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Background: White matter injury is a predominant form of brain injury in preterm infants. However, effective drugs for its treatment are currently lacking. Previous studies have shown the neuroprotective effects of Isoliquiritigenin (ISL), but its impact on white matter injury in preterm infants remains poorly understood. Aims: This study aimed to investigate the protective effects of ISL against white matter injury caused by infection in preterm infants using a mouse model of lipopolysaccharide-induced white matter injury, integrating network pharmacology as well as in vivo and in vitro experiments. Methods: This study explores the potential mechanisms of ISL on white matter injury by integrating network pharmacology. Core pathways and biological processes affected by ISL were verified through experiments, and motor coordination, anxiety-like, and depression-like behaviors of mice were evaluated using behavioral experiments. White matter injury was observed using hematoxylin-eosin staining, Luxol Fast Blue staining, and electron microscopy. The development of oligodendrocytes and the activation of microglia in mice were assessed by immunofluorescence. The expression of related proteins was detected by Western blot. Results: We constructed a drug-target network, including 336 targets associated with ISL treatment of white matter injury. The biological process of ISL treatment of white matter injury mainly involves microglial inflammation regulation and myelination. Our findings revealed that ISL reduced early nerve reflex barriers and white matter manifestations in mice, leading to decreased activation of microglia and release of proinflammatory cytokines. Additionally, ISL demonstrated the ability to mitigate impairment in oligodendrocyte development and myelination, ultimately improving behavior disorders in adult mice. Mechanistically, we observed that ISL downregulated HDAC3 expression, promoted histone acetylation, enhanced the expression of H3K27ac, and regulated oligodendrocyte pro-differentiation factors. Conclusion: These findings suggest that ISL can have beneficial effects on white matter injury in preterm infants by alleviating inflammation and promoting oligodendrocyte differentiation.
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Demyelination occurs widely in the central nervous system (CNS) neurodegenerative diseases, especially the multiple sclerosis (MS), which with a complex and inflammatory lesion microenvironment inhibiting remyelination. Sirtuin6 (SIRT6), a histone/protein deacetylase is of interest for its promising effect in transcriptional regulation, cell cycling, inflammation, metabolism and longevity. Here we show that SIRT6 participates in the remyelination process in mice subjected to LPC-induced demyelination. Using pharmacological SIRT6 inhibitor or activator, we found that SIRT6 modulated LPC-induced damage in motor or cognitive function. Inhibition of SIRT6 impaired myelin regeneration, exacerbated neurological deficits, and decreased oligodendrocyte precursor cells (OPCs) proliferation and differentiation, whereas activation of SIRT6 reversed behavioral performance in mice, demonstrating a beneficial effect of SIRT6. Importantly, based on RNA sequencing analysis of the corpus callosum tissues, it was further revealed that SIRT6 took charge in regulation of glial activation during remyelination, and significant alterations in CHI3L1 were obtained, a glycoprotein specifically secreted by astrocytes. Impaired proliferation and differentiation of OPCs could be induced in vitro using supernatants from reactive astrocyte, especially when SIRT6 was inhibited. Mechanistically, SIRT6 regulates the secretion of CHI3L1 from reactive astrocytes by histone-H3-lysine-9 acetylation (H3K9Ac). Adeno-associated virus-overexpression of SIRT6 (AAV-SIRT6-OE) in astrocytes improved remyelination and functional recovery after LPC-induced demyelination, whereas together with AAV-CHI3L1-OE inhibits this therapeutic effect. Collectively, our data elucidate the role of SIRT6 in remyelination and further reveal astrocytic SIRT6/CHI3L1 as the key regulator for improving the remyelination environment, which may be a potential target for MS therapy.
