46 research outputs found
Epigallocatechin gallate activates miR-193a-3p and protects mice against glucocorticoid-induced osteoporosis by targeting NFATC1 expression
Purpose: To investigate the effect of epigallocatechin gallate (EGCG) on microRNAs in a mouse model of glucocorticoid-induced osteoporosis (GIOP), and the mechanism involved.
Methods: Osteoclast-specific marker mRNA expressions, receptor activator of nuclear factor kappa-B ligand (RANKL), receptor activator of nuclear factor κ B (RANK), and miRNA expressions were determined using reverse transcription polymerase chain reaction (RT-qPCR) analysis. Western blotting was used to assay protein expressions, while miRNA and 3’UTR interaction studies were carried out with reporter assay.
Results: Treatment with EGCG resulted in downregulation of glucocorticoid-induced expressions of RANKL, RANK and osteoclast-specific markers i.e. tumor necrosis factor receptor-associated factor 6, (TRAF6), nuclear factor of activated T cells 1 (NFATc1), cathepsin K, matrix metallopeptidase 9 (MMP9) and tartrate-resistant acid phosphatase (TRAP). Furthermore, EGCG treatment significantly reduced reactive oxygen species (ROS) levels and inflammatory cytokine expressions in GIOP mice. The expression of miRNA-targeting osteoclast marker mmu-mir-193-3p was significantly down-regulated in GIOP mice. However, EGCG treatment increased mmu-mir-193-3p expression and had specific interaction with NFATc1 3’UTR (3’-untranslated region). In vitro results showed that mmu-mir-193-3p mimics downregulated dexamethasone (DXM)-induced osteoclast-specific marker expressions.
Conclusion: These results show that EGCG exerts a protective role against GIOP by upregulating miR- 193a-3p expressions.
Keywords: Epigallocatechin gallate, Glucocorticoids, RANKL, Osteoporosi
Proteomic dissection of LPS-inducible, PHF8-dependent secretome reveals novel roles of PHF8 in TLR4-induced acute inflammation and T cell proliferation
Endotoxin (LPS)-induced changes in histone lysine methylation contribute to the gene-specific transcription for control of inflammation. Still unidentified are the chromatin regulators that drive the transition from a transcriptional-repressive to a transcriptional-active chromatin state of pro-inflammatory genes. Here, using combined approaches to analyze LPS-induced changes in both gene-specific transcription and protein secretion to the extracellular compartment, we characterize novel functions of the lysine demethylase PHF8 as a pro-inflammatory, gene-specific chromatin regulator. First, in the LPS-induced, acute-inflamed macrophages, PHF8 knockdown led to both a reduction of pro-inflammatory factors and an increase in a transcriptional-repressive code (H3K9me2) written by the methyltransferase G9a. Through unbiased quantitative secretome screening we discovered that LPS induces the secretion of a cluster of PHF8-dependent, ‘tolerizable’ proteins that are related to diverse extracellular pathways/processes including those for the activation of adaptive immunity. Specifically, we determined that PHF8 promotes T-cell activation and proliferation, thus providing the first link between the epigenetic regulation of inflammation and adaptive immunity. Further, we found that, in the acute-inflamed macrophages, the acute-active PHF8 opposes the H3K9me1/2-writing activity of G9a to activate specific protein secretions that are suppressed by G9a in the endotoxin-tolerant cells, revealing the inflammatory-phenotypic chromatin drivers that regulate the gene-specific chromatin plasticity
Ground-Based Polarimetric Remote Sensing of Dust Aerosol Properties in Chinese Deserts near Hexi Corridor
One-year observation of dust aerosol properties near Hexi Corridor was obtained from polarimetric measurements by ground-based sunphotometer in the county of Minqin in northwestern China from March 2012 to February 2013. We observed an annual mean AOD of 0.22±0.22 at 0.50 μm and Ångström exponents of 0.1–1.0 fitting a bimode normal distribution centered at 0.18 and 0.50, respectively. The effective radii of fine (0.13–0.17 μm) and coarse (2.49–3.49 μm) modes were found stable at all seasons together with the appearance of a third mode of particle radius at 0.4–1.0 μm when AOD was larger than 0.6. It is noticeable that the real (1.5–1.7) and imaginary (0.0005 to 0.09) parts of complex refractive indices were higher than other studies performed in other desert regions of China, while single scattering albedo was relatively lower (~0.84–0.89) at wavelengths of 0.44, 0.67, 0.87, and 1.02 μm. This is partially due to calcite or hematite in the soil in Minqin or the influence of anthropogenic aerosols containing carbon. Moreover, from our novel polarimetric measurement, the scattering phase function (F11) and degree of linear polarization for incident unpolarized light (-F12/F11) of dust aerosols were also obtained within this deserted area
