Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 343
Filtrar
1.
Structure ; 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38964337

RESUMEN

Ceramide synthases (CerSs) play crucial roles in sphingolipid metabolism and have emerged as promising drug targets for metabolic diseases, cancers, and antifungal therapy. However, the therapeutic targeting of CerSs has been hindered by a limited understanding of their inhibition mechanisms by small molecules. Fumonisin B1 (FB1) has been extensively studied as a potent inhibitor of eukaryotic CerSs. In this study, we characterize the inhibition mechanism of FB1 on yeast CerS (yCerS) and determine the structures of both FB1-bound and N-acyl-FB1-bound yCerS. Through our structural analysis and the observation of N-acylation of FB1 by yCerS, we propose a potential ping-pong catalytic mechanism for FB1 N-acylation by yCerS. Lastly, we demonstrate that FB1 exhibits lower binding affinity for yCerS compared to the C26- coenzyme A (CoA) substrate, suggesting that the potent inhibitory effect of FB1 on yCerS may primarily result from the N-acyl-FB1 catalyzed by yCerS, rather than through direct binding of FB1.

2.
Cell Tissue Bank ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38976150

RESUMEN

Cryopreservation is a method adopted for storage of autologous skulls. Herein, this current research sought to explore the effects of different cryoprotectants on the biological characteristics of rat calvarial osteoblasts after cryopreservation. Neonatal Sprague-Dawley rats were selected and their skull tissues were isolated. The skull tissues were allocated into the refrigerating-3M, refrigerating-6M, M199-3M, M199-6M, povidone iodine-3M, and povidone iodine-6M groups according to the usage of cryoprotectants and treatment time (month) and the fresh group. Osteoblasts were isolated from skull tissues in each group through digestion. The histomorphology of the skull was evaluated by H&E staining and cell morphology was observed by microscopy. The viability, proliferation, apoptosis, and osteogenic activity of osteoblasts were assessed by trypan blue staining, MTT, flow cytometry, and alkaline phosphatase (ALP) staining. The skull histomorphology and osteoblast morphology were similar between the fresh and refrigerating groups. Osteoblast viability was weakened after cryopreservation. The longer the refrigeration time, the lower the number of living cells and the higher the apoptosis rate. However, cryopreservation using different cryoprotectants did not evidently affect osteoblast proliferation and ALP activity. Different cryoprotectants show no apparent effect on the osteogenic activity of rat calvarial osteoblasts after cryopreservation.

3.
Geriatr Nurs ; 58: 238-246, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38838406

RESUMEN

OBJECTIVE: To evaluate the effectiveness of home-based cardiac telerehabilitation based on wearable electrocardiogram or heart rate monitoring devices in patients with heart disease. METHODS: We searched eight electronic databases under the guidance of Cochrane Handbook and PRISMA recommendations. RESULTS: The meta-analysis included data from 14 articles (15 RCTs) representing 1314 participants. A significant improvement in left ventricular ejection fraction [MD = 2.12, 95 % CI (1.21, 3.04), P < 0.001], 6-minute walk distance [MD = 40.00, 95 % CI (21.72, 58.29), P < 0.001] and peak oxygen intake [MD = 2.24, 95 % CI (1.38, 3.10), P < 0.001] were observed in the home-based cardiac telerehabilitation group. But it had no difference in anxiety [SMD = -0.83, 95 % CI (-1.65, -0.02), P = 0.05] and depression [SMD = -0.59, 95 % CI (-1.26, 0.09), P = 0.09]. Subgroup analyses revealed that interventions of no less than 3 months improved anxiety [SMD = -1.11, 95 % CI (-2.05, -0.18), P = 0.02] and depression [SMD = -1.01, 95 % CI (-1.93, -0.08), P = 0.03]. CONCLUSION: Home-based cardiac telerehabilitation based on wearable electrocardiogram or heart rate monitoring devices has a positive effect on cardiac function. Long-term (≥ 3 months) cardiac rehabilitation might benefit individuals suffering from anxiety or depression.