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Astrócitos , Doenças Desmielinizantes , Sirtuínas , Animais , Masculino , Camundongos , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Células Cultivadas , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/metabolismo , Doenças Desmielinizantes/patologia , Lisofosfatidilcolinas/toxicidade , Camundongos Endogâmicos C57BL , Remielinização/efeitos dos fármacos , Remielinização/fisiologia , Sirtuínas/metabolismo , Sirtuínas/genéticaRESUMO
Epigenetics plays a crucial role in regulating gene expression during adolescent brain maturation. In adolescents with depression, microglia-mediated chronic neuroinflammation may contribute to the activation of cellular signaling cascades and cause central synapse loss. However, the exact mechanisms underlying the epigenetic regulation of neuroinflammation leading to adolescent depression remain unclear. In this study, we found that the expression of polycomb group 1 (PCGF1), an important epigenetic regulator, was decreased both in the plasma of adolescent major depressive disorder (MDD) patients and in the microglia of adolescent mice in a mouse model of depression. We demonstrated that PCGF1 alleviates neuroinflammation mediated by microglia in vivo and in vitro, reducing neuronal damage and improving depression-like behavior in adolescent mice. Mechanistically, PCGF1 inhibits the transcription of MMP10 by upregulating RING1B/H2AK119ub and EZH2/H3K27me3 in the MMP10 promoter region, specifically inhibiting microglia-mediated neuroinflammation. These results provide valuable insights into the pathogenesis of adolescent depression, highlighting potential links between histone modifications, neuroinflammation and nerve damage. Potential mechanisms of microglial PCGF1 regulates depression-like behavior in adolescent mice. Microglial PCGF1 inhibits NF-κB/MAPK pathway activation through regulation of RING1B/H2AK119ub and EZH2/H3K27me3 in the MMP10 promoter region, which attenuates neuroinflammation and ameliorates depression-like behaviors in adolescent mice.
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Electrical stimulation holds promise for enhancing neuronal differentiation of neural stem cells to treat traumatic brain injury. However, once the stem cells leave the stimulating material and migrate post transplantation, electrical stimulation on them is diminished. Here, we wrap the stem cells with wireless electrical nanopatches, the conductive graphene nanosheets. Under electromagnetic induction, electrical stimulation can thus be applied in-situ to individual nanopatch-wrapped stem cells on demand, stimulating their neuronal differentiation through a MAPK/ERK signaling pathway. Consequently, 41% of the nanopatch-wrapped stem cells differentiate into functional neurons in 5 days, as opposed to only 16.3% of the unwrapped ones. The brain injury male mice implanted with the nanopatch-wrapped stem cells and exposed to a rotating magnetic field 30 min/day exhibit significant recovery of brain tissues, behaviors, and cognitions, within 28 days. This study opens up an avenue to individualized electrical stimulation of transplanted stem cells for treating neurodegenerative diseases.
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Lesões Encefálicas Traumáticas , Diferenciação Celular , Células-Tronco Neurais , Transplante de Células-Tronco , Animais , Lesões Encefálicas Traumáticas/terapia , Lesões Encefálicas Traumáticas/patologia , Masculino , Camundongos , Células-Tronco Neurais/transplante , Células-Tronco Neurais/citologia , Transplante de Células-Tronco/métodos , Grafite/química , Estimulação Elétrica , Tecnologia sem Fio , Neurônios , Humanos , Encéfalo , Nanoestruturas/químicaRESUMO
2-Ethylhexyl diphenyl phosphate (EHDPP) is a representative organophosphorus flame retardant (OPFR) that has garnered attention due to its widespread use and potential adverse effects. EHDPP exhibits cytotoxicity, genotoxicity, developmental toxicity, and endocrine disruption. However, the toxicity of EHDPP in mammalian oocytes and the underlying mechanisms remain poorly understood. Melatonin is a natural free radical scavenger that has demonstrated cytoprotective properties. In this study, we investigated the effect of EHDPP on mouse oocytes in vitro culture system and evaluated the rescue effect of melatonin on oocytes exposed to EHDPP. Our results indicated that EHDPP disrupted oocyte maturation, resulting in the majority of oocytes arrested at the metaphase I (MI) stage, accompanied by cytoskeletal damage and elevated levels of reactive oxygen species (ROS). Nevertheless, melatonin supplementation partially rescued EHDPP-induced mouse oocyte maturation impairment. Results of single-cell RNA sequencing (scRNA-seq) analysis elucidated potential mechanisms underlying these protective effects. According to the results of scRNA-seq, we conducted further tests and found that EHDPP primarily disrupts mitochondrial distribution and function, kinetochore-microtubule (K-MT) attachment, DNA damage, apoptosis, and histone modification, which were rescued upon the supplementation of melatonin. This study reveals the mechanisms of EHDPP on female reproduction and indicates the efficacy of melatonin as a therapeutic intervention for EHDPP-induced defects in mouse oocytes.