Aerosol Optical and Microphysical Properties of Four Typical Sites of SONET in China Based on Remote Sensing Measurements
The current understanding of columnar aerosol optical and microphysical properties of different regions and seasons in China is insufficient due to the lack of measurements. Aiming to improve descriptions of aerosol models over China, this paper presents a systematic aerosol characterization of different sites based on a newly developed remote sensing network for aerosol observation, the Sun-sky radiometer Observation NETwork (SONET). One year of ground-based solar and sky radiation measurements of four typical sites of SONET (Beijing–urban-industrial site, Zhangye—rural site, Minqin—desert site, Zhoushan–oceanic site) are used to retrieve aerosol properties using similar inversion algorithms with AErosol RObotic NETwork (AERONET), including aerosol optical depth, Ångström exponent, volume size distribution, complex refractive index, single scattering albedo, and percentage of spherical particles. The retrieved properties among sites and seasons are found to be different in terms of magnitude, spectral dependence, and partition of fine and coarse mode, which can be primarily explained by different aerosol composition and mixing states that closely relate to the local climate, the natural environment, and most importantly, the ubiquitous anthropogenic impacts. For example, large dust particles greatly contribute to the low fine mode fraction in both volume concentration and optical depth for the Minqin site through the entire year, while abundant small particles that mainly come from emission sources dominate the size distribution and light extinction of aerosol in the summer at the Beijing site. The results also show general agreements with other studies on the aerosol properties at each site, however, some unique features are still noticeable, especially at the desert site and oceanic site (e.g., the unusually strong aerosol absorptivity indicated by the large imaginary refractive index and low single scattering albedo at the Minqin and Zhoushan sites), which can be partly attributed to the existence of absorbing particles coming from anthropogenic sources
Aerosol Optical and Microphysical Properties of Four Typical Sites of SONET in China Based on Remote Sensing Measurements
The current understanding of columnar aerosol optical and microphysical properties of different regions and seasons in China is insufficient due to the lack of measurements. Aiming to improve descriptions of aerosol models over China, this paper presents a systematic aerosol characterization of different sites based on a newly developed remote sensing network for aerosol observation, the Sun-sky radiometer Observation NETwork (SONET). One year of ground-based solar and sky radiation measurements of four typical sites of SONET (Beijing–urban-industrial site, Zhangye—rural site, Minqin—desert site, Zhoushan–oceanic site) are used to retrieve aerosol properties using similar inversion algorithms with AErosol RObotic NETwork (AERONET), including aerosol optical depth, Ångström exponent, volume size distribution, complex refractive index, single scattering albedo, and percentage of spherical particles. The retrieved properties among sites and seasons are found to be different in terms of magnitude, spectral dependence, and partition of fine and coarse mode, which can be primarily explained by different aerosol composition and mixing states that closely relate to the local climate, the natural environment, and most importantly, the ubiquitous anthropogenic impacts. For example, large dust particles greatly contribute to the low fine mode fraction in both volume concentration and optical depth for the Minqin site through the entire year, while abundant small particles that mainly come from emission sources dominate the size distribution and light extinction of aerosol in the summer at the Beijing site. The results also show general agreements with other studies on the aerosol properties at each site, however, some unique features are still noticeable, especially at the desert site and oceanic site (e.g., the unusually strong aerosol absorptivity indicated by the large imaginary refractive index and low single scattering albedo at the Minqin and Zhoushan sites), which can be partly attributed to the existence of absorbing particles coming from anthropogenic sources
The Identification and Driving Factor Analysis of Ecological-Economi Spatial Conflict in Nanjing Metropolitan Area Based on Remote Sensing Data
