Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Immunity ; 56(12): 2773-2789.e8, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37992711

RESUMO

Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Esclerose Múltipla , Masculino , Feminino , Camundongos , Animais , Esclerose Múltipla/metabolismo , Modelos Animais de Doenças , Transdução de Sinais , Progressão da Doença , Receptores Dopaminérgicos
2.
FASEB J ; 38(1): e23372, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38102977

RESUMO

Embryo vitrification is a standard procedure in assisted reproductive technology. Previous studies have shown that frozen embryo transfer is associated with an elevated risk of adverse maternal and neonatal outcomes. This study aimed to explore the effects of mouse blastocyst vitrification on the phenotype of vitrified-warmed blastocysts, their intrauterine and postnatal development, and the long-term metabolic health of the derived offspring. The vitrified-warmed blastocysts (IVF + VT group) exhibited reduced mitochondrial activity, increased apoptotic levels, and decreased cell numbers when compared to the fresh blastocysts (IVF group). Implantation rates, live pup rates, and crown-rump length at E18.5 were not different between the two groups. However, there was a significant decrease in fetal weight and fetal/placental weight ratio in the IVF + VT group. Furthermore, the offspring of the IVF + VT group at an age of 36 weeks had reduced whole energy consumption, impaired glucose and lipid metabolism when compared with the IVF group. Notably, RNA-seq results unveiled disturbed hepatic gene expression in the offspring from vitrified-warmed blastocysts. This study revealed the short-term negative impacts of vitrification on embryo and fetal development and the long-term influence on glucose and lipid metabolism that persist from the prenatal stage into adulthood in mice.


Assuntos
Criopreservação , Vitrificação , Gravidez , Feminino , Animais , Camundongos , Criopreservação/métodos , Placenta , Desenvolvimento Embrionário , Blastocisto , Glucose , Estudos Retrospectivos
3.
Curr Issues Mol Biol ; 44(9): 4070-4086, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36135191

RESUMO

Phosphorus treatment can reduce Cd accumulation and Cd toxicity in rice, but alterations in the internal regulatory network of rice during this process have rarely been reported. We have removed the effect of cadmium phosphate precipitation from the hydroponic system, treated a pair of different Cd-response rice varieties with different levels of phosphorus and cadmium and examined the changes in physiological indicators and regulatory networks. The results demonstrated that phosphorus treatment significantly reduced Cd accumulation in both types of rice, although the antioxidant systems within the two types of rice produced opposite responses. Overall, 3 mM phosphorus treatment to Cd-N decreased the expression of OsIAA17 and OsACO1 by 32% and 37%, respectively, while increasing the expression of OsNR2 by 83%; these three genes regulate the synthesis of auxin, ethylene, and nitric oxide in rice. IAA and NO levels in rice shoots increased by 24% and 96%, respectively, and these changes contribute to Cd detoxification. The cadmium transporter genes OsHMA2, OsIRT1, and OsABCC1 were significantly down-regulated in Cd-N roots after triple phosphorus treatment. These data suggest that phosphorus treatment can reduce Cd accumulation and enhance Cd resistance in rice by affecting the expression of signaling molecules.