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Retardadores de Chama , Melatonina , Mitocôndrias , Oócitos , Animais , Melatonina/farmacologia , Camundongos , Oócitos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Feminino , Retardadores de Chama/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Organofosfatos/toxicidade , Dano ao DNA/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Compostos Organofosforados/toxicidadeRESUMO
Triocresyl phosphate (TOCP) was commonly used as flame retardant, plasticizer, lubricant, and jet fuel additive. Studies have shown adverse effects of TOCP on the reproductive system. However, the potential harm brought by TOCP, especially to mammalian female reproductive cells, remains a mystery. In this study, we employed an in vitro model for the first time to investigate the effects of TOCP on the maturation process of mouse oocytes. TOCP exposure hampered the meiotic division process, as evidenced by a reduction in the extrusion of the first polar body from oocytes. Subsequent research revealed the disruption of the oocyte cell cytoskeleton induced by TOCP, resulting in abnormalities in spindle organization, chromosome alignment, and actin filament distribution. This disturbance further extended to the rearrangement of organelles within oocytes, particularly affecting the mitochondria. Importantly, after TOCP treatment, mitochondrial function in oocytes was impaired, leading to oxidative stress, DNA damage, cell apoptosis, and subsequent changes of epigenetic modifications. Supplementation with nicotinamide mononucleotide (NMN) alleviated the harmful effects of TOCP. NMN exerted its mitigating effects through two fundamental mechanisms. On one hand, NMN conferred stability to the cell cytoskeleton, thereby supporting nuclear maturation. On the other hand, NMN enhanced mitochondrial function within oocytes, reducing the excess reactive oxygen species (ROS), restoring meiotic division abnormalities caused by TOCP, preventing oocyte DNA damage, and suppressing epigenetic changes. These findings not only enhance our understanding of the molecular basis of TOCP induced oocyte damage but also offer a promising avenue for the potential application of NMN in optimizing reproductive treatment strategies.
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Mononucleotídeo de Nicotinamida , Fosfatos , Tritolil Fosfatos , Feminino , Camundongos , Animais , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Fosfatos/metabolismo , Oócitos , Citoesqueleto , Mitocôndrias , Espécies Reativas de Oxigênio/metabolismo , MamíferosRESUMO
Polycomb group RING finger (PCGF) proteins, a crucial subunits of the Polycomb complex, plays an important role in regulating gene expression, embryonic development, and cell fate determination. In our research, we investigated Pcgf5, one of the six PCGF homologs, and its impact on the differentiation of P19 cells into neural stem cells. Our findings revealed that knockdown of Pcgf5 resulted in a significant decrease in the expression levels of the neuronal markers Sox2, Zfp521, and Pax6, while the expression levels of the pluripotent markers Oct4 and Nanog increased. Conversely, Pcgf5 overexpression upregulated the expression of Sox2 and Pax6, while downregulating the expression of Oct4 and Nanog. Additionally, our analysis revealed that Pcgf5 suppresses Wnt3 expression via the activation of Notch1/Hes1, and ultimately governs the differentiation fate of neural stem cells. To further validate our findings, we conducted in vivo experiments in zebrafish. We found that knockdown of pcgf5a using morpholino resulted in the downregulated expression of neurodevelopmental genes such as sox2, sox3, and foxg1 in zebrafish embryos. Consequently, these changes led to neurodevelopmental defects. In conclusion, our study highlights the important role of Pcgf5 in neural induction and the determination of neural cell fate.
