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1.
Langmuir ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38758706

RESUMO

Viral infections, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are some of the most dangerous threats to humans. SARS-CoV-2 has caused a global pandemic, highlighting the unprecedented demand for rapid and portable diagnostic methods. To meet these requirements, we designed a label-free colorimetric platform that combines the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated proteins (Cas) 12a system for naked-eye detection (named LFP). This method utilizes reverse transcription loop-mediated isothermal amplification (RT-LAMP) and the trans-cleavage activity of the CRISPR/Cas12a system to increase the sensitivity and specificity of the reaction. This platform can detect as few as 4 copies/µL of RNA and produces no false positive results when tested against the influenza virus. To better meet the requirements of point-of-care (POC) detection, we developed a portable device that can be applied in resource-poor and densely populated regions. The LFP assay holds great potential for application in resource-limited settings, and the label-free gold nanoparticle (AuNPs) probe can reduce costs, making it suitable for large-scale screening. We expect that the LFP assay will be promising for the POC screening of COVID-19.

2.
Mol Nutr Food Res ; : e2300871, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38704749

RESUMO

SCOPE: Prenatal nutrition imbalance correlates with developmental origin of cardiovascular diseases; however whether maternal high-sucrose diet (HS) during pregnancy causes vascular damage in renal interlobar arteries (RIA) from offspring still keeps unclear. METHODS AND RESULTS: Pregnant rats are fed with normal drinking water or 20% high-sucrose solution during the whole gestational period. Swollen mitochondria and distributed myofilaments are observed in vascular smooth muscle cells of RIA exposed to prenatal HS. Maternal HS increases phenylephrine (PE)-induced vasoconstriction in the RIA from adult offspring. NG-Nitro-l-arginine (L-Name) causes obvious vascular tension in response to PE in offspring from control group, not in HS. RNA-Seq of RIA is performed to reveal that the gene retinoid X receptor g (RXRg) is significantly decreased in the HS group, which could affect vascular function via interacting with PPARγ pathway. By preincubation of RIA with apocynin (NADPH inhibitor) or capivasertib (Akt inhibitor), the results indicate that ROS and Akt are the vital important factors to affect the vascular function of RIA exposure to prenatal HS. CONCLUSION: Maternal HS during the pregnancy increases PE-mediated vasoconstriction of RIA from adult offspring, which is mainly related to the enhanced Akt and ROS regulated by the weakened PPARγ-RXRg.

3.
Acta Physiol (Oxf) ; : e14159, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767438

RESUMO

AIM: Ferroptosis is a novel type of programmed cell death that performs a critical function in diabetic nephropathy (DN). Augmenter of liver regeneration (ALR) exists in the inner membrane of mitochondria, and inhibits inflammation, apoptosis, and oxidative stress in acute kidney injury; however, its role in DN remains unexplored. Here, we aimed to identify the role of ALR in ferroptosis induction and macrophage activation in DN. METHODS: The expression of ALR was examined in DN patients, db/db DN mice, and HK-2 cells treated with high glucose (HG). The effects of ALR on ferroptosis and macrophage activation were investigated with ALR conditional knockout, lentivirus transfection, transmission electron microscopy, qRT-PCR and western blotting assay. Mass spectrometry and rescue experiments were conducted to determine the mechanism of ALR. RESULTS: ALR expression was reduced in the kidney tissues of DN patients and mice, serum of DN patients, and HG-HK-2 cells. Moreover, the inhibition of ALR promoted ferroptosis, macrophage activation, and DN progression. Mechanistically, ALR can directly bind to carnitine palmitoyltransferase-1A (CPT1A), the key rate-limiting enzyme of fatty acid oxidation (FAO), and inhibit the expression of CPT1A to regulate lipid metabolism involving FAO and lipid droplet-mitochondrial coupling in DN. CONCLUSION: Taken together, our findings revealed a crucial protective role of ALR in ferroptosis induction and macrophage activation in DN and identified it as an alternative diagnostic marker and therapeutic target for DN.

