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Nano-plastics (NPs) have emerged as a significant environmental pollutant, widely existing in water environment, and pose a serious threat to health and safety with the intake of animals. Skeletal muscle, a vital organ for complex life activities and functional demands, has received limited attention regarding the effects of NPs. In this study, the effects of polystyrene NPs (PS-NPs) on skeletal muscle development were studied by oral administration of different sizes (1 mg/kg) of PS-NPs in mice. The findings revealed that PS-NPs resulted in skeletal muscle damage and significantly hindered muscle differentiation, exhibiting an inverse correlation with PS-NPs particle size. Morphological analysis demonstrated PS-NPs caused partial disruption of muscle fibers, increased spacing between fibers, and lipid accumulation. RT-qPCR and western blots analyses indicated that PS-NPs exposure downregulated the expression of myogenic differentiation-related factors (Myod, Myog and Myh2), activated PPARγ/LXRß pathway, and upregulated the expressions of lipid differentiation-related factors (SREBP1C, SCD-1, FAS, ACC1, CD36/FAT, ADIPOQ, C/EBPα and UCP-1). In vitro experiments, C2C12 cells were used to confirm cellular penetration of PS-NPs (0, 100, 200, 400 µg/mL) through cell membranes along with activation of PPARγ expression. Furthermore, to verify LXRß as a key signaling molecule, silencing RNA transfection experiments were conducted, resulting in no increase in the expressions of PPARγ, LXRß, SREBP1C, FAS, CD36/FAT, ADIPOQ, C/EBPα and UCP-1 even after exposure to PS-NPs. However, the expressions of SCD-1and ACC1 remained unaffected. The present study evidenced that exposure to PS-NPs induced lipid accumulation via the PPARγ/LXRß pathway thereby influencing skeletal muscle development.
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Selenium (Se), one of the essential trace elements of fish, regulates immune system function and maintains immune homeostasis. Muscle is the important tissue that generate movement and maintain posture. At present, there are few studies on the effects of Se deficiency on carp muscle. In this experiment, carps were fed with dietary with different Se content to successfully establish a Se deficiency model. Low-Se dietary led to the decrease of Se content in muscle. Histological analysis showed that Se deficiency resulted in muscle fiber fragmentation, dissolution, disarrangement and increased myocyte apoptosis. Transcriptome revealed a total of 367 differentially expressed genes (DEGs) were screened, including 213 up-regulated DEGs and 154 down-regulated DEGs. Bioinformatics analysis showed that DEGs were concentrated in oxidation-reduction process, inflammation and apoptosis, and were related to NF-κB and MAPKs pathways. Further exploration of the mechanism showed that Se deficiency led to excessive accumulation of ROS, decreased the activity of antioxidant enzymes, and also resulted in increased expression of the NF-κB and MAPKs pathways. In addition, Se deficiency significantly increased the expressions of TNF-α, IL-1ß and IL-6, and the pro-apoptotic factors BAX, p53, caspase-7 and caspase-3, while decreased the expressions of anti-apoptotic factors Bcl-2 and Bcl-xl. In conclusion, Se deficiency reduced the activities of antioxidant enzymes and led to excessive accumulation of ROS, which caused oxidative stress and affected the immune function of carp, leading to muscle inflammation and apoptosis.
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Carpas , Desnutrición , Selenio , Animales , Antioxidantes/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Suplementos Dietéticos , Selenio/metabolismo , Carpas/genética , Carpas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Inmunidad Innata , Transducción de Señal , Inflamación/veterinaria , Apoptosis , Músculos/metabolismoRESUMEN
A new ice phase, ice XIX, was discovered in 2018, and is the second hydrogen-ordered polymorph of hydrogen-disordered ice VI. The first hydrogen-ordered polymorph of ice VI is ice XV, and ices XIX, VI, and XV comprise a unique triplet group in the ice family. However, the exact crystal structure of ice XIX has not been confirmed. We constructed four possible conformations of ice XIX using neutron diffraction data obtained by Gasser et al. We then optimized these structures and simulated their Raman scattering spectra using first-principles density functional theory. By comparing these simulated spectra with the experimental Raman scattering spectra, we were able to exclude the existence of a ferroelectric structure with the space group Cc. The other three candidate structures are in good agreement with the experimental Raman scattering data; two of them are ferroelectric structures with the space group P21; and the last one is a weak ferroelectric structure with the space group Cc. We proposed that the partially hydrogen-ordered structure of ice XIX maybe a mixing of several hydrogen-ordered structures.
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The vibrational spectrum of ice II was investigated using the CASTEP code based on first-principles density functional theory (DFT). Based on good agreement with inelastic neutron scattering (INS), infrared (IR), and Raman experimental data, we discuss the translation, libration, bending, and stretching band using normal modes analysis method. In the translation band, we found that the four-bond and two-bond molecular vibration modes constitute three main peaks in accordance with INS ranging from 117 to 318 cm-1. We also discovered that the lower frequencies are cluster vibrations that may overlap with acoustic phonons. Whale et al. found in ice XV that some intramolecular vibrational modes include many isolated-molecule stretches of only one O-H bond, whereas the other O-H bond does not vibrate. This phenomenon is very common in ice II, and we attribute it to local tetrahedral deformation. The pathway of combining normal mode analysis with experimental spectra leads to scientific assignments.
