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1.
Mol Phylogenet Evol ; : 107406, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35031457

RESUMO

The class Karyorelictea, a unique assemblage of ciliates, is a key group in deciphering ciliate evolution history. However, the systematic relationships among members of this class remain poorly understood. Here we newly obtained eight small subunit (SSU) rDNA, 24 large subunit (LSU) rDNA, and 25 ITS1-5.8S-ITS2 sequences (covering 25 species, 10 genera and 4 out of 6 families) to analyze the phylogenetic relationships within Karyorelictea. Our results indicate that: (1) considering its unique morphology and early branching position in the SSU rDNA-based tree, the family Wilbertomorphidae represents a new taxon at order level, hence the new order Wilbertomorphida n. ord. is established; (2) all five families with available molecular information are monophyletic, as expected, and the orders Loxodida and Protostomatida show a closer relationship than with Protoheterotrichida; (3) in Trachelocercidae, the compound circumoral kineties is believed to be a plesiomorphic feature while the single circumoral kinety is synapomorphic; and (4) the freshwater genus Loxodes could be derived from the marine Remanella and both share most morphological features. Taken together, these muti-gene analyses provide further insights into the phylogeny of the diverse clades in Karyorelictea.

2.
J Chromatogr A ; 1663: 462762, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-34974367

RESUMO

Novel poly(ethylvinylbenzene-divinylbenzene) (EVB-DVB) agglomerated with ultrasmall carbonaceous spheres (UCSs) anion-exchange packings for ion chromatography (IC) were constructed. Hydrophilic UCSs with mean sizes of 62-98 nm were synthesized in quantity by the polydiallyl dimethyl ammonium chloride aided hydrothermal carbonization of fructose. The green strategy based on the thiol-ene click reaction with cysteamine in aqueous system was first designed for the hyperbranched polyquaternary amine (HPA) grafting of UCSs with negligible damage on their monodispersity. The HPA modified UCSs were evenly distributed on sulfonated EVB-DVB substrate to form one uniform layer of functional nanospheres without observable coagulum. Seven typical anions (F-, Cl-, NO2-, Br-, NO3-, SO42- and PO43-) were baseline separated on constructed packing in 5 min with high efficiencies in the range of 44,800-71,100 plates m - 1. The rapid separation of polarizable anions, small organic acids and saccharides could be also accomplished under isocratic elution with competitive peak symmetry and efficiency. Good reproducibility was demonstrated by consecutive injection. Thiosulfate in water reducer was further detected on prepared packing in 4 min with detection limit of 0.04 mg L - 1 (S/N = 3) and good repeatability.


Assuntos
Poliestirenos , Ânions , Cromatografia por Troca Iônica , Interações Hidrofóbicas e Hidrofílicas , Reprodutibilidade dos Testes
3.
Sci Rep ; 12(1): 1082, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35058512

RESUMO

Contractile activity is a fundamental property of skeletal muscles. We describe the establishment of a "feeder-supported in vitro exercise model" using human-origin primary satellite cells, allowing highly-developed contractile myotubes to readily be generated by applying electrical pulse stimulation (EPS). The use of murine fibroblasts as the feeder cells allows biological responses to EPS in contractile human myotubes to be selectively evaluated with species-specific analyses such as RT-PCR. We successfully applied this feeder-supported co-culture system to myotubes derived from primary satellite cells obtained from sporadic inclusion body myositis (sIBM) patients who are incapable of strenuous exercise testing. Our results demonstrated that sIBM myotubes possess essentially normal muscle functions, including contractility development, de novo sarcomere formation, and contraction-dependent myokine upregulation, upon EPS treatment. However, we found that some of sIBM myotubes, but not healthy control myotubes, often exhibit abnormal cytoplasmic TDP-43 accumulation upon EPS-evoked contraction, suggesting potential pathogenic involvement of the contraction-inducible TDP-43 distribution peculiar to sIBM. Thus, our "feeder-supported in vitro exercise model" enables us to obtain contractile human-origin myotubes, potentially utilizable for evaluating exercise-dependent intrinsic and pathogenic properties of patient muscle cells. Our approach, using feeder layers, further expands the usefulness of the "in vitro exercise model".

