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1.
Plant Sci ; 304: 110735, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33568287

RESUMO

Alternative oxidase (AOX) is a mitochondrial enzyme encoded by a small nuclear gene family, which contains the two subfamilies, AOX1 and AOX2. In the present study on watermelon (Citrullus lanatus), only one ClAOX gene, belonging to AOX2 subfamily but having a similar gene structure to AtAOX1a, was found in the watermelon genome. The expression analysis suggested that ClAOX had the constitutive expression feature of AOX2 subfamily, but was cold inducible, which is normally considered an AOX1 subfamily feature. Moreover, one single nucleotide polymorphism (SNP) in ClAOX sequence, which led to the change from Lys (N) to Asn (K) in the 96th amino acids, was found among watermelon subspecies. Ectopic expression of two ClAOX alleles in the Arabidopsis aox1a knock-out mutant indicated that ClAOXK-expressing plants had stronger cold tolerance than aox1a mutant and ClAOXN-expressing plants. Our findings suggested watermelon genome contained a single ClAOX that possessed the expression features of both AOX1 and AOX2 subfamilies. A naturally existing SNP in ClAOX differentiated the cold tolerance of transgenic Arabidopsis plants, impling a possibility this gene might be a functional marker for stress-tolerance breeding.

2.
Plant Physiol ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33599732

RESUMO

Ethiopian mustard (Brassica carinata) in the Brassicaceae family possesses many excellent agronomic traits. Here, the high-quality genome sequence of B. carinata is reported. Characterization revealed a genome anchored to 17 chromosomes with a total length of 1.087 Gb and an N50 scaffold length of 60 Mb. Repetitive sequences account for approximately 634 Mb or 58.34% of the B. carinata genome. Notably, 51.91% of 97,149 genes are confined to the terminal 20% of chromosomes as a result of the expansion of repeats in pericentromeric regions. Brassica carinata shares one whole-genome triplication event with the five other species in U's triangle, a classic model of evolution and polyploidy in Brassica. Brassica carinata was deduced to have formed ∼0.047 Mya, which is slightly earlier than B. napus but later than B. juncea. Our analysis indicated that the relationship between the two subgenomes (BcaB and BcaC) is greater than that between other two tetraploid subgenomes (BjuB and BnaC) and their respective diploid parents. RNA-seq datasets and comparative genomic analysis were used to identify several key genes in pathways regulating disease resistance and glucosinolate metabolism. Further analyses revealed that genome triplication and tandem duplication played important roles in the expansion of those genes in Brassica species. With the genome sequencing of B. carinata completed, the genomes of all six Brassica species in U's triangle are now resolved. The data obtained from genome sequencing, transcriptome analysis, and comparative genomic efforts in this study provide valuable insights into the genome evolution of the six Brassica species in U's triangle.

4.
Commun Biol ; 3(1): 779, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33328568

RESUMO

Wasabi, horseradish and mustard are popular pungent crops in which the characteristic bioactive hydrolysis of specialized glucosinolates (GSLs) occurs. Although the metabolic pathways of GSLs are well elucidated, how plants have evolved convergent mechanisms to accumulate identical GSL components remains largely unknown. In this study, we discovered that sinigrin is predominantly synthesized in wasabi, horseradish and mustard in Brassicaceae. We de novo assembled the transcriptomes of the three species, revealing the expression patterns of gene clusters associated with chain elongation, side chain modification and transport. Our analysis further revealed that several gene clusters were convergently selected during evolution, exhibiting convergent shifts in amino acid preferences in mustard, wasabi and horseradish. Collectively, our findings provide insights into how unrelated crop species evolve the capacity for sinigrin super-accumulation and thus promise a potent strategy for engineering metabolic pathways at multiple checkpoints to fortify bioactive compounds for condiment or pharmaceutical purposes.

