Mesenchymal stem cells (MSCs) are a type of adult stem cell that can differentiate into a variety of cell types, including osteoblasts (bone cells), chondrocytes (cartilage cells), and adipocytes (fat cells).
Mesenchymal” refers to the embryonic origin of the cells, specifically cells that arise from the mesoderm germ layer. The mesoderm germ layer is one of the three primary germ layers that form during the early stages of embryonic development.
The mesoderm gives rise to various types of connective tissues, such as muscle, bone, cartilage, and fat, as well as the cells that form blood vessels, blood cells, and the urogenital system. Human mesenchymal stem cells can also differentiate into other cell types, such as myocytes (muscle cells), neurocytes (nerve cells), and stromal cells.
MSCs have been shown to differentiate into various cell types, including:
- Osteoblasts (bone cells)
- Chondrocytes (cartilage cells)
- Adipocytes (fat cells)
- Myocytes (muscle cells)
- Neurocytes (nerve cells)
- Hepatocytes (liver cells)
- Pancreatic cells (pancreas cells)
- Cardiomyocytes (heart muscle cells)
- Endothelial cells (blood vessel cells)
- Epithelial cells (cells that line surfaces)
Differentiation is when a less specialized cell becomes a more specialized cell type. In mesenchymal stem cells, differentiation refers to the process by which stem cells become specific cell types, such as muscle cells, nerve cells, or bone cells.
- A complex interplay of genetic and epigenetic factors controls the differentiation process. Genetic factors include the expression of specific transcription factors and signaling molecules, while epigenetic factors include changes in DNA methylation, histone modification, and non-coding RNA expression.
- The process of differentiation can be divided into several stages. The first stage is the activation of specific genes, which leads to the expression of transcription factors that control the cell’s fate. The second stage is the initiation of cell proliferation and the formation of specific cell types. The final stage is the maturation of the cells, which leads to the formation of functional cells.
Tissue repair and regeneration
Mesenchymal stem cells (MSCs) also can promote tissue repair by releasing growth factors and cytokines, which help recruit other cells to the injury site. These growth factors and cytokines can also promote the formation of new blood vessels essential for tissue repair.
Immunomodulatory properties
Mesenchymal stem cells are known for their immunomodulatory properties, which means they can modulate the activity of the immune system, reduce inflammation and suppress immune responses. This property makes them a promising candidate for cell-based therapies in various conditions, such as autoimmune diseases, graft-versus-host disease, and transplant rejection.
There are several sources of mesenchymal stem cells (MSCs), including:
- Bone Marrow is the most commonly used Mesenchymal stem cell (MSCs) source. Bone marrow is the spongy tissue inside the bones that contains immature cells, including MSCs. These cells can be collected through a procedure called bone marrow aspiration, which is a relatively simple and safe procedure.
- Adipose Tissue (Fat Tissue): Mesenchymal stem cells (MSCs) can also be isolated from adipose tissue, which is the tissue that stores fat in the body. Adipose tissue can be obtained through liposuction, a procedure in which fat is removed from the body using a hollow stainless steel tube.
- Umbilical Cord Tissue: Mesenchymal stem cells (MSCs) can also be obtained from umbilical cord tissue, which is the tissue that connects the fetus to the placenta. The cells can be collected at the time of birth and can be stored for future use.
- Peripheral Blood: Mesenchymal stem cells (MSCs) can be found in small numbers in the peripheral blood of healthy adults. These cells can be collected through a procedure called apheresis, which is similar to donating blood.
- Placental Tissue: Mesenchymal stem cells (MSCs) can also be obtained from placental tissue. The cells can be collected at the time of birth and can be stored for future use.
- Synovial Fluid: Mesenchymal stem cells (MSCs) can be found in small numbers in the synovial fluid of joints. Synovial fluid can be obtained through a procedure called arthrocentesis, which is a relatively simple and safe procedure.
- Dental Pulp: Mesenchymal stem cells (MSCs) can be found in small numbers in the dental pulp of teeth. Dental pulp can be obtained through a procedure called apicoectomy, which is a surgical procedure to remove the tip of a tooth’s root.