4.
Am Heart J ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38762090

RESUMEN

BACKGROUND: As a mega-biobank linked to a national healthcare system, the Million Veteran Program (MVP) can directly improve the health care of participants. To determine the feasibility and outcomes of returning medically actionable genetic results to MVP participants, the program launched the MVP Return Of Actionable Results (MVP-ROAR) Study, with familial hypercholesterolemia (FH) as an exemplar actionable condition. METHODS: The MVP-ROAR Study consists of a completed single-arm pilot phase and an ongoing randomized clinical trial (RCT), in which MVP participants are recontacted and invited to receive clinical confirmatory gene sequencing testing and a telegenetic counseling intervention. The primary outcome of the RCT is 6-month change in low-density lipoprotein cholesterol (LDL-C) between participants receiving results at baseline and those receiving results after 6 months. RESULTS: The pilot developed processes to identify and recontact participants nationally with probable pathogenic variants in low-density lipoprotein receptor (LDLR) on the MVP genotype array, invite them to clinical confirmatory gene sequencing, and deliver a telegenetic counseling intervention. Among participants in the pilot phase, 8 (100%) had active statin prescriptions after 6 months. Results were shared with 16 first-degree family members. Six-month ΔLDL-C (low-density lipoprotein cholesterol) after the genetic counseling intervention was -37 mg/dL (95% CI: -12 to -61; p=0.03). The ongoing RCT will determine between-arm differences in this primary outcome. CONCLUSION: While underscoring the importance of clinical confirmation of research results, the pilot phase of the MVP-ROAR Study marks a turning point in MVP and demonstrates the feasibility of returning genetic results to participants and their providers. The ongoing RCT will contribute to understanding how such a program might improve patient health care and outcomes.

5.
BMC Med Educ ; 24(1): 571, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38789956

RESUMEN

BACKGROUND: Case-based learning (CBL) methods have gained prominence in medical education, proving especially effective for preclinical training in undergraduate medical education. Tetralogy of Fallot (TOF) is a congenital heart disease characterized by four malformations, presenting a challenge in medical education due to the complexity of its anatomical pathology. Three-dimensional printing (3DP), generating physical replicas from data, offers a valuable tool for illustrating intricate anatomical structures and spatial relationships in the classroom. This study explores the integration of 3DP with CBL teaching for clinical medical undergraduates. METHODS: Sixty senior clinical medical undergraduates were randomly assigned to the CBL group and the CBL-3DP group. Computed tomography imaging data from a typical TOF case were exported, processed, and utilized to create four TOF models with a color 3D printer. The CBL group employed CBL teaching methods, while the CBL-3DP group combined CBL with 3D-printed models. Post-class exams and questionnaires assessed the teaching effectiveness of both groups. RESULTS: The CBL-3DP group exhibited improved performance in post-class examinations, particularly in pathological anatomy and TOF imaging data analysis (P < 0.05). Questionnaire responses from the CBL-3DP group indicated enhanced satisfaction with teaching mode, promotion of diagnostic skills, bolstering of self-assurance in managing TOF cases, and cultivation of critical thinking and clinical reasoning abilities (P < 0.05). These findings underscore the potential of 3D printed models to augment the effectiveness of CBL, aiding students in mastering instructional content and bolstering their interest and self-confidence in learning. CONCLUSION: The fusion of CBL with 3D printing models is feasible and effective in TOF instruction to clinical medical undergraduates, and worthy of popularization and application in medical education, especially for courses involving intricate anatomical components.


Asunto(s)
Educación de Pregrado en Medicina , Impresión Tridimensional , Tetralogía de Fallot , Humanos , Tetralogía de Fallot/diagnóstico por imagen , Tetralogía de Fallot/cirugía , Educación de Pregrado en Medicina/métodos , Masculino , Estudiantes de Medicina , Femenino , Aprendizaje Basado en Problemas , Evaluación Educacional , Modelos Anatómicos , Adulto Joven
6.
Int Immunopharmacol ; 134: 112236, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38744174

RESUMEN

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.


Asunto(s)
Macrófagos , Pólipos Nasales , Rinitis , Sinusitis , Humanos , Macrófagos/inmunología , Pólipos Nasales/inmunología , Sinusitis/inmunología , Animales , Rinitis/inmunología , Enfermedad Crónica
7.
BMC Plant Biol ; 24(1): 316, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38654195

