Human mesenchymal stem cells (MSCs) have therapeutic potential because of their ability to self-renew and differentiate into multiple tissues. However, senescence often occurs in MSCs when they are ...cultured in vitro and the molecular mechanisms underlying this effect remain unclear. In this study, we found that NAD-dependent protein deacetylase SIRT1 is differentially expressed in both human bone marrow-derived MSCs (B-MSCs) and adipose tissue-derived MSCs after increasing passages of cell culture. Using lentiviral shRNA we demonstrated that selective knockdown of SIRT1 in human MSCs at early passage slows down cell growth and accelerates cellular senescence. Conversely, overexpression of SIRT1 delays senescence in B-MSCs that have undergone prolonged in vitro culturing and the cells do not lose adipogenic and osteogenic potential. In addition, we found that the delayed accumulation of the protein p16 is involved in the effect of SIRT1. However, resveratrol, which has been used as an activator of SIRT1 deacetylase activity, only transiently promotes proliferation of B-MSCs. Our findings will help us understand the role of SIRT1 in the aging of normal diploid cells and may contribute to the prevention of human MSCs senescence thus benefiting MSCs-based tissue engineering and therapies.
Background：Both Mitofusin 2 （Mfn2） and pelvic organ prolapse （POP） are related to aging.The aim of the present study was to investigate the variations of Mfn2 expression in the uterosacral ligaments ...of patients with and/or without POP and their correlations with the expression of procollagen.Methods：Fibroblasts were cultured using tissue specimens that were harvested from the uterosacral ligaments of POP and non-POP （NPOP） patients （n =10 for each group） from September 2016 to December 2016.The Cell Counting Kit-8 （CCK-8） assay was used to compare the differences in cell proliferation between the two groups.Relative quantitative reverse transcription-polymerase chain reaction and Western blotting assays were employed to assess the differences in the mRNA and protein expression levels of Mfn2 and procollagen 1A1/1A2/3A1 between the two groups.The changes in procollagen expression were assessed following the downregulation of Mfn2 in the POP group using RNAi.The data were assessed with independent sample t-test or general linear model univariate analysis using the SPSS 13.0 software.Results：The results from CCK-8 assay indicated that cell viability in the POP group was significantly lower compared with that of the NPOP group （td5,7,9,11=-5.925,-6.851,-9.129,and-9.661,respectively,all P 〈 0.001,from D5 to D 11）.The mRNA and protein expression levels of Mfn2 in the cultured fibroblasts of the POP group were significantly higher compared with those of the NPOP group （mRNA：t =2.425,P =0.032;protein：t =2.392,P =0.037,respectively）,whereas only the expression levels of procollagen 1A1/1A2/3A1 were significantly higher in the NPOP group （mRNA：t =-2.165,P1A1 =0.041;t =-2.741,P1A2 =0.026;t =-2.147,P3A1 =0.045,respectively;protein：t =-2.418,P1A1 =0.029;t =-2.405,P1A2 =0.033;t =-2.470,P3A1 =0.012,respectively）.The expression levels of procollagen in the POP group increased following the downregulation of Mfn2.Conclusions：The proliferation rate and cell viability of the fibroblasts in the POP group were significantly lower compared with those in the NPOP group.In the POP fibroblasts,Mfn2 expression was increased,while procollagen expression was decreased.
The synergistic antibacterial effects between endolysin Lysqdvp001 and ε-poly-lysine (ε-PL) against Vibrio parahaemolyticus (V. parahaemolyticus) were investigated in this study. Lysqdvp001 combined ...with ε-PL exhibited a strong antibacterial synergism against V. parahaemolyticus. The combinations of Lysqdvp001 (≥60 U/mL) and ε-PL (≥0.2 mg/mL) dramatically decreased cell density of the bacterial suspensions at both 25 °C and 37 °C. Surface zeta potential increment and membrane hyperpolarization of V. parahaemolyticus were observed after treatment by ε-PL and its combination with Lysqdvp001. More β-lactamase and β-galactosidase were leaked from V. parahaemolyticus with combined treatment of Lysqdvp001 and ε-PL than from the bacteria treated with single Lysqdvp001 or ε-PL. Fluorescence and transmission electron microscope revealed that Lysqdvp001 and ε-PL synergistically induced the damage and morphological destruction of V. parahaemolyticus cells. When applying in Gadus macrocephalus, Penaeus orientalis and oyster, the two antimicrobials' cocktail allowed for 3.75, 4.16 and 2.50 log10CFU/g reductions of V. parahaemolyticus, respectively. Besides, Lysqdvp001 in combination with ε-PL removed approximately 44%–68% of V. parahaemolyticus biofilms on polystyrene, glass and stainless steel surfaces. These results demonstrated that Lysqdvp001 and ε-PL might be used together for controlling V. parahaemolyticus and the bacterial biofilms in food industry.