4.
Adv Biol (Weinh) ; : e2300576, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728002

RESUMO

Farnesoid X receptor (FXR) plays critical regulatory roles in cardiovascular physiology/pathology. However, the role of FXR agonist obeticholic acid (OCA) in sepsis-associated myocardial injury and underlying mechanisms remain unclear. C57BL/6J mice are treated with OCA before lipopolysaccharide (LPS) administration. The histopathology of the heart and assessment of FXR expression and mitochondria function are performed. To explore the underlying mechanisms, H9c2 cells, and primary cardiomyocytes are pre-treated with OCA before LPS treatment, and extracellular signal-regulated protein kinase (ERK) inhibitor PD98059 is used. LPS-induced myocardial injury in mice is significantly improved by OCA pretreatment. Mechanistically, OCA pretreatment decreased reactive oxygen species (ROS) levels and blocked the loss of mitochondrial membrane potential (ΔΨm) in cardiomyocytes. The expression of glutathione peroxidase 1 (GPX1), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and nuclear factor erythroid 2-related factor 2 (NRF-2) increased in the case of OCA pretreatment. In addition, OCA improved mitochondria respiratory chain with increasing Complex I expression and decreasing cytochrome C (Cyt-C) diffusion. Moreover, OCA pretreatment inhibited LPS-induced mitochondria dysfunction via suppressing ERK1/2-DRP signaling pathway. FXR agonist OCA inhibits LPS-induced mitochondria dysfunction via suppressing ERK1/2-DRP signaling pathway to protect mice against LPS-induced myocardial injury.

5.
ACS Sens ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659329

RESUMO

Selective and nondisruptive in vivo neurochemical monitoring within the central nervous system has long been a challenging endeavor. We introduce a new sensing approach that integrates neurocompatible galvanic redox potentiometry (GRP) with customizable phosphorothioate aptamers to specifically probe dopamine (DA) dynamics in live rat brains. The aptamer-functionalized GRP (aptGRP) sensor demonstrates nanomolar sensitivity and over a 10-fold selectivity for DA, even amidst physiological levels of major interfering species. Notably, conventional sensors without the aptamer modification exhibit negligible reactivity to DA concentrations exceeding 20 µM. Critically, the aptGRP sensor operates without altering neuronal activity, thereby permitting real-time, concurrent recordings of both DA flux and electrical signaling in vivo. This breakthrough establishes aptGRP as a viable and promising framework for the development of high-fidelity sensors, offering novel insights into neurotransmission dynamics in a live setting.

6.
Materials (Basel) ; 17(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38673209

RESUMO

In this paper, the electrothermal coupling model of metal oxide resistive random access memory (RRAM) is analyzed by using a 2D axisymmetrical structure in COMSOL Multiphysics simulation software. The RRAM structure is a Ti/HfO2/ZrO2/Pt bilayer structure, and the SET and RESET processes of Ti/HfO2/ZrO2/Pt are verified and analyzed. It is found that the width and thickness of CF1 (the conductive filament of the HfO2 layer), CF2 (the conductive filament of the ZrO2 layer), and resistive dielectric layers affect the electrical performance of the device. Under the condition of the width ratio of conductive filament to transition layer (6:14) and the thickness ratio of HfO2 to ZrO2 (7.5:7.5), Ti/HfO2/ZrO2/Pt has stable high and low resistance states. On this basis, the comparison of three commonly used RRAM metal top electrode materials (Ti, Pt, and Al) shows that the resistance switching ratio of the Ti electrode is the highest at about 11.67. Finally, combining the optimal conductive filament size and the optimal top electrode material, the I-V hysteresis loop was obtained, and the switching ratio Roff/Ron = 10.46 was calculated. Therefore, in this paper, a perfect RRAM model is established, the resistance mechanism is explained and analyzed, and the optimal geometrical size and electrode material for the hysteresis characteristics of the Ti/HfO2/ZrO2/Pt structure are found.

