The Molecular Mechanism of Aurora-B Regulating Kinetochore-Microtubule Attachment in Mitosis and Oocyte Meiosis.

BACKGROUND: Aurora kinase B (Aurora-B), a member of the chromosomal passenger complex, is involved in correcting kinetochore-microtubule (KT-MT) attachment errors and regulating sister chromatid condensation and cytoplasmic division during mitosis. SUMMARY: However, few reviews have discussed its mechanism in oocyte meiosis and the differences between its role in mitosis and meiosis. Therefore, in this review, we summarize the localization, recruitment, activation, and functions of Aurora-B in mitosis and oocyte meiosis. The accurate regulation of Aurora-B is essential for ensuring accurate chromosomal segregation and correct KT-MT attachments. Aurora-B regulates the stability of KT-MT attachments by competing with cyclin-dependent kinase 1 to control the phosphorylation of the SILK and RVSF motifs on kinetochore scaffold 1 and by competing with protein phosphatase 1 to influence the phosphorylation of NDC80 which is the substrate of Aurora-B. In addition, Aurora-B regulates the spindle assembly checkpoint by promoting the recruitment and activation of mitotic arrest deficient 2. KEY MESSAGES: This review provides a theoretical foundation for elucidating the mechanism of cell division and understanding oocyte chromosomal aneuploidy.

Reconfiguring the Hydrogen Networks of Aqueous Electrolyte to Stabilize Iron Hexacyanoferrate for High-Voltage Decoupled Cell.

Prussian blue analogs (PBAs) as insertion-type cathodes have attracted significant attention in various aqueous batteries to accommodate metal or non-metal ions while suffering from serious dissolution and consequent inferior lifespan. Herein, we reveal that the dissolution of PBAs primarily originates from the locally elevated pH of electrolytes that are caused by proton co-insertion during discharge. To address this issue, a water-locking electrolyte (WLE) has been strategically implemented, which interrupts the generation and Grotthuss diffusion of protons by breaking the well-connected hydrogen bonding network in aqueous electrolytes. As a result, the WLE enables the iron hexacyanoferrate to endure over 1000 cycles at a 1C rate and supports a high-voltage decoupled cell with an average voltage of 1.95 V. These findings provide insights for mitigating dissolution problems in electrode materials, thereby enhancing the viability and performance of aqueous batteries.

Health benefits of saponins and its mechanisms: perspectives from absorption, metabolism, and interaction with gut.

Saponins, consisting of sapogenins as their aglycones and carbohydrate chains, are widely found in plants and some marine organisms. Due to the complexity of the structure of saponins, involving different types of sapogenins and sugar moieties, investigation of their absorption and metabolism is limited, which further hinders the explanation of their bioactivities. Large molecular weight and complex structures limit the direct absorption of saponins rendering their low bioavailability. As such, their major modes of action may be due to interaction with the gastrointestinal environment, such as enzymes and nutrients, and interaction with the gut microbiota. Many studies have reported the interaction between saponins and gut microbiota, that is, the effects of saponins on changing the composition of gut microbiota, and gut microbiota playing an indispensable role in the biotransformation of saponins into sapogenins. However, the metabolic routes of saponins by gut microbiota and their mutual interactions are still sparse. Thus, this review summarizes the chemistry, absorption, and metabolic pathways of saponins, as well as their interactions with gut microbiota and impacts on gut health, to better understand how saponins exert their health-promoting functions.

Regulation of gut microbiota and alleviation of DSS-induced colitis by vitexin.