4.
Light Sci Appl ; 11(1): 13, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996893

RESUMO

Synthetic gauge fields in synthetic dimensions are now of great interest. This concept provides a convenient manner for exploring topological phases of matter. Here, we report on the first experimental realization of an atom-optically synthetic gauge field based on the synthetic momentum-state lattice of a Bose gas of 133Cs atoms, where magnetically controlled Feshbach resonance is used to tune the interacting lattice into noninteracting regime. Specifically, we engineer a noninteracting one-dimensional lattice into a two-leg ladder with tunable synthetic gauge fields. We observe the flux-dependent populations of atoms and measure the gauge field-induced chiral currents in the two legs. We also show that an inhomogeneous gauge field could control the atomic transport in the ladder. Our results lay the groundwork for using a clean noninteracting synthetic momentum-state lattice to study the gauge field-induced topological physics.

5.
Huan Jing Ke Xue ; 43(1): 93-101, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989493

RESUMO

To investigate the pollution characteristics and sources of nitrated polycyclic aromatic hydrocarbons (NPAHs) in Guangdong-Hong Kong-Macao Greater Bay Area (GBA), 44 ambient air samples were collected using the active sampling method, which were then determined via gas chromatography-triple quadrupole tandem mass spectrometry. The main results showed that filters, polyurethane foam, and XAD-2 resin were the essential materials for sampling NPAHs in ambient air in order to characterize the pollution status accurately. The levels of ρ(Σ18NPAHs) in ambient air at GBA ranged from 162 pg·m-3 to 2094 pg·m-3, and the average levels of ρ(Σ18NPAHs) were (675±430) pg·m-3 in summer and (637±349) pg·m-3 in winter. NPAHs were widely found in the ambient air of GBA and were dominated by 1-nitronaphthalene (220 pg·m-3), 2-nitronaphthalene (146 pg·m-3), 9-nitroanthracene (105 pg·m-3), and 2-nitrofluoranthene (72 pg·m-3). The congener profile characteristics of NPAHs in summer and winter were similar. The gas/particle partitioning characteristics of NPAHs revealed that dicyclic and tricyclic NPAHs tend to occur in the gas phase, and tetracyclic NPAHs tend to be adsorbed in the particle phase. The fraction of NPAHs concentrations in the particulate fraction of their total atmospheric concentrations increased with the increase in their molecular weight. In winter, NPAHs tend to be adsorbed in the particle phase, whereas in summer, NPAHs tend to exist in the gas phase. Based on the ratios of characteristic pollutants, in both the summer and winter season, photochemical reactions were the main source of NPAHs in the atmosphere of GBA and were primarily generated by the reaction of the hydroxyl radical in the daytime. The carcinogenic risk value calculation showed that the current carcinogenic risk of NPAHs in the ambient air of GBA was controllable.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Hong Kong , Macau , Nitratos/análise , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Estações do Ano
7.
PLoS Pathog ; 17(12): e1010134, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34860858

RESUMO

Lysine acetylation is a frequently occurring post-translational modification (PTM), emerging as an important metabolic regulatory mechanism in prokaryotes. This process is achieved enzymatically by the protein acetyltransferase (KAT) to specifically transfer the acetyl group, or non-enzymatically by direct intermediates (acetyl phosphate or acetyl-CoA). Although lysine acetylation modification of glucosyltransferases (Gtfs), the important virulence factor in Streptococcus mutans, was reported in our previous study, the KAT has not been identified. Here, we believe that the KAT ActG can acetylate Gtfs in the enzymatic mechanism. By overexpressing 15 KATs in S. mutans, the synthesized water-insoluble extracellular polysaccharides (EPS) and biofilm biomass were measured, and KAT (actG) was identified. The in-frame deletion mutant of actG was constructed to validate the function of actG. The results showed that actG could negatively regulate the water-insoluble EPS synthesis and biofilm formation. We used mass spectrometry (MS) to identify GtfB and GtfC as the possible substrates of ActG. This was also demonstrated by in vitro acetylation assays, indicating that ActG could increase the acetylation levels of GtfB and GtfC enzymatically and decrease their activities. We further found that the expression level of actG in part explained the virulence differences in clinically isolated strains. Moreover, overexpression of actG in S. mutans attenuated its cariogenicity in the rat caries model. Taken together, our study demonstrated that the KAT ActG could induce the acetylation of GtfB and GtfC enzymatically in S. mutans, providing insights into the function of lysine acetylation in bacterial virulence and pathogenicity.

