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1.
Ann Biol Clin (Paris) ; 78(5): 499-518, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33026346

RESUMO

The French society of clinical biology "Biochemical markers of COVID-19" has set up a working group with the primary aim of reviewing, analyzing and monitoring the evolution of biological prescriptions according to the patient's care path and to look for markers of progression and severity of the disease. This study covers all public and private sectors of medical biology located in metropolitan and overseas France and also extends to the French-speaking world. This article presents the testimonies and data obtained for the "Overseas and French-speaking countries" sub-working group made up of 45 volunteer correspondents, located in 20 regions of the world. In view of the delayed spread of the SARS-CoV-2 virus, the overseas regions and the French-speaking regions have benefited from feedback from the first territories confronted with COVID-19. Thus, the entry of the virus or its spread in epidemic form could be avoided, thanks to the rapid closure of borders. The overseas territories depend very strongly on air and/or sea links with the metropolis or with the neighboring continent. The isolation of these countries is responsible for reagent supply difficulties and has necessitated emergency orders and the establishment of stocks lasting several months, in order to avoid shortages and maintain adequate patient care. In addition, in countries located in tropical or intertropical zones, the diagnosis of COVID-19 is complicated by the presence of various zoonoses (dengue, Zika, malaria, leptospirosis, etc.).

2.
Theranostics ; 10(25): 11607-11621, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33052236

RESUMO

The hypoxic microenvironment in solid tumors severely limits the efficacy of photodynamic therapy (PDT). Therefore, the development of nanocarriers co-loaded with photosensitizers and oxygen, together with imaging guidance ability, is of great significance in cancer therapy. However, previously reported synthetic methods for these multi-functional probes are complicated, and the raw materials used are toxic. Methods: Herein, the human endogenous protein, hemoglobin (Hb), was used for the simultaneous biomimetic synthesis of Gd-based nanostructures and co-loading of Chlorine e6 (Ce6) and oxygen for alleviating the hypoxic environment of tumors and accomplishing magnetic resonance imaging (MRI)-guided enhanced PDT. The Gd@HbCe6-PEG nanoprobes were synthesized via a green and protein biomimetic approach. The physicochemical properties, including relaxivity, oxygen-carrying/release capability, and PDT efficacy of Gd@HbCe6-PEG, were measured in vitro and in vivo on tumor-bearing mice after intravenous injection. Morphologic and functional MRI were carried out to evaluate the efficacy of PDT. Results: The results demonstrated the successful synthesis of compact Gd@HbCe6-PEG nanostructures with desired multi-functionalities. Following treatment with the nanoparticles, the embedded MR moiety was effective in lighting tumor lesions and guiding therapy. The oxygen-carrying capability of Hb after biomimetic synthesis was confirmed by spectroscopic analysis and oxygen detector in vitro. Further, tumor oxygenation for alleviating tumor hypoxia in vivo after intravenous injection of Gd@HbCe6-PEG was verified by photoacoustic imaging and immunofluorescence staining. The potent treatment efficacy of PDT on early-stage was observed by the morphologic and functional MR imaging. Importantly, rapid renal clearance of the particles was observed after treatment. Conclusion: In this study, by using a human endogenous protein, we demonstrated the biomimetic synthesis of multi-functional nanoprobes for simultaneous tumor oxygenation and imaging-guided enhanced PDT. The therapeutic efficacy could be quantitatively confirmed at 6 h post PDT with diffusion-weighted imaging (DWI).

