Structural basis of Streptomyces transcription activation by zinc uptake regulator.

Streptomyces coelicolor (Sc) is a model organism of actinobacteria to study morphological differentiation and production of bioactive metabolites. Sc zinc uptake regulator (Zur) affects both processes by controlling zinc homeostasis. It activates transcription by binding to palindromic Zur-box sequences upstream of -35 elements. Here we deciphered the molecular mechanism by which ScZur interacts with promoter DNA and Sc RNA polymerase (RNAP) by cryo-EM structures and biochemical assays. The ScZur-DNA structures reveal a sequential and cooperative binding of three ScZur dimers surrounding a Zur-box spaced 8 nt upstream from a -35 element. The ScRNAPσHrdB-Zur-DNA structures define protein-protein and protein-DNA interactions involved in the principal housekeeping σHrdB-dependent transcription initiation from a noncanonical promoter with a -10 element lacking the critical adenine residue at position -11 and a TTGCCC -35 element deviating from the canonical TTGACA motif. ScZur interacts with the C-terminal domain of ScRNAP α subunit (αCTD) in a complex structure trapped in an active conformation. Key ScZur-αCTD interfacial residues accounting for ScZur-dependent transcription activation were confirmed by mutational studies. Together, our structural and biochemical results provide a comprehensive model for transcription activation of Zur family regulators.

Supervised Offseason Training Programs are able to mitigate the Effects of Detraining in Youth Men Soccer Players Physical Fitness: A Randomized Parallel Controlled Study.

This study aimed to analyze the effects of three off-season training programs on the aerobic capacity, countermovement jump (CMJ), and linear sprint performance of young male soccer players. The study employed a randomized multi-arm design, consisting of three experimental groups: i) a high-intensity interval training (HIIT) group; (ii) a plyometric jump training (PJT) group; and (iii) a HIIT+PJT group; and an inactive control group. Fifty-eight under-19 male soccer players (aged 17.6 ±0.6 years) were randomly assigned to participate in a 3-week offseason training program exclusively performing HIIT, PJT, or a combination of both, while the fourth group remained inactive. Players underwent assessments twice, using the Yo-Yo Intermittent Recovery Test - Level 1 (YYIRT), CMJ, and 30-meter linear sprint. Significant interactions between time and groups were found in CMJ (p<0.001), YYIRT (p<0.001), and 30-m sprint (p<0.001). Group*time interaction revealed that the control group was significantly different from HIIT (p<0.001), PJT (p<0.001), and HIIT+PJT (p<0.001) considering the CMJ. Moreover, the control group was significantly different from HIIT (p=0.037) in YYIRT. Finally, the control group was significantly different from HIIT (p=0.024), PJT (p<0.001), and HIIT+PJT (p=0.021) considering the 30-m sprint. In conclusion, off-season training programs are effective in significantly reducing declines in CMJ and sprint performance compared to maintaining training cessation. However, in the YYIRT, only HIIT seems to be significantly superior to maintaining inactivity. To mitigate aerobic performance declines, incorporating HIIT sessions twice weekly during the offseason is advisable. To enhance or maintain jump performance, integrating at least one session of PJT weekly is beneficial.

Microdosing Plyometric Training Enhances Jumping Performance, Reactive Strength Index, and Acceleration among Youth Soccer Players: A Randomized Controlled Study Design.

