Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 189
Filtrar
1.
Res Sq ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38947012

RESUMO

Inhibition of translation initiation using eIF4A inhibitors like (-)-didesmethylrocaglamide [(-)-DDR] and (-)-rocaglamide [(-)-Roc] is a potential cancer treatment strategy as they simultaneously diminish multiple oncogenic drivers. We showed that human and dog osteosarcoma cells expressed high levels of eIF4A1/2, particularly eIF4A2. Genetic depletion of eIF4A1 and/or 2 slowed osteosarcoma cell growth. To advance preclinical development of eIF4A inhibitors, we demonstrated the importance of (-)-chirality in DDR for growth-inhibitory activity. Bromination of DDR at carbon-5 abolished growth-inhibitory activity, while acetylating DDR at carbon-1 was tolerated. Like DDR and Roc, DDR-acetate increased the γH2A.X levels and induced G2/M arrest and apoptosis. Consistent with translation inhibition, these rocaglates decreased the levels of several mitogenic kinases, the STAT3 transcription factor, and the stress-activated protein kinase p38. However, phosphorylated p38 was greatly enhanced in treated cells, suggesting activation of stress response pathways. RNA sequencing identified RHOB as a top upregulated gene in both DDR- and Roc-treated osteosarcoma cells, but the Rho inhibitor Rhosin did not enhance the growth-inhibitory activity of (-)-DDR or (-)-Roc. Nonetheless, these rocaglates potently suppressed tumor growth in a canine osteosarcoma patient-derived xenograft model. These results suggest that these eIF4A inhibitors can be leveraged to treat both human and dog osteosarcomas.

2.
LGBT Health ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557209

RESUMO

Purpose: Lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals are more likely to smoke than non-LGBTQ individuals. Smoking has been posited as a coping mechanism for LGBTQ individuals facing minority stress. However, the exact relationship between minority stress and smoking behaviors among LGBTQ individuals is unclear. Therefore, the purpose of this systematic review was to examine how minority stress processes are associated with smoking behaviors for LGBTQ individuals. Methods: Searches of the PubMed and PsycINFO databases were conducted for smoking-, LGBTQ-, and minority stress-related terms. No date, geographic, or language limits were used. For inclusion, the study must have (1) been written in English, (2) had an LGBTQ group as the study population or a component of the study population, (3) assessed the cigarette smoking status of patients, and (4) assessed at least one minority stress-related process (internalized stigma, perceived stigma, or prejudice events). Results: The final review included 44 articles. Aside from two outlier studies, all of the reviewed studies exhibited that increased levels of minority stress processes (internalized queerphobia, perceived stigma, and prejudice events) were associated with increased probability of cigarette use in LGBTQ individuals. Increased minority stress was also associated with greater psychological distress/mental health decline. Conclusion: The findings of this review suggest that minority stress processes represent a contributing factor to smoking health disparities in LGBTQ populations. These results highlight the need for smoking cessation and prevention programs to address minority stress and improve smoking disparities in these populations.

3.
New Phytol ; 241(5): 1950-1972, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38095236

RESUMO

Histone H3 lysine-4 trimethylation (H3K4me3) activating drought-responsive genes in plants for drought adaptation has long been established, but the underlying regulatory mechanisms are unknown. Here, using yeast two-hybrid, bimolecular fluorescence complementation, biochemical analyses, transient and CRISPR-mediated transgenesis in Populus trichocarpa, we unveiled in this adaptation a regulatory interplay between chromatin regulation and gene transactivation mediated by an epigenetic determinant, a PtrSDG2-1-PtrCOMPASS (complex proteins associated with Set1)-like H3K4me3 complex, PtrSDG2-1-PtrWDR5a-1-PtrRbBP5-1-PtrAsh2-2 (PtrSWRA). Under drought conditions, a transcription factor PtrAREB1-2 interacts with PtrSWRA, forming a PtrSWRA-PtrAREB1-2 pentamer, to recruit PtrSWRA to specific promoter elements of drought-tolerant genes, such as PtrHox2, PtrHox46, and PtrHox52, for depositing H3K4me3 to promote and maintain activated state of such genes for tolerance. CRISPR-edited defects in the pentamer impaired drought tolerance and elevated expression of PtrHox2, PtrHox46, or PtrHox52 improved the tolerance as well as growth in P. trichocarpa. Our findings revealed the identity of the underlying H3K4 trimethyltransferase and its interactive arrangement with the COMPASS for catalysis specificity and efficiency. Furthermore, our study uncovered how the H3K4 trimethyltransferase-COMPASS complex is recruited to the effector genes for elevating H3K4me3 marks for improved drought tolerance and growth/biomass production in plants.


