Polystyrene nano-plastics impede skeletal muscle development and induce lipid accumulation via the PPARγ/LXRβ pathway in vivo and in vitro in mice

Nano-plastics (NPs) have emerged as a significant environmental pollutant, widely existing in water environment, and pose a serious threat to health and safety with the intake of animals. Skeletal muscle, a vital organ for complex life activities and functional demands, has received limited attention regarding the effects of NPs. In this study, the effects of polystyrene NPs (PS-NPs) on skeletal muscle development were studied by oral administration of different sizes (1 mg/kg) of PS-NPs in mice. The findings revealed that PS-NPs resulted in skeletal muscle damage and significantly hindered muscle differentiation, exhibiting an inverse correlation with PS-NPs particle size. Morphological analysis demonstrated PS-NPs caused partial disruption of muscle fibers, increased spacing between fibers, and lipid accumulation. RT-qPCR and western blots analyses indicated that PS-NPs exposure downregulated the expression of myogenic differentiation-related factors (Myod, Myog and Myh2), activated PPARγ/LXRβ pathway, and upregulated the expressions of lipid differentiation-related factors (SREBP1C, SCD-1, FAS, ACC1, CD36/FAT, ADIPOQ, C/EBPα and UCP-1). In vitro experiments, C2C12 cells were used to confirm cellular penetration of PS-NPs (0, 100, 200, 400 μg/mL) through cell membranes along with activation of PPARγ expression. Furthermore, to verify LXRβ as a key signaling molecule, silencing RNA transfection experiments were conducted, resulting in no increase in the expressions of PPARγ, LXRβ, SREBP1C, FAS, CD36/FAT, ADIPOQ, C/EBPα and UCP-1 even after exposure to PS-NPs. However, the expressions of SCD-1and ACC1 remained unaffected. The present study evidenced that exposure to PS-NPs induced lipid accumulation via the PPARγ/LXRβ pathway thereby influencing skeletal muscle development.

Green tea polyphenols alleviate TBBPA-induced gastric inflammation and apoptosis by modulating the ROS-PERK/IRE-1/ATF6 pathway in mouse models

Green tea polyphenols (GTP), an important phytochemical in the daily human diet, bind to various cellular receptors and exert anti-inflammatory and antioxidant benefits. The environmental contaminant tetrabromobisphenol A (TBBPA) enters the digestive system through multiple pathways, resulting in oxidative stress (OS), gastroenteritis, and mucosal injury. The aim of this study was to explore the molecular mechanisms of TBBPA-induced gastritis in mice treated with GTP in vivo and in an in vitro model. The results showed that exposure to TBBPA increased reactive oxygen species (ROS) levels, activated oxidative stress (OS) induced endoplasmic reticulum stress (ERS), and the expression of endoplasmic reticulum stress-related factors (e.g., GRP78, PERK, IRE-1, ATF-6, etc.) increased. The inflammatory pathway NF-κB was activated, and the pro-inflammatory factors TNF-α, IL-1β, and IL-6 increased, while triggering a cascade reaction mediated by caspase-3. However, the addition of GTP could inhibit OS, restore the balance of endoplasmic reticulum homeostasis, and improve the inflammatory infiltration and apoptosis of gastric mucosal epithelial cells. Therefore, GTP alleviated ERS, reduced inflammation and apoptosis, and restored the gastric mucosal barrier by alleviating TBBPA-induced OS in mouse gastric tissues and GES-1 cells. This provides basic information for exploring the antioxidant mechanism of GTP and further investigating the toxic effects of TBBPA on mouse gastric mucosa.

Leveraging Isoreticular Principle to Elucidate the Key Role of Inherent Hydrogen-Bonding Anchoring Sites in Enhancing Water Sorption Cyclability of Zr(IV) Metal-Organic Frameworks

Water adsorption/desorption cyclability of porous materials is a prerequisite for diverse applications, including atmospheric water harvesting (AWH), humidity autocontrol (HAC), heat pumps and chillers, and hydrolytic catalysis. However, unambiguous molecular insights into the correlation between underlying building blocks and the cyclability are still highly elusive. In this work, by taking advantage of the well-established isoreticular synthetic principle in Zr(IV) metal-organic frameworks (Zr-MOFs), we show that the inherent density of hydrogen atoms in the organic skeleton can play a key role in regulating the water sorption cyclability of MOFs. The ease of isoreticular practice of Zr-MOFs enables the successful syntheses of two pairs of isostructural Zr-MOFs (NU-901 and NU-903, NU-950 and SJTU-9) from pyrene- or benzene-cored carboxylate linkers, which feature scu and sqc topological nets, respectively. NU-901 and NU-950 comprised of pyrene skeletons carrying more hydrogen-bonding anchoring sites show distinctly inferior cyclability as compared with NU-903 and SJTU-9 built of benzene units. Single-crystal X-ray crystallography analysis of the hydrated structure clearly unveils the water molecule-involved interactions with the hydrogen-bonding donors of benzene moieties. Remarkably, NU-903 and SJTU-9 isomers exhibit outstanding water vapor sorption capacities as well as working capacities at the desired humidity range with potential implementations covering indoor humidity control and water harvesting. Our findings uncover the importance of hydrogen-bonding anchoring site engineering of organic scaffold in manipulating the framework durability toward water sorption cycle and will also likely facilitate the rational design and development of highly robust porous materials.

