OBJECTIVE-Mesenchymal stem cells (MSCs) have been reported to secrete various cytokines that exhibit angiogenic and neurosupportive effects. This study was conducted to investigate the effects of MSC transplantation on diabetic polyneuropathy (DPN) in rats.RESEARCH DESIGN AND METHODS-MSCs were isolated from bone marrow of adult rats and transplanted into hind limb skeletal muscles of rats with an 8-week duration of streptozotocin (STZ)-induced diabetes or age-matched normal rats by unilateral intramuscular injection. Four weeks after transplantation, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) productions in transplanted sites, current perception threshold, nerve conduction velocity (NCV), sciatic nerve blood flow (SNBF), capillary number-to-muscle fiber ratio in soleus muscles, and sural nerve morphometry were evaluated.RESULTS-VEGF and bFGF mRNA expression were significantly increased in MSC-injected thigh muscles of STZ-induced diabetic rats. Furthermore, colocalization of MSCs with VEGF and bFGF in the transplanted sites was confirmed. STZ-induced diabetic rats showed hypoalgesia, delayed NCV, decreased SNBF, and decreased capillary number-to-muscle fiber ratio in soleus muscles, which were all ameliorated by MSC transplantation. Sural nerve morphometry showed decreased axonal circularity in STZ-induced diabetic rats, which was normalized by MSC transplantation. D iabetic polyneuropathy (DPN) is the most common complication of diabetes. It is estimated that ϳ20 -30% of diabetic patients are affected by symptomatic DPN (1). Generally, DPN develops symmetrically in a length-dependent fashion, with dying back or dropout of the longest nerve fibers; both myelinated and unmyelinated, large and small are affected. Diabetic patients suffer from various symptoms of DPN, such as spontaneous pain, hyperalgesia, and diminished sensation (2). It has been shown that tight glycemic control is effective in slowing the progression of DPN but cannot completely prevent it (3). Therefore, additional therapeutic strategies are required. CONCLUSIONS-TheseNeural cell degeneration and decreased nerve blood flow (NBF) have been recognized as pathophysiologically characteristic features of DPN (4). Therefore, therapeutic agents that could act as both neurotrophic and angiogenic factors would be useful for the treatment of DPN even at an advanced stage. We previously demonstrated that local administration of basic fibroblast growth factor (bFGF) by intramusclar injection with crosslinked gelatin hydrogel improved the impaired nerve functions of streptozotocin (STZ)-induced diabetic rats, including amelioration of decreased NBF, hypoalgesia, and the delayed motor nerve conduction velocity (MNCV) on the treated side of sciatictibial nerves and that these effects were maintained for at least 30 days (5). Schratzberger et al. (6) showed that vascular endothelial growth factor (VEGF) gene transfer significantly increased the NCV and NBF as well as the vascular densities in muscle and peripheral nerv...

IntroductionDental 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.MethodsDPSCs 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.ResultsTransplantation 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.ConclusionsWe 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-015-0156-4) contains supplementary material, which is available to authorized users.

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This is the first study to confirm increased nitrosative stress due to periodontitis in diabetic rats. Nitrosative stress may play a crucial role in the exacerbation of periodontitis in diabetic patients.

Objective and Methods An SGLT2 inhibitor (ipragliflozin, dapagliflozin, luseogliflozin, tofogliflozin, or canagliflozin) was administered to 132 outpatients with type 2 diabetes mellitus with or without other antidiabetic drugs for 6 months to evaluate its efficacy, the incidence of adverse events, and its influence on the renal function. Results The patient's mean glycated hemoglobin level significantly improved from 7.52±1.16% to 6.95± 0.98% (p<0.001). The body weight of the patients was significantly reduced from 78.0±15.3 kg to 75.6±15.1 kg (p<0.001). The estimated visceral fat area was also significantly reduced from 108.4±44.6 cm 2 to 94.5± 45.3 cm 2 (p<0.001). The waist circumference, blood pressure, serum alanine aminotransferase, γ-glutamyl transpeptidase, and uric acid levels also showed a significant decrease. The urinary albumin/creatinine ratio (U-ACR) was significantly reduced in the patients whose U-ACR levels were 30-300 mg/gCr at the baseline. The mean eGFR significantly decreased in the patients with a pre-treatment eGFR value of ! 90 mL/min/1.73 m 2 but remained unchanged in the patients with a pre-treatment value of <90 mL/min/1.73 m 2 . A total of 13 adverse events were noted, including systemic eruption (n=1), cystitis (n=2), pudendal pruritus (n=2), nausea (n=1), malaise (n=1), a strong hunger sensation and increased food ingestion (n=1), and non-serious hypoglycemia (n=5). Conclusion SGLT2 inhibitors seemed to be useful in the treatment of obese type 2 diabetes mellitus patients. Furthermore, these data suggest that SGLT2 inhibitors may protect the renal function.