Oxypeucedanin hydrate alleviates rheumatoid arthritis by inhibiting the TLR4-MD2/NF-κB/MAPK signaling axis.

Rheumatoid arthritis (RA) is an idiopathic and chronic autoimmune disease for which there are currently no effective treatments. Oxypeucedanin hydrate (OXH) is a natural coumarin known for its potent anti-inflammatory properties. However, further investigations are needed to determine its therapeutic efficacy in treating RA. In this study, we evaluate the anti-inflammatory activity of OXH by treating LPS-induced RAW264.7 macrophages. Our results show that OXH treatment reverses the changes in iNOS, COX-2, IL-1ß, IL-6, and TNF-α levels. Additionally, OXH reduces ROS production. Further analysis reveals that OXH suppresses the activation of the NF-κB/MAPK pathway. CETSA results show that OXH competes with LPS for binding to the TLR4/MD2 complex. MST experiments demonstrate the specific affinity of OXH for the TLR4/MD2 complex, with a Kd value of 33.7 µM. Molecular docking analysis suggests that OXH binds to the pocket of the TLR4/MD2 complex and interacts with specific amino acids, such as GLY-343, LYS-388, and PHE-345. Molecular dynamics simulations further confirm this conclusion. Finally, we investigate the potential of OXH in treating RA using a collagen-induced arthritis (CIA) model in rats. OXH effectively ameliorates the symptoms of CIA, including improving body weight, reducing swelling and redness, increasing talus volume, and decreasing bone erosion. OXH also decreases the mRNA levels of pro-inflammatory factors in synovial tissue. Transcriptome enrichment analysis and western blot analysis confirm that OXH suppresses the NF-κB/MAPK pathway, which is consistent with our in vitro findings.

Two Undescribed Coumarins from Notopterygium Incisum with Anti-Inflammatory Activity.

Two previously undescribed coumarins (1-2) were isolated from the root of Notopterygium incisum. The structures of new findings were elucidated by analyses of spectral evidences in HRESIMS, NMR, as well as ICD. The absolute configurations were further confirmed by chemical calculations. 1-2 exhibits obviously anti-inflammatory activity by inhibiting the expression of inflammatory mediators (COX-2, iNOS), as well as reducing the release of NO and the accumulation of ROS in cells. Western blotting analysis revealed that 2 could inhibit the PI3K/AKT pathway by reducing the expression of p-PI3K and p-AKT.

Three new coumarins from Notopterygium incisum with potential anti-inflammatory activity.

Three previously undescribed coumarins (1-3) were obtained from the roots of Notopterygium incisum. Their chemical structures were elucidated using a variety of spectroscopic techniques and chemical calculations. The inhibitory effects of these new compounds on NO production and pro-inflammatory factors (IL-1ß, IL-6, and TNF-α) in LPS-stimulated RAW 264.7 cells were investigated. Further studies revealed that compound 1 suppressed the expression of COX-2 and iNOS while also reduced ROS accumulation. Western blot analysis demonstrated that compound 1 could inhibit the PI3K/AKT pathway by decreasing the levels of p-PI3K and p-AKT. Collectively, these findings suggest that compounds 1-3 exhibit promising anti-inflammatory properties.

N-acetyldopamine dimer inhibits neuroinflammation through the TLR4/NF-κB and NLRP3/Caspase-1 pathways.

Neuroinflammation mediated by microglia is an important pathophysiological mechanism in neurodegenerative diseases. However, there is a lack of effective drugs to treat neuroinflammation. N-acetyldopamine dimer (NADD) is a natural compound from the traditional Chinese medicine Isaria cicada. In our previous study, we found that NADD can attenuate DSS-induced ulcerative colitis by suppressing the NF-κB and MAPK pathways. Does NADD inhibit neuroinflammation, and what is the target of NADD? To answer this question, lipopolysaccharide (LPS)-stimulated BV-2 microglia was used as a cell model to investigate the effect of NADD on neuroinflammation. Nitric oxide (NO) detection, reactive oxygen species (ROS) detection and enzyme-linked immunosorbent assay (ELISA) results show that NADD attenuates inflammatory signals and proinflammatory cytokines in LPS-stimulated BV-2 microglia, including NO, ROS, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and interleukin-6 (IL-6). Western blot analysis show that NADD inhibits the protein levels of Toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), ASC and cysteinyl aspartate specific proteinase (Caspase)-1, indicating that NADD may inhibit neuroinflammation through the TLR4/NF-κB and NLRP3/Caspase-1 signaling pathways. In addition, surface plasmon resonance assays and molecular docking demonstrate that NADD binds with TLR4 directly. Our study reveals a new role of NADD in inhibiting the TLR4/NF-κB and NLRP3/Caspase-1 pathways, and shows that TLR4-MD2 is the direct target of NADD, which may provide a potential therapeutic candidate for the treatment of neuroinflammation.

