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1.
Methods Mol Biol ; 2196: 39-51, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32889711

RESUMO

Genetic elements of interest can be introduced into the Saccharomyces cerevisiae genome via homologous recombination. A common method is to link such an element to a selectable marker gene to be integrated into the target locus. However, the marker gene in this method cannot be reused, which limits repeated manipulation of the yeast genome. More importantly, it cannot be conveniently used to integrate a promoter element. An alternative method is to utilize a counterselectable gene, such as URA3, with flanking tandem repeats. After integration, URA3 along with one copy of the repeat can be popped out via internal recombination, leaving behind one copy of the unwanted repeat. Here we describe a method of genetic element shuffling in which the tandem repeats are made of a set of promoters, so that after integration and popping out, only one copy of the promoter remains at the desired locus to function.

2.
Methods Mol Biol ; 2196: 53-62, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32889712

RESUMO

An essential gene is defined as a gene that cannot be completely removed from the genome. Investigation of an essential gene function is limited because its deletion strain cannot be readily created. Here we describe a protocol called plasmid shuffling that can be conveniently employed in yeast to study essential gene functions. The essential gene is first cloned into a YCp-based plasmid with URA3 as a selectable marker and then transformed into host cells. The transformed cells can then be used to delete the chromosomal copy of the essential gene. The gene is then cloned into another YCp-based plasmid with a different selectable marker, and the gene sequence can be altered in vitro. Plasmids carrying the mutated gene sequences are transformed into the above cells, resulting in carrying two plasmids. These cells are grown in medium containing 5-FOA that selects ura3 cells. The 5-FOA-resistant cells are expected to only carry the plasmid containing the mutated essential gene, whose functions can be assessed.

3.
Methods Mol Biol ; 2196: 63-75, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32889713

RESUMO

Labeling a protein of interest is widely used to examine its quantity, modification, localization, and dynamics in the budding yeast Saccharomyces cerevisiae. Fluorescent proteins and epitope tags are often used as protein fusion tags to study target proteins. One prevailing technique is to fuse these tags to a target gene at the precise chromosomal location via homologous recombination. Here we describe a protein labeling strategy based on the URA3 pop-in/pop-out and counterselection system to fuse a fluorescent protein or epitope tag scarlessly to a target protein at its native locus in S. cerevisiae.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33064932

RESUMO

Non-noble electrocatalyst for the oxygen evolution reaction (OER) is essential for water electrolysis and electrochemical conversion of CO 2 . Integrating electrochemical fixation of CO 2 and electrochemical metallurgy to prepare advanced OER electrocatalyst is a promising solution to promote carbon neutrality and renewable energy. Herein, the electrochemical reduction of CO 2 and Fe 2 O 3 are combined in molten salts to prepare cathodic Fe 3 C-based electrocatalyst and anodic oxygen at 600 °C with enhanced current efficiency. The resulting Fe 3 C-based electrocatalyst outperforms precious electrocatalyst towards the OER operation in 1 M KOH due to a dynamic structural evolution to form an interface of Fe 3 C-FeOOH.

5.
Carbohydr Polym ; 250: 116969, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33049865

RESUMO

Natural cellulose features the outstanding merits of biodegradability, large-volume production and worldwide availability, which has become a promising material for achieving a sustainable society. Based on a simple dissolution-regeneration process of natural cellulose, the flexible, transparent, and smooth regenerated cellulose film (RCF) can be easily manufactured. The RCF can become conductive by introducing the conductive materials, which has presented potential applications for high-performance electronic devices. Herein, we summarized the mainly non-derivative solvents for the preparation of the RCF as well as the conductive materials for manufacturing the conducive regenerated cellulose film (CRCF). In addition, the CRCF-based versatile electronic device were also introduced.

6.
Ann Palliat Med ; 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-33040539

RESUMO

Benign metastasizing leiomyoma (BML) is a rare condition that occurs mainly in premenopausal women and is characterized most commonly by pulmonary metastases. Here, we report the case of a 45-yearold woman who presented with multiple bilateral pulmonary nodules on chest examination during a health checkup 13 years after myomectomy. This patient has a normal menstrual cycle, moderate anemia, and no obvious respiratory symptoms. Serum concentrations of cancer markers such as carcinoembryonic antigen, neuron specific enolase, cytokeratin 19 fragments, and pro-gastrin-releasing peptide were within normal limits. Color doppler ultrasound was also performed, several hypoechoic regions were found in uterine bodies and cavity. The computed tomography (CT)-guided lung biopsy was used for histopathological examination. Immunohistochemical staining revealed BML which were positive for smooth muscle antibody, desmin, vimentin, estrogen and progesterone receptors, and Ki-67 positive rate of about 1%. Hysterectomy and bilateral adnexectomy were performed as a part of treatment. The lung nodules were meticulously monitored at follow-up. Three months later, the repeat CT scan showed that the nodules had reduced in size, and no new nodules had appeared, 1 year later, CT scan showed no obvious changes in lung nodules. This study is of great significance as the results will be helpful in diagnosing and treating future pulmonary benign metastasizing leiomyoma (PBML) cases.

