Transient Activation of Autophagy via Sox2-Mediated Suppression of mTOR Is an Important Early Step in Reprogramming to Pluripotency

SummaryAutophagy is an essential cellular mechanism that degrades cytoplasmic proteins and organelles to recycle their components. Here we show that autophagy is required for reprogramming of somatic cells to form induced pluripotent stem cells (iPSCs). Our data indicate that mammalian target of rapamycin (mTOR) is downregulated by Sox2 at an early stage of iPSC generation and that this transient downregulation of mTOR is required for reprogramming to take place. In the absence of Sox2, mTOR remains at a high level and inhibits autophagy. Mechanistically, Sox2 binds to a repressive region on the mTOR promoter and recruits the NuRD complex to mediate transcriptional repression. We also detected enhanced autophagy at the four- to eight-cell stage of embryonic development, and a similar Sox2 and mTOR-mediated regulatory pathway seems to operate in this context as well. Thus, our findings reveal Sox2-dependent temporal regulation of autophagy as a key step in cellular reprogramming processes

Stomatal responses of terrestrial plants to global change

Quantifying the stomatal responses of plants to global change factors is crucial for modeling terrestrial carbon and water cycles. Here we synthesize worldwide experimental data to show that stomatal conductance (gs) decreases with elevated carbon dioxide (CO2), warming, decreased precipitation, and tropospheric ozone pollution, but increases with increased precipitation and nitrogen (N) deposition. These responses vary with treatment magnitude, plant attributes (ambient gs, vegetation biomes, and plant functional types), and climate. All two-factor combinations (except warming + N deposition) significantly reduce gs, and their individual effects are commonly additive but tend to be antagonistic as the effect sizes increased. We further show that rising CO2 and warming would dominate the future change of plant gs across biomes. The results of our meta-analysis provide a foundation for understanding and predicting plant gs across biomes and guiding manipulative experiment designs in a real world where global change factors do not occur in isolation

Combustion Characteristics of Single Particles from Bituminous Coal and Pine Sawdust in O2/N2, O2/CO2, and O2/H2O Atmospheres

Burning fuels in an O2/H2O atmosphere is regarded as the next generation of oxy-fuel combustion for CO2 capture and storage (CCS). By combining oxy-fuel combustion and biomass utilization technology, CO2 emissions could be further reduced. Therefore, this work focuses on investigating the combustion characteristics of single particles from bituminous coal (BC) and pine sawdust (PS) in O2/N2, O2/CO2 and O2/H2O atmospheres at different O2 mole fractions (21%, 30%, and 40%). The experiments were carried out in a drop tube furnace (DTF), and a high-speed camera was used to record the combustion processes of fuel particles. The combustion temperatures were measured by a two-color method. The results reveal that the particles from BC and PS all ignite homogeneously. Replacing N2 by CO2 results in a longer ignition delay time and lower combustion temperatures. After substituting H2O for N2, the ignition delay time is shortened, which is mainly caused by the steam gasification reaction (C + H2O → CO + H2) and steam shift reaction (CO + H2O → CO2 + H2). In addition, the combustion temperatures are first decreased at low O2 mole fractions, and then increased at high O2 mole fractions because the oxidation effect of H2O performs a more important role than its volumetric heat capacity and thermal radiation capacity. At the same condition, particles from PS ignite earlier because of their higher reactivity, but the combustion temperatures are lower than those of BC, which is owing to their lower calorific values

Assessment of the carbon neutral capacity of ecological slopes: A case study of wet-spraying vegetation concrete ecological river revetment

This study evaluates the carbon neutrality of eco-slope protection projects to understand their role in climate change mitigation. Utilizing life cycle assessment, it defines system boundaries and compiles inventories to calculate and analyze carbon emissions and assimilations of a wet-spraying vegetation concrete eco-slope protection project in China, simplifying previous methodologies and emphasizing the critical role of vegetation. Findings indicate lifecycle carbon emissions total 608.01 tCO2e, broken down by source as follows: material (54.69%), maintenance (40.11%), energy (3.27%), transport (1.32%), and workforce (0.6%). Slope protection plants are estimated to assimilate 2,676.30 tCO2. The project is estimated to reach carbon neutrality in its 4.59th year, with an anticipated net carbon sink contribution of 2,068.29 tons over its lifespan. These results underscore eco-slope protection projects’ significant carbon neutral capacity, highlighting their importance in combating climate change and fostering the civil engineering industry's green transformation. HIGHLIGHTS People are getting more serious about global warming. The Paris Climate Agreement of 2015 sets targets to limit global temperature rise.; A large number of traditional slope protection projects have generated a significant amount of GHG emissions, and eco-slope protection methods have attracted widespread attention.; Wet-spraying vegetation concrete eco-slope protection produces 608.01 tCO2e over its lifecycle.; Slope protection vegetations absorb 2,676.30 tCO2 over their lifecycle.

