ABSTRACT
Creating artificial enzymes by the genetic incorporation of noncanonical amino acids with catalytic side chains would expand the enzyme chemistries that have not been discovered in nature. Here, we report the design of an artificial enzyme that uses p-boronophenylalanine as the catalytic residue. The artificial enzyme catalyzes Michael-type Friedel-Crafts alkylation through covalent activation. The designer enzyme was further engineered to afford high yields with excellent enantioselectivities. We next developed a practical method for preparative-scale reactions by whole-cell catalysis. This enzymatic C-C bond formation reaction was combined with palladium-catalyzed dearomative arylation to achieve the efficient synthesis of spiroindolenine compounds.
ABSTRACT
Oxidative stress is involved in the pathological processes of many neurodegenerative diseases. Protein modification by small ubiquitin-like modifiers (SUMOs) has been implicated in oxidative stress injury. By conjugating SUMOs to their selective protein substrates, SUMO ligases play critical roles in regulating functions of proteins involved in oxidative stress injury. In this study, we screened siRNAs to knockdown the SUMO ligase PIAS3 to assess its role in H2O2-induced injury in HT22 cells. H2O2 stimulation increased total protein SUMOylation, facilitated intracellular reactive oxygen species (ROS) release, increased cleaved caspase-3 levels, promoted p38 and JNK activation (phosphorylation), upregulated apoptosis, and decreased cell viability. The siRNA against PIAS3 329-347 (siPIAS3-329) markedly downregulated the protein expression of PIAS3 and reversed these effects, whereas siNC (negative control) had no effect. Our findings demonstrate that PIAS3-mediated SUMOylation facilitates oxidative stress injury and p38/JNK-mediated cell apoptosis and that PIAS3 is a potential target to protect against oxidative stress injury.
Subject(s)
Apoptosis , Hydrogen Peroxide , Oxidative Stress , Protein Inhibitors of Activated STAT , Sumoylation , p38 Mitogen-Activated Protein Kinases , Hydrogen Peroxide/toxicity , Hydrogen Peroxide/pharmacology , Oxidative Stress/drug effects , Protein Inhibitors of Activated STAT/metabolism , Protein Inhibitors of Activated STAT/genetics , Animals , Mice , Apoptosis/drug effects , p38 Mitogen-Activated Protein Kinases/metabolism , Cell Line , RNA, Small Interfering/metabolism , Caspase 3/metabolism , Cell Survival/drug effects , Gene Knockdown Techniques , RNA Interference , Reactive Oxygen Species/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , Molecular Chaperones/metabolismABSTRACT
Several generations of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors have been developed for the treatment of non-small cell lung cancer (NSCLC) in clinic. However, emerging drug resistance mediated by new EGFR mutations or activations by pass, leads to malignant progression of NSCLC. Proteolysis targeting chimeras (PROTACs) have been utilized to overcome the drug resistance acquired by mutant EGFR, newly potent and selective degraders are still need to be developed for clinical applications. Herein, we developed autophagosome-tethering compounds (ATTECs) in which EGFR can be anchored to microtubule-associated protein-1 light chain-3B (LC3B) on the autophagosome with the assistance of the LC3 ligand GW5074. A series of EGFR-ATTECs have been designed and synthesized. Biological evaluations showed that these compounds could degrade EGFR and exhibited moderate inhibitory effects on certain NSCLC cell lines. The ATTEC 12c potently induced the degradation of EGFR with a DC50 value of 0.98 µM and a Dmax value of 81% in HCC827 cells. Mechanistic exploration revealed that the lysosomal pathway was mainly involved in this degradation. Compound 12c also exhibited promising inhibitory activity, as well as degradation efficiency in vivo. Our study highlights that EGFR-ATTECs could be developed as a new expandable EGFR degradation tool and also reveals a novel potential therapeutic strategy to prevent drug resistance acquired EGFR mutations.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , Cell Proliferation , Autophagosomes/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Cell Line, Tumor , ErbB Receptors , Mutation , Drug Resistance, NeoplasmABSTRACT
