Levan is an exopolysaccharide produced by Bacillus licheniformis (strain FRI MY-55) that shows promising pharmacological activity. Phosphorylation is a chemical modification that can increase the ...biological and antioxidant properties of levan. In this study, levan was phosphorylated by microwave-assisted synthesis to achieve a degree of substitution of 0.29. The hydroxyl radical scavenging activity of microwave-assisted phosphorylated levan (microwave P) increased significantly (6-fold) over native levan; this activity was only slightly lower than vitamin C. Other free radical scavenging and reducing power tests revealed that Microwave P activity was increased by 30–40%. Microwave P inhibited the proliferation of HCT-116 and A549 cancer cell lines more readily than native levan with an IC50 of 1.03 mg/mL and 1.38 mg/mL for HCT-116 and A549 cells, respectively. Cells treated with native levan and its derivatives remained in the sub-G1 phase according to cell cycle analysis, whereas Microwave P treatment increased the proportion of cells undergoing apoptosis. Furthermore, Microwave P effectively upregulated pro-apoptosis marker Bax and downregulated anti-apoptosis marker Bcl-2, in addition to inducing the expression of caspase-9 and caspase-3. These findings show that levan phosphorylated via microwave-assisted synthesis showed increased antioxidant and antitumor activity over native levan or levan phosphorylated via traditional long-term heating. In particular, Microwave P possesses antiproliferative activity and can induce apoptosis through mitochondrial pathways in cancerous cells.
Electrodeposition of Al, Mn, Ni, Zn, Sn, and Cu are successfully demonstrnated in the ionic liquids (ILs) composed of 1-methyl-3-alkylimidazolium or
N-methyl-
N-alkylpyrrolidinium cations with ...dicyanamide (DCA) anions. The DCA-based room-temperature ILs exhibit lower viscosities than those ILs based on
BF
4
-
,
PF
6
-
, and bis(trifluoromethylsulfonyl)imide (TFSI) anions. While most of the metal chlorides are insoluble in the
BF
4
-
,
PF
6
-
, and TFSI-based ILs, they exhibit good solubility in DCA-based ILs due to the strong complexing ability of DCA toward the transition metal ions. It is possible to alter the regular reduction sequence for particular metal ions in the DCA-based ILs.
The exclusive single-phase with the exact chemical composition of the constituent phase in 2205 duplex stainless steel (DSS) could be prepared using selective dissolution method. The respective ...electrochemical behavior of each constituent phase could then be measured. The experimental results showed that the two distinct peaks in the active-to-passive transition region of the polarization curve determined in 2
M H
2SO
4
+
0.5
M HCl mixed solution were actually corresponded to the respective anodic peaks of the single austenite and ferrite phases. A polarity reversion was found between austenite and ferrite phases in mixed H
2SO
4
+
HCl solution and HNO
3 solution. Galvanic current measurements also revealed that austenite was anode in HNO
3 solution, but became cathode when exposed in 2
M H
2SO
4
+
0.5
M HCl mixed solution.
Recent studies have shown that adult tissues contain stem/ progenitor cells capable of not only generating mature cells of their tissue of origin but also transdifferentiating themselves into other ...tissue cells. Murine skin‐derived precursor cells, for example, have been described as unique, nonmesenchymal‐like stem cells capable of mesodermal and ectodermal neurogenic differentiation. Human‐derived skin precursors are less well characterized.
In this study, the isolation and characterization of adherent, mesenchymal stem cell–like cells from human scalp tissue (hSCPs) are described. hSCPs initially isolated by both medium‐selection (ms‐hSCPs) and single‐cell (c‐hSCPs) methods were cultured in medium containing epidermal growth factor and fibroblast growth factor‐β. Cultured ms‐hSCPs and c‐hSCPs demonstrated a consistent growth rate, continuously replicated in cell culture, and displayed a stable phenotype indistinguishable from each other. Both hSCPs expressed surface antigen profile (CDw90, SH2, SH4, CD105, CD166, CD44, CD49d‐e, and HLA class I) similar to that of bone marrow mesenchymal stem cells (BM‐MSCs). The growth kinetics, surface epitopes, and differentiation potential of c‐hSCP cells were characterized and compared with BM‐MSCs. In addition to differentiation along the osteogenic, chondrogenic, and adipogenic lineages, hSCPs can effectively differentiate into neuronal precursors evident by neurogenic gene expression of glial fibrillary acid protein, NCAM, neuron filament‐M, and microtubule‐associated protein 2 transcripts. Therefore, hSCPs may potentially be a better alternative of BM‐MSCs for neural repairing, in addition to their other mesenchymal regenerative capacity. Our study suggests that hSCPs may provide an alternative adult stem cell resource that may be useful for regenerative tissue repair and autotransplantations.