3.
J Biomater Sci Polym Ed ; : 1-24, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33035113

RESUMO

Poly(amido-amine) (PAMAM), one of the most widely studied dendrimers in the field of drug and gene delivery, can enhance the stability of DNA and deliver it to cell cytosol; hyaluronic acid (HA), a simple disaccharide unit, can polymerize and is considered a polymer of non-immunogenicity, which has an intrinsic targeting property for many cancer cells by interacting with CD 44. In this study, we had synthesized and characterized a series of PAMAM modified by HA. and PAMAM was conjugated by HA with different grafting density (5%, 15%, 25%) and molecular weight (HA3850, HA17200). We had investigated the particle size, zeta potential and Agarose gel electrophoresis assays of polyplexes. Besides, the cytotoxicity, transfection efficiency and the mechanisms of transfection of new polyplexes were assessed following in vitro transfection in Hela, Bel-7402 and HepG2 cells lines. In the results, modified by HA, the cytotoxicity of polymer had reduced and the size of some polymers also below 200 nm in appropriate weight ratio, and transfection efficiency had also close to the polyplexes G4 PAMAM/DNA were observed. Compared with the unmodified dendrimers compounds, the DNA delivering capacity of PAMAM G4-HA3850-5% and PAMAM G5-HA3850-5% had improved in cancer cells line. It is a potential candidate used for targeted gene delivery.

4.
J Exp Bot ; 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33045083

RESUMO

Nitric oxide (NO) has been implicated as a key signaling molecule involved in a wide spectrum of plant developmental and stress responses. Here, we found that NO also played important role in seed oil content and fatty acid composition. RNAi silencing Arabidopsis thaliana S-nitrosoglutathione reductase 1 (GSNOR1) gene led to higher NO content and up to 5.3% reduction of seed oil content. In contrast, nitrate reductase double mutant nia1nia2 led to an increase of seed oil content by 2.6%, compared to the wild type plant. Moreover, the levels of palmitic acid (C16:0), linoleic acid (C18:2) and linolenic acid (C18:3) were higher, whereas the levels of stearic acid (C18:0), oleic acid (C18:1) and arachidonic acid (C20:1) decreased in the seeds of GSNOR1 RNAi lines. The effects of NO on seed oil content and fatty acid composition were also demonstrated with rapeseed embryos cultured in vitro with NO donor Sodium Nitroprusside (SNP) and NO inhibitor NG-Nitro-L-arginine Methyl Ester (L-NAME). Similar results with that of Arabidopsis were obtained. Compared to non-treated embryo control, the oil contents were decreased by 1.95% and 4.69% in 10µM and 20µM SNP-treated embryos and increased by 1.66% and 2.43% in 200µM and 400µM L-NAME-treated embryos respectively. The relative quantities of C16:0, C18:2 and C18:3 were significantly higher, whereas C18:1 level decreased markedly in rapeseed embryos treated with SNP. Proteomics and transcriptome analysis revealed that three S-nitrosated proteins (PKp2, LACS4, and SSI2) and some key genes involved in oil synthesis were differentially regulated in SNP treated embryos, suggesting that NO regulated seed oil content and fatty acid composition. The seed oil content increase in Arabidopsis and rapeseed was further obtained by spraying L-NAME directly on developing siliques. These results suggested that regulating NO level could be a novel approach to increase seed oil content in oil crops during cultivation in addition to marker-assisted selection breeding and genetically modified breeding.

5.
Oncol Rep ; 44(5): 2288-2296, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33000264

RESUMO

Triptolide, a triterpene extracted from the Chinese herb Tripterygium wilfordii, has been reported to exert multiple bioactivities, including immunosuppressive, anti­inflammatory and anticancer effects. Although the anticancer effect of triptolide has attracted significant attention, the specific anticancer mechanism in non­small­cell lung cancer (NSCLC) remains unclear. The present study aimed to investigate the anticancer effect of triptolide in the H1395 NSCLC cell line and to determine its mechanism of action. The results revealed that triptolide significantly inhibited the cell viability of NSCLC cells in a dose­dependent manner, which was suggested to be through inducing apoptosis. In addition, triptolide was revealed to activate the calcium (Ca2+)/calmodulin­dependent protein kinase kinase ß (CaMKKß)/AMP­activated protein kinase (AMPK) signaling pathway by regulating the intracellular Ca2+ concentration levels, which increased the phosphorylation levels of AMPK and reduced the phosphorylation levels of AKT, ultimately leading to apoptosis. The CaMKKß blocker STO­609 and the AMPK blocker Compound C significantly inhibited the apoptosis­promoting effect of triptolide. In conclusion, the results of the present study suggested that triptolide may induce apoptosis through the CaMKKß­AMPK signaling pathway and may be a promising drug for the treatment of NSCLC.