A conserved GRAS-domain transcriptional regulator links meristem indeterminacy to sex determination in Ceratopteris gametophytes

Most land plants alternate between generations of sexual gametophytes and asexual sporophytes. Unlike seed plants, fern gametophytes are free living and grow independently of their sporophytes. In homosporous ferns such as Ceratopteris, gametophytes derived from genetically identical spores exhibit sexual dimorphism, developing as either males or hermaphrodites. Males lack meristems and promote cell differentiation into sperm-producing antheridia. In contrast, hermaphrodites initiate multicellular meristems that stay undifferentiated, sustain cell division and prothallus expansion, and drive the formation of egg-producing archegonia. Once initiating the meristem, hermaphrodites secrete the pheromone antheridiogen, which triggers neighboring slower-growing gametophytes to develop as males, while the hermaphrodites themselves remain insensitive to antheridiogen. This strategy promotes outcrossing and prevents all individuals in the colony from becoming males. This study reveals that an evolutionarily conserved GRAS-domain transcriptional regulator (CrHAM), directly repressed by Ceratopteris microRNA171 (CrmiR171), promotes meristem development in Ceratopteris gametophytes and determines the male-to-hermaphrodite ratio in the colony. CrHAM preferentially accumulates within the meristems of hermaphrodites but is excluded from differentiated antheridia. CrHAM sustains meristem proliferation and cell division through conserved hormone pathways. In the meantime, CrHAM inhibits the antheridiogen-induced conversion of hermaphrodites to males by suppressing the male program expression and preventing meristem cells from differentiating into sperm-producing antheridia. This finding establishes a connection between meristem indeterminacy and sex determination in ferns, suggesting both conserved and diversified roles of meristem regulators in land plants.

Organosiloxane-Modified Auricularia Polysaccharide (Si-AP): Improved High-Temperature Resistance and Lubrication Performance in WBDFs

This study introduces a novel organosilicon-modified polysaccharide (Si-AP) synthesized via grafting and comprehensively evaluates its performance in water-based drilling fluids (WBDFs). The molecular structure of Si-AP was characterized using Fourier-transform infrared spectroscopy (FTIR) and 1H-NMR experiments. Thermalgravimetric analysis (TGA) confirmed the good thermal stability of Si-AP up to 235 °C. Si-AP significantly improves the rheological properties and fluid loss performance of WBDFs. With increasing Si-AP concentration, system viscosity increases, API filtration rate decreases, clay expansion is inhibited, and drilling cuttings hydration dispersion is suppressed, especially under high-temperature conditions. Additionally, mechanistic analysis indicates that the introduction of siloxane groups can effectively inhibit the thermal degradation of AP chains and enhance their high-temperature resistance. Si-AP can form a lubricating film by adsorbing on the surface of clay particles, improving mud cake quality, reducing the friction coefficient, and significantly enhancing the lubricating performance of WBDFs. Overall, Si-AP exhibits a higher temperature-resistance limit compared to AP and more effectively optimizes the lubrication, inhibition, and control of the filtration rate of WBDFs under high-temperature conditions. While meeting the requirements of drilling fluid systems under high temperatures, Si-AP also addresses environmental concerns and holds promise as an efficient solution for the exploitation of deep-seated oil and gas resources.

Removal of dyes from wastewater using Eucalyptus wood fiber loaded nanoscale zero-valent iron: Characterization and removal mechanism

Wood fiber as a natural and renewable material has low cost and plenty of functional groups, which owns the ability to adsorb dyes. In order to improve the application performance of wood fiber in dye-pollution wastewater, Eucalyptus wood fiber loaded nanoscale zero-valent iron (EWF-nZVI) was developed to give EWF magnetism and the ability to degrade dyes. EWF-nZVI was characterized via FTIR, XRD, zeta potential, VSM, SEM-EDS and XPS. Results showed that EWF-nZVI owned a strong magnetism of 96.51 emu/g. The dye removal process of EWF-nZVI was more in line with the pseudo-second-order kinetics model. In addition, the Langmuir isotherm model fitting results showed that the maximum removal capacities of Congo red and Rhodamine B by EWF-nZVI were 714.29 mg/g and 68.49 mg/g at 328 K, respectively. After five adsorption-desorption cycles, the regeneration efficiencies of Congo red and Rhodamine B were 74 % and 42 % in turn. The dye removal mechanisms of EWF-nZVI included redox degradation (Congo red and Rhodamine B) and electrostatic adsorption (Congo red). In summary, EWF-nZVI is a promising biomass-based material with high dye removal capacities. This work is beneficial to promote the large-scale application of wood fiber in water treatment.

