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1.
Cell ; 167(6): 1650-1662.e15, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27912066

RESUMO

Electrophysiological field potential dynamics are of fundamental interest in basic and clinical neuroscience, but how specific cell types shape these dynamics in the live brain is poorly understood. To empower mechanistic studies, we created an optical technique, TEMPO, that records the aggregate trans-membrane voltage dynamics of genetically specified neurons in freely behaving mice. TEMPO has >10-fold greater sensitivity than prior fiber-optic techniques and attains the noise minimum set by quantum mechanical photon shot noise. After validating TEMPO's capacity to track established oscillations in the delta, theta, and gamma frequency bands, we compared the D1- and D2-dopamine-receptor-expressing striatal medium spiny neurons (MSNs), which are interspersed and electrically indistinguishable. Unexpectedly, MSN population dynamics exhibited two distinct coherent states that were commonly indiscernible in electrical recordings and involved synchronized hyperpolarizations across both MSN subtypes. Overall, TEMPO allows the deconstruction of normal and pathologic neurophysiological states into trans-membrane voltage activity patterns of specific cell types.


Assuntos
Ondas Encefálicas , Camundongos/fisiologia , Neurofisiologia/métodos , Imagens com Corantes Sensíveis à Voltagem/métodos , Animais , Feminino , Masculino , Camundongos Endogâmicos BALB C
2.
Nature ; 605(7911): 713-721, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35589841

RESUMO

Reliable sensory discrimination must arise from high-fidelity neural representations and communication between brain areas. However, how neocortical sensory processing overcomes the substantial variability of neuronal sensory responses remains undetermined1-6. Here we imaged neuronal activity in eight neocortical areas concurrently and over five days in mice performing a visual discrimination task, yielding longitudinal recordings of more than 21,000 neurons. Analyses revealed a sequence of events across the neocortex starting from a resting state, to early stages of perception, and through the formation of a task response. At rest, the neocortex had one pattern of functional connections, identified through sets of areas that shared activity cofluctuations7,8. Within about 200 ms after the onset of the sensory stimulus, such connections rearranged, with different areas sharing cofluctuations and task-related information. During this short-lived state (approximately 300 ms duration), both inter-area sensory data transmission and the redundancy of sensory encoding peaked, reflecting a transient increase in correlated fluctuations among task-related neurons. By around 0.5 s after stimulus onset, the visual representation reached a more stable form, the structure of which was robust to the prominent, day-to-day variations in the responses of individual cells. About 1 s into stimulus presentation, a global fluctuation mode conveyed the upcoming response of the mouse to every area examined and was orthogonal to modes carrying sensory data. Overall, the neocortex supports sensory performance through brief elevations in sensory coding redundancy near the start of perception, neural population codes that are robust to cellular variability, and widespread inter-area fluctuation modes that transmit sensory data and task responses in non-interfering channels.


Assuntos
Neocórtex , Percepção Visual , Animais , Discriminação Psicológica/fisiologia , Camundongos , Neocórtex/fisiologia , Neurônios/fisiologia , Reprodutibilidade dos Testes , Percepção Visual/fisiologia
3.
EMBO J ; 42(19): e113328, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37641865

RESUMO

Eukaryotic organisms adapt to environmental fluctuations by altering their epigenomic landscapes and transcriptional programs. Nucleosomal histones carry vital epigenetic information and regulate gene expression, yet the mechanisms underlying chromatin-bound histone exchange remain elusive. Here, we found that histone H2Bs are globally degraded in Caenorhabditis elegans during starvation. Our genetic screens identified mutations in ubiquitin and ubiquitin-related enzymes that block H2B degradation in starved animals, identifying lysine 31 as the crucial residue for chromatin-bound H2B ubiquitination and elimination. Retention of aberrant nucleosomal H2B increased the association of the FOXO transcription factor DAF-16 with chromatin, generating an ectopic gene expression profile detrimental to animal viability when insulin/IGF signaling was reduced in well-fed animals. Furthermore, we show that the ubiquitin-proteasome system regulates chromosomal histone turnover in human cells. During larval development, C. elegans epidermal cells undergo H2B turnover after fusing with the epithelial syncytium. Thus, histone degradation may be a widespread mechanism governing dynamic changes of the epigenome.