6.
Water Res ; 187: 116454, 2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-33011570

RESUMO

Expansion in the size is an indispensable stage in the granular sludge life cycle, but little attention has been payed to the enlargement mechanism of granular sludge. Here, we propose a novel anammox granule enlargement mechanism by the self-assembly of heterogenous granules. Two different colors of anammox granules, dark-red granules (DR-Granules) and bright-red granules (BR-Granules) were found in an expanded granular sludge bed reactor. These two heterogenous granules were not isolated but were assembled into granules with a larger DR-Granule in the center and many smaller BR-Granules aggregated on the surface, increasing the overall granular size. Their physiochemical characteristics in terms of EPS, adherence, rheological properties, and microbial compositions, were identified and compared to elucidate the interaction between the different colors of granules. The BR-Granules created 92% more extracellular polymeric substances than the DR-Granules. This material blocked the passage of gas and substrate, leading to BR-Granules smaller size and a yield stress approximately 48% lower than that of the DR-Granules. Nevertheless, the BR-Granules had compact extracellular protein secondary structures and a high adherence rate to the surface of the DR-Granules, upon which they formed a compact adhered layer. These unique features enabled them to directionally adhere to DR-Granules in the core, that is, two heterogenous colors of granules self-assembled into large anammox granules. The enlargement mechanism was further supported by the abundance of K-strategy Ca. Kuenenia in the DR-Granules (inner layer) being higher than in the BR-Granules (outer layer; 2.9 ± 0.4% vs. 0.4 ± 0.1%; p = 0.0003) and by visualized confirmation that the larger BR-Granules wrapped around smaller DR-Granules inside. This demonstrates that heterogenous anammox granules actively self-assemble into large granules, which is an important step in the lifecycle of anammox granules.

7.
Atherosclerosis ; 313: 102-110, 2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-33038663

RESUMO

BACKGROUND AND AIMS: Phenotypic switch of vascular smooth muscle cells (VSMC) plays a key role in the pathogenesis of atherosclerosis and restenosis after artery intervention. Transcription repressor element 1-silencing transcription factor (REST) has been identified as key regulator of VSMC proliferation. In the present study, we sought to investigate the potential association of E3-ubiquitin ligase ß-TRCP mediated REST protein degradation with Kv1.3 expression during VSMC phenotypic switch. METHODS: Protein and mRNA expression was measured in ex vivo and in vitro models. Protein interaction and ubiquitination were analyzed by immunoprecipitation assays. ChIP assays were performed to assess the relationship between REST and targeted DNA binding site. RESULTS: We found that the expression level of E3-ubiquitin ligase ß-TRCP is significantly increased during VSMC phenotypic switch. REST protein ubiquitination mediated by ß-TRCP is critical for VSMC proliferation and migration. We also found that the gene KCNA3 encoding potassium channel protein Kv1.3 contains a functional REST binding site and is repressed by REST. Downregulation of REST by ß-TRCP and consequently upregulation of Kv1.3 are important events during VSMC phenotypic switch. Furthermore, upregulated Kv1.3 accelerates ß-TRCP modulated REST degradation through Erk1/2 signaling. CONCLUSIONS: Our results reveal a fundamental role for regulatory interactions between ß-TRCP modulated REST degradation and Kv1.3 in the control of the multilayered regulatory programs required for VSMC phenotype switch.

8.
Zootaxa ; 4809(3): zootaxa.4809.3.5, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-33055925

RESUMO

A new species of a new genus Melanabropsis. tianmuica gen. sp. nov. is described from China. 3 Japanese species of Anabropsinae are transferred to the new genus. A key to the Chinese genera of subfamily Anabropsinae is given. Materials are deposited in Shanghai Entomological Museum, Chinese Academy of Sciences.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33058450

RESUMO

The first electrochemical hydrolysis of hydrosilanes to silanols under mild and neutral reaction conditions is reported. The practical protocol employs commercially available and cheap NHPI as a hydrogen-atom transfer (HAT) mediator and operates at room temperature with high selectivity, leading to various valuable silanols in moderate to good yields. Notably, this electrochemical method exhibits a broad substrate scope and high functional-group compatibility, and it is applicable to late-stage functionalization of complex molecules. Preliminary mechanistic studies suggest that the reaction appears to proceed through a nucleophilic substitution reaction of an electrogenerated silyl cation with H2O.