Assuntos
Histonas , Populus , Histonas/metabolismo , Populus/metabolismo , Resistência à Seca , Biomassa , Cromatina , Saccharomyces cerevisiae/metabolismo
4.
Mol Plant ; 17(1): 112-140, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38102833

RESUMO

Cell walls in plants, particularly forest trees, are the major carbon sink of the terrestrial ecosystem. Chemical and biosynthetic features of plant cell walls were revealed early on, focusing mostly on herbaceous model species. Recent developments in genomics, transcriptomics, epigenomics, transgenesis, and associated analytical techniques are enabling novel insights into formation of woody cell walls. Here, we review multilevel regulation of cell wall biosynthesis in forest tree species. We highlight current approaches to engineering cell walls as potential feedstock for materials and energy and survey reported field tests of such engineered transgenic trees. We outline opportunities and challenges in future research to better understand cell type biogenesis for more efficient wood cell wall modification and utilization for biomaterials or for enhanced carbon capture and storage.


Assuntos
Lignina , Madeira , Madeira/genética , Madeira/metabolismo , Lignina/metabolismo , Ecossistema , Plantas/metabolismo , Parede Celular/metabolismo , Árvores/genética
5.
Science ; 381(6654): 216-221, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37440632

RESUMO

The domestication of forest trees for a more sustainable fiber bioeconomy has long been hindered by the complexity and plasticity of lignin, a biopolymer in wood that is recalcitrant to chemical and enzymatic degradation. Here, we show that multiplex CRISPR editing enables precise woody feedstock design for combinatorial improvement of lignin composition and wood properties. By assessing every possible combination of 69,123 multigenic editing strategies for 21 lignin biosynthesis genes, we deduced seven different genome editing strategies targeting the concurrent alteration of up to six genes and produced 174 edited poplar variants. CRISPR editing increased the wood carbohydrate-to-lignin ratio up to 228% that of wild type, leading to more-efficient fiber pulping. The edited wood alleviates a major fiber-production bottleneck regardless of changes in tree growth rate and could bring unprecedented operational efficiencies, bioeconomic opportunities, and environmental benefits.


Assuntos
Edição de Genes , Lignina , Populus , Madeira , Carboidratos/análise , Lignina/genética , Madeira/genética , Sistemas CRISPR-Cas , Populus/genética , Papel , Crescimento Sustentável
6.
Am J Transplant ; 23(8): 1227-1240, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37156300

RESUMO

Intracardiac thrombosis and/or pulmonary thromboembolism (ICT/PE) is a rare but devastating complication during liver transplantation. Its pathophysiology remains poorly understood, and successful treatment remains a challenge. This systematic review summarizes the available published clinical data regarding ICT/PE during liver transplantation. Databases were searched for all publications reporting on ICT/PE during liver transplantation. Data collected included its incidence, patient characteristics, the timing of diagnosis, treatment strategies, and patient outcomes. This review included 59 full-text citations. The point prevalence of ICT/PE was 1.42%. Thrombi were most often diagnosed during the neohepatic phase, particularly at allograft reperfusion. Intravenous heparin was effective in preventing early-stage thrombus from progressing further and restoring hemodynamics in 76.32% of patients it was utilized for; however, the addition of tissue plasminogen activator or sole use of tissue plasminogen activator offered diminishing returns. Despite all resuscitation efforts, the in-hospital mortality rate of an intraoperative ICT/PE was 40.42%, with nearly half of these patients dying intraoperatively. The results of our systematic review are an initial step for providing clinicians with data that can help identify higher-risk patients. The clinical implications of our results warrant the development of identification and management strategies for the timely and effective treatment of these tragic occurrences during liver transplantation.