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Controlling the nanoparticle-cell membrane interaction to achieve easy and fast membrane anchoring and cellular internalization is of great importance in a variety of biomedical applications. Here we report a simple and versatile strategy to maneuver the nanoparticle-cell membrane interaction by creating a tunable hydrophobic protrusion on Janus particles through swelling-induced symmetry breaking. When the Janus particle contacts cell membrane, the protrusion will induce membrane wrapping, leading the particles to docking to the membrane, followed by drawing the whole particles into the cell. The efficiencies of both membrane anchoring and cellular internalization can be promoted by optimizing the size of the protrusion. In vitro, the Janus particles can quickly anchor to the cell membrane in 1â h and be internalized within 24â h, regardless of the types of cells involved. In vivo, the Janus particles can effectively anchor to the brain and skin tissues to provide a high retention in these tissues after intracerebroventricular, intrahippocampal, or subcutaneous injection. This strategy involving the creation of a hydrophobic protrusion on Janus particles to tune the cell-membrane interaction holds great potential in nanoparticle-based biomedical applications.
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Nanopartículas Multifuncionais , Nanopartículas , Nanopartículas/química , Membrana Celular/metabolismo , Interações Hidrofóbicas e HidrofílicasRESUMO
Dysregulation of decidual macrophages leads to the occurrence of recurrent spontaneous abortion (RSA). However, the role of macrophages in RSA occurrence remains unclear. In this study, we found that the expression of Grim-19 was decreased, and the expression of autophagy related proteins Beclin1, LC3B II/I and BNIP3 was markedly upregulated in decidual macrophages of RSA patients compared with the normal pregnancy group. Furthermore, we demonstrated that downregulation of GRIM-19 increased the expression of autophagy related proteins Beclin1, LC3B II/I, BNIP3 and the proinflammatory cytokines IL1B, IL6 and TNFa in uterine mononuclear cells of GRIM-19+/- mice. The proportion of CD45+CD11b+F4/80+LC3B+ cells in GRIM-19+/- mouse uteri was significantly higher than that in WT mouse uteri. In addition, we confirmed that inhibition of Grim-19 by siRNA enhanced the expression of autophagy related proteins in RAW264.7 cells and THP-1 cells. More importantly, downregulation of Grim-19 in RAW264.7 cells promoted the release of proinflammatory cytokines and promoted phagocytic activity, which could be reversed by autophagy blockade. For THP-1-derived macrophages, the results of RNA-seq suggested that Grim-19 mainly modulates immune and inflammatory-related pathways, leading to cytokine production, and thus contributing to inflammation. Therefore, our data reveal that Grim-19 deficiency influences macrophage function, characterized by enhanced proinflammatory cytokines and phagocytic activity, and this might be regulated by autophagy. This may represent a novel mechanism for the occurrence of RSA.
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Aborto Espontâneo , Proteínas Reguladoras de Apoptose , Autofagia , Macrófagos , NADH NADPH Oxirredutases , Animais , Feminino , Humanos , Camundongos , Gravidez , Aborto Espontâneo/genética , Proteína Beclina-1/metabolismo , Citocinas/metabolismo , Células RAW 264.7 , NADH NADPH Oxirredutases/deficiência , NADH NADPH Oxirredutases/genética , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genéticaRESUMO
Maximum survival area after perforator flap elevation is mainly achieved through vasodilation and angiogenesis, and endothelial Ca2+ signals play a pivotal role in both of them. Transient receptor potential (TRP) channels modulate many endothelial cell functions via mediating the extracellular Ca2+ entry. This study aims to investigate the correlation of TRPV4, TRPV1, and TRPA1 with vascular change after the inferior gluteal artery perforator flap elevation. A total of 50 adult male SD rats were used in this study. Ten rats were used in the part one to assess the flap viability on postoperative day 7. Twenty rats were used in the part two to evaluate blood flow change after flap elevation. The correlation of vascular change with TRPV1, TRPV4, and TRPA1 protein changes was investigated in 20 rats in the part three. The mean flap survival area percentage was 55 ± 5.7%. Blood flow in the overall flap and Zone II after the flap elevation markedly increased from the postoperative day 3. The most marked change of the vasodilation occurred on Days 3 and 5 after flap elevation. The angiogenesis occurred on Day 5 after flap elevation and the microvessel density peaked also on Day 5. Moreover, TRPA1 expression showed a trend towards continuous reduction over time. The expression of TRPV1 and TRPV4 reached the peak value on Day 3. The endothelial NO synthase expression showed an increasing trend at first, followed by a reduction over time, while VEGF expression reached the peak value on Day 3. The vascular changes after flap elevation might be associated with the changes in TRPV4, TRPV1, and TRPA1.
