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1.
Front Physiol ; 12: 719346, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34671271

RESUMO

Antifreeze protein III (AFP III) is used for the cryopreservation of germ cells in various animal species. However, the exact mechanism of its cryoprotection is largely unknown at the molecular level. In this study, we investigated the motility, acrosomal integrity, and mitochondrial membrane potential (MMP), as well as proteomic change, of cynomolgus macaque sperm after cryopreservation. Sperm motility, acrosomal integrity, and MMP were lower after cryopreservation (p < 0.001), but significant differences in sperm motility and MMP were observed between the AFP-treated sperm sample (Cryo+AFP) and the non-treated sample (Cryo-AFP) (p < 0.01). A total of 141 and 32 differentially expressed proteins were, respectively, identified in cynomolgus macaque sperm cryopreserved without and with 0.1 µg/ml AFP III compared with fresh sperm. These proteins were mainly involved in the mitochondrial production of reactive oxygen species (ROS), glutathione (GSH) synthesis, and cell apoptosis. The addition of AFP III in the sperm freezing medium resulted in significant stabilization of cellular molecular functions and/or biological processes in sperm, as illustrated by the extent of proteomic changes after freezing and thawing. According to the proteomic change of differentially expressed proteins, we hypothesized a novel molecular mechanism for cryoprotection that AFP III may reduce the release of cytochrome c and thereby reduce sperm apoptosis by modulating the production of ROS in mitochondria. The molecular mechanism that AFP III acts with sperm proteins for cellular protection against cryoinjuries needs further study.

2.
Cell Biol Toxicol ; 2021 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-34686948

RESUMO

The prognosis of pancreatic ductal adenocarcinoma (PDAC) is poor despite diagnostic progress and new chemotherapeutic regimens. Constitutive activation of NF-κB is frequently observed in PDAC. In this study, we found that YEATS2, a scaffolding protein of ATAC complex, was highly expressed in human PDAC. Depletion of YEATS2 reduced the growth, survival, and tumorigenesis of PDAC cells. The binding of YEATS2 is crucial for maintaining TAK1 activation and NF-κB transcriptional activity. Of importance, our results reveal that YEATS2 promotes NF-κB transcriptional activity through modulating TAK1 abundance and directly interacting with NF-κB as a co-transcriptional factor.

3.
Front Chem ; 9: 758357, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34692648

RESUMO

Cyclometalated iridium (III) complexes are indispensable in the field of phosphorescent organic light-emitting diodes (PhOLEDs), while the improvement of blue iridium (III) complexes is as yet limited and challenging. More diversified blue emitters are needed to break through the bottleneck of the industry. Hence, a novel [3+2+1] coordinated iridium (III) complex (noted as Ir-dfpMepy-CN) bearing tridentate bis-N-heterocyclic carbene (NHC) chelate (2,6-bisimidazolylidene benzene), bidentate chelates 2-(2,4-difluorophenyl)-4-methylpyridine (dfpMepy), and monodentate ligand (-CN) has been designed and synthesized. The tridentate bis-NHC ligand enhances molecular stability by forming strong bonds with the center iridium atom. The electron-withdrawing groups in the bidentate ligand (dfpMepy) and monodentate ligand (-CN) ameliorate the stability of the HOMO levels. Ir-dfpMepy-CN shows photoluminescence peaks of 440 and 466 nm with a high quantum efficiency of 84 ± 5%. Additionally, the HATCN (10 nm)/TAPC (40 nm)/TcTa (10 nm)/10 wt% Ir-dfpMepy-CN in DPEPO (10 nm)/TmPyPB (40 nm)/Liq (2.5 nm)/Al (100 nm) OLED device employing the complex shows a CIE coordinate of (0.16, 0.17), reaching a deeper blue emission. The high quantum efficiency is attributed to rapid singlet to triplet charge transfer transition of 0.9-1.2 ps. The successful synthesis of Ir-dfpMepy-CN has opened a new window to develop advanced blue emitters and dopant alternatives for future efficient blue PhOLEDs.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34617380

