Enhanced PDGF signaling in gestational diabetes mellitus is involved in pancreatic ß-cell dysfunction.

Gestational diabetes mellitus (GDM) is often accompanied by the development of hyperinsulinemia as an adaptation to increased insulin demand, but this subsequently causes insulin resistance. Loss of function in pancreatic ß-cells further aggravates the development of GDM. The level of serum platelet-derived growth factor (PDGF) reportedly increases in GDM patients. The present study investigated whether enhanced PDGF signaling directly causes ß-cell dysfunction during gestation. Serum PDGF levels were negatively correlated with ß-cell function in GDM patients. Administration of PDGF-BB disrupted glucose tolerance and ß-cell function without inducing apoptosis in gestational mice but had no similar effect in non-gestational mice. The ß-cell-specific genes encoding insulin synthesis proteins were decreased in the islets of PDGF-BB-treated gestational mice. In vitro experiments using INS1 insulinoma cells showed that PDGF-BB promoted cell proliferation, whereas it downregulated ß-cell-specific genes. Taken together, these findings suggested that PDGF reduces ß-cell function during gestation possibly through ß-cell dedifferentiation.

Biocompatibility of Fe3O4/DNR magnetic nanoparticles in the treatment of hematologic malignancies.

PURPOSE: The objectives of this research were to assess the biocompatibility of self-assembled Fe(3)O(4) magnetic nanoparticles (MNPs) loaded with daunorubicin (DNR), ie, (Fe(3)O(4)-MNPs/DNR), and to explore their potential application in the treatment of hematologic malignancies. METHODS: A hemolysis test was carried out to estimate the hematologic toxicity of Fe(3)O(4)- MNPs/DNR and a micronucleus assay was undertaken to identify its genotoxicity. Fe(3)O(4)-MNPs/ DNR were injected intraperitoneally into mice to calculate the median lethal dose (LD(50)). The general condition of the mice was recorded, along with testing for acute toxicity to the liver and kidneys. RESULTS: Hemolysis rates were 2.908%, 2.530%, and 2.415% after treatment with different concentrations of Fe(3)O(4)-MNPs/DNR. In the micronucleus assay, there was no significant difference in micronucleus formation rate between the experimental Fe(3)O(4)-MNPs/DNR groups and negative controls (P > 0.05), but there was a significant difference between the experimental groups and the positive controls (P < 0.05). The LD(50) of the Fe(3)O(4)-MNPs/DNR was 1009.71 mg/kg and the 95% confidence interval (CI) was 769.11-1262.40 mg/kg, while that of the DNR groups was 8.51 mg/kg (95% CI: 6.48-10.37 mg/kg), suggesting that these nanoparticles have a wide safety margin. Acute toxicity testing showed no significant difference in body weight between the treatment groups at 24, 48, and 72 hours after intraperitoneal injection. The mice were all in good condition, with normal consumption of water and food, and their stools were formed and yellowish-brown. Interestingly, no toxic reactions, including instability of gait, convulsion, paralysis, and respiratory depression, were observed. Furthermore, alanine transaminase, blood urea nitrogen, and creatinine clearance in the experimental Fe(3)O(4)-MNPs/ DNR groups were 66.0 ± 28.55 U/L, 9.06 ± 1.05 mmol/L, and 18.03 ± 1.84 µmol/L, respectively, which was not significantly different compared with the control and isodose DNR groups. CONCLUSION: Self-assembled Fe(3)O(4)-MNPs/DNR appear to be highly biocompatible and safe nanoparticles, and may be suitable for further application in the treatment of hematologic malignancies.