Assuntos
Cardiopatias , Transplante de Fígado , Embolia Pulmonar , Trombose , Humanos , Ativador de Plasminogênio Tecidual , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Trombose/etiologia , Trombose/diagnóstico , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/tratamento farmacológico , Embolia Pulmonar/etiologia
7.
Mol Metab ; 71: 101712, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36963615

RESUMO

OBJECTIVE: In the fibrotic kidneys, the extent of a formed deleterious microenvironment is determined by cellular mechanical forces. This process requires metabolism for energy. However, how cellular mechanics and metabolism are connected remains unclear. METHODS: A multi-disciplinary approach was employed: the fibrotic kidney disease models were induced by renal ischemia-reperfusion injury and unilateral ureteral obstruction in Calponin 2 (CNN2) knockdown mice. Proteomics, bioinformatics, and in vivo and in vitro molecular experimental pathology studies were performed. RESULT: Our proteomics revealed that actin filament binding and cell metabolism are the two most dysregulated events in the fibrotic kidneys. As a prominent actin stabilizer, CNN2 was predominantly expressed in fibroblasts and pericytes. In CKD patients, CNN2 levels was markedly induced in blood. In mice, CNN2 knockdown preserves kidney function and alleviates fibrosis. Global proteomics profiled that CNN2 knockdown enhanced the activities of the key rate-limiting enzymes and regulators of fatty acid oxidation (FAO) in the diseased kidneys. Inhibiting carnitine palmitoyltransferase 1α in the FAO pathway resulted in lipid accumulation and extracellular matrix deposition in the fibrotic kidneys, which were restored after CNN2 knockdown. Bioinformatics and chromatin immunoprecipitation showed that CNN2 interactor, estrogen receptor 2 (ESR2), binds peroxisome proliferator-activated receptor-α (PPARα) to transcriptionally regulate FAO downstream target genes expression amid kidney fibrosis. In vitro, ESR2 knockdown repressed the mRNA levels of PPARα and the key genes in the FAO pathway. Conversely, activation of PPARα reduced CNN2-induced matrix inductions. CONCLUSIONS: Our results suggest that balancing cell mechanics and metabolism is crucial to develop therapeutic strategies to halt kidney fibrosis.


Assuntos
Proteínas de Ligação a Calmodulina , Nefropatias , Animais , Camundongos , Fibrose , Rim/metabolismo , Rim/patologia , Nefropatias/metabolismo , Nefropatias/patologia , PPAR alfa/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Calponinas
8.
Nat Plants ; 9(1): 96-111, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36624255

RESUMO

Stem vascular cambium cells in forest trees produce wood for materials and energy. WOX4 affects the proliferation of such cells in Populus. Here we show that PtrWOX4a is the most highly expressed stem vascular-cambium-specific (VCS) gene in P. trichocarpa, and its expression is controlled by the product of the second most highly expressed VCS gene, PtrVCS2, encoding a zinc finger protein. PtrVCS2 binds to the PtrWOX4a promoter as part of a PtrWOX13a-PtrVCS2-PtrGCN5-1-PtrADA2b-3 protein tetramer. PtrVCS2 prevented the interaction between PtrGCN5-1 and PtrADA2b-3, resulting in H3K9, H3K14 and H3K27 hypoacetylation at the PtrWOX4a promoter, which led to fewer cambium cell layers. These effects on cambium cell proliferation were consistent across more than 20 sets of transgenic lines overexpressing individual genes, gene-edited mutants and RNA interference lines in P. trichocarpa. We propose that the tetramer-PtrWOX4a system may coordinate genetic and epigenetic regulation to maintain normal vascular cambium development for wood formation.


