43 research outputs found
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TNFAIP1 contributes to the neurotoxicity induced by Aβ25–35 in Neuro2a cells
Background: Amyloid-beta (Aβ) accumulation is a hallmark of Alzheimer’s disease (AD) that can lead to neuronal dysfunction and apoptosis. Tumor necrosis factor, alpha-induced protein 1 (TNFAIP1) is an apoptotic protein that was robustly induced in the transgenic C. elegans AD brains. However, the roles of TNFAIP1 in AD have not been investigated. Results: We found TNFAIP1 protein and mRNA levels were dramatically elevated in primary mouse cortical neurons and Neuro2a (N2a) cells exposed to Aβ25–35. Knockdown and overexpression of TNFAIP1 significantly attenuated and exacerbated Aβ25–35-induced neurotoxicity in N2a cells, respectively. Further studies showed that TNFAIP1 knockdown significantly blocked Aβ25–35-induced cleaved caspase 3, whereas TNFAIP1 overexpression enhanced Aβ25–35-induced cleaved caspase 3, suggesting that TNFAIP1 plays an important role in Aβ25–35-induced neuronal apoptosis. Moreover, we observed that TNFAIP1 was capable of inhibiting the levels of phosphorylated Akt and CREB, and also anti-apoptotic protein Bcl-2. TNFAIP1 overexpression enhanced the inhibitory effect of Aβ25–35 on the levels of p-CREB and Bcl-2, while TNFAIP1 knockdown reversed Aβ25–35-induced attenuation in the levels of p-CREB and Bcl-2. Conclusion: These results suggested that TNFAIP1 contributes to Aβ25–35-induced neurotoxicity by attenuating Akt/CREB signaling pathway, and Bcl-2 expression
Synthesis, Biological Evaluation and Mechanism Studies of Deoxytylophorinine and Its Derivatives as Potential Anticancer Agents
Previous studies indicated that (+)-13a-(S)-Deoxytylophorinine (1) showed profound anti-cancer activities both in vitro and in vivo and could penetrate the blood brain barrier to distribute well in brain tissues. CNS toxicity, one of the main factors to hinder the development of phenanthroindolizidines, was not obviously found in 1. Based on its fascinating activities, thirty-four derivatives were designed, synthesized; their cytotoxic activities in vitro were tested to discover more excellent anticancer agents. Considering the distinctive mechanism of 1 and interesting SAR of deoxytylophorinine and its derivatives, the specific impacts of these compounds on cellular progress as cell signaling transduction pathways and cell cycle were proceeded with seven representative compounds. 1 as well as three most potent compounds, 9, 32, 33, and three less active compounds, 12, 16, 35, were selected to proform this study to have a relatively deep view of cancer cell growth-inhibitory characteristics. It was found that the expressions of phospho-Akt, Akt, phospho-ERK, and ERK in A549 cells were greater down-regulated by the potent compounds than by the less active compounds in the Western blot analysis. To the best of our knowledge, this is the first report describing phenanthroindolizidines alkaloids display influence on the crucial cell signaling proteins, ERK. Moreover, the expressions of cyclin A, cyclin D1 and CDK2 proteins depressed more dramatically when the cells were treated with 1, 9, 32, and 33. Then, these four excellent compounds were subjected to flow cytometric analysis, and an increase in S-phase was observed in A549 cells. Since the molecular level assay results of Western blot for phospho-Akt, Akt, phospho-ERK, ERK, and cyclins were relevant to the potency of compounds in cellular level, we speculated that this series of compounds exhibit anticancer activities through blocking PI3K and MAPK signaling transduction pathways and interfering with the cell cycle progression
The antiviral effect of jiadifenoic acids C against coxsackievirus B3
Coxsackievirus B type 3 (CVB3) is one of the major causative pathogens associated with viral meningitis and myocarditis, which are widespread in the human population and especially prevalent in neonates and children. These infections can result in dilated cardiomyopathy (DCM) and other severe clinical complications. There are no vaccines or drugs approved for the prevention or therapy of CVB3-induced diseases. During screening for anti-CVB3 candidates in our previous studies, we found that jiadifenoic acids C exhibited strong antiviral activities against CVB3 as well as other strains of Coxsackie B viruses (CVBs). The present studies were carried out to evaluate the antiviral activities of jiadifenoic acids C. Results showed that jiadifenoic acids C could reduce CVB3 RNA and proteins synthesis in a dose-dependent manner. Jiadifenoic acids C also had a similar antiviral effect on the pleconaril-resistant