A dual-channel fluorescence probe for simultaneously visualizing cysteine and viscosity during drug-induced hepatotoxicity.

Cysteine (Cys), one of the important participants in protecting cells from oxidative stress, is closely associated with the occurrence and development of various diseases. Moreover, cell viscosity as a pivotal microenvironmental parameter has recently attracted increasing attention due to its dominant role in governing intracellular signal transduction and diffusion of reactive metabolites. Thus, simultaneous detection of Cys and viscosity is imperative for investigating their pathophysiological functions and cross-link. Herein we present a mitochondria-targetable dual-channel fluorescence probe ABDSP by grafting the acrylate modified pyridinium unit to dimethylaminobenzene. Whilst the probe is a seemingly simple, it could simultaneously discriminate Cys and viscosity in a fashion of distinguishable signals. Furthermore, the probe was successfully employed for visualizing mitochondrial Cys and viscosity, and probe into their cross-link during acetaminophen-induced hepatotoxicity.

HILPS, a long noncoding RNA essential for global oxygen sensing in humans.

Adaptation to low levels of oxygen (hypoxia) is a universal biological feature across metazoans. However, the unique mechanisms how different species sense oxygen deprivation remain unresolved. Here, we functionally characterize a novel long noncoding RNA (lncRNA), LOC105369301, which we termed hypoxia-induced lncRNA for polo-like kinase 1 (PLK1) stabilization (HILPS). HILPS exhibits appreciable basal expression exclusively in a wide variety of human normal and cancer cells and is robustly induced by hypoxia-inducible factor 1α (HIF1α). HILPS binds to PLK1 and sequesters it from proteasomal degradation. Stabilized PLK1 directly phosphorylates HIF1α and enhances its stability, constituting a positive feed-forward circuit that reinforces oxygen sensing by HIF1α. HILPS depletion triggers catastrophic adaptation defect during hypoxia in both normal and cancer cells. These findings introduce a mechanism that underlies the HIF1α identity deeply interconnected with PLK1 integrity and identify the HILPS-PLK1-HIF1α pathway as a unique oxygen-sensing axis in the regulation of human physiological and pathogenic processes.

Porous Organic Polymers-Supported Zeigler-Natta Catalysts for Preparing Highly Isotactic Polypropylene with Broad Molecular Weight Distribution.

Porous organic polymers (POPs) have attracted much attention in numerous areas, including catalysis, adsorption and separation. Herein, POP supported Ziegler-Natta catalysts were designed for preparation of isotactic polypropylene (iPP). The POPs-based Ziegler-Natta catalysts exhibited the characteristic of broad molecular weight distribution (MWD > 11) with or without adding an extra internal electron donor. The added internal electron donor 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate (ID-2) used in cat-2 showed good propylene polymerization activity of 15.3 × 106 g·PP/mol·Ti·h, high stereoregularity with 98.2% of isotacticity index and broad molecular weight distribution (MWD) of 12.3. Compared to the MgCl2-supported Ziegler-Natta catalysts (cat-4) with the same ID-2, cat-2 showed higher chain stereoregularity for propylene polymerization. As seen in the TREF results, the elution peak of PP-2 (124.0 °C, 91.7%) is 1.5 °C higher than the isotactic fraction from PP-4 (122.5 °C, 87.2%), and even 1.2 °C higher than PP-5 prepared from ID-3 with the characteristics of high stereoregularity. Moreover, the pentad methyl sequence mmmm of PP-2 (93.0%) from cat-2 is 0.5% higher than that of PP-4 from cat-4. XPS analysis revealed that the minute difference in binding energy of Ti, Mg, C and O atoms exist between the inorganic MgCl2 and the organic polymer based Z-N catalysts. The plausible interaction mechanism of active sites of Mg and Ti with the functional groups in the POP support and the added ID was proposed, which could be explained by their high stereoregularity and the broad molecular weight distribution of the POP-based Z-N catalysts.