The Development Process: from SAHA to Hydroxamate HDAC Inhibitors with Branched CAP Region and Linear Linker.

Histone deacetylases (HDACs) belong to a group of epigenetic regulatory enzymes that participate in modulating the acetylation level of histone lysine residues as well as non-histone proteins, and they play a key role in the regulation of gene expression. HDACs are potential anticancer drug targets highly expressed in various kinds of cancer cells. So far, five small molecules targeting HDACs have been approved for the therapy of cancer, and over 20 inhibitors of HDACs are under different phases of clinical trials. Among them, hydroxamate-based HDAC inhibitors (HDACis) represent a well-investigated series of chemical entities. The current review covers the recent progress in the discovery process, form SAHA to hydroxamate HDAC inhibitors with branched CAP region and linear linker. At the same time, the pharmacological and structure-activity relationship (SAR) studies of the specific derivatives from SAHA and the HDACis with branched CAP region and linear linker are also introduced.

Individual particle analysis of aerosols collected at Lhasa City in the Tibetan Plateau.

To understand the composition and major sources of aerosol particles in Lhasa City on the Tibetan Plateau (TP), individual particles were collected from 2 February to 8 March, 2013 in Tibet University. The mean concentrations of both PM2.5 and PM10 during the sampling were 25.7±21.7 and 57.2±46.7 µg/m3, respectively, much lower than those of other cities in East and South Asia, but higher than those in the remote region in TP like Nam Co, indicating minor urban pollution. Combining the observations with the meteorological parameters and back trajectory analysis, it was concluded that local sources controlled the pollution during the sampling. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectra (EDS) was used to study 408 particles sampled on four days. Based on the EDS analysis, a total of 8 different particle categories were classified for all 408 particles, including Si-rich, Ca-rich, soot, K-rich, Fe-rich, Pb-rich, Al-rich and other particles. The dominant elements were Si, Al and Ca, which were mainly attributed to mineral dust in the earth's crust such as feldspar and clay. Fe-, Pb-, K-, Al-rich particles and soot mainly originated from anthropogenic sources like firework combustion and biomass burning during the sampling. During the sampling, the pollution mainly came from mineral dust, while the celebration ceremony and religious ritual produced a large quantity of anthropogenic metal-bearing particles on 9 and 25 February 2013. Cement particles also had a minor influence. The data obtained in this study can be useful for developing pollution control strategies.

Two undescribed coumarins from Hansenia weberbaueriana.

Two previously undescribed coumarins (1 and 2) were isolated from the root of Hansenia weberbaueriana which have been used to cure inflammatory diseases over thousands of years by Chinese. The structures of new findings were confirmed by comprehensive analyses of spectral evidences in HRESIMS, 1D and 2D NMR combined with chemical calculations. Compounds 1 and 2 exhibited potential anti-inflammatory properties by reducing the mRNA expression levels of TNF-α, IL-6 and IL-1ß in lipopolysaccharide (LPS)-induced RAW264.7 macrophages at a concentration of 15 µM.

Chemical constitutes from Tuber indicum with immunosuppressive activity uncovered by transcriptome analysis.

Three previously undescribed compounds including a polyketide (1) and two lactams (2 and 3) were obtained from Tuber indicum. The structures of new findings were elucidated by HRESIMS, NMR as well as NMR and ECD calculations. Transcriptome analysis through RNA-seq revealed that compound 2 exhibits immunosuppressive activity. Lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages were employed as a model to explore the effect of these compounds in immunosuppressive activity. The results showed that 2 could reduce the generation of inflammatory mediators including nitric oxide (NO), reactive oxygen species (ROS), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). Western blotting analysis demonstrated that 2 could suppressed the PI3K pathway by decreasing the levels of p-PI3K and p-Akt, while increasing the levels of p-PTEN. The anti-inflammatory activity of 2 was further confirmed using a zebrafish in vivo model.

Trichodimerol inhibits inflammation through suppression of the nuclear transcription factor-kappaB/NOD-like receptor thermal protein domain associated protein 3 signaling pathway.