4.
J Transl Med ; 20(1): 198, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35509101

RESUMO

BACKGROUND: Serine/arginine-rich splicing factor 9 (SRSF9) is a classical RNA-binding protein that is essential for regulating gene expression programs through its interaction with target RNA. Whether SRSF9 plays an essential role in colorectal cancer (CRC) progression and can serve as a therapeutic target is largely unknown. Here, we highlight new findings on the role of SRSF9 in CRC progression and elucidate the underlying mechanism. METHODS: CRC cell lines and clinical tissue samples were used. qRT-PCR, Western blotting, immunohistochemistry (IHC), gain- and loss-of-function assays, animal xenograft model studies, bioinformatic analysis, methylated single-stranded RNA affinity assays, gene-specific m6A quantitative qRT-PCR, dual-luciferase reporter assays and RNA stability assays were performed in this study. RESULTS: The expression level of SRSF9 was higher in CRC cell lines than that in an immortal human intestinal epithelial cell line. Overexpression of SRSF9 was positively associated with lymph node metastasis and Dukes stage. Functionally, SRSF9 promoted cell proliferation, migration and invasion in vitro and xenograft growth. The results of bioinformatic analysis indicated that DSN1 was the downstream target of SRSF9. In CRC cells and clinical tissue samples, the expression of SRSF9 was positively associated with the expression of DSN1. Knockdown of DSN1 partially inhibited the SRSF9-induced phenotype in CRC cells. Mechanistically, we further found that SRSF9 is an m6A-binding protein and that m6A modifications were enriched in DSN1 mRNA in CRC cells. Two m6A modification sites (chr20:36773619-36773620 and chr20:36773645-chr20:36773646) in the SRSF9-binding region (chr20:36773597-36773736) of DSN1 mRNA were identified. SRSF9 binds to DSN1 in an m6A motif- and dose-dependent manner. SRSF9 modulates the expression of DSN1 in CRC cells. Such expression regulation was largely impaired upon methyltransferase METTL3 knockdown. Moreover, knockdown of SRSF9 accelerated DSN1 mRNA turnover, while overexpression of SRSF9 stabilized DSN1 mRNA in CRC cells. Such stabilizing was also weakened upon METTL3 knockdown. CONCLUSION: Overexpression of SRSF9 was associated with lymph node metastasis and Dukes stage in CRC. Knockdown of DSN1 eliminated the effects by SRSF9 overexpression in CRC. Our results indicated that SRSF9 functions as an m6A-binding protein (termed "reader") by enhancing the stability of DSN1 mRNA in m6A-related manner. Our study is the first to report that SRSF9-mediated m6A recognition has a crucial role in CRC progression, and highlights SRSF9 as a potential therapeutic target for CRC management.


Assuntos
Neoplasias Colorretais , Metiltransferases , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Processamento de Serina-Arginina
5.
J Transl Med ; 20(1): 485, 2022 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-36274132

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common and malignant tumors in the digestive tract. Tumor Suppressor Candidate 3 (TUSC3) is one subunit of the endoplasmic reticulum Oligosaccharyl transferase (OST) complex, which plays an important role in N-glycosylation during the protein folding process. However, the role of TUSC3 in the initiation and progression of HCC has not been mentioned yet. In the present study, we aim to investigate the effects of TUSC3 on the initiation and progression of HCC. METHODS: Immunohistochemical assay and qRT-PCR were used to detect the expression of TUSC3 and lipase C hepatic type (LIPC) in HCC tissue and cells. Loss-of-function and gain-of-function were applied to detect the function of TUSC3 and LIPC in vivo and in vitro. Immunofluorescence assay and co-immunoprecipitation were used to detect the relationship between TUSC3 and LPC. Western blot was applied to detect the expression of epithelial-mesenchymal transition (EMT) markers and the Akt signaling pathway. RESULTS: TUSC3 was aberrantly decreased in hepatocellular carcinoma tissues compared to the matched adjacent normal tissues, which resulted in bigger size of tumor (P = 0.001, Table 2), worse differentiation (P = 0.006, Table 2) and an advanced BCLC stage. Down-regulation of TUSC3 led to the enhanced proliferation and migration of hepatocellular carcinoma cells in vivo and vitro, whereas the opposite effect could be observed in the TUSC3-overexpression group. The analysis of TUSC3 microarray showed that LIPC, a glycoprotein primarily synthesized and secreted by hepatocytes, was a downstream target of TUSC3, and it negatively modulated the development of HCC. The morphological changes in HCC cells indicated that TUSC3 regulated the epithelial-mesenchymal transition (EMT). Mechanistically, TUSC3 inhibited EMT progression through the LIPC/AKT axis. CONCLUSION: Down-regulation of TUSC3 promotes EMT progression by activating AKT signaling via targeting LIPC in HCC, which is probably the possible mechanism driving TUSC3-deficient hepatocellular carcinoma cells toward a malignant phenotype.


