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1.
Acta Biomater ; 183: 330-340, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838909

RESUMO

Although vaccination with inactivated vaccines is a popular preventive method against pseudorabies virus (PRV) infection, inactivated vaccines have poor protection efficiency because of their weak immunogenicity. The development of an effective adjuvant is urgently needed to improve the efficacy of inactivated PRV vaccines. In this study, a promising nanocomposite adjuvant named as MIL@A-SW01-C was developed by combining polyacrylic acid-coated metal-organic framework MIL-53(Al) (MIL@A) and squalene (oil)-in-water emulsion (SW01) and then mixing it with a carbomer solution. One part of the MIL@A was loaded onto the oil/water interface of SW01 emulsion via hydrophobic interaction and coordination, while another part was dispersed in the continuous water phase using carbomer. MIL@A-SW01-C showed good biocompatibility, high PRV (antigen)-loading capability, and sustained antigen release. Furthermore, the MIL@A-SW01-C adjuvanted PRV vaccine induced high specific serum antibody titers, increased splenocyte proliferation and cytokine secretion, and a more balanced Th1/Th2 immune response compared with commercial adjuvants, such as alum and biphasic 201. In the mouse challenge experiment, two- and one-shot vaccinations resulted in survival rates of 73.3 % and 86.7 %, respectively. After one-shot vaccination, the host animal pigs were also challenged with wild PRV. A protection rate of 100 % was achieved, which was much higher than that observed with commercial adjuvants. This study not only establishes the superiority of MIL@A-SW01-C composite nanoadjuvant for inactivated PRV vaccine in mice and pigs but also presents an effective method for developing promising nanoadjuvants. STATEMENT OF SIGNIFICANCE: We have developed a nanocomposite of MIL-53(Al) and oil-in-water emulsion (MIL@A-SW01-C) as a promising adjuvant for the inactivated PRV vaccines. MIL@A-SW01-C has good biocompatibility, high PRV (antigen) loading capability, and prolonged antigen release. The developed nanoadjuvant induced much higher specific IgG antibody titers, increased splenocyte proliferation and cytokine secretion, and a more balanced Th1/Th2 immune response than commercial adjuvants alum and biphasic 201. In mouse challenge experiments, survival rates of 73.3 % and 86.7 % were achieved from two-shot and one-shot vaccinations, respectively. At the same time, a protection rate of 100 % was achieved with the host animal pigs challenged with wild PRV.


Assuntos
Adjuvantes Imunológicos , Emulsões , Animais , Adjuvantes Imunológicos/farmacologia , Emulsões/química , Camundongos , Suínos , Herpesvirus Suídeo 1/imunologia , Vacinas contra Pseudorraiva/imunologia , Camundongos Endogâmicos BALB C , Óleos/química , Feminino , Água/química , Vacinas de Produtos Inativados/imunologia , Pseudorraiva/prevenção & controle , Pseudorraiva/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Citocinas/metabolismo
2.
PLoS Comput Biol ; 20(6): e1012183, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38857304

RESUMO

Cellular signaling, crucial for biological processes like immune response and homeostasis, relies on specificity and fidelity in signal transduction to accurately respond to stimuli amidst biological noise. Kinetic proofreading (KPR) is a key mechanism enhancing signaling specificity through time-delayed steps, although its effectiveness is debated due to intrinsic noise potentially reducing signal fidelity. In this study, we reformulate the theory of kinetic proofreading (KPR) by convolving multiple intermediate states into a single state and then define an overall "processing" time required to traverse these states. This simplification allows us to succinctly describe kinetic proofreading in terms of a single waiting time parameter, facilitating a more direct evaluation and comparison of KPR performance across different biological contexts such as DNA replication and T cell receptor (TCR) signaling. We find that loss of fidelity for longer proofreading steps relies on the specific strategy of information extraction and show that in the first-passage time (FPT) discrimination strategy, longer proofreading steps can exponentially improve the accuracy of KPR at the cost of speed. Thus, KPR can still be an effective discrimination mechanism in the high noise regime. However, in a product concentration-based discrimination strategy, longer proofreading steps do not necessarily lead to an increase in performance. However, by introducing activation thresholds on product concentrations, can we decompose the product-based strategy into a series of FPT-based strategies to better resolve the subtleties of KPR-mediated product discrimination. Our findings underscore the importance of understanding KPR in the context of how information is extracted and processed in the cell.