Assuntos
Caenorhabditis elegans , Histonas , Animais , Humanos , Histonas/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Insulina/metabolismo , Cromatina , Ubiquitinação , Ubiquitina/metabolismo
4.
PLoS Pathog ; 20(2): e1011928, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38324558

RESUMO

The subgroup J avian leukosis virus (ALV-J), a retrovirus, uses its gp85 protein to bind to the receptor, the chicken sodium hydrogen exchanger isoform 1 (chNHE1), facilitating viral invasion. ALV-J is the main epidemic subgroup and shows noteworthy mutations within the receptor-binding domain (RBD) region of gp85, especially in ALV-J layer strains in China. However, the implications of these mutations on viral replication and transmission remain elusive. In this study, the ALV-J layer strain JL08CH3-1 exhibited a more robust replication ability than the prototype strain HPRS103, which is related to variations in the gp85 protein. Notably, the gp85 of JL08CH3-1 demonstrated a heightened binding capacity to chNHE1 compared to HPRS103-gp85 binding. Furthermore, we showed that the specific N123I mutation within gp85 contributed to the enhanced binding capacity of the gp85 protein to chNHE1. Structural analysis indicated that the N123I mutation primarily enhanced the stability of gp85, expanded the interaction interface, and increased the number of hydrogen bonds at the interaction interface to increase the binding capacity between gp85 and chNHE1. We found that the N123I mutation not only improved the viral replication ability of ALV-J but also promoted viral shedding in vivo. These comprehensive data underscore the notion that the N123I mutation increases receptor binding and intensifies viral replication.


Assuntos
Vírus da Leucose Aviária , Leucose Aviária , Doenças das Aves Domésticas , Animais , Vírus da Leucose Aviária/genética , Vírus da Leucose Aviária/química , Mutação , Galinhas , Isoformas de Proteínas/genética , Proteínas do Envelope Viral/genética
5.
Nature ; 580(7801): 100-105, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238928

RESUMO

How the brain processes information accurately despite stochastic neural activity is a longstanding question1. For instance, perception is fundamentally limited by the information that the brain can extract from the noisy dynamics of sensory neurons. Seminal experiments2,3 suggest that correlated noise in sensory cortical neural ensembles is what limits their coding accuracy4-6, although how correlated noise affects neural codes remains debated7-11. Recent theoretical work proposes that how a neural ensemble's sensory tuning properties relate statistically to its correlated noise patterns is a greater determinant of coding accuracy than is absolute noise strength12-14. However, without simultaneous recordings from thousands of cortical neurons with shared sensory inputs, it is unknown whether correlated noise limits coding fidelity. Here we present a 16-beam, two-photon microscope to monitor activity across the mouse primary visual cortex, along with analyses to quantify the information conveyed by large neural ensembles. We found that, in the visual cortex, correlated noise constrained signalling for ensembles with 800-1,300 neurons. Several noise components of the ensemble dynamics grew proportionally to the ensemble size and the encoded visual signals, revealing the predicted information-limiting correlations12-14. Notably, visual signals were perpendicular to the largest noise mode, which therefore did not limit coding fidelity. The information-limiting noise modes were approximately ten times smaller and concordant with mouse visual acuity15. Therefore, cortical design principles appear to enhance coding accuracy by restricting around 90% of noise fluctuations to modes that do not limit signalling fidelity, whereas much weaker correlated noise modes inherently bound sensory discrimination.


Assuntos
Células Receptoras Sensoriais/fisiologia , Acuidade Visual/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Feminino , Masculino , Camundongos , Estimulação Luminosa , Processos Estocásticos
6.
J Virol ; 98(5): e0018124, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38639485

RESUMO

Infectious bursal disease (IBD) is an acute and fatal immunosuppressive disease caused by infectious bursal disease virus (IBDV). As an obligate intracellular parasite, IBDV infection is strictly regulated by host factors. Knowledge on the antiviral activity and possible mechanism of host factors might provide the theoretical basis for the prevention and control of IBD. In this study, RNA-sequencing results indicated that many host factors were induced by IBDV infection, among which the expression levels of OASL (2´,5´-oligadenylate synthetase-like protein) was significantly upregulated. OASL overexpression significantly inhibited IBDV replication, whereas OASL knockdown promoted IBDV replication. Interestingly, the antiviral ability of OASL was independent of its canonical enzymatic activity, i.e., OASL targeted viral protein VP2 for degradation, depending on the autophagy receptor p62/SQSTM1 in the autophagy pathway. Additionally, the 316 lysine (K) of VP2 was the key site for autophagy degradation, and its replacement with arginine disrupted VP2 degradation induced by OASL and enhanced IBDV replication. Importantly, our results for the first time indicate a unique and potent defense mechanism of OASL against double-stranded RNA virus by interaction with viral proteins, which leads to their degradation. IMPORTANCE: OASL (2´,5´-oligadenylate synthetase-like protein) exhibits broad-spectrum antiviral effects against single-stranded RNA viruses in mammals, potentially serving as a promising target for novel antiviral strategies. However, its role in inhibiting the replication of double-stranded RNA viruses (dsRNA viruses), such as infectious bursal disease virus (IBDV), in avian species remains unclear. Our findings indicated a unique and potent defense mechanism of OASL against dsRNA viruses. It has been previously shown in mammals that OASL inhibits virus replication through increasing interferon production. The groundbreaking aspect of our study is the finding that OASL has the ability to interact with IBDV viral protein VP2 and target it for degradation and thus exerts its antiviral effect. Our results reveal the interaction between avian natural antiviral immune response and IBDV infection. Our study not only enhances our understanding of bird defenses against viral infections but can also inform strategies for poultry disease management.