8.
Front Microbiol ; 12: 768724, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34925276

RESUMO

Four suctorian ciliates, Cyclophrya magna Gönnert, 1935, Peridiscophrya florea (Kormos & Kormos, 1958) Dovgal, 2002, Heliophrya rotunda (Hentschel, 1916) Matthes, 1954 and Dendrosoma radians Ehrenberg, 1838, were collected from a freshwater lake in Ningbo, China. The morphological redescription and molecular phylogenetic analyses of these ciliates were investigated. Phylogenetic analyses inferred from SSU rDNA sequences show that all three suctorian orders, Endogenida, Evaginogenida, and Exogenida, are monophyletic and that the latter two clusters as sister clades. The newly sequenced P. florea forms sister branches with C. magna, while sequences of D. radians group with those from H. rotunda within Endogenida. The family Heliophryidae, which is comprised of only two genera, Heliophrya and Cyclophrya, was previously assigned to Evaginogenida. There is now sufficient evidence, however, that the type genus Heliophrya reproduces by endogenous budding, which corresponds to the definitive feature of Endogenida. In line with this and with the support of molecular phylogenetic analyses, we therefore transfer the family Heliophryidae with the type genus Heliophrya to Endogenida. The other genus, Cyclophrya, still remains in Evaginogenida because of its evaginative budding. Therefore, combined with morphological and phylogenetic analysis, Cyclophyidae are reactivated, and it belongs to Evaginogenida.

9.
Front Microbiol ; 12: 784923, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34925293

RESUMO

Oral bacteria colonize the oral cavity, surrounding complex and variable environments. Post-translational modifications (PTMs) are an efficient biochemical mechanism across all domains of life. Oral bacteria could depend on PTMs to quickly regulate their metabolic processes in the face of external stimuli. In recent years, thanks to advances in enrichment strategies, the number and variety of PTMs that have been identified and characterized in oral bacteria have increased. PTMs, covalently modified by diverse enzymes, occur in amino acid residues of the target substrate, altering the functions of proteins involved in different biological processes. For example, Ptk1 reciprocally phosphorylates Php1 on tyrosine residues 159 and 161, required for Porphyromonas gingivalis EPS production and community development with the antecedent oral biofilm constituent Streptococcus gordonii, and in turn Php1 dephosphorylates Ptk1 and rapidly causes the conversion of Ptk1 to a state of low tyrosine phosphorylation. Protein acetylation is also widespread in oral bacteria. In the acetylome of Streptococcus mutans, 973 acetylation sites were identified in 445 proteins, accounting for 22.7% of overall proteins involving virulence factors and pathogenic processes. Other PTMs in oral bacteria include serine or threonine glycosylation in Cnm involving intracerebral hemorrhage, arginine citrullination in peptidylarginine deiminases (PADs), leading to inflammation, lysine succinylation in P. gingivalis virulence factors (gingipains, fimbriae, RagB, and PorR), and cysteine glutathionylation in thioredoxin-like protein (Tlp) in response to oxidative stress in S. mutans. Here we review oral bacterial PTMs, focusing on acetylation, phosphorylation, glycosylation, citrullination, succinylation, and glutathionylation, and corresponding modifying enzymes. We describe different PTMs in association with some examples, discussing their potential role and function in oral bacteria physiological processes and regulatory networks. Identification and characterization of PTMs not only contribute to understanding their role in oral bacterial virulence, adaption, and resistance but will open new avenues to treat oral infectious diseases.