Assuntos
Processos Estocásticos , Cinética , Ligantes , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/química , Transdução de Sinais/fisiologia , Biologia Computacional/métodos , Modelos Biológicos , Humanos , Replicação do DNA
3.
Nutrients ; 16(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38892618

RESUMO

It is crucial to provide adequate iodine nutrition to infants and toddlers for proper thyroid function and subsequent brain development. Infants are particularly vulnerable to iodine deficiency during the transition from a milk-based diet (breast milk and/or infant formula) to solid food. This study examines the current iodine levels of children during their first two years of life and investigates the association between these levels and feeding behaviors and the iodine status of their mothers in Shanghai, a city located in eastern China. A hospital-based cohort study was conducted to enroll mother-child pairs, where the child is aged 6-23 months, who visited community health service centers in the 16 districts of Shanghai, China. Data on socio-demographic factors and feeding behavior data were collected from the participants. The urinary iodine concentration (UIC) in both the young children and their mothers were analyzed. A total of 2282 mother-child pairs were included in this analysis. The median (p25-p75) UIC for lactating women, weaning women, and children were 121.3 µg/L (68.1-206.4 µg/L), 123.4 µg/L (58.4-227.2 µg/L), and 152.1 µg/L (75.8-268.3 µg/L), respectively. The UIC in children was found to be higher than that in their mothers (p < 0.001). Children who consumed less than 500 mL per day of formula milk in the last week had lower UICs compared with those who consumed 500 mL per day or more (p = 0.026). Furthermore, the children's UIC was positively correlated with the maternal UIC (rs = 0.285, p < 0.001). Multiple quantile regression analysis revealed a statistically significant positive association between maternal UIC and children's UIC between the 0.1 and 0.9 quantiles (all p < 0.001). We found that the iodine status of infants and toddlers, as well as of mothers, was sufficient. However, a large minority of children and mothers may be at risk of iodine deficiency. Furthermore, no associations between children's UIC and feeding behaviors were observed. Moreover, there was a positive correlation between the UIC of young children and their mothers.


Assuntos
Comportamento Alimentar , Iodo , Estado Nutricional , Humanos , Iodo/deficiência , Iodo/urina , Iodo/administração & dosagem , Lactente , Feminino , China/epidemiologia , Masculino , Mães , Adulto , Fenômenos Fisiológicos da Nutrição do Lactente , Análise de Regressão , Estudos de Coortes , Aleitamento Materno/estatística & dados numéricos
4.
ArXiv ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38711425

RESUMO

We introduce a set of gradient-flow-guided adaptive importance sampling (IS) transformations to stabilize Monte-Carlo approximations of point-wise leave one out cross-validated (LOO) predictions for Bayesian classification models. One can leverage this methodology for assessing model generalizability by for instance computing a LOO analogue to the AIC or computing LOO ROC/PRC curves and derived metrics like the AUROC and AUPRC. By the calculus of variations and gradient flow, we derive two simple nonlinear single-step transformations that utilize gradient information to shift a model's pre-trained full-data posterior closer to the target LOO posterior predictive distributions. In doing so, the transformations stabilize importance weights. Because the transformations involve the gradient of the likelihood function, the resulting Monte Carlo integral depends on Jacobian determinants with respect to the model Hessian. We derive closed-form exact formulae for these Jacobian determinants in the cases of logistic regression and shallow ReLU-activated artificial neural networks, and provide a simple approximation that sidesteps the need to compute full Hessian matrices and their spectra. We test the methodology on an n≪p dataset that is known to produce unstable LOO IS weights.