10.
Chin Med J (Engl) ; 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32889914

RESUMO

With the changing lifestyle and the acceleration of aging in the Chinese population, the incidence and mortality of colorectal cancer (CRC) have risen in the last decades. On the contrary, the incidence and mortality of CRC have continued to decline in the USA since the 1980s, which is mainly attributed to early screening and standardized diagnosis and treatment. Rectal cancer accounts for the largest proportion of CRC in China, and its treatment regimens are complex. At present, surgical treatment is still the most important treatment for rectal cancer. Since the first Chinese guideline for diagnosis and treatment of CRC was issued in 2010, the fourth version has been revised in 2020. These guidelines have greatly promoted the standardization and internationalization of CRC diagnosis and treatment in China. And with the development of comprehensive treatment methods such as neoadjuvant chemoradiotherapy, targeted therapy, and immunotherapy, the post-operative quality of life and prognosis of patients with rectal cancer have improved. We believe that the inflection point of the rising incidence and mortality of rectal cancer will appear in the near future in China. This article reviewed the current status and research progress on surgical therapy of rectal cancer in China.

11.
Plant Dis ; 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32886036

RESUMO

Tobacco (Nicotiana tabacum L.) is a leafy, annual, solanaceous plant grown commercially for its leaves in China. In continuing research on foliar diseases of tobacco in Guizhou province in August 2019, diseased leaves of tobacco that had sandy beige, elliptical or irregular shaped lesions, with brown in edge, and surrounded by yellow halos on 40% of leaves on 5% plants were obtained (cv. Yunyan 87) in Zhenan (28.55° N, 107.43° E), Guizhou, China (Fig. 1A, 1B). Diseased leaf segments were surface sterilized and plated on potato dextrose agar (PDA). Isolate (T41) was selected for identification. The colonies had white aerial hyphae, with orange-red on the underside when cultured on PDA (Fig. 1G, 1H). The colonies had woolly aerial hyphae, white to grey eventually, and produced pycnidia on oatmeal agar (OA) (Boerema et al. 2004) (Fig. 1I, 1J). Pycnidia were dark, spherical or flat spherical, and 69.2-178.0 µm in diameter. Conidia were oval mostly, aseptate, usually guttulate, and the size was 5.0 - 6.5 µm × 3.2 - 5.4 µm (Fig. 1K, 1L). The rDNA internal transcribed spacer region (ITS) with primers ITS1f/ITS4 (White et al. 1990; Gardes and Bruns 1993), 28S ribosomal RNA gene (LSU) with primers LROR/LR7 (Rehner and Samuels 1994), beta-tubulin gene (TUB2) with primers Btub2Fd/Btub4Rd (Woudenberg et al. 2009) and RNA polymerase II second largest subunit gene (RPB2) with primers RPB2-5F2/fRPB2-7cR (Liu et al. 1999) of T41 were sequenced (GenBank accession numbers were MN704804, MN710367, MN718012 and MN718013, respectively). Maximum Likelihood (ML) analyses and Bayesian Inferences (BI) analyses based on concatenated these four sequences were conducted with RAxML v. 7.2.6 and MrBayes v. 3.2.1, respectively, which showed that T41 comprised a clade with Epicoccum latusicollum strains (CGMCC 3.18346 and LC 8153) (ML/BI = 100/1) (Fig. 2). Based on morphological and multi-gene molecular data, isolate T41 was identified as E. latusicollum described as a new taxon by Chen et al. (2017). To verify pathogenicity, tobacco plants at seedling stage (7-8 leaves) without visible disease were inoculated using conidial suspension (106 spores/ml), following Guo et al. (2020). All inoculated plants were maintained in a greenhouse with relative humidity ranging from 50% to 85% at 28 °C under a 12/12 h light/dark cycle. Seven days after incubation, typical symptoms were observed on inoculated leaves but not on control leaves (Fig. 1C, 1D, 1E, 1F). Koch's postulates were fulfilled by re-isolation of E. latusicollum from diseased leaves. E. latusicollum has been reported to cause black root on yam in China (Han et al. 2019). Meanwhile, there are many plants could be caused leaf spot by this genus, such as Lablab purpureus (Mahadevakumar et al. 2014) and Bletilla striata (Zhou et al. 2018). However, to the best of our knowledge, this is the first report of E. latusicollum causing leaf spot on tobacco in China. Because considerable loss occurred due to infection from E. latusicollum on tobacco leaves, this pathogen is worthy of further study and disease management practices need to be developed to prevent further losses.