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Retalho Perfurante , Canais de Cátion TRPV , Animais , Artérias/metabolismo , Masculino , Neovascularização Patológica , Retalho Perfurante/irrigação sanguínea , Ratos , Ratos Sprague-Dawley , Canal de Cátion TRPA1 , Canais de Cátion TRPV/metabolismo , CicatrizaçãoRESUMO
Growing evidence indicates that postnatal immune activation (PIA) can adversely increase the lifetime risk for several neuropsychiatric disorders, including anxiety and depression, which involve the activation of glial cells and early neural developmental events. Several glia-targeted agents are required to protect neonates. Folic acid (FA), a clinical medication used during pregnancy, has been reported to have neuroprotective properties. However, the effects and mechanisms of FA in PIA-induced neonatal encephalitis and mood disorders remain unclear. Here, we investigated the roles of FA in a mouse model of PIA, and found that FA treatment improved depressive- and anxiety-like behaviors in adults, accompanied by a decrease in the number of activated microglia and astrocytes, as well as a reduction in the inflammatory response in the cortex and hippocampus of neonatal mice. Furthermore, we offer new evidence describing the functional differences in FA between microglia and astrocytes. Our data show that epigenetic regulation plays an essential role in FA-treated glial cells following PIA stimulation. In astrocytes, FA promoted the expression of IL-10 by decreasing the level of EZH2-mediated H3K27me3 at its promoter, whereas FA promoted the expression of IL-13 by reducing the promoter binding of H3K9me3 mediated by KDM4A in microglia. Importantly, FA specifically regulated the expression level of BDNF in astrocytes through H3K27me3. Overall, our data supported that FA may be an effective treatment for reducing mood disorders induced by PIA, and we also demonstrated significant functional differences in FA between the two cell types following PIA stimulation.
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While blended learning has been growing in popularity in recent years, the effectiveness of this procedure remains controversial. In this report, we assess the effectiveness of blended learning of embryology within international medical students. The participants were international medical students taking embryology in the Bachelor of Medicine and Bachelor of Surgery program. The blended learning group (BLG) consisted of students (n = 43) in the 2018-2019 academic year, taught with blended learning model via a customized small private online course (SPOC). The control traditional teaching group (TTG) consisted students (n = 48) in the 2017-2018 academic year, taught with traditional teaching model. Academic performance, including mean scores and passing ratios on the final exam of two groups were compared and analyzed with a t-test. In addition, a questionnaire directed toward evaluating student's perceptions with the blended learning was administered to students in BLG. The majority of students in BLG actively participated in online self-study activities and discussion in face-to-face class sessions. The mean score and passing ratio were significantly greater than those of students in TTG (p < 0.01). Results from the questionnaire revealed that the majority of BLG students felt that this method was beneficial for their learning of human embryology. The blended learning model, that integrates SPOC with face-to-face class lectures proved a more effective means for the teaching of embryology than the traditional lecture-based teaching model. This blended learning method may serve as a feasible model that can be readily applied for use in other medical courses.