RESUMEN

BACKGROUND: Salt stress significantly reduces soybean yield. To improve salt tolerance in soybean, it is important to mine the genes associated with salt tolerance traits. RESULTS: Salt tolerance traits of 286 soybean accessions were measured four times between 2009 and 2015. The results were associated with 740,754 single nucleotide polymorphisms (SNPs) to identify quantitative trait nucleotides (QTNs) and QTN-by-environment interactions (QEIs) using three-variance-component multi-locus random-SNP-effect mixed linear model (3VmrMLM). As a result, eight salt tolerance genes (GmCHX1, GsPRX9, Gm5PTase8, GmWRKY, GmCHX20a, GmNHX1, GmSK1, and GmLEA2-1) near 179 significant and 79 suggested QTNs and two salt tolerance genes (GmWRKY49 and GmSK1) near 45 significant and 14 suggested QEIs were associated with salt tolerance index traits in previous studies. Six candidate genes and three gene-by-environment interactions (GEIs) were predicted to be associated with these index traits. Analysis of four salt tolerance related traits under control and salt treatments revealed six genes associated with salt tolerance (GmHDA13, GmPHO1, GmERF5, GmNAC06, GmbZIP132, and GmHsp90s) around 166 QEIs were verified in previous studies. Five candidate GEIs were confirmed to be associated with salt stress by at least one haplotype analysis. The elite molecular modules of seven candidate genes with selection signs were extracted from wild soybean, and these genes could be applied to soybean molecular breeding. Two of these genes, Glyma06g04840 and Glyma07g18150, were confirmed by qRT-PCR and are expected to be key players in responding to salt stress. CONCLUSIONS: Around the QTNs and QEIs identified in this study, 16 known genes, 6 candidate genes, and 8 candidate GEIs were found to be associated with soybean salt tolerance, of which Glyma07g18150 was further confirmed by qRT-PCR.


Asunto(s)
Interacción Gen-Ambiente , Genes de Plantas , Glycine max , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Tolerancia a la Sal , Glycine max/genética , Glycine max/fisiología , Tolerancia a la Sal/genética , Sitios de Carácter Cuantitativo/genética , Fenotipo
8.
J Fungi (Basel) ; 10(4)2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38667942

RESUMEN

Histone post-translational modification is one of the main mechanisms of epigenetic regulation, which plays a crucial role in the control of gene expression and various biological processes. However, whether or not it affects fungal virulence in Sclerotinia sclerotiorum is not clear. In this study, we identified and cloned the histone methyltransferase Defective in methylation 5 (Dim5) in S. sclerotiorum, which encodes a protein containing a typical SET domain. SsDim5 was found to be dynamically expressed during infection. Knockout experiment demonstrated that deletion of SsDim5 reduced the virulence in Ssdim5-1/Ssdim5-2 mutant strains, accompanied by a significant decrease in H3K9 trimethylation levels. Transcriptomic analysis further revealed the downregulation of genes associated with mycotoxins biosynthesis in SsDim5 deletion mutants. Additionally, the absence of SsDim5 affected the fungus's response to oxidative and osmotic, as well as cellular integrity. Together, our results indicate that the H3K9 methyltransferase SsDim5 is essential for H3K9 trimethylation, regulating fungal virulence throug mycotoxins biosynthesis, and the response to environmental stresses in S. sclerotiorum.

9.
Regen Ther ; 27: 73-82, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38525238

RESUMEN

Wilson disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive disorder characterized by disorganized copper metabolism caused by mutations in the ATP7B gene. Currently, the main treatment options for WD involve medications such as d-penicillamine, trientine hydrochloride, zinc acetate, and liver transplantation. However, there are challenges that encompass issues of poor compliance, adverse effects, and limited availability of liver sources that persist. Stem cell therapy for WD is currently a promising area of research. Due to the advancement in stem cell directed differentiation technology in vitro and the availability of sufficient stem cell donors, it is expected to be a potential treatment option for the permanent correction of abnormal copper metabolism. This article discusses the research progress of stem cell therapy for WD from various sources, as well as the challenges and future prospects of the clinical application of stem cell therapy for WD.

10.
Plant Commun ; 5(5): 100879, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38486454

RESUMEN

Spike architecture influences both grain weight and grain number per spike, which are the two major components of grain yield in bread wheat (Triticum aestivum L.). However, the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits. Here, we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat. We identified 170 loci that are responsible for variations in spike length, spikelet number per spike, and grain number per spike through genome-wide association study and meta-QTL analyses. We constructed gene regulatory networks for young inflorescences at the double ridge stage and the floret primordium stage, in which the spikelet meristem and the floret meristem are predominant, respectively, by integrating transcriptome, histone modification, chromatin accessibility, eQTL, and protein-protein interactome data. From these networks, we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits. The functions of TaZF-B1, VRT-B2, and TaSPL15-A/D in establishment of wheat spike architecture were verified. This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.