The mechanism study of inhibition effect of prepared Radix Rehmanniainon combined with Radix Astragali osteoporosis through PI3K-AKT signaling pathway.

PURPOSE: To observe the mechanism of prepared Radix Rehmanniainon combined with Radix Astragali in treating osteoporosis. METHODS: Osteoporosis rat model was established by bilateral ovariectomy combined with low-calcium diet feeding. Bone mineral density was measured by bone densitometer. Bone metabolism markers in serum were detected by enzyme linked immunosorbent assay (ELISA), bone tissue structure was observed by hematoxylin-eosin staining, and the effect of prepared Radix Rehmanniainon combined with Radix Astragali on PI3K-AKT signaling pathway was investigated by immunohistochemistry and reverse transcription polymerase chain reaction. RESULTS: Compared with the model group, the bone tissue structure and imbalance of bone metabolism were improved, and the bone mineral density was significantly increased in the prepared Radix Rehmanniainon combined with Radix Astragali groups. After intervention with prepared Radix Rehmanniainon combined with Radix Astragali, the positive expression of PIK3CA and Akt1 in rat bone tissue was enhanced, and the expression levels of Akt1 mRNA were significantly increased. CONCLUSIONS: Prepared Radix Rehmanniainon combined with Radix Astragali may treat osteoporosis by activating PI3K/AKT pathway.

Deep Transfer Learning for Question Classification Based on Semantic Information Features of Category Labels.

Question classification is an important component of the question answering system (QA system), which is designed to restrict the answer types and accurately locate the answers. Therefore, the classification results of the questions affect the quality and performance of the QA system. Most question classification methods in the past have relied on a large amount of manually labeled training data. However, in real situations, especially in new domains, it is very difficult to obtain a large amount of labeled data. Transfer learning is an effective approach to solve the problem with the scarcity of annotated data in new domains. We compare the effects of different deep transfer learning methods on cross-domain question classification. On the basis of the ALBERT fine-tuning model, we extract the category labels of the source domain, the question text, and the predicted category labels of the target domain as input to extract the category labels. Additionally, the semantic information of the category labels is extracted to achieve cross-domain question classification. Furthermore, WordNet is used to expand the question, which further improves the classification accuracy of the target domain. Experimental results show that the above methods can further improve the classification accuracy in new domains based on deep transfer learning.

c-MYC-USP49-BAG2 axis promotes proliferation and chemoresistance of colorectal cancer cells in vitro.

Deubiquitinases (DUBs) play critical roles in tumorigenesis and are emerging as potential therapeutic targets. However, it remains less clear which DUBs may play important roles and represent a realistic vulnerability for a particular type of tumor. Here we revealed that Ubiquitin Specific Peptidase 49 (USP49) is transcriptionally activated by c-MYC in colorectal cancer (CRC), and CRC patients with elevated USP49 levels exhibited significantly shorter survival. Knockdown of USP49 markedly inhibited CRC cell proliferation, colony formation, and chemotherapy resistance in vitro. Investigation of mechanisms unravels that USP49 deubiquitinates and stabilizes Bcl-2-Associated Athanogene 2 (BAG2), a well-known protein that antagonizes apoptosis and enables adaptive response of CRC cells. This study identified a novel mechanism by which USP49 promotes CRC cell survival by stabilizing BAG2 through the c-MYC-USP49-BAG2 axis, indicating that USP49 may become a potential therapeutic target for CRC.

EZH2 depletion potentiates MYC degradation inhibiting neuroblastoma and small cell carcinoma tumor formation.