7.
Environ Sci Pollut Res Int ; 31(21): 30620-30632, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38613749

RESUMO

PPG-CNTs-nZVI bead was synthesized by polyvinyl alcohol, pumice, carbon nanotube, and guar gum-nanoscale zero-valent iron to be applied on simultaneously removal of polycyclic aromatic hydrocarbons (PAHs; phenanthrene) and heavy metals (Pb2+) via adsorption. The individual and simultaneous removal efficiency of phenanthrene and Pb2+ using the PPG-CNTs-nZVI beads was evaluated with a range of initial concentrations of these two pollutants. The kinetics and isotherms of phenanthrene and Pb2+ adsorption by the PPG-CNTs-nZVI beads were also determined. The PPG-CNTs-nZVI beads show reasonably high phenanthrene adsorption capacities (up to 0.16 mg/g), and they absorbed 85% of the phenanthrene (initial concentration 0.5 mg/L) in 30 min. High Pb2+ adsorption capabilities were also demonstrated by the PPG-CNTs-nZVI beads (up to 11.6 mg/g). The adsorption fits the Langmuir model better than the Freundlich model. The adsorption still remained stable with various ionic strength circumstances and a wide pH range (2-5). Additionally, the co-adsorption of phenanthrene and Pb2+ by the PPG-CNTs-nZVI beads resulted in synergistic effects. Particularly, phenanthrene-Pb2+ complex formation via π-cation interactions demonstrated a greater affinity than phenanthrene or Pb2+ alone. The present findings suggest that PPG-CNTs-nZVI beads may be effective sorbents for the simultaneous removal of PAHs and heavy metals from contaminated waters.


Assuntos
Chumbo , Fenantrenos , Fenantrenos/química , Adsorção , Chumbo/química , Nanotubos de Carbono/química , Cinética , Metais Pesados/química , Poluentes Químicos da Água/química
8.
Anal Chim Acta ; 1305: 342590, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38677844

RESUMO

Monitoring extracellular calcium ion (Ca2+) chemical signals in neurons is crucial for tracking physiological and pathological changes associated with brain diseases in live animals. Potentiometry based solid-state ion-selective electrodes (ISEs) with the assist of functional carbon nanomaterials as ideal solid-contact layer could realize the potential response for in vitro and in vivo analysis. Herein, we employ a kind of biomass derived porous carbon as a transducing layer to prompt efficient ion to electron transduction while stabilizes the potential drift. The eco-friendly porous carbon after activation (APB) displays a high specific area with inherit macropores, micropores, and large specific capacitance. When employed as transducer in ISEs, a stable potential response, minimized potential drift can be obtained. Benefiting from these excellent properties, a solid-state Ca2+ selective carbon fiber electrodes (CFEs) with a sandwich structure is constructed and employed for real time sensing of Ca2+ under electrical stimulation. This study presents a new approach to develop sustainable and versatile transducers in solid-state ISEs, a crucial way for in vivo sensing.


Assuntos
Cálcio , Carbono , Nanoestruturas , Cálcio/química , Cálcio/análise , Carbono/química , Nanoestruturas/química , Eletrodos Seletivos de Íons , Animais , Porosidade , Transdutores , Técnicas Eletroquímicas/instrumentação
9.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 36(2): 221-224, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38442943

RESUMO

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host immune response to infection. The development of sepsis is accompanied by the secretion of exosomes by a variety of cells, including non-coding RNA, metabolic small molecules and proteins, which play an important role in immune inflammatory response, oxidative stress, and coagulation dysfunction. The rapid development of new detection technologies has promoted the application of exosomes in the early warning, severity stratification, treatment effect and prognosis evaluation of sepsis. This article reviews the new detection technology of exosomes, the involvement of exosomes in the pathological progress of sepsis, and the latest progress in the early diagnosis, disease assessment and treatment of sepsis, in order to provide new ideas for the diagnosis and treatment of sepsis.