5.
Int J Biol Macromol ; 269(Pt 2): 132172, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38719009

RESUMO

Adjuvants including aluminum adjuvant (Alum) and oil-water emulsion have been widely used in inactivated pseudorabies virus (PRV) vaccines to improve their performance, however, they are not sufficient to protect from PRV infection because of the weak immune response and poor Th1-type immune response. Divalent manganese ion (Mn2+) has been reported to increase the cellular immune response significantly. In this work, a xanthan gum and carbomer-dispersed Mn2+-loaded tannic acid-polyethylene glycol (TPMnXC) nanoparticle colloid is developed and used as an adjuvant to improve the performance of the inactivated PRV vaccine. The good in vitro and in vivo biocompatibility of the developed TPMnXC colloid has been confirmed by the cell viability assay, erythrocyte hemolysis, blood routine analysis, and histological analysis of mouse organs and injection site. The TPMnXC-adjuvanted inactivated PRV vaccine (TPMnXC@PRV) significantly promotes higher and more balanced immune responses indicating with an increased specific total IgG antibody and IgG2a/IgG1 ratio, efficient splenocytes proliferation, and elevated Th1- and Th2-type cytokine secretion than those of control groups. Wild PRV challenge experiment is performed using mice as a model animal, achieving a protection rate of up to 86.67 %, which is much higher than those observed from the commercial Alum. This work not only demonstrates the high potentiality of TPMnXC in practical applications but also provides a new way to develop the Mn2+-loaded nanoadjuvant for veterinary vaccines.


Assuntos
Adjuvantes Imunológicos , Herpesvirus Suídeo 1 , Imunidade Celular , Imunidade Humoral , Manganês , Nanopartículas , Polissacarídeos Bacterianos , Taninos , Animais , Camundongos , Adjuvantes Imunológicos/farmacologia , Nanopartículas/química , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Taninos/química , Taninos/farmacologia , Manganês/química , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Polissacarídeos Bacterianos/imunologia , Herpesvirus Suídeo 1/imunologia , Vacinas contra Pseudorraiva/imunologia , Vacinas de Produtos Inativados/imunologia , Pseudorraiva/prevenção & controle , Pseudorraiva/imunologia , Feminino , Citocinas/metabolismo , Camundongos Endogâmicos BALB C , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Polifenóis
6.
ArXiv ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36911278

RESUMO

There has been renewed interest in understanding the mathematical structure of ecological population models that lead to overcompensation, the process by which a population recovers to a higher level after suffering a permanent increase in predation or harvesting. Here, we apply a recently formulated kinetic population theory to formally construct an age-structured single-species population model that includes a cannibalistic interaction in which older individuals prey on younger ones. Depending on the age-dependent structure of this interaction, our model can exhibit transient or steady-state overcompensation of an increased death rate as well as oscillations of the total population, both phenomena that have been observed in ecological systems. Analytic and numerical analysis of our model reveals sufficient conditions for overcompensation and oscillations. We also show how our structured population partial integrodifferential equation (PIDE) model can be reduced to coupled ODE models representing piecewise constant parameter domains, providing additional mathematical insight into the emergence of overcompensation.

