Tripartite motif protein 52 (TRIM52) promoted fibrosis in LX‐2 cells through PPM1A‐mediated Smad2/3 pathway

To investigate the roles of tripartite motif containing 52 (TRIM52) in human hepatic fibrosis in vitro, human hepatic stellate cell line LX‐2 cells were transfected with hepatitis B virus (HBV) replicon to establish HBV‐induced fibrosis in LX‐2 cells, and then treated with small interfering RNA‐mediated knockdown of TRIM52 (siTRIM52). LX‐2 cells without HBV replicon transfection were treated with lentiviruses‐mediated overexpression of TRIM52 and phosphatase magnesium dependent 1A (PPM1A). Fibrosis response of LX‐2 cells were assessed by the production of hydroxyproline (Hyp) and collagen I/III, as well as protein levels of α‐smooth muscle actin (α‐SMA). PPM1A and phosphorylated (p)‐Smad2/3 were measured to assess the mechanism. The correlation between TRIM52 and PPM1A was determined using co‐immunoprecipitation, and whether and how TRIM52 regulated the degradation of PPM1A were determined by ubiquitination assay. Our data confirmed HBV‐induced fibrogenesis of LX‐2 cells, as evidenced by significant increase in Hyp and collagen I/III and α‐SMA, which was associated with reduction of PPM1A and elevation of transforming growth factor‐β (TGF‐β), p‐Smad2/3, and p‐Smad3L. However, those changes induced by HBV were significantly attenuated with additional siTRIM52 treatment. Similar to HBV, overexpression of TRIM52 exerted promoted effect in the fibrosis of LX‐2 cells. Interestingly, TRIM52 induced the fibrogenesis of LX‐2 cells and the activation of TGF‐β/Smad pathway were significantly reversed by PPM1A overexpression. Furthermore, our data confirmed TRIM52 as a deubiquitinase that influenced the accumulation of PPM1A protein, and subsequently regulated the fibrogenesis of LX‐2 cells. TRIM52 was a fibrosis promoter in hepatic fibrosis in vitro, likely through PPM1A‐mediated TGF‐β/Smad pathway.     

Phosphorylation of Dab2 is involved in inhibited VEGF‐VEGFR‐2 signaling induced by downregulation of syndecan‐1 in glomerular endothelial cell

Disabled‐2 (Dab2) and PAR‐3 (partitioning defective 3) are reported to play critical roles in maintaining retinal microvascular endothelial cells biology by regulating VEGF‐VEGFR‐2 signaling. The role of Dab2 and PAR‐3 in glomerular endothelial cell (GEnC) is unclear. In this study, we found that, no matter whether with vascular endothelial growth factor (VEGF) treatment or not, decreased expression of Dab2 could lead to cell apoptosis by preventing activation of VEGF‐VEGFR‐2 signaling in GEnC, accompanied by reduced membrane VEGFR‐2 expression. And silencing of PAR‐3 gene expression caused increased apoptosis of GEnC by inhibiting activation of VEGF‐VEGFR‐2 signaling and membrane VEGFR‐2 expression. In our previous research, we found that the silencing of syndecan‐1 gene expression inhibited VEGF‐VEGFR‐2 signaling by modulating internalization of VEGFR‐2. And our further research demonstrated that downregulation of syndecan‐1 lead to no significant change in the expression of Dab2 and PAR‐3 both at messenger RNA and protein levels in GEnC, while phosphorylation of Dab2 was significantly increased in GEnC transfected with Dab2 small interfering RNA (siRNA) compared with control siRNA. Atypical protein kinase C (aPKC) could induce phosphorylation of Dab2, thus negatively regulating VEGF‐VEGFR‐2 signaling. And we found that decreased expression of syndecan‐1 lead to activation of aPKC, and aPKC inhibitor treatment could block phosphorylation of Dab2 in GEnC. Besides, aPKC inhibitor treatment could activate VEGF‐VGEFR‐2 signaling in GEnC transfected with syndecan‐1 siRNA in a dose‐dependent manner. In conclusion, we speculated that phosphorylation of Dab2 is involved in preventing activation of VEGF‐VEGFR‐2 signaling in GEnC transfected with syndecan‐1 siRNA. This provides a new target for the therapy of GEnC injury and kidney disease.     