Assuntos
Carcinoma Hepatocelular , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Lipase/genética , Lipase/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
6.
Microb Cell Fact ; 21(1): 47, 2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35331215

RESUMO

BACKGROUND: L-Tryptophan (L-Trp) derivatives such as 5-hydroxytryptophan (5-HTP) and 5-hydroxytryptamine (5-HT), N-Acetyl-5-hydroxytryptamine and melatonin are important molecules with pharmaceutical interest. Among, 5-HT is an inhibitory neurotransmitter with proven benefits for treating the symptoms of depression. At present, 5-HT depends on plant extraction and chemical synthesis, which limits its mass production and causes environmental problems. Therefore, it is necessary to develop an efficient, green and sustainable biosynthesis method to produce 5-HT. RESULTS: Here we propose a one-pot production of 5-HT from L-Trp via two enzyme cascades for the first time. First, a chassis cell that can convert L-Trp into 5-HTP was constructed by heterologous expression of tryptophan hydroxylase from Schistosoma mansoni (SmTPH) and an artificial endogenous tetrahydrobiopterin (BH4) module. Then, dopa decarboxylase from Harminia axyridis (HaDDC), which can specifically catalyse 5-HTP to 5-HT, was used for 5-HT production. The cell factory, E. coli BL21(DE3)△tnaA/BH4/HaDDC-SmTPH, which contains SmTPH and HaDDC, was constructed for 5-HT synthesis. The highest concentration of 5-HT reached 414.5 ± 1.6 mg/L (with conversion rate of 25.9 mol%) at the optimal conditions (substrate concentration,2 g/L; induced temperature, 25℃; IPTG concentration, 0.5 mM; catalysis temperature, 30℃; catalysis time, 72 h). CONCLUSIONS: This protocol provided an efficient one-pot method for converting. L-Trp into 5-HT production, which opens up possibilities for the practical biosynthesis of natural 5-HT at an industrial scale.


Assuntos
Serotonina , Triptofano , 5-Hidroxitriptofano/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Serotonina/metabolismo , Triptofano/metabolismo , Triptofano Hidroxilase/genética , Triptofano Hidroxilase/metabolismo
7.
Cell Biol Int ; 46(2): 278-287, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34854515

RESUMO

T-cell-based immunotherapy and immune checkpoint blockade have been successfully used to treat several human solid cancers. The present study attempted to investigate the feasibility and efficacy of the antitumor effect of adoptive cell therapy along with programmed cell death protein 1 (PD-1) inhibitor on triple-negative breast cancer (TNBC). Tumor infiltration lymphocytes (TILs) from TNBC mouse tumor tissues were isolated and expanded, and TILs for adoptive cell therapy (TILs-ACT) were applied in combination with a PD-1 inhibitor to the TNBC mouse model. The pre- and post-therapy antitumor efficacy, cytokine secretion, and pathological changes were assessed both in vitro and in vivo. We found that TILs exhibited higher IFN-γ and TNF-α secretion than conventional T cells. The TILs-ACT combined with PD-1 inhibitor promoted active T-cell infiltration into the tumor tissue and exerted a strong antitumor effect in an in vivo model. Additionally, the strategy could downregulate the expression of inhibitory marker PD-1 on TILs. In conclusion, PD-1 blockade regulated T-cell exhaustion that synergized with adoptive TIL transfer immunotherapy, leading to eradication of established TNBC tumors. These findings might be useful in developing a feasible and effective therapeutic approach for TNBC.


Assuntos
Linfócitos do Interstício Tumoral , Neoplasias de Mama Triplo Negativas , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Humanos , Imunoterapia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Receptor de Morte Celular Programada 1/uso terapêutico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/terapia
8.
J Pineal Res ; 72(1): e12778, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34726796

RESUMO

Increasing evidence suggests that in vitro fertilization (IVF) may be associated with an increased risk of developing obesity and metabolic diseases later in life in the offspring. Notably, the addition of melatonin to culture medium may improve embryo development and prevent cardiovascular dysfunction in IVF adult mice. This study aimed to determine if melatonin supplementation in the culture medium can reverse impaired glucose metabolism in IVF mice offspring and the underlying mechanisms. Blastocysts used for transfer were generated by natural mating (control group) or IVF with or without melatonin (10-6  M) supplementation (mIVF and IVF group, respectively) in clinical-grade culture media. Here, we first report that IVF decreased hepatic expression of Fbxl7, which was associated with impaired glucose metabolism in mice offspring. Melatonin addition reversed the phenotype by up-regulating the expression of hepatic Fbxl7. In vitro experiments showed that Fbxl7 enhanced the insulin signaling pathway by degrading RhoA through ubiquitination and was up-regulated by transcription factor Foxa2. Specific knockout of Fbxl7 in the liver of adult mice, through tail intravenous injection of recombinant adeno-associated virus, impaired glucose tolerance, while overexpression of hepatic Fbxl7 significantly improved glucose tolerance in adult IVF mice. Thus, the data suggest that Fbxl7 plays an important role in maintaining glucose metabolism of mice, and melatonin supplementation in the culture medium may rescue the long-term risk of metabolic diseases in IVF offspring.