7.
BMC Psychiatry ; 23(1): 918, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-38062399

RESUMO

OBJECTIVE: To report a case of seizure and rapidly progressive cognitive impairment 20 min after intravenous administration of levofloxacin. A 56-year-old woman was admitted to hospital with episodic unconsciousness and unresponsiveness. About 4 days ago, she experienced a loss of consciousness, fell to the floor, and yelled for 2 min, 20 min before the first intravenous dose of levofloxacin. The patient developed symptoms of cognitive impairment after the seizure. Levofloxacin is a synthetic third generation fluoroquinolone used to treat various infectious diseases. Upon admission, the patient was conscious and unresponsive. After 11 days of symptomatic and supportive treatment, the patient was discharged from the hospital with cognition restored to baseline level and no recurrence of seizures 10 months after discharge. DISCUSSION: Epilepsy is a rare adverse reaction to levofloxacin treatment. The patient in this case had infection-related signs before the onset of the disease, and the disease progressed rapidly with fluctuating changes. After ruling out degenerative, infectious, toxic, and autoimmune causes, the patient's symptoms may be attributed to levofloxacin, and this is the first case of seizure and rapidly progressive cognitive impairment after levofloxacin injection reported in the literature. Clinicians should be aware that unexplained, rapidly progressing cognitive impairment with infection-related signs before onset may be a rare side effect of antibiotics.


Assuntos
Disfunção Cognitiva , Epilepsia , Feminino , Humanos , Pessoa de Meia-Idade , Levofloxacino/efeitos adversos , Epilepsia/tratamento farmacológico , Convulsões , Disfunção Cognitiva/induzido quimicamente
8.
J Chem Phys ; 159(20)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38010331

RESUMO

We construct and analyze monomeric and multimeric models of the stochastic disassembly of a single nucleosome. Our monomeric model predicts the time needed for a number of histone-DNA contacts to spontaneously break, leading to dissociation of a non-fragmented histone from DNA. The dissociation process can be facilitated by DNA binding proteins or processing molecular motors that compete with histones for histone-DNA contact sites. Eigenvalue analysis of the corresponding master equation allows us to evaluate histone detachment times under both spontaneous detachment and protein-facilitated processes. We find that competitive DNA binding of remodeling proteins can significantly reduce the typical detachment time but only if these remodelers have DNA-binding affinities comparable to those of histone-DNA contact sites. In the presence of processive motors, the histone detachment rate is shown to be proportional to the product of the histone single-bond dissociation constant and the speed of motor protein procession. Our simple intact-histone model is then extended to allow for multimeric nucleosome kinetics that reveal additional pathways of disassembly. In addition to a dependence of complete disassembly times on subunit-DNA contact energies, we show how histone subunit concentrations in bulk solutions can mediate the disassembly process by rescuing partially disassembled nucleosomes. Moreover, our kinetic model predicts that remodeler binding can also bias certain pathways of nucleosome disassembly, with higher remodeler binding rates favoring intact-histone detachment.


Assuntos
Histonas , Nucleossomos , Histonas/química , Proteínas de Ligação a DNA/química , DNA/química
9.
Virus Evol ; 9(2): vead058, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37841642

RESUMO

Recent studies show that newly sampled monkeypox virus (MPXV) genomes exhibit mutations consistent with Apolipoprotein B mRNA Editing Catalytic Polypeptide-like3 (APOBEC3)-mediated editing compared to MPXV genomes collected earlier. It is unclear whether these single-nucleotide polymorphisms (SNPs) result from APOBEC3-induced editing or are a consequence of genetic drift within one or more MPXV animal reservoirs. We develop a simple method based on a generalization of the General-Time-Reversible model to show that the observed SNPs are likely the result of APOBEC3-induced editing. The statistical features allow us to extract lineage information and estimate evolutionary events.

10.
ArXiv ; 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37731652

RESUMO

We construct and analyze monomeric and multimeric models of the stochastic disassembly of a single nucleosome. Our monomeric model predicts the time needed for a number of histone-DNA contacts to spontaneously break, leading to dissociation of a non-fragmented histone from DNA. The dissociation process can be facilitated by DNA binding proteins or processing molecular motors that compete with histones for histone-DNA contact sites. Eigenvalue analysis of the corresponding master equation allows us to evaluate histone detachment times under both spontaneous detachment and protein-facilitated processes. We find that competitive DNA binding of remodeling proteins can significantly reduce the typical detachment time but only if these remodelers have DNA-binding affinities comparable to those of histone-DNA contact sites. In the presence of processive motors, the histone detachment rate is shown to be proportional to the product of the histone single-bond dissociation constant and the speed of motor protein procession. Our simple intact-histone model is then extended to allow for multimeric nucleosome kinetics that reveal additional pathways of disassembly. In addition to a dependence of complete disassembly times on subunit-DNA contact energies, we show how histone subunit concentrations in bulk solution can mediate the disassembly process by rescuing partially disassembled nucleosomes. Moreover, our kinetic model predicts that remodeler binding can also bias certain pathways of nucleosome disassembly, with higher remodeler binding rates favoring intact-histone detachment.