The acquisition of nutrients from host plants by phytopathogenic fungi is critically important for their invasion success. Melampsora larici-populina, an obligate biotrophic pathogenic fungus, causes the poplar leaf rust disease and can severely damage host poplar plants. Previously, we found that oligopeptide transporters (OPTs) have undergone a convergent expansion, which might reflect adaptation to a phytoparasitic lifestyle. Here, we used various methods to evaluate this hypothesis, including conserved motif identification, positive selection signal mining, expression pattern clustering analysis, and neutral selection tests. The motif composition of the five clades in the OPT family differed, and positive selection was observed during clade differentiation. This suggests that OPTs in these five clades may be functionally differentiated, which would increase the range of transported substrates and promote the absorption of more types of nitrogen compounds from the hosts. According to clustering analysis of gene expression patterns, the expression of most genes from the two expanded clades (clade 2 and 4) was up-regulated during the infection of poplar trees, indicating that the expansion of OPTs likely occurred to promote the uptake of oligopeptides from host poplar plants. The MellpOPT4g gene was determined to be under significant balancing selection based on the neutral selection tests, suggesting that it plays a role in the pathogenic process. In conclusion, these three observations provide preliminary evidence supporting our hypothesis, as they indicate that the expansion of OPTs in M. larici-populina has aided the ability of this pathogen to acquire nutrients from host plants.
Subject(s)
Basidiomycota , Fungal Proteins , Oligopeptides , Plant Diseases , Populus , Populus/genetics , Populus/parasitology , Populus/microbiology , Oligopeptides/metabolism , Oligopeptides/genetics , Basidiomycota/genetics , Basidiomycota/pathogenicity , Basidiomycota/metabolism , Plant Diseases/parasitology , Plant Diseases/microbiology , Plant Diseases/genetics , Fungal Proteins/genetics , Fungal Proteins/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Phylogeny , Adaptation, Physiological/genetics , Gene Expression Regulation, Fungal , Selection, GeneticABSTRACT
Incorporating enzymatic reactions into natural product synthesis can significantly improve synthetic efficiency and selectivity. In contrast to the increasing applications of biocatalytic functional-group interconversions, the use of enzymatic C-C bond formation reactions in natural product synthesis is underexplored. Herein, we report a concise and efficient approach for the synthesis of [7.7]paracyclophane natural products, a family of polyketides with diverse biological activities. By using enzymatic Friedel-Crafts alkylation, cylindrocyclophanes A and F and merocyclophanes A and D were synthesized in six to eight steps in the longest linear sequence. This study demonstrates the power of combining enzymatic reactions with contemporary synthetic methodologies and provides opportunities for the structure-activity relationship studies of [7.7]paracyclophane natural products.
Subject(s)
Biological Products , Polyketides , Biocatalysis , Alkylation , Biological Products/chemistryABSTRACT
As an absolute quantification method at the single-molecule level, digital PCR (dPCR) offers the highest accuracy. In this work, we developed a 3D scalable chamber-array chip that multiplied the number of partitions by stacking chamber-array layers and realized digital loop-mediated isothermal amplification to quantify DNA molecules. It greatly increases the number of partitions to improve the performance of dPCR without increasing the chip size, the operation workflow complicity, and operation time. For the three-chamber-array-layer chip which contains 200,000 reactors of a 0.125 nL volume, it has been proved that the reagent filling and partition were finished within 3 min, and the whole detection could be finished within 1 h. The method demonstrated that it could be scalable to a six-chamber-array layer, which contains 400,000 reactors without increasing the size of the chip and the complication of filling/partition workflow but only takes an additional hour for scanning. Due to its potential for high throughput, low cost, and simple operation, our device may significantly expand the clinical application range of dPCR.
