How to pronounce Mesenchymal Stem Cells? Mesenchymal Stem Cells 🔊 Mesenchymal Stem Cells Word Origin: Greek
What are Mesenchymal Stem Cells? By definition, mesenchymal stem cells are multipotent cells that can differentiate and mature into different types of cells. Mesenchymal cells are characterized[1] by having long and thin bodies and a very prominent nucleus.
They are relatively smaller than fibrocytes and are quite difficult to observe in histological sections. And overall, morphologically speaking, they appear to have no difference from fibroblasts .
Where are they found? A group of mesenchymal stem cells is called mesenchyme, and together, they form the undifferentiated “filling” of the embryo. Mesenchymal stem cells (or tissue) have a wide distribution in the body[1] .
Mesenchymal cells can be isolated from the bone marrow, umbilical cord, and adipose tissues. During fetal development, the mesenchymal cells form the connective tissue in developing tissues and organs. During adulthood, mesenchymal connective tissues are only located[1] in the dental pulp.
Properties of Mesenchymal Stem Cells Like most stem cells, mesenchymal stem cells can self-renewal and differentiate.
Self-renewal is cells’ ability to divide while maintaining their undifferentiated state continuously. By doing this, the stem cell pool can perpetuate throughout the organism’s life. Mesenchymal cells are considered multi-potent. Meaning under certain conditions, whether be it in vitro or in vivo , they can mature and differentiate into multiple specialized cells.
Functions of Mesenchymal Stem Cells Despite its size, the mesenchymal stem cell plays many significant roles within an organism. The following are just some of them.
Functions of Mesenchymal Stem Cells (Image Source: frontiersin.org )
1. Suppression of immune cells activation Aside from being the progenitor of most cells in the body, mesenchymal cells also control the activities of immune cells (i.e., T-lymphocytes, B-lymphocytes, macrophages, mast cells, and neutrophils) during an organ transplant. This is important because it prevents further inflammation and the transplant organ’s eventual rejection.
2. Increase the number of nerve cells Strikingly, recent studies have revealed that mesenchymal stem cells can also differentiate into
nerve cells . This differentiation process usually happens due to a stress response or any related stimuli.
Neurons are one of the few cells that, when damaged, can no longer regenerate. Hence, the idea of mesenchymal cells opens up the possibility to replace any damaged or lost nerve cells in the nervous system
3. Reduction of Cell Death While the process of apoptosis, or programmed
cell death , is important for the regulation of some physiological process, too much of it can be damaging for the body. Hence, mesenchymal stem cells are present to maintain
homeostasis and continually replace lost cells.
4. Secretion of neurotrophic and angiogenic factors Mesenchymal stem cells secrete both neurotrophic and angiogenic factors, which are responsible for stabilizing the extracellular matrix (ECM).
5. Increase synaptic connections When transplanted into the brain, mesenchymal stem cells reduce free radical levels and enhance the synaptic connections of damaged neurons. In addition to that, they also increase the number of astrocytes (star-shaped cells associated with the formation of functional synapses). As a result, impulses (messages) are being passed on faster. Hence, reactions are also immediate.
6. Increase the myelination of axons Myelin sheath is the insulating layer covering nerve cells’ axons. By further enhancing the myelination of axons, mesenchymal cells (similar to above) increase the speed at which impulses are passed.
7. Increase the number of blood vessels and astrocytes in the brain According to a recent study published in the World Journal of Stem Cells [3] , mesenchymal cells are also able to replace and repair any damaged blood vessel in the cerebrum part of the brain. Hence, mesenchymal cells are being viewed as a potential therapeutic remedy for stroke patients.
The Mesengenic Process Mesenchymal cells undergo a mesogenic process to transform into different cell types such as osteocytes (bone cells
The Differentiation of Mesenchymal Stem Cells into different types of cells (Image Source: frontiersin.org ) In this process (shown in the diagram above), the cells undergo proliferation and commitment events following the progression of their progeny into lineages that results in their differentiation. It is important to note that the control of this process provides the principle for designing clinical methods and therapies for the manipulation of mesenchymal stem cells and tissues[2] .
Clinical uses of Mesenchymal Cells Present-day studies are now paving the way for the further applications of mesenchymal stem cells into numerous clinical measures and techniques. In addition to the natural functions of mesenchymal cells mentioned above, several commercialized products from these cells have already been approved.
Examples of such are the Caristem and Cupistem (from South Korea ) for degenerative arthritis and anal fistula respectively, and the Prochymal (from New Zealand and Canada ) for acute GyHD (graft-versus-host-disease). Despite the uses above, stem cells, in general, can be quite dangerous. Potential rejection of the introduced cells or the potential failure of the transplant may occur, leading to more serious problems. Being capable of self-renewal and continuous cell division, stem cells are feared for such characteristics as they may cause the development of cancers and tumors.
Despite their good effect on overall organism health, the knowledge about mesenchymal stem cells is still incomplete. Hence, further research is still needed to ensure the safety of patients and improve quality control.
Cite This Page
[1] – Slomianka, Lutz. “Blue Histology – Connective Tissues. ” Blue Histology – Connective Tissues. Accessed December 30, 2016. Link . [2] – “The mesengenic process. ” Clinics in plastic surgery. Accessed December 30, 2016. Link . [3] – Valenti, Maria Teresa, Antonio Mori, Giovanni Malerba, and Luca Dalle Carbonare. “Mesenchymal stem cells: A new diagnostic tool? ” World Journal of Stem Cells. 2015. Accessed December 30, 2016. Link . 