11.
ArXiv ; 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37608930

RESUMO

Recent studies show that newly sampled monkeypox virus (MPXV) genomes exhibit mutations consistent with Apolipoprotein B mRNA Editing Catalytic Polypeptide-like3 (APOBEC3)-mediated editing, compared to MPXV genomes collected earlier. It is unclear whether these single nucleotide polymorphisms (SNPs) result from APOBEC3-induced editing or are a consequence of genetic drift within one or more MPXV animal reservoirs. We develop a simple method based on a generalization of the General-Time-Reversible (GTR) model to show that the observed SNPs are likely the result of APOBEC3-induced editing. The statistical features allow us to extract lineage information and estimate evolutionary events.

12.
Neurobiol Aging ; 131: 59-73, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37572528

RESUMO

Sporadic Alzheimer's disease and cancer remain epidemiologically inversely related, and exploring the reverse pathogenesis is important for our understanding of both. Cognitive dysfunctions in Alzheimer's disease (AD) might result from the depletion of adaptive reserves in the brain. Energy storage in the brain is limited and is dynamically regulated by neurovascular and neurometabolic coupling. The research on neurodegenerative diseases has been dominated by the neurocentric view that neuronal defects cause the diseases. However, the proposal of the 2-hit vascular hypothesis in AD led us to focus on alterations in the vasculature, especially hypoperfusion. Chronic hypoxia is a feature shared by AD and cancer. It is interesting how contradicting chronic hypoxia's effects on both cancer and AD are. In this article, we discuss the potential links between the 2 diseases' etiology, from comparable upstream circumstances to diametrically opposed downstream effects. We suggest opposing potential mechanisms, including upregulation and downregulation of hypoxia-inducible factor-1α, the Warburg and reverse-Warburg effects, lactate-mediated intracellular acidic and alkaline conditions, and VDAC1-mediated apoptosis and antiapoptosis, and search for regulators that may be identified as the crossroads between cancer and AD.


Assuntos
Doença de Alzheimer , Neoplasias , Humanos , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Encéfalo/patologia , Hipóxia , Neoplasias/complicações
13.
Nat Commun ; 14(1): 3864, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37391417

RESUMO

The eukaryotic single-stranded DNA (ssDNA)-binding protein Replication Protein A (RPA) plays a crucial role in various DNA metabolic pathways, including DNA replication and repair, by dynamically associating with ssDNA. While the binding of a single RPA molecule to ssDNA has been thoroughly studied, the accessibility of ssDNA is largely governed by the bimolecular behavior of RPA, the biophysical nature of which remains unclear. In this study, we develop a three-step low-complexity ssDNA Curtains method, which, when combined with biochemical assays and a Markov chain model in non-equilibrium physics, allow us to decipher the dynamics of multiple RPA binding to long ssDNA. Interestingly, our results suggest that Rad52, the mediator protein, can modulate the ssDNA accessibility of Rad51, which is nucleated on RPA coated ssDNA through dynamic ssDNA exposure between neighboring RPA molecules. We find that this process is controlled by the shifting between the protection mode and action mode of RPA ssDNA binding, where tighter RPA spacing and lower ssDNA accessibility are favored under RPA protection mode, which can be facilitated by the Rfa2 WH domain and inhibited by Rad52 RPA interaction.