PURPOSE: Vitexin is one of the flavonoids in millet and has a variety of biological activities. However, the function of vitexin on colitis is not clear. This research studied the regulation of vitexin on colitis and investigated the possible mechanisms. METHODS: An in vitro fermentation model was used to evaluate the regulation of vitexin on gut microbiota of patients with inflammatory bowel disease (IBD). At the same time, an acute colitis mice model induced by dextran sodium sulfate (DSS) was used to evaluate the effects of vitexin on intestinal inflammation, barrier and gut microbiota. RESULTS: In this study, it was found that vitexin altered the structure of gut microbiota by decreasing harmful bacteria, such as Veillonella, Terrisporobacter, Klebsiella, Paeniclostridium, and increasing beneficial bacteria, such as Parabacteroides, Flavonifractor, Blautia after in vitro fermentation with the feces of colitis patients. Further, DSS-induced colitis mice models revealed that vitexin treatment significantly improved colitis symptoms, maintained intestinal barrier and down-regulated the expression of inflammatory factors, such as IL-1ß and TNF-α. In addition, vitexin also improved the diversity of gut microbiota of colitis mice by decreasing the abundance of harmful bacteria. CONCLUSION: This research suggested that vitexin could alleviate colitis by regulating gut microbiota and attenuated gut inflammation.

In Situ Electrochemical Activation of Hydroxyl Polymer Cathode for High-Performance Aqueous Zinc-Organic Batteries.

The slow reaction kinetics and structural instability of organic electrode materials limit the further performance improvement of aqueous zinc-organic batteries. Herein, we have synthesized a Z-folded hydroxyl polymer polytetrafluorohydroquinone (PTFHQ) with inert hydroxyl groups that could be partially oxidized to the active carbonyl groups through the in situ activation process and then undertake the storage/release of Zn2+ . In the activated PTFHQ, the hydroxyl groups and S atoms enlarge the electronegativity region near the electrochemically active carbonyl groups, enhancing their electrochemical activity. Simultaneously, the residual hydroxyl groups could act as hydrophilic groups to enhance the electrolyte wettability while ensuring the stability of the polymer chain in the electrolyte. Also, the Z-folded structure of PTFHQ plays an important role in reversible binding with Zn2+ and fast ion diffusion. All these benefits make the activated PTFHQ exhibit a high specific capacity of 215 mAh g-1 at 0.1 A g-1 , over 3400 stable cycles with a capacity retention of 92 %, and an outstanding rate capability of 196 mAh g-1 at 20 A g-1 .

Age-related SUMOylation of PLK1 is essential to meiosis progression in mouse oocytes.

Polo like kinase 1 (PLK1) is a protein kinase involved in regulating the spindle assembly and cell cycle control in mammalian oocytes. SUMOylation, one way of post-translational modification, regulates oocyte meiosis by controlling several substrates. However, the relation between PLK1 and SUMOylation in oocytes is still unknown. In this study, we investigated that whether PLK1 was modified by SUMOylation in oocytes and its potential relationship with age-related meiotic abnormalities. We showed that PLK1 had colocalization and protein interaction with Small Ubiquitin-Like Modifier (SUMO)-1 and SUMO-2/3 in mouse oocytes, indicating that PLK1 could be modified by SUMO-1 and SUMO-2/3. Overexpression of PLK1 SUMOylation site mutants PLK1K178R and PLK1K191R caused the increase of the abnormal spindle rate of oocytes and the decline of the first polar body extrusion rate with the abnormal localization of PLK1, suggesting that the SUMOylation modification of PLK1 is essential for normal meiosis in oocytes. Compared with young mice, the expression of PLK1 protein increased and the expression of SUMO-1 and SUMO-2/3 protein decreased in the oocytes of aged mice, indicating that the SUMOylation of PLK1 might be related to the mouse aging. Therefore, our data suggested that PLK1 could be SUMOylated by SUMO-1 and SUMO-2/3 in mouse oocytes and SUMOylation of PLK1 regulated the meiosis progression of oocytes which was related with aging.

Shugoshin Regulates Cohesin, Kinetochore-Microtubule Attachments, and Chromosomal Instability.