Green tea polyphenols inhibit TBBPA-induced lung injury via enhancing antioxidant capacity and modulating the NF-κB pathway in mice

Tetrabromobisphenol A (TBBPA) is a global pollutant. When TBBPA is absorbed by the body through various routes, it can have a wide range of harmful effects on the body. Green tea polyphenols (GTPs) can act as antioxidants, resisting the toxic effects of TBBPA on animals. The effects and mechanisms of GTP and TBBPA on oxidative stress, inflammation and apoptosis in the mouse lung are unknown. Therefore, we established in vivo and in vitro models of TBBPA exposure and GTP antagonism using C57 mice and A549 cells and examined the expression of factors related to oxidative stress, autophagy, inflammation and apoptosis. The results of the study showed that the increase in reactive oxygen species (ROS) levels after TBBPA exposure decreased the expression of autophagy-related factors Beclin1, LC3-II, ATG3, ATG5, ATG7 and ATG12 and increased the expression of p62; oxidative stress inhibits autophagy levels. The increased expression of the pro-inflammatory factors IL-1β, IL-6 and TNF-α decreased the expression of the anti-inflammatory factor IL-10 and activation of the NF-κB p65/TNF-α pathway. The increased expression of Bax, caspase-3, caspase-7 and caspase-9 and the decreased expression of Bcl-2 activate apoptosis-related pathways. The addition of GTP attenuated oxidative stress levels, restored autophagy inhibition and reduced the inflammation and apoptosis levels. Our results suggest that GTP can attenuate the toxic effects of TBBPA by modulating ROS, reducing oxidative stress levels, increasing autophagy and attenuating inflammation and apoptosis in mouse lung and A549 cells. These results provide fundamental information for exploring the antioxidant mechanism of GTP and further for studying the toxic effects of TBBPA.

High-fat diet disrupts the gut microbiome, leading to inflammation, damage to tight junctions, and apoptosis and necrosis in Nyctereutes procyonoides intestines

Given the burgeoning Nyctereutes procyonoides breeding industry and its growing scale, it is imperative to investigate the impact of high-fat diets on the health of these animals. This study involved 30 male Nyctereutes procyonoides of comparable weights (3 kg ±0.5), randomly assigned to either a control group or a high-fat diet group (n = 15 each). The latter group was fed a mixture of lard and basal diet in a 2:5 ratio, establishing a high-fat diet model in Nyctereutes procyonoides. This diet induced diarrhea and histopathological changes in the Nyctereutes procyonoides. Analysis of the small intestine contents using 16S rRNA sequencing revealed a high-fat diet-induced disruption in the gut microbiota. Specifically, Escherichia-Shigella emerged as the biomarker in the high-fat diet group (P = 0.049), while Vagococcus was prevalent in the control group (P = 0.049), indicating a significant increase in harmful bacteria in the high-fat diet group. Furthermore, this disrupted gut flora correlated with inflammation and oxidative stress, as evidenced by marked increases in TNF-α (P < 0.01), IL-1β (P < 0.05), and IL-6 (P < 0.05) levels, measured via q-PCR, Western blot, and oxidative stress assays. In addition, q-PCR analysis revealed significant upregulation of apoptosis and necrosis markers, including Bax, Caspase3, Caspase9, Caspase12, RIPK3, and RIPK1 (P < 0.01 to P < 0.001), and a concurrent downregulation of the anti-apoptotic gene Bcl-2 (P < 0.01) in the high-fat diet group, consistent with protein expression trends. These findings suggest that a high-fat diet alters the gut microbiome toward a more harmful bacterial composition, escalating inflammatory responses and intestinal tissue permeability, culminating in intestinal cell apoptosis and necrosis.IMPORTANCEThis study examines the impact of high-fat diets on Nyctereutes procyonoides. Our research established a Nyctereutes procyonoides model on a high-fat diet, revealing significant health impacts, such as diarrhea, histological anomalies, and alterations in the gut microbiota. These findings emphasize the importance of preventing health issues and promoting sustainable industry growth. They highlight the significant impact of diet on gut microbiota and overall animal health.

Polyethylene microplastics induced gut microbiota dysbiosis leading to liver injury via the TLR2/NF-κB/NLRP3 pathway in mice

Microplastics (MPs) are ubiquitous environmental contaminants that have negative impacts on health and safety. The gut microbiota plays multiple roles as a newly discovered virtual metabolic organ. The objective of this study was to investigate the potential of MPs to cause liver injury by disrupting the balance of gut microbiota. The results indicated that exposure to MPs resulted in liver damage and disrupted the homeostasis of gut microbiota. MPs significantly reduced the liver organ coefficient, leading to liver cell injury and impaired function. Additionally, there was an increase in the expression of fibril-related proteins, which positively correlated with MPs concentration. Furthermore, MPs increased the relative abundances of Desulfovibrio, Clostridia, Enterorhabdus, Bacteroides, and Gemella while decreasing the abundance of Dubosoella. Different concentrations of MPs exhibited varying effects on specific bacterial groups, however, both concentrations resulted in an increase in pathogenic bacteria and a decrease in beneficial bacteria, as well as alterations in microbial structure. Moreover, MPs induced oxidative stress, inflammation, apoptosis and necrosis in liver cells. The study found that MPs disrupted gut microbiota homeostasis and activated TLR2/NF-κB/NLRP3 pathway in the liver, providing a new insight into the mechanism underlying MPs-induced liver injury. These findings serve as a warning regarding environmental pollution caused by MPs.