10.
Eur J Neurol ; 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34725884

RESUMO

BACKGROUND AND PURPOSE: This study was undertaken to screen the circular RNAs (circRNAs) influencing matrix metalloproteinase 9 (MMP9) through the competing endogenous RNA (ceRNA) network and evaluate the prognostic value of these circRNAs for acute ischemic stroke. METHODS: A total of 220 ischemic stroke patients and 62 healthy subjects were included in this study. RNA was isolated from blood collected in PAXgene tubes. Illumina sequencing, quantitative real-time polymerase chain reaction (qRT-PCR) validation, and luciferase reporter assay were explored to construct and verify the existence of a circRNA-microRNA (miRNA)-matrix metalloproteinase-9 (MMP9) network. The 215 ischemic stroke patients were recruited in a prognostic cohort. They were prospectively followed up for 3 months after stroke onset, and a poor functional outcome was defined as a major disability or death. RESULTS: After Illumina sequencing, six circRNAs were predicted to bind miRNAs and then regulate MMP9 messenger RNA (mRNA). qRT-PCR showed that only circSKA3 was significantly increased in ischemic stroke patients compared to healthy controls and positively associated with MMP9 mRNA expression. Luciferase reporter assay further verified a direct interaction between circSKA3, MMP9, and hsa-miR-6796-5p. Patients in the top tertile of circSKA3 had a 2.672-fold (p < 0.05) risk of poor functional outcome, compared with those in the bottom tertile (p for trend = 0.016). The outcome was predicted by circSKA3 with area under the receiver operating characteristic curve at 0.614 (p = 0.004). CONCLUSIONS: circSKA3 functioned as a ceRNA for hsa-miR-6796-5p to aggravate the progression of ischemic stroke via targeting MMP9. Baseline circSKA3 was positively associated with poor outcomes of ischemic stroke. circSKA3 may be a potential biomarker or therapeutic target in ischemic stroke.

11.
Mol Ther Nucleic Acids ; 26: 798-812, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34729249

RESUMO

Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease. The lack of targeted therapies and poor patient outcome have fostered efforts to discover new molecular targets to treat patients with TNBC. Here, we showed that baculoviral IAP repeat containing 6 (BIRC6) is overexpressed and positively correlated with epidermal growth factor (EGF) receptor (EGFR) in TNBC cells and tissues and that BIRC6 overexpression is associated with poor patient survival. Mechanistic studies revealed that BIRC6 stability is increased by EGF-JNK signaling, which prevents ubiquitination and degradation of BIRC6 mediated by the E3 ubiquitin ligase HECTD1. BIRC6 in turn decreases SMAC expression by inducing the ubiquitin-proteasome pathway, thereby antagonizing apoptosis and promoting the proliferation, colony formation, tumorsphere formation, and tumor growth capacity of TNBC cells. Therapeutically, the PEGylated cationic lipid nanoparticle (pCLN)-assisted delivery of BIRC6 small interfering RNA (siRNA) efficiently silences BIRC6 expression in TNBC cells, thus suppressing TNBC cell growth in vitro and in vivo, and its antitumor activity is significantly superior to that of the EGFR inhibitor gefitinib. Our findings identify an important regulatory mechanism of BIRC6 overexpression and provide a potential therapeutic option for treating TNBC.