RESUMO

By using copper(I) homoenolates as nucleophiles, which are generated through the ring-opening of 1-substituted cyclopropane-1-ols, a catalytic asymmetric allylic substitution with allyl phosphates is achieved in high to excellent yields with high enantioselectivity. Both 1-substituted cyclopropane-1-ols and allylic phosphates enjoy broad substrate scopes. Remarkably, various functional groups, such as ether, ester, tosylate, imide, alcohol, nitro, and carbamate are well tolerated. Moreover, the present method is nicely extended to the asymmetric construction of quaternary carbon centers. Some control experiments argue against a radical-based reaction mechanism and a catalytic cycle based on a two-electron process is proposed. Finally, the synthetic utilities of the product are showcased by means of the transformations of the terminal olefin group and the ketone group.

5.
J Neuroinflammation ; 18(1): 241, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34666797

RESUMO

BACKGROUND: Cognitive impairment in the late stage of traumatic brain injury (TBI) is associated with the NOD-, LRR and pyrin domain-containing protein 3 (NLRP3) inflammasome, which plays an important role in neuroinflammation. Although classical inflammatory pathways have been well-documented in the late stage of TBI (4-8 weeks post-injury), the mechanism by which the NLRP3 inflammasome impairs cognition is still unclear. METHODS: Mice lacking the gene encoding for NLRP3 (NLRP3-knockout mice) and their wild-type littermates were used in a controlled cortical impact model of TBI. Levels of NLRP3 inflammasome and inflammatory factors such as IL-1ß and HMGB1 were detected in post-injury hippocampal tissue, as well as long-term potentiation. Behaviors were assessed by T-maze test, novel object recognition, and nesting tests. Glycyrrhizin was used to antagonize HMGB1. Calcium imaging were performed on primary neuronal cultures. RESULTS: By using the NLRP3-knockout TBI model, we found that the continuous activation of the NLRP3 inflammasome and high mobility group box 1 (HMGB1) release were closely related to cognitive impairment. We also found that inhibition of HMGB1 improved LTP reduction and cognitive function by increasing the phosphorylation level of the NMDAR1 subunit at serine 896 while reducing NLRP3 inflammasome activation. CONCLUSION: NLRP3 inflammasome damages memory in the late stage of TBI primarily through HMGB1 upregulation and provides an explanation for the long-term progression of cognitive dysfunction.

6.
ACS Nano ; 15(10): 16019-16029, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34592104

RESUMO

Controllable syntheses of Au nanoclusters (NCs) with different nuclearities are of great significance due to the kernel-dependent physicochemical properties. Herein, two pairs of enantiomeric Au NCs [Au19(R/S-BINAP)4(PhC≡C)Cl4] (SD/Au19) and [Au11(R/S-BINAP)4(PhC≡C)2]·Cl (SD/Au11), both with atropos (rigid axial chirality) diphosphine BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthalene) as the predominant organic ligands, were controllably synthesized through precursor engineering. The former was obtained by direct reduction of HAuCl4·4H2O, while the latter was obtained by reduction of [Au(SMe2)Cl] instead. Intriguingly, the kernel of SD/Au19 contains an Au7 pentagonal bipyramid capped by two boat-like Au6 rings, which represents another type of Au19 kernel, making SD/Au19 a good candidate for comparative study with other Au19 NCs to get more insight into the distinct structural evolution of phosphine-protected Au NCs. Despite the previous chiroptical studies on some other chiral undecagold NCs, the successful attainment of the X-ray crystal structures for SD/Au11 not only provides a step forward toward better correlating the chiroptical activities with their structural details but also reveals that even the auxiliary protecting ligands also play a nontrivial role in tuning the geometrical structures of the metal NCs. The chiroptical activities of both SD/Au19 and SD/Au11 were found to originate from the chiral ligands and core distortions; the extended π-electron systems in the BINAP ligands have proved to positively contribute to the electronic absorptions and thus disturb the corresponding circular dichroism (CD) responses.