Subject(s)
DNA , Nucleic Acid Amplification Techniques , Polymerase Chain Reaction , Nucleic Acid Amplification Techniques/methods , DNA/genetics , Nanotechnology , Oligonucleotide Array Sequence AnalysisABSTRACT
The enantioselective conjugate addition of malonates to α,ß-unsaturated aldehydes catalysed by 4-oxalocrotonate tautomerase is described. High conversions, high enantioselectivities, and good isolation yields were achieved for a range of substrates. We further completed a four-step synthesis of the antidepressant (+)-femoxetine by utilizing this reaction and an enzymatic reductive amination reaction.
Subject(s)
Aldehydes , Malonates , Stereoisomerism , Isomerases , CatalysisABSTRACT
Cells constantly respond to environmental changes by modulating gene expression programs. These responses may demand substantial costs and, thus, affect cell growth. Understanding the regulation of these processes represents a key question in biology and biotechnology. Here, we studied the responses to osmotic stress in glucose-limited environments. By analyzing seventeen osmotic stress-induced genes and stress-activated protein kinase Hog1, we found that cells exhibited stronger osmotic gene expression response and larger integral of Hog1 nuclear localization during adaptation to osmotic stress under glucose-limited conditions than under glucose-rich conditions. We proposed and verified that in glucose-limited environment, glycolysis intermediates (representing "reserve flux") were limited, which required cells to express more glycerol-production enzymes for stress adaptation. Consequently, the regulatory mechanism of osmoresponse was derived in the presence and absence of such reserve flux. Further experiments suggested that this reserve flux-dependent stress-defense strategy may be a general principle under nutrient-limited environments.
ABSTRACT
Dissolved organic matter (DOM) is distributed ubiquitously in water bodies. Ferric ions can flocculate DOM to form stable coprecipitates; however, Al(III) may alter the structures and stability of Fe-DOM coprecipitates. This study aimed to examine the coprecipitation of Fe, Al, and DOM as well as structural developments of Fe-DOM coprecipitates in relation to changes in Fe/Al ratios and pHs. The results showed that the derived Fe/Al/DOM-coprecipitates could be classified into three categories: (1) at pH 3.0 and 4.5, the corner-sharing FeO6 octahedra associated with Fe-C bonds with Fe/(Fe + Al) ratios ≥0.5; (2) the Fe-C bonds along with single Fe octahedra having Fe/(Fe + Al) ratios of 0.25; (3) at pH 6.0, the ferrihydrite-like Fe domains associated with Fe-C bonds with Fe/(Fe + Al) ratios ≥0.5. At pH 3.0, the Fe and C stability of the coprecipitates increased with increasing Al proportions; nonetheless, pure Al-DOM coprecipitates were unstable even if they exhibited the maximum ability for DOM removal. The associations of Al-DOM complexes and/or DOM-adsorbed Al domains with external surfaces of Fe domain or Fe-DOM coprecipitates may stabilize DOM, leading to lower C solubilization at pH 4.5. Although the preferential formation of Fe/Al hydroxides decreased Fe/Al solubilization at pH 6.0, adsorption instead of coprecipitation of DOM with Fe/Al hydroxides may decrease C stabilization in the coprecipitates. Aluminum cations inhibit DOM releases from Fe/Al/DOM-coprecipitates, promoting the treatment and reuse efficiencies of wastewater and resolving water shortages. This study demonstrates that Al and solution pH greatly affect the structural changes of Fe-DOM coprecipitates and indirectly control the dynamics of Fe, Al, and C concentrations in water.