Assuntos
Melatonina , Animais , Blastocisto , Meios de Cultura , Suplementos Nutricionais , Fertilização in vitro , Glucose , Melatonina/farmacologia , Camundongos
9.
Angew Chem Int Ed Engl ; 61(23): e202202046, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35315964

RESUMO

γ-Butenolide and γ-butyrolactone scaffolds are two types of important core structures in numerous natural products and bioactive targets. However, methods to construct the chiral quaternary arylated γ-butenolide are rarely explored. We herein report an efficient Pd-catalyzed enantioselective γ-arylation of ß,γ-unsaturated butenolides with aryl bromides, which shows high γ-selectivity, good functional group tolerance and excellent enantioselectivity. Notably, this protocol also allows for facile construction of tricyclic tetrahydroindolines and tetrahydroisoquinolinones in one step. DFT calculations are consistent with the experimental results, suggesting that the γ-arylation is favoured over the α-arylation. Finally, this method is applied to the rapid synthesis of natural product (R)-(+)-boivinianin A.


Assuntos
4-Butirolactona , Paládio , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , Catálise , Paládio/química , Estereoisomerismo
10.
Cancer Cell Int ; 21(1): 30, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413409

RESUMO

BACKGROUND: Autophagy is a double-edged sword during the initiation and progression of multiple tumors. The Hippo pathway effector YAP has been proved to be involved in autophagy processes. The present study aimed to investigate how YAP regulates cell proliferation via autophagy in lung adenocarcinomas (LUAD). METHODS: Data of LUAD chip GSE43458 was obtained from Gene Expression Omnibus (GEO). RT-qPCR and Western blot were performed to assess YAP expression in LUAD cell lines. CCK-8 assay, xenograft tumor model, immunochemistry and GFP-mRFP-LC3 fusion proteins were utilized to evaluate the effect of YAP on autophagy of LUAD cells in vitro and in vivo. Autophagy inhibitor treatment and rescue experiments were carried out to elucidate the mechanism by which YAP manipulates autophagy in LUAD cells. RESULTS: YAP was significantly overexpressed in samples of LUAD patients and its expression level is related to 5-year survival. YAP manipulated the proliferation and autophagy in A549 and H1299 LUAD cells. YAP could induce activation of Akt/mTOR signaling pathway via suppressing PTEN in a Hippo-pathway-dependent manner. 3-Methyladenine impeded autophagy flux and promoted the proliferation in vitro and in vivo. CONCLUSIONS: Hippo pathway critical transcriptional coactivators YAP manipulates the proliferation of lung adenocarcinoma, which is regulated by PTEN/AKT/mTOR autophagic signaling.

11.
Cancer Sci ; 111(7): 2297-2309, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32378752

RESUMO

Long noncoding RNAs (lncRNAs) have recently been verified to have significant regulatory functions in many types of human cancers. The lncRNA ANRIL is transcribed from the INK4b-ARF-INK4a gene cluster in the opposite direction. Whether ANRIL can act as an oncogenic molecule in cholangiocarcinoma (CCA) remains unknown. Our data show that ANRIL knockdown greatly inhibited CCA cell proliferation and migration in vitro and in vivo. According to the results of RNA sequencing analysis, ANRIL knockdown dramatically altered target genes associated with the cell cycle, cell proliferation, and apoptosis. By binding to a component of the epigenetic modification complex enhancer of zeste homolog 2 (EZH2), ANRIL could maintain lysine residue 27 of histone 3 (H3K27me3) levels in the promoter of ERBB receptor feedback inhibitor 1 (ERRFI1), which is a tumor suppressor gene in CCA. In this way, ERRFI1 expression was suppressed in CCA cells. These data verified the key role of the epigenetic regulation of ANRIL in CCA oncogenesis and indicate its potential as a target for CCA intervention.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/genética , Proteínas Supressoras de Tumor/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose/genética , Neoplasias dos Ductos Biliares/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Colangiocarcinoma/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Xenoenxertos , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas Supressoras de Tumor/metabolismo
12.
FASEB J ; 33(8): 9350-9361, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31125263