12.
Biomater Sci ; 9(24): 8313-8322, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34782897

RESUMO

Furin is an important cellular endoprotease, which is expressed at high levels in various cancer cells. Accurate and real-time detection of endogenous furin with high sensitivity and selectivity is significant for the diagnosis of cancer. Herein an activatable nanoprobe (MoS2@PDA-PEG/peptide, MPPF) with dual-mode near-infrared fluorescence (NIRF)/ratiometric photoacoustic (PA) imaging of endogenous furin activity has been developed. The MPPF nanoprobes were constructed by the covalent functionalization of polydopamine (PDA) coated MoS2 nanosheets (NSs) with Cy7-labeled furin substrate peptides. Upon cleavage of the peptides by furin, Cy7 molecules are released from MPPF nanoprobes and recover their fluorescence, realizing furin activity detection with the limit of detection (LOD) down to 3.73 × 10-4 U mL-1. Meanwhile, the ratio of the PA signal at 768 nm to that at 900 nm (PA768/PA900) decreases over time due to the destruction of fluorescence resonance energy transfer effect from Cy7 to MoS2 NSs and the rapid clearance of small Cy7 molecules from tissues. Thus, the simultaneous change in NIRF and ratiometric PA signals enables the imaging of endogenous furin activity in real time, and with high sensitivity, and high selectivity in both tumor cells and tumor-bearing mice.

13.
Mol Oral Microbiol ; 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34727414

RESUMO

Dental caries is one of the most prevalent and costly biofilm-dependent oral infectious diseases affecting most of the world's population. Streptococcus mutans, a major extracellular polymeric substance (EPS) producing bacteria in dental plaque, plays a vital role in human dental caries. EPS acts as the framework of dental plaque and promotes bacterial adhesion, cohesion, and environmental stress resistance and hinders the diffusion of nutrients and metabolic products. Since EPS is critical for biofilm lifestyle and virulence of cariogenic bacteria, EPS disruption could be a potential strategy to prevent caries. This review sought to summarize potential strategies to inhibit S. mutans biofilms through EPS disruption. The signal network intervention has a positive effect on S. mutans biofilm disruption, which could be achieved by using cyclic dimeric G/AMP inhibitors, quorum sensing inhibitors, and diffusible signal factors. Besides the enzyme degradation of exopolysaccharides, extracellular DNA, and proteins, other novel strategies, such as nanoparticles and phage therapy, could also promote EPS matrix disruption.

14.
Mater Horiz ; 8(2): 336-350, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34821258

RESUMO

Nanozymes aim to mimic enzyme activities. In addition to catalytic activity, nanozymes also need to have specificity and catalyze biologically relevant reactions under physiological conditions to fit in the definition of enzyme and to set nanozymes apart from typical inorganic catalysts. Previous discussions in the nanozyme field mainly focused on the types of reactions or certain analytical, biomedical or environmental applications. In this article, we discuss efforts made to mimic enzymes. First, the catalytic cycles are compared, where a key difference is specific substrate binding by enzymes versus non-specific substrate adsorption by nanozymes. We then reviewed efforts to engineer and surface-modify nanomaterials to accelerate reaction rates, strategies to graft affinity ligands and molecularly imprinted polymers to achieve specific catalysis, and methods to bring nanozyme reactions to neutral pH and ambient temperature. Most of the current nanozyme reactions used a few model chromogenic substrates of no biological relevance. Therefore, we also reviewed efforts to catalyze the conversion of biomolecules and biopolymers using nanozymes. By the efforts to close the gaps between nanozymes and enzymes, we believe nanozymes are catching up rapidly. Still, challenges exist in materials design to further improve nanozymes as true enzyme mimics and achieve impactful applications.

15.
Mater Horiz ; 8(4): 1264-1271, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34821919

RESUMO

Bacterial biofilm infections are intractable to traditional antibiotic treatment and usually cause persistent inflammation. Chemodynamic therapy (CDT) based on the Fenton reaction has recently emerged as a promising anti-biofilm strategy. However, the therapeutic efficacy of current Fenton agents often suffers from inefficient Fenton activity and lacks anti-inflammatory capability. Herein, FePS3 nanosheets (NSs) are explored for the first time as novel microenvironment-selective therapeutic nanoagents for bacterial biofilm infections with both self-enhanced Fenton activity for an anti-biofilm effect and reactive oxygen species (ROS) scavenging properties for an anti-inflammatory effect. In biofilms with acidic microenvironments, FePS3 NSs release Fe2+ to generate toxic ROS by Fenton reaction and reductive [P2S6]4- to enhance the Fenton activity by reducing Fe3+ to Fe2+. In the surrounding normal tissues with neutral pH, FePS3 NSs scavenge ROS by reductive [P2S6]4- with an anti-inflammatory effect. This work demonstrates multifunctional Fenton nanoagents with microenvironment-selective ROS generation and elimination properties for effective treatment of bacterial biofilm infections with both anti-biofilm and anti-inflammatory effects.

