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1.
Eur J Immunol ; 54(3): e2350836, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38234007

RESUMO

T lymphocytes are pivotal in adaptive immunity. The role of the trafficking protein particle complex (TRAPPC) in regulating T-cell development and homeostasis is unknown. Using CD4cre -Trappc1flox/flox (Trappc1 cKO) mice, we found that Trappc1 deficiency in T cells significantly decreased cell number of naive T cells in the periphery, whereas thymic T-cell development in Trappc1 cKO mice was identical as WT mice. In the culture assays and mouse models with adoptive transfer of the sorted WT (CD45.1+ CD45.2+ ) and Trappc1 cKO naive T cells (CD45.2+ ) to CD45.1+ syngeneic mice, Trappc1-deficient naive T cells showed significantly reduced survival ability compared with WT cells. RNA-seq and molecular studies showed that Trappc1 deficiency in naive T cells reduced protein transport from the endoplasmic reticulum to the Golgi apparatus, enhanced unfolded protein responses, increased P53 transcription, intracellular Ca2+ , Atf4-CHOP, oxidative phosphorylation, and lipid peroxide accumulation, and subsequently led to ferroptosis. Trappc1 deficiency in naive T cells increased ferroptosis-related damage-associated molecular pattern molecules like high mobility group box 1 or lipid oxidation products like prostaglandin E2, leukotriene B4, leukotriene C4, and leukotriene D4. Functionally, the culture supernatant of Trappc1 cKO naive T cells significantly promoted neutrophils to express inflammatory cytokines like TNFα and IL-6, which was rescued by lipid peroxidation inhibitor Acetylcysteine. Importantly, Trappc1 cKO mice spontaneously developed severe autoinflammatory disease 4 weeks after birth. Thus, intrinsic expression of Trappc1 in naive T cells plays an integral role in maintaining T-cell homeostasis to avoid proinflammatory naive T-cell death-caused autoinflammatory syndrome in mice. This study highlights the importance of the TRAPPC in T-cell biology.


Assuntos
Ferroptose , Doenças Hereditárias Autoinflamatórias , Camundongos , Animais , Linfócitos T , Camundongos Knockout , Diferenciação Celular
2.
EMBO Rep ; 24(2): e55503, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36440617

RESUMO

Myeloid cell development in bone marrow is essential for the maintenance of peripheral immune homeostasis. However, the role of intracellular protein trafficking pathways during myeloid cell differentiation is currently unknown. By mining bioinformatics data, we identify trafficking protein particle complex subunit 1 (TRAPPC1) as continuously upregulated during myeloid cell development. Using inducible ER-TRAPPC1 knockout mice and bone marrow chimeric mouse models, we demonstrate that TRAPPC1 deficiency causes severe monocyte and neutrophil defects, accompanied by a selective decrease in common myeloid progenitors (CMPs) and subsequent cell subsets in bone marrow. TRAPPC1-deleted CMPs differentiate poorly into monocytes and neutrophils in vivo and in vitro, in addition to exhibiting enhanced endoplasmic reticulum stress and apoptosis via a Ca2+ -mitochondria-dependent pathway. Cell cycle arrest and senescence of TRAPPC1-deleted CMPs are mediated by the activation of pancreatic endoplasmic reticulum kinase and the upregulation of cyclin-dependent kinase inhibitor p21. This study reveals the essential role of TRAPPC1 in the maintenance and differentiation of CMPs and highlights the significance of protein processing and trafficking processes in myeloid cell development.


Assuntos
Medula Óssea , Células Progenitoras Mieloides , Proteínas de Transporte Vesicular , Animais , Camundongos , Medula Óssea/metabolismo , Diferenciação Celular , Camundongos Knockout , Monócitos , Células Progenitoras Mieloides/metabolismo , Neutrófilos , Proteínas de Transporte Vesicular/metabolismo
3.
J Periodontal Res ; 59(2): 366-380, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38189472