5.
Phytochemistry ; 181: 112554, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33152579

RESUMO

Six undescribed compounds, including three sesquiterpenoids [(4S,5S,7S,8S,11R)-7-hydroxyguai-1(10)-en-8,12-olide, aquilarisinone, and 2Z,7(13),9E-humulatrien-12-ol-5-one], one diphenylpentanone [1-(2-hydroxyphenyl)-5-phenylpentan-3-one], and two 2-(2-phenylethyl)chromones (6-epiagarotetrol and triepoxyhexahydrochromone A), along with 15 known compounds, were isolated from the resinous heartwood of Aquilaria sinensis (Thymelaeaceae). Their structures were determined by mass (MS) and nuclear magnetic resonance (NMR) spectroscopic data. The absolute configuration of (4S,5S,7S,8S,11R)-7-hydroxyguai-1(10)-en-8,12-olide was confirmed by X-ray diffraction analysis, and the configurations of (4S,7S,8S,10R,11R)-7,10-epoxyguai-1(5)-en-8,12-olide, aquilarisinone, 6-epiagarotetrol, and triepoxyhexahydrochromone A were confirmed by electronic circular dichroism (ECD) calculations. The neuroprotective activities of the compounds were evaluated using models of BACE1 inhibition and PC12 cells with corticosterone- and 1-methyl-4-phenylpyridine ion (MPP+)-induced damage. At concentrations of 1, 2, and 5 µM, triepoxyhexahydrochromone A, (+)-(7R,10R)-selina-4,11(13)-diene-12,15-dial, (-)-(5R,7R,10R)-12,15-dioxo-α-selinene, and (+)-(1R,4S,5R)-1ß-hydroxyeremophila-7(11),9-dien-8-one exerted significant protective effects (p < 0.01) on PC12 cell injury induced by corticosterone, while triepoxyhexahydrochromone A and (-)-(5R,7R,10R)-12,15-dioxo-α-selinene exerted significant protective effects (p < 0.01) on MPP+-induced PC12 cell injury at concentrations of 1, 2, and 5 µM. No compounds produced significant inhibitory effects on BACE1, with inhibition rates of less than 20% observed at a concentration of 20 µM.

6.
Metallomics ; 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33206094

RESUMO

Rare earth elements (REEs) have caused bioaccumulation and adverse health effects attributed to extensive application. The penetrability of REEs across the blood-brain barrier (BBB) contributes to their neurotoxicity process, but potential mechanisms affecting BBB integrity are still obscure. The present study was designed to investigate the effects of lanthanum on BBB adheren junctions and the actin cytoskeleton in vitro using bEnd.3 cells. After lanthanum chloride (LaCl3, 0.125, 0.25 and 0.5 mM) treatment, cytotoxicity against bEnd.3 cells was observed accompanied by increased intracellular Ca2+. Higher paracellular permeability presented as decreased TEER (transendothelial electrical resistance) and increased HRP (horse radish peroxidase) permeation, and simultaneously reduced VE-cadherin expression and F-actin stress fiber formation caused by LaCl3 were reversed by inhibition of ROCK (Rho-kinase) and MLCK (myosin light chain kinase) using inhibitor Y27632 (10 µM) and ML-7 (10 µM). Moreover, chelating overloaded intracellular Ca2+ by BAPTA-AM (25 µM) remarkably abrogated RhoA/ROCK and MLCK activation and downstream phosphorylation of MYPT1 (myosin phosphatase target subunit 1) and MLC2 (myosin light chain 2), therefore alleviating LaCl3-induced BBB disruption and dysfunction. In conclusion, this study indicated that lanthanum caused endothelial barrier hyperpermeability accompanied by loss of VE-cadherin and rearrangement of the actin cytoskeleton though intracellular Ca2+-mediated RhoA/ROCK and MLCK pathways.

