
Fibroblasts constitute our skin and are involved in the production of collagen, elastin, and hyaluronic acid, the three major components of the dermis, making them active in anti-aging.
Fibroblasts sense mechanical stress such as physical forces and stretching from external sources, activating intracellular signaling pathways to regulate the production of collagen and other substances. The relationship between fibroblasts and mechanical stress is also noteworthy in wound healing, with research being conducted on therapies such as "negative pressure wound therapy," a type of physical therapy.
3．Muscle Cells
Muscle cells are cells that form muscle tissue and respond sensitively to stretching and pressure.
When we exercise, muscles repeatedly contract and relax, and during this process, muscle cells respond to mechanical stress by sending appropriate contraction signals, adjusting the strength of the force.
Mechanical stress is also important for muscle growth. Popular muscle training exercises are believed to cause muscle fibers to be damaged by stress and then repaired, resulting in larger and stronger muscles.
4．Responses of Cells to Applied Pressure
Finally, we will focus on "pressure" within mechanical stress and introduce research on applying pressure to cells while explaining it.
Cells are often exposed to pressure within the body, so applying pressure during culture is considered very effective for replicating in vivo conditions.
「Hydrostatic pressure promotes endothelial tube formation through aquaporin 1 and Ras-ERK signaling」
Sources：SPRINGER NATURE
This paper, published in April 2020 in "Communications Biology," explains the mechanism by which hydrostatic pressure, a form of mechanical stress, promotes tubular formation using human umbilical vein endothelial cells (HUVEC).
It also discusses the need for further in vitro and in vivo studies as future prospects.
「Hydrostatic pressure suppresses fibrotic changes via Akt/GSK-3 signaling in human cardiac fibroblasts」
Sources：The Physiolosical Society
This paper, published in May 2018 in "Physiological Reports," evaluates the effects of hydrostatic pressure (HP) on human cardiac fibroblasts (HCF).
The results indicate that high HP (200 mmHg) inhibits the differentiation of fibroblasts into myofibroblast phenotypes, suggesting potential implications for understanding the pathophysiology of heart diseases.
「Arterial graft with elastic layer structure grown from cells」
Sources：SPRINGER NATURE
This paper, published in March 2017 in "Scientific Reports," evaluates the effects of periodic hydrostatic pressurization (PHP) on stress fiber formation and fibronectin fiber formation in human umbilical artery smooth muscle cells (hUASMC).
It also discusses the potential role of PHP in the fabrication of vascular layer structures in vascular smooth muscle cells (SMCs).
5．Summary
This time, we explained the definition of mechanical stress and the research content related to it.
To summarize the content of the article, it is as follows:
・Mechanical Stress = Various physical forces (pressure, shear stress, etc.) experienced by cells and tissues within the body
・Mechanobiology = The field of study that researches mechanical stress
・Research on mechanical stress is progressing to elucidate the mechanics within living organisms, with notable responsive cells including vascular endothelial cells, fibroblasts, and muscle cells.
・Mechanical stress is considered very effective in cell culture for mimicking in vivo conditions.
Tokai Hit Co., Ltd. has developed applications that allow cell culture under mechanical stress. Additionally, Tokai Hit excels in providing solutions for researchers, so please consider them as a candidate if you are interested.
*Machine Translation
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