Efforts to therapeutically target EZH2 have generally focused on inhibition of its methyltransferase activity, although it remains less clear whether this is the central mechanism whereby EZH2 promotes cancer. In the current study, we show that EZH2 directly interacts with both MYC family oncoproteins, MYC and MYCN, and promotes their stabilization in a methyltransferase-independent manner. By competing against the SCFFBW7 ubiquitin ligase to bind MYC and MYCN, EZH2 counteracts FBW7-mediated MYC(N) polyubiquitination and proteasomal degradation. Depletion, but not enzymatic inhibition, of EZH2 induces robust MYC(N) degradation and inhibits tumor cell growth in MYC(N) driven neuroblastoma and small cell lung carcinoma. Here, we demonstrate the MYC family proteins as global EZH2 oncogenic effectors and EZH2 pharmacologic degraders as potential MYC(N) targeted cancer therapeutics, pointing out that MYC(N) driven cancers may develop inherent resistance to the canonical EZH2 enzymatic inhibitors currently in clinical development.

USP29 coordinates MYC and HIF1α stabilization to promote tumor metabolism and progression.

Tumor cells must rewire cellular metabolism to satisfy the demands of unbridled growth and proliferation. How these metabolic processes are integrated to fuel cancer cell growth remains largely unknown. Deciphering the regulatory mechanisms is vital to develop targeted strategies for tumor-selective therapies. We herein performed an unbiased and functional siRNA screen against 96 deubiquitinases, which play indispensable roles in cancer and are emerging as therapeutic targets, and identified USP29 as a top candidate essential for metabolic reprogramming that support biosynthesis and survival in tumor cells. Integrated metabolic flux analysis and molecular investigation reveal that USP29 directly deubiquitinates and stabilizes MYC and HIF1α, two master regulators of metabolic reprogramming, enabling adaptive response of tumor cells in both normoxia and hypoxia. Systemic knockout of Usp29 depleted MYC and HIF1α in MYC-driven neuroblastoma and B cell lymphoma, inhibited critical metabolic targets and significantly prolonged survival of tumor-bearing mice. Strikingly, mice homozygous null for the Usp29 gene are viable, fertile, and display no gross phenotypic abnormalities. Altogether, these results demonstrate that USP29 selectively coordinates MYC and HIF1α to integrate metabolic processes critical for cancer cell growth, and therapeutic targeting of USP29, a potentially targetable enzyme, could create a unique vulnerability given deregulation of MYC and HIF1α frequently occurs in human cancers.

Investigation of anti-osteoporosis mechanisms of Rehmanniae Radix Preparata based on network pharmacology and experimental verification.

BACKGROUND: Rehmanniae Radix Preparata (RRP) can effectively improve the symptoms of osteoporosis, but its molecular mechanism for treating osteoporosis is still unclear. The objective of this study is to investigate the anti-osteoporosis mechanisms of RRP through network pharmacology. METHODS: The overlapping targets of RRP and osteoporosis were screened out using online platforms. A visual network diagram of PPI was constructed and analyzed by Cytoscape 3.7.2 software. Molecular docking was used to evaluate the binding activity of ligands and receptors, and some key genes were verified through pharmacological experiments. RESULTS: According to topological analysis results, AKT1, MAPK1, ESR1, and SRC are critical genes for RRP to treat osteoporosis, and they have high binding activity with stigmasterol and sitosterol. The main signal pathways of RRP in the treatment of osteoporosis, including the estrogen signaling pathway, HIF-1 signal pathway, MAPK signal pathway, PI3K-Akt signal pathway. Results of animal experiments showed that RRP could significantly increase the expression levels of Akt1, MAPK1, ESR1, and SRC1 mRNA in bone tissue to increase bone density. CONCLUSION: This study explained the coordination between multiple components and multiple targets of RRP in the treatment of osteoporosis and provided new ideas for its clinical application and experimental research.

Effects of Rehmannia glutinosa polysaccharides on bone tissue structure and skeletal muscle atrophy in rats with disuse.

