Skeletal Muscle Regeneration

Skeletal muscle and its application to regenerative medicine

Humans and other such higher forms of life have three types of muscles.

Cardiac muscle
This is the muscle of the heart. Cardiac muscle contraction pushes blood to the entire body.
Smooth muscle
This is the muscle that composes internal organs such as vascular walls and respiratory tract walls.
Skeletal muscle
This is the muscle that connects bones together and moves the body. It is voluntary muscle that a person can move consciously.

Skeletal muscle is known as tissue that has high regenerative capability, but this capability is lost as a person ages.
Symptoms caused by deterioration in muscle strength, muscle mass, and nervous activity are referred to as sarcopenia. In a super-aging society, much importance is placed on countermeasures against sarcopenia so as to allow people to lead healthy lives. The field of muscle regeneration is the foundation of such countermeasures and is hence receiving a lot of attention.
Furthermore, there are expectations for the application of the high regenerative capability of skeletal muscle to regenerative medicine.

Mechanism of skeletal muscle regeneration

Skeletal muscle stem cells, which are called satellite cells, bear the burden of the regenerative capability of skeletal muscles.
Satellite cells manifest the Pax7 transcription factor. When these cells are stimulated by means such as muscle injury, they activate and manifest the myogenic differentiation regulatory factor MyoD. Activated satellite cells repeatedly propagate to supply the muscle cells required to repair the injury. Thereafter, by losing the Pax7 and manifesting the myogenic differentiation determining factor Myogenin, the satellite cells become muscle cells and adhere to existing muscle cells.

Mechanism of skeletal muscle regeneration

Example of the observation of the 3D structure of muscle fiber

In the following example, KEYENCE’s All-in-One Fluorescence Microscope BZ-X800 is used to display muscle fiber in 3D.
The manifestation of Pax7 is captured, showing the situation that triggers the regeneration of muscle cells.

Example of the observation of the 3D structure of muscle fiber

Objective lens: Plan Apo 10x


Using the All-in-One Fluorescence Microscope BZ-X800