Reusable carboxylesterase immobilized in ZIF for efficient degradation of chlorpyrifos in enviromental water.

The past few decades have witnessed biodegradation of pesticides as a significant method in remediation of the environment for its specificity, efficiency and biocompatibility. However, the tolerability and recyclability of the enzymes in pesticide degradation and the development of enzymes that biodegrad pesticides are still urgent problems to be solved so far. Herein, a novel hyper-thermostable and chlorpyrifos-hydrolyzing carboxylesterase EstC was immobilized by biomineralization using zeolitic imidazolate framework (ZIF), one of the metal-organic frameworks (MOFs) with highly diverse structure and porosity. Compared with free enzyme, EstC@ZIF with a cruciate flower-like morphology presented scarcely variation in catalytic efficiency and generally improved the tolerance to organic solvents or detergents. Furthermore, there was scarcely decrease in the catalytic efficiency of EstC@ZIF and it also showed good reusability with about 50% residual activity after 12 continuous uses. Notably, EstC@ZIF could be used in actual water environment with an excellent value of degradation rate of 90.27% in 120 min, and the degradation efficiency remained about 50% after 9 repetitions. The present strategy of immobilizing carboxylesterase to treat pesticide-contaminated water broadens the method of immobilized enzymes on MOFs, and envisions its recyclable applicability in globe environmental remediation.

m5C regulator-mediated methylation modification phenotypes characterized by distinct tumor microenvironment immune heterogenicity in colorectal cancer.

The RNA 5-methylcytosine (m5C) modification has been demonstrated to be an important epigenetic regulator and to impact colorectal cancer (CRC) progression. However, the potential roles of m5C modification in immune cell infiltration in the CRC tumor microenvironment (TME) remain unknown. The m5C modification phenotypes were comprehensively evaluated based on 14 m5C regulators in a meta-CRC cohort of 1792 patients and systematically correlated with the m5C modification phenotypes, immune cell infiltration characteristics and known biological processes. The m5Cscore model was constructed by principal component analysis (PCA) algorithms to quantify the m5C modification phenotypes of individual CRC samples and was used to predict the immunotherapy response. We identified three m5C modification phenotypes associated with distinct clinical outcomes and biological processes among the 1792 meta-CRC patients. Three phenotypes with a highly consistent TME landscape and characteristics were revealed: immune excluded, immune desert and immune inflammation. The meta-CRC patients were divided into high and low m5Cscore subgroups based on the m5Cscore. The m5Cscore was confirmed to have a negative correlation with infiltrating immune cells and PD-L1 expression and a positive correlation with tumor mutation burden (TMB), mutation rate and microsatellite instability (MSI) score. Moreover, patients in the low m5Cscore group had better immunotherapy responses and significant durable survival benefits in independent anti-PD-1/L1 immunotherapy cohorts for the immune checkpoint inhibitor (ICI) therapeutic strategy. This study revealed that m5C modification plays a crucial role in TME composition and complexity. Comprehensive evaluation of the m5C modification phenotypes of individual patients will enhance our understanding of TME characteristics and promote the application of more appropriate and personalized treatment strategies.

Oxidative response and antioxidative mechanism in germinating soybean seeds exposed to cadmium.

Seeds of soybean (Glycinemax L.) exposed to 50 mg/L (Cd50), 100 mg/L (Cd100) and 200 mg/L (Cd200) cadmium solution for 24, 48, 72 and 96 h were examined with reference to Cd accumulation, oxidative stress and antioxidative responses. Soybean seeds accumulated Cd in an exposure time-and dosage-dependent manner. FRAP (ferric reducing ability of plasma) concentration, GSH/hGSH content, and GST activity showed a pronounced exposure time-dependent response. Cd100 enhanced FRAP concentration in germinating soybean seeds as compared to Cd50 treatment after 24 h exposure. Cd200 however increased statistically GST activities after 72 and 96 h exposure. Under all Cd dosages, GSH/hGSH concentrations were depressed with increasing exposure time. Reduction of GSH/hGSH content and concomitant increase of GST activity suggested a possible participation of GSH into GSH-Cd conjugates synthesis. MDA content is a potential biomarker for monitoring Cd phytotoxicity because it responds significantly to treatment dosage, exposure time and dosage × exposure time interaction. Increase of proline content may be a response to acute heavy metal toxicity in soybean seeds.