RESUMO

BACKGROUND AND OBJECTIVE: As a chronic inflammatory disease, periodontitis threatens oral health and is a risk factor for Alzheimer's disease (AD). There is growing evidence that these two diseases are closely related. However, current research is still incomplete in understanding the common genes and common mechanisms between periodontitis and AD. In this study, we aimed to identify common genes in periodontitis and AD and analyze the relationship between crucial genes and immune cells to provide new therapeutic targets for clinical treatment. MATERIALS AND METHODS: We evaluated differentially expressed genes (DEGs) specific to periodontitis and AD. Co-expressed genes were identified by obtaining gene expression profile data from the Gene Expression Omnibus (GEO) database. Using the STRING database, protein-protein interaction (PPI) networks were constructed, and essential genes were identified. We also used four algorithms to identify critical genes and constructed regulatory networks. The association of crucial genes with immune cells and potential therapeutic effects was also assessed. RESULTS: PDGFRB, VCAN, TIMP1, CHL1, EFEMP2, and IGFBP5 were obtained as crucial common genes. Immune infiltration analysis showed that Natural killer cells and Myeloid-derived suppressor cells were significantly differentially expressed in patients with PD and AD compared with the normal group. FOXC1 and GATA2 are important TFs for PD and AD. MiR-23a, miR-23b, miR-23a, and miR-23b were associated with AD and PD. Finally, the hub genes retrieved from the DSigDB database indicate multiple drug molecule and drug-target interactions. CONCLUSION: This study reveals commonalities in common hub genes and immune infiltration between periodontitis and AD, and the analysis of six hub genes and immune cells may provide new insights into potential therapeutic directions for the pathogenesis of periodontitis complicated by AD.


Assuntos
Doença de Alzheimer , MicroRNAs , Periodontite , Humanos , Doença de Alzheimer/genética , Periodontite/genética , Periodontite/terapia , Biologia Computacional , Bases de Dados Factuais , Perfilação da Expressão Gênica
4.
J Immunol ; 209(11): 2181-2191, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36426981

RESUMO

Fatty acid binding protein 5 (FABP5) is mainly involved in the uptake, transport, and metabolism of fatty acid in the cytoplasm, and its role in immune cells has been recognized in recent years. However, the role of FABP5 in macrophage inflammation and its underlying mechanisms were not fully addressed. In our study, the acute liver injury and sepsis mouse models were induced by i.p. injection of LPS and cecal contents, respectively. Oleic acid (0.6 g/kg) was injected four times by intragastric administration every week, and this lasted for 1 wk before the LPS or cecal content challenge. We found that myeloid-specific deletion of FABP5 mitigated LPS-induced acute liver injury with reduced mortality of mice, histological liver damage, alanine aminotransferase, and proinflammatory factor levels. Metabolic analysis showed that FABP5 deletion increased the intracellular unsaturated fatty acids, especially oleic acid, in LPS-induced macrophages. The addition of oleic acid also decreased LPS-stimulated macrophage inflammation in vitro and reduced acute liver injury in LPS-induced or cecal content-induced sepsis mice. RNA-sequencing and molecular mechanism studies showed that FABP5 deletion or oleic acid supplementation increased the AMP/ATP ratio and AMP-activated protein kinase (AMPK) activation and inhibited the NF-κB pathway during the inflammatory response to LPS stimulation of macrophages. Inhibiting AMPK activation or expression by chemical or genetic approaches significantly rescued the decreased NF-κB signaling pathway and inflammatory response in LPS-treated FABP5-knockout macrophages. Our present study indicated that inhibiting FABP5 or supplementation of oleic acid might be used for the treatment of sepsis-caused acute liver injury.


Assuntos
NF-kappa B , Sepse , Camundongos , Animais , Proteínas Quinases Ativadas por AMP , Lipopolissacarídeos , Transdução de Sinais , Macrófagos , Inflamação , Ácidos Oleicos , Proteínas de Neoplasias , Proteínas de Ligação a Ácido Graxo/genética
5.
Cereb Cortex ; 33(13): 8352-8367, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37083264

RESUMO

Numerous functional magnetic resonance imaging (fMRI) studies have examined the neural mechanisms of negative emotional words, but scarce evidence is available for the interactions among related brain regions from the functional brain connectivity perspective. Moreover, few studies have addressed the neural networks for negative word processing in bilinguals. To fill this gap, the current study examined the brain networks for processing negative words in the first language (L1) and the second language (L2) with Chinese-English bilinguals. To identify objective indicators associated with negative word processing, we first conducted a coordinate-based meta-analysis on contrasts between negative and neutral words (including 32 contrasts from 1589 participants) using the activation likelihood estimation method. Results showed that the left medial prefrontal cortex (mPFC), the left inferior frontal gyrus (IFG), the left posterior cingulate cortex (PCC), the left amygdala, the left inferior temporal gyrus (ITG), and the left thalamus were involved in processing negative words. Next, these six clusters were used as regions of interest in effective connectivity analyses using extended unified structural equation modeling to pinpoint the brain networks for bilingual negative word processing. Brain network results revealed two pathways for negative word processing in L1: a dorsal pathway consisting of the left IFG, the left mPFC, and the left PCC, and a ventral pathway involving the left amygdala, the left ITG, and the left thalamus. We further investigated the similarity and difference between brain networks for negative word processing in L1 and L2. The findings revealed similarities in the dorsal pathway, as well as differences primarily in the ventral pathway, indicating both neural assimilation and accommodation across processing negative emotion in two languages of bilinguals.


