Sensitive electrochemical flow injection analysis of H2O2 released from cells with a pass-through mode.

Conventional plate electrodes were commonly used in electrochemical flow injection analysis and only part of molecules diffused to the plane of electrodes could be detected, which would limit the performance of electrochemical detection. In this study, a low-cost native stainless steel wire mesh (SSWM) electrode was integrated into a 3D-printed device for electrochemical flow injection analysis with a pass-through mode, which is different compared with previous flow-through mode. This strategy was applied for sensitive analysis of hydrogen peroxide (H2O2) released from cells. Under the optimal conditions (the applied potentials, the flow rate and the sample volume), the device exhibits high sensitivity toward H2O2. Linear relationships could be achieved between electrochemical responses and the concentration of H2O2 ranging from 1 nM to 1 mM. The excellent analytical performance of the SSWM-based device could be attributed to the pass-through mode based on the mesh microstructure and intrinsic catalytic properties for H2O2 by stainless steel. This approach could be further successfully extended for screening of H2O2 released from HeLa cells with electrochemical responses linear to the number of cells in a range of 3 - 1.35 × 104 cells with an injection volume of 30 µL. This study revealed the potential of mesh electrodes in electrochemical flow injection analysis for cellular function and pathology and its possible extension in cell counting and on-line analysis.

EZH2 Inhibition Enhances PD-L1 Protein Stability Through USP22-Mediated Deubiquitination in Colorectal Cancer.

The regulation of PD-L1 is the key question, which largely determines the outcome of the immune checkpoint inhibitors (ICIs) based therapy. However, besides the transcription level, the protein stability of PD-L1 is closely correlated with its function and has drawn increasing attention. In this study, EZH2 inhibition enhances PD-L1 expression and protein stability, and the deubiquitinase ubiquitin-specific peptidase 22 (USP22) is identified as a key mediator in this process. EZH2 inhibition transcriptionally upregulates USP22 expression, and upregulated USP22 further stabilizes PD-L1. Importantly, a combination of EZH2 inhibitors with anti-PD-1 immune checkpoint blockade therapy improves the tumor microenvironment, enhances sensitivity to immunotherapy, and exerts synergistic anticancer effects. In addition, knocking down USP22 can potentially enhance the therapeutic efficacy of EZH2 inhibitors on colon cancer. These findings unveil the novel role of EZH2 inhibitors in tumor immune evasion by upregulating PD-L1, and this drawback can be compensated by combining ICI immunotherapy. Therefore, these findings provide valuable insights into the EZH2-USP22-PD-L1 regulatory axis, shedding light on the optimization of combining both immune checkpoint blockade and EZH2 inhibitor-based epigenetic therapies to achieve more efficacies and accuracy in cancer treatment.

Targeting LTA4H facilitates the reshaping of the immune microenvironment mediated by CCL5 and sensitizes ovarian cancer to Cisplatin.

Ovarian cancer is the most lethal and aggressive gynecological cancer with a high recurrence rate and is often diagnosed late. In ovarian cancer, multiple metabolic enzymes of lipid metabolism are abnormally expressed, resulting in metabolism disorder. As a characteristic pathway in polyunsaturated fatty acid (PUFA) metabolism, arachidonic acid (AA) metabolism is disturbed in ovarian cancer. Therefore, we established a 10-gene signature model to evaluate the prognostic risk of PUFA-related genes. This 10-gene signature has strong robustness and can play a stable predictive role in datasets of various platforms (TCGA, ICGC, and GSE17260). The high association between the risk subgroups and clinical characteristics indicated a good performance of the model. Our data further indicated that the high expression of LTA4H was positively correlated with poor prognosis in ovarian cancer. Deficiency of LTA4H enhanced sensitivity to Cisplatin and modified the characteristics of immune cell infiltration in ovarian cancer. Additionally, our results indicate that CCL5 was involved in the aberrant metabolism of the AA/LTA4H axis, which contributes to the reduction of tumor-infiltrating CD8+ T cells and immune escape in ovarian cancer. These findings provide new insights into the prognosis and potential target of LTA4H/CCL5 in treating ovarian cancer.