Subject(s)
Dissolved Organic Matter , Salts , Ferric Compounds/chemistry , Hydroxides/chemistry , Iron/chemistry , Water , Aluminum Compounds/chemistryABSTRACT
BACKGROUND: Unintentional injuries to children are a major public health problem. The online social media is a potential way to implement health education for caregivers in online communities. Using WeChat, a free and popular social media service in China, this study evaluated the effectiveness of social online community-based parental health education in preventing unintentional injuries in children aged 0-3. METHODS: We recruited 365 parents from two community health centers in Shanghai and allocated them into intervention and control groups randomly. Follow-up lasted for one year. The intervention group received and followed their WeChat group and a WeChat official account for dissemination of reliable medical information. The control group received only the WeChat group. RESULTS: Between the intervention and control groups, changes in unintentional injuries (OR = 1.71, 95% CI: 1.02-2.87, P = .04), preventability (ß = 0.344, 95% CI: 0.152-0.537, P < .001), daily supervision behavior (ß = 0.503, 95% CI: 0.036-0.970, P = .04), and behaviors for preventing specific injuries (ß = 2.198, 95% CI: 1.530-2.865, P < .001) were significantly different, and change in first-aid skills for treating a tracheal foreign body were nearly significant (P = .06). CONCLUSIONS: The WeChat-group-based parental health education can reduce the occurrence of unintentional child injuries by improving parents' skills, beliefs, and behaviors. Online social communities promote health education and reduce unintentional injuries among children. TRIAL REGISTRATION: ChiCTR1900020753. Registered on January 17, 2019.
Subject(s)
Health Education , Health Promotion , Child , Humans , China , Caregivers , ParentsABSTRACT
Escherichia coli is a common chassis for synthetic gene circuit studies. In addition to the dose-response of synthetic gene circuits, the analysis of dynamic responses is also an important part of the future design of more complicated synthetic systems. Recently, microfluidic-based methods have been widely used for the analysis of gene expression dynamics. Here, we established a two-layered microfluidic platform for the systematic characterization of synthetic gene circuits (eight strains in eight different culture environments could be observed simultaneously with a 5 min time resolution). With this platform, both dose responses and dynamic responses with a high temporal resolution could be easily derived for further analysis. A controlled environment ensures the stability of the bacterial growth rate, excluding changes in gene expression dynamics caused by changes of the growth dilution rate. The precise environmental switch and automatic micrograph shooting ensured that there was nearly no time lag between the inducer addition and the data recording. We studied four four-node incoherent-feedforward-loop (IFFL) networks with different operators using this device. The experimental results showed that as the effect of inhibition increased, two of the IFFL networks generated pulselike dynamic gene expressions in the range of the inducer concentrations, which was different from the dynamics of the two other circuits with only a simple pattern of rising to the platform. Through fitting the dose-response curves and the dynamic response curves, corresponding parameters were derived and introduced to a simple model that could qualitatively explain the generation of pulse dynamics.
Subject(s)
Escherichia coli Proteins , Escherichia coli , Escherichia coli/genetics , Escherichia coli/metabolism , Genes, Synthetic , Gene Regulatory Networks/genetics , Escherichia coli Proteins/genetics , Lab-On-A-Chip DevicesABSTRACT
Miniature energy storage devices simultaneously combining high energy output and bioavailability could greatly promote the practicability of green, safe, and nontoxic in vivo detection, such as for noninvasive monitoring or treatment in the gastrointestinal tract, which is still challenging. Herein, we report ingestible and nutritive zinc-ion-based hybrid micro-supercapacitors (ZMSCs) consisting of an edible active carbon microcathode and zinc microanode, which can be inserted into a standard-sized capsule and ingested in a pig stomach. With features including flexibility, light weight, and shape adaptability, a single microdevice displays a high energy density of 215.1 µWh cm-2, superior to that of state-of-the-art biocompatible SCs/MSCs and even traditional ZMSCs reported previously. It also delivers an areal capacitance of 605 mF cm-2 and a high working voltage of 1.8 V, exceeding that of miniaturized commercial button batteries (1.55 V, RENATA 337). Comprehensive studies in vivo and in vitro demonstrate that the ZMSCs with high biocompatibility and safety not only power electronic equipment in the porcine stomach without a voltage booster but also act as a nutritional supplement of trace element zinc within the dose range, as well as the ability of potent antibacterial activity against bacterium Escherichia coli during the discharging process. This work provides an example for the design and fabrication of edible energy storage devices with high performance.