7.
Eur Heart J ; 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33211823

RESUMO

AIMS: The aim of this study was to clarify the effect of ß-blockers (BBs) on respiratory function and survival in patients with chronic obstructive pulmonary disease with cardiovascular disease (CVD), as well as the difference between the effects of cardioselective and noncardioselective BBs. METHODS AND RESULTS: We searched for relevant literature in four electronic databases, namely, PubMed, EMBASE, Cochrane Library, and Web of Science, and compared the differences in various survival indicators between patients with chronic obstructive pulmonary disease taking BBs and those not taking BBs. Forty-nine studies were included, with a total sample size of 670 594. Among these, 12 studies were randomized controlled trials (RCTs; seven crossover and five parallel RCTs) and 37 studies were observational (including four post hoc analyses of data from RCTs). The hazard ratios (HRs) of chronic obstructive pulmonary disease exacerbation between patients with chronic obstructive pulmonary disease who were not treated with BBs and those who were treated with BBs, cardioselective BBs, and noncardioselective BBs were 0.77 [95% confidence interval (CI) 0.67, 0.89], 0.72 [95% CI 0.56, 0.94], and 0.98 [95% CI 0.71, 1.34, respectively] (HRs <1 indicate favouring BB therapy). The HRs of all-cause mortality between patients with chronic obstructive pulmonary disease who were not treated with BBs and those who were treated with BBs, cardioselective BBs, and noncardioselective BBs were 0.70 [95% CI 0.59, 0.83], 0.60 [95% CI 0.48, 0.76], and 0.74 [95% CI 0.60, 0.90], respectively (HRs <1 indicate favouring BB therapy). Patients with Chronic obstructive pulmonary disease treated with cardioselective BBs showed no difference in ventilation effect after the use of an agonist, in comparison with placebo. The difference in mean change in forced expiratory volume in 1 s was 0.06 [95% CI -0.02, 0.14]. CONCLUSION: The use of BBs in patients with chronic obstructive pulmonary disease is not only safe but also reduces their all-cause and in-hospital mortality. Cardioselective BBs may even reduce chronic obstructive pulmonary disease exacerbations. In addition, cardioselective BBs do not affect the action of bronchodilators. Importantly, BBs reduce the heart rate acceleration caused by bronchodilators. BBs should be prescribed freely when indicated in patients with chronic obstructive pulmonary disease and heart disease.

8.
J Plant Physiol ; 254: 153264, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33032063

RESUMO

Mitochondrial F1F0-ATP synthase (F1F0-ATPase) inhibitor factor 1 (IF1) has been extensively characterized as an endogenous inhibitor that prevents the hydrolysis of adenosine-5'-triphosphate (ATP) by mitochondrial ATPases in mammals and yeasts; however, IF1's functions in plants remain unclear. Here, a comprehensive bioinformatic analysis was performed to identify plant mitochondrial F1F0-ATPase IF1 orthologs. Plant IF1s contain a conserved F1F0-ATPase inhibitory domain, but lack the antiparallel α-helical coiled-coil structure compared with mammalian IF1s. A subcellular localization analysis in Arabidopsis thaliana revealed that AtIF1-green fluorescent protein was present only in mitochondria. Additionally, AtIF1 was widely expressed in diverse organs and intense ß-glucuronidase staining was observed in reproductive tissues and germinating seeds. Compared with the wild-type and p35S:AtIF1-if1 etiolated seedlings, the ATP/ADP ratio was significantly lower in the AtIF1 T-DNA knockout seedlings (if1 mutant) growing under dark conditions, suggesting that AtIF1 can influence the energy state of cells. A significant reduction in seed yield and strong growth retardation under dark conditions were observed in the if1 mutant line. Furthermore, if1 plants exhibited a substantially decreased sensitivity to abscisic acid. Thus, the A. thaliana mitochondrial IF1, which is a conserved F1F0-ATPase inhibitor, is crucial for plant growth and responses to abscisic acid.

9.
Res Rep Urol ; 12: 391-402, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32984087

RESUMO

Introduction: The etiology of lower urinary tract symptoms in patients with non-obstructed non-neurogenic bladder remains largely unknown. Clinical studies divulged a significant correlation between reduced bladder blood flow and low bladder compliance. Animal models of bladder ischemia displayed structural modifications, characterized by loss of smooth muscle cells and accumulation of connective tissue in the bladder wall. The underlying mechanisms contributing to structural damage in bladder ischemia remain largely elusive. We previously reported that structural modifications in bladder ischemia correlate with upregulated stress proteins and cell survival signaling, suggesting the potential role of cellular stress in ischemic damage. However, stress response molecules and downstream pathways eliciting bladder damage in ischemia remain largely undetermined. Methods: Using a rat model of bladder ischemia along with a cell culture hypoxia model, we investigated stress signaling molecules in the ischemic bladder tissues and hypoxic bladder smooth muscle cells. Results: Our data suggest simultaneous upregulation of two major cellular stress-sensing molecules, namely apoptosis signal-regulating kinase 1 (ASK1) and caspase-3, implying degenerative insult via stress signaling pathway in bladder ischemia. Consistent with bladder ischemia, incubation of cultured human bladder smooth muscle cells at low oxygen tension increased both ASK1 and caspase-3 expression, insinuating hypoxia as an essential factor in ASK1 and caspase-3 upregulation. Gene deletion of ASK1 by ASK1 siRNA in cultured smooth muscle cells prevented caspase-3 upregulation by hypoxia, suggesting caspase-3 regulation by ASK1 under the ischemic/hypoxic conditions. Upregulation of ASK1 and caspase-3 in rat bladder ischemia and human bladder smooth muscle cell hypoxia was associated with subcellular structural modifications consistent with the initial stages of apoptotic insult. Conclusion: Our data suggest that stress sensing by ASK1 and caspase-3 may contribute to subcellular structural damage and low bladder compliance. The ASK1/caspase-3 pathway may provide therapeutic targets against cellular stress and degenerative responses in bladder ischemia.

