Transplantation of Human Dental Pulp-Derived Stem Cells or Differentiated Neuronal Cells from Human Dental Pulp-Derived Stem Cells Identically Enhances Regeneration of the Injured Peripheral Nerve

Abstract

Human dental mesenchymal stem cells isolated from the dental follicle, pulp, and root apical papilla of extracted wisdom teeth have been known to exhibit successful and potent neurogenic differentiation capacity. In particular, human dental pulp-derived stem cells (hDPSCs) stand out as the most prominent source for in vitro neuronal differentiation. In this study, to evaluate the in vivo peripheral nerve regeneration potential of hDPSCs and differentiated neuronal cells from DPSCs (DF-DPSCs), a total of 1 × 10 hDPSCs or DF-hDPSCs labeled with PKH26 tracking dye and supplemented with fibrin glue scaffold and collagen tubulization were transplanted into the sciatic nerve resection (5-mm gap) of rat models. At 12 weeks after cell transplantation, both hDPSC and DF-hDPSC groups showed notably increased behavioral activities and higher muscle contraction forces compared with those in the non-cell transplanted control group. In immunohistochemical analysis of regenerated nerve specimens, specific markers for angiogenesis, axonal fiber, and myelin sheath increased in both the cell transplantation groups. Pretransplanted labeled PKH26 were also distinctly detected in the regenerated nerve tissues, indicating that transplanted cells were well-preserved and differentiated into nerve cells. Furthermore, no difference was observed in the nerve regeneration potential between the hDPSC and DF-hDPSC transplanted groups. These results demonstrate that dental pulp tissue is an excellent stem cell source for nerve regeneration, and in vivo transplantation of the undifferentiated hDPSCs could exhibit sufficient and excellent peripheral nerve regeneration potential.

Cholinergic Nerve Differentiation of Mesenchymal Stem Cells Derived from Long-Term Cryopreserved Human Dental Pulp In Vitro and Analysis of Their Motor Nerve Regeneration Potential In Vivo

“…In light of these observations, the present study demonstrated that long-term preserved dental pulp tissues stored under the newly developed tissue cryopreservation protocol could safely conserve multipotent stem cells, as shown by the same MSC characteristics as those derived from fresh dental pulp tissues. Both hDPSCs-fresh and hDPSCs-cryo showed the same cell morphology, proliferation rates, cell-surface markers expression, and in vitro differentiation potential as the mesenchymal lineage [15,16,24]. In accordance with previous reports, hDPSCs-cryo used in this study retained their MSC characteristics and were shown to positively express early transcription factors (Nanog, Oct4, Sox2) and MSC markers (CD29, CD73, CD90), and successfully differentiate into the mesenchymal lineage (osteocytes, adipocytes, and chondrocytes).…”

“…In order to investigate the scale of motor nerve regeneration in vivo, DF-chN were transplanted into experimental rats with sciatic nerve defects using collagen tubulization and a fibrin glue scaffold. In this study, biodegradable bovine collagen dura mater (Lyoplant ® , Aesculap, Melsungen, Germany) was contoured and sutured to create the tube and bridging for the resected nerve ends, as per previous studies [11,16]. This tubulization provided a mechanical support system for regenerating and remodeling nerve fibers.…”

“…This tubulization provided a mechanical support system for regenerating and remodeling nerve fibers. The resected nerve gap was filled with cells and a fibrin glue scaffold (Greenplast ® , Green Cross, Yongin, Korea), which was frequently used as a cell delivery system since it rapidly increases the initial stability of grafted cells and permits a stable three-dimensional structure for transplanted cells [11,16]. …”

“…The OFT is an approved locomotor and behavioral assessment method for small animals, including mice and rats, and is widely used to for the behavioral analysis of experimental animals [16,35,36]. The result of the OFT demonstrated that the DF-chN transplanted group showed a significantly improved walking ability (velocity), distance moved, and number of wall climbs completed, as compared to the control group.…”

“…MSCs from bone marrow, skin, umbilical cord, muscle, and dental tissues successfully differentiate into neuron- or Schwann cell-like cells [10,11,12,13,14,15,16,17,18,19]. In particular, dental pulp-derived stem cells (DPSCs) displayed MSC characteristics and powerful neurogenic differentiation potential in vitro and in vivo [15,16,17,18,19]. One hypothesis explaining this ability is that the origin of dental pulp from the neural crest allows DPSCs to easily differentiate into neuronal cells compared to other cell lines [20].…”