PURPOSE: To study effects of Rehmannia glutinosa polysaccharides (RGP) on bone tissue structure and skeletal muscle atrophy in rats with disuse. METHODS: A rat model of disuse osteoporosis combined with muscle atrophy was established by removing the bilateral ovaries of rats and fixing their hind limbs for a long time. Forty SD rats were administered intragastrically for 12 weeks. The bone histomorphometry parameters and the level of oxidative stress were measured. In addition, the changes of muscle atrophy F-box (MAFbx), muscle RING-finger protein-1 (MuRF1), forkhead box O1 (FOXO1) mRNA expression in skeletal muscle of rats were observed. RESULTS: RGP significantly increased the percentage of fluorescence perimeter and bone mineralization deposition rate of the second lumbar vertebrae of rats. It also significantly increased the wet weight ratio and muscle fiber cross-sectional area of the gastrocnemius muscle of rats. At the same time, RGP significantly increased the levels of super oxide dismutase (SOD) and catalase (CAT) in the skeletal muscle of rats, and reduced the content of malondialdehyde (MDA). Rehmannia glutinosa polysaccharides also significantly reduced the expression levels of FOXO1, MAFbx and MuRF1 mRNA in rat skeletal muscle. CONCLUSIONS: RGP could improve the bone structure of osteoporotic rats. It could also improve muscle that atrophy may be related to the inhibition of FOXO1-mediated ubiquitin-proteasome pathway.

Effects of Rehmannia glutinosa polysaccharides on bone tissue structure and skeletal muscle atrophy in rats with disuse

ABSTRACT Purpose To study effects of Rehmannia glutinosa polysaccharides (RGP) on bone tissue structure and skeletal muscle atrophy in rats with disuse. Methods A rat model of disuse osteoporosis combined with muscle atrophy was established by removing the bilateral ovaries of rats and fixing their hind limbs for a long time. Forty SD rats were administered intragastrically for 12 weeks. The bone histomorphometry parameters and the level of oxidative stress were measured. In addition, the changes of muscle atrophy F-box (MAFbx), muscle RING-finger protein-1 (MuRF1), forkhead box O1 (FOXO1) mRNA expression in skeletal muscle of rats were observed. Results RGP significantly increased the percentage of fluorescence perimeter and bone mineralization deposition rate of the second lumbar vertebrae of rats. It also significantly increased the wet weight ratio and muscle fiber cross-sectional area of the gastrocnemius muscle of rats. At the same time, RGP significantly increased the levels of super oxide dismutase (SOD) and catalase (CAT) in the skeletal muscle of rats, and reduced the content of malondialdehyde (MDA). Rehmannia glutinosa polysaccharides also significantly reduced the expression levels of FOXO1, MAFbx and MuRF1 mRNA in rat skeletal muscle. Conclusions RGP could improve the bone structure of osteoporotic rats. It could also improve muscle that atrophy may be related to the inhibition of FOXO1-mediated ubiquitin-proteasome pathway.

Versatile Polypropylene Copolymers from a Pilot-Scale Spheripol II Process.

Polypropylene (PP) is one of the most widely used polymers. In this paper, three types of PPs including random PP, impact PP, and impact PP with high clarity, were prepared through a 75 kg/h pilot-scale Spheripol II process. The three produced PPs were produced by the selection or combination the two loops and gas phase reactor and controlling the comonomer and hydrogen concentrations. The three prepared PPs then were pelleted with the clarified nucleating agent NX 8000 and tested for mechanical, thermal, and optical properties. Their molecular structures and rubber phase size were also investigated by GPC, 13C NMR, temperature rising elution fractionation (TREF), XRD, SEM analysis, etc. The results showed that the random PP (PP-1) and the impact PP with high clarity (PP-3) obtained excellent optical transparency with a haze of 12.5% and 13.5% due to their small rubber phase size (roughly ≤ 100 nm), while the impact PP (PP-2) obtained bad transparency with a haze of 98.8% due to the large rubber phase size (about 1 µm) caused by the poor thermal compatibility with the PP matrix. The rubber phase content and ethylene/propylene sequence distributions of the three PPs varied much and resulted in different impact strengths and stiffness properties. PP-2 had a high impact strength of 14.5 kJ/m2 due to the rubber phase generated in the gas phase reactor. Except for the optical transparency, PP-3 gained stiffness and toughness, with 914 MPa of flexural modulus and 25.1 kJ/m2 of impact strength due to the unique molecular structure of its rubber phase.