Assuntos
Multilinguismo , Humanos , Mapeamento Encefálico , Idioma , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Emoções , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Imageamento por Ressonância Magnética
6.
Eur J Neurosci ; 57(5): 840-853, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36656284

RESUMO

How speaking two languages affects executive functions has been a long-standing debate and the mechanisms underlying the observed cognitive advantages of bilingualism remain unspecified. Here, using multivariate pattern classification methods, we decoded spatial patterns of neural signals associated with Flanker task performance in mono-dialectal and bi-dialectal speakers of Chinese. While univariate approach to even-related potentials (ERPs) showed no between-group difference, decoding accuracy of ERPs was reduced in bi-dialectal as compared to mono-dialectal speakers in both congruent-neutral and incongruent-neutral classifications. There was no effect of bidialectalism, however, on decoding accuracy of alpha-band oscillations, an electrophysiological index implicated in inhibition. Behavioural data analysed using the Drift Diffusion Model (DDM) showed facilitating effects of bidialectalism on non-decision times but no effect on drift rates. These findings demonstrate that using two dialects on a daily basis enhances general attentional deployment rather than affecting specific component of executive functions such as inhibitory control. Given that the two dialects of Chinese differed almost exclusively in phonology, the bidialectalism effect was most likely motivated by resolving phonological competition at lexical processing level.


Assuntos
Função Executiva , Multilinguismo , Função Executiva/fisiologia , Idioma , Atenção/fisiologia
7.
Eur J Immunol ; 52(11): 1789-1804, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35908180

RESUMO

Thymic epithelial cells (TECs) are important for T cell development and immune tolerance establishment. Although comprehensive molecular regulation of TEC development has been studied, the role of transport protein particle complexes (Trappcs) in TECs is not clear. Using TEC-specific homozygous or heterozygous Trappc1 deleted mice model, we find that Trappc1 deficiency cause severe thymus atrophy with decreased cell number and blocked maturation of TECs. Mice with a TEC-specific Trappc1 deletion show poor thymic T cell output and have a greater percentage of activated/memory T cells, suffered from spontaneous autoimmune disorders. Our RNA-seq and molecular studies indicated that the decreased endoplasmic reticulum (ER) and Golgi apparatus, enhanced unfolded protein response (UPR) and subsequent Atf4-CHOP-mediated apoptosis, and reactive oxygen species (ROS)-mediated ferroptosis coordinately contributed to the reduction of Trappc1-deleted TECs. Additionally, reduced Aire+ mTECs accompanied by the decreased expression of Irf4, Irf8, and Tbx21 in Trappc1 deficiency mTECs, may further coordinately block the tissue-restricted antigen expression. In this study, we reveal that Trappc1 plays an indispensable role in TEC development and maturation and provide evidence for the importance of inter-organelle traffic and ER homeostasis in TEC development.


Assuntos
Células Epiteliais , Timo , Camundongos , Animais , Diferenciação Celular , Homeostase , Retículo Endoplasmático
8.
Hum Brain Mapp ; 44(15): 5065-5078, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37515386

RESUMO

Adopting highly sensitive multivariate electroencephalography (EEG) and alpha-band decoding analyses, the present study investigated proactive and reactive language control during bilingual language production. In a language-switching task, Chinese-English bilinguals were asked to name pictures based on visually presented cues. EEG and alpha-band decoding accuracy associated with switch and non-switch trials were used as indicators for inhibition over the non-target language. Multivariate EEG decoding analyses showed that the decoding accuracy in L1 but not in L2, was above chance level shortly after cue onset. In addition, alpha-band decoding results showed that the decoding accuracy in L1 rose above chance level in an early time window and a late time window locked to the stimulus. Together, these asymmetric patterns of decoding accuracy indicate that both proactive and reactive attentional control over the dominant L1 are exerted during bilingual word production, with a possibility of overlap between two control mechanisms. We addressed theoretical implications based on these findings for bilingual language control models.


