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1.
J Sports Sci Med ; 19(4): 637-644, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33239936

RESUMO

Identifying the factors associated with table tennis performance may provide training information for competitive athletes and guide the general population for active participation. The purpose was to compare the joint, racket, and ball kinematics between the shakehand and penhold grips in table tennis forehand and backhand strokes when returning topspin and backspin balls in advanced male players. Nine penhold-grip players and 18 matched shakehand-grip players performed forehand and backhand strokes when returning topspin and backspin balls using their habitual grip styles, while the kinematics of the trunk, upper extremities, racket, and ball were collected. Racket angles were calculated as the relative motion of the racket to the forearm. For the forehand strokes, no significant differences were observed for ball or racket velocities between the two grips. The shakehand grip tended to demonstrate greater shoulder external rotation angles compared to the penhold grip. The shakehand grip resulted in racket flexion angular velocity compared to racket extension velocity for the penhold grip. For the backhand strokes, greater ball and racket velocities were observed for the shakehand grip. The shakehand grip generally demonstrated decreased final trunk left rotation angles, increased trunk right rotation angular velocities, decreased final shoulder abduction angles, increased shoulder adduction angular velocities, and increased forearm supination angular velocities. The two grips demonstrated similar peak racket and ball velocities but different shoulder rotation range of motion and racket motion in forehand strokes. The penhold grips resulted in decreased peak racket and ball velocities in backhand strokes, likely due to its decreased shoulder, elbow, and forearm motion and less aligned longitudinal axes between the racket and forearm. These findings may help understand the dominance of the shakehand grip over the penhold grip in elite athletes and provide information for grip selection, technique improvements, and exercise training.

2.
New Phytol ; 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33111313

RESUMO

In grasses, two types of phased, small interfering RNAs (phasiRNAs) are expressed largely in young, developing anthers. They are 21 or 24 nucleotides (nt) in length, and are triggered by miR2118 or miR2275, respectively. However, most of their functions and activities are not fully understood. We performed comparative genomic analysis of their source loci (PHAS) in five Oryza genomes, and combined this with analysis of high-throughput sRNA and degradome datasets. In total, we identified 8216 21-PHAS and 626 24-PHAS loci. Local tandem and segmental duplications mainly contributed to the expansion and supercluster distribution of the 21-PHAS loci. Despite their relatively conserved genomic positions, PHAS sequences diverged rapidly, except for the miR2118/2275 target sites, which were under strong selection for conservation. We found 21-nt phasiRNAs with a 5'-terminal uridine (U) demonstrated cis cleavage at PHAS precursors, and these cis-acting sites were also variable among close species. miR2118 could trigger phasiRNA production from antisense transcript of its own, and the derived phasiRNAs might reversely regulate miR2118 precursors. We hypothesized that successful initiation of phasiRNA biogenesis is conservatively maintained, while the phasiRNA products diverged quickly and are not individually conserved. In particular, phasiRNA production is under the control of multiple reciprocal regulation mechanisms.

3.
Plant Cell ; 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077493

RESUMO

In plants, small RNAs (sRNAs) that are 22 nucleotides (nt) in length have the unique capacity to trigger the production of secondary small interfering RNAs (siRNAs) and further enhance silencing. While DCL2-dependent 22-nt siRNAs are rare in Arabidopsis and thought to have few functions except during viral infection, they are abundant in many major crops such as soybean and maize. Here, we studied the endogenous 22-nt siRNAs in Glycine max by applying CRISPR-Cas9 genome editing technology to simultaneously knock out the two copies of soybean DCL2, GmDCL2a and GmDCL2b, in the Tianlong1 cultivar. sRNA sequencing revealed that the majority of 22-nt siRNAs are derived from long inverted repeats (LIRs) and disappeared in Gmdcl2a/2b double mutant. By de novo assembly of a Tianlong1 reference genome and transcriptome profiling, we found an intron-located LIR formed by chalcone synthase (CHS) genes CHS1 and CHS3. This LIR is the source of the primary 22-nt siRNAs that target other CHS family genes and trigger the production of secondary 21-nt siRNAs. Disruption of this process in Gmdcl2a/2b substantially increased the level of CHS mRNAs in the seed coat, and changed the color from yellow to brown. Our results demonstrated that endogenous LIR-derived transcripts in soybean are predominately processed by GmDCL2 into 22-nt siRNAs, and uncovered a previously overlooked role of DCL2 in regulating natural traits.