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Desempenho Acadêmico , Estudantes de Medicina , Currículo , Avaliação Educacional , Humanos , Aprendizagem Baseada em Problemas , EnsinoRESUMO
Colorectal cancer (CRC) stem cells are resistant to cancer therapy and are therefore responsible for tumour progression after conventional therapy fails. However, the molecular mechanisms underlying the maintenance of stemness are poorly understood. In this study, we identified PCGF1 as a crucial epigenetic regulator that sustains the stem cell-like phenotype of CRC. PCGF1 expression was increased in CRC and was significantly correlated with cancer progression and poor prognosis in CRC patients. PCGF1 knockdown inhibited CRC stem cell proliferation and CRC stem cell enrichment. Importantly, PCGF1 silencing impaired tumour growth in vivo. Mechanistically, PCGF1 bound to the promoters of CRC stem cell markers and activated their transcription by increasing the H3K4 histone trimethylation (H3K4me3) marks and decreasing the H3K27 histone trimethylation (H3K27me3) marks on their promoters by increasing expression of the H3K4me3 methyltransferase KMT2A and the H3K27me3 demethylase KDM6A. Our findings suggest that PCGF1 is a potential therapeutic target for CRC treatment.
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Neoplasias Colorretais/enzimologia , Metilação de DNA , Epigênese Genética , Células-Tronco Neoplásicas/enzimologia , Complexo Repressor Polycomb 1/metabolismo , Animais , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Complexo Repressor Polycomb 1/genética , Carga Tumoral , Microambiente TumoralRESUMO
BACKGROUND: Propofol can have adverse effects on developing neurons, leading to cognitive disorders, but the mechanism of such an effect remains elusive. Here, we aimed to investigate the effect of propofol on neuronal development in zebrafish and to identify the molecular mechanism(s) involved in this pathway. METHODS: The effect of propofol on neuronal development was demonstrated by a series of in vitro and in vivo experiments. mRNA injections, whole-mount in situ hybridization and immunohistochemistry, quantitative real-time polymerase chain reaction, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, 5-ethynyl-2'-deoxyuridine labeling, co-immunoprecipitation, and acyl-biotin exchange labeling were used to identify the potential mechanisms of propofol-mediated zisp expression and determine its effect on the specification of retinal cell types. RESULTS: Propofol impaired the specification of retinal cell types, thereby inhibiting neuronal and glial cell formation in retinas, mainly through the inhibition of Zisp expression. Furthermore, Zisp promoted the stabilization and secretion of a soluble form of the membrane-associated protein Noggin-1, a specific palmitoylation substrate. CONCLUSIONS: Propofol caused a severe phenotype during neuronal development in zebrafish. Our findings established a direct link between an anesthetic agent and protein palmitoylation in the regulation of neuronal development. This could be used to investigate the mechanisms via which the improper use of propofol might result in neuronal defects.
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Propofol , Animais , Apoptose , Marcação In Situ das Extremidades Cortadas , Lipoilação , Neurônios , Propofol/farmacologia , Retina , Peixe-Zebra/genéticaRESUMO
Nitrogen and sulfur co-doped carbon dots (abbreviated as N,S-CDs) were obtained by two-step hydrothermal reactions using citric acid/sulfamic acid as precursors, polyethyleneimine (PEI) as passivation agent. It was found that the PEI modified CDs with a fluorescence quantum yield of up to 29.1%, showed an obviously enhanced photoluminescence (PL) compared to the initial CDs. Interestingly, when monitored at the fluorescence emission wavelength of 460 nm, the dispersed N,S-CDs solution exhibits only one excitation band peaked at 355 nm, while one aggregated N,S-CDs solution with good water solubility and excellent fluorescence stability possesses two well-separated excitation bands centered at 310 nm/397 nm. When chlorogenic acid (CGA) was added to this aggregated N,S-CDs solution, the excitation peak at 310 nm was obviously reduced due to the inner filter effect (IFE), whereas another peak at 397 nm almost remained constant. Based on the above phenomenon, a dual-excitation ratiometric fluorescent probe for CGA assay was constructed. Under the optimized conditions, the logarithm of the fluorescence intensity ratios (F397/F310) exhibited a good linear correlation with the CGA concentration over a range from 0.33 to 29.70 µg/mL with a detection limit of 0.12 µg/mL. Moreover, the proposed sensing system was applied to determine CGA content in real samples with satisfactory results. The proposed sensing platform provides a new method for the detection of CGA.