Assuntos
Multilinguismo , Humanos , Idioma , Eletroencefalografia , Atenção/fisiologia , Sinais (Psicologia) , Potenciais Evocados/fisiologia
9.
J Immunol ; 207(8): 2039-2050, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34535574

RESUMO

Thymic epithelial cells (TECs) are critical for the development and generation of functionally competent T cells. Until now, the mechanism that regulates the survival of TECs is poorly understood. In the current study, we found that Tsc1 controls the homeostasis of medullary TECs (mTECs) by inhibiting lysosomal-mediated apoptosis pathway in mice. TEC-specific deletion of Tsc1 predominately decreased the cell number of mTECs and, to a lesser content, affected the development cortical TECs. The defect of mTECs caused by Tsc1 deficiency in mice impaired thymocyte development and peripheral T cell homeostasis. Mechanistically, Tsc1 deficiency did not affect the cell proliferation of mTECs but increased the apoptosis of mTECs significantly. RNA-sequencing analysis showed that pathways involved in lysosomal biogenesis, cell metabolism, and apoptosis were remarkably elevated in Tsc1-deficient mTECs compared with their wild-type counterparts. Tsc1-deficient mTECs exhibited overproduction of reactive oxygen species and malfunction of lysosome, with lysosome membrane permeabilization and the release of cathepsin B and cathepsin L to the cytosol, which then lead to Bid cleaved into active truncated Bid and subsequently intrinsic apoptosis. Finally, we showed that the impaired development of mTECs could be partially reversed by decreasing mTORC1 activity via haploinsufficiency of Raptor Thus, Tsc1 is essential for the homeostasis of mTECs by inhibiting lysosomal-mediated apoptosis through mTORC1-dependent pathways.


Assuntos
Células Epiteliais/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Timo/citologia , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Animais , Apoptose , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Células Epiteliais/citologia , Retroalimentação Fisiológica , Haploinsuficiência , Homeostase , Camundongos , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Proteína Regulatória Associada a mTOR/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética
10.
Cereb Cortex ; 33(1): 35-49, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-35226917

RESUMO

The cognitive function of the human cerebellum could be characterized as enigmatic. However, researchers have attempted to detail the comprehensive role of the cerebellum in several cognitive processes in recent years. Here, using functional magnetic resonance imaging (fMRI) and transcranial direct current stimulation (tDCS), we revealed different functions of bilateral cerebellar lobules in bilingual language production. Specifically, brain activation showed the bilateral posterolateral cerebellum was associated with bilingual language control, and an effective connectivity analysis built brain networks for the interaction between the cerebellum and the cerebral cortex. Furthermore, anodal tDCS over the right cerebellum significantly optimizes language control performance in bilinguals. Together, these results reveal a precise asymmetrical functional distribution of the cerebellum in bilingual language production, suggesting that the right cerebellum is more involved in language control. In contrast, its left counterpart undertakes a computational role in cognitive control function by connecting with more prefrontal, parietal, subcortical brain areas.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Humanos , Estimulação Transcraniana por Corrente Contínua/métodos , Cerebelo/diagnóstico por imagem , Cerebelo/fisiologia , Idioma , Cognição/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética/métodos
11.
J Neuroinflammation ; 19(1): 163, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729645

RESUMO

BACKGROUND: Hydrocephalus is a severe complication of intracerebral hemorrhage with ventricular extension (ICH-IVH) and causes cerebrospinal fluid (CSF) accumulation. The choroid plexus epithelium plays an important role in CSF secretion and constitutes the blood-CSF barrier within the brain-immune system interface. Although the NLRP3 inflammasome, as a key component of the innate immune system, promotes neuroinflammation, its role in the pathogenesis of hydrocephalus after hemorrhage has not been investigated. Therefore, this study aimed to investigate the potential mechanism of NLRP3 in hydrocephalus to discover a potential marker for targeted therapy. METHODS: A rat model of hydrocephalus after ICH-IVH was developed through autologous blood infusion in wild-type and Nlrp3-/- rats. By studying the features and processes of the model, we investigated the relationship between the NLRP3 inflammasome and CSF hypersecretion in the choroid plexus. RESULTS: The ICH-IVH model rats showed ventricular dilation accompanied by CSF hypersecretion for 3 days. Based on the choroid plexus RNA-seq and proteomics results, we found that an inflammatory response was activated. The NLRP3 inflammasome was investigated, and the expression levels of NLRP3 inflammasome components reached a peak at 3 days after ICH-IVH. Inhibition of NLRP3 by an MCC950 inflammasome inhibitor or Nlrp3 knockout decreased CSF secretion and ventricular dilation and attenuated neurological deficits after ICH-IVH. The mechanism underlying the neuroprotective effects of NLRP3 inhibition involved decreased phosphorylation of NKCC1, which is a major protein that regulates CSF secretion by altering Na+- and K+-coupled water transport, via MCC950 or Nlrp3 knockout. In combination with the in vitro experiments, this experiment confirmed the involvement of the NLRP3/p-NKCC1 pathway and Na+ and K+ flux. CONCLUSIONS: This study demonstrates that NKCC1 phosphorylation in the choroid plexus epithelium promotes NLRP3 inflammasome-mediated CSF hypersecretion and that NLRP3 plays an important role in the pathogenesis of hydrocephalus after hemorrhage. These findings provide a new therapeutic strategy for treating hydrocephalus.