Asunto(s)
Redes Reguladoras de Genes , Variación Genética , Estudio de Asociación del Genoma Completo , Sitios de Carácter Cuantitativo , Triticum , Triticum/genética , Triticum/crecimiento & desarrollo , Sitios de Carácter Cuantitativo/genética , Regulación de la Expresión Génica de las Plantas , Fenotipo
12.
CNS Neurosci Ther ; 30(3): e14636, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38430221

RESUMEN

OBJECTIVES: FTO is known to be involved in cerebral ischemia/reperfusion (I/R) injury. However, its related specific mechanisms during this condition warrant further investigations. This study aimed at exploring the impacts of FTO and the FYN/DRP1 axis on mitochondrial fission, oxidative stress (OS), and ferroptosis in cerebral I/R injury and the underlying mechanisms. METHODS: The cerebral I/R models were established in mice via the temporary middle cerebral artery occlusion/reperfusion (tMCAO/R) and hypoxia/reoxygenation models were induced in mouse hippocampal neurons via oxygen-glucose deprivation/reoxygenation (OGD/R). After the gain- and loss-of-function assays, related gene expression was detected, along with the examination of mitochondrial fission, OS- and ferroptosis-related marker levels, neuronal degeneration and cerebral infarction, and cell viability and apoptosis. The binding of FTO to FYN, m6A modification levels of FYN, and the interaction between FYN and Drp1 were evaluated. RESULTS: FTO was downregulated and FYN was upregulated in tMCAO/R mouse models and OGD/R cell models. FTO overexpression inhibited mitochondrial fission, OS, and ferroptosis to suppress cerebral I/R injury in mice, which was reversed by further overexpressing FYN. FTO overexpression also suppressed mitochondrial fission and ferroptosis to increase cell survival and inhibit cell apoptosis in OGD/R cell models, which was aggravated by additionally inhibiting DRP1. FTO overexpression inhibited FYN expression via the m6A modification to inactive Drp1 signaling, thus reducing mitochondrial fission and ferroptosis and enhancing cell viability in cells. CONCLUSIONS: FTO overexpression suppressed FYN expression through m6A modification, thereby subduing Drp1 activity and relieving cerebral I/R injury.


Asunto(s)
Isquemia Encefálica , Ferroptosis , Daño por Reperfusión , Animales , Ratones , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Neuronas/metabolismo , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo
13.
Zhongguo Zhong Yao Za Zhi ; 49(2): 534-549, 2024 Jan.
Artículo en Chino | MEDLINE | ID: mdl-38403328

