title: Side population cells isolated from porcine dental pulp tissue with self-renewal and multipotency for dentinogenesis, chondrogenesis, adipogenesis, and neurogenesis.
abstract: Dental pulp has the potential to form dentin as a regenerative response to caries. This regeneration is mediated by stem/progenitor cells. Thus, stem cell therapy might be of potential utility in induction of reparative dentin. We isolated side population (SP) cells from dental pulp based on the exclusion of the DNA binding dye Hoechst 33342 by flow cytometry and compared its self-renewal capacities and multipotency with non-SP cells and primary pulp cells. The cumulative cell number of the SP cells was greater than the non-SP cells and primary pulp cells. Bmi1 was continuously expressed in SP cells, suggesting longer proliferative lifespan and self-renewal capacity of SP cells. Next, the maintenance of the multilineage differentiation potential of pulp SP cells was investigated. Expression of type II collagen and aggrecan confirmed chondrogenic conversion (30%) of SP cells. SP cells expressed peroxisome proliferator-activated receptor gamma and adaptor protein 2, showing adipogenic conversion. Expression of mRNA and proteins of neurofilament and neuromodulin confirmed neurogenic conversion (90%). These results demonstrate that pulp SP cells maintain multilineage differentiation potential. We further examined whether bone morphogenetic protein 2 (BMP2) could induce differentiation of pulp SP cells into odontoblasts. BMP2 stimulated the expression of dentin sialophosphoprotein (Dspp) and enamelysin in three-dimensional pellet cultures. Autogenous transplantation of the Bmp2-supplemented SP cells on the amputated pulp stimulated the reparative dentin formation. Thus, adult pulp contains SP cells, which are enriched for stem cell properties and useful for cell therapy with BMP2 for dentin regeneration.
authors.affiliation: Laboratory of Oral Disease Research, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Aichi, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Iohara
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
authors.forename: Masataka
authors.initials: M
authors.lastname: Ito
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tomokiyo
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsushita
authors.forename: Misako
authors.initials: M
authors.lastname: Nakashima
mesh_terms: D050156:Adipogenesis; D000293:Adolescent; D000328:Adult; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D020219:Chondrogenesis; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D003786:Dental Pulp Cavity / Q000166:cytology / Q000601:surgery; D003810:Dentinogenesis; D004285:Dogs; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D039902:Multipotent Stem Cells / Q000187:drug effects / Q000276:immunology / Q000637:transplantation; D009474:Neurons; D009804:Odontoblasts / Q000166:cytology / Q000187:drug effects / Q000637:transplantation; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000494:pharmacology; D013552:Swine; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2