[Differential expression of pro-angiogenic miRNAs in dental tissue-derived stem cells under hypoxia].

PURPOSE: To explore pro-angiogenic miRNAs differentially expressed in dental tissue-derived stem cells under hypoxia. METHODS: Stem cells from apical papilla, dental pulp stem cells and periodontal ligament stem cells were obtained from 3 patients, and treated with nomoxia or hypoxia for 1, 3, 5 d, respectively. Real-time PCR was performed to evaluate the expression of 9 specifically identified pro-angiogenic miRNAs and HIF-1α. SPSS 19.0 software package was used for statistical analysis. RESULTS: At the fifth day of hypoxic condition, as for SCAPs, the expression of miR-126 was relatively increased while miR-20a, miR-20b, miR-21, miR-130a, miR-132, miR-210 and miR-503 deceased. As for DPSCs, the expression of miR-21, miR-130a, miR-126 and miR-210 were relatively increased while miR-132 decreased. As for PDLSCs, the expression of miR-126, miR-21 and miR-296 were relatively increased. Finally, the expression of HIF-1α was relatively upregulated in all three type of cells. CONCLUSIONS: Pro-angiogenic miRNAs in dental tissue-derived stem cells under hypoxia exists specific expression profile.

Proteome analysis of maize seeds: the effect of artificial ageing.

Previous understanding of the mechanism of seed ageing is largely based on observations on imbibed seeds rather than dry seeds. The present research was conducted to investigate whether seed ageing has effects on the dry seeds through proteome analysis. Maize (Zea mays cv. Dabaitou) seeds were artificially aged at 50°C (13.58% moisture content) for 5 or 13 days, and the total protein was extracted from embryos of the dry seeds. Two-dimensional electrophoresis was performed and the differentially expressed proteins were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. A total of 40 proteins were identified, in which 16 proteins were upregulated, indicating that artificial ageing affected the proteome of the dry seeds. Proteomic studies revealed that the signal transduction and transcription were disturbed by artificial ageing, which might lead to reduced protection against ageing. Artificial ageing also increased proteases and broke down stored proteins, impaired metabolism and energy supply, and ultimately resulted in seed deterioration. Proteins involved in metabolism and energy were the largest downregulated protein group, with regard to glycolysis, tricarboxylic acid cycle, the electron transport chain and oxidative phosphorylation. The downregulation of these proteins, together with reduction in the specific activity of glucose-6-phosphate dehydrogenase, and the content of glucose 6-phosphate, pyruvic acid and ATP in aged seeds, suggested the important roles of the mobilization of stored carbohydrates and energy supply in seed ageing and seed vigor. The present work provides new information about the proteomic changes during seed ageing and provides a possible mechanism for seed deterioration.