An inducible circular RNA circKcnt2 inhibits ILC3 activation to facilitate colitis resolution

Type 3 innate lymphoid cells (ILC3) are involved in maintaining gut immune homeostasis. Here the authors identify a circular RNA, circKcnt2, to be induced in ILC3s from inflamed gut, yet circKcnt2 deletion aggravates mouse experimental colitis, thereby implicating circKcnt2 as a potential feedback regulator of ILC3 activation and gut immunity

Binding Affinity of Optimized Antibodies to SARS-CoV-2 Variants Spike.

Immobilized WT-RBD, Beta-RBD or Delta-S1 association (t = 0 to 180 s) and dissociation (t > 180 s) with REGN10987 (A) and optimized antibodies d7 (B), d9 (C), A3 (D) measured by surface plasmon resonance (SPR). (TIF)</p

Verification of Mutant scFvs using HEK 293T Antibody Surface Display System.

(A) Verification of single amino acid substitution REGN10987 scFv to WT-RBD and Beta-RBD using HEK 293T antibody surface display system (left). Data were normalized by REGN10987 scFv RBD binding fluorescence. Data are mean ± SEM, n = 2 replicates. Unpaired t test was used to analyze differences between groups. * p (B) Verification of single amino acid substitution REGN10987 scFv to WT-RBD and Delta-S1 using HEK 293T antibody surface display system (lower). Data were normalized by REGN10987 scFv RBD binding fluorescence. Data are mean ± SEM, n = 2 replicates. Unpaired t test was used to analyze differences between groups. * p (C) Binding of combined amino acid substitution REGN10987 scFv to WT-RBD (left) and Beta-RBD (right) using HEK 293T antibody surface display system. Data were normalized by REGN10987 scFv RBD binding fluorescence. Data are mean ± SEM, n = 2 replicates. Unpaired t test was used to analyze differences between groups. * p (D) Binding of combined amino acid substitution REGN10987 scFv to WT-RBD (left) and Delta-S1 (right) using HEK 293T antibody surface display system. Data were normalized by REGN10987 scFv RBD binding fluorescence. Data are mean ± SEM, n = 2 replicates. Unpaired t test was used to analyze differences between groups. *** p < 0.001.</p

Construction of an Antibody Surface Display System in HEK 293T.

(A) Schematic diagram of antibody scFv surface display system on mammalian cells. The VL and VH domain of scFv receptor construct used in anti-CD19 CAR was replaced with a SARS-CoV-2 neutralizing antibody REGN10987. VH, variable region of Ig heavy-chain; VL, variable region of Ig light-chain. (B) Confocal microscopic images of REGN10987 scFv displayed on HEK 293T cells. HEK 293T cells were infected by lentivirus packaged with a plasmid directing surface-expression of REGN10987 scFv. Infected cells (red) were fixed with DAPI nuclear staining followed by detection with biotinylated RBD, and then with streptavidin-FITC (green). Merged staining patterns are shown. Scale bar: 20 μm. (C) RBD bound to REGN10987 scFv-expressing HEK 293T cells at different titers. Concentration of RBD was from 0 nM to 1,000 nM. RBD-FITC signal was measured by flow cytometry. (D) Confocal microscopic images of mutated REGN10987 scFv displaying on HEK 293T cells. Several key amino acids in CDRs were mutated into alanine. Mutated amino acid was showed in S1B Fig. Transfected cells (red) were fixed with DAPI nuclear staining followed by detection with biotinylated RBD, and then with streptavidin-FITC (green). Scale bar: 100 μm. (E) RBD-His added to RBD-FITC competitively bound to REGN10987 scFv-expressing HEK 293T cells. Concentration of RBD-FITC was 10 nM, while different titers of RBD-His was from 0 nM to 10,000 nM. RBD-FITC signal was measured by flow cytometry.</p