SUCLG1 restricts POLRMT succinylation to enhance mitochondrial biogenesis and leukemia progression.

Mitochondria are cellular powerhouses that generate energy through the electron transport chain (ETC). The mitochondrial genome (mtDNA) encodes essential ETC proteins in a compartmentalized manner, however, the mechanism underlying metabolic regulation of mtDNA function remains unknown. Here, we report that expression of tricarboxylic acid cycle enzyme succinate-CoA ligase SUCLG1 strongly correlates with ETC genes across various TCGA cancer transcriptomes. Mechanistically, SUCLG1 restricts succinyl-CoA levels to suppress the succinylation of mitochondrial RNA polymerase (POLRMT). Lysine 622 succinylation disrupts the interaction of POLRMT with mtDNA and mitochondrial transcription factors. SUCLG1-mediated POLRMT hyposuccinylation maintains mtDNA transcription, mitochondrial biogenesis, and leukemia cell proliferation. Specifically, leukemia-promoting FMS-like tyrosine kinase 3 (FLT3) mutations modulate nuclear transcription and upregulate SUCLG1 expression to reduce succinyl-CoA and POLRMT succinylation, resulting in enhanced mitobiogenesis. In line, genetic depletion of POLRMT or SUCLG1 significantly delays disease progression in mouse and humanized leukemia models. Importantly, succinyl-CoA level and POLRMT succinylation are downregulated in FLT3-mutated clinical leukemia samples, linking enhanced mitobiogenesis to cancer progression. Together, SUCLG1 connects succinyl-CoA with POLRMT succinylation to modulate mitochondrial function and cancer development.

Hypothetical chloroplast reading frame 51 encodes a photosystem I assembly factor in cyanobacteria.

Hypothetical chloroplast open reading frames (ycfs) are putative genes in the plastid genomes of photosynthetic eukaryotes. Many ycfs are also conserved in the genomes of cyanobacteria, the presumptive ancestors of present-day chloroplasts. The functions of many ycfs are still unknown. Here, we generated knock-out mutants for ycf51 (sll1702) in the cyanobacterium Synechocystis sp. PCC 6803. The mutants showed reduced photoautotrophic growth due to impaired electron transport between photosystem II (PSII) and PSI. This phenotype results from greatly reduced PSI content in the ycf51 mutant. The ycf51 disruption had little effect on the transcription of genes encoding photosynthetic complex components and the stabilization of the PSI complex. In vitro and in vivo analyses demonstrated that Ycf51 cooperates with PSI assembly factor Ycf3 to mediate PSI assembly. Furthermore, Ycf51 interacts with the PSI subunit PsaC. Together with its specific localization in the thylakoid membrane and the stromal exposure of its hydrophilic region, our data suggest that Ycf51 is involved in PSI complex assembly. Ycf51 is conserved in all sequenced cyanobacteria, including the earliest branching cyanobacteria of the Gloeobacter genus, and is also present in the plastid genomes of glaucophytes. However, Ycf51 has been lost from other photosynthetic eukaryotic lineages. Thus, Ycf51 is a PSI assembly factor that has been functionally replaced during the evolution of oxygenic photosynthetic eukaryotes.

3D Carbon Fiber Skeleton Film Modified with Gradient Cu Nanoparticles as Auxiliary Anode Regulates Dendrite-Free, Bottom-Up Zinc Deposition.

Achieving stable Zn plating/stripping under high current density and large area capacity remains a major challenge for metal Zn anodes. To address this issue, common filter paper is utilized to construct 3D carbon fiber skeleton film modified with gradient Cu nanoparticles (CFF@Cu). The original zincophobic hydrophilic CFF is transformed into gradient zincophilic and reversed gradient hydrophilic composite, due to the gradient distribution of Cu nanoparticles. When CFF@Cu is placed above Zn foil as an auxiliary anode, Zn foil anode exhibits stable, reversible, and dendrite-free Zn plating/stripping for 1200 h at 10 mA cm-2 and 2 mAh cm-2, 2000 h at 2 mA cm-2 and 2 mAh cm-2, 340 h at 10 mA cm-2 and 10 mAh cm-2. Additionally, nucleation barrier of Zn, Zn2+ transport and deposition kinetics are improved. The deposits on the Zn foil anode become homogeneous, dense, and fine. Side reactions and by-products are effectively inhibited. The excellent performance is mainly attributed to the gradient zincophilic field in 3D CFF. A portion of Zn2+ is captured by Cu and deposited within CFF@Cu from bottom to top, which reduces and homogenizes Zn2+ flux on Zn foil, as well as weakens and homogenizes electric field on Zn foil.