Assuntos
Plexo Corióideo , Hidrocefalia , Animais , Hemorragia Cerebral/patologia , Plexo Corióideo/metabolismo , Hidrocefalia/complicações , Hidrocefalia/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ratos , Membro 2 da Família 12 de Carreador de Soluto
12.
Bioorg Med Chem ; 68: 116880, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35714535

RESUMO

l-Threonine aldolases (LTAs) employing pyridoxal phosphate (PLP) as cofactor can convert low-cost achiral substrates glycine and aldehyde directly into valuable ß-hydroxy-α-amino acids such as (2R,3S)-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid ((R,S)-AHNPA), which is utilized broadly as crucial chiral intermediates for bioactive compounds. However, LTAs' stereospecificity towards the ß carbon is rather moderate and their activity and stability at high substrate load is low, which limits their industrial application. Here, computer-aided directed evolution was applied to improve overall activity, selectivity and stability under desired process conditions of a l-threonine aldolase in the asymmetric synthesis of (R,S)-AHNPA. Selectivity and stability determining regions were computationally identified for structure-guided directed evolution of LTA-variants under efficient biocatalytic process conditions using 40% ethanol as cosolvent. We applied molecular modeling to rationalize selectivity improvement and design focused libraries targeting the substrate binding pocket, and we also used MD simulations in nonaqueous process environment as an effective and promising method to predict potential unstable loop regions near the tetramer interface which are hot-spots for cosolvent resistance. An excellent LTA variant EM-ALDO031 with 18 mutations was obtained, which showed âˆ¼ 30-fold stability improvement in 40% ethanol and diastereoselectivity (de) raised from 31.5% to 85% through a three-phase evolution campaign. Our fast and efficient data-driven methodology utilizing a combination of experimental and computational tools enabled us to evolve an aldolase variant to achieve the target of 90% conversion at up to 150 g/L substrate load in 40% ethanol, enabling the biocatalytic production of ß-hydroxy-α-amino acids from cheap achiral precursors at multi-ton scale.


Assuntos
Cloranfenicol , Glicina Hidroximetiltransferase , Aminoácidos/química , Computadores , Etanol , Glicina Hidroximetiltransferase/química , Glicina Hidroximetiltransferase/genética , Glicina Hidroximetiltransferase/metabolismo , Hidrolases/metabolismo , Especificidade por Substrato
13.
Int J Mol Sci ; 23(19)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36233017

RESUMO

Recent studies have confirmed that chlorophyllase (CLH), a long-found chlorophyll (Chl) dephytylation enzyme for initiating Chl catabolism, has no function in leaf senescence-related Chl breakdown. Yet, CLH is considered to be involved in fruit degreening and responds to external and hormonal stimuli. The purpose of this work was to elucidate in detail the biochemical, structural properties, and gene expression of four CLHs from the Solanum lycopersicum genome so as to understand the roles of Solanum lycopersicum chlorophyllases (SlCLHs). SlCLH1/4 were the predominantly expressed CLH genes during leaf and fruit development/ripening stages, and SlCLH1 in mature green fruit was modulated by light. SlCLH1/2/3/4 contained a highly conserved GHSXG lipase motif and a Ser-Asp-His catalytic triad. We identified Ser159, Asp226, and His258 as the essential catalytic triad by site-directed mutagenesis in recombinant SlCLH1. Kinetic analysis of the recombinant enzymes revealed that SlCLH1 had high hydrolysis activities against Chl a, Chl b, and pheophytin a (Phein a), but preferred Chl a and Chl b over Phein a; SlCLH2/3 only showed very low activity to Chl a and Chl b, while SlCLH4 showed no Chl dephytylation activity. The recombinant SlCLH1/2/3 had different pH stability and temperature optimum. Removal of the predicted N-terminal processing peptide caused a partial loss of activity in recombinant SlCLH1/2 but did not compromise SlCLH3 activity. These different characteristics among SlCLHs imply that they may have different physiological functions in tomato.