16.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(6): 939-942, 2021 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-34841758

RESUMO

Oral Microbiology is a vital component of the basic science of stomatology and an important compulsory course for undergraduate students of stomatology, focusing on the oral microbiology and microecology, the pathogenesis of oral infectious diseases, and the relationship between oral microbes and human health. Our faculty team have made reforms of the theory and laboratory teaching of the course Oral Microbiology. We have introduced in the classroom the concept of Three Comprehensive Approaches to Education-the full involvement of everyone, the through-course approach and all-round education-and offered inquiry-based instruction through a combination of extracting the core information from every chapter, using the core information as the foundation, integrating the core information with clinical problems, and using experiment operation to foster in the students an attitude of solving clinical problems through research. These teaching innovations improved the undergraduate students'motivation to learn. We evaluated the teaching effect with questionnaire surveys. The results suggested that the students showed high interest in learning and were satisfied with our teaching innovations. In addition, student performance evaluation for the course showed significant improvement, indicating that the instructional reform program of Oral Microbiology was conducive to students'understanding and mastery of the course content, improved student motivation to learn and their grades, and received positive reviews from the students. We report herein, from three aspects, the course innovations and the experiences gained. We discussed the significance of integrating ideological and political theories teaching in all courses and using innovative teaching materials and teaching models and, highlighted their importance in the education of stomatology students, and proposed suggestions to further improve the course design of Oral Microbiology.


Assuntos
Medicina Bucal , Currículo , Humanos , Aprendizagem , Estudantes , Ensino
17.
J Ethnopharmacol ; 285: 114859, 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34818573

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Panax notoginseng (Burk) F. H. Chen is a well-known traditional Chinese medicine with a long history and is widely used in the treatment of cerebrovascular disease. Panax notoginseng saponins (PNS) are the main active ingredients in Panax notoginseng (Burk) F. H. Chen, and its injection is used to treat nerve damage caused by cerebral ischemia and other conditions. PNS is thought to alleviate cognitive impairment in patients with Alzheimer's disease; however, its mechanism of action is unclear. AIM OF THE STUDY: We elucidated the role of PNS in attenuating cellular mitochondrial damage caused by amyloid ß (Aß) protein and in protecting cell viability from the perspective of regulating autophagy. By investigating the effects of PNS on the targets regulating mitophagy, we wanted to reveal the autophagy related mechanism by which PNS attenuated Aß damage in neuronal cells. MATERIALS AND METHODS: The effect of PNS on the mitochondrial membrane potential of Aß-injured PC12 cells was detected using flow cytometry, which reflected the alleviating effect of PNS on mitochondrial damage. Using mRFP-GFP-LC3-transfected PC12 cells, the effect of PNS on cellular autophagy flux was observed using laser confocal microscopy. Formation of the intracellular autophagosome was observed using transmission electron microscopy, which reflected the activation of autophagy by PNS. The siPINK1 lentivirus was used to silence the PINK1 gene in PC12 cells to obtain siPINK1-PC12 cells. The effects of PNS on the expression of the PINK1 gene and on the autophagy-related proteins LC3II/Ⅰ, p62, PINK1, parkin, NDP52, and OPTN were observed to reveal the possible targets of PNS in regulating autophagy. RESULTS: After PNS treatment, the viability of Aß-injured PC12 cells improved and the mitochondrial membrane potential was restored. PNS treatment significantly enhanced the autophagy flux of damaged cells and increased the levels of LC3II/Ⅰ protein and decreased p62 protein, while significantly improving the structure and mitochondrial morphology of PC12 cells injured by Aß. These changes led to more autophagosomes wrapping around the damaged mitochondria and promoting the depletion of OPTN, a mitophagy receptor. After silencing the PINK1 gene, PNS could not alter the PINK1 gene and protein levels, but could still increase LC3II/Ⅰ, decrease p62 and OPTN, and significantly increase the amount of parkin. CONCLUSIONS: PNS could enhance the autophagic activity of cells, alleviate mitochondrial damage caused by Aß injury, and protect the activity of PC12 cells. It is possible that enhanced autophagy was achieved by promoting the recruitment of parkin protein to the mitochondrial receptors in a non-PINK1-dependent manner.