Bismuth-Antimony Alloy Nanoparticles Embedded in 3D Hierarchical Porous Carbon Skeleton Film for Superior Sodium Storage.

A composite film that features bismuth-antimony alloy nanoparticles uniformly embedded in a 3D hierarchical porous carbon skeleton is synthesized by the polyacrylonitrile-spreading method. The dissolved polystyrene is used as a soft template. The average diameter of the bismuth-antimony alloy nanoparticles is ~34.5 nm. The content of the Bi-Sb alloy has an impact on the electrochemical performance of the composite film. When the content of the bismuth-antimony alloy is 45.27%, the reversible capacity and cycling stability of the composite film are the best. Importantly, the composite film outperforms the bismuth-antimony alloy nanoparticles embedded in dense carbon film and the cube carbon nanobox in terms of specific capacity, cycling stability, and rate capability. The composite film can provide a discharge capacity of 322 mAh g-1 after 500 cycles at 0.5 A g-1, 292 mAh g-1 after 500 cycles at 1 A g-1, and 185 mAh g-1 after 2000 cycles at 10 A g-1. The carbon film prepared by the spreading method presents a unique integrated composite structure that significantly improves the structural stability and electronic conductivity of Bi-Sb alloy nanoparticles. The 3D hierarchical porous carbon skeleton structure further enhances electrolyte accessibility, promotes Na+ transport, increases reaction kinetics, and buffers internal stress.

More Stable Memory Retention of Novel Words Learned from Fast Mapping than from Explicit Encoding.

There is a heated debate on a learning paradigm known as "fast mapping" for its early neocortical dependence and retained memory over time for amnesic patients with hippocampal system damage. Whether the fast mapping allows hippocampus independent learning and induces rapid integration is poorly understood. The present study aims to investigate the effect of fast mapping on very long-term retention, which to our knowledge has not been previously explored. We tested memory retention ranging from 10 min to 1.5 years, for novel word-object associations learned from fast mapping or explicit encoding procedures. The three-alternative forced choice recognition task was employed to assess memory performance. Besides the slight adjustment of the testing schedule, other settings remained the same in Experiment 2 to replicate and verify the findings of Experiment 1. Results showed that overall memory retrieval performance was higher after explicit encoding as compared to fast mapping. However, retrieval performance after explicit encoding dropped after 1.5 years, but remained stable in the fast mapping condition. Furthermore, matching the semantic category of the known and the novel items during the fast mapping paradigm might affect long-term retention. These results suggest that fast mapping creates more stable long-term memory representations as compared to the explicit encoding strategy.

MBD3 promotes hepatocellular carcinoma progression and metastasis through negative regulation of tumour suppressor TFPI2.

BACKGROUND: The mechanism of recurrence and metastasis of hepatocellular carcinoma (HCC) is complex and challenging. Methyl-CpG binding domain protein 3 (MBD3) is a key epigenetic regulator involved in the progression and metastasis of several cancers, but its role in HCC remains unknown. METHODS: MBD3 expression in HCC was detected by immunohistochemistry and its association with clinicopathological features and patient's survival was analysed. The effects of MBD3 on hepatoma cells growth and metastasis were investigated, and the mechanism was explored. RESULTS: MBD3 is significantly highly expressed in HCC, associated with the advanced tumour stage and poor prognosis in HCC patients. MBD3 promotes the growth, angiogenesis and metastasis of HCC cells by inhibiting the tumour suppressor tissue factor pathway inhibitor 2 (TFPI2). Mechanistically, MBD3 can inhibit the TFPI2 transcription via the Nucleosome Remodeling and Deacetylase (NuRD) complex-mediated deacetylation, thus reactivating the activity of matrix metalloproteinases (MMPs) and PI3K/AKT signaling pathway, leading to the progression and metastasis of HCC CONCLUSIONS: Our results unravel the novel regulatory function of MBD3 in the progression and metastasis of HCC and identify MBD3 as an independent unfavourable prognostic factor for HCC patients, suggesting its potential as a promising therapeutic target as well.

Two Structurally Similar Co5 Cluster-Based Metal-Organic Frameworks Containing Open Metal Sites for Efficient C2H2/CO2 Separation.