•Endolysin Lysqdvp001 and ε-PL could synergistically inhibit V. parahaemolyticus.•Endolysin Lysqdvp001 and ε-PL synergistically damaged the Vibrio membrane.•This combination notably inactivated V. parahaemolyticus in seafoods.•This combination eradicated V. parahaemolyticus biofilms on various surfaces.
SPINDLIN1, a new member of the SPIN/SSTY gene family, was first identified as a gene highly expressed in ovarian cancer cells. We have previously shown that it is involved in the process of spindle ...organization and chromosomal stability and plays a role in the development of cancer. Nevertheless, the mechanisms underlying its oncogenic role are still largely unknown. Here, we first showed that expression of SPINDLIN1 is upregulated in clinical tumors. Ectopic expression of SPINDLIN1 promoted cancer cell proliferation and activated WNT/T-cell factor (TCF)-4 signaling. The Ser84 and Ser99 amino acids within SPINDLIN1 were further identified as the key functional sites in WNT/TCF-4 signaling activation. Mutation of these two sites of SPINDLIN1 abolished its effects on promoting WNT/TCF-4 signaling and cancer cell proliferation. We further found that Aurora-A could interact with and phosphorylate SPINDLIN1 at its key functional sites, Ser84 and Ser99, suggesting that phosphorylation of SPINDLIN1 is involved in its oncogenic function. Collectively, these results suggest that SPINDLIN1, which may be a novel substrate of the Aurora-A kinase, promotes cancer cell growth through WNT/TCF-4 signaling activation.
Seed reserves are very important to the earlier growth and survival of plants, and its variation in nutrient contents might make species to form different germination or seedlings growth strategies. ...Here, 203 species collected from an alpine meadow on the northeastern Qinghai–Tibet plateau were used to test the effects of phylogenetic groups, life-history traits, and altitude on carbon (C), nitrogen (N) and phosphorus (P) contents of seeds across species. The results showed that (1) seeds of Brassicaceae had the highest C content, those of Fabaceae had the highest N content, and Asteraceae had the highest P content, and family explained independently 32.7%, 46.4%, and 17.9% of the variation in C, N, and P contents of seeds, respectively; (2) the smaller seeds tended to have higher C and P contents, and seed mass explained independently 2.5% of variation in C, 4.3% in N, and 8.1% in P contents; (3) N content was explained 1% independently by life form, seeds N content of perennials was significantly higher than that of annals, but seeds C and P contents had non-significant difference between them; (4) seeds of wind-adapted species had higher N and P contents, and dispersal mode explained independently 1.7% of variation in C, 1.6% in N, and 5.6% in P contents; (5) seeds from high altitude had the highest N and P contents, and altitude explained independently 4.3% of the variation in N and 4% in P contents.
The reliability of weather radar data in real-time flood forecasting and early warning system remain ambivalent due to high uncertainty in Quantitative Precipitation Forecasts (QPF). In this study, a ...methodology is presented with the objective to improve the flood forecasting results with the application of radar rainfall calculated in three different ways. The QPF radar rainfall forecast data of four typhoon events in Fèngshān River Basin, Taiwan, were simulated using the WASH123D numerical model. The simulated results were corrected using a physical real-time correction technique and compared with direct simulation without correction for all three QPF calculation methods. According to model performance evaluation criteria, in the third method of QPF calculation, flood peak error was the lowest in all three methods, indicating better results for flood forecasting and can be used for flood early warning systems. The impact of the real-time correction technique was assessed using mass balance analysis. It was found that flow change is between 16% and 42% from direct simulation, indicating being on the safe side in case of a flood warning. However, the impact of the real-time physical correction on the water level itself is in a reasonable range. Still, QPF rainfall correction/calculation is more important to obtain accurate results for flood forecasting. Therefore, the application of real-time correction to correct the model water level has a certain degree of credibility, which is the mass balance of the model. This approach is recommended for flood forecasting early warning systems.
