Stem Cell Research & Therapy (Jun 2020)

Transplantation of human dental pulp stem cells ameliorates diabetic polyneuropathy in streptozotocin-induced diabetic nude mice: the role of angiogenic and neurotrophic factors

  • Masaki Hata,
  • Maiko Omi,
  • Yasuko Kobayashi,
  • Nobuhisa Nakamura,
  • Megumi Miyabe,
  • Mizuho Ito,
  • Eriko Makino,
  • Saki Kanada,
  • Tomokazu Saiki,
  • Tasuku Ohno,
  • Yuka Imanishi,
  • Tatsuhito Himeno,
  • Hideki Kamiya,
  • Jiro Nakamura,
  • Shogo Ozawa,
  • Ken Miyazawa,
  • Kenichi Kurita,
  • Shigemi Goto,
  • Jun Takebe,
  • Tatsuaki Matsubara,
  • Keiko Naruse

DOI
https://doi.org/10.1186/s13287-020-01758-9
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 11

Abstract

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Abstract Background Dental pulp stem cells (DPSCs) have high proliferation and multi-differentiation capabilities that maintain their functionality after cryopreservation. In our previous study, we demonstrated that cryopreserved rat DPSCs improved diabetic polyneuropathy and that the efficacy of cryopreserved rat DPSCs was equivalent to that of freshly isolated rat DPSCs. The present study was conducted to evaluate whether transplantation of cryopreserved human DPSCs (hDPSCs) is also effective for the treatment of diabetic polyneuropathy. Methods hDPSCs were isolated from human impacted third molars being extracted for orthodontic reasons. Eight weeks after the induction of diabetes in nude mice, hDPSCs (1 × 105/limb) were unilaterally transplanted into the hindlimb skeletal muscle, and vehicle (saline) was injected into the opposite side as a control. The effects of hDPSCs were analyzed at 4 weeks after transplantation. Results hDPSC transplantation significantly ameliorated reduced sensory perception thresholds, delayed nerve conduction velocity, and decreased the blood flow to the sciatic nerve in diabetic mice 4 weeks post-transplantation. Cultured hDPSCs secreted the vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) proteins. A subset of the transplanted hDPSCs was localized around the muscle bundles and expressed the human VEGF and NGF genes at the transplanted site. The capillary/muscle bundle ratio was significantly increased on the hDPSC-transplanted side of the gastrocnemius muscles in diabetic mice. Neutralizing antibodies against VEGF and NGF negated the effects of hDPSC transplantation on the nerve conduction velocity in diabetic mice, suggesting that VEGF and NGF may play roles in the effects of hDPSC transplantation on diabetic polyneuropathy. Conclusions These results suggest that stem cell transplantation with hDPSCs may be efficacious in treating diabetic polyneuropathy via the angiogenic and neurotrophic mechanisms of hDPSC-secreted factors.

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