Human Satellite Progenitor Cells for Use in Myofascial Repair

Available In Vitro Models for Human Satellite Cells from Skeletal Muscle

Skeletal muscle accounts for almost 40% of the total adult human body mass. This tissue is essential for structural and mechanical functions such as posture, locomotion, and breathing, and it is endowed with an extraordinary ability to adapt to physiological changes associated with growth and physical exercise, as well as tissue damage. Moreover, skeletal muscle is the most age-sensitive tissue in mammals. Due to aging, but also to several diseases, muscle wasting occurs with a loss of muscle mass and functionality, resulting from disuse atrophy and defective muscle regeneration, associated with dysfunction of satellite cells, which are the cells responsible for maintaining and repairing adult muscle. The most established cell lines commonly used to study muscle homeostasis come from rodents, but there is a need to study skeletal muscle using human models, which, due to ethical implications, consist primarily of in vitro culture, which is the only alternative way to vertebrate model organisms. This review will survey in vitro 2D/3D models of human satellite cells to assess skeletal muscle biology for pre-clinical investigations and future directions.

A model system for primary abdominal closures

The foreign body response to medical devices and materials implanted in the human body, including scarring, fibrous encapsulation, and potential rejection, is a longstanding and serious clinical issue. There are no widely acceptable or safe therapies for ameliorating the foreign body response. Clinical complications resulting from the response include disfigurement of silicone prostheses and loss of function of devices such as implanted pacemakers, stents, and shunts. Cellularized implants and stem cells placed in the body are also subject to the foreign body response with the added issue that the regenerative repair intended to be prompted by the graft may be inhibited. Beneficial modification of the body's reaction to implanted materials, medical devices, engineered constructs, or stem cells would be a fundamentally important therapeutic advance.As part of investigating the cellular response, we have developed a model which uses cells isolated from skeletal muscle biopsy, cultured, and proliferated in vitro. These satellite cells, which are mononucleated progenitor cells, reside between the plasma membrane of the muscle fiber and the basal membrane that encompasses the fiber. While usually quiescent, these cells become activated following muscle damage. Once activated, the satellite cells proliferate, migrate to injured muscle, and participate in repair by fusing with existing muscle fibers or by differentiating into new skeletal muscle fibers. Satellite cells have been shown to be heterogeneous populations of stem cells and progenitor cells. We have developed an explant method for isolating, sorting, enriching, and culturing these cells for use in skeletal muscle regenerative medicine to determine if the foreign body response can be inhibited by manipulating the cell-cell communication.