RESUMO

The establishment of ungulate embryonic stem cells (ESCs) has been notoriously difficult via a conventional approach. We combined a traditional ESC culture method with reprogramming factors to assist the establishment of porcine naive-like ESCs (nESCs). Pig embryonic fibroblasts were transfected with a tetracycline-inducible vector carrying 4 classic mouse reprogramming factors, followed by somatic cell nuclear transfer and culturing to the blastocyst stage. Then, the inner cell mass was isolated and seeded in culture medium. The naive-like ESCs had characteristic verys similar to those of mouse ESCs and showed no signs of altered morphology or differentiation, even after 130 passages. They depended on leukemia inhibitory factor signals for maintenance of pluripotency, and the female cell lines had low expression of the X-inactive specific transcript gene and no histone H3 lysine 27 trimethylation spot. Notably, the ESCs differentiated into 3 germ layers in vitro and could be induced to undergo directional neural and kidney precursor differentiation under defined conditions, and the ESCs could keep proliferating after doxycycline was removed. nESCs can be established, and the well-characterized ESC lines will be useful for the research of transgenic pig models for human disease.-Zhang, M., Wang, C., Jiang, H., Liu, M., Yang, N., Zhao, L., Hou, D., Jin, Y., Chen, Q., Chen, Y., Wang, J., Dai, Y., Li, R. Derivation of novel naive-like porcine embryonic stem cells by a reprogramming factor-assisted strategy.


Assuntos
Reprogramação Celular/fisiologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Animais , Células Cultivadas , Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/genética , Células-Tronco Embrionárias/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Camadas Germinativas/citologia , Camadas Germinativas/efeitos dos fármacos , Camadas Germinativas/metabolismo , Imuno-Histoquímica , Fator Inibidor de Leucemia/farmacologia , Camundongos , MicroRNAs/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de RNA , Suínos
13.
J Neurosci ; 38(28): 6299-6309, 2018 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-29899027

RESUMO

Episodic memories are rich in sensory information and often contain integrated information from different sensory modalities. For instance, we can store memories of a recent concert with visual and auditory impressions being integrated in one episode. Theta oscillations have recently been implicated in playing a causal role synchronizing and effectively binding the different modalities together in memory. However, an open question is whether momentary fluctuations in theta synchronization predict the likelihood of associative memory formation for multisensory events. To address this question we entrained the visual and auditory cortex at theta frequency (4 Hz) and in a synchronous or asynchronous manner by modulating the luminance and volume of movies and sounds at 4 Hz, with a phase offset at 0° or 180°. EEG activity from human subjects (both sexes) was recorded while they memorized the association between a movie and a sound. Associative memory performance was significantly enhanced in the 0° compared with the 180° condition. Source-level analysis demonstrated that the physical stimuli effectively entrained their respective cortical areas with a corresponding phase offset. The findings suggested a successful replication of a previous study (Clouter et al., 2017). Importantly, the strength of entrainment during encoding correlated with the efficacy of associative memory such that small phase differences between visual and auditory cortex predicted a high likelihood of correct retrieval in a later recall test. These findings suggest that theta oscillations serve a specific function in the episodic memory system: binding the contents of different modalities into coherent memory episodes.SIGNIFICANCE STATEMENT How multisensory experiences are bound to form a coherent episodic memory representation is one of the fundamental questions in human episodic memory research. Evidence from animal literature suggests that the relative timing between an input and theta oscillations in the hippocampus is crucial for memory formation. We precisely controlled the timing between visual and auditory stimuli and the neural oscillations at 4 Hz using a multisensory entrainment paradigm. Human associative memory formation depends on coincident timing between sensory streams processed by the corresponding brain regions. We provide evidence for a significant role of relative timing of neural theta activity in human episodic memory on a single-trial level, which reveals a crucial mechanism underlying human episodic memory.