To reasonably design and synthesize metal-organic frameworks (MOFs) with high stability and excellent adsorption/separation performance, the pore configuration and functional sites are very important. Here, we report two structurally similar cluster-based MOFs using a pyridine-modified low-symmetry ligand [H4L = 2,6-bis(2',5'-dicarboxyphenyl)pyridine], [(NH2Me2)2][Co5(L)2(OCH3)2(µ3-OH)2·2DMF]·2DMF·2H2O (1) and [Co5(L)2(µ3-OH)2(H2O)2]·2H2O·4DMF (2). The structures of 1 and 2 are built from Co5 clusters, which have one-dimensional open channels, but their microporous environments are different due to the different ways in which ligands bind to the metals. Both MOFs have extremely high chemical stabilities over a wide pH range (2-12). The two MOFs have similar adsorption capacities of C2H2 (144.0 cm3 g-1 for 1 and 141.3 cm3 g-1 for 2), but 1 has a higher C2H2/CO2 selectivity of 3.5 under ambient conditions. The difference in gas adsorption and separation between the two MOFs has been compared by a breakthrough experiment and theoretical calculation, and the influence of the microporous environment on the gas adsorption and separation performance of MOFs has been further studied.

The small molecule chemical compound cinobufotalin attenuates resistance to DDP by inducing ENKUR expression to suppress MYH9-mediated c-Myc deubiquitination in lung adenocarcinoma.

The small molecule chemical compound cinobufotalin (CB) is reported to be a potential antitumour drug that increases cisplatin (DDP) sensitivity in nasopharyngeal carcinoma. In this study, we first found that CB decreased DDP resistance, migration and invasion in lung adenocarcinoma (LUAD). Mechanistic studies showed that CB induced ENKUR expression by suppressing PI3K/AKT signalling to downregulate c-Jun, a negative transcription factor of ENKUR. Furthermore, ENKUR was shown to function as a tumour suppressor by binding to ß-catenin to decrease c-Jun expression, thus suppressing MYH9 transcription. Interestingly, MYH9 is a binding protein of ENKUR. The Enkurin domain of ENKUR binds to MYH9, and the Myosin_tail of MYH9 binds to ENKUR. Downregulation of MYH9 reduced the recruitment of the deubiquitinase USP7, leading to increased c-Myc ubiquitination and degradation, decreased c-Myc nuclear translocation, and inactivation of epithelial-mesenchymal transition (EMT) signalling, thus attenuating DDP resistance. Our data demonstrated that CB is a promising antitumour drug and may be a candidate chemotherapeutic drug for LUAD patients.

Arginine methylation of SIRT7 couples glucose sensing with mitochondria biogenesis.

Sirtuins (SIRTs) are a class of lysine deacylases that regulate cellular metabolism and energy homeostasis. Although sirtuins have been proposed to function in nutrient sensing and signaling, the underlying mechanism remains elusive. SIRT7, a histone H3K18-specific deacetylase, epigenetically controls mitochondria biogenesis, ribosomal biosynthesis, and DNA repair. Here, we report that SIRT7 is methylated at arginine 388 (R388), which inhibits its H3K18 deacetylase activity. Protein arginine methyltransferase 6 (PRMT6) directly interacts with and methylates SIRT7 at R388 in vitro and in vivo R388 methylation suppresses the H3K18 deacetylase activity of SIRT7 without modulating its subcellular localization. PRMT6-induced H3K18 hyperacetylation at SIRT7-target gene promoter epigenetically promotes mitochondria biogenesis and maintains mitochondria respiration. Moreover, high glucose enhances R388 methylation in mouse fibroblasts and liver tissue. PRMT6 signals glucose availability to SIRT7 in an AMPK-dependent manner. AMPK induces R388 hypomethylation by disrupting the association between PRMT6 and SIRT7. Together, PRMT6-induced arginine methylation of SIRT7 coordinates glucose availability with mitochondria biogenesis to maintain energy homeostasis. Our study uncovers the regulatory role of SIRT7 arginine methylation in glucose sensing and mitochondria biogenesis.

Effects and mechanisms of scalp acupuncture on learning and memory in mice with lead poisoning.