The rapid socio-economic development of the metropolitan area has led to the continuous deterioration of the ecological environment. This leads to intense competition and conflict between different spatial use types. Spatial conflict research is essential to achieve ecological-economic coordination and high-quality development. However, existing studies lack comprehensive and direct ecological-economic spatial conflicts, especially those on the spatial-temporal evolution and potential drivers of spatial conflict. In this study, we identified the ecological-economic spatial conflicts in the Nanjing metropolitan area in 2010, 2015, and 2020. This study used the random forest to analyze the factors that influenced the change of spatial conflict. Results show that: (1) From 2010 to 2020, the ecological-economic spatial conflict in the Nanjing metropolitan area changed significantly. (2) Land use change has an important effect on spatial conflicts, which are easily triggered by uncontrolled urban expansion, but ecological land can mitigate spatial conflicts. (3) Relevant driving factors of spatial conflicts show multi-level features, so the development of conflict reconciliation countermeasures needs to be tailored to local conditions. This study provides a significant foundation for the high-quality development of the Nanjing metropolitan area and provides a reference for the planning and management of the territorial space
Remotely Monitoring Vegetation Productivity in Two Contrasting Subtropical Forest Ecosystems Using Solar-Induced Chlorophyll Fluorescence
Subtropical forests can sequester a larger amount of atmospheric carbon dioxide (CO2) relative to other terrestrial ecosystems through photosynthetic activity and act as an important role in mitigating global climate warming. Compared with the model-based gross primary production (GPP) products, satellite-derived solar-induced fluorescence (SIF) opens a new window for quantification. Here, we used the remotely sensed SIF retrievals, two satellite-driven GPP products including MODIS (GPPMOD) and BESS (GPPBESS), and tower-based GPP measurements at two contrasting subtropical forests to provide a systematic analysis. Our results revealed that GPP and the associated environmental factors exhibited distinct seasonal patterns. However, the peak GPP values had large differences, with stronger GPP in the evergreen needleleaf forest site (8.76 ± 0.71 g C m−2 d−1) than that in the evergreen broadleaf forest site (5.71 ± 0.31 g C m−2 d−1). The satellite-derived SIF retrievals showed great potential in quantifying the variability in GPP, especially for the evergreen needleleaf forest with r reaching up to 0.909 (p < 0.01). GPPMOD and GPPBESS showed distinctly different performances for the two subtropical forests, whereas the GPP estimates by exclusive use of satellite-based SIF data promised well to the tower-based GPP observations. Multi-year evaluation again confirmed the good performance of the SIF-based GPP estimates. These findings will provide an alternative framework for quantifying the magnitude of forest GPP and advance our understanding of the carbon sequestration capacity of subtropical forest ecosystems
Optimization of Algicidal Activity for <i>Alteromonas</i> sp. FDHY-03 against Harmful Dinoflagellate <i>Prorocentrum donghaiense</i>
Prorocentrum donghaiense is a harmful-algal-bloom-forming species of planktonic dinoflagellates widely distributed around the world, which threatens the marine environment and human health. Bacteria are promising biological agents to control algal growth in HABs. Previously, we isolated an Alteromonas sp. FDHY-03, a P. donghaiense-lysing bacteria strain, from Xiapu Sea area of China. In order to improve the algicidal activity of this strain, we optimized the medium composition and culture conditions. Based on single-factor method experiment design, the optimum medium component of algicidal effect for strain FDHY-03 was sucrose and peptone. The result of Plackett–Burman design indicated that three significant factors (sucrose, peptone, and rotational speed) appeared. Finally, the concentrations of key factors were confirmed by central composite design (CCD) and response surface methodology (RSM). Under the optimized medium, the algicidal rate of strain FDHY-03 against P. donghaiense improved by 67.15%, and the OD600 value increased by 2.86-fold. The optimal source and condition were sucrose 0.46% (w/v), peptone 4.25% (w/v) addition, and rotation speed 255 rpm. Overall, this study provides an optimized method and optimum medium for improving the algicidal activity against P. donghaiense, and has a positive influence on algae-lysing bacteria for controlling the blooms of the algae in the environment
Derivation of PM10 mass concentration from advanced satellite retrieval products based on a semi-empirical physical approach
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