GFP Labeling and Hepatic Differentiation Potential of Human Placenta-Derived Mesenchymal Stem Cells.

BACKGROUND: Stem cell-based therapy in liver diseases has received increasing interest over the past decade, but direct evidence of the homing and implantation of transplanted cells is conflicting. Reliable labeling and tracking techniques are essential but lacking. The purpose of this study was to establish human placenta-derived mesenchymal stem cells (hPMSCs) expressing green fluorescent protein (GFP) and to assay their hepatic functional differentiation in vitro. METHODS: The GFP gene was transduced into hPMSCs using a lentivirus to establish GFP(+) hPMSCs. GFP(+) hPMSCs were analyzed for their phenotypic profile, viability and adipogenic, osteogenic and hepatic differentiation. The derived GFP(+) hepatocyte-like cells were evaluated for their metabolic, synthetic and secretory functions, respectively. RESULTS: GFP(+) hPMSCs expressed high levels of HLA I, CD13, CD105, CD73, CD90, CD44 and CD29, but were negative for HLA II, CD45, CD31, CD34, CD133, CD271 and CD79. They possessed adipogenic, osteogenic and hepatic differentiation potential. Hepatocyte-like cells derived from GFP(+) hPMSCs showed typical hepatic phenotypes. CONCLUSIONS: GFP gene transduction has no adverse influences on the cellular or biochemical properties of hPMSCs or markers. GFP gene transduction using lentiviral vectors is a reliable labeling and tracking method. GFP(+) hPMSCs can therefore serve as a tool to investigate the mechanisms of MSC-based therapy, including hepatic disease therapy.

A Systematic Analysis Reveals the Prognostic and Immunological Role of Reptin/RUVBL2 in Human Tumors.

Reptin/RUVBL2 is involved in the remodeling of chromatin, DNA damage repair, and regulation of the cell cycle, all of which help to play essential roles in cancer. However, relevant pan-cancer analysis of Reptin is lacking. This study first investigated the potential oncogenic roles of Reptin and revealed a relationship between Reptin with clinicopathological characteristics and immune infiltration based on big data. Here, we showed that Reptin is overexpressed in many cancers. A significant association exists between the expression of Reptin and the prognosis of cancer cases. Reptin had a meaningful interaction with the immune infiltration of CD4+ Th1 cells and immune modulator genes in multiple cancer types. And negative correlation exists between Reptin and cancer-associated fibroblasts in BRCA, PRAD, TGCT, and THYM. A significant negative association exists between Reptin and regulatory T cells in TGCT and THCA. Moreover, Reptin is significantly associated with genomic heterogeneity, DNA mismatch repair genes, methyltransferase, and RNA modification genes in specific cancer types. Spliceosome, Hippo signaling pathway, DNA replication pathway, and acetyltransferase activity-associated functions were observed in the effect of Reptin on the tumor. This systematic analysis highlights Reptin as a vital cancer regulator among numerous genes and proved its potential prognosticator value and therapeutic target role for specific tumor types.

Hierarchical porous ZnMnO3 yolk-shell microspheres with superior lithium storage properties enabled by a unique one-step conversion mechanism.

ZnMnO3 has attracted enormous attention as a novel anode material for rechargeable lithium-ion batteries due to its high theoretical capacity. However, it suffers from capacity fading because of the large volumetric change during cycling. Here, porous ZnMnO3 yolk-shell microspheres are developed through a facile and scalable synthesis approach. This ZnMnO3 can effectively accommodate the large volume change upon cycling, leading to an excellent cycling stability. When applying this ZnMnO3 as the anode in lithium-ion batteries, it shows a remarkable reversible capacity (400 mA h g-1 at a current density of 400 mA g-1 and 200 mA h g-1 at 6400 mA g-1) and excellent cycling performance (540 mA h g-1 after 300 cycles at 400 mA g-1) due to its unique structure. Furthermore, a novel conversion reaction mechanism of the ZnMnO3 is revealed: ZnMnO3 is first converted into intermediate phases of ZnO and MnO, after which MnO is further reduced to metallic Mn while ZnO remains stable, avoiding the serious pulverization of the electrode brought about by lithiation of ZnO.