A novel graphene/triolein complex-based lubricant for improving high temperature water-based drilling fluid

Drilling engineering plays a pivotal role in the exploration and extraction of subsurface resources. It heavily depends on drilling fluid, which serves various essential functions including cooling the drill bit, removing drilled cuttings, maintaining formation pressure equilibrium, stabilizing the wellbore, transmitting hydraulic pressure, and safeguarding oil and gas reservoirs. Nonetheless, drilling fluid encounters multiple obstacles such as leakage control, waste fluid management, prevention of wellbore collapse, avoidance of hole enlargement, and environmental preservation. In order to surmount these challenges, the introduction of lubricants into the drilling fluid yields a multitude of advantages, encompassing equipment safeguarding, enhanced drilling efficiency, preservation of wellbore integrity, and bolstered drilling safety. These factors hold crucial significance in ensuring the triumph of drilling operations. This paper presents the introduction of a new lubricant derived from triolein. Following the preparation of graphene and triolein, they were incorporated into the drilling fluid system. A set of tests was subsequently conducted after aging at 240 °C for 16 hours. To assess the impact of the lubricant on the drilling fluid, an examination of rheological and filtration properties was conducted. Additionally, investigations into the friction coefficient, adhesion coefficient, and extreme pressure lubricity were carried out to evaluate the lubricating performance of the drilling fluid. Adding lubricants at a temperature of 240 degrees Celsius has successfully controlled the adhesion coefficient of the drilling fluid to below 0.2, reaching a minimum of 0.055, resulting in a reduction rate of over 70%. This indicates that the lubricant performs well at high temperatures, effectively reducing friction and enhancing drilling speed.

Development of a Low-Molecular-Weight Filtrate Reducer with High-Temperature Resistance for Drilling Fluid Gel System

Currently, conventional polymeric filtrate reducers with high-temperature resistance for use in drilling fluids have high molecular weights, which greatly affects the rheological properties. Therefore, to address the challenges in regulating the rheology and filtration performance of high-density drilling fluids at high temperatures, it is essential to develop low-molecular-weight filtrate reducers with high-temperature resistance. In this study, a low-molecular-weight filtrate reducer with high-temperature resistance (LMF) was prepared via free radical polymerization from acrylamide and 2-acrylamido-2-methyl-1-propanesulfonic acid as monomers, tertiary dodecyl mercaptan as a chain transfer agent, and ammonium persulfate as the initiator. LMF was then characterized by infrared spectroscopy, thermogravimetric analysis, and gel permeation chromatography. The obtained filtrate reducer exhibits a weight-average molecular weight (Mw) of 3819 and an initial thermal decomposition temperature of 300.7 °C, indicating good thermal stability. The effects of LMF dosage, temperature, and NaCl dosage on the rheology and filtration performance of mud samples were also investigated, and the mechanism of action was revealed by zeta potential, particle size distribution, scanning electron microscopy, and adsorption measurements. The results reveal that LMF increases the mud sample viscosity and reduces its filtration. For example, the filtration of the mud sample with 2 wt% LMF was 7.2 mL, a reduction of 70% compared to that of a blank mud sample. Further, after aging at 210 °C for 16 h, the filtration of the same sample was 11.6 mL, and that of a mud sample with 2 wt% LMF and 35 wt% NaCl after aging at 180 °C for 16 h was 22 mL. Overall, we have reported a scheme to prepare a low-molecular-weight filtrate reducer with high-temperature resistance and superior filtrate-reducing effects, laying the foundation for the investigation and development of low-molecular-weight filtrate reducers.

Effect of Low Gravity Solids on Weak Gel Structure and the Performance of Oil-Based Drilling Fluids

Drilling cuttings from the rock formation generated during the drilling process are generally smashed to fine particles through hydraulic cutting and grinding using a drilling tool, and then are mixed with the drilling fluid during circulation. However, some of these particles are too small and light to be effectively removed from the drilling fluid via solids-control equipment. These small and light solids are referred to as low gravity solids (LGSs). This work aimed to investigate the effect of LGSs on the performance of oil-based drilling fluid (OBDF), such as the rheological properties, high-temperature and high-pressure filtration loss, emulsion stability, and filter cake quality. The results show that when the content of LGSs reached or even exceeded the solid capacity limit of the OBDF, the rheological parameters including the plastic viscosity, gel strength, and thixotropy of OBDF increased significantly. Furthermore, the filtration of OBDF increases, the filter cake becomes thicker, the friction resistance becomes larger, and the stability of emulsion of OBDF also decreases significantly when the concentration of LGSs reached the solid capacity limit of OBDF (6-9 wt% commonly). It was also found that LGSs with a smaller particle size had a more pronounced negative impact on the drilling fluid performance. This work provides guidance for understanding the impact mechanism of LGSs on drilling fluid performance and regulating the performance of OBDF.