Microdosing can facilitate better accommodation to the training stimulus while aligning with the scheduling needs of teams. In this study, the effectiveness of microdosing exposure was investigated by comparing the effects of microdosing plyometric jump training (microPJT) with those of regular plyometric jump training (regPJT) and a control group not exposed to plyometric training. The comparison focused on the effects on jumping performance, reactive strength index (RSI), and acceleration over a 10-meter distance. Fifty-two male youth soccer players (16.3 ± 0.6 years old) from under-17 teams participated in a randomized controlled study, with interventions lasting 8 weeks. Assessments were conducted twice, before and after the intervention, measuring squat jump (SJ), countermovement jump (CMJ), RSI during drop jumps, and acceleration in a 10-meter sprint test. The regPJT group completed 34 bilateral jumps and 48 unilateral jumps per week over two weekly sessions, totaling 82 jumps. Conversely, the microPJT group performed 17 bilateral jumps and 24 unilateral jumps weekly over 4 sessions week, totaling 41 jumps. Significant interactions between groups and time were observed concerning SJ (p < 0.001; η2= 0.282), CMJ (p < 0.001; η2= 0.368), RSI (p < 0.001; η2= 0.400) and 10-m sprint time (p < 0.001; η2 = 0.317). Between-group analysis indicated that both the microPJT (p < 0.001) and regPJT (p < 0.001) groups exhibited significant better results compared to the control group in post-intervention evaluation of SJ, CMJ, RSI and 10-m sprint time, while no significant differences were found between experimental groups (p > 0.050). In conclusion, this study has revealed that both microPJT and regPJT are equally effective in enhancing jumping performance and acceleration time in soccer players. This suggests that a smaller training volume, distributed more frequently across the week, can effectively induce improvements in soccer players.

Enhancing Cross-Lingual Entity Alignment in Knowledge Graphs through Structure Similarity Rearrangement.

Cross-lingual entity alignment in knowledge graphs is a crucial task in knowledge fusion. This task involves learning low-dimensional embeddings for nodes in different knowledge graphs and identifying equivalent entities across them by measuring the distances between their representation vectors. Existing alignment models use neural network modules and the nearest neighbors algorithm to find suitable entity pairs. However, these models often ignore the importance of local structural features of entities during the alignment stage, which may lead to reduced matching accuracy. Specifically, nodes that are poorly represented may not benefit from their surrounding context. In this article, we propose a novel alignment model called SSR, which leverages the node embedding algorithm in graphs to select candidate entities and then rearranges them by local structural similarity in the source and target knowledge graphs. Our approach improves the performance of existing approaches and is compatible with them. We demonstrate the effectiveness of our approach on the DBP15k dataset, showing that it outperforms existing methods while requiring less time.

Coupling Cobalt Phthalocyanine Molecules on 3D Nitrogen-Doped Vertical Graphene Arrays for Highly Efficient and Robust CO2 Electroreduction.

Metallic phthalocyanines (MePcs) have shown their potential as catalysts for CO2 reduction reactions (CO2 RR). However, their low conductivity, easy agglomeration, and poor stability enslave the further progress of their CO2 RR applications. Herein, an integrated heterogeneous molecular catalyst through anchoring CoPc molecules on 3D nitrogen-doped vertical graphene arrays (NVG) on carbon cloth (CC) is reported. The CoPc-NVG/CC electrodes exhibit superior performance for reducing CO2 to CO with a Faradic efficiency of above 97.5% over a wide potential range (99% at an optimal potential), a very high turnover frequency of 35800 h-1 , and decent stability. It is revealed that NVG interacts with CoPc to form highly efficient channels for electron transfer from NVG to CoPc, facilitating the Co(II)/Co(I) redox of CO2 reduction. The strong coupling effect between NVG and CoPc molecules not only endows CoPc with high intrinsic activity for CO2 RR, but also enhances the stability of electrocatalysts under high potentials. This work paves an efficient approach for developing high-performance heterogeneous catalysts by using rationally designed 3D integrated graphene arrays to host molecular metallic phthalocyanines so as to ameliorate their electronic structures and engineer stable active sites.

Effects of bifidobacteria-produced exopolysaccharides on human gut microbiota in vitro.