In this work, a sensitive and efficient method was established and validated for qualitative and quantitative analysis of major bioactive constituents in Dazhu Hongjingtian capsule by liquid ...chromatography tandem mass spectrometry. A total of 32 compounds were tentatively identified using ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry. Furthermore, 12 constituents, namely gallic acid, 3,4‐dihydroxybenzoic acid, salidroside, p‐coumaric acid‐4‐O‐β‐d‐glucopyranoside, bergeninum, 4‐hydroxybenzoic acid, 4‐hydroxyphenylacetic acid, syringate, 6′′‐O‐galloylsalidroside, rhodiosin, rhodionin and kaempferol‐7‐O‐α‐l‐rhamnoside, were simultaneously quantified by the developed ultra‐performance liquid chromatography coupled with a triple quadrupole mass spectrometry method in 9 min. All of them were analyzed on an Agilent ZorBax SB‐C18 column (3.0 × 100 mm, 1.8 μm) with linear gradient elution of methanol–0.1% formic acid water. The proposed method was applied to analyze three batches of samples with acceptable linearity (R, 0.9979–0.9997), precision (RSD, 1.3–4.7%), repeatability (RSD, 1.7–4.9%), stability (RSD, 2.2–4.9%) and recovery (RSD, 0.6–4.4%) of the 12 compounds. As a result, the analytical method possessing high throughput and sensitivity is suitable for the quality control of Dazhu Hongjingtian capsule.
Hydrogen evolution from water electrolysis is one of the effective ways to obtain clean hydrogen energy in the future. Pt-based materials are the effective catalysts in hydrogen evolution reaction, ...but they are expensive, and difficult to recycle, so that their application is impeded in the development of economical hydrogen energy. Therefore it is the key trend to develop efficient non-noble metal electrocatalysts with the aim of providing cost-competitive hydrogen energy. In this review, we highlighted the recent research efforts toward the synthesis of noble metal-free electrocatalysts for the hydrogen evolution reaction (HER), mainly focusing on nanomaterial catalysts supported on carbon fiber materials. We reviewed several important kinds of heterogeneous non-noble metal electrocatalysts, including sulfides, selenides, carbides, phosphides, and oxides. In the discussion, emphasis was given to the synthetic methods of these HER electrocatalysts, and the strategies for performance improvement. In addition, this review briefly summarized the application of carbon fiber material as substrate in the field of electroanalytical chemistry.
Daya Bay, a semi-enclosed bay in the South China Sea, is well known for its aquaculture, agriculture, and tourism. In recent years, many environmental problems have emerged, such as the frequent ...(almost yearly) occurrence of harmful algal blooms and red tides. Therefore, investigations of submarine groundwater discharge (SGD) and associated nutrient inputs to this bay have important theoretical and practical significance to the protection of the ecological system. Such a study was conducted using short-lived radium isotopes 223Ra and 224Ra. The estimated SGD fluxes were 2.89 × 107 m3/d and 3.05 × 107 m3/d based on 223Ra and 224Ra, respectively. The average SGD flux was about 35 times greater than that of all the local rivers. The SGD-associated dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) fluxes ranged from 1.95 × 106 to 2.06 × 106 mol/d and from 5.72 × 104 to 6.04 × 104 mol/d, respectively. The average ratio of DIN to DIP fluxes in SGD was 34, much higher than that in local rivers (about 6.46), and about twice as large as the Redfield ratio (16). Our results indicate that SGD is a significant source of nutrients to the bay and may cause frequent occurrence of harmful algal blooms. This study provides baseline data for evaluating potential environmental effects due to urbanization and economic growth in this region.
Seed shape and seed volume are functionally important traits which are associated with seed germination. To study the ecological and evolutionary significance of seed shape and volume in relation to ...germination, a database comprising seed information for 383 species within 50 families from an alpine meadow on the eastern Qinghai-Tibet plateau was compiled. The independent and interactive effects of seed traits on germination and whether these effects are controlled by phytogeny are discussed. The results show the following: (1) Elongated seeds had higher percentage and faster speed of germination than compact seeds whereas smaller seeds tended to have higher germinability compared to larger ones; (2) Seed volume and shape evolved together but had independent effects on seed germination. Seed volume had no significant influence on seed germination among species with compact seeds, but had a significant effect on those among species with elongated seeds; seed germination of larger seeded species was affected by seed shape, but not by seed volume. These results might be related to their predation pressure and ability to germinate from deeper soil layers. Lastly, (3) Phylogenetic conservation plays an important role in the co-evolution of seed traits and germination characteristics. Species with similarly shaped seeds on a large scale might reflect a common selective pressure, but related species within a family might be more dependent on phylogenetic conservation.
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