Transplantation of cultured dental pulp stem cells into the skeletal muscles ameliorated diabetic polyneuropathy: therapeutic plausibility of freshly isolated and cryopreserved dental pulp stem cells.
BACKGROUND
Dental pulp stem cells (DPSCs) are mesenchymal stem cells located in dental pulp and are thought to be a potential source for cell therapy since DPSCs can be easily obtained from teeth extracted for orthodontic reasons. Obtained DPSCs can be cryopreserved until necessary and thawed and expanded when needed. The aim of this study is to evaluate the therapeutic potential of DPSC transplantation for diabetic polyneuropathy.


METHODS
DPSCs isolated from the dental pulp of extracted incisors of Sprague-Dawley rats were partly frozen in a -80 °C freezer for 6 months. Cultured DPSCs were transplanted into the unilateral hindlimb skeletal muscles 8 weeks after streptozotocine injection and the effects of DPSC transplantation were evaluated 4 weeks after the transplantation.


RESULTS
Transplantation of DPSCs significantly improved the impaired sciatic nerve blood flow, sciatic motor/sensory nerve conduction velocity, capillary number to muscle fiber ratio and intra-epidermal nerve fiber density in the transplanted side of diabetic rats. Cryopreservation of DPSCs did not impair their proliferative or differential ability. The transplantation of cryopreserved DPSCs ameliorated sciatic nerve blood flow and sciatic nerve conduction velocity as well as freshly isolated DPSCs.


CONCLUSIONS
We demonstrated the effectiveness of DPSC transplantation for diabetic polyneuropathy even when using cryopreserved DPSCs, suggesting that the transplantation of DPSCs could be a promising tool for the treatment of diabetic neuropathy.
Department of Removable Prosthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. hata@dpc.agu.ac.jp.
Masaki
M
Hata
Department of Removable Prosthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. ag123d06@dpc.agu.ac.jp.
Maiko
M
Omi
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. totoko721@hotmail.com.
Yasuko
Y
Kobayashi
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. nnaka@dpc.agu.ac.jp.
Nobuhisa
N
Nakamura
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. nrd49075@nifty.com.
Takahiro
T
Tosaki
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. mmiyabe@dpc.agu.ac.jp.
Megumi
M
Miyabe
Department of Removable Prosthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. norinagakojima@yahoo.co.jp.
Norinaga
N
Kojima
Department of Oral Pathology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. bobo@dpc.agu.ac.jp.
Katsutoshi
K
Kubo
Department of Removable Prosthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. ozawa@dpc.aichi-gakuin.ac.jp.
Shogo
S
Ozawa
Department of Oral Pathology, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. hatsu@dpc.aichi-gakuin.ac.jp.
Hatsuhiko
H
Maeda
Department of Removable Prosthodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. kishin@dpc.agu.ac.jp.
Yoshinobu
Y
Tanaka
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. matt@dpc.agu.ac.jp.
Tatsuaki
T
Matsubara
Department of Internal Medicine, School of Dentistry, Aichi Gakuin University, Nagoya, Japan. narusek@dpc.agu.ac.jp.
Keiko
K
Naruse
D000818:Animals; D002478:Cells, Cultured; D015925:Cryopreservation / Q000379:methods; D003782:Dental Pulp / Q000166:cytology; D003929:Diabetic Neuropathies / Q000628:therapy*; D059630:Mesenchymal Stem Cells / Q000166:cytology; D018482:Muscle, Skeletal / Q000502:physiology*; D009416:Nerve Regeneration; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000502:physiology*; D033581:Stem Cell Transplantation / Q000379:methods*