Wnts were previously shown to regulate the neurogenesis of neural stem or progenitor cells. Here, we explored the underlying molecular mechanisms through which Wnt signaling regulates neurotrophins ...(NTs) in the NT-induced neuronal differentiation of human mesenchymal stem cells (hMSCs). NTs can increase the expression of Wnt1 and Wnt7a in hMSCs. However, only Wnt7a enables the expression of synapsin-1, a synaptic marker in mature neurons, to be induced and triggers the formation of cholinergic and dopaminergic neurons. Human recombinant (hr)Wnt7a and general neuron makers were positively correlated in a dose- and time-dependent manner. In addition, the expression of synaptic markers and neurites was induced by Wnt7a and lithium, a glycogen synthase kinase-3β inhibitor, in the NT-induced hMSCs via the canonical/β-catenin pathway, but was inhibited by Wnt inhibitors and frizzled-5 (Frz5) blocking antibodies. In addition, hrWnt7a triggered the formation of cholinergic and dopaminergic neurons via the non-canonical/c-jun N-terminal kinase (JNK) pathway, and the formation of these neurons was inhibited by a JNK inhibitor and Frz9 blocking antibodies. In conclusion, hrWnt7a enhances the synthesis of synapse and facilitates neuronal differentiation in hMSCS through various Frz receptors. These mechanisms may be employed widely in the transdifferentiation of other adult stem cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Over 2 million people suffer from mild traumatic brain injury (mTBI) each year. Predicting symptoms of mTBI and the characterization of those symptoms has been challenging. Biomarkers that correlate ...clinical symptoms to disease outcome are desired to improve understanding of the disease and optimize patient care. Bone marrow kinase on chromosome X (BMX), a member of the TEC family of nonreceptor tyrosine kinases, is up-regulated after traumatic neural injury in a rat model of mTBI. The aim of this investigation was to determine whether BMX serum concentrations can effectively be used to predict outcomes after mTBI in a clinical setting. A total of 63 patients with mTBI (Glasgow Coma Score GCS between 13 and 15) were included. Blood samples taken at the time of hospital admission were analyzed for BMX. Data collected included demographic and clinical variables. Outcomes were assessed using the Dizziness Handicap Inventory (DHI) questionnaire at baseline and 6 weeks postinjury. The participant was asssigned to the case group if the subject's complaints of dizziness became worse at the sixth week assessment; otherwise, the participant was assigned to the control group. A receiver operating characteristic curve was constructed to explore BMX level. Significant associations were found between serum levels of BMX and dizziness. Areas under the curve for prediction of change in DHI postinjury were 0.76 for total score, 0.69 for physical score, 0.65 for emotional score, and 0.66 for functional score. Specificities were between 0.69 and 0.77 for total score and emotional score, respectively. Therefore, BMX demonstrates potential as a candidate serum biomarker of exacerbating dizziness post-mTBI.
The preparation of nanoporous nickel films by electrochemical deposition of Ni−Cu alloy followed by the selective anodic etching of the less-active component (Cu) from the alloy was studied in an ...aqueous solution containing Cu(II) and Ni(II) at room temperature. Constant potential electrodeposition produced columnar Ni−Cu alloys, in which the Ni content increased as the deposition potential became more negative. X-ray diffraction and Auger mapping results indicate the presence of separated Cu-rich and Ni-rich phases in the alloys, with the Cu-rich phase being more concentrated in the middle of the column and surrounded by the Ni-rich phase. Cyclic voltammetric data indicates that anodic dissolution of nickel is retarded by passivation. By taking advantage of nickel passivation, selective anodic etching of copper from the Ni−Cu alloy produces nanohollow nickel tubes on indium−tin−oxide-coated glass substrates. The nanohollow tube structure obtained in this study is different from the interconnected bicontinuous nanopores that are usually obtained by dealloying the less noble component from a homogeneous solid solution alloy. The nanohollow tubes may have resulted from the fact that multiple phases columnar alloy deposits were produced by the electrodeposition step and from the limited mobility of nickel during the anodic etching step.
Noncoding RNA (ncRNA) plays a critical role in modulating a broad range of diseases. All arthropod-borne flaviviruses produce short fragment ncRNA (sfRNA) collinear with highly conserved regions of ...the 3′-untranslated region (UTR) in the viral genome. We show that the molar ratio of sfRNA to genomic RNA in Japanese encephalitis virus (JEV) persistently infected cells is greater than that in acutely infected cells, indicating an sfRNA role in establishing persistent infection. Transfecting excess quantities of sfRNA into JEV-infected cells reduced interferon-β (IFN-β) promoter activity by 57% and IFN-β mRNA levels by 52%, compared to mock-transfected cells. Transfection of sfRNA into JEV-infected cells also reduced phosphorylation of interferon regulatory factor-3 (IRF-3), the IFN-β upstream regulator, and blocked roughly 30% of IRF-3 nuclear localization. Furthermore, JEV-infected sfRNA transfected cells produced 23% less IFN-β-stimulated apoptosis than mock-transfected groups did. Taken together, these results suggest that sfRNA plays a role against host-cell antiviral responses, prevents cells from undergoing apoptosis, and thus contributes to viral persistence.
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