10.
Plant Cell Environ ; 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32978825

RESUMO

Spontaneous fertility reversion has been documented in cytoplasmic male sterile (CMS) plants of several species, influenced in frequency by nuclear genetic background. In this study, we found that MutS HOMOLOG1 (MSH1) mediates fertility reversion via substoichiometric shifting (SSS) of the CMS-associated mitochondrial Open Reading Frame 220 (ORF220), a process that may be regulated by pollination signalling in Brassica juncea. We show that plants adjust their growth and development in response to unsuccessful pollination. Measurable decrease in MSH1 transcript levels and evidence of ORF220 SSS under non-pollination conditions suggest that this nuclear-mitochondrial interplay influences fertility reversion in CMS plants in response to physiological signals. Suppression of MSH1 expression induced higher frequency SSS in CMS plants than occurs normally. Transcriptional analysis of floral buds under pollination and non-pollination conditions, and the response of MSH1 expression to different sugars, supports the hypothesis that carbon flux is involved in the pollination signalling of fertility reversion in CMS plants. Our findings suggest that facultative gynodioecy as a reproductive strategy may incorporate environmentally responsive genes like MSH1 as an "on-off" switch for sterility-fertility transition under ecological conditions of reproductive isolation.

11.
Plant Physiol Biochem ; 155: 613-625, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32853854

RESUMO

Crop plants, such as watermelon, suffer from severe Aluminum (Al3+)-toxicity in acidic soils with their primary root elongation being first arrested. However, the significance of apoplastic or symplastic Al3+-toxicity in watermelon root is scarcely reported. In this work, we identified a medium fruit type (ZJ) and a small fruit type (NBT) as Al+3-tolerant and sensitive based on their differential primary root elongation rate respectively, and used them to show the effects of symplastic besides apoplastic Al distribution in the watermelon's root. Although the Al content was higher in the root of NBT than ZJ, Al+3 allocated in their apoplast, vacuole and plastid fractions were not significantly different between the two cultivars. Thus, only a few proportion of Al+3 differentially distributed in the nucleus and mitochondria corresponded to interesting differential morphological and physiological disorders recorded in the root under Al+3-stress. The symplastic amount of Al+3 substantially induced the energy efficient catalase pathway in ZJ, and the energy consuming ascorbate peroxidase pathway in NBT. These findings coincided with obvious starch granule visibility in the root ultra-structure of ZJ than NBT, suggesting a differential energy was used in supporting the root elongation and nutrient uptake for Al+3-tolerance in the two cultivars. This work provides clues that could be further investigated in the identification of genetic components and molecular mechanisms associated with Al+3-tolerance in watermelon.

12.
Plant J ; 104(3): 706-717, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32772441

RESUMO

The swollen stem is a determinant of yield for the stem-type vegetable Brassica juncea that is representative of vegetative organ formation. However, the genetic mechanism underlying swollen stem formation and its regulation remains unknown. In this study, we identified a casein kinase 2 ß subunit 1 (CK2B1) and revealed its role in swollen stem formation. Genotyping analysis revealed that a homozygous variation in the CK2B1 promoter is responsible for swollen stem formation, and the promoter activity of CK2B1 was significantly associated with the variations between swollen stem and non-swollen stem types. CK2B1 was exclusively located in the nucleus and expressed in the stem nodes of the plant. Swollen stem formation was blocked when CK2B1 expression was silenced, and induced in a backcross population carrying a swollen stem genotype, which indicates that CK2B1 is required for swollen stem formation. Cell numbers were increased during swollen stem formation and decreased in CK2B1-silenced expression plant, indicating that CK2B1 regulates swollen stem formation via cell division. CK2B1 directly interacted with E2Fa, a regulator of G1/S transition in the cell cycle, in which CK2 phosphorylates E2Fa. Our results revealed that CK2B1 affects swollen stem formation via the control of the cell cycle. These findings help to elucidate the signals that control swollen stem formation and provide a promising molecular target to enhance the yield of vegetative organ formation.