Subject(s)
Trace Elements , Zinc , Animals , Anti-Bacterial Agents , Carbon , Stomach , SwineABSTRACT
OBJECTIVES: This study aimed to conduct a systematic review of cost-utility studies of internet-based and face-to-face cognitive behavioral therapy (CBT) for depression from childhood to adulthood and to examine their reporting and methodological quality. METHODS: A structured search for cost-utility studies concerning CBT for depression was performed in 7 comprehensive databases from their inception to July 2020. Two reviewers independently screened the literature, abstracted data, and assessed quality using the Consolidated Health Economic Evaluation Reporting Standards and Quality of Health Economic Studies checklists. The primary outcome was the incremental cost-effectiveness ratio (ICER) across all studies. To make a relevant comparison of the ICERs across the identified studies, cost data were inflated to the year 2020 and converted into US dollars. RESULTS: Thirty-eight studies were included in this review, of which 26 studies (68%) were deemed of high methodological quality and 12 studies (32%) of fair quality. Despite differences in study designs and settings, the conclusions of most included studies for adult depression were general agreement; they showed that face-to-face CBT monotherapy or combination therapy compared with antidepressants and usual care for adult depression were cost-effective from the societal, health system, or payer perspective (ICER -$241 212.4/quality-adjusted life-year [QALY] to $33 032.47/QALY, time horizon 12-60 months). Internet-based CBT regardless of guided or unguided also has a significant cost-effectiveness advantage (ICER -$37 717.52/QALY to $73 841.34/QALY, time horizon 3-36 months). In addition, CBT was cost-effective in preventing depression (ICER -$23 932.07/QALY to $26 092.02/QALY, time horizon 9-60 months). Nevertheless, the evidence for the cost-effectiveness of CBT for children and adolescents was still ambiguous. CONCLUSIONS: Fair or high-quality evidence showed that CBT monotherapy or combination therapy for adult depression was cost-effective; whether CBT-related therapy was cost-effective for children and adolescents depression remains inconclusive.
Subject(s)
Cognitive Behavioral Therapy , Depression , Adolescent , Adult , Child , Cost-Benefit Analysis , Depression/therapy , Humans , Quality-Adjusted Life Years , Young AdultABSTRACT
Introduction: Unintentional injury among children represents a major public health problem. Online-social-network-based parental-health-education is a potential way to reduce child unintentional injuries. The study aimed to explore the mechanisms by which online-social-network-based health education may reduce the unintentional injuries among children aged 0-3 years. Methods: We conducted a participant-blinded, randomized controlled, online-social-network-based health-education intervention study from March 2019 to February 2020 in Shanghai. We established four WeChat groups (two intervention groups and two control groups). For the intervention groups, a doctor's assistant regularly delivered information regarding unintentional injuries among children, and community childcare doctors answered parents' questions concerning their children's health, including unintentional injuries. Meanwhile, the control groups did not receive any information from the assistant. The study selected one intervention group and one control group and compared the ego network and whole network indicators to determine the differences between the intervention and control groups. Results: In the intervention and control groups, 64.5% and 31.9% of the members, respectively, engaged in communication, and 1,736 and 273 records, respectively, were obtained. Regarding ego network, the doctor showed the largest network in the intervention group, and the size of the intervention group's network was twice that of the control group; the number of ties in the intervention group was nine times that of the control group. Fourteen and four parents in the intervention and control group played an active role, respectively. Regarding centrality, all WeChat groups were loose and multiple centers existed. Regarding subgroup cohesion, the intervention group had 28 cliques with 27 members, and the control group had 4 cliques with 4 members. For structural hole, 23.7% and 7.5% members in the intervention and control group actively participated in interactions, respectively, having strong control and influence over other parents; 69.2% and 59.1% members in the intervention and control group, respectively, had values of < 1.000, showing that they had strong ability to cross-jump structural holes. Discussion: Online-social-networks-based health education interventions could enhance communication among parents, and between parents and community childcare doctors, and also shorten the social distance between them. Thus, online-social-network-based parental-health-education-intervention can be a feasible and generalizable means of preventing unintentional injuries among children.
