Proteomic Characterization of Mesenchymal Stem Cell-Like Populations Derived from Ovine Periodontal Ligament, Dental Pulp, and Bone Marrow: Analysis of Differentially Expressed Proteins

Abstract

Postnatal mesenchymal stem/stromal-like cells (MSCs) including periodontal ligament stem cells (PDLSCs), dental pulp stem cells (DPSCs), and bone marrow stromal cells (BMSCs) are capable of self-renewal and differentiation into multiple mesenchymal cell lineages. Despite their similar expression of MSC-associated and osteoblastic markers, MSCs retain the capacity to generate structures resembling the microenvironments from which they are derived in vivo and represent a promising therapy for the regeneration of complex tissues in the clinical setting. With this in mind, systematic approaches are required to identify the differential protein expression patterns responsible for lineage commitment and mediating the formation of these complex structures. This is the first study to compare the differential proteomic expression profiles of ex vivo-expanded ovine PDLSCs, DPSCs, and BMSCs derived from an individual donor. The two-dimensional electrophoresis was performed and regulated proteins were identified by liquid chromatography--electrospray-ionization tandem mass spectrometry (MS and MS/MS), database searching, and de novo sequencing. In total, 58 proteins were differentially expressed between at least 2 MSC populations in both sheep, 12 of which were up-regulated in one MSC population relative to the other two. In addition, the regulation of selected proteins was also conserved between equivalent human MSC populations. We anticipate that differential protein expression profiling will provide a basis for elucidating the protein expression patterns and molecular cues that are crucial in specifying the characteristic growth and developmental capacity of dental and non-dental tissue-derived MSC populations. These expression patterns can serve as important tools for the regeneration of particular tissues in future stem cell-based tissue engineering studies using animal models.

Mesenchymal Stem Cells and Periodontal Regeneration

“…Using mass spectrometric analysis, Mrozik and colleagues investigated proteomic differences between BMSC, DPSC, and PDL MSC derived from the same (ovine) donor and reported 58 proteins that were differentially expressed among the different MSC sources [33]. Similarly, Eleuterio and colleagues carried out mass spectrometric analysis of proteomic differences between PDL MSC and matched DPSC and from BMSC (derived from a difference source) [34•].…”

“…Consequently, studies of phenotypic differences between cells from different donors should be interpreted with caution. Studies using matched cultures derived simultaneously from the same donor may therefore be particularly valuable models in which to investigate true phenotypic differences between cells [33,43].…”

Proteomic Characterization of Mesenchymal Stem Cell-Like Populations Derived from Various Tissue Types

“…For example, periodontal ligament stem cells form cementum/PDL-like tissue while dental pulp stem cells and bone marrow-derived MSCs generate dentin/pulp-like and lamellar bone/marrow-like structures, respectively (Gronthos et al 2000 ;Seo et al 2004 ) . Coupled with a higher proliferation rate than bone marrowderived MSCs, dental MSC-like populations hold great promise for the regeneration of dentin, cementum and periodontal tissue following periodontal trauma or disease (Miura et al 2003 ;Mrozik et al 2010 ) . In addition, it has been postulated that dental pulp stem cells may be extremely useful for the treatment of neurological disorders while gingiva-derived MSCs appear to represent a promising cell-based therapy for infl ammatory bowel disease due to their immunomodulatory properties Zhang et al 2009 ) .…”

“…A direct comparison of protein expression profi les between ovine periodontal ligament stem cells, dental pulp stem cells and bone marrow-derived MSCs identifi ed 49 differentially expressed proteins between at least two MSC populations (Mrozik et al 2010 ) . Importantly, all three cell populations were derived from individual donors eliminating the possibility that differentially expressed proteins were a consequence result of inter-donor variability.…”

Peculiarities of Using Stem Cells for Regeneration of the Bone and Cartilage Tissue

“…These cells can differentiate into osteogenic lineage cells and into specifi c tooth cells [42,68]. Dental pulp MSC (obtained from healthy 6-10-year-old children) produced mineralized matrix under certain conditions in vitro and differentiated into osteocytes and formed compact bone in vivo [68].…”