12.
Int J Legal Med ; 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32865693

RESUMO

As the origin of modern humanity, African populations show high genetic diversity and are attracting increasing academic attention. However, populations living in West Africa have so far received less study and exploration. In this study, we analyze 30 insertion/deletion (InDel) loci of 516 samples from Freetown, Sierra Leone, to evaluate the forensic properties and reveal the genetic structure in Freetown, Sierra Leone, West Africa. No significant linkage disequilibrium (LD) between 30 InDels was observed after the Bonferroni correction. The random match probability (RMP), the combined power of exclusion for duos (CPE duos), and the combined power of exclusion for trios (CPE trios) were 6.823 × 10-11, 0.9168, and 0.9731, respectively. Null alleles and off-ladder alleles were observed, suggesting that we should be cautious when using this kit for forensic caseworks in African populations. In the population comparison study, we found that the Freetown population is genetically closer to geographically distinct West Africans and has a closer genetic relationship with the Bantu-speaking populations than other African populations.

13.
Water Sci Technol ; 82(1): 157-169, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32910800

RESUMO

The dynamic characteristics of N2O emissions and nitrogen transformation in a sequencing batch biofilm reactor (SBBR) using the completely autotrophic nitrogen removal over nitrite (CANON) process coupled with denitrification were investigated via 15N isotope tracing and thermodynamic analysis. The results indicate that the Gibbs free energy (ΔG) values of N2O production by the nitrifier denitrification and heterotrophic denitrification reactions were greater than that of NH2OH oxidation, indicating that N2O was easier to produce via either nitrifier and heterotrophic denitrification than via NH2OH oxidation. Ammonia-oxidizing bacteria (AOB) denitrification exhibited a higher fs0 (the fraction of electron-donor electrons utilized for cell synthesis) than NH2OH oxidation. Therefore, AOB preferred the denitrification pathway because of its growth advantage when N2O was produced by the AOB. The N2O emissions by hydroxylamine oxidation, AOB denitrification and heterotrophic denitrification in the SBBRs using different C/N ratios account for 5.4-7.6%, 45.2-60.8% and 33.8-47.2% of the N2O produced, respectively. The total N2O emission with C/N ratios of 0, 0.67 and 1 was 228.04, 205.57 and 190.4 µg N2O-N·g-1VSS, respectively. The certain carbon sources aid in the reduction of N2O emissions in the process.


Assuntos
Nitritos , Óxido Nitroso , Desnitrificação , Nitrogênio , Termodinâmica
14.
Nat Commun ; 11(1): 4462, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901002

RESUMO

Selective deconstructive functionalization of alkenes, other than the well-established olefin metathesis and ozonolysis, to produce densely functionalized molecular scaffolds is highly attractive but challenging. Here we report an efficient photo-mediated deconstructive germinal dihalogenation of carbon-carbon double bonds. A wide range of geminal diiodoalkanes and bromo(iodo)alkanes (>40 examples) are directly prepared from various trisubstituted alkenes, including both cyclic and acyclic olefins. This C=C cleavage is highly chemoselective and produces geminal dihalide ketones in good yields. Mechanistic investigations suggest a formation of alkyl hypoiodites from benzyl alcohols and N-iodoimides, which undergo light-induced homolytic cleavage to generate active oxygen radical species.