Assuntos
Percepção Auditiva/fisiologia , Memória Episódica , Ritmo Teta/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Adolescente , Adulto , Córtex Auditivo/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Córtex Visual/fisiologia , Adulto Jovem
14.
Xenotransplantation ; 26(3): e12484, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30623494

RESUMO

SIX1 and SIX4 genes play critical roles in kidney development. We evaluated the effect of these genes on pig kidney development by generating SIX1-/- and SIX1-/- /SIX4-/- pig foetuses using CRISPR/Cas9 and somatic cell nuclear transfer. We obtained 3 SIX1-/- foetuses and 16 SIX1-/- /SIX4-/- foetuses at different developmental stages. The SIX1-/- foetuses showed a migration block of the left kidney and a smaller size for both kidneys. The ureteric bud failed to form the normal branching and collecting system. Abnormal expressions of kidney development-related genes (downregulation of PAX2, PAX8, and BMP4 and upregulation of EYA1 and SALL1) were also observed in SIX1-/- foetal kidneys and confirmed in vitro in porcine kidney epithelial cells (PK15) following SIX1 gene deletion. The SIX1-/- /SIX4-/- foetuses exhibited more severe phenotypes, with most foetuses showing retarded development at early stages of gestation. The kidney developed only to the initial stage of metanephros formation. These results demonstrated that SIX1 and SIX4 are key genes for porcine metanephros development. The creation of kidney-deficient porcine foetuses provides a platform for generating human kidneys inside pigs using blastocyst complementation.


Assuntos
Sistemas CRISPR-Cas/genética , Marcação de Genes , Genes Homeobox/genética , Proteínas Nucleares/metabolismo , Animais , Blastocisto/metabolismo , Proteínas de Homeodomínio/genética , Técnicas de Transferência Nuclear , Suínos , Transativadores/genética , Transplante Heterólogo/métodos
16.
Micromachines (Basel) ; 15(3)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38542595

RESUMO

A challenge remains in achieving adequate surface roughness of SLM fabricated interior channels, which is crucial for fuel delivery in the space industry. This study investigated the surface roughness of interior fine flow channels (1 mm diameter) embedded in SLM fabricated TC4 alloy space components. A machine learning approach identified layer thickness as a significant factor affecting interior channel surface roughness, with an importance score of 1.184, followed by scan speed and laser power with scores of 0.758 and 0.512, respectively. The roughness resulted from thin layer thickness of 20 µm, predominantly formed through powder adherence, while from thicker layer of 50 µm, the roughness was mainly due to the stair step effect. Slow scan speeds increased melt pools solidification time at roof overhangs, causing molten metal to sag under gravity. Higher laser power increased melt pools temperature and led to dross formation at roof overhangs. Smaller hatch spaces increased roughness due to overlapping of melt tracks, while larger hatch spaces reduced surface roughness but led to decreased part density. The surface roughness was recorded at 34 µm for roof areas and 26.15 µm for floor areas. These findings contribute to potential adoption of TC4 alloy components in the space industry.

17.
Micromachines (Basel) ; 15(3)2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38542643

RESUMO

The plasma rotating electrode process (PREP) is an ideal method for the preparation of metal powders such as nickel-based, titanium-based, and iron-based alloys due to its low material loss and good degree of sphericity. However, the preparation of silver alloy powder by PREP remains challenging. The low hardness of the mould casting silver alloy leads to the bending of the electrode rod when subjected to high-speed rotation during PREP. The mould casting silver electrode rod can only be used in low-speed rotation, which has a negative effect on particle refinement. This study employed continuous casting (CC) to improve the surface hardness of S800 Ag (30.30% higher than mould casting), which enables a high rotation speed of up to 37,000 revolutions per minute, and silver alloy powder with an average sphericity of 0.98 (5.56% higher than gas atomisation) and a sphericity ratio of 97.67% (36.28% higher than gas atomisation) has been successfully prepared. The dense S800 Ag was successfully fabricated by laser powder bed fusion (LPBF), which proved the feasibility of preparing high-quality powder by the "CC + PREP" method. The samples fabricated by LPBF have a Vickers hardness of up to 271.20 HV (3.66 times that of mould casting), leading to a notable enhancement in the strength of S800 Ag. In comparison to GA, the S800 Ag powder prepared by "CC + PREP" exhibits greater sphericity, a higher sphericity ratio and less satellite powder, which lays the foundation for dense LPBF S800 Ag fabrication.