Assuntos
Exossomos , Sepse , Humanos , Sepse/diagnóstico , Sepse/terapia , Coagulação Sanguínea , Estresse Oxidativo
10.
Math Biosci Eng ; 21(2): 2458-2469, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38454691

RESUMO

Hepatitis B is a major global challenge, but there is a lack of epidemiological research on hepatitis B incidence from a change point perspective. This study aimed to fill this gap by identifying significant change points and trends in hepatitis time series in Xinjiang, China. The datasets were obtained from the Xinjiang Information System for Disease Control and Prevention. The Mann-Kendall-Sneyers (MKS) test was used to detect change points and trend changes on the hepatitis B time series of 14 regions in Xinjiang, and the effectiveness of this method was validated by comparing it with the binary segmentation (BS) and segment regression (SR) methods. Based on the results of change point analysis, the prevention and control policies and measures of hepatitis in Xinjiang were discussed. The results showed that 8 regions (57.1%) with at least one change fell within the 95% confidence interval (CI) in all 14 regions by the MKS test, where five regions (Turpan (TP), Hami (HM), Bayingolin (BG), Kyzylsu Kirgiz (KK), Altai (AT)) were identified at one change point, two change points existed for two regions (Aksu (AK), Hotan (HT)) and three change points was detected in 1 region (Bortala (BT)). Most of the change points occurred at both ends of the sequence. More change points indicated an upward trend in the front half of the sequence, while in the latter half, many change points indicated a downward trend prominently. Finally, in comparing the results of the three change point tests, the MKS test showed a 61.5% agreement (8/13) with the BS and SR.


Assuntos
Hepatite B , Humanos , Fatores de Tempo , China/epidemiologia , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Incidência
11.
Heliyon ; 10(6): e27563, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38524548

RESUMO

Objective: Oxygen and hemodynamic management are important for providing a sufficient adequate oxygen-containing blood to the organs for septic patients. In present study, we aimed to explore the application of sequential respiratory support (SRS) and the association of SRS with the outcome of septic patients who needed continuous renal replacement therapy (CRRT). Methods: We extracted the medical information of septic patients who received CRRT within 24 h of intensive care unit (ICU) admission from the MIMIC-III v1.4. SRS was defined as receiving firstly oxygen therapy followed by mechanical ventilation (MV) within 24 h of admission to ICU. The propensity score matching (PSM) was performed to compare the differences in clinical characteristics and outcomes of patients with or without SRS. Finally, we developed logistic regression models to analyze the effects of SRS on hospital mortality. Results: A total of 181 patients entered in this study, and there were 80 patients undergoing MV including SRS group (n = 61) and non-SRS group (n = 19). In the multivariate logistic regression, the value of SRS was associated with the lower risk of hospital mortality adjusted by minimum systolic BP (SBP), maximum lactate, vasopressor use, and sequential organ failure assessment (SOFA) score or Logistic Organ Dysfunction System (LODS) scores within the first 24 h of ICU stay. After PSM adjusted by SBP, maximum lactate, vasopressor use, SOFA, and LODS, there were 31 patients in SRS group with a and 18 cases in non-SRS group, displaying a significantly lower hospital mortality in SRS group than that in patients without SRS (19.4 % vs. 83.3 %, P < 0.001). In addition, age, qSOFA, necessitating the administration of vasopressor, and duration of vasopressor were significantly correlated with the hospital mortality in septic patients undergoing CRRT and SRS. Conclusions: Receiving SRS within the first 24 h upon admission to the ICU was independently associated with the hospital mortality in patient with sepsis undergoing CRRT, and patients who were directly received MV had a high risk of death.

12.
Nat Commun ; 15(1): 1646, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38388532

RESUMO

Adipose tissue macrophages can promote beige adipose thermogenesis by altering local sympathetic activity. Here, we perform sympathectomy in mice and further eradicate subcutaneous adipose macrophages and discover that these macrophages have a direct beige-promoting function that is independent of sympathetic system. We further identify adipocyte Ets1 as a vital mediator in this process. The anti-inflammatory M2 macrophages suppress Ets1 expression in adipocytes, transcriptionally activate mitochondrial biogenesis, as well as suppress mitochondrial clearance, thereby increasing the mitochondrial numbers and promoting the beiging process. Male adipocyte Ets1 knock-in mice are completely cold intolerant, whereas male mice lacking Ets1 in adipocytes show enhanced energy expenditure and are resistant to metabolic disorders caused by high-fat-diet. Our findings elucidate a direct communication between M2 macrophages and adipocytes, and uncover a function for Ets1 in responding to macrophages and negatively governing mitochondrial content and beige adipocyte formation.