Public environmental attention, media coverage, and corporate green innovation: evidence from heavily polluting industries in China

Against the background of building a multi-environmental co-governance system, it is of great importance to systematically explore how public environmental attention (PEA) affects corporate green innovation (GI). Based on the panel data of Chinese A-share listed enterprises of heavily polluting industries from 2013 to 2020, this paper empirically explores the role of PEA in GI and examines the moderating impacts of media visibility and media favorability. The results indicate that the higher degree of public environmental attention, the more corporate green innovation. After adopting alternative explained variable, instrumental variable analysis and other methods, this conclusion still remains robust. This study also finds that both media visibility (MV) and media favorability (MF) generate significantly positive moderating impacts on the relationship between PEA and GI. Moreover, threshold model tests show that with the increase of MV, the promoting effect of PEA on GI is significantly enhanced, while there exists no threshold for MF. Furthermore, the heterogeneity analysis indicates that PEA mainly prompts symbolic green innovation of enterprises, and the PEA-GI relationship is more obvious in non-state-owned companies and regions with higher marketization process.

B-Cell-Derived TGF-β1 Inhibits Osteogenesis and Contributes to Bone Loss in Periodontitis

B cells play a vital role in the elimination of periodontal pathogens, the regulation of the immune response, and the induction of tissue destruction. However, the role of B cells in the dysfunction of mesenchymal stem cell (MSC) differentiation to osteoblasts in periodontitis (PD) has been poorly studied. Here we show that the frequency of CD45^-CD105⁺CD73⁺ MSCs in inflamed periodontal tissues is significantly decreased in patients with PD compared with that of healthy controls. CD19⁺ B cells dominate the infiltrated immune cells in periodontal tissues of patients with PD. Besides, B-cell depletion therapy reduces the alveolar bone loss in a ligature-induced murine PD model. B cells from PD mice express a high level of TGF-β1 and inhibit osteoblast differentiation by upregulating p-Smad2/3 expression and downregulating Runx2 expression. The inhibitory effect of PD B cells on osteoblast differentiation is reduced by TGF-β1 neutralization or Smad2/3 inhibitor. Importantly, B-cell-specific knockout of TGF-β1 in PD mice significantly increases the number of CD45^-CD105⁺Sca1⁺ MSCs, ALP-positive osteoblast activity, and alveolar bone volume but decreases TRAP-positive osteoclast activity compared with that from control littermates. Lastly, CD19⁺CD27⁺CD38^- memory B cells dominate the B-cell infiltrates in periodontal tissues from both patients with PD and patients with PD after initial periodontal therapy. Memory B cells in periodontal tissues of patients with PD express a high level of TGF-β1 and inhibit MSC differentiation to osteoblasts. Thus, TGF-β1 produced by B cells may contribute to alveolar bone loss in periodontitis, in part, by suppressing osteoblast activity.

Sustained release of tumor cell lysate and CpG from an injectable, cytotoxic hydrogel for melanoma immunotherapy

Many basic research studies have shown the potential of autologous cancer vaccines in the treatment of melanoma. However, some clinical trials showed that simplex whole tumor cell vaccines can only elicit weak CD8⁺ T cell-mediated antitumor responses which were not enough for effective tumor elimination. So efficient cancer vaccine delivery strategies with improved immunogenicity are needed. Herein, we described a novel hybrid vaccine "MCL" (Melittin-RADA₃₂-CpG-Lysate) which was composed of melittin, RADA₃₂, CpG and tumor lysate. In this hybrid vaccine, antitumor peptide melittin and self-assembling fusion peptide RADA₃₂ were assembled to form the hydrogel framework melittin-RADA₃₂(MR). Then, whole tumor cell lysate and immune adjuvant CpG-ODN were loaded into MR to develop an injectable and cytotoxic hydrogel MCL. MCL showed excellent ability for sustained drug release, to activate dendritic cells and directly kill melanoma cells in vitro. In vivo, MCL not only exerted direct antitumor activity, but also had robust immune initiation effects including the activation of dendritic cells in draining lymph nodes and the infiltration of cytotoxic T lymphocytes (CTLs) in tumor microenvironment. In addition, MCL can efficiently inhibit melanoma growth in B16-F10 tumor bearing mice, which suggested that MCL is a potential cancer vaccine strategy for melanoma treatment.