OBJECTIVE: To study the effects and mechanism of scalp acupuncture on learning and memory ability in mice with lead poisoning. METHODS: From March 2018 to December 2018, 30 Kunming mice were randomly divided equally into the control group and the intervention group after intraperitoneal injection of lead acetate The intervention group received scalp acupuncture on the first day of the model establishment; the model group only received conventional feeding without treatment. At the same time, a control group of 15 rats was given the intraperitoneal injections of normal saline for 8 consecutive days, and only after routine feeding, no treatment was given. Determination of lead in blood was detected by Graphite Furnace Atomic Absorption Spectrometry, the Morris water maze test was used to detect the learning and memory function of mice, hydroxylamine colorimetric method was used to measure acetylcholinesterase (AChE) activity, and TUNEL staining was used to detect the apoptotic cells in the hippocampus. RESULTS: The results showed that the blood lead level of the model group (231.42±12.53µg/L) was significantly higher than that of the control group (20.43±4.62µg/L) (P<0.05); and there was no significant difference in blood lead content between the intervention group (228.12±5.21µg/L) and the model group. The Morris water maze test showed that from the fourth day of the orientation navigation experiment, the escape latency of the model group (22.2±4.10s) was longer than that of the control group (13.64±2.93s) (P<0.05); besides, from the third day, the escape latency of mice in the intervention group (13.52±9.18s) was significantly shortened compared with the model group (19.95±3.52s). In the space exploration experiment, in terms of passing through the platform, the distance (1.57±0.49m) and time (15.54±3.72s) of mice in the model group were longer than that of mice in the control group (0.73±0.44m, 3.24±2.24s) (P<0.05), the distance (0.41±0.28m) and time (3.0±1.93s) of mice in the intervention group were shorter than that of mice in the model group, and the difference was statistically significant (P<0.05). The apoptosis rate of hippocampus in the model group (8.79±0.37%) was significantly higher than that in the control group (3.56±0.44%) (P<0.05), and the apoptosis rate of hippocampus in the intervention group (4.36±0.12%0 was significantly lower than that in the model group (P<0.05). The expression of AchE in the model group (0.5±0.13U/ug) was significantly higher than that in the control group (0.23±0.04U/ug), but there was no significant difference in the AChE activity between the intervention group and the model group. CONCLUSIONS: In conclusion, scalp acupuncture can improve the learning and memory ability of mice with lead poisoning, and the decrease of hippocampal apoptotic cells may be a possible mechanism for the improvement of learning and memory function.

Prognostic significance of peripheral CD8+CD28+ and CD8+CD28- T cells in advanced non-small cell lung cancer patients treated with chemo(radio)therapy.

BACKGROUND: Noninvasive prognostic biomarkers are needed for advanced non-small cell lung cancer (NSCLC) patients with different histological types to identify cases with poor survival. Here, we investigated the prognostic values of peripheral CD8+CD28+ T cells and CD8+CD28- T cells in advanced NSCLC patients treated with chemo(radio)therapy and the impact of histological type on them. METHODS: Of 232 registered advanced NSCLC patients, 101 treatment-naïve individuals were eligible and included in our study. Flow cytometry was used to evaluate CD8+CD28+ T cells, CD8+CD28- T cells, CD4+ CD25hi T cells, B cells, natural killer cells, γδT cells, and natural killer T cells in patients' peripheral blood. RESULTS: The median follow-up time was 13.6 months. Fifty-nine (58.4%) patients died by the end of our study. Fifty-three of the 101 advanced NSCLC cases selected for our study were adenocarcinomas (ADs), and 48 were squamous cell carcinomas (SCCs). Multivariate analyses showed that increased levels of CD8+CD28+ T cells independently predicted favorable overall survival (OS) [hazard ratio (HR): 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.021] and progression-free survival (PFS) (HR: 0.66, 95% CI 0.37-0.93, P = 0.038) in ADs, but the prediction in SCCs was not statistically significant. In contrast, high levels of CD8+CD28- T cells independently predicted unfavorable OS (HR: 1.41, 95% CI 1.17-3.06, P = 0.035) and PFS (HR: 2.01, 95% CI 1.06-3.85, P = 0.029) in SCCs, but the prediction in ADs was not statistically significant. ADs had higher levels of CD4+CD25hi T cells and CD8+CD28- T cells and lower NK cells (all P < 0.05) than SCCs. CONCLUSIONS: Our findings uncovered the prognostic values of peripheral CD8+CD28+ T cells and CD8+CD28- T cells in advanced NSCLC patients treated with chemo(radio)therapy, which could help to identify patients with poor outcomes and refine treatment strategies.

The effect of vanadium on essential element uptake of Setaria viridis' seedlings.

