869 research outputs found

    A subset of OPCs do not express Olig2 during development which can be increased in the adult by brain injuries and complex motor learning

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    Oligodendrocyte precursor cells (OPCs) are uniformly distributed in the mammalian brain; however, their function is rather heterogeneous in respect to their origin, location, receptor/channel expression and age. The basic helix–loop–helix transcription factor Olig2 is expressed in all OPCs as a pivotal determinant of their differentiation. Here, we identified a subset (2%–26%) of OPCs lacking Olig2 in various brain regions including cortex, corpus callosum, CA1 and dentate gyrus. These Olig2 negative (Olig2neg) OPCs were enriched in the juvenile brain and decreased subsequently with age, being rarely detectable in the adult brain. However, the loss of this population was not due to apoptosis or microglia-dependent phagocytosis. Unlike Olig2pos OPCs, these subset cells were rarely labeled for the mitotic marker Ki67. And, accordingly, BrdU was incorporated only by a three-day long-term labeling but not by a 2-hour short pulse, suggesting these cells do not proliferate any more but were derived from proliferating OPCs. The Olig2neg OPCs exhibited a less complex morphology than Olig2pos ones. Olig2neg OPCs preferentially remain in a precursor stage rather than differentiating into highly branched oligodendrocytes. Changing the adjacent brain environment, for example, by acute injuries or by complex motor learning tasks, stimulated the transition of Olig2pos OPCs to Olig2neg cells in the adult. Taken together, our results demonstrate that OPCs transiently suppress Olig2 upon changes of the brain activity

    N′-(2-Hydr­oxy-5-chloro­benzyl­idene)-4-nitro­benzohydrazide methanol solvate

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    The title compound, C14H10ClN3O4·CH4O, was synthesized from the reaction of 5-chloro­salicylaldehyde with 4-nitro­benzohydrazide in methanol. The Schiff base mol­ecule is nearly planar, with a dihedral angle of 9.1 (3)° between the two benzene rings. The methanol solvent mol­ecules are linked to the Schiff base mol­ecules by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming chains running parallel to the a axis

    N-Glycosylation-Defective Splice Variants of Neuropilin-1 Promote Metastasis by Activating Endosomal Signals

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    Neuropilin-1 (NRP1) is an essential transmembrane receptor with a variety of cellular functions. Here, we identify two human NRP1 splice variants resulting from the skipping of exon 4 and 5, respectively, in colorectal cancer (CRC). Both NRP1 variants exhibit increased endocytosis/recycling activity and decreased levels of degradation, leading to accumulation on endosomes. This increased endocytic trafficking of the two NRP1 variants, upon HGF stimulation, is due to loss of N-glycosylation at the Asn150 or Asn261 site, respectively. Moreover, these NRP1 variants enhance interactions with the Met and β1-integrin receptors, resulting in Met/β1-integrin co-internalization and co-accumulation on endosomes. This provides persistent signals to activate the FAK/p130Cas pathway, thereby promoting CRC cell migration, invasion and metastasis. Blocking endocytosis or endosomal Met/β1-integrin/FAK signaling profoundly inhibits the oncogenic effects of both NRP1 variants. These findings reveal an important role for these NRP1 splice variants in the regulation of endocytic trafficking for cancer cell dissemination

    A network pharmacology-based study on the anti-hepatoma effect of Radix Salviae Miltiorrhizae