Exposure to polystyrene microplastics triggers lung injury via targeting toll-like receptor 2 and activation of the NF-κB signal in mice

Microplastics are ubiquitous pollutants with a wide range of plastic applications. More recently, microplastics are in the air and can be inhaled into the lungs, causing respiratory diseases. Knowledge of the underlying mechanisms by which microplastics may induce respiratory disease is still limited. This study used intranasal instillation to develop a model of lung injury. The histopathology result showed that the mouse lung had severe inflammatory responses, apoptosis and collagen deposition with chronic exposure to different sizes (Small: 1-5 μm and Large: 10-20 μm) of polystyrene microplastics (PS-MPS), and the damage of smaller sizes was obvious. The expression levels of the Toll-like receptors (TLRs) family, evolutionarily conserved pattern recognition receptors, were detected, and the levels of TLR2 mRNA was significantly increased. In transfection experiments, PS-MPS increased the inflammatory response in HEK293 cells with TLR2 expression. Furthermore, exposure to small polystyrene microplastics promoted oxidative stress and apoptosis, and accelerated the process of fibrosis. Interestingly, inhibition of the NF-κB signal relieves inflammation and oxidative stress, reduces apoptosis, and thus controls the fibrosis process. These results suggested that PS-MPS targeted binding to TLR2 and further exacerbated fibrosis by facilitating inflammation, oxidative stress, and apoptosis with the activation of NF-κB signal.

Polyethylene microplastics trigger cell apoptosis and inflammation via inducing oxidative stress and activation of the NLRP3 inflammasome in carp gills

Microplastics cause varying degrees of damage to aquatic organisms. Exposure to microplastics contaminated water, the gills are among the first tissues, after the skin, to be affected by microplastics. As an essential immune organ, prolonged stimulation by microplastics disrupts immune function not only in the gills but throughout the body, yet the underlying mechanisms remain elusive. A model of gill injury from exposure to polyethylene (PE) microplastics was developed in this study. H&E staining revealed that polyethylene microplastics caused gill inflammation, vascular remodeling, and mucous cell proliferation. An increase in collagen indicates severe tissue damage. Additional analysis showed that polyethylene microplastics profoundly exacerbated oxidative stress in the gills. TUNEL assay demonstrated cell apoptosis induced by polyethylene microplastic. The mRNA levels were subsequently quantified using RT-PCR. The results showed that polyethylene microplastics increased the expression of the nuclear factor-κB (NF-κB) pathway (NF-κB p65, IKKα, IKKβ) and apoptosis biomarkers (p53, caspase-3, caspase-9, and Bax). Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasomes, which is an influential component of innate immunity, were overactive. What's more, the pro-inflammatory factors (TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-1β) that induce immune disorder also increased significantly, while the anti-inflammatory factors (IL-4, IL-10) decreased significantly. These results suggested that oxidative stress acted as an activation signal of apoptosis triggered by the NF-κB pathway and activating the NLRP3 inflammasome to promote inflammatory immune responses. The present study provided a different target for the prevention of toxin-induced gill injury under polyethylene microplastics.

Positional cues and cell division dynamics drive meristem development and archegonium formation in Ceratopteris gametophytes

Fern gametophytes are autotrophic and independent of sporophytes, and they develop pluripotent meristems that drive prothallus development and sexual reproduction. To reveal cellular dynamics during meristem development in fern gametophytes, we performed long-term time-lapse imaging and determined the real-time lineage, identity and division activity of each single cell from meristem initiation to establishment in gametophytes of the fern Ceratopteris richardii. Our results demonstrate that in Ceratopteris gametophytes, only a few cell lineages originated from the marginal layer contribute to meristem initiation and proliferation, and the meristem lacks a distinguishable central zone or apical cell with low division activity. Within the meristem, cell division is independent of cell lineages and cells at the marginal layer are more actively dividing than inner cells. Furthermore, the meristem triggers differentiation of adjacent cells into egg-producing archegonia in a position-dependent manner. These findings advance the understanding of diversified meristem and gametophyte development in land plants.

Time-lapse imaging of the fern Ceratopteris richardii during meristem initiation and proliferation provides insights into the lineage, identity and division activity of each cell throughout the growth of gametophytes.

AB0171 TOWARDS A BETTER IMPLEMENTATION OF TREAT-TO-TARGET STRATEGY IN RHEUMATOID ARTHRITIS: A COMPARISON OF TWO REAL-WORLD COHORTS

Background

Treat-to-target (T2T) strategy has been the core of rheumatoid arthritis (RA) management for over a decade, however implemented distinctly varied in real practices.

Objectives

We tried to investigate the differences in disease activity and target achievement of two cohorts with different T2T implementations.

Methods

We used data of the CENTRA (Collaboratively intENsive Treat-to-target in RA) and TARRA (Treat-to-TARget in RA) cohorts. The CENTRA is a RA cohort prospectively follow-up by a fixed team with tight control, while the TARRA is a longitudinal observational cohort follow-up by a rheumatologist with casual control. Patients from two cohorts were matched 1:3 by propensity score matching (PSM). The primary outcome was simplified disease activity index (SDAI) at 1-year follow-up.