Assuntos
DNA de Cadeia Simples , Rad51 Recombinase , Proteína de Replicação A , DNA de Cadeia Simples/genética , Proteínas de Ligação a DNA/genética , Proteína de Replicação A/genética , Rad51 Recombinase/genética
14.
Front Cardiovasc Med ; 10: 1099124, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37180786

RESUMO

Objective: Long non-coding RNAs (lncRNAs) play pivotal roles in the transcriptional regulation of atrial fibrillation (AF) by acting as competing endogenous RNAs (ceRNAs). In the present study, the expression levels of lncRNAs of sinus rhythm (SR) patients and AF patients were investigated with transcriptomics technology, and the lncRNA-miRNA-mRNA network based on the ceRNA theory in AF was elaborated. Methods: Left atrial appendage (LAA) tissues were obtained from patients with valvular heart disease during cardiac surgery, and they were divided into SR and AF groups. The expression characterizations of differentially expressed (DE) lncRNAs in the two groups were revealed by high-throughput sequencing methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, and the lncRNA-miRNA-mRNA-mediated ceRNA network was constructed. Results: A total of differentially expressed 82 lncRNAs, 18 miRNAs, and 495 mRNAs in human atrial appendage tissues were targeted. Compared to SR patients, the following changes were found in AF patients: 32 upregulated and 50 downregulated lncRNAs; 7 upregulated and 11 downregulated miRNAs; and 408 upregulated and 87 downregulated mRNAs. A lncRNA-miRNA-mRNA network was constructed, which included 44 lncRNAs, 18 miRNAs, and 347 mRNAs. qRT-PCR was performed to verify these findings. GO and KEGG analyses suggested that inflammatory response, chemokine signaling pathway, and other biological processes play important roles in the pathogenesis of AF. Network analysis based on the ceRNA theory identified that lncRNA XR_001750763.2 and Toll-like receptor 2 (TLR2) compete for binding to miR-302b-3p. In AF patients, lncRNA XR_001750763.2 and TLR2 were upregulated, and miR-302b-3p was downregulated. Conclusion: We identified a lncRNA XR_001750763.2/miR-302b-3p/TLR2 network based on the ceRNA theory in AF. The present study shed light on the physiological functions of lncRNAs and provided information for exploring potential treatments for AF.

15.
Front Neurol ; 14: 1108494, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37251232

RESUMO

Depression is the most prevalent psychiatric disorder, which needs deeper mechanism research studies and effective therapy. Zi-Shui-Qing-Gan-Yin (ZSQGY) is a traditional Chinese medicine decoction that has been widely used in China in the treatment of depressive symptoms. The aim of the study was to examine the anti-depressive effects of ZSQGY and the possible mechanism of action in the monosodium glutamate (MSG)-induced depressive model and the corticosterone (CORT)-induced PC12 cell model. Liquid chromatography-mass spectrometry (LC-MS) was performed to determine the major compounds in the water extract of ZSQGY. The depressive behaviors were evaluated by the field swimming test (FST), the sucrose preference test (SPT), and the open field test (OFT). Golgi staining and transmission electron microscopy (TEM) were performed to display the alterations of synaptic ultrastructure. The mitochondrion function and inflammatory factors were also quantified. The changes in peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) expression were evaluated. The results of this study demonstrated that ZSQGY significantly improved depressive behaviors. ZSQGY also reversed the changes in synaptic plasticity, improved mitochondrion function, and reduced the levels of inflammatory factors. The neuroprotective effects were accompanied by the increased expression of PGC-1α. However, the beneficial changes were reversed after the inhibition of PGC-1α. These results indicated that ZSQGY effectively could improve depressive behaviors via the mechanisms that regulate synaptic structural plasticity, improve mitochondrion function, and alleviate neuroinflammation, which could, or partly, attribute to the regulation of PGC-1α.