18.
Micromachines (Basel) ; 14(2)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36838062

RESUMO

Ag and Cu have different advantages and are widely used in key fields due to their typical highly electrical and thermal conductive (HETC) properties. Laser powder bed fusion (LPBF), an innovative technology for manufacturing metallic multi-material components with high accuracy, has expanded the application of Ag-Cu in emerging high-tech fields. In this study, the multi-material sandwich structures of Ag7.5Cu/Cu10Sn/Ag7.5Cu were printed using LPBF, and the formation mechanism, interface characteristics, and molten pool behavior of the Ag7.5Cu/Cu10Sn (A/C) and Cu10Sn/Ag7.5Cu (C/A) interfaces were studied to reveal the influence of different building strategies. At the A/C interface, pre-printed Ag7.5Cu promoted Marangoni turbulence at a relatively low energy density (EA/C = 125 J/mm3). Due to the recoil pressure, the molten pool at the A/C interface transformed from a stable keyhole mode to an unstable keyhole mode. These phenomena promoted the extensive migration of elements, forming a wider diffusion zone and reduced thermal cracking. At the C/A interface, the molten pool was rationed from the conduction mode with more pores to the transition mode with fewer defects due to the high energy density (EC/A = 187.5 J/mm3). This work offers a theoretical reference for the fabrication of HETC multi-material structures via LPBF under similar conditions.

19.
Hum Fertil (Camb) ; 26(6): 1459-1468, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36942474

RESUMO

This retrospective cohort study aimed to compare clinical outcomes following fresh or frozen embryo transfer (FET) in women with advanced reproductive age (ARA). Women aged 35-45 years who underwent their first autologous fresh or frozen cleavage stage embryo transfer cycle in the Centre for Assisted Reproduction of Shanghai First Maternity and Infant Hospital between January 2016 and December 2020 were included. The primary outcome was live birth after the first embryo transfer of the in vitro fertilization (IVF) cycle. Multiple covariates were used for propensity score matching (PSM) and generalized estimating equations were performed to examine the independent association between FET and live birth. Of the total 1453 patients, 327 patients had FET and 1126 patients had fresh ET. After the PSM procedure, 274 patients were included in each group. The live birth rate was 24.8% in the FET group and 25.2% in the fresh ET group (OR 0.98, 95% CI: 0.67-1.44, P = 0.92). Other pregnancy, perinatal and neonatal outcomes were all comparable between the two groups. This study showed that FET did not improve live birth and other clinical outcomes as compared with fresh embryo transfer in women with ARA who underwent their first IVF cycle.


Assuntos
Transferência Embrionária , Fertilização in vitro , Recém-Nascido , Feminino , Gravidez , Humanos , Estudos de Coortes , Estudos Retrospectivos , Pontuação de Propensão , China , Fertilização in vitro/métodos , Transferência Embrionária/métodos , Taxa de Gravidez , Gravidez Múltipla , Nascido Vivo
20.
Cancers (Basel) ; 15(9)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37173894

RESUMO

BACKGROUND: Nicotinamide mononucleotide (NMN) is the physiological circulating NAD precursor thought to elevate the cellular level of NAD+ and to ameliorate various age-related diseases. An inseparable link exists between aging and tumorigenesis, especially involving aberrant energetic metabolism and cell fate regulation in cancer cells. However, few studies have directly investigated the effects of NMN on another major ageing-related disease: tumors. METHODS: We conducted a series of cell and mouse models to evaluate the anti-tumor effect of high-dose NMN. Transmission electron microscopy and a Mito-FerroGreen-labeled immunofluorescence assay (Fe2+) were utilized to demonstrate ferroptosis. The metabolites of NAM were detected via ELISA. The expression of the proteins involved in the SIRT1-AMPK-ACC signaling were detected using a Western blot assay. RESULTS: The results showed that high-dose NMN inhibits lung adenocarcinoma growth in vitro and in vivo. Excess NAM is produced through the metabolism of high-dose NMN, whereas the overexpression of NAMPT significantly decreases intracellular NAM content, which, in turn, boosts cell proliferation. Mechanistically, high-dose NMN promotes ferroptosis through NAM-mediated SIRT1-AMPK-ACC signaling. CONCLUSIONS: This study highlights the tumor influence of NMN at high doses in the manipulation of cancer cell metabolism, providing a new perspective on clinical therapy in patients with lung adenocarcinoma.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA