Cells Isolated from Inflamed Periapical Tissue Express Mesenchymal Stem Cell Markers and Are Highly Osteogenic

Abstract

Introduction We previously reported the presence of mesenchymal stem/progenitor cells (MSCs) in inflamed pulp tissue. Here we asked whether MSCs also exist in inflamed periapical tissues resulting from endodontic infection. The objectives of this study were to detect the expression of MSC markers in periapical inflammatory tissues and to characterize isolated cells from these tissues. Methods Human periapical inflammatory tissues were collected and processed to detect MSC marker expression by immunohistochemistry. Cells were isolated and tested for cell surface marker expression by using flow cytometry and examined for multiple differentiation potential into osteogenic and adipogenic pathways. In vivo formation of mineralized tissues was assessed in a mouse model. Results Immunohistochemistry showed positive staining for MSC markers STRO-1, CD90, and CD146. Isolated cells at passage 0 appeared as typical fibroblastic cells, and a few cells formed colony-forming unit-fibroblasts (CFU-Fs). After passaging, the CFU-F forming ability diminished dramatically, and the population doubling was up to 26. Flow cytometry data showed that these cells at passage 2 expressed low levels of STRO-1 and CD146 and moderate to high levels of CD90, CD73, and CD105. At passage 6, the levels of these markers decreased. When incubated in specific differentiation medium, cells demonstrated a strong osteogenic but weak adipogenic capacity. After in vivo cell transplantation, mineralized tissues formed in immunocompromised mice. Conclusions Human periapical inflammatory tissues expressed MSC markers, suggesting the presence of MSCs. Isolated cells exhibited typical mesenchymal cell immunophenotype with a capacity to form mineralized matrix in vitro and in vivo.

Regenerative Endodontics: A Road Less Travelled

“…These include dental pulp stem cells (DPSCs),stem cells of the apical papilla (SCAP), inflammatory periapical progenitor cells (iPAPCs), periodontal ligament stem cells (PDLSCs), stem cells from human exfoliated deciduous teeth (SHED), dental follicle stem cells (DFSCs), tooth germ progenitor cells (TGPCs), oral epithelial stem cells (OESCs), gingival-derived mesenchymal stem cells (GMSCs), salivary gland stem cells (SGSCs), bone marrow stem cells (BMSCs) and periosteal-derived stem cells (PSCs) [6,7]. Although, stem cells have been identified in most oral tissues, the stem cells that are mostly involved in REPS include DPSCS, SHED, SCAP and PDLSCS.…”

Regenerative Endodontics: An Evidence Based Review

“…[12,13] . One more noteworthy property of these stem cells is their survival in chronically inflamed environment and in the presences of necrotic infected tissue and bacteria.…”

Isolation and Culture of Postnatal Stem Cells from Deciduous Teeth

“…El STRO-1 ha sido utilizado en varios estudios para identificar MSC in vitro de pulpa dental (12,13). Se describe como un antígeno de superficie que se expresa inicialmente con mayor intensidad en las unidades formadoras de colonias (UFC) o nichos (13) que, por lo general, se presenta en los pasajes iniciales.…”