Assuntos
Câmbio , Populus , Câmbio/genética , Populus/genética , Epigênese Genética , Código das Histonas , Madeira , Regulação da Expressão Gênica de Plantas
9.
Bioresour Technol ; 367: 128275, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36347479

RESUMO

Naturally occurring, microbial contaminants were found in plant biomasses from common bioenergy crops and agricultural wastes. Unexpectedly, indigenous thermophilic microbes were abundant, raising the question of whether they impact thermophilic consolidated bioprocessing fermentations that convert biomass directly into useful bioproducts. Candidate microbial platforms for biomass conversion, Acetivibrio thermocellus (basionym Clostridium thermocellum; Topt 60 °C) and Caldicellulosiruptor bescii (Topt 78 °C), each degraded a wide variety of plant biomasses, but only A. thermocellus was significantly affected by the presence of indigenous microbial populations harbored by the biomass. Indigenous microbial growth was eliminated at ≥75 °C, conditions where C. bescii thrives, but where A. thermocellus cannot survive. Therefore, 75 °C is the thermophilic threshold to avoid sterilizing pre-treatments on the biomass that prevents native microbes from competing with engineered microbes and forming undesirable by-products. Thermophiles that naturally grow at and above 75 °C offer specific advantages as platform microorganisms for biomass conversion into fuels and chemicals.


Assuntos
Clostridium thermocellum , Lignina , Biomassa , Fermentação , Lignina/química , Clostridium thermocellum/metabolismo , Plantas/metabolismo
10.
World J Clin Cases ; 10(34): 12605-12609, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36579114

RESUMO

BACKGROUND: Cytomegalovirus (CMV) infection is usually subclinical and asymptomatic in the healthy population, whereas severe complications occur in immunocompromised patients. CASE SUMMARY: In this case report, we described a rare case of acute CMV hepatitis in a 35-year-old male immunocompetent patient who presented with a history of week-long intermittent fever with nonspecific constitutional symptoms. Acute hepatitis was suspected according to the initial serological tests. After ruling out other etiologies, including viral hepatitis A, B, C, drug, alcohol, autoimmune, and Wilson disease, acute CMV hepatitis was diagnosed based on positive CMV IgM and DNA quantitative tests. Because there was no any local acute hepatitis E reported in Taiwan, so hepatitis E was not checked. The patient recovered both clinically and serologically with symptomatic management and without antiviral therapy within 12 days from the onset of symptom. CONCLUSION: In conclusion, a diagnosis of CMV infection should be considered when nonspecific prodromal symptoms occur in acute hepatitis with an uncertain etiology. Antiviral therapy should not be used in immunocompetent patient who had no decompensation of the liver, such as this patient. Widely available noninvasive tests for CMV can facilitate early diagnosis if used appropriately. Harm-benefit analysis is essential before using antiviral therapy in immunocompetent patients.

11.
Cureus ; 14(10): e30474, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36415439

RESUMO

Polyarticular septic arthritis (PASA) is less common than monoarticular septic arthritis (MASA). There is a low incidence of PASA in immunocompetent patients. This case report describes the development of PASA after hemodialysis through the permcath after a single session.

12.
Front Plant Sci ; 13: 883421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35592579

RESUMO

Gene-editing tools, such as Zinc-fingers, TALENs, and CRISPR-Cas, have fostered a new frontier in the genetic improvement of plants across the tree of life. In eukaryotes, genome editing occurs primarily through two DNA repair pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ is the primary mechanism in higher plants, but it is unpredictable and often results in undesired mutations, frameshift insertions, and deletions. Homology-directed repair (HDR), which proceeds through HR, is typically the preferred editing method by genetic engineers. HR-mediated gene editing can enable error-free editing by incorporating a sequence provided by a donor template. However, the low frequency of native HR in plants is a barrier to attaining efficient plant genome engineering. This review summarizes various strategies implemented to increase the frequency of HDR in plant cells. Such strategies include methods for targeting double-strand DNA breaks, optimizing donor sequences, altering plant DNA repair machinery, and environmental factors shown to influence HR frequency in plants. Through the use and further refinement of these methods, HR-based gene editing may one day be commonplace in plants, as it is in other systems.