7.
Adv Nutr ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33002099

RESUMO

Here we provide a comprehensive meta-analysis to summarize and appraise the quality of the current evidence on the associations of tea drinking in relation to cancer risk. PubMed, Embase, and the Cochrane Database of Systematic Reviews were searched up to June 2020. We reanalyzed the individual prospective studies focused on associations between tea drinking and cancer risk in humans. We conducted a meta-analysis of prospective studies and provided the highest- versus lowest-category analyses, dose-response analyses, and test of nonlinearity of each association by modeling restricted cubic spline regression for each type of tea. We graded the evidence based on the summary effect size, its 95% confidence interval, 95% prediction interval, the extent of heterogeneity, evidence of small-study effects, and excess significance bias. We identified 113 individual studies investigating the associations between tea drinking and 26 cancer sites including 153,598 cancer cases. We assessed 12 associations for the intake of black tea with cancer risk and 26 associations each for the intake of green tea and total tea with cancer risk. Except for an association between lymphoid neoplasms with green tea, we did not find consistent associations for the highest versus lowest categories and dose-response analyses for any cancer. When grading current evidence for each association (number of studies ≥2), weak evidence was detected for lymphoid neoplasm (green tea), glioma (total tea, per 1 cup), bladder cancer (total tea, per 1 cup), and gastric and esophageal cancer (tea, per 1 cup). This review of prospective studies provides little evidence to support the hypothesis that tea drinking is associated with cancer risk. More well-designed studies are still needed to identify associations between tea intake and rare cancers.

8.
Plant Cell Environ ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051890

RESUMO

Jasmonic acid (JA) is shown to induce leaf senescence. However, the underlying molecular mechanism is not well understood, especially in woody plants such as fruit trees. In this study, we are interested in exploring the biological role of MdBT2 in JA-mediated leaf senescence. We found that MdBT2 played an antagonistic role in MdMYC2-promoted leaf senescence. Our results revealed that MdBT2 interacted with MdMYC2 and accelerated its ubiquitination degradation, thus negatively regulated MdMYC2-promoted leaf senescence. In addition, MdBT2 acted as a stabilizing factor to improve the stability of MdJAZ2 through direct interaction, thereby inhibited JA-mediated leaf senescence. Furthermore, our results also showed that MdBT2 interacted with a subset of JAZ proteins in apple, including MdJAZ1, MdJAZ3, MdJAZ4, and MdJAZ8. Our investigations provide new insight into molecular mechanisms of JA-modulated leaf senescence. The dynamic JA-MdBT2-MdJAZ2-MdMYC2 regulatory module plays an important role in JA-modulated leaf senescence. This article is protected by copyright. All rights reserved.

9.
Fish Shellfish Immunol ; 107(Pt A): 9-15, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32976972

RESUMO

Tiger frog virus (TFV) belongs to the genus Ranavirus (family Iridoviridae) and causes significant harm in cultured frogs, resulting in substantial losses in ecological and economic field in Southern China. Attachment is the first step in viral life cycle, which is dependent on the interactions of virions with extracellular matrix (ECM) components. Studying this process will help in understanding virus infection and controlling viral diseases. In this study, the roles of primary ECM components in TFV attachment were investigated. The results on the kinetics of virus attachment showed TFV successful attachment to the cell surface as a relatively rapid process after TFV was used to inoculate cells for 10 min at 4 °C. Western blot and quantitative PCR analyses results showed that soluble fibronectin, collagen IV, laminin, or hyaluronic acid treatment with TFV caused no significant effect on virus attachment. Soluble heparin, heparan sulfate and chondroitin sulfate A/B could inhibit TFV attachment in a dose-dependent manner. Enzymic digestion by cell surface heparin/heparan sulfate using heparinase I, II, and III could significantly prevent TFV attachment, suggesting that heparan sulfate plays an important role in TFV attachment. Furthermore, the binding assays of heparin-agarose beads and virion showed that TFV virions specifically bound with heparin in a dose-dependent manner. Given that heparin is a structural analogue of heparan sulfate, the above results suggest that heparan sulfate might serve as an attachment factor of TFV infection. Our work would be beneficial to understand the mechanisms of TFV attachment and the interactions of TFV with cellular receptor(s).