Excessive inflammation causes chronic diseases and tissue damage. Although there has been drug treatment, its side effects are relatively large. Searching for effective anti-inflammatory drugs from natural products has become the focus of attention. First isolated from Trichoderma longibraciatum, trichodimerol is a natural product with TNF inhibition. In this study, lipopolysaccharide (LPS)-induced RAW264.7 macrophages were used as a model to investigate the anti-inflammatory activity of trichodimerol. The results of nitric oxide (NO) detection, enzyme-linked immunosorbent assay (ELISA), and reactive oxygen species (ROS) showed that trichodimerol could reduce the production of NO, ROS, and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Western blotting results showed that trichodimerol could inhibit the production of inflammatory mediators such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) and the protein expression of nuclear transcription factor-kappaB (NF-κB), p-IKK, p-IκB, Toll-like receptor 4 (TLR4), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cysteinyl aspartate specific proteinase (Caspase)-1, and ASC, which indicated that trichodimerol may inhibit inflammation through the NF-κB and NLRP3 pathways. At the same time, molecular docking showed that trichodimerol can directly combine with the TLR4-MD2 complex. Hence, trichodimerol inhibits inflammation by obstructing the interaction between LPS and the TLR4-MD2 heterodimer and suppressing the downstream NF-κB and NLRP3 pathways.

Alteration of MDM2 by the Small Molecule YF438 Exerts Antitumor Effects in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) exhibits a high mortality rate and is the most aggressive subtype of breast cancer. As previous studies have shown that histone deacetylases (HDAC) may represent molecular targets for TNBC treatment, we screened a small library of synthetic molecules and identified a potent HDAC inhibitor (HDACi), YF438, which exerts effective anti-TNBC activity both in vitro and in vivo. Proteomic and biochemical studies revealed that YF438 significantly downregulated mouse double minute 2 homolog (MDM2) expression. In parallel, loss of MDM2 expression or blocking MDM2 E3 ligase activity rendered TNBC cells less sensitive to YF438 treatment, revealing an essential role of MDM2 E3 ligase activity in YF438-induced inhibition of TNBC. Mechanistically, YF438 disturbed the interaction between HDAC1 and MDM2, induced the dissociation of MDM2-MDMX, and subsequently increased MDM2 self-ubiquitination to accelerate its degradation, which ultimately inhibited growth and metastasis of TNBC cells. In addition, analysis of clinical tissue samples demonstrated high expression levels of MDM2 in TNBC, and MDM2 protein levels closely correlated with TNBC progression and metastasis. Collectively, these findings show that MDM2 plays an essential role in TNBC progression and targeting the HDAC1-MDM2-MDMX signaling axis with YF438 may provide a promising therapeutic option for TNBC. Furthermore, this novel underlying mechanism of a hydroxamate-based HDACi in altering MDM2 highlights the need for further development of HDACi for TNBC treatment. SIGNIFICANCE: This study uncovers the essential role of MDM2 in TNBC progression and suggests that targeting the HDAC1-MDM2-MDMX axis with a hydroxamate-based HDACi could be a promising therapeutic strategy for TNBC.

Erratum: Blood TfR+ exosomes separated by a pH-responsive method deliver chemotherapeutics for tumor therapy: Erratum.

[This corrects the article DOI: 10.7150/thno.37220.].

Antibacterial Properties and Application of Nanosilver Material in the Tracheal Tube.

To investigate the antibacterial ability of a new type of antibacterial tracheal tube coated with nanosilver/polyurethane in rats. In January 2016, 48 male SD rats of SPF grade, provided by the medical center of Hong Kong University of science and technology, Peking University, Shenzhen, were selected as the study objects. Twenty-four healthy rats, who underwent endotracheal intubation and retained nanosilver/polyurethane-coated new antibacterial endotracheal tube in vivo, were randomly selected as the experimental group, while 24 healthy rats who underwent endotracheal intubation at the same time and retained common endotracheal tube in vivo were randomly selected as the control group. At 12, 24, 48, and 72 hours after the operation, the number of colonies in the alveolar lavage fluid of the two groups was measured using the plate count method, and the thickness of the biofilm formed by the built-in catheter of the two groups was observed by microscope. Twelve hours after operation, there was no significant difference between the two groups (P <0.05). The colony number in BALF in the experimental group was significantly lower than that in the control group (P < 0.05). At 12 and 24 hours after operation, there was no significant difference in the biofilm thickness between the two groups (P > 0.05). In the experimental group, the thickness of biofilm that had formed by catheterization 48 and 72 hours after operation was significantly lower than that in the control group (P < 0.05). The new type of antibacterial tracheal tube, coated with nanosilver/polyurethane, has stronger antibacterial and anti-biofilm proliferation performance than that of the common tracheal tube.

Blood TfR+ exosomes separated by a pH-responsive method deliver chemotherapeutics for tumor therapy.

