As our understanding and ability to manipulate stem cells grows, they are becoming increasingly used in clinical applications. Researchers outlined potential uses of mesenchymal stem cells in tissue regeneration and treatment of autoimmune disorders.
Stem cells represent a new, promising treatment method that may offer ways to treat previously incurable diseases. In a new paper published in Dental Clinics of America, Mao et al. outlined ways stem cells could be used in dental applications. Their main benefit is that they are undifferentiated, meaning they can turn into different cells depending on their environment or produce more stem cells depending on the needs of the body. Their ability to differentiate into different cell types, or their potency, makes them very versatile in regards to their treatment methods.
There are several types of stem cells, one of which is the mesenchymal stem cells (MSC). MSCs were first found in the bone marrow as cells that had the capacity to differentiate into a number of cell types. While they are still primarily gathered from the bone marrow, MSCs have been identified in almost all tissues, with different properties depending on tissue of origin. These differences mean that MSCs derived from different tissue origins may have different clinical applications.
Key characteristics of MSCs include their self-renewal abilities, potency, and interaction with the immune system. Adult cells are limited in their replication by the length of their telomeres, which are repeating lines of genetic code at the end of a chromosome. With each replication, bits of telomere are cut off, and below a critical level, the cell goes into apoptosis, or cell death. MSCs are able to express telomerase, which regenerates its telomeres, allowing for greater replication before cell death. They are also able to differentiate into a broad variety of tissue types, allowing for application in various parts of the body. Also, when interacting with the immune system, MSCs act in a regulatory fashion. They suppress the immune system through interaction with various cells, leading to research in applications towards treatment of autoimmune disorders.
As noted earlier, MSCs derived from different parts of the body display different characteristics. This remains true for dental pulp stem cells (DPSCs), taken from the centre of the tooth. Compared with bone marrow stem cells, they have greater proliferative properties and have a dentin-like structure formation that is particularly helpful in tooth treatments. They have also shown similar immunosuppressive properties when compared with bone marrow stem cells. These properties allow for DPSCs to be used in biotooth/bioroot engineering, periodontal defect regeneration, dentin-pulp regeneration and treatment of autoimmune diseases such as systemic lupus erythematosus, systemic sclerosis and osteonecrosis of the jaw.
While stem cells appear promising, further research needs to be conducted before they are ready for clinical application. Scientists must continue to investigate the function of MSCs in the immune system and the mechanisms behind their self-renewal and potency to be able to most efficiently manipulate these properties in cell-based treatments.
Written By: Wesley Tin, BMSc