Lecture 5 - Mesenchymal stem cells (MSCs) Flashcards
What are mesenchymal stem cells (MSCs)?
MSCs are multipotential cells that can differentiate into various cell types such as bone, cartilage, and fat.
What are some alternative names for mesenchymal stem cells?
- Bone marrow stromal cells (BMSCs)
- Bone marrow stromal stem cells (BMSSCs)
- Stromal precursor cells (SPCs)
- Mesenchymal stromal cells (MSCs)
Who first isolated MSCs from bone marrow?
Friedenstein and co-workers in 1970.
What are the key properties of MSCs?
- Adherence to plastic in culture
- Expression of CD105, CD73, and CD90 in ≥95% of culture
- Lack of expression of CD34, CD45, CD14, or CD11b, CD79α, CD19, and HLA-DR (≤2% of culture)
- Ability to differentiate into bone, cartilage, and fat.
What is the significance of the MSC niche?
The MSC niche influences MSC heterogeneity and affects their properties and functions.
Fill in the blank: MSCs can differentiate into _______.
[bone, cartilage, fat]
What regulatory signals are involved in MSC differentiation?
- 1-Methyl-3-isobutylxanthine (IBMX)
- Dexamethasone
- Insulin
- Indomethacin
- TGF-β3
- β-glycerol phosphate
- Ascorbate
What are some common positive stains used to identify differentiated MSCs?
- Oil Red O
- Collagen II
- Toluidine blue
- Alkaline phosphatase
- Alizarin Red
What is the role of MSCs in cancer therapy?
MSCs may be used in cancer therapy due to their ability to interact with tumor microenvironments.
True or False: There is a definitive MSC-specific marker.
False.
What is MSC heterogeneity?
MSC heterogeneity refers to the variability in surface marker expression, proliferation, and differentiation among MSCs from different sources.
What are some sources of MSCs?
- Bone marrow
- Adipose tissue
- Skeletal muscle
- Umbilical cord
- Synovium
- Circulatory system
- Spleen
- Kidney
- Lung
- Dental pulp
- Conjunctiva
- Thymus
- Amniotic fluid
- Foetal tissues (liver, lung, marrow, blood)
What is the minimal criteria for MSCs defined by the International Society for Cellular Therapy?
- Adherence to plastic
- Expression of specific surface markers
- Differentiation potential
Fill in the blank: MSCs from different sources may yield cells with similar _______ characteristics.
phenotypic
But differences in surface markers, proliferation and differentiation.
What are some key markers that MSCs lack?
- CD34
- CD45
- CD14
- CD11b
- CD79α
- CD19
- HLA-DR
What is the importance of surface markers in MSCs?
Surface markers help in identifying and characterizing MSCs, although they are not exclusive to them.
What is the typical morphology of MSCs in culture?
Adherent, spindle-shaped, fibroblastic colonies.
In culture (CFU-F)
What are the three sources of therapeutic cells mentioned?
Bone marrow, Adipose, Umbilical cord blood
These sources are commonly used for mesenchymal stem cell (MSC) therapies.
What is the isolation efficacy of bone marrow and adipose tissue?
100% for both
This indicates that both sources have a complete success rate in isolating the desired cells.
What is the maximum expansion capacity of umbilical cord blood?
Highest
This suggests that umbilical cord blood can proliferate more than the other sources.
What is the differentiation potential of umbilical cord blood-derived MSCs?
Osteo- & chondrogenic, NOT adipogenic
Indicates that these cells can differentiate into bone and cartilage but not fat.
What does MSC heterogeneity refer to?
Variability in the properties and behavior of mesenchymal stem cells
This variability can impact their effectiveness in therapies.
What roles do MSCs play in tissue homeostasis and repair?
- Providing daughter cells that differentiate and participate in repair
- Homing to distant sites of injury
- Secretion of paracrine factors that support wound repair
These mechanisms are crucial for tissue regeneration.
True or False: The mechanisms of MSCs in tissue repair are fully understood.
False
Most understanding is based on in vitro data, and the complexities in vivo remain largely unclear.