A high-affinity fluorescent probe for human uridine-disphosphate glucuronosyltransferase 1A9 function monitoring under environmental pollutant exposure.

Uridine-disphosphate glucuronosyltransferase 1A9 (UGT1A9), an important detoxification and inactivation enzyme for toxicants, regulates the exposure level of environmental pollutants in the human body and induces various toxicological consequences. However, an effective tool for high-throughput monitoring of UGT1A9 function under exposure to environmental pollutants is still lacking. In this study, 1,3-dichloro-7-hydroxy-9,9-dimethylacridin-2(9H)-one (DDAO) was found to exhibit excellent specificity and high affinity towards human UGT1A9. Remarkable changes in absorption and fluorescence signals after reacting with UGT1A9 were observed, due to the intramolecular charge transfer (ICT) mechanism. Importantly, DDAO was successfully applied to monitor the biological functions of UGT1A9 in response to environmental pollutant exposure not only in microsome samples, but also in living cells by using a high-throughput screening method. Meanwhile, the identified pollutants that disturb UGT1A9 functions were found to significantly influence the exposure level and retention time of bisphenol S/bisphenol A in living cells. Furthermore, the molecular mechanism underlying the inhibition of UGT1A9 by these pollutant-derived disruptors was elucidated by molecular docking and molecular dynamics simulations. Collectively, a fluorescent probe to characterize the responses of UGT1A9 towards environmental pollutants was developed, which was beneficial for elucidating the health hazards of environmental pollutants from a new perspective.

Water activating fresh NiMo foam for enhanced urea electrolysis.

Recently, production of hydrogen (H2) through the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) has acquired great attention because it is more environmentally friendly and energy-saving. Herein, an approach of water activation was developed for in situ growth of NiMo LDH nanosheet arrays on NiMo foam without using any binder or pressurizing or heating steps. The obtained NiMo foam electrodes showed exceptional catalytic activity and durability for both the UOR and HER. This work offers a new standpoint on designing electrodes with high activation for efficient and sustainable hydrogen production coupled with urea organic oxidation.

Vibration-enhanced disposable electroanalytical platform for selective analysis of tryptophan in fruits based on molecular imprinting.

Although electrochemical detection based on molecular imprinting polymers (MIP) could dramatically improve the selectivity, the procedure is time-consuming because of the essential incubation step. In addition, current MIP electrochemical detections were not suitable for analysis of microliter-level sample solutions, limiting their applications for real samples. This investigation aims at applying vibration to enhance efficiency of MIP electrochemical detection of 20 µL sample solutions. MIP analysis of Tryptophan (Trp) was used as the model with disposable MIP electrodes prepared by electrochemical polymerization of o-phenylenediamine on carbon ink coated on stainless steel sheets. The MIP electrode was integrated in a 3D-printed analytical device for vibration-enhanced electrochemical detection of Trp. Our results showed that this vibration-enhanced strategy could significantly increase electrochemical responses of Trp at the same incubation time. Such improvement might be attributed to the enhanced mass transfer at the surface of the working electrode brought by vibration. It needs to be emphasized that this strategy is suitable for analysis of sample solutions with the volume of microliters, which is superior to normal stirring in MIP electrochemical detection. Our approach could be successfully utilized for differentiation of Trp in different fruits, opening more opportunities for MIP electrochemical detection of real samples. The enhanced efficiency by vibration could pave foundation for extensive practical MIP detection of sample solutions at the level of microliters.

Unlocking the potential of a NiMo foam substrate for water splitting using an ultrafast two-step dipping strategy.

In this paper, a facile and ultrafast two-step dipping process was developed to in situ form an electrocatalyst on a NiMo foam substrate without consuming extra energy. The obtained electrode showed a porous coral-like structure decorated with nanosheets and exhibited excellent overall water splitting properties in alkaline solution. This study provides a feasible strategy for developing an environmentally friendly and energy-efficient non-noble metal electrode for hydrogen production from water splitting.