7.
J Phys Chem Lett ; 12(37): 9132-9141, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34523927

RESUMO

Different nucleotides generate specific ionic currents that discriminate between the nucleotides while they are passing through the nanopore constriction. MspA is a commonly used nanopore for DNA sequencing. However, the reasons of the current variation remain ambiguous. Our work unveils the microscopic mechanism of current variation for an ssDNA passing through the MspA nanopore by all-atom molecular dynamic simulations. Besides the physical rigidity and dimensions of the nucleotides, nucleotide orientation is observed to induce nonignorable current variation. Besides the generally considered MspA nanopore constriction, it is also found that the region below constriction could be used to detect and differentiate single nucleotides when the single-stranded DNA translocates in the form of base-constriction-base meshing and ratcheting across the nanopore constriction compared to other regions. The work provides a novel insight into facilitating the development of low-cost and high-throughput nanopore DNA sequencing.


Assuntos
Nanoporos , Porinas/química , Análise de Sequência de DNA/métodos , DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Simulação de Dinâmica Molecular , Mycobacterium smegmatis/metabolismo , Porinas/metabolismo
8.
Zool Res ; 42(6): 710-720, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34581031

RESUMO

The Chantecler chicken, a unique Canadian indigenous breed, is well adapted to extremely cold environments. However, its genetic characteristics have not been well studied. Here, we analyzed the whole genomes of 10 Chantecler chickens and 121 worldwide chickens, which indicated that Chantecler chickens were derived from commercial chickens and exhibit a high level of inbreeding. Based on a genome-wide scan, we identified two vital candidate regions containing ME3 and ZNF536, which are related to fat metabolism and nervous system in cold adaptation, respectively. We also found that the genetic mechanism of cold adaptation in Chantecler chickens differed from that of chickens from other cold regions, such as northern China. Our study indicated that specialized commercial chickens in the early 20th century contained sufficient genetic diversity to adapt to extreme cold environments over a very short time. These findings enrich our understanding of the adaptive potential of commercial species.


Assuntos
Adaptação Fisiológica/genética , Galinhas/genética , Galinhas/fisiologia , Temperatura Baixa , Estudo de Associação Genômica Ampla/veterinária , Animais , Genoma , Endogamia , Álcool Oxidorredutases Dependentes de NAD(+) e NADP(+)/genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Polimorfismo de Nucleotídeo Único , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Seleção Genética
9.
Nanoscale ; 13(36): 15352-15361, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34498657

RESUMO

Protein sequencing is essential to unveil the mechanism of cellular processes that govern the function of living organisms, and which play a crucial role in the field of drug design and molecular diagnostics. Nanopores have been proved to be effective tools in single molecule sensing, but the fast translocation speed of a peptide through a nanopore is one of the major obstacles that hinders the development of nanopore-based protein sequencing. In this work, by using molecular dynamics simulations (MDS) it is found that the peptide containing more hydrophobic residues permeates slower through a molybdenum disulfide nanopore, which originates from the strong interaction between the membrane surface and the hydrophobic residues. The binding affinity is remarkable especially for benzenoid residues as they contain a hydrophobic aromatic ring that is composed of relatively non-polar C-C and C-H bonds. By tuning the fraction of benzenoid residues of the peptide, the velocity of the protein translocation through the nanopore is well controlled. The peptide with all the hydrophobic residues being benzenoid residues is found to translocate through the nanopore almost ten times slower than the one without any benzenoid residues, which is beneficial for gathering adequate information for precise amino acid identification.