Assuntos
Adipócitos Bege , Adipogenia , Animais , Masculino , Camundongos , Adipócitos/metabolismo , Adipócitos Bege/metabolismo , Adipogenia/genética , Tecido Adiposo/metabolismo , Tecido Adiposo Branco/metabolismo , Macrófagos/metabolismo , Obesidade/metabolismo , Termogênese/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-38424418

RESUMO

Rheumatoid arthritis (RA) is an autoimmune disease with no known cure that results in joint deformities and dysfunction, significantly impacting the quality of life of patients. The abnormal NF-KB signaling pathway in RA has emerged as a crucial research area for the development of RA therapies, with non-coding RNAs (ncRNAs) serving as a potentially meaningful avenue to regulate it. Thus, understanding the role of ncRNAs in RA and the identification of new therapeutic targets have become pressing issues in the field. In this review, we aim to summarize recent studies on ncRNAs that regulate the NF-KB signaling pathway in RA, including miRNAs, lncRNAs, and circRNAs, as well as the mechanisms by which drugs modulate NF-K B activity. By highlighting these recent advances, we hope to promote further research into targeted RA therapy and provide novel directions and ideas for researchers in the field.

14.
Int J Biol Macromol ; 262(Pt 1): 130063, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340925

RESUMO

Waterborne polyurethanes (WPUs) often have limitations like inadequate weathering resistance and thermal stability. To overcome these shortcomings, lignin has been selected as a modifier for its abundant availability, renewability, and biocompatibility. This study synthesized a cationic WPU using isophorone diisocyanate and polyethylene glycol as raw materials. Hydrophilicity was attained through the inclusion of dihydroxyethyl dodecylamine as a chain extender, while the introduction of epoxy monomers and lignin served to modify the polyurethane. Furthermore, a dye dispersion for cotton fabric dyeing was prepared by combining the synthesized polyurethane, chitosan, and dyes. The cationic nature of the polyurethane played a crucial role in facilitating dye adhesion and uptake on the fabric surface, resulting in improved dyeing performance. The incorporation of epoxy side chains and chitosan cross-linking contributed to the excellent color fastness of the dyed fabrics. Moreover, the incorporation of lignin and chitosan endowed the fabric with antibacterial properties. Simultaneously, it provided effective UV protection, characterized by a high UV protection factor value for the fabrics. This lignin-modified WPU exhibits tremendous potential in applications such as textile coatings, adhesives, and color fixation agents. It effectively addresses the limitations of traditional WPUs and offers notable advantages, including a renewable source, cost-effectiveness, and biocompatibility.


Assuntos
Quitosana , Poliuretanos , Poliuretanos/química , Quitosana/química , Lignina , Têxteis , Antibacterianos/química
15.
Eur J Pharmacol ; 967: 176365, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38316247