13.
J Sci Educ Technol ; 31(3): 303-321, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35132301

RESUMO

As students transition into tertiary blended learning environments, their digital literacy in terms of technical capabilities have potential to impact on their access to digital resources. The first foundational year of STEM degrees includes compulsory courses across a broad range of scientific areas, each of which incorporates online technology in a discipline-specific manner. Given the diversity of online resources that STEM students need to access across their first-year coursework, this study applies learning analytical methods to determine whether students' perceived level of digital literacy has an effect on their navigation of learning management systems (LMS) and overall academic performance. The frequency and nature of LMS interactivity were examined across four first-year STEM courses offered in the same semester at a single institution, using a K-means cluster analysis to group student responses. It was observed that high achieving students accessed LMS resources more frequently than mid or low-achieving students across all four STEM courses. Students' perceived level of digital literacy was collected via survey (n = 282), and students were sorted high (n = 106) and low-level (n = 176) of perceived digital literacy-HDL and LDL, respectively. HDL students were not consistently found in the high-achieving academic group and did not perform better in their overall grade when compared to LDL students. LDL students were observed to perform better in specific online assessment tasks, which may be attributed to their increased frequency of LMS interactivity. These findings highlight the delicate balance between students' perceived level of digital literacy, motivation for engaging with online learning environments, and academic performance.

14.
New Phytol ; 234(3): 918-933, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35152419

RESUMO

Wood formation is controlled by transcriptional regulatory networks (TRNs) involving regulatory homeostasis determined by combinations of transcription factor (TF)-DNA and TF-TF interactions. Functions of TF-TF interactions in wood formation are still in the early stages of identification. PtrMYB074 is a woody dicot-specific TF in a TRN for wood formation in Populus trichocarpa. Here, using yeast two-hybrid and bimolecular fluorescence complementation, we conducted a genome-wide screening for PtrMYB074 interactors and identified 54 PtrMYB074-TF pairs. Of these pairs, 53 are novel. We focused on the PtrMYB074-PtrWRKY19 pair, the most highly expressed and xylem-specific interactor, and its direct transregulatory target, PtrbHLH186, the xylem-specific one of the pair's only two direct TF target genes. Using transient and CRISPR-mediated transgenesis in P. trichocarpa coupled with chromatin immunoprecipitation and electrophoretic mobility shift assays, we demonstrated that PtrMYB074 is recruited by PtrWRKY19 and that the PtrMYB074-PtrWRKY19 dimers are required to transactive PtrbHLH186. Overexpressing PtrbHLH186 in P. trichocarpa resulted in retarded plant growth, increased guaiacyl lignin, a higher proportion of smaller stem vessels and strong drought-tolerant phenotypes. Knowledge of the PtrMYB074-PtrWRKY19-PtrbHLH186 regulation may help design genetic controls of optimal growth and wood formation to maximize beneficial wood properties while minimizing negative effects on growth.


Assuntos
Populus , Parede Celular/metabolismo , Dimerização , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ativação Transcricional , Madeira , Xilema/metabolismo
15.
Plant Commun ; 3(1): 100250, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35059630

RESUMO

Tension wood (TW) is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses (e.g., bending). The genetic regulation that underlies this important mechanism remains poorly understood. Here, we used laser capture microdissection of stem xylem cells coupled with full transcriptome RNA-sequencing to analyze TW formation in Populus trichocarpa. After tree bending, PtrLBD39 was the most significantly induced transcription factor gene; it has a phylogenetically paired homolog, PtrLBD22. CRISPR-based knockout of PtrLBD39/22 severely inhibited TW formation, reducing cellulose and increasing lignin content. Transcriptomic analyses of CRISPR-based PtrLBD39/22 double mutants showed that these two genes regulate a set of TW-related genes. Chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify direct targets of PtrLBD39. We integrated transcriptomic analyses and ChIP-seq assays to construct a transcriptional regulatory network (TRN) mediated by PtrLBD39. In this TRN, PtrLBD39 directly regulates 26 novel TW-responsive transcription factor genes. Our work suggests that PtrLBD39 and PtrLBD22 specifically control TW formation by mediating a TW-specific TRN in Populus.