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Hielo/análisis , Teoría Funcional de la Densidad , Enlace de Hidrógeno , Estructura Molecular , VibraciónRESUMEN
It is always difficult to assign the peaks of a vibrational spectrum in the far-infrared region. The two distinct peaks seen in many ice phases are still a mystery to date. The normal modes of ice XV were calculated using the CASTEP code based on first-principles density functional theory. On the basis of vibrational modes analysis, we divided the translational modes into three categories: four-bond vibrations, which have the highest energy levels; two-bond vibrations, which have medium levels of energy; and relative vibrations between two sublattices, which have the lowest energy. Whale et al. found that some intramolecular stretching modes include the isolated vibration of only one O-H bond, whereas the others do not vibrate in ice XV. We verified this phenomenon in this study and attributed it to local tetrahedral deformation. Analysis of normal modes, especially in the translation and stretching band of ice XV, clarified the physical insights of the vibrational spectrum and can be used with other ice phases.
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Biología Computacional/métodos , Hielo/análisis , Algoritmos , Teoría Funcional de la Densidad , Enlace de Hidrógeno , Estructura Molecular , VibraciónRESUMEN
Great progresses have been made in fundamental and clinical stem cell research in China in recent years. The official policy on stem cells, which was announced in 2015, seems as the spring of stem cell therapy in China. However, the regulation, governance, and management of clinical expectations are still challenging. This review summarized the current stem cell research and development in the field, as well as its rapidly evolving commercial, regulatory and ethical environment in China. As expected, the prospects of stem cells in China look prospective.
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Investigación con Células Madre , China , Estudios Prospectivos , Trasplante de Células MadreRESUMEN
Microplastics (MPs) are ubiquitous environmental contaminants that have negative impacts on health and safety. The gut microbiota plays multiple roles as a newly discovered virtual metabolic organ. The objective of this study was to investigate the potential of MPs to cause liver injury by disrupting the balance of gut microbiota. The results indicated that exposure to MPs resulted in liver damage and disrupted the homeostasis of gut microbiota. MPs significantly reduced the liver organ coefficient, leading to liver cell injury and impaired function. Additionally, there was an increase in the expression of fibril-related proteins, which positively correlated with MPs concentration. Furthermore, MPs increased the relative abundances of Desulfovibrio, Clostridia, Enterorhabdus, Bacteroides, and Gemella while decreasing the abundance of Dubosoella. Different concentrations of MPs exhibited varying effects on specific bacterial groups, however, both concentrations resulted in an increase in pathogenic bacteria and a decrease in beneficial bacteria, as well as alterations in microbial structure. Moreover, MPs induced oxidative stress, inflammation, apoptosis and necrosis in liver cells. The study found that MPs disrupted gut microbiota homeostasis and activated TLR2/NF-κB/NLRP3 pathway in the liver, providing a new insight into the mechanism underlying MPs-induced liver injury. These findings serve as a warning regarding environmental pollution caused by MPs.
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Microbioma Gastrointestinal , Polietileno , Animales , Ratones , FN-kappa B , Microplásticos/toxicidad , Plásticos , Receptor Toll-Like 2 , Disbiosis/inducido químicamente , Proteína con Dominio Pirina 3 de la Familia NLR , HígadoRESUMEN
It is difficult to theoretically study the vibrational spectrum of hydrogen-disordered ice XII compared with its hydrogen-ordered counterpart, ice XIV. We constructed a 24-molecule supercell of ice XII to mimic its real structure. We focused on hydrogen bond (HB) vibrational modes in the translation band using first-principles density functional theory (DFT). Our simulated results were in good agreement with inelastic neutron scattering experiments. We found that the optical vibrational modes of HBs are composed of three main components. These are cluster vibrations in the lowest-frequency region, four-bond HB vibrations in the highest-frequency region, and two-bond modes in between. Although the experimentally recorded curve of ice XII is smooth in the translation region, our results support the proposal that two types of intrinsic HB vibrational modes are common in the ice family.
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Rhenium (Re) is an extremely rare and precious element that is mainly used in the construction of aerospace components and satellite stations. However, an efficient and simple method for preparing Re has yet to be devised. To this end, we investigated the vibrational spectrum of ammonium perrhenate (NH4ReO4) using the CASTEP code based on first-principles density functional theory. We assigned the infrared (IR) absorption and Raman scattering spectra for NH4ReO4 using a dynamic process analysis of optical branch normal modes. We examined the IR-active peaks of Re-related vibrational modes in detail and found that the typical IR peak at approximately 914 cm-1 is due to the Re-O bond stretching. Thus, we posit that strong terahertz laser irradiation of NH4ReO4 at 914 cm-1 will lead to sufficient resonance absorption to cleave its Re-O bonds. This method could potentially be used to efficiently separate Re from its oxides.