Assuntos
Nanoporos , Sequência de Aminoácidos , Simulação de Dinâmica Molecular , Transporte Proteico , Proteínas
10.
Front Oncol ; 11: 713637, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34497765

RESUMO

Background: Second primary malignancy (SPM) is becoming a threat for the health of cancer survivors. However, data on the features and results of patients with hepatocellular carcinoma (HCC) with SPMs are scarce. This study aimed to explore the characteristics of HCC patients with SPMs and to screen HCC patients who are at a high risk of developing SPMs. Method: HCC patients diagnosed between 2000 and 2014 in the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. Eligible patients were divided into the only one primary malignancy and SPM groups. The Fine-Gray proportional subdistribution hazards model was used to explore the risk factors of developing SPMs, and a competing-risk model was established to predict the probability of developing SPMs for HCC patients after initial diagnosis. The calibration curves, concordance index (C-index), and decision curve analysis (DCA) were used to evaluate the performance of the nomogram. Results: A total of 40,314 HCC patients were identified, 1,593 (3.95%) of whom developed SPMs 2 months after the initial diagnosis with a maximum follow-up time of approximately 18 years. The 3-, 5-, and 10-year cumulative incidence of SPMs were 2.35%, 3.12%, and 4.51%, respectively. Age at initial diagnosis, extent of disease, tumor size, and treatment were identified as the independent risk factors of developing SPMs and integrated into the competing-risk nomogram. The C-index of the nomogram was 0.677 (95% confidence interval 0.676-0.678), and the calibration curves showed an excellent agreement between the nomogram prediction and the actual observations. Furthermore, DCA indicated that the nomogram had good net benefits in clinical scenarios. Conclusions: HCC survivors remain at a high risk of developing SPMs. The development of SPMs was associated with the clinical features and treatment strategies. A competing-risk nomogram was constructed to help surgeons identify the patients who are at a high risk of developing SPMs and contribute to the further management of SPMs.

11.
Front Aging Neurosci ; 13: 721474, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539383

RESUMO

Tau hyperphosphorylation is a characteristic alteration present in a range of neurological conditions, such as traumatic brain injury (TBI) and neurodegenerative diseases. Treatments targeting high-mobility group box protein 1 (HMGB1) induce neuroprotective effects in these neuropathologic conditions. However, little is known about the interactions between hyperphosphorylated tau and HMGB1 in neuroinflammation. We established a model of TBI with controlled cortical impacts (CCIs) and a tau hyperphosphorylation model by injecting the virus encoding human P301S tau in mice, and immunofluorescence, western blotting analysis, and behavioral tests were performed to clarify the interaction between phosphorylated tau (p-tau) and HMGB1 levels. We demonstrated that p-tau and HMGB1 were elevated in the spatial memory-related brain regions in mice with TBI and tau-overexpression. Animals with tau-overexpression also had significantly increased nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome activation, which manifested as increases in apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), activating caspase-1 and interleukin 1 beta (IL-1ß) levels. In addition, NLRP3-/- mice and the HMGB1 inhibitor, glycyrrhizin, were used to explore therapeutic strategies for diseases with p-tau overexpression. Compared with wild-type (WT) mice with tau-overexpression, downregulation of p-tau and HMGB1 was observed in NLRP3-/- mice, indicating that HMGB1 alterations were NLRP3-dependent. Moreover, treatment with glycyrrhizin at a late stage markedly reduced p-tau levels and improved performance in the Y- and T-mazes and the ability of tau-overexpressing mice to build nests, which revealed improvements in spatial memory and advanced hippocampal function. The findings identified that p-tau has a triggering role in the modulation of neuroinflammation and spatial memory in an NLRP3-dependent manner, and suggest that treatment with HMGB1 inhibitors may be a better therapeutic strategy for tauopathies.