浙江省葡萄属野生葡萄资源调查与开发利用研究

浙江是中国野生葡萄属资源分布较广泛、种类较多的地区之一,但对野生葡萄属资源的深入研究和合理开发利用不多。我们在野外调查和民间走访的基础上,结合查询文献资料,分析浙江境内野生葡萄资源的特点,并提出野生葡萄资源创新利用的思路。     

Photosynthesis Characteristics of Tall Fescue under Snow-Melting Agent,Acid Precipitation and Freeze-Thaw Stress

Russian Journal of Plant Physiology - To explore the physiological response characteristics of plant photosynthesis under acid precipitation stress (A stress), snow-melting agent stress (S stress),...     

Investigation of Tocopherol Biosynthesis in Blackberry Seeds (Rubus spp.)

Russian Journal of Plant Physiology - Tocopherol (vitamin E) is widely recognized as a cellular antioxidant and can prevent oxidative damage during seed quiescence and dormancy in all angiosperms....     

Platelet‐rich plasma inhibits osteoblast apoptosis and actin cytoskeleton disruption induced by gingipains through upregulating integrin β1

The aim of this study was to explore the effects of platelet‐rich plasma on gingipain‐caused changes in cell morphology and apoptosis of osteoblasts. Mouse osteoblasts MC3T3‐E1 cells were treated with gingipain extracts from Porphyromonas gingivalis in the presence or absence of platelet‐rich plasma. Apoptosis was detected with terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling staining. F‐actin was determined by phalloidin‐fluorescent staining and observed under confocal microscopy. Western blot analysis was used to detect integrin β1, F‐actin, and G‐actin protein expressions. A knocking down approach was used to determine the role of integrin β1. The platelet‐rich plasma protected osteoblasts from gingipain‐induced apoptosis in a dose‐dependent manner, accompanied by upregulation of integrin β1. Platelet‐rich plasma reversed the loss of F‐actin integrity and decrease of F‐actin/G‐actin ratio in osteoblasts in the presence of gingipains. By contrast, the effects of platelet‐rich plasma were abrogated by knockdown of integrin β1. The platelet‐rich plasma failed to reduce cell apoptosis and reorganize the cytoskeleton after knockdown of integrin β1. In conclusion, platelet‐rich plasma inhibits gingipain‐induced osteoblast apoptosis and actin cytoskeleton disruption by upregulating integrin β1 expression.     

Statistical and multivariate statistical techniques to trace the sources and affecting factors of groundwater pollution in a rapidly growing city on the Chinese Loess Plateau

Abstract

Groundwater quality is defined by various water quality parameters. The aims of the research are to understand the relationships among different groundwater quality parameters and to trace the sources and affecting factors of groundwater pollution via statistical and multivariate statistical techniques. The 36 shallow groundwater samples collected from shallow pumping wells in Yan’an City were analyzed for various water quality parameters. Correlation analysis, principal component analysis (PCA), hierarchical cluster analysis (HCA), and multivariable linear regressions (MLR) were jointly used in this study to explore the sources and affecting factors of groundwater pollution. The study reveals that the mineral dissolution/precipitation and anthropogenic input are the main sources of the physicochemical indices and trace elements in the groundwater. Groundwater chemistry is predominantly regulated by natural processes such as dissolution of carbonates, silicates, and evaporates and soil leaching, followed by human activities as the second factor. Climatic factors and land use types are also important in affecting groundwater chemistry. Cl^– is the greatest contributor to the overall groundwater quality revealed by the two regression models. The first model which has eight dependent variables is high in model reliability and stability, and is recommended for the overall groundwater quality prediction. The study is helpful for understanding groundwater quality variation in urban areas.     