16.
Molecules ; 28(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37241989

RESUMO

The carbon-nitrogen bond is one of the most prevalent chemical bonds in natural and artificial molecules, as many naturally existing organic molecules, pharmaceuticals, agrochemicals, and functional materials contain at least one nitrogen atom. Radical decarboxylative carbon-nitrogen bond formation from readily available carboxylic acids and their derivatives has emerged as an attractive and valuable tool in modern synthetic chemistry. The promising achievements in this research topic have been demonstrated via utilizing this strategy in the synthesis of complex natural products. In this review, we will cover carbon-nitrogen bond formation via radical decarboxylation of carboxylic acids, Barton esters, MPDOC esters, N-hydroxyphthalimide esters (NHP esters), oxime esters, aryliodine(III) dicarboxylates, and others, respectively. This review aims to bring readers a comprehensive survey of the development in this rapidly expanding field. We hope that this review will emphasize the knowledge, highlight the proposed mechanisms, and further disclose the fascinating features in modern synthetic applications.

17.
Europace ; 25(5)2023 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-37050858

RESUMO

AIMS: The optimal strategy for persistent atrial fibrillation (PerAF) is poorly defined. We conducted a multicentre, randomized, prospective trial to compare the outcomes of different ablation strategies for PerAF. METHODS AND RESULTS: We enrolled 450 patients and randomly assigned them in a 1:1:1 ratio to undergo pulmonary vein isolation and subsequently undergo the following three different ablation strategies: anatomical guided ablation (ANAT group, n = 150), electrogram guided ablation (EGM group, n = 150), and extensive electro-anatomical guided ablation (EXT group, n = 150). The primary endpoint was freedom from atrial fibrillation (AF) lasting longer than 30 s at 12 months after a single ablation procedure. After 12 months of follow-up, 72% (108) of patients in the EXT group were free from AF recurrence, as compared with the 64% (96) in the EGM group (P = 0.116), and 54% (81) in the ANAT group (P = 0.002). The EXT group showed less AF/atrial tachycardia recurrence than the EGM group (60% vs. 50%, P = 0.064) and the ANAT group (60% vs. 37.3%, P < 0.001). The EXT group showed the highest rate of AF termination (66.7%), followed by 56.7% in the EGM group, and 20.7% in the ANAT group. The AF termination signified less AF recurrence at 12 months compared to patients without AF termination (30.1% vs. 42.7%, P = 0.008). Safety endpoints did not differ significantly between the three groups (P = 0.924). CONCLUSIONS: Electro-anatomical guided ablation achieved the most favourable outcomes among the three ablation strategies. The AF termination is a reliable ablation endpoint.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Estudos Prospectivos , Resultado do Tratamento , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Veias Pulmonares/cirurgia , Recidiva
18.
Biophys J ; 122(1): 254-266, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36199250

RESUMO

Under certain cellular conditions, transcription and mRNA translation in prokaryotes appear to be "coupled," in which the formation of mRNA transcript and production of its associated protein are temporally correlated. Such transcription-translation coupling (TTC) has been evoked as a mechanism that speeds up the overall process, provides protection against premature termination, and/or regulates the timing of transcript and protein formation. What molecular mechanisms underlie ribosome-RNAP coupling and how they can perform these functions have not been explicitly modeled. We develop and analyze a continuous-time stochastic model that incorporates ribosome and RNAP elongation rates, initiation and termination rates, RNAP pausing, and direct ribosome and RNAP interactions (exclusion and binding). Our model predicts how distributions of delay times depend on these molecular features of transcription and translation. We also propose additional measures for TTC: a direct ribosome-RNAP binding probability and the fraction of time the translation-transcription process is "protected" from attack by transcription-terminating proteins. These metrics quantify different aspects of TTC and differentially depend on parameters of known molecular processes. We use our metrics to reveal how and when our model can exhibit either acceleration or deceleration of transcription, as well as protection from termination. Our detailed mechanistic model provides a basis for designing new experimental assays that can better elucidate the mechanisms of TTC.


