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Human umbilical cord mesenchymal stem cells (HUC-MSCs) are pluripotent and functional in many biological processes, by which releasing secretary factors to promote the self-repairing of damaged tissue or developing into functional cell at local organ. However, there is a high risk that oxidative stress would reduce the pluripotency and factor-secretion during the preparation and transplantation. Therefore, reducing oxidative stress is expected to improve the efficacy of HUC-MSCs therapy. Zinc (Zn) is an essential trace element which involves in the resistance of oxidative stress. To investigate Zn-regulated signaling pathways, we have profiled the gene expression at transcriptome level in primary HUC-MSCs treated with zinc sulfate, followed with GO and KEGG gene enrichment analysis. Zn treatment improved signal pathways for mineral absorption, cell growth, and cell death. Zn deficiency was mimicked by TPEN administration, which suppressed cell proliferation and reduced the expression of HUC-MSCs surface stem cell markers CD73, CD90 and CD105 by flow cytometry. Nuclear factor erythrocyte 2 related factor 2 (Nrf2) plays an important role in antioxidant biological processes. In vitro treatment of Zn significantly increased Nrf2 and Sirt3 expression at gene level and protein level respectively. Zn supplementation inhibited TPEN-induced failure of cell survival and reversed the reduction of Nrf2 and Sirt3 expression, which further reduced the production of ROS. Zn successfully presented its anti-oxidation effect by activating Nrf2/Sirt3 signaling pathway in HUC-MSCs. Zn supplementation may improve the efficacy of HUC-MSCs therapy with reduced oxidative stress.

The peptide obtained from walnut protein enzymatic hydrolysate had high ACE inhibitory activity. Through centrifugation, ultrafiltration, gel chromatography and high performance liquid chromatography (HPLC), the walnut oligo-peptide, which was denoted as P4-c with high ACE inhibitory activity was obtained. Three novel ACE inhibitory peptides, GVVPHN, EHSLDPLK and KTLLNFGPN, were identified from P4-c by high-resolution ion mobility mass spectrometry (IM-MS). The three novel ACE inhibitory peptides possessed good ACE inhibitory activity and the fraction GVVPHN had high ACE inhibitory activity with 27.3 µmol L−1 of IC50. The molar percentage of hydrophobic amino acids in the peptide GVVPHN was 50% while the hydrophobic amino acid contents of EHSLDPLK and KTLLNFGPN were 37.5% and 44.4%, respectively, which indicates ACE inhibitory activities were hydrophobicity of amino acid-dependent.

In experimental stroke research, anesthesia is common and serves as a major reason for translational failure. Real-time cerebral blood flow (CBF) monitoring during stroke onset can provide important information for the prediction of brain injury; however, this is difficult to achieve in clinical practice due to various technical problems. We created a photothrombotic focal ischemic stroke model utilizing our self-developed miniature headstage in conscious and freely moving rats. In this model, a high spatiotemporal resolution imager using laser speckle contrast imaging technology was integrated to acquire real-time two-dimensional CBF information during thrombosis. The feasibility, stability, and reliability of the system were tested in terms of CBF, behavior, and T2-weighted magnetic resonance imaging (MRI) findings. After completion of occlusion, the CBF in the targeted cortex of the stroke group was reduced to 16 � 9% of the baseline value. The mean infarct volume measured by MRI 24 h postmodeling was 77 � 11 mm 3 and correlated well with CBF (R 2 ¼ 0.74). This rodent model of focal cerebral ischemia and real-time blood flow imaging opens the possibility of performing various fundamental and translational studies on stroke without the influence of anesthetics. © 2014 Society of Photo-Optical