Highly Flowable Nano TiO2/Porous Organic Polymer (POP) Supports for Efficient Metallocene Catalysts.

Porous organic polymers (POPs) have proven to be an efficient support in the olefin polymerization catalyst field. In this paper, nano TiO2 beads were used to modulate the pore structure, bulk density, and surface morphology and flowability of the prepared POPs. With the incorporation of the hydrophilic nano TiO2 beads, the prepared TiO2/POP supports obtained reasonable specific surface area (100-300 m2/g) and higher bulk density (0.26-0.35 g/mL) and flowability than the pure POP supports. The results show that bulk density of the prepared TiO2/POP particles increased when adding an increased amount of TiO2, and when 37.5% TiO2 (weight percent to the total comonomers divinylbenzene (DVB) and 2-hydroxyethyl methacrylate (HEMA)) and 3:1 DVB/HEMA (molar ratio) were added, highly flowable TiO2/POP composites (POP-6 and POP-7) were obtained. With the modulation of the nano TiO2 template during the support synthesis, the prepared POP-7 particles successfully achieved a normal distribution with a narrow particle size distribution (PSD) of 0.717 and average particle size of 24.1 m, a specific surface area (SSA) of 279 m2/g, and relatively high bulk density of 0.30 g/mL. Furthermore, all the prepared TiO2/POP supports obtained higher ethylene polymerization activity than silica gel-supported commercial metallocene catalyst. The immobilized (n-BuCp)2ZrCl2/MAO@POP-7 catalyst exhibited the highest ethylene polymerization activity of 4794 kg PE/mol Zr.bar.h and productivity of 389 g PE/g cat, more than twice that of the commercial counterpart. Even higher catalyst productivity (3197 g PE/g cat) and bulk density of the produced PE (0.36 g/mL) could be obtained in higher ethylene partial pressure at 80 ∘C for 2 h, and the prepared TiO2/POP catalyst shows no obvious Zr+ active sites decay during the ethylene polymerization.

USP49 participates in the DNA damage response by forming a positive feedback loop with p53.

The p53 tumor suppressor is a critical factor in the DNA damage response (DDR), and regulation of p53 stability has a key role in this process. In our study, we identified USP49 as a novel deubiquitinase (DUB) for p53 from a library consisting of 80 DUBs and found that USP49 has a positive effect on p53 transcriptional activity and protein stability. Investigation of the mechanism revealed that USP49 interacts with the N terminus of p53 and suppresses several types of p53 ubiquitination. Furthermore, USP49 rendered HCT116 cells more sensitive to etoposide (Eto)-induced DNA damage and was upregulated in response to several types of cell stress, including DNA damage. Remarkably, USP49 expression was regulated by p53 and USP49 in knockout mice, which are more susceptible to azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon tumors. These findings suggest that USP49 has an important role in DDR and may act as a potential tumor suppressor by forming a positive feedback loop with p53.

Mycoplasma fermentans deacetylase promotes mammalian cell stress tolerance.

Mycoplasma fermentans is a pathogenic bacterium that infects humans and has potential pathogenic roles in respiratory, genital and rheumatoid diseases. NAD+-dependent deacetylase is involved in a wide range of pathophysiological processes and our studies have demonstrated that expression of mycoplasmal deacetylase in mammalian cells inhibits proliferation but promotes anti-starvation stress tolerance. Furthermore, mycoplasmal deacetylase is involved in cellular anti-oxidation, which correlates with changes in the proapoptotic proteins BIK, p21 and BIM. Mycoplasmal deacetylase binds to and deacetylates the FOXO3 protein, similar with mammalian SIRT2, and affects expression of the FOXO3 target gene BIM, resulting in inhibition of cell proliferation. Mycoplasmal deacetylase also alters the performance of cells under drug stress. This study expands our understanding of the potential molecular and cellular mechanisms of interaction between mycoplasmas and mammalian cells.