MicroRNAs (miRNAs) are endogenous and noncoding single-stranded RNA molecules with a length of approximately 18–25 nucleotides, which play an undeniable role in early cancer screening. Therefore, it is very important to develop an ultrasensitive and highly specific method for detecting miRNAs. Here, we present a bottom-up assembly approach for modifying glass microtubes with silica nanowires (SiNWs) and develop a label-free sensing platform for miRNA-21 detection. The three-dimensional (3D) networks formed by SiNWs make them abundant and highly accessible sites for binding with peptide nucleic acid (PNA). As a receptor, PNA has no phosphate groups and exhibits an overall electrically neutral state, resulting in a relatively small repulsion between PNA and RNA, which can improve the hybridization efficiency. The SiNWs-filled glass microtube (SiNWs@GMT) sensor enables ultrasensitive, label-free detection of miRNA-21 with a detection limit as low as 1 aM at a detection range of 1 aM–100 nM. Noteworthy, the sensor can still detect miRNA-21 in the range of 102–108 fM in complex solutions containing 1000-fold homologous interference of miRNAs. The high anti-interference performance of the sensor enables it to specifically recognize target miRNA-21 in the presence of other miRNAs and distinguish 1-, 3-mismatch nucleotide sequences. Significantly, the sensor platform is able to detect miRNA-21 in the lysate of breast cancer cell lines (e.g., MCF-7 cells and MDA-MB-231 cells), indicating that it has good potential in the screening of early breast cancers.
Abstract Deoxygenative alkylation of benzyl alcohols was realized by using acetate as the alcohol activation group. The C–O bond homolysis is achieved by a boryl radical-promoted β-scission process. The strategy is amenable to a variety of benzyl alcohols, including primary, secondary, and more challenging tertiary alcohols. The synthetic practicability was demonstrated by a gram-scale one-pot reaction.
Recently, the incorporation of biomolecules in Metal-organic frameworks (MOFs) attracts many attentions because of controlling the functions, properties and stability of trapped molecules. Although there are few reports on protein/MOFs composites and their applications, none of DNA/MOFs composite is reported, as far as we know. Here, we report a new composite material which is self-assembled from 3D DNA (guest) and pre-synthesized MOFs (host) by electrostatic interactions and hydrophilic interactions in a well-dispersed fashion. Its biophysical characterization is well analyzed by fluorescence spectroscopy, quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). This new composite material keeps 3D DNA nanostructure more stable than only 3D DNA nanostructure in DI water at room temperature and stores amounts of genetic information. It will make DNA as a guest for MOFs and MOFs become a new platform for the development of DNA nanotechnology.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Mitochondria are key regulators of cell fate, maintaining self‐stability by a fine‐tuned quality‐control network including mitophagy, biogenesis, fission and fusion processes. Myocardial mitochondria can be impaired by hypercholesterolemia. Statins, such as atorvastatin, are considered the cornerstone in the management of hypercholesterolaemia primarily due to their marked cholesterol‐lowering ability. The direct effect of atorvastatin on myocardial mitochondria remains unclear. We aimed to explore whether atorvastatin could attenuate myocardial mitochondrial defects induced by high cholesterol, and whether cycloastragenol, a potent telomerase activator, could be used as a potential complementary bioactive compound for obesity and hypercholesterolaemia treatment. We found that atorvastatin at a low dose (3 mg/kg) did not reduce elevated serum cholesterol, but reversed cardiac remodelling and dysfunction in C57BL/6J mice fed with high‐fat diet (HFD). Atorvastatin reversed the upregulated mitophagy, mitochondrial fission and fusion, accompanied by mitochondrial biogenesis activation in HFD‐fed mice hearts. Mitochondrial structural impairments were attenuated by atorvastatin in HFD‐fed mice and oxidized low‐density lipoprotein (ox‐LDL) exposed HL‐1 cardiomyocytes. The depolarized mitochondrial membrane potential and increased mitochondrial oxygen consumption rates in ox‐LDL exposed HL‐1 cells were recovered by atorvastatin. Furthermore, atorvastatin co‐treated with cycloastragenol had better effects on reducing body weight, improving cardiac remodelling and dysfunction, and protecting mitochondria in high cholesterol. Conclusively, low‐dose atorvastatin exhibited a cholesterol‐independent cardioprotective effect through improving the mitochondrial quality‐control network and repairing mitochondrial ultrastructure in high cholesterol. Atorvastatin plus cycloastragenol supplement therapy has a better effect on treating obesity and hypercholesterolaemia.
Objective: A20 is a TNF-inducible primary response gene, which has been found to have antiapoptotic function in several cancer cells. This study investigates A20 expression in human glioma tissues and four glioma cell lines, and its effect on tumorigenesis of glioma cells and a mouse tumor model. Methods: Human glioma tissue samples and cells were subject to reverse transcription-PCR (RT-PCR), western blotting and immunohistochemistry. Glioma cells was tested by flow cytometry. A xenograft tumor model in mice was utilized to examine the knock-down effect of specific A20 siRNAs on tumorigenesis. Results: A20 was overexpressed in clinical glioma tissue samples (63.9%) and correlated with clinical staging. All four human glioma cell lines expressed A20, among which U87 displayed the strongest expression signals. Inhibiting A20 expression by siRNAs in vitro reduced the growth rates of glioma cells and resulted in G1/S arrest and increased apoptosis. In a mouse tumor model, local administration of siRNA significantly suppressed solid tumor growth. Conclusions: A20 was overexpressed both in human glioma tissues and cell lines, and inhibiting A20 expression greatly slowed tumor cell growth in culture and in mice. These findings indicated that A20 is involved in tumorigenesis of human glioma, and may serve as a future therapeutic target.
Abstract A sufficiently high current output of nano energy harvesting devices is highly desired in practical applications, while still a challenge. Theoretical evidence has demonstrated that Coulomb drag based on the ion-electron coupling interaction, can amplify current in nanofluidic energy generation systems, resulting in enhanced energy harvesting. However, experimental validation of this concept is still lacking. Here we develop a nanofluidic chemoelectrical generator (NCEG) consisting of a carbon nanotube membrane (CNTM) sandwiched between metal electrodes, in which spontaneous redox reactions between the metal and oxygen in electrolyte solution enable movement of ions within the carbon nanotubes. Through Coulomb drag effect between moving ions in these nanotubes and electrons within the CNTM, an amplificated current of 1.2 mA·cm -2 is generated, which is 15.6 times higher than that collected without a CNTM. Meanwhile, one single NCEG unit can produce a high voltage of ~0.8 V and exhibit a linear scalable performance up to tens of volts. Different from the other Coulomb drag systems that need additional energy input, the NCEG with enhanced energy harvesting realizes the ion-electron coupling by its own redox reactions potential, which provides a possibility to drive multiple electronic devices for practical application.
Calix[6]arene (CX6) was found to be an efficient ion transmembrane channel, which could be blocked by methylene blue (MB) through host-guest interactions. The blocked CX6 channel could be reopened by 4-sulfonated calix[6]arene owing to its stronger affinity with MB, thereby achieving a reversible ON-OFF-ON type switch.
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