1.The Immunologic Properties of Undifferentiated Stem Cells from Human Exfoliated Deciduous Teeth (SHED) and Its Potential Application in Bone Regeneration
Nurul AA ; Tan SJ ; Asiah AB ; Norliana G ; Nor Shamsuria O
The International Medical Journal Malaysia 2013;12(1):19-26
Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic
cells capable of differentiating into osteoblasts and inducing bone formation. It is a potential alternative for
stem cell bone regeneration therapy. However, stem cell therapy carries the risk of immune rejection mediated
by inflammatory cytokines of the human defense system. Objective: This preliminary research studies the
interaction between SHED and the immune system by determining the inflammatory cytokines profile and
osteogenic potential of SHED. Methods: Human fetal osteoblasts (hFOb) cell line and isolated SHED were
cultured and total RNA was extracted, followed by reverse transcription cDNA synthesis. Semi-quantitative
reverse transcription PCR and Multiplex PCR were performed to detect the expression levels of OPG/RANKL and
TNF-α, IL-1β, IL-6, IL-8 and TGF-β in both cell types. Results: Analysis showed that SHED expressed significantly
lower amounts of IL-1β, IL-6, and IL-8 compared to hFOB. IL-1β is a potent bone-resorbing factor, while IL-6
and IL-8 induce osteoclastogenesis and osteolysis respectively. SHED did not express TNF-α which stimulates
osteoclastic activity. SHED demonstrated high OPG/RANKL ratio, in contrast with that of marrow stem cells
described in previous studies. Our findings suggest that SHED may have improved immunomodulatory profile in
terms of promoting relatively lower inflammatory reaction during transplant and enhancing bone regeneration.
Conclusion: SHED has a potential to be a good source of osteoblasts for bone regeneration therapy. Further
studies on the immunomodulatory properties of SHED-derived osteoblasts are necessary to enable stem cell
therapy in immunocompetent hosts.