Results

102 patients from the CENTRA cohort and 271 patients from the TARRA cohort were included. Both groups were comparable in terms of age, gender, disease course, and seropositivity. At the end of 1 year follow-up, the SDAI of patients in the CENTRA cohort was significantly lower than that of patients in the TARRA cohort (2.1 vs 3.4, p＜0.001). The follow-up interval of patients in the CENTRA cohort was significantly shorter than that in the TARRA cohort when patients have not achieved remission (3.1 vs. 3.3 months, p=0.019).

Conclusion

RA patients may benefit more from a tight control T2T strategy with closer follow-up and appropriate education compared with a casual T2T strategy.

Disclosure of Interests

None declared

POS0599 IMPACT OF TREAT-TO-TARGET THERAPY ON BONE MINERAL DENSITY LOSS IN PATIENTS WITH RHEUMATOID ARTHRITIS: A PROSPECTIVE COHORT STUDY

Background

Osteoporosis is a common comorbidity of rheumatoid arthritis (RA). Although RA disease activity has been demonstrated to be associated with bone loss in previous studies, most of them were cross-sectional studies and not in the context of treat-to-target (T2T) strategies.

Objectives

To evaluate the association of disease activity with bone mineral density (BMD) changes in the context of T2T strategies in a prospective RA cohort.

Methods

RA patients were enrolled from a prospective CENTRA cohort of Peking University First Hospital. BMD was repeated at baseline, 1-year and then every other year. Time-adjusted mean disease activity scores were adopted to reflect the overall disease activity during follow-up. The influence of univariable associations between predictors and BMD was investigated using linear regression.

Results

A total of 268 patients were included in our analysis. Their mean age was 50 (12.9) years old. At enrollment, the mean (SD) DAS28-ESR was 3.70 (1.17), and the median (IQR) CDAI and SDIA was 10 (14.45) and 10.30 (16.53), respectively. Osteoporosis at lumbar spine was observed in 23.1% patients and 9.3% at femoral neck at enrollment. Older age, higher SDAI score and lower BMI were found to be associated with osteoporosis at baseline. Reevaluations of BMD at 1 year was applied in 144 patients. Mean decreases of BMDs were 1.75 % at the lumbar spine and 1.40 % at femoral neck at 1 year form baseline, respectively. Patients who achieved remission had less yearly bone loss at lumbar spine (p=0.036). Female gender was identified as a risk factor in the multiple linear regression analyses, and lower disease activity and bisphosphonates were protective factors of continuous bone loss.

Conclusion

Disease activity is associated with bone loss in RA patients in the context of T2T strategies, and those who achieved remission had less yearly bone loss.

Disclosure of Interests

None declared

POS0315 DIAGNOSTIC PERFORMANCE OF CASPAR CRITERIA FOR PSORIATIC ARTHRITIS WITH OR WITHOUT INTEGRATION OF ULTRASOUND

Background

Although the CASPAR criteria in the diagnosis of psoriatic arthritis (PsA) have been validated, CASPAR based on physical examination (PE) is not “gold standard”. The ultrasound (US) could improve the diagnostic accuracy as compared to clinical examination alone.

Objectives

To evaluate the diagnostic performance of CASPAR criteria for psoriatic arthritis (PsA) with or without integration of ultrasound (US).

Methods

The patients with hint of PsA were enrolled. Tender and swollen joint counts, presents of enthesitis and dactylitis were collected by physical examination (PE). US was performed to evaluate peripheral joints, entheses and tendons. The additional value of US to CASPAR criteria were analysed.

Results

326 consecutive patients were enrolled, with 164 PsA and 162 non-PsA. Significantly higher frequencies of tenosynovitis and enthesitis on US and new bone formation on X-ray were found in PsA than non-PsA patients (56.7% vs. 13.0%; 62.2% vs. 14.2%; 62.2% vs. 8.0%, p<0.01 for all). Logistic regression analysis showed that dactylitis (OR=12.0, p<0.01), family history of PsO/PsA (OR=3.1, p<0.05), nail involvement (OR=3.5, p=0.01), new bone formation (OR=14.8, p<0.01) and tenosynovitis on US (OR=21.3, p<0.01), enthesitis on US (OR=21.7, p<0.01) were independent risk factors for PsA. Adding US tenosynovitis and/or enthesitis to CASPAR criteria showed better performance by improving the specificity (91.4% vs. 67.9%) and meanwhile keeping sensitivity (92.1% vs. 96.3%). When replacing hand X-ray by US in CASPAR criteria, the sensitivity and specificity were comparable to CASPAR criteria adding with US. The diagnostic accuracy was 82.2% for CASPAR criteria based on PE, 91.7% for CASPAR integrated with US, and 91.4% for CASPAR with US to replace X-ray.

Conclusion

CASPAR criteria based on US improve the diagnosis utility of PsA than CASPAR criteria based on PE. US assessment is valuable in the diagnosis of PsA.