Assuntos
Solanum lycopersicum , Hidrolases de Éster Carboxílico , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas , Cinética , Lipase/metabolismo , Solanum lycopersicum/metabolismo
14.
Int J Mol Sci ; 24(1)2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36613975

RESUMO

The fruit of Litchi chinensis contains high levels of proanthocyanidins (PAs) in the pericarp. These substances can serve as substrates of laccase-mediated rapid pericarp browning after the fruit is harvested. In this study, we found that the major PAs in litchi pericarp were (-)-epicatechin (EC) and several procyanidins (PCs), primarily PC A2, B2, and B1, and the EC and the PC content decreased with the development of the fruit. RNA-seq analysis showed that 43 early and late structure genes related to flavonoid/PA biosynthesis were expressed in the pericarp, including five ANTHOCYANIDIN REDUCTASE (ANR), two LEUCOANTHOCYANIDIN REDUCTASE (LAR), and two ANTHOCYANIDIN SYNTHASE (ANS) genes functioning in the PA biosynthesis branch of the flavonoid pathway. Among these nine PA biosynthesis-related genes, ANR1a, LAR1/2, and ANS1 were highly positively correlated with changes in the EC/PC content, suggesting that they are the key PA biosynthesis-related genes. Several transcription factor (TF) genes, including MYB, bHLH, WRKY, and AP2 family members, were found to be highly correlated with ANR1a, LAR1/2, and ANS1, and their relevant binding elements were detected in the promoters of these target genes, strongly suggesting that these TF genes may play regulatory roles in PA biosynthesis. In summary, this study identified the candidate key structure and regulatory genes in PA biosynthesis in litchi pericarp, which will assist in understanding the accumulation of high levels of browning-related PA substances in the pericarp.


Assuntos
Litchi , Proantocianidinas , Frutas/metabolismo , Proantocianidinas/metabolismo , Litchi/química , Transcriptoma , Flavonoides/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
15.
J Cell Physiol ; 236(6): 4725-4737, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33269476

RESUMO

The differentiation of mature medullary thymic epithelial cells (mTECs) is critical for the induction of central immune tolerance. Although the critical effect of mechanistic target of rapamycin complex 1 (mTORC1) in shaping mTEC differentiation has been studied, the regulatory role of mTORC2 in the differentiation and maturation of mTECs is poorly understood. We herein reported that TEC-specific ablation of a rapamycin-insensitive companion of mTOR (RICTOR), a key component of mTORC2, significantly decreased the thymus size and weight, the total cell number of TECs, and the cell number of mTECs with a smaller degree of reduced cortical thymic epithelial cells. Interestingly, RICTOR deficiency significantly accelerated the mTEC maturation process, as indicated by the increased ratios of mature mTECs (MHCIIhi , CD80+ , and Aire+ ) to immature mTECs (MHCIIlo , CD80- , and Aire- ) in Rictor-deficient mice. The RNA-sequencing assays showed that the upregulated nuclear factor-κB (NF-κB) signaling pathway in Rictor-deficient mTECs was one of the obviously altered pathways compared with wild-type mTECs. Our studies further showed that Rictor-deficient mTECs exhibited upregulated expression of receptor activator of NF-κB (RANK) and lymphotoxin ß receptor (LTßR), as well as increased activity of canonical and noncanonical NF-κB signaling pathways as determined by ImageStream and Simple Western. Finally, our results showed that inhibition of NF-κB signaling pathways could partially reverse the accelerated maturation of mTECs in Rictor conditional KO mice. Thus, mTORC2 negatively controls the kinetics of the mTEC maturation process by inhibiting the LTßR/RANK-NF-κB signal axis.


Assuntos
Diferenciação Celular , Células Epiteliais/enzimologia , Receptor beta de Linfotoxina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , NF-kappa B/metabolismo , Proteína Companheira de mTOR Insensível à Rapamicina/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Timo/enzimologia , Animais , Células Epiteliais/patologia , Regulação da Expressão Gênica , Cinética , Receptor beta de Linfotoxina/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Camundongos Knockout , Proteína Companheira de mTOR Insensível à Rapamicina/genética , Receptor Ativador de Fator Nuclear kappa-B/genética , Transdução de Sinais , Timócitos/enzimologia , Timócitos/patologia , Timo/patologia
16.
Invest New Drugs ; 38(4): 1031-1043, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31758360

