Fundamental of Mesenchymal Stem Cells as a promising candidate in

regenerative medicine(The International Journal of Biochemistry & Cell Biology)

Adult Stem Cells

• Undifferentiated cells• Found throughout the body after embryonic

development• Multipotent • Capable of self-renewal and differentiation

with limited extend• Regenerate damaged tissue

Figure 1. When an adult stem cell divides, one of the daughter cells goes on to create specialized tissue cells.

Type of Adult Stem Cells

• Hematopoietic • Mammary • Mesenchymal• Neural

• Endothelial • Olfactory • Neural Crest• Testicular

Mesenchymal Stem Cells (MSCs)

• Marrow stromal cells• Multipotent stromal cells• Mesenchymal stromal cells• Colony-forming unit fibroblast (CFU-Fs)• Bone marrow stromal stem cells • Stromal Precursor cells• Skeletal stem cells • Multipotent adult progenitor cells

Properties

• Fibroblast-like colonies• Readily adhere on the culture surface• Capable of differentiating into

Osteogenic ChondrogenicAdipogenic

Hematopoietic and stromal cell differentiation

Cells origin

• Bone marrow is the richest and most reliable reservoir for MSCs.

• Also found in adipose tissue, synovial membrane, skeletal muscle, dermis, pericytes, trabecular bone, umbilical cord, lung, dental pulp, amniotic fluid, fetal liver and peripheral blood.

Plasticity

• Differentiate into cell types in organs /tissues other than those expected from the cells predicted lineage.

• MSCs could engraft in bone, muscle, brain, lung, heart, liver, gastrointestinal tract and hematopoietic system when transplanted.

• Plasticity nature of MSCs remain arguable due to lack of experiment reproducibility.

Functions

• MSCs in bone marrow contribute to the formation of HSC “niche”.

• MSCs serve as precursors of bone, cartilage and adipocytes.

• MSCs shows a strong tendency to repair tissue damage in response to injury and disease.– Secrete soluble factors

Associated pathologies

• MSCs are immunological immature, thus able to survive in a xenogeneic environment.

• Autologous MSCs are free from immune rejection and carcinogenesis and also circumvent ethical constraints.

• MSCs may be useful in the repair or generation of damaged or mutated tissue including bone, cartilage, myocardium, fat, brain and liver.

Cont.

• MSCs selectively migrate to areas of injury/ inflammation and tumors.

• SDF-1/CXCR4 was suggested to play important role in MSCs migration toward injury site.

• Capable of inhibiting immune responses in a major histocompatibility complex-independent manner.– Acute graft-versus-host disease (GVHD)

Summary

• Mesenchymal Stem Cells– Reside in the connective tissue of most organs.– Can differentiate into multiple mesenchymal

lineages: cartilage, bone and adipose tissues.– Possess the capacity to transdifferentiate.– Can migrate to sites of injury, inflammation and

tumor.– Can alter tissue microenvironment via secretion of

soluble factors.

AcknowledgementChen, Y., Shao, J.Z., Xiang, L.X., Dong, X.J., Zhang, G.R. 2008. Mesenchymal Stem Cells: A promising candidate in regenerative medicine. The International Journal of Biochemistry & Cell Biology 40: 815-820.

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