RESUMEN

This study aimed to systematically review the efficacy and safety of Bidouyan Oral Liquid in the treatment of rhinosinu-sitis(RS). CNKI, Wanfang, SinoMed, VIP, Cochrane Library, PubMed, EMbase, Web of Science, and Ovid were searched for the randomized controlled trial(RCT) of Bidouyan Oral Liquid for the treatment of RS patients. Moreover, the reference lists and the grey literature were searched manually. Two researchers independently screened the literature and extracted data. The Cochrane collaboration's tool for assessing risk of bias(RoB 2.0) in randomized trial was used to assess the methodological quality of the included stu-dies. Meta-analysis was performed in RevMan 5.3 and Stata 12.0, and the grades of recommendation, assessment, development and evaluation(GRADE) was employed to evaluate the quality of evidence. A total of 54 RCTs(35 with drug combinations and 19 with single drugs) comprising 7 511 patients(3 973 in the observation group and 3 538 in the control group) were included. Meta-analysis showed that Bidouyan Oral Liquid + conventional treatment was superior to conventional treatment alone in increasing the total response rate(RR=1.19, 95%CI[1.15, 1.24], P<0.000 01) and decreasing the Lund-Kennedy scores(MD=-1.94, 95%CI[-2.61,-1.26], P<0.000 01), Lund-Mackay scores(MD=-2.14, 95%CI[-2.98,-1.31], P<0.000 01), and visual analogue scale(VAS) scores(MD_(total VAS scores)=-1.28, 95%CI[-1.56,-1.01], P<0.000 01; MD_(nasal congestion VAS scores)=-0.58, 95%CI[-0.89,-0.27], P=0.000 2; MD_(runny nose VAS scores)=-0.61, 95%CI[-0.93,-0.29], P=0.000 2; MD_(olfactory dysfunction VAS scores)=-0.43, 95%CI[-0.52,-0.34], P<0.000 01; MD_(head and facial pain VAS scores)=-0.41, 95%CI[-0.57,-0.26], P<0.000 01). Furthermore, the combined treatment outperformed conventional treatment alone in improving the mucociliary transport rate(MTR)(MD=1.64, 95%CI[1.08, 2.20], P<0.000 01) and lowering the levels of inflammatory cytokines{tumor necrosis factor-α(TNF-α)(SMD=-1.95, 95%CI[-2.57,-1.33], P<0.000 01), interleukin-6(IL-6)(SMD=-2.64, 95%CI[-4.08,-1.21], P=0.000 3)} in RS patients. In addition, the combined treatment did not increase the incidence of adverse reactions(RR=0.83, 95%CI[0.44, 1.57], P=0.57). Bidouyan Oral Liquid was superior to conventional treatment in increasing total response rate(RR=1.25, 95%CI[1.18, 1.32], P<0.000 01), decreasing the Lund-Kennedy(P<0.01) and Lund-Mackay scores(P<0.05), alleviating major symptoms(P_(total VAS scores)<0.01; P_(nasal congestion VAS scores)<0.01; P_(runny nose VAS scores)<0.01; P_(olfactory dysfunction VAS scores)<0.05; P_(head and facial pain VAS scores)<0.01), and decreasing adverse reactions(P=0.03). The results showed that either Bidouyan Oral Liquid or Bidouyan Oral Liquid + conventional treatment can increase the total response rate, decrease the Lund-Kennedy and Lund-Mackay scores, and mitigate major symptoms. In addition, Bidouyan Oral Liquid + conventional treatment improved MTR and reduced the expression of TNF-α and IL-6 without causing serious adverse events. However, due to the limited methodological quality of the included studies, large-sample and high-quality RCTs are needed to provide evidence support.


Asunto(s)
Medicamentos Herbarios Chinos , Trastornos del Olfato , Rinosinusitis , Humanos , Factor de Necrosis Tumoral alfa , Interleucina-6 , Rinorrea , Dolor Facial/inducido químicamente , Trastornos del Olfato/inducido químicamente , Medicamentos Herbarios Chinos/efectos adversos
14.
Adv Sci (Weinh) ; 11(14): e2309254, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38326091

RESUMEN

Achieving a high depth of discharge (DOD) in lithium metal anodes (LMAs) is crucial for developing high areal energy density batteries suitable for wearable electronics. Yet, the persistent growth of dendrites compromises battery performance, and the significant lithium consumption during pre-lithiation obstructs their broad application. Herein, A flexible 3D Li13Sn5 scaffold is designed by allowing molten lithium to infiltrate carbon cloth adorned with SnO2 nanocrystals. This design markedly curbs the troublesome dendrite growth, thanks to the uniform electric field distribution and swift Li+ diffusion dynamics. Additionally, with a minimal SnO2 nanocrystals loading (2 wt.%), only 0.6 wt.% of lithium is consumed during pre-lithiation. Insights from in situ optical microscope observations and COMSOL simulations reveal that lithium remains securely anchored within the scaffold, a result of the rapid mass/charge transfer and uniform electric field distribution. Consequently, this electrode achieves a remarkable DOD of 87.1% at 10 mA cm-2 for 40 mAh cm-2. Notably, when coupled with a polysulfide cathode, the constructed flexible Li/Li13Sn5@CC||Li2S6/SnO2@CC pouch cell delivers a high-areal capacity of 5.04 mAh cm-2 and an impressive areal-energy density of 10.6 mWh cm-2. The findings pave the way toward the development of high-performance LMAs, ideal for long-lasting wearable electronics.

15.
Cell Rep ; 43(2): 113717, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38285738

RESUMEN

The homeostatic regulation of serine palmitoyltransferase (SPT) activity in yeast involves N-terminal phosphorylation of Orm proteins, while higher eukaryotes lack these phosphorylation sites. Although recent studies have indicated a conserved ceramide-mediated feedback inhibition of the SPT-ORM/ORMDL complex in higher eukaryotes, its conservation and relationship with phosphorylation regulation in yeast remain unclear. Here, we determine the structure of the yeast SPT-Orm2 complex in a dephosphomimetic state and identify an evolutionarily conserved ceramide-sensing site. Ceramide stabilizes the dephosphomimetic Orm2 in an inhibitory conformation, facilitated by an intramolecular ß-sheet between the N- and C-terminal segments of Orm2. Moreover, we find that a phosphomimetic mutant of Orm2, positioned adjacent to its intramolecular ß-sheet, destabilizes the inhibitory conformation of Orm2. Taken together, our findings suggest that both Orm dephosphorylation and ceramide binding are crucial for suppressing SPT activity in yeast. This highlights a distinctive regulatory mechanism in yeast involving the collaborative actions of phosphorylation and ceramide.