Ginsenoside Rg5 Improves Sleep by Regulating Energy Metabolism in Sleep-Deprived Rats.

Sleep deprivation (SD) has become a universal social problem. There is a causal relationship between SD and energy metabolism disorder. Phytochemicals have been demonstrated to have excellent sleep-promoting effects, and studies have shown that ginsenoside Rg5 (Rg5) exerts sedative and hypnotic effects. The present study aimed to investigate the role of Rg5 in regulating energy metabolism and explore the potential mechanism of improving sleep. Sleep-deprived rats were randomly divided into a control group (Ctrl), SD model group (SD), Rg5 group (GRg5), and melatonin group (MT). Sleep-deprived model rats were generated by housing rats in an SD box for 4 weeks. The Ctrl and SD groups were given equal volumes of saline. The Rg5 groups were given 25[Formula: see text]mg/kg Rg5 or 50[Formula: see text]mg/kg Rg5, and the MT group was given 0.27[Formula: see text]g/kg MT. A Western blot analysis and ELISA were used to detect the metabolic levels, mitochondrial functional proteins, AMPK pathway proteins, clock-related proteins, adenosine receptors, and neurotransmitter receptors. The results showed that Rg5 corrected abnormal glucose and lipid metabolism as well as improved ATP levels. In addition, Rg5 alleviated mitochondrial structural damage and improved the expression of proteins involved in mitochondrial biosynthesis, fission, and fusion. Moreover, Rg5 improved the expression of AMPK/PGC-1/Nrf-1 pathway proteins, regulated mitochondrial biological functions, and affected the rhythm characteristics of circadian clock-related proteins. Further, Rg5 improved the expression of A1R and A[Formula: see text]R as well as regulated the expression levels of GABAA1[Formula: see text] and mGluR5 to improve sleep in SD rats.

Advances in regulation and function of stearoyl-CoA desaturase 1 in cancer, from bench to bed.

Stearoyl-CoA desaturase 1 (SCD1) converts saturated fatty acids to monounsaturated fatty acids. The expression of SCD1 is increased in many cancers, and the altered expression contributes to the proliferation, invasion, sternness and chemoresistance of cancer cells. Recently, more evidence has been reported to further support the important role of SCD1 in cancer, and the regulation mechanism of SCD1 has also been focused. Multiple factors are involved in the regulation of SCD1, including metabolism, diet, tumor microenvironment, transcription factors, non-coding RNAs, and epigenetics modification. Moreover, SCD1 is found to be involved in regulating ferroptosis resistance. Based on these findings, SCD1 has been considered as a potential target for cancer treatment. However, the resistance of SCD1 inhibition may occur in certain tumors due to tumor heterogeneity and metabolic plasticity. This review summarizes recent advances in the regulation and function of SCD1 in tumors and discusses the potential clinical application of targeting SCD1 for cancer treatment.

Genetic deletion or pharmacological inhibition of soluble epoxide hydrolase attenuated particulate matter 2.5 exposure mediated lung injury.

Air pollution represented by particulate matter 2.5 (PM2.5) is closely related to diseases of the respiratory system. Although the understanding of its mechanism is limited, pulmonary inflammation is closely correlated with PM2.5-mediated lung injury. Soluble epoxide hydrolase (sEH) and epoxy fatty acids play a vital role in the inflammation. Herein, we attempted to use the metabolomics of oxidized lipids for analyzing the relationship of oxylipins with lung injury in a PM2.5-mediated mouse model, and found that the cytochrome P450 oxidases/sEH mediated metabolic pathway was involved in lung injury. Furthermore, the sEH overexpression was revealed in lung injury mice. Interestingly, sEH genetic deletion or the selective sEH inhibitor TPPU increased levels of epoxyeicosatrienoic acids (EETs) in lung injury mice, and inactivated pulmonary macrophages based on the MAPK/NF-κB pathway, resulting in protection against PM2.5-mediated lung injury. Additionally, a natural sEH inhibitor luteolin from Inula japonica displayed a pulmonary protective effect towards lung injury mediated by PM2.5 as well. Our results are consistent with the sEH message and protein being both a marker and mechanism for PM2.5-induced inflammation, which suggest its potential as a pharmaceutical target for treating diseases of the respiratory system.