10.
PLoS One ; 15(8): e0238353, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866964

RESUMO

OBJECTIVE: Our aim was to identify the patterns of multimorbidity among a group of patients who visited primary care in Singapore. METHODS: A cross-sectional study of electronic medical records was conducted on 437,849 individuals aged 0-99 years who visited National Healthcare Group Polyclinics from 1 Jul 2015 to 30 Jun 2016 for the management of chronic conditions. Patients' health conditions were coded with the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10), and patient records were extracted for analysis. Patients' diagnosis codes were grouped by exploratory factor analysis (EFA), and patterns of multimorbidity were then identified by latent class analysis (LCA). RESULTS: EFA identified 19 groups of chronic conditions. Patients with at least three chronic conditions were further separated into eight classes based on demographics and probabilities of various diagnoses. We found that older patients had higher probabilities of comorbid hypertension, kidney disease and ischaemic heart disease (IHD), while younger patients had a higher probability of comorbid obesity. Female patients had higher probabilities of comorbid arthritis and anaemia, while male patients had higher probabilities of comorbid kidney diseases and IHD. Indian patients presented with a higher probability of comorbid diabetes than Chinese and Malay patients. CONCLUSIONS: This study demonstrated that patients with multimorbidity in primary care could be classified into eight patterns. This knowledge could be useful for more precise management of these patients in the multiethnic Asian population of Singapore. Programmes for early intervention for at-risk groups can be developed based on the findings.

11.
Curr Top Med Chem ; 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901585

RESUMO

Berberine as a representative of isoquinoline alkaloid, exhibits significant hypolipidemic activity both in animal model and clinic trials. Recently, a large number of studies on the lipid-lowering mechanism of berberine, and researches for improving its hypolipidemic activity are reported, but they seem to be scattered mostly, or not comprehensive. In addition, there are few specific reviews on the discussion of the lipid-reducing effect of berberine. In this paper, the physicochemical property, the lipid-lowering mechanism, and the modification study of berberine, all are discussed in succession to promote the depth development of berberine as a lipid-lowering agent. Subsequently, this paper would provide some insights into the deficiencies of berberine in the study of lipid-lowering drug, and based on the situation, some proposals are put forward.

12.
Annu Rev Entomol ; 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32931313

RESUMO

Of the approximately 1,200 plant virus species that have been described to date, nearly one-third are single-stranded DNA (ssDNA) viruses, and all are transmitted by insect vectors. However, most studies of vector transmission of plant viruses have focused on RNA viruses. All known plant ssDNA viruses belong to two economically important families, Geminiviridae and Nanoviridae, and in recent years, there have been increased efforts to understand whether they have evolved similar relationship with their respective insect vectors. This review describes the current understanding of ssDNA virus-vector interactions, including how these viruses cross insect vector cellular barriers, the responses of vectors to virus circulation, the possible existence of viral replication within insect vectors, and the three-way virus-vector-plant interactions. Despite recent breakthroughs in our understanding of these viruses, many aspects of plant ssDNA virus transmission remain elusive. More effort is needed to identify insect proteins that mediate the transmission of plant ssDNA viruses and to understand the complex virus-insect-plant three-way interactions in the field during natural infection. Expected final online publication date for the Annual Review of Entomology, Volume 66 is January 11, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

14.
Bioorg Chem ; 103: 104221, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32891001

RESUMO

Thirteen new sesquiterpenoids, arteannoides F-R (1-13), along with 13 known analogues (14-26), were isolated from the dried aerial parts of Artemisia annua L. Their structures, including absolute configurations, were unambiguously determined by a combination of physical data analyses (HRESIMS, 1D and 2D NMR, and ECD) as well as the crystal structures of 1, 5, 6, 15, 19, and 23. Among the isolated compounds, 1 features an unusual 11-oxatricyclo[6.2.1.04,9]undecan-2-ene ring system, 5 possesses an uncommon 4,11-ether bridged tricyclic framework, whereas 6 is a new eudesmane-type sesquiterpenoid formed via rearrangement of its carbon backbone. The systemically anti-inflammatory activities of all isolates were evaluated by measuring their inhibitory effects on PGE2, NO, TNF-α, and IL-6 production in LPS-stimulated RAW 264.7 macrophages. Moreover, the structure activity relationships of some compounds are summarized, this study will provide new structural templates for discovering potential anti-inflammatory agents.