References

[1]Fiorenza A, Bonitta G, Gerratana E, et al. Assessment of enthesis in patients with psoriatic arthritis and fibromyalgia using clinical examination and ultrasound. Clinical and experimental rheumatology 2020;38 Suppl 123:31-9.

[2]Zabotti A, Bandinelli F, Batticciotto A, et al. Musculoskeletal ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review. Rheumatology (Oxford) 2017;56:1518-32.

Figure 1.

ROC curves for adding US or substituting X-ray by US in CASPAR criteria. Receiver operating characteristic (ROC) curve illustrates the diagnosis performance of CASPAR criteria adding US or substituting X-ray by US in CASPAR criteria and CASPAR criteria based on PE alone. The area under the curve of the ROC curve (AUC) was 0.929 (95%CI 0.897, 0.961) (p<0.01) for adding US to CASPAR criteria. AUC was 0.908 (95%CI 0.876, 0.940) (p<0.01) for CASPAR criteria based on PE. And AUC was 0.916 (95%CI 0.880, 0.951) (p<0.01) for substituting X-ray by US in CASPAR criteria. CASPAR: ClASsification criteria for Psoriatic ARthritis; PE: physical examination; US: ultrasound.

Disclosure of Interests

None declared

Iodine-125 brachytherapy for the treatment of central mucoepidermoid carcinoma of the jaw in a pre-teen

Central mucoepidermoid carcinoma (MEC) of the jaw is a rare malignant neoplasm, even rarer in teenagers. Radical surgical resection, such as en bloc resection or segmental resection, is the main treatment for MEC of the jaw. This surgical treatment results in a loss of integrity of the jaw. The successful application of iodine-125 brachytherapy for the treatment of intraosseous MEC of the mandible in an 11-year-old girl is reported here. No local recurrence or distant metastasis was observed during 6 years of follow-up. The integrity of the mandible was preserved and the development of the mandible was not significantly affected. Iodine-125 brachytherapy is a potential alternative treatment for central mucoepidermoid carcinoma of the jaw, especially in teenagers, and may preserve the continuity and function of the jaw.

[Analysis of molecular and clinical characteristics of carbapenem-resistant hypervirulent Klebsiella pneumoniae in the intensive care unit]

To investigate the carbapenemases distribution of carbapenem-resistant Klebsiella pneumoniae (CRKP) in the intensive care unit, and the clinical characteristics between carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) and carbapenem-resistant non-hypervirulent Klebsiella pneumoniae (CR-non-hvKP) were compared. A total of 53 non-repetitive CRKP strains isolated from 49 patients in the intensive care unit of the Second Affiliated Hospital of Xi'an Jiaotong University from May 2020 to March 2021 were retrospectively studied. The carbapenemase inhibitor enhancement test was used for screening carbapenemase-producing strains, and the string test was carried out to screen the hypermucoviscosity phenotype. Using PCR to detect five main carbapenemase genes (bla_KPC-2, bla_NDM, bla_IMP , bla_VIM and bla_OXA-48-like), common serotype (K1 and K2) and virulence gene (rmpA and iutA). Treated the strains with both rmpA and iutA genes as hypervirulent Klebsiella pneumonia (hvKP), and the whole genome sequencing of CR-hvKP was completed. At the same time, the clinical data of 49 patients were sorted out, and the differences in clinical characteristics of CR-hvKP and CR-non-hvKP infected patients were compared using the independent sample t test, Mann-Whitney U test, chi-square test or Fisher's exact probability test. CRKP isolated from the intensive care unit were extensively drug resistance and still had a good sensitivity to polymyxin B and tigecycline. Producing carbapenemases were the main resistance mechanism of CRKP (52/53, 98.1%). Of the 53 CRKP strains, except for 1strain that did not detect carbapenemase, at least one carbapenemase resistance gene was detected in the remaining 52 CRKP strains, of which 45 strains carried an enzyme, including 36 bla_KPC-2 (36/53, 67.9%), 8 bla_NDM (8/53, 15.1%), 1 bla_IMP (1/53, 1.9%), and 7 strains carried with both bla_KPC-2 and bla_NDM (7/53, 13.2%). String test and virulence gene showed that 7 CR-hvKP strains (13.2%) were detected in 53 CRKP strains, and two of which were hypermucoviscosity phenotype. Sequencing results revealed that CR-hvKP were mainly ST11 type. Almost all patients with CR-hvKP infection were over 60 years old (7/7), with invasive treatment (7/7), pulmonary infection with hypermucoviscosity phenotype (2/7) and high mortality (5/7); and the percentage of neutrophils in patients with CR-hvKP infection (86.44±4.70) % was higher than those patients with CR-non-hvKP infection (78.90±19.15) %, the difference was statistically significant (t=-2.225, P=0.032). The CR-hvKP strains in the intensive care unit mainly produced KPC-2 enzyme, with K2 capsular serotype and ST11 type. It is necessary to strengthen the monitoring and control of the CR-hvKP strain to prevent the co-evolution of drug-resistant and hypervirulent strains.