12.
J Exp Clin Cancer Res ; 40(1): 290, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526098

RESUMO

BACKGROUND: Accumulating evidence indicates that circRNAs may serve as essential regulators in the progression of several human cancers, but the function and mechanism of circRNAs in intrahepatic cholangiocarcinoma (ICC) are largely unknown. METHODS: RNA-seq was used to assess differentially expressed circRNAs between 4 ICC and peritumor tissues. Quantitative RT-PCR and in situ hybridization were used to determine the circHMGCS1-016 expression in ICC tissues. The function and mechanism of circHMGCS1-016 were further identified via in vivo experiments. The clinical characteristics and prognostic significance of circHMGCS1-016 were analyzed by a retrospective study. The functions of circHMGCS1-016 were assessed via modifying circRNA expression in ICC cells. Moreover, the molecular mechanisms of circHMGCS1-016 in ICC cells were explored by circRNA precipitation, miRNA immunoprecipitation, SILAC and luciferase reporter assays. RESULTS: We identified that compared with peritumor tissues, ICC tissues expressed hsa_circ_0008621 (circHMGCS1-016) high by RNA-seq, which was further identified by qRT-PCR and in situ hybridization. Moreover, the expression of circHMGCS1-016 was revealed to be associated with survival and recurrence of ICC patients. By regulating circHMGCS1-016 expression, we found that elevated circHMGCS1-016 promoted ICC development both in vitro and in vivo. By SILAC and circRNA-pull down, we demonstrated that circHMGCS1-016 induced ICC cell invasion and reshaped the tumor immune microenvironment via the miR-1236-3p/CD73 and GAL-8 axis. In ICC tissues, we uncovered that a high level of circHMGCS1-016 was positively associated with CD73 and GAL-8 expression and negatively related to the CD8+ T cells infiltration, which was further validated by establishing a humanized mouse tumor model. Importantly, we displayed that ICC patients with high levels of circHMGCS1-016 in tumor tissues benefited less from anti-PD1 treatment compared to those with low levels of circHMGCS1-016. CONCLUSIONS: CircHMGCS1-016 is a forceful contributor in ICC development and immune tolerance via miR-1236-3p/CD73 and GAL-8 axis. CircHMGCS1-016 can be explored as a new potential biomarker and therapeutic target for PD1-resistant ICC.

13.
NPJ Biofilms Microbiomes ; 7(1): 69, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475403

RESUMO

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. However, it is unclear whether microbiota and metabolites have demonstrated changes at early PD due to the difficulties in diagnosis and identification of early PD in clinical practice. In a previous study, we generated A53T transgenic monkeys with early Parkinson's symptoms, including anxiety and cognitive impairment. Here we analyzed the gut microbiota by metagenomic sequencing and metabolites by targeted gas chromatography. The gut microbiota analysis showed that the A53T monkeys have higher degree of diversity in gut microbiota with significantly elevated Sybergistetes, Akkermansia, and Eggerthella lenta compared with control monkeys. Prevotella significantly decreased in A53T transgenic monkeys. Glyceric acid, L-Aspartic acid, and p-Hydroxyphenylacetic acid were significantly elevated, whereas Myristic acid and 3-Methylindole were significantly decreased in A53T monkeys. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (KO0131) and the oxidative phosphorylation reaction (KO2147) were significantly increased in metabolic pathways of A53T monkeys. Our study suggested that the transgenic A53T and α-syn aggregation may affect the intestine microbiota and metabolites of rhesus monkeys, and the identified five compositional different metabolites that are mainly associated with mitochondrial dysfunction may be related to the pathogenesis of PD.

14.
Reproduction ; 162(6): 461-472, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34591784

RESUMO

As a multifunctional transcription factor, YY1 regulates the expression of many genes essential for early embryonic development. RTCB is an RNA ligase that plays a role in tRNA maturation and Xbp1 mRNA splicing. YY1 can bind in vitro to the response element in the proximal promoter of Rtcb and regulate Rtcb promoter activity. However, the in vivo regulation and whether these two genes are involved in the mother-fetal dialogue during early pregnancy remain unclear. In this study, we validated that YY1 bound in vivo to the proximal promoter of Rtcb in mouse uterus of early pregnancy. Moreover, via building a variety of animal models, our study suggested that both YY1 and RTCB might play a role in mouse uterus decidualization and embryo implantation during early pregnancy.

15.
Mitochondrial DNA B Resour ; 6(9): 2478-2479, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368449

RESUMO

Oxytropis glabra DC. is a perennial poisonous plant to livestock belonging to the genus Oxytropis, Leguminosae, mainly distributed in Northwestern China. As a poisonous grass, this species protects plant diversity in degraded grasslands by sheltering adjacent plants. In this study, the complete chloroplast genome with a total size of 122,094 bp was reported. Our annotations showed that the chloroplast genome contains 109 genes, including 76 protein-coding genes, 29 tRNA genes, and four rRNA genes. This work presents complete chloroplast genome information, which will be valuable for studying the evolution and genetic diversity of O. glabra.

