The mechanism by which piR-000699 targets SLC39A14 regulates ferroptosis in aging myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (I/R) injury is a classic type of cardiovascular disease characterized by injury to cardiomyocytes leading to different types of cell death. The degree of irreversible myocardial damage is closely related to age, and ferroptosis is involved in cardiomyocyte damage. However, the mechanisms underlying ferroptosis regulation in aging myocardial I/R injury are still unclear. The present study aims to explore the underlying mechanism of piRNA regulation in ferroptosis. Using left anterior descending coronary artery ligation in an aging rat model and a D-galactose-induced rat cardiomyocyte line (H9C2) to construct an aging cardiomyocyte model, we investigate whether ferroptosis occurs after reperfusion injury in vitro and in vivo. This study focuses on the upregulation of piR-000699 after hypoxia/reoxygenation treatment in aging cardiomyocytes by observing hypoxia/reoxygenation (H/R) injury indicators and ferroptosis-related indicators and clarifying the role of piR-000699 in H/R injury caused by ferroptosis in aging cardiomyocytes. Bioinformatics analysis reveals that SLC39A14 is a gene that binds to piR-000699. Our data show that ferroptosis plays an important role in I/R injury both in vivo and in vitro. Furthermore, the results show the potential role of piR-000699 in regulating SLC39A14 in ferroptosis in aging cardiomyocytes under hypoxia/reoxygenation conditions. Together, our results reveal that the mechanism by which piR-000699 binds to SLC39A14 regulates ferroptosis in aging myocardial I/R injury.

Ecotoxicological effects of co-exposure biodegradable microplastics polylactic acid with cadmium are higher than conventional microplastics polystyrene with cadmium on the earthworm.

Microplastics (MPs) are plastic fragments with particle sizes <5 mm, ubiquitously distributed in terrestrial environments. However, the negative effects of MPs, such as joint-pollution with heavy metals on soil fauna remain controversial. This study investigated survival rate, growth, reproduction, avoidance behavior, histology, biochemical assays, comet assay, qPCR, Cd content, and IBR index. We found that six types of traditional MPs (PC, PP, PVC, LDPE, PET and PS, and PLA (a biodegradable microplastics)) had no adverse effects on earthworm growth, survival and reproduction. Moreover, we found that earthworms exhibit an avoidance behavior towards PLA. Both PS and PLA can exacerbated Cd pollution, leading to loose circular muscle layer, DNA damage in coelomocytes, and impaired antioxidant system due to increased reactive oxygen species (ROS). mRNA level of HSP70 increased under joint-pollution of both PS and Cd or PLA and Cd compared to Cd treatment alone. MPs enhanced Cd accumulation in earthworms in Cd-contaminated soil. Notably, the Integrated Biomarkers Response index revealed that the toxicity of joint PLA and Cd was greater than the joint effect of PS and Cd, which might violate the original intention of biodegradable plastics having non-toxic influence on the soil fauna. Our findings provide new insights into the ecotoxicological effects of MPs, the joint ecotoxicological effects of MPs and Cd on earthworms, and the ecological risks of MPs to soil fauna.

Effects of soybean oil exposure on the survival, reproduction, biochemical responses, and gut microbiome of the earthworm Eisenia fetida.

With increasing production of kitchen waste, cooking oil gradually enters the soil, where it can negatively affect soil fauna. In this study, we explored the effects of soybean oil on the survival, growth, reproduction, tissue structure, biochemical responses, mRNA expression, and gut microbiome of earthworms (Eisenia fetida). The median lethal concentration of soybean oil was found to be 15.59%. Earthworm growth and reproduction were significantly inhibited following exposure to a sublethal concentration of soybean oil (1/3 LC50, 5.2%). The activity of the antioxidant enzymes total superoxide dismutase (T-SOD), peroxidase (POD), and catalase (CAT) were affected under soybean oil exposure. The glutathione (GSH) content decreased significantly, whereas that of the lipid peroxide malondialdehyde (MDA) increased significantly after soybean oil exposure. mRNA expression levels of the SOD, metallothionein (MT), lysenin and lysozyme were significantly upregulated. The abundance of Bacteroides species, which are related to mineral oil repair, and Muribaculaceae species, which are related to immune regulation, increased within the earthworm intestine. These results indicate that soybean oil waste is toxic to earthworms. Thus, earthworms deployed defense mechanisms involving antioxidant system and gut microbiota for protection against soybean oil exposure-induced stress.

Assessing the effects of China's Three-North Shelter Forest Program over 40 years.