Assuntos
2',5'-Oligoadenilato Sintetase , Autofagia , Infecções por Birnaviridae , Galinhas , Vírus da Doença Infecciosa da Bursa , Proteínas Estruturais Virais , Replicação Viral , Vírus da Doença Infecciosa da Bursa/fisiologia , Animais , Infecções por Birnaviridae/virologia , Infecções por Birnaviridae/metabolismo , Proteínas Estruturais Virais/metabolismo , Proteínas Estruturais Virais/genética , 2',5'-Oligoadenilato Sintetase/metabolismo , 2',5'-Oligoadenilato Sintetase/genética , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/metabolismo , Interações Hospedeiro-Patógeno , Células HEK293 , Humanos , Linhagem Celular
7.
J Biol Chem ; 299(7): 104908, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37307919

RESUMO

Whereas it is known that p53 broadly regulates cell metabolism, the specific activities that mediate this regulation remain partially understood. Here, we identified carnitine o-octanoyltransferase (CROT) as a p53 transactivation target that is upregulated by cellular stresses in a p53-dependent manner. CROT is a peroxisomal enzyme catalyzing very long-chain fatty acids conversion to medium chain fatty acids that can be absorbed by mitochondria during ß-oxidation. p53 induces CROT transcription through binding to consensus response elements in the 5'-UTR of CROT mRNA. Overexpression of WT but not enzymatically inactive mutant CROT promotes mitochondrial oxidative respiration, while downregulation of CROT inhibits mitochondrial oxidative respiration. Nutrient depletion induces p53-dependent CROT expression that facilitates cell growth and survival; in contrast, cells deficient in CROT have blunted cell growth and reduced survival during nutrient depletion. Together, these data are consistent with a model where p53-regulated CROT expression allows cells to be more efficiently utilizing stored very long-chain fatty acids to survive nutrient depletion stresses.


Assuntos
Carnitina Aciltransferases , Sobrevivência Celular , Nutrientes , Proteína Supressora de Tumor p53 , Regiões 5' não Traduzidas/genética , Carnitina/metabolismo , Carnitina Aciltransferases/genética , Carnitina Aciltransferases/metabolismo , Processos de Crescimento Celular , Respiração Celular , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Mitocôndrias/metabolismo , Mutação , Nutrientes/deficiência , Nutrientes/metabolismo , Oxirredução , Peroxissomos/enzimologia , Elementos de Resposta/genética , Estresse Fisiológico , Ativação Transcricional , Proteína Supressora de Tumor p53/metabolismo
8.
J Biol Chem ; 299(3): 102962, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36717079

RESUMO

Subgroup K avian leukosis virus (ALV-K) is a novel subgroup of ALV isolated from Chinese native chickens. As for a retrovirus, the interaction between its envelope protein and cellular receptor is a crucial step in ALV-K infection. Tva, a protein previously determined to be associated with vitamin B12/cobalamin uptake, has been identified as the receptor of ALV-K. However, the molecular mechanism underlying the interaction between Tva and the envelope protein of ALV-K remains unclear. In this study, we identified the C-terminal loop of the LDL-A module of Tva as the minimal functional domain that directly interacts with gp85, the surface component of the ALV-K envelope protein. Further point-mutation analysis revealed that E53, L55, H59, and G70, which are exposed on the surface of Tva and are spatially adjacent, are key residues for the binding of Tva and gp85 and facilitate the entry of ALV-K. Homology modeling analysis indicated that the substitution of these four residues did not significantly impact the Tva structure but impaired the interaction between Tva and gp85 of ALV-K. Importantly, the gene-edited DF-1 cell line with precisely substituted E53, L55, H59, and G70 was completely resistant to ALV-K infection and did not affect vitamin B12/cobalamin uptake. Collectively, these findings not only contribute to a better understanding of the mechanism of ALV-K entry into host cells but also provide an ideal gene-editing target for antiviral study.