18.
Opt Express ; 29(21): 32892-32899, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34809111

RESUMO

Herein, we report on the experimental observations and a quantitative determination of the laser-induced frequency shift (LIFS) in the photoassociation (PA) spectra of spinor Bose-Einstein condensate of sodium. Our investigations revealed a nonlinear dependence of the LIFS on the intensity of PA laser. By developing a model within the quadratic Stark effect, we simulate the experimental results via a theoretical model that confirms the former. The experimental observations and the theoretical analysis can further improve the accuracy of investigations on important molecular properties and on preparation of specific molecular states, with possible applications in various key fields.

19.
Mol Oral Microbiol ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34761536

RESUMO

Diadenosine-5',5'''-P1, P4-tetraphosphate (Ap4A) is a second messenger playing a crucial role in various life activities of bacteria. The increase of Ap4A expression is pleiotropic, resulting in an impairment in the formation of biofilm and other physiological functions in some bacteria. However, Ap4A function in Streptococcus mutans, an important pathogen related to dental caries, remains unknown. In this work, the Ap4A hydrolase, YqeK, was identified and characterized in S. mutans. Then, the effects of yqeK deletion on the growth, biofilm formation, and exopolysaccharide (EPS) quantification in S. mutans were determined by the assessment of the growth curve, crystal violet, and anthrone-sulfuric acid, respectively, and visualized by microscopy. The results showed that the in-frame deletion of the yqeK gene in S. mutans UA159 led to an increase in Ap4A levels, lag phase in the early growth, as well as decrease in biofilm formation and water-insoluble exopolysaccharide production. Global gene expression profile showed that the expression of 88 genes was changed in the yqeK mutant, and among these, 42 were upregulated and 46 were downregulated when compared with the wild-type S. mutans UA159. Upregulated genes were mainly involved in post-translational modification, protein turnover, and chaperones, while downregulated genes were mainly involved in carbohydrate transport and metabolism. Important virulence genes related to biofilms, such as gtfB, gtfC, and gbpC, were also significantly downregulated. In conclusion, these results indicated that YqeK affected the formation of biofilms and the expression of biofilm-related genes in S. mutans.

20.
Ultrason Sonochem ; 81: 105849, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34839125

RESUMO

Sonophotocatalysis is one of the most significant outcomes of the exploration of the interaction between piezoelectric field and charge carriers, which exhibits potential applications in dye degradation, water splitting, and sterilization. Although several heterojunction catalysts have been applied to improve the sonophotocatalytic capability, the importance of the morphology on the sonophotocatalytic capability has not been emphasized. In this study, brush-like ZnO nanorod arrays are synthesized on a stainless-steel mesh and subsequently vulcanized into ZnO/ZnS core-shell nanorod arrays to investigate the sonophotocatalytic capability of the heterojunction. The sonophotocatalytic capability increases from 25.1% to 45.4% through vulcanization. Afterward, the ZnO/ZnS nanorods are etched to ZnO/ZnS nanotubes without affecting the crystallography and distribution of the ZnS nanoparticle shell, further improving the capability to 63.3%. The improvement can be ascribed to the coupling effect of the enhanced piezoelectric field and the reduced migration distance, which suppresses the recombination of photoexcited electron-hole pairs while transforming the morphology from nanorod to nanotube, as proven by the electron spin resonance test and numerical simulations. This study explores a novel approach of morphology engineering for enhancing the sonophotocatalytic capability of heterojunction nanoarrays.

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