4.
Plant Cell ; 32(11): 3452-3468, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32917737

RESUMO

Over 80,000 angiosperm species produce flowers with petals fused into a corolla tube. The corolla tube contributes to the tremendous diversity of flower morphology and plays a critical role in plant reproduction, yet it remains one of the least understood plant structures from a developmental genetics perspective. Through mutant analyses and transgenic experiments, we show that the tasiRNA-ARF pathway is required for corolla tube formation in the monkeyflower species Mimulus lewisii Loss-of-function mutations in the M. lewisii orthologs of ARGONAUTE7 and SUPPRESSOR OF GENE SILENCING3 cause a dramatic decrease in abundance of TAS3-derived small RNAs and a moderate upregulation of AUXIN RESPONSE FACTOR3 (ARF3) and ARF4, which lead to inhibition of lateral expansion of the bases of petal primordia and complete arrest of the upward growth of the interprimordial regions, resulting in unfused corollas. Using the DR5 auxin-responsive promoter, we discovered that auxin signaling is continuous along the petal primordium base and the interprimordial region during the critical stage of corolla tube formation in the wild type, similar to the spatial pattern of MlARF4 expression. Auxin response is much weaker and more restricted in the mutant. Furthermore, exogenous application of a polar auxin transport inhibitor to wild-type floral apices disrupted petal fusion. Together, these results suggest a new conceptual model highlighting the central role of auxin-directed synchronized growth of the petal primordium base and the interprimordial region in corolla tube formation.

5.
Nat Commun ; 11(1): 4796, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963231

RESUMO

Cortical thickness, surface area and volumes vary with age and cognitive function, and in neurological and psychiatric diseases. Here we report heritability, genetic correlations and genome-wide associations of these cortical measures across the whole cortex, and in 34 anatomically predefined regions. Our discovery sample comprises 22,824 individuals from 20 cohorts within the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank. We identify genetic heterogeneity between cortical measures and brain regions, and 160 genome-wide significant associations pointing to wnt/ß-catenin, TGF-ß and sonic hedgehog pathways. There is enrichment for genes involved in anthropometric traits, hindbrain development, vascular and neurodegenerative disease and psychiatric conditions. These data are a rich resource for studies of the biological mechanisms behind cortical development and aging.


Assuntos
Envelhecimento/genética , Encéfalo , Estudo de Associação Genômica Ampla , Transtornos Mentais/genética , Doenças Neurodegenerativas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estruturas Cromossômicas , Cognição , Feminino , Genômica , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único
6.
Artigo em Inglês | MEDLINE | ID: mdl-32852145

RESUMO

The innate hypoxic microenvironment of most solid tumors has a major influence on tumor growth, invasiveness, and distant metastasis. Here, a hypoxia-activated self-immolative prodrug of paclitaxel (PTX2 -Azo) was synthesized and encapsulated by a peptide copolymer decorated with the photosensitizer chlorin e6 (Ce6) to prepare light-boosted PTX nanoparticle (Ce6/PTX2 -Azo NP). In this nanoparticle, PTX2 -Azo prevents premature drug leakage and realizes specific release in hypoxic tumor microenvironment and the photosensitizer Ce6 not only efficiently generates singlet oxygen under light irradiation but also acts as a positive amplifier to promote the release of PTX. The combination of photodynamic therapy (PDT) and chemotherapy results in excellent antitumor efficacy, demonstrating the great potential for synergistic cancer therapy.