High concentrations of vanadium, a ubiquitous element in the environment, in growing media leads to deformation of root structure and leaf chlorosis and necrosis, consequently affecting the translocations of nutrients and essential elements. However, the effects of vanadium on essential element uptake, and the interactions of essential elements in the presence of vanadium, remain incompletely understood. To elucidate the effects of different concentrations of vanadium on major and trace essential elements and plant growth, a native plant species growing in a vanadium mining area, Setaria viridis (dog tail's grass), was incubated in solutions containing 0-55.8 mg/L vanadium. The shoot accumulation of four major essential elements and five trace essential elements was detected, and the root length and stem height were measured. The results showed that vanadium in soil solution enhanced the accumulation of all major essential elements in shoot. Vanadium concentrations lower than 47.4 mg/L showed an obvious positive (p < 0.05) effect on P accumulation and translocation. In the case of trace essential elements, there were threshold values for solution vanadium stimulation of element uptake. The threshold values for Cu and Zn, Fe, and Mo uptake were 4.3, 16.3, and 40.6 mg/L, respectively. When vanadium levels surpassed these values, accumulation was suppressed and the solution vanadium concentrations attenuated the solution-to-shoot translocation of most of the essential elements. Among the trace essential elements, translocation of Fe was obviously enhanced (p < 0.05) by vanadium. Solution vanadium also enhanced plant growth at lower concentrations and inhibited it at higher levels. The threshold values for stem height and root length were 36.8 and 16.3 mg/L, respectively. Concentrations of 40 and 55.8 mg/L vanadium in soil solution caused a 50% decrease in root length and stem height, respectively, showing that root length of Setaria viridis is more susceptible to vanadium toxicity than stem growth.

Myeloid-derived suppressor cells regulate immune response in patients with chronic hepatitis B virus infection through PD-1-induced IL-10.

Although myeloid-derived suppressor cells (MDSCs) are well known for their immunosuppressive function in several pathological conditions, the role of MDSCs in hepatitis B virus infection remains obscure. In this study, we investigated the frequency and function of MDSCs in the peripheral blood and liver of 91 chronic hepatitis B (CHB) patients. A higher percentage of MDSCs, defined as CD14(+)HLA-DR(-/low), was detected in peripheral blood of CHB patients than that of the healthy controls. Moreover, high expression of programmed death 1 (PD-1) and secretion of IL-10 in this population were determined. The frequency of MDSCs was positively correlated with serum viral load, but it was negatively correlated with liver inflammatory injury. These cells were also abundant in liver tissue of CHB patients and were related to necroinflammatory activity. Furthermore, we found that these cells could suppress hepatitis B virus-specific CD8(+) T cell response, including reduced proliferation and IFN-γ production, and inhibit degranulation of CD8(+) T cells, including reduced production of granzyme B and perforin. Importantly, PD-1-induced IL-10 production by MDSCs was responsible for the suppressive activity. To our knowledge, for the first time our study proved that CD14(+)HLA-DR(-/low)PD-1(+) MDSCs in CHB patients contribute to an inadequate immune response against the virus and lead to chronic infection, which represents a potential target for therapeutic intervention.

Development and validation of a UPLC-MS/MS method for the determination of cucurbitacin B in rat plasma and application to a pharmacokinetic study.

Cucurbitacin B (CuB), one of the most abundant forms of cucurbitacins, is a promising natural anticancer drug candidate. Although the anticancer activity of CuB has been well demonstrated, information regarding the pharmacokinetics is limited. A rapid, selective and sensitive UPLC-MS/MS for CuB was developed and validated using hemslecin A (HeA) as internal standard (IS). Plasma samples were pre-treated by liquid-liquid extraction with dichloromethane. Separation was achieved on a reversed-phase C18 column (50 × 4.6 mm, 5 µm) at 35°C using isocratic elution with water-methanol (25:75, v/v) at a flow rate of 0.3 mL/min. The analytes were monitored by a triple quadrupole tandem mass spectrometer with positive electrospray ionization mode. The calibration curve was linear (r > 0.995) in a concentration range of 0.3-100 ng/mL with a limit of quantification of 0.3 ng/mL. Intra- and inter-day accuracy and precision were validated by percentage relative error and relative standard deviation, respectively, which were both lower than the limit of 15%. This assay was successfully applied to a pharmacokinetic study of CuB in Wistar rats.