Correct regulation of cohesin at chromosome arms and centromeres and accurate kinetochore-microtubule connections are significant for proper chromosome segregation. At anaphase of meiosis I, cohesin at chromosome arms is cleaved by separase, leading to the separation of homologous chromosomes. However, at anaphase of meiosis II, cohesin at centromeres is cleaved by separase, leading to the separation of sister chromatids. Shugoshin-2 (SGO2) is a member of the shugoshin/MEI-S332 protein family in mammalian cells, a crucial protein that protects centromeric cohesin from cleavage by separase and corrects wrong kinetochore-microtubule connections before anaphase of meiosis I. Shugoshin-1 (SGO1) plays a similar role in mitosis. Moreover, shugoshin can inhibit the occurrence of chromosomal instability (CIN), and its abnormal expression in several tumors, such as triple-negative breast cancer, hepatocellular carcinoma, lung cancer, colon cancer, glioma, and acute myeloid leukemia, can be used as biomarker for disease progression and potential therapeutic targets for cancers. Thus, this review discusses the specific mechanisms of shugoshin which regulates cohesin, kinetochore-microtubule connections, and CIN.

Introducing Polar Groups in Porous Aromatic Framework for Achieving High Capacity of Organic Molecules and Enhanced Self-Cleaning Applications.

Due to the frequent oil/organic solvent leakage, efficient oil/water separation has attracted extensive concern. However, conventional porous materials possess nonpolar building units, which reveal relatively weak affinity for polar organic molecules. Here, two different polarities of superhydrophobic porous aromatic frameworks (PAFs) were synthesized with respective orthoposition and paraposition C=O groups in the PAF linkers. The conjugated structure formed by a large number of alkynyl and benzene ring structures enabled porous and superhydrophobic quality of PAFs. After the successful preparation of the PAF solids, PAF powders were coated on polyester fabrics by a simple dip-coating method, which endowed the resulting polyester fabrics with superhydrophobicity, porosity, and excellent stability. Based on the unique structure, the oil/water separation efficiency of two superhydrophobic flexible fabrics was more than 90% for various organic solvents. Polar LNU-26 PAF showed better separation performance for the polar oils. This work takes the lead in adopting the polar groups as building units for the preparation of porous networks, which has great guiding significance for the construction of advanced oil/water separation materials.

Solvation Effect on the Improved Sodium Storage Performance of N-Heteropentacenequinone for Sodium-Ion Batteries.

The performance of electrode material is correlated with the choice of electrolyte, however, how the solvation has significant impact on electrochemical behavior is underdeveloped. Herein, N-heteropentacenequinone (TAPQ) is investigated to reveal the solvation effect on the performance of sodium-ion batteries in different electrolyte environment. TAPQ cycled in diglyme-based electrolyte exhibits superior electrochemical performance, but experiences a rapid capacity fading in carbonate-based electrolyte. The function of solvation effect is mainly embodied in two aspects: one is the stabilization of anion intermediate via the compatibility of electrode and electrolyte, the other is the interfacial electrochemical characteristics influenced by solvation sheath structure. By revealing the failure mechanism, this work presents an avenue for better understanding electrochemical behavior and enhancing performance from the angle of solvation effect.

A Low-Cost Micro-Volume Nephelometric System for Quantitative Immunoagglutination Assays.

Immunoassays have been widely used in scientific research and clinical diagnosis due to their versatile detection capability and high specificity. Immunoagglutination assays are kinds of immunoassay, which can simply and rapidly measure the concentration of analytes. In this work, we developed a low-cost micro-volume nephelometric system for quantitative immunoagglutination assays. We used off-the-shelf components to build the system, and the total cost of key components is only about 20 US dollars. The total detection volume in our system was as low as 3 µL, which could significantly reduce the reagent cost and required sample volume. We further evaluated the system performance via the immunoagglutination assay to measure the concentration of C-reactive protein, a plasma protein with levels rising in response to inflammation. The results demonstrated that our system could measure the concentration of analytes with relatively high sensitivity and precision within four minutes, and has high potential to be applied for clinical diagnostic tests.