7.
Biochem Biophys Res Commun ; 532(2): 225-230, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-32861420

RESUMO

Angiogenesis plays a vital role in tumor progression and metastasis. To better understand the role of anesthesia in tumor biology, we previously reported that bupivacaine displayed the inhibitory effects in endothelial cells. In this work, we demonstrated that fentanyl, an opioid medication commonly used in cancer patients, stimulated tumor angiogenesis. We found that fentanyl at nanomolar concentrations significantly stimulated capillary network formation of human lung tumor-associated endothelial cell (HLT-EC) in a similar manner as vascular endothelial growth factor (VEGF), and furthermore that the stimulatory effect of fentanyl was mainly involved in early stage of HLT-EC vascular structure assembly. Particularly, fentanyl significantly increased HLT-EC growth and migration. Fentanyl also protected HLT-EC from apoptosis induced by growth factor withdrawal. In contrast, the same concentrations of fentanyl did not affect human lung cancer cell growth and survival. Fentanyl stimulated migration of some but not all tested human lung cancer cells. Mechanism analysis suggested that fentanyl activates multiple pro-angiogenic signaling pathways, including VEGFR2/FAK/PI3K/Akt and small GTPases. Our work systematically demonstrates that fentanyl stimulates tumor angiogenesis via activating multiple pro-angiogenic signaling pathways. Our findings highlight the potential adverse effect of fentanyl in cancer patients.

8.
Plant Cell ; 32(10): 3059-3080, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32817252

RESUMO

Phased secondary small interfering RNAs (phasiRNAs) constitute a major category of small RNAs in plants, but most of their functions are still poorly defined. Some phasiRNAs, known as trans-acting siRNAs, are known to target complementary mRNAs for degradation and to function in development. However, the targets or biological roles of other phasiRNAs remain speculative. New insights into phasiRNA biogenesis, their conservation, and their variation across the flowering plants continue to emerge due to the increased availability of plant genomic sequences, deeper and more sophisticated sequencing approaches, and improvements in computational biology and biochemical/molecular/genetic analyses. In this review, we survey recent progress in phasiRNA biology, with a particular focus on two classes associated with male reproduction: 21-nucleotide (accumulate early in anther ontogeny) and 24-nucloetide (produced in somatic cells during meiosis) phasiRNAs. We describe phasiRNA biogenesis, function, and evolution and define the unanswered questions that represent topics for future research.

9.
Artigo em Inglês | MEDLINE | ID: mdl-32856374

RESUMO

Despite the excellent photovoltaic properties achieved by perovskite solar cells at the laboratory scale, hybrid perovskites decompose in the presence of air, especially at high temperatures and in humid environments. Consequently, high-efficiency perovskites are usually prepared in dry/inert environments, which are expensive and less convenient for scale-up purposes. Here, a new approach based on the inclusion of an in situ polymerizable ionic liquid, 1,3-bis(4-vinylbenzyl)imidazolium chloride ([bvbim]Cl), is presented, which allows perovskite films to be manufactured under humid environments, additionally leading to a material with improved quality and long-term stability. The approach, which is transferrable to several perovskite formulations, allows efficiencies as high as 17% for MAPbI3 processed in air % relative humidity (RH) ≥30 (from an initial 15%), and 19.92% for FAMAPbI3 fabricated in %RH ≥50 (from an initial 17%), providing one of the best performances to date under similar conditions.

10.
Water Res ; 185: 116221, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32731076

RESUMO

River algal blooms have become a challenging environmental problem worldwide due to strong interference of human activities and megaprojects (e.g., big dams and large-scale water transfer projects). Previous studies on algal blooms were mainly focused on relatively static water bodies (i.e., lakes and reservoirs), but less on the large rivers. As the largest tributary of the Yangtze River of China and the main freshwater source of the South-to-North Water Diversion Project (SNWDP), the Han River has experienced frequent algal blooms in recent decades. Here we investigated the algal blooms during a decade (2003-2014) in the Han River by two gradient boosting machine (GBM) models with k-fold cross validation, which used explanatory variables from current 10-day (GBMc model) or previous 10-day period (GBMp model). Our results advocate the use of GBMp due to its higher accuracy (median Kappa = 0.9) and practical predictability (using antecedent observations) compared to GBMc. We also revealed that the algal blooms in the Han River were significantly modulated by antecedent water levels in the Han River and the Yangtze River and water level variation in the Han River, whereas the nutrient concentrations in the Han River were usually above thresholds and not limiting algal blooms. This machine-learning-based study potentially provides scientific guidance for preemptive warning and risk management of river algal blooms through comprehensive regulation of water levels during the dry season by making use of water conservancy measures in large rivers.