13.
iScience ; 23(8): 101422, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32798971

RESUMO

Comparative and evolutionary genomics analyses are the powerful tools to provide mechanistic insights into important agronomic traits. Here, we completed a chromosome-scale assembly of the "neglected" but vital melon subspecies Cucumis melo ssp. agrestis using single-molecule real-time sequencing, Hi-C, and an ultra-dense genetic map. Comparative genomics analyses identified two targeted genes, UDP-sugar pyrophosphorylase and α-galactosidase, that were selected during evolution for specific phloem transport of oligosaccharides in Cucurbitaceae. Association analysis of transcriptome and the DNA methylation patterns revealed the epigenetic regulation of sucrose accumulation in developing fruits. We constructed the melon recombinant inbred lines to uncover Alkaline/Neutral Invertase (CINV), Sucrose-Phosphatase 2 (SPP2), α-galactosidase, and ß-galactosidase loci related to sucrose accumulation and an LRR receptor-like serine/threonine-protein kinase associated with gummy stem blight resistance. This study provides essential genomic resources enabling functional genomics studies and the genomics-informed breeding pipelines for improving the fruit quality and disease resistance traits.

14.
Fungal Genet Biol ; 144: 103440, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32758529

RESUMO

Protein O-mannosyltransferases (PMTs) initiate O-mannosylation of proteins in the ER. Trichoderma reesei strains displayed a single representative of each PMT subfamily, Trpmt1, Trpmt2 and Trpmt4. In this work, two knockout strains ΔTrpmt1and ΔTrpmt4were obtained. Both mutants showed retarded growth, defective cell walls, reduced conidiation and decreased protein secretion. Additionally, the ΔTrpmt1strain displayed a thermosensitive growth phenotype, while the ΔTrpmt4 strain showed abnormal polarity. Meanwhile, OETrpmt2 strain, in which the Trpmt2 was over-expressed, exhibited increased conidiation, enhanced protein secretion and abnormal polarity. Using a lectin enrichment method and MS/MS analysis, 173 O-glycoproteins, 295 O-glycopeptides and 649 O-mannosylation sites were identified as the targets of PMTs in T. reesei. These identified O-mannoproteins are involved in various physiological processes such as protein folding, sorting, transport, quality control and secretion, as well as cell wall integrity and polarity. By comparing proteins identified in the mutants and its parent strain, the potential specific protein substrates of PMTs were identified. Based on our results, TrPMT1 is specifically involved inO-mannosylation of intracellular soluble proteins and secreted proteins, specially glycosidases. TrPMT2 is involved inO-mannosylation of secreted proteins and GPI-anchor proteins, and TrPMT4 mainly modifies multiple transmembrane proteins. The TrPMT1-TrPMT4 complex is responsible for O-mannosylation of proteins involved in cell wall integrity. Overexpression of TrPMT2 enhances protein secretion, which might be a new strategy to improve expression efficiency in T. reesei.

15.
Ann Palliat Med ; 9(4): 1782-1796, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32527124

RESUMO

BACKGROUND: Lung cancer is the most common malignant tumor, and it remains the major cause of cancerrelated death worldwide. Anaplastic lymphoma kinase fusion gene-rearrangement (ALK-positive) nonsmall cell lung cancer (NSCLC) is a unique subgroup that accounts for 3-7% of NSCLC cases. Over the last few years, the introduction of several ALK inhibitors has completely altered the treatment of advanced ALK-positive NSCLC and significantly improved the prognosis for patients. Crizotinib was the first ALK inhibitor developed, and it has demonstrated systemic efficacy and strongly improved outcomes in NSCLC patients with ALK-positive when compared with chemotherapy. Alectinib was designed specifically to be a more potent and selective anti-ALK therapeutic agent that could bypass crizotinib resistance. This study aims to evaluate the different efficacies of alectinib and crizotinib on progression-free survival (PFS), central nervous system (CNS) progression and adverse events (AEs) in NSCLC patients with ALK-positive. METHODS: We searched for relevant literature in four electronic databases: PubMed, EMBASE, Cochrane Library, and Web of Science. The hazard ratio (HR) was calculated, and the effect of alectinib and crizotinib on PFS was evaluated. The quality of the studies was assessed using the Cochrane Risk of Bias tool. Publication bias was assessed using the Begg rank correlation test and the Egger weighted linear regression test. We performed the sensitivity analysis using the method of "removing one study". All analyses were performed in STATA. RESULTS: Ten studies were included, and the total sample size was 2,377. Alectinib showed significant PFS superiority over crizotinib. The pooled HR =0.41 (95% CI: 0.29-0.53) indicated that the alectinib therapy group did have significantly longer PFS than that of the crizotinib group. Based on 5 clinical trials, the cumulative incidence of CNS progression for patients treated with alectinib at 6 months (10%, 95% CI: 5-16%) and 12 months (16%, 95% CI: 9-24%) was calculated. Based on 7 clinical studies, the risk of AEs related to treatment with alectinib was determined: alectinib was associated with 28 cases of AE grade ≤2 and 9 cases of AE grade ≥3; among the top 4 incidences of AE grade ≥3, were blood creatine phosphokinase increased 5.6%, ALT increased 2.5%, AST increased 2.4% and Anemia 1.8%. CONCLUSIONS: Alectinib significantly prolongs PFS and it better controls CNS metastases than crizotinib and good toxicity characteristics in the first-line treatment of NSCLC patients with ALK-positive.