15.
Ann N Y Acad Sci ; 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32909625

RESUMO

Endometriosis is a chronic inflammatory disease defined as the presence of endometrial tissue outside the uterus that causes pelvic pain and infertility. We used the Global Burden of Disease Study (GBD) 2017 to comprehensively analyze the burden of endometriosis between 1990 and 2017. DisMod-MR 2.1 was used to estimate the incidence and prevalence in some countries/territories with sparse or absent data. Annual percent changes were calculated to quantify endometriosis burden estimate trends. Furthermore, the sociodemographic index (SDI) was used to assess the relationship between endometriosis burden estimates and development level. Between 1990 and 2017, endometriosis age-standardized incidence and prevalence and years of life lived with disability (YLDs) decreased globally by 0.21% (95% confidence interval (CI): -0.23% to -0.20%), 0.29% (95% CI: -0.31% to -0.28%), and 0.28% (95% CI: -0.30% to -0.27%) per year, respectively. Apart from the high SDI quintiles with increasing trends of endometriosis incidence rate, prevalence rate, and YLDs, decreasing trends were observed in all SDI quintiles for all burden estimates. In conclusion, it appears that all endometriosis burden estimates have decreased globally between 1990 and 2017. However, these results are based on limited data and highlight the need for increased data collection on the incidence and prevalence of endometriosis.

16.
Mol Cancer ; 19(1): 138, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894144

RESUMO

BACKGROUND: Inactivation of the tumor suppressor p53 is critical for pathogenesis of glioma, in particular glioblastoma multiforme (GBM). MDM2, the main negative regulator of p53, binds to and forms a stable complex with p53 to regulate its activity. Hitherto, it is unclear whether the stability of the p53/MDM2 complex is affected by lncRNAs, in particular circular RNAs that are usually abundant and conserved, and frequently implicated in different oncogenic processes. METHODS: RIP-seq and RIP-qPCR assays were performed to determine the most enriched lncRNAs (including circular RNAs) bound by p53, followed by bioinformatic assays to estimate the relevance of their expression with p53 signaling and gliomagenesis. Subsequently, the clinical significance of CDR1as was evaluated in the largest cohort of Chinese glioma patients from CGGA (n = 325), and its expression in human glioma tissues was further evaluated by RNA FISH and RT-qPCR, respectively. Assays combining RNA FISH with protein immunofluorescence were performed to determine co-localization of CDR1as and p53, followed by CHIRP assays to confirm RNA-protein interaction. Immunoblot assays were carried out to evaluate protein expression, p53/MDM2 interaction and p53 ubiquitination in cells in which CDR1as expression was manipulated. After AGO2 or Dicer was knocked-down to inhibit miRNA biogenesis, effects of CDR1as on p53 expression, stability and activity were determined by immunoblot, RT-qPCR and luciferase reporter assays. Meanwhile, impacts of CDR1as on DNA damage were evaluated by flow cytometric assays and immunohistochemistry. Tumorigenicity assays were performed to determine the effects of CDR1as on colony formation, cell proliferation, the cell cycle and apoptosis (in vitro), and on tumor volume/weight and survival of nude mice xenografted with GBM cells (in vivo). RESULTS: CDR1as is found to bind to p53 protein. CDR1as expression decreases with increasing glioma grade and it is a reliable independent predictor of overall survival in glioma, particularly in GBM. Through a mechanism independent of acting as a miRNA sponge, CDR1as stabilizes p53 protein by preventing it from ubiquitination. CDR1as directly interacts with the p53 DBD domain that is essential for MDM2 binding, thus disrupting the p53/MDM2 complex formation. Induced upon DNA damage, CDR1as may preserve p53 function and protect cells from DNA damage. Significantly, CDR1as inhibits tumor growth in vitro and in vivo, but has little impact in cells where p53 is absent or mutated. CONCLUSIONS: Rather than acting as a miRNA sponge, CDR1as functions as a tumor suppressor through binding directly to p53 at its DBD region to restrict MDM2 interaction. Thus, CDR1as binding disrupts the p53/MDM2 complex to prevent p53 from ubiquitination and degradation. CDR1as may also sense DNA damage signals and form a protective complex with p53 to preserve p53 function. Therefore, CDR1as depletion may play a potent role in promoting tumorigenesis through down-regulating p53 expression in glioma. Our results broaden further our understanding of the roles and mechanism of action of circular RNAs in general and CDR1as in particular, and can potentially open up novel therapeutic avenues for effective glioma treatment.