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BACKGROUND: Glioblastoma stem-like cells (GSCs) are hypothesized to contribute to self-renewal and therapeutic resistance in glioblastoma multiforme (GBM) tumors. Constituting only a small percentage of cancer cells, GSCs possess "stem-like", tumor-initiating properties and display resistance to irradiation and chemotherapy. Thus, novel approaches that can be used to suppress GSCs are urgently needed. A new carbon material-graphene oxide (GO), has been reported to show potential for use in tumor therapy. However, the exact effect of GO on GSCs and the inherent mechanism underlying its action are not clear. In this study, we aimed to investigate the usefulness of GO to inhibit the growth and promote the differentiation of GSCs, so as to suppress the malignancy of GBM. METHODS: In vitro effects of GO on sphere-forming ability, cell proliferation and differentiation were evaluated in U87, U251 GSCs and primary GSCs. The changes in cell cycle and the level of epigenetic modification H3K27me3 were examined. GO was also tested in vivo against U87 GSCs in mouse subcutaneous xenograft models by evaluating tumor growth and histological features. RESULTS: We cultured GSCs to explore the effect of GO and the underlying mechanism of its action. We found, for the first time, that GO triggers the inhibition of cell proliferation and induces apoptotic cell death in GSCs. Moreover, GO could promote the differentiation of GSCs by decreasing the expression of stem cell markers (SOX2 and CD133) and increasing the expression of differentiation-related markers (GFAP and ß-III tubulin). Mechanistically, we found that GO had a striking effect on GSCs by inducing cell cycle arrest and epigenetic regulation. GO decreased H3K27me3 levels, which are regulated by EZH2 and associated with transcriptional silencing, in the promoters of the differentiation-related genes GFAP and ß-III tubulin, thereby enhancing GSC differentiation. In addition, compared with untreated GSCs, GO-treated GSCs that were injected into nude mice exhibited decreased tumor growth in vivo. CONCLUSION: These results suggested that GO could promote differentiation and reduce malignancy in GSCs via an unanticipated epigenetic mechanism, which further demonstrated that GO is a potent anti-GBM agent that could be useful for future clinical applications.
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Neoplasias Encefálicas , Glioblastoma , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Epigênese Genética , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Grafite , Camundongos , Camundongos Nus , Células-Tronco NeoplásicasRESUMO
To modify a fixation method improving the intensity and clarity of the single blastomeric signal detection by fluorescence in situ hybridization (FISH) in preimplantation genetic diagnosis. 333 cycles of assisted reproduction with preimplantation genetic diagnosis FISH (PGD-FISH) performed in our hospital were analyzed and a total of 3452 single blastomeres were obtained. For the conventional fixation method, the blastomeres were kept in 0.1% sodium citrate with 0.2 mg/ml bovine serum albumin (BSA) for 2-5 min. FISH was performed and the internal relationship between embryo quality and fixed rate, signal detection rate, and signal determination rate was explored. With the modified method, 91.54% of blastomeres were fixed, while 88.30% were fixed with the conventional method. The signal detection rate was significantly increased for the modified group than for the conventional group (compared 98.53% with 94.78%, P < 0.001). Especially, the signal determination rate also showed a significant difference between the two methods (compared 90.51% with 74.17%, P < 0.001). After the development of the fixation method, the fixation efficiency and the signal determination rate were greatly improved, providing more definite diagnosis for the patient. It will hopefully allow more assisted reproduction programs to offer their patients preimplantation genetic diagnosis with FISH.
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Tri-ortho-cresyl phosphate (TOCP) is an extensively used organophosphate in industry. It has been proven to lead to toxicity in different organ systems, especially in the nervous system. Neural stem cells (NSCs) play important roles in both embryonic and adult nervous systems. However, whether TOCP induces cytotoxicity in embryonic NSCs remains unclear. In this study, mouse NSCs were exposed to different concentrations of TOCP for 24 h. The results showed that TOCP led to impaired proliferation of NSCs and induced the autophagy of NSCs by increasing the generation of intracellular reactive oxygen species (ROS) and decreasing the phosphorylation of extracellular regulated protein kinase (ERK1/2). Melatonin has been reported to exert neuroprotective effects via various mechanisms. Therefore, we further investigate whether melatonin has potential protective effects against TOCP-induced cytotoxicity on NSCs. Our data showed that melatonin pretreatment attenuated TOCP-induced autophagy by suppressing oxidative stress and restoring ERK1/2 phosphorylation consistently. Taken together, the results indicated that TOCP induced the autophagy in mouse NSCs, and melatonin may effectively protect NSCs against TOCP-induced autophagy.