Assuntos
Vírus da Leucose Aviária , Doenças das Aves Domésticas , Receptores Virais , Vitamina B 12 , Animais , Vírus da Leucose Aviária/genética , Galinhas/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores Virais/metabolismo , Proteínas do Envelope Viral/metabolismo , Complexo Vitamínico B , Vitamina B 12/metabolismo
9.
J Biol Chem ; 299(1): 102739, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36435197

RESUMO

Recent discovery of the ribosomal protein (RP) RPL11 interacting with and inhibiting the E3 ubiquitin ligase function of MDM2 established the RP-MDM2-p53 signaling pathway, which is linked to biological events, including ribosomal biogenesis, nutrient availability, and metabolic homeostasis. Mutations in RPs lead to a diverse array of phenotypes known as ribosomopathies in which the role of p53 is implicated. Here, we generated conditional RPL11-deletion mice to investigate in vivo effects of impaired RP expression and its functional connection with p53. While deletion of one Rpl11 allele in germ cells results in embryonic lethality, deletion of one Rpl11 allele in adult mice does not affect viability but leads to acute anemia. Mechanistically, we found RPL11 haploinsufficiency activates p53 in hematopoietic tissues and impedes erythroid precursor differentiation, resulting in insufficient red blood cell development. We demonstrated that reducing p53 dosage by deleting one p53 allele rescues RPL11 haploinsufficiency-induced inhibition of erythropoietic precursor differentiation and restores normal red blood cell levels in mice. Furthermore, blocking the RP-MDM2-p53 pathway by introducing an RP-binding mutation in MDM2 prevents RPL11 haploinsufficiency-caused p53 activation and rescues the anemia in mice. Together, these findings demonstrate that the RP-MDM2-p53 pathway is a critical checkpoint for RP homeostasis and that p53-dependent cell cycle arrest of erythroid precursors is the molecular basis for the anemia phenotype commonly associated with RP deficiency.


Assuntos
Anemia , Proteína Supressora de Tumor p53 , Animais , Camundongos , Anemia/genética , Haploinsuficiência , Mutação , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
10.
Nat Methods ; 18(8): 893-902, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312566

RESUMO

Complex biological processes such as embryogenesis require precise coordination of cell differentiation programs across both space and time. Using protein-fusion fluorescent reporters and four-dimensional live imaging, we present a protein expression atlas of transcription factors (TFs) mapped onto developmental cell lineages during Caenorhabditis elegans embryogenesis, at single-cell resolution. This atlas reveals a spatiotemporal combinatorial code of TF expression, and a cascade of lineage-specific, tissue-specific and time-specific TFs that specify developmental states. The atlas uncovers regulators of embryogenesis, including an unexpected role of a skin specifier in neurogenesis and the critical function of an uncharacterized TF in convergent muscle differentiation. At the systems level, the atlas provides an opportunity to model cell state-fate relationships, revealing a lineage-dependent state diversity within functionally related cells and a winding trajectory of developmental state progression. Collectively, this single-cell protein atlas represents a valuable resource for elucidating metazoan embryogenesis at the molecular and systems levels.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Análise de Célula Única/métodos , Análise Espaço-Temporal , Fatores de Transcrição/metabolismo , Animais , Caenorhabditis elegans/embriologia , Diferenciação Celular , Linhagem da Célula
11.
J Virol ; 97(1): e0178522, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36511697

