Aims/Introduction: We previously reported that stem cell transplantation into limb skeletal muscle improved diabetic polyneuropathy (DPN) in diabetic animal models. In this study, we examined whether the secreted factors from stem cells from human exfoliated deciduous teeth (SHED) had beneficial effects on DPN.
Materials and Methods: The conditioned medium from SHED(SHED-CM) was collected 48 hours after culturing in serum-free DMEM and was separated into four fractions according to molecular weight. Dorsal root ganglion (DRG) neurons isolated from C57BL/6J mice were cultured with SHED-CM, each fraction of SHED-CM or DMEM. Streptozotocin induced diabetic mice were injected with 100µl of SHED-CM or DMEM into unilateral hindlimb muscles twice a week over 4 weeks. Peripheral nerve functions were evaluated by the plantar test and motor and sensory nerve conduction velocities (MNCV and SNCV). Intraepidermal nerve fiber densities (IENFDs), capillary number-to-muscle fiber ratio (CNMFR) and morphometry of sural nerves were also evaluated. The angiogenic profile of SHED-CM was evaluated by MTT, transwell migration, and wound healing assay using human umbilical vein endothelial cells (HUVECs).
Results: SHED-CM significantly promoted neurite outgrowth of DRG neurons. Only less than 6 kDa of SHED-CM promoted the neurite outgrowth. SHED-CM significantly prevented decline in SNCVs compared with DMEM in diabetic mice. SHED-CM did not cause any change in MNCVs or sensory functions. Though SHED-CM did not improve IENFDs or morphometry of sural nerves, CNMFR was ameliorated by the administration of SHED-CM. SHED-CM significantly increased the proliferation and the migration of HUVECs.
Conclusions: These results suggested that SHED-CM had the therapeutic effect on DPN by promoting neurite outgrowths and improving microcirculation in peripheral nerves.
E. Miura-Yura: None. S. Tsunekawa: None. K. Naruse: None. M. Kawai: None. M. Kato: None. H. Shimoda: None. Y. Yamada: None. M. Motegi: None. S. Asano: None. T. Himeno: None. M. Kondo: None. Y. Kato: Speaker's Bureau; Self; Merck & Co., Inc. J. Nakamura: Research Support; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Eli Lilly and Company, Japan Tobacco Inc., Kissei Pharmaceutical Co., Ltd., Merck Sharp & Dohme Corp., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi K.K., Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited. Speaker's Bureau; Self; Astellas Pharma Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Eli Lilly and Company, Kowa Pharmaceu. Co. Ltd., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi K.K., Takeda Pharmaceutical Company Limited, Terumo Medical Corporation. H. Kamiya: Speaker's Bureau; Self; Astellas Pharma Inc., Eli Lilly Japan K.K., MSD K.K., Novartis Pharma K.K., Novo Nordisk Oharma Ltd., Ono Pharmaceutical Co., Ltd., Sanofi K.K.