Life cycles,phenology and genetic structure of endangered Megacrania tsudai Shiraki (Phasmatodea: Phasmatidae): Male individuals from a geographic parthenogenesis species

Megacrania tsudai, a peripherally distributed member of Megacrania, requires conservation in Taiwan; it has limited distribution in Taiwan and its eastern offshore islands. It feeds on screw pines (Pandanus odoratissimus) in nature and has demonstrated a specific defensive mechanism involving actinidine secretion from the prothoracic gland. However, details of its distribution area, life cycle and developmental phenology remain largely unknown. In this study, a field survey and review of published works revealed M. tsudai distribution in coastal zones and along river shores near estuaries. At room temperature, the egg period was 128 days. The development of the first to sixth instars required 17, 26, 27, 26, 34 and 43 days, respectively, on average; and a generation cycle required approximately 204 days. The phenology of the mesonotal granules was recorded. Moreover, genetic analysis of the mitochondrial cytochrome oxidase I (COI), 16S ribosomal DNA (16S rDNA) and the nuclear ribosomal spacer indicated the occurrence of genetic drift. Therefore, the rearing procedures proposed in this study for the primary and last instars of M. tsudai can facilitate its conservation. Megacrania tsudai was previously recorded as parthenogenetic; however, two male individuals were fostered unexpectedly. The male body length was 91 mm, which is shorter than the female length (120 mm). During mating, the male climbs onto the female's back and protrudes its genitalia downward. Geographical parthenogenesis is likely the reproductive strategy among peripheral M. tsudai; however, the rarely found M. tsudai male could be an intermediate link of reproductive strategy in the transition from tychoparthenogenesis to parthenogenesis.     

Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand?

Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model‐data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are as follows: (a) Inter‐model variation is generally large and model agreement varies with timescales. In severely water‐limited sites, models only agree on the interannual variability of evapotranspiration and to a smaller extent on gross primary productivity. In more mesic sites, model agreement for both water and carbon fluxes is typically higher on fine (daily–monthly) timescales and reduces on longer (seasonal–annual) scales. (b) Models on average overestimate the relationship between ecosystem productivity and mean rainfall amounts across sites (in space) and have a low capacity in reproducing the temporal (interannual) sensitivity of vegetation productivity to annual rainfall at a given site, even though observation uncertainty is comparable to inter‐model variability. (c) Most models reproduced the sign of the observed patterns in productivity changes in rainfall manipulation experiments but had a low capacity in reproducing the observed magnitude of productivity changes. Models better reproduced the observed productivity responses due to rainfall exclusion than addition. (d) All models attribute ecosystem productivity changes to the intensity of vegetation stress and peak leaf area, whereas the impact of the change in growing season length is negligible. The relative contribution of the peak leaf area and vegetation stress intensity was highly variable among models.     

Grazing simplifies soil micro‐food webs and decouples their relationships with ecosystem functions in grasslands

Livestock grazing often alters aboveground and belowground communities of grasslands and their mediated carbon (C) and nitrogen (N) cycling processes at the local scale. Yet, few have examined whether grazing‐induced changes in soil food webs and their ecosystem functions can be extrapolated to a regional scale. We investigated how large herbivore grazing affects soil micro‐food webs (microbes and nematodes) and ecosystem functions (soil C and N mineralization), using paired grazed and ungrazed plots at 10 locations across the Mongolian Plateau. Our results showed that grazing not only affected plant variables (e.g., biomass and C and N concentrations), but also altered soil substrates (e.g., C and N contents) and soil environment (e.g., soil pH and bulk density). Grazing had strong bottom‐up effects on soil micro‐food webs, leading to more pronounced decreases at higher trophic levels (nematodes) than at lower trophic levels (microbes). Structural equation modeling showed that changes in plant biomass and soil environment dominated grazing effects on microbes, while nematodes were mainly influenced by changes in plant biomass and soil C and N contents; the grazing effects, however, differed greatly among functional groups in the soil micro‐food webs. Grazing reduced soil C and N mineralization rates via changes in plant biomass, soil C and N contents, and soil environment across grasslands on the Mongolian Plateau. Spearman's rank correlation analysis also showed that grazing reduced the correlations between functional groups in soil micro‐food webs and then weakened the correlation between soil micro‐food webs and soil C and N mineralization. These results suggest that changes in soil micro‐food webs resulting from livestock grazing are poor predictors of soil C and N processes at regional scale, and that the relationships between soil food webs and ecosystem functions depend on spatial scales and land‐use changes.