RESUMO

Chemotherapy has always been the first therapeutic option for patients with advanced non-small cell lung cancer (NSCLC) with untreatable oncogenic mutations. However, chemotherapy has demonstrated limited success and is associated with severe side effects. This research aimed to investigate the antitumor efficacy and cytotoxic safety of the conjugate ZHER2:V2-pemetrexed, a novel targeted chemotherapeutic drug. In this context, human epidermal growth factor receptor 2 (HER2) + A549 lung xenografts were treated using ZHER2:V2-pemetrexed, pemetrexed or physiological saline. Therapeutic efficacy was monitored by single photon emission computed tomography (SPECT) imaging using the 99mTc-labeled ZHER2:V2-pemetrexed conjugate and further confirmed by performing apoptosis assays using flow cytometry analysis and hematoxylin-eosin (H&E) staining. To evaluate the expression of HER2 in tumor tissues, immunohistochemistry was performed, accompanied by quantitative analysis using flow cytometry. A toxicological evaluation was also conducted. Imaging with 99mTc-ZHER2:V2-pemetrexed demonstrated that in HER2+ A549 models, ZHER2:V2-pemetrexed showed better antineoplastic effects than pemetrexed. Compared with pemetrexed, the results from the pathological and flow cytometry analyses also revealed that ZHER2:V2-pemetrexed exhibits high antitumor activity against A549 tumors, inducing necrosis, apoptosis and cell cycle arrest. In addition, the clinical signs of toxicity in the ZHER2:V2-pemetrexed treated group were reduced compared with those in the pemetrexed treated group. These data revealed that the ZHER2:V2-pemetrexed conjugate encompasses promising targeted antitumor activity against HER2-positive lung adenocarcinoma, with reduced side effects compared with pemetrexed. Thus, the ZHER2:V2-pemetrexed conjugate may serve as a novel molecular agent with tremendous clinical breakthrough potential in the diagnosis and treatment of HER2-positive lung adenocarcinoma.


Assuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Antineoplásicos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Pemetrexede/uso terapêutico , Receptor ErbB-2/genética , Proteínas Recombinantes de Fusão/uso terapêutico , Células A549 , Adenocarcinoma de Pulmão/diagnóstico por imagem , Adenocarcinoma de Pulmão/patologia , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Tomografia Computadorizada de Emissão de Fóton Único , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Eur J Nucl Med Mol Imaging ; 47(5): 1137-1146, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31728587

RESUMO

PURPOSE: To assess the predictive power of pre-therapy 18F-FDG PET/CT-based radiomic features for epidermal growth factor receptor (EGFR) mutation status in non-small cell lung cancer. METHODS: Two hundred and forty-eight lung cancer patients underwent pre-therapy diagnostic 18F-FDG PET/CT scans and were tested for genetic mutations. The LIFEx package was used to extract 47 PET and 45 CT radiomic features reflecting tumor heterogeneity and phenotype. The least absolute shrinkage and selection operator (LASSO) algorithm was used to select radiomic features and develop a radiomics signature. We compared the predictive performance of models established by radiomics signature, clinical variables, and their combinations using receiver operating curves (ROCs). In addition, a nomogram based on the radiomics signature score (rad-score) and clinical variables was developed. RESULTS: The patients were divided into a training set (n = 175) and a validation set (n = 73). Ten radiomic features were selected to build the radiomics signature model. The model showed a significant ability to discriminate between EGFR mutation and EGFR wild type, with area under the ROC curve (AUC) equal to 0.79 in the training set, and 0.85 in the validation set, compared with 0.75 and 0.69 for the clinical model. When clinical variables and radiomics signature were combined, the AUC increased to 0.86 (95% CI [0.80-0.91]) in the training set and 0.87 (95% CI [0.79-0.95]) in the validation set, thus showing better performance in the prediction of EGFR mutations. CONCLUSION: The PET/CT-based radiomic features showed good performance in predicting EGFR mutation in non-small cell lung cancer, providing a useful method for the choice of targeted therapy in a clinical setting.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Fluordesoxiglucose F18 , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/genética , Mutação , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada
18.
Neuroimage ; 199: 454-465, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31200066

RESUMO

For bilinguals, language control is needed for selecting the target language during language production. Numerous studies have examined the neural correlates of language control and shown a close relationship between language control and domain-general cognitive control. However, it remains unknown how these brain regions coordinate with each other when bilinguals exert cognitive control over linguistic and nonlinguistic representations. We addressed this gap using an extended unified structural equation modeling (euSEM) approach. Sixty-five Chinese-English bilinguals performed language switching and nonverbal switching tasks during functional magnetic resonance imaging (fMRI) scanning. The results showed that language control was served by a cooperative brain network, including the frontal lobe, the parietal cortex, subcortical areas, and the cerebellum. More importantly, we found that language control recruited more subcortical areas and connections from frontal to subcortical areas compared with domain-general cognitive control, demonstrating a reconfigurable brain network. In addition, the reconfiguration efficiency of the brain network was mainly determined by general cognitive ability but was also mediated by second language (L2) proficiency. These findings provide the first data-driven connectivity model that specifies the brain network for language control in bilinguals and also shed light on the relationship between language control and domain-general cognitive control.