variant of CVB3. We further examined the impact of jiadifenoic acids C on the synthesis of viral structural and non-structural proteins, finding that jiadifenoic acids C could reduce VP1 and 3D protein production. A time-course study with Vero cells showed that jiadifenoic acids C displayed significant antiviral activities at 0–6 h after CVB3 inoculation, indicating that jiadifenoic acids C functioned at an early step of CVB3 replication. However, jiadifenoic acids C had no prophylactic effect against CVB3. Taken together, we show that jiadifenoic acids C exhibit strong antiviral activities against all strains of CVB, including the pleconaril-resistant variant. Our study could provide a significant lead for anti-CVB3 drug development
FaSmi1 Is Essential for the Vegetative Development, Asexual Reproduction, DON Production and Virulence of <i>Fusarium asiaticum</i>
Smi1 is a protein required for cell cycle progression, morphogenesis, stress response and life span of Saccharomyces cerevisiae. FaSmi1 was identified as a Smi1 homolog in a wheat scab pathogenic fungus Fusarium asiaticum strain 2021. The deletion of FaSmi1 leads to defects in mycelial growth, asexual reproduction, and virulence. The FaSmi1 deletion mutant also exhibited increased sensitivity to osmotic stresses generated by NaCl and KCl, but increased tolerance to oxidative stresses and cell wall integrity inhibitors. All of these defects were restored by genetic complementation of the mutant with the whole parental FaSmi1 gene. Interestingly, the antioxidant system-associated genes exhibit a lower expression level and the mycotoxins’ DON content was decreased in the FaSmi1 deletion mutant compared with the parental strain 2021. These results indicate that FaSmi1 plays a critical role in the vegetative development, asexual reproduction, DON production and virulence of F. asiaticum
Facile Synthesis of Molecularly Imprinted Graphene Quantum Dots for the Determination of Dopamine with Affinity-Adjustable
A facilely prepared fluorescence
sensor was developed for dopamine (DA) determination based on polyindole/graphene
quantum dots molecularly imprinted polymers (PIn/GQDs@MIPs). The proposed
sensor exhibits a high sensitivity with a linear range of 5 ×
10<sup>–10</sup> to 1.2 × 10<sup>–6</sup> M and
the limit of detection as low as 1 × 10<sup>–10</sup> M
in the determination of DA, which is probably due to the tailor-made
imprinted cavities for binding DA thought hydrogen bonds between amine
groups of DA and oxygen-containing groups of the novel composite.
Furthermore, the prepared sensor can rebind DA in dual-type: a low
affinity type (noncovalent interaction is off) and a high affinity
type (noncovalent interaction is on), and the rebinding interaction
can be adjusted by tuning the pH, which shows a unique potential for
adjusting the binding interaction while keeping the specificity, allowing
for wider applications
All-Solid-State Flexible Supercapacitors Based on Highly Dispersed Polypyrrole Nanowire and Reduced Graphene Oxide Composites
Highly dispersed polypyrrole nanowires
are decorated on reduced graphene oxide sheets using a facile in situ
synthesis route. The prepared composites exhibit high dispersibility,
large effective surface area, and high electric conductivity. All-solid-state
flexible supercapacitors are assembled based on the prepared composites,
which show excellent electrochemical performances with a specific
capacitance of 434.7 F g<sup>–1</sup> at a current density
of 1 A g<sup>–1</sup>. The as-fabricated supercapacitor also
exhibits excellent cycling stability (88.1% capacitance retention
after 5000 cycles) and exceptional mechanical flexibility. In addition,
outstanding power and energy densities were obtained, demonstrating
the significant potential of prepared material for flexible and portable
energy storage devices
Eremophilane Sesquiterpenes and Polyketones Produced by an Endophytic <i>Guignardia</i> Fungus from the Toxic Plant <i>Gelsemium elegans</i>
A cultured endophytic fungus, <i>Guignardia mangiferae</i>, isolated from the toxic plant <i>Gelsemium elegans</i> yielded five new sesquiterpenes (<b>1</b>–<b>5</b>), two new polyketones (<b>6</b> and <b>7</b>), and two known terpene polyketones (<b>8</b> and <b>9</b>). Their structures were elucidated using spectroscopic
methods. On the basis of circular dichroism, the absolute configurations
of the new compounds were determined. Compounds <b>1</b>, <b>3</b>, <b>4</b>, and <b>9</b> inhibited lipopolysaccharide-induced
NO production in BV2 cells with IC<sub>50</sub> values of 15.2, 6.4,
4.2, and 4.5 μM, respectively (positive control curcumin, IC<sub>50</sub> = 3.9 μM)