17.
Mol Neurobiol ; 57(12): 5286-5298, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32876840

RESUMO

Oxidative stress is a key component of the pathological cascade in subarachnoid hemorrhage (SAH). Fucoxanthin (Fx) possesses a strong antioxidant property and has shown neuroprotective effects in acute brain injuries such as ischemic stroke and traumatic brain injury. Here, we investigated the beneficial effects of Fx against SAH-induced oxidative insults and the possible molecular mechanisms. Our data showed that Fx could significantly inhibit SAH-induced reactive oxygen species production and lipid peroxidation, and restore the impairment of endogenous antioxidant enzymes activities. In addition, Fx supplementation improved mitochondrial morphology, ameliorated neural apoptosis, and reduced brain edema after SAH. Moreover, Fx administration exerted an improvement in short-term and long-term neurobehavior functions after SAH. Mechanistically, Fx inhibited oxidative damage and brain injury after SAH by deacetylation of forkhead transcription factors of the O class and p53 via sirtuin 1 (Sirt1) activation. EX527, a selective Sirt1 inhibitor, significantly abated Fx-induced Sirt1 activation and abrogated the antioxidant and neuroprotective effects of Fx after SAH. In primary neurons, Fx similarly suppressed oxidative insults and improved cell viability. These effects were associated with Sirt1 activation and were reversed by EX527 treatment. Taken together, our study explored that Fx provided protection against SAH-induced oxidative insults by inducing Sirt1 signaling, indicating that Fx might serve as a potential therapeutic drug for SAH.

19.
Microb Ecol ; 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32995929

RESUMO

Piezophiles, by the commonly accepted definition, grow faster under high hydrostatic pressure (HHP) than under ambient pressure and are believed to exist only in pressurized environments where life has adapted to HHP during evolution. However, recent findings suggest that piezophiles have developed a common adaptation strategy to cope with multiple types of stresses including HHP. These results raise a question on the ecological niches of piezophiles: are piezophiles restricted to habitats with HHP? In this study, we observed that the bacterial strains Sporosarcina psychrophila DSM 6497 and Lysinibacillus sphaericus LMG 22257, which were isolated from surface environments and then transferred under ambient pressure for half a century, possess moderately piezophilic characteristics with optimal growth pressures of 7 and 20 MPa, respectively. Their tolerance to HHP was further enhanced by MgCl2 supplementation under the highest tested pressure of 50 MPa. Transcriptomic analysis was performed to compare gene expression with and without MgCl2 supplementation under 50 MPa for S. psychrophila DSM 6497. Among 4390 genes or transcripts obtained, 915 differentially expressed genes (DEGs) were identified. These DEGs are primarily associated with the antioxidant defense system, intracellular compatible solute accumulation, and membrane lipid biosynthesis, which have been reported to be essential for cells to cope with HHP. These findings indicate no in situ pressure barrier for piezophile isolation, and cells may adopt a common adaptation strategy to cope with different stresses.

20.
Small ; : e2003098, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32997380

RESUMO

The crystalline orientation and phase distribution are two important parameters for high-performance 2D perovskite solar cells. Therefore, it is essential to understand how the structure of spacer ligands influences the orientation and phase distribution of resulting 2D perovskite films. In this work, a new member of Dion-Jacobson (DJ) phase 2D perovskites based on trans-1,4-cyclohexanediamine (CHDA) is demonstrated and it is found that the crystalline orientation is self-aligned spontaneously, which is different from the well-known graded distribution in controlled sample with its isomer 1,6-diaminohexane (HDA) as spacer ligand. Grazing incident X-ray scattering suggests that the exact alignment is strongly slantwise to the substrate while it is still beneficial for charge transfer along the vertical structure of devices. The devices can achieve high efficiency up to 15.01% for (CHDA)MA3 Pb4 I13 (n = 4), one of the highest efficiencies reported by now. The encapsulated (CHDA)MA3 Pb4 I13 (n = 4) devices can retain 80.7% efficiency for 270 min under continuous maximum power point tracking. (CHDA)MA3 Pb4 I13 (n = 4) devices can retain 96.5% efficiency under 60 °C and 74.4% efficiency under 70 °C heating for 68 h. The results demonstrate the slantwise aligned DJ phase perovskite solar cells with excellent stability.

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