Plasma-spray-enabled microcosmic explosion to construct Ni mesh-based electrodes for water splitting.

Currently, the fabrication of low cost and high efficiency electrocatalysts is a hotspot in the study of water splitting. Herein, plasma spray (PS) was used to induce a microcosmic explosion (me) on Ni mesh to modify the nanoscale Ni for the preparation of me-PS-NM electrodes with excellent hydrogen evolution. We also demonstrated that oxygen evolution could be significantly enhanced after the me-PS-NM electrodes were doped with Fe3+. Both electrodes formed a system exhibiting superior activity and stability for overall water splitting without noble metals.

Effectiveness of a Quality Improvement Intervention on Reperfusion Treatment for Patients With Acute Ischemic Stroke: A Stepped-Wedge Cluster Randomized Clinical Trial.

Importance: Reperfusion therapy is the most effective treatment for acute ischemic stroke but remains underused in China. Objective: To evaluate the effect of a problem-oriented, culturally adapted, targeted quality improvement intervention on reperfusion therapy for patients with acute ischemic stroke in China. Design, Setting, and Participants: In this stepped-wedge cluster randomized clinical trial, patients from 16 secondary and 33 tertiary hospitals in China with acute ischemic stroke within 6 hours of symptom onset were consecutively recruited between July 1, 2018, and June 30, 2020. Interventions: Hospitals were randomly assigned to 1 of 3 sequences to receive the targeted quality improvement intervention (n = 5689), in which workflow reconstruction was promoted to reduce in-hospital reperfusion treatment delays, or usual care (n = 6443), in which conventional stroke care was left to the discretion of the stroke team. Main Outcomes and Measures: The primary outcome was the reperfusion therapy rate, a composite outcome of intravenous recombinant tissue plasminogen activator (IV rtPA) or endovascular thrombectomy (EVT) for eligible patients who arrived within 3.5 or 4.5 hours of symptom onset. Secondary outcomes were the IV rtPA administration rate among eligible patients who arrived within 3.5 hours of symptom onset, the EVT rate among eligible participants who arrived within 4.5 hours of symptom onset, the proportion of patients with door-to-needle time within 60 minutes, the proportion of patients with door-to-puncture time within 90 minutes, in-hospital mortality, and 3-month disability as measured by a modified Rankin Scale score greater than 2. Results: All 12 132 eligible patients (mean [SD] age, 66 [12.1] years; 7759 male [64.0%]) completed the trial. The reperfusion rate was 53.5% (3046 of 5689) for the eligible patients in the intervention period and 43.9% (2830 of 6443) in the control period. No significant improvement in primary outcomes was found for the intervention after adjusting for cluster, period, and imbalanced baseline covariates (adjusted risk difference [ARD], 5.5%; 95% CI, -8.0% to 19.0%; adjusted odds ratio [AOR], 1.26; 95% CI, 0.72-2.21) or for the secondary outcomes. However, significant improvements were found in secondary hospitals for reperfusion therapy (1081 of 1870 patients [57.8%] vs 945 of 2022 patients [42.9%]; ARD, 19.0%; 95% CI, 6.4%-31.6%; AOR, 2.24; 95% CI, 1.29-3.88), IV rtPA administration (1062 of 1826 patients [58.2%] vs 916 of 2170 patients [42.2%]; ARD, 20.3%; 95% CI, 7.4%-33.1%; AOR, 2.37; 95% CI, 1.34-4.19), and EVT (51 of 231 patients [22.1%] vs 37 of 259 patients [14.3%]; ARD, 13.6%; 95% CI, 1.0%-26.3%; AOR, 3.03; 95% CI, 1.11-8.25) in subgroup analyses. Conclusions and Relevance: In this stepped-wedge cluster randomized clinical trial of patients with acute ischemic stroke in China, the use of a targeted quality improvement intervention compared with usual care did not improve the reperfusion therapy rate. However, the intervention may be effective in secondary hospitals. Trial Registration: ClinicalTrials.gov Identifier: NCT03578107.