Assuntos
Monitoramento Ambiental , Rios , China , Eutrofização , Humanos , Lagos
11.
J Colloid Interface Sci ; 580: 785-793, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721635

RESUMO

Redox stimulus responsive drug delivery systems have been widely investigated and proved to be promising prospects for efficient cancer therapy due to the abnormal high level of reactive oxygen species and glutathione in tumor microenvironment. Herein, three paclitaxel dimers (named as PTX2-R, R = S, Se and Te) bridged with alkyl sulfide, selenide or telluride are synthesized. These dimers can self-assemble into stable uniform nanoparticles (named as PTX2-R NPs, R = S, Se and Te) with impressively high drug loading. As expected, sulfur/selenium/tellurium bonds exhibit different redox responsiveness, thereby affecting the drug release and cytotoxicity. Of note, tellurium bridged paclitaxel dimer shows ultra-sensitivity to hydrogen peroxide, which rapidly cleaves into two paclitaxel under the subsequent dithiothreitol stimulation. Our findings provide deep insight into the redox sensitivity of chalcogenide elements and offer the rational design strategies to biologically redox condition for programmed drug release.

12.
Stroke ; 51(7): 2111-2121, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32517579

RESUMO

BACKGROUND AND PURPOSE: Periventricular white matter hyperintensities (WMH; PVWMH) and deep WMH (DWMH) are regional classifications of WMH and reflect proposed differences in cause. In the first study, to date, we undertook genome-wide association analyses of DWMH and PVWMH to show that these phenotypes have different genetic underpinnings. METHODS: Participants were aged 45 years and older, free of stroke and dementia. We conducted genome-wide association analyses of PVWMH and DWMH in 26,654 participants from CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology), ENIGMA (Enhancing Neuro-Imaging Genetics Through Meta-Analysis), and the UKB (UK Biobank). Regional correlations were investigated using the genome-wide association analyses -pairwise method. Cross-trait genetic correlations between PVWMH, DWMH, stroke, and dementia were estimated using LDSC. RESULTS: In the discovery and replication analysis, for PVWMH only, we found associations on chromosomes 2 (NBEAL), 10q23.1 (TSPAN14/FAM231A), and 10q24.33 (SH3PXD2A). In the much larger combined meta-analysis of all cohorts, we identified ten significant regions for PVWMH: chromosomes 2 (3 regions), 6, 7, 10 (2 regions), 13, 16, and 17q23.1. New loci of interest include 7q36.1 (NOS3) and 16q24.2. In both the discovery/replication and combined analysis, we found genome-wide significant associations for the 17q25.1 locus for both DWMH and PVWMH. Using gene-based association analysis, 19 genes across all regions were identified for PVWMH only, including the new genes: CALCRL (2q32.1), KLHL24 (3q27.1), VCAN (5q27.1), and POLR2F (22q13.1). Thirteen genes in the 17q25.1 locus were significant for both phenotypes. More extensive genetic correlations were observed for PVWMH with small vessel ischemic stroke. There were no associations with dementia for either phenotype. CONCLUSIONS: Our study confirms these phenotypes have distinct and also shared genetic architectures. Genetic analyses indicated PVWMH was more associated with ischemic stroke whilst DWMH loci were implicated in vascular, astrocyte, and neuronal function. Our study confirms these phenotypes are distinct neuroimaging classifications and identifies new candidate genes associated with PVWMH only.