16.
Ther Adv Med Oncol ; 12: 1758835920917562, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32499837

RESUMO

Background: There is an immediate need for research on the mechanism underlying telomerase activation and overexpression. Materials & Methods: A total of 174 patients with lung cancer (n = 106) and benign lung disease (n = 68) were recruited for the current study. The mRNA expression levels of E6, E7, LKB1, Sp1, and hTERC in brushing cells were detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), and hTERC amplification was also detected by fluorescence in situ hybridization (FISH). To investigate the potential mechanism, bidirectional genetic manipulation was performed in well-established lung cancer cell lines. Results: Our results indicated that the mRNA expression levels of E6, E7, Sp1, and hTERC and the amplification level of hTERC were significantly increased in the malignant group compared with those of the benign group (p < 0.01). Conversely, the mRNA expression level of LKB1 was significantly decreased in the malignant group (p < 0.01). The correlation between E6, E7, Sp1, and hTERC expression was positive but was negative with LKB1 (p < 0.01). Our results also showed that HPV16 E6/E7 downregulated the expression of LKB1 at both the protein and mRNA levels. The loss of LKB1 upregulated Sp1 expression, and also promoted Sp1 activity. Sp1 further upregulated hTERC at the mRNA and gene amplification levels. Thus, we proposed a HPV-LKB1-Sp1-hTERC axis of E6/E7 upregulation of hTERC expression. Conclusion: We demonstrated for the first time that E6 and E7 promoted hTERC mRNA expression and the amplification of hTERC by relieving the effect of LKB1 on the phosphorylation of Sp1. Sp1 further activated hTERC by directly binding to the promoter regions of hTERC.

17.
Metallomics ; 12(4): 592-606, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32163055

RESUMO

Lanthanum (La) is a kind of rare earth element (REE) widely found in nature. La has neurotoxicity and can impair learning and memory, but the underlying mechanism is still not completely clear. The mitochondrial calcium uniporter (MCU) complex can cause the uptake of cytoplasmic calcium ([Ca2+]c) into mitochondria and thereby resist [Ca2+]c overload. However, the abnormal increase of calcium in the mitochondrial matrix ([Ca2+]m) can also disturb the mitochondrial fission-fusion balance, and then induce excessive mitophagy, and disrupt mitochondrial quality control (MQC). It is unclear whether La can interfere with the function of nerve cells through the above-mentioned mechanism and thus impair learning and memory. In this study, four groups of Wistar rats were treated with 0%, 0.25%, 0.5% and 1.0% (w/v) lanthanum chloride (LaCl3) from the embryonic phase to 1 month after weaning. The results showed that La could impair the spatial learning and memory of rats, promote the uptake of [Ca2+]c by MCU, induce the abnormal increase of [Ca2+]m, up-regulate p-Drp1 Ser616 expression and inhibit Mfn1/2 expression, enhance mitochondrial fission and lead to mitochondrial fission-fusion disturbance in hippocampal nerve cells. Meanwhile, La could also activate the PINK1-Parkin signaling pathway, up-regulate LC3B-II expression and decrease p62 expression, and thereby induce excessive mitophagy. These results suggested that learning and memory impairment caused by La may be related to MQC disturbance. The present data provide some novel clues for elucidating the neurotoxic effect mechanism of La.