American ginseng with different processing methods ameliorate immunosuppression induced by cyclophosphamide in mice via the MAPK signaling pathways.

This study aimed to clarify the effects of two processed forms of American ginseng (Panax quinquefolius L.) on immunosuppression caused by cyclophosphamide (CTX) in mice. In the CTX-induced immunosuppressive model, mice were given either steamed American ginseng (American ginseng red, AGR) or raw American ginseng (American ginseng soft branch, AGS) by intragastric administration. Serum and spleen tissues were collected, and the pathological changes in mice spleens were observed by conventional HE staining. The expression levels of cytokines were detected by ELISA, and the apoptosis of splenic cells was determined by western blotting. The results showed that AGR and AGS could relieve CTX-induced immunosuppression through the enhanced immune organ index, improved cell-mediated immune response, increased serum levels of cytokines (TNF-α, IFN-γ, and IL-2) and immunoglobulins (IgG, IgA, and IgM), as well as macrophage activities including carbon clearance and phagocytic index. AGR and AGS downregulated the expression of BAX and elevated the expression of Bcl-2, p-P38, p-JNK, and p-ERK in the spleens of CTX-injected animals. Compared to AGS, AGR significantly improved the number of CD4+CD8-T lymphocytes, the spleen index, and serum levels of IgA, IgG, TNF-α, and IFN-γ. The expression of the ERK/MAPK pathway was markedly increased. These findings support the hypothesis that AGR and AGS are effective immunomodulatory agents capable of preventing immune system hypofunction. Future research may investigate the exact mechanism to rule out any unforeseen effects of AGR and AGS.

Vibration for enhancement of electrochemical analysis of biomolecules in a droplet on the rough surface of a disposable working electrode.

Although electrochemical detection of microliters-level solutions is attractive for analysis of low-amount biological samples, its performance could be weakened by limited mass transfer due to low Reynolds number and laminar flow. Herein we designed a 3D-printed electroanalytical device to apply vibration for improvement of mass transfer during electrochemical detection. In our approach, the droplet-size sample solution containing Indole-3-acetic acid (IAA, as a model) was directly applied on the effective surface of a disposable working electrode. We demonstrated that vibration could enhance electrochemical responses of IAA more on the rough surface than on the smooth surface of the working electrodes. After optimization, the sensitivity for electrochemical detection of a 20-µL droplet under vibration with the voltage of 7 V increased more than 100% compared with the static condition. The enhanced electrochemical responses brought by vibration could be achieved reproducibly, which could be ascribed to improved mass transfer. Our strategy could be practically applied for differentiation of IAA in different tissues of Marchantia polymorpha with enhanced responses. This study suggested that vibration might become a simple and effective method to improve mass transfer in analysis of microliter-volume solutions, which might be extended for more biochemical assays.

Potassium-rich mining waste addition can shorten the composting period by increasing the abundance of thermophilic bacteria during high-temperature periods.

Conventional compost sludge has a long fermentation period and is not nutrient rich. Potassium-rich mining waste was used as an additive for aerobic composting of activated sludge to make a new sludge product. The effects of different feeding ratios of potassium-rich mining waste and activated sludge on the physicochemical properties and thermophilic bacterial community structure during aerobic composting were investigated. The results showed that potassium-rich waste minerals contribute to the increase in mineral element contents; although the addition of potassium-rich waste minerals affected the peak temperature and duration of composting, the more sufficient oxygen content promoted the growth of thermophilic bacteria and thus shortened the overall composting period. Considering the requirements of composting temperature, it is recommended that the addition of potassium-rich waste minerals is less than or equal to 20%.

Facile method to activate substrate for oxygen evolution by a galvanic-cell reaction.