Assuntos
Encéfalo/patologia , Doenças de Pequenos Vasos Cerebrais/genética , Doenças de Pequenos Vasos Cerebrais/patologia , Predisposição Genética para Doença/genética , Substância Branca/patologia , Idoso , Encéfalo/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Substância Branca/diagnóstico por imagem
13.
Mol Plant ; 13(8): 1194-1202, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32585190

RESUMO

The rapid development of high-throughput sequencing techniques has led biology into the big-data era. Data analyses using various bioinformatics tools rely on programming and command-line environments, which are challenging and time-consuming for most wet-lab biologists. Here, we present TBtools (a Toolkit for Biologists integrating various biological data-handling tools), a stand-alone software with a user-friendly interface. The toolkit incorporates over 130 functions, which are designed to meet the increasing demand for big-data analyses, ranging from bulk sequence processing to interactive data visualization. A wide variety of graphs can be prepared in TBtools using a new plotting engine ("JIGplot") developed to maximize their interactive ability; this engine allows quick point-and-click modification of almost every graphic feature. TBtools is platform-independent software that can be run under all operating systems with Java Runtime Environment 1.6 or newer. It is freely available to non-commercial users at https://github.com/CJ-Chen/TBtools/releases.

14.
Nat Plants ; 6(7): 780-788, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32541953

RESUMO

In eukaryotes, genes are transcribed by RNA polymerase-II (Pol-II) and introns are removed by the spliceosome largely cotranscriptionally1-3; analysis using long-read sequencing revealed that splicing occurs immediately after Pol-II passes introns in yeast4,5. Here, we developed a Nanopore-based method to profile chromatin-bound RNA that enables the simultaneous detection of splicing status, Pol-II position and polyadenylation at the genome-wide scale in Arabidopsis. We found that more than half of the introns remain unspliced after Pol-II transcribes 1 kb past the 3' splice site, which is much slower than the rate of splicing reported in yeast4,5. Many of the full-length chromatin-bound RNA molecules are polyadenylated, yet still contain unspliced introns at specific positions. These introns are nearly absent in the cytoplasm and are resistant to nonsense-mediated decay, suggesting that they are post-transcriptionally spliced before the transcripts are released into the cytoplasm; we therefore termed these introns post-transcriptionally spliced introns (pts introns). Analysis of around 6,500 public RNA-sequencing libraries found that the splicing of pts introns requires the function of splicing-related proteins such as PRMT5 and SKIP, and is also influenced by various environmental signals. The majority of the intron retention events in Arabidopsis are at pts introns, suggesting that chromatin-tethered post-transcriptional splicing is a major contributor to the widespread intron retention that is observed in plants, and could be a mechanism to produce fully spliced functional mRNAs for rapid response.

15.
J Orthop Surg Res ; 15(1): 199, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32487194

RESUMO

BACKGROUND: The correlation between inflammatory responses caused by spinal cord injury (SCI) and the prognosis of patients with SCI still remains controversial. METHODS: In the present study, we preliminary investigated the serum levels of interleukin (IL)-4, IL-10, major histocompatibility complex (MHC)-I, and inducible nitric oxide synthase (iNOS) and compared the serum IL-4 and IL-10 expression in rats of high Basso-Beattie-Bresnahan (BBB) scores with these of low BBB scores. Besides, the infiltration of macrophage and the axonal regeneration of the injured spinal cord were observed from day 10 to day 30. RESULTS: We found that higher serum levels of IL-4 and IL-10 can reflect the restorability degree of SCI and could be potential biomarkers for the prognosis of SCI. The infiltration of the M2 subtype of macrophage and the axons regrowth might contribute to a better prognosis. CONCLUSIONS: The current study demonstrates that the serum levels of IL-4 and IL-10 are preliminarily adopted as serologic markers to forecast SCI, and high serum levels of IL-4 and IL-10 may indicate a better prognosis. Moreover, the way to promote macrophage polarization from M1 to M2 may contribute to better axonal regeneration.