18.
J Pharm Biomed Anal ; 185: 113225, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32163850

RESUMO

Stephania tetrandra S. Moore, a widely used traditional antirheumatic herbal medicine (HM), is a rich source of isoquinoline alkaloids. With the exception of the two recognized isoquinolines, viz. tetrandrine and fangchinoline, the other isoquinoline alkaloids present in S. tetrandra have not been clearly clarified. In addition, due to their similar names and morphological similarities, S. tetrandra is often mistakenly substituted and adulterated with the nephrotoxic Aristolochia fangchi. In this study, ultra-high-performance liquid chromatography-triple time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was initially employed to comprehensively profile the isoquinolines from S. tetrandra. To overcome the complexities arising due to the similar mass behaviors of the isoquinolines, a stepwise diagnostic fragment ion (DFI) and neutral loss (NL)-dependent structure annotation algorithm was proposed, and this accelerated the identification of 393 isoquinolines distributed over twenty classes. Consequently, liquid microjunction surface sampling-high-resolution mass spectrometry (LMJ-HRMS) was deployed in an attempt to directly authenticate S. tetrandra by the chemical profiling of its crude slice. By matching the 393 isoquinolines, the 87 peaks detected by LMJ-HRMS were assigned to 270 isoquinolines, including the recognized tetrandrine and fangchinoline. The absence of aristolochic acid-related mass signals confirmed the authentication of S. tetrandra. In summary, LMJ-HRMS can be considered a direct, nondestructive, high-throughput, and environment-friendly analytical method for the authentication of HMs. Moreover, the stepwise DFI- and NL-dependent structure annotation algorithm-based UHPLC-Q-TOF-MS method allowed high-coverage detection and high-quality data processing of the inherent structural similarity and complexity of isoquinolines or other phytochemical compounds.

19.
3 Biotech ; 10(2): 75, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32051808

RESUMO

Eukaryotic translation initiation factors (eIFs) are essential protein complexes involved in the translation of mRNA into proteins. These initiation factors are generally used as targets in the control of plant RNA virus infections. In the present study, we identified a total 190 eIFs, clustered phylogenetically into 40 distinct subfamilies in the allopolyploid Brassica juncea. Extensive evolutionary duplications of the eIFs in B. juncea suggest their increased genetic diversity and wide adaptability. The induction of expressions in some of the eIFs after inoculation against Turnip mosaic virus (TuMV) provided candidate targets to be used in the control of viral infections. In addition, the expression profiles of eIFs under different temperatures suggested that the TuMV epidemic was temperature dependent. The eIFs expressions suggested that the systemic viral infections were more acute in plants grown between 20 °C and 28 °C. In addition, our results revealed that new subgroups of eIFs, eIF2ß, eIF2α, eIF2Bß, EF1A, and PABP could be represented as targets for antiviral strategies in B. juncea. In summary, our findings would be helpful in studying the complex mechanisms of eIF-mediated, temperature-dependent RNA virus control in B. juncea.

20.
Plant Biotechnol J ; 18(4): 1066-1077, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31610078

RESUMO

Fruit rind plays a pivotal role in alleviating water loss and disease and particularly in cracking resistance as well as the transportability, storability and shelf-life quality of the fruit. High susceptibility to cracking due to low rind hardness is largely responsible for severe annual yield losses of fresh fruits such as watermelon in the field and during the postharvest process. However, the candidate gene controlling the rind hardness phenotype remains unclear to date. Herein, we report, for the first time, an ethylene-responsive transcription factor 4 (ClERF4) associated with variation in rind hardness via a combinatory genetic map with bulk segregant analysis (BSA). Strikingly, our fine-mapping approach revealed an InDel of 11 bp and a neighbouring SNP in the ClERF4 gene on chromosome 10, conferring cracking resistance in F2 populations with variable rind hardness. Furthermore, the concomitant kompetitive/competitive allele-specific PCR (KASP) genotyping data sets of 104 germplasm accessions strongly supported candidate ClERF4 as a causative gene associated with fruit rind hardness variability. In conclusion, our results provide new insight into the underlying mechanism controlling rind hardness, a desirable trait in fresh fruit. Moreover, the findings will further enable the molecular improvement of fruit cracking resistance in watermelon via precisely targeting the causative gene relevant to rind hardness, ClERF4.


Assuntos
Citrullus/genética , Etilenos , Frutas , Proteínas de Plantas/genética , Proteínas Repressoras/genética , Dureza , Fenótipo
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