Assuntos
Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Genes de Plantas , Populus , Madeira , Fenômenos Biomecânicos , Regulação da Expressão Gênica de Plantas/fisiologia , Redes Reguladoras de Genes/fisiologia , Genes de Plantas/genética , Genes de Plantas/fisiologia , Microdissecção e Captura a Laser , Populus/genética , Populus/fisiologia , Madeira/genética , Madeira/fisiologia , Xilema
16.
Bioresour Technol ; 348: 126780, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35093526

RESUMO

A variety of chemical and biological processes have been proposed for conversion of sustainable low-cost feedstocks into industrial products. Here, a biorefinery concept is formulated, modeled, and analyzed in which a naturally (hemi)cellulolytic and extremely thermophilic bacterium, Caldicellulosiruptor bescii, is metabolically engineered to convert the carbohydrate content of lignocellulosic biomasses (i.e., soybean hulls, transgenic poplar) into green hydrogen and acetone. Experimental validation of C. bescii fermentative performance demonstrated 82% carbohydrate solubilization of soybean hulls and 55% for transgenic poplar. A detailed technical design, including equipment specifications, provides the basis for an economic analysis that establishes metabolic engineering targets. This robust industrial process leveraging metabolically engineered C. bescii yields 206 kg acetone and 25 kg H2 per metric ton of soybean hull, or 174 kg acetone and 21 kg H2 per metric ton transgenic poplar. Beyond this specific case, the model demonstrates industrial feasibility and economic advantages of thermophilic fermentation.


Assuntos
Acetona , Lignina , Biomassa , Caldicellulosiruptor , Fermentação , Hidrogênio , Lignina/química
17.
Front Plant Sci ; 12: 727932, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34691108

RESUMO

Co-enzyme A (CoA) ligation of hydroxycinnamic acids by 4-coumaric acid:CoA ligase (4CL) is a critical step in the biosynthesis of monolignols. Perturbation of 4CL activity significantly impacts the lignin content of diverse plant species. In Populus trichocarpa, two well-studied xylem-specific Ptr4CLs (Ptr4CL3 and Ptr4CL5) catalyze the CoA ligation of 4-coumaric acid to 4-coumaroyl-CoA and caffeic acid to caffeoyl-CoA. Subsequently, two 4-hydroxycinnamoyl-CoA:shikimic acid hydroxycinnamoyl transferases (PtrHCT1 and PtrHCT6) mediate the conversion of 4-coumaroyl-CoA to caffeoyl-CoA. Here, we show that the CoA ligation of 4-coumaric and caffeic acids is modulated by Ptr4CL/PtrHCT protein complexes. Downregulation of PtrHCTs reduced Ptr4CL activities in the stem-differentiating xylem (SDX) of transgenic P. trichocarpa. The Ptr4CL/PtrHCT interactions were then validated in vivo using biomolecular fluorescence complementation (BiFC) and protein pull-down assays in P. trichocarpa SDX extracts. Enzyme activity assays using recombinant proteins of Ptr4CL and PtrHCT showed elevated CoA ligation activity for Ptr4CL when supplemented with PtrHCT. Numerical analyses based on an evolutionary computation of the CoA ligation activity estimated the stoichiometry of the protein complex to consist of one Ptr4CL and two PtrHCTs, which was experimentally confirmed by chemical cross-linking using SDX plant protein extracts and recombinant proteins. Based on these results, we propose that Ptr4CL/PtrHCT complexes modulate the metabolic flux of CoA ligation for monolignol biosynthesis during wood formation in P. trichocarpa.