Exopolysaccharides (EPSs) are carbohydrate polymers that are synthesized and present on the surface of bifidobacteria. Due to their potential applications in diverse sectors, such as food, biotechnology, cosmetics, and medicine, EPSs synthesized by bifidobacteria have recently attracted more attention. EPS production not only has benefits in food and health but also has effects on probiotics in the microbial ecosystem. In this study, we investigated the interaction between bifidobacteria EPSs and human gut microbiota in vitro using thin-layer chromatography, 16S rDNA high-throughput sequencing, and gas chromatography. The results showed that human gut microbiota has the capacity to degrade EPSs, although the degradation rate was approximately 50% after fermenting for 48 h. On the other hand, EPSs regulate the human gut microbiota. Fermented samples in the VI_Bif group clustered together according to the bacterial community compared to the VI_Starch group, in which starch was added as a carbon source. The bifidobacteria EPS promoted the growth of phylum Deinococcus_Thermus, class Deinococci, order Deinococcales, and genus Coprococcus. EPSs also increased the production of propionic acid compared to the starch group. The detection results of Dionex ICS 5000 high-purity capillary ion chromatography system showed that EPSs had absorption peaks of fucose, rhamnose, galactose/acetyl glucosamine, glucose, and ribose, and the molecular proportion of these monosaccharides was approximately 2: 2: 440: 3: 53. The monosaccharide composition of this EPS appears to be more complex than previously reported for bifidobacteria EPS. Additional studies are needed to elucidate its structure and functions.

Tivantinib Hampers the Proliferation of Glioblastoma Cells via PI3K/Akt/Mammalian Target of Rapamycin (mTOR) Signaling.

BACKGROUND Glioblastoma, the most common and malignant glial tumor, often has poor prognosis. Tivantinib has shown its potential in treating c-Met-high carcinoma. No studies have explored whether tivantinib inhibits the development of glioblastoma. MATERIAL AND METHODS The correlation between c-Met expression and clinicopathological characteristics of glioblastoma was investigated. U251 and T98MG glioblastoma cells treated with tivantinib, PI3K inhibitor (LY294002), PI3K activator (740 Y-P), and/or mammalian target of rapamycin (mTOR) inhibitor were subjected to MTT assay or colony formation assay to evaluate cell proliferation. The expression of mTOR signaling and caspase-3 in tivantinib-treated glioblastoma cells was differentially measured by western blotting. RESULTS In a group of Chinese patients, expression of c-Met was elevated with the size of glioblastoma, but not with the other clinicopathological characteristics, including gender, age, grade, IDH status, 1p/19q status, and Ki67 status. High dose of tivantinib (1 µmol/L) obviously repressed the proliferation and colony formation of U251 and T98MG glioblastoma cells, but low dose (0.1 µmol/L) of tivantinib failed to retard cell proliferation. Tivantinib blocked PI3K/Akt/mTOR signaling but did not change the expression of cleaved caspase-3. PI3K activator 740 Y-P (20 µmol/L) significantly rescued tivantinib-induced decrease of cell proliferation. Tivantinib (1 µmol/L) in combination with PI3K inhibitor LY294002 (0.5 µmol/L) and mTOR inhibitor rapamycin (0.1 nmol/L) largely inhibited the proliferation of glioblastoma cells. CONCLUSIONS c-MET inhibitor tivantinib blocks PIKE/Akt/mTOR signaling and hampers the proliferation of glioblastoma cells, which endows the drug a therapeutic effect.

In vitro evaluation of the effects of various additives and polymers on nerve growth factor microspheres.

OBJECTIVE: To evaluate the effects of various additives or polymers on the in vitro characteristics of nerve growth factor (NGF) microspheres. MATERIALS AND METHODS: NGF microspheres were fabricated using polyethylene glycol (PEG), ovalbumin (OVA), bovine serum albumin (BSA) or glucose as protein protectors, and poly(lactide-co-glycolide) (PLGA) or poly(lactic acid) (PLA)/PLGA blends as encapsulation materials. RESULTS: Encapsulation efficiencies of the NGF microspheres with various additives or polymers were not more than 30%. A comparative study revealed that OVA was somewhat superior over others, and was thus chosen as the protective additive in subsequent experiments. Polymer analysis showed that NGF release from 1:1 PLA (η = 0.8):PLGA (75/25, η = 0.45) microspheres lasted for 90 d with a burst release rate of 12.7%. About 40% of the original bioactivity was retained on the 28th day, while 10% was left on the 90th day. DISCUSSION AND CONCLUSION: The combination of OVA as an additive and the PLA/PLGA blend as the coating matrix is suitable for encapsulation of NGF in microspheres for extended release.