NiFe layered double hydroxide (NiFe LDH) is a promising material with multiple functions. In this communication, a novel method is used to prepare NiFe LDH. This synthesis method is achieved via galvanic-cell corrosion between nickel and iron substrates in aqueous solutions containing a halogen group anion (e.g., Cl) at ambient temperature. The as-prepared NiFe LDH electrodes are developed as electrocatalysts for the oxygen evolution reaction (OER) and exhibit excellent catalytic activities and durability. This work provides an energy-efficient, cost-effective, and scaled-up corrosion engineering approach for manufacturing NiFe LDH materials.

Macrophage Inactivation by Small Molecule Wedelolactone via Targeting sEH for the Treatment of LPS-Induced Acute Lung Injury.

Soluble epoxide hydrolase (sEH) plays a critical role in inflammation by modulating levels of epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs). Here, we investigate the possible role of sEH in lipopolysaccharide (LPS)-mediated macrophage activation and acute lung injury (ALI). In this study, we found that a small molecule, wedelolactone (WED), targeted sEH and led to macrophage inactivation. Through the molecular interaction with amino acids Phe362 and Gln384, WED suppressed sEH activity to enhance levels of EETs, thus attenuating inflammation and oxidative stress by regulating glycogen synthase kinase 3beta (GSK3ß)-mediated nuclear factor-kappa B (NF-κB) and nuclear factor E2-related factor 2 (Nrf2) pathways in vitro. In an LPS-stimulated ALI animal model, pharmacological sEH inhibition by WED or sEH knockout (KO) alleviated pulmonary damage, such as the increase in the alveolar wall thickness and collapse. Additionally, WED or sEH genetic KO both suppressed macrophage activation and attenuated inflammation and oxidative stress in vivo. These findings provided the broader prospects for ALI treatment by targeting sEH to alleviate inflammation and oxidative stress and suggested WED as a natural lead candidate for the development of novel synthetic sEH inhibitors.

Acid etching followed by water soaking: a top-down strategy to induce highly reactive substrates for electrocatalysis.

A top-down strategy using acid etching followed by water soaking is utilized to in situ synthesize autologous NiFe LDH nanosheets on NiFe foam without other metal ions, oxidizing agents or heating steps. The NiFe foam serves as both the metal source and substrate, and the obtained nanosheets are firmly anchored on the foam. The obtained ultrathin nanosheet arrays could greatly increase the electrocatalytic active sites. This factor together with the synergistic effect between Fe and Ni simultaneously leads to an enhanced catalytic effect for water splitting and urea oxidation. This strategy could be scaled up to pave a viable way for low-cost fabrication of highly efficient electrodes for electrocatalysis.

Inula japonica ameliorated the inflammation and oxidative stress in LPS-induced acute lung injury through the MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

OBJECTIVES: To investigate the protective effect and underlying mechanism of Inula japonica (TEIJ) in the treatment of acute lung injury (ALI). METHODS: Protective effects of TEIJ in the inflammation and oxidative stress were studied in lipopolysaccharide (LPS)-induced ALI mice. Meanwhile, Western blot and real-time qPCR were carried out to investigate the underlying mechanism of TEIJ for ALI as well as immunohistochemistry. KEY FINDINGS: TEIJ significantly alleviated the course of ALI via suppressing the interstitial infiltrated inflammatory cells, the increase of inflammatory factors and the decrease of anti-oxidative factors. TEIJ inactivated the MAPK/NF-κB signalling pathway to suppress the transcription of its downstream target genes, such as TNF-α, IL-6, etc. Meanwhile, TEIJ activated the Keap1/Nrf2 signalling pathway to regulate expression levels of Nrf2 and its target proteins. The results of LC-QTOF-MS/MS indicated potential active constituents of I. japonica, terpenoids and flavonoids. Additionally, terpenoids and flavonoids synergistically alleviated LPS-induced ALI depending on MAPK/NF-κB and Keap1/Nrf2 signalling pathways. CONCLUSION: I. japonica could be considered a potential agent to treat ALI via regulating the MAPK/NF-κB and Keap1/Nrf2 signalling pathways.