18.
Artigo em Inglês | MEDLINE | ID: mdl-34635549

RESUMO

BACKGROUND: This study investigated the association between socioeconomic status and type 2 diabetes (T2D) prevalence in Scotland in 2021 and tested the null hypothesis that inequalities had not changed since they were last described for 2001-2007. METHODS: Data from a national population-based diabetes database for 35-to-84-year-olds in Scotland for 2021 and mid-year population estimates for 2019 stratified by sex and fifths of the Scottish Index of Multiple Deprivation were used to calculate age-specific prevalence of T2D. Age-standardised prevalence was estimated using the European Standard Population with relative risks (RRs) compared between the most (Q1) and least (Q5) deprived fifths for each sex, and compared against similar estimates from 2001 to 2007. RESULTS: Complete data were available for 255 764 people (98.9%) with T2D. Age-standardised prevalence was lowest for women in Q5 (3.4%) and highest for men in Q1 (11.6%). RRs have increased from 2.00 (95% CI 1.52 to 2.62) in 2001-2007 to 2.48 (95% CI 2.43 to 2.53) in 2021 for women and from 1.58 (95% CI 1.20 to 2.07) in 2007 to 1.89 (95% CI 1.86 to 1.92) in 2021 for men. CONCLUSIONS: Socioeconomic inequalities in T2D prevalence have widened between 2001-2007 and 2021. Further research is required to investigate potential medium-term effects of the COVID-19 pandemic.

19.
Plant Biotechnol J ; 19(11): 2221-2234, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34160888

RESUMO

Lignins are cell wall-located aromatic polymers that provide strength and hydrophobicity to woody tissues. Lignin monomers are synthesized via the phenylpropanoid pathway, wherein CAFFEOYL SHIKIMATE ESTERASE (CSE) converts caffeoyl shikimate into caffeic acid. Here, we explored the role of the two CSE homologs in poplar (Populus tremula × P. alba). Reporter lines showed that the expression conferred by both CSE1 and CSE2 promoters is similar. CRISPR-Cas9-generated cse1 and cse2 single mutants had a wild-type lignin level. Nevertheless, CSE1 and CSE2 are not completely redundant, as both single mutants accumulated caffeoyl shikimate. In contrast, the cse1 cse2 double mutants had a 35% reduction in lignin and associated growth penalty. The reduced-lignin content translated into a fourfold increase in cellulose-to-glucose conversion upon limited saccharification. Phenolic profiling of the double mutants revealed large metabolic shifts, including an accumulation of p-coumaroyl, 5-hydroxyferuloyl, feruloyl and sinapoyl shikimate, in addition to caffeoyl shikimate. This indicates that the CSEs have a broad substrate specificity, which was confirmed by in vitro enzyme kinetics. Taken together, our results suggest an alternative path within the phenylpropanoid pathway at the level of the hydroxycinnamoyl-shikimates, and show that CSE is a promising target to improve plants for the biorefinery.


Assuntos
Populus , Sistemas CRISPR-Cas/genética , Carboxilesterase , Regulação da Expressão Gênica de Plantas , Lignina/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Populus/genética , Populus/metabolismo
20.
Plant Physiol ; 186(1): 250-269, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33793955

RESUMO

Tension wood (TW) is a specialized xylem tissue developed under mechanical/tension stress in angiosperm trees. TW development involves transregulation of secondary cell wall genes, which leads to altered wood properties for stress adaptation. We induced TW in the stems of black cottonwood (Populus trichocarpa, Nisqually-1) and identified two significantly repressed transcription factor (TF) genes: class B3 heat-shock TF (HSFB3-1) and MYB092. Transcriptomic analysis and chromatin immunoprecipitation (ChIP) were used to identify direct TF-DNA interactions in P. trichocarpa xylem protoplasts overexpressing the TFs. This analysis established a transcriptional regulatory network in which PtrHSFB3-1 and PtrMYB092 directly activate 8 and 11 monolignol genes, respectively. The TF-DNA interactions were verified for their specificity and transactivator roles in 35 independent CRISPR-based biallelic mutants and overexpression transgenic lines of PtrHSFB3-1 and PtrMYB092 in P. trichocarpa. The gene-edited trees (mimicking the repressed PtrHSFB3-1 and PtrMYB092 under tension stress) have stem wood composition resembling that of TW during normal growth and under tension stress (i.e., low lignin and high cellulose), whereas the overexpressors showed an opposite effect (high lignin and low cellulose). Individual overexpression of the TFs impeded lignin reduction under tension stress and restored high levels of lignin biosynthesis in the TW. This study offers biological insights to further uncover how metabolism, growth, and stress adaptation are coordinately regulated in trees.


Assuntos
Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Populus/genética , Madeira/metabolismo , Xilema/metabolismo , Populus/anatomia & histologia , Transcrição Gênica , Madeira/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...