RESUMO

Type I interferon (IFN) response is the first line of host-based innate immune defense against viral infections. However, viruses have developed multiple strategies to counter host IFN responses, so they may continue infecting hosts via effective replication. Avian reovirus (ARV), an RNA virus, causes viral arthritis or tenosynovitis in chickens. Previous studies have shown that ARV is highly resistant to the antiviral effects of IFN. However, the underlying mechanisms that enable ARV to block the IFN pathway remain unclear. In this study, we found that ectopic expression of ARV protein, σA, significantly inhibited the production of IFN-ß induced by melanoma-differentiation-associated gene 5 (MDA5) and poly(I·C). Knockdown of σA during ARV infection enhances the IFN-ß response and suppresses viral replication. ARV σA inhibited the MDA5-mediated IFN-ß activation by targeting interferon regulatory factor 7 (IRF7). Further studies demonstrated that σA interacts with IRF7, thereby blocking IRF7 dimerization and nuclear translocation, finally leading to the inhibition of IFN-ß production. These findings reveal a novel mechanism that allows ARV to evade host antiviral immunity. IMPORTANCE ARV, the causative agent of viral arthritis or tenosynovitis in chickens, has a significant economic impact as it results in poor weight gain and increased feed conversion ratios. The MDA5-mediated IFN-ß signal pathway plays an important role in host antiviral defense. Therefore, RNA viruses have developed mechanisms to counter this signaling pathway and successfully establish infection. However, the strategies adopted by ARV to block MDA5-IRF7 signaling remain unclear. In the current study, we demonstrated that ARV σA inhibits this pathway by binding to IRF7, which blocked IRF7 dimerization and nuclear translocation. Our findings may provide insights into how avian reovirus counteracts the innate antiviral immunity of the host to ensure viral replication.


Assuntos
Fator Regulador 7 de Interferon , Interferon Tipo I , Orthoreovirus Aviário , Tenossinovite , Proteínas do Core Viral , Animais , Linhagem Celular , Galinhas/virologia , Interações Hospedeiro-Patógeno , Imunidade Inata , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/metabolismo , Interferon Tipo I/metabolismo , Orthoreovirus Aviário/fisiologia , Tenossinovite/veterinária , Tenossinovite/virologia , Proteínas do Core Viral/metabolismo , Proteínas de Ligação a RNA/metabolismo
12.
Virol J ; 21(1): 109, 2024 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734674

RESUMO

BACKGROUND: Syndrome coronavirus-2 (SARS-CoV-2) has developed various strategies to evade the antiviral impact of type I IFN. Non-structural proteins and auxiliary proteins have been extensively researched on their role in immune escape. Nevertheless, the detailed mechanisms of structural protein-induced immune evasion have not been well elucidated. METHODS: Human alveolar basal epithelial carcinoma cell line (A549) was stimulated with polyinosinic-polycytidylic acid (PIC) and independently transfected with four structural proteins expression plasmids, including nucleocapsid (N), spike (S), membrane (M) and envelope (E) proteins. By RT-qPCR and ELISA, the structural protein with the most pronounced inhibitory effects on IFN-ß induction was screened. RNA-sequencing (RNA-Seq) and two differential analysis strategies were used to obtain differentially expressed genes associated with N protein inhibition of IFN-ß induction. Based on DIANA-LncBase and StarBase databases, the interactive competitive endogenous RNA (ceRNA) network for N protein-associated genes was constructed. By combining single-cell sequencing data (GSE158055), lncRNA-miRNA-mRNA axis was further determined. Finally, RT-qPCR was utilized to illustrate the regulatory functions among components of the ceRNA axis. RESULTS: SARS-CoV-2 N protein inhibited IFN-ß induction in human alveolar epithelial cells most significantly compared with other structural proteins. RNA-Seq data analysis revealed genes related to N protein inhibiting IFNs induction. The obtained 858 differentially expressed genes formed the reliable ceRNA network. The function of LINC01002-miR-4324-FRMD8 axis in the IFN-dominated immune evasion was further demonstrated through integrating single-cell sequencing data. Moreover, we validated that N protein could reverse the effect of PIC on LINC01002, FRMD8 and miR-4324 expression, and subsequently on IFN-ß expression level. And LINC01002 could regulate the production of FRMD8 by inhibiting miR-4324. CONCLUSION: SARS-CoV-2 N protein suppressed the induction of IFN-ß by regulating LINC01002 which was as a ceRNA, sponging miR-4324 and participating in the regulation of FRMD8 mRNA. Our discovery provides new insights into early intervention therapy and drug development on SARS-CoV-2 infection.


Assuntos
COVID-19 , MicroRNAs , RNA Longo não Codificante , SARS-CoV-2 , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , COVID-19/virologia , COVID-19/imunologia , SARS-CoV-2/genética , Células A549 , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Interferon beta/genética , Interferon beta/metabolismo , Evasão da Resposta Imune , Proteínas do Nucleocapsídeo de Coronavírus/genética , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , RNA Endógeno Competitivo , Fosfoproteínas
13.
Arch Microbiol ; 206(4): 178, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498224