Subject(s)
Parents , Social Network Analysis , Humans , Child , China , Health Education , Social NetworkingABSTRACT
Gallium (Ga) is widely used in high-tech industries and is an emerging contaminant in the environment. This study aimed to determine Ga speciation in soils and Ga accumulation in rice plants (Oryza sativa L.) grown in three Ga-contaminated soils. The results showed that, among the soils, the acidic soil with a coarse texture had the highest soil Ga availability, which enhanced Ga uptake by rice roots. The Ga K-edge X-ray absorption near edge structure and sequential extraction results of the soils showed that the predominant species of Ga associated with iron hydroxides transformed to Ga(OH)3 precipitates, and the residue fraction increased with rice-growing time, resulting in lower Ga uptake by rice roots in the second half period of rice cultivation. A large fraction of Ga was accumulated in the rice roots, with only a small portion of Ga was transferred to the shoots and then to the rice grains. This study revealed that Ga speciation in soil-rice plant systems varied during rice cultivation and determined soil Ga availability to rice plants. Gallium accumulated in rice grains is distributed homogenously in the endosperm of the grains, suggesting a potential risk to public health via the intake of rice grains harvested from Ga-contaminated paddy fields.
Subject(s)
Gallium , Oryza , Soil Pollutants , Cadmium/analysis , Environmental Pollution , Plant Roots/chemistry , Soil , Soil Pollutants/analysisABSTRACT
The causes and consequences of aging have always been a concern. In recent studies, changes in the stress response capacity of cells during aging were quantitatively analyzed. It was found that aging was accompanied by a decline in response capacity. When the response capacity decreased to a critical value, which we assumed was the internal noise level, the cell soon died. To survive, the response capacity should be, at minimum, sufficiently strong to resist intracellular noise. Here, we discuss the role of stress response capacity in aging and conjecture that lifespan might be extended by enhancing stress response capacity.
Subject(s)
Aging/genetics , DNA Replication/genetics , Longevity/genetics , Saccharomyces cerevisiae Proteins/genetics , Aging/pathology , Gene Expression Regulation, Fungal/genetics , Humans , Saccharomyces cerevisiae/genetics , Stress, Physiological/geneticsABSTRACT
Stereoselective syntheses of terpenoids in a more efficient manner have been a long-term pursuit for synthetic chemists. Herein we describe the two-step, enantiospecific and protecting-group-free synthesis of (+)-schisanwilsonene A from a carotane compound, which was produced in E. coli. We also completed the first enantiomeric synthesis of (+)-tormesol in five steps. The two-stage strategy offers a step- and redox-economical approach to prepare terpene natural products and their analogues.
ABSTRACT
Subsurface storm flow of phosphorus (P), including particulate P, has been recently discussed as an important P transport path in contrast to typical surface runoff events. However, P speciation, and P concentration during storm events has not been extensively investigated; therefore, its contribution to the water quality is not clearly understood. In this study, the physicochemical properties of particulate P in tile water samples during a high flow event were investigated in Midwestern agricultural lands using wet chemical methods, 31P Nuclear Magnetic Resonance spectroscopy and P K-edge X-ray absorptions near edge structure spectroscopy. In slightly alkaline pH tile water, total P was ranging from â¼0.06 to 0.22 mg L-1, which is significantly greater than dissolved reactive P (DRP) (â¼0.02-0.08 mg L-1). The tile water contains P enriched particulate matters (â¼200-660 mg L-1). Total P in the colloidal fraction was from 1013 to 2270 mg kg-1. Phosphate and organic P species, especially monoesters, are sorbed in soil colloids like calcite, and iron oxides, and colloids are effective carriers of P in the subsurface transport process during storm events. The results of this study show that storm events can accelerate the subsurface transport of P with soil particles in addition to DRP.