A sensitive and selective LC-MS/MS method for the quantitative determination of segetalin A from the plasma of rats.

A sensitive and selective LC-MS/MS method was developed and validated for the determination and pharmacokinetic investigation of segetalin A in rat plasma. Sample preparation was accomplished through a simple SPE procedure for the removal and preconcentration of the analyte and IS. Plasma samples were separated by HPLC on a Symmetry C18 column using a mobile phase consisting of methanol and 0.1% formic acid in water (70:30, v/v) with isocratic elution. The quantification was performed using multiple reaction monitoring with the transitions m/z 610.3 → 511.2 for segetalin A and m/z 779.4 → 751.4 for IS, respectively. The calibration curve was linear over the range of 8.0-4000 ng/mL with a limit of quantitation (LOQ) of 8.0 ng/mL. This method was applied in a pharmacokinetic study of segetalin A in rats. For intravenous (i.v.) administration, the plasma concentrations of segetalin A decreased quickly (t1/2z, 1.31 ± 0.341 h). For oral administration, the plasma concentrations of segetalin A increased to a peak value at 1.50 ± 0.577 h, followed by a gradual decrease to the LOQ in 12 h. The mean AUC values after i.v. and oral administration were 553 ± 105 and 1482 ± 110 ng h/mL, respectively.

[Effect of Wenyang Decoction on the Differentiation of CD34+ Progenitor Cells in Occupational Asthma Model Rats].

OBJECTIVE: To study the effect of Wenyang Decoction (WD) on the differentiation of CD34+ progenitor cells of occupational asthma (OA) model rats. METHODS: Fifty healthy male SD rats were randomly divided into five groups, i.e., the model group, the blank control group,the WD group,the Western medicine group,the combined group, 10 in each group. Prednisone suspension (10 mg/kg) was administered to rats in the Western medicine group by gastrogavage. WD (20 g/kg) was administered to rats in the WD group by gastrogavage. Prednisone suspension plus WD was administered to rats in the combined group by gastrogavage. Normal saline was administered to rats in the model group and the blank control group by gastrogavage. The general condition of rats was observed. Expression levels of peripheral blood IL-5 and eotaxin, eosinophils (EOS), CD34+, CC chemokine receptor 3 (CCR3+) in bone marrow suspension were detected by ELISA, Wirght-Giemsa, and flow cytometry, respectively. RESULTS: Compared with the blank control group,expression levels of IL-5 and eotaxin in peripheral blood were significantly higher (P < 0.01), and the count of EOS and CD34+ cells, as well as CD34+ /CCR3+ significantly increased (P < 0.01) in the model group. Compared with the model group, expression levels of IL-5 and eotaxin, the count of EOS, CD34+ cells, CD34+ / CCR3+ were lowered in three treated groups (P < 0.01). Compared with the Western medicine group, the count of EOS and CD34+ / CCR3+ decreased in the combined group (P < 0.01). The count of EOS was significantly lower in the combined group than in the WD group (P < 0.01). CONCLUSION: WD could reduce levels of in vivo inflammatory factors, and restrain the differentiation and recruitment of EOS,thereby alleviating the differentiation of CD34 progenitor cells to EOS.

[Mechanisms regulating p21 gene expression by retinoic acid-induced gene G protein].

OBJECTIVE: To investigate the mechanisms by which retinoic acid-induced gene G (RIG-G) protein regulates p21 gene expression. METHODS: Western blot was used to detect the effects of RIG-G protein overexpression on p21 protein expression level in leukemia cell line NB4 cells and the phosphorylation of both c-Jun and JNK in U937 cells. The c-Jun expression plasmid and p21 gene promoter-containing reporter plasmid were co-transfected into 293T cells, to explore the regulatory effect of c-Jun protein on p21 gene expression by luciferase reporter assay. RESULTS: Western blot showed that the overexpression of RIG-G protein significantly upregulated p21 protein level in the NB4 cells, and the level of p21 protein largely increased along with the induction of endogenous RIG-G protein during the differentiation of NB4 cells treated by all-trans retinoic acid (ATRA). Moreover, the phosphorylation of both c-Jun and JNK decreased in RIG-G-overexpressing U937 cells while total c-Jun and JNK proteins remained unchanged. After using the JNK inhibitor SP600125 to block JNK phosphorylation, the level of c-Jun phosphorylation was still dramatically reduced in the RIG-G-overexpressing U937T-RIG-G cells, compared with the control U937T-pTRE cells. These results indicated that the inhibitory effect of Rig-G protein on c-Jun phosphorylation could not only be through the JNK pathway, but also via some JNK-independent pathways. Luciferase reporter assay showed that when 0.1, 0.5, 1.0 and 2.0 µg c-Jun-expressing plasmids were respectively transfected into 293T cells, compared with the empty vector-transfected group, the relative luciferase activities were (83.0 ± 1.7)%, (73.7 ± 0.7)%, (68.9 ± 0.9)% and (64.1 ± 0.9)%, indicating that the transcriptional activity of p21 gene could be inhibited by c-Jun protein. CONCLUSIONS: RIG-G protein may suppress the phosphorylation of c-Jun protein through different signal pathways, thereby increasing the expression of p21 gene, arresting the cell cycle and inhibiting the cell growth in U937 cells.