15.
Small ; : e2002628, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32964688

RESUMO

While organic-inorganic halide perovskite solar cells (PSCs) show great potential for realizing low-cost and easily fabricated photovoltaics, the unexpected defects and long-term stability against moisture are the main issues hindering their practical applications. Herein, a strategy is demonstrated to address the main issues by introducing lead sulfide quantum dots (QDs) on the perovskite surface as the multifunctional interface layer on perovskite film through establishing perovskite as the ligand on PbS QDs. Meanwhile, the multifunctions are featured in three aspects including the strong interactions of PbS QDs with perovskites particularly at the grain boundaries favoring good QDs coverage on perovskites for ultimate smooth morphology; an inhibition of iodide ions mobilization by the strong interaction between iodide and the incorporated QDs; and the reduction of the dangling bonds of Pb2+ by the sulfur atoms of PbS QDs. Finally, the device performances are highly improved due to the reduced defects and non-radiative recombination. The results show that both open-circuit voltage and fill factor are significantly improved to the high values of 1.13 V and 80%, respectively in CH3 NH3 PbI3 -based PSCs, offering a high efficiency of 20.64%. The QDs incorporation also enhances PSCs' stability benefitting from the induced hydrophobic surface and suppressed iodide mobilization.

16.
Phytomedicine ; 79: 153326, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32992083

RESUMO

BACKGROUND: Lung cancer is the most common and mortal cancer worldwide. Rhodiola rosea L. (RR), a well-known traditional Chinese medicine (TCM), has been turned out to be effective in anti-lung cancer therapy, but its molecular mechanism of action has not been clearly understood. PURPOSE: In this study, we aimed to elucidate the possible molecular mechanism underlying the effect of RR against non-small cell lung cancer (NSCLC) by systems pharmacology. METHODS: The effects of RR on NSCLC were examined in Lewis lung carcinoma (LLC) tumor-bearing mice models. The possible molecular mechanism was unraveled by systems pharmacology, which includes pharmacokinetics evaluation, active compounds screening, target prediction and network analysis. Cell proliferation was examined by cell counting kit-8 (CCK-8) assay; cell apoptosis was detected by flow cytometry; protein and proinflammatory cytokines expression were evaluated by Western blot and qRT-PCR. RESULTS: In vivo, RR significantly inhibited the tumor growth and prolonged the survival of the tumor bearing mice. In silico, we identified 19 potential active molecules (e.g., salidroside and rhodiosin), 112 targets (e.g., COX-2 and AKT) and 27 pathways (e.g., PI3K/AKT signaling pathway and NF-κB signaling pathway) for RR. Additionally, targets analysis and networks construction further revealed that RR exerted anti-cancer effects by regulating apoptosis, angiogenesis and inflammation. In vitro, salidroside could significantly decrease expression of pro-angiogenic factors (e.g., VEGF and eNOS) and proinflammatory cytokines (e.g., COX-2, iNOS and TNF-α). Also, Bcl-2, an anti-apoptotic protein was decreased whereas Bax, a pro-apoptotic protein, was increased. Further flow cytometry analysis showed that salidroside could induce apoptosis in H1975 cells. CONCLUSIONS: Mechanistically, the antitumor effect of RR on NSCLC was responsible for the synergy among anti-inflammatory, anti-angiogenic and pro-apoptotic.

17.
BMC Neurol ; 20(1): 331, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32878608

RESUMO

BACKGROUND: Susceptibility weighted imaging (SWI) provides an approximate assessment of tissue perfusion and shows prominent hypointense cortical veins in the ischemic territory because of the increased concentration of deoxyhemoglobin. We aimed to evaluate whether asymmetrical prominent cortical vein sign (APCVS) on SWI can predict early neurological deterioration (END) in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion (SIASO). METHODS: One hundred and nine acute ischemic stroke patients with SIASO who underwent SWI were retrospectively recruited. END was defined as an increase in the National Institutes of Health Stroke Scale score ≧2 points despite standard treatment in the first 72 h after admission. The APCVS was defined as more and/or large vessels with greater signal loss than those in the opposite hemisphere on SWI. RESULTS: Thirty out of the 109 (27.5%) patients developed END. Sixty (55.0%) patients presented with APCVS on SWI. APCVS occurred in 24 (80%) patients with END, whereas it only occurred in 36 (45.6%) patients without END (P = 0.001). Patients with APCVS were more likely to have END (40.0%, vs. 12.2%, P = 0.001) than those without END. Multivariate logistic regression indicated that APCVS (OR = 4.349, 95% C.I. = 1.580-11.970, P = 0.004) was a significant predictor of END in acute ischemic stroke patients with SIASO, adjusted for previous stroke history and acute infarct volume. CONCLUSIONS: In acute ischemic stroke patients with SIASO, the APCVS might be a useful neuroimaging marker for predicting END, which suggests the importance of evaluation of perfusion status.