Antheraea pernyi silk fibroin-coated PEI/DNA complexes for targeted gene delivery in HEK 293 and HCT 116 cells.

Polyethylenimine (PEI) has attracted much attention as a DNA condenser, but its toxicity and non-specific targeting limit its potential. To overcome these limitations, Antheraea pernyi silk fibroin (ASF), a natural protein rich in arginyl-glycyl-aspartic acid (RGD) peptides that contains negative surface charges in a neutral aqueous solution, was used to coat PEI/DNA complexes to form ASF/PEI/DNA ternary complexes. Coating these complexes with ASF caused fewer surface charges and greater size compared with the PEI/DNA complexes alone. In vitro transfection studies revealed that incorporation of ASF led to greater transfection efficiencies in both HEK (human embryonic kidney) 293 and HCT (human colorectal carcinoma) 116 cells, albeit with less electrostatic binding affinity for the cells. Moreover, the transfection efficiency in the HCT 116 cells was higher than that in the HEK 293 cells under the same conditions, which may be due to the target bonding affinity of the RGD peptides in ASF for integrins on the HCT 116 cell surface. This result indicated that the RGD binding affinity in ASF for integrins can enhance the specific targeting affinity to compensate for the reduction in electrostatic binding between ASF-coated PEI carriers and cells. Cell viability measurements showed higher cell viability after transfection of ASF/PEI/DNA ternary complexes than after transfection of PEI/DNA binary complexes alone. Lactate dehydrogenase (LDH) release studies further confirmed the improvement in the targeting effect of ASF/PEI/DNA ternary complexes to cells. These results suggest that ASF-coated PEI is a preferred transfection reagent and useful for improving both the transfection efficiency and cell viability of PEI-based nonviral vectors.

Can heat conditions affect the heart rate responses, perception of effort, and technical performance of young male football players during small-sided games? a comparative study.

BACKGROUND: Soccer coaches often employ small-sided games (SSGs) to elicit both physiological and technical responses from players. However, numerous contextual factors can influence the outcomes of these games. This comparative study aimed to investigate how environmental temperature (< 21ºC and > 29ºC) impacts heart rate responses, perception of effort, and technical performance in young male football players during SSGs. METHODS: This study compares temperatures below 21ºC (∼ 20.4 ± 0.4ºC) with temperatures above 29ºC (∼ 29.7 ± 0.6ºC). This repeated measures study design involved 60 male football players at a trained/developmental level, selected from under-16 and under-19 teams. It aimed to assess the effects of the 3v3 format, conducted repeatedly under conditions of 21ºC and above 29ºC. Throughout the games, mean heart rate responses (HRmean), measured via heart rate sensors; rate of perceived exertion (RPE), assessed using the CR-10 Borg scale; and successful passes and lost balls, tracked through an ad hoc observational analysis tool, were monitored. RESULTS: No significant interactions were observed (time*age group) in meanHR (F = 0.159; p = 0.691; [Formula: see text]=0.003), RPE (F=0.646; p=0.425; [Formula: see text]=0.011), number of passes completed (F=0.204; p=0.654; [Formula: see text]=0.003), and number of lost balls (F = 0.157; p = 0.694; [Formula: see text]=0.003). Overall, significantly higher heart rate responses in mean HR (p<0.001) and RPE (p<0.001) were observed at temperatures above 29ºC, while significantly more passes were completed at temperatures below 21ºC (p<0.001). CONCLUSIONS: Heat conditions significantly intensified the psychophysiological responses in players, concurrently leading to a significant impairment in the number of passes. Coaches should contemplate implementing mitigation strategies to avert performance declines during heat conditions when utilizing SSGs.