Assuntos
Biossíntese de Proteínas , Transcrição Gênica , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/metabolismo , Ribossomos/metabolismo
19.
Cell Biol Int ; 47(2): 394-405, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36525374

RESUMO

Alveolar epithelial cells (AECs) function as a vital defense barrier avoiding the invasion of exogenous agents and preserving the functional and structural integrity of lung tissues, while damage/breakdown of this airway epithelial barrier is frequently associated with the pathogenesis of acute lung injury (ALI). NOD-like receptor family, pyrindomain-containing 3 (NLRP3) inflammasome activation-associated pyroptosis is involved in the development of ALI. Yet, how the activity of NLRP3 inflammasome is regulated in the context of ALI remains unknown. Herein we hypothesized that USP9X, an important deubiquitinase, participates in modulating the activation of NLRP3 inflammasome, thereby affecting the phenotypes in a lipopolysaccharide (LPS)-stimulated AEC model. Human pulmonary AECs were subjected to LPS/adenosine triphosphate (ATP) treatment to induce NLRP3 inflammasome activation and cell pyroptosis. Knockdown and overexpression of USP9X were applied to validate the function of USP9X. Inhibitors of proteinase and protein synthesis, as well as approach of co-immunoprecipitation coupled with Western blot, were utilized to explore the molecular mechanism. LPS/ATP challenge resulted in pronouncedly increased pyroptosis of AECs, activation of NLRP3 inflammasome and release of interleukin (IL)-1ß and IL-18 cytokines, while downregulation of USP9X could reverse these alterations. USP9X was found to have marked impact on NLRP3 protein instead of mRNA level. Furthermore, increased ubiquitination of NLRP3 was observed upon downregulating USP9X. Additionally, the inhibitory effect of USP9X downregulation was reversed by NLRP3 overexpression, while the promoting impact of USP9X overexpression was dampened by NLRP3 inhibitor in terms of cell pyroptosis and cytokine secretion. USP9X modulated the activity of NLRP3 inflammasome and pyroptosis of AECs via its deubiquitination function.


Assuntos
Lesão Pulmonar Aguda , Proteína 3 que Contém Domínio de Pirina da Família NLR , Humanos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Lipopolissacarídeos/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Trifosfato de Adenosina , Ubiquitina Tiolesterase
20.
Heliyon ; 8(12): e12182, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36536902

RESUMO

Ethnopharmacological relevance: Guipi Tang (GPT) is a widely used traditional Chinese medicine that is used to treat major depressive disorder. However, the molecular mechanisms of its effects remain unclear. Aim of the study: This study aimed to investigate the antidepressant-like effects of GPT and explore its underlying molecular mechanisms. Materials and methods: Male Sprague-Dawley rats were subjected to a chronic unpredictable mild stress (CUMS) procedure and treated with various doses of GPT, with fluoxetine treatment as a positive control. Behavioural tests (including sucrose preference test, novelty-suppressed feeding test, open-field test and forced swim test), terminal deoxynucleotidyl transferase dUTP nick end labeling and enzyme-linked immunosorbent assay were conducted. The levels of Bax, Bcl-2, cleaved caspase-3, PI3K, p-PI3K, AKT, p-AKT, BDNF, TrkB and CREB or p-CREB were assessed at the protein level using western blotting or immunofluorescence. Results: GPT consists of mainly known drugs, such as liquiritin and ginsenosides. It reversed depressive behaviours and decreased cell apoptosis in the hippocampi of CUMS rats. It significantly upregulated the protein level of Bax, p-Akt, p-PI3K, BDNF, TrkB and p-CREB and downregulated the level of cleaved caspase-3 and Bcl-2. Conclusions: GPT had anti-depressive activity as indicated by the amelioration of depression-like behaviour and the inhibition of hippocampal neuronal apoptosis in CUMS rats. This inhibition was mediated partly by modulating the PI3K/Akt and/or BDNF/TrkB/CREB pathway, in which, glycosides, the main components of GPT, might be involved.

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