Forests provide vital ecosystem services such as soil and water conservation, climate regulation, and carbon storage. Large-scale afforestation programs are being attempted in many countries to improve environmental conditions in deteriorated or unfavorable locations. China's Three Northern Protected Forest Program (TNSFP), accounting for 42.40 % of China's total land area, is the world's largest afforestation program to date. The TNSFP has continued providing critical ecosystem services to humans over 73 years (1978-2050) with a total investment of CNY 93.3 billion. To facilitate understanding of the TNSFP's contribution, the effects of the TNSFP for last 43 years were comprehensively evaluated by using integrated review of structured literature, bibliometric analysis, and thematic analysis. We incorporated and expanded the direct ecosystem services evidence of the TNSFP from wind and sand control, soil erosion control and carbon sequestration to indirect economic benefits, e.g. increasing crop yield and promoting economic development. We found that over the past 40 years of TNSFP construction, wind and sand hazards and soil erosion in China's Three-North areas have been effectively controlled, and forest carbon sequestration, grain production and economic output have steadily increased. The ecosystem services provided by the TNSFP are highly consistent with the thrust of the UN Sustainable Development Goals, and the TNSFP has contributed to the realization of SDG2, SDG8, SDG13, and SDG15. Although achieving tremendous ecological, economic, and social benefits, the TNSFP still has knowledge gaps in its scientific basis. And the limited local engagement and insufficient investment highly hinder the TNSFP from playing its multiple functions. We suggest several urgent actions and directions to address these limitations. This review could help researchers gain insight into key areas of ecological restoration in the TNSFP, providing a reference for future research in the TNSFP construction in China and other regions of the world embarking on similar journeys.

The upper bound of cumulative return of a trading series.

We present an upper bound of cumulative return in financial trading time series to formulate the most possible profit of many trades. The bound can be used to formally analyze the cumulative return varied by the number of trades, the mean return, and transaction cost rate. We also prove and show the validation of the upper bound, and verify the trend of cumulative return is consistent with that of the proposed bound via simulation experiments. Introducing a set of stochastic assessment methodology based on bootstrap into the organization of experimental data, we illustrate the influence on cumulative return from the relationship between the mean of return and transaction cost rate, technical trading rules, and stock indexes. To the best of our knowledge, this is the first to present and prove a bound of cumulative return of a stock trading series in theory. Both theoretical analyses and simulation experiments show the presented bound is a good mathematical tool to evaluate the trading risks and chances using given trading rules in stock trading markets.

Photosynthetic compensation of non-leaf organ stems of the invasive species Sphagneticola trilobata (L.) Pruski at low temperature.

Biological invasion is a hot topic in ecological research. Most studies on the physiological mechanisms of plants focus on leaves, but few studies focus on stems. To study the tolerance of invasive plant (Sphagneticola trilobata L.) to low temperature, relevant physiological indicators (including anthocyanin and chlorophyll) in different organs (leaves and stems) were analyzed, using a native species (Sphagneticola calendulacea L.) as the control. The results showed that, upon exposure to low temperature for 15 days, the stems of two Sphagneticola species were markedly reddened, their anthocyanin content increased, chlorophyll and chlorophyll fluorescence parameters decreased, and the accumulation of reactive oxygen species in the stem increased. The percentage increases of antioxidants and total antioxidant capacities in stems were significantly higher in S. trilobata than in S. calendulacea. This showed that S. trilobata had higher cold tolerance in stems while leaves were opposite. To further verify the higher cold tolerance of the stem of S. trilobata, a defoliation experiment was designed. We found that the defoliated stem of S. trilobata reduced anthocyanin accumulation and increased chlorophyll content, while alleviating membrane lipid damage and electrical conductivity, and the defoliated stem still showed an increase in stem diameter and biomass under low temperature. The discovery of the physiological and adaptive mechanisms of the stem of S. trilobata to low temperature will provide a theoretical basis for explaining how S. trilobata maintains its annual growth in South China. This is of great significance for predicting the future spread of cloned and propagated invasive plants.

The Changing Distribution of Anthocyanin in Mikania micrantha Leaves as an Adaption to Low-Temperature Environments.

Anthocyanins, a protective substance in plant leaves, can accumulate in large quantities under low-temperature induction. In order to explore the effect of anthocyanins in Mikania micrantha leaves, the Rubisco, photosynthesis, pigments, and antioxidative capacity in mature leaves (ML) and young leaves (YL) of M. micrantha were investigated in winter. YL were red on both the adaxial and abaxial surfaces, while ML was red on the abaxial surfaces and green on the adaxial surfaces. Compared with ML, the relative expression of the genes related to anthocyanin synthesis and anthocyanin content were significantly higher in YL. Antioxidants such as flavonoids and total phenols were found in higher quantities, and the total antioxidant capacity was also significantly higher in YL. However, in ML, the Rubisco and chlorophyll content related to photosynthesis were significantly higher. The stomata of ML displayed a larger aperture than YL, and the stomatal conductance and photosynthetic rate were significantly higher in ML. The results suggested that M. micrantha leaves could better adapt to the winter environment through changing the distribution of anthocyanins in leaves of different maturity.