RESUMO

Glycyrrhizic acid (GA), one of the major active components derived from licorice root, exerts liver-protecting activity. Its molecular mechanisms of action, however, remain not completely understood. The angiotensin (Ang) converting enzyme (ACE) 2/Ang-(1-7)/Mas axis, regulated by ACE2 through converting Ang II into Ang-(1-7) to activate Mas receptor, counteracts the pro-inflammatory and pro-steatotic effects of the ACE/Ang II/Ang II receptor type 1 (AT1) axis. Here, it was found that pretreatment with GA suppressed LPS/D-galactosamine-induced serum hyperactivities of alanine aminotransferase and aspartate aminotransferase, hepatomegaly, pathological changes, and over-accumulation of triglycerides and fatty droplets in the liver of mice. GA also diminished LPS/free fatty acid-induced inflammation and steatosis in cultured hepatocytes. Mechanistically, GA restored hepatic protein hypoexpression of ACE2 and Mas receptor, and the decrease in hepatic Ang-(1-7) content. Hepatic overexpression of angiotensin II and AT1 was also suppressed. However, GA did not alter hepatic protein expression of renin and ACE. In addition, GA inhibited hepatic protein over-phosphorylation of the p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, extracellular signal-regulated kinase, and nuclear factor κB at Ser536. Hepatic overexpression of tumor necrosis factor α, interleukin 6, interleukin 1ß, sterol regulatory element-binding protein 1c, and fatty acid synthase was also inhibited. GA-elicited recovery of ACE2 and Mas protein hypoexpression was further confirmed in the hepatocyte. Thus, the present results demonstrate that GA restores the downregulated hepatic ACE2-mediated anti-inflammatory and anti-steatotic signaling in the amelioration of steatohepatitis. We suggest that GA may protect the liver from injury by regulating the hepatic ACE2-mediated signaling.


Assuntos
Enzima de Conversão de Angiotensina 2 , Fígado Gorduroso , Camundongos , Animais , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Lipopolissacarídeos , Peptidil Dipeptidase A/metabolismo , Fragmentos de Peptídeos/farmacologia , Angiotensina II , Angiotensina I/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
16.
Food Funct ; 15(1): 79-95, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38031758

RESUMO

In this study, a polysaccharide known as PAPS2 was eluted from Pleurotus abieticola fruiting bodies using 0.1 M NaCl solutions. PAPS2 has a Mw of 19.64 kDa and its backbone is mainly composed of →6)-α-D-Galp-(1→, →6)-ß-D-Glcp-(1→ and →2,6)-α-D-Galp-(1→ residues, and its branches mainly end with ß-D-Manp-(1→, which is attached at C2 of →2,6)-α-D-Galp-(1→. PAPS2 elicited several effects in high-fat diet (HFD)-fed ApoE-/- mice. It significantly reduced the body weight, liver index, and serum levels of total cholesterol (TC) and triglycerides (TGs), and it alleviated lipid accumulation in the aorta. Intestinal microflora analysis showed that PAPS2 suppressed the abundances of Adlercreutzia, Turicibacter, and Helicobacter and enriched that of Roseburia. It also influenced lipid metabolism, suggesting that it reduced the levels of TGs, lysophosphatidylcholine (LPC), phosphatidylcholine (PC), and ceramide (Cer). Moreover, it suppressed oxidative response by increasing nuclear factor erythroid 2 (Nrf2)-related factor expression and activating the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) to reduce the level of reactive oxygen species (ROS). Meanwhile, it showed anti-inflammatory effects partially related to the inhibition of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling induced by lipopolysaccharide (LPS) in RAW 264.7 cells, as well as in the aorta of HFD-fed ApoE-/- mice. This study provides experimental evidence of the auxiliary applicability of PAPS2 in atherosclerosis treatment.


Assuntos
Aterosclerose , NF-kappa B , Camundongos , Animais , NF-kappa B/genética , NF-kappa B/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/genética , Aterosclerose/metabolismo , Polissacarídeos/farmacologia , Triglicerídeos/metabolismo , Apolipoproteínas E/genética
18.
Virology ; 589: 109918, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37944362

RESUMO

Stem-pitting (SP) disease results from disruption of normal phloem and xylem development. In citrus, a characteristic manifestation of SP caused by Citrus tristeza virus (CTV) is phloem regeneration. We hypothesized that phloem regeneration occurs due to reduced functionality of CTV infected phloem cells. To examine phloem cell occlusions in CTV-SP, we analyzed callose and phloem-protein (PP) accumulation in Citrus macrophylla trees infected with CTV mutants exhibiting different SP phenotypes from very mild (CTVΔp13) to severe (CTVΔp33), in addition to full-length CTV and healthy plants. CTV infection was accompanied by callose and PP accumulation in the phloem. With the increase in the SP symptoms from very mild to severe, there was a constant increase in the levels of callose and PP, accompanied by an increase in PHLOEM-PROTEIN 2 and a decrease in BETA-1,3-GLUCANASE gene expression levels. These results indicate that SP symptom development is associated with increased phloem occlusion.


