

Mesenchymal
Stem Cells (MSCs)
What is stem cell?
Stem cell can be known as the mother cell in the body with two main abilities which are self-renewal capability and specialized cell production. The former ability means that it can divide indefinitely producing its own clones, more stem cells in the maintenance of stem cell pool (He et al., 2009); the latter one shows its ability in giving rise to the specialized cells such as red blood cell, white blood cell, epithelial cell, adipose cell and etc to carry out specific functions in our body (Mayo Clinic, 2021).
Types of stem cell
There are several types of commonly known stem cells: embryonic stem cell, adult stem cell, induced pluripotent stem cell and perinatal stem cell (umbilical cord and cord blood).
i) Embryonic stem cell (ESC)
Can be found in embryo (a 3-5 days old fertilized egg) which is harvested during in-vitro fertilization process. This type of stem cell can virtually give rise to all types of cells in the body, this ability is known as pluripotency (Cafasso, 2017). https://www.healthline.com/health..

ii) Adult stem cell (ASC)
Can be found in organs or tissues in the body, eg: mesenchymal stem cell and haematopoietic stem cell. This type of stem cell mainly used to repair the tissues or replace the damaged cells in the body. Without being misled by the word, adult stem cell can be found in infants and children too (Cafasso, 2017).
https://www.healthline.com/health/..
Unlike embryonic stem cell, adult stem cell can only give rise to specific types of specialized cells in the body known as multipotency. For instance, haematopoietic stem cell in the bone marrow can only produce blood cells in replacing the worn-out blood cells in the body (Thermo Fisher, 2021).

iii) Induced pluripotent stem cell (iPSC)
This type of stem cell cannot be found naturally, it is created by scientist in the lab by using any type of cell from an adult body (for example: skin cell) and genetically modify it to become a “stem cell” which can give rise to all cell types in the body (pluripotency) (Brazier, 2018).

iii) Induced pluripotent stem cell (iPSC)
This type of stem cell cannot be found naturally, it is created by scientist in the lab by using any type of cell from an adult body (for example: skin cell) and genetically modify it to become a “stem cell” which can give rise to all cell types in the body (pluripotency) (Brazier, 2018).
What is mesenchymal stem cell (MSC)?
Mesenchymal stem cell (MSC) is one of the types of adult stem cell in our body which can self-renew (proliferative capability) and differentiate into various types of cells (multilineage differentiation) such as bone cells, cartilage cells, fats cells and etc (Fu et al., 2019). Besides, the other eye-catching properties of MSC are anti-inflammatory and strong immunomodulation potential (Li et al., 2019). Due to these abilities of MSCs, they play important roles in tissue healing and regenerative medicine, treating many types of regenerative diseases.


Sources of MSC
MSC can be sourced from different parts of the body, for example bone marrow, adipose tissues, dental pulp, inner organs or young sources such as umbilical cord, amniotic fluid, amniotic membrane or placenta (Cona, 2021) (Elahi et al., 2015).

Best source of mesenchymal stem cell
Bone marrow mesenchymal stem cell (BMSC) is common before umbilical cord mesenchymal stem cell (UCMSC) is discovered. UCMSC has proven to be a better source for stem cell therapy (Yousefifard, 2016) due to the younger age of the cells, the age of the cells harvested is tallied with the age of the host, hence, UCMSC is as young as the baby host. Besides, the collection method for UCMSC is not invasive at all as the umbilical cord is the discarded part during the labouring procedure.

How does MSC work?
MSC can be administered into the body by various means and the methods which are more common are either by intravenous infusion (IV) or intramuscular infusion (IM). After MSC is introduced to the body, MSC will start the healing process via few mechanisms which can be simplified as homing effect, immunomodulation and differentiation (Musial-Wysocka, 2019).
Homing effect and migration
MSC detects the rescue signals from the injured sites in the body and expresses homing effect to move to the destination effectively. MSC is proven to be possessing the chemotactic property as well, in which after administration, MSC approaches and binds to the endothelium, allowing it to migrate through the cells and reaching the targeted site accurately in the response of factors that are upregulated under inflammatory conditions (Musial-Wysocka, 2019).
Paracrine effect - Immunomodulation and local stem cell activation
MSC secretes factors (paracrine effect) to modulate the inflammatory state at the injured tissues either activating or suppressing it. MSC can control the proliferation of the immune cells, for example T-cells (Weiss and Dahlke 2019), directly (cell-cell interaction) or indirectly (factors secretion).The proliferation rate of T-cells reflects the stage of inflammation at the site and hyperinflammation is not good at all as it will damage the tissues more. MSC can effectively control the proliferation of T-cells and thus supressing the inflammation, saving the healthy cells (Musial-Wysocka, 2019). Besides, MSC secretes factor to activate the local stem cell present in tissues to produce new cells in replacing the dead cells.
Differentiation
As mentioned previously, MSC has the multi-lineage differentiation ability that allows it to differentiate into the specific cells at the injured site. For example, in the stem cell therapy for injured lungs, MSC will turn into lung cells to replace the dead lung cell, maintaining the number of cells in the lungs.

What is stem cell therapy?
Stem cell therapy is one of the therapies in regenerative medicine using stem cell to promote regeneration in the body to restore diseased and injured tissues or whole organs. Instead of healing the internal injuries within the body, stem cell allows the body to heal the injuries itself (Mao and Mooney, 2015).