RESUMO

Deoxynivalenol (DON) poses significant challenges due to its frequent contamination of grains and associated products. Microbial strategies for mitigating DON toxicity showed application potential. Eight bacterial isolates with DON degradation activity over 5% were obtained from various samples of organic fertilizer in this study. One of the isolates emerged as a standout, demonstrating a substantial degradation capability, achieving a 99.21% reduction in DON levels. This isolate, underwent thorough morphological, biochemical, and molecular characterization to confirm its identity, and was identified as a new strain of Achromobacter spanius P-9. Subsequent evaluations revealed that the strain P-9 retains its degradation activity after a 24-h incubation, reaching optimal performance at 35 °C with a pH of 8.0. Further studies indicated that Ca2+ ions enhance the degradation process, whereas Zn2+ ions exert an inhibitory effect. This is the pioneering report of DON degradation by Achromobacter spanius, illuminating its prospective utility in addressing DON contamination challenges.


Assuntos
Achromobacter , Tricotecenos , Achromobacter/genética , Achromobacter/metabolismo , Íons
14.
J Org Chem ; 89(12): 8363-8375, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38848119

RESUMO

Palladium-catalyzed decarboxylation of 5-methylene-1,3-oxazinan-2-ones and 5-methylene-1,3-dioxan-2-ones to generate aza-π-allylpalladium and oxa-π-allylpalladium 1,4-dipoles for [4 + 2] cycloaddition reaction with 1,3,5-triazinanes was developed, affording a wide range of hexahydropyrimidine and 1,3-oxazinane derivatives in good to excellent yields (up to 99%). The acyclic sulfonamido-substituted allylic carbonates as aza-π-allylpalladium 1,4-dipole precursors also apply to the developed synthesized strategy, achieving the synthesis of hexahydropyrimidines. Moreover, the in situ-generated aza-π-allylpalladium 1,4-dipoles undergoing dimeric [4 + 4] cycloaddition were also demonstrated by the construction of 1,5-diazocane derivatives.

15.
Physiol Plant ; 176(2): e14248, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38488424

RESUMO

The Chinese tallow tree (Triadica sebifera) is an economically important plant on account of its ornamental value and oil-producing seeds. Leaf colour is a key characteristic of T. sebifera, with yellow-, red- and purple-leaved varieties providing visually impressive displays during autumn. In this study, we performed metabolomic and transcriptomic analyses to gain a better understanding of the mechanisms underlying leaf colour development in purple-leaved T. sebifera at three stages during the autumnal colour transition, namely, green, hemi-purple, and purple leaves. We accordingly detected 370 flavonoid metabolites and 10 anthocyanins, among the latter of which, cyanidin-3-xyloside and peonidin-3-O-glucoside were identified as the predominant compounds in hemi-purple and purple leaves. Transcriptomic analysis revealed that structural genes associated with the anthocyanin biosynthetic pathway, chlorophyll synthesis pathway and carotenoid synthesis pathway were significantly differential expressed at the three assessed colour stages. Additionally, transcription factors associated with the MYB-bHLH-WD40 complex, including 22 R2R3-MYBs, 79 bHLHs and 44 WD40 genes, were identified as candidate regulators of the anthocyanin biosynthetic pathway. Moreover, on the basis of the identified differentially accumulated anthocyanins and key genes, we generated genetic and metabolic regulatory networks for anthocyanin biosynthesis in T. sebifera. These findings provide comprehensive information on the leaf transcriptome and three pigments of T. sebifera, thereby shedding new light on the mechanisms underlying the autumnal colouring of the leaves of this tree.


Assuntos
Antocianinas , Euphorbiaceae , Transcriptoma , Antocianinas/metabolismo , Clorofila , Perfilação da Expressão Gênica , Metaboloma , Carotenoides/metabolismo , Regulação da Expressão Gênica de Plantas , Cor
16.
BMC Gastroenterol ; 24(1): 124, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566038

RESUMO

BACKGROUND: Proper sedation of patients, particularly elderly individuals, who are more susceptible to sedation-related complications, is of significant importance in endoscopic retrograde cholangiopancreatography (ERCP). This study aims to assess the safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation in elderly patients undergoing ERCP, compared to a group of middle-aged patients. METHODS: The medical records of 610 patients with common bile duct stones who underwent elective ERCP under deep sedation with a three-drug regimen, including midazolam, alfentanil, and propofol at Shandong Provincial Third Hospital from January 2023 to September 2023 were retrospectively reviewed in this study. Patients were categorized into three groups: middle-aged (50-64 years, n = 202), elderly (65-79 years, n = 216), and very elderly (≥ 80 years, n = 192). Intraoperative vital signs and complications were compared among these groups. RESULTS: The three groups showed no significant difference in terms of intraoperative variation of systolic blood pressure (P = 0.291), diastolic blood pressure (P = 0.737), heart rate (P = 0.107), peripheral oxygen saturation (P = 0.188), bispectral index (P = 0.158), and the occurrence of sedation-related adverse events including hypotension (P = 0.170) and hypoxemia (P = 0.423). CONCLUSION: The results suggest that a low-dose three-drug regimen consisting of midazolam, alfentanil, and propofol seems safe and effective for deep sedation of elderly and very elderly patients undergoing ERCP procedures. However, further studies are required to verify these findings and clarify the benefits and risks of this method.