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It is difficult to investigate the hydrogen-bonding dynamics of hydrogen-disordered ice VI. Here, we present a comparative method based on our previous study of its counterpart hydrogen-ordered phase, ice XV. The primitive cell of ice XV is a 10 molecule unit, and the vibrational normal modes were analyzed individually. We constructed an 80 molecule supercell of ice VI to mimic the periodic unit and performed first-principles density functional theory calculations. As the two vibrational spectra show almost identical features, we compared the molecular translation vibrations. Inspired by the phonon analysis of ice XV, we found that the vibrational modes in the translation band of ice VI are classifiable into three groups. The lowest-strength vibration modes represent vibrations between two sublattices that lack hydrogen bonding. The highest-strength vibration modes represent the vibration of four hydrogen bonds of one molecule. The middle-strength vibration modes mainly represent the molecular vibrations of only two hydrogen bonds. Although there are many overlapping stronger and middle modes, there are only two main peaks in the inelastic neutron scattering (INS) spectra. This work explains the origin of the two main peaks in the far-infrared region of ice VI and illustrates how to analyze a hydrogen-disordered ice structure.
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Zinc (Zn) is an important trace element in the body that has antioxidant effects. It has been proven that Zn deficiency can cause oxidative stress. The purpose of the present study was to clarify the effect and mechanism of Zn deficiency on myocardial fibrosis. Mice were fed with different Zn levels dietary for 9 weeks: Zn-normal group (ZnN, 34 mg Zn/kg), Zn-deficient group (ZnD, 2 mg Zn/kg), and Zn-adequate group (ZnA, 100 mg Zn/kg). We found that the Zn-deficient diet reduced the Zn concentration in myocardial tissue. Moreover, the TUNEL results demonstrated that cardiomyocytes in the ZnD group died in large numbers. Furthermore, ROS levels were significantly increased, and metallothionein (MT) expression levels decreased in the ZnD group. The results of Sirius Red staining indicated an increase in collagen in the ZnD group. Moreover, the ELISA results showed that collagen I, III, and IV and fibronectin (FN) were increased. In addition, the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) was detected by RT-qPCR. The results showed that the expression of TIMP-1 in the ZnD group was increased, while MMPs were decreased. Immunohistochemical results showed an increase in the content of α-smooth muscle actin (α-SMA), while H&E staining showed an increase in interstitial width and a decrease in the number of cardiac cells. All data suggest that Zn deficiency enhances the oxidative stress response of myocardial tissue and eventually triggers myocardial fibrosis.
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Fibrosis/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Metaloproteasas/metabolismo , Miocardio/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Zinc/metabolismo , Animales , Dieta , Masculino , Ratones , Ratones Endogámicos BALB C , Especies Reactivas de Oxígeno/análisis , Zinc/administración & dosificación , Zinc/deficienciaRESUMEN
Assimilable organic carbon (AOC) serves as an indicator of the biostability of drinking water distribution systems; however, the properties of the released organic metabolites by Pseudomonas fluorescens (P17) and Spirillum (NOX) used in AOC bioassays are seldom discussed. In this study, fluorescence excitation emission matrix (FEEM) was selected to characterize organic metabolites after substrate biotransformation and their divergences at different growth stages of both strains in AOC bioassay. Excellent correlation between ATP and colony-forming units (CFUs) was observed for both strains. The concentration of ATP per colony was six times higher in the P17 strain than in the NOX strain. A retarding phenomenon was observed for the NOX strain in the presence of high acetate-C content (100-150⯵g acetate-C/L). The fluorescence wavelength peaks were wider for the protein-like substance released by the P17 strain than for those released by the NOX strain. However, fluorescent fulvic-like substances only existed in the NOX strain. Relative humus accumulation (RHA), the ratio of protein-like fluorescence intensity to humus-like fluorescence intensity, decreased in the P17 strain but substantially increased in the NOX strain in the logarithmic growth phase. RHA showed a descending trend for the P17 strain as compared to that of the NOX strain during the progress from logarithmic to stationary growth phase at three different acetate-C concentrations; however, the opposite was observed at 100⯵g acetate-C/L, indicating that high acetate-C content may affect the properties of released organic matter from both strains.
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Carbono/análisis , Agua Potable/normas , Pseudomonas fluorescens/metabolismo , Spirillum/metabolismo , Acetatos/farmacología , Colorantes , Compuestos Orgánicos/análisis , Compuestos Orgánicos/metabolismo , Purificación del AguaRESUMEN
The normal modes of ice IX were investigated using the CASTEP code package, which is based on density functional theory. We found that the translational modes could be divided into three categories: four-bond vibrations, which possessed the highest energy; two-bond vibrations, which possessed the medium energy; and cluster vibrations with the lowest energy. The former two categories represent monomers vibrating against neighbors and present as two distinct peaks in many ice phases recorded in inelastic neutron-scattering experiments. It is typically difficult to assign the molecular vibration peaks in the far infrared region. The method we developed to analyze the normal modes, especially in the translation band of ice IX, provided physical insights into the vibrational spectrum of ice.