Homology modeling and molecular dynamics simulation of the HIF2α degradation-related HIF2α-VHL complex.

BACKGROUND: Hypoxia-inducible factor 2 alpha (HIF2α), prolyl hydroxylase domain protein 2 (PHD2), and the von Hippel Lindau tumor suppressor protein (pVHL) are three principal proteins in the oxygen-sensing pathway. Under normoxic conditions, a conserved proline in HIF2α is hydroxylated by PHD2 in an oxygen-dependent manner, and then pVHL binds and promotes the degradation of HIF2α. However, the crystal structure of the HIF2α-pVHL complex has not yet been established, and this has limited research on the interaction between HIF and pVHL. Here, we constructed a structural model of a 23-residue HIF2α peptide (528-550)-pVHL-ElonginB-ElonginC complex by using homology modeling and molecular dynamics simulations. We also applied these methods to HIF2α mutants (HYP531PRO, F540L, A530 V, A530T, and G537R) to reveal structural defects that explain how these mutations weaken the interaction with pVHL. METHODS: Homology modeling and molecular dynamics simulations were used to construct a three-dimensional (3D) structural model of the HIF2α-VHL complex. Subsequently, MolProbity, an active validation tool, was used to analyze the reliability of the model. Molecular mechanics energies combined with the generalized Born and surface area continuum solvation (MM-GBSA) and solvated interaction energy (SIE) methods were used to calculate the binding free energy between HIF2a and pVHL, and the stability of the simulation system was evaluated by using root mean square deviation (RMSD) analysis. We also determined the secondary structure of the system by using the definition of secondary structure of proteins (DSSP) algorithm. Finally, we investigated the structural significance of specific point mutations known to have clinical implications. RESULTS: We established a reliable structural model of the HIF2α-pVHL complex, which is similar to the crystal structure of HIF1α in 1LQB. Furthermore, we compared the structural model of the HIF2α-pVHL complex and the HIF2α (HYP531P, F540L, A530V, A530T, and G537R)-pVHL mutants on the basis of RMSD, DSSP, binding free energy, and hydrogen bonding. The experimental data indicate that the stability of the structural model of the HIF2α-pVHL complex is higher than that of the mutants, consistently with clinical observations. CONCLUSIONS: The structural model of the HIF2α-pVHL complex presented in this study enhances understanding of how HIF2α is captured by pVHL. Moreover, the important contact amino acids that we identified may be useful in the development of drugs to treat HIF2a-related diseases.

UPLC-MS-based serum metabonomics for identifying acute liver injury biomarkers in Chinese miniature pigs.

Metabonomics has emerged as an important technology for exploring the underlying mechanisms of diseases and screening for biomarkers. In this investigation, to comprehensively assess metabolite changes in D-galactosamine (GalN)-induced liver injury in Chinese miniature pigs and to increase our understanding of physiological changes in normal and pathological states, we used ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) to analyze metabolites and identify biomarkers in serum. Blood samples were collected both from 18 h after GalN treatment group and control group pigs. We performed multivariate analyses on the metabolite profiles to identify potential biomarkers of acute liver injury, which were then confirmed by tandem MS. Based on "variable of importance in the project" (VIP) values and S-plots, four groups of biomarkers were identified--namely conjugated bile acids, lysophosphatidylcholines (LPCs), phosphatidylcholines (PCs) and fatty acid amides (FAAs)--that were present at significantly different levels in the control and GalN-induced groups. LPCs, PCs, and FAAs showed marked decreases in the GalN-treated group, whereas conjugated bile acids in the treated group showed considerable increases. Taken together, our results suggested that obvious metabolic disturbances occur during acute liver injury, which provided novel insights into the molecular mechanism(s) of D-galactosamine (GalN)-induced liver injury, and will facilitate future research and management of liver injury.