16.
Circ Genom Precis Med ; 13(4): e002766, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32525743

RESUMO

BACKGROUND: DNA methylation patterns associated with habitual diet have not been well studied. METHODS: Diet quality was characterized using a Mediterranean-style diet score and the Alternative Healthy Eating Index score. We conducted ethnicity-specific and trans-ethnic epigenome-wide association analyses for diet quality and leukocyte-derived DNA methylation at over 400 000 CpGs (cytosine-guanine dinucleotides) in 5 population-based cohorts including 6662 European ancestry, 2702 African ancestry, and 360 Hispanic ancestry participants. For diet-associated CpGs identified in epigenome-wide analyses, we conducted Mendelian randomization (MR) analysis to examine their relations to cardiovascular disease risk factors and examined their longitudinal associations with all-cause mortality. RESULTS: We identified 30 CpGs associated with either Mediterranean-style diet score or Alternative Healthy Eating Index, or both, in European ancestry participants. Among these CpGs, 12 CpGs were significantly associated with all-cause mortality (Bonferroni corrected P<1.6×10-3). Hypermethylation of cg18181703 (SOCS3) was associated with higher scores of both Mediterranean-style diet score and Alternative Healthy Eating Index and lower risk for all-cause mortality (P=5.7×10-15). Ten additional diet-associated CpGs were nominally associated with all-cause mortality (P<0.05). MR analysis revealed 8 putatively causal associations for 6 CpGs with 4 cardiovascular disease risk factors (body mass index, triglycerides, high-density lipoprotein cholesterol concentrations, and type 2 diabetes mellitus; Bonferroni corrected MR P<4.5×10-4). For example, hypermethylation of cg11250194 (FADS2) was associated with lower triglyceride concentrations (MR, P=1.5×10-14).and hypermethylation of cg02079413 (SNORA54; NAP1L4) was associated with body mass index (corrected MR, P=1×10-6). CONCLUSIONS: Habitual diet quality was associated with differential peripheral leukocyte DNA methylation levels of 30 CpGs, most of which were also associated with multiple health outcomes, in European ancestry individuals. These findings demonstrate that integrative genomic analysis of dietary information may reveal molecular targets for disease prevention and treatment.

17.
BMJ Open ; 10(4): e034965, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32299999

RESUMO

INTRODUCTION: Cognitive frailty (CF) is a clinical manifestation characterised by the simultaneous presence of both physical frailty and cognitive impairment among older adults without dementia and has become a new target for healthy ageing. Increasing evidence shows that regular Baduanjin (a traditional Chinese mind-body exercise) training is beneficial in improving physical function and cognitive ability in the older adults. The primary aim of this trial is to observe the effect of Baduanjin on physical and cognitive functions in older adults with CF. METHODS AND ANALYSIS: In this prospective, outcome assessor-blind, two-arm randomised controlled trial, a total of 102 participants with CF will be recruited and randomly allocated (1:1) into the Baduanjin training or usual physical activity control group. The control group will receive health education for 30 min at least once a month. Based on health education, participants in the Baduanjin exercise group will receive a 24-week Baduanjin training with 60 min per session and 3 sessions per week, while those in the usual physical activity control group will maintain their original lifestyle. Primary outcomes (frailty index and global cognitive ability), body composition, grip force, balance, fatigue, specific cognitive domain, including memory, execution and visual spatial abilities, and life quality of secondary outcomes will be measured at baseline, and at 13 and 25 weeks after randomisation, while the structural and functional MRI will be measured at baseline and 25 weeks after randomisation. The mixed linear model will be conducted to observe the intervention effects. ETHICS AND DISSEMINATION: The study has been approved by the ethics committee of the second people's hospital of Fujian province (Approval no. 2018-KL015). Results will be submitted for publication in peer-reviewed journals and disseminated at scientific conferences. TRIAL REGISTRATION NUMBER: ChiCTR1800020341; Pre-results.