Multifunctional Anti-Icing Gel Surface with Enhanced Durability.

Materials with low ice adhesion and long-lasting anti-icing properties remain an ongoing challenge in ultralow temperature environments (≤-30 °C). This study presents a gel material consisting of a polymer matrix (copolymer of polyurethane and acrylamide) and an anti-icing agent, ethylene glycol (EG), designed for anti-icing applications at ultralow temperatures. The surface shows a prolonged droplet freezing delay of ca. 322 s at -30 °C and frost resistance properties. It also exhibits an ice adhesion strength of 1.1 kPa at -10 °C and 39.8 kPa at -50 °C, resulting from the interaction between EG and water molecules that hinders the crystallization of ice as well as the significant mismatch between elastic gel and ice. In addition, the gel surface exhibits favorable anti-icing durability, with an ice adhesion strength below 20.0 kPa after 25 icing/deicing cycles and mechanical scratch tests. The gel demonstrates remarkable thermal durability, achieved through the H-bonds between the EG and polymer matrix. The H-bonds further enhance the anti-icing performance, thereby remarkably decreasing EG depletion and improving anti-icing durability. Overall, these properties suggest the potential application of this gel material in harsh environments including polar regions.

Thermomechanically Resilient Polyionic Elastomers with Enhanced Anti-Icing Performances.

Anti-icing gels inhibit ice formation and accretion; however, current iterations face prevalent drawbacks such as poor strength, weak substrate adhesion, and limited anti-icing properties. Herein, we propose a novel approach to address these challenges by developing a thermomechanical robust polyionic elastomer (PIE) with enhanced anti-icing properties. The PIE surface exhibits an icing delay time up to 5400 s and remains frost-free after exposure to -10 °C for 3.5 h, attributed to the inhibitory effect on ice formation by ions from ILs and the polyelectrolyte network. Moreover, the PIE exhibits remarkable anti-icing durability, with ice adhesion strengths below 35 kPa after undergoing 30 icing/deicing cycle tests at -20 °C. Following sandpaper abrasion (300 cycles), scratching, and heat treatment (100 °C, 16 h), the adhesion strength remains ca. 20 kPa, highlighting its resilience under various thermal and mechanical conditions. This exceptional durability is attributed to the low volatility of the IL and the robust ionic interactions within the PIE network. Furthermore, the PIE demonstrates favorable self-healing properties and strong substrate adhesion in both low-temperature and ambient environments, facilitated by the abundance of hydrogen bonds and electrostatic forces within PIE. This work presents an innovative approach to developing high-performance, durable, and robust anti-icing materials with potential implications across various fields.

Hackflex library preparation enables low-cost metagenomic profiling.

Shotgun metagenomic sequencing provides valuable insights into microbial communities, but the high cost of library preparation with standard kits and protocols is a barrier for many. New methods such as Hackflex use diluted commercially available reagents to greatly reduce library preparation costs. However, these methods have not been systematically validated for metagenomic sequencing. Here, we evaluate Hackflex performance by sequencing metagenomic libraries from known mock communities as well as mouse fecal samples prepared by Hackflex, Illumina DNA Prep, and Illumina TruSeq methods. Hackflex successfully recovered all members of the Zymo mock community, performing best for samples with DNA concentrations <1 ng/uL. Furthermore, Hackflex was able to delineate microbiota of individual inbred mice from the same breeding stock at the same mouse facility, and statistical modeling indicated that mouse ID explained a greater fraction of the variance in metagenomic composition than did library preparation method. These results show that Hackflex is suitable for generating inventories of bacterial communities through metagenomic sequencing.