Asunto(s)
Ceramidas , Proteínas de Saccharomyces cerevisiae , Ceramidas/metabolismo , Saccharomyces cerevisiae/metabolismo , Esfingolípidos/metabolismo , Fosforilación , Proteínas/metabolismo , Serina C-Palmitoiltransferasa/genética , Serina C-Palmitoiltransferasa/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
16.
Mol Metab ; 80: 101885, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38246588

RESUMEN

OBJECTIVE: Genome-scale CRISPR-Cas9 knockout coupled with single-cell RNA sequencing (scRNA-seq) has been used to identify function-related genes. However, this method may knock out too many genes, leading to low efficiency in finding genes of interest. Insulin secretion is controlled by several electrophysiological events, including fluxes of KATP depolarization and K+ repolarization. It is well known that glucose stimulates insulin secretion from pancreatic ß-cells, mainly via the KATP depolarization channel, but whether other nutrients directly regulate the repolarization K+ channel to promote insulin secretion is unknown. METHODS: We used a system involving CRISPR-Cas9-mediated knockout of all 83 K+ channels and scRNA-seq in a pancreatic ß cell line to identify genes associated with insulin secretion. RESULTS: The expression levels of insulin genes were significantly increased after all-K+ channel knockout. Furthermore, Kcnb1 and Kcnh6 were the two most important repolarization K+ channels for the increase in high-glucose-dependent insulin secretion that occurred upon application of specific inhibitors of the channels. Kcnh6 currents, but not Kcnb1 currents, were reduced by one of the amino acids, lysine, in both transfected cells, primary cells and mice with ß-cell-specific deletion of Kcnh6. CONCLUSIONS: Our function-related CRISPR screen with scRNA-seq identifies Kcnh6 as a lysine-specific channel.


Asunto(s)
Insulina , Lisina , Ratones , Animales , Secreción de Insulina , Lisina/metabolismo , Insulina/metabolismo , Glucosa/farmacología , Adenosina Trifosfato/metabolismo
17.
IEEE Trans Cybern ; 54(4): 2566-2578, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37318961

RESUMEN

This work solves the countermeasure design problems of distributed resilient output time-varying formation-tracking (TVFT) of heterogeneous multiagent systems (MASs) against general Byzantine attacks (GBAs). Inspired by the concept of Digital Twin, a hierarchical protocol equipped with a twin layer (TL) is proposed, which decouples the above problem into the defense against Byzantine edge attacks (BEAs) on the TL and the defense against Byzantine node attacks (BNAs) on the cyber-physical layer (CPL). First, a secure TL with respect to (w.r.t.) the high-order leader dynamics is designed, which achieves resilient estimation against BEAs. A trusted-node strategy against BEAs is proposed, which promotes network resilience by protecting almost the smallest fraction of crucial nodes on the TL. It is proven that strongly (2f+1) -robustness w.r.t. the above trusted nodes is sufficient for the resilient estimation performance of the TL. Second, a decentralized adaptive and chattering-free controller against potentially unbounded BNAs is designed on the CPL. This controller has the merit of uniformly ultimately bounded (UUB) convergence and an assignable exponential decay rate when converging into the above UUB bound. To the best of our knowledge, this article is the first to achieve resilient output TVFT against GBAs, rather than under GBAs. Finally, the practicability and validity of this new hierarchical protocol are illustrated via a simulation example.