Blood transferrin receptor-positive (TfR+) exosomes are a kind of optimized drug delivery vector compared with other kinds of exosomes due to their easy access and high bio-safety. Their application facilitates the translation from bench to bedside of exosome-based delivery vehicles. Methods: In this study, a pH-responsive superparamagnetic nanoparticles cluster (denoted as SMNC)-based method was developed for the precise and mild separation of blood TfR+ exosomes. Briefly, multiple superparamagnetic nanoparticles (SPMNs) labeled with transferrins (Tfs) could precisely bind to blood TfR+ exosomes to form an exosome-based cluster due to the specific recognition of TfR by Tf. They could realize the precise magnetic separation of blood TfR+ exosomes. More importantly, the pH-responsive dissociation characteristic of Tf and TfR led to the mild collapse of clusters to obtain pure blood TfR+ exosomes. Results: Blood TfR+ exosomes with high purity and in their original state were successfully obtained through the pH-responsive SMNC-based method. These can load Doxorubicin (DOX) with a loading capacity of ~10% and dramatically increase the tumor accumulation of DOX in tumor-bearing mice because of their innate passive-targeting ability. In addition, blood TfR+ exosomes changed the biodistribution of DOX leading to the reduction of side effects. Compared with free DOX, DOX-loaded blood TfR+ exosomes showed much better tumor inhibition effects on tumor-bearing mice. Conclusion: Taking advantage of the pH-responsive binding and disaggregation characteristics of Tf and TfR, the SMNC-based method can precisely separate blood TfR+ exosomes with high purity and in their original state. The resulting blood TfR+ exosomes showed excellent bio-safety and enable the efficient delivery of chemotherapeutics to tumors, facilitating the clinical translation of exosome-based drug delivery systems.

Identification of the typical metal particles among haze, fog, and clear episodes in the Beijing atmosphere.

For a better understanding of metal particle morphology and behaviors in China, atmospheric aerosols were sampled in the summer of 2012 in Beijing. The single-particle analysis shows various metal-bearing speciations, dominated by oxides, sulfates and nitrates. A large fraction of particles is soluble. Sources of Fe-bearing particles are mainly steel industries and oil fuel combustion, whereas Zn- and Pb-bearing particles are primarily contributed by waste incineration, besides industrial combustion. Other trace metal particles play a minor rule, and may come from diverse origins. Mineral dust and anthropogenic source like vehicles and construction activities are of less importance to metal-rich particles. Statistics of 1173 analyzed particles show that Fe-rich particles (48.5%) dominate the metal particles, followed by Zn-rich particles (34.9%) and Pb-rich particles (15.6%). Compared with the abundances among clear, haze and fog conditions, a severe metal pollution is identified in haze and fog episodes. Particle composition and elemental correlation suggest that the haze episodes are affected by the biomass burning in the southern regions, and the fog episodes by the local emission with manifold particle speciation. Our results show the heterogeneous reaction accelerated in the fog and haze episodes indicated by more zinc nitrate or zinc sulfate instead of zinc oxide or carbonate. Such information is useful in improving our knowledge of fine airborne metal particles on their morphology, speciation, and solubility, all of which will help the government introduce certain control to alleviate metal pollution.

Characteristics and chemical compositions of particulate matter collected at the selected metro stations of Shanghai, China.

A campaign was conducted to assess and compare the air quality at the different metro platforms at Shanghai City, focusing on particulate matter (PM) levels, chemical compositions, morphology and mineralogy, as well as species of iron. Our results indicated that the average PM2.5 concentrations for the three metro lines were 177.7 µg/m(3), 105.7 µg/m(3) and 82.5 µg/m(3), respectively, and the average PM1 concentrations for the three lines were 122.3 µg/m(3), 84.1 µg/m(3) and 59.6 µg/m(3), respectively. Fe, Mn, Cr, Cu, Sr, Ba and Pb concentrations in all of the sampling sites were significantly higher than that in the urban ambient air, implicating that these trace metals may be associated with the metro systems working. Individual airborne dusts were studied for morphology and mineralogy characteristics. The results revealed that the presence of most individual particles were with no definite shape and most of them were with a large metal content. Furthermore, Fe-rich particles had significantly higher abundance in the metro systems, which were more frequently encountered in the underground lines than the aboveground line. The 2D distribution map of an interested Fe-rich particle showed an uneven Fe distribution, implying that a hollow or core of other substance exists in the particle center during the formation process. Cluster analysis revealed that Fe-rich particles were possibly a mixture of Fe species. Fitting of X-ray absorption near-edge fine structure spectra (XANES) showed the main iron species within the particles collected from the three contrasting metro lines of Shanghai to be hematite, magnetite, iron-metal and mineral Fe. Hematite and mineral Fe were all found in three lines, while magnetite only existed in aboveground metro line. Iron-metal was determined in both the older and younger underground lines, based on the X-ray diffraction (XRD) analysis. As diverse Fe species have different physical-chemical characteristics and toxicity, the speciation of Fe-containing metro particles is important in the context of public health and control measures.