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    This work is licensed under a Creative Commons Attribution 4.0 International License.Background Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicine, has been shown to inhibit tumorigenesis in various human cancers. However, the anticancer effects of RSM on human hepatocellular carcinoma (HCC) and the underlying mechanisms of action remain to be fully elucidated. Methods In this study, we aimed to elucidate the underlying molecular mechanisms of RSM in the treatment of HCC using a network pharmacology approach. In vivo and in vitro experiments were also performed to validate the therapeutic effects of RSM on HCC. Results In total, 62 active compounds from RSM and 72 HCC-related targets were identified through network pharmacological analysis. RSM was found to play a critical role in HCC via multiple targets and pathways, especially the EGFR and PI3K/AKT signaling pathways. In addition, RSM was found to suppress HCC cell proliferation, and impair cancer cell migration and invasion in vitro. Flow cytometry analysis revealed that RSM induced cell cycle G2/M arrest and apoptosis, and western blot analysis showed that RSM up-regulated the expression of BAX and down-regulated the expression of Bcl-2 in MHCC97-H and HepG2 cells. Furthermore, RSM administration down-regulated the expression of EGFR, PI3K, and p-AKT proteins, whereas the total AKT level was not altered. Finally, the results of our in vivo experiments confirmed the therapeutic effects of RSM on HCC in nude mice. Conclusions We provide an integrative network pharmacology approach, in combination with in vitro and in vivo experiments, to illustrate the underlying therapeutic mechanisms of RSM action on HCC

    Gut microbiota therapy for nonalcoholic fatty liver disease: Evidence from randomized clinical trials

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    Nonalcoholic fatty liver disease (NAFLD) has a high prevalence worldwide, but there are no medications approved for treatment. Gut microbiota would be a novel and promising therapeutic target based on the concept of the gut–liver axis in liver disease. We reviewed randomized controlled trials on gut microbiota therapy in NAFLD in this study to evaluate its efficacy and plausibility in NAFLD

    Anti-tumor effects of brucine immuno-nanoparticles on hepatocellular carcinoma

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    BACKGROUND: Hepatocellular carcinoma is difficult to diagnose early, and most patients are already in the late stages of the disease when they are admitted to hospital. The total 5-year survival rate is less than 5%. Recent studies have showed that brucine has a good anti-tumor effect, but high toxicity, poor water solubility, short half-life, narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study evaluated the effects of brucine immuno-nanoparticles (BIN) on hepatocellular carcinoma. MATERIALS AND METHODS: Anionic polymerization, chemical modification technology, and phacoemulsification technology were used to prepare a carboxylated polyethylene glycol-polylactic acid copolymer carrier material. Chemical coupling technology was utilized to develop antihuman AFP McAb-polyethylene glycol-polylactic acid copolymer BIN. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these immune-nanoparticles were studied in vitro. The targeting, and growth, invasion, and metastasis inhibitory effects of this treatment on liver cancer SMMC-7721 cells were tested. RESULTS: BIN were of uniform size with an average particle size of 249 ± 77 nm and zeta potential of -18.7 ± 4.19 mV. The encapsulation efficiency was 76.0% ± 2.3% and the drug load was 5.6% ± 0.2%. Complete uptake and even distribution around the liver cancer cell membrane were observed. CONCLUSION: BIN had even size distribution, was stable, and had a slow-releasing effect. BIN targeted the cell membrane of the liver cancer cell SMMC-7721 and significantly inhibited the growth, adhesion, invasion, and metastasis of SMMC-7721 cells. As a novel drug carrier system, BIN are a potentially promising targeting treatment for liver cancer

    Continuous spin excitations in the three-dimensional frustrated magnet K2Ni2(SO4)3

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    Continuous spin excitations are widely recognized as one of the hallmarks of novel spin states in quantum magnets, such as quantum spin liquids (QSLs). Here, we report the observation of such kind of excitations in K2Ni2(SO4)3, which consists of two sets of intersected spin-1 Ni2+ trillium lattices. Our inelastic neutron scattering measurement on single crystals clearly shows a dominant excitation continuum, which exhibits a distinct temperature-dependent behavior from that of spin waves, and is rooted in strong quantum spin fluctuations. Further using the self-consistent-gaussian-approximation method, we determined the fourth- and fifth-nearest neighbor exchange interactions are dominant. These two bonds together form a unique three-dimensional network of corner-sharing tetrahedra, which we name as ''hyper-trillium'' lattice. Our results provide direct evidence for the existence of QSL features in K2Ni2(SO4)3 and highlight the potential for the hyper-trillium lattice to host frustrated quantum magnetism.Comment: 6 pages and 5 figures, plus several pages of supplemental material, comments are welcom
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