Assuntos
Sedação Profunda , Propofol , Idoso , Pessoa de Meia-Idade , Humanos , Propofol/efeitos adversos , Midazolam/efeitos adversos , Alfentanil/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Hipnóticos e Sedativos/efeitos adversos , Sedação Profunda/efeitos adversos , Sedação Profunda/métodos , Estudos Retrospectivos , Sedação Consciente/efeitos adversos , Sedação Consciente/métodos
17.
Headache ; 64(2): 195-210, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38288634

RESUMO

OBJECTIVE: To characterize the circadian features of the trigeminal ganglion in a mouse model of headache. BACKGROUND: Several headache disorders, such as migraine and cluster headache, are known to exhibit distinct circadian rhythms of attacks. The circadian basis for these rhythmic pain responses, however, remains poorly understood. METHODS: We examined trigeminal ganglion ex vivo and single-cell cultures from Per2::LucSV reporter mice and performed immunohistochemistry. Circadian behavior and transcriptomics were investigated using a novel combination of trigeminovascular and circadian models: a nitroglycerin mouse headache model with mechanical thresholds measured every 6 h, and trigeminal ganglion RNA sequencing measured every 4 h for 24 h. Finally, we performed pharmacogenomic analysis of gene targets for migraine, cluster headache, and trigeminal neuralgia treatments as well as trigeminal ganglion neuropeptides; this information was cross-referenced with our cycling genes from RNA sequencing data to identify potential targets for chronotherapy. RESULTS: The trigeminal ganglion demonstrates strong circadian rhythms in both ex vivo and single-cell cultures, with core circadian proteins found in both neuronal and non-neuronal cells. Using our novel behavioral model, we showed that nitroglycerin-treated mice display circadian rhythms of pain sensitivity which were abolished in arrhythmic Per1/2 double knockout mice. Furthermore, RNA-sequencing analysis of the trigeminal ganglion revealed 466 genes that displayed circadian oscillations in the control group, including core clock genes and clock-regulated pain neurotransmitters. In the nitroglycerin group, we observed a profound circadian reprogramming of gene expression, as 331 of circadian genes in the control group lost rhythm and another 584 genes gained rhythm. Finally, pharmacogenetics analysis identified 10 genes in our trigeminal ganglion circadian transcriptome that encode target proteins of current medications used to treat migraine, cluster headache, or trigeminal neuralgia. CONCLUSION: Our study unveiled robust circadian rhythms in the trigeminal ganglion at the behavioral, transcriptomic, and pharmacogenetic levels. These results support a fundamental role of the clock in pain pathophysiology. PLAIN LANGUAGE SUMMARY: Several headache diseases, such as migraine and cluster headache, have headaches that occur at the same time each day. We learned that the trigeminal ganglion, an important pain structure in several headache diseases, has a 24-hour cycle that might be related to this daily cycle of headaches. Our genetic analysis suggests that some medications may be more effective in treating migraine and cluster headache when taken at specific times of the day.


Assuntos
Cefaleia Histamínica , Transtornos de Enxaqueca , Neuralgia do Trigêmeo , Camundongos , Animais , Gânglio Trigeminal , Transcriptoma , Neuralgia do Trigêmeo/genética , Nitroglicerina , Cefaleia , Perfilação da Expressão Gênica , Dor , Ritmo Circadiano/genética , Camundongos Knockout
18.
Bioorg Chem ; 144: 107115, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38232684

RESUMO

Ferroptosis is an iron-dependent form of oxidative cell death induced by lipid peroxidation accumulation. Glutathione peroxidase 4 (GPX4) plays a key role in the regulation of ferroptosis and is considered to be a promising therapeutic target for cancer and other human diseases. Herein, we describe our design, synthesis, and biological evaluation of a series of HyT-based degraders of the GPX4. One of the most promising compounds, 7b (ZX782), effectively induces dose- and time-dependent degradation of GPX4 protein and potently suppresses the growth of human fibrosarcoma HT1080 cells, which are highly sensitive to ferroptosis and widely used for evaluating compound specificity in ferroptosis. Mechanism investigation indicated that 7b depletes GPX4 through both the ubiquitin-proteasome and the autophagy-lysosome. Furthermore, the degradation of GPX4 induced by 7b could significantly increase the accumulation of lipid reactive oxygen species (ROS) in HT1080 cells, ultimately leading to ferroptosis. Overall, compound 7b exhibits robust potency in depleting endogenous GPX4, thereby modulating ferroptosis in cancer cells.