Accumulation of Anthocyanins: An Adaptation Strategy of Mikania micrantha to Low Temperature in Winter.

The accumulation of anthocyanins in leaves and stems of Mikania micrantha improves its adaptability to low-temperature environments during winter in areas where this species is invasive. The accumulation of anthocyanins in M. micrantha causes the plants to exhibit red coloration when encountering low-temperature environments during winter. Many studies have reported that the accumulation of anthocyanins near the plant surface filters light and improves photoprotection. However, the results of this study showed that the main role of anthocyanins accumulation in M. micrantha during winter was to increase both antioxidant capability and tolerance to low temperature. The results showed that the anthocyanin contents were significantly higher in red leaves and stems than in green leaves and stems, with more than 60-fold greater content in red leaves than in green leaves. In addition, the total antioxidant capability was significantly greater in red leaves and stems than in green leaves and stems. After 4°C treatment for 12 h, a large amount of reactive oxygen species accumulated in green leaves and stems, and the maximum photochemical efficiency decreased significantly. Compared with that of the green leaves, the net photosynthetic rate of red leaves was significantly higher. The biomass statistics revealed that the dry matter accumulation of M. micrantha plants with relatively large amounts of anthocyanins was significantly greater than that of plants with relatively low anthocyanin levels during the same period. Our results suggest that the accumulation of anthocyanins during winter is an adaptation strategy of M. micrantha to low winter temperatures.

Corrigendum: Accumulation of Anthocyanins: An Adaptation Strategy of Mikania micrantha to Low Temperature in Winter.

[This corrects the article DOI: 10.3389/fpls.2019.01049.].

[Regulation of pyocyanin biosynthesis by transcriptional factor sigma38 in Pseudomonas aeruginosa PAO1].

Pyocyanin, an important virulence factor, is synthesized and secreted by Pseudomonas aeruginosa PAO1and plays a critical role in pathogen-host interaction during infection. Sigma38 (σ38, σS) is a central regulator for many virulence production in pathogens. Objective: Our aim is to identify expression and regulation of two phenazine-producing operons mediated by the sigma38 factor in Pseudomonas aeruginosa PAO1. Methods: We first cloned the flanking fragments of rpoS from the chromosomal DNA of P. aeruginosa PAO1 and constructed the deletion mutant ΔrpoS with the insertion of gentamycin resistance cassette (aacC1). Complementation of rpoS was then carried out after construction and introduction of pME10S (containing the whole rpoS region). Finally, we created the mutant ΔrpoSphz1 and ΔrpoSphz2, and measured pyocyanin production by these mutants in GA medium, using the parental strain Δphz1 and Δphz2 as controls. Results: In GA medium, pyocyanin production by mutant ΔrpoS increased dramatically in comparison with the wild-type strain PAO1. Production of pyocyanin, however, was decreased to the level of the wild-type strain with complementation of the derivative ΔrpoS harboring pME10S. Mutant ΔrpoSphz2 produced much more pyocyanin than mutant Δphz2. Mutant ΔrpoSphz1, however, produced much less pyocyanin than mutant Δphz1. Conclusion: By positively regulating the expression of phz2 and negatively regulating the phz1, sigma38 factor exerts negative modulation on pyocyanin biosynthesis in P. aeruginosa PAO1.

Synthesis, structure, and reactions of a copper-sulfido cluster comprised of the parent Cu2S unit: {(NHC)Cu}2(µ-S).

The synthesis of the first CuI2(µ-S) complex, {(IPr*)Cu}2(µ-S) (IPr* = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene; 1), has been accomplished via three synthetic routes: (1) salt metathesis between (IPr*)CuCl and Na2S; (2) silyl-deprotection reaction between (IPr*)Cu(SSiMe3) and (IPr*)CuF; and (3) acid-base reaction between (IPr*)Cu(SH) and (IPr*)Cu(O t Bu). The X-ray crystal structure of 1 exhibits two two-coordinate copper centers connected by a bent Cu-S-Cu linkage. Application of these synthetic routes to analogous precursors containing the sterically smaller ligand IPr (1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidene), in place of IPr*, resulted in the formation of a transient product proposed as {(IPr)Cu}2(µ-S) (2), which decomposes quickly in solution. The instability of 2 probably results from the insufficient steric protection provided by IPr ligands to the unsaturated Cu2(µ-S) core; in contrast, 1 is stable both in solution and solid state for weeks. The nucleophilic sulfido ligand in 1 reacts with haloalkyl electrophiles (benzyl halides and dibromoalkanes) with formation of C-S bonds, affording (IPr*)Cu(SCH2Ph) and cyclic thioethers, respectively.