Assuntos
Encéfalo/fisiologia , Conectoma/métodos , Função Executiva/fisiologia , Multilinguismo , Rede Nervosa/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Psicolinguística , Adulto Jovem
19.
BMC Plant Biol ; 19(1): 315, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307378

RESUMO

BACKGROUND: Abaxially anthocyanic leaves of deeply-shaded understorey plants play important ecological significance for the environmental adaption. In contrast to the transient pigmentation in other plants, anthocyanins are permanently presented in these abaxially red leaves, however, the mechanism for the pigment maintenance remains unclear. In the present study, we investigated phenolic metabolites that may affect pigment stability and degradation in Excoecaria cochinchinensis (a bush of permanently abaxial-red leaves), via a comparison with Osmanthus fragrans (a bush of transiently red leaves). RESULTS: High levels of galloylated anthocyanins were identified in the Excoecaria but not in the Osmanthus plants. The galloylated anthocyanin showed slightly higher stability than two non-galloylated anthocyanins, while all the 3 pigments were rapidly degraded by peroxidase (POD) in vitro. High levels of hydrolysable tannins [mainly galloylglucoses/ellagitannins (GGs/ETs)] were identified in Excoecaria but none in Osmanthus. GGs/ETs showed inhibition effect on POD, with IC50 ranged from 35.55 to 83.27 µM, correlated to the markedly lower POD activities detected in Excoecaria than in Osmanthus. Strong copigmentation was observed for GGs/ETs and anthocyanins, with more than 30% increase in the red intensity of non-galloylated anthocyanin solutions. In the leaf tissue, the hydrolysable tannins were observed to be co-localized with anthocyanins at the abaxial layer of the Excoecaria leaves, correlated to the low POD activity, more acidity and increased red intensity of the tissue. CONCLUSION: The results suggest that the Excoecaria leaves accumulate a distinct group of phenolic metabolites, mainly GGs/ETs, at the abaxial layer, which prevent anthocyanin degradation and increase the pigment stability, and consequently lead to the permanent maintenance of the red leaves.


Assuntos
Antocianinas/metabolismo , Euphorbiaceae/metabolismo , Taninos Hidrolisáveis/metabolismo , Peroxidase/antagonistas & inibidores , Pigmentação , Folhas de Planta/metabolismo , Euphorbiaceae/enzimologia , Oleaceae/metabolismo , Peroxidase/metabolismo , Folhas de Planta/crescimento & desenvolvimento
20.
Int J Mol Sci ; 20(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901821

RESUMO

Brunfelsia calycina flowers lose anthocyanins rapidly and are therefore well suited for the study of anthocyanin degradation mechanisms, which are unclear in planta. Here, we isolated an anthocyanin-ß-glycosidase from B. calycina petals. The MS/MS (Mass Spectrometry) peptide sequencing showed that the enzyme (72 kDa) was a ß-xylosidase (BcXyl). The enzyme showed high activity to p-Nitrophenyl-ß-d-galactopyranoside (pNPGa) and p-Nitrophenyl-ß-d-xylopyranoside (pNPX), while no activity to p-Nitrophenyl-ß-d-glucopyranoside (pNPG) or p-Nitrophenyl-ß-D-mannopyranoside (pNPM) was seen. The optimum temperature of BcXyl was 40 °C and the optimum pH was 5.0. The enzyme was strongly inhibited by 1 mM D-gluconate and Ag⁺. HPLC (High Performance Liquid Chromatography) analysis showed that BcXyl catalyzed the degradation of an anthocyanin component of B. calycina, and the release of xylose and galactose due to hydrolysis of glycosidic bonds by BcXyl was detected by GC (Gas Chromatography) /MS. A full-length mRNA sequence (2358 bp) of BcXyl (NCBI No. MK411219) was obtained and the deduced protein sequence shared conserved domains with two anthocyanin-ß-glycosidases (Bgln and BadGluc, characterized in fungi). BcXyl, Bgln and BadGluc belong to AB subfamily of Glycoside hydrolase family 3. Similar to BcPrx01, an anthocyanin-degradation-related Peroxidase (POD), BcXyl was dramatically activated at the stage at which the rapid anthocyanin degradation occurred. Taken together, we suggest that BcXyl may be the first anthocyanin-ß-glycosidase identified in higher plants.


Assuntos
Antocianinas/metabolismo , Flores/enzimologia , Glicosídeo Hidrolases/metabolismo , Solanaceae/enzimologia , Xilosidases/isolamento & purificação , Xilosidases/metabolismo , Sequência de Aminoácidos , Ativação Enzimática , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica de Plantas , Glicosídeo Hidrolases/química , Filogenia , Desenvolvimento Vegetal/genética , Solanaceae/classificação , Solanaceae/genética , Xilosidases/química
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