Assuntos
Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Humanos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Glutationa Peroxidase/metabolismo , Morte Celular , Peroxidação de Lipídeos , Oxirredução
19.
Nature ; 557(7704): 177-182, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29720658

RESUMO

Loss of dopamine in Parkinson's disease is hypothesized to impede movement by inducing hypo- and hyperactivity in striatal spiny projection neurons (SPNs) of the direct (dSPNs) and indirect (iSPNs) pathways in the basal ganglia, respectively. The opposite imbalance might underlie hyperkinetic abnormalities, such as dyskinesia caused by treatment of Parkinson's disease with the dopamine precursor L-DOPA. Here we monitored thousands of SPNs in behaving mice, before and after dopamine depletion and during L-DOPA-induced dyskinesia. Normally, intermingled clusters of dSPNs and iSPNs coactivated before movement. Dopamine depletion unbalanced SPN activity rates and disrupted the movement-encoding iSPN clusters. Matching their clinical efficacy, L-DOPA or agonism of the D2 dopamine receptor reversed these abnormalities more effectively than agonism of the D1 dopamine receptor. The opposite pathophysiology arose in L-DOPA-induced dyskinesia, during which iSPNs showed hypoactivity and dSPNs showed unclustered hyperactivity. Therefore, both the spatiotemporal profiles and rates of SPN activity appear crucial to striatal function, and next-generation treatments for basal ganglia disorders should target both facets of striatal activity.


Assuntos
Dopamina/metabolismo , Discinesias/patologia , Discinesias/fisiopatologia , Neurônios/metabolismo , Transtornos Parkinsonianos/patologia , Transtornos Parkinsonianos/fisiopatologia , Animais , Sinalização do Cálcio , Dopamina/deficiência , Discinesias/etiologia , Discinesias/metabolismo , Feminino , Levodopa/metabolismo , Levodopa/farmacologia , Masculino , Camundongos , Modelos Biológicos , Movimento/efeitos dos fármacos , Neostriado/metabolismo , Neostriado/patologia , Neostriado/fisiopatologia , Transtornos Parkinsonianos/metabolismo , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/metabolismo
20.
Environ Res ; 256: 119268, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38815721

RESUMO

In this study, electrochemistry was used to enhance the advanced oxidation of Fe(Ⅱ)/PAA (EC/Fe(Ⅱ)/PAA) to disintegrate waste activated sludge, and its performance and mechanism was compared with those of EC, PAA, EC/PAA and Fe(Ⅱ)/PAA. Results showed that the EC/Fe(Ⅱ)/PAA process effectively improved sludge disintegration and the concentrations of soluble chemical oxygen demand, polysaccharides and nucleic acids increased by 62.85%, 41.15% and 12.21%, respectively, compared to the Fe(Ⅱ)/PAA process. Mechanism analysis showed that the main active species produced in the EC/Fe(Ⅱ)/PAA process were •OH, R-O• and FeIVO2+. During the reaction process, sludge flocs were disrupted and particle size was reduced by the combined effects of active species oxidation, electrochemical oxidation and PAA oxidation. Furthermore, extracellular polymeric substances (EPS) was degraded, the conversion of TB-EPS to LB-EPS and S-EPS was promoted and the total protein and polysaccharide contents of EPS were increased. After sludge cells were disrupted, intracellular substances were released, causing an increase in nucleic acids, humic acids and fulvic acids in the supernatant, and resulting in sludge reduction. EC effectively accelerated the conversion of Fe(Ⅲ) to Fe(Ⅱ), which was conducive to the activation of PAA, while also enhancing the disintegration of EPS and sludge cells. This study provided an effective approach for the release of organic matter, offering significant benefits in sludge resource utilization.


Assuntos
Esgotos , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Oxirredução , Técnicas Eletroquímicas/métodos , Ferro/química , Análise da Demanda Biológica de Oxigênio
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