18.
J Exp Bot ; 71(14): 4069-4082, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32227110

RESUMO

Abscission is triggered by multiple environmental and developmental cues, including endogenous plant hormones. KNOTTED-LIKE HOMEOBOX (KNOX) transcription factors (TFs) play an important role in controlling abscission in plants. However, the underlying molecular mechanism of KNOX TFs in abscission is largely unknown. Here, we identified LcKNAT1, a KNOTTED-LIKE FROM ARABIDOPSIS THALIANA1 (KNAT1)-like protein from litchi, which regulates abscission by modulating ethylene biosynthesis. LcKNAT1 is expressed in the fruit abscission zone and its expression decreases during fruitlet abscission. Furthermore, the expression of the ethylene biosynthetic genes LcACS1, LcACS7, and LcACO2 increases in the fruit abscission zone, in parallel with the emission of ethylene in fruitlets. In vitro and in vivo assays revealed that LcKNAT1 inhibits the expression of LcACS/ACO genes by directly binding to their promoters. Moreover, ectopic expression of LcKNAT1 represses flower abscission in tomatoes. Transgenic plants expressing LcKNAT1 also showed consistently decreased expression of ACS/ACO genes. Collectively, these results indicate that LcKNAT1 represses abscission via the negative regulation of ethylene biosynthesis.

19.
Fundam Clin Pharmacol ; 34(5): 581-590, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32145095

RESUMO

Although substantial evidence shows the link of local anesthesia and decreased tumor recurrence, the role of amide-linked local anesthetics, particularly bupivacaine, on angiogenesis (a hallmark of tumor progression and metastasis) has not been revealed. In this work, we demonstrate the anti-angiogenic activity of bupivacaine and its underlying mechanism in endothelial cells. We show that bupivacaine inhibits early stage of capillary network formation via suppressing endothelial cell migration without affecting adhesion to matrix. Bupivacaine also inhibits endothelial cell growth and survival. Mechanism analysis indicates that bupivacaine inhibits mitochondrial respiration via decreasing mitochondrial respiratory activity of complex I and II but not IV or V, resulting in energy depletion, oxidative stress, inhibition of Akt/mTOR, and activation of AMPK pathway. The rescue of an antioxidant NAC on the effects of bupivacaine confirms that bupivacaine inhibits angiogenesis through oxidative stress-dependent inhibition of Akt/mTOR and activation of AMPK. Our work clearly demonstrates the inhibitory effects of bupivacaine on angiogenesis via targeting mitochondria. Our findings are in line with the previous work providing the preclinical evidence on how local anesthetics could influence the outcome of cancer patients.

20.
Mol Carcinog ; 59(5): 533-544, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32181526

RESUMO

Elevated expression of Copine 1 (CPNE1) has been observed in multiple cancers; however, the underlying mechanisms by which it affects cancer cells are unclear. We aimed to study the effect of CPNE1 on the tumorigenesis and radioresistance of triple-negative breast cancer (TNBC). Quantitative real-time polymerase chain reaction was used to detect the expression of CPNE1 in TNBC tissues and cell lines. Western blot, immunohistochemistry, and immunofluorescence were used to investigate the levels of CPNE1, p-AKT, AKT, cleaved caspase-3, cleaved PARP1, and γ-H2AX. Cell viability and apoptosis were measured by CCK-8 and flow cytometry, respectively. CPNE1 was overexpressed in TNBC tissues and cell lines and was associated with tumor size, distant metastases, and survival rates of patients with TNBC. Moreover, function study shows that CPNE1 promoted cell viability and inhibited cell apoptosis in vitro and inhibited the radiosensitivity of TNBC. Importantly, inactivation of AKT signaling inhibited the tumorigenesis and radioresistance mediated by CPNE1 in TNBC cells. In vivo xenograft study also shows that CPNE1 knockdown inhibited tumor growth and promoted cell apoptosis. Overall, our findings suggest that CPNE1 promotes tumorigenesis and radioresistance in TNBC by regulating AKT activation and targeted CPNE1 expression may be a strategy to sensitize TNBC cells toward radiation therapy.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proliferação de Células , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tolerância a Radiação , Neoplasias de Mama Triplo Negativas/patologia , Animais , Apoptose , Biomarcadores Tumorais/genética , Proteínas de Ligação ao Cálcio/genética , Estudos de Coortes , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Taxa de Sobrevida , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/radioterapia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
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