16.
Artigo em Inglês | MEDLINE | ID: mdl-34444539

RESUMO

COVID-19 might have long-term mental health impacts. We aim to investigate the longitudinal changes in mental problems from initial COVID-19 peak to its aftermath among general public in China. Depression, anxiety and insomnia were assessed among a large-sample nationwide cohort of 10,492 adults during the initial COVID-19 peak (28 February 2020 to 11 March 2020) and its aftermath (8 July 2020 to 8 August 2020) using the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and Insomnia Severity Index. We used generalized estimating equations and linear mixed models to explore factors associated with long-term mental health symptoms during COVID-19. During the five months, mental health symptoms remained consistently elevated (baseline 46.4%; follow-up 45.1%). Long-term depression, anxiety and insomnia were associated with several personal and work-related factors including quarantine (adjusted OR for any mental health symptoms 1.31, 95%CI 1.22-1.41, p < 0.001), increases in work burden after resuming work (1.77, 1.65-1.90, p < 0.001), occupational exposure risk to COVID-19 (1.26, 1.14-1.40, p < 0.001) and living in places severely affected by initial COVID-19 peak (1.21, 1.04-1.41, p = 0.01) or by a COVID-19 resurgence (1.38, 1.26-1.50, p < 0.001). Compliance with self-protection measures, such as wearing face masks (0.74, 0.61-0.90, p = 0.003), was associated with lower long-term risk of mental problems. The findings reveal a pronounced and prolonged mental health burden from the initial COVID-19 peak through to its aftermath in China. We should regularly monitor the mental health status of vulnerable populations throughout COVID-19.


Assuntos
COVID-19 , Saúde Mental , Adulto , Ansiedade/epidemiologia , China/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Humanos , Estudos Longitudinais , SARS-CoV-2
17.
J Sep Sci ; 44(18): 3441-3449, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34291571

RESUMO

Plant-derived alkaloids are bioactive natural ingredients, but their contents are relatively low in plants. Therefore, the efficient enrichment of alkaloids is a prerequisite for purification and further pharmacological research. In this study, an efficient and simple strategy for enrichment of steroidal alkaloids in Fritillaria was developed for the first time based on the fluorinated reverse-phase stationary phase (FC8HL). Superior selectivity between alkaloids and non-alkaloids was achieved in a non-aqueous system, and a simple solvent system containing low-content additives was applied to elute alkaloids. Key parameters that affected the elution were investigated, including different types of buffer salts and optimized concentrations. The optimized elution system was then applied to selectively enrich alkaloids from five species of Fritillaria. Its practicability was further demonstrated by enrichment of alkaloids from Fritillaria cirrhosa D.Don at a preparative level. This developed method has great potential for other types of hydrophobic alkaloids.

18.
Neurochem Int ; 149: 105145, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34324942

RESUMO

The heteromeric complexes of adenosine 2A receptor (A2AR) and N-methyl-D-aspartate receptor (NMDAR) have recently been confirmed in cell experiments, while its in situ detection at the subcellular level of brain tissue has not yet been achieved. Proximity Ligation Assay (PLA) enables the detection of low-abundance proteins and their interactions at the cellular level with high specificity and sensitivity, while Transmission electron microscope (TEM) is an excellent tool for observing subcellular structures. To develop a highly efficient and reproducible technique for in situ detection of protein interactions at subcellular levels, in this study, we modified the standard PLA sample preparation method to make the samples suitable for analysis by transmission electron microscopy. Using this technique, we successfully detected the heteromers of A2AR and NMDAR1, the essential subunit of NMDA receptor on the hippocampal synaptic structure in mice. Our results show that the distribution of this heteromer is different in different hippocampal subregions. This technique holds the potential for being a reliable method to detect protein interactions at the subcellular level and unravel their unknown functions.