18.
Curr Biol ; 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32916110

RESUMO

During post-embryonic development, the pericycle specifies the stem cells that give rise to both lateral roots (LRs) and the periderm, a suberized barrier that protects the plant against biotic and abiotic stresses. Comparable auxin-mediated signaling hubs regulate meristem establishment in many developmental contexts; however, it is unknown how specific outputs are achieved. Using the Arabidopsis root as a model, we show that while LR formation is the main auxin-induced program after de-etiolation, plants with age become competent to form a periderm in response to auxin. The establishment of the vascular cambium acts as the developmental switch required to trigger auxin-mediated periderm initiation. Moreover, distinct auxin signaling components and targets control LR versus periderm formation. Among the periderm-specific-promoting transcription factors, WUSCHEL-RELATED HOMEOBOX 4 (WOX4) and KNAT1/BREVIPEDICELLUS (BP) stand out as their specific overexpression in the periderm results in an increased number of periderm layers, a trait of agronomical importance in breeding programs targeting stress tolerance. These findings reveal that specificity in pericycle stem cell fate is achieved by the integration of developmental cues into distinct regulatory modules.

19.
Am J Chin Med ; 48(6): 1455-1473, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32933312

RESUMO

Uric acid nephropathy (UAN) is caused by excessive uric acid, which results in the damage of renal tissue via urate crystals deposition in the kidneys. The roots and rhizomes of Salvia miltiorrhiza Bunge (S. miltiorrhiza) have been clinically used in many prescriptions to treat uric acid-induced renal damage. This study investigates the uricosuric and nephroprotective effects of the ethyl acetate extract of S. miltiorrhiza (EASM) and tanshinone IIA (a major component of S. miltiorrhiza, Tan-IIA) on UAN and explores the underlying molecular mechanism. Both EASM and Tan-IIA significantly decreased serum uric acid (SUA), serum creatinine (SCR), urine uric acid (UUA), and increased urine creatinine (UCR), and blood urea nitrogen (BUN) levels in experimental UAN mice. In adenine and potassium oxonate-induced mice, EASM and Tan-IIA treatment alleviated renal dysfunction and downregulated the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Moreover, EASM treatment significantly prevented excessive reactive oxygen species (ROS) production in uric acid-induced HK-2 cells and suppressed the expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). EASM also suppressed ROS-activated mitogen-activated protein kinases (MAPKs) in vivo and in vitro. These results suggest that both EASM and Tan-IIA demonstrated inhibitory effects on UAN through relieving NOX4-mediated oxidative stress and suppressing MAPK pathways activation.

20.
J Nat Prod ; 83(9): 2545-2558, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32935986

RESUMO

A phytochemical study on the aerial parts of Leonurus japonicus led to the isolation and identification of 38 labdane diterpenoids, including 18 new (1, 2, 11, 12, 16-21, 24, 30-34, 37, 38) and 20 known (3-10, 13-15, 22, 23, 25-29, 35, 36) analogues. Their structures were elucidated based on physical data analysis, including 1D and 2D NMR, HRMS, UV, IR, and X-ray diffraction. The structure of the known compound 4 was confirmed by single-crystal X-ray diffraction data. These compounds can be divided into furanolabdane (1-10), tetrahydrofuranolabdane (11-15), lactonelabdane (16-23), labdane (24-29), and seco-labdane (30-38) type diterpenoids. All compounds were screened by lipopolysaccharide (LPS)-induced nitric acid (NO) production in RAW264.7 cells to evaluate anti-inflammatory effects. Compounds 1, 5, 10-13, 16-19, 31-33, and 38 inhibited NO production with IC50 values lower than 50 µM, with compound 30 being the most active, with an IC50 value of 3.9 ± 1.7 µM. Further studies show that compound 30 inhibits pro-inflammatory cytokine production and IKK α/ß phosphorylation and restores the IκB expression levels in the NF-κB signaling pathway.

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