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Rationale: Glioblastoma multiforme (GBM) almost invariably gain invasive phenotype with limited therapeutic strategy and ill-defined mechanism. By studying the aberrant expression landscape of gliomas, we find significant up-regulation of p-MAPK level in GBM and a potent independent prognostic marker for overall survival. DHHC family was generally expressed in glioma and closely related to the activation of MAPK signaling pathway, but its role and clinical significance in GBM development and malignant progression are yet to be determined. Method: Bioinformatics analysis, western blotting and immunohistochemistry (IHC) were performed to detect the expression of ZDHHC17 in GBM. The biological function of ZDHHC17 was demonstrated by a series of in vitro and in vivo experiments. Pharmacological treatment, flow cytometry, Transwell migration assay, Co- Immunoprecipitation and GST pulldown were carried out to demonstrate the potential mechanisms of ZDHHC17. Results: ZDHHC17 is up-regulated and coordinated with MAPK activation in GBM. Mechanistically, ZDHHC17 interacts with MAP2K4 and p38/JNK to build a signaling module for MAPK activation and malignant progression. Notably, the ZDHHC17-MAP2K4-JNK/p38 signaling module contributes to GBM development and malignant progression by promoting GBM cell tumorigenicity and glioma stem cell (GSC) self-renewal. Moreover, we identify a small molecule, genistein, as a specific inhibitor to disrupt ZDHHC17-MAP2K4 complex formation for GBM cell proliferation and GSC self-renewal. Moreover, genistein, identified herein as a lead candidate for ZDHHC17-MAP2K4 inhibition, demonstrated potential therapeutic effect in patients with ZDHHC17-expressing GBM. Conclusions: Our study identified disruption of a previously unrecognized signaling module as a target strategy for GBM treatment, and provided direct evidence of the efficacy of its inhibition in glioma using a specific inhibitor.
Assuntos
Aciltransferases/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Glioblastoma/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase 4/metabolismo , Proteínas do Tecido Nervoso/fisiologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
The neural induction constitutes the initial step in the generation of the neural tube. Pcgf1, as one of six Pcgf paralogs, is a maternally expressed gene, but its role and mechanism in early neural induction during neural tube development have not yet been explored. In this study, we found that zebrafish embryos exhibited a small head and reduced or even absence of telencephalon after inhibiting the expression of Pcgf1. Moreover, the neural induction process of zebrafish embryos was abnormally activated, and the subsequent NSC self-renewal was inhibited after injecting the Pcgf1 MO. The results of in vitro also showed that knockdown of Pcgf1 increased the expression levels of the neural markers Pax6, Pou3f1, and Zfp521, but decreased the expression levels of the pluripotent markers Oct4, Hes1, and Nanog, which further confirmed that Pcgf1 was indispensable for maintaining the pluripotency of P19 cells. To gain a better understanding of the role of Pcgf1 in early development, we analyzed mRNA profiles from Pcgf1-deficient P19 cells using RNA-seq. We found that the differentially expressed genes were enriched in many functional categories, which related to the development phenotype, and knockdown of Pcgf1 increased the expression of histone demethylases. Finally, our results showed that Pcgf1 loss-of-function decreased the levels of transcriptional repression mark H3K27me3 at the promoters of Ngn1 and Otx2, and the levels of transcriptional activation mark H3K4me3 at the promoters of Pou5f3 and Nanog. Together, our findings reveal that Pcgf1 might function as both a facilitator for pluripotent maintenance and a repressor for neural induction.