19.
J Phys Chem Lett ; 12(28): 6469-6477, 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34240883

RESUMO

Many biological assays require effectively and sensitively sorting DNA fragments. Here, we demonstrate a solid-state nanopore platform for label-free detection and separation of short single-stranded DNA (ssDNA) fragments (<100 nt), based on their length-dependent translocation behaviors. Our experimental data show that each sized pore has a passable length threshold. The negative charged ssDNA fragments with length smaller than the threshold can be electrically facilitated driven through the correspondingly sized nanopore along the direction of electric field. In addition, the passable length threshold increases with the pore size enlarging. As a result, this phenomenon is able to be applicable for the controllable selectivity of ssDNA by tuning nanopore size, and the selectivity limitation is up to 30nt. Numerical simulation results indicate the translocation direction of ssDNA is governed by the competition of electroosmosis and electrophoresis effects on the ssDNA and offer the relationship between passable length threshold and pore size.


Assuntos
DNA de Cadeia Simples/análise , DNA de Cadeia Simples/isolamento & purificação , Nanoporos , Nanotecnologia/métodos , Eletroforese , Limite de Detecção , Osmose
20.
Huan Jing Ke Xue ; 42(8): 3985-3996, 2021 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-34309285

RESUMO

Straw returning is an effective technique for improving soil fertility and maintaining crop productivity in agro-ecosystems. The effects of straw returning, when combined with chemical fertilizer, on soil nutrients, enzyme activity, and microbial community were explored in rice-rape rotation farmland in the Chaohu Area. We carried out a 4-year field experiment (2016-2020) and set up four treatments (no straw+no fertilization, CK; conventional fertilization, F; straw returning+conventional fertilization, SF; and straw returning+conventional fertilization minus 20%, SDF) to explore the key environmental factors affecting soil enzyme activity and microbial and fungal communities. The results showed that straw returning combined with chemical fertilizer could improve soil nutrient content, with the SF treatment resulting in the highest soil nutrient content. Compared with F, the SF treatment significantly increased the organic matter (OM) and total phosphorus (TP) content of the soil, by 7.94% and 24.07%, respectively, in rice seasons (P<0.05), while the alkaline nitrogen (AN) content was significantly increased by 13.62% in rape seasons (P<0.05). Compared with F, the SF treatment also significantly increased soil phosphatase and urease, by 28.54% and 24.13% in rice seasons and 38.97% and 30.70% in rape seasons, respectively (P<0.05). Compared with F, SDF treatments significantly increased urease activity by 20.31% in rice seasons and 24.33% in rape seasons (P<0.05). The results indicated that straw returning increased both the Chao1 and Shannon indices of soil bacteria in rice seasons, whereas decreased these indices in rape seasons. However, the Chao1 and Shannon index of the fungal community increased after straw returning. In terms of microbial community structure, the relative abundance of Proteobacteria in SF and SDF treatments increased by 8.22% and 7.88% in rice seasons and 18.53% and 5.68% in rape seasons, respectively, compared with the F treatment. Compared with F, the relative abundance of Chloroflexi in SF and SDF treatments increased by 12.00% and 11.25% in rice seasons and 15.02% and 8.43% in rape seasons, respectively. Compared with F, the relative abundance of Basidiomycota in SF and SDF treatments in rice seasons increased by 70% and 43.42% (P<0.05), respectively, while ascomycetes in rape seasons increased by 69.79% and 43.72% (P<0.05), respectively. In conclusion, straw returning combined with chemical fertilizer can improve soil nutrient content. Soil urease and phosphatase were more sensitive to straw returning. The compositional changes in the bacterial community of the soil were mainly affected by soil TP and available phosphorus (AP), whereas OM, AN, and pH were the main environmental factors causing changes in the fungal community composition. Consequently, straw returning can improve soil fertility and maintain ecosystem health.


Assuntos
Micobioma , Oryza , Agricultura , Ecossistema , Fertilizantes/análise , Rotação , Solo , Microbiologia do Solo
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