Assuntos
Citrus , Closterovirus , Floema , Closterovirus/genética , Fenótipo , Doenças das Plantas
19.
Plant Cell Environ ; 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38073433

RESUMO

Drought is a key environmental stress that inhibits plant growth, development, yield and quality. Whole-genome replication is an effective method for breeding drought resistant cultivars. Here, we evaluated the tolerance of Lilium distichum Nakai diploids (2n = 2× = 24) and artificially induced autotetraploids (2n = 4× = 48) to drought simulated by polyethylene glycol (PEG) stress. Autotetraploids showed stronger drought tolerance than diploids, and high-throughput sequencing during PEG stress identified five differentially expressed miRNAs. Transcriptome analysis revealed significantly different reactive oxygen species (ROS)-scavenger expression levels between diploids and autotetraploids, which increased the drought tolerance of autotetraploids. Specifically, we identified ldi-miR396b and its only target gene (LdPMaT1) for further study based on its expression level and ROS-scavenging ability in response to drought stress (DS). Autotetraploids showed higher expression of LdPMaT1 and significantly downregulated expression of ldi-miR396b under DS compared with diploids. Through a short tandem target mimic (STTM) in transgenic lilies, functional studies revealed that miR396b silencing promotes LdPMaT1 expression and the DS response. Under PEG stress, STTM393 transgenic lines showed improved drought resistance mediated by lowered MDA content but exhibited high antioxidant enzyme activity, consistent with the autotetraploid results. Collectively, these findings suggest that ldi-miR396b-LdPMaT1 potentially enhances ROS-scavenging ability, which contributes to improved stress adaptation in autotetraploid lilies.

20.
PLoS Pathog ; 19(12): e1011859, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38060601

RESUMO

Microsporidia are a group of obligate intracellular parasites that infect almost all animals, causing serious human diseases and major economic losses to the farming industry. Nosema bombycis is a typical microsporidium that infects multiple lepidopteran insects via fecal-oral and transovarial transmission (TOT); however, the underlying TOT processes and mechanisms remain unknown. Here, we characterized the TOT process and identified key factors enabling N. bombycis to invade the ovariole and oocyte of silkworm Bombyx mori. We found that the parasites commenced with TOT at the early pupal stage when ovarioles penetrated the ovary wall and were exposed to the hemolymph. Subsequently, the parasites in hemolymph and hemolymph cells firstly infiltrated the ovariole sheath, from where they invaded the oocyte via two routes: (I) infecting follicular cells, thereby penetrating oocytes after proliferation, and (II) infecting nurse cells, thus entering oocytes following replication. In follicle and nurse cells, the parasites restructured and built large vacuoles to deliver themselves into the oocyte. In the whole process, the parasites were coated with B. mori vitellogenin (BmVg) on their surfaces. To investigate the BmVg effects on TOT, we suppressed its expression and found a dramatic decrease of pathogen load in both ovarioles and eggs, suggesting that BmVg plays a crucial role in the TOT. Thereby, we identified the BmVg domains and parasite spore wall proteins (SWPs) mediating the interaction, and demonstrated that the von Willebrand domain (VWD) interacted with SWP12, SWP26 and SWP30, and the unknown function domain (DUF1943) bound with the SWP30. When disrupting these interactions, we found significant reductions of the pathogen load in both ovarioles and eggs, suggesting that the interplays between BmVg and SWPs were vital for the TOT. In conclusion, our study has elucidated key aspects about the microsporidian TOT and revealed the key factors for understanding the molecular mechanisms underlying this transmission.


Assuntos
Bombyx , Nosema , Animais , Humanos , Vitelogeninas/metabolismo , Esporos Fúngicos/metabolismo , Nosema/metabolismo , Bombyx/metabolismo
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