18.
CNS Neurosci Ther ; 30(3): e14441, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37735974

RESUMEN

OBJECTIVE: The feature of Parkinson's disease (PD) is the heavy dopaminergic neuron loss of substantia nigra pars compacta (SNpc), while glutaredoxin (GLRX) has been discovered to modulate the death of dopaminergic neurons. In this context, this study was implemented to uncover the impact of GRX1 on motor dysfunction and dopamine neuron degeneration in PD mice and its potential mechanism. METHODS: A PD mouse model was established via injection with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into mice. After gain- and loss-of-function assays in mice, motor coordination was assessed using rotarod, pole, and open-field tests, and neurodegeneration in mouse SNpc tissues was determined using immunohistochemistry of tyrosine hydroxylase and Nissl staining. NRF1, methyltransferase-like 3 (METTL3), and GLRX expression in SNpc tissues were evaluated using qRT-PCR, Western blot, and immunohistochemistry. The N6-methyladenosine (m6 A) levels of GLRX mRNA were examined using MeRIP. The relationship among NRF1, METTL3, and GLRX was determined by RIP, ChIP, and dual luciferase assays. RESULTS: Low GLRX, METTL3, and NRF1 expression were observed in MPTP-induced mice, accompanied by decreased m6 A modification level of GLRX mRNA. GLRX overexpression alleviated motor dysfunction and dopamine neuron degeneration in MPTP-induced mice. METTL3 promoted m6 A modification and IGF2BP2-dependent stability of GLRX mRNA, and NRF1 increased METTL3 expression by binding to METTL3 promoter. NRF1 overexpression increased m6 A modification of GLRX mRNA and repressed motor dysfunction and dopamine neuron degeneration in MPTP-induced mice, which was counteracted by METTL3 knockdown. CONCLUSION: Conclusively, NRF1 constrained motor dysfunction and dopamine neuron degeneration in MPTP-induced PD mice by activating the METTL3/GLRX axis.


Asunto(s)
Dopamina , Enfermedad de Parkinson , Animales , Ratones , Modelos Animales de Enfermedad , Dopamina/metabolismo , Neuronas Dopaminérgicas/metabolismo , Glutarredoxinas/metabolismo , Metilación , Ratones Endogámicos C57BL , Degeneración Nerviosa/patología , ARN Mensajero/metabolismo , Regulación hacia Arriba
19.
IEEE Trans Cybern ; 54(5): 3313-3326, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37983158

RESUMEN

This article delves into the distributed resilient output containment control of heterogeneous multiagent systems against composite attacks, including Denial-of-Service (DoS) attacks, false-data injection (FDI) attacks, camouflage attacks, and actuation attacks. Inspired by digital twin technology, a twin layer (TL) with higher security and privacy is employed to decouple the above problem into two tasks: 1) defense protocols against DoS attacks on TL and 2) defense protocols against actuation attacks on the cyber-physical layer (CPL). Initially, considering modeling errors of leader dynamics, distributed observers are introduced to reconstruct the leader dynamics for each follower on TL under DoS attacks. Subsequently, distributed estimators are utilized to estimate follower states based on the reconstructed leader dynamics on the TL. Then, decentralized solvers are designed to calculate the output regulator equations on CPL by using the reconstructed leader dynamics. Simultaneously, decentralized adaptive attack-resilient control schemes are proposed to resist unbounded actuation attacks on the CPL. Furthermore, the aforementioned control protocols are applied to demonstrate that the followers can achieve uniformly ultimately bounded (UUB) convergence, with the upper bound of the UUB convergence being explicitly determined. Finally, we present a simulation example and an experiment to show the effectiveness of the proposed control scheme.

20.
J Agric Food Chem ; 71(49): 19408-19421, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38039319

RESUMEN

Olfaction plays an instrumental role in host plant selection by phytophagous insects. Helicoverpa assulta and Helicoverpa armigera are two closely related moth species with different host plant ranges. In this study, we first comparatively analyzed the function of 11 female-biased odorant receptors (ORs) and their orthologs in the two species by the Drosophila T1 neuron expression system and then examined the electroantennography responses of the two species to the most effective OR ligands. Behavioral assays using a Y-tube olfactometer indicate that guaiene, the primary ligand of HassOR21-2 and HarmOR21-2, only attracts the females, while benzyl acetone, the main ligand of HassOR35 and HarmOR35, attracts both sexes of the two species. Oviposition preference experiments further confirm that guaiene and benzyl acetone are potent oviposition attractants for the mated females of both species. These findings deepen our understanding of the olfactory coding mechanisms of host plant selection in herbivorous insects and provide valuable attractants for managing pest populations.


Asunto(s)
Mariposas Nocturnas , Receptores Odorantes , Atractivos Sexuales , Femenino , Animales , Masculino , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Ligandos , Mariposas Nocturnas/metabolismo , Atractivos Sexuales/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA