August, 2010
Novel Applications for Stem Cells From Human Exfoliated Deciduous Teeth – Paving the Way For Further Solutions
PRINCIPAL AUTHOR
1. Dr. Vishal Seth
Post graduate student
Department of orthodontics
Syamala reddy dental college and hospital
Marathalli
Bangalore – 5600037
E-Mail: drvishal13@rediffmail.com
Phone: 9986514414
OTHER AUTHOR’S
2. Dr. Prasanth Kamath, M.D.S
Professor and head
Department of orthodontics
Syamala reddy dental college and hospital
Marathalli
Bangalore – 5600037
E- mail- kamathpk@yahoo.com
Phone- 9886041212
3. Dr. Venkatesh M.J, M.D.S
Professor
Department of orthodontics
Syamala reddy dental college and hospital
Marathalli
Bangalore – 5600037
Phone- 9844069010
ABSTRACT & KEY WORDS
ABSTRACT
Obtaining stem cells from human exfoliated deciduous teeth (SHED) is simple and convenient, with little or no trauma. Every child loses primary teeth, which creates the perfect opportunity to recover and store this convenient source of stem cells – should they be needed to treat future injuries or ailments and presents a far better alternative to simply discarding the teeth or storing them as mementos from the past. Stem cells can also be recovered from developing wisdom teeth, permanent teeth, primary teeth, mesiodens, supernumerary teeth. Individuals have different opportunities at different stages of their life to bank these valuable cells. It is best to recover stem cells when a child is young and healthy and the cells are strong and proliferative.. The authors discuss the present scenario as well as the technical details of tooth banking and its applications.
KEYWORDS
Stem Cells, Deciduous teeth, shed.
Dental Stem Cells
In a child, the most accessible stem cells are from the oral cavity. For deciduous teeth, the best candidates are moderately resorbed canine and incisors with the presence of healthy pulp. In children, other sources of easily accessible stem cells are supernumerary teeth; mesodens, over-retained deciduous teeth associated with congenitally missing permanent teeth, and prophylactically removed deciduous molars for orthodontic indications.
Conceptually, dental stem cells have the potential to differentiate into neural cell lineages. Recently, investigators have discovered a unique type of stem cell in the dental pulp of deciduous teeth. Stem cells from deciduous teeth, which are formed during the sixth week of human development, behave differently than other adult stem cells. These immature stem cells are capable of extensive proliferation and differentiation, which make them an important resource of stem cells for the regeneration and repair of craniofacial defects, tooth loss, and bone regeneration.
However, a number of recent studies show that stem cells from teeth may be manipulated to grow into cell types of a completely different tissue. This ability is called transdifferentiation or plasticity, and different types of adult stem cells have varying degrees of plasticity. Given their ability to produce and secrete neurotrophic factors, dental stem cells may also be beneficial for the treatment of neurodegenerative diseases and the repair of motoneurons following injury.
Indeed, dental stem cells from deciduous teeth have been induced to express neural markers such as nestin. The expression of neural markers in dental stem cells stimulates the imagination for their potential use in neural regeneration such as in the treatment of Parkinson’s disease. The potential of dental stem cells in both dental and non-dental regeneration continues to be further explored by researchers. Dental stem cells that have been isolated to date, either from deciduous teeth or permanent teeth, are considered non-embryonic or adult stem cells (Fig.1). Stem cells recovered from dental pulp can differentiate into bone, cartilage, and adipose cells in vitro.
PRIMARY TEETH CONTAIN STEM CELLS
Primary teeth contain a rich supply of stem cells in their dental pulp that remain vital after a child loses a tooth, said researchers in an article published online April 25 in the Proceedings of the National Academy of Sciences.
Researchers at the National Institute of Dental and Craniofacial Research extracted pulp from children’s exfoliated incisors and discovered that 12 to 20 stem cells from each tooth had the ability to colonize and grow in culture. They also found that the stem cells grow rapidly and have the potential to form specialized dentin, bone and neuronal cells. They named these special cells Stem cells from Human Exfoliated Deciduous teeth, or SHED.
The transition from deciduous teeth to adult permanent teeth is a very unique and dynamic process in which the development and eruption of permanent teeth coordinate with the resorption of the roots of deciduous teeth. It may take 7 years in humans to complete the ordered replacement of 20 deciduous teeth.1 stem cells from the remnant pulp of exfoliated deciduous teeth.Deciduous teeth are significantly different from permanent teeth with regards to their developmental processes, tissue structure, and function (SHED: Stem cells from human exfoliated deciduous teeth).2
The mechanisms controlling the growth and replacement of teeth are largely unknown1, in particular with respect to how craniofacial components including bone and soft tissues surrounding teeth participate in the process of tooth development. Dental pulp cells are known to produce neurotrophic factors and even rescue motoneurons after spinal cord injury3 .Recent studies have shown that SHED have the ability to develop into more types of body tissues than other types of stem cells.4,5,6.
Researchers have found the pulp of exfoliated deciduous. Cells are being discovered and will continue to emerge in the decades to come. Abbas et al (2008)7 investigated the possible neural crest origin of dental pulp stem cells from exfoliated deciduous teeth (SHED). Neural crest cells are multipotent cells that are capable of self-renewal and multi-lineage differentiation and play a major role in tooth development as they give rise to mesenchymal components of teeth including odonto-lasts, pulp, apical vasculature and periodontal ligament. They found that SHED are heterogeneous population that shares common molecular characteristics with neural crest cells and stem cells in vitro.7.No doubt stem cells of dental origin have got multiple applications; there are certain limitations as well.
Types of Stem Cells in Human Exfoliated Deciduous teeth
Adipocytes; Adipocytes have successfully been used to repair damage to the heart muscle caused by severe heart attack. There is also preliminary data to indicate they can be used to treat cardiovascular disease, spine and orthopedic conditions, congestive heart failure, Crohn’s disease, and to be used in plastic surgery.8,9
Chondrocytes and Osteoblasts: Chondrocytes and Osteoblasts have successfully been used to grow bone and cartilage suitable for transplant. They have also been used to grow intact teeth in animals.10,11,12,13
Mesenchymal: Mesenchymal stem cells have successfully been used to repair spinal cord injury and to restore feeling and movement in paralyzed human patients. Since they can form neuronal clusters, mesenchymal stem cells also have the potential to treat neuronal degenerative disorders such as Alzheimer’s and Parkinson’s diseases, cerebral palsy, as well as a host of other disorders.10,14,13 This comprehensive list of diseases and conditions currently being treated using stem cells include Stem Cell Disorders, Acute and chronic Leukemias, Myeloproliferative Disorders, Myelodysplastic Syndromes, Lymphoproliferative Disorders, Inherited Erythrocyte Abnormalities, Liposomal Storage Diseases, Histiocytic Disorders, Phagocyte Disorders, Congenital Immune System Disorders, Inherited Platelet Abnormalities, Plasma Cell Disorders and malignancies.16,14,
BIBLIOGRAPHY
1. Parner, E. T., Heidmann, J. M., Kjaer, I., Vaeth, M. & Poulsen, S. (2002) J.Dent. Res. 81, 451–454
2. Masako Miura, Stan Gronthos,Mingrui Zhao,Bai Lu,Larry W. Fisher, Pamela Gehron Robey, and Songtao Shi. PNAS 2003; 100 (10): 5802-5812.
3. Nosrat, I. V., Widenfalk, J., Olson, L. & Nosrat, C. A. (2001) Dev. Biol. 238, 120–132.
4. Miura M, Gronthos S, Zhao M, Lu B, Fisher LW, Robey PG, Shi S. SHED: stem cells from human e xfoliated deciduous teeth. Proc Natl Acad Sci U S A, 100(10): 5807–12, 2003.
5. de Mendonça Costa A, Bueno DF, Martins MT, Kerkis I, Kerkis A, Fanganiello RD, Cerruti H, Alonso N, Passos-Bueno MR.Reconstruction of large cranial defects in nonimmunosuppressed experimental design with human dental pulp stem cells. J Craniofac Surg, 19(1): 204–10, 2008.
6. Seo BM, Sonoyama W, Yamaza T, Coppe C, Kikuiri T, Akiyama K, Lee JS, Shi S. SHED repair critical-size calvarial defects in mice. Oral Dis, 14(5): 428–34, 2008.
7. Abbas, Diakonov I., Sharpe P. Neural Crest Origin of Dental Stem Cells. Pan European Federation of the International Association for Dental Research (PEF IADR). Seq #96 – Oral Stem Cells: Abs, 0917, 2008
8. Gandia C, Armiñan A, García-Verdugo JM, Lledó E, Ruiz A, Miñana MD, Sanchez-Torrijos J, Payá R, Mirabet V, Carbonell-Uberos F, Llop M, Montero JA, Sepúlveda P Human dental pulp stem cells improve left ventricular function, induce angiogenesis, and reduce infarct size in rats with acute myocardial infarction. Stem Cells, 26(3): 638–45, 2007.
9. Perry BC, Zhou D, Wu X, Yang FC, Byers MA, Chu TM, Hockema JJ, Woods EJ, Goebel WS. Collection, cryopreservation, and characterization of human dental pulp-derived mesenchymal stem cells for banking and clinical use. Tissue Eng Part C Methods, 14(2): 149–56, 2008.
10. Shi S, Bartold PM, Miura M, Seo BM, Robey PG, Gronthos S.The efficacy of mesenchymal stem cells to regenerate and repair dental structures. Orthod Craniofac Res, 8(3): 191–9, 2005.
11. Jeremy J. Mao. Stem Cells and the Future of Dental Care. New York State Dental Journal, 74(2): 21–24, 2008.
12. Irina Kerkis, Carlos E Ambrosio, Alexandre Kerkis, Daniele S Martins, Eder Zucconi, Simone AS Fonseca, Rosa M Cabral, Carlos MC Maranduba, Thais P Gaiad, Adriana C Morini, Natassia M Vieira, Marina P Brolio, Osvaldo A Sant’Anna, Maria A Miglino, and Mayana Zatz Early transplantation of human immature dental pulp stem cells from baby teeth to golden retriever muscular dystrophy (GRMD) dogs: Local or systemic? J Transl Med, 6: 35, 2008.
13. Arthur A, Rychkov G, Shi S, Koblar SA, Gronthos S. Adult human dental pulp stem cells differentiate toward functionally active neurons under appropriate environmental cues. Stem Cells, 26(7): 1787–95, 2008.
14. Perry BC, Zhou D, Wu X, Yang FC, Byers MA, Chu TM, Hockema JJ, Woods EJ, Goebel WS. Collection, cryopreservation, and characterization of human dental pulp-derived mesenchymal stem cells for banking and clinical use. Tissue Eng Part C Methods, 14(2): 149–56, 2008.
15. Jay B. Reznick. Continuing Education: Stem Cells: Emerging Medical and Dental Therapies for the Dental Professional. Dentaltown magazine, Oct: 42–53, 2008.
16. Mao JJ, Giannobile WV, Helms JA, Hollister SJ, Krebsbach PH, Longaker MT, Shi S. Craniofacial tissue engineering by stem cells. J Dent Res, 85(11): 966–79, 2006
